Low-temperature fluid flow measurement and calibration device and calibration method

Abstract

According to a low-temperature fluid flow measurement and calibration device and method, by designing the two subcoolers, it can be guaranteed that a medium is in a pure liquid state before entering an element to be measured and a weighing system, and by combining a standard meter comparison method and a weighing method, the measurement and calibration device which is simple in structure and high in precision is provided for the deep hypothermia field. Measurement and calibration in an actual working state in a real sense are realized. According to the device, the calibration working condition can be consistent with the actual working condition, working condition conversion is not needed in the calibration process, for example, if the actual working condition of the flow meter is 0.6 MPa and 83K, the calibration system can be directly adjusted to the working condition of 0.6 MPa and 83K, and the flow meter and the like are measured and calibrated. Meanwhile, two functions are provided, the flowmeter and the low-temperature pump can be tested, metered and calibrated respectively, the flowmeter and the low-temperature pump can be tested and calibrated at the same time through one-time operation, efficiency is high, and cost is low. According to the structure, multiple paths can be selected, and the calibration cost is reduced as much as possible.

Description

technical field [0001] The invention relates to the technical field of flow calibration, in particular to a cryogenic fluid flow measurement and calibration device and a calibration method. Background technique [0002] In the field of scientific research and industrial cryogenics, liquid nitrogen is often used as a conventional cryogenic cold source; in the entire cryogenic liquid nitrogen system, the accuracy of flow measurement is extremely important; The liquid nitrogen flowmeter is calibrated and calibrated to achieve the accuracy we need. In the commonly used flowmeter calibration devices, the basic principles are usually carried out by volumetric method, weighing method and standard meter method. Among them, for systems with large flow rates, the weighing method and standard meter method are basically used. [0003] The principle of the standard table method is as follows figure 1 shown. This method needs to first determine a precisely calibrated flowmeter, and con...

AI Technical Summary

Problems solved by technology

However, at present, the analogy calibration method is routinely used in scientific research and industrial deep low temperature fields, that is, to use normal temperature water for calibration, and then perform flow conversion under analogous low temperature conditions. Obviously, this method cannot achieve a calibration accuracy of 0.2‰

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