1. The air supply is insufficient. This phenomenon mainly includes the blockage of the return air duct, the blockage of the filter screen that are used for too long, the failure of the fan to rotate or the decrease of the rotational speed, which may cause the heat transfer insufficiency. The evaporation pressure will go down and the evaporation temperature will also fall.
2. Because of the MVR evaporator heat exchanger itself, the heat exchanger is often used in the equipment, if the heat transfer performance of the equipment decreases, the pressure of the evaporator will go down, which will result in the equipment frosting.
3. When the exterior temperature is too low, it will also lead to frost, because the temperature of MVR evaporator of general civil refrigeration will not be lower than 20℃, but it will cause insufficient heat transfer function in the low temperature environment, and the evaporation pressure is too low.
4. When the expansion valve of MVR evaporator is blocked or the pulse motor that controls the opening is damaged, the impurities will be blocked and the system will not work properly. Therefore, the refrigerant flow reduces and so does the pressure of MVR evaporator.http://www.wxhtshen.com/