Reciprocating refrigeration compressor discharge temperature control and overheating failure analysis
The recommended maximum continuous discharge temperature of reciprocating refrigeration compressor is 130℃. When discharge temperature exceeds 145℃, lubricant cracking rate rises by 3.8 times.
Xiteliduo reciprocating compressor equips built-in discharge temperature sensor; protection shutdown will trigger if discharge temperature stays above 140℃ for more than 10 seconds.
Small 4-cyl reciprocating refrigeration compressor is sensitive to insufficient suction superheat. Suction superheat below 3K causes liquid slugging, while superheat over 12K pushes discharge temperature up by 18℃.
Medium 4-cyl reciprocating refrigeration compressor water jacket cooling directly suppresses cylinder temperature; cooling water inlet temperature rise by 5℃ will increase discharge temperature by 9℃.
Large 4-cyl reciprocating refrigeration compressor operating at high compression ratio has higher discharge temperature; compression ratio exceeding 10 will push discharge temperature close to protection threshold.
Large 6-cyl reciprocating refrigeration compressor with multi-cylinder balanced operation has more stable discharge temperature distribution; single cylinder abnormal heating can be detected by separate temperature monitoring.
Many commissioning engineers set excessive suction superheat to avoid liquid slugging. This practice wastes power and increases discharge temperature by 12~20℃ under normal operating conditions.
Single-unit two-stage refrigeration compressor relies on intercooler to reduce discharge temperature of low-pressure stage; poor intercooler efficiency will make high-stage inlet temperature rise by 25℃.
Screw refrigeration compressor uses oil injection cooling to control discharge temperature, so it can tolerate higher compression ratio without sharp temperature rise compared with reciprocating refrigeration compressor.
### FAQ
Q1: What is the maximum allowable continuous discharge temperature for reciprocating refrigeration compressor?
A1: The maximum continuous discharge temperature should not exceed 130℃ for long-term safe operation.
Q2: What is the discharge temperature protection setting for xiteliduo reciprocating compressor?
A2: It will shut down automatically when discharge temperature remains above 140℃ for more than 10 seconds.
Q3: What will happen if suction superheat of small 4-cyl reciprocating refrigeration compressor exceeds 12K?
A3: The compressor discharge temperature will increase by about 18℃ under this condition.
Q4: What compression ratio threshold will bring large 4-cyl reciprocating compressor close to overheating protection?
A4: When compression ratio exceeds 10, discharge temperature will approach the protection threshold.
Q5: What component controls low-stage outlet temperature for single-unit two-stage refrigeration compressor?
A5: The intercooler is the core component to cool low-pressure stage discharged refrigerant.
Q6: Why can screw refrigeration compressor maintain stable temperature under high compression ratio?
A6: Screw compressor adopts oil injection cooling to directly reduce internal gas temperature.
Q7: What is the consequence of sustained discharge temperature above 145℃ for reciprocating compressor?
A7: Lubricant cracking rate increases 3.8 times, forming carbon deposits and damaging internal seals.