Investigation And Experimental Research On The Heat Transfer Characteristics Of The Mesh Regenerator Matrix

With the development of cryogenic technique, the application scope of cryocoolers is enlarging. This put forward a higher request to the cryogenic technique and the low temperature product development. Regenerator as an important component of the low-temperature field, it can influence the refrigerator cooling performance. This paper analyses the regenerator basing on VM refrigeration cycle, according to performance pa-rameter the author puts up the design calculating, research the refrigerator and regenera-tor internal loss, analysis the heat transfer characteristics of regenerator and carried out the structure optimization design.VM cryocooler belong to regenerative cryocooler, the irreversible loss including shuttle loss, pump gas loss, the resistance to flow pressure drop loss, axial thermal loss, back to the heat loss, thermal leak loss, the ideal heat loss and some other losses. Analy-sis the loss of the VM cryocooler form different companies shows that:the loss of the regenerator the proportion of the loss is the biggest to more than50%. So the heat regen-erator efficiency is the key for improving the performance of the refrigerator. Regenera-tor losses are composed of limited heat loss, flow pressure drop loss, packing tempera-ture fluctuations loss, air inlet temperature change loss and working medium deviating from the ideal gas loss.The flow resistance of the metal nets format regenerator is lesser and the increase of heat transfer area increased regenerator efficiency, so it is suit for as the regenerator packing of VM regenerator. The metal nets format regenerator heat transfer is related to Reynolds number and packing air void ratio. The experiment shows that the regenerator efficiency increases with the increase of cold fluid and thermal fluid flow. Thermal fluid flow influence coefficient of heat exchange is greater than the cold fluid flow.Because the flow in the regenerator is laminar and its thermal process can be seen as the endothermic process and exothermic process which are combined of many gas micro group. Based on the thermo acoustic theory, the thermodynamic processes of the regen-erator are analyzed. Established the regenerator physical model, and with a double-stage VM cryocooler to be example, optimizing the design of the regenerator and determining to use the0.03mm350mesh stainless steel wire mesh packing as the packing of twin-stage regenerator. The size of one-stage regenerator is Φ30×50(DNxlength, Unit mm), the size of two-stage regenerator isΦ20×30. And the purpose is making the theory temperature of refrigerator reaches15K.