Load adjusting system of coal-fired unit

Abstract

The utility model relates to a coal-fired unit load adjusting system. The coal-fired unit load adjusting system comprises a coal mill unit and a load adjusting device, wherein the coal mill unit comprises a first type of coal mills and a second type of coal mills; the pulverized coal burner group comprises a first type of pulverized coal burners and a second type of pulverized coal burners, the first type of pulverized coal burners correspond to and are communicated with the first type of coal mills, the second type of pulverized coal burners correspond to and are communicated with the second type of coal mills, and a second type of pulverized coal pipeline is provided with an adjusting turn-off device; a powder-containing burner; and the pulverized coal classifier is connected to the second-class coal mill through a second-class pulverized coal pipeline, and is connected to the pulverized coal-containing burner, the first-class pulverized coal burner and the second-class pulverized coal burner through the second-class pulverized coal pipeline, so that pulverized coal is controllably conveyed in a working state. In this way, the load of the coal-fired unit can be rapidly adjusted.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of energy technology especially relates to coal-fired unit load regulating system. BACKGROUND

[0002] The coal-fired unit is a kind of power generation equipment using coal as fuel, it generates heat energy by burning coal, and then converts into electric energy.The coal-fired unit is the most common type in thermal power plant.The coal powder conveyor is a kind of equipment for conveying coal powder from one place to another.Coal powder is fine powder material produced in the process of crushing and grinding coal, commonly used in the field of fuel supply of power plant, raw material of industrial production, etc.

[0003] In the process of participating in peak regulation operation of thermal coal-fired unit, there are many problems such as difficult rapid rise of unit load.According to the "two rules" standard of State Grid, on the one hand, the boiler can reduce load, and on the other hand, it can quickly rise to rated load, to realize the goal of "sharp peak can be topped, low valley can be pressed, and operation can be stabilized".But the biggest obstacle to realize "sharp peak can be topped" is that the thermal load of unit cannot rise rapidly, that is, the load cannot rise rapidly, that is, the boiler load "does not come up" in a very short time, the main reason is that the required coal powder cannot be supplied quickly.When the boiler rises from 30% and below load to 100% load, the stopped coal mill needs to be restarted, which takes a long time, the coal mill cannot follow the speed of coal powder, and the boiler has not enough coal powder to burn, which directly affects the rapid rise of unit load.

[0004] In addition, the coal powder conveyor adopts chain wheel and chain transmission to drive the coal powder to advance in the process of use, and the coal dust is easy to adhere to the surface of chain wheel and chain, which causes the coal dust to be caked under the extrusion of chain wheel and chain, cannot be cleaned in time, is easy to cause the chain wheel and chain to slip, causes the coal powder conveying efficiency to decline, and further affects the rapid climbing and regulation of load of coal-fired unit, causes the unit load response rate to be poor.For example, the coal powder conveyor disclosed in authorization announcement No.CN217229026U sets up conveying assembly that can use relatively closed space to avoid the falling of coal powder material, to prevent the environment health from being damaged and protect the health of staff in the area, but the coal dust is easy to adhere to the surface of chain wheel and chain, which affects the coal powder conveying efficiency.

[0005] Therefore, a coal-fired unit load regulating system is needed to at least partially solve the problems in the current technology. UTILITY MODEL CONTENT

[0006] The utility model aims at overcoming the shortcomings of prior art, and provides a coal-fired unit load regulating system.

[0007] According to a first aspect of the present application, a coal-fired unit load regulating system is disclosed. The coal-fired unit load regulating system comprises: a coal milling unit comprising a first type of coal mill and a second type of coal mill; a pulverized coal burner set disposed within a boiler of the coal-fired unit and comprising a first type of pulverized coal burner and a second type of pulverized coal burner, wherein the first type of pulverized coal burner corresponds to the first type of coal mill and is in communication via a first type of pulverized coal conduit, the second type of pulverized coal burner corresponds to the second type of coal mill and is in communication via a second type of pulverized coal conduit, and the second type of pulverized coal conduit is provided with a regulating shutoff device; a pulverized coal burner disposed within the boiler; and a pulverized coal classifier connected to at least one of the second type of coal mills via the second type of pulverized coal conduit, and connected to the pulverized coal burner, the first type of pulverized coal burner, and the second type of pulverized coal burner via the second type of pulverized coal conduit, respectively, to controllably deliver pulverized coal to at least one of the pulverized coal burner, one or more of the first type of pulverized coal burners, and one or more of the second type of pulverized coal burners in an operating state.

[0008] In some embodiments, the coal-fired unit load regulating system can further comprise: a pulverized coal storage bin connected to the pulverized coal classifier via at least one of the first type of pulverized coal conduit or the second type of pulverized coal conduit to receive pulverized coal from the pulverized coal classifier, and connected to the first type of pulverized coal burner and the second type of pulverized coal burner via the second type of pulverized coal conduit.

[0009] In some embodiments, the coal-fired unit load regulating system can further comprise: a pulverized coal conveyor disposed between the pulverized coal storage bin and the coal milling unit and adapted to deliver pulverized coal from the pulverized coal storage bin to the pulverized coal burner set.

[0010] In some embodiments, the coal powder conveyor can include a housing and a cleaning mechanism arranged inside the housing for cleaning the coal ash adhered to the coal powder conveying element, and a transmission mechanism arranged on one side of the housing for driving the coal powder conveyor to convey the coal powder, the cleaning mechanism includes an arc-shaped knife and a scraper, a reciprocating screw rod is arranged at the middle position of the housing, a driving block is arranged on the outer side of the reciprocating screw rod, a double-shaft electric push rod is arranged at one end of the driving block, a rubber seat is arranged at the elongated end of the double-shaft electric push rod, the arc-shaped knife is fixed to one end of the rubber seat through bolts, the scraper is installed below the driving block, the transmission mechanism includes a toothed belt wheel A, a driving motor A is arranged at one end of the housing, a driving roller is arranged at the rotating end of the driving motor A, the toothed belt wheel A is fixed to one end of the driving roller through bolts, a toothed belt A is arranged on the outer side of the toothed belt wheel A, a driven roller is arranged at one end of the toothed belt A, a toothed belt wheel B is arranged at one end of the driven roller, a toothed belt B is arranged on the outer side of the toothed belt wheel B, and one end of the toothed belt B is in transmission connection with the reciprocating screw rod.

[0011] In some embodiments, an adding mechanism is arranged above the housing for adding the coal powder to be conveyed, the adding mechanism includes an adding hopper, the adding hopper is welded to the upper side of the housing, a round rod is arranged on the inner wall of the adding hopper, and a driving motor B is arranged at one end of the round rod.

[0012] In some embodiments, a protective shell is arranged on the outer side of the driving motor B, and a dome is arranged above the protective shell.

[0013] In some embodiments, a plurality of material blocking inclined plates are arranged at the bottom of the housing, and a discharging baffle is arranged on the outer side of the housing.

[0014] In some embodiments, telescopic protective covers are arranged at both ends of the driving block, and a sliding rod is arranged at the top of the driving block.

[0015] In some embodiments, a box body is arranged below the driving block, a lifting block is arranged on the inner wall of the box body, and an arc-shaped plate spring is arranged inside the box body, and the lifting block is fixedly connected with the lifting block.

[0016] In some embodiments, a conveying belt is arranged on the outer side of the driving roller and the driven roller, and a plurality of shifting plates are arranged on the outer side of the conveying belt.

[0017] In summary, due to the adoption of the above technical scheme, the beneficial effects of the present application are:

[0018] The embodiment of the utility model can keep the running coal mill at high or maximum output when the boiler is running at low load, and store the excess qualified coal powder in the independent coal powder storage bin as a standby coal powder source.

[0019] The embodiment of the utility model can guarantee the requirement of the boiler from low load to high load or full load, solve the problem that the boiler load is difficult to quickly rise under the traditional mode due to long time of restarting the coal mill, and cannot meet the demand of the power grid load "peak", so that the boiler can timely respond to the load change of the power grid and better adapt to the requirement of the power grid peak regulation operation.

[0020] The embodiment of the utility model shortens the transition time of the boiler load from low to high, improves the boiler load response rate, enhances the flexibility and adaptability of the boiler in the power grid peak regulation, and helps to improve the stability and reliability of the entire power grid.

[0021] The system does not affect the normal operation of the unit at high load, and can quickly and stably switch the powder supply mode during the process of low load rising to high load, avoid the problems of unstable boiler combustion and reduced efficiency caused by rapid load change, ensure that the boiler can be operated efficiently, safely, stably and environmentally for a long time, prolong the service life of the boiler, and reduce the operation and maintenance cost.

[0022] The coal conveying device provided by the utility model drives the driven roller and the reciprocating screw rod to rotate under the transmission of the toothed belt wheel B and the toothed belt B by the driving motor A, drives the reciprocating screw rod to drive the scraper to scrape the coal ash adhered to the conveying belt, and the arc-shaped knife timely cleans the coal ash adhered to the outside of the driving roller and the driven roller, avoids the coal ash adhered to the surface of the sprocket and the chain, prevents the sprocket and the chain from slipping, guarantees the conveying efficiency of the coal conveying device, and provides support for rapid load adjustment. BRIEF DESCRIPTION OF DRAWINGS

[0023] These and other objects, features, and advantages will become apparent when read in conjunction with the following detailed description of exemplary embodiments, in which:

[0024] Figure 1 This diagram shows the system layout of a coal-fired power unit in the prior art;

[0025] Figure 2 A schematic diagram of a coal-fired power unit load regulation system according to an embodiment of the present invention is shown;

[0026] Figure 3 A schematic diagram of a coal-fired power unit load regulation system according to another embodiment of the present invention is shown;

[0027] Figure 4 A schematic diagram of the front view structure according to an embodiment of the present utility model is shown;

[0028] Figure 5 A rear view structural schematic diagram according to an embodiment of the present utility model is shown;

[0029] Figure 6 A schematic diagram of the assembly structure provided according to an embodiment of the present utility model is shown;

[0030] Figure 7 A partial structural schematic diagram according to an embodiment of the present utility model is shown;

[0031] Figure 8 The present invention provides an embodiment of the present invention. Figure 7 Schematic diagram of cross-section structure;

[0032] Figure 9 The present invention provides an embodiment of the present invention. Figure 8 A magnified schematic diagram of the structure at point A in the middle. Detailed Implementation

[0033] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of this invention. Therefore, the drawings and description are considered exemplary in nature and not restrictive.

[0034] In the utility model, unless otherwise expressly provided and limited, the first feature is "on" or "under" the second feature, which can include that the first and second features are in direct contact, or can include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the first feature "on", "above" and "on the surface of" the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "under", "below" and "under" the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature. In the context, the pulverized coal burner and the burner express the same or similar content.

[0035] As mentioned above, the current coal-fired unit is difficult to realize the unit load "peak top, low valley pressure down, and stable operation". The main problems are that the unit thermal load cannot be quickly increased, that is, the load climbing speed is slow, that the coal mill is restarted for a long time when the boiler is from low load to rated load, that the pulverizing speed cannot keep up, that the boiler has not enough coal powder to burn, and that the load rapid climbing is affected.

[0036] The utility model creatively puts forward that the excess qualified coal powder is stored in the independent coal powder storage bin as a backup when the low load operation is increased. When the low load is converted to high load rapid climbing, the standby coal powder in the storage bin is used instantly, so that the pulverizing speed is timely followed, the standby coal powder is directly sent into the furnace for combustion, the instantaneous powder feeding is realized when the boiler rapidly increases the load, the input heat is rapidly increased, and the load "peak" demand is met. The example embodiment of the utility model ensures the normal output of the coal mill when the low load operation is ensured, and the excess coal powder is stored in the independent coal powder storage bin. The standby coal powder source carries a small amount of powder-containing air, which is sent into the furnace for combustion through the pipeline and the newly added powder-containing air burner. When the full load operation is stopped, the powder-containing air and the burner are supplied. The passageway is installed on the coal powder pipeline at the outlet of the coal mill and the inlet pipeline of the burner, so that the coal powder is transported and adjusted in multiple paths. When the high load operation is directly burned through the pipeline, the standby coal powder in the storage bin is used instantly when the low load is rapidly climbed to the high load, and the standby coal powder outlet system is closed after the coal mill is fully operated, so that the rapid load increasing goal is achieved, the unit low valley is reduced, the peak is reached, and the unit load response rate is improved.

[0037] The embodiments of the utility model will be described in detail below with reference to the drawings.

[0038] Figure 1 The current coal-fired unit system layout is shown. Figure 1As shown, the coal-fired unit includes a plurality of coal mills connected to a boiler, wherein the boiler is provided with a plurality of pulverized coal burners, which can be arranged in layers to allow uniform combustion of the pulverized coal in the boiler. The plurality of coal mills can form a coal mill group, and the plurality of pulverized coal burners (labeled as layer A burner to layer F burner) form a pulverized coal burner group. It should be understood that although Figure 1 Six coal mills (labeled as coal mill A to coal mill F) and six layers of pulverized coal burners are shown in FIG. 6, but this is merely exemplary, and the coal-fired unit can also be provided with other suitable numbers of coal mills and pulverized coal burners. In Figure 1 In FIG. 6, each coal mill is connected to a pulverized coal burner in the boiler through an independent pulverized coal pipeline, ensuring that the pulverized coal can be effectively transported into the boiler for combustion. It should be understood that each burner in the A layer to the F layer burners can be a single burner or a collective term for a plurality of sub-burners.

[0039] In such a coal-fired unit, part of the unit needs to be shut down at low load, and when it is necessary to climb to high load or even full load, the start-up time of the shut-down coal mills and burners is long, and when it is necessary to quickly adjust the load, multiple burners can be difficult to adjust synchronously, resulting in slow response speed and affecting the peak shaving ability of the unit. Moreover, such a unit does not have a high-efficiency pulverized coal conveyor, and if the pulverized coal pipeline is not reasonably designed or is aged, it can cause loss of pulverized coal during transportation, reduce the transportation efficiency, and further affect the rapid adjustment of the load of the unit.

[0040] In one embodiment, taking six coal mills (A / B / C / D / E / F) as an example, when the boiler is running at full load, five or six coal mills are usually required to run simultaneously to meet the coal consumption of the boiler. However, after low-load flexibility modification, only 2 or 3 coal mills need to be running when the boiler is running at 30% and below. This design allows energy consumption to be reduced and equipment wear to be reduced at low load.

[0041] However, this design has obvious shortcomings when the boiler needs to quickly rise from 30% and below to 100% load. The main problem is that the coal grinding capacity of the 2 or 3 coal mills running alone cannot meet the coal consumption required for 100% load. In order to meet the demand for full-load operation, other stopped coal mills must be started. This process takes a long time because the start-up and normal operation of the coal mills require gradual increase of coal quantity and adjustment of the operating parameters of the coal mills, which results in the inability to meet the requirement of immediate and rapid load increase. In addition, the system transports the pulverized coal through a pulverized coal pipeline, and the transportation efficiency cannot be guaranteed.

[0042] Referring to Figure 2 and Figure 3The coal-fired unit load rapid regulating system comprises a coal mill unit, a pulverized coal burner group, a pulverized coal burner, a pulverized coal classifier, a pulverized coal storage bin and a pulverized coal conveyor. Each component is connected through a pulverized coal pipeline for conveying pulverized coal. The coal mill unit is composed of a first type of coal mill and a second type of coal mill, and is responsible for producing pulverized coal suitable for boiler combustion. The pulverized coal burner group can be arranged in layers in the boiler and comprises a first type of pulverized coal burner connected to the first type of coal mill and a second type of pulverized coal burner connected to the second type of coal mill. Specifically, the first type of coal mill is in one-to-one correspondence with the first type of pulverized coal burner and is connected through a first type of pulverized coal pipeline. The first type of pulverized coal pipeline can be a pulverized coal pipeline as shown in FIG. 1 or any other suitable pulverized coal pipeline in the art, and the utility model does not make any limitation in this regard. Figure 1

[0043] Further, the second type of coal mill is in one-to-one correspondence with the second type of pulverized coal burner and is connected through a second type of pulverized coal pipeline. The second type of pulverized coal pipeline can be a pulverized coal pipeline with an adjusting and shutting device mounted thereon, allowing accurate control of the flow of pulverized coal, including shutting operation, opening operation and flow control operation. In addition, the pipeline part of the second type of pulverized coal pipeline can be the same as the pulverized coal pipeline as shown in FIG. 2 or any other suitable pulverized coal pipeline in the art, and the utility model does not make any limitation in this regard. Figure 1

[0044] In one embodiment, the pulverized coal burner can be directly installed inside the boiler for direct combustion of pulverized coal under certain working conditions. The pulverized coal classifier is connected to the second type of coal mill and conveys the pulverized coal to the pulverized coal burner, the first type of pulverized coal burner and the second type of pulverized coal burner through the second type of pulverized coal pipeline, realizing controlled distribution of the pulverized coal. That is, the pulverized coal classifier can receive part of the pulverized coal from the first type of coal mill as a branch for standby use. When running at low load, the system can reduce the number of coal mills in operation, and when it is necessary to rapidly increase the load, the pulverized coal can be rapidly supplemented through the pulverized coal storage bin connected to the pulverized coal classifier through the first type of pulverized coal pipeline or the second type of pulverized coal pipeline and further connected to the pulverized coal burner group.

[0045] In one embodiment, the position of the adjusting and shutting device on the second type of pulverized coal pipeline is adjustable. For example, the adjusting and shutting device on the second type of pulverized coal pipeline connected to the second type of coal mill and the second type of pulverized coal burner can be arranged in parallel with the adjusting and shutting device on the pulverized coal classifier, thereby forming a "three-way" to realize accurate adjustment of the pulverized coal conveying. In other embodiments, the adjusting and shutting device can also be arranged at any other suitable position as long as it can achieve the corresponding technical effect, and the utility model does not make any limitation in this regard.

[0046] ​​In one embodiment, a pulverized coal conveyor is positioned between the pulverized coal storage bin and the coal mill unit, acting as a bridge to ensure efficient delivery of pulverized coal from the storage bin to the burner group. The pulverized coal conveyor can be connected to the pulverized coal storage bin via either a first-type or a second-type pulverized coal pipeline; this invention does not impose any limitations on this. In a preferred embodiment, the pulverized coal conveyor is connected to the pulverized coal burner group via a second-type pulverized coal pipeline. It can be directly connected to each burner in the pulverized coal burner group, or it can be connected to the corresponding pulverized coal pipeline connecting the pulverized coal burner group and the coal mill unit; this invention also does not impose any limitations on this. This optimizes its pulverized coal delivery efficiency, enabling it to better adapt to the rapid load adjustment requirements of coal-fired power units. The following will combine... Figures 4 to 9 A more detailed explanation of the specific implementation of the pulverized coal conveyor is provided.

[0047] The following text combines Figure 2 and Figure 3 Specific embodiments of this utility model are described below. Figure 2 A schematic diagram of a coal-fired power unit load regulation system according to an embodiment of the present invention is shown, and Figure 3 A schematic diagram of a coal-fired power unit load regulation system according to another embodiment of the present invention is shown.

[0048] like Figure 2 As shown, after the boiler underwent low-load flexibility modification, two mills were operated at 30% load or below. Figure 2 The example assumes that the two mills are A / B, but they could be any other two mills. Mills C / D / E / F need to be shut down. For example... Figure 2As shown, the coal-fired unit only operates A / B coal mill at low load, and the coal consumption is reduced at low load. The A / B coal mill does not need to operate at maximum output, but the embodiment of the utility model can still make the A / B coal mill operate at maximum output at low load. Under the premise of ensuring the required amount of pulverized coal for low load operation of the boiler, the excess ground qualified pulverized coal is directly stored in the independent pulverized coal storage bin as a standby pulverized coal source for "rapid powder feeding". That is, a tee joint can be additionally installed on the pulverized coal pipeline at the outlet of the A coal mill and the B coal mill. A part of the ground qualified pulverized coal is input into the boiler through the pulverized coal pipeline, and a part of the pulverized coal enters the pulverized coal classifier. The first adjusting and shutting device 1, the second adjusting and shutting device 2, the third adjusting and shutting device 3, and the fourth adjusting and shutting device 4 are arranged at each outlet respectively, and the amount of pulverized coal entering each branch is adjusted and controlled through the first adjusting and shutting device 1, the second adjusting and shutting device 2, the third adjusting and shutting device 3, and the fourth adjusting and shutting device 4. The standby pulverized coal passing through the pulverized coal classifier enters the independent pulverized coal storage bin in one way, and enters the newly added pulverized coal burner through the pipeline in another way, and is sent into the furnace for combustion. The amount of the pulverized coal is controlled through the fifth adjusting and shutting device 5. Once the unit is required to be low load and to be upgraded to high load for "rapid climbing", the standby pulverized coal which has been ground in the pulverized coal storage bin is immediately and instantaneously used rapidly. The pulverized coal is directly sent into the pulverized coal burner through the tee joint at the inlet of the pulverized coal pipeline of the burner, and is sent into the furnace for combustion. The amount of the pulverized coal entering the furnace is adjusted through the sixth adjusting and shutting device 6, the seventh adjusting and shutting device 7, the eighth adjusting and shutting device 8, the ninth adjusting and shutting device 9, the tenth adjusting and shutting device 10, and the eleventh adjusting and shutting device 11. After the coal mill is "fully started" and operates at full output, the sixth adjusting and shutting device 6, the seventh adjusting and shutting device 7, the eighth adjusting and shutting device 8, the ninth adjusting and shutting device 9, the tenth adjusting and shutting device 10, and the eleventh adjusting and shutting device 11 are immediately shut down, the delivery of the standby pulverized coal is stopped, and the goal of "instant powder feeding" during the rapid load upgrade of the boiler is achieved. The system does not affect the normal operation of the unit at high load. When the unit operates at high load, the pulverized coal at the outlet of the boiler coal mill is directly sent into the burner through the pulverized coal pipeline, and is sent into the furnace for combustion. The first adjusting and shutting device 1 and the third adjusting and shutting device 3 are opened, and the second adjusting and shutting device 2, the fourth adjusting and shutting device 4, the fifth adjusting and shutting device 5, the sixth adjusting and shutting device 6, the seventh adjusting and shutting device 7, the eighth adjusting and shutting device 8, the ninth adjusting and shutting device 9, the tenth adjusting and shutting device 10, and the eleventh adjusting and shutting device 11 are all closed, and the newly added pulverized coal burner is stopped.

[0049] As Figure 3 shown, three mills are operated when the boiler is operated at 30% and below load after low load flexibility modification, Figure 3 assuming that the A / B / C coal mills, or other any three mills, the D / E / F coal mills need to be stopped. As Figure 3As shown, only A / B / C coal mills are put into operation at low load, the coal consumption is reduced at low load, and the A / B / C coal mills do not need to be operated at maximum output. The utility model still makes the A / B / C coal mills operate at maximum output at low load, and the excess ground qualified coal powder is directly stored in the independent coal powder storage bin as a standby coal powder source for "quick powder feeding" under the premise of ensuring the required coal powder amount for low load operation of the boiler. That is, a tee joint is additionally arranged on the coal powder pipeline at the outlet of each of the coal mills A / B / C, a part of the ground qualified coal powder is input into the boiler through the coal powder pipeline, and a part of the coal powder enters the coal powder classifier. The first adjusting and shutting device 1, the second adjusting and shutting device 2, the third adjusting and shutting device 3, the fourth adjusting and shutting device 4, the fifth adjusting and shutting device 5, and the sixth adjusting and shutting device 6 are arranged at each outlet respectively, and the amount of the coal powder entering each branch is adjusted and controlled through the first adjusting and shutting device 1, the second adjusting and shutting device 2, the third adjusting and shutting device 3, the fourth adjusting and shutting device 4, the fifth adjusting and shutting device 5, and the sixth adjusting and shutting device 6. The standby coal powder passing through the coal powder classifier enters the independent coal powder storage bin in one way and is carried by a small amount of powder-containing air to enter the newly added powder-containing burner through the pipeline and is sent into the furnace for combustion in another way. The amount of the small amount of powder-containing air is controlled through the seventh adjusting and shutting device 7. Once the unit is required to be upgraded from low load to high load "quickly", the standby coal powder which has been ground in the coal powder storage bin is immediately and instantaneously fed into the coal powder burner through the coal powder feeder and is sent into the furnace for combustion through the tee joint at the inlet of the coal powder pipeline of the burner. The amount of the coal powder entering the furnace is adjusted through the eighth adjusting and shutting device 8, the ninth adjusting and shutting device 9, the tenth adjusting and shutting device 10, the eleventh adjusting and shutting device 11, the twelfth adjusting and shutting device 12, and the thirteenth adjusting and shutting device 13. After the coal mills are "all started" and operate at full load, the eighth adjusting and shutting device 8, the ninth adjusting and shutting device 9, the tenth adjusting and shutting device 10, the eleventh adjusting and shutting device 11, the twelfth adjusting and shutting device 12, and the thirteenth adjusting and shutting device 13 are immediately shut down, and the standby coal powder is stopped from being fed, thereby achieving the goal of "instant powder feeding" when the boiler is quickly upgraded in load. The system does not affect the normal operation of the unit at high load. When the unit is normally operated at high load, the coal powder at the outlet of the boiler coal mill is directly fed into the burner through the coal powder pipeline and is sent into the furnace for combustion. The first adjusting and shutting device 1, the third adjusting and shutting device 3, and the fifth adjusting and shutting device 5 are opened, and the second adjusting and shutting device 2, the fourth adjusting and shutting device 4, the sixth adjusting and shutting device 6, the seventh adjusting and shutting device 7, the eighth adjusting and shutting device 8, the ninth adjusting and shutting device 9, the tenth adjusting and shutting device 10, the eleventh adjusting and shutting device 11, the twelfth adjusting and shutting device 12, and the thirteenth adjusting and shutting device 13 are all closed, and the newly added powder-containing burner is stopped.

[0050] In this way, the coal-fired unit will still ensure normal output operation of the coal mill when the boiler is running at low load. Under the premise of ensuring the amount of pulverized coal required for low load operation of the boiler, the excess qualified coal powder ground by the running coal mill will be directly stored in the independent coal powder storage bin as a "quick powder feeding" standby coal powder source. The trace amount of powder-containing air entrained by the standby coal powder source is sent into the furnace through the pipeline and the newly added powder-containing air burner. When the boiler is running at full load, the trace amount of powder-containing air entrained by the standby coal powder source stops being supplied, and the powder-containing air burner stops running.

[0051] A "T-shaped pipe" is designed and installed on the coal mill outlet pulverized coal pipeline and the burner inlet pipeline, i.e., the coal mill outlet pulverized coal pipeline is "changed from one to two". One route directly passes through the burner to be sent into the furnace for combustion; one route enters the coal powder classifier and then one route enters the independent coal powder storage bin, and one route enters the pipeline to be sent into the furnace for combustion through the newly added powder-containing burner. The burner inlet pulverized coal pipeline is "changed from two to one". By setting an adjusting and shutting device on the pulverized coal pipeline, the coal powder from different routes is controlled to be injected into the furnace for combustion through the burner. When the unit is running at high load, the boiler coal mill outlet pulverized coal directly enters the pulverized coal pipeline to be sent into the furnace for combustion through the burners of each layer. When the unit is running at low load and climbing to high load "quickly", the standby coal powder already ground in the coal powder storage bin is immediately and instantaneously used quickly, which is directly sent into the pulverized coal pipeline through the coal powder conveyor to be sent into the furnace for combustion through the pulverized coal burners of each layer. After the coal mill is "started completely" and runs at full load, the standby coal powder outlet system on the burner inlet pipeline is immediately shut off, thereby achieving the goal of "instant powder feeding" and rapid increase of boiler input heat when the boiler is climbing to high load quickly.

[0052] In order to further improve the speed of "instant powder feeding" and rapid increase of boiler input heat when the boiler is climbing to high load quickly, for example, Figure 4 , Figures 5 to 9As shown, a coal powder conveyor is provided.The coal powder conveyor comprises a shell 100 and a cleaning mechanism arranged inside the shell 100, which is used for cleaning the coal ash adhered to the coal powder conveying element, and a transmission mechanism arranged at one side of the shell 100, which is used for driving the coal powder conveyor to convey the coal powder. The cleaning mechanism comprises an arc-shaped cutter 105 and a scraper 106. A reciprocating screw rod 101 is rotatably connected to the middle position of the shell 100. A driving block 102 is drivingly connected to the outer side of the reciprocating screw rod 101. The reciprocating screw rod 101 drives the driving block 102 to reciprocate, thereby driving the arc-shaped cutter 105 and the scraper 106 to reciprocate, so as to scrape off the coal powder adhered to the conveying belt 400, the driving roller 202 and the driven roller 205. The both ends of the driving block 102 are fixedly provided with telescopic protective covers 110 through bolts. The telescopic protective covers 110 prevent the coal powder from entering between the reciprocating screw rod 101 and the driving block 102. A slide rod 120 is slidingly connected to the top of the driving block 102. A double-shaft electric push rod 103 is fixedly arranged at one end of the driving block 102 through a bolt. A rubber base 104 is fixedly arranged at the elongated end of the double-shaft electric push rod 103 through a bolt. The arc-shaped cutter 105 is fixedly arranged at one end of the rubber base 104 through a bolt. The double-shaft electric push rod 103 drives the arc-shaped cutter 105 to tightly adhere to the outer surface of the driving roller 202 and the driven roller 205. The scraper 106 is arranged below the driving block 102. A plurality of material blocking inclined plates 200 are fixedly arranged at the bottom of the shell 100 through bolts. A discharging baffle 300 is slidingly connected to the outer side of the shell 100. The material blocking inclined plates 200 gather the scraped coal powder, which is discharged from the coal powder conveyor through the discharging baffle 300. A box body 130 is welded below the driving block 102. A lifting block 140 is slidingly connected to the inner wall of the box body 130. An arc-shaped plate spring 150 is fixedly arranged in the box body 130 through a bolt. The arc-shaped plate spring 150 elastically presses the scraper 106, so as to ensure the tightness of the scraper 106 and the conveying belt 400. The lifting block 140 is fixedly connected with the lifting block 140. The transmission mechanism comprises a toothed belt wheel A 203. One end of the shell 100 is fixedly provided with a driving motor A 201 through a bolt. The rotating end of the driving motor A 201 is fixedly provided with the driving roller 202 through a bolt. The toothed belt wheel A 203 is fixedly arranged at one end of the driving roller 202 through a bolt. The outer side of the toothed belt wheel A 203 is drivingly connected with a toothed belt A 204. One end of the toothed belt A 204 is drivingly connected with the driven roller 205. The driving motor A 201 drives the toothed belt wheel A 203 to rotate through the driving roller 202. The toothed belt A 204 drives a plurality of driven rollers 205 to synchronously rotate. The outer sides of the driving roller 202 and the driven roller 205 are rotatably connected with the conveying belt 400. The outer side of the conveying belt 400 is fixedly provided with a plurality of push plates 500 through bolts. One end of the driven roller 205 is fixedly provided with a toothed belt wheel B 206 through a bolt. The outer side of the toothed belt wheel B 206 is drivingly connected with a toothed belt B 207. One end of the toothed belt B 207 is drivingly connected with the reciprocating screw rod 101. The toothed belt wheel B 206 and the toothed belt B 207 drive the driven roller 205 and the reciprocating screw rod 101 to be linked.

[0053] In the embodiment, the operator starts the driving motor A201, the driving motor A201 drives the driven roller 205 and the reciprocating screw rod 101 to rotate under the transmission of the toothed belt wheel B206 and the toothed belt B207, without external power source, which reduces the complexity of the pulverized coal conveying and cleaning mechanism, the driving motor A201 drives the conveyor belt 400 to rotate to convey the pulverized coal, meanwhile, the driving motor A201 drives the reciprocating screw rod 101 to drive the scraper 106 to scrape the coal ash adhered to the conveyor belt 400, the arc-shaped knife 105 timely cleans the coal ash adhered to the outer side of the driving roller 202 and the driven roller 205, which avoids the pulverized coal dust adhered to the surface of the chain wheel and the chain, the pulverized coal dust clumps, prevents the chain wheel and the chain from slipping, and ensures the conveying efficiency of the pulverized coal conveyor.

[0054] With reference to the above Figures 4 to 9 , the upper portion of the shell 100 of the pulverized coal conveyor is provided with an adding mechanism for adding the pulverized coal to be conveyed, the adding mechanism comprises an adding hopper 301 welded to the upper portion of the shell 100, the adding hopper 301 pours the coal ash to be conveyed into the shell 100, the inner wall of the adding hopper 301 is fixedly provided with a round rod 302 through bolts, one end of the round rod 302 is fixedly provided with a driving motor B303 through bolts, the outer side of the driving motor B303 is fixedly provided with a protective shell 310 through bolts, the protective shell 310 prevents dust from entering the driving motor B303, the upper portion of the protective shell 310 is fixedly provided with a dome 320 through bolts, the dome 320 prevents the protective shell 310 from shielding the pulverized coal, and the rotating end of the driving motor B303 is fixedly provided with a spiral blade 304 through bolts.

[0055] In the embodiment, the operator starts the driving motor B303, the driving motor B303 drives the spiral blade 304 to rotate along the adding hopper 301, which prevents the pulverized coal adding process from being blocked and ensures the discharging pressure of the pulverized coal.

[0056] The method comprises the following steps: when the boiler is in low-load operation, the second type of coal mill is put into operation, and the second type of coal mill is in high-power operation, a part of the ground coal is input into the second type of coal powder burner in the boiler through the coal powder pipeline, and another part of the coal powder enters the coal powder classifier; the adjusting and shutting devices are arranged on the coal powder pipeline at the outlet of the second type of coal mill respectively, and the amount of the coal powder is adjusted and controlled through the corresponding adjusting and shutting devices; the standby coal powder of the coal powder classifier enters the coal powder storage bin in one way, and the other way is that a small amount of the powder-containing air is carried into the powder-containing burner through the pipeline to be burned in the boiler furnace, and the amount of the small amount of the powder-containing air is controlled through the corresponding adjusting and shutting device; when the coal-fired unit needs to be rapidly lifted from low load to high load, the standby coal powder that has been ground in the coal powder storage bin is immediately and instantaneously used, the coal powder is sent into the first type of coal powder burner through the coal powder feeder, the coal powder is sent into the boiler for burning, the amount of the coal powder is adjusted through the corresponding adjusting and shutting device; after the coal mill unit is started and reaches full power operation, the corresponding adjusting and shutting device is shut off, the delivery of the standby coal powder to the second type of coal powder burner is stopped, and the target of instant powder feeding during rapid load increase of the boiler is achieved; when the unit is in high-load normal operation, the coal powder at the outlet of the boiler coal mill directly enters the burner group through the coal powder pipeline to be burned in the furnace, the adjusting and shutting device is completely closed, and the powder-containing burner is stopped.

[0057] Specifically, when the boiler is in low-load operation, the coal-fired unit load rapid regulation system puts the second type of coal mill into operation, and makes it in high-power operation state, effectively improves the coal powder yield. A part of the coal powder is directly input into the second type of coal powder burner in the boiler through the coal powder pipeline, which meets the basic burning demand, and another part of the coal powder enters the coal powder classifier. The adjusting and shutting devices arranged on the coal powder pipeline at the outlet of the second type of coal mill can accurately control the flow of the coal powder, and ensure the stable supply of the coal powder.

[0058] At the same time, the coal powder classifier guides part of the coal powder to the coal powder storage bin as a standby coal powder source. In addition, the coal powder classifier also allows a part of the coal powder to carry a small amount of powder-containing air through the pipeline into the powder-containing burner, and directly into the boiler furnace for burning, so as to control the delivery amount of the small amount of powder-containing air through the adjusting and shutting device, and further optimize the utilization efficiency of the coal powder.

[0059] When the coal-fired unit needs to be rapidly lifted from low load to high load, the system can immediately and rapidly use the standby coal powder that has been ground in the coal powder storage bin. Through the coal powder feeder, the coal powder is rapidly sent into the first type of coal powder burner inlet to achieve instant powder feeding, which meets the demand of rapid load increase of the boiler. After the coal mill unit is started and reaches full power operation, the system will shut off the corresponding adjusting and shutting device, stop the delivery of the standby coal powder to the second type of coal powder burner, and complete the target of instant powder feeding during rapid load increase of the boiler.

[0060] When the unit is in normal operation at high load, the coal powder from the outlet of the coal pulverizing unit directly enters the burner group through the coal powder pipeline and is fed into the furnace for combustion. At this time, all the regulating shutoff devices are in the closed state, and the powder-containing burners are also stopped, ensuring the stability and economy of the system.

[0061] In this way, the method not only improves the load regulation capability of the coal-fired unit, but also optimizes the distribution and combustion process of the coal powder, thereby quickly responding to changes in the load of the coal-fired unit. In addition, the system can reduce energy consumption and equipment wear and tear when operating at low load, and can quickly utilize the stored coal powder or increase the supply of coal powder through the regulating shutoff devices to achieve rapid response when the load needs to be quickly increased. This enables the coal-fired unit to more flexibly adapt to the demand of the power grid, improves the operation efficiency and economy, and maintains the stability of the operation.

[0062] In summary, the embodiments of the present utility model can maintain the high or maximum output operation of the running coal pulverizer when the boiler is operating at low load, and store the excess qualified coal powder in the independent coal powder storage bin as a standby coal powder source. When the unit is climbing from low load to high load, the standby coal powder is immediately used instantaneously and quickly, and is directly fed into the coal powder pipeline at the inlet of the burner through the coal powder conveyor, and is fed into the furnace for combustion. After the coal pulverizer is fully started and operates at full capacity, the delivery of the standby coal powder is immediately shut off, realizing the "instant" delivery of coal powder when the boiler load is rapidly increased, and avoiding the problem of slow load climbing caused by the restart of the coal pulverizer and the inability of the coal pulverizing speed to keep up with the load, so that the coal pulverizing speed can "keep up" with the load, and the coal powder can be "instantly" delivered when the boiler load is rapidly increased.

[0063] The embodiments of the present utility model ensure the demand of the boiler to rapidly climb from low load to high load or full load, solve the problem that the boiler load is difficult to rapidly increase under the traditional mode due to the long time consumption of the restart of the coal pulverizer, and make the boiler able to timely respond to the load change of the power grid and better adapt to the requirements of the power grid peak shaving operation.

[0064] The embodiments of the present utility model store the standby coal powder in advance, shorten the transition time of the boiler load from low to high, improve the boiler load response rate, enhance the flexibility and adaptability of the boiler in the power grid peak shaving, and help to improve the stability and reliability of the entire power grid. At the same time, through the control of the regulating shutoff devices, not only can the load of the coal-fired unit be rapidly increased, but also the descending rate of the load of the coal-fired unit can be effectively controlled.

[0065] The system does not affect normal operation of the unit at high load, and can quickly and smoothly switch the powder supply mode during the process of increasing the load from low to high, thereby avoiding problems such as unstable boiler combustion and reduced efficiency caused by rapid load change, and ensuring that the boiler can be operated efficiently, safely, stably and environmentally for a long time, prolonging the service life of the boiler and reducing operation and maintenance costs.

[0066] The coal conveying device provided by the utility model drives driven roller and reciprocating screw rod to rotate through the transmission of driving motor A, gear belt wheel B and toothed belt B, drives the reciprocating screw rod to drive the scraper to scrape off the coal ash adhered to the conveying belt, and the arc-shaped knife timely cleans the coal ash adhered to the outside of the driving roller and driven roller, avoids the adhesion of coal dust on the surface of the chain wheel and chain, prevents the chain wheel and chain from slipping, ensures the conveying efficiency of the coal conveying device, and thus provides support for rapid load adjustment. The coal conveying device provided by the utility model can also drive the spiral blade to rotate along the adding hopper through driving motor B, prevents the coal powder from being blocked during the adding process, ensures the discharging pressure of the coal powder, and further improves the conveying efficiency.

[0067] The above is only the preferred specific embodiment of the utility model, but the protection scope of the utility model is not limited to this, any skilled person in the art can make equivalent replacement or change according to the technical scheme and the utility model concept of the utility model within the technical range disclosed by the utility model, which should be covered in the protection scope of the utility model.

Claims

1. A load regulation system for a coal-fired power unit, characterized in that, include: Coal mill units include Class I coal mills and Class II coal mills; A pulverized coal burner group is installed in the boiler of a coal-fired unit and includes a first type of pulverized coal burner and a second type of pulverized coal burner. The first type of pulverized coal burner corresponds to a first type of coal mill and is connected via a first type of pulverized coal pipeline. The second type of pulverized coal burner corresponds to a second type of coal mill and is connected via a second type of pulverized coal pipeline. An adjustment and shut-off device is installed on the second type of pulverized coal pipeline. A pulverized coal burner is installed inside the boiler. as well as A pulverized coal separator is connected via a second type of pulverized coal pipeline to at least one of the second type of pulverized coal mills, and is also connected via a second type of pulverized coal pipeline to the pulverized coal burner, the first type of pulverized coal burner, and the second type of pulverized coal burner, respectively, to controllably deliver pulverized coal to at least one of the following in operation: the pulverized coal burner, one or more burners of the first type of pulverized coal burner, and one or more burners of the second type of pulverized coal burner.

2. The load regulation system for coal-fired power units according to claim 1, characterized in that, Also includes: A pulverized coal storage bin is connected to the pulverized coal separator via at least one of the first type of pulverized coal pipe or the second type of pulverized coal pipe to receive pulverized coal from the pulverized coal separator, and is connected to the first type of pulverized coal burner and the second type of pulverized coal burner via the second type of pulverized coal pipe.

3. The load regulation system for coal-fired power units according to claim 2, characterized in that, Also includes: A pulverized coal conveyor is disposed between the pulverized coal storage bin and the coal mill unit and is adapted to convey pulverized coal from the pulverized coal storage bin to the pulverized coal burner unit.

4. The load regulation system for coal-fired power units according to claim 3, characterized in that, The pulverized coal conveyor includes: Casing (100); A cleaning mechanism, located inside the housing (100), is used to clean coal ash adhering to the coal powder conveying elements. The cleaning mechanism includes an arc-shaped blade (105) and a scraper (106). A reciprocating screw (101) is located in the middle of the housing (100). A drive block (102) is located on the outer side of the reciprocating screw (101). A dual-axis electric actuator (103) is located at one end of the drive block (102). A rubber seat (104) is located at the extended end of the dual-axis electric actuator (103). The arc-shaped blade (105) is fixed to one end of the rubber seat (104) by bolts. The scraper (106) is installed below the drive block (102). A transmission mechanism is provided on one side of the housing (100) for driving the coal powder conveyor to convey coal powder. The transmission mechanism includes a toothed pulley A (203). A drive motor A (201) is provided at one end of the housing (100). A drive roller (202) is provided at the rotating end of the drive motor A (201). The toothed pulley A (203) is fixed to one end of the drive roller (202) by bolts. A toothed belt A (204) is provided on the outside of the toothed pulley A (203). A driven roller (205) is provided at one end of the toothed belt A (204). A toothed pulley B (206) is provided at one end of the driven roller (205). A toothed belt B (207) is provided on the outside of the toothed pulley B (206). One end of the toothed belt B (207) is connected to the reciprocating screw (101) for transmission.

5. The load regulation system for coal-fired power units according to claim 4, characterized in that, An adding mechanism is provided above the housing (100) for adding pulverized coal that needs to be conveyed; the adding mechanism includes an adding hopper (301), which is welded to the top of the housing (100). A round rod (302) is provided on the inner wall of the adding hopper (301), and a drive motor B (303) is provided at one end of the round rod (302). A spiral blade (304) is provided at the rotating end of the drive motor B (303).

6. The load regulation system for coal-fired power units according to claim 5, characterized in that, The drive motor B (303) is provided with a protective shell (310) on its outer side, and a dome (320) is provided on the top of the protective shell (310).

7. The load regulation system for coal-fired power units according to claim 4, characterized in that, The bottom of the housing (100) is provided with a plurality of baffles (200), and the outer side of the housing (100) is provided with a discharge baffle (300).

8. The load regulation system for coal-fired power units according to claim 4, characterized in that, The drive block (102) is provided with telescopic protective covers (110) at both ends, and a slide rod (120) is provided at the top of the drive block (102).

9. The load regulation system for a coal-fired power unit according to claim 4, characterized in that, A housing (130) is provided below the drive block (102), a lifting block (140) is provided on the inner wall of the housing (130), an arc-shaped leaf spring (150) is provided inside the housing (130), and the lifting block (140) is fixedly connected to the lifting block (140); and A conveyor belt (400) is provided on the outer side of the drive roller (202) and the driven roller (205), and a plurality of baffles (500) are provided on the outer side of the conveyor belt (400).

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