Horizontal internal combustion boiler capable of adjusting flue gas temperature

Abstract

The application discloses a horizontal internal combustion boiler capable of adjusting flue gas temperature, which comprises a furnace body, a main combustion pipe, a back-combustion chamber and a bypass flue; the flue gas inlet end of the bypass flue is communicated with the back-combustion chamber, the flue gas outlet end of the bypass flue is arranged in a rear flue box, the flue gas outlet end is opened or closed under the control of a controller, the back-combustion chamber and the main combustion pipe jointly serve as a return pass of the horizontal internal combustion boiler, the back-combustion chamber is communicated with the rear flue box through the bypass flue, and the flue gas outlet end of the bypass flue is opened or closed under the control of the controller; when the boiler is in low-load operation, the controller opens the bypass flue, so that high-temperature flue gas in the back-combustion chamber does not pass through the second and third return passes and directly enters the rear flue box. The design can not only increase the flue gas temperature entering a denitration device through the bypass flue and effectively improve the denitration efficiency, but also can accurately control the flue gas temperature entering the denitration device, so that the flue gas temperature entering the denitration device is in a temperature window of flue gas denitration technology.

Description

Technical Field

[0001] This invention relates to an internal combustion boiler, and more particularly to a horizontal internal combustion boiler with adjustable flue gas temperature. Background Technology

[0002] A three-pass boiler is a widely used thermal energy equipment. Its typical structure includes the boiler body, the furnace inside the boiler body, and the front smoke box and rear smoke box located at the front and rear of the boiler.

[0003] A three-pass boiler operates by mixing and burning fuel and air within the furnace (first pass). The resulting high-temperature flue gas flows backward, transferring most of its heat to the boiler water outside the furnace through radiative heat exchange. Subsequently, after reaching the rear of the furnace, the high-temperature flue gas deflects 180 degrees and enters the first set of smoke tubes (second pass), flowing forward to the front smoke box. During this process, it continues to release heat through convective heat exchange. Finally, the flue gas deflects 180 degrees again within the front smoke box, entering the second set of smoke tubes (third pass), flowing backward to the rear smoke box, and exiting the boiler. Through these three passes, the flue gas and boiler water undergo thorough heat exchange, thus achieving efficient boiler operation.

[0004] Although this type of internal combustion boiler can achieve sufficient heat exchange, it still has the following drawbacks:

[0005] When the boiler is operating at low load, the amount of fuel input decreases, the total heat generated in the furnace decreases, while the heat exchange area of ​​the boiler remains unchanged, resulting in an excessive drop in flue gas temperature. The exhaust gas temperature may be lower than the optimal operating window required by subsequent environmental protection facilities.

[0006] 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

[0007] The purpose of this invention is to overcome the shortcomings of low denitrification efficiency in existing technologies when operating at low loads, and to provide a horizontal internal combustion boiler with adjustable flue gas temperature that has high denitrification efficiency when operating at low loads.

[0008] To achieve the above objectives, the technical solution of the present invention is:

[0009] A horizontal internal combustion boiler with adjustable flue gas temperature, the horizontal internal combustion boiler comprising: a furnace body, a main combustion tube, a combustion chamber, and a bypass flue;

[0010] The furnace body is a horizontal structure. A front smoke box and a rear smoke box are respectively provided on the outer walls of both sides of the furnace body. A flue gas inlet is opened on the side wall of the furnace body where the front smoke box is provided. The rear smoke box is connected to the denitrification device.

[0011] The main combustion tube is a tubular structure. The main combustion tube is arranged horizontally inside the furnace body. One end of the main combustion tube is inserted into the flue gas inlet and then sealed to the side wall of the furnace body. The other end of the main combustion tube is located inside the furnace body and is connected to the combustion chamber. The combustion chamber is connected to the external space of the furnace body through the main combustion tube.

[0012] The combustion chamber is connected to the front smoke box via at least two two-pass smoke pipes, and the front smoke box is connected to the rear smoke box via at least two three-pass smoke pipes.

[0013] The inlet of the bypass flue is connected to the combustion chamber, and the outlet of the bypass flue is located inside the rear smoke box. The outlet is opened or closed under the control of the controller.

[0014] The controller includes an actuator, a connecting rod, and a plug. The actuator is located directly above the rear smoke box. The power output end of the actuator is connected to one end of the connecting rod, and the other end of the connecting rod is fixedly connected to the plug. The plug is positioned directly opposite the smoke outlet end of the bypass flue.

[0015] The actuator is used to drive the plug to close or open the smoke outlet.

[0016] The plug is a frustoconical plug.

[0017] The smoke outlet is vertically arranged, and the actuator is located directly above the smoke outlet.

[0018] The actuator is used to control the plug to move up and down in the vertical direction;

[0019] The plug is used to adjust the flue gas flow rate of the bypass flue by moving it up and down.

[0020] The main combustion tube is a corrugated main combustion tube, and the interior of the main combustion tube forms a channel for flue gas to flow. A space for accommodating boiler water is formed between the main combustion tube and the inner wall of the furnace body.

[0021] The flue gas inlet is used to introduce a mixture of natural gas and high-temperature flue gas into the main combustion tube, where the mixture is continuously burned.

[0022] The bypass flue is used to directly discharge the high-temperature flue gas in the combustion chamber into the rear smoke box and increase the temperature of the flue gas entering the denitrification device.

[0023] The top of the furnace body is also equipped with a steam outlet, two water inlets, and two temperature sensor ports.

[0024] A manhole is provided on the top of the furnace body.

[0025] The top of the furnace body is also provided with two lifting lugs, which are symmetrically arranged on both sides of the furnace body.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0027] 1. In this invention, a horizontal internal combustion boiler with adjustable flue gas temperature is described. The combustion chamber and main combustion tubes together form the first pass of the boiler. The combustion chamber is connected to the rear smoke box via a bypass flue. The outlet of the bypass flue is opened or closed under the control of a controller. When the boiler is operating at low load, the controller opens the bypass flue. At this time, a portion of the high-temperature flue gas from the first pass continues to flow and exchange heat along the second and third pass flue tubes, while another portion of the high-temperature flue gas bypasses the second and third passes and directly enters the rear smoke box. The two flue gases mix in the rear smoke box, increasing the temperature of the flue gas entering the denitrification device, thereby improving the denitrification efficiency. Therefore, this design can effectively improve the denitrification efficiency by increasing the temperature of the flue gas entering the denitrification device through the bypass flue.

[0028] 2. In a horizontal internal combustion boiler with adjustable flue gas temperature according to the present invention, the controller includes an actuator, a connecting rod, and a plug. The plug is a frustoconical plug. The actuator controls the plug to move up and down vertically. The plug adjusts the flue gas flow rate of the bypass flue by moving up and down, thereby precisely controlling the temperature of the flue gas entering the denitrification device. Therefore, this design can precisely control the temperature of the flue gas entering the denitrification device, ensuring that the temperature of the flue gas entering the denitrification device is within the temperature window of the flue gas denitrification technology. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the structure of the present invention.

[0030] Figure 2 yes Figure 1 A schematic diagram of the controller structure.

[0031] In the diagram: Furnace body 1, front smoke box 11, rear smoke box 12, flue gas inlet 13, second pass smoke pipe 14, third pass smoke pipe 15, manhole 16, steam outlet 17, water inlet 18, temperature sensor port 19, lifting lug 20, main combustion pipe 2, combustion chamber 3, bypass flue 4, smoke inlet end 41, smoke outlet end 42, controller 5, actuator 51, connecting rod 52, plug 53. Detailed Implementation

[0032] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] Example 1:

[0034] See Figure 1A horizontal internal combustion boiler with adjustable flue gas temperature is disclosed. The boiler comprises a boiler body 1, a main combustion tube 2, a combustion chamber 3, and a bypass flue 4. The boiler body 1 is horizontal, with a front smoke box 11 and a rear smoke box 12 respectively located on its two outer walls. A flue gas inlet 13 is provided on the side wall of the front smoke box 11, and the rear smoke box 12 is connected to a denitrification device. The main combustion tube 2 is tubular and horizontally positioned within the boiler body 1. One end of the main combustion tube 2 is inserted into the flue gas inlet 13 and then connected to the boiler body. The side wall of the main combustion pipe 2 is sealed and connected. The other end of the main combustion pipe 2 is located inside the furnace body 1 and is connected to the combustion chamber 3. The combustion chamber 3 is connected to the external space of the furnace body 1 through the main combustion pipe 2. The combustion chamber 3 is connected to the front smoke box 11 through at least two two-pass flue pipes 14. The front smoke box 11 is connected to the rear smoke box 12 through at least two three-pass flue pipes 15. The smoke inlet end 41 of the bypass flue 4 is connected to the combustion chamber 3. The smoke outlet end 42 of the bypass flue 4 is located inside the rear smoke box 12. The smoke outlet end 42 is opened or closed under the control of the controller 5.

[0035] The main combustion tube 2 and the re-combustion chamber 3 together form the first pass of the horizontal internal combustion boiler. The second pass flue 14 forms the second pass of the horizontal internal combustion boiler. The third pass flue 15 forms the third pass of the horizontal internal combustion boiler. The main combustion tube 2, the re-combustion chamber 3, the second pass flue 14, and the third pass flue 15 are all channels for flue gas to circulate. When the high-temperature flue gas circulates in the three passes, it exchanges heat with the boiler water in the furnace body 1.

[0036] The controller 5 includes an actuator 51, a connecting rod 52, and a plug 53. The actuator 51 is located directly above the rear smoke box 12. The power output end of the actuator 51 is connected to one end of the connecting rod 52, and the other end of the connecting rod 52 is fixedly connected to the plug 53. The plug 53 is positioned directly opposite the smoke outlet 42 of the bypass flue 4. The actuator 51 is used to drive the plug 53 to close or open the smoke outlet 42.

[0037] The plug 53 is a frustoconical plug.

[0038] The smoke outlet 42 is arranged vertically, and the actuator 51 is located directly above the smoke outlet 42;

[0039] The actuator 51 is used to control the plug 53 to move up and down in the vertical direction;

[0040] The plug 53 is used to adjust the flue gas flow rate of the bypass flue 4 by moving it up and down.

[0041] Since the surface areas of the main combustion tube 2, the re-combustion chamber 3, the second-pass flue tube 14, and the third-pass flue tube 15 are fixed, when the boiler is running at low load, the fixed and relatively large heat-receiving area will "excessively" absorb the already reduced heat of the flue gas, causing the flue gas temperature to drop sharply when leaving the third pass, and the exhaust gas temperature may be lower than the optimal operating window required by subsequent environmental protection facilities.

[0042] With reduced fuel input, the total heat generated in the furnace decreases, while the boiler's heat exchange area remains constant, leading to an excessive drop in flue gas temperature. The exhaust gas temperature may be lower than the optimal operating window required by subsequent environmental protection facilities.

[0043] At this time, the actuator 51 controls the up and down position of the plug 53 according to the flue gas temperature leaving the three-pass flue pipe 15, thereby adjusting the flue gas flow rate of the bypass flue 4, so that the high-temperature flue gas in the combustion chamber 3 directly enters the rear smoke box 12 and mixes with the low-temperature flue gas leaving the three-pass flue pipe 15, thereby adjusting the flue gas temperature entering the denitrification device.

[0044] The main combustion tube 2 is a corrugated main combustion tube, and the interior of the main combustion tube 2 forms a channel for flue gas to flow. The space between the main combustion tube 2 and the inner wall of the furnace body 1 is formed to accommodate boiler water.

[0045] Example 2:

[0046] Example 2 is basically the same as Example 1, except that:

[0047] The flue gas inlet 13 is used to introduce a mixture of natural gas and high-temperature flue gas into the main combustion pipe 2. The mixture continues to burn in the main combustion pipe 2 and the reburning chamber 3. The bypass flue 4 is used to directly discharge the high-temperature flue gas in the reburning chamber 3 into the rear smoke box 12 and increase the temperature of the flue gas entering the denitrification device.

[0048] The mixture continues to burn in the main combustion tube 2 and the re-combustion chamber 3, ensuring the stability and sufficiency of the combustion process and providing a stable high-temperature heat source for the entire system.

[0049] Example 3:

[0050] Example 3 is basically the same as Example 2, except that:

[0051] The top of the furnace body 1 is also provided with a steam outlet 17, two water inlets 18 and two temperature sensor ports 19.

[0052] The steam outlet 17 is used to discharge the steam generated during the use of the horizontal internal combustion boiler, thereby maintaining the internal pressure of the boiler. The water inlet 18 is used to add boiler water into the boiler. The temperature sensor port 19 is used to monitor the temperature of the boiler water inside the boiler.

[0053] A manhole 16 is provided on the top of the furnace body 1;

[0054] The manhole 16 is used to facilitate personnel access when installing and maintaining horizontal internal combustion boilers.

[0055] The top of the furnace body 1 is also provided with two lifting lugs 20, which are symmetrically arranged on both sides of the furnace body 1;

[0056] The lifting lug 20 is used for hoisting when installing a horizontal internal combustion boiler.

[0057] 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 horizontal internal combustion boiler with adjustable flue gas temperature, characterized in that, The horizontal internal combustion boiler includes: a furnace body (1), a main combustion tube (2), a combustion chamber (3), and a bypass flue (4). The furnace body (1) is a horizontal structure. A front smoke box (11) and a rear smoke box (12) are respectively provided on the outer walls of both sides of the furnace body (1). A flue gas inlet (13) is opened on the side wall of the furnace body (1) where the front smoke box (11) is provided. The rear smoke box (12) is connected to the denitrification device. The main combustion tube (2) is a tubular structure. The main combustion tube (2) is set in the furnace body (1) in a horizontal direction. One end of the main combustion tube (2) is inserted into the flue gas inlet (13) and then sealed to the side wall of the furnace body (1). The other end of the main combustion tube (2) is located in the furnace body (1) and is connected to the combustion chamber (3). The combustion chamber (3) is connected to the external space of the furnace body (1) through the main combustion tube (2). The combustion chamber (3) is connected to the front smoke box (11) through at least two two-pass smoke pipes (14), and the front smoke box (11) is connected to the rear smoke box (12) through at least two three-pass smoke pipes (15). The smoke inlet (41) of the bypass flue (4) is connected to the combustion chamber (3), and the smoke outlet (42) of the bypass flue (4) is located in the rear smoke box (12). The smoke outlet (42) is opened or closed under the control of the controller (5).

2. A horizontal internal combustion boiler with adjustable flue gas temperature according to claim 1, characterized in that, The controller (5) includes an actuator (51), a connecting rod (52), and a plug (53). The actuator (51) is located directly above the rear smoke box (12). The power output end of the actuator (51) is connected to one end of the connecting rod (52), and the other end of the connecting rod (52) is fixedly connected to the plug (53). The plug (53) is positioned directly opposite the smoke outlet (42) of the bypass flue (4). The actuator (51) is used to drive the plug (53) to close or open the smoke outlet (42).

3. A horizontal internal combustion boiler with adjustable flue gas temperature according to claim 2, characterized in that, The plug (53) is a frustum-shaped plug.

4. A horizontal internal combustion boiler with adjustable flue gas temperature according to claim 3, characterized in that, The smoke outlet (42) is arranged vertically, and the actuator (51) is located directly above the smoke outlet (42); The actuator (51) is used to control the plug (53) to move up and down in the vertical direction; The plug (53) is used to adjust the flue gas flow of the bypass flue (4) by moving it up and down.

5. A horizontal internal combustion boiler with adjustable flue gas temperature according to any one of claims 1 to 4, characterized in that: The main combustion tube (2) is a corrugated main combustion tube. The interior of the main combustion tube (2) forms a channel for flue gas to flow. The space between the main combustion tube (2) and the inner wall of the furnace body (1) is used to accommodate boiler water.

6. A horizontal internal combustion boiler with adjustable flue gas temperature according to claim 5, characterized in that, The flue gas inlet (13) is used to introduce a mixture of natural gas and high-temperature flue gas into the main combustion pipe (2), and the mixture continues to burn in the main combustion pipe (2); The bypass flue (4) is used to directly discharge the high-temperature flue gas in the combustion chamber (3) into the rear smoke box (12) and increase the temperature of the flue gas entering the denitrification device.

7. A horizontal internal combustion boiler with adjustable flue gas temperature according to claim 1, characterized in that, The top of the furnace body (1) is also provided with a steam outlet (17), two water inlets (18) and two temperature sensor ports (19).

8. A horizontal internal combustion boiler with adjustable flue gas temperature according to claim 1, characterized in that, The top of the furnace body (1) is provided with a manhole (16).

9. A horizontal internal combustion boiler with adjustable flue gas temperature according to claim 1, characterized in that, The top of the furnace body (1) is also provided with two lifting lugs (20), which are symmetrically arranged on both sides of the furnace body (1).

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