Frosting at the return port of the central air-conditioning compressor is a very common phenomenon in the refrigeration system. Under normal circumstances, system problems will not occur immediately, and subtle frosting is generally not handled. If the frosting phenomenon is more serious, you need to find out the cause of the frosting first.
Frosting on compressor return port
Frosting at the air return port indicates that the return air temperature of the compressor is too low, so what will cause the return air temperature of the compressor to be too low?
If the volume and pressure of the refrigerant of the same quality are changed, the temperature will behave differently. If the return air temperature of the compressor is low, it will generally show both a low return air pressure and a high amount of refrigerant of the same volume. The root cause of this situation is that the refrigerant flowing through the evaporator cannot fully absorb itself and expand to a predetermined pressure. The amount of heat required for the temperature value.
There are two reasons for this problem:
1. The liquid refrigerant supply of the throttle valve is normal, but the evaporator cannot absorb heat normally.
2. The evaporator absorbs heat normally, but the throttle valve refrigerant supply is too much, that is, the refrigerant flow is too much. We usually understand that there is too much refrigerant gas.
Lack of fluorine causes frosting of compressor return air
1. Because the flow of refrigerant is extremely small. Too little refrigerant expansion will not use all of the evaporator area, but will only form a low temperature in the evaporator. In some areas, due to the small amount of refrigerant and rapid expansion, the local temperature is too low and the evaporator frosts.
After partial frost formation, due to the formation of a heat insulation layer on the surface of the evaporator and the low heat exchange in this area, the expansion of the refrigerant will transfer to other areas, and frost or icing of the entire evaporator will gradually appear, and the entire evaporator will form heat insulation As a result, the expansion will spread to the compressor return pipe, causing the compressor return air to frost.
2. Due to the small amount of refrigerant. The low evaporation pressure of the evaporator leads to a low evaporation temperature, which will gradually cause condensation in the evaporator to form an insulating layer, and transfer the expansion point to the return air of the compressor to cause frosting of the return air of the compressor.
The above two points will show the frosting of the evaporator before the compressor return air is frosted.
In fact, in most cases, for the frosting phenomenon, just adjust the hot gas bypass valve. Specific method: Open the rear end cover of the hot gas bypass valve, and then use a No. 8 Allen key to turn the adjustment nut inside clockwise. The adjustment process should not be too fast. Generally, you should pause after a half-turn to let the system run for a while After seeing the frosting situation, decide whether to continue the adjustment. After the operation is stable and the frosting of the compressor disappears, tighten the end cover.
Too much refrigerant in the system. The liquid level in the condenser is higher, the condensation heat exchange area is reduced, and the condensing pressure increases, that is, the pressure before the expansion valve increases, and the amount of refrigerant flowing into the evaporator increases. The liquid refrigerant cannot be completely evaporated in the evaporator. Therefore, the compressor sucks in wet steam, the cylinder hair is cold or even frosted, which may cause "liquid hammer", and the evaporation pressure will be high.
Inquiry central air conditioner , please feel free contact with me .
Company :Guangdong Head-Power Air Conditioning Co.,Ltd
Contact person :Cindy
Email: [email protected]
Telephone:86-757-88364517
Mobile Phone/Wechat/Whatsapp:+86-13794014063