• Journal of the Korean Society of Industry Convergence
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• v.14 no.2
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• pp.79-85
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• 2011

This study has been experimented about refrigeration capacity difference. It has been used 3 method, Manual expansion valve, thermostatic expansion valve and capillary expansion valve, and tested under the same condition by using the performance testing of parallel expansion. In temperature change of the temperature room, thermostatic expansion valve method displayed the most lower temperature, $-18^{\circ}C$. In addition, the temperature, just before the expansion, also displayed the best result which was $4^{\circ}C$ lower than other expansion valve. In these results, it can be used for performance testing of parallel expansion refrigeration system.

• Journal of the Korean Society of Industry Convergence
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• v.14 no.3
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• pp.113-119
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• 2011

This study analyzed facts affecting the performance of refrigeration systems after throttling actions, by changing the amount of refrigerant according to adjusting the opening of manual expansion valve to 80%, or 20% with vapor compressional refrigeration training equipment. At opening of 20%, the inlet and outlet temperature of compressor, subcooling and superheat, condenser heat, refrigeration effect, flash gas heat, coefficient of performance were higher, while at 80%, condensing pressure, evaporating pressure, compression work were higher, Thus, we could see changes in the amount of refrigerant affect the performance of the refrigeration system.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.1264-1269
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• 2004

This research describes the application of hydrocarbon refrigerants for heat pump system which is needed for fish farm. Tested refrigerants are HCFC-22 and hydrocarbon refrigerants(CARE 50 and ASR-20). CARE 50 is mixture of R-290 and R-170, and ASR-20 is mixture of R-152a, R-290 and other additives. Heat pump consist of shell and tube heat exchanger, scroll compressor, expansion valve and accumulator. Manual expansion valve is used for testing of wide range evaporating temperature. Hydrocarbon refrigerants show a good performance as an alternative for HCFC-22 in the range of evaporating temperature from $-6^{\circ}C$ to $6^{\circ}C$.

• Journal of Advanced Marine Engineering and Technology
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• v.22 no.3
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• pp.285-293
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• 1998

This paper presents an experimental study on condensing heat transfer characteristics of R-22 alternative refrigerants, R-290 and R-410a on water sources heat pump. The apparatus mainly consisted of vapor pump condenser used to the test section evaporator manual expansion valve and measuring device. Test section constructed a smoothed tube of 10.07 mm ID and 12.7mm OD with a total length 6,300 mm was horizontal double pipe counterflow condenser. The refrigerants R-22, R-290 and R-410a were cooled by a coolant circulated in a surrounding annulus. Experimental range of mass velocities was changed from about 100 to 300 kg/($m^2$.s) and inlet quality 1.0 The credibility of experimental apparatus was 6 percent between heating capacity and cooling capacity added to compressor shaft power. The condensing heat transfer coefficients were increased with increasing mass velocity. However in case of R-290 they were more increasing than those of R-410a and R-22 Comparing the heat transfer coefficient between the experimental data and other's data the Cavallini-Zecchin's data was revealed to more similar prediction of author's experimental results on the average heat transfer coefficients.