低温制冷室降温时间的理论与数值模拟联合计算探究

摘要

为计算大型低温制冷室达到极端试验温度所需的降温时间,基于动态热平衡理论,建立了低温制冷室温度随时间的降温数学模型,并结合有限元数值模拟软件ANSYS进行辅助计算,进而绘制了在低温制冷机组满负荷运行的情况下,低温制冷室内空气温度的降温曲线.研究结果表明,低温制冷机组制冷降温过程中,制冷室内空气温度下降的速率先快后慢,在低温制冷机组的制冷容量为240.5 kW时,低温制冷室由极端高温(55 ℃)降低至极端低温(-42 ℃)需要1.45 h.其理论与数值模拟联合方法对计算低温制冷室的降温时间具有借鉴意义.%In order to calculate large cryogenic refrigeration room cooling time from extreme high temperature to extreme low temperature, this paper establishes a cooling mathematical model of temperature with time for cryogenic refrigeration room based on dynamic thermal equilibrium theory, then plots the air cooling curve of cryogenic refrigeration room under full load of cryogenic refrigeration unit with the help of numerical simulation software ANSYS.The result shows that in the process of cryogenic refrigeration unit cooling, air cooling rate is fast at first, then becomes slow.It takes 1.45 h to reduce air temperature from extreme high temperature (55 ℃) to extreme low temperature (-42 ℃).At the same time, the joint method of combining theory with numerical simulation has certain reference to calculating cryogenic refrigeration room cooling time.