Coal blending system and method for variable-load combustion high-alkali coal

Abstract

The invention provides a coal blending system and method of high-alkali coal for variable-load combustion, and belongs to the technical field of variable-load operation and coal blending combustion, in the method, high-quality coal and low-quality coal are mixed in front of a furnace to serve as coal blending types, and the coal feeding amount of the two types of coal is changed to adapt to variable loads of a boiler; in addition, high-alkali coal is subjected to blending combustion in the furnace, slag-bonding and ash deposition of combustion of the high-alkali coal can be effectively relieved through coal blending combustion, and ash content can be captured through blending combustion of inferior coal in a high load so as to achieve the effect of slowing down slag-bonding. And finally, an online monitoring system is arranged to monitor key parameters of a hearth outlet in real time and feed back the key parameters to corresponding components. Corresponding parts achieve the purposes of low-load stable combustion, high-load slow-down of high-alkali coal slagging and the like by adjusting the coal amount of the three kinds of coal and the air supply amount of an air feeder, the economic benefits of combustion of the high-alkali coal are effectively improved, and safe and stable operation of the boiler is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of variable load operation and coal blending combustion, and in particular to a coal blending system and method for variable load combustion of high-alkali coal. Background Art

[0002] The characteristics of my country's energy structure are rich in coal, poor in oil, and little gas, which also determines that my country's energy consumption is mainly coal. my country's Xinjiang region has abundant reserves of high-alkali coal. Xinjiang high-alkali coal is one of my country's important power coals, but its alkali metal content in coal ash is relatively high, which also leads to the direct burning of high-alkali coal. It is very easy to cause serious slagging and contamination of the boiler. Especially when the boiler is running at variable load, the temperature field, flow field and alkali metal precipitation characteristics of the coal in the boiler furnace will change dramatically, aggravating the degree of slagging and contamination. The slagging and ash accumulation on the heating surface and flue of the boiler will lead to a decrease in heat transfer resistance and heat transfer efficiency. In severe cases, it may also cause various safety problems such as over-temperature pipe explosion and severe corrosion and wear of the superheater, affecting the efficient utilization of high-alkali coal and the safe operation of the boiler. Therefore, it is of great significance to solve the slagging and ash accumulation problem of high-alkali coal combustion under variable load conditions. Summary of the invention

[0003] The purpose of the present invention is to provide a coal blending system and method for variable load combustion of high-alkali coal, which can solve the problem in the prior art of how to burn high-alkali coal under variable load conditions and reduce slagging and ash accumulation after combustion.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] In the first aspect, the present invention provides a coal blending system for variable load combustion of high-alkali coal, including an out-of-furnace blending and conveying system for superior and inferior coals, an in-furnace blending and conveying system for high-alkali coals, a furnace combustion system, an air supply system, and a monitoring system;

[0006] The superior and inferior coal blending and conveying system outside the furnace includes a coal conveying belt, a coal hopper, a partition plate, an electric gate, a coal mill, a coal feeder and a coal powder exhaust fan, which blends the superior and inferior coals according to a certain amount outside the furnace, grinds them into coal powder and then feeds them into the lower burner;

[0007] The high-alkali coal in-furnace blending and conveying system includes a coal conveying belt, a coal hopper, an electric gate, a coal mill, a coal feeder and a coal powder exhaust fan, which grinds the high-alkali coal into coal powder and then feeds it into the upper burner;

[0008] The furnace combustion system includes six layers of burners A, B, C, D, E, and F, a main combustion zone, a blending zone, and a burnout zone, and burns the fed fuel in the furnace;

[0009] The air supply system includes an air blower and an air preheater, which inputs hot air into the coal mill, burner and burnout zone, transports coal powder and provides air for combustion;

[0010] The monitoring system monitors key parameters such as furnace outlet temperature, furnace outlet heating rate, furnace load and furnace outlet excess air coefficient, and feeds back to corresponding components to adjust the operating status according to the operating conditions. The corresponding components include the high-quality coal hopper electric gate, the low-quality coal hopper electric gate, the high-alkali coal hopper electric gate and the air blower.

[0011] In a second aspect, the present invention provides a coal blending method for variable load combustion of high-alkali coal using the above system, comprising the following steps:

[0012] S1, the system mixes two kinds of coal of different qualities, good and bad, outside the furnace. The good and bad coals fall into the coal hopper from the coal conveyor belt respectively, pass through the electric gate, fall into the coal feeder, and then are sent to the coal mill and the powder exhaust fan, and finally are sent to the three-layer burners A, B, and C for combustion in the main combustion area.

[0013] S2, high-alkali coal is mixed and burned in the furnace. It falls from the coal conveyor belt into the coal hopper, passes through the electric gate, falls into the coal feeder, and is then sent to the coal mill and the pulverized coal exhaust fan, and finally sent to the D and E burners to be burned in the mixed burning area.

[0014] S3, during the combustion process, the F layer burner is on standby, and the monitoring system monitors key parameters such as furnace outlet temperature, furnace outlet heating rate, furnace load and furnace outlet excess air coefficient in real time.

[0015] S4, when the furnace is running at low load, the monitoring system will feed back the load situation to the coal distribution hopper electric gate, the high-alkali coal hopper electric gate and the air blower. In terms of fuel, the opening of the electric gate of the high-quality coal hopper becomes larger, and the opening of the electric gate of the low-quality coal hopper becomes smaller, increasing the amount of high-quality coal entering and reducing the amount of low-quality coal entering, so as to stabilize the combustion; the opening of the electric gate of the high-alkali coal hopper is appropriately adjusted to ensure that the furnace outlet temperature and the heating rate are lower than the set value. In terms of air supply, the air blower increases the air supply to increase the oxygen content in the furnace and stabilize the combustion; at the same time, the monitoring system monitors the excess air coefficient at the furnace outlet in real time to determine whether the oxygen content in the furnace has reached the expected value.

[0016] S5, when the furnace is running at high load, the monitoring system will feed back the load situation to the electric gate of the coal hopper for coal blending, the electric gate of the high-alkali coal hopper and the blower. In terms of fuel, the opening of the electric gate of the high-quality coal hopper becomes smaller, and the opening of the electric gate of the low-quality coal hopper becomes larger, reducing the amount of high-quality coal entering and increasing the amount of low-quality coal entering, thereby improving the economic benefits of combustion. In addition, the content of alumina, silica, etc. in low-quality coal is relatively high, so when more low-quality coal is burned as high-alkali coal blending, it can effectively capture alkali metal ash and slow down the slagging and ash accumulation of the boiler. The opening of the electric gate of the high-alkali coal hopper is appropriately adjusted to ensure that the furnace outlet temperature and the heating rate are both lower than the set value. In terms of air supply, the blower reduces the air supply volume to reduce the oxygen content in the furnace and prevent the main combustion zone from burning too violently and coking; at the same time, the monitoring system monitors the excess air coefficient at the furnace outlet in real time to determine whether the oxygen content in the furnace has reached the expected value.

[0017] S6, when the monitoring system detects that the furnace outlet temperature or heating rate is high, it means that the furnace slagging and ash accumulation is serious or the slagging and ash accumulation rate is fast. At this time, the electric gate opening of the high-alkali coal hopper becomes smaller, and the amount of high-alkali coal entering is reduced. At the same time, the electric gate opening of the coal hoppers of the superior and inferior coal blends is appropriately increased to increase the amount of coal blending, slow down the slagging and ash accumulation of the boiler, and ensure the safe operation of the boiler. The monitoring system monitors the parameters in real time and feeds back to the corresponding components. The corresponding components repeat the above adjustment operations until the furnace outlet temperature and heating rate are both lower than the set values.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The present invention proposes a coal blending system and method for variable load combustion of high-alkali coal. By combining external blending with internal blending, the system can adjust the amount of both superior and inferior coal to adapt to variable load combustion of high-alkali coal while alleviating slagging and ash accumulation during combustion of high-alkali coal. The present invention also provides a monitoring system that can monitor the change of furnace load and slagging and ash accumulation in real time and feed back to the corresponding components. The corresponding components can timely adjust the amount of coal and air intake of the internal and external coal types in the furnace, realize the automatic intelligent regulation of fuel and air supply during the combustion process, and improve production efficiency and the safety and stability of boiler operation.

[0020] Furthermore, the present invention uses high-alkali coal in the upper layer of the burner to reduce the emission rate of alkali metals by increasing the mixing and burning position. At the same time, the temperature of the upper combustion area is relatively low, which can also slow down the slagging and ash accumulation caused by the combustion of high-alkali coal.

[0021] Furthermore, the present invention can improve economic benefits by using inferior coal as fuel under high load, and components such as alumina and silicon dioxide in the ash after the inferior coal is burned can also capture the alkali metal ash produced by the combustion of high-alkali coal, further slowing down the slagging and ash accumulation of the high-alkali coal combustion;

[0022] Furthermore, the monitoring system and corresponding components arranged in the present invention can quickly respond to changes in unit load, and the way to adapt to variable load is simple and reliable, avoiding the time lag in adapting to variable load in the past and the inability to respond to rapid load changes in a timely manner. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0024] Figure 1 It is a schematic diagram of a coal blending system for variable load combustion of high-alkali coal;

[0025] Figure 2 It is an overall flow chart of a coal blending method for variable load combustion of high-alkali coal;

[0026] Figure 3 The present invention is a schematic block diagram of the operation of a monitoring system in a coal blending system for variable load combustion of high-alkali coal.

[0027] Among them: 1-high-quality coal conveyor belt; 2-low-quality coal conveyor belt; 3-partition plate; 4-high-quality coal hopper electric gate; 5-low-quality coal hopper electric gate; 6-coal hopper; 7-coal feeder; 8-coal pulverizer; 9-coal exhaust fan; 10-high-alkali coal conveyor belt; 11-high-alkali coal hopper; 12-high-alkali coal hopper electric gate; 13-high-alkali coal feeder; 14-high-alkali coal pulverizer; 15-high-alkali coal exhaust fan; 16-A, B, C, D, E, F six-layer burners; 17-slag discharge device; 18-air blower; the black dotted arrows are the parameters monitored by the monitoring system, the blue dotted arrows are the corresponding components fed back by the monitoring system, and the orange dotted arrows are the air supply of the air preheater. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0029] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0031] In the description of the embodiments of the present invention, it should be noted that if the terms "upper", "lower", "horizontal", "inner", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the accompanying drawings, or the orientation or position relationship in which the invented product is usually placed when in use. This is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance. In addition, if the term "horizontal" appears, it does not mean that the component is required to be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0032] In the description of the embodiments of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0033] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0034] See also Figure 1The present invention proposes a coal blending system for variable load combustion of high-alkali coal, including an external blending and conveying system for superior and inferior coals, an internal blending and burning conveying system for high-alkali coal, a furnace combustion system, an air supply system and a monitoring system; the external blending and conveying system for superior and inferior coals includes a high-quality coal conveying belt 1, an inferior coal conveying belt 2, a blending coal hopper 6, a partition plate 3, an electric gate 4 for the superior coal hopper, an electric gate 5 for the inferior coal hopper, a blending pulverizer 8, a blending coal feeder 7 and a blending coal powder exhaust fan 9, which blends superior and inferior coals according to a certain amount outside the furnace, grinds them into coal powder and then feeds them into three-layer burners A, B and C; the internal blending and burning conveying system for high-alkali coal includes a high-alkali coal conveying belt 10, a high-alkali coal hopper 11, a high-alkali coal hopper electric gate 12, a high-alkali coal pulverizer 14, a high-alkali coal feeder 13 and a high The alkaline coal powder exhaust fan 15 grinds the high-alkali coal into coal powder and then feeds it into the two-layer burners D and E; the furnace combustion system includes six-layer burners 16 of A, B, C, D, E, and F, the main combustion zone, the blending zone, and the burnout zone, and burns the fed fuel in the furnace; the air supply system includes a blower 18 and an air preheater, and inputs hot air into the coal blending mill 8, the high-alkali coal mill 14, the five-layer burners 16 of A, B, C, D, and E, and the burnout zone; the monitoring system monitors key parameters such as the furnace outlet temperature, the furnace outlet heating rate, the furnace load, and the furnace outlet excess air coefficient, and feeds back to the corresponding components to adjust the operating status according to the operating conditions. The corresponding components include the high-quality coal hopper electric gate 4, the low-quality coal hopper electric gate 5, the high-alkali coal hopper electric gate 12 and the blower 18.

[0035] See also Figure 2 The present invention proposes a coal blending method for variable load combustion of high-alkali coal, comprising the following steps:

[0036] S1, the system mixes two kinds of coal of different qualities, good and bad, outside the furnace. The good and bad coals fall into the coal hopper from the coal conveyor belt respectively, pass through the electric gate, fall into the coal feeder, and then are sent to the coal mill and the powder exhaust fan, and finally are sent to the three-layer burners A, B, and C for combustion in the main combustion area.

[0037] S2, high-alkali coal is mixed and burned in the furnace. It falls from the coal conveyor belt into the coal hopper, passes through the electric gate, falls into the coal feeder, and is then sent to the coal mill and the pulverized coal exhaust fan, and finally sent to the D and E burners to be burned in the mixed burning area.

[0038] S3, during the combustion process, the F layer burner is on standby, and the monitoring system monitors key parameters such as furnace outlet temperature, furnace outlet heating rate, furnace load and furnace outlet excess air coefficient in real time.

[0039] S4, when the furnace is running at low load, the monitoring system will feed back the load situation to the coal distribution hopper electric gate, the high-alkali coal hopper electric gate and the air blower. In terms of fuel, the opening of the electric gate of the high-quality coal hopper becomes larger, and the opening of the electric gate of the low-quality coal hopper becomes smaller, increasing the amount of high-quality coal entering and reducing the amount of low-quality coal entering, so as to stabilize the combustion; the opening of the electric gate of the high-alkali coal hopper is appropriately adjusted to ensure that the furnace outlet temperature and the heating rate are lower than the set value. In terms of air supply, the air blower increases the air supply to increase the oxygen content in the furnace and stabilize the combustion; at the same time, the monitoring system monitors the excess air coefficient at the furnace outlet in real time to determine whether the oxygen content in the furnace has reached the expected value.

[0040] S5, when the furnace is running at high load, the monitoring system will feed back the load situation to the electric gate of the coal hopper for coal blending, the electric gate of the high-alkali coal hopper and the blower. In terms of fuel, the opening of the electric gate of the high-quality coal hopper becomes smaller, and the opening of the electric gate of the low-quality coal hopper becomes larger, reducing the amount of high-quality coal entering and increasing the amount of low-quality coal entering, thereby improving the economic benefits of combustion. In addition, the content of alumina, silica, etc. in low-quality coal is relatively high, so when more low-quality coal is burned as high-alkali coal blending, it can effectively capture alkali metal ash and slow down the slagging and ash accumulation of the boiler. The opening of the electric gate of the high-alkali coal hopper is appropriately adjusted to ensure that the furnace outlet temperature and the heating rate are both lower than the set value. In terms of air supply, the blower reduces the air supply volume to reduce the oxygen content in the furnace and prevent the main combustion zone from burning too violently and coking; at the same time, the monitoring system monitors the excess air coefficient at the furnace outlet in real time to determine whether the oxygen content in the furnace has reached the expected value.

[0041] S6, when the monitoring system detects that the furnace outlet temperature or heating rate is high, it means that the furnace slagging and ash accumulation is serious or the slagging and ash accumulation rate is fast. At this time, the electric gate opening of the high-alkali coal hopper becomes smaller, and the amount of high-alkali coal entering is reduced. At the same time, the electric gate opening of the coal hoppers of the superior and inferior coal blends is appropriately increased to increase the amount of coal blending, slow down the slagging and ash accumulation of the boiler, and ensure the safe operation of the boiler. The monitoring system monitors the parameters in real time and feeds back to the corresponding components. The corresponding components repeat the above adjustment operations until the furnace outlet temperature and heating rate are both lower than the set values.

[0042] See also Figure 3 , key parameters such as furnace outlet temperature, heating rate, operating load and excess air coefficient are input into the monitoring system for real-time monitoring. When the monitoring system detects that parameters such as furnace outlet temperature, heating rate and excess air coefficient do not meet the set standards, it will feedback to the air blower, high-quality coal hopper electric gate, low-quality coal hopper electric gate or high-alkali coal hopper electric gate to adjust the air supply of the air blower, the opening of the high-quality coal hopper electric gate, the opening of the low-quality coal hopper electric gate or the opening of the high-alkali coal hopper electric gate until the monitoring data returns to the standard range or can adapt to the current load.

[0043] The present invention adopts a coal blending system and method for variable load combustion of high-alkali coal of the above structure to solve the serious slagging and ash accumulation problem caused by variable load combustion of high-alkali coal in the boiler. The present invention is reasonably designed and can scientifically and intelligently adapt to the variable load process and the amount of high-alkali coal blended in the furnace, thereby improving the economic benefits and safety stability of boiler combustion.

[0044] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A coal blending system for variable load combustion of high-alkali coal, characterized in that: include: The high-alkali coal in-furnace mixing and conveying system comprises a high-alkali coal conveying belt 1, a low-quality coal conveying belt 2, a coal-mixing hopper 6, a partition plate 3, an electric gate 4 for the high-quality coal hopper, an electric gate 5 for the low-quality coal hopper, a coal-mixing mill 8, a coal-mixing feeder 7 and a coal-mixing exhaust fan 9; the high-alkali coal in-furnace mixing and conveying system comprises a high-alkali coal conveying belt 10, a high-alkali coal hopper 11, a high-alkali coal hopper electric gate 12, a high-alkali coal pulverizer 14, a high-alkali coal feeder machine 13 and high-alkali coal exhaust fan 15; the furnace combustion system includes six layers of burners 16, A, B, C, D, E, F, the main combustion zone, the blending zone and the burnout zone; the air supply system includes a blower 18 and an air preheater; the monitoring system monitors key parameters such as furnace outlet temperature, furnace outlet temperature rise rate, furnace load and furnace outlet excess air coefficient, and feeds back to corresponding components to adjust the operating status according to the operating conditions, and the corresponding components include high-quality coal hopper electric gate 4, low-quality coal hopper electric gate 5, high-alkali coal hopper electric gate 12 and blower 18.

2. A coal blending system for variable load combustion of high-alkali coal according to claim 1, characterized in that: In the system, a combination of off-furnace premixing and in-furnace co-firing is adopted. In-furnace co-firing can alleviate slagging and ash accumulation during the combustion of high-alkali coal, and off-furnace premixing can adapt to rapid load changes, enhance the economy of coal combustion, and further alleviate slagging and ash accumulation during the combustion of high-alkali coal under high load.

3. The coal blending system for variable load combustion of high-alkali coal according to claim 1, characterized in that: In the above-mentioned operation, the oxygen content in the furnace is determined by monitoring the excess air coefficient at the furnace outlet.

4. The coal blending system for variable load combustion of high-alkali coal according to claim 1, characterized in that: In the above operation, the furnace slagging and ash accumulation condition is judged by monitoring the furnace outlet temperature and the furnace outlet heating rate. When the furnace outlet temperature or the furnace outlet heating rate is higher than the preset value, it indicates that the furnace slagging and ash accumulation is serious.

5. The coal blending system for variable load combustion of high-alkali coal according to claim 1, characterized in that: The system status is monitored in real time and fed back to the corresponding components. The corresponding components adjust the opening of the coal hopper electric gate of high-quality coal, low-quality coal and high-alkali coal, and the air supply of the fan to quickly change the coal blending amount and respond to load changes.

6. A method for blending high-alkali coal for variable load combustion using a coal blending system for variable load combustion of high-alkali coal according to claims 1 to 5, characterized in that: The following steps are involved: S1, the system mixes two kinds of coal of different qualities, good and bad, outside the furnace. The good and bad coals fall from the coal conveyor belt into the coal hopper, pass through the electric gate, fall into the coal feeder, and then into the coal mill and the pulverized coal exhaust fan, and finally into the three-layer burners A, B, and C for combustion in the main combustion area; S2, high-alkali coal is mixed and burned in the furnace. It falls from the coal conveyor belt into the coal hopper, passes through the electric gate, falls into the coal feeder, and then is sent to the coal mill and the pulverized coal exhaust fan, and finally sent to the D and E burners to be burned in the mixed burning area; S3, during the combustion process, the F layer burner is on standby, and the monitoring system monitors key parameters such as furnace outlet temperature, furnace outlet heating rate, furnace load and furnace outlet excess air coefficient in real time; S4, when the furnace is running at low load, the monitoring system will feed back the load situation to the coal distribution hopper electric gate, the high-alkali coal hopper electric gate and the blower. In terms of fuel, the opening of the high-quality coal hopper electric gate becomes larger, and the opening of the low-quality coal hopper electric gate becomes smaller, increasing the amount of high-quality coal entering and reducing the amount of low-quality coal entering, so as to stabilize the combustion; the opening of the high-alkali coal hopper electric gate is appropriately adjusted to ensure that the furnace outlet temperature and heating rate are lower than the set value. In terms of air supply, the blower increases the air supply volume to increase the oxygen content in the furnace and stabilize the combustion; at the same time, the monitoring system monitors the excess air coefficient at the furnace outlet in real time to determine whether the oxygen content in the furnace reaches the expected value; S5. When the furnace is running at high load, the monitoring system will feed back the load situation to the electric gate of the coal hopper, the electric gate of the high-alkali coal hopper and the blower. In terms of fuel, the opening of the electric gate of the high-quality coal hopper becomes smaller, and the opening of the electric gate of the low-quality coal hopper becomes larger, reducing the amount of high-quality coal entering and increasing the amount of low-quality coal entering, so as to improve the economic benefits of combustion. In addition, the content of alumina and silica in low-quality coal is relatively high, so when more low-quality coal is burned as high-alkali coal blending, it can effectively capture alkali metal ash and slow down the slagging and ash accumulation of the boiler. The opening of the electric gate of the high-alkali coal hopper is appropriately adjusted to ensure that the furnace outlet temperature and the heating rate are lower than the set value. In terms of air supply, the blower reduces the air supply volume to reduce the oxygen content in the furnace and prevent the main combustion zone from burning too violently and coking. At the same time, the monitoring system monitors the excess air coefficient at the furnace outlet in real time to determine whether the oxygen content in the furnace has reached the expected value. S6. When the monitoring system detects that the furnace outlet temperature or the heating rate is high, it means that the furnace slagging and ash accumulation is serious or the slagging and ash accumulation rate is fast. At this time, the electric gate opening of the high-alkali coal hopper becomes smaller, reducing the amount of high-alkali coal entering. At the same time, the electric gate openings of the two types of coal hoppers with good and bad coal blending become appropriately larger, increasing the amount of coal entering, slowing down the slagging and ash accumulation of the boiler and ensuring the safe operation of the boiler. The monitoring system monitors the parameters in real time and feeds back to the corresponding components. The corresponding components repeat the above adjustment operations until the furnace outlet temperature and the heating rate are lower than the set values.

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