At the bottom of the air source heat pump and the central air conditioning outdoor unit compressor, we will configure the compressor heating belt (also known as the crankcase heater). Do you know what a crankcase heater does? Let me explain:
The heating element of the compressor crankcase heating belt is arranged nickel-chromium alloy resistance wire, heating fast, uniform temperature, the insulation layer is made of high and low temperature resistance, anti-corrosion, high insulation, aging resistance of silicone rubber and non-chemical fiber cloth, imported foam rubber and other materials, composed of lining, intermediate thermal insulation layer, outer protective layer three layers, good heat resistance, reliable insulation performance, flexibility, Can be in close contact with the heated object, high thermal efficiency, easy to use, can be directly wound on the surface of the heated part.
The main function of the compressor bottom heating belt is to prevent liquid compression during the start-up and operation of the compressor. In the seasonal operation of the air conditioner, or after the central air conditioning has just been installed, before the first boot (or commissioning), it is necessary to preheat the unit in advance (generally more than 6 hours). After the advance power supply, the compressor crankcase heater power supply, the liquid refrigerant in the compressor can be evaporated in advance to ensure the service life of the compressor. (Tip, when the air conditioner is not used for a long time, it is necessary to power off the internal and external units, because the electric heating zone will produce a certain amount of power loss.)
The control logic of the crankcase heater belt is mainly controlled according to the temperature sensor at the bottom of the compressor, and the central air conditioning will be more complicated, involving the superheat problem corresponding to the detection value of the low-pressure pressure sensor. The function of the compressor heating belt is to make the temperature of the compressor lubricating oil higher than the saturation temperature, that is, to control the oil temperature of the compressor is greater than 0, to prevent the lubricating oil from being diluted by the refrigerant and to ensure that the lubricating oil does not dissolve too much liquid refrigerant, otherwise it will start with liquid, reduce the viscosity of the lubricating oil, and thus make the compressor pump body lubricating insufficient. In the case of low temperature, refrigerant migration refers to the dynamic migration of refrigerant in the closed system when the compressor does not operate for a long time, so that there will be a phenomenon of liquid refrigerant accumulation in the compressor. When starting and running, the outdoor unit and the gas-liquid separator evaporate and boil a lot, because the temperature of the press is low, the condensate is entered, and the press oil is discharged from the press.
The simple understanding is to prevent the compressor from hitting and oil shortage when the low-temperature standby starts and runs for a long time to ensure its reliability.
Post time: Nov-09-2024