Intelligent combustion control technology for waste incineration is a key component of the "Research and Demonstration of Large-Scale (700t/d) Intelligent Waste Incineration Equipment" project, part of the 12th Five-Year Plan for Science and Technology Support. Approved by the Ministry of Science and Technology for implementation at the end of 2014, it was initially piloted on the 700t/d incineration line #3 in Nan'an, Fujian Province.
This project focuses on developing an intelligent automatic combustion control system (ITCC) tailored to the incineration of municipal solid waste in my country. This aims to minimize the impact of varying characteristics of municipal solid waste on incineration conditions and improve the automation level of municipal solid waste incineration plants.
Grate-type waste incinerators in operation in my country typically regulate the feeder and grate operation based on furnace temperature during startup and main steam flow rate during operation. Some grate technologies also incorporate slag thermal burn-off rate, bed thickness, and oxygen content as control factors into the grate control system. However, incorporating multiple factors related to grate feeding and grate-type waste incineration into the waste incineration combustion control system is worthy of research and development.
Intelligent combustion control technology for waste incineration incorporates multiple factors into the control system, including waste input volume, waste calorific value prediction, flame monitoring, main steam flow rate, uniform feeding, bed temperature and thickness, burnout rate, oxygen content, and primary and secondary air distribution. By applying a variety of calculation and algorithmic techniques, it automatically and effectively controls the operation of the feeder, reverse and forward grates, and the air volume entering the furnace, achieving uniform feeding and combustion in large grate-type waste incinerators.
The practical applications of intelligent combustion control technology for waste incinerators mainly include: furnace flame radiation temperature field and bed thickness monitoring technology, waste calorific value calculation and verification control system, air volume ratio scheme and control algorithm, application of online calculation algorithm software package for municipal solid waste calorific value, air volume ratio scheme and control algorithm for waste incinerators with unstable waste calorific value, fuzzy online adjustment of control parameters for waste incineration plant operation, coordination with DCS, and digital measurement, control, and interface technologies.
(1) The garbage calorific value calculation module calculates the calorific value of the garbage entering the furnace in real time through the real-time accumulation of the main steam volume of the garbage incinerator and the real-time accumulation of the garbage entering the furnace, combined with the boiler heat balance, and directly reflects the data on the main control interface. The main control interface of the garbage incinerator heat balance principle diagram has the real-time numerical value of the garbage calorific value
(2) Monitoring the temperature field of the combustion section of the garbage incinerator Due to the large volume of the large grate-type incinerator, the temperature distribution in the furnace is uneven, that is, the temperature in different parts of the furnace is different, and it is more difficult to monitor the central part of the grate. The incineration temperature here refers to the highest temperature that can be achieved by the incineration of garbage in the combustion section. Generally speaking, the temperature in the area above the garbage layer in the combustion section and close to the combustion flame is the highest, reaching 850~1100℃. The higher the calorific value of domestic garbage, the higher the incineration temperature that can be achieved, which is more conducive to the incineration of domestic garbage. At the same time, temperature and residence time are a pair of related factors. Appropriately shortening the residence time at a higher temperature can also maintain a better incineration effect. The intelligent combustion control technology for garbage incineration is equipped with four high-temperature cameras on the upper part of the two-stage garbage incineration grate, which can cover the combustion section and drying section of the grate. The flame intensity is converted into data and fed back to the DCS system through the flame radiation temperature field software. The flame intensity data is displayed on the DCS in the flame temperature analysis system software interface of the garbage furnace. (3) Intelligent combustion control system The intelligent combustion control system inputs data such as the amount of garbage, garbage calorific value, flame intensity, main steam flow, material layer temperature and thickness, burnout rate, oxygen content, primary air volume, and secondary air volume related to the feeder and grate operation into the system. According to the set logical relationship, it automatically calculates the stroke, start and stop time and operating speed of the feeder, reverse grate, and forward grate; the control system can realize the independent drive of a single grate or the synchronous drive of multiple grates. It avoids the instability caused by human factors during operation. (4) The thickness of the material layer in the garbage combustion section is inconsistent. The operator must judge the combustion status according to the incineration effect of the garbage in the furnace (combustion area, flame height, brightness), and reasonably adjust the material layer thickness to ensure stable combustion of the garbage. Too much thickness may lead to incomplete combustion and unstable combustion; too thin thickness will not produce enough combustion heat, which will reduce the processing capacity of the incinerator and cause the combustion conditions to fluctuate unstably. Therefore, it is particularly important to control the thickness of the material layer. By collecting the pressure difference between the upper and lower grate, combining the primary air volume and high-temperature camera equipment to obtain flame intensity data, a calculation model for the material layer thickness is established, and the material layer thickness is directly turned on the control interface, so that the operator can directly judge the material layer thickness. With the support of the National "Twelfth Five-Year Plan" Science and Technology Support Plan, the application of intelligent combustion control technology for garbage incineration has achieved the expected results on 700 tons/day. The experimental engineering application shows that the input of automatic control is compared with manual control, and the fluctuation range of furnace temperature, garbage layer thickness, oxygen content in flue gas, furnace negative pressure, etc. is reduced by more than 30%. Reverse New Century has begun to apply this control technology to small and medium-sized furnaces to promote the application and serialization of intelligent combustion control technology for waste incineration, and provide positive and effective technical equipment and means for the stable operation and standard emission of grate-type waste incinerators.
Intelligent combustion control technology for waste incineration is a key component of the "Research and Demonstration of Large-Scale (700t/d) Intelligent Waste Incineration Equipment" project, part of the 12th Five-Year Plan for Science and Technology Support. Approved by the Ministry of Science and Technology for implementation at the end of 2014, it was initially piloted on the 700t/d incineration line #3 in Nan'an, Fujian Province.
This project focuses on developing an intelligent automatic combustion control system (ITCC) tailored to the incineration of municipal solid waste in my country. This aims to minimize the impact of varying characteristics of municipal solid waste on incineration conditions and improve the automation level of municipal solid waste incineration plants.
Grate-type waste incinerators in operation in my country typically regulate the feeder and grate operation based on furnace temperature during startup and main steam flow rate during operation. Some grate technologies also incorporate slag thermal burn-off rate, bed thickness, and oxygen content as control factors into the grate control system. However, incorporating multiple factors related to grate feeding and grate-type waste incineration into the waste incineration combustion control system is worthy of research and development.
Intelligent combustion control technology for waste incineration incorporates multiple factors into the control system, including waste input volume, waste calorific value prediction, flame monitoring, main steam flow rate, uniform feeding, bed temperature and thickness, burnout rate, oxygen content, and primary and secondary air distribution. By applying a variety of calculation and algorithmic techniques, it automatically and effectively controls the operation of the feeder, reverse and forward grates, and the air volume entering the furnace, achieving uniform feeding and combustion in large grate-type waste incinerators.
The practical applications of intelligent combustion control technology for waste incinerators mainly include: furnace flame radiation temperature field and bed thickness monitoring technology, waste calorific value calculation and verification control system, air volume ratio scheme and control algorithm, application of online calculation algorithm software package for municipal solid waste calorific value, air volume ratio scheme and control algorithm for waste incinerators with unstable waste calorific value, fuzzy online adjustment of control parameters for waste incineration plant operation, coordination with DCS, and digital measurement, control, and interface technologies.
(1) The garbage calorific value calculation module calculates the calorific value of the garbage entering the furnace in real time through the real-time accumulation of the main steam volume of the garbage incinerator and the real-time accumulation of the garbage entering the furnace, combined with the boiler heat balance, and directly reflects the data on the main control interface. The main control interface of the garbage incinerator heat balance principle diagram has the real-time numerical value of the garbage calorific value
(2) Monitoring the temperature field of the combustion section of the garbage incinerator Due to the large volume of the large grate-type incinerator, the temperature distribution in the furnace is uneven, that is, the temperature in different parts of the furnace is different, and it is more difficult to monitor the central part of the grate. The incineration temperature here refers to the highest temperature that can be achieved by the incineration of garbage in the combustion section. Generally speaking, the temperature in the area above the garbage layer in the combustion section and close to the combustion flame is the highest, reaching 850~1100℃. The higher the calorific value of domestic garbage, the higher the incineration temperature that can be achieved, which is more conducive to the incineration of domestic garbage. At the same time, temperature and residence time are a pair of related factors. Appropriately shortening the residence time at a higher temperature can also maintain a better incineration effect. The intelligent combustion control technology for garbage incineration is equipped with four high-temperature cameras on the upper part of the two-stage garbage incineration grate, which can cover the combustion section and drying section of the grate. The flame intensity is converted into data and fed back to the DCS system through the flame radiation temperature field software. The flame intensity data is displayed on the DCS in the flame temperature analysis system software interface of the garbage furnace. (3) Intelligent combustion control system The intelligent combustion control system inputs data such as the amount of garbage, garbage calorific value, flame intensity, main steam flow, material layer temperature and thickness, burnout rate, oxygen content, primary air volume, and secondary air volume related to the feeder and grate operation into the system. According to the set logical relationship, it automatically calculates the stroke, start and stop time and operating speed of the feeder, reverse grate, and forward grate; the control system can realize the independent drive of a single grate or the synchronous drive of multiple grates. It avoids the instability caused by human factors during operation. (4) The thickness of the material layer in the garbage combustion section is inconsistent. The operator must judge the combustion status according to the incineration effect of the garbage in the furnace (combustion area, flame height, brightness), and reasonably adjust the material layer thickness to ensure stable combustion of the garbage. Too much thickness may lead to incomplete combustion and unstable combustion; too thin thickness will not produce enough combustion heat, which will reduce the processing capacity of the incinerator and cause the combustion conditions to fluctuate unstably. Therefore, it is particularly important to control the thickness of the material layer. By collecting the pressure difference between the upper and lower grate, combining the primary air volume and high-temperature camera equipment to obtain flame intensity data, a calculation model for the material layer thickness is established, and the material layer thickness is directly turned on the control interface, so that the operator can directly judge the material layer thickness. With the support of the National "Twelfth Five-Year Plan" Science and Technology Support Plan, the application of intelligent combustion control technology for garbage incineration has achieved the expected results on 700 tons/day. The experimental engineering application shows that the input of automatic control is compared with manual control, and the fluctuation range of furnace temperature, garbage layer thickness, oxygen content in flue gas, furnace negative pressure, etc. is reduced by more than 30%. Reverse New Century has begun to apply this control technology to small and medium-sized furnaces to promote the application and serialization of intelligent combustion control technology for waste incineration, and provide positive and effective technical equipment and means for the stable operation and standard emission of grate-type waste incinerators.