report_chiller(by sayan roy)

Report on Industrial Training

At

IFB Industries Limited 14, Taratala Road, Kolkata-700088

2

Report

On

Study and Performance

Analysis of

Chilling Plant

Submitted By

Sayan Roy

Department of Mechanical Engineering (3rd

year)

Future Institute of Engineering & Management

Training Period: 23/12/2014 - 15/1/2015

Under the guidance of:

Mr. Soumen Ghosh (Head), Mr. Suvra Bose,

Mr. Sumanta Panja, Mr. Arijit Boral

(Maintenance Department)

IFB Industries Ltd., Taratala

3

Sl. No. Contents Page No.

1. Acknowledgement 4

2. Introduction 5-8

3. IFB Profile 9

4. Process of the Plant 10

5. Fine Blanking Technology 11 -13

6. Fine Blanking Process 14-16

7. Manufactured Products 17-18

8. Chilling plant 19-20

9. Refrigeration Systems 21-23

10. Chilling Plant Components 24-28

11. IFB Chilling plants 29-32

12. Observation Data Sheets 33-38

13. Performance Terminology & Measurement 39-40

14. Sample Calculation 41-42

15. Performance Analysis 43-45

16. Energy Saving Opportunity 46-47

17. Conclusion 48

18. References 49

4

Acknowledgement West Bengal University of Technology (WBUT) curriculum

includes industrial training which can benefit the student in many

ways to gather practical knowledge and to be aware of industry

environment. I am very obliged to the management and the

maintenance department of IFB INDUSTRIES LTD, Taratala

for giving me an opportunity to do my industrial training there.

I want to express my gratitude and sincere thanks to Mr.

Shantanu Chakraborty(Head of Quality Assurance Dept.),Mr.

Soumen Ghosh (Head of Maintenance Department), Mr. Suvra

Bose, Mr.Sumanta Panja, Mr Arijit Boral, ,Arindam Bose, Mr.

Koushik Sinha (HR manager) and all officials who have helped

us to undertake and complete my project on industrial training.

I also thank all employees of IFB who helped me in our training

directly or indirectly and it is because of them I completed my

project successfully.

5

Introduction

The fine blanking process was patented for the first time in 1923 in

Germany. The original idea was to apply a counter pressure force while

blanking to prevent the edges from breaking and causing them to shear

over the total thickness of the material. This technology was initially

employed mainly in the office machine industry and the watch and clock

industry.

During the early years, fine blanking dealt mainly with materials from 1

to 3 mm. Today more than 60% of fine blanked parts are used in the

automotive industry with thicknesses of up to 19 mm.

Considerable technological breakthroughs have been made in tooling,

presses and materials for fine blanking in recent years. Companies are

considering fine blanking at the design stage, taking full advantage of its

capabilities.

Today, the fine blanking method of manufacturing has become a

necessity in several major industrial sectors. Although first initiated in

Europe, fine blanking has taken an important place particularly in the

Japanese and North American automotive industry, replacing many of

the more expensive manufacturing options.

[1]

6

IFB: Company Overview

IFB Industries, originally known as Indian Fine Blanks, started its

operations in India during 1974 in collaboration with Switzerland’s

Hienrich Schmid AG. The product range includes fine blanked

components, tools and related machine tools like straighteners, de-

coilers, strip loaders and others.

The engineering divisions of the company are located at Kolkata

and Bangalore. The Bangalore unit, apart from fine blanked

components, manufactures motors for white goods as well as automotive

applications. It also has an ultra-modern plant under subsidiary

European Fine Blanking at Wrexham, Wales, and UK.

It had recently acquired a microwave oven plant at Bhopal, which is

being upgraded for increased production of better microwave ovens and

plans to start a new line in dish-washers.

The Bangalore and Kolkata works are ISO 9001 and QS 9000 certified

by TUV SDI. The Bangalore unit has been certified for TS 16949 by

TUV SDI.

The launch of fully automatic washing machines in 1990, jointly

with Bosch, Germany, marked IFB's entry into the white goods sector.

IFB is the premier Fine Blanker in India having Fine Blanking Presses,

with capacities ranging from 90T to 800T.

The company has excellent facilities for tool design and tool making

enabling it to meet up the expectations of all the automobile

7

manufacturers in the country as well as some overseas customers, by

supplying high quality fine blanking components on schedule.

Its philosophy is to deliver the parts in fully finished conditions at the

customers' delivery point. Its mission is to be an enabler to the customer

in design of the components during initial stage of product development

IFB has a research and development centre equipped with high-end

software’s like Solid modelling, CATIA, FEA and Mold Flow for the

design and analysis of various products. Besides it also has highly skilled

and experienced tool designers designing fine blanking parts and tools

to international standards.

The company’s international business division has become a recognized

Export House dealing in not only IFB's own products but also third-party

exports.

The company’s customers include Maruti Udyog, Ford India, Fiat India,

Toyota Kirloskar Motors, Lucas TVS, Brakes India, Autoliv India, Rane

TRW, IFB Automotive,

Germany’s Takata Petri, BorgWarner, Avtec and Bosch chassis.

Subsidiaries:

IFB, in collaboration with Germany’s RHW and Sweden’s Electrolux,

has two joint venture subsidiaries -- RHW India and RHW

Autoliv India -- to manufacture automotive seat recliners or seating

systems and safety equipment.

Latest Development:

The Committee of Directors of IFB Industries had recently allotted 68,

00,000 equity shares of Rs.10 (at par) to IFB Automotive, a promoter

group company. The promoters brought in above fund in line with the

direction of Board for Industrial and Financial Reconstruction (BIFR)

in the sanctioned scheme.

8

Automotive Sector:

Non-Automotive Sector:

[2]

9

IFB PROFILE

IFB INDUSTRIES LIMITED was founded in Kolkata in 1974 in

collaboration with Heinrich Schmidt AG of Switzerland by Mr. Bijon

Nag, a technocrat entrepreneur, having practical experience in fine

blanking in Germany and Switzerland for many years.

1. IFB is the Premier Fine Blanker in India having fine blanking

presses ranging in size from 90 to 1160 T.

2. Having factories in Kolkata and Bangalore the second unit was

established in 1988.

3. The company has total of 6 fine blanking presses in Kolkata,

capacity range from 90T to 650T.

4. The company has excellent facilities for tool making and tool

design enabling the company to meet up the expectation of all the

automobile manufacturer in the country as well as some overseas

customers, by supplying high quality fine blanking component on

schedule.

5. Quickest possible delivery :The company’s philosophy is to deliver

the parts in fully finished conditions at the customers’ delivery

point and thanks to the company’s innovative capability in post fine

blanking operations like grinding, CNC machining ,forming and

specialized techniques.

6. The Company’s Mission is to be an enabler to the customer in

design of the components during initial stage of product

development.

7. Support to the customers on technical problems.

8. Highest level of quality control.

9. Regular monitoring on customers’ satisfaction. [3]

10

Process of the Plant

Serial No. Process Name Location Machine

1. RAW MATERIAL

INSPECTION

IFB TARATALA MANUAL

2. FINE BLANKING IFB TARATALA BLANKING

PRESSES

3. HAND LINISHING

& FILING

VENDOR HAND LINISHING

M/C

4. STRESS

RELIEVING

IFB

GANGARAMPUR

TEMPERING

FURNACE

5. BARRELING IFB

GANGARAMPUR

VIBRO BARREL

6. BENDING VENDOR MECHANICAL

PRESS

7. PIERCING VENDOR MECHANICAL

PRESS

8. CSK ON ROLL

OVER & BURR

SIDE

VENDOR DRILLING M/C

9. FINAL

INSPECTION

IFB TARATALA MANUAL

10. OILING &

PACKAGING

IFB TARATALA STRAPPING M/C

[4]

11

Fine Blanking Technology

Blanking:

Blanking is a mechanical process of cutting, punching or shearing a piece

of metal into a desired shape. In other words we can define blanking as

metal fabrication process during which a metal work piece is removed

from the primary metal strip or sheet when it is punched. The material

that is removed is the new metal work piece or blank.

Application of Blanking:

Blanking process is widely used by electronic and micromechanical

industries to produce small and thin components in large production.

To take into little consideration the influence of strain rate and

temperature on precision blanking of thin sheet in copper alloy a thermo

elasto visco plastic modelling has been developed.

[5]

Fine Blanking

Fine blanking is a specialized type of blanking where there is no

fracture zone while shearing. This is achieved by compressing

the whole part and then an upper and lower punch extract the

blank. This allows the process to hold very tight tolerance and

perhaps eliminate secondary operation. Materials that can be

fine blanked include aluminium, brass, copper and carbon

alloy and stainless steel.

12

Application of Fine Blanking:

In today’s scenario, fine banking technology has created

exclusive positions in automobile industry for producing high

precision parts for engine, door clutch, window filters, and gear

box. The process is used in vehicles, textile machines, packing

machines, electronics and electrical equipment, sewing

machines, household appliances etc.

[6]

FINE BLANKING PROCESS

Blanking & Piercing Blanking and piercing are shearing processes in which a punch and die are used

to modify webs. The tooling and processes are the same between the two, only

the terminology is different: in blanking the punched out piece is used and called

a blank; in piercing the punched out piece is scrap. The process for parts

manufactured simultaneously with both techniques is often termed 'pierce and

blank'. An alternative name of piercing is punching.

[7]

13

Difference between Fine Blanking & Blanking

Conventional Blanking Fine Blanking

Edges are sheared up to one-third of the

thickness the rest remaining fractured. .

Edges are 100% sheared and bright over

the entire thickness

Components get dished in blanking,

especially with material above 1.5 mm

thickness.

No deformation occurs in blanking even

up to a thickness of 14 mm, i.e.

component remains flat.

Not possible

A wall thickness of 60% of the material

thickness can be achieved in the blank.

Practically impossible, especially in

the case of material thickness of over

1.5 mm

Hole diameter of even 60% of the

material thickness can be pierced to close

tolerances.

Practically impossible

Hardness of the sheared edges can be

achieved up to 150-200% over the

original hardness, due to work hardening.

This gives better wear resistance and

avoids heat-treatment in some cases.

[8]

14

Fine Blanking Process

A typical fine blanking tool is a single station compound tool

for producing a finished part in one press stroke. The only one

additional operation needed is the removal of a slight burr.

Three forces act during fine blanking operation. They are –

1. Main force

2. Counter force

3. Vee ring force

The entire process is depicted step by step here:

Step 1: This represents a simple sliding punch fine blanking tool making a round washer

with a hole at its centre.

Step 2: This tool closes, pressure embeds impingement ring into stock. This prevents

material flowing away from the punch, ensuring a smooth, extruded end on the

punch. The ring is ‘v’ shaped as shown in the figure below and hence we it is also

called V ring

15

Step 3: Blanking punch advances until the punch is fully sheared and resting in upper die

opening. In the same action the pierce punch provides a hole in the work piece.

Simultaneously, the counter punch pressure holds the part firmly against face of

the advancing blanking punch. This maintains flatness and enhances the sheared

edges, eliminating die break or edge fracture.

Step 4:

All forces are relaxed and the tool starts to open. The ram descends by gravity.

Step 5:

Blanking pressure reverses and the punch pulls back and the ejector pin pushes

out slag. Simultaneously raw material advances for the next cycle.

16

Step 6:

Counter pressure is reapplied pushing the part out of the die opening.

Step 7:

Air blasts or mechanical sweeps remove part and slug from the die area

Step 8: The system is ready to start the next cycle

[9]

IFB, Taratala has six fine blanking presses –

1. Mori (FB 650 – FDE) 4. Mori ( FB 250-FDE)

2. Mori (FB 250 – FDE) 5. Mori ( FB 320-FDE)

3. Italian (500 Ton) 6. Heinrich Schmid ( 90 Ton

17

Manufactured Products

[10]

Different parts of a car made by fine blanking

Four Wheeler Components:

[11]

18

Two Wheeler Components:

[12]

19

Chilling Plant

A chilling plant involves a chiller which is a machine that removes heat from a

liquid via a vapour-compression or absorption refrigeration cycle. This liquid can

then be circulated through a heat exchanger to cool air or equipment as required.

As a necessary by-product, refrigeration creates waste heat that must be exhausted

to ambient or, for greater efficiency, recovered for heating purposes. Concerns in

design and selection of chillers include performance, efficiency, maintenance, and

product life cycle environmental impact.

[13]

General schematic procedure of a chilling plant

Use in industry:

In industrial application, chilled water or other liquid from the chiller is pumped

through process or laboratory equipment. Industrial chillers are used for controlled

cooling of products, mechanisms and factory machinery in a wide range of

industries. They are often used in the plastic industry in injection and blow

molding, metal working cutting oils, welding equipment, die-casting and machine

tooling, chemical processing, pharmaceutical formulation, food and beverage

processing, paper and cement processing, vacuum systems, X-ray diffraction,

power supplies and power generation stations, analytical equipment,

semiconductors, compressed air and gas cooling. They are also used to cool high-

heat specialized items such as MRI machines and lasers, and in hospitals, hotels

and campuses.

Chillers for industrial applications can be centralized, where a single chiller serves

multiple cooling needs, or decentralized where each application or machine has its

own chiller. Each approach has its advantages. It is also possible to have a

combination of both centralized and decentralized chillers, especially if the cooling

requirements are the same for some applications or points of use, but not all.

20

Decentralized chillers are usually small in size and cooling capacity, usually from

0.2 to 10 short tons (0.179 to 8.929 long tons; 0.181 to 9.072 t). Centralized chillers

generally have capacities ranging from ten tons to hundreds or thousands of tons.

Chilled water is used to cool and dehumidify air in mid- to large-size commercial,

industrial, and institutional (CII) facilities. Water chillers can be water-cooled, air-

cooled, or evaporatively cooled. Water-cooled chillers incorporate the use of

cooling towers which improve the chillers' thermodynamic effectiveness as

compared to air-cooled chillers. This is due to heat rejection at or near the air's

wet-bulb temperature rather than the higher, sometimes much higher, dry-bulb

temperature. Evaporatively cooled chillers offer higher efficiencies than air-cooled

chillers but lower than water-cooled chillers.

Water-cooled chillers are typically intended for indoor installation and operation,

and are cooled by a separate condenser water loop and connected to outdoor

cooling towers to expel heat to the atmosphere.

Air-cooled and evaporatively cooled chillers are intended for outdoor installation

and operation. Air-cooled machines are directly cooled by ambient air being

mechanically circulated directly through the machine's condenser coil to expel heat

to the atmosphere. Evaporatively cooled machines are similar, except they

implement a mist of water over the condenser coil to aid in condenser cooling,

making the machine more efficient than a traditional air-cooled machine. No

remote cooling tower is typically required with either of these types of packaged

air-cooled or evaporatively cooled chillers.

Industrial chiller selection

Important specifications to consider when searching for industrial chillers include

the total life cycle cost, the power source, chiller IP rating, chiller cooling capacity,

evaporator capacity, evaporator material, evaporator type, condenser material,

condenser capacity, ambient temperature, motor fan type, noise level, number of

compressors, type of compressor, number of fridge circuits, coolant requirements,

fluid discharge temperature, and COP (the ratio between the cooling capacity in

TR to the energy consumed by the whole chiller in KW). For medium to large

chillers this should range from 3.5 to 7.0, with higher values meaning higher

efficiency. Chiller efficiency is often specified in kilowatts per refrigeration ton

(kW/TR).If the cold water temperature is lower than −5 °C, then a special pump

needs to be used to be able to pump the high concentrations of ethylene glycol.

Other important specifications include the internal water tank size and materials

and full load current. Control panel features that should be considered when

selecting between industrial chillers include the local control panel, remote control

panel, fault indicators, temperature indicators, and pressure indicators.

21

Refrigeration Systems

o Small capacity modular units of direct expansion type similar to

domestic refrigerators, small capacity refrigeration units.

o Centralized chilled water plants with chilled water as a secondary

coolant for temperature range over 5°C typically. They can also be

used for ice bank formation.

o Brine plants, which use brines as lower temperature, secondary

coolant, for typically sub-zero temperature applications, which

come as modular unit capacities as well as large centralized plant

capacities.

o The plant capacities up to 50 TR are usually considered as small

capacity, 50 – 250 TR as medium capacity and over 250 TR as

large capacity units.

Two principle types of refrigeration plants found in industrial use are:

Vapour Compression Refrigeration (VCR)

Vapour Absorption Refrigeration (VAR).

VCR uses mechanical energy as the driving force for refrigeration, while VAR uses

thermal energy as the driving force for refrigeration.

Vapour Compression Refrigeration

Heat flows naturally from a hot to a colder body. In refrigeration system the

opposite must occur i.e. heat flows from a cold to a hotter body. This is achieved

by using a substance called a refrigerant, which absorbs heat and hence boils or

evaporates at a low pressure to form a gas. This gas is then compressed to a higher

pressure, such that it transfers the heat it has gained to ambient air or water and

turns back (condenses) into a liquid. In this way heat is absorbed, or removed, from

a low temperature source and transferred to a higher temperature source. The

refrigeration cycle can be broken down into the following stages (see Figure 4.2):

1 – 2: Low pressure liquid refrigerant in the evaporator absorbs heat from its

surroundings, usually air, water or some other process liquid. During this process

it changes its state from a liquid to a gas, and at the evaporator exit is slightly

superheated.

22

[14]

2 – 3: The superheated vapour enters the compressor where its pressure

is raised. There will also be a big increase in temperature, because a

proportion of the energy input into the compression process is

transferred to the refrigerant.

3 – 4: The high pressure superheated gas passes from the compressor

into the condenser. The initial part of the cooling process (3 - 3a)

desuperheats the gas before it is then turned back into liquid (3a - 3b).

The cooling for this process is usually achieved by using air or water. A

further reduction in temperature happens in the pipe work and liquid

receiver (3b - 4), so that the refrigerant liquid is sub-cooled as it enters

the expansion device.

4 – 1: The high-pressure sub-cooled liquid passes through the expansion

device, which both reduces its pressure and controls the flow into the

evaporator.

Vapour Absorption Refrigeration

The absorption chiller is a machine, which produces chilled water by

using heat such as steam, hot water, gas, oil etc. Chilled water is produced

by the principle that liquid (refrigerant), which evaporates at low

temperature, absorbs heat from surrounding when it evaporates. Pure

water is used as refrigerant and lithium bromide solution is used as

23

absorbent Heat for the vapour absorption refrigeration system can be

provided by waste heat extracted from process, diesel generator sets etc.

Absorption systems require electricity to run pumps only. Depending on

the temperature required and the power cost, it may even be economical

to generate heat / steam to operate the absorption system.

[15]

In order to keep evaporating, the refrigerant vapour must be discharged

from the evaporator and refrigerant (water) must be supplied. The

refrigerant vapour is absorbed into lithium bromide solution which is

convenient to absorb the refrigerant vapour in the absorber. The heat

generated in the absorption process is led out of system by cooling water

continually. The absorption also maintains the vacuum inside the

evaporator.

24

Chilling Plant Components

A chilling plant has the following components-

Refrigerants :

A variety of refrigerants are used in vapour compression systems. The

choice of fluid is determined largely by the cooling temperature

required. Commonly used refrigerants are in the family of chlorinated

fluorocarbons (CFCs, also called Freon): R-11, R-12, R-21, R-22 and

R-502.

[16]

Compressor:

For industrial use, open type systems (compressor and motor as separate

units) are normally used, though hermetic systems (motor and

compressor in a sealed unit) also find service in some low capacity

applications. Hermetic systems are used in refrigerators, air

conditioners, and other low capacity applications. Industrial applications

largely employ reciprocating, centrifugal and, more recently, screw

compressors, and scroll compressors. Water-cooled systems are more

efficient than air-cooled alternatives because the temperatures produced

by refrigerant condensation are lower with water than with air.

Centrifugal Compressors

Centrifugal compressors are the most efficient type when they are operating near

full load. Their efficiency advantage is greatest in large sizes, and they offer

25

considerable economy of scale, so they dominate the market for large chillers.

They are able to use a wide range of refrigerants efficiently, so they will probably

continue to be the dominant type in large sizes.

[17]

A Centrifugal Compressor

Reciprocating Compressors

[18]

The maximum efficiency of reciprocating compressors is lower than that of

centrifugal and screw compressors. Efficiency is reduced by clearance volume (the

compressed gas volume that is left at the top of the piston stroke), throttling losses

at the intake and discharge valves, abrupt changes in gas flow, and friction. Lower

efficiency also results from the smaller sizes of reciprocating units, because motor

losses and friction account for a larger fraction of energy input in smaller systems.

Screw Compressors

Screw compressors, sometimes called “helical rotary” compressors, compress

refrigerant by trapping it in the “threads” of a rotating screw-shaped rotor. Screw

compressors have increasingly taken over from reciprocating compressors of

medium sizes and large sizes, and they have even entered the size domain of

centrifugal machines. Screw compressors are applicable to refrigerants that have

higher condensing pressures, such as HCFC-22and ammonia. They are especially

26

compact. A variety of methods are used to

control the output of screw compressors.

There are major efficiency differences

among the different methods. The most

common is a slide valve that forms a

portion of the housing that surrounds the

screws

[19]

Scroll Compressors

The scroll compressor is an old invention that has finally come to the market. The

gas is compressed between two scroll-shaped vanes.

One of the vanes is fixed, and the other moves within

it. The moving vane does not rotate, but its centre

revolves with respect to the centre of the fixed vane.

This motion squeezes the refrigerant gas along a

spiral path, from the outside of the vanes toward the

centre, where the discharge port is located. The

compressor has only two moving parts, the moving

vane and a shaft with an off-centre crank to drive the

moving vane. Scroll compressors have only recently

become practical, because close machining

tolerances are needed to prevent leakage between

the vanes, and between the vanes and the casing. [20]

Evaporators:

Two types of evaporators are used in water chillers—the flooded shell and tube and

the direct expansion evaporators (DX). Both types are shell and tube heat

exchangers. Flooded shell and tube heat exchangers are typically used with large

screw and centrifugal chillers, while DX evaporators are usually used with positive

displacement chillers like the rotary and reciprocating machines. While water is

the most common fluid cooled in the evaporator, other fluids are also used. These

include a variety of antifreeze solutions, the most common of which are mixtures

of ethylene glycol or propylene glycol and water. The use of antifreeze solutions

significantly affects the performance of the evaporator but may be needed for low

temperature applications. The fluid creates different heat transfer characteristics

within the tubes and has different pressure drop characteristics. Machine

performance is generally derated when using fluids other than water.

27

Flooded Shell and Tube

The flooded shell and tube heat exchanger has the cooled fluid (usually water)

inside the tubes and the refrigerant on the shell side (outside the tubes). The liquid

refrigerant is uniformly distributed along the bottom of the heat exchanger over the

full length. The tubes are partially submerged in the liquid. Eliminators are used as

a means to assure uniform distribution of vapour along the entire tube length and

to prevent the violently boiling liquid refrigerant from entering the suction line. The

eliminators are made from parallel plates bent into Z shape, wire mesh screens, or

both plates and screens. An expansion valve maintains the level of the refrigerant.

The tubes for the heat exchanger are usually both internally and externally

enhanced (ribbed) to improve heat transfer effectiveness. [21]

Direct Expansion

The direct expansion (DX) evaporator has the refrigerant inside the tubes and the

cooled fluid (usually water) on the shell side (outside the tubes). Larger DX

evaporators have two separate refrigeration circuits that help return oil to the

positive displacement compressors during part-load. DX coolers have internally

enhanced (ribbed) tubes to improve heat transfer effectiveness. The tubes are

supported on a series of polypropylene internal baffles, which are used to direct

the water flow in an up-and-down motion from one end of the tubes to the other.

Water velocities do not exceed approximately 1½ to 2½ feet per second due to

pressure drop considerations.

[22]

28

Condensers:

There are a number of different kinds of condensers manufactured for the

packaged water chiller. These include water-cooled, air-cooled, and

evaporative-cooled condensers. A horizontal shell and tube condenser has

straight tubes through which water is circulated while the refrigerant surrounds

the tubes on the outside. Hot gas from the compressor enters the condenser at

the top where it strikes a baffle. The baffle distributes the hot gas along the entire

length of the condenser. The refrigerant condenses on the surface of the tubes

and falls to the bottom where it is collected and directed back to the evaporator.

[23]

Heat rejection commonly used in chiller plants is the air-cooled refrigerant

condenser. This can be coupled with the compressor and evaporator in a

packaged air-cooled chiller or can be located remotely.. Air-cooled condensers,

whether remote or packaged within an air-cooled chiller, normally operate with

a temperature difference between the refrigerant and the ambient air of 10 to

30°F with fan power consumption of less than 0.08 hp/ton (> 69

COP).Maximum size for remote air-cooled refrigerant condensers is about 500

tons, with 250-ton maximum being more common. Air-cooled chillers are

available up to 400 tons.

Centrifugal Pump:

In the chilled water plant centrifugal pumps are the prime movers that create

the differential pressure necessary to circulate water through the chilled and

condenser water distribution system. In the centrifugal pump a motor rotates an

impeller that adds energy to the water after it enters the centre (eye). The

centrifugal force coupled with rotational (tip speed) force imparts velocity to the

water molecules. The pump casing is designed to maximize the conversion of

the velocity energy into pressure energy. In the HVAC industry most pumps

are single stage (one impeller) volute-type pumps that have either a single inlet

or a double inlet (double suction). Axial-type pumps have bowls with rotating

vanes that move the water parallel to the pump shaft. These pumps are likely to

have more than one stage (bowls).

29

IFB Chilling plants IFB, Taratala plant has three chilling plants out of them two were

operational during making this report. The chilling plants are –

36 TR Blue Star Air Cooled Scroll Chiller ( Old )

36 TR Blue Star Air Cooler Scroll Chiller (New)

24 TR Blue Star Air Cooled Scroll Chiller

In this report performance of only the 36 TR chillers will be noted

as the 24 TR chiller was not operational.

Chilling Plant Layout

In the layout, pump 3 and pump 4 are pumping hot water from hot water tank

and delivering it to the chiller. These pumps are called Primary Pumps. When

one pump is operational the other one is stand-by.

Pump 1 and pump 2 are pumping chilled water from the chiller output and

delivering it to the chilled water tank. These pumps are called Secondary Pumps.

When one pump is operational the other one is stand-by.

Pump 5 is provided as a bypass pump to balance the whole chiller plant and on

case of high load this pump distribute hot water to the other chiller.

30

In the layout, pump 3 and pump 4 are pumping hot water from hot water tank

and delivering it to the chiller. These pumps are called Primary Pumps.

When one pump is operational the other one is stand-by.

Pump 1 and pump 2 are pumping chilled water from the chiller output and

delivering it to the chilled water tank. These pumps are called Secondary

Pumps. When one pump is operational the other one is stand-by.

Pump 5 is provided as a bypass pump to balance the whole chiller plant and

on case of high load this pump distribute hot water to the other chiller. The

extra tank is provided to incorporate the chilled water from the 24 TR chiller.

Source of hot water:

Inside the fine blanking presses, for smooth operation of every [24]

31

moving components, hydraulic oil are provided in the machines

and in the hydraulic cylinders, actuators oil is constantly moving

thus generating a massive amount of heat. The fine blanking

presses are provided with oil coolers, i.e. heat exchangers where

the hot oil and chilled water are exchanging heat so that oil gets

cooled and water absorbs the heat. By pipeline connection the hot

water from every blanking presses are coming to hot water tank in

the chilling plant.

A typical oil cooler specification of the 650 Ton FB press is -

Oil cooler – 1pc

Heat Exchange Capacity – 80 kw/h

Flow rate of cooling water 150 or more Litre / min

Specifications of Chilling Plant Components:

Air Cooled Scroll Chiller Package

[25]

32

Manufactured by Blue Star

Model No. – XAC 3S – 036

3 Compressor type- Scroll hermetic

Compressor manufactured by Danfross

Thermally protected system

Refrigerant – R 22

Lubricant mineral oil – 160 P

Capacity- 36 TR

Refrigerant Air Dryer

Centrifugal Pump

In both the chilling plants (old and new) centrifugal pumps are provided

with high head and flow capacity value. Due to decay some specifications

cannot be collected for calculation it is assumed that all the pumps are

specified as:

Manufactured By – Kirloskar Brothers [26][27]

For Old Chiller Model No. – KDS 325 ++ KW/HP- 2.2 / 3 Efficiency – 60 % Head Range- 10 – 26 m

Capacity Range – 9.2 – 4. 9 litre / sec and For New Chiller Model No. - KDS 1040+ kW/HP=7.5/10

33

Observation Data Sheet

EWT – Entry Water Temperature LWT – Leaving Water Temperature (units are in degree

centigrade)

C1: Current in compressor 1 C2: Current in compressor 2 C3: Current in compressor 3 (units in A)

Date: 24/12/2014 Old Chiller (Left)

Time EWT LWT C1 C2 C3

10:00 12.2 10.1 21 0 * 0

10:30 13.4 11.2 0 22 0

11:00 15.3 11.0 22 22 0

11:30 14.9 12.6 22 22 0

12:00 17.2 12.4 22 21 22

12:30 18.4 11.9 22 21 23

01:00 16.2 12.2 21 21 0

02:00 13.2 12.5 21 0 0

02:30 15.3 12.0 21 22 0

03:00 18.2 12.1 22 22 22

03:30 19.6 12.9 22 22 22

04:00 18.2 13.2 22 22 22

04:30 14.2 11.2 22 22 0

Date: 24/12/2014 New Chiller (Right)


10:00 14.1 10.1 21 26 0

10:30 15.2 11.6 21 25 0

11:00 16.9 12.9 22 27 21

11:30 17.1 12.6 22 27 23

12:00 16.8 12.4 22 28 22

12:30 14.2 11.9 22 0 23

01:00 14.5 11.1 21 27 0

02:00 19.2 12.4 21 28 22

02:30 17.3 14.0 21 28 0

03:00 19.3 12.8 23 27 22

03:30 18.4 12.6 22 26 22

04:00 16.9 10.2 22 27 22

04:30 18.2 13.5 22 28 21



10:30 11.6 10.0 21 0 0

11:00 13.3 10.9 22 0 0

11:30 15.6 9.3 22 22 23

12:00 14.2 8.2 22 23 22

12:30 15.1 10.9 22 22 23

01:00 14.7 11.2 22 22 22

02:00 12.4 11.3 21 0 0

02:30 16.3 12.0 21 23 0

03:00 15.3 12.8 23 22 22

*Compressor current = 0 means the corresponding compressor is off

34



10:30 17.4 12.0 21 26 22

11:00 16.2 11.9 22 27 23

11:30 18.6 12.3 21 27 23

12:00 19.2 13.2 22 28 22

12:30 18.5 10.9 22 27 23

01:00 14.8 11.2 22 27 22

02:00 11.4 11.3 0 0 0

02:30 15.2 11.4 21 0 22

03:00 15.8 11.8 22 0 23



10:00 18.3 12.1 21 22 22

10:30 17.9 12.5 22 22 22

11:00 18.3 11.9 22 22 23

11:30 16.1 12.8 22 22 0

12:00 18.8 12.4 22 22 23

12:30 17.9 11.8 22 22 23

01:00 15.3 10.1 21 21 23

02:00 14.2 11.4 21 0 23

02:30 15.3 10.0 21 22 22

03:00 16.3 10.4 22 23 22

03:30 17.4 12.7 22 22 22

04:00 15.8 11.2 22 22 22



10:00 12.3 11.9 0 0 0

10:30 13.2 11.5 21 0 0

11:00 14.3 12.1 22 0 23

11:30 14.9 10.8 22 27 0

12:00 13.7 9.4 22 28 21

12:30 15.8 11.7 22 26 22

01:00 16.3 11.4 21 26 21

02:00 16.8 10.8 21 27 22

02:30 15.3 12.0 21 0 22

03:00 16.3 11.5 22 28 22

03:30 19.2 12.1 21 27 22

04:00 18.2 12.2 22 28 22



10:30 16.6 10.7 21 22 22

11:00 15.5 11.4 0 21 23

11:30 16.3 12.2 21 22 23

12:00 17.2 12.9 22 22 22

12:30 17.8 13.5 22 0 23

01:00 18.1 12.0 22 22 22

02:00 17.4 11.3 21 22 20

02:30 16.5 11.2 21 24 21

03:00 17.6 11.6 20 24 20

35



10:30 25.3 16.7 20 26 22

11:00 26.1 17.3 22 27 21

11:30 23.2 16.2 22 28 22

12:00 19.6 13.1 22 28 22

12:30 18.5 11.1 21 26 23

01:00 19.5 12.2 22 27 22

02:00 15.4 11.3 22 0 22

02:30 19.4 12.8 21 25 22

03:00 20.9 13.2 22 26 22



10:15 14.8 9.4 22 23 23

10:30 12.2 10.1 23 0 0

11:00 12.3 8.7 0 24 0

11:30 12.5 10.8 25 0 0

12:00 11.2 11.1 0 0 0

12:30 11.9 10.5 0 0 25

01:00 13.2 9.3 24 24 0

02:00 15.5 9.9 24 25 25

02:30 11.9 11.8 0 0 0



10:15 19.9 13.5 23 27 23

10:30 19.1 13.0 23 27 23

11:00 17.8 11.7 24 28 23

11:30 14.5 10.6 25 28 0

12:00 12.6 10.8 0 28 0

12:30 13.8 13.7 0 0 0

01:00 15.1 11.2 24 23 0

02:00 17.7 11.7 24 28 24

02:30 15.7 11.6 25 0 24



10:30 21.6 14.8 22 25 24

11:00 23.8 16.6 23 24 24

11:30 21.4 14.7 23 24 24

12:00 11.6 11.8 24 0 0

12:30 11.9 11.0 0 0 0

01:00 12.5 10.3 0 0 24

02:00 11.6 10.0 0 0 24

02:30 17.2 11.3 23 24 24

03:00 18.2 12.2 23 25 24



10:30 20.2 13.9 24 28 24

11:00 20.8 14.7 23 27 23

11:30 20.9 14.9 23 28 23

36

12:00 21.2 14.9 25 28 24

12:30 22.0 15.6 25 28 24

01:00 21.1 14.9 23 29 25

02:00 21.6 15.2 25 28 24

02:30 18.3 12.5 24 28 24

03:00 16.5 10.6 24 28 23



10:30 11.7 11.6 0 0 0

11:00 12.4 11.0 22 0 0

11:30 11.5 10.0 23 0 0

12:00 11.7 11.6 0 0 0

12:30 12.9 10.4 0 0 24

01:00 12.5 10.3 0 0 24

02:00 13.7 10.1 0 22 0

02:30 14.2 9.3 23 24 21

03:00 15.2 10.2 23 22 21



10:30 23.2 13.9 24 25 25

11:00 25.8 14.7 0 (Tripped) 26 25

11:30 21.2 14.9 0(Tripped) 28 25

12:00 26.4 14.9 0(Tripped) 28 25

12:30 24.1 15.6 0(Tripped) 27 24

01:00 26.8 14.9 0(Tripped) 25 25

02:00 22.3 15.2 0(Tripped) 26 25

02:30 23.6 12.5 23 24 25

03:00 20.3 10.6 21 25 23



10:30 12.5 8.3 21 21 0

11:00 13.8 10.6 21 21 21

11:30 15.4 10.0 21 22 22

12:00 14.6 11.9 22 22 0

12:30 14.9 11.4 21 23 0

01:00 11.2 10.2 0 0 22

02:00 12.6 11.1 0 0 22

02:30 12.9 11.8 21 0 21

03:00 16.5 12.3 23 0 22



10:30 15.5 13.1 22 0 0

11:00 15.1 10.5 21 25 0

11:30 15.3 11.2 22 24 0

12:00 14.2 9.6 22 26 0

12:30 15.4 10.9 21 25 0

01:00 14.1 11.1 0 25 0

02:00 16.2 12.1 22 26 0

02:30 14.9 11.5 23 26 0

03:00 15.4 12.6 21 26 23

37



10:30 25.5 17.5 23 23 24

11:00 18.9 12.1 23 23 24

11:30 18.3 11.4 22 22 22

12:00 15.7 9.5 22 22 22

12:30 14.5 8.5 21 23 22

01:00 12.6 10.8 0 0 22

02:00 12.9 11.5 0 0 22

02:30 14.6 11.4 21 0 23

03:00 18.6 12.4 23 22 21



10:30 18.4 11.2 22 26 22

11:00 16.4 10.3 22 26 22

11:30 15.3 11.6 0 26 22

12:00 18.1 11.0 22 26 22

12:30 17.6 13.5 0 26 22

01:00 19.0 12.0 21 25 22

02:00 18.8 12.6 22 26 22

02:30 17.5 11.9 23 26 22

03:00 18.6 12.1 21 26 23



10:30 15.4 9.9 23 23 22

11:00 15.7 12.2 23 23 0

11:30 18.9 11.8 22 23 24

12:00 17.5 10.9 22 22 22

12:30 18.2 13.1 21 22 22

01:00 15.6 10.7 0 22 22

02:00 13.5 12.5 0 0 22

02:30 14.6 10.3 21 0 23

03:00 16.7 11.4 23 24 22



10:30 23.4 16.2 22 26 22

11:00 22.4 15.6 22 27 22

11:30 20.5 14.0 23 26 22

12:00 21.1 14.5 22 26 22

12:30 19.5 13.1 22 26 22

01:00 19.0 12.3 23 27 22

02:00 19.6 13.4 21 28 22

02:30 16.5 12.2 0 26 22

03:00 17.8 11.1 21 26 23

38

Date: 15/1/2015 Old Chiller (Left) Test Duration – 60 min Steady State Condition Test (BEE Approved)

Time EWT LWT C1 C2 C3 KWh

12:45 11.6 10.0 21 0 * 0 836

12:50 11.6 9.9 0 22 21 841

12:55 13.3 10.9 22 21 0 846

1:00 15.4 9.3 23 22 22 851

01:05 14.2 8.2 22 22 22 856

01:10 14.2 7.9 22 20 23 862

01:15 15.6 9.3 21 21 24 868

01:20 14.0 8.0 21 22 22 874

01:25 14.1 8.0 21 22 22 880

01:30 15.0 8.7 22 21 22 886

01:35 13.6 7.8 22 20 22 893

01:40 13.5 9.1 22 22 22 899

01:45 14.7 8.3 22 22 22 905

Date: 13/1/2015 New Chiller (Right) Test Duration – 60 min Steady State Condition Test (BEE Approved)

Time EWT LWT C1 C2 C3 KWh

12:46 16.6 11.4 22 25 22 207

12:51 15.5 12.2 0 24 21 218

12:56 17.2 12.9 22 0 21 221

1:01 17.8 13.5 23 24 21 228

01:06 18.1 12.0 22 24 21 235

01:11 17.4 11.3 22 26 23 241

01:16 16.3 11.3 21 27 24 249

01:21 16.5 10.4 21 28 22 257

01:26 16.9 10.5 21 0 22 265

01:31 17.3 10.9 22 26 22 272

01:36 17.2 11.2 22 25 22 279

01:41 17.7 11.6 22 27 22 287

01:46 18.1 12.3 22 28 22 295

According to Bureau of Energy Efficiency standard, after establishing

that steady-state conditions, three sets of data shall be taken, at a

minimum of five-minute intervals. To minimize the effects of transient

conditions, test readings should be taken as nearly simultaneously.

39

Performance Terminologies & Measurement

Tons of refrigeration (TR): One ton of refrigeration is the amount of cooling obtained by one

ton of ice melting in one day: 3024 kCal/h, 12,000 Btu/h or 3.516 thermal kW.

Net Refrigerating Capacity: A quantity defined as the mass flow rate of the evaporator water

multiplied by the difference in enthalpy of water entering and leaving the cooler, expressed in

kCal/h, tons of Refrigeration.

KW/ton rating: Commonly referred to as efficiency, but actually power input to compressor

motor divided by tons of cooling produced, or kilowatts per ton (kW/ton). Lower kW/ton

indicates higher efficiency.

Coefficient of Performance (COP): Chiller efficiency measured in Btu output (cooling) divided

by Btu input (electric power).

Energy Efficiency Ratio (EER): Performance of smaller chillers and rooftop units is frequently

measured in EER rather than kW/ton. EER is calculated by dividing a chiller's cooling capacity

(in Btu/h) by its power input (in watts) at full-load conditions. The higher the EER, the more

efficient the unit.

Performance calculations:

The energy efficiency of a chiller is commonly expressed in one of the three

following ratios: [28]

[29]

IPLV (Integrated Part Load Value):

Chillers rarely operate at their full rated cooling capacity. In fact, most chillers operate at full

load for less than one percent of their total operating hours. Thus, it follows that selecting a

40

chiller based solely on its full load efficiency might not lead to the most efficient selection on a

year-round basis.

Integrated Part Load Value (IPLV) is a metric that is often used to express average chiller

efficiency over the range of loads encountered by most chillers. IPLV is the weighted average

cooling efficiency at part load capacities related to a typical season rather than a single rated

condition, based upon a representative load profile that assumes the chiller operates as follows:

Where: A = kW/ton at 100% capacity B = kW/ton at 75% capacity C = kW/ton at 50%

capacity D = kW/ton at 25% capacity

100% load: 1% of operating hours 75% load: 42% of operating hours50% load: 45% of

operating hours 25% load: 12% of operating hours. When the chiller energy efficiency is

expressed in kW/ton,

[30]

Measurement:

1. Flow rate of chilled water:

In the absence of an on-line flow meter the chilled water flow can be measured by the following

methods

• In case where hot well and cold well are available, the flow can be measured from the tank

level dip or rise by switching off the secondary pump.

• Non-invasive method would require a well calibrated ultrasonic flow meter using which the

flow can be measured without disturbing the system

• If the waterside pressure drops are close to the design values, it can be assumed that the

water flow of pump is same as the design rated flow.

2. Hot water and chilled water temperatures: Directly from chiller control-panel.

3. Compressor Power: The compressor power can be measured by a portable power analyser

which would give reading directly in kW.If not, the ampere has to be measured by the available

on-line ammeter or by using a tong tester. The power can then be calculated by assuming a

power factor of 0.9 Power (kW) = √3 x V x I x cosφ V= Line Voltage; I= Current in

compressor; cosφ= power factor

Calculation of capacity of chiller: [31]

41

Sample Calculation

Old Chiller (Left):

Calculation of Refrigeration capacity

The required parameters are 1. Mass flow rate of chilled water 2. Specific

heat 3. Chilled water temperature at evaporator inlet 4. Chilled water temperature

at evaporator outlet

Assumption: 1.Mass flow rate of chilled water is not measured by any flowmeter

but calculated from chilled water pump capacity range data. 2. The inlet and

outlet temperature value is noted from the chiller control panel in steady-

state condition.

Pump capacity range – 9.2 – 4.9 litre/sec (10 m – 26 m head)

Taken value = 4.9 litre / sec = 17640 kg/hr Cp = 1 kCal/kg oC for water

Taken steady state value= T inlet = 15.2 oC T outlet = 9.6 oC

Net Refrigeration Capacity = ((17640)*1*(15.2 - 9.6)) /3024 = 32.66 TR

Calculation of Compressor Power:

Compressor power is calculated from three phase line voltage neglecting other power

consumptions. Compressor current is noted from the chiller control panel.

Line Voltage – 415 V Power factor(cosφ)= 0.9 A sample data is taken from steady

state condition. C1=22 A C2 = 22 A C3 = 22 A

Compressor power = (W) = √3 x V x I x cosφ=√3 x 415 x (22+22+22) x 0.9

=42.696 kW

kW/Ton Rating for chiller = (42.696/32.66) = 1.334

Coefficient of Performance (COP) = 3.516/1.334= 2.63

Energy Efficient Ratio (EER) = 12 / 1.334 = 8.99

Chilled water pump energy consumption:

kW=(17.6 x 26x1)/(270x1.36x.6)= 2.07

kW/Ton rating for pump= 2.07/32.66=.063 kW/TR

Overall kW/TR= 1.334+.063=1.397

42

New Chiller (Right):

Calculation of Refrigeration capacity

Taken value = 5.6 litre / sec = 20160 kg/hr Cp = 1 kCal/kg oC for water

Taken steady state value= T inlet = 16.2 oC T outlet = 11.8 oC

Net Refrigeration Capacity = ((20160)*1*(16.2 – 11.8)) /3024 = 29.3 TR

Calculation of Compressor Power:

Compressor power is calculated from three phase line voltage neglecting other

power consumptions. Compressor current is noted from the chiller control panel.

Line Voltage – 415 V Power factor (cosφ) = 0.9

A sample data is taken from steady state condition. C1=21 A C2 = 26 A C3 = 23 A

Compressor power = (W) = √3 x V x I x cosφ=√3 x 415 x (21+26+23) x 0.9

=45.284 kW

kW/Ton Rating = (42.696/32.66) = 1.545

Coefficient of Performance (COP) = 3.516/1.545= 2.275

Energy Efficient Ratio (EER) = 12 / 1.545 = 7.76

Chilled water pump power consumption

kW=(20.2 x 40x1)/(270x1.36x.6)= 3.66

kW/Ton rating for pump= 3.66/29.3=.125 kW/TR

Overall kW/TR= 1.545+.125=1.670

*Due to unavailability of some measuring instruments like anemometer, flow

meter , dry bulb temperature meter , condenser fan wattage cannot be calculated.

43

Performance Analysis

The theoretical Coefficient of Performance (Carnot), COP Carnot - a standard

measure of refrigeration efficiency of an ideal refrigeration system- depends on

two key system temperatures, namely, evaporator temperature Te and condenser

temperature Tc with COP being given as:

COPCarnot = Te / (Tc - Te)

This expression also indicates that higher COPCarnot is achieved with higher

evaporator temperature and lower condenser temperature. [32]

Based on calculation in the previous section, COP is determined with hourly data

of the new and old chiller in the IFB plant.

Old Chiller (left)

Date Time COP % Load EER kW/TR

24/12/2014 10:00 2.85 34 9.75 1.23

12:00 2.14 77 7.31 1.64

2:00 1.037 11 3.53 3.39

4:00 2.39 81 8.15 1.47

Average 2.10 50.75 7.185 1.93

26/12/2014 10:00 2.42 25 8.2 1.45

12:00 2.85 97 9.75 1.23

2:00 1.66 17 5.686 2.11

4:00 1.168 40 3.38 3.01

Average 2.02 44.75 6.754 1.95

27/12/2014 10:00 2.97 98 10.13 1.18

1:00 2.54 84 8.68 1.38

4:00 2.21 74 7.53 1.59

44

Average 2.57 85.3 8.78 1.38

30/12/2014 10:00 2.88 95 9.81 1.22

1:00 2.81 98 9.97 1.25

4:00 2.52 82 8.62 1.39

Average 2.73 91.6 9.46 1.28

2/01/2015 10:00 2.56 88 8.73 1.37

1:00 2.58 63 8.78 1.36

4:00 2.40 90 8.18 1.46

Average 2.51 80.33 8.56 1.39

3/01/2015 10:00 2.45 61 8.39 1.43

1:00 2.62 45 8.95 1.34

4:00 2.39 95 8.16 1.47

Average 2.48 67 8.5 1.39

New Chiller (Right)

Date Time COP % Load EER kW/TR

24/12/2014 10:00 3.16 76 10.81 1.11

1:00 2.56 63 8.75 1.37

4:00 2.56 92 8.75 1.37

Average 2.76 77 9.43 1.28

26/12/2014 10:00 2.81 100 9.6 1.25

12:00 1.84 66 6.28 1.91

4:00 3.22 74 11.00 1.09

Average 2.62 80 8.96 1.95

27/12/2014 10:00 2.95 31 10.08 1.19

1:00 2.62 90 8.95 1.34

4:00 2.511 53 8.57 1.40

Average 2.69 58 9.2 1.38

30/12/2014 10:00 3.33 75 11.385 1.054

1:00 2.72 100 9.30 1.29

4:00 1.81 70 6.18 1.94

Average 2.62 81 8.95 1.28

2/01/2015 10:00 1.74 75 6.97 1.72

1:00 3.03 72 10.34 1.16

4:00 3.03 76 10.34 1.16

Average 2.60 74.33 9.21 1.34

3/01/2015 10:00 2.09 81 7.14 1.68

1:00 2.31 91 7.89 1.52

4:00 2.28 87 7.79 1.54

Average 2.22 86.33 7.60 1.58

45

IPLV Calculation for Old Chiller(Left):

From the above chart

A = kW/TR at 100 % load=1.25

B= kW/TR at 75 % load =1.59

C= kW/TR at 50 % load = 1.93

D= kW/TR at 25 % load = 1.45

IPLV=1/ ((0.01/1.25) + (.42 / 1.59 ) + (.45/1.93) + (.12/1.45)) = 1.70

IPLV Calculation for New Chiller (Right):

From the above chart

A = kW/TR at 100 % load=1.25

B= kW/TR at 75 % load =1.34

C= kW/TR at 50 % load = 1.38

D= kW/TR at 25 % load = 1.19

IPLV=1/ ((0.01/1.25) + (.42 / 1.34 ) + (.45/1.38) + (.12/1.19)) = 1.33

The term IPLV is used to signify the cooling efficiency related to a typical

(hypothetical) season rather than a single rated condition. The IPLV is calculated

by determining the weighted average efficiency at part-load capacities specified by

an accepted standard. It is also important to note that IPLVs are typically

calculated using the same condensing temperature for each part-load condition

and IPLVs do not include cycling or load/unload losses. The units of IPLV are

not consistent in the literature; therefore, it is important to confirm which units

are implied when the term IPLV is used. ASHRAE Standard 90.1 (using ARI

reference standards) uses the term IPLV to report seasonal cooling efficiencies

for both seasonal COPs (unit less) and seasonal EERs (Btu/Wh), depending on

the equipment capacity category; and most chillers manufacturers report seasonal

efficiencies for large chillers as IPLV using units of kW/ton. Depending on how a

cooling system loads and unloads (or cycles), the IPLV can be between 5 and

50% higher than the EER at the standard rated condition

*here IPLV is calculated on short term basis.

46

Energy Saving Opportunity

Maintenance Maintenance of Heat Exchanger Surfaces: Heat transfer can also be improved by ensuring proper separation of the lubricating

oil and the refrigerant, timely defrosting of coils, and increasing the velocity of the

secondary coolant (air, water, etc.). However, increased velocity results in larger

pressure drops in the distribution system and higher power consumption in pumps

/ fans. Therefore, careful analysis is required to determine the most effective and

efficient option. Fouled condenser tubes force the compressor to work harder to

attain the desired capacity.

For example, a 0.8 mm scale build-up on condenser tubes can increase energy

consumption by as much as 35 %. Similarly, fouled evaporators (due to residual

lubricating oil or infiltration of air) result in increased power consumption. Equally

important is proper selection, sizing, and maintenance of cooling towers. A

reduction of 0.55°C temperature in water returning from the cooling tower reduces

compressor power consumption by 3.0 %.

Multi-Staging for Efficiency

Efficient compressor operation requires that the compression ratio be kept low, to

reduce discharge pressure and temperature. For low temperature applications

involving high compression ratios, and for wide temperature requirements, it is

preferable (due to equipment design limitations) and often economical to employ

multi-stage reciprocating machines or centrifugal / screw compressors. Multi-

staging systems are of two-types: compound and cascade – and are applicable to all

types of compressors. With reciprocating or rotary compressors, two-stage

compressors are preferable for load temperatures from –20 to –58°C, and with

centrifugal machines for temperatures around –43°C.In multi-stage operation, a

first-stage compressor, sized to meet the cooling load, feeds into the suction of a

second-stage compressor after inter-cooling of the gas. A part of the high-pressure

liquid from the condenser is flashed and used for liquid sub-cooling. The second

compressor, therefore, has to meet the load of the evaporator and the flash gas. A

single refrigerant is used in the system, and the work of compression is shared

equally by the two compressors. Therefore, two compressors with low compression

ratios can in combination provide a high compression ratio.

Matching Capacity to System Load During part-load operation, the evaporator temperature rises and the condenser

temperature falls, effectively increasing the COP. But at the same time, deviation

from the design operation point and the fact that mechanical losses form a greater

proportion of the total power negate the effect of improved COP, resulting in lower

47

part-load efficiency. Therefore, consideration of part-load operation is important,

because most refrigeration applications have varying loads. The load may vary due

to variations in temperature and process

Chilled Water Storage Depending on the nature of the load, it is economical to provide a chilled water

storage facility with very good cold insulation. Also, the storage facility can be fully

filled to meet the process requirements so that chillers need not be operated

continuously. This system is usually economical if small variations in temperature

are acceptable. This system has the added advantage of allowing the chillers to be

operated at periods of low electricity demand to reduce peak demand charges -

Low tariffs offered by some electric utilities for operation at night time can also be

taken advantage of by using a storage facility. An added benefit is that lower ambient

temperature at night lowers condenser temperature and thereby increases the

COP.

Some ways to minimize energy consumption are -

a) Cold Insulation

Insulate all cold lines / vessels using economic insulation thickness to minimize

heat gains; and choose appropriate (correct) insulation.

b) Building Envelope

Optimise air conditioning volumes by measures such as use of false ceiling and

segregation of critical areas for air conditioning by air curtains.

c) Building Heat Loads Minimisation

Minimise the air conditioning loads by measures such as roof cooling, roof

painting, efficient lighting, pre-cooling of fresh air by air- to-air heat exchangers,

variable volume air system, optimal thermo-static setting of temperature of air

conditioned spaces, sun film applications, etc.

e) Process Heat Loads Minimisation

Minimize process heat loads in terms of TR capacity as well as refrigeration level,

i.e., temperature required, by way of:

i) Flow optimization

ii) Heat transfer area increase to accept higher temperature coolant

iii) Avoiding wastages like heat gains, loss of chilled water, idle flows.

iv) Frequent cleaning / de-scaling of all heat exchangers [33]

48

Conclusion

I have gained knowledge by this training in various aspects as an

Engineering student, as I had first-hand experience in IFB Industries

Limited. This training enhanced my cognition, as the employee has

explained, with commitment, all the doubts and question that arise in

my mind. This chance thrown at me, was a boon as I had only seen

that real about all the equipment seen in the industry, which now, I am

able to distinguish well enough. This was not possible with theoretical

knowledge. I heartily thanks all employees of IFB, Taratala to have

help me all throughout my training.

Doing this project on HVAC system in IFB, I have gathered clear

knowledge about the chiller performance and also many RAC systems.

I would like to express my gratitude to all those who gave me the

possibility to complete this training. I want to thank the HR department

of IFB for giving me permission to commence this training. It is really

great opportunity for me by which I had learned here many more about

engineering discipline.

49

Reference The data are taken from following references- [1] http://www.google.com/images980

[2] Indian Fine Blanks.ppt

[3] http://www.ifbbangalore.com/html/profile.htm

[4] IFB Taratala plant

[5] http://www.google.com/images987

[6] http://www.google.com/images




[10] http://www.ifbbangalore.com



[13] Bureau of Energy Efficiency – HVAC guide book- Chapter 4 page -1

[14] Chilling Water Plant – Guide book (Energy Resources Guide )

[15] Bureau of Energy Efficiency – HVAC guide book- Chapter 4 page -3

[16] Bureau of Energy Efficiency – HVAC guide book- Chapter 4








[24] http://www.moriiron.com/english/cpt_product/fb

[25] blue star air cooled scroll chiller brochure

[26] blue star air cooled scroll chiller brochure

[27] http://www.kirloskarpumps.com/brochure

[28] Bureau of Energy Efficiency – HVAC energy performance guide book- Chapter 8



[31] Chilling Water Plant – Guide book (Energy Resources Guide)



The list of documents required for preparing this report –

1. ASHRAE Handbook

2. Bureau Of Energy Efficiency guide books

3. ARI Standard 550/590

4. HVAC chillers code draft

5. Energy Star Tools

6. HVAC Systems 7. COOLTOOLS™ CHILLED WATER PLANT DESIGN GUIDE

report_chiller(by sayan roy)

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