Electric heating element and processing method for high-flow, high-temperature, high-pressure, and high-speed gas environment

Abstract

The invention belongs to the technical field of hypersonic wind tunnel test equipment, and discloses an electric heating element and a processing method used in a high-flow, high-temperature, high-pressure, and high-speed gas environment. The electric heating element adopts a splint structure, including several electric heating tubes arranged side by side, an upper surface splint covering the upper surface of the electric heating tube, a lower surface splint on the lower surface, and a protective box covering the neutral end of the electric heating tube. This processing method uses tooling to clamp and close the upper surface splint, electric heating tube and lower surface splint, then uses pins to penetrate the upper surface splint and lower surface splint, and uses argon arc welding to weld the upper surface splint, lower surface splint and protection box, Make the electric heating element become a square body. The electric heating element adopts a splint structure, which can increase the strength of the electric heating element, increase the contact area, improve the heat exchange efficiency, and ensure the quality and efficiency of the wind tunnel test. The processing method is simple and reliable, with high precision and small deformation.

Description

technical field [0001] The invention belongs to the field of hypersonic wind tunnel test equipment, and in particular relates to an electric heating element and a processing method used in a high-flow, high-temperature, high-pressure, and high-speed gas environment. Background technique [0002] In a conventional hypersonic wind tunnel using air as the test medium, due to the extremely high gas flow velocity, reaching Mach number 5 to Mach number 10, the violent expansion of the gas flow through the nozzle will cause water vapor and carbon dioxide to condense, resulting in irregularities in the flow field. The uniformity makes the test data inaccurate, which is not allowed in the hypersonic wind tunnel aerodynamic test. Therefore, in a conventional hypersonic wind tunnel with a large flow of high-speed air as the medium, it is necessary to install a regenerative heater to heat the airflow to the required anti-condensation temperature. [0003] Conventional hypersonic wind t...

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Problems solved by technology

[0005] The direct application of traditional electric heating tubes to hypersonic wind tunnel regenerative heaters has the following disadvantages: a. Under the conditions of large flow, high pressure, and high speed, the traditional electric heating tubes are not strong enough, and they are easy to deform and bend, resulting in damage to the electric heating tubes ; b. The contact area between the electric heating tube and the heat storage element is small, the heat conduction area is small, and the heat transfer efficiency is low, resulting in a low heating rate of the heat storage element, the airflow temperature cannot reach the anti-condensation temperature, and the electric heating tube is overheated and damaged; c. The temperature control thermocouple of the tube is fixed on the surface of the electric heating tube with a clamp. Under repeated impacts, the insulating ceramics are easily damaged and lead to insulation failure; e. It is difficult to install and fix multiple electric heating tubes inside the heater. Normal use affects the quality and efficiency of wind tunnel tests

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