The capacity of the refrigeration machine should be matched with the heat load of the warehouse. This can be achieved through reasonable machine configuration and the use of energy regulation devices, etc. Of course, the most important thing is to have relatively good energy-saving measures for the installation of cold storage. If the heat load of the warehouse remains unchanged but the capacity of the compressor is large, it will cause the evaporation temperature of the system to drop or the compressor to malfunction. This is a very difficult refrigeration system to adjust and the stability of the refrigeration equipment is also poor. Conversely, if the capacity of the refrigeration machine decreases, as the machine fails to draw back the refrigerant gas formed in the evaporator in time, the temperature of the evaporator will rise again, making it difficult to cool down the warehouse.
When the heat load of the warehouse and the capacity of the refrigeration machine remain unchanged, if there is an oil film on the inner surface of the evaporator tubes or a frost layer on the outer surface of the tubes, it will also affect the cooling effect and make it difficult to cool down the warehouse. It is incorrect for the evaporation temperature to be either too high or too low than the design requirement. If it is too high, it cannot meet the requirements of food processing technology; if it is too low, it will deteriorate the energy index and operational economy of the refrigeration machine. The specific manifestations are as follows:
① A decrease in evaporation temperature leads to a reduction in the cooling capacity of the refrigeration machine. This is because the specific volume of the gas in the evaporator increases, reducing the cooling capacity per unit volume. As a result, the mass of refrigerant liquid circulating by the refrigeration machine per hour decreases.
② The evaporation temperature decreases, and the energy consumed for compressing each kilogram of gas increases.
