液氮罐内低温氮气的温度场研究

Approaches on temperature distribution in a liquid nitrogen tank filled with liquid nitrogen partially

对装有少量液氮的液氮罐内的温度分布进行了系统研究,提出了相应的温度分布模型。研究表明,在10 L容积的液氮罐内注入少量液氮时,罐内温度可保持低于-130℃持续约25天,适用于多种场合的超低温保存。通过调节距离液氮面的高度,可选择保存样品的温度范围并控制样品的升降温速度。理论计算的温度分布与测量的结果符合较好,证实了所建立模型的合理性和有效性。

Temperature distribution in a liquid nitrogen tank filled with liquid nitrogen partially was in- vestigated, and a model was proposed to describe the distribution in the tank. Results demonstrate that a very low temperature （ 〈 - 130 ~C ） can be maintained in a 10 L liquid nitrogen tank for about one month when it contains a little liquid nitrogen. The temperature range and the speed of temperature change can be adjusted by controlling the distance between the sample and the surface of liquid nitrogen in the tank. The simulation results were in good agreements to the actual temperature measurements, which prove the validity and rationality of the model. Our research provides more useful results for the preserving samples noncon- tactly in an ultra-low temperature environment in biology, medicine, material science and industry, and theoretical reference for the research and manufacture in using uhralow temperature technology.