The refrigerant will flow into the evaporator when the compressor is shut down

In this process, due to the rapid drop in the pressure inside the evaporator, the liquid working medium in which it resides absorbs a large amount of its own heat and vaporizes it, and then is compressed and sent to the condenser. It takes a certain amount of time for the excess working fluid of the evaporator to completely return to the condenser. During this time period, although the compressor is working, the system has no cooling output. In other words, this process consumes power but does not generate cooling. Further, during the shutdown, the refrigerant continues to flow into the evaporator, and part of the liquid refrigerant vaporizes, causing an increase in the amount of gaseous refrigerant, which causes the evaporation pressure to rise.

The temperature of the working fluid in the evaporator rises at the same time, so that the temperature inside the refrigerator box rises rapidly, which will shorten the downtime of the compressor. In addition, for the compressor, due to the increase of the refrigerant in the evaporator, when the engine is restarted, the phenomenon of "clashing" is easy to occur. Therefore, by adding a frequency converter to change the power supply frequency f of the compressor motor, the motor speed can be changed. This changes the speed of the compressor, which in turn matches the compressor cooling capacity to the thermal load. In this way, the total number of starts and stops of the compressor is correspondingly reduced. The energy loss due to start-stop is also reduced or even completely avoided. The use of frequency conversion for energy adjustment brings many benefits: energy saving, high energy efficiency ratio, which is the most outstanding advantage of frequency conversion air conditioner; low starting current, using step-down measures, can be used for "soft start"; stepless speed regulation, adjustment range Wide, low temperature fluctuations; high control accuracy. However, due to the need to add a frequency converter to the equipment, the cost of equipment has increased, and it has been obtained in household air conditioners.