A power plant boiler dry slag machine furnace bottom air leakage treatment device

Abstract

The utility model discloses a kind of power station boiler dry slag machine furnace bottom air leakage management devices, specifically related to the field of energy saving and emission reduction of power station boiler, including dry slag machine body, its furnace bottom air leakage is led out through cooling air exhaust interface, furnace bottom air leakage exhaust interface, tail air leakage exhaust interface;Connection pipe;Air blower one, air blower two;Booster fan;Secondary air box outlet;Slag bin, slag discharge room;Transition slag hopper.The power station boiler dry slag machine furnace bottom air leakage management device described in the utility model, by the redesign of the way that traditional dry slag machine cooling air enters hearth, solve the dry slag machine cooling air that is completed heat exchange with furnace bottom slag, as furnace bottom air leakage directly enter hearth to the disturbance of combustion, change dry slag machine cooling air from disordered furnace bottom air leakage to orderly air by secondary air, can effectively improve the stability of hearth combustion, reduce flue gas temperature, reduce fly ash combustible carbon content, thereby improve boiler efficiency, reduce coal consumption.

Description

Technical Field

[0001] This utility model relates to the field of energy conservation and emission reduction in power plant boilers, and in particular to a device for treating air leakage at the bottom of a power plant boiler dry slag machine. Background Technology

[0002] In recent years, boiler dry ash discharge systems have been widely used. In this system, to ensure that large ash does not coke or overheat after cooling before entering the ash bin, the large ash falling into the cold ash hopper must be thoroughly cooled. However, the cooled air is converted into hot air and enters the furnace directly from the bottom. For the furnace, this air is unorganized cold air. Once it enters the furnace, it lowers the furnace temperature, causing the flame center to shift upwards, leading to an increase in the flue gas temperature at the furnace outlet. Under high load conditions, if there is significant air leakage in the furnace, the superheater will face the risk of overheating; while under low load conditions, significant air leakage may cause unstable combustion, increased incomplete combustion losses, and even flameout. Furthermore, a large increase in air leakage from the furnace bottom will increase the oxygen content in the main combustion zone, leading to an increase in the NOx concentration at the furnace outlet.

[0003] Chinese patent document CN119393780A discloses a system and method for controlling air leakage at the bottom of a dry ash removal furnace in a power plant pulverized coal boiler, relating to the field of dry ash removal technology for power plant boilers. Its main purpose is to reduce the entry of unorganized cold air into the furnace, minimize its adverse effects on furnace temperature, stabilize the combustion process, and improve combustion efficiency. The main technical solution of this utility model is as follows: The system for controlling air leakage at the bottom of a dry ash removal furnace in a power plant pulverized coal boiler includes a cold ash hopper, a ash removal box, and an exhaust / exhaust device. A dry ash conveyor belt is installed inside the ash removal box, and a ash discharge port is located on the ash removal box relative to the cold ash hopper. Exhaust ports are respectively provided on both sides of the ash discharge port along the length of the dry ash conveyor belt. The exhaust ports are connected to the exhaust / exhaust device via a connecting duct. A switch valve is installed on the connecting duct, and the opening degree of the switch valve is adjustable.

[0004] However, this device only discharges the leaked air through the connecting air duct via the intake and exhaust device, resulting in heat waste and failing to improve the boiler's thermal efficiency. Utility Model Content

[0005] The main purpose of this utility model is to provide a device for treating air leakage at the bottom of a power plant boiler dry slag machine, which can effectively solve the problem of heat waste and failure to improve boiler thermal efficiency.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0007] A device for controlling air leakage at the bottom of a power plant boiler dry ash machine includes: a dry ash machine body, wherein the air leakage at the bottom of the machine is led out through a cooling air discharge port, a bottom air leakage discharge port, and a tail air leakage discharge port.

[0008] The connecting pipe is used to connect dust collector one and dust collector two.

[0009] Blower 1, blower 2 and their outlet secondary air boxes 1 and 2, and the two sides of the secondary air annular large air box 1 and secondary air annular large air box 2;

[0010] The booster fan and its inlet and outlet shut-off valves;

[0011] Secondary air box shut-off valve 1 and secondary air box shut-off valve 2 at the outlet of the secondary air box, and secondary air annular air box shut-off valve 1 and secondary air annular air box shut-off valve 2 at the inlet of the secondary air box.

[0012] The slag bin, slag discharge room, and cooling air inlet of the dry slag machine body are also equipped with an adjustment door, and the interior of the slag discharge room is equipped with a negative pressure regulating door;

[0013] The transition slag hopper is located between the dry slag machine body and the connecting pipe. It is used to receive the slag discharged from the dry slag machine body and guide it to the subsequent processing. Its bottom is connected to the steel belt conveyor system of the dry slag machine, and its top is connected to the air leakage collection path of the connecting pipe through an interface to achieve the initial separation of slag and air leakage.

[0014] Preferably, the bottom of the dust collector is provided with a first air lock, a second air lock, and a slag discharge pipe from top to bottom, and the bottom of the slag discharge pipe is connected to the dry slag machine body.

[0015] Preferably, the first and second airlocks are connected in series to prevent short circuit of the cooling air of the dry slag machine body and to enable the continuous discharge of slag separated by the dust collector to the slag discharge pipe.

[0016] Preferably, the cooling air regulating door of the dry slag machine is installed on the top of the dry slag machine, and the cooling air volume entering the dry slag machine is adjusted in real time according to the change of slag temperature at the bottom of the furnace.

[0017] Preferably, multiple dust collectors are provided, including dust collector one and dust collector two, depending on the unit capacity. Their inlets are connected to the slag discharge station through connecting pipes, and the internal components are treated with three-stage dust removal and wear prevention.

[0018] Preferably, the adjustment gate 1 adjusts the cooling air volume inside the dry slag machine body in real time according to the change in the slag temperature at the bottom of the furnace.

[0019] Preferably, the adjustment door is installed on the top of the dry slag machine and can adjust the cooling air volume entering the dry slag machine body in real time according to the slag temperature at the bottom of the furnace; the negative pressure adjustment door is set in the slag discharge room and is used to create negative pressure when slag is discharged from the slag bin to suppress dust.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. This utility model uses a three-stage dust removal structure (cyclone dust removal + filter dust removal + electrostatic dust removal) of dust collector one and dust collector two to reduce the dust concentration of leaking air at the bottom of the furnace to below the environmental protection standard, thereby reducing wear on the booster fan and dust pollution. The leaking air after dust removal is pressurized by the booster fan and can be switched to a secondary air box to mix and heat with cold secondary air before being sent into the furnace to realize heat recovery and utilization to improve boiler thermal efficiency, or switched to a secondary air annular large air box to blow away accumulated ash, reducing maintenance and cleaning workload, thus achieving both energy efficiency improvement and environmental protection benefits.

[0022] 2. This utility model uses a double-layer flap counterweight structure with one airlock and two airlocks connected in series to achieve continuous slag discharge while preventing short circuit of the cooling air of the dry slag machine, enhancing the system's sealing performance and suppressing dust leakage; the cooling air adjustment door at the top of the dry slag machine is linked with the slag temperature sensor at the bottom of the furnace, which can adjust the cooling air volume in real time to accurately control the heat exchange efficiency; the negative pressure adjustment door in the slag discharge room is linked with the slag discharge signal of the slag bin, which automatically forms a negative pressure to suppress dust during slag discharge. Through dynamic sealing and intelligent adjustment, the system's operational stability and environmental protection requirements are ensured.

[0023] 3. This utility model solves the problem of the disturbance to combustion caused by the cooling air of the dry slag machine entering the furnace directly from the bottom of the furnace, which is the cooling air of the dry slag machine that has completed heat exchange with the bottom slag and is leaking from the bottom of the furnace. It transforms the disordered bottom leakage of the dry slag machine cooling air into an orderly air use organized by secondary air, which can effectively improve the stability of combustion in the furnace, reduce the flue gas temperature, reduce the carbon content of combustibles in fly ash, and reduce the amount of desuperheating water, thereby improving boiler efficiency and reducing coal consumption. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0025] In the diagram: 1. Dry slag machine body; 2. Cooling air exhaust port; 3. Furnace bottom air leakage exhaust port; 4. Tail air leakage exhaust port; 5. Connecting pipe; 6. Transition slag hopper; 7. Dust collector one; 8. Dust collector two; 9. First airlock; 10. Second airlock; 11. Slag discharge pipe; 12. Booster fan; 13. Inlet shut-off valve; 14. Outlet shut-off valve; 15. Secondary air box shut-off valve one; 16. Secondary air box shut-off valve two; 17. Secondary air box one; 18. Secondary air box two; 19. Secondary air annular air box shut-off valve one; 20. Secondary air annular air box shut-off valve two; 21. Blower one; 22. Blower two; 23. Secondary air annular large air box one; 24. Secondary air annular large air box two; 25. Adjusting valve one; 26. Negative pressure regulating valve; 27. Slag bin; 28. Slag discharge room. Detailed Implementation

[0026] To make the technical means, creative features, objectives and effects of this utility model easier to understand, the present utility model will be further described below in conjunction with specific embodiments.

[0027] Example 1

[0028] like Figure 1 As shown, a device for controlling bottom air leakage in a power plant boiler ash removal machine includes a ash removal machine body 1, a cooling air discharge port 2, a bottom air leakage discharge port 3, and a tail air leakage discharge port 4. These ports are connected via a connecting pipe 5 and then to dust collectors 7 and 8 respectively. The bottoms of dust collectors 7 and 8 are connected to a first airlock 9 and a second airlock 10 respectively. The bottom of the second airlock 10 is connected to a slag discharge pipe 11, which is connected to the ash removal machine body 1. Through the efficient separation by dust collectors 7 and 8, the amount of ash particles carried in the discharged bottom air leakage can be effectively reduced, minimizing the wear of the booster fan 12.

[0029] The booster fan 12 is equipped with an inlet shut-off valve 13 at its inlet end and an outlet shut-off valve 14 at its outlet end. Both valves are electrically operated gates and are linked to the booster fan control system. When the booster fan 12 starts, stops, or malfunctions, the inlet shut-off valve 13 and the outlet shut-off valve 14 automatically close, cutting off the air leakage path and preventing backflow of air or system pressure fluctuations from affecting boiler operation.

[0030] Inlet shut-off door 13: Installed on the connecting pipe 5 between the booster fan 12 and dust collector 7 and dust collector 8, it is used to isolate the booster fan 12 from the dust removal system.

[0031] Outlet shut-off valve 14: Installed on the connecting pipe 5 between the booster fan 12 and the secondary air box / annular large air box, it controls the delivery path of leaked air to the secondary air system.

[0032] Secondly, the bottom of dust collector 7 and dust collector 8 are connected by a first airlock 9 and a second airlock 10. The ingenious combination of the first airlock 9 and the second airlock 10 enables the continuous and efficient discharge of the slag separated by the dust collector. The design of two airlocks avoids short-circuiting of the cooling air inside the dry slag machine, making the airflow inside the dust collector smoother and further improving the dust removal effect. Furthermore, the separated slag is discharged into the dry slag machine body 1 through the slag discharge pipe 11, and then carried by a steel belt into the slag bin 27, avoiding environmental pollution caused by slag scattering, making the entire system simple, safe and reliable.

[0033] Meanwhile, the airlock effectively prevents dust leakage during the descent of the slag, reducing environmental pollution. The combination of a primary airlock 9 and a secondary airlock 10 provides double protection, further improving the system's sealing performance and environmental friendliness. Furthermore, the airlock design also considers the smooth discharge of slag. Through reasonable structure and material selection, the airlock ensures both sealing performance and the smooth descent of slag, preventing blockages or accumulation.

[0034] Reference Figure 1 The tops of dust collector 17 and dust collector 28 are connected to a booster fan 12 via a connecting pipe 5. The outlet of the booster fan 12 sends the furnace bottom leakage air evenly into the secondary air box 17 and the secondary air box 28 via the connecting pipe 5, mixing the furnace bottom leakage air with the secondary air. This design not only achieves effective heat recovery and reuse, but also improves the thermal efficiency of the entire system and reduces energy waste.

[0035] Moreover, the secondary air can be controlled to enter the furnace, which solves the problem of the furnace bottom air leakage disturbing the combustion in the furnace. Furthermore, during operation, the furnace bottom air leakage can be switched at any time to the secondary air annular wind box shut-off door 19 and the secondary air annular wind box shut-off door 20, which blows up the ash accumulated at the bottom of the large annular wind box and sends it into the furnace together with the secondary air, preventing ash accumulation at the bottom of the large annular wind box and saving time and cost of cleaning ash during maintenance.

[0036] The air leakage at the bottom of the furnace after separation by dust collector 7 and dust collector 8 is close to the environmentally friendly emission level. Therefore, the booster fan 12 can ensure its safe and long-term stable operation, and also provides a strong guarantee for the continuity and stability of the boiler ash discharge process, making the entire renovation system more efficient and environmentally friendly.

[0037] The air preheater is an important component of a power plant boiler system. Its main function is to preheat the air entering the boiler using the heat from the flue gas at the boiler's tail end. Air preheated by the air preheater facilitates the combustion process, improves boiler combustion efficiency, and thus contributes to energy conservation and emission reduction. Air leaking from the furnace bottom is sent to the secondary air box 17 and secondary air box 28 before entering the air preheater, where it mixes with the cold secondary air and is then heated together.

[0038] The slag discharged from the dry slag machine body 1 first falls into the transition slag hopper 6. Its internal guide plate design allows the slag to slide down the hopper wall onto the dry slag machine's steel belt. Meanwhile, the leaking air enters the connecting pipe 5 through the ventilation opening at the top of the transition slag hopper 6, merging with the airflow from the cooling air outlet 2, the furnace bottom leaking air outlet 3, and the tail air outlet 4. This design prevents slag and leaking air from mixing and entering the dust collector, reducing the dust collector's processing load, while also preventing large slag particles from clogging the connecting pipe 5, ensuring a smooth airflow collection path.

[0039] Reference Figure 1The processing capacity of dust collector 7 and dust collector 8 are designed with different dimensions according to the different unit capacities. Moreover, they undergo three-stage dust removal and internal anti-wear treatment, which means that they can effectively separate a large amount of dust-laden gas from the bottom air leakage according to their different size designs, ensuring that the gas emitted into the atmosphere meets national or local environmental protection standards.

[0040] Because the dust collector needs to face a harsh working environment with high temperature and high dust content during the continuous operation of the modified system, the high-efficiency dust removal and wear-resistant design ensures that the dust collector can operate stably for a long time in such a harsh environment, providing a reliable guarantee for the safe operation of the modified system.

[0041] Example 2

[0042] This embodiment explains the treatment method of the bottom air leakage control device for the dry slag machine of a power plant boiler, based on Embodiment 1.

[0043] A. Air leakage collection and dust removal

[0044] After the dry slag machine body 1 completes heat exchange with the bottom slag, the cooling air and the bottom slag leakage air are orderly merged into the connecting pipe 5 through the cooling air discharge port 2, the bottom slag leakage air discharge port 3, and the tail slag leakage air discharge port 4, forming a mixed leakage airflow.

[0045] The mixed leaking air is diverted through the connecting pipe 5 to the parallel dust collectors 7 and 8. Utilizing the three-stage dust removal structure inside the dust collectors (cyclone dust removal + filtration dust removal + electrostatic dust removal), the dust particles carried in the airflow are efficiently separated, reducing the dust concentration to below the environmental emission standards and reducing the wear of the subsequent booster fan 12.

[0046] After heat exchange between the dry slag machine body 1 and the bottom slag, the cooling air and bottom slag leakage air flow together through the cooling air discharge port 2, the bottom slag leakage air discharge port 3, the tail slag leakage air discharge port 4, and the top ventilation port of the transition slag hopper 6, and converge into the connecting pipe 5 to form a mixed airflow. The flow guiding structure of the transition slag hopper 6 ensures efficient separation of slag and leakage air, with the leakage air carrying only a small amount of fine ash into dust collector 7 and dust collector 8, further improving dust removal efficiency.

[0047] B. Heat recovery and reuse

[0048] Clean air leaking after dust removal enters the booster fan 12, and after being pressurized, it is switched to two paths through the outlet shut-off valve 14 and the connecting pipe 5:

[0049] Path 1: Open the secondary air box shut-off valve 15 and the secondary air box shut-off valve 26 to send the leaked air into the secondary air box 17 and the secondary air box 28, where it mixes with the cold secondary air output from the blower 1 21 and the blower 2 22. After being heated by the air preheater, it is sent into the furnace as hot secondary air to achieve heat recovery and participate in the combustion process, thereby improving the boiler's thermal efficiency.

[0050] Path 2: Switch to the secondary air annular air box shut-off door 19 and the secondary air annular air box shut-off door 20 to send the leaked air into the secondary air annular large air box 1 23 and the secondary air annular large air box 2 24. The high-speed airflow blows away the ash accumulated at the bottom of the large air box to prevent the ash accumulation from affecting the operation of the equipment. The ash enters the furnace for combustion with the airflow, reducing the amount of maintenance and cleaning work.

[0051] C. Slag Discharge and Sealing

[0052] The slag separated by the dust collector falls sequentially into the slag discharge pipe 11 through the series structure of the first air lock 9 and the second air lock 10 at the bottom of the dust collector, and returns to the dry slag machine body 1. It is then transported to the slag bin 27 by the steel belt of the dry slag machine.

[0053] The airlock adopts a double-layer flap design. The opening and closing of the flap is controlled by the counterweight, which ensures the continuous discharge of slag while preventing the cooling air in the dry slag machine from flowing back into the dust collector through the slag discharge pipe 11. This avoids airflow short-circuiting and damages the dust removal efficiency, while also inhibiting dust leakage.

[0054] D. Dynamic airflow adjustment

[0055] Cooling air volume adjustment: The cooling air adjustment gate 25 on the top of the dry slag machine is linked to the bottom slag temperature sensor. When the slag temperature is detected to rise, the opening of the adjustment gate 25 is automatically increased to increase the cooling air volume entering the dry slag machine and enhance the heat exchange and cooling effect on the bottom slag. When the slag temperature decreases, the opening is reduced to maintain the cooling air volume matching the actual needs.

[0056] Slag discharge dust control: When slag is discharged from slag bin 27, the negative pressure regulating door 26 in slag discharge room 28 will open automatically. The suction action will create a local negative pressure to suppress the dust generated during the slag discharge process and prevent dust from overflowing and polluting the environment.

[0057] It will be readily understood by those skilled in the art that the aforementioned advantageous methods can be freely combined and superimposed without conflict.

[0058] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of this utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model. The above are only preferred embodiments of this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of this utility model, and these improvements and modifications should also be considered within the protection scope of this utility model.

Claims

1. A power plant boiler dry slag machine furnace bottom air leakage treatment device, characterized in that, include: The dry slag machine body (1) has its bottom air leakage outlet (2), bottom air leakage outlet (3), and tail air leakage outlet (4) leading out; The connecting pipe (5) is used to connect dust collector one (7) and dust collector two (8); Blower 1 (21), blower 2 (22) and its outlet secondary air box 1 (17), secondary air box 2 (18) and the two sides secondary air ring large air box 1 (23) and secondary air ring large air box 2 (24); The booster fan (12) and its inlet shut-off valve (13) and outlet shut-off valve (14); Secondary air box shut-off valve 1 (15) and secondary air box shut-off valve 2 (16) at the outlet of the secondary air box and secondary air ring air box shut-off valve 1 (19) and secondary air ring air box shut-off valve 2 (20) at the inlet of the secondary air box. The slag bin (27), slag discharge room (28), and the cooling air inlet of the dry slag machine body (1) are also equipped with an adjustment door (25), and the interior of the slag discharge room (28) is equipped with a negative pressure regulating door (26); The transition slag hopper (6) is located between the dry slag machine body (1) and the connecting pipe (5). It is used to receive the slag discharged from the dry slag machine body and guide it to the subsequent processing flow. Its bottom is connected to the dry slag machine steel belt conveyor system, and its top is connected to the air leakage collection path of the connecting pipe (5) through an interface to achieve the initial separation of slag and air leakage.

2. The air leakage control device for the furnace bottom of a dry slag machine of a power plant boiler according to claim 1, characterized in that: The bottom of the dust collector is provided with a first air lock (9), a second air lock (10), and a slag discharge pipe (11) from top to bottom, and the bottom of the slag discharge pipe (11) is connected to the dry slag machine body (1).

3. The air leakage control device for the furnace bottom of a dry slag machine of a power plant boiler according to claim 1, characterized in that: The first airlock (9) and the second airlock (10) are connected in series to prevent the cooling air of the dry slag machine body (1) from short-circuiting and to realize the continuous discharge of the slag separated by the dust collector to the slag discharge pipe (11).

4. The air leakage control device for the furnace bottom of a power plant boiler dry slag machine according to claim 2, characterized in that: The cooling air regulating door of the dry slag machine is installed on the top of the dry slag machine and adjusts the cooling air volume entering the dry slag machine in real time according to the change of slag temperature at the bottom of the furnace.

5. The air leakage control device for the furnace bottom of a power plant boiler dry slag machine according to claim 2, characterized in that: The dust collector 1 (7) and dust collector 2 (8) are provided in multiple units according to the unit capacity. Their inlets are connected to the slag discharge room (28) through the connecting pipe (5). The internal dust collection and anti-wear treatment are carried out in three stages.

6. The air leakage control device for the furnace bottom of a power plant boiler dry slag machine according to claim 1, characterized in that: The adjustment gate (25) adjusts the cooling air volume inside the dry slag machine body (1) in real time according to the change of slag temperature at the bottom of the furnace.

7. The device for controlling air leakage at the bottom of a power plant boiler dry ash machine according to claim 1, characterized in that: The adjustment door (25) is installed on the top of the dry slag machine and can adjust the cooling air volume entering the dry slag machine body (1) in real time according to the slag temperature at the bottom of the furnace; the negative pressure adjustment door (26) is set in the slag discharge room (28) and is used to form negative pressure when slag is discharged from the slag bin (27) to suppress dust.

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