R134a와 R1234yf 냉매 적용에 따른 냉동탑차 냉장시스템의 성능비교

Abstract

Recently, the importance of delivery system has being developed according to the growth of online and mobile shopping market. Especially, transportation of frozen food by online and home shopping is increasing significantly. Therefore, the demand of refrigeration truck is also increasing. In this study, performance characteristics of refrigeration system using R134a and R1234yf in a refrigeration truck were compared by experimental method. When the refrigerant charging amounts increased from 1.1 to 1.4 kg, COP of R134a system was increased and the maximum COP was 2.63 at the charge amount of 1.4 kg. And that of R1234yf system was 2.49 at the optimal charge amount of 1.3 kg. The optimal EEV opening of R134a and R1234yf system was 60% and 50%, respectively. Besides, the COP was 2.69 and 2.49 for R134a and R1234yf at the optimal EEV opening. When the outdoor air temperature increased from 25℃ to 35℃, the system COP of R134a and R1234yf decreased by 15.0% and 11.6%, respectively. Besides, When the compressor rotating speed increased from 1000 to 2000 rpm, the system COP of R134a and R1234yf decreased by 37.5% and 35.9%, respectively. The R134a system showed a higher performance than R1234yf system, but the R134a system showed the larger reduction in the performance according to compressor rotating speed.