Theoretical Analysis And Experimental Research On Heat Transfer Of The Compact Heat Exchangers In Cryogenic Engineering

Compact heat exchangers used in the field of cryogenics are important component parts of the cryogenic equipments. This paper has carried out the heat transfer mechanism analysis and experimental research of cryogenic compact heat exchanger with liquid nitrogen. According to the thermophysical properties and transmission properties of liquid nitrogen, a calculation program on the thermodynamic properties is established. By analyzing the flow of liquid nitrogen film and heat transfer characteristics, the physical models of hydrodynamics and heat transfer are established. The relationships of film thickness and heat transfer coefficient on flowing direction are given in present paper, including the effects of the volume of steam, the intensity of interfacial convection heat transfer and Reynolds numbers. It has also conducted exergy analysis of the cryogenic compact heat exchanger. Finally, using the laboratory equipments, the influence of the flow capacity and temperature on the heat transfer coefficient are analyzed.