The first part mentioned two reasons for the slow temperature drop of commercial refrigerators. Next, we will continue to introduce two situations that will slow down the temperature of refrigerators:
1. There are more air or refrigeration oil in the evaporator of commercial reach in fridge, and the heat transfer effect decreases
Once more refrigeration oil is attached to the inner surface of the evaporator heat transfer tube, its heat transfer coefficient will reduce. Similarly, if there is more air in the heat transfer tube, the heat exchange area of the evaporator will reduce, and the heat transfer efficiency will also significantly decline, which will lead to the slow temperature drop in the refrigerator. Therefore, in the daily operation and maintenance, attention should be paid to the timely removal of the oil on the inner surface of the evaporator heat transfer tube and 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 is too large or too small
Improper adjustment or blockage of the throttle valve will directly affect the refrigerant flow into the evaporator. When the throttle valve is opened too large, the refrigerant flow will be too large, the evaporation pressure and evaporation temperature will also increase, and the temperature drop rate of the commercial grade fridge will slow down;
At the same time, when the throttle valve is too small or blocked, the refrigerant flow will decrease, the cooling capacity of the system will also decline, and the temperature drop rate of the refrigerator will slow down. Generally, the refrigerant flow of the throttle valve can be judged by observing evaporation pressure, evaporation temperature, and frosting condition of the suction pipe. The blockage of the throttle valve is an important factor affecting the flow rate of refrigerant. The main causes of throttle valve blockage are ice blockage and dirty blockage. Ice blockage is due to the poor drying effect of the dryer and the moisture in the refrigerant. When the refrigerant flows through the throttle valve, the temperature drops below 0°C, and the water in the refrigerant forms ice and blocks the orifice of the throttle valve.