Double-channel industrial furnace gas combustion safety interlocking control system

Abstract

The invention belongs to the technical field of industrial combustion safety control, and provides a double-channel industrial furnace gas combustion safety interlocking control system which comprises a gas / air flow ratio dynamic monitoring module, a flue CO concentration online detection module, a double-channel data conflict arbitration processor and a visual human-computer interface. Aiming at the prominent problems of incomplete combustion of coal gas, carbon deposition, detonation risk and the like which are easy to occur under the working condition of accelerated temperature rise, the system integrates visual double-insurance safety control of dynamic calculation of a flow ratio and real-time analysis of tail gas components, and all-directional safety protection in the combustion process is realized through a multi-parameter cooperative monitoring and intelligent interlocking mechanism; the detonation risk is obviously reduced; meanwhile, the air-fuel ratio fluctuation is accurately controlled within the range of + / -5%, and the carbon deposition phenomenon is effectively reduced; and remarkable economic benefits are created while reliable operation of equipment is guaranteed.

Description

Technical Field

[0001] This invention belongs to the field of industrial combustion safety control technology, and relates to the safety protection technology for excess combustion of coal gas in continuous annealing furnaces (NOF furnaces) in the metallurgical industry. Specifically, it is a dual-channel industrial furnace gas combustion safety interlock control system. Background Technology

[0002] Traditional industrial furnace gas combustion control systems suffer from three major technical bottlenecks: First, the hardware interlocking mechanism is simplistic and cannot monitor the excess gas state in real time, making it difficult for operators to intuitively grasp the combustion conditions. Second, during the accelerated heating phase, the rapid opening of gas valves causes instantaneous air-fuel ratio imbalance (L value can reach 1), while the system lacks dynamic adjustment capabilities. Third, the complete absence of online detection methods for flue gas CO concentration results in a severe lag in detonation risk warnings (E value reaches level 6), threatening both production safety and energy waste.

[0003] At the same time, there are three key technological gaps in the field of industrial combustion control: first, there is a lack of integrated solutions for the coordinated monitoring of the gas / air flow ratio and the CO concentration in the exhaust gas; second, there is no interactive system that can present the combustion status in real time with a visual interface; and third, there is no intelligent protection system based on a graded early warning and interlocking mechanism (dual threshold early warning value / safety value).

[0004] The aforementioned technical bottlenecks and gaps make it difficult for existing industrial furnace gas combustion control systems to accurately regulate excess gas conditions and effectively prevent safety hazards such as detonation risks, which seriously restricts the safe and stable operation and energy efficiency improvement of industrial furnaces. Summary of the Invention

[0005] The purpose of this invention is to provide a dual-channel industrial furnace gas combustion safety interlock control system, which effectively solves the prominent problems of high explosion risk and serious carbon accumulation in traditional industrial furnace combustion control, and significantly improves combustion efficiency while ensuring safe operation.

[0006] The technical solution adopted by the present invention to achieve the above objectives is as follows: A dual-channel industrial furnace gas combustion safety interlock control system includes a gas / air flow ratio dynamic monitoring module, a flue gas CO concentration online detection module, a dual-channel data conflict arbitration processor, and a visual human-machine interface. The gas / air flow ratio dynamic monitoring module uses a high-precision sensor to collect the combustion coefficient L in real time and dynamically calculates the optimal ratio using an adaptive algorithm. The flue gas CO concentration online detection module performs millisecond-level continuous monitoring of exhaust gas components based on tunable diode laser absorption spectroscopy technology. The dual-channel data conflict arbitration processor constructs a data verification matrix; when deviations occur between the flow ratio and CO concentration data, it performs intelligent arbitration and fault-tolerant processing according to preset conflict arbitration rules. The visual human-machine interface supports multi-dimensional data visualization and full-cycle data management.

[0007] Furthermore, the calculation method for the combustion coefficient L is as follows: Combustion coefficient L = AIR(PV) ÷ Natural gas air-fuel ratio ÷ COG(PV); By continuously collecting data through a 0.5-level high-precision flow transmitter, an early warning is triggered when the combustion coefficient is ≤0.8, thus achieving precise quantitative monitoring of the excess state of coal gas.

[0008] Furthermore, the flue gas CO concentration online detection module is equipped with a laser CO analyzer with a range of 0-5000ppm, which monitors flue gas in real time and activates an audible and visual alarm when the flue gas CO concentration is ≥1000ppm.

[0009] Furthermore, conflict arbitration rules: Establish a priority mechanism for exhaust gas component analysis channels. When CO concentration data conflicts with flow ratio data, the system automatically uses CO concentration data as the basis for triggering safety interlocks, with a response time of ≤500ms.

[0010] Furthermore, the combustion safety interlock control system adopts a three-level safety response mechanism, the details of which are as follows: S1. Early warning stage: When the combustion coefficient L≤0.8 or the CO concentration≥1000ppm, the system immediately triggers an audible and visual alarm, the visual human-machine interface switches to the red zone warning mode, and the abnormal data is encrypted and stored in the historical database at the same time to provide a complete record for subsequent analysis. S2. Intervention Phase: If the parameters continue to deteriorate to the critical value, and the combustion coefficient is ≤0.6 or CO is ≥1500ppm, the system will automatically implement a graded adjustment strategy: prioritize adjusting the proportional valve at a rate of ±5% / s, and push optimization suggestions through the visual human-machine interface to maintain production continuity to the maximum extent while ensuring safety.

[0011] S3 Emergency Shutdown Phase: When the parameters exceed the safety threshold, i.e., the combustion coefficient ≤ 0.5 or CO ≥ 2000ppm, the PLC controller directly shuts off the safety valve via a hard-wired signal. The response time of the safety valve is ≤ 500ms. Simultaneously, an emergency command containing fault location and handling suggestions is pushed to the central control room to ensure that the entire process complies with the mandatory requirements of safety interlocking for industrial combustion systems.

[0012] Furthermore, the visual human-machine interface uses both line graphs and heat maps to display the real-time trend of combustion coefficient changes. The view supports multi-level time axis zooming, and automatically triggers a red flashing marker when the L value is ≤0.2, realizing an immediate visual warning of abnormal conditions. The CO concentration is displayed through a digital dashboard and a color grading system, combined with audible and visual alarms, to build a three-dimensional safety warning system. Based on 30 days of historical data storage, it provides an accident playback function to support time point location and parameter correlation analysis, and can automatically generate PDF reports containing trend charts and operation logs, providing a complete data chain for accident diagnosis.

[0013] The beneficial effects of this invention are: This invention's system, through dual-channel collaborative control, significantly optimizes the combustion coefficient L value from 1.0 to a stable range of 0.2, substantially reducing the risk of detonation. Simultaneously, it precisely controls air-fuel ratio fluctuations within ±5%, effectively reducing carbon buildup. Its interlock response time is strictly controlled within 500 milliseconds, fully complying with the highest safety standards of GB / T 32201-2015, ensuring reliable equipment operation while creating significant economic benefits. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of the present invention applied in an embodiment; Figure 2 This is a control flowchart of an embodiment of the present invention; In the diagram: 1. Flow transmitter; 2. Flow meter; 3. CO concentration online detection module; 4. Processor; 5. Safety valve; 6. First proportional valve; 7. Second proportional valve. Detailed Implementation

[0015] The present invention will be further described below with reference to the accompanying drawings and embodiments: A dual-channel industrial furnace gas combustion safety interlock control system includes a gas / air flow ratio dynamic monitoring module, a flue gas CO concentration online detection module, a dual-channel data conflict arbitration processor, and a visual human-machine interface. The gas / air flow ratio dynamic monitoring module uses a high-precision sensor to collect the combustion coefficient L in real time and dynamically calculates the optimal ratio through an adaptive algorithm. The combustion coefficient L = AIR(PV) ÷ natural gas air-fuel ratio ÷ COG(PV). Data is continuously collected through a 0.5-level high-precision flow transmitter, and an early warning is triggered when the combustion coefficient L ≤ 0.8, realizing precise quantitative monitoring of the excess gas state.

[0016] The flue gas CO concentration online detection module is based on tunable diode laser absorption spectroscopy technology to continuously monitor the components of exhaust gas at the millisecond level. The flue gas CO concentration online detection module is equipped with a laser CO analyzer with a range of 0-5000ppm, which monitors the flue gas in real time and activates an audible and visual alarm when the flue gas CO concentration is ≥1000ppm.

[0017] The dual-channel data conflict arbitration processor constructs a data verification matrix. When there is a deviation between the flow ratio and CO concentration data, it performs intelligent arbitration and fault tolerance processing according to the preset conflict arbitration rules. Conflict arbitration rules: Establish a priority mechanism for the exhaust gas component analysis channel. When there is a conflict between the CO concentration data and the flow ratio data, the system automatically uses the CO concentration data as the basis for triggering the safety interlock, with a response time of ≤500ms.

[0018] The combustion safety interlock control system adopts a three-level safety response mechanism, the details of which are as follows: S1. Early warning stage: When the combustion coefficient L≤0.8 or the CO concentration≥1000ppm, the system immediately triggers an audible and visual alarm, the visual human-machine interface switches to the red zone warning mode, and the abnormal data is encrypted and stored in the historical database at the same time to provide a complete record for subsequent analysis. S2. Intervention Phase: If the parameters continue to deteriorate to the critical value, and the combustion coefficient is ≤0.6 or CO is ≥1500ppm, the system will automatically implement a graded adjustment strategy: prioritize adjusting the proportional valve at a rate of ±5% / s, and push optimization suggestions through the visual human-machine interface to maintain production continuity to the maximum extent while ensuring safety.

[0019] S3 Emergency Shutdown Phase: When the parameters exceed the safety threshold, i.e., the combustion coefficient ≤ 0.5 or CO ≥ 2000ppm, the PLC controller directly shuts off the safety valve via a hard-wired signal. The response time of the safety valve is ≤ 500ms. Simultaneously, an emergency command containing fault location and handling suggestions is pushed to the central control room to ensure that the entire process complies with the mandatory requirements of safety interlocking for industrial combustion systems.

[0020] The visual human-computer interface supports multi-dimensional data visualization and full-cycle data management, including: 1) Dynamic trend visualization: The system uses both line chart and heat map modes to display the real-time trend of the combustion coefficient. It supports multi-level time axis zooming in 1 minute / hour / day view. When the L value is ≤0.2, a red flashing mark is automatically triggered to realize the instant visual warning of abnormal status.

[0021] 2) Multi-dimensional concentration display: CO concentration is displayed in two ways: a digital instrument panel (accuracy 1ppm) and a color grading system (green 0-800ppm / yellow 801-1500ppm / red ≥1501ppm). Combined with audible and visual alarms (buzzer + interface pulse effect), a three-dimensional safety warning system is constructed.

[0022] 3) Intelligent retrospective analysis: Based on 30 days of historical data storage (1-second sampling interval), it provides accident playback function to support time point location and parameter correlation analysis, and can automatically generate PDF reports containing trend charts and operation logs, providing a complete data chain for accident diagnosis. Example

[0023] Taking the industrial application of the annealing furnace unit in the company's silicon steel division as an example: A dual-channel industrial furnace gas combustion safety interlock control system includes: The dynamic monitoring module for the gas / air flow ratio uses a combination of a 0.5-class differential pressure flow transmitter 1 (range 0-10kPa) and a DN50 standard orifice plate flow meter 2, which are installed in the main gas pipe and the combustion air pipe respectively to achieve high-precision flow detection.

[0024] The flue gas CO concentration online detection module 3 is equipped with a laser CO analyzer (range 0-5000ppm, accuracy ±2%FS), and the flue gas sampling tube is made of SUS304 high temperature resistant material (temperature resistance 300℃) to ensure stable operation in harsh environments.

[0025] The dual-channel data conflict arbitration processor 4 is built on Siemens S7-400 PLC (CPU416-3H), integrates a PROFIBUS-DP communication module, has a high-speed scan cycle of 10ms, supports real-time cross-validation of dual-channel data, and improves system reliability.

[0026] The system employs the OPC UA communication protocol to achieve real-time data interaction between the WinCC 7.5 configuration software and the dual-channel data conflict arbitration processor. A 1920×1080 high-resolution industrial touchscreen serves as the visual human-machine interface. The actuator is a pneumatic quick-opening safety valve 5, achieving a rapid shut-off response of ≤500ms via electromagnetic drive. The overall design complies with the mandatory requirements for combustion system safety interlocks in GB / T32201-2015 "Safety Technical Requirements for Industrial Furnaces and Kilns". The system integration solution, through standardized protocol interfaces and high-performance hardware combinations, ensures highly reliable transmission of monitoring data and millisecond-level emergency response capabilities.

[0027] System collaborative control process, such as Figure 2 As shown: 1. Collect gas flow rate and combustion air flow rate; 2. Real-time calculation of the combustion coefficient L; 3. Collect CO concentration in the flue gas, cross-validate the combustion coefficient L with the CO concentration in the flue gas, and then analyze the response. The system operation strategy is as follows: (1) Hierarchical control threshold 1) Combustion coefficient L: Warning value ≤ 0.8 (yellow warning), intervention value ≤ 0.6 (red warning), safety cut-off value ≤ 0.5 (automatic trigger) 2) CO concentration: Level 1 alarm ≥1000ppm (audible and visual alert), Level 2 alarm ≥1500ppm (proportional valve adjustment), Level 3 alarm ≥2000ppm (emergency shut-off) (2) Response strategy 1) Warning stage: Trigger an 85dB audible and visual alarm (compliant with GB / T 34012-2017 standard), the red zone of the visual human-machine interface flashes as a warning, and the abnormal parameters are recorded to the historical database with a millisecond-level timestamp (1ms accuracy).

[0028] 2) Intervention phase: Dynamically adjust at a precise rate of ±5% / s through the first proportional valve 6 and the second proportional valve 7, and intelligently push operation suggestions through the visual human-machine interface (such as reducing the gas flow rate by 10%, calculated based on the real-time combustion coefficient L value).

[0029] 3) Emergency shut-off: The solenoid valve drives the safety valve to operate (response time ≤ 500ms, meeting the requirements of GB / T 32201-2015), and simultaneously sends an emergency command to the central control room (OPC UA communication delay ≤ 100ms).

[0030] This system, through dual-channel detection (gas / air flow ratio + CO concentration) and intelligent control algorithms, successfully and precisely controlled the combustion coefficient L value from 1.0 to 0.2, significantly reducing the detonation accident rate by 80%. At the same time, through dynamic adjustment function, the air-fuel ratio fluctuation is strictly controlled within ±5%, effectively reducing carbon deposits in the furnace by 70%. In terms of system reliability, the mean time between failures (MTBF) has been increased to 5000 hours, reaching the industrial-grade stable operation standard.

Claims

1. A dual-channel industrial furnace gas combustion safety interlock control system, characterized in that: It includes a dynamic monitoring module for the gas / air flow ratio, an online detection module for CO concentration in the flue, a dual-channel data conflict arbitration processor, and a visual human-machine interface; the dynamic monitoring module for the gas / air flow ratio uses a high-precision sensor to collect the combustion coefficient L in real time and dynamically calculates the optimal ratio through an adaptive algorithm; the online detection module for CO concentration in the flue is based on tunable diode laser absorption spectroscopy technology to perform millisecond-level continuous monitoring of the exhaust gas composition. The dual-channel data conflict arbitration processor constructs a data verification matrix. When there is a deviation between the flow ratio and CO concentration data, it performs intelligent arbitration and fault tolerance processing according to preset conflict arbitration rules. The visual human-computer interface supports multi-dimensional data visualization and full-cycle data management.

2. The dual-channel industrial furnace gas combustion safety interlock control system according to claim 1, characterized in that: The calculation method for the combustion coefficient L is as follows: Combustion coefficient L = AIR(PV) ÷ Natural gas air-fuel ratio ÷ COG(PV); By continuously collecting air and natural gas data through a 0.5-level high-precision flow transmitter, an early warning is triggered when the combustion coefficient is ≤0.8, thus achieving precise quantitative monitoring of the excess state of coal gas.

3. The dual-channel industrial furnace gas combustion safety interlock control system according to claim 1, characterized in that: The flue gas CO concentration online detection module is equipped with a laser CO analyzer with a range of 0-5000ppm, which monitors flue gas in real time and activates an audible and visual alarm when the flue gas CO concentration is ≥1000ppm.

4. The dual-channel industrial furnace gas combustion safety interlock control system according to claim 1, characterized in that: The conflict arbitration rule is as follows: a priority mechanism for exhaust gas component analysis channels is established. When CO concentration data and flow ratio data conflict, the system automatically uses CO concentration data as the basis for triggering safety interlocks, with a response time of ≤500ms.

5. The dual-channel industrial furnace gas combustion safety interlock control system according to claim 1, characterized in that: The combustion safety interlock control system adopts a three-level safety response mechanism, the details of which are as follows: S1. Early warning stage: When the combustion coefficient L≤0.8 or the CO concentration≥1000ppm, the system immediately triggers an audible and visual alarm, the visual human-machine interface switches to the red zone warning mode, and the abnormal data is encrypted and stored in the historical database at the same time to provide a complete record for subsequent analysis. S2, Intervention Phase: If the parameters continue to deteriorate to the critical value, and the combustion coefficient is ≤0.6 or CO is ≥1500ppm, the system will automatically implement a graded adjustment strategy: prioritize adjusting the proportional valve at a rate of ±5% / s, and push optimization suggestions through the visual human-machine interface to maintain production continuity to the maximum extent while ensuring safety. S3 Emergency Shutdown Phase: When the parameters exceed the safety threshold, i.e., the combustion coefficient ≤ 0.5 or CO ≥ 2000ppm, the PLC controller directly shuts off the safety valve via a hard-wired signal. The response time of the safety valve is ≤ 500ms. Simultaneously, an emergency command containing fault location and handling suggestions is pushed to the central control room to ensure that the entire process complies with the mandatory requirements of safety interlocking for industrial combustion systems.

6. The dual-channel industrial furnace gas combustion safety interlock control system according to claim 1, characterized in that: The visual human-machine interface uses a dual mode of line graph and heat map to display the real-time trend of the combustion coefficient. The view supports multi-level time axis zoom. When the L value is ≤0.2, a red flashing mark is automatically triggered to realize the instant visual warning of abnormal status. The CO concentration is displayed by both a digital dashboard and a color grading system, and is combined with a synchronized audible and visual alarm to create a three-dimensional safety warning system. Based on 30 days of historical data storage, it provides an accident playback function to support time point location and parameter correlation analysis, and can automatically generate PDF reports containing trend charts and operation logs, providing a complete data chain for accident diagnosis.

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