Return ash discharging device of circulating fluidized bed boiler

Abstract

The invention discloses a return ash discharging device of a circulating fluidized bed boiler. Comprising a boiler furnace, a return feeder, an air chamber, a slag cooler, a slag discharging pipe and a manual gate valve, wherein the return feeder and the boiler furnace are circularly arranged; the air chamber is arranged at the bottom of the boiler furnace and connected with an air supply pipeline; the slag cooler is arranged below the air chamber; a return ash conveying pipeline is arranged between the return feeder and the slag discharging pipe, an electric ash discharging valve is arranged on the return ash conveying pipeline, and redundant return ash in the return feeder can be conveyed into the slag discharging pipe along the return ash conveying pipeline to be discharged after the electric ash discharging valve is opened remotely. Remote control can be achieved, the discharging amount of returned ash is adjusted by judging the material bed temperature and the hearth differential pressure of the boiler by an operator, it is guaranteed that the material bed temperature is stabilized at 800 DEG C or above, and therefore sufficient combustion of coal is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of automatic ash discharge equipment for circulating fluidized bed boilers, and in particular to a circulating fluidized bed boiler return ash discharge device. Background Art

[0002] At present, when the circulating fluidized bed boiler return ash is automatically discharged, there are generally two ways for the boiler to discharge the return ash. One is through the ash cooler, which is not easy to install due to the limitations of on-site space and location. The second is to discharge the ash by manpower, which is labor-intensive and has low work efficiency. In addition, the return ash temperature is high and the fluidity is strong during the discharge process, which is very dangerous and prone to burn accidents. Excessive or insufficient return ash from the circulating fluidized bed boiler has a great impact on the boiler load and bed temperature. If the circulating ash amount is too much, it will lead to incomplete combustion, low bed temperature, and reduced boiler output. Excessive circulating ash will also cause the circulating material to become unstable, the material circulation balance will be destroyed, and ash collapse is likely to occur. In severe cases, forced shutdown accidents may occur.

[0003] In the dense phase area of ​​the circulating fluidized bed, about 50% of the fuel is burned and releases heat. Except for a part of this heat being used to heat the fuel and air, most of the remaining heat must be taken away by the circulating material to maintain stability. If the circulating material is insufficient, the bed temperature will be too high. In other words, sufficient circulating ash is an effective means to control the excessive bed temperature. Therefore, how to design a safe and reliable circulating fluidized bed boiler return ash discharge device has become a current problem to be solved. Summary of the invention

[0004] In order to solve one or some technical problems existing in the prior art, the purpose of this application is to provide a circulating fluidized bed boiler return ash discharge device, which can realize remote control. Through the operator's judgment of the boiler's bed temperature and furnace differential pressure, the discharge amount of return ash is adjusted to ensure that the bed temperature is stable at above 800°C, thereby ensuring sufficient combustion of the coal.

[0005] In order to solve the above existing technical problems, this application adopts the following technical solutions:

[0006] A circulating fluidized bed boiler return ash discharge device comprises a boiler furnace, a return material device circulated with the boiler furnace, a wind chamber arranged at the bottom of the boiler furnace and connected to an air supply duct, a slag cooler arranged below the wind chamber, a slag discharge pipe arranged between the slag cooler and the boiler furnace, and a manual plug valve arranged on the slag discharge pipe. A return ash conveying pipe is provided between the return material device and the slag discharge pipe, and an electric ash discharge valve is provided on the return ash conveying pipe. Excess return ash in the return material device can be remotely opened by the electric ash discharge valve and then conveyed along the return ash conveying pipe to the slag discharge pipe for discharge.

[0007] Preferably, the return ash conveying pipeline includes a first pipeline vertically arranged at the bottom of the return material device, a third pipeline with one end obliquely arranged on one side of the slag discharge pipe, and a second pipeline inclined and bent downward between the first pipeline and the third pipeline. The electric ash discharge valve is arranged on the first pipeline, and the other end of the third pipeline is provided with an air supply mechanism, and the return ash in the third pipeline is fed into the slag discharge pipe through the air supply mechanism.

[0008] Preferably, the air supply mechanism includes a metal hose with one end arranged at the end of the third pipe, a manual damper arranged at the outer end of the metal hose, and a diverter pipe with one end arranged at the air inlet of the manual damper, and the other end of the diverter pipe is connected to one side of the air supply duct of the air chamber.

[0009] Preferably, a metal expansion joint is provided on the second pipeline.

[0010] Preferably, a discharge pipe vertically arranged downward is further provided at the bottom of the first pipeline, and a manual valve is provided on the discharge pipe.

[0011] Preferably, a manual ash valve is also provided on the second pipeline.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] (1) When the amount of boiler return ash is large and the bed temperature is low, a certain amount of return ash can be discharged to ensure stable boiler combustion and stable bed temperature;

[0014] (2) Continue to use the existing slag cooler, design and install it reasonably without damaging the original equipment function;

[0015] (3) After the device is installed, the labor intensity of manually discharging the return ash is reduced, the personal safety of the operators is ensured, and burn accidents can be prevented.

[0016] (4) During boiler operation, the discharge of return ash can reduce the material concentration in the dilute phase area of ​​the furnace, improve the combustion conditions in the furnace, and reduce the occurrence of ash collapse, thereby ensuring safe, stable and economical operation of the boiler. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the structure of the present invention;

[0018] In the figure: 1. Slag cooler; 2. Slag discharge pipe; 3. Wind chamber; 4. Manual ash valve; 5. Boiler furnace; 6. Returner; 7. First pipeline; 8. Electric ash discharge valve; 9. Pipeline for conveying return ash; 10. Discharge pipe; 11. Manual valve; 12. Second pipeline; 13. Metal expansion joint; 14. Diverter pipe; 15. Manual damper; 16. Metal hose; 17. Third pipeline; 18. Manual gate valve. DETAILED DESCRIPTION

[0019] Below, the present application is further described in conjunction with the accompanying drawings and specific implementation methods. It should be noted that, under the premise of no conflict, the various embodiments or technical features described below can be arbitrarily combined to form a new embodiment.

[0020] In the description of the present application, it should be understood that the terms "up", "down", "left", "right", etc., indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present application.

[0021] The terms "first", "second", etc. in this application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0022] like Figure 1 As shown, a circulating fluidized bed boiler return ash discharge device includes a boiler furnace 5, a return material device 6 circulated with the boiler furnace 5, a wind chamber 3 connected to an air supply duct and arranged at the bottom of the boiler furnace 5, a slag cooler 1 arranged below the wind chamber 3, a slag discharge pipe 2 arranged between the slag cooler 1 and the boiler furnace 5, and a manual plug valve 18 arranged on the slag discharge pipe 2. A return ash conveying pipe 9 is provided between the return material device 6 and the slag discharge pipe 2, and an electric ash discharge valve 8 is provided on the return ash conveying pipe 9. The excess return ash in the return material device 6 can be remotely opened by the electric ash discharge valve 8 and then conveyed along the return ash conveying pipe 9 to the slag discharge pipe 2 for discharge.

[0023] Through the combination of the return ash conveying pipeline 9 and the electric ash discharge valve 8, the return ash can be discharged directly from the return device 6 when the circulating ash concentration of the boiler is high and the material bed temperature is low, thereby adjusting the temperature of the boiler furnace 5, ensuring stable combustion of the boiler, and improving the thermal efficiency of the boiler. During operation, the discharge of return ash can improve the operating conditions of the boiler, increase the material bed temperature to operate above 800°C, ensure that the coal can be fully burned, reduce the carbon content of fly ash, and thus improve the efficiency of the boiler. It is expected to recover the investment cost within one year and create significant economic benefits in the next few years. Specifically, it includes a 40% increase in production efficiency, reduced equipment wear, and a 20% reduction in maintenance costs. The economic value created is expected to be 400,000 yuan. The successful implementation and promotion of this project will provide valuable experience and technical support for enterprises in the same industry, and promote technological progress and innovation in the entire industry. It can inspire more companies to engage in the research and development of boiler equipment and jointly promote the transformation, upgrading and sustainable development of the local economy.

[0024] A further improvement is that the return ash conveying pipeline 9 includes a first pipeline 7 vertically arranged at the bottom of the return material device 6, a third pipeline 17 with one end inclined at one side of the slag discharge pipe 2, and a second pipeline 12 inclined downward and bent between the first pipeline 7 and the third pipeline 17, the electric ash discharge valve 8 is arranged on the first pipeline 7, and the other end of the third pipeline 17 is provided with an air supply mechanism, and the return ash in the third pipeline 17 is fed into the slag discharge pipe 2 through the air supply mechanism.

[0025] When the excess return ash in the return hopper 6 is directly transported to the slag cooler 1 through the return ash conveying pipeline 9, the electric ash discharge valve 8 is remotely started, and the return ash at the bottom of the return hopper 6 can be quickly discharged outward along the downward vertical first pipeline 7, and then pass through the second pipeline 12 arranged at a downward inclination, and enter the third pipeline 17 installed obliquely on one side of the slag discharge pipe 2, and transported to the slag discharge pipe 2 through the third pipeline 17, thereby realizing the transportation of the return ash. In particular, since there is no return ash conveying pipeline between the return hopper 6 and the slag discharge pipe 2, The method of vertical connection makes it difficult to discharge the return ash quickly after it is transported to the third pipe 17. Therefore, an air supply mechanism is connected to the upper end of the third pipe 17. After a stream of air is blown into the third pipe 17 by the air supply mechanism, the return ash is quickly sent into the slag discharge pipe 2 by the blown air. At the same time, when the air entering through the air supply mechanism blows toward the slag discharge pipe 2 in the third pipe belt, a tangential micro-negative pressure can be formed on the end of the second pipe 12, which facilitates the return ash in the second pipe 12 to flow into the third pipe 17. The return ash discharged from the third pipe 17 is also cooled and discharged by the slag cooler 1, which can avoid accidents in which operators are burned by high-temperature ash, completely solve the problem of fly ash and dust in the manual discharge process, and reduce pollution to the on-site environment.

[0026] A further improvement is that the air supply mechanism includes a metal hose 16 with one end arranged at the end of the third pipe 17, a manual damper 15 arranged at the outer end of the metal hose 16, and a diverter pipe 14 with one end arranged at the air inlet of the manual damper 15, and the other end of the diverter pipe 14 is connected to one side of the air supply duct of the air chamber 3.

[0027] When the third pipe 17 is blown by the air supply mechanism, it is composed of a metal hose 16, a manual damper 15 and a diverter pipe 14, and one end of the diverter pipe 14 is connected to one side of the air supply pipe of the air chamber 3. When the air supply pipe supplies air to the air chamber 3, it is only necessary to open the manual damper 15 to supply air to the third pipe 17. The structure is simpler, and it is only necessary to extend the air supply pipe in the direction of the air supply pipe to achieve connection through a very short diverter pipe 14, and the modification cost is lower.

[0028] As a further improvement, a discharge pipe 10 vertically arranged downward is further provided at the bottom of the first pipeline 7 , and a manual valve 11 is provided on the discharge pipe 10 .

[0029] When the returner 6 needs to be maintained, by opening the manual valve 11, all the ash inside the returner 6 can be directly discharged to the outside through the discharge pipe 10, which makes it easier to clean the inside of the returner 6.

[0030] A further improvement is that a metal expansion joint 13 is provided on the second pipeline 12 ; a manual ash valve 4 is also provided on the second pipeline 12 .

[0031] The metal expansion joint 13 can make the second pipeline 12 have a sufficient adjustable length after installation, avoiding the problem of being unable to be connected in series due to shaking or position displacement of the first pipeline 7 and the third pipeline 17. At the same time, the manual ash valve 4 is normally in the normally open state. When the ash return pipeline 9 needs to be closed and the electric ash discharge valve 8 cannot be closed, it can be cut off through the manual ash valve 4. The manual ash valve 4 can also be used to cut off the second pipeline 12 separately, thereby facilitating the discharge maintenance of the discharge pipe 10.

[0032] The above-mentioned implementation modes are only preferred implementation modes of the present application and cannot be used to limit the scope of protection of the present application. Any non-substantial changes and substitutions made by technicians in this field on the basis of the present application shall fall within the scope of protection required by the present application.

Claims

1. A circulating fluidized bed boiler return ash discharge device, characterized in that: The invention comprises a boiler furnace (5), a returner (6) circulated with the boiler furnace (5), a wind chamber (3) arranged at the bottom of the boiler furnace (5) and connected to an air supply duct, a slag cooler (1) arranged below the wind chamber (3), a slag discharge pipe (2) arranged between the slag cooler (1) and the boiler furnace (5), and a manual gate valve (18) arranged on the slag discharge pipe (2); a return ash conveying pipe (9) is arranged between the returner (6) and the slag discharge pipe (2); an electric ash discharge valve (8) is arranged on the return ash conveying pipe (9); excess return ash in the returner (6) can be remotely opened by the electric ash discharge valve (8) and then conveyed along the return ash conveying pipe (9) to the slag discharge pipe (2) for discharge.

2. A circulating fluidized bed boiler return ash discharge device according to claim 1, characterized in that: The return ash conveying pipeline (9) comprises a first pipeline (7) vertically arranged at the bottom of the return device (6), a third pipeline (17) with one end obliquely arranged on one side of the slag discharge pipe (2), and a second pipeline (12) arranged between the first pipeline (7) and the third pipeline (17) in a downwardly inclined manner. The electric ash discharge valve (8) is arranged on the first pipeline (7), and the other end of the third pipeline (17) is provided with an air supply mechanism, and the return ash in the third pipeline (17) is sent into the slag discharge pipe (2) through the air supply mechanism.

3. A circulating fluidized bed boiler return ash discharge device according to claim 2, characterized in that: The air supply mechanism comprises a metal hose (16) with one end arranged at the end of the third pipe (17), a manual damper (15) arranged at the outer end of the metal hose (16), and a shunt pipe (14) with one end arranged at the air inlet of the manual damper (15), and the other end of the shunt pipe (14) is connected to one side of the air supply pipe of the air chamber (3).

4. A circulating fluidized bed boiler return ash discharge device according to claim 3, characterized in that: The second pipeline (12) is provided with a metal expansion joint (13).

5. A circulating fluidized bed boiler return ash discharge device according to any one of claims 2 to 4, characterized in that: A discharge pipe (10) vertically arranged downward is also provided at the bottom of the first pipeline (7), and a manual valve (11) is provided on the discharge pipe (10).

6. The circulating fluidized bed boiler return ash discharge device according to claim 5, characterized in that: The second pipeline (12) is also provided with a manual ash valve (4).

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