真空冷冻干燥机冷阱中的气体换热分析

Gas Heat Transfer in the Cold Trap of the Freeze Dryer

从理论上分析了螺旋盘管式冻干机冷阱中气体的换热。对真空冷阱中处于滑流区的气体换热 ,应考虑温度跳跃和速度滑移对换热的影响。基于冷阱内表面定热流和恒壁温的假设 ,建立了相应的分析模型 ,导出了冻干机冷阱内处于滑流区的气体换热 Nusselt数表达式 ,认为随着冷阱压力的降低 ,换热

In this paper, the heat transfer of the gas in the spiral coil cold trap of the freeze dryer has been studied analytically. The effects of the temperature jump and the velocity slip on the heat transfer for the slip-flow regime in the cold trap of the freeze dryer are considered. The analysis model is built on the assumption of the uniform wall heat flux and the uniform wall temperature, and then the expression of Nusselt number for the slip-flow regime is gotten. Research results reveal that Nusselt number will decrease with the decrease of the pressure in the cold trap.