Boiler flue with water-cooled structure for flue gas inlet

Abstract

A boiler flue gas inlet flue with water cooling structure, comprising an upper header, a lower header and a membrane wall, the upper header and the lower header are tubular structures, one end of the upper header and the lower header is closed structure, the other end is communicated with the water side of the boiler, the upper header and the lower header are communicated through the membrane wall, the upper header, the lower header and the membrane wall form an integrated tubular flue, one end of the tubular flue is communicated with the main combustion chamber of the boiler, the water in the upper header, the lower header and the membrane wall is heated to produce steam-water mixture during use, the steam-water mixture is collected in the upper header and flows into the boiler body, at the same time, the boiler water in the boiler enters the lower header, forming water circulation. The design not only can reduce the temperature of the inlet flue through water circulation, prevent high temperature flue gas leakage, effectively improve the safety, but also can recover the heat energy received by the inlet flue during the use of the boiler in the form of steam-water mixture, effectively avoid the waste of heat energy.

Description

Technical Field

[0001] This invention relates to a boiler flue gas inlet duct, and more particularly to a boiler flue gas inlet duct with a water-cooled structure. Background Technology

[0002] In boiler systems, especially those that require the treatment of high-temperature flue gas, the high-temperature flue gas connection duct that connects the boiler to upstream waste heat equipment (such as gas turbines, smelting furnaces, etc.) is a critical component. This duct needs to withstand the scouring of high-temperature flue gas at hundreds or even thousands of degrees Celsius for a long time, and the reliability and safety of its structure directly affect the stable operation of the entire system.

[0003] The main structure of existing high-temperature flues is usually made of carbon steel plates to form a skeleton and shell. On the inner side, that is, the side that is in direct contact with high-temperature flue gas, a thick layer of refractory castable is built. This castable is made of high-temperature resistant inorganic non-metallic materials and has a certain structural strength and excellent thermal insulation performance.

[0004] Although this type of boiler flue gas inlet duct has a certain structural strength and excellent thermal insulation performance, it still has the following defects:

[0005] 1. The structure is bulky and the castable is prone to cracking and falling off after being heated and expanded. There is also a risk of high-temperature flue gas leakage over a long period of time, resulting in poor safety.

[0006] 2. Traditional flues only provide passive insulation, so the heat is either trapped inside or lost to the environment. This results in a waste of heat energy because the heat energy of the high-temperature flue gas is not utilized.

[0007] The information disclosed in this background section is intended only to enhance understanding of the overall background of this application and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0008] The purpose of this invention is to overcome the shortcomings of existing technologies, such as poor safety and waste of heat energy, and to provide a boiler flue gas inlet duct with a water-cooled structure that is safer and can recover heat energy.

[0009] To achieve the above objectives, the technical solution of the present invention is:

[0010] A boiler flue gas inlet flue with a water-cooled structure, the flue comprising: an upper header, a lower header, and a membrane wall;

[0011] Both the upper and lower headers are tubular structures, with one end of each header being a closed structure, and the other end of each header being connected to the water side of the boiler.

[0012] The upper and lower headers are connected by a membrane wall, and the upper header, lower header, and membrane wall form an integral tubular flue.

[0013] One end of the tubular flue is connected to the main combustion chamber of the boiler.

[0014] The cross-sectional area of ​​the tubular flue formed by the upper header, lower header, and membrane wall that connects to the boiler is larger than the cross-sectional area of ​​the other end.

[0015] The end of the upper header connected to the boiler is the water outlet, and the end of the lower header connected to the boiler is the water inlet.

[0016] The water outlet is located above the main combustion chamber of the boiler, and the water inlet is located below the main combustion chamber of the boiler.

[0017] The height of the upper header and lower header near the boiler end is higher than the height away from the boiler end.

[0018] The upper header is used to transport the steam-water mixture with bubbles generated by the heating of water in the upper header, lower header and membrane wall back into the boiler.

[0019] The lower header is used to receive water from the boiler under gravity after the steam-water mixture has been transported back into the boiler.

[0020] The membrane wall includes multiple finned tubes, which are symmetrically arranged in pairs on both sides of the connection surface between the upper and lower headers.

[0021] Each of the finned tubes is arranged parallel to each other, and the finned tubes on the same side are connected by fins to form an airtight tube screen structure.

[0022] The upper header, lower header, and membrane wall are all filled with boiler water.

[0023] The circumferential cross-section of the tubular flue is rectangular, and the width of the tubular flue cross-section is greater than the height of the cross-section.

[0024] The central axes at both ends of the tubular flue are set horizontally, and the central axis of the middle part of the tubular flue is lower at the end far from the boiler than at the end near the boiler.

[0025] The bottom of the tubular flue at the far end of the boiler is lower than the bottom of the boiler.

[0026] The outer wall of the tubular flue formed by the upper header, lower header, and membrane wall is uniformly covered with thermal insulation cotton.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0028] 1. This invention discloses a water-cooled boiler flue gas inlet duct, comprising an upper header, a lower header, and a membrane wall. Both the upper and lower headers are tubular structures, with one end closed and the other end connected to the water side of the boiler. The upper and lower headers are connected by the membrane wall, forming an integrated tubular flue. One end of the tubular flue is connected to the main combustion chamber of the boiler. During operation, the upper and lower headers and the membrane wall are filled with boiler water. When high-temperature flue gas passes through, the water in these components is heated, generating a steam-water mixture. This mixture collects in the upper header and flows into the boiler body, while the boiler water enters the lower header, creating a water circulation system. Therefore, this design can reduce the temperature of the inlet flue gas through water circulation, preventing high-temperature flue gas leakage and effectively improving safety.

[0029] 2. In the boiler flue gas inlet duct with a water-cooled structure of the present invention, the heat energy received by the inlet flue during boiler operation is returned to the boiler in the form of a steam-water mixture. Therefore, this design can recover the heat energy received by the inlet flue during boiler operation in the form of a steam-water mixture, effectively avoiding heat energy waste. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure of the present invention.

[0031] Figure 2 yes Figure 1 A schematic diagram of the structure of a central tubular flue.

[0032] In the diagram: Upper header 1, outlet 11, lower header 2, inlet 21, membrane wall 3, finned tube 31, tubular flue 4, main combustion chamber 5. Detailed Implementation

[0033] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0034] Example 1:

[0035] See Figure 1 A boiler flue gas inlet duct with a water-cooled structure, the duct comprising: an upper header 1, a lower header 2, and a membrane wall 3; both the upper header 1 and the lower header 2 are tubular structures, one end of both the upper header 1 and the lower header 2 are closed structures, and the other end of both the upper header 1 and the lower header 2 are connected to the water side of the boiler; the upper header 1 and the lower header 2 are connected to each other through the membrane wall 3, and the upper header 1, the lower header 2, and the membrane wall 3 form an integral tubular flue duct 4; one end of the tubular flue duct 4 is connected to the main combustion chamber 5 of the boiler.

[0036] The height of the upper header 1 and the lower header 2 near the boiler end is higher than the height away from the boiler end;

[0037] The upper header 1 is used to transport the steam-water mixture with bubbles generated by the heating of water in the upper header 1, lower header 2 and membrane wall 3 back into the boiler.

[0038] The lower header 2 is used to receive water from the boiler under gravity after the steam-water mixture is transported back into the boiler.

[0039] When the boiler is in use, the water in the upper header 1, lower header 2 and membrane wall 3 is heated and transformed into a steam-water mixture with bubbles. The water density in the upper header 1 and membrane wall 3 is greater than that of the steam-water mixture, causing the steam-water mixture to flow upward into the upper header 1 and then into the boiler. At the same time, the water enters the lower header 2 and is heated and transformed into a steam-water mixture with bubbles, forming a natural water circulation system.

[0040] The cross-sectional area of ​​the tubular flue 4 formed by the upper header 1, lower header 2 and membrane wall 3, which is connected to the boiler, is larger than the cross-sectional area of ​​the other end.

[0041] The change in the cross-sectional area of ​​the tubular flue gradually slows down the velocity of the high-temperature flue gas flowing inside, thereby ensuring the stability and sufficiency of the heating process and providing a stable high-temperature heat source for the entire system.

[0042] The end of the upper header 1 connected to the boiler is the water outlet 11, and the end of the lower header 2 connected to the boiler is the water inlet 21.

[0043] The water outlet 11 is located above the main combustion chamber 5 of the boiler, and the water inlet 21 is located below the main combustion chamber 5 of the boiler.

[0044] The membrane wall 3 includes a plurality of finned tubes 31, which are symmetrically arranged in pairs on both sides of the connecting surface between the upper header 1 and the lower header 2.

[0045] Each of the finned tubes 31 is arranged in parallel to each other, and the finned tubes 31 located on the same side are connected by fins on them to form an airtight tube screen structure.

[0046] The upper header 1, lower header 2, and membrane wall 3 are all filled with boiler water;

[0047] The circumferential cross-section of the tubular flue 4 is rectangular, and the width of the cross-section of the tubular flue 4 is greater than the height of the cross-section.

[0048] Example 2:

[0049] Example 2 is basically the same as Example 1, except that:

[0050] The central axes at both ends of the tubular flue 4 are set horizontally, and the end of the central axis far from the boiler in the middle of the tubular flue 4 is lower than the end near the boiler; the bottom of the end of the tubular flue 4 far from the boiler is lower than the bottom of the boiler.

[0051] The angle of the tubular flue 4 is set so that the steam-water mixture generated inside it can automatically enter the boiler under the influence of gravity.

[0052] Example 3:

[0053] Example 3 is basically the same as Example 2, except that:

[0054] The outer wall of the tubular flue 4 formed by the upper header 1, lower header 2 and membrane wall 3 is uniformly provided with thermal insulation cotton.

[0055] The insulation cotton can provide passive insulation, preventing excessive heat from the tubular flue 4 from diffusing into the environment.

[0056] The above description is only a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. Any equivalent modifications or changes made by those skilled in the art based on the content disclosed in the present invention should be included within the scope of protection set forth in the claims.

Claims

1. A boiler flue gas inlet duct with a water-cooled structure, characterized in that, The flue includes: an upper header (1), a lower header (2), and a membrane wall (3); The upper header (1) and the lower header (2) are both tubular structures. One end of the upper header (1) and the lower header (2) are both closed structures. The other end of the upper header (1) and the lower header (2) are both connected to the water side of the boiler. The upper header (1) and the lower header (2) are connected by a membrane wall (3), and the upper header (1), the lower header (2) and the membrane wall (3) form an integral tubular flue (4). One end of the tubular flue (4) is connected to the main combustion chamber (5) of the boiler.

2. The boiler flue gas inlet duct with a water-cooled structure according to claim 1, characterized in that, The cross-sectional area of ​​the tubular flue (4) formed by the upper header (1), lower header (2) and membrane wall (3) connected to the boiler is larger than the cross-sectional area of ​​the other end.

3. A boiler flue gas inlet duct with a water-cooled structure according to claim 1, characterized in that, The upper header (1) is connected to the boiler at one end as the outlet (11), and the lower header (2) is connected to the boiler at one end as the inlet (21). The outlet (11) is located above the main combustion chamber (5) of the boiler, and the inlet (21) is located below the main combustion chamber (5) of the boiler.

4. A boiler flue gas inlet duct with a water-cooled structure according to claim 1, characterized in that, The height of the upper header (1) and the lower header (2) near the boiler end is higher than the height away from the boiler end; The upper header (1) is used to transport the steam-water mixture with bubbles generated by heating the water in the upper header (1), lower header (2) and membrane wall (3) back into the boiler; The lower header (2) is used to receive water from the boiler under gravity after the steam-water mixture is transported back into the boiler.

5. A boiler flue gas inlet duct with a water-cooled structure according to claim 1, characterized in that, The membrane wall (3) includes multiple finned tubes (31), which are symmetrically arranged in pairs on both sides of the connecting surface between the upper header (1) and the lower header (2); Each of the fin tubes (31) is arranged in parallel to each other, and the fin tubes (31) located on the same side are connected by fins on them to form an airtight tube screen structure.

6. A boiler flue gas inlet duct with a water-cooled structure according to claim 1, characterized in that, The upper header (1), lower header (2), and membrane wall (3) are all filled with boiler water.

7. A boiler flue gas inlet duct with a water-cooled structure according to claim 1, characterized in that, The circumferential cross-section of the tubular flue (4) is rectangular, and the width of the cross-section of the tubular flue (4) is greater than the height of the cross-section.

8. A boiler flue gas inlet duct with a water-cooled structure according to claim 1, characterized in that, The central axis of both ends of the tubular flue (4) is set horizontally, and the central axis of the middle part of the tubular flue (4) is lower at the end far from the boiler than at the end near the boiler. The bottom of the tubular flue (4) at the far end of the boiler is lower than the bottom of the boiler.

9. A boiler flue gas inlet duct with a water-cooled structure according to claim 1, characterized in that, The outer wall of the tubular flue (4) formed by the upper header (1), lower header (2) and membrane wall (3) is uniformly covered with heat-insulating cotton.

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