1. Basic information

Refrigeration Oil (Refrigerant Oil)

The oil used for the lubrication of the moving parts in the refrigeration compressor is called refrigeration oil. In the compressor, the refrigerant oil mainly plays the functions of lubrication, sealing, cooling and energy regulation.

2. Function

In the compressor, the refrigeration oil mainly plays four roles: lubrication, sealing, cooling and energy regulation.

(1) Lubrication The refrigerating oil plays a lubricating role during the operation of the compressor to reduce the friction and wear of the compressor, thereby extending the service life of the compressor.

(2) Sealing refrigeration oil plays a sealing role in the compressor, so that the piston in the compressor and the cylinder surface, and the rotating bearings are sealed to prevent refrigerant leakage.

(3) Cooling When the refrigerating oil is lubricated between the moving parts of the compressor, it can take away the heat generated during the working process and keep the moving parts at a lower temperature, thereby improving the efficiency and reliability of the compressor.

(4) Energy adjustment For a refrigeration compressor with an energy adjustment mechanism, the oil pressure of the refrigeration oil can be used as energy to adjust the power of the machine.

3POE and PAG Meaning

In order to protect the ozone layer, the refrigerant of air conditioning equipment has been restricted in the world, and various alternative refrigerants have appeared, and the refrigeration oil has also changed accordingly. The alternative refrigerants for air conditioning are R134a and R410a/R407c, which are replaced by PAG and POE respectively.

3.POE and PAG Meaning

In order to protect the ozone layer, the refrigerant of air conditioning equipment has been restricted in the world, and various alternative refrigerants have appeared, and the refrigeration oil has also changed accordingly. The alternative refrigerants for air conditioning are R134a and R410a/R407c, which are replaced by PAG and POE respectively.

York Refrigeration Oil

POE is the abbreviation of Polyol Ester, also known as polyester oil, which is a kind of synthetic polyol ester oil. PAG is an abbreviation of Polyalkylene Glycol, a synthetic poly (ethylene) glycol-based lubricating oil. Among them, POE oil can be well used not only in HFC refrigerant systems, but also in hydrocarbon refrigeration. PAG oil can be used as HFC, hydrocarbon and ammonia as refrigerant in the refrigeration system of lubricating oil.

4. Requirements

Due to the use of different occasions and refrigerants, refrigeration equipment on the choice of frozen oil is not the same. The requirements for refrigeration oil are as follows:

(1) Freezing point The temperature at which the freezing oil cools to stop flowing under the experimental conditions is called the freezing point. The freezing point of the refrigeration oil used in the refrigeration equipment should be as low as possible (such as the compressor of R22, the refrigeration oil should be below -55°C), otherwise it will affect the flow of the refrigerant and increase the flow resistance, which will lead to poor heat transfer. consequence.

(2) the viscosity of frozen oil is an important parameter in the characteristics of the oil, the use of different refrigerants to choose different frozen oil. If the freezing oil viscosity 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 due lubrication and cooling effect cannot be achieved.

(3) Cloud point The cloud point of a frozen oil refers to the temperature at which paraffin begins to precipitate in the frozen oil when the temperature drops to a certain value, making the lubricating oil turbid. The cloud point of the refrigeration oil used in the refrigeration equipment should be lower than the evaporation temperature of the refrigerant, otherwise it will cause the throttle valve to block or affect the heat transfer performance.

(4) Others such as chemical stability and oxygen resistance, moisture and mechanical impurities, and insulation properties.

(5) Flash point The flash point of frozen oil refers to the lowest temperature at which the lubricating oil is heated to the point where the steam contacts the flame. The flash point of the refrigeration oil used in the refrigeration equipment must be 15~30 ℃ higher than the exhaust temperature, so as not to cause the combustion and coking of the lubricating oil.

5. Temperature and pressure

The oil temperature should generally be maintained between 45~60 ℃, the highest should not exceed 70 ℃, and stable, if the oil temperature has been unstable and slowly rising, it means there is a fault. Oil temperature is too low or too high will make the deterioration of lubricating oil, at the same time, often foreshadow the arrival of failure. The key to the freezing oil pressure is the oil pressure difference. Due to various reasons, the oil pump cannot be oiled, that is to say, the oil pressure difference cannot be established. The oil pressure depends on the structure of the compressor. The external gear oil pressure difference of the vertical compressor is 0.5~1.5MPa, and the oil pressure difference of the new series compressor is 0.5~1.5MPa. Newly purchased compressors often use high oil pressure differences in operation and debugging, so as to increase the amount of lubricating oil, better complete the running-in period of moving parts such as cylinders, and extend the service life of the machine.