Thermal analysis on optimizing the capillary tube length of a milk chiller using DC compressor operated with HFC-134a and environment-friendly HC-600a refrigerants
Restricted accessResearch articleFirst published online August, 2020
Thermal analysis on optimizing the capillary tube length of a milk chiller using DC compressor operated with HFC-134a and environment-friendly HC-600a refrigerants
In this work, the thermal analysis on optimizing the capillary tube lengths of a dual circuit refrigeration system was carried out experimentally. Two refrigeration circuits were individually operated using two DC powered compressors (HFC-134a and HC-600a) instead of conventional AC powered compressors. The capillary tube optimization was done to maximize the coefficient of performance and exergy efficiency. From the results, it was found that the power consumption and the refrigerant mass flow rate decreases with the increase of capillary tube length for both the HFC-134a and HC-600a circuits, while the refrigeration capacity and coefficient of performance increased up to the capillary tube length of 4.57 m and then decreased. The maximum refrigeration capacity, ice formed, power consumption, and coefficient of performance experienced in the HC-600a circuit were 9.65%, 19.03%, 3.53%, and 7.34% lower than those of the HFC-134a circuit at the optimum capillary tube length. It was also found that at the optimum capillary length, the COP was maximum for the HFC-134a circuit while the exergy efficiency was maximum for the HC-600a circuit. The exergy efficiency of the HC-600a circuit was 11.13% higher than that of the HFC-134a circuit. At the optimum capillary tube length, the total equivalent warming impact values of the HFC-134a and HC-600a circuits were 961.13 kg CO2-eq and 785.77 kg CO2-eq, respectively.
MengZZhangHLeiM, et al.Performance of low GWP R1234yf/R134a mixture as a replacement for R134a in automotive air conditioning systems. Int J Heat Mass Transfer2018; 116: 362–370.
3.
United Nations Environment Programme (UNEP). The Kigali Amendment to the Montreal Protocol: HFC phase-down. In: 28th meeting of parties to Montreal Protocol, Kigali, Rwanda, 10–16 October 2016.
4.
SethiABecerraEVMottaSY. Low GWP R134a replacements for small refrigeration (plug-in) applications. Int J Refrig2018; 66: 64–72.
5.
Hwang Y and Radermacher R. Opportunities with alternative refrigerants, thermal and thermo-mechanical phenomena in electronic systems. In: The 8th intersociety conference on ITHERM, 2002, pp. 777–784. New York: IEEE.
6.
CalmJM. The next generation of refrigerants historical review, considerations, and outlook. Int J Refrig2008; 31: 1123–1133.
7.
Wennerstrom P. HC in domestic refrigeration, natural refrigerant heat pumps. Royal Institute of Technology (KTH), Energy Technology Department, Sweden, 2007.
8.
MohanrajMJayarajSMuraleedharanC. Comparative assessment of environment-friendly alternatives to R134a in domestic refrigerators. Energy Efficiency2008; 1: 189–198.
9.
RastiMAghamiriSHatamipourMS. Energy efficiency enhancement of a domestic refrigerator using R436A and R600a as alternative refrigerants to R134a. Int J Therm Sci2013; 74: 86–94.
10.
JoybariMMHatamipourMSRahimiA, et al.Exergy analysis and optimization of R600a as a replacement of R134a in a domestic refrigerator system. Int J Refrig2013; 36: 1233–1242.
11.
ThomachanAKattakayamSK. Thermal performance characterization of a photovoltaic driven domestic refrigerator. Int J Refrig2000; 23: 190–196.
12.
OpokuRAnaneSEdwinIA, et al.Comparative techno-economic assessment of a converted DC refrigerator and a conventional AC refrigerator both powered by solar PV. Int J Refrig2016; 72: 1–11.
13.
AxaopoulosPJTheodoridisMP. Design and experimental performance of a PV ice-maker without battery. Sol Energy2009; 83: 1360–1369.
14.
DriemeierCZillesR. An ice machine adapted into an autonomous photovoltaic system without batteries using a variable-speed drive. Prog Photovolt: Res Appl2010; 18: 299–305.
15.
Torres-ToledoVMeissnerKTaschnerP, et al.Design and performance of a small-scale solar ice-maker based on a DC-freezer and an adaptive control unit. Sol Energy2016; 139: 433–443.
16.
DaffallahaKO. Experimental study of 12V and 24V photovoltaic DC refrigerator at different operating conditions. Phys B: Condens Matter2018; 545: 237–244.
17.
ReddyDVRBhramaraPGovindarajuluK. Experimental evaluation of the effect of refrigerant charge and capillary tube length on the performance of household refrigerator with different configurations of R290 and R600a. Mater Today: Proc2018; 5: 11845–11852.
18.
Abou-ZiyanHFatouhM. Transient and cyclic characteristics of a household refrigerator using ternary hydrocarbon mixture – an experimental investigation. Appl Therm Eng2018; 129: 446–462.
19.
DincerIKanogluM. Refrigeration systems and applications, 2nd ed. New York: John Wiley and Sons Ltd., 2010.
20.
EkrenOYilanciACetinE, et al.Experimental performance evaluation of a PV-powered refrigeration system. Electron Electr Eng2011; 8: 114–114.
21.
EkrenOSerdarCBradN, et al.Performance evaluation of a variable speed DC compressor. Int J Refrig2013; 36: 745–757.
22.
Sidney S and Mohan DL. Exergy analysis of a solar PV driven DC refrigerator for different ambient conditions. IEEE Xplore Digital Library, 2016, pp. 280–284.
23.
StoeckerWFJonesJW. Refrigeration and air conditioning, New York: McGraw-Hill, 1982.
24.
The Australian Institute of Refrigeration, Air Conditioning and Heating (AIRAH). Methods of calculating Total Equivalent Warming Impact (TEWI) – best practice guidelines, Fitzroy Victoria, 2012.
25.
Bureau of Indian Standards (BIS) BIS 1476-1. Performance of household refrigerating appliance-refrigerators with or without low temperature compartment, part 1: energy consumption and performance, 2000.
26.
XuYMaXHassanienRHE, et al.Performance analysis of static ice refrigeration air conditioning system driven by household distributed photovoltaic energy system. Sol Energy2017; 158: 147–160.
27.
HanYLiMWangY, et al.Impedance matching control strategy for a solar cooling system directly driven by distributed photovoltaics. Energy2019; 168: 953–965.
28.
Prabakaran R, Lal DM, Prabhakaran A, et al. Experimental investigations on the performance enhancement using minichannel evaporator with integrated receiver-dryer condenser in an automotive air conditioning system. Heat Transf Eng 2018; 40: 667–678.
29.
Danfoss Refrigeration and Air Conditioning Division, Danfoss BD Compressors Direct Current and Multi Voltage Applications, 2009.
30.
PrabakaranRLalDM. A novel exergy based charge optimisation for a mobile air conditioning system - an experimental study. J Therm Anal Calorim2018; 132: 1241–1252.
31.
MoffatRJ. Describing the uncertainties in experimental results. Exp Therm Fluid Sci1988; 1: 3–17.
32.
Alok P and Sahu D. Flow analysis of isobutane (R-600a) inside an adiabatic capillary tube. IOP Conf Ser: Mater Sci Eng 2018; 310.
33.
JabarajDBVettrikathirvelALalDM. Flow characteristics of HFC407C / HC600a / HC290 refrigerant mixture in adiabatic capillary tubes. Appl Therm Eng2006; 26: 1621–1628.
34.
FatouhMAbou-ZiyanH. Energy and exergy analysis of a household refrigerator using a ternary hydrocarbon mixture in tropical environment – effects of refrigerant charge and capillary length. Appl Therm Eng2018; 145: 14–26.
35.
PuniaSSSinghJ. An experimental study of the flow of LPG as refrigerant inside an adiabatic helical coiled capillary tube in vapour compression refrigeration system. Heat Mass Transf2015; 51: 1571–1571.
36.
Maykot R, Weber GC and Maciel RA. Using the TEWI methodology to evaluate alternative refrigeration technologies. In: International refrigeration and air conditioning conference, Purdue, 2004, pp. 1–8.
37.
Mohanraj M. Experimental investigations on R430A as a drop-in substitute for R134a in domestic refrigerators. Proc IMechE, Part E: J Process Mechanical Engineering 2018; 233: 728–738.
