Reasons and solutions for the freezer not cooling

1. There is more air or refrigeration oil in the evaporator, and the heat transfer effect is reduced

Once more refrigeration oil is attached to the inner surface of the evaporator heat transfer tube on the freezer, its heat transfer coefficient will decrease. Similarly, if there is more air in the heat transfer tube, the heat transfer area of ​​the evaporator will be reduced, and its The heat transfer efficiency will also drop significantly, and the temperature drop in the warehouse will slow down. Therefore, in the daily operation and maintenance, attention should be paid to promptly removing the oil stains on the inner surface of the evaporator heat transfer tube and discharging the air in the evaporator to improve the heat transfer efficiency of the evaporator.

2. The throttle valve is improperly adjusted or blocked, and the refrigerant flow of the freezer is too large or too small

Improper adjustment or blockage of the throttle valve will directly affect the flow of refrigerant into the evaporator. When the throttle valve is opened too large, the refrigerant flow rate is too large, the evaporating pressure and evaporating temperature will also increase, and the temperature drop rate of the warehouse will slow down; at the same time, when the throttle valve is opened too small or blocked, the refrigerant The flow rate is also reduced, the cooling capacity of the system is also reduced, and the temperature drop rate of the warehouse will also slow down. Generally, it can be judged whether the refrigerant flow rate of the throttle valve is appropriate by observing the evaporating pressure, evaporating temperature and the frosting condition of the suction pipe. Blockage of the throttle valve is an important factor affecting the flow of refrigerant, and the main causes of blockage of the throttle valve are ice blockage and dirty blockage. Ice blocking is due to the poor drying effect of the dryer, and the refrigerant in the freezer contains moisture. When it flows through the throttle valve, the temperature drops below 0 °C, and the moisture in the refrigerant freezes into ice and blocks the throttle valve hole; dirty blocking It is due to the accumulation of more dirt on the filter screen at the inlet of the throttle valve, and the flow of refrigerant is not smooth, resulting in blockage.