Such a low design target temperature is difficult for ordinary single-stage compressors, especially after equipment aging.

As for the expansion valve, it is necessary to select the compressor first, and then select it according to the nominal capacity and working standard conditions of the compressor.

The heat exchange capacity of air cooler, condenser and evaporator should also be determined according to the nominal conditions of compressor.

The type of refrigerant required by refrigeration system, such as R404, is the best. The required quantity can only be known when the actual system is debugged, and it is impossible to determine the system capacity without knowing it.

It is recommended to find a professional to discuss in detail and determine the general plan.