Why can't the refrigerator spray water to cool down?

Refrigerator is an indispensable part of our daily life. It can help us store food to keep it fresh, but it is not as simple as we think. Water spraying is an example. This problem involves thermodynamic principles and fluid dynamics.

The principle of thermodynamics tells us that in a closed system, the temperature difference leads to the flow of heat. The freezing room inside the refrigerator needs to discharge heat to keep the temperature low, and the heat can only be taken away by heat conduction and convection. Spraying water can increase convection transfer, but it will not change heat conduction. Therefore, if you only use water spray to cool down, you can only achieve short-term results, because the water will be heated quickly and lose its cooling effect. The real refrigeration power is composed of coolant and compressor.

In addition, the refrigerant voltage in the refrigerator and the compression in the refrigeration system will cool the refrigerant to a very low temperature, so the temperature in the refrigerator can be reduced by transferring heat. During the cycle, the compressor can release the compressed refrigerant into the condenser, and the condenser reduces the pressure of the compressed refrigerant, thus producing a cooling effect. This process requires a very high energy input, which explains why refrigerators need electricity.

To sum up, water spraying cannot be used as a cooling method in the refrigeration process because it cannot change the heat conduction mechanism. Only by using compressor and refrigerant can we provide enough refrigeration power, reduce the internal temperature of refrigerator and keep the freshness of food. Therefore, only the refrigeration system, insulation materials and sealing performance in the refrigerator meet the requirements, can the best refrigeration effect be achieved.