Thermal And Performance Analysis Of R600a In Vapour .
Published by :http://www.ijert.orgInternational Journal of Engineering Research & Technology (IJERT)ISSN:ISSN:2278-01812278-0181Vol. 7 Issue 01, January-2018Thermal and Performance Analysis of R600a inVapour Compression CycleShailesh GolabhanviVivekanand NavadagiAssistant Professor, Mechanical departmentAlva’s Institute of Engineering and TechnologyMoodbidri-574225, Manglore, DK, Karnataka, IndiaAssistant Professor, Mechanical departmentJSPM’s Imperial College of Engineering and ResearchWagholi, Pune-412107, Maharashtra, IndiaAbstract— The aim of this project is to comparatively analyze ofCOP using R134a & R600a Refrigerant in Domestic refrigeratorat steady state condition. Two different refrigerant are R600a(Isobutene) and R134a (tetrafluoroethae). R134a is zero ozonedepletion layer and high global warning and R600a is zero ozonedepletion layer and negligible global warning. In domesticrefrigerator was selected by the obtained result from R134a andan experiment using 170 g of R600a which indicate the similarresult as R134a. Based on outcomes R600a charge amount,condenser evaporator and compressor coefficient of performancewere selected for design. The analysis of variance result isindicated that R600a charge amount was the most effectiveparameter. At optimum condition the amount of charge isrequired for R600a was 170 g, 66% lower than R134a one, whichnot only being economic advantages, but also significantly reducesthe of flammability of the hydrocarbon refrigerant. Thus in thepresent work comparatively analyze of COP using R134a &R600a Refrigerant in Domestic refrigerator at steady statecondition. All the result were compared. Comparison ofperformance domestic refrigerator at steady state condition of thesystem was also studied. The result is indicate that R600a COP ismore than R134a.CFD Analysis of condenser & evaporator alsoshows system effectiveness with respect to the R134a & R600a.II.METHODOLGYA. Properties of R600aIts numerical designation is R600a or Isobutane. Its chemicalformula (CH3) 3 CH.Normal boiling point 260-264 K at atm pressureCritical Temperature 135 CCritical pressure 3.65 MPaVapour pressure 204.8 KPa at 21 CSpecific heat of liquid 2.38 KJ/Kg C at 25 CMolar mass 58.12 g mol 1Density 2.51 kg/m3, gas (15 C, 1atm) 593.4kg/m3, liquidMelting point -159.6 C, 114 K, -255 FBoiling point -11.7 C, 261 K, 11 FSolubility in water InsolubleOzone depletion potential (ODP) 0Global warming potential (GWP) 3Flash point -83 C, 117 F; 190 KLatent heat of evaporation 362.6 KJ/Kg at atm pressureSpecific Heat Ratio Cp/Cv 1.091(atm,25.C)Assigned colour code Colourless gasI.INTRODUCTIONRefrigeration may be defined as the process of achieving andmaintaining a temperature below that of the surroundings, theaim being to cool some product or space to the requiredtemperature. One of the most important applications ofrefrigeration has been the preservation of perishable foodproducts by storing them at low temperatures. Refrigerationsystems are also used extensively for providing thermalcomfort to human beings by means of air conditioning. AirConditioning refers to the treatment of air so as tosimultaneously control its temperature, moisture content,cleanliness, odour and circulation, as required by occupants, aprocess, or products in the space. The subject of refrigerationand air conditioning has evolved out of human need for foodand comfort, and its history dates back to centuries. The historyof refrigeration is very interesting since every aspect of it, theavailability of refrigerants, the prime movers and thedevelopments in compressors and the methods of refrigerationall are a part of it. The French scientist Roger ThÝvenot haswritten an excellent book on the history of refrigerationthroughout the world.B. Vapour compression cycleIJERTV7IS010024Fig 1. VCC Cyclewww.ijert.orgwww.ijert.org(This work is licensed under a Creative Commons Attribution 4.0 International License.)35
Published by :http://www.ijert.orgInternational Journal of Engineering Research & Technology (IJERT)ISSN:ISSN:2278-01812278-0181Vol. 7 Issue 01, January-2018C. Component listTABLE ILIST OF COMPONENTSD. System descriptionIn refrigeration test rig, working medium is liquid; whichinvolves sensible as well as latent heat. And coefficient ofperformance of refrigeration test rig is more than that ofaircompression system. Most of the modern refrigerators workon refrigeration test rig. Therefore it is necessary forengineering students to Study the performance of refrigerationcycle & its different parameter, performance, calculations isfocus of this trainer.diameter reduce the pressure from condensing pressure toevaporator pressure. Overall Dimension is (Bore x Length) 0.50” x 5” x 1Drier: The primary function of the drier is to separate gas andliquid. The secondarypurpose is to remove moisture and filter out dirt.Pt 100-sensors (Pencil Type & Bulb Type): The temperaturesat different points in the system are measured by using RTD(PT – 100) sensors. These are Resistance TemperatureDetectors operating on principle of change in Resistance withchange in temperature.Evaporator: This is made up of S.S material having inbuilt coiland heater. It is used as an evaporator in the system.Rotameter: This is a variable area glass tube liquid flowmeasuring device. The glass tube is enclosed in M.S. structurewith transparent glass at two sides to read the readings.Calibrated scale is mounted in the enclosure. The float is liftedup as liquid flows through the glass tube and the lift isproportional to the flow rate. Its range is 6.8-68 LPHPressure Gauge (0 to 300 PSI.): It is a Bourdon type pressuregauge. This is used to measure pressures at discharge point ofcompressor.Compound Gauge. (-30 to 150 PSI.): This Bourdon typepressure gauge measures both negative pressure (Vacuum) aswell as positive pressure. This is used to measure pressures atsuction point of compressor.Motor pump: the pump is used as stirrer in the system so as therefrigeration effect should uniformly done.Energy meter : its main purpose is to indicate the energyconsumed by the compressorThermostat: it acts as a cut off of the system it switch off thecompressor as soon as the temperature of the evaporator dropsbelow set point.Herter coil: it acts as the load to the refrigeration effect and theheater is placed inside the evaporator.Volt and Ammeter meter: the volt meter indicates the voltageacross the heater coil while the ammeter indicates the currentdrawn by the heat.Specification:Base Stand: This is made up of CRCI square tubes & sheets.This is painted specially with Powder coating. All equipmentsare mounted on Base stand.Hermetically Sealed Compressor: This is used to take therefrigerant Vapor at low pressure & low temperature &compress it to a high pressure & high temperature. Thecapacity of compressor is 0.75 HPCondenser: The condenser is the forced air-cooled type forwhich condenser fan and motor has been provided. Thefunction of condenser is to convert high-pressure refrigerantVapor into high-pressure refrigerant liquid. The outsidediameter of condenser is 3/8”. Size of condenser as perstandard specification is 11” x 10” x 3 RowsTABLE 2. DIMENSIONS OF CONDENSORPIPEExpansion Devices: (Capillary Tube): Capillary tube is theexpansion devicewhich is used for small units of ½ to 3 tons. The purpose ofexpansion valve in a refrigeration system is to reduce the highside pressure to the low side pressure so that liquid canevaporate by picking up heat. The length and the smallTABLE 4. DIMESIONS OF CONDENSOR SHELLSIJERTV7IS010024TABLE 3. DIMESIONS OF FINSwww.ijert.orgwww.ijert.org(This work is licensed under a Creative Commons Attribution 4.0 International License.)36
Published by :http://www.ijert.orgInternational Journal of Engineering Research & Technology (IJERT)ISSN: 2278-0181Vol. 7 Issue 01, January-2018Fig. 2 EvaporatorFig. 3 g(This work is licensed under a Creative Commons Attribution 4.0 International License.)37
Published by :http://www.ijert.orgInternational Journal of Engineering Research & Technology (IJERT)ISSN: 2278-0181Vol. 7 Issue 01, January-2018TABLE 6. Components of experimental setupE. Experimental procedureFig 4. CompressorFig 5. CompressorTABLE 5. Evaporator dimension Fill the evaporator tank up to the end level. Ensure that hand valve is in fully closed. Apply 230 V supply by inserting the three pin top in socketprovided on the distribution board in your laboratory. Switch on the mains supply and stirrer on/off switch. Switch on electric heater by rotating dimmer in clockwisedirection, and if the ambient temp is less Please load thesystem initially to 35 0 C before starting the compressor. Switch on the compressor on/off switch. Check that compressor energy meter starts & Rotameterfloat is lifted up indicating that the compressor is working.The pressure gauge reading is increasing and compoundgauge reading is decreasing. Observe that Temperature of load tank (T5) decreasesshowing cooling effect. Note down the readings according to observation table Switch off the compressor on/off & stirrer on/off switch. Switch off the main switch. Repeat the above procedure for other experiments.Installation Procedure: Connect the 230-VA.C. Supply to the unit. Use Properneutral & Earthing. Fill the water in the evaporator tank. . Switch on the Compressor on/off switch only if thepressure shows on the Gauges are nearly equal. Check that temperature indicatortemperature for all 12 channels. The Rotameter shows the flow of refrigerant gas, which isindicated by lift of float in the glass tube. Also check thatsuction pressure P1 drops and discharge pressure P2increases. Observe with channel 7, the temperature T7 of theEvaporator tank & see that it is reducing. That means thetrainer is giving refrigeration effect.Fig 6. Experimental s work is licensed under a Creative Commons Attribution 4.0 International License.)showsambient38
Published by :http://www.ijert.orgInternational Journal of Engineering Research & Technology (IJERT)ISSN:ISSN:2278-01812278-0181Vol. 7 Issue 01, January-2018F. NomenclatureTABLE 7. NomenclatureCalculation for R134a:Suction temp.-28.2oCDischarge temp.-86.2 oCTemp. at condenser outlet-39.9Temp. at evaporator inlet-0.6H1 428 KJ/KgH2 485 KJ/KgH3 251 KJ/KgH4 251 KJ/KgG. COP CalculationObservation table: (R134a)Fig 7. Representation of cycle of R134a on ph chartRefrigerating Effect H1- H4Refrigerating Effect 428-251Refrigerating Effect 171 KJ/KgCompressor Work H2- H1Compressor Work 485-428Compressor Work 57 KJ/KgCOPtheoretical RefrigetatingworkCOPtheoretical 171/57COPtheoretical 3.effect/CompressorActual COP:Rotameter reading 45-47 lph, mass of Fluid 20 kgPressure in bar- P1 1.24 barP2 9.13 barRefrigerating effect 0.3256 KWR600a:Compressor Work (10*3600)/(33*3200) 0.3409KWCOPActualIJERTV7IS010024 Refrigerating effect/Compressor work 0.3256/0.3409 0.9556 1www.ijert.orgwww.ijert.org(This work is licensed under a Creative Commons Attribution 4.0 International License.)39
Published by :http://www.ijert.orgInternational Journal of Engineering Research & Technology (IJERT)ISSN:ISSN:2278-01812278-0181Vol. 7 Issue 01, January-2018Tonnage Capacity:Tonnage capacity Refrigerating effect/3.51 0.3256/3.51 0.092 tonnCalculation: (R600a)Rotameter reading 35-37 lph :mass of Fluid 20 kgPressure in bar P1 1.37 barP2 6.2 barSuction temp-9.4oCH1 580 KJ/KgDischarge temp-60.4oCH2 640 KJ/KgTemp. at condenser outlet-42.8o C H3 360 KJ/KgTemp. at evaporator inlet-6.9oC H4 360 KJ/KgActual COP:R. E m*Cp*(T11@3:55-T11@4:25)/Time(sec) 20*4.187*(18.3-10.1)/( 30*60) 0.3814KWCompressor Work (10*3600)/(Time*3200) (10*3600)/(36.5*3200) 0.3082 KW.COPActual Refrigerating effect/Compressor work 0.3814/0.3082 1.23Tonnage Capacity:Tonnage capacity Refrigerating effect/3.51 0.3814/3.51 0.108 III. CONCLUSIONBy Changing the Refrigerant from R134a to R600a thesystem theoretical COP is increased by 22.2% and actualCOP by 29.4%.Power Consumption is reduced considerably by 9.5%.Compressor works controlled temperature under 63 oCwhich less as compared to R134a i.e. 82 oC.We get better cooling effect in less time in evaporator byusing R600a.Load on the compressor while running on R600a asrefrigerant is less as Compared to the compressor runningon R134a as refrigerant.REFERENCES[1][2][3][4][5]Fig 8. Representation of cycle of R600a on ph chartRefrigerating Effect H1- H4Refrigerating Effect 580-360Refrigerating Effect 220 KJ/KgCompressor Work H2- H1Compressor Work 640-580Compressor Work 60 KJ/KgCOPtheoretical Refrigetating effect/Compressor work 220/60 3.66IJERTV7IS010024[6][7]D.Bulter, life after cfcs and HCFC, CIBSE national conference 2001.S.Devotta, S.gopichand, comparative assessment of HFC 134a and somerefrigerant as alternative to CFC12, International general of refrigeration15(1992) 112-118.C.P.Arora, Third edition of refrigeration and air conditioning, TataMcGraw Hill Education Private limited New Delhi P.G. No (3-4)D.Ravindra, “Difference between CFC/HCFC and HFC refrigerant” AirConditioning and refrigeration journal Part-II January-February 2014.Vincenzo La Rocca, Giuseppe Panno “Experimental performanceevolution of a vapour compression refrigerating plant when replacingR22 with alternative refrigerant.Mihail-Dan & N. Staicovici, International Journal of Heat and MassTransfer, Are investigates “A method of improving the effectiveness of amechanical vapour compression process and of its applications inrefrigeration” 3 August 2010.Bilal Ahmed Qureshi, Syed M. Zubair, International Journal ofRefrigeration, Performance degradation of a vapour compressionrefrigeration system under fouled conditions Mechanical EngineeringDepartment, King Fahd University of Petroleum & Minerals, KFUPMBox # 1474, Dhahran 31261, Saudi Arabia.www.ijert.orgwww.ijert.org(This work is licensed under a Creative Commons Attribution 4.0 International License.)40
indicated that R600a charge amount was the most effective parameter. At optimum condition the amount of charge is required for R600a was 170 g, 66% lower than R134a one, which not only being economic advantages, but also significantly reduces the of flammability of the hydrocarbon refrigerant. Thus in the
Energies 2018, 11, 1879 3 of 14 R3 Thermal resistance of the air space between a panel and the roof surface. R4 Thermal resistance of roof material (tiles or metal sheet). R5 Thermal resistance of the air gap between the roof material and a sarking sheet. R6 Thermal resistance of a gabled roof space. R7 Thermal resistance of the insulation above the ceiling. R8 Thermal resistance of ceiling .
Thermal Control System for High Watt Density - Low thermal resistance is needed to minimize temperature rise in die-level testing Rapid Setting Temperature Change - High response thermal control for high power die - Reducing die-level test time Thermal Model for New Thermal Control System - Predict thermal performance for variety die conditions
thermal models is presented for electronic parts. The thermal model of an electronic part is extracted from its detailed geometry configuration and material properties, so multiple thermal models can form a thermal network for complex steady-state and transient analyses of a system design. The extracted thermal model has the following .
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Thermal analyzers are an essential tool in the semiconductor packaging industry. Not only are they important in the design and development phase, but thermal analyzers can also be used for failure analysis and quality control purposes. Many Standard Methods describe the use of Thermal Analysis (Figure 12). With PerkinElmer Thermal Analyzers,
for the simple piston and reduced skirt length piston. by changing the geometry of the piston and it is suggested that which piston is better for same thermal load. Steady state thermal analysis of the Piston have been done in ANSYS 14.5. KEYWORDS . Thermal stress, ANSYS 14.5, Heat flux, Thermal analysis. 1.INTRODUCTION
for evaluating thermal shock resistance of ceramic composites. Jin and Batra [9], Jin and Luo [10], and Jin and Feng [11] developed theo-retical thermo-fracture mechanics models to evaluate the critical thermal shock and thermal shock residual strength of FGMs. This entry introduces concepts of the critical thermal shock and the thermal shock .
