In order to protect the global environment, it was decided that CFCS should be phased-out by 1995 and HCFCs phased-out by the year 2020. We developed a refrigerator for land transport using R-404A (HFC) with a zero ozone depletion potential. The saturation vapor pressure of R-404A is higher than that of R-22. Also the cooling capacity of-R-404A by the suction pressure regulator system is lower than for R-22. For use with refrigerants of high vavor pressure, we developed a valve control technique that controls multicontrol systems by one valve. A high accuracy temperature control system was also developed using fuzzy control. These techniques produce a higher cooling capacity of the R-404A system compared to that of the R-22 system, and achieve the accurate temperature control of fresh foods.
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