MÁY LẠNH MỘT CẤP NHIỆT ĐỘ SÔI ÂM 70 oC

Abstract

Single stage refrigerating machine with vapour temperature -70 ^oC

For reaching the negative temperature of 70 ^oC, the same cascade refrigerating machines but simplicity in terms of structure and operation of the device, single stage refrigerating machine with mixture of the five components Ar/R14/R23/R134a/R123 with mole fraction 0,5/37,5/36/8,5/17,5 is used.

With this approach, the startup period of this single-stage refrigerating machine could be reduced 15 minutes in comparison with non adjusting by the optimum value. In addition, at the vapour temperature negative 70 ^oC and condensing temperature 40 ^oC, energy efficiency of the machine and volumetric efficiency of compressor are 0,664 and 0,751 but at the same temperature regime, energy efficiency and volumetric efficiency of single stage refrigerating machine with the single-component refrigerant is near zero because its compression ratio is above 30.

Key words: refrigerant, refrigerating machine, startup period.