Screw Refrigerant Compressors

Fusheng screw refrigerant compressors comprise 5 series: CSR, CSRL/SRL, SRT, SDL and SST. They share the same screw technology foundation while being purpose-designed for different duties. Understanding these technical points helps selection more than memorizing model numbers.

1. The Rotor Profile Is the Foundation

Several series use the Fusheng 5:6 asymmetric rotor profile, with rotors formed on HOLROYD machines from the UK and KAPP and Klingelnberg precision grinders from Germany. The profile and the machining precision together determine volumetric efficiency and running smoothness — the less gas leakage and the more complete the compression, the lower the power consumed by the system for the same cooling capacity.

2. Single-Machine Two-Stage: Handling High Pressure Differential

Low-temperature refrigeration and high-temperature heat pumps have a large pressure differential, and single-stage compression tends to give an excessively high discharge temperature and falling efficiency. The SRT uses a pair of rotors each for the high and low pressure stages, driven synchronously by a direct-coupled motor, with high-precision curved-tooth couplings, bringing the whole into ideal balance; the SST goes further, using a screw for the low-pressure stage and a scroll for the high-pressure stage, solving the screw's leakage-triangle problem in the high-pressure section while greatly reducing machine room floor space.

3. Capacity Control and Operating Protection

• Capacity slide valve: the CSRL/SRL offers four-step or stepless options, with an optional built-in volume ratio, adapting to different refrigerant duties;
• VSD operation: down-frequency 20–60 Hz and up-frequency 20–80 Hz, letting cooling capacity follow the load;
• Economizer port: effectively improves system performance efficiency;
• Multiple units in parallel: meets large cooling capacity needs and eases phased expansion;
• Motor protection: a built-in PTC thermistor with an upgraded protection module precisely monitors coil temperature.

Conclusion

From rotor profile to single-machine two-stage, and on to capacity control and parallel operation, Fusheng places efficiency and reliability within one design logic. In selection, look at the duty first — refrigeration or heat pump, and how low the evaporating temperature — then match accordingly.