This document is a capstone project submitted by four students for their Bachelor of Technology degree in Mechanical Engineering. It outlines the development of a solar absorption domestic refrigeration system. Key components discussed include an absorber, pump, heat exchanger, generator, condenser, capillary tube, and evaporator. Experimental work was conducted to test the system and various calculations were performed to analyze heat transfer and efficiency. The project was completed under the guidance of a faculty member to fulfill degree requirements.

1. SOLAR ABSORPTION DOMESTIC REFRIGERATION
SYSTEM
CAPSTONE PROJECT
Submitted in Partial Fulfillment of the
Requirement for Award of the Degree
Of
BACHELOR OF TECHNOLOGY
In
MECHANICAL ENGINEERING
VIKAS TIWARI (11107080)
RAHISH KUMAR SAHA (11105204)
MOHAN LAL SAHU (11100839)
ANUPAM DWIVEDI (11105812)
Under the Guidance of
Mr. ASHISH KUMAR PATEL
DEPARTMENT OF MECHANICAL ENGINEERING
LOVELY PROFESSIONAL UNIVERSITY
PHAGWARA, PUNJAB (INDIA) -144411
2015

2. i
Lovely Professional University Jalandhar, Punjab
CERTIFICATE
I hereby certify that the work which is being presented in the Capstone
project/Dissertation entitled “SOLAR ABSORPTION DOMESTIC REFRIGERATION
SYSTEM” in partial fulfillment of the requirement for the award of degree of Bachelor
of technology and submitted in Department of Mechanical Engineering, Lovely
Professional University, Punjab is an authentic record of my own work carried out during
period of Capstone/Dissertation under the supervision of Mr. ASHISH KUMAR
PATEL(Asst. Prof.) Department of Mechanical Engineering, Lovely Professional
University, Punjab.
The matter presented in this dissertation has not been submitted by me anywhere for
the award of any other degree or to any other institute.
This is to certify that the above statement made by the candidate is correct to best of
my knowledge.
Date: ….. APRIL, 2015 Mr. ASHISH KUMAR PATEL
(Asst. Prof.)
Supervisor
The B-Tech Capstone project/ M-Tech Dissertation examination, has been held on
Signature of Examiner

3. ii
ACKNOWLEDGEMENT
The satisfaction that accompanies the successful completing of any task would be
incomplete without mentioning names of people whose ceaseless co-operation made the task
possible. Their constant guidance and encouragement plays a much important role in
successful completion of this Capstone project. Making capstone project at LPU gave a good
practical experience to us. We would like to express my regards to all my seniors & fellow
trainees who supervised us in one or another way. So, at the outset we express my deep sense
of gratitude to Mr. ASHISH KUMAR PATEL (Mentor) and other staff members who have
been the perennial source of inspiration and guidance in the completion of this project.

4. iii
TABLE OF CONTENTS
Contents Page No.
Certificate i
Acknowledgement ii
Abstract v
1. Introduction……………………………….………………….……1
2. Review of Literature………………………….…………….….…..3
3. Scope of the study……………………………….…….…….……..5
4. Objective and Hypothesis of the study…………….….….………..6
5. Research Methodology…………………………………….……....7
6. Components of Refrigeration……………………………………....8
6.1.1 Absorber…………………………………………………9
6.1.2 Pump…………………………………………………….9
6.1.3 Heat Exchanger…………………………………………10
6.1.4 Generator………………………………………………..11
6.1.4.1 Working of Generator………………………….11
6.1.5 Condenser………………………………………………12
6.1.6 Capillary tube…………………………………………..13
6.1.7 Evaporator……………………………………………...13
6.1.8 DC Battery……………………………………………..14
6.1.9 Solar system……………………………………………15

5. iv
7 Work plan with Timeline………………………………………..16
8 Expected Outcomes of the study………………………………..17
9. Experimental Work done………………………………………..18
9.1 Working……………………………………………………...18
9.2 Ammonia Water chart……………………………….………...21
9.2.1 Data obtained from graph………………………………22
9.3 Calculation…………………………………………….………24
9.3.1 Calculation of Heat…………………………………….24
9.3.2 Calculation of COP…………………………………….25
9.3.3 Calculation for Pump…………………………………..26
9.3.4 Calculation for Capillary tube………………………….27
9.3.5 Calculation for Heat Exchanger………………………..32
9.4 Specification of Components……………………………..……34
10. Result and Discussion………………………………………….37
11. Conclusion……………………………………………………..38
12. References……………………………………………………...39
13. Approved project topic in the prescribed format…………………40

6. v
TABLE OF FIGURE
List of figure Page No.
6.1 Absorber…………………………………………….…………….9
6.2 Centrifugal pump……………………………….………………..10
6.3 Heat Exchanger………………………………….……………….11
6.4 Generator………………………………………….……………...12
6.5 Condenser……………………………………….………………..12
6.6 Capillary tube…………………………………………………….13
6.7 Evaporator………………………………………………………..14
6.9a Solar panel………………………………………………………15
6.9b Components of solar power system……………………………..15
9.1 Circuit diagram VARS system…………………………………...20
9.2 Ammonia Water chart……………………………………………21
9.3 Ammonium hydroxide…………………………………………...36

7. vi
ABSTRACT
For past few decades, energy has played a prominent role in the development of
technology and economy. Energy has now become inevitable factor for production as well.
The objective of this project is to develop an environment friendly vapour absorption system.
Vapour absorption system uses heat energy, instead of mechanical energy as in vapour
compression system, in order to change the condition of refrigerant required for the operation
of the cycle. R 717(NH3) and water are used as working fluids in this system. The basic idea
of this project is derived from the solar heating panel to obtain heat energy, instead of using
any conventional source of heat energy. In this project various observations are done by
varying operating conditions related to heat source, condenser, absorber and evaporator
temperatures. The drawback of this system is that, it remains idle in the cloudy weather
conditions.
Keyword: - Absorber, Condenser, Capillary tube, Dc battery, Evaporator, Generator, Heat
exchanger, Pump, Solar panel

8. 1
CHAPTER-1
INTRODUCTION
Refrigeration is defined as the process of achieving and maintaining a temperature
below that of the surroundings, the aim being to cool some product or space to the required
temperature. One of the most important applications of refrigeration has been the
preservation of perishable food products by storing them at low temperatures. Refrigeration
systems are also used extensively for providing thermal comfort to human beings by means
of air conditioning.
The subject of refrigeration and air conditioning has evolved out of human need for
food and comfort, and its history dates back to centuries.
Vapour Absorption Refrigeration Systems (VARS) belong to the class of vapour
cycles similar to vapour compression refrigeration systems. However, unlike vapour
compression refrigeration systems, the required input to absorption systems is in the form of
heat. Hence these systems are also called as heat operated or thermal energy driven systems.
Since conventional absorption systems use liquids for absorption of refrigerant, these are also
sometimes called as wet absorption systems. Similar to vapour compression refrigeration
systems, vapour absorption refrigeration systems have also been commercialized and are
widely used in various refrigeration and air conditioning applications. Since these systems
run on low-grade thermal energy, they are preferred when low-grade energy such as waste
heat or solar energy is available. Since conventional absorption systems use natural
refrigerants such as water or ammonia they are environment friendly.
The development of refrigeration and air conditioning industry depended to a large
extent on the development of refrigerants to suit various applications and the development of
various system components. At present the industry is dominated by the vapour compression
refrigeration systems, even though the vapour absorption systems have also been developed
commercially. The success of vapour compression refrigeration systems owes a lot to the
development of suitable refrigerants and compressors. The theoretical thermodynamic
efficiency of a vapour compression system depends mainly on the operating temperatures.
However, important practical issues such as the system design, size, initial and operating
costs, safety, reliability, and serviceability etc. depend very much on the type of refrigerant
and compressor selected for a given application.
The power from the sun intercepted by the earth is approximately 1.8 ×1011
MW
which is much larger than the present consumption rate on the earth of all commercial energy
sources. Thus, in principle, solar energy could supply all the present and future energy needs
of the world on the continuing basis. This makes it one of the most promising of the

9. 2
unconventional energy sources. In addition to its size, solar energy has two other factors in its
favour. First unlike fossil fuels and nuclear power, it is an environmental clean source of
energy. Second, it is free and available in adequate quantities in almost all parts of the world
where people live. So it can prove very economical to use solar energy for refrigeration and
air conditioning system. The change done in this project is the change in the mode of
obtaining energy for generator in vapour absorption system. By producing an adsorption
refrigeration system we are not only cutting down the energy costs but also preserving our
environment. This refrigeration system doesn’t use any of the CFCs so our ozone layer is
safe. Greenhouse gases and their damaging effects on the atmosphere have received increased
attention following the release of scientific data by United Nations Environment Programme
and World Meteorological Organization that show carbon dioxide to be the main contributor
to increased global warming. The domestic refrigerator-freezers operating on alternative
refrigerants such as HFC-134a, contribute indirectly to global warming by the amount of
carbon dioxide produced by the power plant in generating electricity to operate over a unit
over its lifetime. This contribution is nearly 100 times greater than the direct contribution of
the refrigerant alone.
Moreover, approximately 62 million mew units are being manufactured worldwide
every year, and hundreds of millions are currently in. use. It is anticipated that the production
of refrigerator-freezers will substantially increase in the near future as a result of the
increased demand, especially in the developing countries. Therefore, in response to global
concerns over greenhouse resorts are being made to produce refrigerator-freezers with low
energy consumption.

10. 3
CHAPTER-2
LITERATURE REVIEW
An extensive review of the literature has been done on vapour absorption
refrigeration. The main idea was to have possible future direction of research, with the aim of
obtaining fundamental understandings of solar absorption systems and to gain useful
guidelines regarding designs parameters as applied in both air-conditioning and refrigeration.
A large number of researchers have carried out research in the field of vapor absorption
refrigeration using different working pairs and the most common working pairs are LiBr-
H2O and NH3-H2O.
1. Solar absorption refrigeration (October 30, 1990)
Tyagi carried out the detailed study on aqua-ammonia VAR system and
plotted the coefficient of performance, mass flow rates as a function of operating
parameters i.e. absorber, evaporator and generator temperatures. He showed that COP
and work done are the function of evaporator, absorber, and condenser and generator
temperature and also depends on the properties of binary solution.
2. Aqua-ammonia absorption refrigeration (June 24, 1994)
Gogus showed the irreversibility’s in components of aqua-ammonia
absorption refrigeration system by second law analysis. They calculated the
dimensionless exergy loss of each component, exergetic coefficient of performance,
coefficient of performance and circulation ratio for different generator, absorber
evaporator and Condenser temperature. They concluded that aqua-ammonia system
needs a rectifier for high ammonia concentrations but it will lead to additional exergy
loss in the system. They observed the highest exergy loss in evaporator followed by
absorber. I was also concluded that the dimensionless total exergy loss depends on
generator temperature.
3. Ammonia water absorption refrigeration system (June 21, 2005)
Sozen studied the effect of heat exchangers on the system performance in an
ammonia water absorption refrigeration system. Thermodynamic performance of the
system is analyzed and the irreversibility’s in the system components have been
determined for three different cases. The COP, circulation ratio, and non dimensional
exergy loss of each component of the system is calculated. They concluded that the
evaporator, absorber, generator, mixture heat exchanger and condenser show high
non-dimensional exergy losses. They also concluded that using refrigerant exchanger
in addition to mixture heat exchanger does not increase the system performance.

11. 4
4. Solar water cooler (August 21, 2007)
Fernandez-Seara and Vazquez studied the optimal generator temperature in
single stage ammonia – water absorption refrigeration system. They studied the
behavior of this temperature on thermal operating conditions and system design
parameters. They carried out study based on parametric analysis by developing a
computer program and based on the results designed a control system. The control
system developed maintains a constant temperature for the space to be refrigerated
and also control the optimal temperature in the system generator.
5. Vapour absorption refrigeration (May 12, 2008)
Yamankaradeniz performed calculations for a 10kW cooling load system. The
evaporator and condenser temperature was taken as 4oC and 38oC respectively. The
generator temperature was taken as 90oC. Effectiveness of solution heat exchanger
was assumed as 0.5 and efficiency of pump was assumed equal to 0.9. They
concluded that entropy generation of the generator is an important fraction of the total
entropy generation in the system basically due to the temperature differences between
25 the heat source and the working fluid and in order to decrease the total entropy
generation of the system, the generator should be developed.

12. 5
CHAPTER-3
SCOPE OF THE STUDY
The prices of energy have been increasing exponentially worldwide. Industrial
Refrigeration is one of the most energy consuming sector. What if a refrigeration system is
designed which uses no energy or minimal amount of energy?
In the present times, the conventional sources of energy are depleting rapidly. Then these
sources may not available in future. This demands increase the price of conventional energy.
The only way to reduce the consumption of these sources of energy as well as to fulfil the
demands of the ever increasing population is shift to the renewable source of energy, such as
solar energy.
By producing an adsorption refrigeration system we are not only cutting down the energy
costs but also preserving our environment. This refrigeration system doesn’t use any of the
CFCs so our ozone layer is safe.
This invention can improve refrigerating unit, raise coefficient of performance, reduce
energy cost of refrigerating unit and has notably social and economic benefit.

13. 6
CHAPTER-4
OBJECTIVE & HYPOTHESIS OF THE STUDY
The main objective of Solar Refrigerator system is given below-
 To improve the COP of the adsorption/absorption refrigerator to make it more
attractive for usage.
 To reduce the size of the assembly by making it more compact.
 Cost is the biggest barrier in implementation of absorption refrigeration. We aim to
minimize it as far as possible.
 The absorption/adsorption refrigeration system is too bulky. Its weight reduction is
also one of the aims. It can be reduced by using other materials.
 Till date absorption refrigeration is limited for industrial purposes. We aim to make it
available for mass rural use as stated above in small capacities by using solar
absorption.

14. 7
CHAPTER-5
RESEARCH METHODOLOGY
1. Selection of the project as it has vast scope in future.
2. Selection of raw material for different component.
3. Design and selection of different components.
4. Setup of base of the whole arrangement was done.
5. Different components of the system were prepared.
6. Mathematical modelling of generator, absorber, heat exchanger and condenser was done.
7. Assembly of different component were done by brazing.
8. Ammonia was made to flow through the system.
9. Observations were taken.
10. Calculation and successful results were obtained.

15. 8
CHAPTER-6
COMPONENTS USED IN SOLAR ABSORPTION
REFRIGERATION SYSTEM
I. ABSORBER
II. PUMP
III. HEAT EXCHANGER
IV. GENERATOR
V. SOLAR PANEL
VI. CONDENSER
VII. CAPILLARY TUBE
VIII. EVAPORATOR
IX. DC BATTERY, INVERTER
The detailed explanation given below-
6.1.1 ABSORBER
Absorber in absorption system is used to store the mixture of water and ammonia in
particular proportion. It is actually a box which has three ports. First port connects the pump
to the absorber. Second port connects the capillary tube to the absorber. Third port connects
the evaporator to the absorber. It is kept at the lowest position in the system.
Heat is dissipated from the absorber as shown in the below diagram. It is important
that the temperature of absorber should be kept low so that the vapour of ammonia can get
mixed with the water, coming from the generator through throttle valve, thus producing the
aqua ammonia solution. This aqua ammonia solution is then pump to the generator with the
help of pump as shown in the above diagram.

16. 9
Fig 6.1 Absorber
6.1.2 PUMP
A pump is a device that moves fluids (liquids or gases), or sometimes slurries, by
mechanical action. In the absorption system, the compressor is replaced by an absorber which
dissolves the refrigerant in a suitable liquid, a liquid pump which raises the pressure and a
generator which, on heat addition, drives off the refrigerant vapour from the high-pressure
liquid. Some work is needed by the liquid pump but, for a given quantity of refrigerant, it is
much smaller than needed by the compressor in the vapour compression cycle. In an
absorption refrigerator, a suitable combination of refrigerant and absorbent is used. The most
common combinations are ammonia (refrigerant) with water (absorbent). Generally in the
absorption system pump work is negligible.

17. 10
Fig 6.2 centrifugal pump
6.1.3 HEAT EXCHANGER
A heat exchanger is equipment built for efficient heat transfer from one medium to
another. The heat exchanger provided between the pump and the generator is used to cool the
weak hot solution returning from the generator to the absorber. The heat removed from the
weak solution raises them temperature of the strong solution leaving the pump and going to
generator. This operation reduces the heat supplied to the generator and the amount of
cooling required for the absorber. Thus the economy of the plant increases.
Generally shell and tube type heat exchanger are used for better effectiveness, where
hot and cold fluid flow in opposite to each other.
Figure of heat exchanger is given next,

18. 11
Fig 6.3 Heat exchanger
6.1.4 GENERATOR
This is unit of a system which separates the dissolved ammonia from the water-
ammonia solution. It has a heating coil inside it. The purpose of heating coil is to heat the
mixture up to a boiling temperature of ammonia solution. Since boiling point of ammonia
solution is lower than the boiling point of water, the ammonia gets converted into vapour and
water remains in its liquid state. It is not possible to separate ammonia solution from water
completely; therefore we use rectifier for achieving 99 percent separation of ammonia vapour
from solution.
6.1.4.1 Working of Generator-
In generator we have a coil through which current is passed. Due to current heat is
generated in the generator. The temperature is maintained so as to vaporize the ammonia and
thus separating ammonia from strong solution of aqua-ammonia. For getting 99 percent of
pure ammonia in form of vapour, we are required to use analyser and rectifier. In present
project we are using only simple generator without any analyser. Electricity required by
heating coil we be obtained from the solar panel. Generator has pressure greater than
absorber. Therefore it is required to increase the pressure of the strong aqua-ammonia
solution so that it can be transferred to the generator, and this is obtained with the help of the

19. 12
liquid pump. Once the strong aqua-ammonia solution reaches the generator, it is heated and
the liquid ammonia present in strong aqua-ammonia solution is converted into vapour. These
ammonia vapours then move towards the condenser due to pressure difference between the
generator and condenser. The weak solution, after the separation of ammonia vapour, is then
transferred to the absorber.
Fig 6.4 Generator
6.1.5 CONDENSER
A condenser is a device or unit used to condense a substance from its gaseous to
its liquid state, typically by cooling it. In so doing, the latent heat is given up by the
substance, and will transfer to the condenser coolant. Condensers are typically heat
exchangers which have various designs and come in many sizes ranging from rather small
(hand-held) to very large industrial-scale units used in plant processes.

20. 13
Fig 6.5 Condenser
6.1.6 CAPILLARY TUBE
Capillary tube is an expansion device having very narrow diameter. This device
connects between condenser and evaporator to reduce the pressure or for expansion process
at constant enthalpy. Due to this refrigerant comes to saturation states and able to extract heat
from cabin in evaporator.
Another capillary tube is used in between generator and absorber in vapour absorption
refrigeration system for the same purpose to reduce the pressure.
Fig 6.6 Capillary tube

21. 14
6.1.7 EVAPORATOR
An evaporator is a device used to turn the liquid into its gaseous form. The liquid is
evaporated, or vaporized, into a gas.
In evaporator low temperature, low pressure refrigerant extract the heat from the cabin or
system which we have to cool.
It is in the evaporators where the actual cooling effect takes place in the refrigeration.
The evaporators are heat exchanger surfaces that transfer the heat from the substance to be
cooled to the refrigerant, thus removing the heat from the substance. The evaporators are used
for wide variety of diverse applications in refrigeration and air conditioning processes and
hence they are available in wide variety of shapes, sizes and designs.
Fig 6.7 Evaporator
6.1.8 DC BATTERY
Direct current is the unidirectional flow of electric charge. Direct current is produced
by sources such as batteries, thermocouples. Here battery is used to power the pump and

22. 15
another battery and inverter set up to powered the heater inside generator. Battery is
charged by solar system, which produces dc power and this dc power converted into ac by
using inverter.
6.1 .9 SOLAR SYSTEM
A solar cell, or photovoltaic cell, is an electrical device that converts the energy
of light directly into electricity by the photovoltaic effect. It is a form of photoelectric cell,
defined as a device whose electrical characteristics, such as current, voltage, or resistance,
vary when exposed to light. Solar cells are the building blocks of photovoltaic modules,
otherwise known as solar panels.
Fig 6.9a Solar panel
As solar radiation is irradiance on solar panel dc power is generated by photovoltaic effect
and this power is regulated or controlled by regulator. For ac supply this dc power must be
change into ac power by using inverter.

23. 16
Fig 6.9b components of solar power system

24. 17
CHAPTER-7
WORK PLAN WITH TIMELINE
S.N ACTIVITY START
DATE
END DATE
1. Selection of design parameter of the project 16th
march 20th
march
2. Selection of condenser as per requirement 21st
march 21st
march
3. Selection of evaporator as per requirement 23rd
march 23rd
march
4. Calculation and selection of pump 24th
march 27th
march
5. Calculation and selection of capillary tubes 25th
march 2nd
April
6. Preparation of absorber and generator box 24th
march 26th
march
7. Calculation and preparation of heat exchanger 28th
march 5th
April
8. Calculation of heat required and selection of heater 1st
April 4th
April
9. Selection of battery, inverter 5th
April 5th
April
10. Assembly of all components of project in a circuit 7th
April 12th
April
11. Observation of project 15th
April 15th
April

25. 18
CHAPTER-8
EXPECTED OUTCOMES OF THE STUDY
The outcome of the project will be a working prototype of an NH3/water
based absorption refrigerator designed for rural application.
The construction of the assembly is relatively simple and we are sure will not take much
time. Keeping the objective of the project in mind we will be stressing upon the design and
idea part to enhance the learning experience and improving the efficiency and portability of
the system.
As per our design expected capacity of the refrigerator is 0.15TR and expected COP will be
1.53.

26. 19
CHAPTER-9
EXPERIMENTAL WORKDONE
9.1 WORKING
1-2
Solution of ammonia is heated to generate ammonia vapour, which is transferred to the
condenser. In condenser ammonia vapour is cooled by air and vapour ammonia changes to
ammonia liquid.
2-3
After condenser liquid ammonia is passed through narrow capillary tube where pressure
reduces from 14bar to 5bar.
3-4
Saturated liquid ammonia at low pressure comes to evaporator, where it extract the heat from
cabin or system which we have to cool. After extracting heat liquid ammonia become vapour
again.
4-5
Ammonia vapour is then transferred to absorber where it is absorbed by water as absorber
and form strong solution of ammonia called ammonium hydroxide.
5-6
Strong solution of ammonia then pumped to generator by pump.
6-7
Heat exchanger connected between absorber and generator extracts the heat of coming weak
solution and give to strong solution.

27. 20
7-1 and 7-8
Strong solution coming from absorber is then heated up to 90 degree Celsius. Ammonia
vapour then passes through rectifier and transferred to condenser again.
And weak solution of ammonia comes back to absorber again.
8-9
In heat exchanger heat of weak solution transferred to strong solution of ammonia so that it
will preheat before generator.
9-10
High pressure refrigerant in generator is reducing to low pressure by another capillary tube
before absorber.

28. 21

29. 22
9.2AMMONIA WATER CHART

30. 23
9.2.1 FROM GRAPH OBTAINED DATA
Calculation for Pump:-
State 1- saturated vapour state at =14 bar, C=1
= C, =1700 kj/kg
State 2- saturated liquid at =14 bar, C=1
= C, =500kj/kg
State 3- isenthalpic process: - at C=1, =5bar
= C, = =500 kj/kg
State 4- saturated vapour at =5 bar, C=1
=1660 kj/kg
State 5- From absorber (strong solution) at P=5bar
= C, C=0.53, =70 kj/kg
State 6- After pump, negligible enthalpy change
Therefore =
State 7-after heat exchanger, =200kj/kg
State 8-P=14 bar, =305 kj/kg
State 9- =150 kj/kg
State 10- = =150 kj/kg
=-190 kj/kg
=1790 kj/kg
(Weak) = 0.42

31. 24
(Strong) = 0.53
Concentration:-
0.98
0.42
0.53
Pressure:-
Bar (Condenser pressure)
5 Bar (Evaporator pressure)
Mass flow rate:-
0.0271 kg/min.
0110 kg/min.
0.137 kg/min.

32. 25
9.3 CALCULATIONS
Refrigerant: - (Ammonia)
Boiling point = C
Melting point = C
Specific gravity= 0.91
Solubility in o = 47% at C
31% at C
18% at C
Absorbent: - o (water)
Boiling point = C
Density = 1000kg/m3
9.3.1 Calculation of heat
Assume capacity=0.15TR
Heat extracted by Evaporator:-
= 0.0271 kg/min.
= ( ) = 0.15 210 = 31.5 kj/min.
Heat removed by condenser:-
= ( ) =32.52 kj/min.
Heat removed on absorber:-
= ( ) =50.135 kj/min.
Heat given in Generator:-

33. 26
= ( ) =53.658 kj/min.
Again =894.3 watt
Heater of 894.3 watt is required for generator.
9.3.2Coefficient of performance:-
Actual COP: - = = 0.587
Theoretical COP: - = = 1.53
At absorber
By using equations
Or,
&
Then,
-----eq. (1)
& 0.0265= --------eq. (2)
From eq. (1) & eq. (2)
We get,
=0.137 kg/min.
=0.110 kg/min.

34. 27
For :-
By using formula
&
From the refrigeration table
At 5 bar = 0.001096
At 5 bar = 0.00158
=0.00127 /kg
= 70+ = 71.104 kj/kg
9.3.3 Power consumed by pump:-
P =
Then, P = = 0.0025 kW
P=2.52 watt
Assume efficiency =0.7
Then Power required to pump =3.6 watt
9.3.4 Tube design:-Capillary
For capillary 1
Diameter of capillary tube, D = 0.914 mm

35. 28
Area of cross section, A = 0.000000486
From the refrigeration table
AT 14 BAR
Viscosity of ammonia
=116 Ns/
Specific volume of ammonia
=1.71
Mass flow rate of ammonia
=0.0271kg/min. = 0.0004516kg/sec.
G = = 927.88
Then velocity at entrance of capillary tube
=G =1.585 m/sec.
Now, Reynold number
= =6295.18 ….eq (i)
Then, friction factor
= =0.036 ….eq (ii)
Enthalpy at entrance of the capillary tube
=357.25kj/kg
AT 5 BAR
From refrigeration table

36. 29
Various parameters of ammonia at liquid and vapour states
= 171.63 kj/kg
= 1269.45 kj/kg
= 0.174 Ns/
= 0.00916 Ns/
Now,
…..eq (a)
Dryness fraction
X= 0.146
Now, at exit of capillary tube
Similarly by using formula as eq (a)
Specific volume
Velocity at exit
44.18 m/sec
Viscosity:-
Similarly by using formula as eq (a)
Ns/
And friction factor

37. 30
By using equation i and ii
Now,
Change in pressure = P0-P1
= 9 Ns/
Change in velocity = u1-u0
=42.6 m/s
Average velocity
u= =22.88 m/sec.
Average fiction factor
f= =0.037
Now, Length of capillary tube
By using formula,
L= =1.72m.
L = 5.6 ft
For capillary 2
=0.11kg/min. = 0.00183kg/sec.
G = 3771.6 kg/m2s
From refrigeration table
At :-

38. 31
Specific volume
=0.00121
Then velocity at entrance
= G =4.5 m/sec
Viscosity,
= 0.45 Ns/ , 0.098 Ns/
At concentration 0.42
=0.42 ( ) +0.58 ( )
= 0.302 Ns/
And, friction factor
By using equation i and ii
=0.032
At 4 bar & at concentration 0.42
From refrigeration table
Specific volume
= 0.00158 , = 0.001
0.42 ( ) +0.58 ( ) = 0.0012436
Then velocity at exit
= G = 4.7 m/sec
Viscosity.
= 0.153 Ns/ , 1 Ns/

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Then, by using above equation
= 0.644 Ns/
And friction factor
By using eq i and ii
= 0.038
Now,
Change in pressure P0-P1 =9bar
Change in velocity
=0.2 m/s
Average velocity
u= =4.6 m/sec
Average friction factor.
f = 0.035
Then Length of capillary tube
By using formula
L= =2.3m. =7.5ft
9.3.5 Design of heat exchanger:-
From our design data
Temp of hot fluid at inlet

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Temp of hot fluid at exit
Temp of cold fluid at exit
Temp of cold fluid at inlet
Now, Q1= Th1-Tc1
Q2= Th2-Tc2
For calculation of LMTD
By using equation
Qm = (Q1- Q2)/lnQ1/Q2
Then = =294.5 k
Heat transferred in heat exchanger,
By using formula
Q = =300 watt
Taking Overall heat transfer coefficient of ammonia solution
U = 80 w/m2.degree
Then,
Q = UA
300 = 80
Length of pipe inside heat exchanger,
l=1.6 m.

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9.4 SPECIFICATION OF PARTS OF THE SYSTEM
1. ABSORBER -
Specification:
Length= 10.16 cm, Breadth= 10.16 cm, Height= 10.16 cm.
Material used: Galvanized iron.
Volume: (1048.77) cm^3
2. GENERATOR-
Specification:
Length= 38.1 cm, Diameter 12.7cm
Material used: Galvanized iron.
Volume: (4826.4) cm^3
It has three ports.
3. CONDENSER
Specification:
Length= 38 cm, Width= 38 cm
Number of turns= 9
Outer diameter of condenser pipe= 5.5mm
4. A. CAPILLARY TUBE
Specification:
Length=1.72 m
Outer diameter= 0.914mm

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B. CAPILLARY TUBE
Specification: Length= 2.3 m
Outer diameter=0.914mm
5. PUMP
Type: Centrifugal pump.
Specification: 4 W, 12V DC
6. Evaporator
Type: evaporator with cabin
Specifications:
Length=76cm, breadth=45cm, height= 25cm
Pipe diameter= 6mm
7. Heat exchanger
Type: Shell and tube
Length =12.7 cm
Inner dia. of shell= 7.6 cm
Outer dia. of shell= 10 cm
Length of pipe= 1.6 m
8. Heater
Type: immersion rod
Power= 500watt

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9. Battery 1
Specification: 12volt, 7Amp
10. Battery 2
Specification: 12volt, 40Amp
11. REFRIGERANT
Quantity: 1 Litre
Type: R-717(Ammonia Hydroxide- (50%-60%) concentration)
Specific gravity=0.91
Fig 9.1 ammonium hydroxide

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CHAPTER 10
RESULTS & DISCUSSION
As calculated earlier, the heat input required to run the 0.15TR vapour refrigeration
system, for the operating conditions design is about 900 watt.
For this system the coefficient of performance is also calculated. The result can be
summarized as
 Condenser pressure : 14 Bar
 Evaporator pressure : 5 Bar
 Heat input required : 900 watt
 Power of solar panel : 100watt
 Theoretical COP : 1.53
 Actual COP : 0.58
 Evaporator temp : 10 – 20 degree Celsius
The natural cooling arrangement was sufficient. Condensing temperature averaged at 37
degree Celsius
The cold box temperature increased over 10 °C and up to 20 °C during the day phase, thus
the aim of maintaining low temperatures in the chamber was not attained. This comes from
the higher heat gain of the box than expected. An improved box of lower heat losses must be
built in order to improve the results, especial the connection between the condenser and the
evaporator.
Final analysis shows that the process of solar absorption-assisted cooling could be an
alternative for vapour compression system for cold room applications.

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CHAPTER 11
CONCLUSION
This project solar powered vapour absorption refrigeration system is operated by low
grade solar energy, AC supply or any other unconventional low grade energy, so its running
cost will be less. Mainly this project is done for those rural areas where electricity is limited
and for the outside city playground where players can drink cold water.
This project is different is different from today’s refrigerator because refrigerator is normally
run by vapour compression system as high grade energy, which become heavy and bulky due
to compressor used.
By producing an adsorption refrigeration system we are not only cutting down the
energy costs but also preserving our environment. This refrigeration system doesn’t use any
of the CFCs so our ozone layer is safe.

46. 39
REFERENCES
 www.iaeng.org/publication/WCE2012/WCE2012_pp2016-2020
By VK Bajpai - 2012.
 www.ijetae.com/files/Volume4Issue9/IJETAE_0914_64
By K Karthik.
 www.students.iitk.ac.in/ge3/ART%20PI%20copy
By IIT Kanpur.
 www.ijates.com/images/short_pdf/1396856289_P10-16.pdf
By International Journal of Emerging Technology and Advanced engineering
September 2014.
 “REFRIGERATION AND AIR CONDITIONING” By C P Arora.
Tata McGraw-Hill Education, 01-Jul-2001
 “REFRIGERATION AND AIR CONDITIONING” By P L Ballaney
Khanna, 2005.

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APPROVED PROJECT TOPIC IN THE PRESCRIBED
FORMAT

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