980452

Research ArticleThermodynamic Analysis and Optimization of a HighTemperature Triple Absorption Heat Transformer

Mehrdad Khamooshi1 Kiyan Parham1 Mortaza Yari23 Fuat Egelioglu1

Hana Salati1 and Saeed Babadi4

1 Department of Mechanical Engineering Eastern Mediterranean University G Magosa North Cyprus Mersin 10 Turkey2 Faculty of Engineering Department of Mechanical Engineering University of Mohaghegh Ardabili Ardabil 179 Iran3 Faculty of Mechanical Engineering University of Tabriz Tabriz Iran4Department of Electrical and Computer Engineering University of Concordia Montreal QC Canada

Correspondence should be addressed to Mehrdad Khamooshi mehrdadkhamooshiyahoocom

Received 31 January 2014 Revised 24 June 2014 Accepted 30 June 2014 Published 17 July 2014

Academic Editor Xuehu Ma

Copyright copy 2014 Mehrdad Khamooshi et al This is an open access article distributed under the Creative Commons AttributionLicense which permits unrestricted use distribution and reproduction in any medium provided the original work is properlycited

First law of thermodynamics has been used to analyze and optimize inclusively the performance of a triple absorption heattransformer operating with LiBrH

2O as the working pair A thermodynamic model was developed in EES (engineering equation

solver) to estimate the performance of the system in terms of the most essential parameters The assumed parameters are thetemperature of the main components weak and strong solutions economizersrsquo efficiencies and bypass ratios The whole cycle isoptimized by EES software from the viewpoint of maximizing the COP via applying the direct search method The optimizationresults showed that the COP of 02491 is reachable by the proposed cycle

1 Introduction

Pollution carbon dioxide production environmental haz-ards and global warming are the main disadvantages offossil fuels Alternative choices which can assist decisionmakers to avoid using fossil fuels have become a big challengenowadays Also huge amount of low or midlevel waste heat(60∘C lt 119879 lt 100∘C) [1] Absorption heat transformers whichare capable of upgrading the energy efficiency of industrialapplications appear to be a noble choice for utilizing thesewaste heats They are systems that operate in a cycle oppositeto that of absorption heat pumps (AHPs) Due to the fact thatthe fundamental of the AHTs is close to AHPs absorptionheat transformers will have the same advantages of theabsorption systems such as quite operation less maintenancerequirement less mechanical work input and simple design[1ndash7]

The amount of gross temperature lift (GTL) basicallydepends on the additional stages added to the single absorp-tion heat transformers (SAHTs) Table 1 shows the coefficient

of performance (COP) and GTL of the different types ofabsorption heat transformers

The system performance of the SAHTs with differentconfigurations using LiBrH

2O was presented by Horuz and

Kurt [1] They reported some enhancements in the COP ofthe SAHTs for modified configurations Parham et al [8]continued and optimized their work [1] and integrated theminto a desalination system They studied the effects of somemajor parameters such as heat source temperature maincomponents temperature flow ratio on the performance ofthe systems and fresh water production rate Khamooshi etal [9] conducted a similar research and coupled six differentconfigurations of triple absorptions heat transformers intodesalination systems Zare et al [10] proposed a new com-bined cogeneration system consisting of two organic Rankinecycles (ORCs) and a single absorption heat transformer Therequired power for this system was provided by the wasteheat of a gas turbine-modular helium reactor (GT-MHR)They demonstrated that the COP and the water productionrate have direct relations with the heat source temperature

Hindawi Publishing Corporatione Scientific World JournalVolume 2014 Article ID 980452 10 pageshttpdxdoiorg1011552014980452

2 The Scientific World Journal

of the AHT Yari presented a novel cogeneration cyclecomprised of a transcritical CO

2power cycle and a LiBrH

2O

single absorption heat transformer [11] The maximum waterproduction rate of 3317 kgs was acquired by the cycle Sozenand Yucesu [6] performed a mathematical simulation inorder to compare the absorption heat transformers utilizingejectors to the basic AHTs Both cycles used H

2ONH

3as

the working pair and employed the waste heat from a solarpond The results demonstrated that both energy and exergyefficiency improvements were achievable by using ejector inthe absorption heat transformer

Siqueiros and Romero conducted two studies aboutrecycling energy with and without increasing heat sourcetemperature in AHT systems [12 13] They noticed someimprovements in the proposed cycles than that of simpleabsorption heat transformer Performance evaluation of theabsorption heat transformers is possible by using artificialneural network analysis [14 15] Zhao et al [16 17] con-ducted a study to analyze three different configurations ofdouble absorption heat transformers by the working pairsof LiBrH

2O They concluded that the temperature of the

absorbing evaporator is not an independent variable andmainly depends on the absorber temperature

First and second law analysis of a double absorptionheat transformer operating with LiBrH

2O were studied by

Martınez and Rivera [18] They formulated a mathematicalmodel for estimating theCOP ECOP total exergy destructionin the system and exergy destruction in all the components asa function of temperature Horuz and Kurt [19] investigatedand compared single series and parallel double absorptionheat transformers They proved that the parallel doubleAHT system could generate more water vapor than thatof the series double AHT system A performance compar-ison of the single effect and double effect absorption heattransformer systems was made by Gomri [20] The resultsshowed that the double effect absorption heat transformers(DAHTs) had higher exergy and energy efficiencies andsmaller water production than that of the single effectabsorption heat transformers (SAHT) Also they discussed asolar absorption heat transformer coupled to a desalinationsystem in a different study [21] The proposed system couldproduce fresh water of 500 L per day in July for a beachhouse

The performance of the absorption cycles depends notonly on their configuration but also on thermodynamicproperties of working pairs which are regularly composedof refrigerants and absorbents [22] A comparison wasmade between H

2ONH

3and LiBrH

2O solutions in single

absorption heat transformer by Horuz [23] Sun et al [24]conducted a review study about different kinds of workingpairs in absorption cycles Furthermore Khamooshi et al[25] did a similar work for employed ionic liquids as work-ing fluids The same team published their second reviewpaper wherein AHTs from the view point of applicationscrystallization risk working fluids performance evalua-tion and economic aspects were reviewed comprehensively[26]

Donnellan et al [27] introduced six different configura-tions of triple absorption heat transformers using LiBrH

2O

Table 1 System performances of different types of absorption heattransformers

Type GTL COP ReferenceSingle absorption heattransformer (SAHT) 50∘C sim05 [1 8 19]

Double absorption heattransformer (DAHT) 80∘C sim035 [16ndash19]

Triple absorption heattransformer (THAT) sim140 sim023 [27 28]

as the working fluid They optimized the number and loca-tions of the heat exchangers within the system by reassem-bling them In the second work a rigorous multidimensionalanalysis wasmade for evaluating the performance of the tripleabsorption heat transformers by Donnellan et al [28]

In this study a triple absorption heat transformer willbe represented with a modified configuration described byDonnellan et al [27] However their study did not investigatethe effect of some major parameters on the performance ofthe system

A thorough and comprehensive thermodynamic analysiswill be performed for the best configuration of the lattermentioned study by the purpose of continuing it A paramet-ric study will be carried out and validated by other studiesavailable from the literature in order to identify the effects ofsome parameters such as the temperatures of the condenserevaporator absorber generator first absorberevaporator(ABEV1) and second absorberevaporator (ABEV2) con-centration of the weak and strong solution and economizereffectiveness

2 System Description

Figure 1 shows the general schematic of the absorptionheat transformer in single stage mode The SAHT basicallyconsists of an evaporator a condenser a generator anabsorber and a solution heat exchanger (SHE)The generatorand evaporator are supplied with waste heat at the sametemperature leading to increased heat that can be collectedat the absorber [26]

Refrigerant vapor is produced at state 4 in the evaporatorby low or medium-grade heat source The refrigerant vapordissolves and reacts with the strong refrigerant-absorbentsolution that enters the absorber from state 10 and the weaksolution returns back to the generator at state 5 The heatreleased from the absorber will be higher than the input heatin generator and evaporator due to the exothermic reaction ofLiBr and water in it In the generator some refrigerant vaporis removed from theweak solution to be sent to the condenserand consequently the strong solution from the generatoris returned to the absorber After condensing the vaporizedrefrigerant in the condenser it is pumped to a higher pressurelevel as it enters the evaporator The waste heat delivered tothe evaporator causes its vaporization Again the absorberabsorbs the refrigerant vapor at a higher temperature There-fore the absorption cycles have the capability of raising the

The Scientific World Journal 3

ABRestrictor

Solutionpump

GE

AHTCO

RefrigerationpumpAHT

EV

1

23

4

5 6 7

8910

Qabsorber

Qevaporator

Qgenerator

Qcondenser

ECO

Figure 1 Schematic diagram of a single stage absorption heat transformer

Wastewater

Generator1Condenser

9

2

RP1

3

34 35

4

RP2

10

ABEV1

11

19

RP320

HEX3

8

5

ABEV2

21

22

Evaporator

12

18

28 Combo

29

2723

Absorber

SplitSplit

13 24 33

HEX1

17 14

2532

3031

SP1 SP2 SP3v1

v2

v3

7 6 16 15 26

HEX2

Figure 2 Schematic diagram of a triple absorption heat transformer

temperature of the solution above the temperature of thewaste heat [19]

Figure 2 displays the modified configuration of the tripleabsorption heat transformer This cycle mainly consists ofa generator a condenser an evaporator an absorber twoabsorberevaporators and three economizers In this systemheat is transferred to the evaporator and the generator fromthe waste hot water of a textile factory at the same timeThe rejected heat from the absorber provides the thermalenergy demanded by the desalination system Superheatedwater vapor which works as refrigerant comes out from thegenerator and enters to the condenser where it is condensedas saturated liquid One part of the condensed refrigerantis pumped to the higher pressure level of the evaporator(P1) In the evaporator water is heated to saturated vapor

phase with the same waste heat provided to the generatorThis vapor is absorbed in the first absorberevaporator bythe strong solution of LiBrH

2O coming back from the

generator One portion of the released heat in the absorberis used to retain the absorber-evaporator-1 at a temperature

higher than that of the evaporator The second split of thecondensed refrigerant leaving the condenser is pumped tothe pressure level of P

2which is higher than that of P

1and

provides heat to the saturated vapor by utilizing the heatof the absorption preserved by ABEV1 This vapor is thenabsorbed inABEV2 by the strong LiBrH

2Osolution flowing

from the generator Some parts of the absorption heat areused to maintain the ABEV2 at a temperature higher thanthat of ABEV1The final split of the condensed refrigerant ispumped to the highest pressure level (P

3) and consequently

the water is heated in ABEV2 to saturated vapor by theretained heat in the ABEV2 Finally this saturated vapor isabsorbed by the strong absorbent-refrigerant coming backfrom generator and the exothermic reaction in the absorbermakes the temperature approximately (30ndash60∘C [27]) hotterthan that of the temperature of the ABEV2 The residualpart of the released heat is transferred to impure water aslatent and sensible heat in desalination system as shown inFigure 2 The weak solutions coming back from the absorberand ABEV2 are divided into two parts One part of each is


directly returned to generator and used in heat recovery partof the first and second heat exchangerThe second fractions ofthe weak solution are combined together in order to be usedin heat recovery part of the third heat exchanger

3 Thermodynamic Analysis

The following section describes the thermodynamics modelused for simulation of the TAHT Each component of theconsidered system has been treated as a control volume andthe principles of mass and energy conservation are applied tothem EES software is used for solving the equations [32]

31 Assumption The following assumptions have been madein the analysis

(1) Changes in kinetic and potential energies areneglected [8 27 28]

(2) The pressure losses due to the frictional effects in theconnecting pipes of the AHT are neglected [8 18 2728]

(3) The system is in thermodynamic equilibrium and allthe processes are assumed to be steady flow processes[8 18 27 28]

(4) Some proper values of effectiveness are considered forthe heat exchangers [8 18]

(5) In the TAHT the solution at the generator andthe absorber outlets as well as the refrigerant atthe condenser and the evaporator outlets is all atsaturated states [8 18 27 28]

(6) The salt utilized in the absorbent solution is assumedto have negligible vapor pressure [27 28]

(7) Heat losses from components are very small relativeto heat fluxes and are thus not included in the model[27 28]

(8) The evaporator and the generator of the AHT work atthe same temperature [8]

(9) The refrigerant vapor is assumed to evaporateand condense completely in the two absorber-evaporators the evaporator and the condenser [2728]

(10) The heat source for the AHT system is the hotwater generated by a cogeneration system in a textilecompany The industrial system has four differentunits each of them producing 15 tonh water at 90 plusmn2∘C [1 8]

(11) The mechanical energy consumed by pumps can beneglected [8]

32 Performance Evaluation Table 2 summarizes the basicassumptions and used input parameters in the simulation

The systemrsquos COP is determined as the ratio of useful heatoutput systems over the systems input energy Due to thefact that COP is the most important criterion of the cyclersquoscapability for upgrading the delivered thermal energy to the

Table 2 The input data of simulation

Parameters Value119879con (

∘C) 20ndash35a

119879abs (∘C) 180ndash215b

119879eva (∘C) 80ndash110c

119879eva = 119879gen (∘C) d

119879ABEV1 (∘C) 110ndash145e

119879ABEV2 (∘C) 150ndash180e

119879heat source(∘C) 90 plusmn 2∘Cf

m-dot heat source (tonh) 60f

120576ECO () 80g

The values are obtained from various studies such as a [29ndash31] b [27 28] c[27]d [8 12 13 20 21] e [27 28] f [1 8] g [8 20 21]

system it plays an important role in analyzing the absorptioncycles The COP is given in the following equation [33ndash35]

COP =119876abs119876gen + 119876eva

(1)

Another fundamental parameter for designing and optimiz-ing the absorption cycles is the flow ratio It is defined as theratio of the total mass flow rate of weak solution entering thegenerator to the mass flow rate of refrigerant vapour leavingthe generator [27]

119891 =

mass flow of salt solution entering the generatormass flow of vapour leaving the generator

(2)

The heat capacities of the main components of the cycles areas follow

119876eva = 34 (ℎ34 minus ℎ35) = 4 (ℎ4 minus ℎ3)

119876gen = 1ℎ1 + 7ℎ7 + 16ℎ16 + 31ℎ31 minus 6ℎ6

minus 15ℎ15minus 30ℎ30

119876con = 1ℎ1 minus 2ℎ2 minus 9ℎ9 minus 19ℎ19

119876abs = 22ℎ22 + 33ℎ33 minus 23ℎ23

119876ABEV1 = 10 (ℎ11 minus ℎ10) = 4ℎ4 + 8ℎ8 minus 5ℎ5


(3)

The heat capacity of absorber also can be calculated by usingthe equation below [1 19]

119902abs =119876abs4

= (119891 + 1) ℎ23minus 119891ℎ22minus ℎ33 (4)

Bypass ratio is an imperative parameter defined for theweak solutions coming back from the absorber and ABEV2defined as

BP1 = 1198982411989827

BP2 =11989813

11989828

(5)


33 Optimization Method The cyclersquos performance funda-mentally depends on temperature of the main componentstherefore the optimumCOP of the cycles can be expressed asfollows

Maximize COP (119879abs 119879gen 119879con 119879ABEV1 119879ABEV2 119879eva)

Subject to 20 le 119879con le 35∘C

90 le 119879eva le 105∘C

90 le 119879gen le 105∘C

110 le 119879AB1 le 145∘C

165 le 119879AB2 le 180∘C

180 le 119879abs le 215∘C

(6)

By applying the constraint for each variable and by settingbounds the performance of the whole cycle is optimized byEES software from the viewpoint of maximizing the COP

Direct search method is best known as unconstrainedoptimization technique that does not explicitly use deriva-tives [36]

34 Model Validation The available data in the literaturewere used to validate the simulation results For the case ofthe AHT cycle the experimental results reported by Rivera etal [31] are usedThe conditions and assumptions used in theirwork are applied for the aim of validation The assumptionsare as follows

(I) Heat losses and pressure drops in the connectingpipes and the components are considered negligible

(II) The flow through the expansion valves is isenthalpic(III) The effectiveness of the economizer is 70(IV) The absorber temperature is 123∘C(V) The generator and evaporator temperatures being the

same are 741∘C

Figure 3 shows the comparison between the COPobtained from the present work with that reported by Riveraet al [31] The figure shows an excellent agreement betweenthe two and indicates a decrease in the COP as the condensertemperature of the AHT system increases

The available result in the Donnellan et alrsquos [27] work wasalso used to validate the simulation The similarity betweenFigures 4 and 5 verifies the validity of our simulationsLikewise the obtained COP of the system is qualitatively inagreement with the latter mentioned study

In Figures 4 and 5 it is evident that as 119879eva is higherthan 105∘C COP drops and there is a satisfactory agreementbetween them

4 Results and Discussion

Figures 6 and 7 show the variation of the COP by the firstand second Bypass ratios It is clear that the COP is higher

20 24 280

01

02

03

04

05

Present study

COP

Tcon (∘C)

Tabs = 123∘C

Tgen = Teva = 741∘C

Rivera et al (2003)

Figure 3 Validation of the simulation model developed for AHTsystem

80 90 100 11002

021

022

023

024

025

COP

Tcon = 25∘C

Teva = Tgen TABEV2 = 165∘C

TABEV1 = 130∘C BP1 = 1

BP2 = 1

COP Tabs = 205∘C

COP Tabs = 215∘C

COP Tabs = 195∘C

Teva (∘C)

Figure 4 Effect of 119879eva on the COP of the system

for smaller amounts of BP1 and higher quantities of BP2This means that the temperature of the point 29 will becomehigher with considered amounts of bypass ratios which leadsto increasing heat recovery in the third heat exchangerThis isin agreementwith those reported in [27] whom stated the factthat the third heat exchanger has a much greater influence onthe cyclersquos performance than any other heat exchanger

As it can be seen in Figure 8 when 119879eva which is equal to119879gen increases the COP would also increase This is due tothe fact that the maximum pressure of the system has directrelation with the evaporatorrsquos temperature By increasingthe maximum pressure of the system the weak solutionconcentration will decrease by decreasing flow ratio Thelower flow ratio means higher absorber heat capacity andthe higher COP This result achieves harmony with thosereported in [1 10 19 27] Also it is clear that as the grosstemperature lift (GTL = 119879abs minus 119879eva) decreases the COP andincreases rapidly From the first law of thermodynamics itis explicit that the system has to reduce its efficiency as theabsorber increases its temperature which is in accordancewith the results available in [8 27 37 38]


002

0

minus002

minus004

minus006

minus008

minus01

004002

0minus002minus004minus006minus008minus01minus012

140135

130125

120115

110 8085

9095

100105

110

COP

GTL

Evaporator temperature (∘ C)35

Figure 5 Effect of 119879eva on the COP of the system [27]

0225

023

0235

024

0245

COP

05 1 15 2

BP1

Tcon = 25∘C

Teva = Tgen

TABEV2 = 165∘C

TABEV1 = 130∘C BP2 = 1

Tabs = 215∘C

COP Teva = 90∘C

COP Teva = 95∘C

COP Teva = 100∘C

Figure 6The effect of BP1 on theCOPof the cycle for three different119879eva

Figure 9 depicts the variation of COP with 119879abs in threedifferent evaporator temperatures It is clear that it has a sim-ilar trend with that of Figure 8 which shows the decreasingbehavior of COP by increasing GTL Also by increasing 119879absthe concentration of the weak solution and consequently theflow ratio increase which leads into a decrease in the absorberheat capacity [8 10 20 39]

Figure 10 shows the effect of condenserrsquos temperatureon the COP of the system This is by reason of the factthat the minimum system pressure raises with increasingthe condenser temperature By boosting the 119879con the strongsolution concentration will go down which increases the flowratio of the system The bigger flow ratio will result in thelower absorber heat capacity and lower COP [19] Figure 10proposes that the condensation temperature should alwaysbe kept at its lowest setting [28] and the system has its bestperformance during the winter

Concentration of the working pair in the system can beclassified into two categories firstly strong solution whichis the concentration of the solution flowing from generatorto absorber (119883

31) and secondly the weak solution that is

024

023

COP

05 1 15 2

BP2

COP Teva = 90∘C

COP Teva = 95∘C

COP Teva = 100∘C

Tcon = 25∘C

Teva = Tgen

TABEV2 = 165∘C

TABEV1 = 130∘C BP2 = 1

Tabs = 215∘C


025

024

023

022

021

02

01980 90 100

COP

COP Tabs = 205∘C

COP Tabs = 215∘C

COP Tabs = 195∘C

Tcon = 25∘C


TABEV1 = 130∘C BP1 = 1

BP2 = 1

Teva (∘C)

Figure 8The effect of119879eva on theCOPof the cycle for three different119879abs

180 190 200 210 2200225

023

0235

024

0245

COP

COP Teva = 90∘C

COP Teva = 95∘C

COP Teva = 100∘C

Tcon = 25∘C


TABEV1 = 130∘C BP1 = 1

BP2 = 1

Tabs (∘C)

Figure 9The effect of119879abs on theCOPof the cycle for three different119879eva


021

0215

022

0225

023

0235

024

0245

COP

20 25 30 35

Teva = Tgen

TABEV2 = 165∘C

TABEV1 = 130∘C BP1 = 1

BP2 = 1Tabs = 215∘C

Tcon (∘C)

COP Teva = 90∘C

COP Teva = 95∘C

COP Teva = 100∘C

Figure 10 The effect of 119879con on the COP of the cycle for threedifferent 119879eva

180 190 200 210 22003

04

05

06

07

08

Xw

Xs

Tcon = 25∘C

Teva = TgenTABEV2 = 165

∘CTABEV1 = 130

∘CTeva = 90

∘C

Tabs (∘C)

BP1 = 1

BP2 = 1

Xw

Xs

(wt

abso

rben

t)

Figure 11 The effect of 119879abs on the concentration of the strong andweak solution

the concentration of the solution coming back from theabsorber to the generator (119883

23)

In Figure 11 both 119883119904and 119883

119908are plotted against the

absorber temperature It is obvious that when generatingcondensing and absorberevaporator temperatures are keptconstant119883

119904does not vary with119879abs but the119883119908 is increasing

The higher the evaporator or generator temperature is thebigger the strong solution is Consequently the higher 119883

119904

results in the higher flow ratio and can also increase theamount of the demanded heat input into the cycle [1]

The concentration difference (Δ119883 = 119883119904minus 119883119908) exhibits

a parabolic decrease by increasing absorber temperature asshown in Figure 12 As mentioned correspondingly in theliterature [8 10 40] when generation evaporation ABEVand condensing temperatures are constant the Δ119883 and 119879abswill only vary with 119891 which is an important and easilycontrollable operation parameter Larger 119891 also results inhigher 119879abs and more mechanical power losses This iscompletely in agreement with the results of Horuz and Kurt

180 190 200 210 220015

02

025

03

035

04

ΔX

998779X

(wt

abso

rben

t)

Tcon = 25∘C

Teva = Tgen

TABEV2 = 165∘C

TABEV1 = 130∘C

Teva = 90∘C

BP1 = 1

Tabs (∘C)

BP2 = 1

Figure 12 The effect of 119879abs on Δ119909

110 115 120 125 130 135 1400215

022

0225

023

0235

024

0245

COP

BP1 = 1

BP2 = 1

Tcon = 25∘C


∘C

Tabs = 215∘C

COP Teva = 90∘C

COP Teva = 95∘C

COP Teva = 100∘C

TABEV1 (∘C)

Figure 13 The effect of 119879ABEV1 on COP of the system

[1] which proved that if the evaporator temperature is biggerthe AHT performs better

The effects of 119879ABEV1 and 119879ABEV2 on the COP of thesystem have been shown in Figures 13 and 14 for theconsidered settings In Figure 13 the COP is at the highestvalue within the midpoint temperature of 119879ABEV1 But asdemonstrated in Figure 14 119879ABEV2 should remain as low aspossible in order to achieve maximum COP

In Figure 15 the COP is plotted against heat exchangerefficiencies (120576) It is obviously evident that 120576 has a major roleon the COP of the system The variation of the economizereffectiveness can increase the COP up to 21 It can beconcluded that the effectiveness of the economizers shouldbe as high as possible that is a reasonable result according tothe heat transfer phenomenon

41 A General Comparison among Different Configurationsof AHTs In our previous work [26] the variation of COPwith gross temperature lift under different evaporation tem-perature conditions was compared for single double andtriple AHTs using LiBrH

2O the working fluid As seen in

Figure 16 any increase in GTL will cause a drop in the COPThis is due to the fact that as 119879abs increases the concentration


Table 3 The results of optimization for maximum value of the COP

119879eva BP1 BP2 119879con 119879gen 119879ABEV1 119879ABEV2 119879abs COP90 05 1977 20 90 110 165 2105 0242395 05 2 20 95 111 165 2112 02461100 05 2 20 100 1123 165 213 02487105 05 2 20 105 1154 165 215 02491

165 170 175 1800225

023

0235

024

COP

COP Teva = 90∘C

COP Teva = 95∘C

COP Teva = 100∘C

Tcon = 25∘C


∘CTabs = 215∘C

BP1 = 1

BP2 = 1

TABEV2 (∘C)


01 02 03 04 05 06 07 08019

02

021

022

023

024

025

Economizer effectiveness

COP

COP

Tcon = 25∘C


TABEV1 = 130∘C

Teva = 90∘C Tabs = 215

∘C

BP1 = 1

BP2 = 1

Figure 15 The effect of economizer on COP of the cycle

of the weak solution and consequently the flow ratio (119891)increases resulting in a decrease in the absorber heat capacityThis result is in agreement with that reported in the literature[1 8]

Additionally the higher the evaporation temperature isthe higher the absorption temperature and the correspondinggross temperature are It is observed that SAHT has thehighest COP and the TAHT owns the lowest The same trendhas been reported by Donnellan et al [27]

5 Optimization

By using direct search method in EES software the COPmagnitude of the cycle has been optimized as a function of

30 40 50 60 70 80 90 100 110 120

02

025

03

035

04

045

05

COP

SingleDoubleTriple

Teva = 75∘C

Teva = 80∘C Teva = 85

∘C

Tcon = 25∘C

Teva = Tgen Tabs1 = Teva1 = 130∘C

Tabs2 = Teva2 = 165∘CTabs(single ) = 130

∘CTabs(double ) = 165

∘C

Tabs(triple ) = 215∘C

ΔT (∘C)

Figure 16 Effects of GTL on COP for different types of AHTs atdifferent evaporation temperatures [26]

main componentsrsquo temperaturesThe results are summarizedin Table 3 The optimization was performed for 4 differentevaporator temperatures

The results are completely in coherence with the previ-ously discussed results in the figuresThe COP has ascendingtrend with increasing the temperature of the evaporator asearlier in Figure 8

As shown in Table 3 the 119879con is always at the lowestpossible amount of the setting which is 20∘C (discussed inFigure 10) Also the bypass ratios show a proper amount incomparison with Figures 6 and 7 The maximum amount ofCOP which is 02491 is obtained at the 119879eva = 105

∘C

6 Conclusion

In this study a triple absorption heat transformer is proposedfor waste heat recovery from the industrial processes Ther-modynamic models were developed and parametric studieswere carried out Also performances of the whole cycle wereoptimized for maximum COP

It is proven that in the triple absorption heat transformersystems

(i) the systems condensation temperature should alwaysbe kept at minimum value

(ii) the lower gross temperature lift is the higher the COPwill be

(iii) the third heat exchanger has a much greater influenceupon the cyclersquos performance than the any other heatexchanger


(iv) single stage absorption heat transformer has thehighest COP and the TAHT owns the lowest

(v) the maximum COP of 02491 is obtained from thecycle

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

References

[1] I Horuz and B Kurt ldquoAbsorption heat transformers and anindustrial applicationrdquo Renewable Energy vol 35 no 10 pp2175ndash2181 2010

[2] E Kurem and I Horuz ldquoA comparison between ammonia-water and water-lithium bromide solutions in absorption heattransformersrdquo International Communications in Heat and MassTransfer vol 28 no 3 pp 427ndash438 2001

[3] W Rivera and J Cerezo ldquoExperimental study of the use ofadditives in the performance of a single-stage heat transformeroperating with water-lithium bromiderdquo International Journal ofEnergy Research vol 29 no 2 pp 121ndash130 2005

[4] A Sencan O Kizilkan N C Bezir and S A KalogirouldquoDifferent methods for modeling absorption heat transformerpowered by solar pondrdquo Energy Conversion and Managementvol 48 no 3 pp 724ndash735 2007

[5] S Smolen and M Budnik-Rodz ldquoLow rate energy use forheating and in industrial energy supply systems-Some technicaland economical aspectsrdquo Energy vol 31 no 14 pp 2252ndash22672006

[6] A Sozen and H S Yucesu ldquoPerformance improvement ofabsorption heat transformerrdquo Renewable Energy vol 32 no 2pp 267ndash284 2007

[7] J Yin L Shi M Zhu and L Han ldquoPerformance analysis ofan absorption heat transformer with different working fluidcombinationsrdquo Applied Energy vol 67 no 3 pp 281ndash292 2000

[8] K Parham M Yari and U Atikol ldquoAlternative absorption heattransformer configurations integrated with water desalinationsystemrdquo Desalination vol 328 pp 74ndash82 2013

[9] M Khamooshi K Parham F Egelioglu M Yari and H SalatildquoSimulation and optimization of novel configurations of tripleabsorption heat transformers integrated to a water desalinationsystemrdquo Desalination vol 348 pp 39ndash48 2014

[10] V ZareM Yari and SM SMahmoudi ldquoProposal and analysisof a new combined cogeneration system based on the GT-MHRcyclerdquo Desalination vol 286 pp 417ndash428 2012

[11] M Yari ldquoA novel cogeneration cycle based on a recompressionsupercritical carbon dioxide cycle for waste heat recovery innuclear power plantsrdquo International Journal of Exergy vol 10no 3 pp 346ndash364 2012

[12] J Siqueiros and R J Romero ldquoIncrease of COP for heattransformer in water purification systemsmdashpart I increasingheat source temperaturerdquo Applied Thermal Engineering vol 27no 5-6 pp 1043ndash1053 2007

[13] R J Romero J Siqueiros and A Huicochea ldquoIncrease of COPfor heat transformer in water purification systems Part IImdashwithout increasing heat source temperaturerdquo Applied ThermalEngineering vol 27 no 5-6 pp 1054ndash1061 2007

[14] J A Hernandez A Bassam J Siqueiros andD Juarez-RomeroldquoOptimumoperating conditions for awater purification processintegrated to a heat transformer with energy recycling usingneural network inverserdquo Renewable Energy vol 34 no 4 pp1084ndash1091 2009

[15] J A Hernandez D Juarez-Romero L I Morales and JSiqueiros ldquoCOP prediction for the integration of a waterpurification process in a heat transformer with and withoutenergy recyclingrdquo Desalination vol 219 no 1ndash3 pp 66ndash802008

[16] Z Zhao Y Ma and J Chen ldquoThermodynamic performanceof a new type of double absorption heat transformerrdquo AppliedThermal Engineering vol 23 no 18 pp 2407ndash2414 2003

[17] Z Zhao F Zhou X Zhang and S Li ldquoThe thermodynamicperformance of a new solution cycle in double absorption heattransformer usingwaterlithiumbromide as theworking fluidsrdquoInternational Journal of Refrigeration vol 26 no 3 pp 315ndash3202003

[18] H Martınez and W Rivera ldquoEnergy and exergy anal-ysis of a double absorption heat transformer operatingwith waterlithium bromiderdquo International Journal of EnergyResearch vol 33 no 7 pp 662ndash674 2009

[19] I Horuz and B Kurt ldquoSingle stage and double absorption heattransformers in an industrial applicationrdquo International Journalof Energy Research vol 33 no 9 pp 787ndash798 2009

[20] R Gomri ldquoThermal seawater desalination possibilities of usingsingle effect and double effect absorption heat transformersystemsrdquo Desalination vol 253 no 1ndash3 pp 112ndash118 2010

[21] R Gomri ldquoEnergy and exergy analyses of seawater desalinationsystem integrated in a solar heat transformerrdquoDesalination vol249 no 1 pp 188ndash196 2009

[22] K Parham U Atikol M Yari and O P Agboola ldquoEvaluationand optimization of single stage absorption chiller using (LiCl +H2O) as the working pairrdquoAdvances inMechanical Engineering

vol 2013 Article ID 683157 8 pages 2013[23] I Horuz ldquoA comparison between ammonia-water and water-

lithium bromide solutions in vapor absorption refrigerationsystemsrdquo International Communications in Heat and MassTransfer vol 25 no 5 pp 711ndash721 1998

[24] J Sun L Fu and S Zhang ldquoA review of working fluids ofabsorption cyclesrdquo Renewable and Sustainable Energy Reviewsvol 16 no 4 pp 1899ndash1906 2012

[25] M Khamooshi K Parham and U Atikol ldquoOverview of ionicliquids used as working fluids in absorption cyclesrdquo AdvancesinMechanical Engineering vol 2013 Article ID 620592 7 pages2013

[26] K Parham M Khamooshi D B K Tematio M Yari andU Atikol ldquoAbsorption heat transformersmdasha comprehensivereviewrdquo Renewable and Sustainable Energy Reviews vol 34 pp430ndash452 2014

[27] P Donnellan E Byrne and K Cronin ldquoInternal energy andexergy recovery in high temperature application absorptionheat transformersrdquoAppliedThermal Engineering vol 56 no 1-2pp 1ndash10 2013

[28] P Donnellan E Byrne J Oliveira and K Cronin ldquoFirst andsecond lawmultidimensional analysis of a triple absorption heattransformer (TAHT)rdquoApplied Energy vol 113 pp 141ndash151 2014

[29] R Best and W Rivera ldquoThermodynamic design data forabsorption heat transformers Part six operating on water-carrolrdquo Heat Recovery Systems amp CHP vol 14 no 4 pp 427ndash436 1994


[30] M A R Eisa R Best and F A Holland ldquoThermodynamicdesign data for absorption heat transformers-Part II Operatingon water-calcium chloriderdquo Journal of Heat Recovery Systemsvol 6 no 6 pp 443ndash450 1986

[31] W Rivera J Cerezo R Rivero J Cervantes and R BestldquoSingle stage and double absorption heat transformers used torecover energy in a distillation column of butane and pentanerdquoInternational Journal of Energy Research vol 27 no 14 pp 1279ndash1292 2003

[32] S A Klein and F AlvaradoEngineering Equation Solver Version9237 F-Chart Software Middleton Wis USA 2012

[33] W Rivera M J Cardoso and R J Romero ldquoSingle-stage andadvanced absorption heat transformers operating with lithiumbromide mixtures used to increase solar pondrsquos temperaturerdquoSolar Energy Materials and Solar Cells vol 70 no 3 pp 321ndash333 2001

[34] M Ahachad M Charia and A Bernatchou ldquoSolar absorp-tion heat transformer applications to absorption refrigeratingmachinesrdquo International Journal of Energy Research vol 17 no8 pp 719ndash726 1993

[35] X Zhang and J Li ldquoExergy analysis of double absorptionheat transformers with a new solution cyclerdquo Journal of DalianUniversity of Technology vol 47 no 3 pp 333ndash337 2007

[36] T G Kolda R M Lewis and V Torczon ldquoOptimization bydirect search new perspectives on some classical and modernmethodsrdquo SIAM Review vol 45 no 3 pp 385ndash482 2003

[37] W Rivera A Huicochea H Martınez J Siqueiros D Juarezand E Cadenas ldquoExergy analysis of an experimental heattransformer for water purificationrdquo Energy vol 36 no 1 pp320ndash327 2011

[38] S Sekar and R Saravanan ldquoExperimental studies on absorptionheat transformer coupled distillation systemrdquoDesalination vol274 no 1ndash3 pp 292ndash301 2011

[39] R J Romero and A Rodrıguez-Martınez ldquoOptimal waterpurification using low grade waste heat in an absorption heattransformerrdquo Desalination vol 220 no 1ndash3 pp 506ndash513 2008

[40] L Garousi Farshi S M Seyed Mahmoudi and M A RosenldquoAnalysis of crystallization risk in double effect absorptionrefrigeration systemsrdquo AppliedThermal Engineering vol 31 no10 pp 1712ndash1717 2011

TribologyAdvances in

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

FuelsJournal of


Journal ofPetroleum Engineering


Industrial EngineeringJournal of


Power ElectronicsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

CombustionJournal of


Journal of


Renewable Energy

Submit your manuscripts athttpwwwhindawicom


StructuresJournal of


RotatingMachinery


EnergyJournal of


Hindawi Publishing Corporation httpwwwhindawicom

Journal ofEngineeringVolume 2014

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy


Nuclear InstallationsScience and Technology of


Solar EnergyJournal of


Wind EnergyJournal of


Nuclear EnergyInternational Journal of


High Energy PhysicsAdvances in

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014


of the AHT Yari presented a novel cogeneration cyclecomprised of a transcritical CO

2power cycle and a LiBrH

2O

single absorption heat transformer [11] The maximum waterproduction rate of 3317 kgs was acquired by the cycle Sozenand Yucesu [6] performed a mathematical simulation inorder to compare the absorption heat transformers utilizingejectors to the basic AHTs Both cycles used H

2ONH

3as

the working pair and employed the waste heat from a solarpond The results demonstrated that both energy and exergyefficiency improvements were achievable by using ejector inthe absorption heat transformer

Siqueiros and Romero conducted two studies aboutrecycling energy with and without increasing heat sourcetemperature in AHT systems [12 13] They noticed someimprovements in the proposed cycles than that of simpleabsorption heat transformer Performance evaluation of theabsorption heat transformers is possible by using artificialneural network analysis [14 15] Zhao et al [16 17] con-ducted a study to analyze three different configurations ofdouble absorption heat transformers by the working pairsof LiBrH

2O They concluded that the temperature of the

absorbing evaporator is not an independent variable andmainly depends on the absorber temperature

First and second law analysis of a double absorptionheat transformer operating with LiBrH

2O were studied by

Martınez and Rivera [18] They formulated a mathematicalmodel for estimating theCOP ECOP total exergy destructionin the system and exergy destruction in all the components asa function of temperature Horuz and Kurt [19] investigatedand compared single series and parallel double absorptionheat transformers They proved that the parallel doubleAHT system could generate more water vapor than thatof the series double AHT system A performance compar-ison of the single effect and double effect absorption heattransformer systems was made by Gomri [20] The resultsshowed that the double effect absorption heat transformers(DAHTs) had higher exergy and energy efficiencies andsmaller water production than that of the single effectabsorption heat transformers (SAHT) Also they discussed asolar absorption heat transformer coupled to a desalinationsystem in a different study [21] The proposed system couldproduce fresh water of 500 L per day in July for a beachhouse

The performance of the absorption cycles depends notonly on their configuration but also on thermodynamicproperties of working pairs which are regularly composedof refrigerants and absorbents [22] A comparison wasmade between H

2ONH

3and LiBrH

2O solutions in single

absorption heat transformer by Horuz [23] Sun et al [24]conducted a review study about different kinds of workingpairs in absorption cycles Furthermore Khamooshi et al[25] did a similar work for employed ionic liquids as work-ing fluids The same team published their second reviewpaper wherein AHTs from the view point of applicationscrystallization risk working fluids performance evalua-tion and economic aspects were reviewed comprehensively[26]

Donnellan et al [27] introduced six different configura-tions of triple absorption heat transformers using LiBrH

2O

Table 1 System performances of different types of absorption heattransformers

Type GTL COP ReferenceSingle absorption heattransformer (SAHT) 50∘C sim05 [1 8 19]

Double absorption heattransformer (DAHT) 80∘C sim035 [16ndash19]

Triple absorption heattransformer (THAT) sim140 sim023 [27 28]

as the working fluid They optimized the number and loca-tions of the heat exchangers within the system by reassem-bling them In the second work a rigorous multidimensionalanalysis wasmade for evaluating the performance of the tripleabsorption heat transformers by Donnellan et al [28]

In this study a triple absorption heat transformer willbe represented with a modified configuration described byDonnellan et al [27] However their study did not investigatethe effect of some major parameters on the performance ofthe system

A thorough and comprehensive thermodynamic analysiswill be performed for the best configuration of the lattermentioned study by the purpose of continuing it A paramet-ric study will be carried out and validated by other studiesavailable from the literature in order to identify the effects ofsome parameters such as the temperatures of the condenserevaporator absorber generator first absorberevaporator(ABEV1) and second absorberevaporator (ABEV2) con-centration of the weak and strong solution and economizereffectiveness

2 System Description

Figure 1 shows the general schematic of the absorptionheat transformer in single stage mode The SAHT basicallyconsists of an evaporator a condenser a generator anabsorber and a solution heat exchanger (SHE)The generatorand evaporator are supplied with waste heat at the sametemperature leading to increased heat that can be collectedat the absorber [26]

Refrigerant vapor is produced at state 4 in the evaporatorby low or medium-grade heat source The refrigerant vapordissolves and reacts with the strong refrigerant-absorbentsolution that enters the absorber from state 10 and the weaksolution returns back to the generator at state 5 The heatreleased from the absorber will be higher than the input heatin generator and evaporator due to the exothermic reaction ofLiBr and water in it In the generator some refrigerant vaporis removed from theweak solution to be sent to the condenserand consequently the strong solution from the generatoris returned to the absorber After condensing the vaporizedrefrigerant in the condenser it is pumped to a higher pressurelevel as it enters the evaporator The waste heat delivered tothe evaporator causes its vaporization Again the absorberabsorbs the refrigerant vapor at a higher temperature There-fore the absorption cycles have the capability of raising the


ABRestrictor

Solutionpump

GE

AHTCO


EV

1

23

4

5 6 7

8910

Qabsorber

Qevaporator

Qgenerator

Qcondenser

ECO


Wastewater

Generator1Condenser

9

2

RP1

3

34 35

4

RP2

10

ABEV1

11

19

RP320

HEX3

8

5

ABEV2

21

22

Evaporator

12

18

28 Combo

29

2723

Absorber

SplitSplit

13 24 33

HEX1

17 14

2532

3031

SP1 SP2 SP3v1

v2

v3

7 6 16 15 26

HEX2









1and


2Osolution flowing


3) and consequently






















∘C) 20ndash35a

119879abs (∘C) 180ndash215b

119879eva (∘C) 80ndash110c

119879eva = 119879gen (∘C) d

119879ABEV1 (∘C) 110ndash145e

119879ABEV2 (∘C) 150ndash180e



120576ECO () 80g



COP =119876abs119876gen + 119876eva

(1)


119891 =


(2)



119876gen = 1ℎ1 + 7ℎ7 + 16ℎ16 + 31ℎ31 minus 6ℎ6



119876abs = 22ℎ22 + 33ℎ33 minus 23ℎ23



(3)


119902abs =119876abs4

= (119891 + 1) ℎ23minus 119891ℎ22minus ℎ33 (4)


BP1 = 1198982411989827

BP2 =11989813

11989828

(5)





90 le 119879eva le 105∘C

90 le 119879gen le 105∘C

110 le 119879AB1 le 145∘C

165 le 119879AB2 le 180∘C

180 le 119879abs le 215∘C

(6)






same are 741∘C






20 24 280

01

02

03

04

05

Present study

COP

Tcon (∘C)

Tabs = 123∘C


Rivera et al (2003)


80 90 100 11002

021

022

023

024

025

COP

Tcon = 25∘C


TABEV1 = 130∘C BP1 = 1

BP2 = 1

COP Tabs = 205∘C

COP Tabs = 215∘C

COP Tabs = 195∘C

Teva (∘C)





002

0

minus002

minus004

minus006

minus008

minus01

004002


140135

130125

120115

110 8085

9095

100105

110

COP

GTL



0225

023

0235

024

0245

COP

05 1 15 2

BP1

Tcon = 25∘C

Teva = Tgen

TABEV2 = 165∘C

TABEV1 = 130∘C BP2 = 1

Tabs = 215∘C

COP Teva = 90∘C

COP Teva = 95∘C

COP Teva = 100∘C






024

023

COP

05 1 15 2

BP2

COP Teva = 90∘C

COP Teva = 95∘C

COP Teva = 100∘C

Tcon = 25∘C

Teva = Tgen

TABEV2 = 165∘C

TABEV1 = 130∘C BP2 = 1

Tabs = 215∘C


025

024

023

022

021

02

01980 90 100

COP

COP Tabs = 205∘C

COP Tabs = 215∘C

COP Tabs = 195∘C

Tcon = 25∘C


TABEV1 = 130∘C BP1 = 1

BP2 = 1

Teva (∘C)


180 190 200 210 2200225

023

0235

024

0245

COP

COP Teva = 90∘C

COP Teva = 95∘C

COP Teva = 100∘C

Tcon = 25∘C


TABEV1 = 130∘C BP1 = 1

BP2 = 1

Tabs (∘C)



021

0215

022

0225

023

0235

024

0245

COP

20 25 30 35

Teva = Tgen

TABEV2 = 165∘C

TABEV1 = 130∘C BP1 = 1

BP2 = 1Tabs = 215∘C

Tcon (∘C)

COP Teva = 90∘C

COP Teva = 95∘C

COP Teva = 100∘C


180 190 200 210 22003

04

05

06

07

08

Xw

Xs

Tcon = 25∘C


∘CTABEV1 = 130

∘CTeva = 90

∘C

Tabs (∘C)

BP1 = 1

BP2 = 1

Xw

Xs

(wt

abso

rben

t)



23)






119904




180 190 200 210 220015

02

025

03

035

04

ΔX

998779X

(wt

abso

rben

t)

Tcon = 25∘C

Teva = Tgen

TABEV2 = 165∘C

TABEV1 = 130∘C

Teva = 90∘C

BP1 = 1

Tabs (∘C)

BP2 = 1


110 115 120 125 130 135 1400215

022

0225

023

0235

024

0245

COP

BP1 = 1

BP2 = 1

Tcon = 25∘C


∘C

Tabs = 215∘C

COP Teva = 90∘C

COP Teva = 95∘C

COP Teva = 100∘C

TABEV1 (∘C)











165 170 175 1800225

023

0235

024

COP

COP Teva = 90∘C

COP Teva = 95∘C

COP Teva = 100∘C

Tcon = 25∘C


∘CTabs = 215∘C

BP1 = 1

BP2 = 1

TABEV2 (∘C)


01 02 03 04 05 06 07 08019

02

021

022

023

024

025


COP

COP

Tcon = 25∘C


TABEV1 = 130∘C


∘C

BP1 = 1

BP2 = 1




5 Optimization


30 40 50 60 70 80 90 100 110 120

02

025

03

035

04

045

05

COP

SingleDoubleTriple

Teva = 75∘C


∘C

Tcon = 25∘C




∘C


ΔT (∘C)





∘C

6 Conclusion











References















































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of


















ABRestrictor

Solutionpump

GE

AHTCO


EV

1

23

4

5 6 7

8910

Qabsorber

Qevaporator

Qgenerator

Qcondenser

ECO


Wastewater

Generator1Condenser

9

2

RP1

3

34 35

4

RP2

10

ABEV1

11

19

RP320

HEX3

8

5

ABEV2

21

22

Evaporator

12

18

28 Combo

29

2723

Absorber

SplitSplit

13 24 33

HEX1

17 14

2532

3031

SP1 SP2 SP3v1

v2

v3

7 6 16 15 26

HEX2









1and


2Osolution flowing


3) and consequently






















∘C) 20ndash35a

119879abs (∘C) 180ndash215b

119879eva (∘C) 80ndash110c

119879eva = 119879gen (∘C) d

119879ABEV1 (∘C) 110ndash145e

119879ABEV2 (∘C) 150ndash180e



120576ECO () 80g



COP =119876abs119876gen + 119876eva

(1)


119891 =


(2)



119876gen = 1ℎ1 + 7ℎ7 + 16ℎ16 + 31ℎ31 minus 6ℎ6



119876abs = 22ℎ22 + 33ℎ33 minus 23ℎ23



(3)


119902abs =119876abs4

= (119891 + 1) ℎ23minus 119891ℎ22minus ℎ33 (4)


BP1 = 1198982411989827

BP2 =11989813

11989828

(5)





90 le 119879eva le 105∘C

90 le 119879gen le 105∘C

110 le 119879AB1 le 145∘C

165 le 119879AB2 le 180∘C

180 le 119879abs le 215∘C

(6)






same are 741∘C






20 24 280

01

02

03

04

05

Present study

COP

Tcon (∘C)

Tabs = 123∘C


Rivera et al (2003)


80 90 100 11002

021

022

023

024

025

COP

Tcon = 25∘C


TABEV1 = 130∘C BP1 = 1

BP2 = 1

COP Tabs = 205∘C

COP Tabs = 215∘C

COP Tabs = 195∘C

Teva (∘C)





002

0

minus002

minus004

minus006

minus008

minus01

004002


140135

130125

120115

110 8085

9095

100105

110

COP

GTL



0225

023

0235

024

0245

COP

05 1 15 2

BP1

Tcon = 25∘C

Teva = Tgen

TABEV2 = 165∘C

TABEV1 = 130∘C BP2 = 1

Tabs = 215∘C

COP Teva = 90∘C

COP Teva = 95∘C

COP Teva = 100∘C






024

023

COP

05 1 15 2

BP2

COP Teva = 90∘C

COP Teva = 95∘C

COP Teva = 100∘C

Tcon = 25∘C

Teva = Tgen

TABEV2 = 165∘C

TABEV1 = 130∘C BP2 = 1

Tabs = 215∘C


025

024

023

022

021

02

01980 90 100

COP

COP Tabs = 205∘C

COP Tabs = 215∘C

COP Tabs = 195∘C

Tcon = 25∘C


TABEV1 = 130∘C BP1 = 1

BP2 = 1

Teva (∘C)


180 190 200 210 2200225

023

0235

024

0245

COP

COP Teva = 90∘C

COP Teva = 95∘C

COP Teva = 100∘C

Tcon = 25∘C


TABEV1 = 130∘C BP1 = 1

BP2 = 1

Tabs (∘C)



021

0215

022

0225

023

0235

024

0245

COP

20 25 30 35

Teva = Tgen

TABEV2 = 165∘C

TABEV1 = 130∘C BP1 = 1

BP2 = 1Tabs = 215∘C

Tcon (∘C)

COP Teva = 90∘C

COP Teva = 95∘C

COP Teva = 100∘C


180 190 200 210 22003

04

05

06

07

08

Xw

Xs

Tcon = 25∘C


∘CTABEV1 = 130

∘CTeva = 90

∘C

Tabs (∘C)

BP1 = 1

BP2 = 1

Xw

Xs

(wt

abso

rben

t)



23)






119904




180 190 200 210 220015

02

025

03

035

04

ΔX

998779X

(wt

abso

rben

t)

Tcon = 25∘C

Teva = Tgen

TABEV2 = 165∘C

TABEV1 = 130∘C

Teva = 90∘C

BP1 = 1

Tabs (∘C)

BP2 = 1


110 115 120 125 130 135 1400215

022

0225

023

0235

024

0245

COP

BP1 = 1

BP2 = 1

Tcon = 25∘C


∘C

Tabs = 215∘C

COP Teva = 90∘C

COP Teva = 95∘C

COP Teva = 100∘C

TABEV1 (∘C)











165 170 175 1800225

023

0235

024

COP

COP Teva = 90∘C

COP Teva = 95∘C

COP Teva = 100∘C

Tcon = 25∘C


∘CTabs = 215∘C

BP1 = 1

BP2 = 1

TABEV2 (∘C)


01 02 03 04 05 06 07 08019

02

021

022

023

024

025


COP

COP

Tcon = 25∘C


TABEV1 = 130∘C


∘C

BP1 = 1

BP2 = 1




5 Optimization


30 40 50 60 70 80 90 100 110 120

02

025

03

035

04

045

05

COP

SingleDoubleTriple

Teva = 75∘C


∘C

Tcon = 25∘C




∘C


ΔT (∘C)





∘C

6 Conclusion











References















































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of





































∘C) 20ndash35a

119879abs (∘C) 180ndash215b

119879eva (∘C) 80ndash110c

119879eva = 119879gen (∘C) d

119879ABEV1 (∘C) 110ndash145e

119879ABEV2 (∘C) 150ndash180e



120576ECO () 80g



COP =119876abs119876gen + 119876eva

(1)


119891 =


(2)



119876gen = 1ℎ1 + 7ℎ7 + 16ℎ16 + 31ℎ31 minus 6ℎ6



119876abs = 22ℎ22 + 33ℎ33 minus 23ℎ23



(3)


119902abs =119876abs4

= (119891 + 1) ℎ23minus 119891ℎ22minus ℎ33 (4)


BP1 = 1198982411989827

BP2 =11989813

11989828

(5)





90 le 119879eva le 105∘C

90 le 119879gen le 105∘C

110 le 119879AB1 le 145∘C

165 le 119879AB2 le 180∘C

180 le 119879abs le 215∘C

(6)






same are 741∘C






20 24 280

01

02

03

04

05

Present study

COP

Tcon (∘C)

Tabs = 123∘C


Rivera et al (2003)


80 90 100 11002

021

022

023

024

025

COP

Tcon = 25∘C


TABEV1 = 130∘C BP1 = 1

BP2 = 1

COP Tabs = 205∘C

COP Tabs = 215∘C

COP Tabs = 195∘C

Teva (∘C)





002

0

minus002

minus004

minus006

minus008

minus01

004002


140135

130125

120115

110 8085

9095

100105

110

COP

GTL



0225

023

0235

024

0245

COP

05 1 15 2

BP1

Tcon = 25∘C

Teva = Tgen

TABEV2 = 165∘C

TABEV1 = 130∘C BP2 = 1

Tabs = 215∘C

COP Teva = 90∘C

COP Teva = 95∘C

COP Teva = 100∘C






024

023

COP

05 1 15 2

BP2

COP Teva = 90∘C

COP Teva = 95∘C

COP Teva = 100∘C

Tcon = 25∘C

Teva = Tgen

TABEV2 = 165∘C

TABEV1 = 130∘C BP2 = 1

Tabs = 215∘C


025

024

023

022

021

02

01980 90 100

COP

COP Tabs = 205∘C

COP Tabs = 215∘C

COP Tabs = 195∘C

Tcon = 25∘C


TABEV1 = 130∘C BP1 = 1

BP2 = 1

Teva (∘C)


180 190 200 210 2200225

023

0235

024

0245

COP

COP Teva = 90∘C

COP Teva = 95∘C

COP Teva = 100∘C

Tcon = 25∘C


TABEV1 = 130∘C BP1 = 1

BP2 = 1

Tabs (∘C)



021

0215

022

0225

023

0235

024

0245

COP

20 25 30 35

Teva = Tgen

TABEV2 = 165∘C

TABEV1 = 130∘C BP1 = 1

BP2 = 1Tabs = 215∘C

Tcon (∘C)

COP Teva = 90∘C

COP Teva = 95∘C

COP Teva = 100∘C


180 190 200 210 22003

04

05

06

07

08

Xw

Xs

Tcon = 25∘C


∘CTABEV1 = 130

∘CTeva = 90

∘C

Tabs (∘C)

BP1 = 1

BP2 = 1

Xw

Xs

(wt

abso

rben

t)



23)






119904




180 190 200 210 220015

02

025

03

035

04

ΔX

998779X

(wt

abso

rben

t)

Tcon = 25∘C

Teva = Tgen

TABEV2 = 165∘C

TABEV1 = 130∘C

Teva = 90∘C

BP1 = 1

Tabs (∘C)

BP2 = 1


110 115 120 125 130 135 1400215

022

0225

023

0235

024

0245

COP

BP1 = 1

BP2 = 1

Tcon = 25∘C


∘C

Tabs = 215∘C

COP Teva = 90∘C

COP Teva = 95∘C

COP Teva = 100∘C

TABEV1 (∘C)











165 170 175 1800225

023

0235

024

COP

COP Teva = 90∘C

COP Teva = 95∘C

COP Teva = 100∘C

Tcon = 25∘C


∘CTabs = 215∘C

BP1 = 1

BP2 = 1

TABEV2 (∘C)


01 02 03 04 05 06 07 08019

02

021

022

023

024

025


COP

COP

Tcon = 25∘C


TABEV1 = 130∘C


∘C

BP1 = 1

BP2 = 1




5 Optimization


30 40 50 60 70 80 90 100 110 120

02

025

03

035

04

045

05

COP

SingleDoubleTriple

Teva = 75∘C


∘C

Tcon = 25∘C




∘C


ΔT (∘C)





∘C

6 Conclusion











References















































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of





















90 le 119879eva le 105∘C

90 le 119879gen le 105∘C

110 le 119879AB1 le 145∘C

165 le 119879AB2 le 180∘C

180 le 119879abs le 215∘C

(6)






same are 741∘C






20 24 280

01

02

03

04

05

Present study

COP

Tcon (∘C)

Tabs = 123∘C


Rivera et al (2003)


80 90 100 11002

021

022

023

024

025

COP

Tcon = 25∘C


TABEV1 = 130∘C BP1 = 1

BP2 = 1

COP Tabs = 205∘C

COP Tabs = 215∘C

COP Tabs = 195∘C

Teva (∘C)





002

0

minus002

minus004

minus006

minus008

minus01

004002


140135

130125

120115

110 8085

9095

100105

110

COP

GTL



0225

023

0235

024

0245

COP

05 1 15 2

BP1

Tcon = 25∘C

Teva = Tgen

TABEV2 = 165∘C

TABEV1 = 130∘C BP2 = 1

Tabs = 215∘C

COP Teva = 90∘C

COP Teva = 95∘C

COP Teva = 100∘C






024

023

COP

05 1 15 2

BP2

COP Teva = 90∘C

COP Teva = 95∘C

COP Teva = 100∘C

Tcon = 25∘C

Teva = Tgen

TABEV2 = 165∘C

TABEV1 = 130∘C BP2 = 1

Tabs = 215∘C


025

024

023

022

021

02

01980 90 100

COP

COP Tabs = 205∘C

COP Tabs = 215∘C

COP Tabs = 195∘C

Tcon = 25∘C


TABEV1 = 130∘C BP1 = 1

BP2 = 1

Teva (∘C)


180 190 200 210 2200225

023

0235

024

0245

COP

COP Teva = 90∘C

COP Teva = 95∘C

COP Teva = 100∘C

Tcon = 25∘C


TABEV1 = 130∘C BP1 = 1

BP2 = 1

Tabs (∘C)



021

0215

022

0225

023

0235

024

0245

COP

20 25 30 35

Teva = Tgen

TABEV2 = 165∘C

TABEV1 = 130∘C BP1 = 1

BP2 = 1Tabs = 215∘C

Tcon (∘C)

COP Teva = 90∘C

COP Teva = 95∘C

COP Teva = 100∘C


180 190 200 210 22003

04

05

06

07

08

Xw

Xs

Tcon = 25∘C


∘CTABEV1 = 130

∘CTeva = 90

∘C

Tabs (∘C)

BP1 = 1

BP2 = 1

Xw

Xs

(wt

abso

rben

t)



23)






119904




180 190 200 210 220015

02

025

03

035

04

ΔX

998779X

(wt

abso

rben

t)

Tcon = 25∘C

Teva = Tgen

TABEV2 = 165∘C

TABEV1 = 130∘C

Teva = 90∘C

BP1 = 1

Tabs (∘C)

BP2 = 1


110 115 120 125 130 135 1400215

022

0225

023

0235

024

0245

COP

BP1 = 1

BP2 = 1

Tcon = 25∘C


∘C

Tabs = 215∘C

COP Teva = 90∘C

COP Teva = 95∘C

COP Teva = 100∘C

TABEV1 (∘C)











165 170 175 1800225

023

0235

024

COP

COP Teva = 90∘C

COP Teva = 95∘C

COP Teva = 100∘C

Tcon = 25∘C


∘CTabs = 215∘C

BP1 = 1

BP2 = 1

TABEV2 (∘C)


01 02 03 04 05 06 07 08019

02

021

022

023

024

025


COP

COP

Tcon = 25∘C


TABEV1 = 130∘C


∘C

BP1 = 1

BP2 = 1




5 Optimization


30 40 50 60 70 80 90 100 110 120

02

025

03

035

04

045

05

COP

SingleDoubleTriple

Teva = 75∘C


∘C

Tcon = 25∘C




∘C


ΔT (∘C)





∘C

6 Conclusion











References















































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of


















002

0

minus002

minus004

minus006

minus008

minus01

004002


140135

130125

120115

110 8085

9095

100105

110

COP

GTL



0225

023

0235

024

0245

COP

05 1 15 2

BP1

Tcon = 25∘C

Teva = Tgen

TABEV2 = 165∘C

TABEV1 = 130∘C BP2 = 1

Tabs = 215∘C

COP Teva = 90∘C

COP Teva = 95∘C

COP Teva = 100∘C






024

023

COP

05 1 15 2

BP2

COP Teva = 90∘C

COP Teva = 95∘C

COP Teva = 100∘C

Tcon = 25∘C

Teva = Tgen

TABEV2 = 165∘C

TABEV1 = 130∘C BP2 = 1

Tabs = 215∘C


025

024

023

022

021

02

01980 90 100

COP

COP Tabs = 205∘C

COP Tabs = 215∘C

COP Tabs = 195∘C

Tcon = 25∘C


TABEV1 = 130∘C BP1 = 1

BP2 = 1

Teva (∘C)


180 190 200 210 2200225

023

0235

024

0245

COP

COP Teva = 90∘C

COP Teva = 95∘C

COP Teva = 100∘C

Tcon = 25∘C


TABEV1 = 130∘C BP1 = 1

BP2 = 1

Tabs (∘C)



021

0215

022

0225

023

0235

024

0245

COP

20 25 30 35

Teva = Tgen

TABEV2 = 165∘C

TABEV1 = 130∘C BP1 = 1

BP2 = 1Tabs = 215∘C

Tcon (∘C)

COP Teva = 90∘C

COP Teva = 95∘C

COP Teva = 100∘C


180 190 200 210 22003

04

05

06

07

08

Xw

Xs

Tcon = 25∘C


∘CTABEV1 = 130

∘CTeva = 90

∘C

Tabs (∘C)

BP1 = 1

BP2 = 1

Xw

Xs

(wt

abso

rben

t)



23)






119904




180 190 200 210 220015

02

025

03

035

04

ΔX

998779X

(wt

abso

rben

t)

Tcon = 25∘C

Teva = Tgen

TABEV2 = 165∘C

TABEV1 = 130∘C

Teva = 90∘C

BP1 = 1

Tabs (∘C)

BP2 = 1


110 115 120 125 130 135 1400215

022

0225

023

0235

024

0245

COP

BP1 = 1

BP2 = 1

Tcon = 25∘C


∘C

Tabs = 215∘C

COP Teva = 90∘C

COP Teva = 95∘C

COP Teva = 100∘C

TABEV1 (∘C)











165 170 175 1800225

023

0235

024

COP

COP Teva = 90∘C

COP Teva = 95∘C

COP Teva = 100∘C

Tcon = 25∘C


∘CTabs = 215∘C

BP1 = 1

BP2 = 1

TABEV2 (∘C)


01 02 03 04 05 06 07 08019

02

021

022

023

024

025


COP

COP

Tcon = 25∘C


TABEV1 = 130∘C


∘C

BP1 = 1

BP2 = 1




5 Optimization


30 40 50 60 70 80 90 100 110 120

02

025

03

035

04

045

05

COP

SingleDoubleTriple

Teva = 75∘C


∘C

Tcon = 25∘C




∘C


ΔT (∘C)





∘C

6 Conclusion











References















































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of


















021

0215

022

0225

023

0235

024

0245

COP

20 25 30 35

Teva = Tgen

TABEV2 = 165∘C

TABEV1 = 130∘C BP1 = 1

BP2 = 1Tabs = 215∘C

Tcon (∘C)

COP Teva = 90∘C

COP Teva = 95∘C

COP Teva = 100∘C


180 190 200 210 22003

04

05

06

07

08

Xw

Xs

Tcon = 25∘C


∘CTABEV1 = 130

∘CTeva = 90

∘C

Tabs (∘C)

BP1 = 1

BP2 = 1

Xw

Xs

(wt

abso

rben

t)



23)






119904




180 190 200 210 220015

02

025

03

035

04

ΔX

998779X

(wt

abso

rben

t)

Tcon = 25∘C

Teva = Tgen

TABEV2 = 165∘C

TABEV1 = 130∘C

Teva = 90∘C

BP1 = 1

Tabs (∘C)

BP2 = 1


110 115 120 125 130 135 1400215

022

0225

023

0235

024

0245

COP

BP1 = 1

BP2 = 1

Tcon = 25∘C


∘C

Tabs = 215∘C

COP Teva = 90∘C

COP Teva = 95∘C

COP Teva = 100∘C

TABEV1 (∘C)











165 170 175 1800225

023

0235

024

COP

COP Teva = 90∘C

COP Teva = 95∘C

COP Teva = 100∘C

Tcon = 25∘C


∘CTabs = 215∘C

BP1 = 1

BP2 = 1

TABEV2 (∘C)


01 02 03 04 05 06 07 08019

02

021

022

023

024

025


COP

COP

Tcon = 25∘C


TABEV1 = 130∘C


∘C

BP1 = 1

BP2 = 1




5 Optimization


30 40 50 60 70 80 90 100 110 120

02

025

03

035

04

045

05

COP

SingleDoubleTriple

Teva = 75∘C


∘C

Tcon = 25∘C




∘C


ΔT (∘C)





∘C

6 Conclusion











References















































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of




















165 170 175 1800225

023

0235

024

COP

COP Teva = 90∘C

COP Teva = 95∘C

COP Teva = 100∘C

Tcon = 25∘C


∘CTabs = 215∘C

BP1 = 1

BP2 = 1

TABEV2 (∘C)


01 02 03 04 05 06 07 08019

02

021

022

023

024

025


COP

COP

Tcon = 25∘C


TABEV1 = 130∘C


∘C

BP1 = 1

BP2 = 1




5 Optimization


30 40 50 60 70 80 90 100 110 120

02

025

03

035

04

045

05

COP

SingleDoubleTriple

Teva = 75∘C


∘C

Tcon = 25∘C




∘C


ΔT (∘C)





∘C

6 Conclusion











References















































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of






















References















































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of

































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of

















980452

Documents

Transcript of 980452