7. PLANT AND EQUIPMENT DESIGN CRITERIA

7.1 GENERAL

The proposed Co-Gen will have the facility to operate the plant with bagasse and coal as fuels independently or combined in any ratio.

This Co-Gen facility will also be designed to meet the entire process steam and power requirements of the sugar plant and any other future requirement. The remaining power generated in this Co-Gen facility, after meeting the in-house requirements will be exported to the (APGENCO) Grid. The Co-Gen plant can be operated for a period of 330 days in a year and hence, the design of machinery and equipment.

The proposed Co-Gen plant, operating during the cane-crushing season, will generate a gross output of 25000 KW at the Generator Terminals. After meeting the in-house power requirement for both the sugar plant and the Co-Gen plant auxiliaries, which is about 9318 KW, net power of 15682 KW will be exported to (APGENCO) Grid. The voltage level of generation will be at 11 kV and exportable power will be stepped upto 132 kV and paralleled with (APGENCO) grid. In house power for the plant will be at 415 V and hence suitably rated step-down transformers will be provided as per requirement.

All the plant and systems shall be designed to achieve the best possible efficiency under the specific operating conditions. The cycle shall be designed with one Deaerator, a H.P and L.P Feed water heaters and the steam requirement of the above equipment shall be met from the turbine extractions.

The Co-Gen plants instrumentation and control shall be based on the Distributed control system (DCS) philosophy covering the total functioning requirements of measuring, monitoring, alarming and controlling, logging, sequence interlocks and equipment protection etc.

It is proposed to introduce a suitable bagasse/ coal conveying and feeding system with storage and retrieval facilities. Normally, the bagasse storage silos of the boiler will receive bagasse from the mills directly through a dedicated conveying system and the excess bagasse will be directed to the Storage yard. Bagasse/ coal from the yard will be reclaimed during any interruption in the crushing / during cleaning day and during entire off-season.

The plant layout shall make optimum use of the land and facilities to minimise the cost. The optimum equipment layout shall be determined by the considerations of functional requirements, economy of piping & electrical cables, economy of equipment supports, installation & maintenance access requirements, ventilation requirements and equipment generated noise level and vibrations. Vaasthu Sastra will also be considered while designing the plant layout.

This section of the report gives the basic criteria for the design of the Co-Gen plant. The design parameters like the size, layout, ratings, quantities, materials for construction, type of equipment etc., described in this report are tentative. There may be some changes required during the detailed engineering of the plant and such changes are permitted till the detailed engineering of the plant is completed.

3.6 Ambient Conditions

Plant Elevation above Mean Sea Level (MSL): 64 M Temperatures: Maximum Temperature: 39.0 Deg. C Minimum Temperature: 29.0 Deg. C Plant Design Dry Bulb Temperature: 38.0 Deg. C Plant Design Wet Bulb Temperature: 28.0 Deg. C Plant Design Temp. for Electrical Equipment: 50.0 Deg. CRelative Humidity: Maximum: 41% Minimum: 25% Plant Design Relative Humidity: 85%Precipitation: Total Annual Rainfall: 900-1100 mmWind: Wind Direction: South - West (July & Aug): North East (Oct to Dec) Design Wind Velocity: As per IS 875Seismic Coefficient: Design: As per IS 1893Soil Bearing Capacity: At 1 to 2.5 m Depth: 20 T/Sq. M

3.7 Design & Guarantee Fuel

The design and guarantee fuel for the Co-Gen plant will be bagasse generated from the sugar mill. The following will be the ultimate analysis and the Gross Calorific Value (GCV) of the design fuel (Bagasse & coal). The boiler shall be designed for 100% coal firing and 100% bagasse firing.

Ultimate Analysis of Fuel: (Bagasse) Carbon: 23.5% Hydrogen: 3.25% Oxygen: 21.75% Moisture: 50% Ash: 1.5% GCV with 50% moisture: 2272 Kcal/KgUltimate Analysis of Fuel: (Imported Coal) Carbon: 68.6% Hydrogen: 4.3% Oxygen: 8.5% Moisture: 10% Ash: 6.75% Sulphur: 0.6% Nitrogen: 1.25% GCV: 4250 Kcal/Kg

3.8 Raw Water

The raw water for the plant will be drawn from the existing bore wells and also from the nearby dam. This raw water will be used as make up for the losses in the process steam, boiler blow down, cooling tower blow down, service water, etc. The water requirement for the Co-Gen plant will be 1800 cum/ day during cane crushing season and 3400 cum/day during off-season.

The design of the water treatment plant will be based on the actual chemical analysis of the borewell / dam water to be made available at the plant site. The actual water sample has to be collected during the preliminary design of the plant and it should be tested to ensure the correct specification be given to the water treatment plant vendor.

3.9 Steam Generator & Auxiliaries

The proposed steam generating system for the Co-Gen plant will consist of one bagasse fired boiler with a Maximum Continuous Rating (MCR) of 135 TPH, with the outlet steam parameters at 87 ata and 515 Deg. C. The tolerance on the superheater outlet temperature shall be 5 Deg. C. The combustion system of the boiler shall be stoker with traveling grate. However, the coal feeding to the grate shall be fed through gravity from the rear side of the boiler or through mechanical spreaders located on the front side of the boiler. The boiler efficiency when firing 100% bagasse shall be a minimum of 73% on GCV basis and that of coal shall be 84%.

The dust concentration in the flue gases leaving the ESP shall be design to meet the latest norms of the pollution control board of 100 Mg/N Cu. M.

The design of the boiler shall be of Bi-drum / single drum, natural circulation, radiant furnace with water cooled membrane walls, two stage superheater with inter-stage De-superheater and balanced draft. The boiler shall be top supported and shall be of semi-outdoor type. The boiler shall be capable of a peak generation of 110% of the MCR generation for a period of One (1) Hour in a shift. The operating excess air percentage at the outlet of the boiler shall be less than 30%.

Boiler Feed WaterThe boiler shall be capable of operating with the following feed water quality requirements.pH:8.8 - 9.2

Oxygen:0.007 ppm

Hardness:0.00

Total Iron:Nil

Total Copper:0.01 ppm

Total Silica:0.02 ppm

Hydrazine:0.02-0.04 ppm

Specific Elec. Conductivity at 25 Deg. C measured after Cation exchanger in the. H + form and after CO2 removal (max):0.2 micro-ohms/cm

Steam PurityThe boiler shall be capable of supplying uninterrupted steam at the MCR rating with the following steam purity levels. Total Dissolved Solids: 0.1 ppm (max) Silica (max): Less than 0.02 ppm Performance Guarantee Tests Maximum Continuous Rating (MCR) of 135 TPH of the boiler, while firing bagasse with the feed water temperature of 180 Deg. C (with De-aerator & HP & LP Heaters charged) and superheater outlet parameters of 87 ata and 515 Deg. C 5 Deg. C. Boiler Efficiency at MCR on GCV basis while firing bagasse. Auxiliary Power Consumption under MCR operating conditions. Steam purity for all operating loads. Dust Concentration in the flue gases leaving the ESP, while firing Bagasse with boiler outlet flue gas temperature after the Air heater limited to a maximum of 160 Deg C.

3.10 Turbo generator & Auxiliaries

The 27000 KW Turbo-Generator shall be a Double extraction cum condensing machine. The first extraction shall be at 11.7 ata the second extraction shall be at 3.4 ata. The speed of the turbine shall be not more than 8000 RPM; however, a direct coupled machine (3000 rpm) is preferred. The turbine extraction quantities shall be as given in the HMBD as per Drawing No.PP-0-NCL-0128-DPR-MEC-001 and PP-0-NCL-0128- DPR-MEC-002. The exhaust steam shall be cooled in a surface condenser. Performance Guarantee Tests of the TG:The performance test shall be conducted for the following parameters as per ASME PTC 6 and DIN 1943: Power Output at Generator Terminals with the Inlet steam parameters of 85 ata and 510 5 Deg. C, and at a specified power factor. The first and second extractions shall be at the indicated normal flow conditions. The Extraction Pressure and Temperature with the inlet steam parameters of 85 ata and 510 Deg. C. Auxiliary Power Consumption under Guarantee conditions. Maximum temperature rise in the generator windings. Cooling water consumption under Guarantee condition Heat Rate under Guarantee condition

3.11 Auxiliary Plant and Equipment3.11.1 Fuel handlingThe main fuel for the Co-Gen plant operation during the season is bagasse from the sugar plant. The bagasse from the mill is conveyed to the boiler by a combination of belt and slat-chain conveyors. The system shall have provision for returning the excess bagasse to the storage yard and also the provision for back-feeding the bagasse from the storage yard to the boiler. The bagasse handling system shall be designed for a capacity of 85.0 TPH (max) to convey the entire bagasse produced from the mills and also to have 25% additional capacity for handling the reclaimed bagasse. The bulk density of bagasse shall be 150 Kg/Cu. M @ 50% Moisture. Allowable inclination for the belt conveyor is 16 degree. The Belt speed shall be approximately 1.33 meters/sec. The maximum moisture percentage in bagasse shall be 52%.

There shall be a separate coal handling system with coal crushers, screens, etc. to feed coal to the boiler bunkers during season / off-season operation. The coal handling system shall be designed to operate for 12 hours/day effectively and about 480 tons of coal is required to be made ready for the boiler. Considering some breakdowns for maintenance and other interruptions during the preparation, the system shall be designed to handle a capacity of 50 TPH and the boiler bunker in front of the boiler shall have a storage capacity of 12 hours. Three (3) coal bunkers of 80 Tons capacity/ bunker will be installed to feed six (6) Nos of mechanical spreaders.

3.11.2 Ash handlingThe ash handling system envisaged for the Co-Gen plant is of two types: Submerged scrapper conveyor system for bottom ash. Dense phase system for fly ash.The total ash quantity generated in the boiler, by the burning of bagasse/ coal during operation of the boiler is approximately 1500 Kg/Hr. Ash removed from the travelling grate is approximately 500 Kg/Hr. and the Fly Ash quantity is approximately 1000 Kg/Hr. For the system to work effectively with bagasse firing, the density of bagasse ash on which the system design should be based shall be 300 Kg/cum.

The temperature of ash received at the grate discharge hoppers will be around 500 Deg. C, with ash lumps of size 200 mm Maximum. The ash from ash riddling hopper will be dry and powdery in nature and occasionally with hot solids. The temperature of this ash will be around 200 Deg. C maximum.

The fly ash from Electrostatic Precipitator Hoppers will be dry and powdery in nature and occasionally with hot solids. The temperature of ash will be around 200 Deg. C maximum.

The fly ash from the Air Heater Hopper will be dry and powdery in nature and occasionally with hot solids. The temperature of the ash will be around 300 Deg. C maximum.

All the ash will be collected in RCC storage silo having a storage capacity suitable for 12 Hrs generation of ash. From the ash silo, the ash will be disposed from the plant by trucks / trailers.

3.11.3 Cooling TowerThe cooling tower shall be RCC counter flow draft cooling tower of capacity of 5700 M3/Hr. having three (3) cells. The cooling tower shall be designed for a cooling range of 10 Deg. C and an approach temperature of 5 Deg. C, while operating under the atmospheric wet bulb temperature of above 29 Deg. C. The RCC frame of the tower shall be integral with the basin. The structure shall be of RCC construction. The structure shall be designed for wind and other loads as per IS: 875 and earthquake resistance as per IS: 1893. The cooling tower shall be carefully sited that there is no re-entrainment of the vapour into the cooling tower and shall be away from the fuel storage yards.

3.11.4 PumpsThe head / flow characteristics of pumps will be such that the head continuously rises with decreasing capacity until a maximum head is reached at zero flow. Maximum run-out flow should atleast 130% of duty point flow.

The shut off head should be atleast 1.1 times the duty point head and should not be more than 1.2 times the duty point head.

The power curve should be of non-overloading type with the maximum power occurring at or near duty point or towards maximum run out flow.

The NPSHR curve should be a continuously rising one in the range of operation, from the minimum flow in the range to the maximum flow in the range. Required NPSH values shall not exceed available values over the entire range from minimum to rated flow.

3.11.5 Condensate SystemThe extraction steam from the turbine is taken to the sugar plant process, and a substantial quantity of this returns as condensate, which is called as the exhaust condensate. The exhaust condensate along with the condensate from the hotwell of the turbine will be used to meet the complete feed water requirements of the Co-Gen boiler. The exhaust condensate will be available at the battery limits at 95 Deg. C from the existing condensate tank available with the sugar plant. No vapour condensate shall be used as boiler feed water, unless its quality is 100% checked and approved for feed water usage. Two separate vapor condensate storage tanks of 100 Cu M capacity each will be constructed to store the Vapour condensate from the sugar plant. An on-line & continuous pH and conductivity monitors will be installed in the pipeline to ensure the condensate is free from any contamination due to entry of sugar syrup. Under normal circumstances, the makeup water for the cycle will be De-mineralized water. If required, the vapour condensate will be polished and used in the boiler. A separate condensate polishing system shall be introduced at a later date.

3.11.6 DM PlantThe DM plant shall be designed to have Two (2) streams with the capacity of each of the streams at 25 Cu M/Hr. the DM plant shall be designed based on the raw water analysis to be carried out at the contract stage.The Demineralized water quality at the outlet of the DM plant shall be as follows: Hardness (ppm)0

pH @ 25C8.8 - 9.2

Conductivity @ 25C (micro Siemen / Cm)

0.2

Oxygen (maximum) (ppm)0.007

Total Iron (maximum) (ppm)Nil

Total Copper (maximum) (ppm)0.01

Total Silica (maximum)(ppm)0.02

Residual Hydrazine (ppm)0.01-0.02

The raw water at the inlet of the DM plant will be delivered at a pressure of 3.0 Kg/ Sq. Cm. The Treated water at the outlet of the DM Plant will be delivered at a pressure of 3.0 Kg/ Sq. Cm.

All vessels shall be designed with adequate free board. Only seamless pipe shall be used wherever rubber lining is done. Stainless steel pipes also can be used. All fabricated equipment shall be designed according to IS: 2062.

The regenerates like Hydrochloric Acid and Caustic Soda shall be stored in bulk in the DM plant premises, and pumped to the DM plant for regeneration. Manual handling of the regenerates shall be avoided to the maximum extent.

Adequately sized neutralizing pit and effluent treatment plant shall be provided near the DM plant for collecting the discharges from the DM plant, boiler blow done water, other waters etc., and effectively neutralizing the same before pumping the waste to effluent treatment system.

3.11.7 Vessels & Heat ExchangersThe design shall be as per ASME Sec. VIII, HEI and TEMA. All heat exchangers and vessels for steam application shall be designed for full vacuum conditions. The heat exchangers shall be provided with start-up vent connections. The design shall have provision for complete drainage on both shell and tube sides. The heat exchangers shall be provided with emergency drains, shell side safety valves, and individual bypass with manual valves. A minimum corrosion allowance of 1.6 mm shall be provided. The tube bundle shall be of removable type. The tube material shall be stainless steel, unless otherwise specified in the specifications.

3. 1 1.8 TanksThe Co-Gen plant tanks will have storage capacities as required by design of the systems. Tanks will be of the closed top type. Tanks will be fabricated in accordance with guidelines established by API or AWWA, as determined by the service. A corrosion allowance of 1.5 mm shall be provided.

Overflow connections and lines shall be provided where required and will be at least one pipe size larger than the largest input line or combination of inputs that can discharge simultaneously.

Maintenance drain connections shall be provided of an adequate size to facilitate drainage of tanks within a reasonable time. Manholes where provided on tanks and pressure vessels shall be of size NB 400. Ladders and cleanout doors will be provided on large tanks. DM water tank shall be in-housely lined with natural rubber or painted with three coats of Epoxy Coating.

3.11.9 PipingAll piping system shall be designed as per ASME B 31.1. In addition statutory requirements of Indian Boiler Regulations (IBR) shall be complied with for those lines under the purview of IBR.Stress Analysis shall be carried out for all possible operating modes and shall be as per ASME B 31.1 requirements. Supports, guides, Directional Anchors shall be selected to satisfy all the operating conditions.

Pipe Sizing:All piping shall be sized considering the allowable velocity and allowable pressure drop in the system. The suggested Flow velocities of various mediums are,

Superheated Steam: 45 to 55 M/Sec Saturated Steam: 15 to 30 M/Sec Boiler Feed Water Pump Suction: < 1M/Sec Pump Discharge: 2.5 to 4 M/Sec Water Pump Suction: < 1M/Sec Pump Discharge: 2.5 M/Sec Condensate Pump Suction: 0.6 to 0.7 M/Sec Pump Discharge: 2.5 M/Sec Compressed Air: 12 to 18 M/Sec Lube Oil & molasses Pump Suction: 0.3 to 0.4 M/Sec Pump Discharge: 1.0 M/Sec

3.11.10 Piping MaterialsThe piping material selection shall be based on the following recommendations. For temperatures above 510 Deg. C, SA 335 Gr. P22 shall be used. For temperature 400C to 510 Deg. C, SA 335 Gr. P11/ P12/ P22 shall be used. For temperature 399 Deg. C & below SA 106 Gr. B/C or ASTM A- 53 seamless shall be used. For HP/LP chemical dosing SA 312 TP 304, Stainless Steel shall be used. All pipe fittings other than those mentioned shall confirm to ASTM A 234 standard and dimension as per ANSI B 13.9 / B 13.28 / B 13.11. For Cooling water, Raw water, Service Water, Safety/ Relief valve exhaust IS: 1239 / IS: 3589 ERW/EFW pipes shall be used. For Service air applications the piping shall be IS 1239 Black Medium Class. For instrument air applications: Galvanized pipe (Iron. Pipe) to IS: 1239 Part I shall be used. The fittings for ERW applications shall be as per IS 1239 Part II.

3.11.11 Insulation All exposed portions of the plant which operate at temperatures of 60 Deg. C and above during normal operation shall be thermally insulated so that the temperature on the outer surface of the cladding shall not exceed by more than 20 Deg. C above ambient, based on an ambient temperature indicated in site data. The specified insulation thicknesses shall not include the thicknesses of wire netting, finishing cement or any other finishing or weatherproofing application. Insulation shall not fill the contours of the expansion bellows. Piping and equipment that are not insulated but having a surface temperature exceeding 50 Deg. C shall be insulated for personnel protection.In refractory walls suitable expansion gaps shall be provided at regular intervals.

The following recommended minimum thickness for thermal insulation with mineral wool.

NOMINAL DIA IN MMOPERATING TEMPERATURE (Deg. C)

Below100101-150151-200201-250251-300301-350351-400401-450451-500

65 & below253030354045455060

80303540404550556070

100353550455060657075

125354045505565707580

150354050556070758090

2003545666065708095100

25040506065708085100110

30040556065808590105120

350455560758090100110120

4004560707580808590105

45050607590

5005060759090105115125135

5505560809095105115125135

6005565809595110120130140

Above 600 8& Flat Surfaces55658095100110120130140

3.12 Civil & StructuralsThe reinforced concrete structures shall be designed in accordance with the latest version of IS 456, "Code of practice for plain and reinforced concrete". The structural steel design shall be as per IS: 800. The design wind speed and seismicity shall be in accordance with IS: 875 Part III and IS 1893 Part IV respectively. The structures shall be designed to withstand the calculated Dead loads, Live loads, along with the wind and seismic loads in appropriate combinations recommended by the Codes. The- minimum dead and live loads for the design of the platforms and walkways shall be 500 kg/sq. m.

Structural steel shapes, plates and other structural materials shall conform to IS 800, with minimum yield strength of 25 kg/sq.mm. The connection bolts shall conform to IS 1367. Welding electrodes shall be as per AWS, HYSD reinforcement steel bars shall conform to IS: 1783. All structural steel (IS: 2062) and MS members will be painted with two coats of red oxide zinc chromate paint and two coats of synthetic enamel paint.

All foundations shall be of the spread footing or mat type. Soil Bearing Capacity shall be 20 T/Sq. m at 1.0 Mtr to 2.5 Mtr depth and Settlement shall be 25 mm at a depth of 2.5 m below ground level. The above soil bearing capacity shall be verified by soil investigation before final design. The site is not relatively flat, requiring minimal grading and leveling (leveling & grading upto 2.5m). Moderate grading / leveling work are envisaged. All excavation work shall be done by conventional manual methods or by mechanical equipment method (wherever required). For substructures & superstructures Ordinary Portland Cement (grade 43) will be used. Grade of Concrete for steam turbogenerator & heavy rotating equipment foundations & chimney shall be M-25 and all other foundations / pedestals / buildings etc. shall be of M-20.

3.13 Electrical systemAll equipment for the Co-Gen unit shall be designed for satisfactory operation for a life time of minimum 30 years under specified site conditions. All equipment shall be suitable for rated voltage of 10% and frequency of 50 Hz with 5% variation and 10% (absolute sum) combined voltage and frequency variation.

The generator shall be of synchronous type with brushless excitation system, and shall be designed for rated voltage & frequency of 11 kV & 50 Hz, with corresponding variations of +10% and +5%. The generator shall have closed circuit air cooled system with external Water circuit (CACW cooling) and the windings shall have class 'F' insulation, with temperature rise limited to class 'B' insulation limits, under specified cooing water & ambient air temperatures.

All the auxiliaries of the Co-Gen unit and drives shall be connected at 415V level, by providing Two (2) Nos. 3.15 MVA, 11 / 0.433 kV and One (1) No. 1.0 MVA, 11 / 0.433 kV distribution transformers and Two (2) Nos. 3.15 MVA, 11 / 0.433 / 0.433 kV converter transformers. For mill drives, two (2) Nos. of 3.15 MVA 11 / 0.69 / 0.69 kV converter transformers shall be provided. Provision is made for feeding distillery also only in case of emergency conditions when the 1.5 MW back pressure TO in the distillery is not in operation.

Surplus power from the high pressure 27 MW Co-Gen TG unit, after feeding the in-house loads, shall be exported to APGENCO grid by stepping-up the power to 132 kV, through one number 30 MVA, 11 / 132 kV transformer. All required protections and metering for transformer shall be provided in switchyard relay and metering panel. The line interconnection switchyard along with tariff metering equipment shall be provided at plant end. Transmission system and other terminal equipment shall be arranged between the plant and the APGENCO's sub-station at Nagalapuram All the equipment including switchyard and the transmission system shall, be designed to have provision for future expansion with additional Co-Gen unit.

It is envisaged to start-up the Co-Gen unit, which require power at 415 V level, by installing one (1) number 1500 kVA Start-up / Stand-by DG set along with one (1) number emergency DG set of 250 kVA rating in the plant. Once the Co-Gen TG unit is ready to take-up the loads, the TG set will be momentarily synchronised with the DG sets to avoid interruption of supply to the Co-Gen auxiliary loads and then the TG will be synchronised with the grid through 25 / 31.5 MVA, 110 kV / 11 kV transformer.

The nominal voltage of main DC system for protection & control systems, turbine emergency oil pumps and emergency lighting shall be 220 V.

UPS system with rated voltage of 230 V AC shall be envisaged, for meeting UPS power requirements of the plant DCS and other instrumentation / control loads. All equipment shall comply with the applicable provisions of relevant IS / IEC / IEEE standards, as listed elsewhere in this document.

Breakers for various systems shall be as below: 132 kV breaker: SF6 circuit breaker 11 kV breaker: VCB 415 V breakers: Air break circuit breakerConnection between the turbo-generator and the 11 kV switchgear shall be through phase segregated bus duct. All other connections at 11 kV (between 11 kV switchgear and generator transformer / distribution transformers) shall be carried out through 11 kV, UE grade, armoured, XLPE insulated cables. Connection between secondary of the distribution transformers and the respective PCC / Panels shall be through non-segregated phase bus duct, with electrolytic grade aluminum bus bars and aluminum alloy enclosure. All other LT connections (power as well as control) shall be with PVC insulated, armoured, aluminum / copper cables.

The cables shall be derated for the site ambient and ground temperatures, grouping and soil resistivity. Cables shall be selected to limit the maximum voltage drop at equipment terminals, during normal operation and starting conditions, to be well within permissible values.

Cables in circuits controlled by circuit breakers shall be capable of withstanding the maximum system fault current till that breaker opens by main protection. Fuse protected cables shall withstand maximum let through fault current for fuse operating time. For 11 kV grade cables, screen shall be suitable for carrying earth fault current of 1 kA for duration of 1 sec.

Current ratings of the cables shall be assigned considering continuous conductor temperature of not more than 70 Deg. C for PVC and 90 Deg. C for XLPE. Cables should also be sized to carry system fault current for the duration specified in above without exceeding the temperature limit of 160 Deg. C for PVC and 250 Deg. C for XLPE.

The panels shall have breakers for ratings 800A and above and FSUs for lesser ratings. FSU+Contactor+Microprocessor based OLR/BMOLR for motor feeders shall be planned.

AC Variable Frequency Drives (VFDs) shall be provided for the following applications:

BFP, ID, FD and SA fan motors and all bagasse feeder / extractor motors, cooling tower fans, cooling water pumps and compressors in Co-Gen plant.

All AC Motors shall be of energy efficient type. The windings will be insulated by class 'F' insulation material and maximum rise shall be limited to class 'B insulation limit over an ambient of 50 Deg. C.

3.14 Fault LevelAll equipment shall be designed to withstand the maximum fault, under voltage variation of 10%, 31.5 kA for 3 sec in 110 kV & 40 kA for 3 sec for 11 kV systems and 50 kA for 1 sec in 415 V systems.Distribution transformers and all accessories shall be capable of withstanding for two seconds without damage during any external short circuit at the terminal. All Switchgears, MCC & Distribution Boards shall be capable of withstanding the maximum fault currents .that may arise, duly considering the maximum fault levels on high voltage system, negative tolerance on transformer impedance and maximum possible motor contribution for maximum possible fault clearing time on ultimate backup protection but not lower than one second in any case.

Degree of Protection.11 kV Switchgear: IP42.LT Switchgears: IP52Switchgears located outdoors: IP55LT bus duct Enclosure: IP52 (in the indoor portion): IP55 (in the outdoor portion)Control Panels: IP42 (in air-conditioned area): IP52 (in other areas)Push Button Stations: IP54 (indoor): IP55 (outdoor)Synchronous Generator: IP54Induction Motors: IP54 (indoor): IP55 (outdoor)

3.15 Neutral GroundingThe 11 kV system neutral earthing shall be low resistance earthed type to limit the earth fault current to 1.00A, which shall be earthed by providing neutral grounding resistor on the neutral of the generator.

All 415V transformer neutrals and 110 kV transformer neutral shall be solidly earthed through bolted links.

The system shall be compatible for accepting / sending signals from / to DCS. Winding, bearing and cooling circuit (where applicable) RTDs shall be hooked up to DCS for signal processing and necessary tripping shall be arranged from DCS, for tripping of the corresponding motor.

Signals from all transformers for winding temperatures, oil temperatures, oil level gauges, Buchholz relay outputs for alarm and tripping shall be brought to DCS.

Status (ON/OFF/TRIP) of all breakers, LT breakers in PCCs and all motor feeders shall be brought to DCS, for plant monitoring. Control of motor feeders, as per system requirement, shall also be arranged for control from the DCS system.

3.16 Instrumentation & Control systemThe Co-Gen plant's Instrumentation and Control system, based on Distributed Control System philosophy, will be designed to provide monitoring and control capabilities to ensure safe and reliable operation, minimize operator manual actions and alert operators on any conditions or situations requiring manual intervention in a timely manner. The control functions shall be backed up by interlocks and safety systems which cause pre-planned actions like tripping or sequential shut down of equipments during situations where unsafe conditions develop faster than the controls or the operator's reaction time. All I&C equipment will be of proven design and will be selected to achieve highest level of plant availability and facilitate equipment maintenance.

All field control element for modulating control will have actuators of pneumatic type. Signals of various process parameters shall be electrical signals generated by field mounted electronic smart type transmitters. The above signals will be processed in the DCS cabinets top produce electrical signal output of 4-20mA DC, which will be converted to control pneumatic signal 0.2-1.0 Kg/sq. cm (g) , through E/P convertors to operate the pneumatic actuators. All computation, signal conditioning and control function generation will be configured in the DCS. 3.17 Codes & StandardsSystems and equipment-will be designed in accordance with the applicable sections of the following codes, standards and regulations in effect at the date of this Contract. Applicable sections of codes, standards and regulations will be defined in specifications

Indian Standards (IS)IS: 6:Moderate heat duty fire clay refractories Group-A

IS: 8:High heat duty fire clay refractories

IS: 325:Three-phase induction motors

IS: 456:RCC Structures

IS: 800:Code of practice for Constructions in Steel

IS: 807 :Code of Practice for Design, Manufacture, Erection and Testing (Structural Portion of Cranes & Hoists)

IS: 875:Code of practice for Design loads for buildings structures.

IS: 1554:PVC insulated (heavy duty) electric cables

IS: 1651:Stationary cells and batteries, lead-acid type (with tubular positive plates)

IS: 1893:Criteria for Earthquake Resistant Design of Structures

IS: 2026:Power Transformers

IS: 2042:Insulating bricks

IS: 2309:Practice for the protection of the buildings and allied structures against lightning - code of practice

IS:2429:Round Steel Short link chain electric butt welded Gr.30

IS:2544:Porcelain post-insulators for systems With Nominal voltage greater than 1000 V.

IS:2705:Current Transformers

IS 2825:Code for unfired pressure vessels

IS:3043:Code of practice for earthing

IS: 3144:"Methods of test for Mineral Wool Thermal Insulation Material"

IS: 3156:Voltage Transformers

IS: 3177:Code of Practice for design of Electric Overhead Traveling Crane and Gantry Cranes

IS: 3427:Metal-enclosed switchgear and control gear for rated voltages above 1 kV and upto and including 52 kV

IS: 3646:Code of practice for interior illumination

IS: 3832:Hand Operated Chain pulley blocks

IS: 3938:Specification for Electric Wire Rope Hoists

IS: 4503:Shell and Tube Heat Exchangers

IS: 4776:Troughed Belt Conveyors

IS: 5422:Turbine type generators

IS: 6547:Specification for Electrical Chain Hoists

IS: 7098:Cross linked polyethylene insulated PVC Sheathed cables

IS: 7155:Code of recommended practice for Conveyor Safety

IS: 8183:"Specification for Bonded Mineral Wool"

IS: 8531:Pulleys for Belt Conveyors

IS: 8598:Idlers and Idler Sets for Belt Conveyors

1S: 8623:Low voltage switchgear and control gear assemblies

IS: 9921:Alternating current disconnectors (isolators) & earthing switches for voltage above 1000V

IS: 10556:Code of practice for storage and handling of insulating materials.

IS: 11592:Code of Practice for Selection and Design of Belt Conveyors

IS: 13118:High voltage alternating current circuit breakers

IS: 13947:LV switchgears and control gear

IS: 13779:Static watt-hour meters, class 1 and 2

IS: 14164:Industrial application and finishing of Thermal insulating materials at Temperatures above 80 Deg. C and upto 700 Deg. C

American Society of Mechanical Engineers (ASME)ASME section IRules for construction of power boilersASME Section IXWelding & Brazing QualificationsASME Section VIIIUnfired Pressure Vessels CodeASME Section IXWelding QualificationASME Performance Test Code

ASME PTC 4.1:Steam Generating Units

ASME PTC 4.3:Air Heaters

ASME PTC 3.0:Guide for evaluation of Measurement Uncertainty in Performance test of Steam Turbine

ASME PTC 19.11:Water and Steam in the Power Cycle (Purity and Quality, Leak detection and Measurement)

ASME PTC 25.3Safety and Relief Valves

American National Standards Institute

ASME B13.5:Pipe flanges and flanged fittings

ASME B 13.9:Butt welding fittings

ASME B 13.11:Socket Welding and Threaded. Fittings

ASME B 31.1:Code for Power piping

IEEE STANDARDSIEEE: 80:Guide for safety in AC substation Grounding

IEEE: 141:Recommended Practice for Electric Power Distribution for Industrial Plants

IEEE: 242:Recommended Practice for Grounding of Industrial and Commercial Power Systems

IEEE: 241:Recommended Practice for Electric Power Systems in Commercial Buildings

IEEE: 242:Recommended Practice for Protection and Coordination of Industrial and Commercial Power Systems

IEEE: 399:Recommended Practice for Industrial and Commercial Power System Analysis

IEEE: 446:Recommended Practice for Emergency and Standby Power for Industrial and Commercial Applications.

IEEE: 493:Recommended Practice for the Design of Reliable Industrial and Commercial Power Systems.

IEC StandardsIEC: 34:Rotating Electric machines

IEC: 44:Instrument Transformers

IEC: 56:HVAC circuit breakers

IEC: 71:Coordination of Insulation

IEC: 76:Power Transformers

IEC: 85:Thermal evaluation and classification of Electrical insulations

IEC: 99:Lightning Arrestors

IEC: 129:Alternating current dis-connectors (isolators) and earthing switches

IEC: 144:Degrees of protection of enclosures for low Voltage switchgear & control gear

IEC: 137:Bushings for Alternating Voltages Above 1000 V

IEC: 183:Guide for selection of I-1V cables

IEC: 185:Current Transformers

IEC: 186:Potential Transformers

IEC: 214:On load tap changers

IEC: 227:PVC insulated electric cables

IEC: 255:Electrical relays

IEC: 269:LV Fuses

IEC: 270:Partial discharge requirements

IEC: 296:Insulating oils

IEC: 298:AC metal enclosed switch gear and control gear for rated voltages above 11 kV and up to and including 52 kV

IEC: 354:Loading guide for oil immersed Power transformers

IEC: 376:Specification and acceptance of new Sulphur hexafluoride

IEC: 439:LV switchgears and control gear assembly

IEC: 502:Extruded solid dielectric insulated power for Rated voltages from 1 kV upto 30 kV

IEC: 529:Classification of degree of protection

IEC: 542:Application guide for on load tap changers

IEC: 606:Application guide for power transformers

IEC: 694:Degrees of protection provided by enclosure (IP code)

IEC: 885:Electric test methods for electric cables

IEC: 909:Short-circuit current calculation in Three phase AC systems

IEC: 947:LV switchgears and control gear

IEC: 1036:Static meters

Industry Standards (As determined to be applicable by Contractor) Indian Boiler Regulations (IBR) American Gear Manufacturers Association (AGMA) American Petroleum Institute (API) American Society for Heating, Refrigeration and Air-Conditioning Engineers (ASHRAE) Handbook American Society for Testing and Materials (ASTM) American Water Works Association (AWWA) American Welding Society (AWS) Structural Welding Code (AWS D1.1) Conveyor Equipment Manufacturers Association (CEMA) Cooling Tower Institute (CTI) Heat Exchange Institute (HEI) Hydraulic Institute (HI) Institute of Electrical and Electronics Engineers (IEEE) Instrument Society of America (ISA) Manufacturers Standardization Society (MSS) of the Valve and Fitting Industry National Electrical Manufacturers Association (NEMA) National Fire Protection Association (NFPA) Pipe Fabrication Institute (PFI) Tubular Exchanger Manufacturers Association (TEMA) Turbine: IEC Recommendation Publication No: 45 CSN 080030 DIN 1943

British StandardsBS: 4592Industrial type metal floors, walkways and Stair treads

BS: 5395Stairs, ladders and walkways

BS: 2573Permissible Stresses in Cranes

BS: 466EOT Cranes for general use in factories, workshops &Warehouses

BS: 5316Performance Testing of Pumps Part-I Class C