CN106369819B

CN106369819B - A kind of casing tube type gas electric heater unit

Info

Publication number: CN106369819B
Application number: CN201610727998.4A
Authority: CN
Inventors: 孙陆军; 吴宜灿; 黄群英; 朱志强; 李春京
Original assignee: Hefei Institutes of Physical Science of CAS
Current assignee: Hefei Institutes of Physical Science of CAS
Priority date: 2016-08-25
Filing date: 2016-08-25
Publication date: 2019-04-05
Anticipated expiration: 2036-08-25
Also published as: CN106369819A

Abstract

The invention discloses a sleeve-type electric gas heating device, which includes an air inlet, an air outlet, a casing, an inner tube, an outer tube, an electric heating wire, fins, a thermal insulation layer and other components. The above-mentioned gas electric heating device adopts a sleeve. Type structure design, the inner tube is provided with spiral fins, the heating wire is wound around the outer surface of the inner tube along the gap between two adjacent spiral fins, the outer tube is arranged on the outside of the fins, and the entire sleeve is fixed inside the shell , an insulating layer is arranged between the outer tube and the shell; in the present invention, a spirally wound gas flow channel is formed between the spiral fin and the outer tube, which increases the length of the gas flow channel. The heating gas first flows through the winding flow channel on the outside of the inner tube, and after heating to a certain temperature, it is heated again through the inner side of the inner tube, and the wall temperature of the outer tube is relatively low. The heat dissipation loss is reduced and the thermal efficiency of the device is improved.

Description

A kind of casing tube type gas electric heater unit

Technical field

The invention belongs to technical field of heat exchangers, are related to a kind of electric gas heater, and in particular to a kind of casing tube type gas Electric heater unit.

Background technique

Gas heater is a kind of with extensive heating equipment, according to the difference of heat gas, can refine and be divided into very much Type, common are nitrogen heater, air heater etc., and gas heater has been widely used aerospace, weapons Many research and production laboratories such as industry, chemical engineering industry and institution of higher learning.But in the technical solution of existing gas electrically heating device The gas flow paths of bending are mostly used to design, although the gas flow channel compared to through type has extension gas flow paths Effect, but path increases unobvious, at most doubles compared to using the channel of through type, heat exchanger effectiveness still compared with It is low；Furthermore the cross-sectional area of gas flow channel is in structures such as rectangle, circle or ellipse or based on these structures mostly Distressed structure, distance when air-flow passes through runner on the outside of air-flow to center is very long, on the outside of can be contacted with calandria, but Air-flow middle position difficulty is contacted with calandria, and temperature is difficult to be changed in a very short period of time, causes the gas of output heated not Uniformly, the gas temperature fluctuation of output is big, and gas flow rate is fast in the air delivering pipeline with pressure, uses above-mentioned electric heater unit When gas and calandria time of contact with regard to shorter, therefore heat exchanger effectiveness will reduce, also just more obvious using defect.

It further include the big disadvantage of thermal losses in addition to above-mentioned technological deficiency, the insulating layer in common gases electric heater unit rises Insulation effect reduces heat and sheds from shell losss, but the shell radial dimension of general heater is all larger, outside setting guarantor Warm layer finite thickness, the heat of the heating member of concentrated setting is much larger than the heat that the insulating layer of the wall thickness can maintain, so that hot Amount is lost easily from shell, so existing electric heater unit there are problems that significantly being lost.

Summary of the invention

It is logical by changing the technical problem to be solved by the present invention is to increase the length of gas flow channel in a limited space Road structure realizes that gas is heated evenly, and reduces and distributes loss caused by heat as shell, the purpose of the present invention is to provide one Kind heat exchanger effectiveness is high, is heated evenly, the electric heater unit for heat gas that thermal insulation property is strong.

The technical solution adopted by the present invention are as follows: a kind of casing tube type gas electric heater unit, described device include air inlet 1, Gas outlet 12, shell 13, inner tube 2, outer tube 5, fin 4, heating wire 3, power supply line intake 6a, power supply line outlet 6b, insulation Layer 7, lower perforated plate 8, sagging plate 9, upper end cover 10, upper perforated plate 11, gas outlet 12, shell 13 and lower cover 14；Wherein inner tube 2 with Outer tube 5 is concentric locking collar tube designs, and the outer diameter of inner tube 2 is less than the internal diameter of outer tube 5, and fin 4 is fastened in the shape of a spiral in inner tube 2 The outer edge of outer surface, fin 4 is contacted with the inner surface of outer tube 5, and an annular is constituted on the inside of 2 outside of inner tube, fin 4, outer tube 5 Wound form gas flow；Heating wire 3 is armouring heating wire, gap spiral winding of the heating wire 3 between 4 two adjacent fins of fin It is welded to connect in the outer surface of inner tube 2, and with 2 outer surface of inner tube, heating wire 3 is placed in wound form gas flow, can be to winding The gas heating flowed in formula runner；Shell 13 is straight, which is provided with air inlet 1, gas outlet 12, power supply line intake The casing heating element that 6a, power supply line outlet 6b, inner tube 2 and outer tube 5 form is fixed on inside shell 13 by tube sheet, outer tube 5 outsides and shell are equipped with heat insulation layer 7 between 13 inside, and air inlet 1 is fixedly connected on 13 side of shell, gas outlet 12 and upper end cover 10 are fixedly connected, and edge of a knife flanged joint are used between upper end cover 10 and shell 13, lower cover 14 and shell 13 weld, in inner tube 2 End is fixed on inside shell 13 by upper perforated plate 11, and 2 lower end of inner tube is fixed on inside shell 13 by lower perforated plate 8,5 upper end of outer tube It is fixedly connected with sagging plate 9,5 lower end of outer tube is fixedly connected with lower perforated plate 8.

Further, inner tube 2, outer tube 5, fin 4 are all made of austenite heat-resistance steel alloy Incoloy 800H, 4 bottom of fin Portion and 2 outer surface of inner tube are welded to connect.

Further, fin 4 and outer tube 5 use tolerance fit, and 4 top of fin is completely attached to 5 inner surface of outer tube, fin The angle of climb and fin number very close to each other between 4 tops and 5 inner surface of outer tube, that fin 4 is wound can be designed according to device and be heated The size of power suitably increases or reduces.

The principle of the invention lies in:

The flow channel of a kind of casing tube type gas electric heater unit of the present invention, gas is designed using sleeve type structure, the set Pipe is divided into two layers, including outer tube 5 and inner tube 2, and the internal diameter of outer tube 5 is greater than the outer diameter of inner tube 2, the space between outer tube 5 and inner tube 2 Spiral wound formula runner is divided by fin 4；Heating wire 3 is armouring heating wire, and heating wire 3 is wound in 2 outer surface of inner tube, and It is welded with 2 outer surface of inner tube, the height of heating wire 3 is less than the height of fin 4, it is wound in the gap between adjacent two fin, The winding direction of heating wire 3 is identical as 4 direction of fin, and inner tube 2, fin 4 and outer tube 5 are all metal materials and use is welded and fixed Connection type, heat transmission ability is big, and after heating wire is powered, outer tube 5, fin 4 and inner tube 2 are all rapidly heated, and all become The heating surface of heat gas increases the heat exchange area between gas；Gas enters apparatus of the present invention by air inlet 1, first passes through Wound form runner downward spiral flowing between outer tube 5 and inner tube 2, gas is by 5 inner surface of outer tube, fin during flowing 4, the outer surface heating of inner tube 2, gas flow channel length is several times of Straight-through heater, so that apparatus of the present invention heating speed Degree is faster；After gas reaches apparatus of the present invention bottom along wound form runner, by 2 flows upward inside of inner tube, in flow process In heated again by inner tube 2, flowed out eventually by gas outlet.

Heating wire 3 and inner tube 2, fin 4, outer tube 5 together constitute a bushing type heats in apparatus of the present invention, should Heats is in the form of a column, and is fixed on inside shell 13 by upper perforated plate 11, middle tube sheet 9 and lower perforated plate 8 respectively, effluent in outer tube 5 Dynamic is the relatively low gas of the temperature that heats for the first time, and the high-temperature gas being heated again is from 2 internal flow of inner tube, Ci Zhongjie Structure designs the temperature for advantageously reducing outer tube 5, and heat insulation layer is equipped between outer tube 5 and shell 13, and heat insulation layer is micro- using nanometer Hole heat-insulating material, 1000 DEG C of maximum operation (service) temperature, 200~400kg/m of density³, 0.021~0.034W/m.k of thermal coefficient has Effect reduces the radiation loss of apparatus of the present invention external environment, improves heating efficiency.

Of the invention having the prominent advantages that is designed using sleeve type structure, and helical fin and casing constitute winding stream Road increases the heating surface (area) (HS of this electric heater unit and the flow channel length of gas, and heating speed is fast, and gas is heated evenly；Into this The gas of invention device is flowed through winding on the outside of inner tube first, is heated rear high-temperature gas and is flowed from internal tube, outer tube wall temperature Spend it is relatively low, while between electric heater unit shell and outer tube be equipped with heat insulation layer, reduce radiation loss, improve the heat of device Efficiency.

Detailed description of the invention

Fig. 1 is a kind of casing tube type gas electric heater unit structure chart of the present invention；

Fig. 2 is a kind of casing tube type gas electric heater unit cannula structure detail drawing of the present invention.

In figure: 1 is air inlet；2 be inner tube；3 be heating wire；4 be fin；5 be outer tube；6a is power supply line intake；6b For power supply line outlet；7 be heat insulation layer；8 be lower perforated plate；9 be sagging plate；10 be upper end cover；11 be upper perforated plate；12 be outlet Mouthful；13 be shell；14 be lower cover.

Specific embodiment

With reference to the accompanying drawing and specific embodiment further illustrates the present invention.

As shown in Figure 1, the present invention is a kind of casing tube type gas electric heater unit, especially suitable for the gas pipeline with pressure In, swiftly flowing gas is heated, the present invention is described further with reference to the accompanying drawing.A kind of casing tube type gas electricity Heating device, including air inlet 1, inner tube 2, heating wire 3, fin 4, outer tube 5, power supply line intake 6a, power supply line outlet 6b, Heat insulation layer 7, lower perforated plate 8, sagging plate 9, upper end cover 10, upper perforated plate 11, gas outlet 12, shell 13 and lower cover 14.

The flow channel of a kind of casing tube type gas electric heater unit of the present invention, gas is designed using sleeve type structure, the set Pipe is divided into two layers, including outer tube 5 and inner tube 2, and the internal diameter of outer tube 5 is greater than the outer diameter of inner tube 2, the space between outer tube 5 and inner tube 2 Spiral wound formula runner is divided by fin 4, fin 4 and outer tube 5 use tolerance fit, 4 top of fin and 5 inner surface of outer tube It completely attaches to, it is very close to each other between 4 top of fin and 5 inner surface of outer tube；Heating wire 3 is armouring heating wire, and heating wire 3 is wound in 2 outer surface of inner tube, and welded with 2 outer surface of inner tube, the height of heating wire 3 is less than the height of fin 4, is wound in adjacent two fin Gap between, the winding direction of heating wire 3 is identical as 4 direction of fin, and inner tube 2, fin 4 and outer tube 5 are austenite heat-resistance Steel alloy Incoloy 800H material, and welding connecting mode is used, thermal coefficient is big, after heating wire is powered, outer tube 5, wing Piece 4 and 2 heating rate of inner tube are fast, all as the heating surface of heat gas, increase the heat exchange area between gas；Gas by Air inlet 1 enters electric heater unit of the present invention, and gas first passes through the wound form runner downward spiral stream between outer tube 5 and inner tube 2 Dynamic, gas is by 5 inner surface of outer tube, the outer surface heating of fin 4, inner tube 2, wound form gas flow length during flowing It is several times of through type electric heater, so that apparatus of the present invention heating speed is fast；Gas reaches apparatus of the present invention along winding runner It behind bottom, by 2 flows upward inside of inner tube, is heated again by inner tube 2 in flow process, flows out this eventually by gas outlet Invention device.

As shown in Fig. 2, heating wire 3 and inner tube 2, fin 4, outer tube 5 together constitute a bushing type in apparatus of the present invention Heats, the heats are in the form of a column, and are fixed on inside shell 13 by upper perforated plate 11, middle tube sheet 9 and lower perforated plate 8 respectively, What is flowed on the inside of outer tube 5 is the relatively low gas of the temperature that heats for the first time, and the high-temperature gas being heated again is inside inner tube 2 Flowing, such structure design are conducive to that outer tube 5 is made to be in relatively low temperature, and between 13 inside of 5 outside of outer tube and shell Filled with heat insulation layer 7, heat insulation layer 7 uses nanometer micropore heat-insulating material, and 1000 DEG C of maximum operation (service) temperature, 200~400kg/ of density m³, 0.021~0.034W/m.k of thermal coefficient effectively reduces the radiation loss of apparatus of the present invention external environment, improves Device heating efficiency.

Claims

1. A casing type gas electric heating device, characterized in that: the device comprises an air inlet (1), an inner tube (2), an outer tube (5), a fin (4), and a heating wire (3) , power cord inlet (6a), power cord outlet (6b), thermal insulation layer (7), lower tube sheet (8), middle tube sheet (9), upper end cover (10), upper tube sheet (11), The air outlet (12), the casing (13) and the lower end cover (14); the inner tube (2) and the outer tube (5) are of concentric sleeve type design, and the outer diameter of the inner tube (2) is smaller than that of the outer tube (5) ), the fins (4) are spirally wound and fixed on the outer surface of the inner tube (2), the outer edges of the fins (4) are in contact with the inner surface of the outer tube (5), the outer side of the inner tube (2), the fins The inner side of the sheet (4) and the outer tube (5) forms a ring-shaped winding gas flow channel; the heating wire (3) is an armored heating wire, and the heating wire (3) is along the line between two adjacent fins of the fin (4). The gap is spirally wound on the outer surface of the inner tube (2), and is welded and connected with the outer surface of the inner tube (2), and the heating wire (3) is placed in the winding gas flow channel to heat the gas flowing through the winding gas flow channel; The casing (13) is in the shape of a straight cylinder, and is provided with an air inlet (1), an air outlet (12), a power cord inlet (6a), a power cord outlet (6b), an inner tube (2) and an outer tube. The sleeve heating component composed of (5) is fixed inside the casing (13) through the tube sheet, and an insulating layer (7) is provided between the outer side of the outer tube (5) and the inner side of the casing (13), and the air inlet (1) The air outlet (12) is fixedly connected to the upper end cover (10), and the upper end cover (10) is connected to the casing (13) ) are connected by knife-edge flange, the lower end cover (14) is welded with the shell (13), the upper end of the inner tube (2) is fixed inside the shell (13) through the upper tube plate (11), and the lower end of the inner tube (2) The lower tube plate (8) is fixed inside the casing (13), the upper end of the outer tube (5) is fixedly connected to the middle tube plate (9), and the lower end of the outer tube (5) is fixedly connected to the lower tube plate (8).

2. A casing type gas electric heating device according to claim 1, characterized in that: the inner tube (2), the outer tube (5) and the fins (4) are all made of austenitic heat-resistant alloy steel Incoloy800H , the bottom of the fin (4) is welded and connected with the outer surface of the inner tube (2).

3. A casing type gas electric heating device according to claim 1, characterized in that: there is no gap between the top of the fins (4) and the inner surface of the outer tube (5), and the fins (4) are wound up and up The number of corners and fins can be appropriately increased or decreased according to the power requirements of the heating device.