Automatic control system for boiler combustion

Abstract

The utility model discloses an automatic boiler combustion control system which comprises a PLC (programmable logic controller), a heat exchange chamber, an induced draft fan, an air blower, a bubble water level adjusting device and a discharging device. The bubble water level adjusting device comprises a liquid level sensor arranged in a boiler drum, a water inlet header pipe communicated with a water inlet of the boiler drum and a main steam header pipe communicated with a steam outlet of the boiler drum. A steam flow sensor electrically connected with the PLC is arranged on the side, close to a steam outlet of a boiler drum, of the main steam main pipe, and a steam pressure sensor electrically connected with the PLC is arranged on the side, extending out of the heat exchange chamber, of the main steam main pipe. And thermocouples are respectively arranged at different height positions on the front side and the rear side in the boiler furnace. According to the utility model, the slag adding amount of boiler combustion and the air supply amount can be automatically controlled, the steam stability is ensured, and manual operation is not needed under the normal operation state of the boiler.

Description

Technical Field

[0001] The utility model belongs to the technical field of boiler combustion control, and in particular relates to an automatic boiler combustion control system. Background Art

[0002] Boiler is an energy conversion device; it is used to convert the heat energy of electric energy or fuel combustion through the boiler, and output steam, high-temperature water or organic heat carrier with certain heat energy to meet people's production and living needs. In the process of steam generation and transportation, the combustion condition of the boiler has a very significant impact on the generation and transportation utilization rate of steam; its fuel is mainly natural gas, coal gas or coal. With the decreasing coal resources, the production cost is getting higher and higher. At present, sugarcane sugar factories use sugarcane bagasse or pith as boiler fuel. The existing boiler control system of sugarcane sugar factories is that except for the automatic control of boiler feed water, other links need to be manually adjusted and controlled by the manual experience of boiler operators. The automation degree of boiler combustion system is not high, the control of bagasse or pith feeding is unstable, and it is difficult to adjust the boiler operating conditions in time, resulting in incomplete combustion, which has a great impact on the balanced production of steam, causing large fluctuations in steam pressure and flow, affecting the steam use of sugar making equipment. The thermal utilization efficiency of steam and combustion is not high, which affects the energy saving effect, resulting in high energy consumption and flue gas emission standards, resulting in energy waste. Utility Model Content

[0003] The purpose of this utility model is to provide a boiler combustion automatic control system. The control system of this utility model can automatically control the amount of slag added to the boiler combustion and the amount of air supply according to the needs of production operation. When the boiler is operating normally and production is normal, no manual operation is required. In order to achieve the above purpose, this utility model adopts the following technical effects:

[0004] According to one aspect of the utility model, a boiler combustion automatic control system is provided, the combustion automatic control system comprises a PLC controller, a heat exchange chamber, an induced draft fan and a blower, a bubble water level regulating device and a discharge device for delivering combustion materials into the boiler furnace, the outlet end of the discharge device is connected to one side of the combustion material delivery inlet of the boiler, the smoke outlet of the boiler is connected to the inner top of the heat exchange chamber through a heat transport pipe, the blast transport main pipe connected to the air outlet of the blower enters the heat exchange chamber and then extends out to be connected to the air inlet of the boiler, the bottom end of the heat exchange chamber is connected to the induced draft fan through an exhaust pipe, the bubble water level regulating device comprises a liquid level sensor arranged in the boiler drum, a water inlet main pipe connected to the water inlet of the boiler drum, and a liquid level sensor arranged in the boiler drum. A pipe and a main steam main pipe connected to the steam outlet of the boiler drum, a section of the main pipe between the water outlet and the water inlet of the water inlet main pipe is coiled in the heat exchange chamber, a section of the main pipe between the steam inlet end and the outlet end of the main steam main pipe is coiled in the heat exchange chamber, a steam flow sensor electrically connected to the PLC controller is arranged on the main steam main pipe close to the steam outlet of the boiler drum, a steam pressure sensor electrically connected to the PLC controller is arranged on the main steam main pipe located on the side where the main steam main pipe extends out of the heat exchange chamber, thermocouples are respectively arranged at different heights on the front and rear sides of the boiler furnace, and the output ends of the thermocouples and the output ends of the liquid level sensor are respectively electrically connected to the PLC controller.

[0005] The above scheme is further preferred, that is, the combustion control system also includes a secondary blast device, the outlet end of the secondary blast device is connected to the air inlet of the boiler through a first air supply pipe, an air volume control valve is provided on the blast delivery main pipe close to the air outlet side of the blower, and an induced draft control valve is provided on the exhaust pipe close to the induced draft side of the induced draft fan.

[0006] The above scheme is further preferred, wherein the secondary air blast device includes a first fan, a three-way pipe head, a first air supply pipe and a secondary air duct, the three-way pipe head is arranged at the outlet end of the first fan, the outlet end of the first fan is connected to the air inlet of the boiler through the first output end of the three-way pipe head, the first air supply pipe, and the outlet end of the first fan is connected to the front and rear sides of the boiler furnace through the second output end of the three-way pipe head and the secondary air duct.

[0007] The above scheme is further preferred that a primary air supply flow control valve is arranged on the first air supply pipe on the side close to the first output end of the three-way pipe head, first branch air ducts connected to the secondary air duct are respectively arranged at the upper end of the front side and the upward and lower ends of the rear side in the boiler furnace, a second branch air duct connected to the first air supply pipe is arranged at the lower end of the front side in the boiler furnace, and secondary air supply control valves are respectively arranged on the first branch air duct and the second branch air duct.

[0008] The above scheme is further preferred, wherein the unloading device includes a combustion material conveyor belt, a unloading hopper, a dropping pipe and a scraper plate, and a plurality of unloading hoppers are respectively arranged below the combustion material conveyor belt, and the outlet end of each unloading hopper is connected to the combustion material inlet of the boiler through a dropping pipe, and the scraper plates are respectively arranged on the sides of the combustion material conveyor belt above each unloading hopper.

[0009] The above scheme is further preferred, that is, one or two independent exchange chambers are respectively provided at the bottom end of the heat exchange chamber from bottom to top, and the air outlet end of the air blast conveying main pipe passes through one or two independent exchange chambers in the heat exchange chamber and then extends out to be connected to the air inlet of the boiler; a water inlet branch pipe is also connected in parallel to the water inlet main pipe, and the water outlet end of the water inlet branch pipe passes through one or two exchange chambers in the heat exchange chamber and then is connected to the water inlet main pipe in the heat exchange chamber.

[0010] The above scheme is further preferred, in which a section of the main steam main pipe between the steam inlet end and the outlet end is coiled in the heat exchange chamber above the exchange cavity, and a steam control valve is provided on the main steam main pipe located on the side extending out of the heat exchange chamber and at the rear end of the steam pressure sensor, a steam exhaust pipe is connected to the input side of the steam control valve, and a steam discharge valve is provided on the steam exhaust pipe.

[0011] The above scheme is further preferred, in which a water inlet regulating valve is provided on the water inlet main pipe near the side extending into the heat exchange chamber, a water supply valve is provided on the water inlet branch pipe near the water inlet end of the water inlet main pipe, a bypass water inlet pipe is connected in parallel to the water inlet branch pipe, and a bypass valve is provided on the bypass water inlet pipe.

[0012] In summary, the utility model adopts the above technical solution, and the utility model has the following technical effects:

[0013] The combustion control system of the utility model reduces the combustion energy consumption of the boiler, improves the packaging rate of bagasse, can provide stable steam pressure to the sugar making equipment during the steam use process through the boiler drum, can automatically control the amount of slag added to the boiler combustion and the coordination of the automatic control air supply volume according to the needs of production operation during the boiler combustion process, can stably provide high-temperature steam without manual operation under the normal operation of the boiler and normal production conditions, realizes true automatic control of boiler combustion, reduces the complexity of manual monitoring and operation, improves combustion efficiency and automation, thereby realizing automatic adjustment and optimization of steam flow and steam pressure by the combustion control system, reduces the influence of manual control factors, makes the boiler burn more fully, and can also improve the combustion efficiency and thermal energy utilization rate of the boiler and reduce energy waste. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic diagram of the system principle of a boiler combustion automatic control system of the utility model;

[0015] Figure 2 This is a control schematic diagram of a boiler combustion automatic control system of the utility model;

[0016] In the drawings, a boiler 1, a discharge device 2, a heat exchange chamber 3, an induced draft fan 5, a blower 6, a bubble water level regulating device 7, a boiler drum 8, a thermocouple 9, a heat transport pipe 10, an exhaust pipe 11, an induced draft control valve 11a, a first air supply pipe 12, a primary air supply flow control valve 12a, an air inlet 13, a first fan 41, a three-way pipe head 41a, a secondary air pipe 42, a first branch air pipe 42a, a second branch air pipe 42b, a secondary air supply control valve 42c, a cross The exchange chamber 30, the blast conveying main pipe 60, the air volume control valve 61, the water delivery pump 70, the water inlet main pipe 70a, the water inlet regulating valve 70b, the main steam main pipe 71, the steam discharge pipe 71b, the steam discharge valve 71c, the steam flow sensor 72, the steam pressure sensor 73, the water inlet branch pipe 74, the bypass water inlet pipe 75, the bypass valve 75a, the liquid level sensor 81, the combustion material conveyor belt 201, the discharge hopper 202, the drop pipe 203, and the scraper plate 204. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail with reference to the accompanying drawings and preferred embodiments. However, it should be noted that many details listed in the specification are only for the purpose of enabling readers to have a thorough understanding of one or more aspects of the utility model, and these aspects of the utility model can be realized even without these specific details.

[0018] Combination Figure 1 and Figure 2As shown, according to a boiler combustion automatic control system of the utility model, the combustion automatic control system includes a PLC controller, a heat exchange chamber 3, an induced draft fan 5 and a blower 6, a bubble water level regulating device 7 and a discharge device 2 for delivering combustion materials into the furnace of the boiler 1, the smoke exhaust port of the boiler 1 is connected to the inner top of the heat exchange chamber 2 through a heat transport pipe 10, the blast transport main pipe 60 connected to the air outlet of the blower 6 enters the heat exchange chamber 3 and then extends to the air inlet 13 of the boiler 1, the bottom end of the heat exchange chamber 6 is connected to the induced draft fan 5 through an exhaust pipe 11, the bubble water level regulating device 7 includes a liquid level sensor 81 arranged in the boiler drum 8, a water inlet main pipe 70a connected to the water inlet of the boiler drum 8 and a steam outlet connected to the boiler drum 8. A main steam main pipe 71 is connected to the heat exchange chamber 3, a section of the main pipe between the water outlet and the water inlet of the water inlet main pipe 70a is coiled in the heat exchange chamber 3, a section of the main pipe between the steam inlet end and the outlet end of the main steam main pipe 71 is coiled in the heat exchange chamber 3, a steam flow sensor 72 electrically connected to the PLC controller is arranged on the main steam main pipe 71 near the steam outlet side of the boiler drum 8, a steam pressure sensor 73 electrically connected to the PLC controller is arranged on the main steam main pipe 71 on the side where the main steam main pipe 71 extends out of the heat exchange chamber 3, and thermocouples 13 are respectively arranged at different heights on the front and rear sides of the furnace of the boiler 1, and the output end of the thermocouple 13 and the output end of the liquid level sensor 81 are respectively electrically connected to the PLC controller;

[0019] In the present utility model, combined with Figure 1 and Figure 2As shown, the water delivery pump 70 delivers water into the boiler drum 8 through the water inlet main pipe 70a. A water inlet regulating valve 70b is provided on the water inlet main pipe 70a near the side extending into the heat exchange chamber 3. The water temperature in the boiler drum 8 is adjusted by the water inlet regulating valve 70b. The unloading device 2 delivers bagasse or sugarcane pith into the furnace of the boiler 1 for combustion. The hot exhaust gas generated by the combustion is delivered to the heat exchange chamber 3 through the exhaust pipe 11 for heat exchange. After the temperature of the exhaust gas is reduced, it is delivered to the exhaust chimney 50 through the induced draft fan 5 for discharge. The heat generated by the combustion of bagasse or sugarcane pith in the furnace of the boiler 1 heats the water in the boiler drum 8 to generate water vapor, which is delivered to the sugar making equipment for use through the main steam main pipe 71. The heat exchange chamber 3 is provided on the pipeline of the main steam main pipe 71 for heat preservation and temperature regulation of the steam to ensure the saturation of the steam and prevent the overheated or low-temperature steam from being input into the sugar making equipment. The temperature of the air sent into the furnace by the blower 6 is too low, which affects the temperature in the furnace. Therefore, the pipeline of the blast conveying main pipe 60 enters the heat exchange chamber 3 to perform heat exchange on the air in the blast conveying main pipe 60. After the temperature of the air is increased, the air is sent to the air inlet 13 of the boiler 1 through the blast conveying main pipe 60 to provide combustion-supporting oxygen for the combustion of bagasse or pith, thereby improving the combustion efficiency of bagasse in the furnace of the boiler 1. The thermocouple 9 is used to detect the temperature in the furnace of the boiler 1. The steam flow sensor 72 is used to detect the steam flow flowing through the main steam main pipe 71. The steam pressure sensor 73 is used to detect the internal pressure of the main steam main pipe 71 on the steam-using side of the sugar-making equipment. The steam pressure inside the main steam main pipe 71 is stably maintained by changing the amount of bagasse or pith sent into the boiler furnace by the unloading device 2, the internal temperature of the main steam main pipe 71 and the amount of combustion-supporting air.

[0020] In the present utility model, combined with Figure 1 and Figure 2As shown, the combustion control system also includes a secondary blast device 4, the outlet end of the secondary blast device 4 is connected to the air inlet 13 of the boiler 1 through the first air supply pipe 12, an air volume control valve 61 is provided on the blast delivery main pipe 60 near the air outlet side of the blower 6, and an induced draft control valve 11a is provided on the exhaust pipe 11 near the induced draft side of the induced draft fan 5. The blower 6 sends most of the air through the blast delivery main pipe 60, passes through the heat exchange chamber 3 for preset, and then is sent to the air inlet 13 of the boiler 1 to reach the combustion chamber ( furnace), thereby assisting the combustion of bagasse, and controlling the air flow rate blown into the air inlet 13 of the boiler 1 through the air volume control valve 61, adjusting the burning speed of the bagasse and adjusting the speed of the hot air moving in the furnace of the boiler 1, the secondary blast device 4 comprises a first fan 41, a three-way pipe head 41a, a first air supply pipe 12 and a secondary air pipe 42, the outlet end of the first fan 41 is provided with the three-way pipe head 41a, the outlet end of the first fan 41 is connected to the first output end of the three-way pipe head 41a, the first air supply pipe 12 and the secondary air pipe 42 of the boiler 1. The first blower 41 is connected to the air inlet 13, and the outlet end of the first blower 41 is connected to the front and rear sides of the furnace of the boiler 1 through the second output end of the three-way pipe head 41a and the secondary air duct 42; a primary air supply flow control valve 12a is provided on the first air supply pipe 12 near the first output end of the three-way pipe head 41a, and first branch air ducts 42a connected to the secondary air duct 42 are respectively provided at the upper end of the front side of the furnace of the boiler 1 and the upper and lower ends of the rear side, and a first branch air duct 42a connected to the secondary air duct 42 is provided at the lower end of the front side of the furnace of the boiler 1. 2, the first branch air duct 42a and the second branch air duct 42b are respectively provided with secondary air supply control valves 42c, and the first blower 41 controls the air supplied through the first air supply duct 12 and the primary air supply flow control valve 12a, and the first branch air duct 42a and the secondary air supply control valve 42c to be directly supplied to various positions of the furnace of the boiler 1 without being preheated, thereby saving the air preheating process and directly providing the oxygen required for the combustion process, and being able to directly adjust the temperature of the combustion process in the boiler 1.

[0021] In the present utility model, combined with Figure 1 and Figure 2As shown, the unloading device 2 includes a combustion material conveyor belt 201, a discharge hopper 202, a drop pipe 203 and a scraper plate 204. A plurality of discharge hoppers 202 are respectively arranged below the combustion material conveyor belt 201. The outlet end of each discharge hopper 202 is connected to the combustion material delivery inlet of the boiler 1 through the drop pipe 203. The scraper plates 204 are respectively arranged on the side of the combustion material conveyor belt 201 above each discharge hopper 202. The opening of the discharge plate (discharge valve) on the discharge hopper 202 is adjusted according to the steam flow and steam pressure of the main steam main 71, and the required amount of bagasse is delivered into the furnace of the boiler 1, so as to meet the required amount of bagasse to control the heating of the boiler drum 8. For this purpose, the transmission speed of the combustion material conveyor belt 201 is controlled according to the required amount of bagasse.

[0022] Combination Figure 1 and Figure 2 As shown, the bottom end of the heat exchange chamber 3 is respectively provided with one or two independent exchange chambers 30 from bottom to top, and the air outlet end of the blast conveying main pipe 60 passes through the one or two independent exchange chambers 30 in the heat exchange chamber 3 and then extends to the air inlet 13 of the boiler 1; a water inlet branch pipe 74 is also connected in parallel to the water inlet main pipe 70, and a water supply valve 74a is provided on the water inlet branch pipe 74 near the water inlet end of the water inlet main pipe 70, and a bypass water inlet pipe 75 is connected in parallel to the water inlet branch pipe 74, and a bypass valve 75a is provided on the bypass water inlet pipe 75, and the water outlet end of the water inlet branch pipe 74 passes through one or two independent exchange chambers 30 in the heat exchange chamber 3. After entering the exchange chamber 30, it is connected to the water inlet main pipe 70 in the heat exchange chamber 3; the temperature at the bottom end of the heat exchange chamber 3 is lower than the temperature at the top end. The water inlet main pipe 70 presets the water in the exchange chamber 30 and then gathers with the water inlet main pipe 70 before being sent to the boiler drum 8 for heating. The air transported by the blast transport main pipe 60 is preset in the exchange chamber 30 and then sent to the air inlet 13 of the boiler 1, so as to realize the heat exchange between the exhaust flue gas and the cold water and cold air, reduce the emission of high-temperature gas, and when the water inlet main pipe 70 replenishes the water level in the boiler drum 8, it can reduce the heating time of the water, improve the utilization rate of filtering combustion, and save bagasse fuel. In the utility model, an emergency drain pipe 76 connected to the inside of the boiler drum 8 is arranged on the side of the steam outlet away from the boiler drum 8, and an emergency drain valve 77 is arranged on the emergency drain pipe 76. When the steam pressure or water level is too high, part of the hot water is discharged through the emergency drain valve 77 to reduce the internal pressure of the boiler drum 8.

[0023] Combination Figure 1 and Figure 2As shown, a section of the main steam main pipe 71 between the steam inlet end and the outlet end is coiled in the heat exchange chamber 3 above the exchange cavity 30, and a steam control valve 71a is arranged on the main steam main pipe 71 located on the side extending out of the heat exchange chamber 3 and at the rear end of the steam pressure sensor 73. A steam exhaust pipe 71b is connected to the input end of the steam control valve 71a, and a steam discharge valve 71c is arranged on the steam discharge pipe 71b. The main steam main pipe 71 is coiled in the heat exchange chamber 3, that is, the coiled section of the main pipe located in the heat exchange chamber 3 is between the top of the heat exchange chamber 3 and the top of the exchange cavity 30. The temperature of the spatial position of the heat exchange chamber 3 is close to the temperature of the flue gas delivered by the heat delivery pipe 10. The main steam main pipe 71 extends out from the heat exchange chamber 3 and delivers steam to the sugar making equipment for use, so that the steam maintains temperature and pressure. When the pressure is too high, the steam is depressurized through the steam discharge valve 71c.

[0024] Combination Figure 1 , Figure 2As shown, the utility model also provides a combustion control process of a boiler combustion automatic control system as follows: the normal operating condition parameters of the boiler 1 are preset, and the normal operating condition parameters include a preset temperature value in the furnace of the boiler 1, a preset opening value of the discharge valve of the discharge hopper 202, a preset water level height value in the boiler drum 8, and a preset steam flow value and a preset steam pressure value in the main steam main pipe 71; the PLC controller obtains a plurality of first steam flow values ​​in the main steam main pipe 71 through the steam flow sensor 72 and obtains a plurality of first steam pressure values ​​through the steam pressure sensor 73 within a first preset time t1. a steam pressure value; performing a difference comparison analysis between each first steam flow value and a preset steam flow value and performing a difference comparison analysis between each first steam pressure value and a preset steam pressure value; according to the flow difference analysis result and the real-time temperature value in the furnace of the boiler 1, controlling the opening of the discharge valve in the discharge hopper 202 to adjust the discharge amount of the combustion material; adjusting the air supply volume of the blower 6 and the secondary air blower 4 according to the air supply volume ratio coefficient according to the discharge amount, and adjusting the exhaust volume of the induced draft fan 5; the air supply volume ratio coefficient is the opening of the discharge valve of each discharge hopper 202 and is adjusted by When the corresponding drop pipe 203 delivers the combustible into the boiler 1, the ratio between the first air flow rate delivered into the furnace of the boiler 1 by the blower 6 through the air volume control valve 61 on the blast delivery main pipe 60 and the second air flow rate delivered into the furnace of the boiler 1 by the first blower 41 through the primary air supply flow control valve 12a on the first air supply pipe 12 is adjusted in real time according to the real-time temperature value in the furnace and the steam flow rate; when the steam flow rate is lower than the preset steam flow rate value or the furnace temperature is lower than the preset temperature value in the furnace of the boiler 1, it indicates that the delivered combustible is insufficient and it is necessary to increase the sugarcane bagasse combustible, and the air supply volume is adjusted according to the real-time temperature value in the furnace and the steam flow rate; when the steam flow rate is lower than the preset steam flow rate value or the furnace temperature is lower than the preset temperature value in the furnace of the boiler 1, it indicates that the delivered combustible is insufficient and it is necessary to increase the sugarcane bagasse combustible, and the ratio between the first air flow rate and the second air flow rate delivered into the furnace of the boiler 1 by the first blower 41 through the primary air supply flow control valve 12a on the first air supply pipe 12 is adjusted in real time according to the real-time temperature value in the furnace and the steam flow rate; when the steam flow rate is lower than the preset steam flow rate value or the furnace temperature is lower than the preset temperature value in the furnace of the boiler 1, it indicates that the delivered combustible is insufficient and it is necessary to increase the sugarcane bagasse combustible, and the ratio between the first air flow rate and the second air flow rate is adjusted according to the real-time temperature value in the furnace and the steam flow rate; The proportioning coefficient increases the air supply into the furnace of the boiler 1, and adjusts the exhaust air volume of the induced draft fan 5 according to the proportion of the air supply. Through real-time air distribution adjustment, the main air flow blown in by the blower 6 and the secondary air flow sent in by the first fan 41 are rotated in an interlaced manner, so that the sugarcane combustibles can be fully burned in the furnace, the generation of flue gas particles during the combustion of the sugarcane combustibles can be reduced, the temperature deviation between the front and rear sides of the furnace of the boiler 1 can be maintained, the boiler combustion rate and heat utilization rate can be improved, so that the boiler drum 8 can generate stable steam, the generation of waste flue gas during the combustion of the sugarcane combustibles can be reduced, and fuel waste can be avoided.In the utility model, the water level in the boiler drum 8 and the air pressure in the main steam main 71 are adjusted according to the pressure difference analysis result and the real-time acquisition of the real-time water level height value in the boiler drum 8; if the real-time water level height value is lower than the preset water level height value when the air pressure in the main steam main 71 changes, water is added to the boiler drum 8; if the real-time water level height value is greater than or equal to the preset water level height value when the air pressure in the main steam main 71 changes (when the pressure increases or decreases), the opening of the discharge valve in the discharge hopper 202 is controlled to automatically adjust the discharge amount of the combustion material, thereby optimizing the amount of sugarcane combustion material entering the furnace of the boiler, reducing the influence of the furnace temperature change on the steam pressure during the combustion of sugarcane bagasse, and making the steam pressure and water level in the boiler drum 8 of the boiler 1 stable, truly realizing automatic control of boiler combustion and stable steam supply.

[0025] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A boiler combustion automatic control system, characterized in that: The combustion automatic control system includes a PLC controller, a heat exchange chamber, an induced draft fan and a blower, a bubble water level regulating device and a discharge device for delivering the combustion material into the furnace of the boiler. The outlet end of the discharge device is connected to one side of the combustion material delivery inlet of the boiler. The smoke exhaust port of the boiler is connected to the inner top of the heat exchange chamber through a heat transport pipe. The blast transport main pipe connected to the air outlet of the blower enters the heat exchange chamber and then extends to the air inlet of the boiler. The bottom end of the heat exchange chamber is connected to the induced draft fan through an exhaust pipe. The bubble water level regulating device includes a liquid level sensor arranged in the boiler drum, a water inlet main pipe connected to the water inlet of the boiler drum, and a steam outlet connected to the boiler drum. A main steam main pipe is connected to the heat exchange chamber, a section of the main pipe between the water outlet and the water inlet of the water inlet main pipe is coiled in the heat exchange chamber, a section of the main pipe between the steam inlet end and the outlet end of the main steam main pipe is coiled in the heat exchange chamber, a steam flow sensor electrically connected to the PLC controller is arranged on the main steam main pipe close to the steam outlet of the boiler drum, a steam pressure sensor electrically connected to the PLC controller is arranged on the main steam main pipe located on the side where the main steam main pipe extends out of the heat exchange chamber, thermocouples are respectively arranged at different heights on the front and rear sides of the boiler furnace, and the output ends of the thermocouples and the output ends of the liquid level sensor are respectively electrically connected to the PLC controller.

2. A boiler combustion automatic control system according to claim 1, characterized in that: The automatic combustion control system also includes a secondary blast device, the outlet end of which is connected to the air inlet of the boiler through a first air supply pipe, an air volume control valve is provided on the blast delivery main pipe on the side close to the air outlet of the blower, and an induced draft control valve is provided on the exhaust pipe on the side close to the induced draft fan's induced draft port.

3. A boiler combustion automatic control system according to claim 2, characterized in that: The secondary air blast device includes a first fan, a three-way pipe head, a first air supply pipe and a secondary air duct. The three-way pipe head is arranged at the outlet end of the first fan. The outlet end of the first fan is connected to the air inlet of the boiler through the first output end of the three-way pipe head and the first air supply pipe. The outlet end of the first fan is connected to the front and rear sides of the boiler furnace through the second output end of the three-way pipe head and the secondary air duct.

4. A boiler combustion automatic control system according to claim 3, characterized in that: A primary air supply flow control valve is arranged on the first air supply pipe on the side close to the first output end of the three-way pipe head, and first branch air ducts connected to the secondary air duct are respectively arranged at the upper end of the front side and the upward and lower ends of the rear side in the boiler furnace, and a second branch air duct connected to the first air supply pipe is arranged at the lower end of the front side in the boiler furnace, and secondary air supply control valves are respectively arranged on the first branch air duct and the second branch air duct.

5. The boiler combustion automatic control system according to claim 1 is characterized in that: The unloading device includes a combustion material conveyor belt, a unloading hopper, a drop pipe and a scraper plate. A plurality of unloading hoppers are respectively arranged below the combustion material conveyor belt. The outlet end of each unloading hopper is connected to the combustion material delivery inlet of the boiler through a drop pipe. The scraper plates are respectively arranged on the side of the combustion material conveyor belt above each unloading hopper.

6. The boiler combustion automatic control system according to claim 1, characterized in that: One or two independent exchange chambers are respectively arranged at the bottom end of the heat exchange chamber from bottom to top, and the air outlet end of the blast conveying main pipe passes through one or two independent exchange chambers in the heat exchange chamber and then extends out to be connected to the air inlet of the boiler; a water inlet branch pipe is also connected in parallel to the water inlet main pipe, and the water outlet end of the water inlet branch pipe passes through one or two exchange chambers in the heat exchange chamber and then is connected to the water inlet main pipe in the heat exchange chamber.

7. The boiler combustion automatic control system according to claim 1, characterized in that: A section of the main steam main pipe between the steam inlet end and the outlet end is coiled in the heat exchange chamber above the exchange cavity. A steam control valve is arranged on the main steam main pipe located on the side extending out of the heat exchange chamber and at the rear end of the steam pressure sensor. A steam exhaust pipe is connected to one side of the input end of the steam control valve, and a steam discharge valve is arranged on the steam exhaust pipe.

8. The boiler combustion automatic control system according to claim 1, characterized in that: A water inlet regulating valve is arranged on the water inlet main pipe near the side extending into the heat exchange chamber, a water supply valve is arranged on the water inlet branch pipe near the water inlet end of the water inlet main pipe, a bypass water inlet pipe is connected in parallel to the water inlet branch pipe, and a bypass valve is arranged on the bypass water inlet pipe.

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