A high temperature pure air heater

Abstract

The invention provides a high-temperature pure air heater, comprising a pressure-resistant shell (1), a grate (2), an air inlet pipe (3), a heat insulation layer (4), an inner lining cylinder (5), and an air outlet pipe (6) ), upper cover plate (7), fastening bolts (8), corundum parts (9‑1, 9‑2, 9‑3), electric heating assembly (10), heat exchange assembly (11), power connector (12) , the bracket (13); the heat insulation layer (4) is installed in the pressure-resistant housing (1), the electric heating assembly (10) is combined with the heat exchange assembly (11) up and down, and each electric heating assembly (11) is located in the heat exchange assembly (10) the lower part; the heat exchange tubes of the heat exchange assembly (11) are arranged in involute helix and connected in series up and down, and the interface adopts a conical disc shape for insertion; the lower part of the device is the air inlet pipe (3), and the upper part is the air outlet pipe (6). According to the air heater of the present invention, the air flow path is long, the heat exchange area is large, and the temperature of the outlet air flow is stable; the heat exchange components are vertically arranged, and the internal heat insulation layer is evenly stressed, which is convenient for manufacturing and processing, and convenient for installation.

Description

technical field [0001] The invention relates to the field of aerodynamics, in particular to a hypersonic wind tunnel main airflow preheating device and a pure air heating device, belonging to the hypersonic wind tunnel technical field. Background technique [0002] Currently, there are two heating methods used in conventional hypersonic wind tunnels; instant heating and thermal storage. [0003] Instantaneous heaters are difficult to use in general laboratories due to the requirement of large electric power; general research test equipment, the number of operations is limited, the utilization rate is small, and conventional laboratories do not provide high-power power supply equipment, which limits this heater application. For example, in a hypersonic wind tunnel, the instantaneous electric heater needs a lot of electric power, and the power adjustment equipment. The wind tunnel of CARDC needs 8000KW electric power. For the small wind tunnel FD-03 hypersonic wind tunnel, on...

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Problems solved by technology

[0007] However, in the existing electric heat storage heaters, the heat storage body is arranged in a single heat exchange channel, and the designed heater, the area of ​​the heat exchange channel is given according to the flow rate, and the length of the heater is determined; limited by the equipment site, the long If the diameter ratio is difficult to obtain too large, the heat exchange channel will be too short; the residence time of the air flow in the heat storage channel is short, and the temperature of the outlet air flow will not meet the requirements; if the preheating temperature of the heat storage body is simply increased , will cause the heater to overheat and cause safety problems;

[0008] In addition, the current vertically installed heater with a single channel, due to air convection, the upper temperature will continue to rise without restriction, and the temperature of the furnace top is very high; it will affect the safety of use

[0009] In the actual application of the heater, it is very difficult to install a high-temperature fast valve at the outlet of the heater in the wind tunnel to avoid the impact of the heat storage material by the air flow; this valve must be resistant to high temperature and high pressure, and the opening and closing speed must be fast; Products generally do not have such valves, and a lot of money is spent to design such valves; this brings a lot of trouble to the planning of the wind tunnel

[0010] The current heater forms, including plate heaters, pebble bed heaters, honeycomb heaters, etc., the heat exchange airflow will be mixed with the shedding powder of the heat insulation layer and the scale debris of the electric heating element, causing pollution to the airflow; wind tunnel In the middle, I also want to take the way of filter dust removal to eliminate these effects, but the filter is difficult to withstand the impact of high-temperature and high-pressure airflow, and no suitable method has been found for material selection and structural design to solve this problem.

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