A casing type gas electric heating device

Abstract

The invention discloses a casing pipe type gas electric heating device. The device comprises a gas inlet, a gas outlet, a shell, an inner pipe, an outer pipe, an electric heating wire, fins, a heat insulation layer and other components; the casing pipe type structural design is adopted in the gas electric heating device, the spiral fins are arranged outside the inner pipe, the electric heating wire is wound on the outer surface of the inner pipe along a gap between two adjacent spiral fins, the outer pipe is arranged on the outer sides of the fins, a whole casing pipe is fixed in the shell, and the heat insulation layer is arranged between the outer pipe and the shell. A spiral winding gas flow way is formed between the spiral fins and the outer pipe, the gas flow way is prolonged, and the device is high in heating speed and uniform in gas heating; heated gas flows through the winding type flow way on the outer side of the inner pipe, is heated to a certain temperature and then is reheated through the inner side of the inner pipe, the wall temperature of the outer pipe is relatively low, meanwhile, the heat insulation layer is arranged between the shell and the outer pipe of the electric heating device, heat dissipation losses are reduced, and the heat efficiency of the device is improved.

Description

technical field [0001] The invention belongs to the technical field of heat exchangers, and relates to a gas electric heater, in particular to a casing type gas electric heating device. Background technique [0002] Gas heater is a widely used heating equipment. According to the different heating gases, it can be subdivided into many types. The common ones are nitrogen heaters, air heaters, etc. Gas heaters have been widely used in aerospace, There are many scientific research and production laboratories in the weapon industry, chemical industry and colleges and universities. However, in the technical solutions of existing gas electric heating devices, the curved gas flow path design is mostly used. Although the gas flow path can be extended compared with the straight-through type gas flow path, the path increase is not obvious. Compared with the straight-through type gas flow path The channel is doubled at most, and the heat exchange efficiency is still low; in addition, t...

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Problems solved by technology

However, in the technical solutions of existing gas electric heating devices, the curved gas flow path design is mostly used. Although the gas flow path can be extended compared with the straight-through type gas flow path, the path increase is not obvious. Compared with the straight-through type gas flow path The channel is doubled at most, and the heat exchange efficiency is still low; in addition, the cross-sectional area of ​​the gas flow channel is mostly rectangular, circular or elliptical, or a deformed structure based on these structures. The distance is very long, and the outer side can be in contact with the heating body, but it is difficult to contact the heating body in the middle of the airflow, and the temperature is difficult to change in a very short time, resulting in uneven heating of the output gas, and large fluctuations in the temperature of the output gas. The gas flow rate in the gas pipeline with pressure is fast, and the contact time between the gas and the heating body is shorter when the above-mentioned electric heating device is used, so the heat exchange efficiency will be reduced, and the defects in use will be more obvious

[0003] In addition to the above-mentioned technical defects, it also includes the disadvantage of large heat loss. The insulation layer in ordinary gas electric heating devices plays the role of heat preservation and reduces the loss of heat from the shell. However, the radial size of the shell of the general heater is relatively large. , the thickness of the external insulation layer is limited, and the heat of the centrally installed heating elements is much greater than the heat that can be maintained by the insulation layer with this wall thickness, so that the heat is easily lost from the shell, so the existing electric heating device has obvious loss problems

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