The problem of frosting in evaporator for cold room storage
For cold room storage, it is common that evaporator have ice while worked for a period of time. And, frosting evenly in the evaporator is normal. But, if the frost is uneven, the refrigeration unit is meeting some problems. Four unnormal frostings as below:
Problem 1: The inlet port of the evaporator is with frost, but without in the outlet part.
The reason is that not enough liquid refrigerant is a pump to the evaporator. The liquid refrigerant is already evaporated completely before flow out the evaporator.
Problem 2: The outlet port of the evaporator is with frost, but without in the inlet part.
The reason is that too much liquid refrigerant pump to the evaporator.
Problem 3: Top part of the evaporator is with frost, bottom part without frost.
Too much lubricating oil at the bottom of the evaporator. Liquid refrigerant can not evaporate well in the bottom.
Problem 4: The frost is covered in the evaporator but uneven.
The reason is that the evaporator full of oil and the efficiency of exchange heat is not good.