The influence of excessively low discharge water temperature of condenser
1, The impact on the refrigeration cycle main road
If the outlet temperature of the condenser is low, it means that the condensation saturation temperature is low and the condensation pressure is low. We know that the pressure difference between the condenser and the evaporator is equal to the saturation pressure of the condenser - the saturation pressure of the evaporator. Under the same working conditions of the evaporator, the saturation pressure of the condenser is reduced, and the pressure difference is naturally reduced. At this time, there may be too little refrigerant flowing to the evaporator, which causes the unit low pressure alarm.
2, the effect on the motor cooling circuit
Most brands of chillers use a closed motor, using a refrigerant for cooling, as shown in the figure below, a small part of the refrigerant from the condenser is sprayed into the stator winding of the motor, after absorbing heat and then back to the evaporator, so the flow resistance of the refrigerant also needs to be overcome by the pressure difference between the condenser and the evaporator. If the outlet water temperature of the condenser is too low, resulting in too low condensing pressure, it is likely to trigger the motor overheating protection.
Why control the cooling water temperature? Can you figure it out?
3, the impact on the system oil circuit
At present, most of the chillers' compressors use plain bearings, which require lubricating oil to be continuously lubricated, and if they work in low condenser outlet temperature conditions for a long time, the unit is likely to be short of oil and alarm.
4, the impact on centrifugal chiller
If the cold water temperature is too low, the condensing pressure will also be too low, which will easily cause the centrifugal chiller to surge.