Hanbell RC2-100AF, Manual

Page: 107 / 117

106
Air cooled oil cooler application
Note:
1. The oil cooler should be controlled according to the discharge gas line temperature. Using entry oil
temperature as control reference should be confirmed by Hanbell for safety issue.
2. The oil cooler should be installed near the compressor to avoid long piping which will cause higher pressure
drop.
3. The pressure drop in oil cooler should not exceed 0.5 bar during normal operation.
4. The arrangement of piping for oil cooler should avoid gas accumulation and ensure that the oil cooler is
installed below the compressor and external oil separator.
5. The control algorithm of oil line solenoid valve should ensure no oil flows into compressor during the
compressor off period.
6. Service valve (ball valve) is recommended to be installed after the oil cooler for service purpose.
7. For low ambient working temperature (below 20
℃
), an oil bypass line at oil cooler will be needed to ensure a
quick warm up.
d. Liquid compression
Liquid compression can be classified as oil compression and liquid refrigerant compression. For oil compression it
is extremely dangerous to the compressor because oil can
’t be compressed. If oil compression occurs, bearings
need to suffer very big load which might cause severe damage to rollers and balls in bearing. Therefore, be aware
of oil management and not to charge oil into compressor when the compressor is not running.
Liquid refrigerant compression is also a killer to short the compressor life. When liquid refrigerant flow into the
compressor, the liquid refrigerant will wash out the oil where passed by. Those bearings might work without
lubrication temporarily and causes wear on them. The same situation will occur at those rotors and higher
possibility of mechanical contact between rotors can be predicted. This will also lead to scratches on rotors and
become the origin of higher noise and lower volumentric efficiency for compressor. To avoid liquid
’s flooding back