There are probably the following reasons for insufficient heat exchange in the evaporator.
First, the evaporator water flow is insufficient. The main factors that cause this phenomenon are that the pump is broken or there is a froeign body in the pump impelier, ot the water pump inlet pipe leaks caused by insufficient water flow. Need to replace the pump, or clear the impeller internal foreign body can remove the faults.
Second, the foreign bocy of the evaporator is blocked or the surface of the evaporator tube is fouled, or crystallized, resulting in insufficient heat exchange. To judge whether the evaporator is blocked or the evaporation pipe is fouled, we should first ecxlude the problem of the water pump, and determine it in order t ensure that the water pump and the water inlet pipe are normal. Evaporator blocjage or structure has a common and very distinct feature (for medium temperature units only). when the equipment is normal at ordinary times, there will not be a lot of condensed water or ice on the surface of the compressor. When you see a large amount of condensate or frost on the surface of the commpressor, you can basically determine that the evaporator is blocked. If the evaporator is blocked or the evaporator tube is fouled, the evaporator should be disassembled, and the evaporator should be washed by high=pressure water gun or soaked and cleaned with special liquid medicine.