CN111928292A - Horizontal tubular air preheater for small gas boiler - Google Patents

Abstract

The invention relates to a horizontal tubular air preheater for small gas-fired boilers. At present, if the conventional preheater is still used in the layout of the preheater, the hot air can only enter the furnace from the left or right side of the furnace. This arrangement is not allowed for boiler combustion, which will cause uneven heat load distribution in the furnace. many questions. A horizontal tubular air preheater for small gas-fired boilers. A diverter shield (3) is installed between A and the preheater B, which divides the flue into two, so that the flue gas can flow into the preheater A and the preheater B evenly, and the flow is divided into two parts. The lower part of the guard plate is fixedly connected with the anti-vibration partition plate (4) of the pipe box, and each layer of the pipe box plate (5) is fixedly connected at the middle position of the anti-vibration plate of the pipe box. The present invention is applied to an air preheater.

Description

Horizontal tubular air preheater for small gas boilers

Technical field:

The invention relates to a horizontal tubular air preheater for small gas-fired boilers.

Background technique:

The main function of the air preheater is to recover the heat of the flue gas leaving the steam-water heat-absorbing section of the boiler, heat the combustion air, and reduce the exhaust gas temperature. Its main functions are to strengthen combustion, enhance heat transfer, improve boiler efficiency and facilitate fuel delivery. In order to improve the comprehensive economy of the boiler, the preheater is often regarded as an important part of the boiler body system. The commonly used horizontal preheater tubes of power station boilers are installed horizontally, the air flows longitudinally in the tubes, and the flue gas scours the tube bundles laterally outside the tubes. The flue gas and air flow in opposite directions perpendicular to each other. Usually in the tail flue, the horizontal air preheater has the advantages of slightly higher wall temperature, convenient replacement and maintenance of several rows of tubes at the cold end, and less occurrence of overheating, warping and deformation defects of the tube sheet.

At present, the horizontal preheater is usually arranged according to the form of the steel frame and the direction of the air duct and other factors. Generally, it is one side in and one side out. That is, the cold air enters the horizontal air preheater from one side of the low temperature section (mostly from the back of the furnace, because the general blower is arranged behind the furnace), and the hot air comes out from one side of the high temperature section (before or after the furnace). The hot air generally comes out from the front or back of the furnace and is mixed and then divided into two paths from the left and right of the furnace to enter the furnace at the same time to participate in the combustion (see Figure 1). However, in this project, the air supply fans are arranged on the left and right sides of the boiler, and the distance between the front and rear columns of the furnace is relatively small, and the space on the left and right sides of the furnace is large. If it is not used, it will be wasted. Therefore, the preheater adopts a 90-degree rotation arrangement. However, if the conventional preheater is still used in this arrangement, the hot air can only enter the furnace from the left or right side of the furnace. This arrangement is not allowed for boiler combustion, which will cause many problems such as uneven heat load distribution in the furnace.

Invention content:

The purpose of the present invention is to provide a horizontal tubular air preheater for small gas boilers.

The above purpose is achieved through the following technical solutions:

A horizontal tubular air preheater for small gas-fired boilers, comprising: a preheater A and a preheater B, the preheater A is connected to the preheater B, and the A split shield is installed between the preheater A and the preheater B, which divides the flue into two, so that the flue gas can flow into the preheater A and the preheater B evenly. Inside, the lower part of the shunt shield is fixedly connected with the tube box anti-vibration baffle, and each layer of the tube box tube plate is fixedly connected at the middle position of the tube box shock absorbing plate, and the shunt shield is connected to each A sealed cavity is formed between the tube-box and tube-sheets described in the first layer, and two of the tube-box and tube-sheets are installed with sealing flanges. One side of the sealing flanges is fixedly connected with the tube sheets, and the other side is connected The box guard is fixedly connected to ensure the rigidity and tightness of the connection box with the preheater A and the preheater B in the width direction, and sealing plates are installed on both sides of the sealing cavity in the air circulation area.

The horizontal tubular air preheater for small gas-fired boilers, the preheater A and the preheater B are arranged in the form of single input and single output respectively, the preheater A and the The hot air ducts of the preheater B respectively protrude from the left and right sides of the boiler, and simultaneously extend to the front of the furnace, and simultaneously send the hot air into the boiler hearth from the left and right sides.

For the horizontal tubular air preheater for small gas-fired boilers, the height of the sealing plate is 20-40 mm larger than the steel plate of the connecting beam, and the width of the sealing plate is the same as the width of the preheater.

For the horizontal tubular air preheater for small gas-fired boilers, there is a distance of 500-600 mm between the preheater A and the preheater B.

For the horizontal tubular air preheater for small gas boilers, the bottoms of the preheater A and the preheater B are fixedly connected with a preheater supporting steel beam.

Beneficial effects of the present invention:

1. The present invention solves the big problem of the boiler combustion air supply mode with a simple and feasible solution, which simplifies the arrangement of the air duct and saves the space of the boiler. Moreover, the method is simple, the installation is convenient, and the materials used are simple and easy to obtain. This makes the horizontal tubular preheater another successful arrangement in the application of small gas boilers.

Description of drawings:

1 is a schematic structural diagram of the present invention.

FIG. 2 is a sectional view a-a of the preheater A in FIG. 1 .

FIG. 3 is a b-b cross-sectional view of the preheater A in FIG. 1 .

FIG. 4 is a J-J cross-sectional view of FIG. 1 .

FIG. 5 is an M-M cross-sectional view of FIG. 1 .

Figure 6 is a schematic structural diagram of the original preheater.

FIG. 7 is a B-B sectional view of FIG. 6 .

In the picture: 1. Preheater A, 2. Preheater B, 3. Diverter guard plate, 4. Tube box shockproof baffle, 5. Tube box tube plate, 6. Sealing flange, 7. Connecting box guard plate , 8, sealing plate, 9, tube box tube, 10, sealing cavity, 11, preheater support steel beam, 12, connecting beam steel plate, 13, connecting beam, 14, air communication area, 15, boiler centerline.

Detailed ways:

Example 1:

A horizontal tubular air preheater for small gas-fired boilers, which consists of a preheater A1 and a preheater B2, the preheater A is connected to the preheater B, and the A split shield 3 is installed between the preheater A and the preheater B, which divides the flue into two, so that the flue gas can flow into the preheater A and the preheater evenly. In B, the lower part of the said diverter shield is fixedly connected with the tube box anti-vibration partition 4, and each layer of the tube box tube plate 5 is fixedly connected at the middle position of the said tube box anti-vibration plate, the said diverter shield A sealed cavity 10 is formed between the plate and the tube-box tube-sheet of each layer, the two-stage tube-box-tube-sheets are installed with sealing flanges 6, and one side of the sealing-flange is fixed with the tube-box-tube-sheet The other side is fixedly connected to the connecting box guard plate 7 to ensure the rigidity and tightness of the connecting box connecting with the preheater A and the preheater B in the width direction, and sealing plates are installed on both sides of the sealing cavity in the air circulation area 8. The bottoms of the preheater A and the preheater B are fixedly connected with the preheater supporting steel beam 11 , and the height of the sealing plate is generally larger than the connecting beam steel plate 12 .

Example 2:

The preheater is to realize the function of two independent preheaters (named A preheater and B preheater respectively) by rotating one preheater after 90 degrees. There is a certain distance between the two preheaters A and B (the two communication boxes cannot collide within this distance, generally 500~600mm). Before the flue gas enters the preheater, a split shield is designed to divide the flue into two, so that the flue gas can flow to the A and B preheaters evenly. The lower part of the protective plate is welded with the shockproof partition of the pipe box. Each layer of tube box tube sheet is welded in the middle (see M-M), which not only ensures the sealing but also ensures the overall rigidity of the tube sheet. A sealed cavity is formed between the shunt shield and each layer of tube box tube sheets. Sealing flanges are designed on both sides of the tube plate of the tube box. One side of this flange is welded with the tube plate, and the other side is welded with the protective plate of the connecting box (see J-J), which ensures the connection between the connecting box and the preheater in the width direction. Rigidity and tightness. Sealing plates are designed on both sides of the sealing cavity in the air circulation area, and the height of the sealing plate is generally 20~40mm higher than that of the connecting beam steel plate. The width of the sealing plate may be the same as that of the preheater.

Example 3:

The two preheaters of B are single-in and single-out respectively (such as a-a and b-b sections, the cold air of A preheater enters from the left of the furnace and the hot air exits from the right, and the preheater B is vice versa; or the cold air of A preheater flows from the furnace In this way, the hot air ducts can come out from the left and right sides of the boiler and extend to the front of the furnace at the same time, and the hot air is sent into the furnace from the left and right sides at the same time. This arrangement makes one preheater realize the function of two preheaters, which can not only meet the needs of boiler combustion, but also make full use of the boiler space.

Example 4:

The other structures of the preheater shown in the present invention are the same as those of the conventional horizontal tubular air preheater, and the size of the flue gas interface and the arrangement of the heating surface of all the preheaters will be different according to the boiler capacity and fuel.

Claims (5)

1. A horizontal tubular air preheater for small gas boiler, comprising: preheater A and preheater B, characterized by: the preheater A is connected with the preheater B, a shunt guard plate is arranged between the preheater A and the preheater B to divide a flue into two parts, so that flue gas can uniformly flow into the preheater A and the preheater B, the lower part of the shunt guard plate is fixedly connected with a shockproof partition plate of a pipe box, and each layer of tube box tube plate is fixedly connected with the middle position of the tube box shock insulation plate, a sealing cavity is formed between the flow dividing protection plate and each layer of tube box tube plate, sealing flanges are arranged on the two tube box tube plates, one side of each sealing flange is fixedly connected with the tube box tube plate, the other side of each sealing flange is fixedly connected with a communicating box protective plate, the rigidity and the sealing performance of the communicating box connected with the preheater A and the preheater B in the width direction are guaranteed, and sealing plates are arranged on two sides of a sealing cavity of an air circulation area.

2. The horizontal tube type air preheater for a small gas boiler as set forth in claim 1, wherein: the preheater A and the preheater B respectively adopt a single-inlet single-outlet arrangement form, hot air ducts of the preheater A and the preheater B respectively extend out of the left side and the right side of the boiler and simultaneously extend to the front of the boiler, and hot air is simultaneously fed into a hearth of the boiler from the left side and the right side.

3. The horizontal tube type air preheater for a small gas boiler as set forth in claim 1 or 2, wherein: the height of the sealing plate is 20-40 mm larger than that of the steel plate of the communication beam, and the width of the sealing plate is equal to that of the preheater.

4. The horizontal tube type air preheater for a small gas boiler as set forth in claim 1, 2 or 3, wherein: and a distance of 500-600 mm is reserved between the preheater A and the preheater B.

5. The horizontal tube type air preheater for a small gas boiler as set forth in claim 1 or 2 or 3 or 4, wherein: the preheater A with preheater B bottom fixedly connected with preheater support girder steel.

Images