The common problems of refrigeration equipment，usually on the compressor.
1.The suction temperature is too high
The suction temperature is too high-mainly due to the increase of the suction superheat. Note that a high suction temperature does not mean that the suction pressure is high, because the suction is superheated steam.
Under normal circumstances, the compressor cylinder head should be half cold and half hot. If the suction temperature is too high, all the cylinder heads become hot. If the intake temperature is higher than normal, the exhaust temperature will increase accordingly.
The main reasons for the high suction temperature are:
(1) Insufficient refrigerant charge in the system: Even if the expansion valve is opened to the maximum, the liquid supply amount will not change, so that the refrigerant vapor overheats in the evaporator and causes suction. Gas temperature rises.
(2) The opening degree of the expansion valve is too small: the circulation of the refrigerant in the system is insufficient, the amount of refrigerant entering the evaporator is small, the degree of overheating is large, and the intake temperature is high.
(3) The clogging screen of the expansion valve is blocked: the liquid supply in the evaporator is insufficient, the amount of refrigerant liquid is reduced, and a part of the evaporator is occupied by the superheated steam, so the suction temperature rises.
(4) The suction temperature is too high for other reasons: if the return pipe is not well insulated or the pipe is too long, it can cause the suction temperature to be too high.
- The suction temperature is too low
The suction temperature is too low -mainly due to the large amount of liquid supplied by the evaporator, resulting in low suction superheat.
(1) Too much refrigerant charge: Occupies a part of the volume of the condenser and increases the condensation pressure, and the liquid entering the evaporator increases accordingly. The liquid in the evaporator cannot be completely vaporized, so that the gas sucked by the compressor has liquid droplets. In this way, the temperature of the return air pipe decreases, but the evaporation temperature does not change because the pressure does not decrease, and the superheat degree decreases. Even when the small expansion valve is closed, there is no significant improvement.
(2) The expansion valve opening is too large: the temperature of the temperature sensing element is not accurate because the temperature sensing element is loosely banded, the contact area with the return pipe is small, or the temperature sensing element is not banded with thermal insulation material and its banding position is wrong. , Close to the ambient temperature, the expansion of the expansion valve action is increased, resulting in excessive liquid supply.
