Thermal expansion valve chooses the impact on the refrigeration system
The normal choice is: 1.2 times the compressor's cooling capacity.
If the selection is too large, the evaporation temperature will increase, so that the expected cooling effect will not be achieved, and even cooling will not occur.
The large expansion valve has the following disadvantages:
1. Insecure. Because of the change of the superheat heat, the change of the opening of the expansion valve is controlled. Under the same degree of superheat, the large valve will cause the liquid supply of the valve to increase, so the compressor may have the possibility of liquid compression (or liquid strike).
2. The superheat adjustment during operation makes the large-sized expansion valve work in a small opening space, ie a smaller opening range. Because of the influence of lag, it can cause system oscillations, that is, instability. Because of the influence of lag, it can cause system oscillations, that is, instability.
3. The accumulation of liquid in the evaporator results in a small heat transfer area and a decreased cooling capacity. Long-term operation may cause the refrigerant liquid in the condenser to transfer to the evaporator and cause a failure.
4. Wasting costs.