A test device for testing the performance of heat exchangers in the large Reynolds number range at low temperature

Abstract

The invention discloses an experimental device for testing heat exchange properties at low temperate within wide Reynolds number range, comprising a compressor, a flow adjusting and allocating system, a helium cooling segment, a finned chip test segment and a measurement and acquisition system; three levels of flow adjustment are adopted herein, two mass-flow controllers are connected in parallel for measuring, Reynolds number testing precision is high, and the measurement range is wide; a scheme where covering with heat-insulating boards is performed and a scheme of placement in a high-vacuum multilayer heat-insulating environment are used to lower thermal balance errors, and heat transfer factor testing precision is high; temperature, pressure, flow and power values of the finned chip test segment are measured dynamically in real time during testing, heat transfer factor and friction factor are calculated in real time in the computer, and comparison with existing conclusions is facilitated; a temperature alarm monitor is arranged in the a control panel, so that operational safety and effectiveness of the device are ensured.

Description

technical field [0001] The invention relates to the technical field of low-temperature heat exchangers, in particular to a performance test device for heat exchangers in the range of large Reynolds numbers at low temperatures. Background technique [0002] As the main component of cryogenic equipment, cryogenic heat exchanger has been widely used in refrigeration, gas liquefaction and separation, cryogenic engineering and other fields. Its heat transfer and flow performance directly affect the economy, compactness and safety of cryogenic equipment. sex. For example, plate-fin heat exchangers are widely used in helium refrigerators / helium liquefiers because the heat transfer area per unit volume is about 10 times that of shell-and-tube heat exchangers. In order to facilitate the engineering design and application, it is an effective solution to measure the heat transfer and flow performance of the heat exchanger fin unit. [0003] At present, many domestic factories and des...

AI Technical Summary

Problems solved by technology

However, in the application of helium cryogenic systems, due to the differences in production and processing precision, performance of fins with different shape parameters, and different flow media, the existing fin performance data still needs to be fully considered

The traditional heat exchanger test platform mostly uses air, water vapor, water, heat transfer oil, etc. as the circulation medium, while experiments with low-temperature fluids as the medium are relatively rare, especially for helium at low temperature, and there is no reliable performance test data yet.

In addition, the traditional steady-state test mostly uses the separation method to separate the thermal resistance of one side to obtain the heat transfer coefficient of the end to be tested. This method will introduce the calculation error caused by the thermal resistance of the other side and the separation method into the performance results.

Images