A boiler combustion optimization method, system and adjustment system based on an AGC mode

Abstract

The application discloses a boiler combustion optimization method and system based on an AGC mode and an adjusting system, and relates to the field of combustion control of thermal power plants. According to multiple influence factors and AGC instructions issued by a power grid, the related parameters of the boiler are adjusted until the rated load of the boiler combustion is kept within a first preset range. The scheme comprehensively uses multiple influence factors of the stable combustion capability during deep peak regulation obtained according to the combustion degree of a furnace to control the furnace air leakage rate, improve the drying output of a pulverizing system, adjust the secondary air distribution, improve the plasma combustion support, optimize the operation mode of the pulverizing system and the like, so that the minimum technical output of the boiler is reduced to 15% of the design output, the deep peak regulation capability range of the unit is effectively expanded, and the stability, safety and economy of the unit operation are ensured.

Description

Technical Field

[0001] This invention relates to the field of combustion control in thermal power plants, and in particular to a boiler combustion optimization method, system, and adjustment system based on AGC (Automatic Generative Control). Background Technology

[0002] Currently, coal-fired power units still account for a large proportion of my country's electricity market. Taking the Beijing-Tianjin-Tangshan region as an example, coal-fired power capacity accounts for 55% of the total installed capacity, while renewable energy generation is subject to seasonality and randomness. Due to their inherent characteristics, coal-fired power units cannot perform rapid start-up and shutdown for peak shaving. With the vigorous development of clean energy, the peak-valley difference rate of the power grid is increasing year by year. In order to absorb clean energy, the demand for the "deep peak shaving" capability of thermal power units in power grid dispatching is becoming increasingly prominent.

[0003] Deep peak shaving in thermal power plants faces a series of problems, such as poor combustion stability of boilers at low loads and the inability to operate normally due to low temperatures in the denitrification and ammonia injection systems. Moreover, during deep peak shaving, boiler operating parameters deviate significantly from design parameters, which places more stringent requirements on the stability, safety, and economy of unit operation.

[0004] Currently, the mainstream deep peak shaving methods are based on the boiler's own equipment usage methods, reducing the unit load to the minimum design technical output. Generally, deep peak shaving to 30-40% of the design output cannot meet the boiler's requirement for stable combustion without oil injection. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a boiler combustion optimization method, system and adjustment system based on AGC to address the shortcomings of the prior art.

[0006] The technical solution of the present invention to solve the above-mentioned technical problems is as follows:

[0007] A boiler combustion optimization method based on AGC includes:

[0008] S1, based on the degree of combustion in the furnace, obtains multiple influencing factors that affect the boiler's stable combustion capability during deep peak shaving;

[0009] S2, adjust the relevant parameters of the boiler based on multiple influencing factors and AGC instructions issued by the power grid;

[0010] S3, until the boiler combustion is maintained at the rated load within the first preset range.

[0011] The beneficial effects of this invention are as follows: This solution adjusts the relevant parameters of the boiler based on multiple influencing factors and AGC instructions issued by the power grid until the boiler combustion is maintained within the rated load of the first preset range. This solution comprehensively utilizes multiple influencing factors on the stable combustion capability during deep peak shaving obtained based on the degree of combustion in the furnace to control the furnace air leakage rate, improve the drying output of the pulverizing system, adjust the secondary air distribution, use plasma combustion assistance, and optimize the operation mode of the pulverizing system. This reduces the minimum technical output of the boiler to 15% of the design output, effectively expands the range of deep peak shaving capability of the unit, and ensures the stability, safety, and economy of the unit operation.

[0012] Furthermore, the multiple influencing factors include cold air leakage.

[0013] S2 specifically includes:

[0014] Adjust the cold air leakage rate using the first preset method;

[0015] Adjust the boiler load parameters according to the adjusted cold air leakage rate.

[0016] The beneficial effects of adopting the above-mentioned further scheme are: this scheme adjusts the boiler load parameters by regulating the cold air leakage, thereby enhancing in-furnace combustion, increasing radiant heat, and increasing the boiler load response capability.

[0017] Furthermore, the multiple influencing factors also include: secondary air distribution method;

[0018] S2 specifically includes:

[0019] The secondary air distribution method can be adjusted by adjusting the vertical or horizontal swing angle of the SOFA air burner nozzle.

[0020] Adjust the steam temperature deviation, flue gas deviation, and oxygen deviation on both sides of the boiler according to the adjusted secondary air distribution method.

[0021] The beneficial effects of adopting the above-mentioned further scheme are: by adjusting the steam temperature deviation, flue gas deviation and oxygen deviation on both sides of the boiler according to the adjusted secondary air distribution method, this scheme is conducive to stable combustion and keeps the flue gas temperature deviation, steam temperature deviation and oxygen deviation on both sides of the furnace outlet within the required range, effectively controlling the steam temperature deviation, flue gas deviation and oxygen deviation on both sides of the boiler.

[0022] To improve the combustion conditions inside the furnace, thereby stabilizing the main steam pressure, and to ensure that the rate of change of main steam pressure and steam temperature is relatively stable during boiler load increases and decreases, so that the boiler response speed meets the grid requirements.

[0023] Furthermore, the multiple influencing factors also include: plasma immersion time;

[0024] S2 specifically includes:

[0025] When the boiler's stable combustion load point is within the second preset range, the superheated steam flow parameters inside the boiler are adjusted by regulating the plasma injection time.

[0026] The beneficial effects of adopting the above-mentioned further scheme are: this scheme adjusts the superheated steam flow parameters in the boiler by adjusting the plasma input time, meets the minimum technical output requirements of the boiler, selects the best time to input the plasma device, and realizes the deep peak-shaving combustion control requirements of the boiler.

[0027] Furthermore, the multiple influencing factors also include coal powder fineness;

[0028] S2 specifically includes:

[0029] The boiler's stable combustion parameters can be adjusted by regulating the fineness of the pulverized coal.

[0030] The beneficial effects of adopting the above-mentioned further scheme are: this scheme adjusts the boiler's stable combustion capability parameters by adjusting the fineness of pulverized coal, thereby improving the boiler's stable combustion capability during deep peak shaving, and the optimized adjustment of the fineness of pulverized coal in the coal mill achieves the boiler's deep peak shaving combustion control requirements.

[0031] Furthermore, the multiple influencing factors also include the coal bed thickness of the boiler's coal mill;

[0032] The coal bed thickness of the coal mill is adjusted by the second preset adjustment method;

[0033] The vibration parameters of the moving parts of the boiler are adjusted by adjusting the coal bed thickness of the pulverizer.

[0034] The beneficial effects of adopting the above-mentioned further solution are: this solution adjusts the vibration parameters of the moving parts of the boiler by adjusting the coal bed thickness of the coal mill, thereby preventing the coal mill vibration caused by further reduction of coal feed, reducing the rubbing failure of the moving parts of the main body, and reducing the hydraulic loading force of the grinding roller to solve the problem of coal mill body vibration.

[0035] Another technical solution of the present invention to solve the above-mentioned technical problems is as follows:

[0036] A boiler combustion optimization system based on AGC includes: an influencing factor acquisition module, a parameter adjustment module, and a load adjustment module;

[0037] The influencing factor acquisition module is used to obtain multiple influencing factors that affect the boiler's stable combustion capability during deep peak shaving based on the degree of combustion in the furnace.

[0038] The parameter adjustment module is used to adjust the relevant parameters of the boiler based on multiple influencing factors and AGC instructions issued by the power grid.

[0039] The load adjustment module is used to adjust the load until it is adjusted to the rated load that keeps the boiler combustion within a first preset range.

[0040] The beneficial effects of this invention are as follows: This solution adjusts the relevant parameters of the boiler based on multiple influencing factors and AGC instructions issued by the power grid until the boiler combustion is maintained within the rated load of the first preset range. This solution comprehensively utilizes multiple influencing factors on the stable combustion capability during deep peak shaving obtained based on the degree of combustion in the furnace, and controls the furnace air leakage rate, improves the drying output of the pulverizing system, adjusts the secondary air distribution, uses plasma combustion assistance, and optimizes the operation mode of the pulverizing system, thereby reducing the minimum technical output of the boiler to 15% of the design output, effectively expanding the range of deep peak shaving capability of the unit, and ensuring the stability, safety, and economy of the unit operation.

[0041] Furthermore, the multiple influencing factors include cold air leakage.

[0042] The parameter adjustment module is also specifically used to adjust the cold air leakage volume through a first preset method.

[0043] Adjust the boiler load parameters according to the adjusted cold air leakage rate.

[0044] The beneficial effects of adopting the above-mentioned further scheme are: this scheme adjusts the boiler load parameters by regulating the cold air leakage, thereby enhancing in-furnace combustion, increasing radiant heat, and increasing the boiler load response capability.

[0045] Furthermore, the multiple influencing factors also include: secondary air distribution method;

[0046] The parameter adjustment module is also specifically used to adjust the secondary air distribution mode by adjusting the vertical or horizontal swing angle position of the SOFA air burner nozzle.

[0047] Adjust the steam temperature deviation, flue gas deviation, and oxygen deviation on both sides of the boiler according to the adjusted secondary air distribution method.

[0048] The beneficial effects of adopting the above-mentioned further scheme are: by adjusting the steam temperature deviation, flue gas deviation and oxygen deviation on both sides of the boiler according to the adjusted secondary air distribution method, this scheme is conducive to stable combustion and keeps the flue gas temperature deviation, steam temperature deviation and oxygen deviation on both sides of the furnace outlet within the required range, effectively controlling the steam temperature deviation, flue gas deviation and oxygen deviation on both sides of the boiler.

[0049] To improve the combustion conditions inside the furnace, thereby stabilizing the main steam pressure, and to ensure that the rate of change of main steam pressure and steam temperature is relatively stable during boiler load increases and decreases, so that the boiler response speed meets the grid requirements.

[0050] Furthermore, the multiple influencing factors also include: plasma immersion time;

[0051] The parameter adjustment module is also specifically used to adjust the superheated steam flow parameters in the boiler by adjusting the plasma injection time when the boiler's stable combustion load point is within the second preset range.

[0052] The beneficial effects of adopting the above-mentioned further scheme are: this scheme adjusts the superheated steam flow parameters in the boiler by adjusting the plasma input time, meets the minimum technical output requirements of the boiler, selects the best time to input the plasma device, and realizes the deep peak-shaving combustion control requirements of the boiler.

[0053] Furthermore, the multiple influencing factors also include coal powder fineness;

[0054] The parameter adjustment module is also specifically used to adjust the boiler's combustion stability parameters by adjusting the fineness of the pulverized coal.

[0055] The beneficial effects of adopting the above-mentioned further scheme are: this scheme adjusts the boiler's stable combustion capability parameters by adjusting the fineness of pulverized coal, thereby improving the boiler's stable combustion capability during deep peak shaving, and the optimized adjustment of the fineness of pulverized coal in the coal mill achieves the boiler's deep peak shaving combustion control requirements.

[0056] Furthermore, the multiple influencing factors also include the coal bed thickness of the boiler's coal mill;

[0057] The parameter adjustment module is also specifically used to adjust the coal bed thickness of the coal mill through a second preset adjustment method;

[0058] The vibration parameters of the moving parts of the boiler are adjusted by adjusting the coal bed thickness of the pulverizer.

[0059] The beneficial effects of adopting the above-mentioned further solution are: this solution adjusts the vibration parameters of the moving parts of the boiler by adjusting the coal bed thickness of the coal mill, thereby preventing the coal mill vibration caused by further reduction of coal feed, reducing the rubbing failure of the moving parts of the main body, and reducing the hydraulic loading force of the grinding roller to solve the problem of coal mill body vibration.

[0060] Another technical solution of the present invention to solve the above-mentioned technical problems is as follows:

[0061] A boiler combustion adjustment system includes: a boiler combustion optimization system based on AGC as described in any of the above embodiments.

[0062] The beneficial effects of this invention are as follows: This solution adjusts the relevant parameters of the boiler based on multiple influencing factors and AGC instructions issued by the power grid until the boiler combustion is maintained within the rated load of the first preset range. This solution comprehensively utilizes multiple influencing factors on the stable combustion capability during deep peak shaving obtained based on the degree of combustion in the furnace, and controls the furnace air leakage rate, improves the drying output of the pulverizing system, adjusts the secondary air distribution, uses plasma combustion assistance, and optimizes the operation mode of the pulverizing system, thereby reducing the minimum technical output of the boiler to 15% of the design output, effectively expanding the range of deep peak shaving capability of the unit, and ensuring the stability, safety, and economy of the unit operation.

[0063] The advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0064] Figure 1 A schematic flowchart of a boiler combustion optimization method based on AGC is provided for an embodiment of the present invention;

[0065] Figure 2 A structural block diagram of a boiler combustion optimization method based on AGC is provided for embodiments of the present invention;

[0066] Figure 3 A schematic diagram of the DCS main combustion secondary air damper control screen provided for other embodiments of the present invention;

[0067] Figure 4 A schematic diagram of the DCS SOFA wind deflector control screen provided for other embodiments of the present invention. Detailed Implementation

[0068] The principles and features of the present invention are described below with reference to the accompanying drawings. The embodiments described are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0069] like Figure 1 As shown, an embodiment of the present invention provides a boiler combustion optimization method based on AGC, comprising:

[0070] S1, based on the degree of combustion in the furnace, obtain multiple influencing factors that affect the stable combustion capability of the boiler during deep peak shaving; it should be noted that, in one embodiment, the multiple influencing factors may include: furnace air leakage rate, improving the drying output of the pulverizing system, secondary air distribution adjustment, plasma combustion assistance, and the operation mode of the pulverizing system.

[0071] S2, adjusts the relevant parameters of the boiler based on multiple influencing factors and AGC instructions issued by the power grid; the relevant parameters of the boiler may include: boiler load parameters, steam temperature deviation, flue gas deviation and oxygen deviation on both sides of the boiler, superheated steam flow parameters, boiler stability parameters, and vibration parameters of moving parts of the boiler.

[0072] It should be noted that, in one embodiment, S2 may include:

[0073] The parameter adjustment module is also specifically used to adjust the cold air leakage volume through a first preset method.

[0074] Adjust the boiler load parameters according to the adjusted cold air leakage rate.

[0075] In another embodiment, S2 may further include: adjusting the secondary air distribution method by adjusting the vertical or horizontal sway angle position of the SOFA air burner nozzle;

[0076] Adjust the steam temperature deviation, flue gas deviation, and oxygen deviation on both sides of the boiler according to the adjusted secondary air distribution method.

[0077] In another embodiment, S2 may further include: when the boiler's stable combustion load point is within a second preset range, adjusting the superheated steam flow parameters within the boiler by adjusting the plasma injection time. The second preset range may include: injecting one layer of plasma at a 35% load point and injecting a second layer of plasma at a 30% load point.

[0078] In another embodiment, S2 may further include: adjusting the boiler combustion stability parameters by adjusting the fineness of the pulverized coal.

[0079] In another embodiment, S2 may further include: adjusting the coal bed thickness of the coal mill by a second preset adjustment method;

[0080] The vibration parameters of the moving parts of the boiler are adjusted by adjusting the coal bed thickness of the pulverizer.

[0081] S3, until the boiler combustion is maintained at the rated load within the first preset range.

[0082] This solution adjusts relevant boiler parameters based on multiple influencing factors and AGC commands issued by the power grid until the boiler combustion is maintained within the rated load of the first preset range. This solution comprehensively utilizes multiple influencing factors on the stable combustion capability during deep peak shaving, obtained based on the degree of combustion in the furnace, and controls furnace air leakage rate, improves the drying output of the pulverizing system, adjusts secondary air distribution, uses plasma combustion assistance, and optimizes the operation mode of the pulverizing system. This reduces the minimum technical output of the boiler to 15% of the design output, effectively expands the range of deep peak shaving capability of the unit, and ensures the stability, safety, and economy of the unit operation.

[0083] Preferably, in any of the above embodiments, the plurality of influencing factors includes cold air leakage.

[0084] S2 specifically includes:

[0085] Adjust the cold air leakage rate using the first preset method;

[0086] Adjust the boiler load parameters according to the adjusted cold air leakage rate.

[0087] It should be noted that, in one embodiment, the first preset method may include: reducing the cold air leakage in the furnace and pulverizing system may include:

[0088] 1) Seal the gaps between each burner and SOFA air nozzle to reduce disorderly air leakage in the boiler;

[0089] 2) Block the wall-mounted air nozzles in the main combustion zone and cancel the wall-mounted low-level burnout air nozzles;

[0090] 3) Air leakage control of the dry slag machine: By optimizing the sealing of the dry slag machine manholes and inspection holes, the air leakage rate of the dry slag machine is controlled to be less than 2% of the total boiler air volume;

[0091] It should be noted that during the deep peak shaving period of the unit, the hydraulic shut-off valve at the bottom of the dry slag machine is completely closed, and the boiler itself settles and slags, naturally sealing the air leakage of the hydraulic shut-off valve. During the actual deep peak shaving period, the air leakage rate of the dry slag machine is reduced to close to 0%. The dry slag machine is shut down by utilizing the ash storage capacity of the boiler cold ash hopper. After the unit ends the deep peak shaving period, the hydraulic shut-off valve is opened one by one to release ash at intervals.

[0092] 4) The furnace inspection holes and viewing holes have been changed from simple packing type or no seal to labyrinth structure seal to reduce cold air leakage.

[0093] 5) By modifying the sealing structure of the cold air regulating baffle of the coal mill, the cold air leakage is reduced by 50%, and the concentration of the coal-air mixture at the coal mill outlet is increased to 90-95℃, which enhances combustion in the furnace, increases radiant heat, and increases the boiler load response capability.

[0094] This solution adjusts the boiler's load parameters by regulating the amount of cold air leakage, thereby enhancing in-furnace combustion, increasing radiant heat, and improving the boiler's load response capability.

[0095] Preferably, in any of the above embodiments, the plurality of influencing factors further includes: secondary air distribution method;

[0096] S2 specifically includes:

[0097] The secondary air distribution method can be adjusted by adjusting the vertical or horizontal swing angle of the SOFA air burner nozzle.

[0098] Adjust the steam temperature deviation, flue gas deviation, and oxygen deviation on both sides of the boiler according to the adjusted secondary air distribution method.

[0099] Preferably, in one embodiment, the automatic control scheme for burner adjustment and secondary air distribution may include:

[0100] 1) Adjustment of the vertical swing angle of the burner and secondary air damper

[0101] The reduced air leakage in the furnace improved the flue gas filling rate. Combustion adjustment tests revealed that the vertical oscillation of the burner had minimal impact on parameters such as steam temperature. During the oscillation process, the boiler parameters showed minimal changes, primarily due to the small vertical temperature gradient in the furnace. Therefore, the vertical oscillation of the burner had little effect on boiler parameters like steam temperature, and the steam temperature and desuperheating water flow could not be adjusted using the burner's vertical oscillation angle. Furthermore, the oscillation mechanism was prone to jamming or pin breakage, leading to inconsistent burner nozzle angles within the furnace and affecting normal boiler operation. Therefore, in deep peak-shaving conditions, maintaining the vertical oscillation angle of the burner and SOFA air nozzles at 50% of their horizontal position is beneficial for stable combustion and flame detection.

[0102] 2) SOFA air burner horizontal swing angle adjustment

[0103] For boilers with tangential combustion, the presence of residual combustion at the furnace outlet leads to significant deviations in flue gas temperature on both sides of the superheater inlet and oxygen content in the flue gas ducts on both sides of the furnace outlet. The horizontal oscillation of the SOFA (Steam-Off-Fan) burner eliminates the residual rotational momentum at the furnace outlet, thus keeping the deviations in flue gas temperature, steam temperature, and oxygen content on both sides of the furnace outlet within the required range.

[0104] In one embodiment, the horizontal swing angle can only be adjusted manually on-site, with an adjustment range of ±15°. When adjusting the horizontal swing angle of the SOFA air burner at each corner facing the furnace on both side walls, when adjusting the horizontal swing angle of the SOFA air burner: when the swing rods at corners 1 and 3 move towards the furnace, the nozzle swings to the right; when the swing rods at corners 2 and 4 are pushed towards the furnace, the nozzle swings to the left; that is, the scale indicator on the left indicates that the nozzle swings towards the left hand, and the scale indicator on the right indicates that the nozzle swings towards the right hand.

[0105] After various air distribution combination adjustment tests, as shown in Table 1, the position of the SOFA air horizontal swing angle after adjustment can effectively control the steam temperature deviation, flue gas deviation and oxygen deviation on both sides of the boiler.

[0106] project Horn 1 Horn 2 Horn 3 Horn 4 SOFA4 +5 +5 +10 +5 SOFA3 +5 +5 +10 +5 SOFA1-2 +5 +5 +10 +5

[0107] Table 1

[0108] Preferably, in one embodiment, adjusting the secondary air distribution method may include: a reasonable secondary air distribution method has a significant effect on organizing the high-temperature flue gas flow field in the furnace and improving the combustion conditions in the furnace, especially on reducing the flue gas temperature deviation on both sides of the furnace outlet, the exhaust gas temperature, and the desuperheating water volume, and will also affect the changes in superheated steam temperature, reheated steam temperature, boiler coking, and NOx concentration at the boiler outlet.

[0109] While keeping other boiler operating parameters basically unchanged, the distribution ratio of secondary air in each layer is changed by adjusting the opening of the secondary small damper to examine the impact of the secondary air distribution method on the boiler's combustion safety, economy, and environmental characteristics, and to determine the optimal secondary air distribution method for boiler operation.

[0110] Considering the quality of the coal used, stabilizing the main steam pressure is the primary condition for the normal operation of the entire combustion system. Therefore, optimizing the secondary air distribution first considers stabilizing the main steam pressure. Regarding the boiler's combustion characteristics, the lower burner area primarily aims to stabilize or increase the main steam pressure. This is achieved by opening the secondary air dampers of the lower burners wider, thus enhancing the ignition of pulverized coal in the lower burner area and achieving stable main steam pressure. Therefore, under high load conditions, the secondary air dampers of the AA layer are generally kept fully open at 80%, and the vertical angle of the secondary air nozzles in the AA layer is adjusted from an upward tilt of 5° to 0°.

[0111] For low loads, especially loads below 350MW, particularly deep-load conditions, the key is to adjust the pressure difference of the secondary air box. Tests show that the pressure difference of the secondary air box should not be lower than 400pa during operation, otherwise "flue gas temperature deflection" is likely to occur. Under the premise that the total air volume and operating oxygen volume are appropriate, the first choice is to adjust the pressure difference of the secondary air box by opening or closing the AB, CD, and EF secondary air dampers.

[0112] Based on a comprehensive evaluation of various indicators and after a long period of experimentation and exploration, a principle-based air distribution guideline for burnout air, perimeter air, and secondary air is finally provided. The static command of the secondary air damper is integrated into the DCS control logic. The static logic of automatic secondary air distribution is shown in Tables 2.1, 2.2, and 2.3, and the overshoot logic of automatic secondary air distribution is shown in Table 3.

[0113]

[0114] Table 2.1

[0115]

[0116]

[0117] Table 2.2

[0118]

[0119] Table 2.3

[0120]

[0121] Table 3

[0122] By setting the overshoot feedforward of the secondary air damper in the main combustion zone when the load fluctuates using PID control, and the delayed opening and closing logic of the SOFA damper, the secondary air damper in the main combustion zone is overshooted and opened during the process of increased combustion as the load increases, and the SOFA damper is opened after a delay. During the process of decreased fuel quantity as the load decreases, the secondary air damper in the main combustion zone is overshooted and closed after a delay. After the overshoot ends, the opening degree of each damper returns to the preset opening degree. This achieves the goal of relatively stable main steam pressure and steam temperature change rate during boiler load increase and decrease, and the boiler response speed meets the grid demand.

[0123] Through the above adjustments and logic optimizations, the secondary air distribution system can be automatically operated within the 100% to 15% rated load range to meet the load increase and decrease requirements. Figure 3 The secondary air damper in the main combustion zone is displayed on the DCS screen. Figure 4 The secondary air damper in the SOFA wind zone is displayed on the DCS screen during unit load changes. Figure 3 , 4 The main combustion zone regulating baffle shown in the figure automatically adjusts according to the set static and overshoot logic to realize automatic adjustment of boiler air distribution and meet the load rise and fall requirements.

[0124] This solution adjusts the steam temperature deviation, flue gas deviation, and oxygen content deviation on both sides of the boiler according to the adjusted secondary air distribution method. This helps to stabilize the combustion flame and keep the flue gas temperature deviation, steam temperature deviation, and oxygen content deviation on both sides of the furnace outlet within the required range, effectively controlling the steam temperature deviation, flue gas deviation, and oxygen content deviation on both sides of the boiler.

[0125] To improve the combustion conditions inside the furnace, thereby stabilizing the main steam pressure, and to ensure that the rate of change of main steam pressure and steam temperature is relatively stable during boiler load increases and decreases, so that the boiler response speed meets the grid requirements.

[0126] Preferably, in any of the above embodiments, the plurality of influencing factors further include: plasma immersion time;

[0127] S2 specifically includes:

[0128] When the boiler's stable combustion load point is within the second preset range, the superheated steam flow parameters inside the boiler are adjusted by regulating the plasma injection time.

[0129] Preferably, in one embodiment, plasma injection time control may include: determining through experiments that the plasma injection timing is below 40% of the boiler's minimum stable combustion load point, injecting one layer of plasma at 35% load point and injecting a second layer of plasma at 30% load point, which can meet the boiler's minimum technical output requirements.

[0130] This solution adjusts the superheated steam flow parameters in the boiler by regulating the plasma activation time, thereby meeting the minimum technical output requirements of the boiler and selecting the optimal activation time of the plasma device to achieve the deep peak-shaving combustion control requirements of the boiler.

[0131] Preferably, in any of the above embodiments, the plurality of influencing factors further include coal powder fineness;

[0132] S2 specifically includes:

[0133] The boiler's stable combustion parameters can be adjusted by regulating the fineness of the pulverized coal.

[0134] Preferably, in one embodiment, the optimization adjustment of pulverized coal fineness in the coal mill may include, comprehensively considering the stable combustion of the deep peak-shaving boiler, the unit's load response capability, and the maximum output of the pulverizing system, determining through field tests, adjusting the opening of the deflector baffle at the coal mill outlet, and adjusting the pulverized coal fineness R90 at the coal mill outlet from an average of 21.9% to 17.1%, thereby improving the boiler's stable combustion capability during deep peak-shaving. The relationship between the coal mill, pulverized coal fineness, and the deflector baffle is shown in Figure 4:

[0135]

[0136] Table 4

[0137] This solution adjusts the boiler's stable combustion capability parameters by regulating the fineness of pulverized coal, thereby improving the boiler's stable combustion capability during deep peak shaving. The optimized adjustment of the fineness of pulverized coal in the coal mill achieves the boiler's deep peak shaving combustion control requirements.

[0138] Preferably, in any of the above embodiments, the plurality of influencing factors further include the coal bed thickness of the boiler's coal mill;

[0139] The coal bed thickness of the coal mill is adjusted by the second preset adjustment method;

[0140] The vibration parameters of the moving parts of the boiler are adjusted by adjusting the coal bed thickness of the pulverizer.

[0141] Preferably, in one embodiment, the second preset adjustment method may include: vibration control of the coal mill body. During the deep peak shaving period, the coal mill operates at low output, resulting in significant vibration. This vibration affects the operational safety of the coal mill itself, causing mortar-related failures in moving parts, powder leakage at the connection of the coal mill's discharge pipe, and displacement of the reducer and motor coupling. Furthermore, the vibration transmitted from the coal mill body to the main plant foundation and steel beams increases the failure rate of equipment on the same operating platform, such as the feeder frequency converter and critical control equipment in the centralized control electronics room. Sometimes, the strong vibration of the coal mill may even affect the turbine shaft system vibration, threatening the safe operation of the turbine. Therefore, controlling the vibration of the coal mill body is particularly important.

[0142] The coal mill is designed with a minimum output of 20.06 t / h. When the coal mill maintains its rated speed, if the coal feed rate is lower than the minimum output, the amount of coal stored between the grinding rollers and the grinding disc decreases, the coal bed thickness decreases, and direct contact between the grinding rollers and the grinding disc may occur, leading to coal mill vibration. To prevent further reduction in the coal feed rate and subsequent coal mill vibration, the following methods are adopted to increase the coal bed thickness:

[0143] 1) Reduce the hydraulic loading force of the coal mill to 0MPa and rely on the weight of the grinding rollers to grind the raw coal. Replace the manual reversing valve of the coal mill hydraulic oil station with a solenoid valve, which can be easily switched on the DCS. This method has shown good results in the cold start test of the unit. It can effectively reduce the vibration of the coal mill body and the coal powder at the separator outlet meets the requirements of plasma combustion.

[0144] 2) Adjust the deflection baffle of the coal mill outlet separator from 50% to 35% to increase the amount of material returned by the coal mill separator, thereby increasing the coal bed thickness. At the same time, it compensates for the increased fineness of coal powder caused by the reduction of loading force, and can even further reduce the fineness of coal powder, which is beneficial to the combustion of the boiler during cold start-up.

[0145] 3) While ensuring the drying output of the coal mill, appropriately reduce the inlet air volume of the coal mill, maintain the lowest possible air-coal ratio, increase the amount of circulating powder in the separator, and at the same time promote combustion.

[0146] This solution adjusts the vibration parameters of the moving parts of the boiler by adjusting the coal bed thickness of the coal mill, thereby preventing further reduction in coal feed and reducing the vibration of the coal mill body. It also reduces the rubbing failure of the moving parts and lowers the hydraulic loading force of the grinding rollers to solve the problem of coal mill body vibration.

[0147] In one embodiment, such as Figure 2 As shown, a boiler combustion optimization system based on AGC includes: an influencing factor acquisition module 1101, a parameter adjustment module 1102, and a load adjustment module 1103;

[0148] The influencing factor acquisition module 1101 is used to obtain multiple influencing factors that affect the boiler's stable combustion capability during deep peak shaving based on the furnace combustion degree.

[0149] The parameter adjustment module 1102 is used to adjust the relevant parameters of the boiler according to multiple influencing factors and AGC instructions issued by the power grid;

[0150] The load adjustment module 1103 is used to adjust the load until it is adjusted to the rated load that keeps the boiler combustion within a first preset range.

[0151] This solution adjusts relevant boiler parameters based on multiple influencing factors and AGC commands issued by the power grid until the boiler combustion is maintained within the rated load of the first preset range. This solution comprehensively utilizes multiple influencing factors on the stable combustion capability during deep peak shaving, obtained based on the degree of combustion in the furnace, and controls furnace air leakage rate, improves the drying output of the pulverizing system, adjusts secondary air distribution, uses plasma combustion assistance, and optimizes the operation mode of the pulverizing system. This reduces the minimum technical output of the boiler to 15% of the design output, effectively expands the range of deep peak shaving capability of the unit, and ensures the stability, safety, and economy of the unit operation.

[0152] Preferably, in any of the above embodiments, the plurality of influencing factors includes cold air leakage.

[0153] The parameter adjustment module 1102 is also specifically used to adjust the cold air leakage volume through a first preset method;

[0154] Adjust the boiler load parameters according to the adjusted cold air leakage rate.

[0155] This solution adjusts the boiler's load parameters by regulating the amount of cold air leakage, thereby enhancing in-furnace combustion, increasing radiant heat, and improving the boiler's load response capability.

[0156] Preferably, in any of the above embodiments, the plurality of influencing factors further includes: secondary air distribution method;

[0157] The parameter adjustment module 1102 is also specifically used to adjust the secondary air distribution mode by adjusting the vertical or horizontal swing angle position of the SOFA air burner nozzle.

[0158] Adjust the steam temperature deviation, flue gas deviation, and oxygen deviation on both sides of the boiler according to the adjusted secondary air distribution method.

[0159] This solution adjusts the steam temperature deviation, flue gas deviation, and oxygen content deviation on both sides of the boiler according to the adjusted secondary air distribution method. This helps to stabilize the combustion flame and keep the flue gas temperature deviation, steam temperature deviation, and oxygen content deviation on both sides of the furnace outlet within the required range, effectively controlling the steam temperature deviation, flue gas deviation, and oxygen content deviation on both sides of the boiler.

[0160] To improve the combustion conditions inside the furnace, thereby stabilizing the main steam pressure, and to ensure that the rate of change of main steam pressure and steam temperature is relatively stable during boiler load increases and decreases, so that the boiler response speed meets the grid requirements.

[0161] Preferably, in any of the above embodiments, the plurality of influencing factors further include: plasma immersion time;

[0162] The parameter adjustment module 1102 is also specifically used to adjust the superheated steam flow parameters in the boiler by adjusting the plasma injection time when the boiler's stable combustion load point is within the second preset range.

[0163] This solution adjusts the superheated steam flow parameters in the boiler by regulating the plasma activation time, thereby meeting the minimum technical output requirements of the boiler and selecting the optimal activation time of the plasma device to achieve the deep peak-shaving combustion control requirements of the boiler.

[0164] Preferably, in any of the above embodiments, the plurality of influencing factors further include coal powder fineness;

[0165] The parameter adjustment module 1102 is also specifically used to adjust the boiler's combustion stability parameters by adjusting the fineness of the pulverized coal.

[0166] This solution adjusts the boiler's stable combustion capability parameters by regulating the fineness of pulverized coal, thereby improving the boiler's stable combustion capability during deep peak shaving. The optimized adjustment of the fineness of pulverized coal in the coal mill achieves the boiler's deep peak shaving combustion control requirements.

[0167] Preferably, in any of the above embodiments, the plurality of influencing factors further include the coal bed thickness of the boiler's coal mill;

[0168] The parameter adjustment module 1102 is also specifically used to adjust the coal bed thickness of the coal mill through a second preset adjustment method;

[0169] The vibration parameters of the moving parts of the boiler are adjusted by adjusting the coal bed thickness of the pulverizer.

[0170] This solution adjusts the vibration parameters of the moving parts of the boiler by adjusting the coal bed thickness of the coal mill, thereby preventing further reduction in coal feed and reducing the vibration of the coal mill body. It also reduces the rubbing failure of the moving parts and lowers the hydraulic loading force of the grinding rollers to solve the problem of coal mill body vibration.

[0171] It is understood that in some embodiments, some or all of the optional implementations as described in the above embodiments may be included.

[0172] It should be noted that the above embodiments are product embodiments corresponding to the prior method embodiments. For the description of each optional implementation in the product embodiments, please refer to the corresponding description in the above method embodiments, which will not be repeated here.

[0173] In one embodiment, a boiler combustion adjustment system includes: a boiler combustion optimization system based on AGC as described in any of the above embodiments.

[0174] This solution adjusts relevant boiler parameters based on multiple influencing factors and AGC commands issued by the power grid until the boiler combustion is maintained within the rated load of the first preset range. This solution comprehensively utilizes multiple influencing factors on the stable combustion capability during deep peak shaving, obtained based on the degree of combustion in the furnace, and controls furnace air leakage rate, improves the drying output of the pulverizing system, adjusts secondary air distribution, uses plasma combustion assistance, and optimizes the operation mode of the pulverizing system. This reduces the minimum technical output of the boiler to 15% of the design output, effectively expands the range of deep peak shaving capability of the unit, and ensures the stability, safety, and economy of the unit operation.

[0175] Readers should understand that in the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0176] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative. For instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed.

[0177] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of the embodiments of the present invention, depending on actual needs.

[0178] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0179] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0180] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A boiler combustion optimization method based on AGC (Automatic Generative Control) is characterized in that, include: S1. Based on the degree of combustion in the furnace, obtain multiple influencing factors that affect the stable combustion capability of the boiler during deep peak shaving. These multiple influencing factors include: furnace air leakage rate, improving the drying output of the pulverizing system, secondary air distribution adjustment, plasma combustion assistance, and the operation mode of the pulverizing system. S2, adjust the relevant parameters of the boiler according to multiple influencing factors and AGC instructions issued by the power grid. The relevant parameters of the boiler include: boiler load parameters, steam temperature deviation, flue gas deviation and oxygen deviation on both sides of the boiler, superheated steam flow parameters, boiler stability parameters, and vibration parameters of moving parts of the boiler. S3, until the boiler combustion is maintained at the rated load within the first preset range; The multiple influencing factors include cold air leakage; S2 specifically includes: Adjust the cold air leakage rate using the first preset method; Adjust the boiler load parameters according to the adjusted cold air leakage rate; The first preset method includes: reducing the cold air leakage in the furnace and pulverizing system, including: 1) Seal the gaps between each burner and SOFA air nozzle to reduce disorderly air leakage in the boiler; 2) Block the wall-mounted air nozzles in the main combustion zone and cancel the wall-mounted low-level burnout air nozzles; 3) Air leakage control of the dry slag machine: By optimizing the sealing of the manhole and inspection hole of the dry slag machine, the air leakage rate of the dry slag machine is controlled to be less than 2% of the total boiler air volume; 4) The furnace inspection holes and viewing holes have been changed from simple packing type or no seal to labyrinth structure seal to reduce cold air leakage; 5) By modifying the sealing structure of the cold air regulating baffle of the coal mill, the cold air leakage is reduced by 50%, and the concentration of the coal-air mixture at the coal mill outlet is increased to 90~95℃, which enhances combustion in the furnace, increases radiant heat, and increases the boiler load response capability.

2. The boiler combustion optimization method based on AGC according to claim 1, characterized in that, The multiple influencing factors also include: secondary air distribution method; S2 specifically includes: The secondary air distribution method can be adjusted by adjusting the vertical or horizontal swing angle of the SOFA air burner nozzle. Adjust the steam temperature deviation, flue gas deviation, and oxygen deviation on both sides of the boiler according to the adjusted secondary air distribution method.

3. The boiler combustion optimization method based on AGC according to claim 1, characterized in that, The multiple influencing factors also include: plasma deployment time; S2 specifically includes: When the boiler's stable combustion load point is within the second preset range, the superheated steam flow parameters inside the boiler are adjusted by regulating the plasma injection time.

4. The boiler combustion optimization method based on AGC according to claim 1, characterized in that, The multiple influencing factors also include the fineness of coal powder; S2 specifically includes: The boiler's stable combustion parameters can be adjusted by regulating the fineness of the pulverized coal.

5. The boiler combustion optimization method based on AGC according to claim 1, characterized in that, The multiple influencing factors also include the coal bed thickness of the boiler's coal mill; The coal bed thickness of the coal mill is adjusted by the second preset adjustment method; The vibration parameters of the moving parts of the boiler are adjusted by adjusting the coal bed thickness of the pulverizer.

6. A boiler combustion optimization system based on AGC (Automatic Generative Control) method, characterized in that, The boiler combustion optimization method based on AGC as described in claim 1 includes: an influencing factor acquisition module, a parameter adjustment module, and a load adjustment module. The influencing factor acquisition module is used to obtain multiple influencing factors of the boiler's stable combustion capability during deep peak shaving based on the degree of combustion in the furnace. The parameter adjustment module is used to obtain multiple influencing factors that affect the boiler's stable combustion capability during deep peak shaving, based on the degree of combustion in the furnace. The load adjustment module is used to adjust the load until it is adjusted to the rated load that keeps the boiler combustion within a first preset range.

7. A boiler combustion optimization system based on AGC according to claim 6, characterized in that, The multiple influencing factors also include: secondary air distribution method; The parameter adjustment module is also specifically used to adjust the secondary air distribution mode by adjusting the vertical or horizontal swing angle position of the SOFA air burner nozzle. Adjust the steam temperature deviation, flue gas deviation, and oxygen deviation on both sides of the boiler according to the adjusted secondary air distribution method.

8. A boiler combustion adjustment system, characterized in that, include: A boiler combustion optimization system based on AGC as described in claim 6 or 7.

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