Refrigerant Oil
Lubricate the moving parts in the air-conditioning system, and must be refilled when performing air-conditioning work.
The function and classification of refrigeration oil and the requirements of refrigeration equipment for refrigeration oil
1 Shigong is refrigeration oil?
The oil used to lubricate the moving parts in the refrigeration compressor is called refrigeration oil, also known as lubricating oil,
2. What are the functions of refrigeration oil
In the compressor, the refrigeration oil mainly plays four functions: lubrication, sealing, cooling and energy regulation
(1) Lubrication Refrigerant oil plays a lubricating role in the operation of the compressor to reduce the friction and wear of the compressor, thereby prolonging the service life of the compressor.
(2) Sealing The refrigeration oil plays a sealing role in the compressor, so that the piston and the cylinder in the compressor are sealed.
Between the surfaces and between the rotating bearings to achieve the sealing effect to prevent the leakage of the upper refrigerant.
(3) Cooling: When the refrigeration oil is lubricating the moving parts of the compressor, it can take away the working process.
The heat generated in the compressor keeps the temperature of all moving parts low, thereby improving the efficiency and reliability of the compressor.
(4) Energy regulation For refrigeration compressors with energy regulation mechanisms, refrigeration can be used
The oil pressure of the oil is used as the power for the energy regulating machinery.
3 What is POE and PAG refrigeration oil?
In order to protect the ozone layer, the refrigerants of air-conditioning equipment have been restricted internationally, and various alternative refrigerants have appeared, and the refrigeration oil has also changed accordingly. With PAG. POE.
POE is the abbreviation of Polyol Ester, also known as polyester oil, which is a kind of synthetic polyol ester oil. PAG is the abbreviation of Polyalkylene Clycol, which is a synthetic poly(ethylene) glycol lubricating oil. Among them, POE oil can be well used not only in HFC refrigerant system, but also in hydrocarbon refrigeration. PAG oils can be used as lubricants in refrigeration systems where HFCs, hydrocarbons and ammonia are used as refrigerants
4. What are the requirements of refrigeration equipment for refrigeration oil?
Due to the different use occasions and refrigerants, the selection of refrigeration oil for refrigeration equipment is also different. The requirements for refrigeration oil are as follows:
(1) Viscosity is an important parameter in the oil characteristics of refrigeration oil viscosity, and different refrigeration oils should be selected accordingly when using different refrigerants. If the viscosity of the refrigeration oil is too large, the mechanical friction power, friction heat and starting torque will increase. On the contrary, if the viscosity is too small, the required oil film cannot be formed between the moving parts, so that the proper lubrication and cooling effects cannot be achieved.
(2) Cloud point The cloud point of refrigeration oil refers to the temperature at which paraffin begins to precipitate in the refrigeration oil when the temperature drops to a certain value, making the lubricating oil cloudy. The cloud point of the refrigeration oil used in the refrigeration equipment should be lower than the evaporation temperature of the refrigerant, otherwise the throttle valve will be blocked or the heat transfer performance will be affected.
(3) Freezing point The temperature at which the freezing oil is cooled to stop flowing under the experimental conditions is called the freezing point. The freezing point of the freezing oil used in the refrigeration equipment should be as low as possible (such as the compressor of R22, the freezing oil should be below -55C), otherwise it will be Affect the flow of refrigerant and increase the flow resistance, resulting in the consequence of poor heat transfer.
(4) Flash point The flash point of refrigerated oil refers to the lowest temperature at which the lubricating oil ignites when its steam is heated to contact with the flame. The flash point of the refrigeration oil used in the refrigeration equipment must be 15~30C higher than the exhaust temperature to avoid burning and coking of the lubricating oil.
(5) Others such as chemical stability and oxidation resistance, moisture and mechanical impurities, and insulating properties.