The invention discloses a microchannel
heat exchanger belonging to the technical field of
heat transfer and heat exchange. The microchannel
heat exchanger comprises a fluid channel, wherein a
working fluid inlet (2) and a refrigerating medium outlet (9) are molded at one end of the fluid channel, and a
working fluid outlet (5) and a refrigerating medium inlet (6) are molded at the other end. A heat exchange segment (1) is arranged in the fluid channel and is formed by alternately superposing a refrigerating medium layer (11) and a
working fluid layer (13), the refrigerating medium layer (11) and the working
fluid layer (13) are isolated through a baffle plate layer (12), and the refrigerating medium layer (11), the baffle plate layer (12) and the working
fluid layer (13) are homogenously bonded. A plurality of parallel microchannels are respectively arranged on the refrigerating medium layer (11) and the working
fluid layer (13), the heat exchange units are in homogenous structures, and the ratio of the hydraulic
diameter of the microchannels of the refrigerating medium layer (11) to the hydraulic
diameter of the microchannels of the working fluid layer (13) is 1:(0.25-15). In the invention, according to the use conditions of the
heat pump system, a group of optimized hydraulic
diameter values of the refrigerating medium microchannels and the working fluid microchannels are obtained through the
heat transfer theory and fluid
mechanics calculation and analysis. The
heat transfer efficiency of microchannel
heat exchanger is higher than that of the traditional heat exchange product.