CN202002141U

CN202002141U - Horizontal air preheater

Info

Publication number: CN202002141U
Application number: CN2011201293641U
Authority: CN
Inventors: 张宏
Original assignee: Zhangjiagang Jiangnan Boiler & Pressure Vessel Co Ltd
Current assignee: Zhangjiagang Jiangnan Boiler & Pressure Vessel Co Ltd
Priority date: 2011-04-27
Filing date: 2011-04-27
Publication date: 2011-10-05
Anticipated expiration: 2021-04-27

Abstract

The utility model discloses a horizontal air preheater, which is capable of heating air by means of hot smoke and comprises a body case with a smoke inlet and a smoke outlet. A heat exchanging channel is formed inside the body case, a plurality of hollow heat exchanging pipes are arranged inside the heat exchanging channel, a pipe plate is hermetically embedded on a side wall of the body case, first through holes equal to the heat exchanging pipes in quantity are arranged on the upper portion of the pipe plate perpendicular to the direction of the plate surface, and second through holes equal to the heat exchanging pipes in quantity are arranged on the lower portion of the pipe plate perpendicular to the direction of the plate surface. Each heat exchanging pipe is provided with a first end and a second end, the first ends of the heat exchanging pipes are hermetically inserted into the first through holes in one-to-one correspondence, and the second ends of the heat exchanging pipes are hermetically inserted into the second through holes in one-to-one correspondence, and each heat exchanging pipe is in a U shape. By adopting the U-shaped heat exchanging pipes, influence of thermal stress can be reduced, and especially the thermal stress of the connecting portion of the U-shaped heat exchanging pipes and the pipe plate can be greatly reduced.

Description

A kind of horizontal air preheater

Technical field

The utility model relates to a kind of smoke exhaust heat of boiler, industrial furnace or other power that utilizes and comes the heat-exchanger rig of preheated burning with air, more particularly, relates to a kind of horizontal air preheater, especially can be widely used in the medium small boiler system.

Background technology

Utilize boiler; industrial furnace or other dynamic metallurgy; the device of chemical industry is in operation and can produces hot flue gas; in order to utilize smoke exhaust heat; usually air preheater can be set; the operation principle of air preheater is: a side of heating surface is by hot flue gas; opposite side passes through air; carry out heat exchange; the temperature of hot flue gas is descended; make air obtain heating; temperature raises; reach the purpose of utilizing fume afterheat; it not only can effectively utilize the used heat of smoke evacuation; reduce environmental pollution, be enhanced the also depressed burning of air after the temperature, and flameholding; the efficient height.

The structure of traditional horizontal pipe air preheater mostly as shown in Figure 1, comprise horizontally disposed many straight tubes, the front-end and back-end of each straight tube are respectively by front tube sheet and back tube sheet sealing and fixing installation mutually, the right part of these straight tubes all links with an air turning case, the left part of the straight tube on top and a hot air outlet case connect, the left part of the straight tube of bottom and an inlet of cold air case link, the thermal chimney road vertically is provided with perpendicular to these straight tubes, top-down each straight tube of blowing over of hot flue gas wherein, from entering the straight tube on top, heating the right-hand member of the straight tube on top again after the cold air straight tube that enters the bottom from the inlet of cold air case enters the air turning case on right side after preliminary heating like this, discharge from the hot air outlet case then, remained in the process that hot flue gas is top-down blows over along the straight tube outer wall, the hot flue gas that temperature is lowered is discharged from the bottom.This traditional air preheater is in the process of operation, the straight tube on top is because extraneous temperature is higher, temperature in the pipe is also higher, and the straight tube of bottom is just in time opposite, extraneous temperature is relatively low, temperature in the pipe is also relatively low, so the temperature difference between the straight tube on top and the straight tube of bottom is very big, the existence of this temperature difference causes the swell increment difference of the straight tube of levels, different swell incremenies will produce thermal stress in the junction of front and back tube sheet and straight tube, when this thermal stress reaches certain numerical value, to cause crackle even come off, cause that equipment performance descends, severe patient can cause security incident.

The utility model content

The purpose of this utility model provides a kind of simple in structure, stable horizontal air preheater.

For solving the problems of the technologies described above, the utility model adopts following technical scheme:

A kind of horizontal air preheater, it utilizes hot flue gas to add hot-air, comprise and have the into body case of mouth and outlet flue, the inside of this body case forms a hot switching path, be provided with the heat exchanger tube of several hollows in the described hot switching path, sealing is embedded with a tube sheet on one sidewall of described body case, the upper vertical of this tube sheet offers the same number of first through hole with described heat exchanger tube in the direction of plate face, lower vertical offers the same number of second through hole with described heat exchanger tube in the direction of plate face, each described heat exchanger tube all has first end and second end, the corresponding one by one sealing of first end of these described heat exchanger tubes assigns in these described first through holes, the corresponding one by one sealing of second end of these described heat exchanger tubes assigns in these described second through holes, and each described heat exchanger tube all is " U " shape.

Preferably, each described heat exchanger tube is all along the traffic direction setting perpendicular to hot flue gas.

Preferably, the outer cup of these described first through holes is provided with the hot air box of taking gas port out of; The outer cup of these described second through holes is provided with the cold air case of bringing gas port into, and the inner chamber of each described heat exchanger tube connects with the inner chamber of described hot air box and the inner chamber of described cold air case respectively.

Further preferably, describedly enter the top that mouth is positioned at described body case, described outlet flue is positioned at the bottom of described body case.

The beneficial effects of the utility model are: the utility model uses the heat exchanger tube of " U " shape to replace the heat exchanger tube of the straight tube shape in traditional horizontal air preheater, weakened the influence of thermal stress greatly, because the design of " U " shape heat exchanger tube, in the course of work, the temperature of the first half of each heat exchanger tube can be higher, and the latter half is just in time opposite, temperature can be lower, there is differential expansion between the first half of " U " shape heat exchanger tube and the latter half, but because the existence of the bending section of " U " shape, its elasticity and flexibility make most thermal stress, and particularly the thermal stress amplitude of " U " shape heat exchanger tube and tube sheet connecting portion reduces greatly.

Description of drawings

Accompanying drawing 1 is the structural representation of traditional horizontal straight pipe type air preheater;

Accompanying drawing 2 is the structural representation of horizontal air preheater of the present utility model (part is analysed and observe).

In the accompanying drawing: 1, body case; 2, hot switching path; 3, heat exchanger tube; 4, first through hole; 5, second through hole; 6, first end; 7, second end; 8, tube sheet; 9, hot air box; 10, cold air case.

The specific embodiment

Below in conjunction with embodiment shown in the drawings the utility model is done following detailed description the in detail:

(accompanying drawing hollow core arrow is represented the traffic direction of air as shown in Figure 2, filled arrows is represented the traffic direction of hot flue gas), horizontal air preheater of the present utility model comprises having the into body case 1 of mouth and outlet flue, the inside of this body case 1 forms a hot switching path 2, be provided with the heat exchanger tube 3 of several hollows in the hot switching path 2, sealing is embedded with a tube sheet 8 on one sidewall of body case 1, the upper vertical of this tube sheet 8 offers the same number of first through hole 4 with heat exchanger tube 3 in the direction of plate face, lower vertical offers the same number of second through hole 5 with heat exchanger tube 3 in the direction of plate face, each heat exchanger tube 3 all has first end 6 and second end 7, the corresponding one by one sealing of first end 6 of these heat exchanger tubes 3 assigns in these first through holes 4, the corresponding one by one sealing of second end 7 of these heat exchanger tubes 3 assigns in these second through holes 5, each heat exchanger tube 3 all is " U " shape, each heat exchanger tube 3 is all along the traffic direction setting perpendicular to hot flue gas, and the outer cup of these first through holes 4 is provided with the hot air box 9 of taking gas port out of; The outer cup of these second through holes 5 is provided with the cold air case 10 of bringing gas port into, the inner chamber of each heat exchanger tube 3 connects with the inner chamber of hot air box 9 and the inner chamber of cold air case 10 respectively, enter the top that mouth is positioned at body case 1, outlet flue is positioned at the bottom of body case 1, in order to carry out heat exchange more efficiently, the distributing position of these heat exchanger tubes 3 can upper and lower, forward and backward entanglement setting, and first end 6 that only needs to guarantee them all can connect with hot air box 9, second end 7 all can connect with cold air case 10.

The course of work of this horizontal air preheater: cold air enters the back from the air inlet of cold air case 10 and discharges until the gas outlet from hot air box 9 along the inner chamber operation of each heat exchanger tube 3, in this process, top-down hot flue gas exchange heat pipe 3 and inner air wash away in the hot switching path 2, thereby the temperature of the air in the heat exchanger tube 3 is raise, and the temperature of hot flue gas itself is lowered, and so realizes the exchange of heat.In the above-mentioned process, because the temperature of the hot flue gas of hot switching path 2 internal upper parts is higher, the temperature of the first half of each heat exchanger tube 3 is also higher relatively, and the temperature of the hot flue gas of bottom is relatively low, and the temperature of the air that has just entered is also lower, so can cause the top of heat exchanger tube 3 and bottom to have differential expansion, but because " U " shape structure of heat exchanger tube 3, compare with the traditional horizontal air preheater shown in the accompanying drawing 1, horizontal air preheater of the present utility model can make most thermal stress be absorbed at bending section, weakened the influence of thermal stress greatly, particularly heat exchanger tube 3 descends significantly with the internal stress of the welding position of tube sheet 8, can not cause crackle or come off, improve the overall performance of equipment, stop potential safety hazard.

The foregoing description only is explanation technical conceive of the present utility model and characteristics, and its purpose is to allow the personage who is familiar with this technology can understand content of the present utility model and enforcement according to this, can not limit protection domain of the present utility model with this.All equivalences of being done according to the utility model spirit change or modify, and all should be encompassed within the protection domain of the present utility model.

Claims

1. A horizontal air preheater, which utilizes hot flue gas to heat air, comprising a body box with a smoke inlet and a smoke outlet, the inside of the body box forms a heat exchange channel, characterized in that: A number of hollow heat exchange tubes are arranged in the heat exchange channel, and a tube sheet is sealed and embedded on the side wall of the body box. The first through holes with the same number of heat pipes, the lower part is provided with the same number of second through holes as the heat exchange tubes in the direction perpendicular to the plate surface, each of the heat exchange tubes has a first end and a For the second end, the first ends of the heat exchange tubes are sealed and inserted in the first through holes one by one, and the second ends of the heat exchange tubes are sealed and inserted in the first through holes one by one. In the second through hole, each of the heat exchange tubes is in a "U" shape.

2. A horizontal air preheater according to claim 1, characterized in that each of the heat exchange tubes is arranged along a direction perpendicular to the running direction of the hot flue gas.

3. A horizontal air preheater according to claim 1, characterized in that: the outer cover of the first through holes is provided with a hot air box with an air outlet; The outer cover of the hole is provided with a cold air box with an air inlet, and the inner cavity of each heat exchange tube communicates with the inner cavity of the hot air box and the inner cavity of the cold air box respectively.

4. A horizontal air preheater according to any one of claims 1 to 3, characterized in that: said smoke inlet is located on the upper part of said body box, said smoke outlet is located on The lower part of the body box.