CN-121993789-A - Safety control system of burner for negative pressure furnace

CN121993789ACN 121993789 ACN121993789 ACN 121993789ACN-121993789-A

Abstract

The invention discloses a safety control system of a burner for a negative pressure furnace, relates to the technical field of combustion control of the negative pressure furnace, and aims to solve the technical problems of lag in single closed-loop control response and poor system stability of the existing burner of the negative pressure furnace. The system builds a double-closed-loop control framework of cooperative work of an inner-layer combustion stability closed loop and an outer-layer negative-pressure closed loop, wherein the inner-layer closed loop takes flame characteristic parameters and fuel gas/air ratio as core control objects, the opening degree of a fuel gas proportional valve and the rotating speed of a fan are regulated in real time through a PID algorithm, the combustion state is kept stable, the outer-layer closed loop dynamically adjusts the opening degree of a hearth baffle valve based on an inner-layer regulation result to keep the negative pressure in a preset range, and when any closed loop is abnormal, the system automatically triggers a cross-closed-loop compensation mechanism, and the other closed loop optimizes self-regulation parameters in real time to realize dynamic compensation. The invention greatly improves the control response speed and the operation safety of the negative pressure furnace burner by the double closed loop cooperation and the abnormal compensation design, effectively solves the problem of response lag of single closed loop control, and is suitable for safety control of various industrial negative pressure furnace combustion systems.

Inventors

LIU JIYUN
DAI JINZHI
MU GUIJIN
CHEN PENG
DOU WEISHAN
LIU YONGJUAN

Assignees

沧州市天龙燃烧设备有限公司

Dates

Publication Date: 20260508
Application Date: 20260209

Claims (10)

1. A safety control system of a burner for a negative pressure furnace is characterized by comprising a combustion state monitoring module, an inner layer combustion stability closed-loop control unit, an outer layer negative pressure closed-loop control unit and an abnormality compensation module, The combustion state monitoring module is used for collecting flame characteristic parameters, gas flow, air flow and hearth negative pressure values of the negative pressure furnace burner and transmitting collected data to the inner layer and outer layer closed-loop control units in real time.
2. The inner layer combustion stability closed-loop control unit is in communication connection with the combustion state monitoring module, takes flame characteristic parameters and gas/air ratio as control objects, embeds a PID (proportion integration differentiation) regulation algorithm, and regulates the opening of a gas proportional valve and the rotating speed of a fan in real time according to the acquired flame characteristic parameters, gas flow and air flow; the outer layer negative pressure closed-loop control unit is respectively in communication connection with the combustion state monitoring module and the inner layer combustion stability closed-loop control unit, takes a hearth negative pressure value as a control object, and dynamically adjusts the opening of a hearth baffle valve based on the adjustment result of the inner layer combustion stability closed-loop control unit so as to maintain the hearth negative pressure in a preset range; The abnormal compensation module is respectively in communication connection with the inner layer combustion stability closed-loop control unit and the outer layer negative pressure closed-loop control unit, and is used for monitoring the running states of the two closed loops, and triggering the other closed loop to automatically optimize the PID regulation parameter or the baffle valve regulation parameter of the other closed loop to compensate when detecting that any closed loop is abnormal, so that the whole running stability of the system is ensured.
3. The burner safety control system for a negative pressure furnace according to claim 1, wherein, The flame characteristic parameters comprise at least two of flame brightness, flame morphology, flame temperature and flame ion current; the burner safety control system for a negative pressure furnace according to claim 1, wherein the PID adjustment algorithm of the closed loop control unit for the combustion stability of the inner layer comprises the steps of: Setting a flame characteristic parameter target value and a fuel gas/air ratio target value; Calculating a first deviation of an actual value of the acquired flame characteristic parameter from a target value and a second deviation of an actual value of the fuel gas/air ratio from the target value; Inputting the first deviation and the second deviation into a PID algorithm, and outputting a gas proportional valve opening adjustment quantity and a fan rotating speed adjustment quantity; And adjusting the fuel gas proportional valve and the fan according to the adjustment quantity, and feeding back the adjusted parameters in real time to form closed-loop control.
4. The safety control system for a burner for a negative pressure furnace according to claim 1, wherein the dynamically adjusted flapper valve opening is: acquiring a gas proportional valve opening and a fan rotating speed real-time value output by an inner layer combustion stability closed-loop control unit, and calculating a hearth negative pressure theoretical value based on a preset mapping relation; Comparing the hearth negative pressure theoretical value with the acquired actual negative pressure value, and calculating negative pressure deviation; and dynamically outputting a baffle valve opening adjusting instruction according to the negative pressure deviation, wherein the adjusting amplitude is positively correlated with the inner layer adjusting quantity.
5. The burner safety control system for a negative pressure furnace according to claim 1, wherein, The abnormality determination condition of the abnormality compensation module includes: the inner layer closed loop is that the flame characteristic parameter deviation exceeds a first preset threshold value and the duration time is more than or equal to a first preset duration time, or the fuel gas/air ratio deviation exceeds a second preset threshold value and the duration time is more than or equal to a second preset duration time; The outer layer is closed, namely the negative pressure value of the hearth deviates from a preset range to exceed a third preset threshold value, and the duration is more than or equal to a third preset duration; When any abnormality judgment condition is met, the abnormality compensation module sends a compensation instruction to the other closed loop, and the other closed loop optimizes self-adjusting parameters based on a preset compensation coefficient.
6. The burner safety control system for a negative pressure furnace according to claim 5, wherein, The compensation coefficient is calibrated in advance according to the rated power of the negative pressure furnace, the hearth volume and the fuel gas type and is stored in a parameter library of the abnormal compensation module.
7. The burner safety control system for a negative pressure furnace according to claim 1, wherein, The characteristic parameters of the flame are collected by a flame sensor, and the gas flow is collected by a gas flowmeter; air flow is collected through an air flow meter, and a hearth negative pressure value is collected through a negative pressure sensor.
8. The burner safety control system for a negative pressure furnace according to claim 7, wherein, The flame sensor is arranged on the inner wall of the hearth beside the flame spraying port of the burner of the negative pressure furnace and is opposite to the flame burning area, and flame characteristic parameters are acquired in real time; The gas flowmeter is arranged in the gas inlet pipeline of the burner in series, is positioned in the pipe section between the gas proportional valve and the flame spraying port of the burner, and is used for collecting the real-time flow in the gas conveying process; the air flowmeter is arranged in the air inlet pipeline of the burner in series, and is positioned at the pipe section between the air outlet of the fan and the flame spraying port of the burner, so that the air flow rate of the fan to the burner is collected in real time; The negative pressure sensor is arranged at the position of the middle upper part of the side wall of the hearth of the negative pressure furnace, which is free of flame direct blowing and smoke vortex, and the real-time negative pressure value inside the hearth is collected.
9. The burner safety control system for a negative pressure furnace according to claim 1, wherein, The outer layer negative pressure closed-loop control unit and the inner layer combustion stability closed-loop control unit share the same PLC.
10. The burner safety control system for a negative pressure furnace according to claim 9, wherein, The abnormality compensation module is integrated in the PLC and presets abnormality judgment conditions.

Description

Safety control system of burner for negative pressure furnace Technical Field The invention relates to the technical field of negative pressure furnace combustion control, in particular to a safety control system of a combustor for a negative pressure furnace. Background The negative pressure furnace is widely applied to the industrial fields of chemical industry, metallurgy, energy sources and the like, and the safety problems of flame overflow, smoke leakage and the like can be effectively prevented by maintaining the negative pressure state in the hearth. The burner is used as a core component of the negative pressure furnace, and the combustion stability of the burner directly determines the operation safety and energy efficiency of the negative pressure furnace. The control scheme of the existing negative pressure furnace burner mainly adopts single closed-loop control, namely the closed-loop control only aiming at the combustion state maintains flame stability by adjusting the fuel gas/air ratio, but cannot adapt to the change of the hearth negative pressure in real time, so that insufficient combustion and even flameout are easily caused by negative pressure fluctuation, and the closed-loop control only aiming at the hearth negative pressure maintains the negative pressure by adjusting the opening of a baffle valve, but responds to the change of the combustion state, and when the combustion working condition suddenly changes, the negative pressure adjustment cannot be followed in time, so that abnormal hearth pressure is easily caused. Part of the improvement schemes try to link the combustion state with the negative pressure control, but only simple sequential control (firstly adjusting the combustion parameters and then lagging the negative pressure parameters) is adopted, no real double closed loop coordination is formed, the problems of lagging response and no compensation mechanism under abnormal working conditions still exist, and the operation requirements of high safety and high stability of the industrial negative pressure furnace cannot be met. Disclosure of Invention The embodiment of the invention aims to provide a safety control system for a burner of a negative pressure furnace, which aims to solve the problems of lag single closed-loop control response, no abnormal compensation mechanism and poor system stability of the burner of the negative pressure furnace in the prior art. The embodiment of the invention is realized in such a way that the safety control system of the burner for the negative pressure furnace comprises a combustion state monitoring module, an inner layer combustion stability closed-loop control unit, an outer layer negative pressure closed-loop control unit and an abnormality compensation module, The combustion state monitoring module is used for collecting flame characteristic parameters, gas flow, air flow and hearth negative pressure values of the negative pressure furnace burner and transmitting collected data to the inner layer and outer layer closed-loop control units in real time. The inner layer combustion stability closed-loop control unit is in communication connection with the combustion state monitoring module, takes flame characteristic parameters and gas/air ratio as control objects, embeds a PID (proportion integration differentiation) regulation algorithm, and regulates the opening of a gas proportional valve and the rotating speed of a fan in real time according to the acquired flame characteristic parameters, gas flow and air flow; the outer layer negative pressure closed-loop control unit is respectively in communication connection with the combustion state monitoring module and the inner layer combustion stability closed-loop control unit, takes a hearth negative pressure value as a control object, and dynamically adjusts the opening of a hearth baffle valve based on the adjustment result of the inner layer combustion stability closed-loop control unit so as to maintain the hearth negative pressure in a preset range; The abnormal compensation module is respectively in communication connection with the inner layer combustion stability closed-loop control unit and the outer layer negative pressure closed-loop control unit, and is used for monitoring the running states of the two closed loops, and triggering the other closed loop to automatically optimize the PID regulation parameter or the baffle valve regulation parameter of the other closed loop to compensate when detecting that any closed loop is abnormal, so that the whole running stability of the system is ensured. The beneficial effects of the invention are that The invention provides a safety control system of a combustor for a negative pressure furnace, which constructs a double closed loop control framework of cooperative work of an inner layer combustion stability closed loop and an outer layer negative pressure closed loop, wherein the inner layer closed loop takes flame characteristic pa