The document describes the design and performance analysis of an absorption heat transformer (AHT) using the first law of thermodynamics. The AHT uses industrial waste heat at 90°C to enhance the temperature in the absorber. The COP of the 2kW system is 0.4528 while the Carnot COP is 0.75. The absorber, generator, condenser, and evaporator are designed as shell and tube heat exchangers, while the solution heat exchanger is designed as a single pass annular tube heat exchanger. Equations for heat and mass transfer, circulation factor, COP, and heat exchanger design are presented to model and size the components of the AHT.

1. 1
Proceedings of the 23rd National Heat and Mass Transfer Conference and
1st International ISHMT-ASTFE Heat and Mass Transfer Conference
IHMTC2015
17-20 December, 2015, Thiruvananthapuram, India
IHMTC2015- 234
DESIGN AND PERFORMANCE ANALYSIS OF ABSORPTION HEAT TRANSFORMER USING
FIRST LAW OF THERMODYNAMICS
1
Navneet,
3
Mahesh Kumar,
4
Pankaj Khatak
Department of Mechanical Engineering
Guru Jambheshwar University of Science and
Technology, Hisar (Haryana)
1
navneet.rohilla@rocketmail.com
2
Gulshan Sachdeva
Department of Mechanical Engineering
National Institute of Technology,
Kurukshetra (Haryana)
gulshan4you@gmail.com
ABSTRACT
This paper addresses the performance and design of
various heat exchangers employed in a 2kW absorption
heat transformer (AHT), which is used to enhance the
temperature of the waste heat. The LiBr-H2O is the
working fluid in this system. The necessary heat and mass
transfer equations used in the mathematical model of AHT
are solved by using Engineering Equation Solver (EES).
COP of the system is found to be 0.4528 while the Carnot
COP is 0.75. Performance of the AHT is analyzed while
varying the temperature of absorber, evaporator, condenser
and generator. The sizing of the heat exchangers can help
the design engineers in manufacturing and experimenting
AHT. The absorber, generator, condenser and evaporator
are designed as shell and tube heat exchangers while the
solution heat exchanger is designed as a single pass
annular tube heat exchanger.
Keywords: absorption heat transformer, COP, heat
exchanger, design
INTRODUCTION
Almost every industrial process requires thermal
energy and this energy is mainly provided by the burning
of the fossil fuels. After carrying out the processes in
industries, heat is rejected to the surroundings as waste
heat with its temperature varying from 40°C to70°C, ref.
K. P. Tyagi [1]. Upgrading this waste heat at low
temperature to higher temperature can be a step towards
the sustainable development of any nation as the increase
in the quality of heat makes it possible to use it in other
applications. It can be achieved by using absorption heat
transformer with minimum consumption of high grade
energy i.e. electricity and low maintenance cost.
Absorption heat transformer consists of generator,
absorber, evaporator, condenser and expansion valve
similar to the vapor absorption refrigeration system
(VARS). But unlike the vapor absorption refrigeration
system, the absorber & the evaporator are at high pressure
and the generator & the condenser are at low pressure.
Therefore, a liquid pump is used to increase the pressure of
the condensate to travel from condenser to the evaporator
in AHT whereas in VARS, an expansion valve is used to
reduce the pressure and temperature of the condensate
before going into the evaporator. Working of both the
systems is same but due to these differences in the two
systems, the desired high temperature is available in the
absorber of AHT, whereas the low temperature is
maintained in the evaporator of VARS.
Broadly the research work carried out in the field of
absorption heat transformers can be divided into two
categories. The first is based on the thermodynamic
analysis of the AHT using different working fluid pair e.g.
Water–Lithium Bromide (H2O-LiBr), Tri-Fluoro Ethanol &
N-Methy1-2-Pyrrolidone (TFE-NMP), Di-Methyl Ether
&Tetra Ethylene Glycol (TFE-E181) etc. This includes the
work of Best et al. [2], Zongchang et al. [3], Xiadong et al.

2. 2
[4] etc. Second category deals with the research on the
optimization of the state points and the enhancement of the
system performance by varying the operating parameters
This category includes the work of Tarun et al. [5], George
et al. [6], Rivera et al. [7], Zebbar et al. [8] etc. The third
category includes the study on the use of AHT in various
applications like desalination etc. The research works of
sekar et al. [9], Huicochea et al. [10], Rosenberg et al. [11],
and Gomri [12, 13] etc. fall in this section.
From available literature, it is concluded that a
considerable amount of research work is carried out on
AHT to analyze its performance by first/second law of
thermodynamics. But a little work is available on the sizing
of the components of AHT and its variation with the
operating parameters of the system. So, present work aims
to develop the thermodynamic model of AHT to predict its
performance and size of the various heat exchangers used
in the system.
DESCRIPTION OF THE SYSTEM
Industrial waste heat is channelized to heat the water
which is used as an external fluid to provide heating in the
evaporator and generator as shown in Fig.1. The
temperature of the hot water supplied to the evaporator and
generator is assumed to be 90°C. The heat supplied by the
hot water in the evaporator produce refrigerant vapor
(water) which is absorbed in the absorber by the Water-
LiBr solution. The heat produces during the exothermic
absorption process and the temperature is found to increase
in the absorber. This high temperature heat produced in the
absorber is the desired effect. The solution gets weak in
terms of LiBr after absorbing water vapor from the
evaporator and this weak solution travel to the generator
through the solution heat exchanger and pressure reducing
valve. In generator, hot water is supplied externally and the
refrigerant (water) is vaporized from it and is passed to the
condenser. After condensation, the refrigerant (water) is
pumped to the evaporator. The remaining solution in the
generator, now in a strong state of LiBr, is pumped to the
absorber through solution heat exchanger and the cycle
continues. Thus, the AHT has the unique capability of
raising the temperature of heat with negligible amount of
electrical energy consumption in the pump. A counter flow
heat exchanger between the weak and strong solutions is
used to increase the performance of AHT. A temperature
lift of 30°C is obtained in the present AHT.
ASSUMPTIONS AND MODELLING
The following assumptions have been made to
develop the mathematical model of the system as under:
FIGURE 1. ABSORPTION HEAT TRANSFORMER
 Isenthalpic process occurs in the pressure reducing
valve.
 The pressure drop due to friction in the connecting
pipes and in the heat exchangers is neglected.
 There is no heat loss to the environment from the
system due to poor insulation.
 The refrigerant leaves the evaporator and condenser
in saturated state.
 The pump work is neglected.
The mass and energy equations in its general form are
written as under:
Mass balance,
= 0; = 0 (1)
Energy balance,
+ + ℎ = 0 (2)
These governing equations are modified for all the
components of AHT as in ref. Tarun et al. [5]. The set of
equations obtained for the various components contains a
large number of dependent variables which make them
non-linear. These non-linear equations are solved in EES.
The performance indicators of AHT are based on energy
analysis and are computed as follows:
Circulation factor (f) is the ratio of weak solution exiting
from the absorber to the total mass flow rate of refrigerant.
In terms of mass concentration it can be obtained as
= /(x − x ) (3)
PRV
Hot Water Water
Water at
desire Hot Water
Work given to
Pump
9
5
6
7
1
4
3
2
1
Evaporator
Condenser
Pump 1
Generator
Absorber
SHX
Pump 2
Waste Heat Source
8

3. 3
where x is the concentration of LiBr in the solution.
The coefficient of Performance ( ) of AHT is defined
as the ratio of amount of heat available in the absorber to
the total heat supplied to the system. Numerically it is
expressed as
= /( + ) (4)
Carnot COP of the system is given by
COP = (T − T ) ∗ T /(T − T ) ∗ T (5)
DESIGN OF HEAT EXCHANGERS
Absorber, generator, condenser and evaporator are
designed as shell and tube heat exchanger as in ref
Bakhtiar et al [14] whereas solution heat exchanger is
designed as single pass annular tube counter flow heat
exchanger as in ref Florides et al [15]. After evaluating the
amount of thermal load on each component, area of that
component can be found using Eqn. 6 provided U and
LMTD is available.
= ∗ ∗ (6)
where, Q = amount of heat exchanged in the component
U = overall heat transfer coefficient
A = area of heat exchanger
LMTD = logarithmic mean temperature difference
Over all heat transfer coefficient can be found as in ref
Samant [16]
1
1 1
ln
2
o o o o
i o
i i i i o
U
D D D D
F F
D h D k D h

           
              
           
(7)
where Fo and Fi are the fouling factors for outside and
inside tube surface respectively and their values are 9E-6
m2
°C/kW as in ref Howell et al [17]. The Do and Di are the
outside and inside diameters of tubes respectively and are
fixed for each heat exchanger.
The material of tubes is taken as copper and value of
thermal conductivity is considered as 383.2 W/m°C as in
ref Ozisik et al [18].
External fluid, which is assumed to be turbulent, flows
inside the smooth tubes of the heat exchanger. Internal
convective heat transfer coefficient (hi) for each heat
exchanger is calculated using Petukhov – Popov relation as
given in Eqn. 8 as in ref Kreith et al [19].
=
∗ ∗
∗( )
( )
∗( )
(8)
Where = ( . ∗ ( ) − )
= + . , and = . + (
.
)
Eqn. 8 is valid for the range of Reynolds numbers <
< 5 × and Prandtl numbers . < < 2000.
The Petukhov – Popov equation agrees within ±5% with
the experimental results for the specified range as in ref
Florides et al [15]. After getting the Nusselt number by
using the Eqn. 8, for each heat exchanger can be
determined by the following equation:
=
∗
(9)
It is to be noted that there are different conditions on the
outer surface of the tubes of different heat exchangers, so
outside heat transfer coefficient (ho) is calculated
separately for each heat exchanger as explained further.
After knowing both the inside and outside convective heat
transfer coefficients, the overall heat transfer coefficient is
found by using Eqn. 7 which is used to find the surface
area of the heat exchanger. Then the length of the tubes (L)
of each heat exchanger is found by using the following
equation.
=
. ∗
(10)
Absorber
Absorber provides the desired useful heat at elevated
temperature. For designing the absorber, outside ( ) and
inside ( ) tube diameters are taken as 19.05mm and
16.91mm respectively. The temperature of the external
fluid entering into the absorber is 80°C. It takes heat from
the absorber and leaves it at the temperature of 110°C.
Formulation provided by Andberg et al. [20] is used for
calculating the outside heat transfer coefficient (ho) and is
given by:
ℎ = 0.3 ∗ .
∗ ∗ [1.5 ∗ μ ∗
∗
]( )
(11)
Here FL is flow rate per unit length of tube.
Condenser
In condenser, refrigerant vapor change its phase to
liquid by rejecting heat to the external fluid entering at
30°C. External fluid leaves the condenser at the
temperature of 35°C after taking the latent heat of the
refrigerant. For designing the condenser, outside ( ) and
inside ( ) tube diameters are assumed to be 15.87mm and
13.84mm respectively. Nusselt’s analysis [21] of
condensation is used for calculating the outside heat
transfer coefficient (ho) and is given by following equation.
ℎ = 0.725[
∗ ∗( )∗ ∗
∗( )∗
] .
(12)
In Eqn. 12, and are the density of water and steam at
the condenser temperature. μ is the dynamic viscosity of
water at condenser temperature and is mean
temperature of inlet and outlet temperature of external fluid

4. 4
TABLE 1: PREDICTED DESIGN PARAMETERS
of condenser. ℎ is the enthalpy of wet steam and is the
thermal conductivity of water at the condenser temperature
Generator
The inside and outside diameter of the tubes are
16.92mm and 19.05mm respectively. External water enters
at the temperature of 90°C and leaves it at 85°C. Jakob and
Hawkings [22] correlation for nucleate boiling is used for
calculating outside heat transfer coefficient (ℎ ) as given
by the following equation.
ℎ = 1042 ∗ ( − )( )
∗ ( ) .
(13)
In Eqn. 13, is the saturation pressure at the condenser
temperature and is the atmospheric pressure.
Evaporator
In evaporator, external water enters at 90°C and
supplies heat to the refrigerant and then leaves it at the
temperature of 85°C. Internal ( ) and external diameter
( ) of tube used in evaporator are 13.84mm and 15.87mm
respectively.
Outside heat transfer coefficient is calculated using
Rohesnow correlation [23] and is given by the following
relation.
= μ ∗ ℎ ∗ [ ∗
( )
]
. ∗[
∗
∗ ∗
]
(14)
In Eqn. 14, is a constant and its value is 0.0130 for
water copper surface. The outer surface convective heat
transfer coefficient ho is calculated by using the following
formulation.
∗ 1000 = ℎ ∗ (15)
Here is the temperature difference between the inlet
and outlet temperature of external fluid in the evaporator.
Solution Heat Exchanger
Mass flow rate in solution heat exchange is calculated
using energy and mass balance equations and is found to
be 0.008857Kg/s. Internal ( ) and external diameter ( )
of the tubes used in solution heat exchanger are 9.5mm and
15mm respectively as in ref Florides et al [15].
Internal heat transfer coefficient (hi) and outside heat
transfer coefficient (ho) is calculated using Eqn. 8 and 9
respectively.
Table 1 show the various design parameters obtained by
the simulation of absorption heat transformer.
VALIDATION OF THE MODEL
In order to validate the simulation, the results of
energy analysis of the AHT are compared with the
theoretical results of the second model of AHT by Ilhami
Horuz and Bener Kurt [24] and the details are presented in
Tab 2. For this purpose input conditions in present work
are taken same as of the reference work [24]. It can be
seen from Tab 2 that the results obtained are in good
agreement with that of [24].
TABLE 2: VALIDATION
S.N. Parameters
Present
Work
Ilhami’s
Work[24]
1
Available heat in
absorber
491.6KW 487.3KW
2
Heat rejection in
condenser
567.6KW 589.8KW
3
Heat supplied to
evaporator
559.6KW 558.14KW
4
Heat supplied to
generator
496.1KW 495.6KW
5 COP AHT 0.4642 0.46
6 Flow ratio 18.72 18.63
7
Strong solution
concentration
0.6243 0.6244
8
Weak solution
concentration
0.5962 0.59260
PERFORMANCE ANALYSIS
Applying the mass and energy equations on all the
components of AHT, 271 equations are obtained with 46
independent variables while remaining are the dependent
Description Evaporator Absorber Generator Condenser Solution heat exchanger
LMTD ( ºC ) 4.971 18.2 4.971 7.224 12.35
U (kW/m2
ºC ) 1600 689.1 534.2 1261 67.23
A (m2
) 0.2727 0.1594 0.7552 0.238 0.6274
Length (m) 5.473 2.665 12.63 4.785 13.32
Capacity (kW) 2.169 2 2.005 2.174 0.5209

5. 5
variables. All these non-linear equations are simultaneously
solved in EES by the variant of Newton-Rapson method
For the input condition as given in Tab 3, the
simulation results using the first law of thermodynamics
are obtained and are shown in Tab 4. The effect on the
performance of AHT by the temperature variation in the
different components is discussed further.
Effect of Absorber Temperature The mass flow
rate is increased by 37.2% due to increase in the absorber
temperature because at high temperature absorption
capacity of LiBr decreases. Fig. 2 shows that the Carnot
and of the system are decreased by 2.5% and
25.4% respectively with the increase in absorber
temperature.
TABLE 3: INPUT PARAMETERS
S.N. Parameters Inputs
1 Absorber Capacity (kW) 2
2
Solution heat exchanger
outlet temperature (°C)
110
3
Solution heat exchanger
inlet temperature (°C)
80
4
Condenser Temperature
Tco (°C)
40
5
Evaporator Temperature
Tev (°C)
80
6
Absorber Temperature
Tab (°C)
120
7
Generator Temperature
Tge (°C)
80
Effect of Generator Temperature Carnot COP and
COP of the system increases by 8% and 21% with the
increase in generator temperature. Total mass of the
solution decreases by 75% due to increase in the
concentration of LiBr by 5% in the strong solution. Figure
3 shows the effect of generator on the performance of
AHT.
Effect of Condenser Temperature With the increase
in condenser temperature, COP of system is found to
decrease by 24%. Carnot COP is also decreased by 7.2% as
the condenser temperature is inversely proportional to
Carnot COP and also the gross temperature lift (GTL)
reduces with the increase in condenser temperature. Mass
of external fluid in the condenser is also found to increase
by 58% and the mass of refrigerant increases by 60% as
shown in Fig.4.
TABLE 4: FIRST LAW RESULTS
S. N. Parameters Results
1 0.4528
2 Carnot 0.75
3
Mass of external fluid for
condenser ( kg/s)
0.1168
4
Mass of refrigerant (mref
in kg/s)
0.0009739
5
Weak solution
concentration (x5)
0.5489
6
Strong solution
concentration (x8)
0.5762
7
Mass of external fluid for
evaporator ( kg/s)
0.1165
Absorber Temperature, Tab
116 117 118 119 120 121 122 123 124
COPaht,COPcarnot,x5
0.3
0.4
0.5
0.6
0.7
0.8
massflowrateofweaksolution(Kg/s)
0.01
0.02
0.03
0.04
0.05
0.06
0.07
COPaht
COPcarnot
x5
mass flow rate of weak solution
FIGURE 2. EFFECT OF ABSORBER TEMPERATURE
Effect of Evaporator Temperature As the evaporator
temperature changes ±3°C, system COP is increased by
24%. Carnot COP is independent of evaporator
temperature and remains constant as shown in Fig. 5.
Mass of external fluid circulating in the evaporator reduces
by 32% and mass of refrigerant (mref) also reduced by 31%.
DESIGN ANALYSIS
After successfully sizing the components of AHT, the
decision variables are varied to find out their effect on the
areas of different components.

6. 6
Generator Temperature, Tge
76 77 78 79 80 81 82 83 84
COPaht,COPcarnot,x8
0.3
0.4
0.5
0.6
0.7
0.8
massflowrateofweaksolution(Kg/s)
0.01
0.02
0.03
0.04
0.05
0.06
COPaht
COPcarnot
x8
mass flow rate of weak solution
FIGURE 3. EFFECT OF GENERATOR
TEMPERATURE
Condenser Temperature, Tco
36 37 38 39 40 41 42 43 44
COPaht,COPcarnot
0.3
0.4
0.5
0.6
0.7
0.8
massofexternalfluid(mef),(mref*100)kg/s
0.08
0.10
0.12
0.14
0.16
0.18
COPaht
COPcarnot
mef
mref
FIGURE 4. EFFECT OF CONDENSER
TEMPERATURE
Evaporator Temperature, Tev
76 77 78 79 80 81 82 83 84
COPaht,COPCarnot
0.3
0.4
0.5
0.6
0.7
0.8
massofextenalfluid(mef),(mref*100)(kg/s)
0.08
0.10
0.12
0.14
0.16
0.18
COPaht
COPcarnot
mef
mref
FIGURE 5. EFFECT OF EVAPORATOR
TEMPERATURE
Decision variables are the temperature of the heat
exchangers and are varied ±3°C from their design
temperature to analyze the effect on the areas of different
components.
Effect of Evaporator Temperature (Tev) As the
temperature of evaporator changes ±3°C from its design
temperature, while keeping the temperature of external
fluid as constant, causes an increase in the evaporator area
(Aev) by 67% and decreases the solution heat exchanger
area (Ashx) by 76.6% as shown in Fig. 6. The increase in
the area of evaporator is due to the reduction in LMTD and
overall heat transfer coefficient (U) across it. Moreover,
changing the evaporator temperature from 77°C to 83°C
reduces the thermal load in solution heat exchanger (Qshx),
generator (Qge) and condenser (Qco) by 82%, 0.65% and
32% respectively.
.
Effect of Absorber Temperature (Tab) The change in
the absorber temperature does not affect the area of the
absorber but areas of condenser, evaporator and solution
heat exchanger are found to increase by 48.82%, 53% and
236% respectively as shown in Fig. 7.

7. 7
Evaporator Temperature, Tev
77 78 79 80 81 82 83 84
Areaofdiff.components(Aab,Aco,Aev,Age)m2
0.1
0.2
0.3
0.4
0.5
0.6
Areaofshx(m2
),Qev(kW)
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
Aab
Aco
Aev
Age
Ashx
Qev
FIGURE 6. EFFECT OF EVAPORATOR
TEMPERATURE
Further due to increase in the absorber temperature, heat
load across solution heat exchanger is increased by 420%,
where as heat load across the condenser and evaporator is
increased by 65%.
Absorber Temperature, Tab
116 117 118 119 120 121 122 123 124
Areaofdiffcomponents(Aab,Aco,Age,Aev)m2
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0.45
0.50
Areaofshx(m2
),Qshx(kW)
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
Aab
Aco
Aev
Age
Ashx
Qshx
FIGURE 7. EFFECT OF ABSORBER TEMPERATURE
Effect of Condenser Temperature (Tco) The change
in the temperature of condenser from 37°C to 43°C causes
the thermal load across it to increase from 2.32kW to
3.536kW while keeping other conditions of AHT as
constant. Fig. 8 shows the drastically increase of 630% in
solution heat exchanger area. The areas of condenser,
evaporator, and generator are found to reduce by 39%,
48% and 3.5% respectively but the area of the absorber
remains constant. Moreover, the heat load across
evaporator and solution heat exchanger are increased by
58.37% and 557% respectively due to the increase in the
condenser temperature from 37°C to 43°C.
Condenser Temperature, Tco
36 37 38 39 40 41 42 43 44
Areaofdiff.components(Aab,Aco,Aev,Age)m2
0.1
0.2
0.3
0.4
0.5
0.6
Areaofshx(m2
),Qco(kW)
0
1
2
3
4
5
6
7
Aab
Aco
Aev
Age
Ashx
Qco
FIGURE 8. EFFECT OF CONDENSER
TEMPERATURE
Generator Temperature, Tge
76 77 78 79 80 81 82 83 84
Areaofdiff.components(Aab,Aco,Aev,Age)m2
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
Areaofshx(m2
),Qgeload(kW)
0
1
2
3
4
5
6
Aab
Aco
Aev
Age
Ashx
Qge
FIGURE 9. EFFECT OF GENERATOR TEMPERATURE
Effect of Generator Temperature (Tge) With the
increase in Tge from 77°C to 83°C while keeping all other

8. 8
conditions as constant, it is found that the area of generator
is increased by 150% and there is a decrease in the area of
solution heat exchanger by 83%, while areas of condenser
and evaporator are found to increase by 24% and 25.3%
respectively. The area of absorber remains constant.
Further heat load across the generator does not change but
in solution heat exchanger it is found to decrease by 82%,
and for condenser and evaporator it decreases by 29% each
as shown in Fig. 9.
CONCLUSION
First law analysis predicts that the efficiency of the
AHT system increases with the decrease in absorber and
condenser temperature and the increase in evaporator and
generator temperature. Sizing of the various heat
exchangers shows the area variation with the change of
operating temperatures. It can also be concluded that the
optimization of the area of heat exchangers with their
operating temperatures is required to keep the total fixed
and running cost at the minimum which is scope of future
work.
REFERENCES
[1] K. P. Tyagi., 1989, “Performance Analysis of
Resorption and Two Stage Absorption Heat
Transformers”. Corporate Research and Development
Division, BHEL, 1885 – 1890
[2] R. Best., M. A. R. Eisa., and F. A. Holland., 1987.
“Thermodynamic design data for absorption heat
transformer operating on ammonia – water”. Heat
recovery Systems & CHP Vol. 7, No.3, 259 – 272.
[3] Zongchang Zhao., Xiaodong Zhang., and Xuehu Ma.,
2005. “Thermodynamic Performance of a Double
Effect Absorption Heat Transformer Using TFE/E181
as the Working Fluid”. Applied Energy 82, 107-116.
[4] Xiaodong Zhang., and Dapeng Hu., 2012.
“Performance Analysis of the Single Stage Absorption
Heat Transformer using a New Working Pair
Composed of Ionic Liquid and Water”. Applied
Thermal Engineering 37, 129 – 135
[5] T. Goel., G. Sachdeva., 2015. “Exergy Analysis of
Various Absorption Heat Transformer System Using
Classical and Modified Gouy – Stodola Equation”.
International Journal of Air – Conditioning and
Refrigerants, Vol. 23, No. 1, 1550006, 14 pages.
[6] John M. George., and S. Srinivasa Murthy., 1992.
“Experiments on a Vapor Absorption Heat
Transformer”. Refrigeration and Air-Conditioning
Laboratory, Department of Mechanical Engineering,
IIT Madrass.
[7] Rivera W, Cerezo J, Rivero R, Cervantes J, Best R.,
2003. “Single stage and double absorption heat
transformers used to recover energy in a distillation
column of butane and pentane”. Int J Energy Res,
27:1279e92
[8] Djallel Zebbar., Sahraoui Kherris., Souhila Zebbar.,
and Kouider Mostefa., 2012. “Thermodynamic
Optimization of an Absorption Heat Transformer”
International Journal of Refrigeration 35, 1393 – 1401.
[9] S. Sekar., and R. Saravanan., 2011. “Experimental
Studies on Absorption Heat Transformer Coupled
Distillation System”. Desalination 274, pp 292 – 301.
[10]Armando Huicochea., Wilfrido Rivera., Hiram
Martínez., Javier Siqueiros., and Erasmo Cadenas,
2013. “Analysis of the Behavior of an Experimental
Absorption Heat Transformer for Water Purification
for Different Mass Flux Rates in the Generator”.
Applied Thermal Engineering 52, 38 – 45.
[11]Rosenberg J. Romero., and A. Rodriguez – Martinez.,
2008. “Optimal Water Purification using low grade
Waste Heat in an Absorption Heat Transformer”.
Desalination 220, 506-513.
[12]Rabah Gomri., 2010. “Thermal Seawater Desalination:
Possibilities of Using Single Effect and Double Effect
Absorption Heat Transformer Systems”. Desalination
253, 112 – 118.
[13]Rabah Gomri., 2009. “Energy and Exergy Analysis of
Seawater Desalination System Integrated in a Solar
Heat Transformer”. Desalination 249,188 – 196.
[14]Bakhtiar B., Fradette L.,, Legros R., and Paris J., 2011.
“A Model for Analysis and Design of H2O–LiBr
Absorption Heat Pumps”. Energy Conversion
Management, 52, 1439–1448.
[15]Florides G.A., Kalogirou S.A., Tassou S.A., and
Wrobel L.C. 2003. “Design and Construction of a
LiBr–Water Absorption Machine”. Energy Conversion
Management, 44, 2483–2508.
[16]M. Tech. Thesis, Samant M.D.S., 2008. “Design and
development of two stage cascaded refrigeration
system”. Department of Mechanical Engineering: IIT
Delhi.
[17]Howell R.H., Sauer J.H., and Coad J.W., 1998.
“Principal of HVAC”. ASHRAE, Refrigeration
Equipment Section 18.21.
[18]Ozisik M., 1985. “Heat Transfer – a basic approach”.
McGraw-Hill Book Company
[19]Kreith F., Bohn M.S., ed. 1997. “Principles of Heat
Transfer” 5th
ed., PWS Publishing Company
[20]Andberg J.W., Vliet G.C., 1983. “Design Guidelines
for Water-Lithium Bromide Absorbers”. ASHRAE
Trans 89, Part 1B, 220-232.
[21]Nusselt in Ozisik M., ed. 1985 “Heat Transfer-A Basic
Approach”. McGraw-Hill Book Company.
[22]Jakob., M.G. Hawkings., Element of Heat Transfer “.
3rd
ed., John wiley & sons, Newyork,U.S.A.
[23]Rohesnow W.M., Hartnet J.P., and Cho Y.I., 1998.
“Handbook of heat transfer”.
[24]Ilhami Horuz., Bener Kurt., 2010. “Absorption Heat
Transformer and an Industrial Application”.
Renewable Energy 35, 2175-2188.