A Method for On-line Measurement of Cold Loss in Dewar's Full Temperature Range

Abstract

The invention discloses a method for online measurement of cold loss in the full temperature range of Dewar. The method utilizes the functional relationship between the temperature change of the Dewar cold head and the radiation heat leakage and conduction heat leakage, and calculates the numerical value of the temperature change curve of the cold head. Fitting, so as to inversely derive the expression of cold loss. The invention overcomes the fact that neither the usual liquid nitrogen weighing method nor the standard refrigerator calibration method can give the radiation heat leakage and heat conduction heat leakage respectively, and can only obtain a total cooling loss value, and cannot be coupled with a refrigerator. In order to realize the measurement of the radiation heat leakage and heat conduction heat leakage of the Dewar without destroying the original coupling state, and at the same time, the heat leakage of the Dewar cold head at each temperature point is given. It provides an effective measurement method for Dewar's thermal design and thermal failure analysis.

Description

technical field [0001] The invention relates to a Dewar technology, in particular to a method for online measurement of the cold loss of the Dewar in the full temperature range. The method can obtain the radiation leakage of the Dewar at each temperature point without changing the coupling state of the Dewar. heat, conduction heat leakage, and total heat leakage. Background technique [0002] Cold loss is an important parameter of Dewar. The heat transfer methods mainly include radiation heat transfer, heat conduction heat transfer and convective heat transfer. Because it is vacuum packaged, convective heat transfer is generally very small in Dewar and is often ignored. Therefore, in Dewar In the heat leakage of tiles, usually only radiation heat leakage and heat conduction heat leakage are considered. Usually, the measurement method of cold loss cannot give the radiation heat leakage and heat conduction heat leakage respectively, and can only obtain a total cold loss value...

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Problems solved by technology

[0003] The purpose of the present invention is to provide a full-state on-line measurement method for Dewar cold loss, which solves the problem in the prior art that it can only be measured when the Dewar is not coupled with the refrigerator, and cannot separately measure radiation heat leakage and conduction. Heat Leakage Technical Issues

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