ASeminar Report

On“Automotive air-conditioning system”

Submitted in partial fulfillment of the requirementFor the award of the Degree of

Bachelor of Technology

Under the supervision of Submitted byMr. Susheel Surana Himanshu Katara

10ESKME045

Department of Mechanical Engineering

SWAMI KESHVANAND INSTITUTE OF TECHNOLOGY,

MANAGEMENT & GRAMOTHAN

I

CERTIFICATE

This is to certify that Mr. Himanshu Katara, a student of

B.Tech.(Mechanical Engineering) VIII semester has submitted

His/her Seminar entitled “Automotive air-conditioning system”

under my/our guidance.

Mr. Susheel Surana Professor

Mechanical Deptt. SKIT, Jaipur

II

Acknowledgement

I would like to take this opportunity to express our thanks and

gratitude to all the persons who have directly or indirectly availed us in

guiding my seminar entitled “Automotive air-conditioning system”.

The assiduous help presumed by my guide Mr.Susheel Surana was

an inevitable part of the successful consummation of my seminar.

I thank my college authorities for permitting me to make use of the

facilities available in the department to carry out the seminar successfully.

I thank my parents and friends for all their support during the making of the

seminar. I also thank all other seen as well as unseen members who made me

available all the hardware resources as well as other inevitable help for the

successful completion of the Seminar.

III

SYNOPSIS

Major commercial refrigerant chloro fluoro carbons (CFCs) are going to be phase out

shortly as part of Montreal Protocol since they caused the phenomenon called green house

effect and depletion of ozone layer. Being very environment friendly amoniya water

combination is the most suitable working fluid pair for vapour absorption refrigeration

system. Energy from the exhaust gas of an internal combustion engine is used to power an

absorption refrigeration system to air-condition an ordinary passenger car.

According to a cautious estimate, approximately 10% of the energy available at the

crankshaft in a diesel operated vehicle is used for operating the compressor of the vehicle’s

air-conditioning system. This is a huge loss if one takes into account the fact that the

thermal efficiencies of most diesel operated vehicles range from 20-30% when in pristine

condition. The bottom line is that a great deal of diesel is consumed to generate electricity.

In addition to this, alternating current via an alternator is necessary for the operation of the

conventional a/c system. The refrigerant, usually R12 or R22 leaks easily. Being a

secondary refrigerant, it is also harmful to the environment.

A new driving scheme is put forward in this report, in which primary exhaust heat

sources is used to drive the air conditioner. There requires quite a few moving parts in this

new scheme. If the low power engine is mounted in the car, additional solar energy can be

combined to drive the air conditioner. The principle of the new air- conditioning system and

its structure are illustrated in this report. The automatic control system for this new Air-

condition System driven by of Exhaust Heat of Engine and Solar Energy is described in

detail as well. This new system is energy conserving, environment-protective, low-carbon,

and high efficient. It has a promising application prospect.

This seminar report presents a revolutionary ammonia water absorption system for air

conditioning in automobiles. The cooling effect is achieved by recovering waste thermal

energy from the exhaust gases. The system is cheap and easy to fabricate. The refrigerant,

being water, is environment friendly.

IV

List of figures

Sr No Fig No Caption Page

1. 2.1 Compressor 7

2. 2.2 Condenser 8

3. 2.3 Expansion Valve 10

4. 2.4 Evaporator 11

5. 3.1 Schematic diagram of vapour absorption refrigeration system

14

6. 4.1 Components of Absorption A/C[2] 22

7. 4.2 Schematic diagram of three fluid vapor

absorption system[7]

24

V

List of Tables

# Table No Tabe Name page

1 Table 3.1 Properties of Ammonia (R717). 12

2 Table 3.2 Enthalpy values on different points on enthalpy entropy chart of Ammonia (R717).

14

VI

Contents

Certificate I

Acknowledgement II

Synopsis III

List of figures IV

List of tables V

Content

Sr. No Chapter name Page no.

1. Introduction 11.1 History of air conditioning 11.2 Development 3

2. Conventional Vehicle air conditioning 52.1 Need for Air Conditioning 52.2 Cycle 52.3 Working 62.4 Sources Of Heat To The car 62.5 Components 72.6 Advantages 112.7 Drawbacks 112.8 Alternatives 12

3. Vapour Absorption Refrigeration System 13 3.1VARS 13 3.2 Methodology 14 3.3Theoretical Calculation of the System 15 3.4 Conclusions 19

4. Vapour Absorption Refrigeration System In Automobiles 20

4.1 Methods Of Implementation In An Automobile 204.2 Components of VARS 224.3 Working Of The System 24

5. Comparison between VCRS and VARS 255.1 Advantages of Absorption Refrigeration over Compression Refrigeration Cycle 265.2 Disadvantages of Absorption Refrigeration over 28

Vapor Compression Refrigeration Cycle

VII

6. Indian Scenario

307. World Scenario 328. Conclusion 34

REFRENCES 36 42 BIBLIOGRAPHY 38

ANNEXURES 39

Page | 1

Chapter-1

Introduction

1.1 History

With the invention of the R-12 in 1928 by GM researchers, the dawn of

the automotive air-conditioning started. The first prototype self-contained system was

installed in a 1939 Cadillac. Packard Motor Company in 1939 was the first company to offer

complete auto air-conditioning system for cooling in summer and heating in winter using

R12 refrigerant. The first bus A/C proto developed in

1934 by a joint venture between Houde Engineering Corporation of Buffalo, NY and Career

Engineering Corporation of Newark, NJ and others followed. Initial air- conditioners had a

number of problems as well as Second World War hampered the production/progress. In the

1953 model year, many of the problems had been resolved and General Motors and Chrysler

came back with improved air conditioning and that luxury became the necessity now for a

common car owner for ever Until then most of the A/C parts were placed in the trunk

and took up whole space of trunk. In 1953, Harrison Radiator Division of General Motors

came up with a revolutionary air conditioner that was totally spaced in the underhood and

dashboard (eliminating it from the trunk). The use of desiccant material to absorb moisture in

refrigerant line started in 1953. The following were the milestones of the development

in the succeeding years.

In 1955, GM developed the first A/C and heating unit that was front mounted, totally

pre-assembled and pre-tested. By 1957, all car makers followed this design approach.

To provide the evaporator freeze protection, a hot gas bypass valve was

introduced in the A/C system in 1956.

In 1957, air conditioning became a standard item in Cadillac Eldorado

Broughams. The average price of all air conditioners sold in 1957 was $435.

The popularity of auto A/C soared and the number of installed A/C systems on the

vehicle tripled from 1961 to 1964. During 1963, Ford set A/C unit price at $232.

In August 1965, GM crossed the five million A/C unit production mark. GM

also introduced first the Climate Control system on Cadillac. Industry wide

penetration of A/C reached 70% by 1980.

Due to oil embargo in 1973, the emphasis was placed on the fuel economy.

Page | 2

Harrison Radiator Division of General Motors developed a cycling clutch orifice

tube (CCOT) system replacing Frigidaire Valve-in Receiver (VIR) system that

resulted in the compressor off for 1/3 of the time rather than continuously

running, thus improving fuel economy. By 1979 all GM vehicles used this CCOT

system.

In 1974, world came to know the ozone depletion in stratosphere due to R12

use. Harrison Radiator analyzed nine refrigerants and by 1976 arrived at R134a as the

replacement of R12 eliminating chlorine. However, there was no commercial

availability of R134a then; Allied Chemicals, the major company conducting research

on R134a then, would supply about 1 lb of refrigerant per week and the need was

about 1000 lb per week for A/C system development work at Harrison in those days.

Although the viability of R134a was proven by Harrison through wind tunnel tests

on 1978 Chevrolet, the development of A/C system with R134a was discontinued

due to the lack of availability of R134a till the Montreal Protocol was adopted by

United Nations in September.

1987.

The first major revolution in the A/C system thus came starting 1990s by

replacement of R-12 to R-134a to eliminate the ozone depletion in stratosphere

by introducing a refrigerant having chlorine replaced by fluorine in its composition.

The commercial production of R134a started with DuPont and ICI in 1990.

The changeover of R12 to R134a necessitated the following changes in the

A/C system: about 20% higher condensing capacity condenser (to maintain the

same operating pressure so that new compressor is not needed), and change of

lubricant from mineral oil to synthetic polyalkylene glycol (PAG) oil.

Conversion from R12 to R134a in the USA, Europe and Japan took place

during 1991-1994. The rest of the world has changed to R134a as the refrigerant for

the A/C system during late 1990s and early 2000s.

Global warming potential (GWP) was not an issue when changeover from

R12 to R134a took place.

although the global warming potential of R134a was significantly lower than R12,

1300 vs 7800; carbon dioxide is the basis for global warming potential yardstick

having GWP of 1. According to the European Union F-gas regulation, the

refrigerant in all new A/C systems introduced in EU must have GWP of 150 or less

starting 2011.

Page | 3

1.2 Development

Automotive air-conditioning system has played an important role in human

comfort and to some extent safety during vehicle driving in varied atmospheric

conditions. It has become an essential part of the vehicles of all categories worldwide. Even

in India, 96% of all new cars manufactured in 2005 had factory-built air conditioning. After

discussing the basic operation of the A/C system, in this report, a brief summary is provided

on historical development of the vehicular A/C system, refrigerant history from the

inception of the A/C system to future systems: R-12, R-134a, enhanced A/C system to

next generation refrigerants having no ozone layer depletion potential and negligible

global warming potential. The discussion also includes the direct and indirect emissions

from vehicles due to the use of the A/C system. This would explain why we continue

to change the refrigerants in the automotive A/C system in spite of billions of dollars of the

previous refrigerant change cost.

The system design considerations are then outlined for minimizing the impact of A/C

operation on the vehicle fuel consumption. Finally, new concept design of A/C system

and vehicle heat load reduction ideas are discussed to further minimize the impact of A/C

system operation on the environment without impacting the human comfort. It is anticipated

that this report will provide the overall and detailed prospective of the A/C system

developments and provide an opportunity to the researchers to accelerate R&D for the

refrigerant changeover.

According to the ASHRAE, air conditioning is the science of controlling the

temperature, humidity, motion and cleanliness of the air within an enclosure. In a

passenger/driver cabin of a vehicle, air conditioning means controlled and

comfortable environment in the passenger cabin during summer and winter, i.e., control

of temperature (for cooling or heating), control of humidity (decrease or increase),

control of air circulation and ventilation (amount of air flow and fresh intake vs. partial or

full recirculation), and cleaning of the air from odor, pollutants, dust, pollen, etc. before

entering the cabin. While the A/C system provides comfort to the passengers in a vehicle,

its operation in a vehicle has twofold impact on fuel consumption: (1) burning extra

fuel to power compressor for A/C operation, and (2) carrying extra A/C component load

in the vehicle all the time. In addition, the A/C running depends on the climatic condition

Page | 4

of the concerned geographical region and the time of the year. The most important impact on

the fuel economy is when the A/C is running. Clodic et al. (2005) report the additional fuel

consumption due to MAC operation as 2.5 to 7.5% (in USA/Europe) considering the climatic

conditions, engine type (diesel or gasoline) and user profile. Corresponding CO2 emission

due to MAC operation is between 54.7 and 221.5 kg CO2 per year per vehicle. Of

course, the impact on the fuel consumption is more significant when the A/C is installed in

compact and sub-compact vehicles.

Page | 5

Chapter -2

Conventional Vehicle air conditioning

Introduction

The use of refrigeration and air conditioning for transporting purpose proves to

be very advantageous. Air conditioning is very much used in cars i.e. Automobiles, railways

and ships. The use of air conditioning in automobiles is a luxury in India but it is commonly

used in western countries to provide better human comfort.

Today automobile air conditioning has acquired a growing market. The AC in

automobiles is a need of persons who are suffering from the hot climate in India which

may be carry about 8 to 10 months per year. The new cars are so designed as to accommodate

A.C. in its cabin. Premier 118NE Contessa Classic, Tata Instat., Tata Siera, Opel Astra, Ford

and Mercedes Bens are some of the models which are having A.C. system.

2.1Need for Air ConditioningAutomobile air conditioning system works on the principle of vapour compression

refrigeration cycle and employees R12 as refrigerant to run the system. The following factors

are controlled by A.C. which leads to human comfort.

1) Heating of cabin,

2) Cooling,

3) Circulation of air,

4) Cleaning and filtering,

5) Humidity control.

As per the standards the temperature at 250 C and humidity of 50% R.H. is maintained to

provide better comfort. This can be achieved very easily in a room or office but it is very

difficult to maintain such temperature and R.H. factor because of different sources of heat

addition to the automobile system. This heat sources are stated later.

2.2 Cycle

Vapour compression refrigeration cycle is used in the car air conditioning system.

Page | 6

Vapour (fairly dry vapour) leaves the evaporator and enters the compressor at point 1. The

vapour is compressed is entropically to point 2. During compression, the pressure and

temperature increases. The temperature at point 2 should be greater than the temperature of

the Condenser cooling medium. The vapour leaves the compressor in dry saturated state and

enters the condenser at 2. The vapour is condensed and latent heat of condensation is

removed in condenser. The high pressure saturated liquid leaves the condenser and enters

the throttle valve at 3. Thus the flow through valve causes decrease in pressure and

temperature of refrigerant and causes it to evaporate partly. This refrigerant liquid at every

low temperature enters the evaporator where it absorbs heat from the space to be

cooled thus producing refrigerating effect. This increases its pressure and temperature and the

refrigerant is now dry vapour , which is supplied to compressor. This completes the cycle.

2.3 WorkingCool refrigerant gas is drawn into the compressor from the evaporator and

pumped from the compressor to the condenser under high pressure and temperature due to

compression, As this gas passes through the condenser, high pressure, high temperature gas

rejects etc. Heat to the outside air as the air passes over the surface of condenser. The coding

of the gas causes it to condense into a liquid refrigerant. The liquid refrigerant still in high

pressure passes to receiver drier (dehydrator), The receiver acts as a reservoir for refrigerant.

The liquid refrigerant flows from the receiver dehydrator to the thermostat expansion valve

refrigerant will loses its pressure and temperature.This low pressure low temperature liquid

enters the evaporator. The evaporator coil is mounted below front dash board. As the

temperature of refrigerant passing through evaporator is low„ it absorbs heat and continues to

boil, drawing heat from the surface of the evaporator core warmed by the rush of air

passing over the surface of the evaporator core. In addition to the warm air passing over-

the evaporator rejecting its heat to the cooler surfaces of the evaporator core, any moisture in

the air condenses on the cool surface of the core resulting in cool dehydrated air passing into

the compartment of the car. By the time the gas leaves the evaporator, it gets completely

vapourised and is slightly superheated. The pressure in evaporator is controlled by suction

throttle valve. R12 vapour passing through the evaporator flows through the suction throttle

valve and is returned to compressor where refrigeration cycle is repeated.

2.4 Sources Of Heat To The Car

The cooling load is affected by many factors. Some of them are listed below

Page | 7

1) Faster the car moves, the greater amount of infiltration into the car and better rate of heat

transfer .

2) The sun baking down on the blank road will raise the temp. up to 50 0 C to 60 0 C

and thus increases the amount of heat transferred into the car through the floor.

3) Because of the relatively large glass areas, metal construction and the flow of air around

the moving vehicle (automobile) is very large, so the air conditioning capacity is also large in

comparison with A. C. installed at home.

4) Quantity of fresh air in.

5) Number of occupants.

6) Quantity of heat directly rejected by sun on car.

For all the above sources, it is necessary that capacity of automobile A.C. should be large, be

capable to take overloads and operate for relatively long periods.

The cooling capacity of automobile A.C. system ranges from 1 to 4 tones, which is the

amount of refrigeration needed to cool a small house.

2.5 Components1) Compressor :-

Compressor is a driver of the system. The construction is much rigid and the unit is

semi sealed. i.e. the power to drive the compressor is directly taken from the crank shaft by

means of v-belt pulley and electromagnetic clutch. The heavy-duty gaskets are provided at joint

to prevent vibration, noise and leakage. A typical value arrangement is provided to suit the

requirements. The high and high pressure refrigerant enters in compressor which further gets

compressed causing hot vapour exit from the compressor unit, The compressor can start or stop

by means of thermostat arrangements which engages or disengages the electromagnetic clutch

so as to run compressor as per requirements. Lubrication oil is placed inside the chamber. The

noise of compressor is very least as compared to that of engine. The vibration of compressor

creats problem in Diesel air conditioning system.

Fig 2.1

Page | 8

Compressor

2) Electromagnetic Clutch :-

The pulley assembly contains an electrically controlled magnetic: clutch, permitting the

compressor to operate only when air conditioning is actually desired. All automobile A.C.

systems employs the clutch to drive the compressor on demand from the thermostat inside the

car (i.e. the knob). When the compressor clutch is not engaged, the compressor shaft does not

rotate, although the pulley is being rotated by belt from the engine. The clutch armature plate,

which is movable member of the drive plate assembly is attached to the thrive hub through

drive springs and is riveted to both driver and armature plate. The hub of this assembly is

pressed over the compressor shaft is aligned with a square drive key located in the key way on

the compressor shaft. The pulley assembly consist of pulley rim, pulley hub and power

element ring.

3) Condenser -

A condenser is similar to an ordinary automobile radiator but are designed to withstand

much high pressure, It contains a fan to provide forced circulation of air. This whole assembly

is fitted in front of the car radiator so that it receives high volume of air. The high temperature

and high pressure refrigerant vapour loses its heat to forced air flowing through it causing

change of this phase into high pressure liquid. The fan and electromagnetic clutch are

electrically coupled. Rapid condensation of refrigerant can be done by fan.

Fig 2.2

condenser

Page | 9

4) Receiver:-

The purpose of receiver is to ensure a solid column of liquid refrigerant to the

thermostatic expansion valve. Automobile A.C. units are more susceptible to leaks than units

because of vibration. Over a period of time, small leaks will occur, which may requires addition

of refrigerant,, Also the evaporator requirements vary because of the changing heat load. A

small receiver is used in the system to compensate all the above variables, Refrigerant is stored

in the unit untitled it is needed by the evaporator. A liquid Automobile Air Conditioning

indicator or slight glass is provided at outlook pipe of receiver unit. The appearance of bubbles

or foam in the slight glass indicates the shortage of refrigerant in the system. Drier part of this

unit consists of sillicagel to absorb moisture if any in the system, also it traps foreign material

which may have entered the system during assembly. It is temporary storage and purifying unit.

5) Expansion Valve:-

The expansion valve fulfils the following two functions.

a. The temperature and pressure of refrigerant is reduced to such a low-level due to

sudden expansion by throttling process. This is helpful to create low temperature

than the evaporator.

b. According to cooling load, the quantity of refrigerant supplied to evaporator can be

controlled. It automatically regulates the flow of liquid refrigerant. The valve is

located at the inlet to evaporator core. It consists of a (capillary bulb and tube, which

are connected to an operating diaphragm (sealed within the valve). When the cooling

load increases, the refrigerant evaporates at a faster rate in evaporator than the

compressor can suck. As a result., the degree of superheat and pressure in evaporator

increases which cause the valve to

open more allowing more refrigerant to enter into the evaporator. At, the same time

the increases in suction pressure also enables the compressor to deliver increased

refrigerating capacity. When cooling load decreases; the refrigerant evaporates at a

slower rate than the compressor can suck, As a result the evaporator pressure drops

and the degree of superheat will decrease., The valve tenets to close and the

compressor delivers less refrigerant capacity. Thus this valve is capable of meeting

the varying load requirements. This valve keeps the evaporator full of refrigerant,

thus ensures safety to compressor.

Page | 10

Fig 2.3

Expansion Valve

6) Evaporator:-

Evaporator is a place where the refrigerant evaporates and absorbs heat from the air

passed over it. Air is forced to flow over the evaporator with the help of blower, which is

installed in the evaporator itself and cooled before distributing in seating compartment. The

design of evaporator is more critical as the space limitations are very severe and worse than

compact room conditioners. The evaporator is placed under dashboard of car. We can provide

more ducts if the car seating capacity is more. The purpose of evaporator is to cool and

dehumidify the air passing over it into passenger's cabin.

The refrigerant in cooled liquid state boils immediately in evaporator when air loses its heat

and moisture to it. Heat from the core surface is lost to boiling and vapourizing refrigerant,

which is cooler than the core, thereby cooling the core. The moisture collected is then drained

of as it may reduce the cooling effect.

Dirt or other foreign matter on the core surface or in evaporator housing will restrict

the airflow. A cracked or broken housing can result in insufficient air-or warm air supply to

passenger’s compartment. The dirt can be removed by forcing dry air on it

under pressure.

Page | 11

Fig 2.4

Evaporator

7) Controls:-

These units ensures safe operation of air conditioner. The thermostat is used to

prevent the formation of frost on the evaporator coil. The cabin air temperature is also

controlled to the desired level. Once the evaporator fins temperature approaches near freezing

point, the thermostat sends signals to the thermo amplifier which in turn cuts all power supply

to electromagnetic clutch, thereby A.C. operation stops temporarily.

2.6 Advantages

The main advantage of this system is to travel with comfort for a long

distance in any type of atmospheric conditions without tired. During summer the

temperature inside the car can he maintained low and this is very necessary for comfort

conditions. There may be more advantages rather than this.

2.7 Drawbacks

1) Moving parts are in the compressor. Therefore, more wear, tear and noise.

2) It uses high grade energy like Mechanical work. Engine speed, average and power

will reduce due to power supplied to run A.C. system.

3) High operating cost, since fuel economy is affected, high maintenance cost, costly

refrigeration. A loss in economy level of the order of 1 to 1.5 km/liter can occur

due to the use A/C.

Page | 12

4) CFC’s (Chlorofluorocarbon) if leaks out of the system causes great damage to the

ozone layer.

5) If the car’s reserve power is less, it can affect its acceleration.

6) Maintenance and initial cost of unit is high.

2.8 Alternatives-

Adsorption/Absorption Air-Conditioning Using Waste Heat :- In this system

the compressor is replaced by the combination of Absorber, Generator and Pump that

uses a waste heat source to provide the energy needed to drive the cooling system.

Adsorption - Adsorption is the phenomenon in which, the liquid or gas (refrigerant)

molecules in the adsorbing pair gets deposited on the solid (adsorbent) surface without

any chemical change .This is an exothermic process. For ex: the silica gel acts as an

adsorbent, which adsorbs the water molecules on its surface.

Absorption- The phenomenon of absorption is the mixture of a gas in a liquid, the two

fluid present strong affinity, to form a solution (uptake of molecules into the interior of

another substance).

Page | 13

Chapter-3

Vapour Absorption Refrigeration System

IntroductionThe vapour absorption system uses heat energy, instead of mechanical energy as in

vapour compression system, in order to change the condition of the refrigerant required for

the operation of the refrigeration cycle. In this system, the compressor is replaced by an

absorber, a pump, a generator, and a pressure reducing valve. This complete chapter discuss

about the theoretical calculations are made of different components of the systems like

evaporator, absorber, condenser and pump of vapour absorption system for a capacity of 1

TR and experimentally developed and run system to validated for reducing the temperature

for the free of cost of operation.

3.1VARS

In the vapour absorption refrigeration (VAR) system, a physicochemical process

replaces the mechanical process of the vapour compression refrigeration (VCR) system by

using energy in the form of heat rather than mechanical work. The main advantage of this

system lies in the possibility of utilizing waste heat energy from industrial plants or other

sources and solar energy as the energy input.

The VAR systems have many favourable characteristics. Typically a much smaller

electrical input is required to drive the solution pump, compared to the power requirements

of the compressor in the VCR systems, also, fewer moving parts means lower noise

levels, higher reliability, and improved durability in the VAR systems. A vapour

absorption refrigeration system is a heat operated unit which uses refrigerant (NH3) that

is alternately absorbed by and liberated from the absorbent (water).

The vapour absorption system uses heat energy, instead of mechanical energy as in

vapour compression system, in order to change the condition of the refrigerant

required for the operation of the refrigeration cycle. In this system, the compressor is replaced

by an absorber, a pump, a generator, and a pressure reducing valve. These components

in the system perform the same function as that of compressor in vapour compression system.

Page | 14

The vapour refrigerant from evaporator is drawn into an absorber where it is absorbed by the

weak solution of refrigerant forming a strong solution. This strong solution is pumped to

the generator where it is heated by utilizing solar energy. During the heating process, the

vapour refrigerant is driven off by the solution and enters into the condenser where it is

liquefied. The liquid refrigerant then flows into the evaporator and thus the cycle is

completed.

3.2 Methodology

Fig.1 shows the schematic diagram of a vapour absorption system. Ammonia vapour is

produced in the generator at high pressure from the strong solution of NH3 by an external

heating source. A solar cooker will produce the heat and generate ammonia gas. Ammonia

gas then enters into the condenser. High pressure NH3 vapour is condensed in the condenser.

The cooled NH3 solution is passed through a throttle valve and the pressure and temperature

of the refrigerant are reduced below the temperature to be maintained in the evaporator. The

low temperature refrigerant enters the evaporator and absorbs the required heat from the

evaporator and leaves the evaporator as saturated vapour. Slightly superheated, low pressure

NH3 vapour is absorbed by the weak solution of NH3 which is sprayed in the absorber.

Fig.3.1

Schematic diagram of vapour absorption refrigeration system [1]

Page | 15

Table 3.1

Properties of Ammonia(R717).

3.3 Theoretical Calculation of the System

The following specific parameters are assumed for theoretical calculation of the

complete system design:

Condenser pressure: 5 bar,

Evaporator pressure: 2 bar, Capacity

of refrigeration: 0.25 TR,

i) Heat removed in condenser (Qc): The amount of heat removed in the condenser is given

by:

Page | 16

Qc = (h2-h1) kJ/kg of NH3. (1)

Where h is enthalpy at different points on chart. As NH3 saturated vapour enters in and

NH3 saturated liquid comes out.

ii) Heat absorbed in the evaporator (Qe): The amount of heat absorbed in the evaporator is

given by:

Qe = (h4-h3) kJ/kg of NH3. (2)

where h4 is the heat of saturated vapour at Pc and h3 is the heat of mixture of NH3 liquid

and vapour at Pe or heat of NH3 liquid at points ‘2’ as 2-3 is constant enthalpy throttling

process.

iii) Heat removed from the absorber (Qa):

When NH3 vapour at point 4 and aqua at point 10 are mixed, the resulting condition of the

mixture in the absorber is represented by 7’’ and after losing the heat in the absorber (as it is

cooled), the aqua comes out at condition 5. Therefore, the heat removed in the absorber is

given by:

Qa = (h7-h5) kJ/kg of aqua. (3)

iv) Heat given in the generator (Qg):

Qg is the heat supplied in the generator and Qd is the heat removed from the water vapour,

then the heat removed per kg of aqua is given by:

(Qg-Qd) = (h7’-h7) kJ/kg of aqua. (4)

As the aqua goes in at point 7 and comes out at condition 8 and 1 which can be considered a

combined condition at 7’. By extending the triangle 8-7-7’ towards right till 8-7’ cuts at 1 and

8-7 cuts at ‘a’ on y-axis then, the heat removed per kg of NH3 is given by:

(Qg- Qd) = h1-ha kJ/kg of NH3. (5)

Page | 17

For finding out Qd separately, extend the vertical line 7-7’ till it cuts the auxillary Pc line and

mark the point ‘b’. Then draw horizontal line through ‘b’ which cuts the Pc line in (in

vapour region) at point 11. Then join the points 7 and 11 and extend that line till it cuts y-axis

at 12. Therefore, Qd is given by:

Qd = (h12-h1) kJ/kg of NH3. (6)

The table 2 shows the values obtained on enthalpies based on enthalpy concentration

chart of Ammonia (R717).

Table 3.2

Enthalpy values on different points on enthalpy entropy chart of Ammonia (R717).

Based on above enthalpies calculation values the following results are obtained for the

design load of different component of the system.

i) Mass flow rate of NH3 through evaporator (mf):

Page | 18

mf = Cooling load/ h4 - h3

= (0.25x0.35)/(1632.462-376.722)

mf = 6.968×10-4kg/s=2.51kg/h.

ii) Heat rejected in absorber (Qa): Qa

= mr× x× (h4-ha)

= 6.968 x 10-4 x (1632.462-(-334.864)) Qa

=1.371kW.

iii) Heat removed in condenser (QC): QC

= mr ×x× (h1- h2)

= 6.968 x 10^-4 x (1632.462-376.722)

QC = 0.875kW.

iv) Mass of strong solution handled by pump per second (ms):

Enthalpy balance across heat exchanger is,

Heat lost by weak solution = heat gained by strong solution, mw ×

(h8-h9) = (mw + 1 )×(h7-h6)

mw× (209.92-92.0876) = (mw+1)× (133.9456-41.858)

mW = 3.6667kg/kg of NH3.

Hence, mass of strong solution handled by pump (ms), ms =

mr × (mw +1) = 6.968 x 10-4× (3.6667+1) Therefore, ms=

3.2517×10-3 kg/s.

v) Heat supplied to generator temperature = 75°C.

Qg = mr x (h12 – ha)

= 6.968 x 10-4 x (1820.823-(-334.864))

Therefore, Qg = 1.502kW.

Page | 19

vi) Design of pressure vessel for generator:

At pressure 5bar, with diameter (d) =200mm, and assuming 33% overload, the design

pressure,(Pd) obtained 6.65bar.Design pressure (Pd) =1.33 xP = 6.65bar. Therefore, thickness

of pressure vessel as thin cylinder, [(Pd x d)/2 xt] =330N/mm2 (330N/mm2 assuming C40 as

a material for pressure vessel from PSG data book).

Therefore, t=8mm.

vii) Design of air cooled condenser:

Calculations are made and obtained LMTD (Log Mean Temperature Difference) =

42.45°C, and length of coil=1.87m.

3.4ConclusionsAfter designing, manufacturing and run the system the achieved

temperature drop of 3.5oC below ambient temperature with the time period of 32.5s as shown

in Fig.3. Although the system was designed for a capacity of 0.25TR the desired capacity was

not completely achieved. This was due to fact that certain parameters could not be achieved

during the practical design as compared to the theoretical design as stated below.

1 Less number of turns of condenser& tube length resulted in inefficient heat rejection. This

caused the hot vapour from the generator to enter the evaporator coil without changing its

phase completely and thus reduced the cooling effect.

2 The system couldn’t sustain desired pressure range. The pressure capacity of the flexible

hoses used in the system limited the system pressure and thus the design pressure could not

be achieved due to fear of failure.

3 Concentration of ammonia in the system design was for 50% concentration of ammonia but

in the ammonia commercially available is of 25% concentration. This was also a limitation.

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Chapter-4

Vapour Absorption Refrigeration System In

Automobiles

Introduction

Much of an internal combustion engine’s heat from combustion is discarded out of

the exhaust or carried away via the engine cooling water. All this wasted energy could

be useful. The common automobile, truck or bus air conditioner uses shaft work of the

engine to turn a mechanical compressor. Operating the mechanical compressor increases the

load on the engine and therefore increases fuel consumption, emissions and engine operating

temperature. With an absorption refrigeration system, we can utilize the exhaust heat and the

heat absorbed by the engine’s cooling water. This heat, which could be considered as free

energy, would be enough to drive an adsorption refrigeration.

It is well known that an IC engine has an efficiency of about 35-40%, which means that

only one-third of the energy in the fuel is converted into useful work and about 60-65% is

wasted to environment. In which about 28-30% is lost by cooling water and lubrication

losses, around 30-32% is lost in the form of exhaust gases and remainder by radiation, etc. In a

Vapour Absorption Refrigeration System, a physicochemical process replaces the mechanical

process of the Vapour Compression Refrigeration System by using energy in the form of heat

rather than mechanical work. The heat required for running of a Vapour Absorption

Refrigeration System can be obtained from the exhaust of any vehicle working with an IC

engine, which would otherwise be exhausted into the atmosphere. Hence using a Vapour

Absorption Refrigeration System will not only prevent the loss of power from the vehicles

engine but will also produce refrigeration using the low grade energy (i,e. exhaust) from the

engine. The use of a Vapour Absorption Refrigeration System will also reduce pollution by

reducing the amount of fuel burned while working the conventional vapour compression

refrigerating unit.

4.1 Methods Of Implementation In An Automobile

Page | 21

For a road transport utilizing Vapour Absorption Refrigeration System heat energy

can be supplied in two ways:

1. Using heat of combustion of a separate fuel- By using a separate fuel for working

the refrigeration system i,e. a fuel for example natural gas can be used for the working of

a Vapour Absorption Refrigeration System. This can be achieved by burning the fuel in a

separate combustion chamber and then, supplying the Generator of a Vapour Absorption

Refrigeration System with the products of its combustion to produce the required refrigerating

effect. However this prospect is eliminated since it requires a separate fuel and a separate

combustion chamber which makes it uneconomical and the system becomes inefficient.

2. Using waste heat of the IC engine- Another method is by utilizing the heat of

combustion which is wasted into the atmosphere. By designing a generator capable of extracting

the waste heat of an IC engine without any decrease in engine efficiency, a Vapour Absorption

Refrigeration System can be brought to work. Since this arrangement does not require any extra

work expect a small amount of work required for the pump, which can be derived from the

battery, this system can be used in automobiles where engine efficiency is the primary

consideration.

In an IC engine, fuel (usually petrol or diesel) is combusted inside the cylinder due to

which the piston moves outward and rotates the crank, and hence the engine produces work. In

IC engines the combustion of the fuel produces heat, which is converted to mechanical work

using the piston and crank arrangement. From the heat produced from combustion of fuel

only 30% (approx) of heat is converted into useful mechanical work.

The remaining heat energy is wasted into the atmosphere in the form of:

(i) heat carried away by the cooling water,

(ii) heat taken away by the exhaust gases,

(iii) heat carried away by the lubricating oil,

(iv) and, heat lost by radiation.

The cooling water and exhaust gases carry away the maximum amount of heat from the

engine, ie around 60% (approx). This heat is called the low grade energy of the engine.

Page | 22

4.2 Components of VARS

Figure 4.1

Components of Absorption A/C [2]

4.2.1 Generator

It is basically a container where the solution is maintained at constant

level. The exhaust pipe is passed through it and its heat is extracted in the generator. It has

two exits and an inlet. From the two exits, one is for the flow of refrigerant to the condenser

and the other for the flow of solution back to absorber. The exhaust pipe passing through the

generator is made of copper while the other components are made of steel.

4.2.2 Condenser

Usually the condenser of an automobile is of an oval cross-section. It is made

of aluminum to have easy transfer of heat from the refrigerant coming from generator to the

atmosphere. A large number of fins are provided to increase the surface area and thereby

increase the heat transferred from the refrigerant to the atmosphere.

Page | 23

4.2.3 Expansion valve

A needle valve is used to drop the pressure of the refrigerant from high

pressure to low pressure side. A needle valve can be easily adjusted to obtain the required

pressure within the system.

4.2.4 Evaporator

The refrigerant from the expansion valve enters the evaporator where the cold

refrigerant absorbs heat from the surroundings. To have maximum heat transfer from

surroundings to the refrigerant the evaporator is made of copper tubes.

4.2.5 Absorber

This is the container which has two inlets, one for the refrigerant coming from the

evaporator while the other for the weak solution coming from the generator. The one exit is

for pumping the solution to the generator. It has a perforated sheet to strain the solution

coming from the generator to have a proper mixing of the weak solution with the refrigerant

coming from the evaporator. Fins are provided around the container to increase the surface

area, to remove the heat developed during the mixing of the refrigerant and the weak solution.

4.2.6 Pump

Since the system is small the flow rate required is also small. Hence a fuel pump is

used to pump solution from the absorber to the generator. The power to run the pump is

derived from the engine battery.

4.2.7 Control valve

This is placed in between the generator and the absorber to bring the solution pressure

from high pressure to low pressure. The control valve may be another needle valve which

could also be used to control the flow rate of the weak solution back to the absorber.

4.2.8 Pre-heater

Page | 24

This is a container containing coiled tubes through which the solution passes. It is

placed in between the generator and the pump of the absorber. Cooling water is passed

through the container, ie it is placed in the path way of hot water flowing from the engine

jacket to the radiator. The quantity of cooling water inside the pre-heater is always fixed. The

coils for the flow of solution are made of copper to have maximum heat transfer fro the

cooling water to the solution and the remaining parts are of cast iron.

4.3 Working Of The System

Figure 4.2

Schematic diagram of three fluid vapor absorption system [7]

The strong solution at 35°C is pumped from the absorber to the pre-heater where the

solution of the strong solution is increased to 75°C from the cooling water at 80°C. This

solution then enters the generator where the refrigerant, ie water at 40°C gets vapourizes and

is passed through the condenser, where the latent heat is removed from the refrigerant. This

refrigerant is then passed through the expansion valve to bring the temperature to around

10°C, after which it is passed through the evaporator coil to absorb the latent heat of the

refrigerant at 10°C. The vapourized refrigerant then enters the absorber where the weak

solution coming from the generator gets mixed liberating heat. This formed solution is again

Page | 25

pumped to the generator using the pump and the cycle is repeated again.

Page | 26

Chapter-5

Comparison between VCRS and VARS

5.1 Advantages of Absorption Refrigeration over Vapor

Compression Refrigeration Cycle

1) Method of compression of the refrigerant: One of the most important parts of any

refrigeration cycle is the compression of the refrigerant since all the further operations

depend on it. In the vapor compression refrigeration system the compression of the

refrigerant is done by compressor which can be of reciprocating, rotating or centrifugal type.

In the vapor absorption refrigeration system, the compression of the refrigerant is done by

absorption of the refrigerant by the absorbent. As the refrigerant is absorbed, it gets

converted from the vapor state to liquid state so its volume reduces.

2) Power consumption devices: In the vapor compression cycle the compressor is the major

power consuming device while in the vapor absorption cycle the pump used for pumping

refrigerant-absorbent solution is the major power consuming device.

3) The amount of power required: The compressor of the vapor compression cycle requires

large quantities of power for its operation and it increases as the size of the refrigeration

system increases. In case of the vapor absorption refrigeration system, the pump requires very

small amount of power and it remains almost the same (or may increase slightly) even for

higher capacities of refrigeration. Thus the power consumed by the vapor absorption

refrigeration system is much more than that required by the vapor compression system.

4) Type of energy required: The vapor absorption system runs mainly on the waste or the

extra heat in the plant. Thus one can utilize the extra steam from the boiler, or generate extra

steam for the purpose and also use the hot available water. Similarly the waste heat from the

diesel engine, hot water from the solar water heater, etc. can also be utilized. In case of the

vapor compression refrigeration system, the compressor can be run by electric power supply

only; no other types of energy can be utilized in these systems.

5) Running cost: The vapor compression refrigeration system can run only on electric

power, and they require large amount of power. These days the electric power has

become very expensive, hence the running cost of the vapor compression refrigeration system

is very high. In case of the absorption refrigeration system only small pump requires

electric power and it is quite low. In most of the process

Page | 27

industries, where the absorption refrigeration is used, there is some extra steam available

from the boiler, which can be used for running the system. Thus in absorption refrigeration

system no extra power in the pure electric form is required and the energy that would have

otherwise gone wasted is utilized in the plant. Thus the running cost of the absorption

refrigeration system is much lesser than the vapor compression system.

6) Foundations required and noise: The compressor of the vapor compression system

is operated at very high speeds and it makes lots of vibrations and noise. It also requires very

strong foundation so that it can remain intact under vibrations and high pressures of the

refrigerant. In the absorption refrigeration system there are no major moving parts hence they

don’t vibrate, don’t make noise and also don’t require heavy foundations. The absorption

refrigeration systems operate silently.

7) Maintenance: Compressor is the crucial part of the vapor compression cycle, and it has

number of moving parts. It is very important to do the thorough lubrication of the

compressor and also keep checking it regularly for any defects. The compressor also requires

changing of the piston, piston rings, cylinder liner etc. from time-to- time. Thus the vapor

compression system requires lots of maintenance. Failure of compressor can be very

expensive at times as the suction and the discharge valve of the compressor are very

expensive. Even the motor of the compressor is very heavy and expensive. The compressor

also requires cooling, for which special pump is required to pump the water from the cooling

tower to the compressor. Since there are number of moving parts of the compressor that move

at very fast speed some or the other failure occurs regularly. In the absorption refrigeration

system the only moving part is the small pump that fails rarely. Thus the maintenance

required by the vapor compression system is much more than that required by the vapor

absorption system.

8) Capacity control of the system: In the vapor compression cycle the capacity control of

the system is done from the compressor and in most of the cases stepwise capacity control is

obtained. In case of the absorption refrigeration system it is possible to obtain stepless

capacity control and zero capacity when there is no load on the system. Though these days

compressors with stepless capacity control are available, but they will consume lots of power

even if there is zero load on the refrigeration system. In absorption system, when there is zero

load the power consumption is almost zero.

9) Type of refrigerant used and its cost: In ammonia-water absorption refrigeration system,

ammonia is used as the refrigerant, which is easily and cheaply available. In lithium bromide

system, water is used as the refrigerant, which is also available

Page | 28

cheaply and easily. In case of the vapor compression refrigeration system

halocarbons are used as the refrigerants, which are very expensive.

10) Leakage of the refrigerant: In the absorption refrigeration system there are no (or very

few) leakages of the refrigerant and the refrigerant itself is very cheap. Thus there are almost

zero refrigerant recharging costs. In case of the vapor compression systems there are lots of

leakages of the refrigerant thus regular recharge of the refrigerant is required which is very

expensive.

11) Greenhouse effect: Most of the halocarbon refrigerants used in the compression

refrigeration system produces greenhouse effect. As per the Montreal Protocol, their use has

to stop completely by the year 2020. In the absorption refrigeration system no refrigerant

produces the greenhouse effect, so their use won’t be stopped in future.

5.2 Disadvantages of Absorption Refrigeration over Vapor Compression

Refrigeration Cycle

1) Initial capital cost: Though the running cost of the absorption refrigeration system is

much lesser than the vapor compression system, its initial capital cost is much higher.

2) Corrosive nature of lithium bromide: In the lithium bromide absorption refrigeration system,

lithium bromide is corrosive in nature, which reduces the overall life of the system. In case of

the ammonia system, ammonia is corrosive to copper.

In the vapor compression system copper is used with the halocarbon refrigerants and they are

quite safe thus ensuring long life of the refrigeration system. As such the vapor compression

system with reciprocating or centrifugal compressor has longer life than the lithium bromide

absorption refrigeration system.

3) Low working pressures: The working pressures of the absorption refrigeration cycle are

very low. In case of the lithium bromide system these pressures are so low that even the

expansion valve is not required since the drop in pressure of the refrigerant due to its flow is

good enough to produce its expansion. Due to this the refrigeration system should be sealed

thoroughly so that no atmospheric gases would enter the refrigeration system. As such the

system of the compression refrigeration should also be packed tightly, but this is to prevent

the leakage of the refrigerant to the atmosphere.

Page | 29

4) Coefficient of Performance (COP): The coefficient of performance of the absorption

refrigeration systems is very low compared to the vapor compression systems. For

instance, the COP of the two stage lithium bromide system is about

1.1, while that of the vapor compression system used for the air conditioning

applications it is about 4 to 5. Thus the absorption refrigeration system becomes

competitive only if the ratio of the electricity to fuel (oil, gas or coal used to generate

the steam in the boiler) becomes more than four. If this ratio is lesser there are chances

that excess fuel would be required to generate the steam. However, if there is excess

steam in the industry, this ratio may not be given importance.

5) Higher heat rejection: In the absorption refrigeration heat has to be rejected from number

of parts like condenser, absorber, analyzer, rectifier etc. thus heat rejection factor for

absorption refrigeration system is high and it can be around 2.5. In the compression

refrigeration system the heat is given up only from the condenser, so it heat rejection factor is

small, which is about 1.2. Thus the cooling tower and pump capacities for pumping the

cooling water have to be higher in case of the absorption refrigeration system, which leads to

increase in the running cost of the system.

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chapter-6

Indian Scenario

In air conditioning of automobile the vapour compression refrigeration system causes

the loss in economy level of the order of 1 to 1.5 km/liter can occur due to the use A/C. In

India there are no automobile absorption refrigeration system which is working on the exhaust

heat of the engine because following reasons.

1. Initial capital cost -Though the running cost of the absorption refrigeration system is much

lesser than the vapor compression system, its initial capital cost is much higher.

2. Size -The size of this system is more than vcrs. Mainly in India there is small size of cars.

The space occupied by generator is main limiting factor.

3. Coefficient of Performance (COP)- The coefficient of performance of the absorption

refrigeration systems is very low compared to the vapor compression systems.

4. Lack of cooling potential in the exhaust gases at low and idling speeds.

In India there is laboratory test done on this system in automobile air conditioning at SVNIT

Surat by A. C. Deshpande which is currently working as a Jr. Research Fellow at SVNIT, Surat under

BARC. Another college where laboratory test is done is Jawaharlal Darda Institute Of Engineering

& Technology, Yavatmal.

These factors affect the use of this system in automobile but in other areas like power

plants and other industries where waste heat can be utilized by installing vapour absorption

refrigeration system.

In India Thermax Ltd working on these systems. This uses waste heat from steam, solar power,

flue gases, and hot water.This serving for Bhilai steel plant Raurkela steel plant Reliance

industries ltd Gas authority of India ltd. Products are

Steam Driven Vapour Absorption Machine- Capacities: From 50 to 2000 TR

Page | 31

Steam pressure: From 0.6 to 3.5 Kg/cm² (g)

Chilled water temperature: Up to 3.5ºC (0ºC for brine) Heat source: Steam

Hot Water Driven Vapour Absorption Machine

Capacities: From 10 to 2000 TR

Chilled water temperature: Up to 3.5ºC (0ºC for brine) Water temperature: From 75ºC to 200ºC

Exhaust Vapour Absorption Machine-

From 50 to 2000 TR,

chilled water temperature Up to 3.5ºC (0ºC for brine)

Page | 32

Chapter-7

World Scenario

Vapour absorption refrigeration system based on exhaust heat (or waste heat from solar)

is not widely used due to its limitations.

Refrigerating effect will be reduced or will be difficult to produce should the

vehicle be at rest or in a very slow moving traffic condition.

The refrigerating effect produced using a Vapour Absorption Refrigeration

System is less compared to a Vapour compression Refrigeration System.

But still Toyota developed solar ac based on absorption refrigeration in his car in 2010

in model Toyota Prius.

Nowhere is the greenhouse effect more noticeable than inside a car on a hot day.

But the new Toyota Prius comes with new green technologies including cooling fans run by

optional solar panels.The Prius includes a solar panel on the roof of the car, which can only

provide enough power to run the ventilation system while the car is parked, to keep the

interior cooler in sunny warm conditions. For the U.S. market only the Prius Two, Three,

Four and Five were offered.

Even when the car is off and locked, these fans whir around, so when you step back

into it you don't need to crank up the power-hungry air conditioning. And the air-con system

on the 2010 Prius.

Nissan developed prototype in 2008 Nissan 1400 truck and the results indicate a

successful prototype and encouraging prospects for future development.The developed

prototype and give following results

1. In the exhaust gases of motor vehicles, there is enough heat energy that can be utilised

to power an air-conditioning system. Therefore, if air-conditioning is achieved

without using the engine’s mechanical output, there will be a net reduction in fuel

consumption and emissions.

Page | 33

2. The coefficient of performance of the absorption refrigeration systems is very low

compared to the vapor compression systems. The low COP value is an indication that

improvements to the cycle are necessary.

3. Size -The size of this system is more than vcrs. The space occupied by generator is

main limiting factor.

Page | 34

Conclusion

Chapter-8

Experimental study of an aqua-ammonia absorption system used for automobile air conditioning system, this system using the exhaust waste heat of an internal combustion diesel engine as energy source. The energy availability that can be used in the generator and the effect of the system on engine performance, exhaust emissions, auto air conditioning performance and fuel economy are evaluated. Because automotive air conditioning is one the most equipment that heavily uses CFC compounds and the leakage of CFCs from such air conditioners impact on the environment. The main purpose of this investigation to explore the feasibility of using waste energy to design the absorber and generation since these components are the most important components of absorption and they are directly influence the performance of the whole system. It has been found that the aqua -ammonia concentration effect the cooling capacity.

The estimated cooling load for the automobile found to be within acceptable ranges which are about 1.37 ton refrigeration. The obtained results show that the coefficient of performance (COP) values directly proportional with increasing generator and evaporator temperatures but decrease with increasing condenser and absorber temperatures. Measured values for generator, absorber, and evaporator and condenser temperature were recorded and the coefficient of performance of the system varied between 0.85 and 1.04. The main components of the absorption cycle were designed and fabricated for optimal performance and could be rapidly transfer to the industry, The system was found to be applicable and ready to produce the required conditioning effect without any additional load to the engine. The proposed system decreases vehicle operating costs and environmental pollution caused by the heating system as well as causing a lower global warming. The following conclusion can be drawn-

Performance of auto air conditioner using exhaust waste energy from diesel engine has been carried out in this investigation. It is evident that COP strongly depends on working conditions such as generator, absorber, condenser and evaporating temperature.The aqua-ammonia vapour absorption automobile air conditioner is an economically attractive concept for utilizing exhaust waste heat because most of the energy input comes from the heat available in the exhaust gases, with only small electric power used to operate the pump. The engine exhaust gas was confirmed as a potential power source for absorption automobile air conditioner system. In other words, the absorption refrigeration system may

be able to take advantage of the exhaust gas power availability and provide the cooling capacity required for automotive air conditioning.

Overall, carbon monoxide emission was decreased when the absorptionrefrigeration system was installed in the exhaust gas. So, changes in exhaust components concentration were a consequence of the major modifications in the exhaust system. The absorption cycle has the economic advantage of having few high precision components, thus reducing manufacturing costs.

The low efficiency, however, is a negative economic factor. AmmoniaAbsorption cycle, should be considered as a viable alternative to mechanical vapor compression cycle. Appreciable cooling load reduction can be realized by modification on the automobile body and the door and windows design.

With flexibility in operation, absence of compressor noise, very lowmaintenance and high reliability.

The waste heat energy available in exhaust gas is directly proportional to the engine speed and exhaustgas flow rates.

Feasibility study should made to decide the unit’s chances to be produced on commercial scales. Also, applying this project practically in Jordan, because it has many advantages from the pollution and economic point of view.

References

1. International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 National Conference on Emerging Trends in Engineering& Technology (VNCET-30 Mar’12) V.D.Patel , A.J.Chaudhari, R.D.Jilte , Theoretical and Experimental Evaluation of Vapour Absorption Refrigeration System,2012

2. Journal of Energy in Southern Africa, G Vicatos,J Gryzagoridis, A car air- conditioning system based on an absorption refrigeration cycle using energy from exhaust gas of an internal combustion engine, 2008

3. International Journal of Modern Engineering Research (IJMER) ,Manu.S, T.K.Chandrashekar, Theoritical Model of Absorber for Miniature LiBr-H2o Vapor Absorption Refrigeration System , 2012

4. Energy procedi, aKhaled AlQdah , Sameh Alsaqoor , Assem Al-Jarrah , Design and Fabrication of Auto Air Conditioner Generator Utilizing Exhaust Waste Energy from a Diesel Engine ,2011

5. Second International Conference on Emerging Trends in Engineering and Technology, ICETET-09, A C Deshpande, R M Pillai,Adsorption Air- Conditioning (AdAC) for Automobiles Using Waste Heat Recovered from Exhaust Gases ,2009

6. Zhong Ji-Xiang, Research on A Novel Air-condition System driven by combination of Exhaust Heat of Engine and Solar Energy,2009

7. The 2nd Joint International Conference on “Sustainable Energy and Environment (SEE 2006)”, 21-23 November 2006, Bangkok, Thailand, Shah Alam, A Proposed Model for Utilizing Exhaust Heat to run Automobile Air-conditioner, The 2nd Joint International Conference on SEE,2006

8. Khaled S. AlQdah Tafila Technical University Tafila, Jordan, Performance and Evaluation of Aqua Ammonia Auto Air Conditioner System Using Exhaust Waste Energy,2011

9. Nahla Bouaziz, Ridha Ben Iffa and Lakhdar kairouani, Performance of a water ammonia absorption system operating at three pressure levels,2011

10. R.H.L. Eichhorn - Eindhoven University of Technology , Waste EnergyDriven Air Conditioning System (WEDACS), 2009.

11. ASHARE Hand book, 2008

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Annexures

Adsorption air conditioning working h tt p : // w w w . y ou t ube. c o m / w a tc h? v = aM F -S T B1 8 X o

2010 Prius: Solar Powered Ventilation Systemhtt p:// www. yout ub e.c om/ watc h?v=Cc hHI y7J gvA

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