Issues related to refrigeration compressors
Thread Content
Dear experts: Our company uses a refrigerant containing over 85% isobutane (along with some propane and olefins). During operation, the liquid separation tank at the first stage inlet of the compressor often contains liquid, which causes the compressor to stop working. The opening degree of the anti-surge valve is only 25%. How can we solve the problem of liquid in the compressor’s inlet liquid separation tank? (The temperature of the flash tank and the primary inlet separation tank is around 1 degree, with a pressure of 0.05 MPa; the pressure at the compressor outlet is 0.7 MPa.)
1. For the inlet liquid separation tank, an external heating coil is effective, while an internal vaporization coil yields the best results; however, this approach can lead to steam leakage； 2. If the compressor outlet pressure is too high, it indicates that there is a lot of non-condensable gas in the refrigerant; it is recommended to reduce the outlet pressure ； 3. Reduce the operating liquid level in the flash tank ； 4. Increase the flow from the compressor outlet to the flash tank, and reduce the anti-surge setting. Surge is generally not caused by liquid in the inlet; however, liquid in the inlet can cause equipment vibration and a significant increase in displacement, leading to shutdown sequences, and in severe cases, it can result in safety accidents.