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TRANSCRIPT
Feasibility Study Report
of
India Muerta Small Hydro Power Plant
In Uruguay
Prepared by
International Center on Small Hydro Power (ICSHP)
for
United Nations Industrial Development Organization (UNIDO)
January, 2013
I
TABLE OF CONTENTS
Chapter 1 Executive Summary ................................................................... 1
Chapter 2 Basic Information ....................................................................... 2
2.1 General Description of Uruguay .......................................................................... 2
2.2 Brief Introduction of India Muerta Reservoir Project.......................................... 2
2.3 Project Owner and Background ........................................................................... 4
2.4 Local Social and Economic Conditions of the Project ........................................ 4
2.5 Transportation and Communication ..................................................................... 4
2.6 Grid and Power Supply ........................................................................................ 5
2.7 Electricity Tariff and Water Price ......................................................................... 5
2.8 Prices of Main Marterials..................................................................................... 5
Chapter 3 Hydrology .................................................................................. 6
3.1 General Information of the Drainage Area .......................................................... 6
3.2 Climate ................................................................................................................. 6
3.3 Precipitation ......................................................................................................... 6
3.4 Runoff .................................................................................................................. 7
3.5 Flood .................................................................................................................. 10
3.6 Sediment ............................................................................................................ 10
Chapter 4 Engineering Geology ............................................................... 11
Chapter 5 Project Tasks and Installation Scale ......................................... 12
5.1 Project Tasks ...................................................................................................... 12
5.2 Installation Scale ................................................................................................ 12
5.2.1 Determination of Characteristic Water Level ................................................................ 12
5.2.2 Runoff Regulation and Determination of Generating Flow .......................................... 13
5.2.3 Determination of Installation Capacity ......................................................................... 14
II
5.2.4 Calculation of Multi-year Mean Output ........................................................................ 17
Chapter 6 Project Layout and Main Civil Works ..................................... 20
6.1 Project Layout .................................................................................................... 20
6.1.1 Layout and Situation of the Dam .................................................................................. 20
6.1.2 Layout of the Hydropower Station System ................................................................... 20
6.2 Design of Main Civil Works .............................................................................. 20
6.2.1 Diversion System Structures ......................................................................................... 21
6.2.2 Powerhouse ................................................................................................................... 23
6.2.3 Draft Tube and Tailrace Channel .................................................................................. 23
6.2.4 Step-up Switchyard ....................................................................................................... 24
6.2.5 Irrigation Bypass Valve System .................................................................................... 24
Chapter 7 Hydraulic Machinery, Electrical Equipment & Metal Structures ................................................................................................................... 25
7.1 Hydraulic Machinery ......................................................................................... 25
7.1.1 Selection of Hydraulic Turbines ................................................................................... 25
7.1.2 Selection of Generators ................................................................................................. 25
7.1.3 Basic Parameters of Units ............................................................................................. 26
7.1.4 Selection of Regulating Device ..................................................................................... 26
7.1.5 Excitation System ......................................................................................................... 27
7.1.6 Selection of Lifting Device in Powerhouse .................................................................. 27
7.1.7 Water Supply and Drainage System .............................................................................. 27
7.1.8 Irrigation Water Supply System .................................................................................... 28
7.2 Electrical Engineering ........................................................................................ 29
7.2.1 Primary Electrics ........................................................................................................... 29
7.2.2 Secondary Electrics ....................................................................................................... 33
7.2.3 DC System .................................................................................................................... 35
III
7.2.4 Lighting System ............................................................................................................ 36
7.2.5 Dispatch and Communication System .......................................................................... 36
7.3 Metal Structure ................................................................................................... 38
7.3.1 Trash Rack and Intake Gate .......................................................................................... 38
7.3.2 Penstock ........................................................................................................................ 38
7.3.3 Irrigation Bypass Valve and Bypass Pipe ...................................................................... 38
Chapter 8 Construction Organization and Design .................................... 40
8.1 Construction Condition ...................................................................................... 40
8.1.1 Project Condition .......................................................................................................... 40
8.2 Construction of the Main Structures .................................................................. 41
8.2.1 Diversion System .......................................................................................................... 43
8.2.2 Powerhouse and Tailrace............................................................................................... 44
8.3 Transportation for Construction ......................................................................... 45
8.3.1 External Transportation ................................................................................................. 45
8.3.2 Field Transportation ...................................................................................................... 45
8.4 Construction Facilities ....................................................................................... 45
8.4.1 Mixing System .............................................................................................................. 45
8.4.2 Machinery Factory ........................................................................................................ 46
8.4.3 Comprehensive Processing Factory .............................................................................. 46
8.4.4 Electricity, Water and Wind Supply for Construction ................................................... 46
8.5 Construction Layout........................................................................................... 46
8.5.1 Field Layout Scheme .................................................................................................... 46
8.5.2 Waste Slag Scheme ....................................................................................................... 47
8.5.3 Estimation of Main Temporary Construction Quantity and Construction Occupation . 47
8.6 Total Construction Schedule .............................................................................. 47
8.6.1 Preparation Period of Project ........................................................................................ 47
IV
8.6.2 Construction Period of Main Structures ........................................................................ 48
8.6.3 Completion Period of Project ........................................................................................ 48
Chapter 9 Engineering Management ........................................................ 49
9.1 Management Institution ..................................................................................... 49
9.1.1 Establishment of Management Institution .................................................................... 49
9.1.2 Authorization of Management Staff .............................................................................. 49
9.1.3 Management Range ...................................................................................................... 49
9.2 Engineering Management and Operation .......................................................... 49
9.2.1 Operation of Reservoir .................................................................................................. 49
9.2.2 Engineering Management Facilities .............................................................................. 50
Chapter 10 Investment Estimation ............................................................ 51
10.1 Budget Preparation........................................................................................... 51
10.1.1 Project Description ...................................................................................................... 51
10.1.2 Main References ......................................................................................................... 51
10.1.3 References for Budget Quota ...................................................................................... 51
10.1.4 Unit Rates ................................................................................................................... 51
10.1.5 Prices of Equipment .................................................................................................... 52
10.1.6 To consider the difference in project budget between China and Uruguay, the
following costs are not included into the budget estimation of the project. ........................... 52
10.1.7 Compensation Fee for Construction Land Tenure: ..................................................... 52
10.2 Budget list ........................................................................................................ 52
10.2.1 General Budget List .................................................................................................... 52
10.2.2 Project Cost List .......................................................................................................... 53
Chapter 11 Economic Evaluation ............................................................. 55
11.1 Costs Calculation (Only the actual expenses directly spent on project construction included) .............................................................................................. 55
V
11.1.1 Project investment ....................................................................................................... 55
11.1.2 Annual Running Expense ............................................................................................ 55
11.2 Income Calculation .......................................................................................... 55
11.3 Financial Evaluation ........................................................................................ 55
11.4 Conclusion ....................................................................................................... 56
Annex Quote of Mechanical and electric equipment .............................. 57
1
Chapter 1 Executive Summary
Entrusted by UNIDO, ICSHP experts paid a preliminary on-site visit to the India Muerta Reservoir Project which the local government intends to renovate it into a small hydropower station in Uruguay. And after the consultation trip the “Proposal of the India Muerta Hydro Power Project in Uruguay” has been submitted. In April 2012 UNIDO entrusted ICSHP to conduct the survey and design for the India Muerta Reservoir Project, Uruguay. Three SHP experts were dispatched by ICSHP to pay the second visit to the site to make a field survey for the project from July 15-20 2012. The tasks included topographic survey on dam site and powerhouse area, general geographic investigation, survey on flood discharge at reservoir area, survey on irrigation area, average annual rainfall data collection, irrigation data collection, owner‟s background investigation, main materials rates, traffic situation and highroads investigation，grid and tariff investigation. To acquire the above data and information is essentially required for engineering design of the project.
It is much appreciated that during the stay in Uruguay, the ICSHP technical experts got strong support and active cooperation from Mr. Alberto, general manager and Mr. Rodrigo, engineer, of the project owner company Comisaco s.a., as well as the considerate concerns from the officials of UNIDO Uruguay Office and Ministry of Industry, Energy and Mines of Uruguay.
2
Chapter 2 Basic Information
2.1 General Description of Uruguay
The Oriental Republic of Uruguay (República Oriental del Uruguay) is a country in the southeastern part of South America. It lies on the east bank of the La Plata River and the Uruguay River, neighboring Brazil in north, Argentina in west and the Atlantic Ocean in southeast. It has a land area of 176,215 square kilometers. An approximately 90% of the population is of European descent and 8% is other races. Catholicism is the main religion of the country, and Spanish is the official language. The capital city is Montevideo. It declared independence on 25 August 1825. The country has a flat landform in most of the area with highly developed agriculture and animal husbandry. Uruguay's climate is relatively mild. It has natural scenes and stable social environment.
2.2 Brief Introduction of India Muerta Reservoir Project
The India Muerta Reservoir, which is located on the India Muerta River, Rocha Province, Uruguay, is to serve the local agriculture irrigation, with annual irrigation capacity of 8000 hectares. The reservoir area, dam and irrigation area are showed in Figure 1- layout.
Figure 1 – The India Muerta Reservoir Area
The dam of India Muerta Reservoir has 12 m of height, ▽52.2m of altitude of dike top and 3221m length of axe of dam and 65,700 hectares of catchment area. The India Muerta Reservoir has ▽47m of normal storage level, 3530 hectares of corresponding water area and 127.5 million m3 of effective storage capacity. The dam type and characteristics of the reservoir are showed in Figure 2 – 4.
3
Figure 2 – Characteristic Curve of the India Muerta Reservoir
Figure 3 – Layout of the India Muerta Reservoir Dam
Figure 4 – Cross Section of the India Muerta Reservoir Dam
The irrigation system contains the east canal and the west canal (fronting the downstream, the left is the east and the right is the west). The east canal has 68km of length, with 10.5 m3/s of design flow discharge, and it is 40.2m in altitude of top and 37.2m in altitude of bottom; the west canal has 45km of length, with 10.5m3/s of design flow discharge, with 39m in altitude of top and 36m in altitude of bottom. Please see the canal data from Table 1.
4
Table 1 – Irrigation Canal Data
Length（km） Discharge（m3/s） Main canal (the east canal) 68 10.500 Main canal (the west canal) 45 10.500
Secondary canal (east-1) 16 3.500 Secondary canal (Los Ajos) 38 0.500
Secondary canal (Laguna de los Ajos) 30 3.000 Secondary canal (Alferez) 15 2.000 Secondary canal (Talita) 16 2.000
Irrigation canal (India Muerta) 22 4.000 Irrigation canal (Talita) 11 2.000
Secondary canal (el Sauce) 15 3.000 Secondary canal (Lascano) 6 1.200
Auxiliary canal 436 variable Generally speaking, the India Muerta Reservoir reaches its normal high level every August, then continuously discharging the water within 200 days for irrigation until March of next year, with probably water releasing in every September to October.
2.3 Project Owner and Background
The owner of the India Muerta Reservoir Project is Comisaco s. a.. This is a private company located in Lascano City, 35km away from the Reservoir. It is invested by two of the biggest grain processing enterprises in Uruguay. The grains procured in the area irrigated by the India Muerta Reservoir are all purchased by the two grain processing companies who invest in Comisaco s. a.. The Comisaco s. a.‟s profit through irrigation equals 1000kg grains of each hectare of the land. This will be paid by the processing companies when purchasing the grains.
2.4 Local Social and Economic Conditions of the Project
The India Muerta Reservoir Project is surrounded with pastures with highly developed animal husbandry. The farmers have an annual per capita income of 8000-10000 USD. The Lascano City, the nearest city to the Reservoir has 7000 residents. The city has good infrastructures and civil facilities, convenient transportation, prosperous economy. The distance to the capital city Montevideo is 250km.
2.5 Transportation and Communication
The distance from the capital city Montevideo to Lascano City is 250km with four-
5
lane highroad. It is 35km between Lascano city to the India Muerta Reservoir, with 30km long double-lane (8m in width) highroad with asphalt pavement and 5km double-lane highroad (6m in width) with sand and gravel pavement. This provides a better traffic condition and good transport network. The country has a developed communication network. Strong phones signals are covered in the India Muerta Reservoir area. This provides a better communication condition.
2.6 Grid and Power Supply
The national grid in Uruguay belongs to the state electric power corporation – UTE. The investigation along the way tells that Uruguay has a good electric power supply grid with high level facilities and technology. The grid has a voltage of 15/0.4(0.2) kV, and supplied with both three-phase and single phase currents. The 15kV grid extends to the place 500m far away from the India Muerta Reservoir
2.7 Electricity Tariff and Water Price
In Uruguay the electricity tariff is decided in a wide range. It is learnt that the household electricity tariff is 0.3 USD/kWh. The irrigation water is provided by the India Muerta Reservoir at a rate of 1000kg/ton grains, equivalent to 240 USD.
2.8 Prices of Main Marterials
Cement: 250-300 USD/ton Steel: 2300 USD/ton Timber: 32 UDS/m3 Sand: 35 UDS/m3 Rock: 45 UDS/m3
6
Chapter 3 Hydrology
3.1 General Information of the Drainage Area
The India Muera River rises in the northwest of Rocha Province, Uruguay, 60km away from the coast of the Atlantic Ocean. The river is oriented from an area of hilly grassland, flowing through the gently sloping grassland in middle stream and reaching the flat grassland in downstream. The whole drainage area has well-grown vegetation and mostly are grazing land with a low density of herds.
3.2 Climate
Uruguay has a subtropical humid climate in the Southern Hemisphere. The winter temperature is 2-14℃ from April to September while the summer temperature is 17-28℃ from October to March. Although it is influenced by the dry west wind from the Andes, owing to its location near the ocean, warm ocean current also flows through it, the country has a plenty of rainfall. The annual precipitation increases from 950mm in the south up to the 1250mm in the north.
3.3 Precipitation
The project owner company Comisa s. a. provides us with the monthly rainfall data of 28 years from 1984-2011(see Table 2). The maximum year precipitation is 1567mm (in 2003) and the minimum is 852mm (in 2008). The average annual precipitation is 1209.4m. According to the analysis on the long-term precipitation data, this area has a plenty of rainfall which ranges evenly among the years but unevenly among the months in one year. For example: in the high flow year as 2002 it ranges 671mm in the highest flow month to the 45mm in the lowest flow month; in the normal flow year as 1993 it ranges from 180mm in the highest month to the 13mm in the lowest month; in the low flow year as 2008 it is from 160mm to the 2mm. In irrigation period of the Reservoir from October to March (summer) the average annual precipitation is 602.4mm and the average monthly precipitation is 100.4mm. In the storage period of the Reservoir from April to September (winter) the average annual precipitation is 608.7mm and the average monthly precipitation is 101.5mm. Thus it proves that the rainfall in this drainage area distribute half in the irrigation period and the other half in the storage period of the Reservoir.
7
Due to a lack of discharge data, the average annual precipitation in this drainage area can be calculated through frequency analysis so as to achieve a basis evaluation on the flow variation of the Reservoir. The calculation results are listed in Table 3 and Figure 5.
Table 2 – Monthly Precipitation of the India Muerta Reservoir from 1984-2011
Table 3 – Distribution of Annual Precipitation in the Example Years (mm)
3.4 Runoff
There is no hydrological station in the India Muerta drainage area so the related hydrological data was not obtained. In an experience-oriented view, the runoff amount at the cross section of the dam site can be calculated according to the runoff coefficient determined by the annual precipitation data in this drainage area. However, the India Muerta Dan has been put into operation for 30 years, and the operation schedule of the Reservoir that the irrigation is adjusted according to the growth period
Month 1 2 3 4 5 6 7 8 9 10 11 12 Total High Flow Year （P=25%）
(example year 2010） 81 355 79 87 71 78 196 131 93 17 96 65 1347
Normal Flow Year （P=50%）
(example year 2005) 18 54 33 240 185 323 89 60 54 43 34 45 1175
Low Flow Year （P=75%）
(example year 1987) 106 51 124 53 13 157 82 195 31 79 65 77 1032
8
requirement of the grains in this irrigation area could not be changed. Therefore the calculation of the runoff amount at the cross section of the dam site is not necessary. On the other hand, a document of “Daily Records of the Irrigation Level & Flow of the India Muerta Reservoir from January 2008 to June 2012” (See part of Table 4) provided by the project owner company Comisaco s.a. is very helpful for the calculation of the average annual electricity output.
Figure 5 – Precipitation Frequency Curve from 1988-2011
Table 4 – Irrigation Level & Flow, Sluice Gate Position and Overflow Amount
DAN OF INDIA MUERTA Level at Sluice Gate and Position of Gate
Month Jan. Year 2008 Q1+Q2 Sluice Gate Position m3/s
Date Water Level of
Reservoir
GATES (CMS.) Spillway Volume
Overflow Discharge
Irrigation Amount
Irrigation Discharge
Left Right 1 45.96 15 115 - -
1,089,747 12.6
2 45.92 15 115 - - 1,085,820
12.6
3 45.89 15 115 - - 1,082,866
12.5
4 45.84 35 115 - - 1,254,073
14.5
5 45.79 35 115 - - 1,248,296
14.4
9
6 45.74 35 115 - - 1,242,493
14.4
7 45.69 35 115 - - 1,236,662
14.3
8 45.65 35 115 - - 1,231,978
14.3
9 45.61 35 115 - - 1,227,276
14.2
10 45.57 20 115 - - 1,094,014
12.7
11 45.53 20 115 - - 1,089,774
12.6
12 45.49 20 115 - - 1,085,517
12.6
13 45.45 20 115 - - 1,081,243
12.5
14 45.41 20 115 - - 1,076,952
12.5
15 45.36 20 115 - - 1,071,565
12.4
16 45.31 20 115 - - 1,066,150
12.3
17 45.26 20 115 - - 1,060,708
12.3
18 45.21 20 115 - - 1,055,237
12.2
19 45.16 20 115 - - 1,049,738
12.1
20 45.12 20 115 - - 1,045,318
12.1
21 45.08 20 115 - - 1,040,880
12.0
22 45.04 35 115 - - 1,158,197
13.4
23 44.99 35 115 - - 1,151,939
13.3
24 44.94 35 115 - - 1,145,648
13.3
25 44.89 35 115 - - 1,139,322
13.2
26 44.84 35 120 - - 1,162,763
13.5
27 44.79 35 120 - - 1,156,197
13.4
28 44.74 35 125 - - 1,177,988
13.6
29 44.69 45 125 - - 1,248,146
14.4
30 44.65 45 125 - - 1,242,314
14.4
31 44.61 45 125 - - 1,236,454
14.3
10
3.5 Flood
There is in the absence of actual peak flow or flood calculation data in the basin. As the terrain in the basin is flat and vegetation coverage is good, therefore, the formation of flood peak is slow and the waveform variation rate of flood peak is small. Thorough the regulation by India Muerta Reservoir, the flood peak value is decreased greatly when the flood peak flows out of the spillway of reservoir. According to spillway flow log of year 2008-2011 (see irrigation water level and flow logs of India Muerta reservoir) provided by the owner, we can see that the maximum flood during these 4 years happened on 9th, February, 2010 with peak flow of 276.9 m3/s. According to owner‟s introduction, the flood disaster also happened at the downstream of reservoir. Led by Mr. Alberto, we investigated the downstream submerged area. Because the terrain of submerged area is also flat, it still looks like an extension of swamp. The India Muerta Reservoir has operated for 30 years. The powerhouse of station is planned to be equipped between the stilling pool (at the exit of irrigation pipe) and diversion section of the east and west trunk canals. It is about 3 km away from the spillway of dam and will not be influenced by the flood discharge.
3.6 Sediment
There is in the absence of sediment data. According to our on-site investigation, the vegetation coverage of reservoir area is good, the gradient of river is small, and the water quality of reservoir is clear with a small amount of sand silting on the reservoir bank. Therefore, we can reach the conclusion that the India Muerta River has a small amount of sediment content, including a small amount of suspended load but basically without any bed load.
11
Chapter 4 Engineering Geology
There is in the absence of relevant data. According to our preliminary on-site investigation, the soil around the dam site is sandy and the rocks under the grassland on the left side are exposed to the air. According to the visual inspection, these rocks are basalts. According to owner‟s introduction, the dam foundation has been excavated to the bed rocks. The thickness of the overburden layer is 3-8 meters without fracture.
12
Chapter 5 Project Tasks and Installation Scale
5.1 Project Tasks
The main task of India Muerta Reservoir is to provide water for agricultural irrigation. According to owner‟s introduction, at primary stage of construction, it planned to install one turbine-generator unit and construct a surge tank at the exit of the irrigation pipe for power generation. However, because of technical problems, this plan was not accomplished. The project tasks: On the premise that the irrigation function of India Muerta Reservoir should be ensured, it plans to generate electricity through utilizing the drop between reservoir normal water level and water level at the exit of irrigation pipe, and potential water power in irrigation flow. It plans to install one turbine-generator unit on proper place at the exit of each of two irrigation pipes. The tail water of turbine-generator unit will connect to diversion section of east and west trunk canals, which ensures that the tail water will flow into east and west trunk canals respectively according to irrigation design requirements. The distribution of discharge will be controlled by the throttle valve nearby the diversion section of east and west trunk canals.
5.2 Installation Scale
5.2.1 Determination of Characteristic Water Level
1.The normal high level of reservoir (Zj) is 47 meters. According to design and operation situation, when the normal water level is higher than 47 m, it begins to overflow the right bank of the spillway. Therefore, the normal water level of reservoir will be determined as 47 m. 2. The highest operating water level of reservoir (Zg) is 48 meters. According to the Operation Log of Reservoir, the overflow discharge of reservoir reached the maximum record 276.9 m3/s on 9th Feb. 2010, meanwhile the corresponding water level of reservoir was 48.05 m. Therefore, the highest operating water level of reservoir should be 48 m. 3.The generation dead water level of reservoir is 42.5 meters. As the bottom elevation of irrigation pipes is 39.01 m and the pipe diameter is 1.75 m, the top elevation of irrigation pipes will be 39.01+1.75=40.76 m. As the submerged depth will be considered as 0.5 m, the generation dead level will be 40.76+1.0=41.76 m. To be
13
considered good for operation, a generation dead level of 42.5 m has been determined. 4.The design tail water level of downstream (Zw) is 40.0 meters. The turbine-generator unit will be equipped near the stilling pool at the exit of irrigation pipes. The crest and bottom elevation of tailrace canal correspond respectively to the crest elevation (40.2 m) and bottom elevation (37.2 m) of the east trunk canal. Therefore, the design tail water level of downstream (Zw) will be determined as 40.0 m, taking into account 0.2 m of super elevation. As the bottom elevation of tailrace canal is determined, the design tail water level will be relied on cross section design of tailrace canal. 5.The lowest tail water level of downstream (Zd) is 39.5 meters. 1) As with small pressure fluctuation of tail water pipe, the operation stability of unit will raise, therefore, the fluctuating depth of downstream tail water level should be small. 2) The minimum requirement of submerged depth at exit of tail water pipe should be considered. Therefore, this characteristic value is also controlled by cross section design of tailrace canal.
5.2.2 Runoff Regulation and Determination of Generating Flow
1.Runoff Regulation: India Muerta Reservoir has a total storage capacity of 127 million m3, which is classified as large scale reservoir. According to catchment area of 670 km2, data of multi-year rainfall and runoff coefficient determined by the vegetation condition in the basin, the storage capacity coefficient of India Muerta reservoir is calculated more than 15%, so it has annual regulation capacity. However, because of following reasons: 1) the adequate of runoff data; 2) the water supply for irrigation wholly follows growth period of crops in irrigation area; 3) limit of pipe diameter, the runoff regulation calculation and the change of operation method are both impossible. Therefore, the function of runoff is only to regulate its operation method during overflow period based on original operation method, in order to achieve the aim that the flood within 21 m3/s can be utilized to generate electricity. 2.Determination of Generating Flow(Q): According to operation log of India Muerta Reservoir, the reservoir has 4 operation modes: 1) discharge of irrigation water (Qg)﹥0, and discharge of overflow (Qy) = 0; 2) discharge of irrigation water (Qg)﹥0, and discharge of overflow (Qy)﹥0; 3) discharge of irrigation water (Qg) = 0, and discharge of overflow (Qy)﹥0; 4) discharge of irrigation water (Qg) = 0, and discharge of overflow (Qy) = 0. In our design, the discharge of irrigation water (Qg) and discharge of overflow (Qy) will both be utilized to generate electricity, so Q = Qg + Qy. As the maximum design flow of irrigation pipe is 21 m3/s, therefore, Q≯21
14
m3/s. When Qg + Qy﹥21 m3/s, the redundant flow will be discharged through spillway. As installation of turbine-generator units should meet the requirement of maximum irrigation flow, therefore, the design generating flow is determined as 21 m3/s (Qj = 21 m3/s).
5.2.3 Determination of Installation Capacity
1. Output Calculation of Station: As the diameter of irrigation pipe is fixed, and the generation should meet the requirements of irrigation. Therefore, the rule mentioned above „the discharge of irrigation water (Qg) and discharge of overflow (Qy) will both be utilized to generate electricity, so Q = Qg + Qy, and Q≯21 m3/s‟ should be adopted to calculate the output of station. According to irrigation log of reservoir (2008 – 2011) and output formula: N = 9.81 × H × Q × η In this formula: N – Output, kW; H – Water Head, m; H = Drop between upstream water level and downstream water level. For convenience of calculation, we adopt design tail water level (Zw = 40.0 m) as the downstream water level. η – Comprehensive Efficiency of Turbine-Generator Unit. We set it as 0.8 m. Therefore, the results of output calculation are as follows:
Daily Output Hydrograph of Year 2008
0
200
400
600
800
1000
1200
1
20 39 58 77 96 115
134
153
172
191
210
229
248
267
286
305
324
343
362
Days
Output
（kW）
15
Figure 6 Daily Output Hydrograph of Year 2008 (N-T)
Daily Output Hydrograph of Year 2009
0
200
400
600
800
1000
12001 20 39 58 77 96
115
134
153
172
191
210
229
248
267
286
305
324
343
362
Days
Output
（kW）
Figure 7 Daily Output Hydrograph of Year 2009 (N-T)
Daily Output Hydrograph of Year 2010
0
200
400
600
800
1000
1200
1400
1
20 39 58 77 96 115
134
153
172
191
210
229
248
267
286
305
324
343
362
Days
Output
（kW）
Figure 8 Daily Output Hydrograph of Year 2010 (N-T)
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Daily Output Hydrograph of Year 2011
0
200
400
600
800
1000
1200
1
20 39 58 77 96 115
134
153
172
191
210
229
248
267
286
305
324
343
362
Days
Output
（kW）
Figure 9 Daily Output Hydrograph of Year 2011 (N-T)
The maximum output Nmax = 1250 kW, which happened on 9th, February, 2010.
2. Determination of Installed Capacity: 1) Water Head of Station: Maximum water head Hmax = 48.0 - 39.5 = 8.5 m; Minimum water head Hmin = 42.5- 40.0 = 2.5 m; Arithmetical average water head HP =（8.5 + 2.5）/ 2 = 5.5 m; Taking into account characteristics of reservoir storage capacity and operation, we set design water head Hj = 6.5 m. 2) Design flow Qj: taking into account requirement of maximum irrigation flow, we set Qj = 21 m3/s. 3) Design output of station Nj = 9.81 × 6.5 × 21 × 0.8 ≈ 1071.3 (kW). 4) Determination of installed capacity of station: taking into account requirements of maximum irrigation flow and operation condition at high water level during overflow period, we set installation coefficient as 1.2, therefore the installed capacity of station Nzj = 1.2 × Nj = 1.2 × 1071.3 ≈ 1285.6 (kW). Taking into account the standardization of unit capacity, the installed capacity of station is determined as 1260 kW, which agrees with the maximum output mentioned in above calculation. 3. Selection of Unit Number and Type
17
As taking into account following points: 1) to match the number of water supply pipes; 2) the reliability and flexibility of operation and 3) changes of operating conditions, we recommend equipping 2 turbine-generator units with rated output of 630 kW each for this station. The Kaplan turbine and Shaft Extension Tubular turbine can both be used for this station. Compared from the application scope of spectrum and operation experience of similar stations, we recommend the Shaft Extension Tubular turbine to be equipped for this station. The advantages of Shaft Extension Tubular turbine: 1) less hydraulic loss and high efficiency; 2) convenience for installation and maintenance; and 3) less excavation of powerhouse.
5.2.4 Calculation of Multi-year Mean Output
1. Calculation of Annual Output of Year 2008-2011: based on above calculation of daily output, we can use formula E = N × T (T = 24 hours) (kWh) to calculate out the daily energy output and obtain the annual output by accumulating all the daily energy output. The results of calculation are as follows:
Daily Output Cumulative Hydrograph of Year 2008
0
200000
400000
600000
800000
1000000
1200000
1400000
1
21
41
61
81
101
121
141
161
181
201
221
241
261
281
301
321
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kWh）
Figure 10 Daily Output Cumulative Hydrograph of Year 2008
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Daily Output Cumulative Hydrograph of Year 2009
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Figure 11 Daily Output Cumulative Hydrograph of Year 2009
Daily Output Cumulative Hydrograph of Year 2010
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Figure 12 Daily Output Cumulative Hydrograph of Year 2010
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Daily Output Cumulative Hydrograph of 2011
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Figure 13 Daily Output Cumulative Hydrograph of Year 2011
2. Calculation of Multi-year Mean Output: according to calculation results of annual output of year 2008-2011, we can reach the conclusion that the annual output is basically proportional to annual rainfall of this project. According to this conclusion, we can calculate out the multi-year mean output form year 1988 to year 2011: 2008-2011: mean rainfall of 1126.3 mm, and mean output of 207.2 × 104 kWh. 1988-2011: mean rainfall of 1209.4 mm, and mean output of 222.5 × 104 kWh. 3. Annual Utilization Hours of the Station: Tn = 222.5 × 104 / 1260 ≈ 1766 (h).
20
Chapter 6 Project Layout and Main Civil Works
6.1 Project Layout
6.1.1 Layout and Situation of the Dam
The India Muerta Reservoir dam consists of a Main dam, dam abutment, auxiliary dam, spillway, intake, pipeline, stilling basin, distributary point, the heads of the east and west canal, the east and west throttle valve, etc. The dam body and the right dam abutment are arranged in a straight line, while the left dam abutment is at a folded angle inwards of 30°to the dam axis. The auxiliary dam is located at the right dam abutment at a folded angle inwards of 50°to the dam axis. The tower structure at intake is on the left side of the dam, and the water supply pipeline is located inside the dam and connected to the stilling basin downstream. The stilling basin is connected to the apron and extends 20 m to the distributary point and then separates into the east and west canal. The spillway, at a width of 200 m, is built in another small valley approximately 1.5 km far away from the auxiliary dam (Figure 3).
6.1.2 Layout of the Hydropower Station System
The powerhouse is arranged at the existing stilling base and apron, with two 630 kW shaft-extension type tubular turbines installed inside. The tail channel is connected to the distributary point, and the throttle valves of the east and west canal need to be shifted about 10 m down river. The switchyard is in the left side of the powerhouse, with two 800 kWA step-up transformers installed. At the upstream side of the powerhouse, a Φ1000mm hole is opened on outside for each penstock before both are extended into the powerhouse. Also the gate valves are fixed to connect the by-pass tube for the reason that when the hydraulic turbine and generator units are under maintenance, irrigation water could be supplied through the by-pass tube to ensure a constant irrigation system.
6.2 Design of Main Civil Works
With reference to China‟s national “Classification and Design Standards for Water Resources and Hydroelectric Projects" (SL217-87), the India Muerta Reservoir Project is classified as a Grade-3 project of middle size, the main hydraulic structures as Grade-3 buildings, other minor buildings as Grade-4 buildings, whilst temporary
21
structures such as the construction cofferdam are classified as Grade-5 buildings. The structures for the generating system of this project are built behind the dam instead of being located.... due to the area‟s more stable geology. As a consequence, according to the regulation SL217-87 the buildings can be regarded as "minor" buildings (meaning of secondary importance) compared to the dam. They are therefore designed following up requirements as Grade 4 buildings.
6.2.1 Diversion System Structures
1. Intake. The intake of the irrigation pipelines is in the dam slope on the upstream side of the dam body, connected to the highroad on the top of the dam through a working bridge. A vertical trashrack is put at intake to connect the two intakes. The two intakes are both equipped with two screw driven sluice gates, of which one is a working gate and the other an alternate one. Required by the owner, the intake will not be changed and only a steal trashrack is added. 2. Existing Penstocks (water supply pipeline). Two concrete pipelines are set after intake, each with an internal diameter of 1.75 m, a wall thickness of 0.3 m, elevation in the centre of ▽40m and a total length of 80 m. (See figure 14). The two pipelines join up into one at the stilling base behind the dam, before going through the tower surge tank and turning off at outtake（See Figure 15）. The outtake is 2.5m in diameter of and at an elevation in the centre of ▽39.385m (See Figure 16).
Figure 14 Vertical and horizontal cross section of the Water supply pipeline (penstocks)
22
Figure15 Plan of the two water supply pipelines (penstocks) joining in one, Tower surge tank, and outtake
Figure16 Partial cross section of the water supply pipeline (penstocks) from the outtake to the stilling base
23
The extension and rehabilitation of the penstock: At the point which the existing pipelines joins in one (see Figure 15), remove the rear section and construct an anchorage block to support the pipelines. The pipeline extends along the flow and makes a horizontal 30°turn outward. When the central line of the pipe reaches the point of 6 m away from the units, it goes forward and makes a horizontal 30°turn inward. Thus the two pipelines are both parallel to the flow, with 6 m distance between each other. It is required to construct the anchorage blocks to support the turns of the pipes. The sizes of the anchorage blocks are decided through stability calculation.
6.2.2 Powerhouse
It is proposed to equip this plant with two shaft-extension type tubular turbines of model GD008-WZ-140, with total installed capacity of 1260 kW. According to the parameters and size of the units provided by the manufacturers and with reference to the plants of a similar scale and equipped with the units of the same type, the size of the main powerhouse (length×width×height) is designed as 18×13×8 m (the height of the powerhouse refers to the elevation difference between ceiling and floor). The installation room, 6.0 m in length and at the same height as the highroad approaching the powerhouse, is built on the left side of the powerhouse to store the two units. The two units are installed 6.0 m apart without a division line. The units are installed at an elevation of ▽40.32 m on level with the centre of the existing outtake. The elevation at the bottom of generators is ▽39.32 m , and the floor of installation room is ▽41.0 m. For easy installation and maintenance, a 15 ton electrical single-girder overhead travelling crane is equipped, having a span of 11.5 m and an elevation of ▽47.48 m on its track top. The auxiliary powerhouse is located down the left side of the main one and links to the installation room via the gate. It contains the panels and boards of the protection, control and direct current systems for the units in addition to duty desks for the operators. The auxiliary powerhouse has the following dimensions: 6.0×7.5×5.5m - length×width×height), and the ground elevation is▽41.0 m , while the ceiling elevation is ▽46.5m. The powerhouse is constructed in a framed structure, with the roof assembled with a prefabricated light steelwork.
6.2.3 Draft Tube and Tailrace Channel
Draft tube is supplied together with the units by the equipment manufacturer. It
24
consists of a bend, straight, expansion and rectangular level section. The concrete lining around the draft tube requires a minimum thickness of 0.7 m. The draft tube is connected to an adverse slope of 1:3 (height∶width) at the end of the level section, and before going through a 6.12 m transition section and finally connects to the tailrace channel. The tailrace channel is at an elevation of ▽38.76 m from the bottom, with the cross section of rectangle, which has 12.0 m of width and 43 m. The channel dike is built with sandy soil and concrete lined with a minimum thickness of 0.25 m. The tailrace channel is about 68 m in length from the transition section to the sluice gate distributing the flow to the east and west canal.
6.2.4 Step-up Switchyard
The step-up switchyard is located on the left side of the powerhouse and in close proximity to the outer wall of the auxiliary powerhouse, which size should be 8.0×10.0 m (length×width) and▽41.0m of the bottom. Two S11-800KVA/15/0.4kv
transformers and one 15kV transmission line are installed in the switchyard whilst an iron fence at a height of 1.7 m is built around it.
6.2.5 Irrigation Bypass Valve System
As it is essential that irrigation is guaranteed during the unit maintenance period, aΦ1500 orifice is opened on the each of the two anchorage blocks of the water supply pipeline (penstocks) before they enter the powerhouse （2×Φ1500）. A valve of Φ1500 is fixed to connect aΦ1500 bypass pipe and then to the tailrace channel. Under normal conditions, the valve is closed; and if the units are under maintenance during the irrigation period, the bypass valve will be opened to draw the water through the bypass pipe for irrigation use.
25
Chapter 7 Hydraulic Machinery, Electrical Equipment &
Metal Structures
7.1 Hydraulic Machinery
7.1.1 Selection of Hydraulic Turbines
Selection of Turbines. Having made careful comparison and reference to the similar cases, we recommend the shaft-extension type tubular turbines for this plant. Only two models of the shaft-extension type tubular turbines, namely the Model GD008-WZ-140 and the Model GD006-WZ-160 could satisfy the operating conditions as attributed by the head and flow. Parameters of the above two models are listed in Table 5. Each model has its advantages and disadvantages. The Model GD008-WZ-140 is smaller in size, has a lower price and relatively less civil works would be involved. In addition it has a high rated output with a certain overload capacity but lower turbine efficiency. The Model GD006-WZ-160 is more efficient due to its larger size, consequently its price is higher and the amount of civil works would increase. Furthermore, the second model has a lower rated output and a limited overload capacity. After comparison of the above two models, the former model (GD006-WZ-140) is considered the most appropriate.
Table 5 Comparison of Turbine Parameters
Turbine Model GD008-WZ-140 GD006-WZ-160 Rated Output KW 589 556 Runner Diameter cm 140 160 Max. Head m 8.0 8.0 Min. Head m 2.5 2.5 Rated Head m 6.5 6.5 Rated Discharge Q3/S 10.5 10.5 Rated Rotational Speed r/min 300 250 Rated Efficiency η% 88 90.18 Optimum Efficiency η% 90.1 91.75 Suction Height m 0.5 (2.3-▽/900)
7.1.2 Selection of Generators
The three-phase synchronous AC generator, Model SF-J550-20/1430, utilized in the plant is directly connected to the hydraulic turbine. The generator adopts an open
26
structure for ventilation and cooling. It works at a synchronous rotating speed of 300 r / min, with machine base number of 1430 mm and a power factor of 0.8.
7.1.3 Basic Parameters of Units
1. Turbine Type： GD008-WZ-140 Max. Head： 8.0m Design Head： 6.5m Min. Head： 2.5m Rated Discharge： 10.5m3/s Rated Output： 589KW Rated Rotational Speed： 300r/min Runner Diameter： 140cm Number of Turbines Installed： 2 Turbines 2. Generator Type: SF-J550-20/1430 Rated Capacity： 550KW Rated Voltage： 400V Rated Rotating Speed： 300r/min Rated Efficiency： 50Hz Power Factor： 0.8 Excitation System： Silicon controlled Static Excitation Cooling Method： Open structure for ventilation and cooling
7.1.4 Selection of Regulating Device
To realize the automatic control, YWT Step Programmable Computer-based Governor is adopted. The governor works at a capacity of 1000kg.m and with Operating Oil Pressure of 4.0Mpa. The main regulating parameters are: Proportion Coefficient KP 0～20 Integral Coefficient KI 0～10（1/s） Differential Coefficient KD 0～5（s） Permanent Speed Droop bp 0～10% man-made frequency dead-band △f 0～±1% Given Frequency Range fG 0～50Hz Given Power Range PG 0～100%
27
Power AC～220V±10% ≤500w
7.1.5 Excitation System
Since faults are generally more likely to be found in generator excitation systems, an excitation system of high-level redundancy with PLC double computer, full-bridge and in double DC side switching mode, is selected. The excitation model is SWJL-65.
7.1.6 Selection of Lifting Device in Powerhouse
For easy installation and maintenance, an electrical single-girder overhead travelling crane is fixed in the powerhouse. According to the maximum weight of the object as well as the dimension of the main powerhouse, it is decided to choose a span of 11.5m for the crane with a weight limit of 15t.
7.1.7 Water Supply and Drainage System
1. Technical water supply system: The water is flowing by itself through the penstock. A pressurization pump is added before the main valve of the water supply, in case the water pressure is insufficient when the units operates at the lowest water level. In a situation, where the water pressure is lower than the required technical water supply pressure, the pump will start and add pressure to realize a normal water supply. 2. Seepage Water Drainage System in Powerhouse: As the normal level of the tailrace ▽40m is higher than the bottom elevation of the generator, a seepage pumping shaft for leakage water is set in the right corner of the main powerhouse, in an elevation of ▽36.5m of the shaft bottom and dimension of 4.0×2.0m (length×width). Also two centrifugal seepage water pumps, Model 2BA-6B are installed over the seepage pumping shaft (in the same elevation of the bottom of the generator). The main parameters of the centrifugal pump are: Type 2BA-6B Discharge 25m3/s（6.9l/s） Total Lift 16.3m Rotating Speed 2900r/min Shaft Power 1.73KW Electrical Motor Y90L-2 2.2KW Efficiency 94% Allowed Suction Head（HS） 6.6m
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Runner Diameter 132mm Weight (Pump and bed) 42/28Kg 3. Maintenance Water Drainage System in Powerhouse: For the shaft-extension type tubular turbines, less inspection and maintenance inside the draft tube is required, therefore, it is not necessary to apply a fixed maintenance water drainage system. The drainage measures could be taken temporarily when the draft tube needs to be drained. 4. Drainage System in Powerhouse Site: The station is built after the dam, having its tail water directly flowing into the irrigation channel. It is far away from the flood discharge river, and the elevation of the powerhouse is on the same level of the normal tailrace at downstream, so the powerhouse has remote possibility to be submerged or flooded by back flow. Therefore, no fixed drainage system will be set in the powerhouse.
7.1.8 Irrigation Water Supply System
1. Irrigation water supply system under normal operating condition of the units: The rated discharge of the two units is decided in accordance to the maximum water quantity supplied for irrigation. Under normal operating condition of the units, the tail water of the station goes through the tailrace channel to the east and west canal, with sufficient water quantity to satisfy the irrigation demands.
2. Irrigation water supply system when the water head is lower than the maximum head of the unit: If the water level of the reservoir is too low to reach the maximum head of the unit, the turbine & generator units must be stopped. On such occasions, the by-pass tube system will be used to transfer the water for irrigation. There are two options for the by-pass valve: Z941-6，DN=1000. They are both manually operated. 3. Irrigation water supply system during repair period of the unit: When one unit breaks down and requires examination, but the other unit works as normal, only one by-pass valve for the broken unit is needed to make up for the lost water supply.
Table 6 Main Devices of Hydraulic Machinery
No. Name Model Unit Number 1 Turbine GD008-WZ-140
N=589KW set 2
2 Generator SF-J550-20/1430 N=550KW 0.4KV
set 2
3 Governor YWT-1000 set 2
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A=1000kg.m PG=4.0Mpa 4 Excitation System SWJL-65 set 2 5 Overhead Travelling
Crane CXTS-10 G=15t
set 1
6 Seepage Water Drainage System
2BA-6B。 H=16.3m Q=25m3/h
set 2
7 By-pass Valve Z941-6 DN=1000
set 2
7.2 Electrical Engineering
7.2.1 Primary Electrics
1.The Connection of Power Station and Electrical System According to distribution grid standard of Usinas y Trasmisiones Electricas (UTE), the power station will be accessed by the electrical system with a voltage line of 15 kV. The access point is at the end of distribution grid, which is in the village 500 m far away from the power station. The generator voltage of the power station is 0.4 kV, which will be boosted to 15 kV by a step-up transformer and transmitted to the access point through a 15kV one-circuit overhead transmission line. The type of transmission line is a LGJ-70. 2.Main Electrical Connection According to the requirements of design principle, two connection schemes are proposed for comparison. One of them will be recommended for current stage design. Scheme 1: The two units will connect with the main transformer. The enlarged unit connection is adopted at the generator voltage side (0.4 kV). The air circuit breaker and isolation switch will be equipped at the generator outlet whilst the main transformer low voltage side will be equipped with an isolation switch only. The main transformer line unit connection is adopted at the transformer high voltage side (15 kV), which will be equipped with one outdoor high voltage vacuum circuit breaker and one group of outdoor isolation switches. Scheme 2: Each unit will connect to main transformer. The single bus sectional connection is adopted at the generator voltage side (0.4 kV). The air circuit breaker and isolation switch will be equipped at the generator outlet, and the main transformer low voltage side will be equipped with an isolation switch only. The single bus connection is adopted at the main transformer high voltage side (15 kV), which will then be equipped with an outdoor high voltage vacuum circuit breaker and a group of outdoor isolation switches. The line side will not be equipped with a circuit breaker
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and isolation switch. Comparison of the two schemes: Scheme 1 has a simpler connection and represents a lower level of investment, however it lacks operational flexibility and reliability. If the main transformer were to break down, the operation of both units would be stopped. This will influence not only the benefits from power generation, but also the water supply for normal irrigation. Scheme 2 has a more complicated connection and thus a higher investment and as a result it has more operational flexibility and reliability. Scheme 2 includes the following operational modes: 1) At normal conditions, the isolation switches of the bus at the generator voltage side will open, so that the No. 1 and 2 generators will connect to the No. 1 and 2 main transformers respectively to form two generator-transformer units for generation; 2) If one of the main transformers breaks down, the operation of fault generator-transformer unit will stop leaving the other non-faulty generator-transformer unit operating; 3) If one of the main transformers of one generator-transformer unit and one generator of another generator-transformer unit breaks down, both generator-transformer units will stop. After closing isolation switches of the bus at the generator voltage side, the non-faulty generator will connect the non-fault main transformer to form a new generator-transformer unit for generation. According to the features of the power station, “irrigation will combine generation, but irrigation is more important than generation”, and therefore scheme 2 is recommended for current stage design. 3.Selection of Main Electrical Equipment 1) Selection of Main Transformer The selection will be in accordance with rated output and voltage. The type of main transformer is S11-M-800/15 with the following parameters: Type S11-M-800/15 Rated Output 800KVA Voltage 16.5±2×2.5%/0.4kv Connection Group Ynyn0 No-load Loss P0 980W Load Loss PF 7500W No-load Current I% 0.8 Weight of Oil 500Kg Weight of Equipment 1640Kg Total Weight 2750Kg Dimension (Length × Width × Height) 1540×930×1560 2) Selection of Outdoor Vacuum Circuit Breaker
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The selection will be in accordance with rated voltage and current, and be checked by rated short-circuit breaking current. The type of circuit breaker is ZW32-15/630 with the following parameters: Type ZW32-15/630 Rated Voltage 15KV Rated Current 630A Rated Frequency 50Hz Rated Short-circuit Breaking Current 20KA Rated Peak Withstand Current 50KA Life 100000 times Operational Voltage AC220V or DC220V、110V 3) Selection of Outdoor High Voltage Isolation Switch The selection will be in accordance with rated voltage and current. The type of isolation switch is GW4-15/200 with the following parameters: Type GW4-15/200 Rated Voltage 15KV Rated Current 200A Rated Frequency 50Hz Maximum Peak Current 15KA 5s Thermal Stable Current 5KA Number of Poles 3 Life 20000 times 4) Selection of 0.4 kV Air Circuit Breaker (Equipped in Control Panel of Generator) The selection will be in accordance with rated voltage and current. The type of circuit breaker is TDKW1-2000 (tripolar drawer type, microprocessor) with the following parameters: Type TDKW1-2000 Rated Voltage 0.4KV Rated Current 1250A Rated Short-circuit Breaking Current 80KA 5) Selection of Low Voltage Distribution Panel: The selection will be in accordance with the features of the panel or cabinet. The control panel at the generator outlet will select GGD type and the distribution panel for station power supply will select GCK or GCS type. 6) Selection of Power Cable from Generator Outlet to Control Panel: According to voltage, laying mode, current-carrying capacity, the low voltage power cable of VV-1KV-1×500 type will be selected. 7) Selection of Power Cable from Control Panel to main transformer: According to
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voltage, laying mode, current-carrying capacity, the low voltage power cable of VV-1KV-1×500 type will be selected. 8) Selection of 15 kV Overhead Conductor: According to the condition that △U%＜
5% under rated load, steel reinforced aluminum conductor of LGJ-70 will be selected. 4.Station Power Supply System 1) Main Load of Station Power Supply System: Lighting for station, bridge crane, oil pump of governor, maintenance of drainage pump, side irrigation gate-valve, DC panel, distribution box in maintenance room, etc.
2) Power of Station Power Supply System: It includes two power sources, which connect to two 0.4 kV buses of generator respectively. Both power sources are mutual locked. 3) Connection of Station Power Supply System: Single bus connection. 4) Selection of Control Panel for Station Power Supply System: GCK or GCS type. 5.Layout of Electrical Equipments 1) The control panel of generator, main transformer control panel, busbar panel, station power supply panel and DC panel are laid in the control room of the auxiliary powerhouse. 2) The excitation panel, control panel of governor and temperature brake panel are laid beside units in main powerhouse. 6. Lightening Prevention and Grounding 1) Over-voltage Protection Caused by Lightening Invasion Wave: In order to prevent over-voltage caused by lightning invasion wave, a group of zinc oxide arresters of YH5W-15 type should be installed on the terminal pole at the 15 kV overhead outlet wire of booster station, and two groups of arresters of HY1.5W-0.5/2.6 type should be installed in the control panel on the 0.4 kV bus (1 group for each section). 2) Direct Lightening Prevention: A metal lightning rod is adopted to prevent lightening from affecting the system. One metal lightning rod, 25 meters high, should be installed downstream of the tailrace side of booster station. Any lightening will be directly led into grounding system through metal conductor. 3) Grounding System: The protection and ground working for high and low voltage equipment of the station adopt public grounding network. The grounding network is laid on the base layer of the powerhouse and booster station floor, which utilizes a galvanized angle steel as the vertical grounding object (supplemental grounding object) and uses a galvanized flat steel as the horizontal grounding object (main grounding object). The total grounding resistance of grounding network required is
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less than 4 Ω.
7.2.2 Secondary Electrics
1.Control and Monitoring As the station has the possibility to adopt remote control and monitoring, both conventional and computer control and monitoring methods are adopted. 1) Conventional Control and Monitoring System ① Each unit will be equipped with one panel, which consists of secondary examine, control, protection equipment and primary electrical equipment. The total system has distinct layers, a flexible structure, high practicality, convenient expansion and high performance. ② Control and Monitoring Functions: Through meters on the control panel, the following data and signals can be directly monitored: generator voltage, generator frequency, 3-phase current, active power, reactive power, excitation voltage, excitation current, signals of air circuit breaker location, and monitoring signals of start and close circuit. Meanwhile, the operations of start and close unit, manual and automatic quasi synchronous connection, load increase and decrease, and excitation increase and decrease can be directly implemented on control panel. 2) Computer Control and Monitoring System ① System Settings: The computer control and monitoring system of the station adopts duplex computer control and monitoring method, which is designed according to “Unattended Fewer People on Duty” rules. The total system adopts open hierarchical distribution structure and open UNIX/RISE workstation with mature application and operation experience and excellent anti-virus capability, in addition to adopting redundancy requirements to set station layer. The sockets of the local control unit and on-site equipment both adopt modules which have excellent anti-interference capability and can directly connect to Ethernet and hot plug. ② Control Methods: The control methods include remote and local control, which can shift between each other. The remote control possibility means operations are controlled from higher level control center whilst local control means operations are controlled on on-site at LCU. The right of control will be set by the local terminal with priority of “Local-Remote”. The “Local-Remote” control right would ensure operation of the station without destabilization during shift process. ③ System Structure: In order to enhance anti-interference capability of the system, to minimize electromagnetic interference and reduce the relationship between electrical equipment, the computer control and monitoring system of station adopts a
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hierarchical distribution structure. Meanwhile, it also strengthens capability to prevent lightening invasion, and promotes the security and reliability of system. In order to ensure progressiveness and openness of the system, the system network adopts an adaptive switch type fiber-optical Ethernet bus network with TCP/IP communication protocol of international standard. ④ Control and Monitoring Functions of System: The system has the following control and monitoring functions: - All functions of a conventional control and monitoring system; - Warnings in the event of an emergency and/or other abnormal activity such as faults originating from either the generator, transformer or wires; Announcement of faults originating in the main auxiliary equipment; - Automatic formation of operation logs and reports; - Fill in operation orders and locking of illegal operations; - Remote communication, control and monitoring (if necessary). 2. Relay Protection (Microprocessor Type) Relay protection is equipped to the principal equipment as follows: 1) Generator Protection ① Main generator protection adopts a microprocessor protection system of the NSA3191A type with the following functions: - Generator differential protection; - Single element sensitive current transverse differential protection (while extraction of branches); - Longitudinal residual voltage inter-turn short-circuit protection (while installation of specific zero TV); - Stator circuit one-point grounding protection; - Rotor one-point grounding and rotor two-points grounding protection. In next stage of design, the protection unit should be selected according to specific requirements. ② Backup generator protection adopts microprocessor protection system of NSA3192A type with following functions: - Two constant time-lag composite voltage latch over-current protection (with memory); - Generator loss of excitation protection; - Generator constant or reverse time-lag overload protection; - Generator constant or reverse time-lag negative overload protection; - Generator over-voltage protection; - Generator low voltage islanding protection;
35
- Generator high frequency tripping protection; - Generator low frequency islanding protection; - Generator reverse power protection; - Zero over-current and over-voltage protection (with zero power direction); - Two groups of non-electrical delay protection; - PT (TV) and CT (TA) disconnection protection; - Fault recorder. In next stage of design, the protection unit should be selected according to specific requirements. 2) Transformer Protection ① Main Protection: Heavy gas protection. ② Backup Protection: It adopts a microprocessor protection system of NSA3192A type with following selected functions: - Two constant time-lag composite voltage latch over-current protection (with memory); - Fault recorder. 3) Wire Protection: It adopts microprocessor protection system of ZSA3111D type with following functions: - Two constant time-lag over-current protection; - Zero over-current protection and selection of small current grounding; - Three phases and one time closing (no pressure check or without check); - Overload protection; - Closing acceleration protection (former-acceleration and after-acceleration); - Load shedding under low frequency protection; - Fault recorder and independent operation circuit. Metering and Control: - 9-way remote telecommunication; - 5-way remote mitering: Ia, Ic, P, Q, COSф - Remote control on-off switch of circuit breaker and small current grounding probe; - Statistics of switch emergency and opening times, and event SOE. Item for selection: Interval online 5-protection. In next stage of design, the protection unit should be selected according to specific requirements.
7.2.3 DC System
The operation power of station adopts DC 220V and is equipped with one set of microprocessor controlled by the high-frequency switching DC panel power of
36
GZDW-100 type. The storage battery adopts one group of 100 Ah maintenance-free lead-acid batteries. In normal conditions, the high-frequency switching power will supply electricity to operation power. However, in abnormal conditions such as loss of AC, the storage battery will supply electricity to operation power and for emergency lighting.
7.2.4 Lighting System
1. Normal Lighting 1)Main Powerhouse: As the main powerhouse has clearance height of 6 m, three dark lights for powerhouse are equipped at ceiling height in the center of the installation room, where the No.1 and No.2 unit are located. Additionally three fluorescent lamps are equipped at the height of 1.8 m on both the upstream and downstream walls of the powerhouse. 2) Control Room: Four double tube fluorescent lamps are equipped at the ceiling height. 2. Emergency Lighting: In accordance with the non-pressure auto-switch method, the storage battery will supply electricity to the power of emergency lighting through one DC contactor. The backup power will be automatically switched. 1)Main Powerhouse: Three filament lamps are equipped on both the upstream and downstream walls of powerhouse, which will connect to the emergency lighting system. 2)Control Room: Four filament lamps are equipped at the ceiling height, which will also connect to the emergency lighting system.
7.2.5 Dispatch and Communication System
1.Main Communication Method: The digital microwave communication equipment is equipped to achieve communication with the dispatch authority of the power system (according to the requirements of power system). 2.Auxiliary Communication Method: Telecom fiber-optical communication and mobile communication. Main electrical equipment and materials are listed in following table.
Table 7 Main Electrical Equipments and Materials
No. Item Specification Unit Number Remarks 1 Electrical
Transformer S11-M-800/15 Set 2
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2 Outdoor Vacuum Circuit Breaker
ZW32-15/630 Set 2
3 Outdoor Isolation Switch
GW4-15/200 Group 4
4 Outdoor Current Transformer
LBZ3-15 50：5 0.2/B
Set 1 15 kV Outlet, for Protection
5 Outdoor Voltage Transformer JDWZ-15 15/
0.13
/0.1
Set 3 Connect to 15 kV Bus
6 15 kV Lightening Arrester
YH5W-15 Group 1
7 Generator Control and Protection Panel
GGD2-A Piece 2 Equipped in Control Room
8 Unit Control and Protection Panel
GGD1-C Piece 2 Equipped beside Units
9 Station Power Supply Panel
GCK Piece 1
10 DC Panel GZDW-100 Set 1 2 Pieces 11 Main Transformer
Control and Protection Cabinet
GGD2-A Piece 2
12 Busbar Cabinet GGD2-A Piece 1 13 Public Metering and
Control Communication Cabinet
DCAP Piece 1
14 Industrial Control Computer
SIMATIC PC 840 Set 1 PIV2.4/256/60GB/19,, LED Rack Type
15 Industrial Ethernet Switches
100/10mb TCP/IP Set 1 16 Ports, Rack Type
16 UPS Power AC220 2KVA Set 1 17 Electrical Cable VV-1KV-1×500 m 450 18 Electrical Cable VV-1KV-1×120 m 100 0.4 kV Side 19 Control Cable KVV22 m 500 20 Communication
Cable m 300
21 Suspension Insulator XP40-C Piece 30 22 Pin Insulator ZP-15T Piece 40 23 Steel Reinforced
Aluminum Conductor
LGJ-70 t 0.6
24 Galvanized Flat Steel 18×6 t 1.5 Horizontal Grounding Object
25 Galvanized Angle Steel
40×40×5 t 0.15 Vertical Grounding Object
26 Cross Arm Pair 12 27 Ball Hanging Ring Q-7 Piece 20 28 Bowl Hanging Plate W7-A Piece 20 29 U Type Hanging
Ring U-7 Piece 20
30 Stain Clamp NLL-1 Piece 20 31 Equipment Clamp SLG-1A Piece 30 32 U-steel 5﹟
、6.5﹟、8﹟ t 0.3
33 Steel Plate 3～6mm t 0.15 Simple Steel Plate 34 Lamps Fluorescent Lamp Set 12
38
35 Lamps Dark Light, Filament Lamp
Piece 15 3 Dark LIghts
35 Lighting Distribution Box
Piece 2 Each for Main and Auxiliary Powerhouse
36 Insulated Conductor BVV-1.5、2.4、6
m 500 Lighting, Air Conditioning
37 Lightening Rod Steel Structure 25m
Piece 1 Installed at Tailrace Side of Booster Station
7.3 Metal Structure
7.3.1 Trash Rack and Intake Gate
1.Trash Rack: As the trash rack slot is currently set at the intake of irrigation supply pipe, one steel trash rack of 2.6×2.6 m will be remanufactured. 2. Intake Gate: Two intake gates are equipped to each water supply pipe, in which one is working gate and the other a backup gate. The two intake gates provide mutual backup. The operation method of the intake gate is the hand screw type. According to the on-site investigation, the gates and its operation parts are in relatively good condition. Therefore, in the owner‟s opinion, the gates should continue to be used. However, after installation of turbine-generator units, in order to enhance the speed ability and the automation extent of intake gate operation, the operation parts of gate could be changed into electrical worm gear operation parts. In the next stage of design, an improvement scheme proposal is recommendable.
7.3.2 Penstock
1.Current Water Supply Pipe: Current water supply pipes are two reinforced concrete pipes with a diameter of 1.75 m, wall thickness of 0.3 m and a length of approximately 80 m. 2. Extension of Penstock: In order to layout station powerhouse and direct flow into turbine conveniently, the penstock of 25 m length approximately should be extended to the current water supply pipes. The diameter of penstock is 2.15 m and the wall thickness is 10 mm. Furthermore, the central line of the pipes should move a distance of about 6 m away from their current location through planar turn.
7.3.3 Irrigation Bypass Valve and Bypass Pipe
1.Irrigation Bypass Valve: It will select hand operation gate valve by type of Z941-6
39
and DN=1000. 2. Irrigation Bypass Pipe: It will select steel pipe with diameter of 1.00 m, wall thickness of 8 mm and a length of around 40 m.
40
Chapter 8 Construction Organization and Design
8.1 Construction Condition
8.1.1 Project Condition
1.Project Condition The India Muerta Reservoir Hydropower Station is located in India Muerta Village, Lascano Town, Rocha Province, Uruguay. The hydropower station utilizes irrigation water of India Muerta Reservoir to produce electricity. The India Muerta Reservoir is located on the middle of the India Muerta River, with 65,700 hectares of catchment area of dam site. The dam has 12 m of height, 52.2 m of crest elevation and 3221 m of length of dam axe. The India Muerta Reservoir has 47 m of normal storage level, 3,530 hectares of corresponding water area and 127.5 million m3 of effective storage capacity. It provides a good traffic condition for the India Muerta Reservoir. It is 35 km between Lascano Town and the India Muerta Reservoir Power Station, consisting of 30 km road with asphalt pavement and 5 km road with sand and gravel pavement. The distance between the Capital City Montevideo to Lascano town is 250 km with whole highroad. Therefore, it is convenient to transport construction materials and equipments through highroad. The India Muerta Reservoir Power Station project is composed by penstock (modification of diversion system), powerhouse, tailrace, irrigation bypass system and booster station. All buildings of this project will be located on the back of dam of the India Muerta Reservoir, where has wide and flat field, and be far away from the spillway. The project almost has none of under-water construction. The main structure of this project is the powerhouse, with the size of 18.0×13.0×8.0 m (length×width×height). The two shaft-extension tubular turbine-generator units are installed in the main powerhouse with total rated output of 1260 kW. The auxiliary powerhouse of this project is located at the left downstream side of main powerhouse, connecting to the installation room. The protection and control panels of units, DC system panels and desks for staff on duty are equipped in the auxiliary powerhouse. The size of the auxiliary powerhouse is 6.0×7.5×5.0 m (length×width×height). The frame construction method is adopted for the construction of powerhouse, and the assembly light roof of steel structure is also adopted. 2 Natural Condition
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The project site has a subtropical humid climate in the Southern Hemisphere. It is 2-14℃ in winter from April to September while the in summer the temperature is 17-28℃ from October to March. Although it is influenced by the dry west wind from the Andes, owing to its location near the ocean, warm ocean current from Brazil also flows through it, it has a plenty of rainfall. The mean average waterfall is around 1000 mm. 3 Market Condition The required construction materials, such as rubbles, gravels, sand and bricks, should be bought in the market with average transportation distance of about 30 km. Steel and cement should be bought in the Capital City Montevideo. The necessaries, auxiliary materials and spare parts can be bought in Lascano town, and excavation and transportation equipments also can be rented in Lascao town. The 15kV distribution grid of UTE is nearby the power station, which will provide electricity for construction. According to our observation, Lascano town can‟t provide maintenance and processing for equipments, so the construction company should provide maintenance tools and technicians by itself. Normal labors can be employed in local area and required lumber for project can be bought in nearby market. 4. Construction Characteristics 1) This project doesn‟t need diversion measures and almost has none of under-water construction. 2) As all buildings of power station are located at the back of dam and almost with the excavation area of powerhouse pit, the basic excavation work can be done at the same time. 3) The distribution of rainfall is clear and centralized, so the construction procedure can be arranged according to rule of rainfall. 4) This project belongs to innovation supplemental project, so the size of relevant buildings and layout should be fit to original buildings.
8.2 Construction of the Main Structures
The main structures of the India Muerta Reservoir Power Station include penstock, powerhouse, tailrace, booster station and transmission lines. The main construction quantity is listed in Table 8.
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Table 8 Main Construction Quantity of the India Muerta Reservoir Power Station Project
Item Unit Penstock Tailrace Booster
Station Total
Excavation
Soil
Excavation M3 560 1872 300 2732
Rock
Excavation M3 143 457 600
Backfill M3 160 160
Stone Masonry M3 70 1311 180 1561
Concrete M3 435 1664 503 2602
Steel Bar t 7.5 101.146 111.606
Trash Rack
Trash
Rack t 4.5
Embedded
Parts t 1
3t Manual
Block t 0.085
Irrigation
Bypass Pipe
Gate
Valve t 2.2
DN1000 t 6.8
Embedded
Parts t 0.50
Penstock
DN1750 t 16.6
Embedded
Parts t 2
Transmission
and
Transformer
Project
Lines t 1.5
Standard
Fittings t 0.2
Non-
standard
Fittings
t 1.5
Pole t 5.0
Insulation t 0.55
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8.2.1 Diversion System
1. The existing small surge shaft and outlet should be removed. The surge shaft and outlet can be seen in the following photo.
In the photo, the location of the surge shaft and outlet will be location for the joint of reinforced concrete pipe and penstock. Therefore, the surge shaft and outlet should be removed. As it is near to the dam, the directional blasting with little quantity of explosive will be adopted. 2. Excavation of Penstock Foundation As it is 25 m far between the anchored pier of penstock and the side wall of powerhouse along the central line of penstock, the construction of penstock foundation excavation can be undertaken at the same time with the excavation of powerhouse foundation pit. 3. Anchored Pier, Joint of Water Supply Pipe and Penstock The anchored pier will function as the joint of concrete pipe and penstock. When the excavation of foundation of anchored pier reaches the designed elevation, the block stones will be used to fill the foundation and the block stones will be covered with 5 cm depth of C15 concrete as undercourse. After then, the packing compact and placement of concrete of anchored pier will be undertaken according to construction
44
design drawings. At the connection part of concrete pipe and anchored pier, the measures for sealing up and leakage proof should be adopted. 4.Production and Installation of Penstock Each joint of penstock will be produced and processed in the factory according to master drawings. As it has large caliber, the cross inner supporting structures will be adopted during transportation. After completion of placement of penstock foundation and basic maintenance period, every joint of penstock will be hoisted on the foundation and welded on site.
8.2.2 Powerhouse and Tailrace
1. Foundation Excavation According to on-site observation, there is loose soil in the place of foundation pit. The excavation of foundation pit will adopt slope of 1:1.5 at all sides and sheet-pile supporting partly. The foundation excavation will mainly adopt 0.8～1.2 m3 excavator and be supplemented by manual excavation. The waste slag will be transported to the joint place of left side of powerhouse and western trunk canal by the 5-10 t dump truck. When the waste slag forms a hill, trees and flowers can be planted on the hill to prettify the environment of the power station. 2. Concrete Construction Two 0.8 m3 traveling mixers will be adopted to mix the concrete. The hand car will be adopted to transport concrete to the storehouse. And the rod type vibrator will be adopted to vibrate and pour the concrete. For the upper-ground structures of powerhouse, the hoister will be adopted to hoist concrete, or hand car will be adopted to transport concrete to the storehouse by setting up framed bent. The temperature control and maintenance of concrete will be in accordance with climate during construction period. 3. Installation of Metal Structures and Electromechanical Equipments 1) Installation of Metal Structures: The construction equipments for civil work will be adopted to install the embedded parts of metal structures. The construction equipments for civil work and wheel crane will be adopted to hoist and install the penstock, gate valve, and etc. 2) The indoor bridge crane will be adopted to hoist and install the indoor electromechanical equipments. The installation outline and network drawings should be formulated for installation of turbine-generator units and relevant auxiliary equipments in order to ensure the installation quality and procedure. And the 16 t autocrane will be adopted to hoist and install the outdoor electromechanical
45
equipments.
8.3 Transportation for Construction
8.3.1 External Transportation
1. Transportation Quantity and Intensity The materials and equipments required for this project include: cement, steel, lumber, sand and stone, mechanical equipments for construction, permanent electromechanical equipments, explosive materials, oil materials, building construction materials, living materials and so on. 2. Transportation Scheme It provides a good traffic condition for the India Muerta Reservoir. It is 35 km between Lascano town and the India Muerta Reservoir Power Station, consisting of 30 km road with asphalt pavement and 5 km road with sand and gravel pavement. The distance between the Capital City Montevideo to Lascano town is 250 km with highroad. Therefore, it is convenient to transport construction materials and equipments through highroad.
8.3.2 Field Transportation
The main aim of field transportation layout is to connect the construction of main structures to the mixing system, temporary dumps for materials and equipments, auxiliary processing factory, dumps for soil and slag, and living facilities to form a safe and convenient traffic network. It also should be connected to the external traffic network efficiently. The construction of field transportation ranks grade 4 with 2 km of temporary roads.
8.4 Construction Facilities
8.4.1 Mixing System
The 0.8 m3 traveling mixer will be adopted to process the concrete. The installation place of the mixer can be adjusted according to the concrete pouring place and concrete transportation distance.
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8.4.2 Machinery Factory
As it is 35 km between Lascano town and the India Muerta Reservoir Power Station, the normal maintenance of construction machinery and tools will be undertaken on site. There is a courtyard of 3000 m2 located 200 m far away from the construction site at left side of dam. The on-site machinery factory will be located in one corner of this courtyard.
8.4.3 Comprehensive Processing Factory
The processing of formwork and steel bar will be undertaken in the processing factory. It will be located in one corner of the courtyard.
8.4.4 Electricity, Water and Wind Supply for Construction
1.Electricity Supply: One 315 KVA step-down transformer and relevant panels, switches and control devices will be installed in the courtyard to serve as the main power for the project. One VV-120 low-voltage cable will be laid from the main power to the construction field with main panel. It will serve as the main power for construction field. 2.Water Supply: There is living water supply network in the courtyard to meet the requirements of living water for construction. One temporary water pool will be excavated on the left slope land of construction field and the 1.5 kW submersible pump with lift of 15 m will be adopted to draw water from the reservoir to the pool. It will be the main water resource for construction. 3.Wind Supply: The traveling air compressor will be adopted to provide wind power.
8.5 Construction Layout
8.5.1 Field Layout Scheme
The field of the project is divided into two areas. One is the living and processing area, which is located 200 m far away from the construction site at left side of dam. This area takes an area of 2500 m2 with flat and capacious field, which can meet the requirements of processing, living, dumping of instruments, materials and tools. Within this area, there are 2 buildings with an area of 500 m2. Another area is located in the construction field, which includes foundation pit, concrete mixing field, temporary dumps, waste slag field, temporary road, water supply pool and pipe
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network, power supply cabinet and network, and air compressor.
8.5.2 Waste Slag Scheme
As the total quantity of waste slag is not large and the construction site is surrounded by grass land, the waste slag can be placed at the joint area of left side of powerhouse and western trunk canal. When the waste slag forms a hill, trees and flowers can be planted on the hill to prettify the environment of the power station.
8.5.3 Estimation of Main Temporary Construction Quantity and Construction Occupation
The construction, office and living area takes an area of 3000 m2, within 1000 m2 of temporary houses and 300 m2 of rented houses. The temporary transportation road of 2 km ranks grade 4.
8.6 Total Construction Schedule
The irrigation period of the India Muerta Reservoir Power Station is October to March of next year. Therefore, the construction of main structures can only be arranged within non-irrigation period. In prevention of influence on irrigation of present year, the total construction period plans to be 11 months, composed by preparation period of 2.5 months, construction period of main structures of 6 months and completion period of 1.5 months.
8.6.1 Preparation Period of Project
As the construction should not influence the irrigation, the construction of main structures can only be arranged within non-irrigation period. Therefore, the preparation work should be ample. The preparation period plans to be from 1st, December of previous year to 15th, February of first year, which lasts for 2.5 months. The preparation work includes: living and office facilities, electricity supply facilities, water supply facilities, storehouse, temporary dumps for equipments and materials, processing factory, machinery factory, and dumps for construction machinery. In addition, the sources of materials, sand and stone, lumbers should be contacted.
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8.6.2 Construction Period of Main Structures
The construction period of main structures plans to be from 1st, March to 30th, September of first year, which lasts for 6 months. The construction work includes: penstock, powerhouse, tailrace, installation of electromechanical equipments, booster station and transmission lines. (1) Penstock: From 1st, March to 1st, May of first year. (2) Powerhouse: From 1st, March to 25th, July of first year. (3) Tailrace: From 1st, June to 1st, August of first year. (4) Installation and Commissioning of Electromechanical Equipments: From 15th, July to 25th, September of first year. (5) Booster Station: From 25th, May to 10th, July of first year. (6) Transmission Lines: From 10th, January to 25th, February of first year.
8.6.3 Completion Period of Project
The completion period plans to be from 1st, October to 1st, November of first year. The main tasks include: completion of commissioning of units, site clearing by construction company, resuming of environment, leave of all construction staff, accounting of project and approval of completion.
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Chapter 9 Engineering Management
9.1 Management Institution
9.1.1 Establishment of Management Institution
The branch company of India Muerta Reservoir Power Station is suggested to be established by Comisaco a.s., the owner of India Muerta Reservoir project. The branch company will take responsibility for operation and management of reservoir and power station.
9.1.2 Authorization of Management Staff
The India Muerta Reservoir originally has 3 management staff. After completion of the power station, 3 management staff will be added. Total of 6 management staff can meet operation and management requirements of India Muerta Reservoir Power Station.
9.1.3 Management Range
The management scope includes: irrigation and operation of reservoir, power production, flood protection and maintenance.
9.2 Engineering Management and Operation
9.2.1 Operation of Reservoir
1. Irrigation Period: The reservoir draws off water and the power station produces electricity according to irrigation requirements. When the required discharge Q≤
10m3/s, one turbine-generator unit will operate. When the required discharge 10m3/s＜Q＞12.5m3/s, one turbine-generator unit will operate and one bypass gate valve for irrigation will open to appropriate opening. When the required discharge Q＞12.5m3/s, two turbine-generator units will operate. If the rainstorm appears during irrigation period and the reservoir has the possibility to overflow, the two turbine-generator units will fully produce electricity in advance. After production, the surplus discharge to the required irrigation discharge will flow through overflow canal in irrigation area. If possible, one canal can be excavated near
50
the west trunk canal and spillway of reservoir to connect them, and the gate can be set on the connection canal at the west trunk canal side. Therefore, the potential overflow can be utilized to produce electricity. 2. Non-irrigation Period: The overflow will be utilized to produce electricity. After production, the tail water will flow back to downstream of reservoir spillway through the connection canal between the west trunk canal and spillway of reservoir.
9.2.2 Engineering Management Facilities
1. Establishment of automatic water regimen forecasting system; 2. Transportation equipments: one tool vehicle and one motor vessel; 3. Observation equipments: one current meter, one computer, one digital video camera, one camera, and one telescope; 4. Telecom equipments: commercial telecom tools and internal voice telecom of company; 5. Establish of information management system.
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Chapter 10 Investment Estimation
10.1 Budget Preparation
10.1.1 Project Description
The India Muerta Reservior Hydropower Station is located on the middle reach of the India Muerta River in India Muerta Village, Lascno Town, Rocha Province, Uruguay. The Reservoir was initially built in 1983 with a total storage capacity 0.127 billion m3.Irrigation for local agriculture is its main function with an annual irrigation capacity of 8000 hectare. This upgrading hydropower project utilizes the irrigation water supply pipeline to generate electricity. It has an installed capacity of 2×550kW, and the main structures are penstock, powerhouse after dam, tailrace channel, step-up switchyard, etc. The total construction period is six months. The static investment of the project is 2.3274 million USD.
10.1.2 Main References
The budget estimation is made with reference to “Regulations on Preparing Investment Estimation of Water Resources and Hydropower Project Design”( SZ[2002] No. 116) issued by the Ministry of Water Resources of the People‟s Republic of China (hereinafter referred to as “Regulations”).
10.1.3 References for Budget Quota
Civil Engineering: with reference to “Budget Estimation Quota of Water Resources Civil Engineering”(SZ[2002] No. 116) issued by the Ministry of Water Resources of the People‟s Republic of China; Mechanical and Electrical Equipment Installation Engineering: with reference to the “Budget Estimation Quota of Water Resources and Hydropower Installation Engineering” issued by the Ministry of Water Resources of the People‟s Republic of China.
10.1.4 Unit Rates
The unit rates of the costs for labor, main materials, electricity and water are all according to the rates in local market in Uruguay.
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10.1.5 Prices of Equipment
The prices of the mechanical and electrical equipment: is quoted by the Chinese equipment manufacturers and with reference to the related engineering equipment in similar cases. The equipment shipping charges: For the transportation within China it is calculated according to the current rate in the country; for the shipping from China to Uruguay it is calculated according to the shipping rate.
10.1.6 To consider the difference in project budget between China and Uruguay, the following costs are not included into the budget estimation of the project.
1. Other costs: Other costs mainly include costs for survey and design, land expropriation, production preparation, commissioning, etc. They are estimated according to the relevant rates and appropriate readjustment.
2. Reserve Fund: It is 6% of the total investment sum from 10.1.1 to 10.1.5.
3. Interest on Construction Loan: It is supposed that 50% of the static investment is borrowed from the bank, the interest rate is 7.5% per year and the construction period is 6 months, thus the real interest rate is 3.75%.
4. Compensation for Construction Land It can be estimated with reference to the “Regulations”
10.1.7 Compensation Fee for Construction Land Tenure:
It is estimated based on the “Regulations”.
10.2 Budget list
10.2.1 General Budget List
Unit: Million USD
No. Project and Cost Item Structures
Reservoir
Inundation
Treatment
Total
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1 Civil engineering 1.0138
2 M/e equipment and installation 0.9720
3 Metal structures and installation 0. 1332
4 Transmission 0.0360
5 Temporary structures 0.1724
SUM from item 10.1.1-10.1.5 2.3274
Total static investment 2.3274
10.2.2 Project Cost List
Project Cost List No. Project and Cost Item Unit Quantity Unit Price
（USD） Sum
（103USD） I Civil engineering 1013.8
1
Powerhouse Construction
Soil excavation M3 7125.7 1.484 10.6 2 Rock excavation M3 1336.1 21.427 28.6 3 Groove digging M3 445.4 49.205 21.9
4 Soil and rock wasted transportation 2KM M3 8907.1 8.334 74.2
5 lower part concrete M3 843.2 300.387 253.2 6 Upper part concrete M3 558.6 350.297 195.7
7 Building of the powerhouse M2 279.0 100.0 27.9
8 reinforcing steel T 71.6 4277.215 306.2 9 Expansion joint M2 240.25 31.711 7.6
10 Red copper water-stop M 10.0 145.665 1.5
11 Pulp stone block M3 561.0 158.0 86.4
II M/e equipment and installation USD Piece 972
1
M/e Equipment
Turbine & generator units USD 2 3.65×105 730
2 Crane USD 1 6.6×104 66 3 Main transformer USD 2 2.55×104 51
4 High-voltage equipment USD 1 6.8×104 68
5 Others USD 1 5.7×104 57 III Metal structures USD 133.2
1 Metal structures
Embedded parts T 2 2800.0 5.6 2 trashrack T 4.5 3200.0 14.4 3 Steel pipes T 35.36 3200.0 113.2
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IV Transmission lines 36
1 Transmission lines
15KVtransmission line KM 0.8 4.5 36
V Total above USD 2155.0
VI Temporary structures USD 2.155×106 8.00% 172.4
VII Total USD 2327.4 The above total cost is equivalent to RMB ￥1466.262 at the current exchange rate of USD $1 to RMB ￥1.
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Chapter 11 Economic Evaluation
11.1 Costs Calculation (Only the actual expenses directly spent on project construction included)
11.1.1 Project investment
The total static investment is 2.3274 million USD.
11.1.2 Annual Running Expense
The reservoir will work for irrigation and electricity generation at the same time, and three operators will be added to the existing staff. The annual payment for three new operators totals 30,000 USD at the rate of 10,000 USD/person/year. In addition, other expenses such as those for allowance, maintenance, administrative use, transportation, etc. will be included. The above makes a total annual running expense of 45,000 USD.
11.2 Income Calculation
This project makes profit only from power generation. According to the information provided by the project owner, the feed-in tariff of the electricity generated in Uruguay is 100 USD/Mwh. According to hydropower capacity calculation, the average annual output of the project is 2.225 million kWh, Thus the annual income of power generation is calculated as follows: 2.225×0.1=0.2225 million USD
11.3 Financial Evaluation
Uruguay has a complex taxation system, so the tax rate is set as 6% which refers to the value-added tax rate in China, and average annual tax is 60000 USD. With reference to the China‟s industrial standards “Economic Evaluation Code for Small Hydropower Projects”, this project is evaluated as follows Financial Internal Return Rate (FIRR): 8% Investment returning period: 12 years
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11.4 Conclusion
1. The above evaluation results show that the financial data of this project is in a ordinary condition. And the FIRR reaches 8%, so it is economically viable in general. 2. This project is actually an upgrading project reutilizing the engineering potential. The India Muerta Reservior has been built for 30 years. However, without the supporting hydropower station, a large amount of electric power, over 2 million kWh every year, is wasted. With accordance to the current electricity consumption level in Uruguay, this amount of wasted electric power could satisfy the annual energy demand for 800 households in the country. In the sense of full utilization of energy resources, it is very necessary to develop this hydropower project. 3. This project has good conditions for construction, and also supported with reliable technology and equipment. There is no technical risk. 4. It is proposed to initiate the project at the earliest to reduce the waste of energy resources.
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Annex Quote of Mechanical and electric equipment
In order to reveal SHP equipment price level of different areas, for reference, here attached 3 equipment selection schemes and quotations by different SHP equipment manufacturers from China, Canada and Italy. All equipment selections and quotations are based on technical specifications of the India Muerta project. However, because of different equipment manufacturing standards, the 3 schemes select different types of equipments. The 3 quotations all include FOB price. The quotation date from China is August, 2012, and the rest two are November, 2012. Quotation from China
No. Description Technical
Specifications Unit Quanti
ty Unit Price FOB(USD)
Total Price FOB(USD)
Item 1 – Turbines, Governors
Unit Price FOB(USD)
$280,000.00
1 Turbine GD008-WZ-140 Set 2
115,000.00 230,000.00
2 Governor YWT-1000 Set 2 25,000.00 50,000.00
Item 2 –Generators and Associated Equipment
$295,000.00
1 Generator
SF-J550-20/1430 Set 2
110,000.00 220,000.00
2 Excitation System SWJL-65
Set 2 2,500.00 50,000.00
Item 3– Automatic element:
25,000.00 $25,000.00
Item 4–Controls, Instrumentation, Metering and Protection
$60,000.00
1 generator switchgear panel GGD2-A Set 2
30,000.00 60,000.00 2 generator -turbine
protection panel GGD1-C Set 2
Item5 DC system $40,000.00
1 DC Panel GZDW-100 Item 2 40,000.00
Item6 Main Valve 2
15,000.00 $30,000.00 Item7 Crane $66,000.00
Item 8–Transformers
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1 Power Transformer
S11-M-800/15 16.52±2×2.5%/0.4kV Set 2 25,500.00 51,000.00
Item9 15KV electrical Equipment
$68,000.00
1 Outdoor Vacuum Circuit Breaker
ZW32-15/630 Set 2
2 Outdoor Isolation Switch
GW4-15/200 Group
4
3 Outdoor Current Transformer
LBZ3-15 50：5 0.2/B
Set 1
4 Outdoor Voltage Transformer
JDWZ-15
15/0.1
3 /0.1
Set 3
5 15 kV Lightening Arrester
YH5W-15 Group
1
Item 10- Cable, accessories complete and special tools
$57,000.00
Total item1~10(USD)
$947,000.00 Quotation from Canada
No. Description Technical Specifications Unit Quantity Unit Price
FOB(USD) Total Price FOB(USD)
Item 1 – Turbines, Governors
$1,310,000.00
1 Turbine IM-HEPP 555 Set 2 600,000.00 1,200,000.00
2 Governor IM-HEPP Set 2 55,000.00 110,000.00
Item 2 –Generators and Associated Equipment
$400,000.00
1 Generator with Excitation systems IM-HEPP 20P Set 2 200,000.00 400,000.00
Item 3– systerm of common equipment, including:
$51,500.00
1 Water Level Measuring System Item 1 9,500.00 9,500.00
2 cooling water supply system Item 1 28,000.00 28,000.00
3 Compressed air system Item 1 14,000.00 14,000.00
Item 4–Transformers
$160,000.00
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1) Power Transformer
S10-800/15
15±2×2.5%/
0.4kV
800KVA
YN,d11 Set
2 80,000.00 160,000.00
Item 5–Controls, Instrumentation, Metering and Protection
$400,000.00
1） generator switchgear panel
Set 2 110,000.00 190,000.00
2） generator -turbine protection panel
Set 2 135,000.00 210,000.00
Item6 DC system item 1 $85,000.00
1） Complete battery cubicle
110V, 65Ah，No maintenance type Item
1
2) Battery changers 3 modul 10A
Set 1
3) DC distribution cubicle Set
1
Item7 15KV electrical Equipment item
1 $125,000.00
1) 15kv outgoing cubicle
Set 1
2) 15kv PT cubicle
Set 1
3) 15kv drop off Fuse
Lot 1
Item 8- Cable and accessories complete
$120,000.00
1) Cable( including power and control cable)
Item 1 80,000.00 120,000.00
Item 9- Spare parts and special tools
Item 1 50,000.00 $50,000.00
Total item1~9(USD)
$2,701,500.00
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Quotation from Europe
No. Description Technical Specifications
Unit Quantity Unit Price FOB(EUR)
Total Price FOB(EUR)
Item 1 – Turbines, Governors
€ 1,016,000.00
1 Turbine TUBU-160 Set 2 448,000.00 896,000.00
2 Governor GOVE-50 Set 2 60,000.00 120,000.00
Item 2 –Generators and Associated Equipment
€ 124,000.00
1 Speed increaser 300 to 750 rpm Set 2 16,000.00 32,000.00
2 Generator with Excitation systems GENE-555 Set 2 46,000.00 92,000.00
Item 3– system of common equipment, including:
€ 13,000.00
1 Water Level Measuring System Item 1 5,000.00 5,000.00
2 cooling water supply system
Item 1 8,000.00 8,000.00
Item 4–Transformers
€ 24,000.00
1 Power Transformer
S10-800/15 15±2×2.5%/0.4kV 800KVA YN,d11 Set 2
12,000.00 24,000.00
Item 5–Controls, Instrumentation, Metering and Protection
€ 90,000.00
1 generator switchgear panel
Set 2
20,000.00 40,000.00
2 generator -turbine protection panel
Set 2
25,000.00 50,000.00
Item6 DC system item 1 € 19,000.00
1 Complete battery cubicle
110V, 65Ah，No maintenance type Item 1
15,000.00 15,000.00
2 Battery changers 3 modul 10A
set 1
2,000.00 2,000.00
3 DC distribution cubicle set 1
2,000.00 2,000.00
Item7 15KV electrical Equipment item 1
€ 24,000.00
61
1 15kv outgoing cubicle
set 1
5,000.00 5,000.00
2 15kv PT cubicle
Set 1
18,000.00 18,000.00
3 15kv drop off Fuse
Lot 1
1,000.00 1,000.00
Item 8- Cable and accessories complete
€ 15,000.00
1 Cable( including power and control cable)
Item 1
15,000.00 15,000.00
Total item1~8(EUR)
€ 1,325,000.00