Model building method and detection device of gm refrigerator compressor unit

Abstract

The invention discloses a model building method for a GM refrigerator compressor unit. The model building method comprises the steps that under different suction and exhaust pressures of the GM refrigerator compressor unit, mass flow, suction and exhaust pressures and consumed electric power of the GM refrigerator compressor unit to be detected are tested, and a volume flow and pressure ratio function relation and an efficiency and pressure ratio function relation of the GM refrigerator compressor unit are obtained; high pressure volume and low pressure volume of the GM refrigerator compressor unit are solved, and determination of model parameters of the GM refrigerator compressor unit is completed. According to the model building method, the characteristics such as flow, efficiency and volume distribution of a compressor are obtained through analyzing and fitting on the basis of actually tested compressor data to form a compressor model, and the compressor model is used for simulating the properties of the compressor under the different working conditions; on the basis of the compressor model, optimized design can be conducted on a cold head of a GM type refrigerator, and the built model can better reflect the properties of an actual refrigerator.

Description

technical field [0001] The invention belongs to the field of low-temperature refrigeration, and in particular relates to a model building method and a detection device for a compressor unit of a GM refrigerator. Background technique [0002] With the rapid development of cryogenic vacuum, small helium liquefier and low temperature superconducting technologies, the demand for small cryogenic refrigerators is increasing day by day. In these industries, the low-temperature refrigerators that have been applied in large quantities are currently only GM refrigerators. Compared with GM refrigerators, GM type pulse tube refrigerators have outstanding advantages such as no moving parts at low temperature, simple structure, high reliability, low mechanical vibration and electromagnetic noise, etc. In applications requiring extremely low vibration, It can be an alternative model of GM refrigerator. GM type pulse tube refrigerator and GM refrigerator (hereinafter collectively referred...

AI Technical Summary

Problems solved by technology

[0005] Compared with the previous method, some people have tested the compressor and used it as a reference to design the refrigerator, but failed to summarize the flow and efficiency characteristics of the compressor (independent of the charging pressure), and did not take into account the impact of the internal volume distribution of the compressor on The impact of the refrigerator as a whole

For the simulation design of the refrigerator, the previous research methods did not consider the influence of the performance change of the compressor, and always assumed that the high and low pressures were fixed, or the pressure wave input to the cold head of the refrigerator was fixed, or even simplified as Piecewise linear functions such as figure 1 shown

Therefore, these simulation methods can only simulate the results within a small range of operating conditions, and cannot reflect the performance of the refrigerator in different operating environments

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