Control method for automatic burning of flue gas furnace
The automatic combustion method for flue gas furnaces, which utilizes multi-point temperature field monitoring and fuzzy PID feedforward control, solves the problems of inaccurate temperature control and energy waste in traditional flue gas furnaces. It achieves precise temperature control and reduced energy consumption, and is applicable to industries such as steel, non-ferrous metal smelting, and chemicals.
Patent Information
- Application Number
- CN202511556813.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-29
- Publication Date
- 2026-02-06
AI Technical Summary
In the traditional flue gas furnace combustion process, the temperature control accuracy is low, energy waste is serious, and reliance on manual experience leads to large temperature fluctuations inside the furnace, affecting production stability and resulting in high energy consumption.
By employing multi-point temperature field monitoring combined with fuzzy PID feedforward control, and through coordinated control of air-fuel ratio and segmented adjustment of valve opening, precise control of furnace temperature is achieved, and safety parameters are monitored in real time to trigger interlock protection.
It can control furnace temperature fluctuations within ±3℃, reduce energy consumption by 20%-30%, reduce manual intervention by 90%, and prevent operational errors and accidents. It is suitable for the steel, non-ferrous metal smelting, and chemical industries.
Smart Images
Figure CN121474585A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of automated control technology for industrial heating equipment, and in particular to a control method for automatic combustion of a flue gas furnace. Background Technology
[0002] Flue gas furnaces are core equipment in industrial production used to heat materials or generate flue gas at specific temperatures (such as drying kilns in the steel industry and roasting furnaces in non-ferrous smelting). Their operating status directly affects product quality, energy efficiency, and production safety. Traditional flue gas furnace combustion processes rely on manual experience for adjustment: operators must manually adjust burner openings, fuel valve openings, and fan speeds based on parameters such as furnace temperature, fuel flow rate, and combustion air volume. This presents the following significant problems: Low temperature control accuracy: It is difficult for humans to respond to temperature fluctuations in the furnace in real time (such as local hot spots or cold spots), which can easily lead to overshooting or undershooting of the target temperature, affecting the stability of subsequent processes. Serious energy waste: The ratio of fuel to combustion air depends on experience, and an unreasonable excess air coefficient (usually 1.5-2.0, far higher than the theoretical value of 1.0-1.2) will cause an increase in flue gas volume and an increase in exhaust heat loss.
[0003] Based on this, the present invention provides a control method for automatic combustion of flue gas furnace. Summary of the Invention
[0004] To address the aforementioned technical problems and overcome the shortcomings of existing technologies, this invention provides a control method for automatic combustion of flue gas furnaces. By using multi-point temperature field monitoring and fuzzy PID feedforward control, the furnace temperature fluctuation is controlled within ±3℃, achieving precise temperature control, meeting the requirements of high-end processes, and significantly reducing energy consumption.
[0005] The automatic combustion control method for flue gas furnaces provided in this solution includes the following steps: Initialization steps: Set the target range for the mill inlet temperature; Air-fuel ratio coordinated control steps: Set the air-fuel ratio of coal gas to air, and achieve proportional adjustment by adjusting the opening of the coal gas regulating valve and the air regulating valve; Temperature control adjustment steps: Based on the gas pressure, adjust the opening of the gas regulating valve and the air regulating valve in real time, and based on the deviation between the actual temperature and the set temperature, use segmented control steps to dynamically adjust the opening of the gas regulating valve and the air regulating valve so that the mill inlet temperature is stable within the target range.
[0006] The technical solution further defined in this invention is: Furthermore, in the initialization step, the target range for the mill inlet temperature is 201°C to 295°C.
[0007] Furthermore, in the air-fuel ratio coordinated control step, the air-fuel ratio is a volume ratio of coal gas to air of 1:0.8.
[0008] Furthermore, the temperature control adjustment step, which adjusts the valve opening based on the gas pressure, specifically includes: When the gas pressure is in the range of 6 kPa to 10 kPa, the gas regulating valve opening X is set to 38%, and the air regulating valve opening Y = X + 10%; When the gas pressure is greater than 10 kPa, reduce the opening of the gas regulating valve X by 5% and adjust the opening of the air regulating valve Y accordingly. When the gas pressure is less than 6 kPa, increase the opening degree X of the gas regulating valve by 3% and adjust the opening degree Y of the air regulating valve accordingly.
[0009] Furthermore, the segmented control steps include: When the actual temperature is more than 10°C lower than the set temperature, the first heating control step is executed, namely rapid heating control, and the opening of the gas regulating valve is set to (set temperature - 200) / 80 × 18% + 20%; When the actual temperature is within the range of -10℃ to -3℃ of the set temperature, the system checks every 30 seconds and executes the second heating control step, namely medium-speed heating control, by increasing the opening of the gas regulating valve by 0.5%. When the actual temperature is within the range of -3℃ to the set temperature, the system checks every 45 seconds and executes the third heating control step, namely low-speed heating control, by increasing the opening of the gas regulating valve by 0.3%. When the actual temperature is within the range of the set temperature to the set temperature +3℃, the system checks every 45 seconds and executes the first cooling control step, namely low-speed cooling control, by reducing the opening of the gas regulating valve by 0.3%. When the actual temperature is within the range of set temperature +3℃ to set temperature +10℃, it is checked every 30 seconds, and the second cooling control step, namely medium-speed cooling control, is executed, reducing the opening of the gas regulating valve by 0.5%. When the actual temperature is more than 10°C higher than the set temperature, the third cooling control step is executed, and the gas regulating valve opening is set to (set temperature - 200) / 200 × 18% + 20%.
[0010] Furthermore, in the segmented control step, the opening degree of the air regulating valve is adjusted synchronously with the opening degree of the gas regulating valve, and the opening degree of the air regulating valve is Y=X+10%.
[0011] Furthermore, the furnace temperature, gas pressure, and CO concentration are monitored in real time. When any parameter exceeds the safety threshold, the interlock protection is triggered within 1 second, automatically cutting off the fuel supply or adjusting the valve opening.
[0012] The beneficial effects of this invention are: (1) The automatic combustion control method of flue gas furnace proposed in this invention controls the furnace temperature fluctuation within ±3℃ (the traditional manual control is ±10-15℃) through multi-point temperature field monitoring and fuzzy PID feedforward control, so as to achieve precise temperature control and meet the requirements of high-end processes; and based on the real-time gas analysis and dynamic adjustment of air-fuel ratio, the excess air coefficient is reduced from the traditional 1.5-2.0 to 1.05-1.15, the exhaust heat loss is reduced by 20%-30%, and the fuel consumption is reduced by 15%-25%, which significantly reduces energy consumption. It is suitable for flue gas furnace scenarios in industries such as steel, non-ferrous metal smelting, and chemical industry that require stable furnace temperature control, optimized fuel consumption and reduced manual intervention. (2) The present invention features full-process automated control (from ignition and heating to constant temperature maintenance), supports remote monitoring and fault diagnosis, and reduces the frequency of manual intervention by more than 90%; the multi-parameter interlock protection (temperature, pressure, CO concentration) has a response time of less than 1 second, eliminating explosion and poisoning accidents caused by operational errors. Attached Figure Description
[0013] Figure 1 This is a schematic diagram of the automatic combustion system of the flue gas furnace in a specific embodiment of the present invention. Detailed Implementation
[0014] This embodiment provides an automatic combustion control method for a flue gas furnace, such as... Figure 1 As shown, the automatic control applied to the automatic combustion system of the flue gas furnace specifically includes the following steps: Initialization steps: Set the target range for the mill inlet temperature to 201-295 degrees Celsius; Air-fuel ratio coordinated control steps: Set the air-fuel ratio of coal gas to air, with the coal gas to air air-fuel ratio set to 1:0.8, and achieve proportional adjustment by adjusting the opening of the coal gas regulating valve and the air regulating valve; Temperature control adjustment steps: Based on the gas pressure, adjust the opening of the gas regulating valve and the air regulating valve in real time, and based on the deviation between the actual temperature and the set temperature, use segmented control steps to dynamically adjust the opening of the gas regulating valve and the air regulating valve so that the mill inlet temperature is stable within the target range.
[0015] Specifically, the temperature control adjustment steps include: for gas pressures between 6 kPa and 10 kPa, the gas regulating valve opening X = 38%, and the combustion air regulating valve opening Y = X + 10%. When the gas pressure is greater than 10 kPa, the opening X decreases by 5%, and when the gas pressure is less than 6 kPa, the opening X increases by 3%, with Y increasing or decreasing accordingly. When the inlet temperature is set to 200 degrees Celsius, the gas regulating valve opening X = 20%, and the air regulating valve opening Y = X + 10%. When the temperature is greater than 280 degrees Celsius, the opening of both the gas and air regulating valves decreases by 2%, and vice versa. The gas regulating valve opening X% = 18% * (set temperature t - 200) / 80 + 20%, with an inlet temperature control range of ±5 degrees Celsius.
[0016] The segmented control process, which enables automatic control of the mill inlet temperature (gas regulating valve, air regulating valve), specifically includes: When the actual temperature is more than 10°C lower than the set temperature, the first heating control step is executed, namely rapid heating control, and the opening of the gas regulating valve is set to (set temperature - 200) / 80 × 18% + 20%; When the actual temperature is within the range of -10℃ to -3℃ of the set temperature, the system checks every 30 seconds and executes the second heating control step, namely medium-speed heating control, by increasing the opening of the gas regulating valve by 0.5%. When the actual temperature is within the range of -3℃ to the set temperature, the system checks every 45 seconds and executes the third heating control step, namely low-speed heating control, by increasing the opening of the gas regulating valve by 0.3%. When the actual temperature is within the range of the set temperature to the set temperature +3℃, the system checks every 45 seconds and executes the first cooling control step, namely low-speed cooling control, by reducing the opening of the gas regulating valve by 0.3%. When the actual temperature is within the range of set temperature +3℃ to set temperature +10℃, it is checked every 30 seconds, and the second cooling control step, namely medium-speed cooling control, is executed, reducing the opening of the gas regulating valve by 0.5%. When the actual temperature is more than 10°C higher than the set temperature, the third cooling control step is executed, and the gas regulating valve opening is set to (set temperature - 200) / 200 × 18% + 20%.
[0017] In the aforementioned segmented control steps, the opening degree of the air regulating valve is adjusted synchronously with the opening degree of the gas regulating valve, and the opening degree of the air regulating valve is Y=X+10%.
[0018] Meanwhile, the furnace temperature, gas pressure and CO concentration are monitored in real time. When any parameter exceeds the safety threshold, the interlock protection is triggered within 1 second, automatically cutting off the fuel supply or adjusting the valve opening.
[0019] In addition to the embodiments described above, the present invention may have other implementations. All technical solutions formed by equivalent substitution or equivalent transformation fall within the protection scope claimed by the present invention.
Claims
1. A method for automatic stove burning control of a smoke stove, characterized by, The method comprises the following steps: An initialization step: setting a target range of the mill inlet temperature; An air-fuel ratio coordinated control step: setting the air-fuel ratio of the coal gas and air, and realizing proportional adjustment by adjusting the opening degrees of the coal gas adjusting valve and the air adjusting valve; A temperature main control adjustment step: adjusting the opening degrees of the coal gas adjusting valve and the air adjusting valve based on the coal gas pressure in real time, and dynamically adjusting the opening degrees of the coal gas adjusting valve and the air adjusting valve based on the deviation of the actual temperature from the set temperature by using a segmented control step, so as to stabilize the mill inlet temperature in the target range.
2. The automatic stove control method of flue gas stove according to claim 1, characterized by, In the initialization step, the target range of the mill inlet temperature is 201-295℃.
3. The automatic stove control method of flue gas stove according to claim 1, characterized by, In the air-fuel ratio coordinated control step, the air-fuel ratio is the volume ratio of the coal gas to the air, which is 1:0.
8.
4. The automatic stove control method of flue gas stove according to claim 1, characterized by, The temperature main control adjustment step based on the coal gas pressure to adjust the valve opening degree specifically comprises: When the coal gas pressure is in the range of 6-10 Kpa, the opening degree X of the coal gas adjusting valve is set to 38%, and the opening degree Y of the air adjusting valve is X+10%; When the coal gas pressure is greater than 10 Kpa, the opening degree X of the coal gas adjusting valve is reduced by 5%, and the opening degree Y of the air adjusting valve is adjusted accordingly; When the coal gas pressure is less than 6 Kpa, the opening degree X of the coal gas adjusting valve is increased by 3%, and the opening degree Y of the air adjusting valve is adjusted accordingly.
5. The automatic stove control method of flue gas stove according to claim 1, characterized by, The segmented control step comprises: When the actual temperature is 10℃ higher than the set temperature, a first temperature rising control step is executed, the opening degree of the coal gas adjusting valve is set to (set temperature-200) / 80×18%+20%; When the actual temperature is in the range of set temperature-10℃ to set temperature-3℃, the detection is performed every 30 seconds, a second temperature rising control step is executed, the opening degree of the coal gas adjusting valve is increased by 0.5%; When the actual temperature is in the range of set temperature-3℃ to set temperature, the detection is performed every 45 seconds, a third temperature rising control step is executed, the opening degree of the coal gas adjusting valve is increased by 0.3%; When the actual temperature is in the range of set temperature to set temperature+3℃, the detection is performed every 45 seconds, a first temperature falling control step is executed, the opening degree of the coal gas adjusting valve is reduced by 0.3%; When the actual temperature is in the range of set temperature+3℃ to set temperature+10℃, the detection is performed every 30 seconds, a second temperature falling control step is executed, the opening degree of the coal gas adjusting valve is reduced by 0.5%; When the actual temperature is 10℃ higher than the set temperature, a third temperature falling control step is executed, the opening degree of the coal gas adjusting valve is set to (set temperature-200) / 200×18%+20%.
6. The automatic stove control method of flue gas stove according to claim 5, characterized by, In the segmented control step, the opening degree of the air adjusting valve is adjusted synchronously with the opening degree of the coal gas adjusting valve, and the opening degree Y of the air adjusting valve is X+10%.
7. The automatic stove control method of flue gas stove according to claim 1, characterized by, The furnace temperature, the coal gas pressure and the CO concentration are monitored in real time, and when any parameter exceeds the safety threshold, the interlock protection is triggered within 1 second to automatically cut off the fuel supply or adjust the valve opening degree.