Boiler peak regulation fire coal blending combustion device and method

Abstract

The invention discloses a boiler peak regulation fire coal blending combustion device and method. The boiler peak regulation fire coal blending combustion device comprises a coal bunker body, a first coal bucket, a second coal bucket, a first coal feeder, a second coal feeder and a coal feeder platform, wherein a feeding hole is formed in the top of the coal bunker body; the first coal bucket and the second coal bucket are arranged at the bottom end of the coal bunker body; the first coal feeder and the second coal feeder are used for communicating the first coal bucket and the second coal bucket with the adjacent boiler coal bunker respectively; a first insertion plate door is arranged between the first coal feeder and the first coal hopper; and a second insertion plate door is arranged between the second coal feeder and the second coal hopper. The first coal bucket and the second coal bucket are arranged, so that coal blending combustion under different loads can be realized; by arranging the first coal feeder and the second coal feeder, coal feeding mixing between the coal feeder and the adjacent boiler coal bunkers can be achieved, then rapid and flexible coal quality allocation can be conducted according to changes of unit loads and combustion conditions, and the requirements for the peak regulation capacity and the load response speed of a coal-fired thermal power unit in a peak regulation operation mode are met.

Description

Technical Field

[0001] The present invention belongs to the technical field of coal-fired power plant boilers, and particularly relates to a device and method for peak shaving coal blending in boilers. Background Art

[0002] The deep peak shaving ability of coal-fired thermal power units mainly depends on the stable combustion ability of boilers at low loads. The main technical measures to improve the stable combustion ability of boilers at low loads include: burner transformation suitable for flexible peak shaving, pulverizing system transformation, transformation of blending high-volatile coal quality, and combustion assistance transformation such as plasma, micro-oil, and oxygen enrichment.

[0003] When the load of a coal-fired thermal power unit is relatively high, the furnace temperature of the boiler is relatively high, the flue gas volume is relatively large, and the combustion stability is relatively good. At this time, if more coal with lower volatile matter and calorific value can be blended, the production operation cost can be reduced on the basis of ensuring the load-carrying capacity of the unit; when the load of the coal-fired thermal power unit is relatively low and close to the minimum stable combustion load without oil injection of the boiler, the furnace temperature of the boiler is relatively low, the flue gas volume is relatively small, and the combustion stability is relatively poor. At this time, it is required that the volatile matter and calorific value of the coal entering the furnace are relatively high to ensure the combustion stability of the boiler and prevent unsafe events such as boiler flameout caused by unstable combustion.

[0004] However, when a coal-fired thermal power unit participates in power grid peak shaving operation, its load change is subject to the requirements of power grid dispatching, and it may suddenly change to a high load or a low load at any time. The existing raw coal bunker structure cannot flexibly blend the coal quality entering the furnace according to the change of the unit load, which affects the peak shaving ability and load response speed of the unit. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a device and method for peak shaving coal blending in boilers, aiming to solve the technical problem of poor load response of the existing blending devices.

[0006] To achieve the above purpose, the present invention provides the following technical solution: A device for peak shaving coal blending in boilers includes a coal bunker body with a feed inlet at the top, a first coal hopper and a second coal hopper arranged at the bottom of the coal bunker body, a first coal feeder and a second coal feeder for respectively connecting the first coal hopper and the second coal hopper with adjacent boiler coal bunkers to transport different coal qualities, and a coal feeder platform for supporting the second coal feeder. A first slide gate for adjusting the coal feeding amount is arranged between the first coal feeder and the first coal hopper, and a second slide gate for adjusting the coal feeding amount is arranged between the second coal feeder and the second coal hopper.

[0007] Further, the stored coal weights of the first coal hopper and the second coal hopper are equal.

[0008] Further, a plurality of dredging devices for dredging coal materials are arranged at intervals along the height direction of the second coal hopper.

[0009] Further, the dredging device is any one of an air cannon and an air hammer.

[0010] Further, a transition bin is provided between the coal bunker body and the first coal hopper and the second coal hopper.

[0011] Further, the first coal hopper and the second coal hopper are respectively welded to the inner wall of the transition bin.

[0012] Further, reinforcing ribs are provided between the coal bunker body and the transition bin.

[0013] Further, the connecting end of the transition bin and the coal bunker body is circular, and the connecting ends of the transition bin and the first coal hopper and the second coal hopper are square.

[0014] This application also discloses a control method for peak shaving and coal blending combustion of a boiler, which uses a boiler peak shaving and coal blending combustion device as described in any one of the above, and includes the following steps:

[0015] S01: Real-time monitor the load demands of the boiler unit and the power grid;

[0016] S02: Obtain the load demand parameters of the boiler unit and the power grid through the DCS system, control the coal feeding amounts, motor currents of the first coal feeder and the second coal feeder, and control the operation modes in the first coal hopper and the second coal hopper, so as to achieve a rapid response to the load demands of the boiler unit and the power grid synchronously.

[0017] Further, the step SO2 includes:

[0018] When the DCS system monitors that the boiler units are all at full load, at this time, use the high-calorific-value coal stored in the first coal hopper and the second coal hopper; and increase the coal feeding amount by starting the motor currents of the first coal feeder and the second coal feeder to ensure the load-carrying capacity of the unit;

[0019] When the DCS system monitors that the boiler units are all operating at medium and low loads, at this time, stop the coal feeding of the first coal feeder and the second coal feeder, and operate the original pulverized coal system for storing low-calorific-value coal to ensure the demand for burning low-calorific-value coal under the low-load operating conditions of the unit.

[0020] The beneficial effects of the present invention are as follows: Compared with the prior art, in a boiler peak shaving coal blending device of the present invention, by providing a first coal hopper and a second coal hopper, coal blending of different coal types can be achieved at different loads; by providing a first coal feeder and a second coal feeder, coal feeding and mixing with adjacent boiler coal bins can be achieved, and thus rapid and flexible allocation of coal quality can be carried out according to changes in unit load and combustion conditions to meet the requirements for peak shaving capacity and load response speed of two coal-fired power generation units under peak shaving operation modes; by providing a first slide gate and a second slide gate, the coal dropping and shut-off of the coal feeder can be controlled respectively to meet the requirements of boiler combustion and further improve coal combustion efficiency; through this device, flexible two-way coal distribution can be realized, different types of raw coal can be provided for different working conditions of the unit, greatly meeting the need for rapid response to load and improving the flexibility of the unit.

[0021] Other advantages, objectives and features of the present invention will be described in the subsequent description, and to some extent will be obvious to those skilled in the art, or those skilled in the art can obtain teachings from the practice of the present invention. The objectives and other advantages of the present invention can be achieved and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to make the objectives, technical solutions and beneficial effects of the present invention clearer, the present invention provides the following drawings for illustration:

[0023] Figure 1 It is a schematic structural diagram of a boiler peak shaving coal blending device proposed in an embodiment of the present invention;

[0024] Figure 2 It is a schematic diagram of the connection between a boiler peak shaving coal blending device proposed in an embodiment of the present invention and other adjacent boiler coal bins.

[0025] Reference Numerals in the Drawings:

[0026] 1 - Coal bin body;

[0027] 2 - First coal hopper;

[0028] 3 - Second coal hopper;

[0029] 4 - Second coal feeder;

[0030] 5 - Coal feeder platform;

[0031] 6 - Unclogging device;

[0032] 7 - Transition bin;

[0033] 8 - Reinforcing rib;

[0034] 9 - Observation window;

[0035] 10 - Boiler coal bin. Specific implementation mode

[0036] As Figures 1 to 2 shown, this embodiment proposes a boiler peak shaving coal blending device. The coal blending device includes a coal bunker body 1 with a feed inlet at the top. At the bottom end of the coal bunker body 1, there are a first coal hopper 2 and a second coal hopper 3. In addition, the coal blending device further includes a first coal feeder (not shown in the attached drawing), a second coal feeder 4, and a coal feeder platform 5. The first coal feeder can connect the first coal hopper 2 with an adjacent boiler coal bunker. The second coal feeder 4 can connect the second coal hopper 3 with an adjacent boiler coal bunker 10. The coal feeder platform 5 can be used to support the first coal feeder and the second coal feeder 4. There is a first slide gate between the first coal feeder and the first coal hopper 2, and a second slide gate between the second coal feeder 4 and the second coal hopper 3. By setting the first coal hopper 2 and the second coal hopper 3, coal blending of different loads can be realized. By setting the first coal feeder and the second coal feeder 4, the transportation of the stored coal between the adjacent boiler coal bunkers 10 can be realized, and thus the rapid and flexible allocation of coal quality can be carried out according to the changes in the unit load and combustion conditions, so as to meet the requirements for the peak shaving capacity and load response speed of two coal-fired power generation units under the peak shaving operation mode. By setting the first slide gate and the second slide gate, the coal dropping and shut-off of the coal feeder can be controlled respectively to meet the requirements of boiler combustion, further improving the coal combustion efficiency. Through this device, flexible two-way coal distribution can be realized, providing different types of raw coal for different working conditions of the unit, greatly meeting the need for rapid response to load and improving the flexibility of the unit.

[0037] In this application, please refer to Figure 2. The filler in the coal bunker body 1 is high calorific value coal quality, while the filler in the adjacent boiler coal bunker 10 is low calorific value coal quality. The transmission of different types of coal quality is realized through the first coal feeder and the second coal feeder 4. When the boiler units are all at full load, start the first coal feeder and the second coal feeder 4 to use high calorific value coal quality to ensure the load-carrying capacity of the unit. When the boiler units are all operating at medium and low loads, stop the first coal feeder and the second coal feeder, and operate the original coal bunker 10 to store the low calorific value coal pulverizing system to ensure the demand for burning low calorific value coal under the low load operation condition of the unit and reduce the production and operation cost.

[0038] Preferably, the weights of the first coal hopper 2 and the second coal hopper 3 are equal. By making their weights equal, the stress balance at both ends of the coal bunker body 1 is ensured, avoiding the inclination or damage of the coal bunker body caused by uneven stress, improving the stability and service life of the entire coal blending device. In addition, the equal-weight coal hoppers are also helpful for achieving more uniform coal blending, further enhancing the coal combustion efficiency and the stability of boiler operation.

[0039] Further, please refer to Figure 2As shown, the second coal hopper 3 is equipped with multiple dredging devices 6 along its height. These dredging devices 6 effectively prevent coal from becoming clogged or accumulating within the second coal hopper 3, ensuring smooth coal flow. These dredging devices can promptly clear coal blockages, ensuring the proper functioning of the coal hopper and improving the continuity and stability of coal blending. Preferably, the dredging device 6 is an air cannon or an air hammer. In this application, the air cannon uses the impact force generated by the instantaneous release of high-pressure air to effectively break up clogged coal and restore its flow; the air hammer, on the other hand, vibrates the coal through periodic striking action, preventing it from sticking together due to prolonged static conditions. Both dredging devices have the advantages of simple structure, easy operation, and low maintenance costs, and have demonstrated excellent dredging effects in actual applications. In addition, depending on the different coal quality characteristics and operating environment, operators can flexibly choose to use either the air cannon or the air hammer, or alternate between the two, to achieve the optimal dredging effect.

[0040] Further, see Figure 1 As shown, a transition bin 7 is provided between the coal bunker body 1 and the first and second coal hoppers 2 and 3. This transition bin 7 allows coal from the coal bunker body 1 to flow into the adjacent pulverizing system. This design not only makes coal distribution more flexible but also ensures uniformity during the distribution process, avoiding unstable combustion caused by uneven coal distribution. Furthermore, the transition bin 7 acts as a buffer, reducing the direct impact of coal on the coal hoppers and extending their service life.

[0041] Preferably, the first coal hopper 2 and the second coal hopper 3 are respectively welded to the inner wall of the transition bin 7. This welding connection not only improves the connection strength between the coal hopper and the transition bin 7, ensuring structural stability and safety, but also avoids coal leakage caused by loose or detached connections. This connection method offers the advantages of simple processing, low cost, and reliable connection, making it suitable for various working conditions and environments. Furthermore, the welding connection reduces the gap between the coal hopper and the transition bin 7, further improving the sealing and storage efficiency of the coal.

[0042] Further, see Figure 1 As shown, a reinforcing rib 8 is provided between the coal bunker body 1 and the transition bin 7. The provision of the reinforcing rib 8 can further improve the connection strength and stability between the coal bunker body 1 and the transition bin 7, and prevent structural deformation or damage caused by excessive coal weight or vibration during operation.

[0043] Preferably, the connecting end of the transition bin 7 with the main body of the coal bin 1 is circular, and the connecting ends of the transition bin 7 with the first coal hopper 2 and the second coal hopper 3 are square. By setting the transition bin 7 to a structure similar to the round sky and square earth, the occurrence of coal blockage is effectively prevented. Of course, in this application, according to the actual situation and specific requirements, the structure of the transition bin 7 can also be set to other structures, which is not uniquely limited here.

[0044] Preferably, the first coal feeder and the second coal feeder 4 are respectively connected to the DCS system of the power plant. During actual operation, operators can remotely control and monitor the first coal feeder and the second coal feeder 4 through the DCS system. The DCS system can collect the operation data of the coal feeder in real time, such as the coal feeding amount, motor current, etc., and automatically adjust the operation parameters of the coal feeder according to the changes in the unit load and combustion conditions, so as to realize the rapid and flexible allocation of coal quality. This automatic control method greatly improves the operation efficiency of the co-firing device, realizes the rapid and flexible allocation of coal quality, and improves the unit peak shaving ability and load response speed.

[0045] Furthermore, an observation window 9 is provided on the first coal hopper 2 and / or the second coal hopper 3. By setting the observation window 9, the remaining amounts of coal lumps, coal slime, and sludge in the inner cavities of the first coal hopper 2 and / or the second coal hopper 3 can be observed in real time through the observation window 9, which is convenient for timely replenishment.

[0046] This application also discloses a control method for boiler peak shaving coal co-firing, which uses a boiler peak shaving coal co-firing device as described in any one of the above, and includes the following steps:

[0047] S01: Real-time monitor the load demands of the boiler unit and the power grid;

[0048] S02: Obtain the load demand parameters of the boiler unit and the power grid through the DCS system, control the coal feeding amounts, motor currents of the first coal feeder and the second coal feeder, and control the operation modes in the first coal hopper 2 and the second coal hopper 3, so as to realize the rapid response to the load demands of the boiler unit and the power grid synchronously.

[0049] In this application, through the above control method, precise control of the boiler coal co-firing process can be achieved. After the load demands of the boiler unit and the power grid are monitored in real time, the DCS system can respond quickly, and by adjusting the coal feeding amounts and motor currents of the coal feeders, the types of boiler combustion co-firing can be realized, ensuring the stability and efficiency of boiler combustion. This control method not only improves the utilization rate of coal, but also significantly enhances the unit peak shaving ability and load response speed, enabling the coal-fired power unit to better adapt to the dispatching requirements of the power grid and improving the stability and reliability of the entire power system.

[0050] In addition, through the integrated control of the DCS system, remote monitoring and automatic regulation of the coal blending combustion process are realized, greatly reducing the labor intensity of operators and improving work efficiency. At the same time, the device and method also have good adaptability and flexibility, and can be flexibly adjusted according to different coal quality characteristics and operating environments to meet the coal blending combustion requirements under various working conditions.

[0051] Further, the step SO2 includes:

[0052] When the DCS system monitors that the boiler units are all at full load, at this time, the high-calorific-value coal stored in the first coal bunker 2 and the second coal bunker 3 is used; and the motor current of the first coal feeder and the second coal feeder 4 is started to increase the coal feeding amount to ensure the load-carrying capacity of the unit.

[0053] When the DCS system monitors that the boiler units are all operating at medium and low loads, at this time, the coal feeding of the first coal feeder and the second coal feeder 4 is stopped, and the original pulverized coal system for storing low-calorific-value coal is operated to ensure the demand for burning low-calorific-value coal under the low-load operating conditions of the unit.

[0054] In this application, the preset conditions are determined comprehensively according to factors such as the current combustion efficiency, emission indexes, and coal quality characteristics of the boiler units. For example, when the combustion efficiency of the boiler units is low or the emission indexes exceed the standard, the DCS system can automatically adjust the coal type and coal feeding amount to improve the combustion efficiency and reduce emissions; when the coal quality characteristics change, such as the content of volatile matter, ash, moisture, etc. in the coal changes, the DCS system can also make corresponding adjustments according to the preset conditions to ensure the stable operation and efficient combustion of the boiler.

[0055] In this application, the DCS control system can monitor the load status of the boiler units, the coal quality type in the coal bunkers, and the operating status of the coal feeders in real time. The system automatically adjusts the motor current of the coal feeders, thereby accurately controlling the coal feeding amount of the boiler units to ensure that the two boiler units can operate stably under different load states and realize the efficient coal blending combustion at the same time.

[0056] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention and are not restrictive. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. A boiler peak shaving coal blending device, characterized in that, It includes a coal bunker body with a feed inlet at the top, a first coal hopper and a second coal hopper arranged at the bottom end of the coal bunker body, a first coal feeder and a second coal feeder for respectively connecting the first coal hopper and the second coal hopper with adjacent boiler coal bunkers to convey different coal qualities, and a coal feeder platform for supporting the second coal feeder. A first sluice gate for adjusting the coal feeding amount is arranged between the first coal feeder and the first coal hopper, and a second sluice gate for adjusting the coal feeding amount is arranged between the second coal feeder and the second coal hopper.

2. The peak shaving coal blending combustion device for boilers according to claim 1, wherein The stored coal weights of the first coal hopper and the second coal hopper are equal.

3. A boiler peak shaving coal blending combustion device according to claim 1, characterized in that, A plurality of dredging devices for dredging coal materials are arranged at intervals along the height direction of the second coal hopper.

4. The boiler peak shaving coal blending combustion device according to claim 3, characterized in that The dredging device is any one of an air cannon and an air hammer.

5. A boiler peak shaving coal blending combustion device according to claim 1, characterized in that, A transition bin is arranged between the coal bunker body and the first coal hopper and the second coal hopper.

6. The boiler peak shaving coal blending combustion device according to claim 5, characterized in that, The first coal hopper and the second coal hopper are respectively welded to the inner wall of the transition bin.

7. A boiler peak shaving coal blending combustion device according to claim 5, characterized in that, Reinforcing ribs are arranged between the coal bunker body and the transition bin.

8. A boiler peak shaving coal blending combustion device according to claim 5, characterized in that, The connection end of the transition bin with the coal bunker body is circular, and the connection ends of the transition bin with the first coal hopper and the second coal hopper are square.

9. A control method for peak shaving coal blending combustion in a boiler, characterized in that, Using a boiler peak shaving coal blending combustion device according to any one of claims 1 to 8, it includes the following steps: S01: Real-time monitor the load demands of the boiler unit and the power grid. S02: Obtain the load demand parameters of the boiler unit and the power grid through the DCS system, control the coal feeding amounts, motor currents of the first coal feeder and the second coal feeder, and control the operation modes in the first coal hopper and the second coal hopper to achieve a rapid response to the load demands of the boiler unit and the power grid.

10. A boiler peak shaving coal blending combustion device according to claim 9, characterized in that, The step S02 includes: When the DCS system monitors that both boiler units are in rapid load increase or full load, at this time, use the high calorific value coal stored in the first coal hopper and the second coal hopper; and increase the coal feeding amount by starting the motor currents of the first coal feeder and the second coal feeder to ensure the load carrying capacity of the unit. When the DCS system monitors that both boiler units are in medium and low load operation, at this time, stop the coal feeding amount conveyance of the first coal feeder and the second coal feeder, and operate the original pulverized coal system storing low calorific value coal to ensure the demand for burning low calorific value coal under the low load operation condition of the unit.

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