Akademik Veri Yönetim Sistemi
Science and Technology for the Built Environment, 2024 (SCI-Expanded)
The performance merits of a mobile air conditioning (MAC) system with an orifice tube (OT) were experimentally evaluated for R1234yf relative to R134a. The effect of employing a suction/liquid line internal heat exchanger (HEX) was also investigated for R1234yf. To this end, an experimental unit employing the components of an R134a MAC system was set up, equipped with a coaxial internal HEX, and tested at various compressor speeds for both refrigerants. The air temperatures entering the condenser and evaporator were simultaneously maintained at 30, 35, and 40 °C. The R1234yf unit provided on average 22.5% lower and 6.9% higher cooling capacity than the R134a unit for the inactive and active HEX, respectively. Furthermore, the coefficient of performance (COP) for the R1234yf unit without and with HEX was on average 10.9% and 3.5% lower than that for the R134a unit, respectively. The R1234yf unit without and with HEX yielded on average 41.5% and 8.4% lower exergetic efficiency than the R134a unit, respectively. These results revealed that the use of an internal HEX in an R1234yf MAC unit with an OT compensates for the cooling capacity degradation, and the R1234yf unit has almost as high performance as the R134a unit.