Proper choice of chiller oil
Believe that knowledgeable friends know each industrial chillers in the normal operation of the process requires fitted with refrigerant oil can ensure the use of our cold water machine, freezer oil, it is mainly used for refrigerator compressor lubricant must be lubricated parts, and compressor operation performance and service life have a certain close contact, so the selection and Application of will decide we chiller efficiency and service life.
In fact of the chiller refrigeration oil it is different to other mechanical equipment, due to the different occasions of the use of refrigerant. Therefore, it is necessary to choice suitable we own chiller refrigeration oil, let us together with East Star Xiaobian to learn about how to cold water machine for our correct choice of optimal freezing oil.
1 Viscosity: the viscosity of refrigeration oil is an important parameter in oil characteristics, using different refrigerants to choose different refrigeration oil. In addition, the viscosity of refrigeration oil is also related to the temperature of the cold water machine, the temperature rises, the oil viscosity is reduced. Chiller refrigeration oil viscosity over the General Assembly the mechanical friction power, the friction heat and the starting torque is increased, if the viscosity is too small, to moving parts cannot be the required oil film formed is not up to the proper lubrication and cooling effect.
2 freezing point: freezing oil in the experimental conditions to stop the flow of temperature is known as the freezing point. In the refrigeration system, heat exchange equipment and pipeline, usually work at low temperatures, and the tube wall has more or less oil film appears, how oil solidification point is too high will affect the refrigerant flow, increase flow resistance and the heat transfer effect is influenced. In general, for freezing equipment, its freezing point should be the lower the better, such as R-22 of the compressor, refrigeration oil should be below -55. If used in cryogenic equipment, the freezing point should be lower.
3 chemical stability and anti oxygen properties: pure refrigeration oil chemical composition is stable, not oxidation, not corrosive metal. However, when the refrigeration oil contains a refrigerant or water will produce corrosion, the oxidation of oil will produce acid, corrosion of metal. When the lubricating oil in high temperature, it will appear coke, if the material attached to the valve, will affect the normal work of the valve, while the filter and throttle valve will cause clogging. So it must be used with chemical stability and oxidation resistance are better refrigeration oil.
4. Insulation performance: in closed and semi closed cold water machine, lubricant oil and refrigerant directly and the motor winding and a wiring terminal contact, thus requiring refrigeration oil has good insulating property and high breakdown voltage. Pure lubricating oil has good insulation performance, but its insulation performance will decline when it contains moisture, impurities and dust.
5. Due to the characteristics of refrigerants have different refrigeration system working temperature difference is larger, the refrigerator oil can generally be chosen in such a manner that low, under the condition of low temperature refrigeration equipment can select the lubricating oil with low viscosity, low solidifying point and high speed or air condition refrigeration equipment should choose the lubricating oil of high viscosity and high freezing point.