At present, the vehicle refrigerator technology mainly includes thermoelectric semiconductor refrigeration technology and compression refrigeration technology. There are essential differences between the two in terms of working principles, and thus produce different technical characteristics.

Compression refrigeration uses the reverse cycle of Carnot's principle, that is, a refrigeration method of refrigeration cycle. Compression refrigeration utilizes the phenomenon of heat absorption and exotherm occurring in the process of gas-liquid phase transition of a refrigerant with a very low boiling point to achieve refrigeration. The whole process includes the suction and compression of the compressor, the exothermic condensation (heat dissipation) of the condenser, the throttling and pressure reduction of the throttle valve, and the endothermic vaporization (refrigeration) of the evaporator. Therefore, compression refrigeration includes four core components, namely compressor, throttle valve, condenser and evaporator, and its volume is generally large. At present, the compression refrigeration technology is relatively mature, the refrigeration efficiency is high, and the refrigeration capacity can reach -18 °C. However, due to the volume limitation of the compressor refrigeration system, the size of the vehicle-mounted compressor refrigerator is usually larger, which is more suitable for the large-volume vehicle-mounted refrigerator with large layout space.

Semiconductor refrigeration uses thermoelectric semiconductor "Peltier effect" for refrigeration, also known as electronic refrigeration. Semiconductor refrigeration belongs to electronic physical refrigeration. As shown in Figure 1, there is no refrigeration working medium and mechanical moving parts at all, thus completely solving the application problems that cannot be solved by mechanical refrigeration refrigerators such as medium pollution and mechanical vibration. It is a real green environmental protection refrigeration technology. .

https://www.chinarykay.com/product/vehicle-refrigerator/