Hanbell RC2-D, Technical Manual

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RC2-D Technical Manual
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6. Lubricating oil
The main functions of lubricating oil are lubrication, cooling and capacity control. The oil pressure in
the piston cylinder pushes the piston and slide valve forward and backward in the compression
chamber. The differential pressure oil supply system in RC2-D series can replace the external oil
pump. In some special applications, an external oil pump is still needed to ensure the safe operation.
The bearing of RC2-D series compressor only needs a small amount of oil for lubrication. The oil
injected into the compression chamber can form an oil film in the compression chamber to increase
the efficiency of the compressor and absorb part of the heat generated in the compression process.
During the operation, special attention should be paid to the temperature of lubricating oil, which is
an important factor affecting the bearing life of compressor. High lubricating oil temperature will
reduce the viscosity, resulting in the decrease of lubricating capacity and heat absorption capacity. It
is recommended to keep the viscosity of the oil above 10mm2/s. When the ambient temperature is
too high, the oil temperature should be kept above the condensation temperature of the system to
avoid the migration of refrigerant into the system. When the ambient temperature is too low, the
viscosity of the lubricating oil is high, and the pressure drop in the oil circuit is too large to load
normally, which leads to the heavy load start. Therefore, an oil heater is needed to heat the
lubricating oil to improve the oil temperature in a short time.
If the compressor is operating under limit condition, it is necessary to install an external oil cooler -
please use hanbel program to determine the cooling capacity and oil flow.
It is suggested to use the lubricating oil with higher viscosity under bad working conditions; at this
time, the discharge temperature is higher, which can reduce the viscosity of the lubricating oil. In
addition, sometimes insufficient return oil of evaporator may happen in such as full liquid systems,
which will resul in oil loss of compressor. If there is insufficient return oil in the system, it is
recommended to install a secondary oil separator between the compressor discharge port and the
condenser to further reduce the amount of lubricating oil entering the system
It is recommended to install the optional oil level switch to avoid the oil level too low.
Compared with the piston compressor, the screw compressor can withstand a certain short-term
liquid compresson, but the long-term liquid compression affects the viscosity of the lubricating oil,
and the bearing lubrication is insufficient, which easily causes the compressor to jam.
6.1 Lubricant configuration
Each compressor is specially equipped with different lubricating oil according to refrigerant. Please
contact Hanbell for details.
Note: please contact Hanbell for special oil requirement.