Refrigerators use refrigerants to absorb heat and vaporize from the evaporator inside the box, then release heat and liquefy to the condenser outside the box, and then absorb heat and vaporize in the evaporator ... This cycle is refrigeration. Because the evaporator temperature is low and the condenser temperature is high, in the refrigeration process, the refrigerant in the evaporator is pumped out by the compressor and then compressed into the condenser to realize the heat transfer from the low-temperature object to the high-temperature object. The compressor does work on the refrigerant vapor, and the electric energy is converted into internal energy, so the refrigerant absorbs more heat from the evaporator than the whole refrigerator releases.

Train of thought analysis: In the refrigerator, the refrigerant absorbs heat and vaporizes from the evaporator inside the refrigerator, then releases heat and liquefies in the condenser outside the refrigerator, and then absorbs heat and vaporizes in the evaporator ... and so on.

Comment on test questions: This question examines the change of indoor temperature through the understanding of the working principle of refrigerator.