CN-116428879-B - Control method and system for combustion optimization of heating furnace

CN116428879BCN 116428879 BCN116428879 BCN 116428879BCN-116428879-B

Abstract

The invention provides a control method and a control system for combustion optimization of a heating furnace, which comprise the steps of S1, connecting a control station with an original combustion control system through an Ethernet, connecting a control manual channel of the original combustion control system, S2, performing temperature control, confirming the corresponding relation between the variable quantity and the temperature variation of a valve by using relevant valve experience data and hearth variation response data, S3, performing operation judgment by using actual temperature field variation data, and sending an execution signal to the relevant valve by performing calculation and selection through temperature difference, S4, completing air flow control by the relevant air valve, and S5, sending a control signal to the original combustion control system to complete control. The invention improves the combustion stability of the heating furnace, reduces the high dependence on the manual operation experience at present, reduces the fuel gas consumption and the oxidation burning loss, and has the advantages of high control precision, quick response, stable combustion trend, reasonable air-fuel ratio, low transformation difficulty and safe connection.

Inventors

LI FENGZHAO
YANG HAI
JIN WEI

Assignees

上海宝信软件股份有限公司

Dates

Publication Date: 20260508
Application Date: 20220104

Claims (8)

1. A control method for combustion optimization of a heating furnace, comprising: step S1, connecting a control station with an original fuel control system through an Ethernet, and connecting a control manual channel of the original fuel control system; S2, performing temperature control, and confirming the corresponding relation between the variable quantity of the valve and the temperature change by using relevant valve experience data and hearth change response data; Step S3, calculating and judging by using the actual temperature field change data, and calculating and selecting by using the temperature difference to send an execution signal to the related valve, wherein the temperature difference is the actual difference between the actual heating temperature and the set heating temperature; S4, finishing air flow control by the related air valve; step S5, a control signal is issued to the primary combustion control system to complete control; in the step S2: estimating the output deviation of the gas valve by using the experience data of the related valve and the hearth change response data, calculating the period, confirming the corresponding relation between the change quantity of the valve and the temperature change, and changing the related parameters according to the actual debugging condition in the debugging process; The relevant valve experience data is the actual response time of each executing mechanism, when a feedback signal exists, the actual time difference between the output signal and the change of the feedback signal is used, and when no feedback signal exists, the change time of the relevant flow signal on site is considered; The hearth change response data is segment temperature response time, wherein the segment temperature response time is the response time from the action of the related valve to the segment heating temperature, and is the period of gas valve output, and the period is more than 2 times of the related valve experience data.
2. The control method for combustion optimization of a heating furnace according to claim 1, characterized in that in the step S1: The Ethernet uses OPC communication protocol and primary combustion control system, connects the relative control manual channel of the primary combustion control system gas and air, and adds soft switching mode to switch the primary system and the primary system, and uses the relative signal of the primary system for all signals.
3. The control method for combustion optimization of a heating furnace according to claim 1, characterized in that in the step S3: calculating the opening of the valve according to the actual temperature field change data and the temperature difference, and sending an execution signal to the related valve; the actual temperature field change data is the change amount of the heating temperature in the actual operation period; Q_Air=Ratio_AirGas*Q_Gas*Coefficient_Air*Coefficient_K; q_air is the Air quantity; Ratio_ AirGas is taken as a basic air-fuel Ratio, extracted from on-site operation data, and the change condition of the heat value is referred when the heat value exists; Q_Gas is the fuel Gas quantity, and filtering data processing is needed; the Coefficient_air is a manual intervention Coefficient, and when the condition that the system cannot be identified but can be identified manually occurs, manual intervention is carried out; Coefficient_K is a system intervention Coefficient, and when a preset working condition occurs, the system selects a proper Coefficient through an experience database to realize quick adjustment; The experience database is used for obtaining different system intervention coefficients according to data extracted from the on-site actual operation database, data of the change direction of the temperature field in the hearth and verification data of residual oxygen detection under different conditions.
4. The control method for combustion optimization of a heating furnace according to claim 1, characterized in that: in the step S4: The air flow control is carried out by the related air valve, before the flow control is finished, after the corresponding gas valve automatically acts, a feedforward parameter is added on the corresponding air valve acting quantity, so that the combustion quality is ensured; in the step S5: and sending a control signal to the primary combustion control system through OPC to complete control.
5. A control system for furnace combustion optimization, comprising: the module M1 is used for connecting the control station with the primary combustion control system through the Ethernet and connecting a control manual channel of the primary combustion control system; The module M2 is used for controlling the temperature, and confirming the corresponding relation between the variable quantity of the valve and the temperature variation by using the related valve experience data and the hearth variation response data; The module M3 is used for carrying out operation judgment by using the actual temperature field change data, calculating and selecting an execution signal to be sent to the related valve through the temperature difference, wherein the temperature difference is the actual difference between the actual heating temperature and the set heating temperature; the module M4 is used for controlling the air flow rate by the related air valve; The module M5 is used for transmitting a control signal to the primary combustion control system to complete control; in the module M2: estimating the output deviation of the gas valve by using the experience data of the related valve and the hearth change response data, calculating the period, confirming the corresponding relation between the change quantity of the valve and the temperature change, and changing the related parameters according to the actual debugging condition in the debugging process; The relevant valve experience data is the actual response time of each executing mechanism, when a feedback signal exists, the actual time difference between the output signal and the change of the feedback signal is used, and when no feedback signal exists, the change time of the relevant flow signal on site is considered; The hearth change response data is segment temperature response time, wherein the segment temperature response time is the response time from the action of the related valve to the segment heating temperature, and is the period of gas valve output, and the period is more than 2 times of the related valve experience data.
6. The control system for furnace combustion optimization according to claim 5, characterized in that in the module M1: The Ethernet uses OPC communication protocol and primary combustion control system, connects the relative control manual channel of the primary combustion control system gas and air, and adds soft switching mode to switch the primary system and the primary system, and uses the relative signal of the primary system for all signals.
7. The control system for furnace combustion optimization according to claim 5, characterized in that in the module M3: calculating the opening of the valve according to the actual temperature field change data and the temperature difference, and sending an execution signal to the related valve; the actual temperature field change data is the change amount of the heating temperature in the actual operation period; Q_Air=Ratio_AirGas*Q_Gas*Coefficient_Air*Coefficient_K; q_air is the Air quantity; Ratio_ AirGas is taken as a basic air-fuel Ratio, extracted from on-site operation data, and the change condition of the heat value is referred when the heat value exists; Q_Gas is the fuel Gas quantity, and filtering data processing is needed; the Coefficient_air is a manual intervention Coefficient, and when the condition that the system cannot be identified but can be identified manually occurs, manual intervention is carried out; Coefficient_K is a system intervention Coefficient, and when a preset working condition occurs, the system selects a proper Coefficient through an experience database to realize quick adjustment; The experience database is used for obtaining different system intervention coefficients according to data extracted from the on-site actual operation database, data of the change direction of the temperature field in the hearth and verification data of residual oxygen detection under different conditions.
8. The control system for furnace combustion optimization of claim 5, wherein: In the module M4: The air flow control is carried out by the related air valve, before the flow control is finished, after the corresponding gas valve automatically acts, a feedforward parameter is added on the corresponding air valve acting quantity, so that the combustion quality is ensured; in the module M5: and sending a control signal to the primary combustion control system through OPC to complete control.

Description

Control method and system for combustion optimization of heating furnace Technical Field The invention relates to the field of combustion control of metallurgical heating furnaces, in particular to an optimization control method of fuel gas and air in a billet heating process flow, and more particularly relates to a control method and system for combustion optimization of a heating furnace. Background The heating furnace is a large energy consumption user of the hot rolling production line generally, and the energy consumption of the heating furnace is about more than half of the total energy consumption of hot rolling. In the actual production process, because of the influence of related factors such as gas quality, gas pressure, gas heat value, air pressure fluctuation, equipment and the like, the manual adjustment timeliness is poor, the fluctuation range of the furnace gas temperature is large, and the product quality is directly influenced. The dynamic automatic adjustment of the atmosphere in the heating furnace is very important, and the influence of the combustion atmosphere in the furnace on the oxidation burning loss and the yield is large. The air-fuel ratio is adjusted by heating furnace operators mainly according to the residual oxygen amount, the flame color change in the furnace and other relevant factors and by combining the experiences of the operators, the working strength of the operators is high, the atmosphere in each section of the furnace is difficult to control due to the lack of detection means and hysteresis, and a large energy-saving space exists. In order to improve the combustion stability of the heating furnace, reduce the high dependence on manual operation experience at present and reduce the fuel gas consumption and the oxidation burning loss, the invention provides a combustion optimization control scheme of the heating furnace. The scheme has the advantages of high control precision, quick speed response, stable combustion trend, reasonable air-fuel ratio, low transformation difficulty and safe connection. The traditional combustion control calculates the amount of fuel gas to be increased or decreased according to the deviation between the set temperature and the actual temperature, and then the temperature control is completed through the control of the related valve. Because of the measurement deviation of the gas flowmeter and the combustion lag in the gas furnace chamber, the temperature control method generally has slower reaction, so that the overshoot of the temperature control temperature is larger and the reaction is slower. Compared with the prior conventional heating furnace combustion control system which is generally based on accurate flow detection data, the invention takes the theoretical air-fuel ratio as a control basis and assists in technical means such as double-cross control and feedforward control. Patent document CN112178685A (application number: CN 202010892268.6) discloses a heating furnace combustion optimization control system, which comprises an air regulating valve, a gas component on-line detector, a gas flowmeter, a flue gas CO2 on-line detector and a controller, wherein the controller is used for acquiring the gas flow detected by the gas flowmeter, the gas component detected by the gas component on-line detector, the CO2 content in the heating furnace detected by the flue gas CO2 on-line detector and the current time of current acquired data, acquiring a first air flow according to the gas flow and the gas component, adjusting the flow of the air regulating valve to the first air flow after time delay based on the current time, further performing feedback adjustment on the air regulating valve according to the first air flow and the CO2 content to acquire a second air flow, and performing one-step improvement on adjustment precision in feedback adjustment. However, the invention emphasizes the concept of air-fuel ratio, the valve cannot be directly controlled, and the intelligent degree of the combustion control of the heating furnace is not enough. Patent document CN106468446B (application number: CN 201610793434.0) discloses a heating furnace control and combustion optimization method, which adopts a control strategy combining an advanced control algorithm and a conventional control algorithm, adopts O2 and CO switching control, adopts a national standard simplified formula as an optimization target, and adopts a self-optimizing algorithm to realize real-time optimization of the oxygen content of the flue gas. However, the invention can not carry out rapid system modification on the heating furnace, and reasonably optimizes the existing combustion control degree. Disclosure of Invention Aiming at the defects in the prior art, the invention aims to provide a control method and a control system for combustion optimization of a heating furnace. The control method for optimizing the combustion of the heating furnace provided by the invention