Low-carbon clean combustion dry slag air leakage recycling system for boiler

Abstract

The utility model relates to the technical field of boiler bottom air leakage recycling, in particular to a boiler low-carbon clean combustion dry slag air leakage recycling system which comprises a boiler. A slag extractor; a bellows; a dust remover; a slag bin; a secondary air unit; according to the boiler bottom air leakage device, boiler bottom air leakage is recycled as much as possible, slag extractor cooling air and slag extractor air leakage enter a hearth from the boiler bottom under the action of negative pressure of the hearth, disordered boiler bottom air leakage is formed, and due to the fact that the interior of the hearth is in a negative pressure state in the operation process of the boiler, the boiler bottom air leakage is avoided. A small amount of heated furnace bottom leaked air directly enters the hearth, furnace bottom leaked air in other slag discharging machines enters the air bellow through the air feeder and then enters the dust remover for dust removal, the furnace bottom leaked air after dust removal enters the secondary air unit through the induced draft fan and then is input into the hearth again, and under the condition that it is guaranteed that a flow field in the hearth is not disturbed, the furnace bottom leaked air enters the secondary air unit through the induced draft fan. Recycling of furnace bottom air leakage heat is improved, and furnace bottom air leakage heat loss is reduced.

Description

Technical Field

[0001] This utility model relates to the field of furnace bottom air leakage recovery technology, and in particular to a boiler low-carbon clean combustion dry ash air leakage recovery and reuse system. Background Technology

[0002] The design temperature for slag discharge from the slag bin is below 100℃, but the actual slag discharge temperature is around 62℃. The cooling air volume of the dry slag machine is much higher than the design value. Cooling air entering the furnace directly from the bottom creates "disordered" bottom air leakage. This leakage air has a low temperature, affecting the air distribution to the boiler burners and combustion adjustment. This leads to a shift in the flame center and an increase in flue gas temperature (currently 140-150℃), exceeding the design value. Experiments have shown that closing all hydraulic shut-off valves at the bottom of the boiler reduced the flue gas temperature by about 20℃. Regardless of load, the furnace negative pressure is maintained at -50~-100Pa during normal operation. Therefore, at low loads, bottom air leakage accounts for a larger proportion of the boiler's air volume, having a greater impact on combustion because it increases oxygen levels at the bottom of the boiler, leading to increased nitrogen oxide production.

[0003] For combustion methods that require oxygen deficiency in the main combustion zone and reduction of NOx generation in the main combustion zone, the NOx generation concentration gradually increases with decreasing load and increasing cooling air ratio, and the lower the load, the greater the impact.

[0004] Chinese Patent Publication No. CN202040832U discloses a connection system between a regenerative air preheater leakage recovery device and a dry ash removal machine. This system is designed for boilers equipped with a regenerative air preheater leakage recovery system and a dry ash removal system. Connecting the two systems completely solves the negative impacts of these systems on the boiler and improves boiler combustion efficiency. The specific technical solution includes a leakage recovery fan and a dry ash removal machine. The leakage recovery air supply duct at the outlet of the leakage recovery fan is connected to the dry ash removal machine. There are two connection methods: (1) The leakage recovery air supply duct is connected to the end of the dry ash removal machine. (2) The leakage recovery air supply duct is connected to the horizontal section and the inclined section of the dry ash removal machine, respectively. A control baffle is provided on the connection channel. A ventilation box is provided on each of the horizontal and inclined sections of the dry ash removal machine. To further reduce the amount of cold air entering the furnace, a ash-removing airlock is installed at the ash discharge port of the dry ash removal machine.

[0005] However, existing technologies still have the following problems:

[0006] The cooling air volume control at the bottom of the furnace is out of control. Excessive cooling air volume will increase air leakage at the bottom of the boiler, affecting the boiler's secondary air ratio, oxygen control, and reducing furnace temperature, thus affecting boiler combustion adjustments. This will cause the flame center to shift upward, increase the flue gas temperature, reduce the boiler's combustion economy, disrupt the air-stage combustion of the low-NOx burner, and increase the amount of nitrogen oxides generated. Summary of the Invention

[0007] To address this, the present invention provides a boiler low-carbon clean combustion dry ash leakage recovery and reuse system to overcome the problems in the prior art where the cooling air volume control at the furnace bottom is out of control. Excessive cooling air volume will increase air leakage at the bottom of the boiler, affecting the boiler secondary air ratio, oxygen control, and reducing furnace temperature, thus causing the flame center to shift upward, the flue gas temperature to rise, reducing the boiler's combustion economy, disrupting the air staged combustion of the low-NOx burner, and increasing the amount of nitrogen oxides generated.

[0008] To achieve the above objectives, this invention provides a boiler low-carbon clean combustion dry ash leakage recovery and reuse system. It includes:

[0009] boiler;

[0010] A slag discharge machine, which is connected to the boiler, is used to cool and transport the slag at the bottom of the boiler;

[0011] The bellows, which is connected to the slag discharge machine, is used to receive air leakage from the furnace bottom;

[0012] A dust collector, which is connected to the air box, is used to remove dust from the air leaking from the bottom of the furnace in the air box;

[0013] The slag bin is connected to the slag discharge machine and the dust collector to collect the slag output by the slag discharge machine and the dust collector.

[0014] A secondary air unit, which is connected to the dust collector, is used to receive the furnace bottom leakage air output by the dust collector;

[0015] An air preheater, which is connected to the boiler and the secondary air unit, is used to receive the bottom air leakage output from the secondary air unit and to heat the air entering the boiler using the bottom air leakage.

[0016] Furthermore, the slag discharger is a dry slag discharger.

[0017] Furthermore, the top of the boiler is equipped with a damper, wherein the cold air entering through the damper is used to reverse-cool the hot slag inside the slag discharge machine.

[0018] Furthermore, the slag discharge machine is provided with a side air door, wherein the cold air entering through the side air door is used to cool the slag discharge machine's housing, conveyor belt rollers, and conveyor steel belt.

[0019] Furthermore, the slag discharge machine is also equipped with an air-cooling device, which is connected to the air damper and the side air damper respectively, to control the conveying output and slag discharge temperature of the equipment.

[0020] Furthermore, several pipes are provided between the slag discharge machine and the air box to transport the leaked air from the furnace bottom.

[0021] Furthermore, each of the aforementioned pipes is equipped with a valve, which is used to control the air supply volume between the slag discharge machine and the air box.

[0022] Furthermore, each of the aforementioned pipes is equipped with a blower, which is used to pressurize the air entering through the damper at the top of the slag discharge machine.

[0023] Furthermore, an induced draft fan is provided between the dust collector and the secondary air unit, wherein the induced draft fan is used to transport the air output by the dust collector.

[0024] Furthermore, the air preheater is connected to the damper and the side damper respectively, and the air preheater is used to input air into the damper and the side damper respectively.

[0025] Compared with the prior art, the beneficial effect of this utility model is that it recovers as much furnace bottom air leakage as possible. Under the negative pressure of the furnace, the cooling air of the slag discharge machine that has completed heat exchange with the hot slag and the leakage air of the slag discharge machine enter the furnace from the bottom, forming disordered furnace bottom air leakage. Since the furnace is under negative pressure during boiler operation, a small amount of heated furnace bottom air leakage directly enters the furnace. The furnace bottom air leakage in the other slag discharge machine enters the air box through the blower, and then enters the dust collector for dust removal. After dust removal, the furnace bottom air leakage enters the secondary air unit through the induced draft fan, and then enters the furnace again. While ensuring that the flow field in the furnace is not disturbed, the heat recovery and reuse of furnace bottom air leakage is improved, and the heat loss of furnace bottom air leakage is reduced. Attached Figure Description

[0026] Figure 1 A schematic diagram of a boiler low-carbon clean combustion dry ash leakage recovery and reuse system;

[0027] Figure 2 This is a schematic diagram of the air-cooling device;

[0028] Figure 3 This is a schematic diagram of the slag discharge machine;

[0029] Figure 4 This is a schematic diagram of the slag bin structure;

[0030] In the diagram: 1-Boiler; 2-Slag discharger; 3-Blowbox; 4-Dust collector; 5-Slag bin; 6-Secondary air unit; 7-Air preheater; 8-Damper; 9-Side damper; 10-Air cooling device; 11-Valve; 12-Forced draft fan; 13-Induced draft fan; 14-Air inlet duct; 15-Forced air duct; 16-Cooling air inlet; 17-Cooling shell; 18-Furnace body; 19-Conveyor belt; 20-Slag crusher. Detailed Implementation

[0031] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0032] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0033] It should be noted that in the description of this invention, the terms "upper", "lower", "left", "right", "inner", "outer", etc., which indicate directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and is not intended to indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0034] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the term "connected" should be interpreted broadly. For example, it can refer to a fixed connection, a detachable connection, or an integral connection; it can refer to a mechanical connection or an electrical connection; it can refer to a direct connection or an indirect connection through an intermediate medium; and it can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0035] Please see Figures 1-4 As shown, Figure 1 A schematic diagram of a boiler low-carbon clean combustion dry ash leakage recovery and reuse system; Figure 2 This is a schematic diagram of the air-cooling device; Figure 3 This is a schematic diagram of the slag discharge machine; Figure 4 This is a schematic diagram of the slag bin structure.

[0036] This utility model provides a boiler low-carbon clean combustion dry ash leakage recovery and reuse system, including:

[0037] Boiler 1;

[0038] Slag discharger 2, which is connected to the boiler, is used to cool and transport slag from the bottom of the boiler;

[0039] The air box 3 is connected to the slag discharge machine and is used to receive air leakage from the furnace bottom;

[0040] Dust collector 4, which is connected to the air box, is used to remove dust from the air leaking from the bottom of the furnace in the air box;

[0041] The slag bin 5 is connected to the slag discharge machine and the dust collector to collect the slag output by the slag discharge machine and the dust collector.

[0042] Secondary air unit 6 is connected to the dust collector and is used to receive the furnace bottom leakage air output by the dust collector;

[0043] Air preheater 7 is connected to the boiler and the secondary air unit to receive the bottom air leakage output from the secondary air unit and to heat the air entering the boiler using the bottom air leakage.

[0044] Specifically, in this embodiment, the slag at the bottom of the boiler enters the slag discharge machine, part of the slag directly enters the slag bin, and part of the slag enters the air box under the action of the blower along with the air leakage at the bottom of the furnace, and then enters the dust collector, and enters the slag bin after dust removal.

[0045] Specifically, in this embodiment, under the negative pressure of the furnace, the cooling air of the slag discharge machine that has completed heat exchange with the hot slag and the leakage air of the slag discharge machine enter the furnace from the bottom of the furnace, forming disordered bottom leakage air. Since the furnace is under negative pressure during boiler operation, a small amount of heated bottom leakage air enters the furnace directly from the air damper and the side air damper, respectively. The bottom leakage air in the other slag discharge machines enters the air box through the blower, and then enters the dust collector for dust removal. After dust removal, the bottom leakage air enters the secondary air unit through the induced draft fan, and then is preheated by the air preheater before being reintroduced into the furnace from the air damper and the side air damper, respectively.

[0046] Specifically, the slag discharge machine is a dry slag discharge machine.

[0047] Specifically, the boiler is equipped with an air damper 8 at its top, wherein:

[0048] The cold air introduced by the damper is used to cool the hot slag inside the slag discharge machine in the reverse direction.

[0049] Specifically, the slag discharge machine is provided with a side air door 9 on its side, wherein:

[0050] The cold air introduced by the side air vent is used to cool the slag discharge machine's housing, conveyor belt rollers, and conveyor steel belt.

[0051] Specifically, the slag discharge machine is also equipped with an air-cooling device 10, which is connected to the air damper and the side air damper respectively, and is used to control the conveying output and slag discharge temperature of the equipment.

[0052] Specifically, several pipes are provided between the slag discharge machine and the air box to transport the leaked air from the furnace bottom.

[0053] Specifically, each of the aforementioned pipes is equipped with a valve 11, wherein:

[0054] Valves are used to control the air volume between the slag discharge machine and the air box.

[0055] Specifically, each of the pipes is equipped with a blower 12, which is used to pressurize the air entering through the damper at the top of the slag discharge machine.

[0056] Specifically, an induced draft fan 13 is also provided between the dust collector and the secondary air unit, wherein...

[0057] The induced draft fan is used to transport the air output from the dust collector.

[0058] Specifically, the air preheater is connected to the damper and the side damper respectively, and the air preheater is used to input air into the damper and the side damper respectively.

[0059] Specifically, in this embodiment, during operation, cooling air enters the air supply duct 15 through the cooling air inlet 16 and enters the interior of the cooling housing 17 through the air inlet duct 14, cooling the ash and slag simultaneously from both the top and bottom directions, ensuring full contact between the cooling air and the ash and slag.

[0060] Specifically, in this embodiment, during operation, the slag inside the furnace body 18 is conveyed to the slag crusher 20 by the conveyor belt 19, and after being crushed, it enters the slag bin 5.

[0061] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

[0062] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A boiler low-carbon clean combustion dry ash leakage recovery and reuse system, characterized in that, include: boiler; A slag discharge machine, which is connected to the boiler, is used to cool and transport the slag at the bottom of the boiler; The bellows, which is connected to the slag discharge machine, is used to receive air leakage from the furnace bottom; A dust collector, which is connected to the air box, is used to remove dust from the air leaking from the bottom of the furnace in the air box; The slag bin is connected to the slag discharge machine and the dust collector to collect the slag output by the slag discharge machine and the dust collector. A secondary air unit, which is connected to the dust collector, is used to receive the furnace bottom leakage air output by the dust collector; An air preheater, which is connected to the boiler and the secondary air unit, is used to receive the bottom air leakage output from the secondary air unit and to heat the air entering the boiler using the bottom air leakage.

2. The boiler low-carbon clean combustion dry ash leakage recovery and reuse system according to claim 1, characterized in that, The slag discharge machine is a dry slag discharge machine.

3. The boiler low-carbon clean combustion dry ash leakage recovery and reuse system according to claim 1, characterized in that, The boiler is equipped with a damper at the top, through which cold air is introduced to cool the hot slag inside the slag discharge machine in the reverse direction.

4. The boiler low-carbon clean combustion dry ash leakage recovery and reuse system according to claim 3, characterized in that, The slag discharge machine is equipped with a side air door, through which cold air is introduced to cool the machine's housing, conveyor belt rollers, and conveyor steel belt.

5. The boiler low-carbon clean combustion dry ash leakage recovery and reuse system according to claim 4, characterized in that, The slag discharge machine is also equipped with an air-cooling device, which is connected to the air damper and the side air damper respectively, and is used to control the conveying output and slag discharge temperature of the equipment.

6. The boiler low-carbon clean combustion dry ash leakage recovery and reuse system according to claim 1, characterized in that, Several pipes are provided between the slag discharge machine and the air box to transport the leaked air from the furnace bottom.

7. The boiler low-carbon clean combustion dry ash leakage recovery and reuse system according to claim 6, characterized in that, Each of the aforementioned pipelines is equipped with a valve, which is used to control the air supply between the slag discharge machine and the air box.

8. The boiler low-carbon clean combustion dry ash leakage recovery and reuse system according to claim 7, characterized in that, Each of the aforementioned pipes is equipped with a blower, which is used to pressurize the air entering through the damper at the top of the slag discharge machine.

9. The boiler low-carbon clean combustion dry ash leakage recovery and reuse system according to claim 1, characterized in that, An induced draft fan is also provided between the dust collector and the secondary air unit, wherein the induced draft fan is used to transport the air output by the dust collector.

10. The boiler low-carbon clean combustion dry ash leakage recovery and reuse system according to claim 4, characterized in that, The air preheater is connected to the damper and the side damper respectively, and the air preheater is used to input air into the damper and the side damper respectively.

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