The suction temperature of the chiller generally refers to the suction temperature of the refrigeration compressor. The suction temperature of the refrigeration compressor of the piston chiller is the temperature of the refrigerant gas in the suction chamber of the refrigeration compressor. For the refrigeration compressor of centrifugal chiller, it refers to the refrigerant gas temperature on the suction guide blade.
The suction temperature of chiller not only affects the exhaust temperature of chiller, but also has an important influence on the volume cooling capacity of compressor. When the suction temperature of the compressor is high, the exhaust temperature is also high. When the refrigerant is inhaled, the refrigerant specific capacity is large, and the cooling capacity per unit volume of the compressor is small. On the contrary, the compressor suction temperature is low, its unit volume cooling capacity is large.
If the suction temperature of the chiller is too low, the refrigerant liquid may be sucked into the compressor, causing wet stroke of the compressor of the piston chiller. For centrifugal chiller, too low suction temperature will make the suction pressure of the compressor too low, which may cause surge.
In order to ensure the normal operation of the chiller, the suction temperature needs to be higher than the evaporation temperature, that is, there should be a certain super heat. For the piston chiller, the suction super heat is generally 5 ℃-10 ℃; If dry evaporator is used, the size of super heat can be adjusted by adjusting the screw of the thermal expansion valve. The suction super heat of centrifugal chiller is generally 2 ℃-3 ℃. Centrifugal water chiller generally uses full-liquid evaporator.
In addition, we should pay attention to the length of the suction pipe of the refrigeration compressor and the performance of the wrapped insulation material, which will have a certain influence on the super heat.
The refrigerant level in the evaporator. The size of super heat can also have a greater impact. When the refrigerant filling amount is small, the suction super heat increases when the liquid level in the evaporator is low. Therefore, in the operation of the water chiller, attention must be paid to the control of the suction temperature of the refrigeration compressor.