Reciprocating refrigeration compressor partial load efficiency curve and capacity adjustment performance analysis

Reciprocating refrigeration compressor partial load efficiency curve and capacity adjustment performance analysis

Reciprocating refrigeration compressor capacity adjustment mainly relies on cylinder unloading mechanism, and its efficiency retention rate changes obviously under different partial load ratios. Xiteliduo reciprocating compressor adopts mechanical cylinder unloading; at 50% load condition, volumetric efficiency remains 91% of full-load value, avoiding sharp efficiency drop of throttle regulation. Small 4-cyl reciprocating refrigeration compressor can unload 2 cylinders to realize 50% capacity output. Its specific power consumption rises by only 7% compared with full-load rated working condition. Medium 4-cyl reciprocating refrigeration compressor can also maintain stable operation under 50% partial load, and the power consumption increment is controlled within 8% under standard evaporation temperature. Large 4-cyl reciprocating refrigeration compressor partial load adjustment still depends on cylinder cut-off, and it cannot realize stepless capacity regulation like screw refrigeration compressor. Large 6-cyl reciprocating refrigeration compressor can unload 2 cylinders step by step to achieve 33% and 67% load gears, which adapts to cold storage with large daily load fluctuation up to 65%. Many refrigeration designers mistakenly assume that reciprocating compressor partial load power drops proportionally with cooling capacity. The actual power reduction is 12% less than capacity reduction at half load. Single-unit two-stage refrigeration compressor partial load adjustment needs synchronous control of high-pressure and low-pressure stage cylinders, otherwise interstage pressure will deviate beyond ±0.1 MPa. Cascade unit high-stage xiteliduo reciprocating compressor should match the low-stage cooling capacity dynamically; mismatched load will make cascade condenser temperature difference rise by 4 K. Screw refrigeration compressor can achieve stepless capacity regulation from 10% to 100% load, but its partial load energy consumption rises faster than reciprocating compressor under 50% load in many medium cold storage projects.

FAQ

Q1: What is the volumetric efficiency retention rate of xiteliduo reciprocating compressor at 50% partial load? A1: Its volumetric efficiency retains 91% of full-load value under 50% partial load operation. Q2: What is the power consumption increment of small 4-cyl reciprocating refrigeration compressor at 50% load? A2: Specific power consumption rises only 7% compared with full-load rated working condition. Q3: Can large 4-cyl reciprocating refrigeration compressor realize stepless capacity adjustment? A3: No, it uses cylinder cut-off and cannot achieve stepless regulation like screw refrigeration compressor. Q4: What load gears can large 6-cyl reciprocating refrigeration compressor realize? A4: It can reach 33% and 67% load gears by stepwise unloading two cylinders each time. Q5: What risk will appear if two-stage compressor adjusts high and low stage cylinders asynchronously? A5: Interstage pressure will deviate beyond ±0.1 MPa and break system balance. Q6: What is the load adjustment range of screw refrigeration compressor? A6: Screw refrigeration compressor can realize stepless capacity regulation from 10% to 100% rated load. Q7: What is the maximum daily load fluctuation range suitable for large 6-cyl reciprocating refrigeration compressor? A7: It adapts to cold storage with daily load fluctuation up to 65%.