Circulating ash load adjusting device and method for circulating fluidized bed boiler

Abstract

The invention discloses a circulating fluidized bed boiler circulating ash load adjusting device and method, and belongs to the technical field of circulating fluidized bed boilers. The problem that when an existing circulating fluidized bed boiler operates in a rapid load rising and falling mode, the load cannot be rapidly changed according to requirements is solved. One end of the ash inlet pipe is fixedly connected with the material returning device in a communicated mode, the other end of the ash inlet pipe is inserted into the ash storage bin, a first manual stop valve and a first electric stop valve are sequentially arranged on the ash inlet pipe, one end of the ash outlet pipe is fixedly connected with the bottom of the ash storage bin in a communicated mode, and the other end of the ash outlet pipe is fixedly connected with an inlet of the ash conveying main pipe in a communicated mode. An outlet of each ash conveying main pipe is fixedly connected with the corresponding ash conveying branch pipe in a communicating mode, and a second manual cut-off valve, a second electric cut-off valve and an electric rotary ash feeding valve are sequentially arranged on the ash outlet pipe from top to bottom. Ash in the ash storage bin can be added into the hearth in time through the discharging device, and the boiler load can be rapidly increased and decreased.

Description

Technical Field

[0001] The invention relates to a circulating fluidized bed boiler circulating ash load regulating device and regulating method, belonging to the technical field of circulating fluidized bed boilers. Background Art

[0002] Circulating fluidized bed boilers are widely used due to their wide fuel adaptability, the ability to burn inferior fuels, stable and efficient combustion, superior environmental performance, and good load regulation characteristics. Many industrial plants use circulating fluidized bed boilers as self-contained power stations, and the load of circulating fluidized bed units needs to be flexibly adjusted according to the power and steam consumption of the plant. Because a large amount of wear-resistant refractory castables and a large amount of circulating materials are laid inside the circulating fluidized bed boiler, the boiler has a large heat storage capacity, and the heat storage and release speed is slow. When the boiler needs to operate with variable load, it relies on its own heat, and the response of load and parameters is relatively slow, and it cannot quickly keep up with the requirements of changes in working conditions, and there is a problem that the load cannot be changed quickly according to requirements. Summary of the invention

[0003] The present invention is to solve the above problems and further provides a circulating fluidized bed boiler circulating ash load regulating device and regulating method.

[0004] The technical solution adopted by the present invention to solve the above technical problems is:

[0005] A circulating fluidized bed boiler circulating ash load regulating device comprises a return device, an ash storage device, an ash storage bin, an ash adding device, a loosening device, a pressure relief valve and a high and low material level gauge, wherein the ash storage device comprises an ash inlet pipe, a first manual shut-off valve and a first electric shut-off valve, one end of the ash inlet pipe is connected and fixedly connected to the return device, and the other end of the ash inlet pipe is inserted into the ash storage bin, and the first manual shut-off valve and the first electric shut-off valve are sequentially arranged on the ash inlet pipe, and the ash adding device comprises an ash outlet pipe, a second manual shut-off valve, a second electric shut-off valve, an electric rotary ash feeding valve, an ash delivery mother pipe and a plurality of delivery pipes. An ash branch pipe, one end of the ash outlet pipe is connected and fixedly connected to the bottom of the ash storage bin, the other end of the ash outlet pipe is connected and fixedly connected to the inlet of the ash conveying main pipe, and each ash conveying main pipe outlet is connected and fixedly connected to the corresponding ash conveying branch pipe. A second manual shut-off valve, a second electric shut-off valve and an electric rotary ash feeding valve are sequentially arranged on the ash outlet pipe from top to bottom. The loosening device includes a rapping device and a compressed air actuating pipeline. The rapping device is installed on the side wall of the ash storage bin, the compressed air actuating pipeline is inserted in the ash storage bin, the pressure relief valve is inserted in the ash storage bin, and the high and low level meters are installed on the side wall of the ash storage bin.

[0006] Furthermore, the two detection heads of the high and low material level meters are respectively installed between the high material point and the low material point of the ash storage bin.

[0007] Furthermore, the electric rotary ash feeding valve is connected and fixedly connected to the high-pressure fluidizing air duct.

[0008] Furthermore, the top of the ash storage bin is covered with a cloth.

[0009] Furthermore, the ash inlet pipe, compressed air actuation pipeline and pressure relief valve are all inserted into the ash storage bin through the covering cloth.

[0010] Furthermore, a high temperature resistant isolation valve is provided on each of the ash conveying branch pipes.

[0011] Furthermore, the first manual shut-off valve and the second manual shut-off valve remain in a normally open state.

[0012] Furthermore, the ash inlet pipe is made of high temperature resistant material.

[0013] A circulating ash load regulation method for a circulating fluidized bed boiler includes an ash storage process and an ash adding process. The ash storage process is to close the second electric shut-off valve, open the first electric shut-off valve, and store the ash in a return device in an ash storage bin. The ash adding process is to close the first electric shut-off valve, open the compressed air actuation system to introduce compressed air into the ash storage bin to loosen the ash at the bottom of the ash storage bin, and at the same time, a vibrating device vibrates the side wall of the ash storage bin to make the loosened ash flow downward smoothly into the ash outlet pipe, and then the second electric shut-off valve, the electric rotary ash supply valve and the high-pressure fluidizing air duct are opened in sequence to make the ash smoothly enter the ash conveying main pipe, and the high-temperature resistant isolation valve is opened to allow the ash in the ash conveying main pipe to enter the furnace through the ash conveying branch pipe.

[0014] Furthermore, the ash storage process is used for boiler load reduction operation, and the ash adding process is used for boiler load increase operation.

[0015] Compared with the prior art, the present invention has the following effects:

[0016] The present invention can effectively store the ash in the furnace into the ash storage bin through the ash storage device, and can timely add the ash in the ash storage bin into the furnace through the ash adding device, thereby achieving the technical effect of quickly raising and lowering the boiler load as required;

[0017] The present invention realizes precise control of the ash storage amount and the ash adding amount in the ash storage process and the ash adding process through the first electric shut-off valve in the ash storage device and the second electric shut-off valve and the electric rotary ash feeding valve in the ash adding device, thereby improving the device response speed and realizing rapid lifting and lowering of the boiler load.

[0018] The present invention provides an alternative solution for the ash storage process and the ash adding process by setting a first manual shut-off valve in the ash storage device and a second manual shut-off valve in the ash adding device. When power is off or other emergency situations occur, the ash storage amount and the ash adding amount can still be accurately controlled to ensure safe and stable operation of the device.

[0019] The present invention can increase or decrease the load of the fine ash separated from the circulating fluidized bed boiler according to the boiler's needs through the ash storage device and the ash adding device, and can store and use it at any time. The system has fast response, safe and stable operation, convenient maintenance, and reduced use cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0021] Figure 1 It is the front view of the circulating ash load regulating device of the circulating fluidized bed boiler;

[0022] Figure 2 for Figure 1 Enlarged view of point A in the middle;

[0023] In the figure: 1. return device; 2. ash inlet pipe; 3. first manual shut-off valve; 4. first electric shut-off valve; 5. ash storage bin; 6. vibrating device; 7. ash outlet pipe; 8. electric rotary ash valve; 9. high-pressure fluidizing air duct; 10. ash conveying main pipe; 10-1. ash conveying main pipe inlet; 10-2. ash conveying main pipe outlet; 11. ash conveying branch pipe; 12. high-temperature resistant isolating valve; 13. compressed air actuated pipe; 14. pressure relief valve; 15. high and low material level gauges; 16. furnace; 17. covering cloth; 18. second manual shut-off valve; 19. second electric shut-off valve. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely explain the technical solutions in the embodiments of the present invention. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict, and the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0025] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0026] See attached Figure 1-2The present embodiment is described as a circulating ash load regulating device for a circulating fluidized bed boiler. The inlet of the device is arranged below the return device of the circulating fluidized bed boiler, and the outlet is connected to the furnace cone section. The overall height is the same as the furnace entry elevation of the return device. It includes a return device 1, an ash storage device, an ash storage bin 5, an ash adding device, a loosening device, a pressure relief valve 14 and a high and low level gauge 15. The ash storage device includes an ash inlet pipe 2, a first manual shut-off valve 3 and a first electric shut-off valve 4. One end of the ash inlet pipe 2 is connected and fixedly connected to the return device 1, and the other end of the ash inlet pipe 2 is inserted into the ash storage bin 5. The first manual shut-off valve 3 and the first electric shut-off valve 4 are sequentially arranged on the ash inlet pipe 2. The ash adding device includes an ash outlet pipe 7, a second manual shut-off valve 18, a second electric shut-off valve 19, an electric rotary ash supply valve 8, an ash delivery main pipe 10 and a plurality of ash delivery branch pipes 11. One end of the ash outlet pipe 7 It is connected and fixedly connected to the bottom of the ash storage bin 5, the other end of the ash discharge pipe 7 is connected and fixedly connected to the ash conveying main pipe inlet 10-1, and each ash conveying main pipe outlet 10-2 is connected and fixedly connected to the corresponding ash conveying branch pipe 11. The ash discharge pipe 7 is provided with a second manual shut-off valve 18, a second electric shut-off valve 19 and an electric rotary ash supply valve 8 from top to bottom. The loosening device includes a rapping device 6 and a compressed air actuating pipe 13. The rapping device 6 is installed on the side wall of the ash storage bin 5. The compressed air actuating pipe 13 is inserted in the ash storage bin 5. The pressure relief valve 14 is inserted in the ash storage bin 5. The high and low level meter 15 is installed on the side wall of the ash storage bin 5. Specifically, a compressed air actuating valve is provided on the compressed air actuating pipe 13. Specifically, an ash conveying main pipe inlet 10-1 and at least two ash conveying main pipe outlets 10-2 are provided on the ash conveying main pipe 10.

[0027] The present invention can effectively store the ash in the furnace 16 into the ash storage bin 5 through the ash storage device, and can timely add the ash in the ash storage bin 5 into the furnace 16 through the ash adding device, so as to achieve the technical effect of quickly raising and lowering the boiler load as required; the present invention realizes the precise control of the ash storage amount and the ash adding amount in the ash storage process and the ash adding process through the first electric shut-off valve 4 in the ash storage device and the second electric shut-off valve 19 and the electric rotary ash feeding valve 8 in the ash adding device, improves the device response speed, and realizes the rapid raising and lowering of the boiler load; the present invention provides an alternative scheme for the ash storage process and the ash adding process through the setting of the first manual shut-off valve 3 in the ash storage device and the second manual shut-off valve 18 in the ash adding device, and can still accurately control the ash storage amount and the ash adding amount in the event of power outage or other emergency situations, so as to ensure the safe and stable operation of the device; the present invention can raise and lower the load of the fine ash separated from the circulating fluidized bed boiler according to the needs of the boiler through the ash storage device and the ash adding device, and can store and use it at any time, thereby reducing the use cost, facilitating maintenance, improving the system response speed, and ensuring safe and stable operation.

[0028] The two detection heads of the high and low material level meter 15 are respectively installed between the high material point and the low material point of the ash storage bin 5. Specifically, the high material point is the position in the ash storage bin 5 where the maximum ash storage amount is allowed, and the low material point is the position in the ash storage bin 5 where the minimum ash storage amount is allowed. The ash storage amount in the ash storage bin 5 is detected by the high and low material level meter 15. By installing the probe of the high and low material level meter 15 between the high material point and the low material point of the ash storage bin 5, it can be ensured that the pressure in the ash storage bin 5 is kept within a normal range. When it is detected that the pressure in the ash storage bin 5 is too high, the pressure is released through the pressure relief valve 14.

[0029] The electric rotary ash supply valve 8 is connected and fixedly connected with the high-pressure fluidizing air duct 9. The electric rotary ash supply valve 8 allows the ash to smoothly enter the ash conveying main pipe 10, and the high-pressure fluidizing air is introduced into the high-pressure fluidizing air duct 9 to prevent the ash from escaping from the electric rotary ash supply valve 8. The high-pressure fluidizing air duct 9 plays a role of sealing and actuation.

[0030] The top of the ash storage bin 5 is covered with a cloth 17. The top of the ash storage bin 5 is covered with a cloth 17 to prevent dust.

[0031] The ash inlet pipe 2 , the compressed air actuating pipeline 13 and the pressure relief valve 14 are all inserted into the ash storage bin 5 through the covering cloth 17 .

[0032] Each of the ash conveying branches 11 is provided with a high temperature resistant isolation valve 12. The high temperature isolation valve can cut off the isolation ash adding device to prevent the ash in the furnace from being reversely transferred to the ash storage bin 5.

[0033] The first manual shut-off valve 3 and the second manual shut-off valve 18 are kept in a normally open state. Specifically, the first manual shut-off valve 3 and the second manual shut-off valve 18 can accurately control the ash storage amount and the ash addition amount through manual control in the event of power failure or other emergency situations.

[0034] The ash inlet pipe 2 is made of a high temperature resistant material. Preferably, the ash inlet pipe 2 is made of high temperature resistant stainless steel.

[0035] A circulating ash load regulation method for a circulating fluidized bed boiler includes an ash storage process and an ash adding process. The ash storage process is to close the second electric shut-off valve 19, open the first electric shut-off valve 4, and store the ash in the return device 1 in the ash storage bin 5. The ash adding process is to close the first electric shut-off valve 4, open the compressed air actuation system to introduce compressed air into the ash storage bin 5 to loosen the ash at the bottom of the ash storage bin 5, and at the same time, the rapping device 6 raps the side wall of the ash storage bin 5 to make the loosened ash flow downward smoothly into the ash outlet pipe 7, and sequentially open the second electric shut-off valve 19, the electric rotary ash valve 8 and the high-pressure fluidizing air duct 9 to make the ash smoothly enter the ash conveying main pipe 10, and open the high-temperature resistant isolation valve 12, so that the ash in the ash conveying main pipe 10 enters the furnace 16 through the ash conveying branch pipe 11. Specifically, when the circulating fluidized bed boiler is running at a stable load and the circulating ash load of the circulating fluidized bed boiler does not need to be adjusted, the first manual shut-off valve 3 is in a normally open state, the first electric shut-off valve 4 is in a closed state, and the high-temperature resistant isolation valve 12 of the ash conveying branch pipe is in a closed state; when the circulating fluidized bed boiler needs to be operated at a reduced load, the heat exchange in the furnace does not require too much circulating material, and the ash carried by the flue gas at the furnace outlet is separated and enters the return device 1. At this time, the first electric shut-off valve 4 on the ash inlet pipe can be opened to allow the ash to enter the ash storage bin 5 for storage; when the circulating fluidized bed boiler needs to be operated at a increased load, the heat exchange in the furnace does not require too much circulating material, and the ash carried by the flue gas at the furnace outlet is separated and enters the return device 1. At this time, the first electric shut-off valve 4 on the ash inlet pipe can be opened to allow the ash to enter the ash storage bin 5 for storage. When necessary, more circulating materials are needed for heat exchange in the furnace. Since this system has not been used for a long time, the ash in the ash storage bin will be compacted due to natural sedimentation. The vibration device on the side wall can be opened to loosen the ash in the bin, and the compressed air actuation system can be turned on to introduce pressurized compressed air into the bin to promote the ash in the bin to flow downward and smoothly enter the ash outlet pipe 7. The ash is smoothly introduced into the ash conveying main pipe through the electric rotary ash valve 8. In order to prevent the ash from escaping from the electric rotary ash valve 8, high-pressure fluidizing air is introduced into the high-pressure fluidizing air duct 9 to play a sealing and actuating role. The whole process strictly prevents ash leakage and takes measures to ensure reliable sealing.

[0036] The present invention loosens the ash at the bottom of the ash storage bin 5 through a compressed air actuation system, and vibrates the side wall through a vibrating device 6 to allow the loosened ash to enter the ash outlet pipe 7, thereby ensuring that the ash can be smoothly discharged even if it is compacted due to long-term storage in the bin.

[0037] The ash storage process is used for boiler load reduction operation, and the ash adding process is used for boiler load increase operation.

[0038] Obviously, the embodiments of the present invention disclosed above are only used to help illustrate the present invention. The embodiments do not describe all the details in detail, nor do they limit the invention to specific implementation methods. According to the content of this specification, many modifications and changes can be made. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. It is not necessary and impossible to exhaustively list all implementation methods here.

Claims

1. A circulating fluidized bed boiler circulating ash load regulating device, characterized in that: The invention comprises a material return device (1), an ash storage device, an ash storage bin (5), an ash adding device, a loosening device, a pressure relief valve (14) and a high and low material level gauge (15). The ash storage device comprises an ash inlet pipe (2), a first manual shut-off valve (3) and a first electric shut-off valve (4). One end of the ash inlet pipe (2) is connected and fixedly connected to the material return device (1), and the other end of the ash inlet pipe (2) is inserted into the ash storage bin (5). The first manual shut-off valve (3) and the first electric shut-off valve (4) are sequentially arranged on the ash inlet pipe (2). The ash adding device comprises an ash outlet pipe (7), a second manual shut-off valve (18), a second electric shut-off valve (19), an electric rotary ash supply valve (8), an ash delivery main pipe (10) and a plurality of ash delivery branch pipes (11). The ash outlet pipe (7) is One end is connected and fixedly connected to the bottom of the ash storage bin (5), the other end of the ash discharge pipe (7) is connected and fixedly connected to the ash conveying main pipe inlet (10-1), and each ash conveying main pipe outlet (10-2) is connected and fixedly connected to the corresponding ash conveying branch pipe (11). The ash discharge pipe (7) is provided with a second manual shut-off valve (18), a second electric shut-off valve (19) and an electric rotary ash feeding valve (8) from top to bottom in sequence. The loosening device comprises a rapping device (6) and a compressed air actuating pipe (13). The rapping device (6) is installed on the side wall of the ash storage bin (5), the compressed air actuating pipe (13) is inserted in the ash storage bin (5), the pressure relief valve (14) is inserted in the ash storage bin (5), and the high and low material level meter (15) is installed on the side wall of the ash storage bin (5).

2. The circulating ash load regulating device for a circulating fluidized bed boiler according to claim 1, characterized in that: The two detection heads of the high and low material level meter (15) are respectively installed between the high material point and the low material point of the ash storage bin (5).

3. The circulating ash load regulating device for a circulating fluidized bed boiler according to claim 1, characterized in that: The electric rotary ash feeding valve (8) is connected and fixedly connected to the high-pressure fluidizing air duct (9).

4. The circulating ash load regulating device for a circulating fluidized bed boiler according to claim 1, characterized in that: The top of the ash storage bin (5) is covered with a covering cloth (17).

5. The circulating ash load regulating device for a circulating fluidized bed boiler according to claim 4, characterized in that: The ash inlet pipe (2), the compressed air actuating pipe (13) and the pressure relief valve (14) are all inserted into the ash storage bin (5) through the covering cloth (17).

6. The circulating ash load regulating device for a circulating fluidized bed boiler according to claim 1, characterized in that: A high temperature resistant isolation valve (12) is provided on each of the ash conveying branch pipes (11).

7. The circulating ash load regulating device for a circulating fluidized bed boiler according to claim 1, characterized in that: The first manual shut-off valve (3) and the second manual shut-off valve (18) remain in a normally open state.

8. The circulating ash load regulating device for a circulating fluidized bed boiler according to claim 1, characterized in that: The ash inlet pipe (2) is made of high temperature resistant material.

9. A method for regulating the circulating ash load regulating device of a circulating fluidized bed boiler according to any one of claims 1 to 8, characterized in that: The invention comprises an ash storage process and an ash adding process. The ash storage process is to close the second electric shut-off valve (19), open the first electric shut-off valve (4), and store the ash in the return device (1) in the ash storage bin (5). The ash adding process is to close the first electric shut-off valve (4), open the compressed air actuating system to introduce compressed air into the ash storage bin (5) to loosen the ash at the bottom of the ash storage bin (5), and at the same time, the vibrating device (6) vibrates the side wall of the ash storage bin (5) to make the loosened ash flow downward smoothly into the ash outlet pipe (7), and then sequentially open the second electric shut-off valve (19), the electric rotary ash supply valve (8) and the high-pressure fluidizing air duct (9) to make the ash smoothly enter the ash conveying main pipe (10), and open the high-temperature resistant isolating valve (12), so that the ash in the ash conveying main pipe (10) enters the furnace (16) through the ash conveying branch pipe (11).

10. The adjustment method according to claim 9, characterized in that: The ash storage process is used for boiler load reduction operation, and the ash adding process is used for boiler load increase operation.

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