COMPARISON OF THE OPTIMAL REFRIGERANT CHARGE WITH R134A AND R1234YF ON THE AU-TOMOTIVE AIR CONDITIONING OFF-ROAD AGRICULTURAL VEHICLES

Juliano Noetzold¹; Jacqueline Biancon Copetti¹; Mario Henrique Macagnan¹

¹ Universidade do Vale do Rio dos Sinos, Unisinos

Resumo

Automotive air conditioning for agricultural machinery presents some particular characteristics compared with others air conditioning systems for vehicles: operates under highly transient climatic conditions, relatively high cooling capacity to provide a rapid cool down. In this work, experiments were carried out to compare the performance of a typical AC for off-road vehicles using R-134a in a drop-in to R-1234yf. This system was installed in an experimental setup and the main parameters were meas-ured. The optimum refrigerant charge for each refrigerant was established and the cycle parameters like evaporator capacity, COP, compressor power, compressor discharge pressure, degree of subcooling and superheat was compared. The experimental results indicate that for air inlet conditions in the evaporator and condenser at 40 ºC and a relative humidity of the 43%, the system running with the R-1234yf, has slightly lower values of: evaporator capacity, COP and a higher superheat in the evaporator, reach the optimal refrigerant charge with 50g more than with R-134a.

Palavras-chave: R-1234yf; Automotive air conditioning; Drop-in; Off-Road Agricultural Machinery; Tractors