SIMULATION STUDY ON REFRIGERATION PERFORMANCE UNDER FROST CONDITION IN A R404A REFRIGERATOR TRUCK TYPE |
S. H. KIM, T. J. KIM, Y. C. SHIN, H. H. CHO |
Chosun university |
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ABSTRACT |
The formation of frost causes a decrease in the heat exchanger performance because of increased thermal resistance. In this study, the performance of a refrigeration system in a refrigerator truck with frost growth was determined and the performance characteristics were analyzed considering the indoor and outdoor temperature, outdoor air velocity, and compressor rotating speed. As a result, under frost growth conditions, refrigeration capacity was decreased by 30.4% when the operating time passed by 3 hours which had a blocking ratio of 40.1%. In addition, the mass flow rate was decreased, but the pressure ratio was increased with an increase in frost thickness, leading to a decrease in the refrigeration capacity and COP. The maximum system COP was found at a compressor rotating speed of 1500 rpm: 2.30 and 1.86 for a blocking ratio of 0% and 40.1%, respectively. It gradually decreased over 1500 rpm. |
Key Words:
Refrigerantor truck, Refrigeration capacity, Frost, COP, R404A, Blocking ratio |
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