Application of microchannel heat exchangers in transcritical CO2 refrigeration system

Heat exchangers are the main components in refrigeration systems. Up to now, there are various types of heat exchangers applied in the transcritical CO2 refrigeration system. Because the operating pressure in transcritical CO2 refrigeration cycle is much higher than that in the conventional vapor compression system, it is much more suitable to use microchannel heat exchangers, which can make the system more safety, compact and high efficient. However, microchannel heat exchangers Of CO2 are different from those of common refrigerants in design and performance. The heat transfer coefficient and pressure drop in CO2 microchannel heat exchangers are unlike to those of conventional refrigerants too. This can be explained by the fact that it has special thermo-physical and transport properties in the near critical region. So how to design high efficient microchannel heat exchangers is more helpful to improve the system performance.