PERFORMANCE ANALYSIS OF VAPOUR COMPRESSION
Int. J. Mech. Eng. & Rob. Res. 2013Jyoti Soni and R C Gupta, 2013ISSN 2278 – 0149 www.ijmerr.comVol. 2, No. 1, January 2013 2013 IJMERR. All Rights ReservedResearch PaperPERFORMANCE ANALYSIS OF VAPOURCOMPRESSION REFRIGERATION SYSTEM WITHR404A, R407C AND R410AJyoti Soni1* and R C Gupta1*Corresponding Author: Jyoti Soni, Jyoti.soni45@gmail.comThis paper provides a detailed exergy analysis for theoretical vapour compression refrigerationcycle using R404A, R407C and R410A. The equations of exergetic efficiency and exergydestruction for the main system components such as compressor, condenser expansion device,liquid-vapour heat exchanger and evaporator are developed. The relations for total exergydestruction in the system, the overall exegetic efficiency of the system and Exergy DestructionRatio (EDR) related to exergetic efficiency are obtained. Also, an expression for Coefficient ofPerformance (COP) of refrigeration cycle is developed. The investigations shows that variousresults are obtained for the effect of evaporating temperatures, condensing temperatures, degreeof subcooling and effectiveness of liquid-vapour heat exchanger on COP, exergetic efficiencyand EDR of theoretical vapour compression refrigeration cycle.Keywords: Exergetic analysis, Refrigeration system, Modelling, R404A, R407C, R410AINTRODUCTIONrules for sustainable development andreduction of Global Warming Potential(GWP) including the regulations of HCFC’s(United Nations, 2011). Both of CFC andHCFC have high ODP and GWP. Becauseof their high GWP, alternatives to refrigerantsCFC and HCFC such as azeotropic mixturesrefrigerants with their zero ODP have beenpreferred for use in many industrial anddomestic applications intensively for adecade.In the past decades, the Ozone DepletionPotential (ODP) and Global WarmingPotential (GWP) have becomes the dominantenvironmental issues, caused by the leakagesof the CFC and HCFC refrigerants. TheMontreal protocol (UNEP, 1997) declared thephasing out of CFC’s and HCFC’s asrefrigerants that deplete the ozone layer(ODP) (UNEP, 1997). The Kyoto protocol(UNFCC, 2011) encouraged promotion of1Jabalpur Engineering College, Gokulpur, Ranjhi, Jabalpur 482011, Madhya Pradesh, India.25
Int. J. Mech. Eng. & Rob. Res. 2013Jyoti Soni and R C Gupta, 2013in order to pinpoint those contributing most tothe decrease in the exergetic performance ofR407C. Aprea et al. (2004) conducted anexperimental analysis to study theperformances of a vapour compression plantworking both as a water chiller and as a heatpump, using as refrigerant fluids R22 and itssubstitute R417A. The results revealed thatR22 gives best performances in comparisonwith R417A in terms of COP, exergeticefficiency and exergy destroyed in thecomponents. Akhilesh and Kaushik (2008)present a detailed exergy analysis of an actualvapour compression refrigeration cycle. Acomputational model has been developed forcalculating the COP, exergetic efficiency,exergy destruction and efficiency defects forR502, R404A and R507A. The results of thisinvestigations revealed that R507A is a bettersubstitutes to R502 than R404A. Comakliet al. (2009) experimentally investigated theeffects of gas mixture rate, evaporator air inlettemperature (from 24 to 32), evaporator airmass flow rate (from 0.58 to 0.74), condenserair inlet temperature (from 22 to 34) andcondenser air mass flow rate (from 0.57 to0.73) on the COP and the exergetic efficiencyvalues of vapour compression heat pumpsystems. The investigation has been done forrefrigerants R22 and R404A five of their binarymixtures which contain about 0%, 25%, 50%,75% and 100% mass fractions of R404A weretested. It was observed that the most effectiveparameters are found to be condenser air inlettemperature on COP and exergetic efficiency.Miguel et al. (2010) presents an exergyanalysis of the impact of direct replacements(retrofit) of R12 with the zeotropic mixtureR413a on the performance of a domesticvapour compression refrigeration system,Various researches have suggesteddifferent HC, HFC and HCFC blends aspotential substitutes for CFCs and comparedthe performance of these substitutes eithertheoretically or experimentally. Douglas et al.(1999) describes the development andapplication of a cost-based method forcomparing alternative refrigerants applied toR22 systems. A computational model basedon this method was used to analyze theperformance of several leading R22replacements candidates for window airconditioners. From the investigations it wasrevealed that for the optimized systems, all thealternatives had system costs that were withinabout 4% of those for R22. Also, differencesbetween most of the alternative refrigerantswere smaller than the uncertainties in theanalysis. Havelsky (2000) conducted anexperimental analysis for R12 replacementswith the influence on energy efficiency andglobal warming expressed by the values ofCoefficient of Performance (COP) and TotalEquivalent Warming Impact (TEWI). PresentedExperimental analysis, relate the use ofrefrigerants R134a, R401A, R409A, R22 andthe mixture of R134a with R12 to the values ofCOP and TEWI of refrigerating system incomparison with R12 application. Their resultsshowed that the use of R134a, R401A andR409A refrigerants enables the values of TEWIin comparison with R12 application. Aprea andGreco (2002) presents an experimentalinvestigation for R22 replacements in vapourcompression plant with most widely useddrop-in substitute i.e. the zeotropic mixtureR407C. The experimental analysis was carriedout with the help of exergetic approach. Theexergetic performance of the individualcomponents of the plant has been analyzed,26
Int. J. Mech. Eng. & Rob. Res. 2013Jyoti Soni and R C Gupta, 2013originally designed to work with R12. Theresults of this experimental investigationshowed that overall energy and exergyperformance of the system working with R413Ais consistently better than that of R12.Venkataramanamurthy and Senthil (2010)conducted an experimental test for the analysisthe comparisons of energy, exergy flow andsecond law efficiency of R22 and its substitutesR-436b in vapour compression refrigerationsystem. The investigations present the effectsof the evaporating temperatures on the exergyflow losses and second law efficiency andcoefficient of performance of a vapourcompression refrigeration cycle. Bilal andSyed (2011) investigated performancedegradation due to fouling in a vapourcompression cycle for various applications.For the analysis consider the two sets ofrefrigerants depending upon the assumptionand their some properties. Considering the firstset of refrigerants R134a, R410A and R407Cwhile second set include the refrigerants ofR717, R404A and R290. From a first lawstandpoint, the COP of R134a alwaysperforms better than R410A and R407C unlessonly the evaporator is being fouled. From asecond law standpoint, the second lawefficiency of R134a performs the best in allcases. From a first law standpoint, the COPof R717 always performs better than R404Aand R290 unless only the evaporator is beingfouled. From a second law standpoint, thesecond law efficiency of R717 performs thebest in all cases. Volumetric efficiency ofR410A and R717 remained highest under allthe respective conditions. Furthermore,performance degradation of evaporator haslarger effect on compressor powerconsumption while the performancedegradation of condenser has larger effect onCOP of the vapour compression cycle.In this paper exergetic approach is usedto analysis the performance of theoreticalvapour compression refrigeration cycle usingR404A, R407C and R410A. The equationsof exergetic efficiency and exergy destructionfor the main system components such ascompressor, condenser expansion device,liquid-vapour heat exchanger and evaporatorare developed. The relations for total exergydestruction in the system, the overall exergeticefficiency of the system and EDR related toexergetic efficiency are obtained. Also, anexpression for COP of refrigeration cycle isdeveloped. This investigations shows thatresults are obtained for the effects ofevaporating temperatures, condensingtemperature, degree of subcooling andeffectiveness of liquid-vapour heat exchangeron COP, exergetic efficiency and EDR oftheoretical refrigeration cycle. Commonly,simple vapour compression refrigerationsystems are used for comfort cooling and coldstorage application. Depending upon theapplications evaporating temperature variesfrom –50 C to 7 C (Bilal and Syed, 2011).The scientists investigate moreenvironmentally friendly refrigerants to resolvethe problems of ODP and GWP. Currently, thefollowing three refrigerants are being used asalternatives to CFC in various applications:R404A, R407C and R410A. Though, thesethree refrigerants are completely harmless toozone layer, but sometimes they can add toglobal warming due to their leaks. The maincharacteristics of the tested refrigerants asshown in Table 1.27
Int. J. Mech. Eng. & Rob. Res. 2013Jyoti Soni and R C Gupta, 2013enter the liquid-vapour heat exchanger at state33, where it rejects the heat to low pressuretemperature refrigerant. The expansion deviceallows to flowing the liquid refrigerant atconstant enthalpy from high pressure to lowpressure. At state 4, it leaves the expansionvalve as a low temperature, low pressure, andliquid-vapour mixture and enters theTable 1: The Main Characteristicsof the Tested RefrigerantsRefrigerantR404AR407CR410AMolar Mass97.6086.2072.58Boiling Point ( C)–46.45–43.56–51.6Critical Temperature ( C)72.0786.7472.5Critical Pressure (bar)3.73154.61914.95Critical Density (kg/m )484.5527.305003Critical Volume (m /kg)30.00206 0.00190 0.00205Ozone Depletion Potential000Global Warming Potential385915261725A1A1A1Certainty ClassFigure 1: Schematic of Typical VapourCompression Refrigeration Systemwith a Liquid-Vapour Heat ExchangerSource: Mohanraj et al. (2009)EXERGY ANALYSISA modified vapour compression refrigerationsystem consists of five components such asevaporator, liquid-vapour heat exchanger,compressor, condenser and expansiondevice. All the components connected in aclosed loop through piping that has heattransfer with the surrounding can be shown inFigure 1. At point 11, refrigerant leaves theevaporator at a low pressure, low temperature,saturated vapour and enter the liquid vapourheat exchanger where it absorbs the heat fromhigh pressure-temperature refrigerant flowsfrom the condenser. At state 1, the refrigerantfrom the liquid-vapour heat exchanger enterinto compressor through the suction line whereboth temperature and pressure increases. Thisprocess can be shown in Figure 2. At state 2,it leaves the compressor at a high pressure,high temperature, superheated vapourconditions and enter the condenser where itreject heat to surrounding medium at constantpressure after undergoing heat transfer in thedischarge line. Refrigerant leaves thecondenser at state 3, as a high pressure,medium temperature, saturated liquid andFigure 2: Pressure-Enthalpy DiagramShowing Effect of an Idealized LiquidVapour Heat Exchanger28
Int. J. Mech. Eng. & Rob. Res. 2013Jyoti Soni and R C Gupta, 2013evaporator where it absorbs the heat atconstant pressure from the space to be cooledand changed into saturated vapour and cycleis completed.For analysis the performance of vapourcompression refrigeration system, followingassumption are made:COP QewCOP h1 h4h2 h2.(1)The modern approach based on secondlaw of thermodynamic, i.e., exergy analysiscan be used to measures the performanceof the vapour compression refrigerationsystem. This analysis derives the concept ofexergy, which is always decreasing due tothermodynamic irreversibilities. Exergy is themaximum useful work that could be obtainedfrom the system at a given state in a specifiedenvironment. Exergy balance for a controlvolume undergoing steady state process isexpressed as: Degree of subcooling of liquidrefrigerant in liquid-vapour heatexchanger ( Tsub) 5 C. Mechanical efficiency of compressor( mech) 75%. Electrical efficiency of compressor( el) 75%. Difference between evaporator andspace temperature (Tr – Te) 20 C.E d i me x in me x out Effectiveness of liquid vapour heatexchanger ( ) 0.8. Q 1 T0 / T in Q 1 T0 / T out Evaporator temperature Tevap (in C)ranging from –50 C to 0 C. W Condenser temperature Tcond (in C) 40 C, 55 C.(2)Exergy Destruction (ED) in the SystemComponents Mass flow rate of refrigerant (mr) 1 kg/sExergy destruction in each component of thecycle is calculated as: Dead state temperature (T0) 30 C.Exergy destruction in Evaporator There is no pressure loss in pipelines. T Ede E x 4 Qe 1 0 E x11 Tr In all components steady stateoperations are considered.The energy analysis based on first law ofthermodynamic, the performance of vapourcompression refrigeration system can bepredicted in terms of Coefficient ofPerformance (COP), which is defined as theratio of net refrigerating effect produced by therefrigerator to the work done by thecompressor. It is expressed as: T mr h4 T0S4 Qe 1 0 Tr mr h11 T0S11 Exergy destruction in CompressorEd comp E x1 W E x229.(3)
Int. J. Mech. Eng. & Rob. Res. 2013 mr T0S2 Jyoti Soni and R C Gupta, 2013w mech el mr h2 T0S2 EP Qe 1 .(4) ex Edc E x2 E x3.(5)Qe 1 ex Exergy destruction in Throttle valveE d t E x 33 E x 4.(11)T0Tr.(12)WExergy Destruction Ratio (EDR)Exergy destruction ratio is the ratio of the totalexergy destruction in the system to the exergyin the product and it is given by mr h33 T0S33 mr h4 T0S4 .(6)Exergy destruction in liquid vapour heatexchangerEDR E d ivhe E x1 E x33 E x11 E x1EDtotalEPEDR related to the exergetic efficiency givenby: mr h3 h33 h11 h1 .(7)EDR Total Exergy DestructionTotal exergy destruction in the system is thesum of the exergy destruction in differentcomponents of the system and is given by1 1 ex.(13)RESULTS AND DISCUSSIONFigures 3-4 shows the effects of evaporatingtemperatures on coefficient of performance.With increase in evaporator temperature, thepressure ratio across the compressordecreases, causing work done by thecompressor decrease and cooling capacityincreases due to increase in refrigeratingeffect. Hence, the combined effect of these twofactors increases the COP of the vapourcompression refrigeration system. R407Cpresents the maximum COP among all the Ed i Ede Edcomp Edc Ed t Ed ivhe .(8)Now, total exergy supplied is given by:EF EP E d iExergy in product EP Exergy of fuelEFand exergy of fuel is actual compressor workinput, W. Hence exergetic efficiency is givenby: mr h2 T0S2 mr h3 T0S3 T0 S3 S33 S11 S1 .(10)Exergetic Efficiency ( ex)Exergy destruction in Condenser T Qc 1 0 Tc T0Tr.(9)For refrigeration system, product is theexergy of the heat abstracted into theevaporator from the space to be cooled attemperature Tr, i.e.30
Int. J. Mech. Eng. & Rob. Res. 2013Jyoti Soni and R C Gupta, 2013refrigerants corresponding to evaporator andcondenser temperatures considered. R404Ashows better COP than R410A at bothcondenser temperatures, i.e., at 40 C and 55 C. The maximum difference observedbetween COPs of R404A and R410A is4.03% at 55 C at higher end of evaporatortemperatures. The COP of R407C is 7-14%higher than the COP for R404A and R410A at40 C condenser temperature. This differenceis increases to 8-18% at 55 C condensertemperature.i.e. , Qe 1 T0. With increase in evaporatorTrtemperature Qe increases whereas the term1 T0Trreduces. Second parameter is thecompressor work required by compressor Wwhich decreases with increase in evaporatortemperature. Both terms Qe and W havepositive effect on increase of exergeticFigure 4: Effect of EvaporatingTemperatures on Exergetic EfficiencyFigure 3: Effect of EvaporatingTemperatures on COPFigure 5: Effect of EvaporatingTemperatures on EDRFigures 4-5 shows the effect of evaporatortemperatures on exergetic efficiency ( ex) andEDR. W ith increase in evaporatortemperatures exergetic efficiency increases tillthe optimum evaporator temperature andbeyond this optimum temperature itdecreases. The optimum evaporator is thetemperature at which maximum exergeticefficiency is obtained. The curves trend forEDR almost reverses to curves of exergeticefficiency. The rise and fall of the exergeticefficiency, depends upon the two parameters.First parameter is the exergy of cooling effects,31
Int. J. Mech. Eng. & Rob. Res. 2013Jyoti Soni and R C Gupta, 2013Figure 6: Variation of COP with Degreeof SubcoolingT0hasTrnegative effect on increase of exergeticefficiency. The combined effects of these twoparameters, increases exergetic efficiency tillthe optimum evaporator temperature andbeyond the optimum temperature decrease.Because of exergetic efficiency is inverselyproportional to EDR; the curves trend for EDRalmost reverses to curves of exergeticefficiency. With increases in evaporatingtemperatures, EDR decreases till the optimumevaporator temperature and beyond thisoptimum temperature it increase. Theoptimum evaporator is the temperature atwhich minimum EDR is obtained. Theexergetic efficiency of R407C is 10-18%higher than R404A and 14-20% higher thanR410A at 40 C condenser temperature. Thecorresponding values at 55 C condensertemperature are 13-20% and 15-21% higher,respectively, for R407C. At both 40 C and55 C condensers temperatures, R407C isbetter than R404A and R410A. It also confirmsthat with increase in condenser temperaturethe difference among the exergetic efficiencyof R407C, R404A and R410A increases.efficiency whereas the term 1 Figure 7: Variation of Exergetic Efficiencywith Degree of SubcoolingFigure 8: Variation of EDR with Degreeof SubcoolingFigures 6-8 presents the effect of degreeof subcooling on COP, exergetic efficiency andEDR. It is evident that increase in degree ofsubcooling increases the cooling capacitybecause of increase in refrigerating effect andthere is no change in compressor work, henceCOP increases. From the study, it is evidentthat increase in COP increases the exergeticefficiency and reduces the EDR. The rate ofincrease in COP is approximately 0.99%/ C,0.7%/ C, and 0.85%/ C of subcooling in caseof R404A, R407C and R410A.32
Int. J. Mech. Eng. & Rob. Res. 2013Jyoti Soni and R C Gupta, 2013The rate of increase in exergetic efficiency isapproximately 1%/ , 0.73%/ and 0.84%/ forR404A, R407C and R410A. The total increasein exergetic efficiency for R404A, R407C andR410A is 10.52%, 7.55% and 8.71% for 10subcoolingFigure 11: Effect of Effectiveness ofLiquid-Vapour Heat Exchanger on EDRFigures 9-11 shows the effect ofeffectiveness of liquid-vapour heat exchangeron COP, exergetic efficiency and EDR. Withincrease in effectiveness of liquid-vapour heatexchanger COP and exergetic efficiencyFigure 9: Effect of Effectiveness of LiquidVapour Heat Exchanger on COPreduces whereas EDR increase. The totalCOP decreases by 17.39% and exergeticefficiency decreases by 9.05% for R407C. Thetotal COP decreases by22.82% and exergeticefficiency decreases by 5.85% for R410A. Thetotal COP decreases by 20.91% and exergeticefficiency decreases by 6.05% for R404A.CONCLUSIONA computational model based exergy analysisis presented for the investigation of the effectsof evaporating temperatures, condensertemperature, degree of subcooling, andeffectiveness of the liquid vapour heatexchanger on the COP, exergetic efficiencyand EDR of the vapour compressionrefrigeration cycle for R404A, R407C andR410A. The conclusions present in thisanalysis are given as follows:Figure 10: Effect of Effectivenessof Liquid-Vapour Heat Exchangeron Exergetic Efficiency The COP and exergetic efficiency ofR407C are better than that of R404A andR410A. The EDR of R410A is higher thanthat of R407C and R404A. This analysisperformed at condenser temperatures40 C and 50 C and evaporatortemperature ranging from 50 C to 0 C.33
Int. J. Mech. Eng. & Rob. Res. 2013Jyoti Soni and R C Gupta, 2013Compression Refrigeration System withR502, R404A and R507A”, InternationalJournal of Refrigeration, Vol. 31,pp. 998-1005. For all refrigerants, i.e., R404A, R407C andR410A, COP and exergy efficiency improveby subcooling of high pressure condensedliquid refrigerant. The rate of increase inCOP is approximately 0.99%/ C, 0.7%/ C,and 0.85%/ C of subcooling in case ofR404A, R407C and R410A. The rate ofincrease in exergetic efficiency isapproximately 1%/ C, 0.73%/ C and0.84%/ C for R404A, R407C and R410A.The total increase in exergetic efficiency forR404A, R407C and R410A is 10.52%,7.55% and 8.71% for 10 C subcooling.2. Aprea C and Greco A (2002), “AnExergetic Analysis of R22 Substitution”,Applied Thermal Engineering, Vol. 22,pp. 1455-1469. With increase in dead state temperaturesexergetic efficiency increases and EDRreduces while coefficient of performanceremains constant. The curves trends of allrefrigerants are identical and their curvesfor both exergetic efficiency and EDR arenearly overlapping. The exergetic efficiencyof R-407C is 0.3-0.85% higher than R404Aand1.8-2.6% higher than R410A forconsidered range of dead statetemperatures.4. Bilal Ahmed Qureshi and Syed M Zubair(2011), “Performance Degradation of aVapour Compression RefrigerationSystem Under Fouled Conditions”,International Journal of Refrigeration,Vol. 34, pp. 1016-1027.3. Aprea C, Mastrullo R and Renno C (2004),“An Analysis of the Performance of aVapour Compression Refrigeration PlantWorking Both as a Water Chiller and aHeat Pump Using R-22 and 417A”,Applied Thermal Engineering, Vol. 24,pp. 487-499.5. Comakli K, Simsek F, Comakli O andSahin B (2009), “Determination ofOptimum Conditions R-22 and R404aRefrigerant Mixtures in Heat Pumps UsingTaguchi Method”, Applied Energy,Vol. 86, pp. 2451-2458. With increase in effectiveness of liquidvapour heat exchanger COP and exergeticefficiency decreases while EDRincreases. The total COP decreases by17.39% and exergetic efficiencydecreases by 9.05% for R407C. The totalCOP decreases by 22.82% and exergeticefficiency decreases by 5.85% for R410A.The total COP decreases by 20.91% andexergetic efficiency decreases by 6.05%for R404A.6. Douglas J D, Braun J E, Groll E A and TreeD R (1999), “A Cost Method ComparingAlternative Refrigerant Applied to R-22System”, International Journal ofRefrigeration, Vol. 22, pp. 107-125.7. Havelsky V (2000), “Investigation ofRefrigeration System with R12 RefrigerantReplacements”, Applied ThermalEngineering, Vol. 20, pp. 133-140.REFERENCES1. Akhilesh Arora and Kaushik S C (2008),“Theoretical Analysis of a Vapour8. Miguel Padilla, Remi Revellin and JocelynBonjour (2010), “Exergy Analysis of34
Int. J. Mech. Eng. & Rob. Res. 2013Jyoti Soni and R C Gupta, A as Replacement of R12 in aDomestic Refrigeration System”, EnergyConversion and Management, Vol. 51,pp. 2195-2201.11. United Nation Environment Programme(UNEPs) (1997), The Montreal Protocolon Substances that Deplete the OzoneLayer.9. Mohanraj M, Jayaraj S andMuraleedharan C (2009), “EnvironmentFriendly Alternatives to HalogenatedRefrigerants—A Review”, InternationalJournal of Greenhouse Gas Control,Vol. 3, pp. 108-119.12. Venkataramanamurthy V P and SenthilKumar P (2010), “ExperimentalComparative Energy, Exergy Flow andSecond Law Efficiency Analysis of R22,R436bVapourCompressionRefrigeration Cycles”, InternationalJournal of science and Technology,Vol. 2, No. 5, pp. 1399-1412.10. United Nations (2011), Kyoto Protocol tothe United Nations Framework Conventionon Climate Change, available at http://35
Int. J. Mech. Eng. & Rob. Res. 2013Jyoti Soni and R C Gupta, 2013APPENDIXNomenclatureCOPCoefficient of performance (non-dimensional)EFExergy rate of fuel (kW)ELThermal exergy loss rate (kW)WWork rate (kW)EDRExergy destruction ratio (non-dimensional)sEntropy (kJ/kg K) PPressure drop (bar)EdExergy destruction rate (kW)EPExergy rate of product (kW)ExExergy rate of refrigerant (kW)hEnthalpy (kJ/kg)TTemperature (K)Greek Notations exExergetic Efficiency Effectiveness of the liquid vapour heat exchanger TsubDegree of subcooling of liquid refrigerant in lvhe (K) TsupDegree of superheating of vapour refrigerant in lvhe (K)SubscriptsCCondenserRSpace temperatureEEvaporator temperatureCompressorTRefrigerant throttle valveODead state36
Performance (COP) of refrigeration cycle is developed. The investigations shows that various results are obtained for the effect of evaporating temperatures, condensing temperatures, degree of subcooling and effectiveness of liquid-vapour heat exchanger on COP, exergetic efficiency and EDR of theoretical vapour compression refrigeration cycle.
2. Cycle with wet vapor after compression, 3. Cycle with superheated vapor after compression, 4. Cycle with superheated vapor before compression, and 5. Cycle with under cooling or sub cooling of refrigerant, Advantages of Vapour Compression System : It has a smaller size for the given capacity of refrigeration. It has less running cost.
used refrigeration systems, and each system employs a compressor. Basic vapour compression refrigeration cycle consists of four major thermal processes; evaporation, compression, condensation and expansion. There are many applications where refrigeration plant is required to meet the v
The mechanical sub-cooling of main VCR cycle has been carried out through the subcooler or evaporator of another simple VCR cycle designated as subcooler VCR cycle. (a) (b) Figure 2. (a) Schematic diagram of dedicated mechanically subcooled vapour compression refrigeration cycle, (b) P-h diagram of dedicated sub-cooled vapour compression cycle
Experimental Analysis of Vapour Compression Refrigeration System using Al 2 O 3 /CuO-R134a Nano Fluid as Refrigerant 1T. Coumaressin., 2K. Palaniradja., 3R. Prakash., 4V. Vinoth Kumar 1Research Scholar, Department of Mechanical Engineering, Pondicherry Engineering College 2Professor, Department of Mechanical Engineering, Pondicherry Engineering College
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This analysis forecasts the global adventure tourism market to grow at a CAGR of 45.99% during the period 2016-2020. According to the adventure tourism market report, increased preference for adventure over other tourism activities will be a key driver for market growth (PR Newswire, Adventure Tourism Market Growing at Nearly 46% CAGR to 2020