System and method for increasing ignition temperature and saving coal gas by using sintering waste heat

Abstract

The invention relates to the technical field of sintering production, and discloses a system and method for increasing the ignition temperature and saving coal gas through sintering waste heat, and the system comprises a waste heat capturing and conveying module which is used for leading out high-temperature waste gas from an annular cooler and conveying the high-temperature waste gas as combustion air; the state sensing module is used for monitoring the temperature of the combustion-supporting air and / or the hearth temperature of the ignition furnace in real time; the intelligent decision and control module is electrically connected with the state sensing module and is used for generating a control instruction for fuel supply of the ignition furnace according to the monitored temperature information; and the combustion execution and safety guarantee module is connected with the waste heat capturing and conveying module and the intelligent decision-making and control module. The waste heat of the sintering circular cooler is recycled and utilized for preheating combustion supporting in the ignition process, fuel supply is dynamically adjusted in combination with the closed-loop control technology, fuel consumption is reduced, and meanwhile it is ensured that the ignition temperature is constant.

Description

Technical Field

[0001] This invention relates to the field of sintering production technology, specifically to a system and method for using sintering waste heat to increase ignition temperature and save coal gas. Background Art

[0002] In the sintering process of iron and steel metallurgy, the ignition step is one of the core components. This step involves heating and igniting the surface layer of the sintering mixture on the mixing cart using an ignition furnace, thereby initiating the subsequent solid-state sintering reaction. Traditional ignition furnaces typically use gaseous fuels such as coal gas, which are mixed with combustion air for combustion. In current technological practices, the combustion air used for combustion is mostly taken directly from the surrounding environment of the production site, i.e., ambient temperature air participates in the combustion process as an oxidant. Because ambient temperature air has a low enthalpy, a considerable amount of gaseous fuel is required to heat the mixture with the fuel to its ignition point and further heat the sintering material surface to the specified target ignition temperature.

[0003] Meanwhile, downstream of the sintering process, the freshly sintered high-temperature sinter is transported to an annular cooler for forced cooling. During this cooling process, a large amount of cooling air passes through the high-temperature sinter layer, absorbing its sensible heat and becoming high-temperature waste gas. This high-temperature waste gas carries a significant amount of heat energy and is a major waste heat source in the production process. In existing disposal methods, this waste heat resource is usually not effectively utilized, or is only used in situations where thermal efficiency requirements are not high, and is not directly linked to the energy-intensive ignition process, resulting in energy waste and directly increasing the fuel costs of the ignition process.

[0004] To address these issues, some preliminary explorations have emerged within the industry attempting to utilize the waste heat from the annular cooler for ignition and combustion. However, these existing solutions still suffer from a series of technical shortcomings in practical applications. Because the operating conditions of the annular cooler and the temperature of the sinter are not constant, the temperature of the exhaust gas fluctuates. Directly using this unstable hot air as combustion air, without corresponding control measures, can cause changes in the combustion conditions within the ignition furnace, leading to deviations in the furnace temperature from the required process range and affecting the stability of the ignition effect.

[0005] Furthermore, existing solutions lack sufficient system reliability and production continuity assurance. These systems are highly dependent on the stable operation of a single device that extracts hot air from the annular cooler. If this device malfunctions or shuts down for any reason, the supply of high-temperature combustion air will be immediately interrupted. Without an automated, fast-response backup air source switching mechanism and fuel supply linkage adjustment logic, the ignition process will be at risk of interruption, which may lead to the shutdown of the entire sintering production line and cause a production accident. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a system and method for improving ignition temperature and saving coal gas by utilizing sintering waste heat. This solves the problems of unstable furnace temperature and production interruption risks caused by the lack of adaptive adjustment to combustion air temperature fluctuations and automated response to waste heat source failures in existing technologies.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a system and method for utilizing sintering waste heat to increase ignition temperature and save coal gas, comprising:

[0008] A waste heat capture and transport module is used to extract high-temperature waste gas from the annular cooler and transport it as combustion air.

[0009] A status sensing module is used to monitor the temperature of the combustion air and / or the furnace temperature of the ignition furnace in real time.

[0010] The intelligent decision-making and control module is electrically connected to the state perception module and is used to generate control commands for the fuel supply to the ignition furnace based on the monitored temperature information.

[0011] The combustion execution and safety assurance module is connected to the waste heat capture and delivery module and the intelligent decision and control module. It is used to receive the combustion air and fuel and execute combustion operations according to the control instructions. The module also includes a backup ambient temperature air path and an air source switching device controlled by the intelligent decision and control module, which is used to switch the combustion air source under preset conditions.

[0012] A hot air coordinated distribution module is located downstream of the waste heat capture and conveying module, and is used to distribute the high-temperature waste gas to the ignition furnace and at least one other heat-using device according to a preset strategy.

[0013] The intelligent decision-making and control module also has a built-in collaborative allocation algorithm for generating control commands for the hot air collaborative allocation module.

[0014] Preferably, the waste heat capture and transport module includes:

[0015] One end is connected to the waste heat extraction pipe in the high-temperature zone of the annular cooler;

[0016] A high-temperature resistant induced draft fan, the inlet of which is connected to the waste heat outlet pipe;

[0017] The hot air delivery pipe has its inlet connected to the outlet of the high-temperature induced draft fan, and its outlet connected to the air source switching device of the combustion execution and safety assurance module.

[0018] Preferably, the status perception module further includes an induced draft fan status monitor, used to monitor the operating status of the high-temperature induced draft fan and send the status signal to the intelligent decision and control module.

[0019] Preferably, the intelligent decision-making and control module has a built-in safety switching logic, and the preset conditions include: the induced draft fan status monitor detects an induced draft fan malfunction, or the temperature of the combustion air is lower than a preset temperature threshold.

[0020] Preferably, the intelligent decision-making and control module has a built-in ignition temperature closed-loop control algorithm, which generates the control command based on the deviation between the furnace temperature monitored by the state perception module and a preset target ignition temperature.

[0021] Preferably, the ignition temperature closed-loop control algorithm is a proportional-integral-derivative control algorithm.

[0022] Preferably, the air source switching device in the combustion execution and safety assurance module can switch between the high-temperature exhaust gas combustion-supporting air path and the backup ambient temperature air path when it receives a switching command from the intelligent decision and control module.

[0023] Preferably, the hot air coordinated distribution module includes a flow regulating valve disposed on a branch pipe leading to the ignition furnace and other heat-using equipment, the flow regulating valve being controlled by the intelligent decision and control module.

[0024] A method for increasing ignition temperature and saving coal gas by utilizing sintering waste heat includes the following steps:

[0025] Waste heat combustion-assisted step: High-temperature waste gas is drawn from the annular cooler and sent into the ignition furnace as combustion-assisted air, where it is mixed with fuel for combustion;

[0026] Status awareness step: Real-time monitoring of at least one of the following operating parameters: the temperature of the combustion air, the furnace temperature of the ignition furnace, and the operating status of the induced draft fan used to extract high-temperature exhaust gas;

[0027] Intelligent decision-making and closed-loop control steps: Based on the deviation between the monitored furnace temperature and the preset target temperature, the fuel supply is dynamically adjusted through a closed-loop control algorithm to stabilize the ignition temperature.

[0028] Safety switching procedure: When the monitored operating parameters meet the preset fault conditions, the combustion air is automatically switched from the high-temperature exhaust gas to the backup ambient temperature air, and the fuel supply is adjusted simultaneously to maintain ignition.

[0029] This invention provides a system and method for utilizing sintering waste heat to increase ignition temperature and save coal gas. It has the following beneficial effects:

[0030] 1. This invention, by setting up a waste heat capture and conveying module, converts the high-temperature waste gas that was originally directly or indirectly discharged from the sintering ring cooler into preheated combustion air for the ignition furnace combustion process. Since this combustion air itself carries a high enthalpy, under the same process conditions to achieve the same target ignition temperature, it can effectively reduce the amount of fuel required for the ignition process, thereby directly reducing production and operating costs and achieving effective recovery and utilization of waste heat resources in the sintering process.

[0031] 2. This invention uses a state sensing module to continuously and in real-time measure key thermal parameters such as combustion air temperature and furnace temperature. A closed-loop control algorithm built into the intelligent decision-making and control module continuously and automatically adjusts the electric regulating valve in the gas supply and regulation system. This technical solution proactively overcomes the interference of fluctuating exhaust gas temperature caused by changes in the operating conditions of the annular cooler on the ignition process, maintaining the ignition furnace temperature constant at the set value required by the process. This improves the stability of the ignition conditions and provides technical assurance for stabilizing the final quality of the sintered ore.

[0032] 3. This invention establishes a complete fault-tolerant mechanism by setting up a backup ambient temperature air path, an air source switching device, and corresponding safety switching procedures. When the status sensing module detects a preset fault such as induced draft fan failure or excessively low waste heat temperature in the waste heat system, which serves as the main heat source, the intelligent decision-making and control module can automatically and quickly switch the air source and adjust the gas supply to a preset state matching the new air source. This design ensures that the ignition process can continue uninterrupted even when the waste heat source experiences an unexpected fault, avoiding sintering production stoppages caused by ignition interruptions and improving the overall system reliability and production continuity. Attached Figure Description

[0033] Figure 1 This is a system architecture diagram of the present invention;

[0034] Figure 2 This is a schematic diagram of the process of the present invention. Detailed Implementation

[0035] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] Please see the appendix Figure 1-2 This invention provides a system for increasing ignition temperature and saving coal gas by utilizing sintering waste heat, comprising:

[0037] Waste heat capture and transport module, used to extract high-temperature waste gas from the annular cooler and transport it as combustion air;

[0038] In this embodiment, addressing the technical problems of high fuel consumption due to ambient temperature combustion air in the ignition furnace in existing sintering processes, and the inability to directly utilize waste heat from the annular cooler for ignition and combustion, this invention provides a waste heat capture and delivery module. The function of this module is to extract waste gas with high enthalpy from the high-temperature region of the sintering annular cooler and stably and continuously deliver it to the ignition furnace as preheating combustion air for the ignition and combustion process.

[0039] The structure and operation mode of the waste heat capture and transport module are as follows.

[0040] This module includes waste heat extraction pipes, high-temperature resistant induced draft fans, and hot air delivery pipes.

[0041] One end of the waste heat extraction pipe is connected to the casing of the sintering ring cooler. To extract high-temperature waste gas for fuel savings in the subsequent combustion process, the waste heat extraction pipe is preferably located in the middle to front section of the ring cooler, where high-temperature sintered ore is covered. This area is where the cooling air first penetrates the high-temperature sintered ore layer and converges, resulting in a relatively high and stable waste gas temperature. The inlet end of the pipe is sealed with a flange to prevent the ingress of cold air and the leakage of high-temperature waste gas. The waste heat extraction pipe can be made of a metal capable of withstanding long-term high temperatures and corrosive media such as sulfur oxides that may be present in the waste gas, such as boiler steel or heat-resistant stainless steel.

[0042] The high-temperature induced draft fan has its inlet connected to the outlet of the waste heat extraction pipe via a pipeline. This fan is the power source for extracting waste gas from the annular cooler and forcibly transporting it to the ignition furnace. The selection of the induced draft fan must meet two core technical indicators: First, its flow-through components, including the impeller and casing, must be made of heat-resistant alloy steel and other materials, and can be equipped with water-cooled bearing housings or independent forced air cooling devices to ensure safe and reliable long-term operation under continuous high-temperature conditions; second, its aerodynamic performance, especially the total pressure and flow parameters, must be based on the total system network resistance ΔP. total The rated combustion air requirement Q of the ignition furnace req Perform precise calculations and matching.

[0043] Total system network resistance ΔP total The calculation of this is the technical basis for selecting the induced draft fan. The total pipeline resistance consists of two parts: friction loss and local resistance loss, and its calculation formula can be expressed as:

[0044] ΔP total =ΔP pipe +ΣΔP local ;

[0045] Where: ΔP total The total system pipeline resistance that the induced draft fan needs to overcome; ΔP pipe ΣΔP represents the frictional resistance loss caused by the viscosity and friction between the high-temperature exhaust gas and the pipe wall as it flows through all straight pipe sections. This value is a function of the total pipe length, pipe inner diameter, absolute pipe wall roughness, and the density and average velocity of the high-temperature exhaust gas. local This is the algebraic sum of all local resistance losses, which are mainly caused by the rapid changes in velocity and direction of the high-temperature waste gas as it flows through various non-straight pipe components in the pipeline. Specifically, these losses include pressure losses caused by pipe bends, tees, reducers, valves, and the inlet and outlet of the pipeline.

[0046] The hot air conveying duct connects at its inlet to the outlet of a high-temperature induced draft fan, and at its outlet to the subsequent combustion execution and safety assurance module. To reduce heat loss of the high-temperature exhaust gas during long-distance transport and ensure that the temperature of the combustion air reaching the ignition furnace remains at a high level, the outer wall of the hot air conveying duct needs to be insulated. Preferably, this insulation layer can adopt a multi-layer composite structure, for example, an inner layer of high-density ceramic fiber blanket, an outer layer of low thermal conductivity aluminum silicate board or rock wool, and an outermost layer of metal (such as galvanized iron or aluminum sheet) protective shell.

[0047] During operation, the high-temperature induced draft fan is started first. After the induced draft fan starts running, a negative pressure is formed at its inlet. This negative pressure causes the exhaust gas from the high-temperature zone of the annular cooler to be continuously drawn into the waste heat extraction pipeline. The exhaust gas flow is pressurized after passing through the induced draft fan, obtaining sufficient pressure to overcome the total resistance ΔP of the subsequent pipeline network. total The kinetic and pressure energy of the exhaust gas is then used to pressurize and transport the high-temperature exhaust gas into the hot air delivery pipeline. This process forces the waste heat resources that were originally emitted directly or indirectly into effective thermal energy for the ignition and combustion process, thus providing a physical basis for reducing ignition fuel consumption.

[0048] The status sensing module is used to monitor the temperature of the combustion air and / or the furnace temperature of the ignition furnace in real time.

[0049] In this embodiment, to address the technical problem in existing technologies that utilize sintering waste heat for combustion, where the lack of real-time and accurate monitoring of key system operating parameters hinders precise closed-loop control and reliable safety interlocking, this invention provides a state sensing module. The function of this module is to continuously monitor key thermal parameters and equipment status within the system, and convert the monitoring results into standardized electrical signals, providing the necessary real-time data for subsequent intelligent decision-making and control modules.

[0050] The state awareness module is structured and operates as follows.

[0051] This module includes combustion air temperature sensors, furnace temperature sensors, and induced draft fan status monitors. These sensors are physically distributed at different key nodes of the system, and electrically connected to the input interface of the programmable logic controller or distributed control system of the intelligent decision and control module.

[0052] The combustion air temperature sensor is installed to obtain the actual temperature of the high-temperature exhaust gas transported by the waste heat capture and transport module before entering the ignition furnace, denoted as T. air This temperature parameter is a crucial disturbance variable for achieving precise control of the combustion process and a key criterion for determining the effectiveness of the hot air source and whether a safety switching logic needs to be triggered. To ensure the accuracy and representativeness of the measured values, the sensor is preferably installed on a relatively long straight section of hot air delivery pipe before entering the ignition furnace. Its temperature probe needs to extend into the central region of the pipe's cross-section to avoid temperature deviations caused by the pipe wall boundary layer effect. In specific implementations, industrial-grade armored thermocouples, such as type K or type N thermocouples, can be selected, with their range and material suitable for the temperature range and environment of the exhaust gas in this system.

[0053] The furnace temperature sensor is set up to directly measure the core controlled variable of the ignition process—the actual flame zone temperature inside the ignition furnace, denoted as T. f This parameter is the main feedback signal of the entire closed-loop control system, and the accuracy and stability of its measurement directly affect the control effect. Since the temperature field inside the ignition furnace may be unevenly distributed, a multi-point measurement scheme is preferred to obtain a temperature value that comprehensively reflects the overall ignition conditions. That is, multiple furnace temperature sensors are symmetrically arranged at different locations near the sintering material layer inside the ignition furnace.

[0054] The intelligent decision-making and control module receives temperature values ​​T measured by these multiple sensors. f,1 ,T f,2 ,...,T f,n Then, the final furnace temperature T used for control is calculated using a preset algorithm. f One feasible way to calculate this is to take their arithmetic mean:

[0055]

[0056] Where n is the total number of sensors, T f,i Let be the real-time measurement value of the i-th sensor.

[0057] Considering the extremely harsh high temperature and flame environment inside the ignition furnace, the furnace temperature sensor preferably uses a precious metal thermocouple such as type S, type B or type R, and is equipped with a protective sleeve made of high-alumina ceramic or heat-resistant alloy to ensure its long-term stability and service life.

[0058] The induced draft fan status monitor is installed to monitor the operating status of the high-temperature induced draft fan, the core power equipment in the waste heat capture and transport module, in real time. Unexpected fan shutdown is one of the most common failure modes of this system, and the status signal S provided by this monitor... fan This is the primary and highest priority condition for triggering the system security switchover process. The monitor's functionality can be achieved through at least one of the following methods:

[0059] Firstly, by installing a current transformer in the power supply circuit of the induced draft fan drive motor, its operating current I can be monitored in real time. fan The intelligent decision-making and control module receives the current signal through its analog input channel and compares it with the preset normal operating current range [I]. min ,I max ] for comparison. When I fan Below the lower limit I min If the motor loses power, runs idle, or exceeds the upper limit I max If the motor stalls, it is determined that the induced draft fan is in a faulty state.

[0060] Secondly, the auxiliary contacts of the main contactor or circuit breaker controlling the induced draft fan can be utilized within the motor control center (MCC). Typically, a normally open auxiliary contact can be led out; this contact closes when the induced draft fan starts and opens when the fan stops or trips. This switch signal can be directly connected to the digital input channel of the intelligent decision and control module to determine the fan's running and stopped status.

[0061] During system operation, each of the aforementioned sensors converts its measured physical quantities, such as temperature, current, or switching signals, into standard industrial electrical signals in real time, such as 4-20mA DC current signals or 24VDC switching signals, and transmits them to the intelligent decision and control module via shielded cables. The intelligent decision and control module collects, processes, and analyzes these signals, thus forming a comprehensive perception of the entire system's operating status. This provides a real-time, accurate, and reliable data foundation for the execution of subsequent upper-level algorithms, such as PID closed-loop control, safety interlock protection, and optional collaborative allocation.

[0062] The intelligent decision-making and control module, which is electrically connected to the state perception module, is used to generate control commands for the fuel supply to the ignition furnace based on the monitored temperature information.

[0063] In one specific embodiment of the present invention, to address the technical problems of unstable furnace temperature due to fluctuations in combustion air temperature when using waste heat for combustion, and the lack of automated and systematic countermeasures when the waste heat source malfunctions, which may lead to production interruptions or deterioration of process parameters, the present invention provides an intelligent decision-making and control module. The function of this module is to integrate and process all real-time data provided by the state perception module, and, based on internally preset control algorithms and logic rules, generate and issue control commands to each execution component in the system, thereby achieving automation, stabilization, and safety of system operation.

[0064] The intelligent decision-making and control module is structured and operates as follows.

[0065] The core hardware of this module is a central controller, preferably an industrial-grade programmable logic controller (PLC) with high reliability, strong anti-interference capabilities, and abundant input / output interfaces, or it can serve as a control station of a distributed control system (DCS). This central controller connects electrically to all sensors in the status sensing module, as well as all actuators in the combustion execution and safety assurance module and the optional hot air coordinated distribution module, through its input / output (I / O) modules. The core functions of this module are implemented through internally programmed and embedded software algorithms and logic programs.

[0066] This module contains at least two main control logic programs: an ignition temperature closed-loop control program and a safety protection switching program.

[0067] The ignition temperature closed-loop control program is the main control logic for the system under normal operating conditions. Its control objective is to maintain the combustion air temperature T... air Under conditions of constantly changing disturbance factors, the actual furnace temperature T of the ignition furnace is... f The temperature remains stable at the target ignition temperature T preset by the operator. sp The program achieves this by executing a discrete proportional-integral-derivative (PID) control algorithm.

[0068] Within each control cycle, the central controller first obtains the real-time furnace temperature measurement value T from the status sensing module. f (t), and the preset value T sp By comparison, the current temperature deviation e(t) is calculated:

[0069] e(t) = T sp -T f (t);

[0070] Subsequently, based on this deviation, the controller calculates the control output U for the gas electric regulating valve in the combustion execution and safety module using the following PID algorithm. gas (t):

[0071]

[0072] Among them: U gas (t) represents the control signal output to the gas regulating valve in the current control cycle t, for example, a 4-20mA current value; e(t) represents the temperature deviation in the current cycle, and e(t-1) represents the temperature deviation in the previous control cycle; Δt represents the scan cycle or sampling time of the control program; K p K is the proportional gain coefficient, whose function is to make the controller output proportional to the current deviation. The larger the deviation, the stronger the control action, so as to ensure the system's response speed; i K is the integral gain coefficient, which accumulates historical deviations to eliminate static errors caused by factors such as changes in combustion air temperature that cannot be overcome by simple proportional control, thus ensuring that the furnace temperature can be accurately stabilized at the set value over a long period of time; d The differential gain coefficient is used to pre-control the system based on the trend of deviation changes. It can effectively suppress temperature overshoot, reduce system oscillation, and improve the dynamic stability of the system.

[0073] The controller will calculate U gas (t) is sent to the gas electric regulating valve through its analog output channel, thereby realizing continuous and dynamic regulation of gas flow.

[0074] The safety assurance switching program is a set of logic judgment and linkage execution programs that run permanently in the background and have the highest execution priority. Its function is to monitor the system in real time for serious faults that may cause production interruptions, and automatically execute preset safety response plans that can ensure production continuity when such faults occur.

[0075] The central controller continuously receives and interprets key status signals provided by the status awareness module. Its core triggering condition is a logical expression:

[0076] Trigger fault =(S fan =FALSE)∨(T air <T air_min );

[0077] Among them: Trigger fault S is a Boolean fault trigger flag; fan =FALSE indicates that the induced draft fan status monitor determines that the induced draft fan is in a stopped or faulty state; T air <T air_min The real-time temperature T of the combustion air air The temperature was below the preset minimum temperature threshold T that would produce effective energy savings. air_min .

[0078] Once the central controller determines the trigger fault If the value is true, it will immediately execute the following linked operation:

[0079] First, interrupt the normal output of the above PID closed-loop control program;

[0080] Second, send a switching command to the air source switching device in the combustion execution and safety assurance module to activate it and switch the combustion air source from the high-temperature exhaust gas air path to the backup normal temperature air path.

[0081] Third, a second switching command is sent to the gas electric regulating valve to forcibly set its control quantity to a preset safety value U that matches the normal temperature combustion air condition. gas_preset This value is sufficient to maintain basic stability of ignition under normal temperature combustion conditions;

[0082] Fourth, send alarm signals to the human-machine interface (HMI) in the central control room and to the on-site audible and visual alarms.

[0083] In an optional embodiment, when the system further includes a hot air coordinated distribution module, the intelligent decision-making and control module also incorporates a coordinated distribution algorithm. One priority-based distribution strategy is as follows: the controller, according to preset logic, prioritizes satisfying the rated hot air flow rate F required by the ignition furnace. ign_req If the total hot air volume F total If there is insufficient hot air, all hot air will be supplied to the ignition furnace; if there is surplus hot air, the remaining portion will be supplied to the furnace. total -F ign_req The flow is allocated to other heat-consuming equipment. The controller calculates and generates control commands for each branch flow regulating valve to implement this allocation strategy.

[0084] In summary, this intelligent decision-making and control module receives multi-dimensional state inputs, executes multi-objective control algorithms and logical rules, and generates precise control outputs for multiple actuators, thereby achieving adaptive stable control and fault safety assurance of the system under different operating conditions.

[0085] The combustion execution and safety assurance module is connected to the waste heat capture and transport module and the intelligent decision and control module. It is used to receive combustion air and fuel and execute combustion operations according to control commands. The module also includes a backup ambient temperature air path and an air source switching device controlled by the intelligent decision and control module, which is used to switch the combustion air source under preset conditions.

[0086] In one specific embodiment of the present invention, to address the technical problems of ignition process interruption when the waste heat source fails in a waste heat-assisted combustion system, and the lack of a matching fuel regulation actuator for different combustion air temperatures, the present invention provides a combustion execution and safety assurance module. The function of this module is to provide the ignition furnace with a switchable combustion air source according to instructions, and to serve as the final execution unit for fuel regulation instructions, thereby ensuring the continuity and safety of the ignition process under different operating conditions.

[0087] The combustion execution and safety assurance module is structured and operates as follows.

[0088] This module is physically located downstream of the waste heat capture and transport module and upstream of the ignition furnace, and it interacts bidirectionally with the intelligent decision-making and control module. It mainly includes a backup ambient temperature air path, an air source switching device, and a gas supply and regulation system.

[0089] The backup ambient temperature air duct is designed to provide the system with a reliable, redundant combustion air source independent of the high-temperature waste heat source. This air duct is an independent pipe with its inlet located in the outdoor atmosphere and preferably equipped with a filter to prevent impurities from being drawn in; its outlet is connected to an inlet of the air source switching device.

[0090] The air source switching device is the core actuator that enables the switching of the combustion air source between high-temperature exhaust gas and ambient air. The device is preferably a single electric or pneumatic three-way valve, such as a three-way ball valve or a valve group consisting of two butterfly valves and corresponding three-way fittings. The device has at least two inlets and one outlet: its first inlet is connected to the end of the hot air delivery pipe of the waste heat capture and delivery module to receive high-temperature exhaust gas; its second inlet is connected to the outlet of the backup ambient air path to receive ambient air; and its outlet is connected to the main combustion air box or burner duct of the ignition furnace. The electric or pneumatic actuator of the air source switching device is electrically connected to the digital output channel of the intelligent decision and control module to receive discrete switching commands from the control module.

[0091] The gas supply and regulation system supplies fuel to the ignition furnace burner and precisely regulates its flow rate according to instructions. The system includes a main gas pipe, manual valves, filters, and a key electrically operated gas regulating valve. This electrically operated gas regulating valve is a proportional control valve capable of continuous opening adjustment. Its valve positioner or integrated actuator is electrically connected to the analog output channel of the intelligent decision and control module to receive continuous control signals (e.g., a current signal ranging from 4-20mA) from the control module and adjust the valve opening to the corresponding position accordingly.

[0092] The working process of this module can be divided into two modes. The switching between the two modes is automatically determined and executed by the intelligent decision and control module based on the system's operating status.

[0093] In normal operation mode, the intelligent decision-making and control module determines that the waste heat source is working properly. At this time, the module sends a command to the air source switching device to connect the first inlet (high-temperature waste gas) and the outlet, while simultaneously closing the second inlet (normal temperature air). In this mode, the gas-electric regulating valve receives the continuous control signal U calculated and output in real time by the PID closed-loop control program in the intelligent decision-making and control module. gas (t), whose valve opening changes dynamically with the signal, thereby achieving precise regulation of fuel flow to maintain stable furnace temperature.

[0094] In safety mode, when the intelligent decision-making and control module detects that a preset fault condition (such as induced draft fan failure or excessively low combustion air temperature) has been triggered, the module immediately issues a set of linkage instructions to the combustion execution and safety module. First, a switching instruction is sent to the air source switching device, causing its actuator to actuate, quickly closing the first inlet and opening the second inlet, thereby seamlessly switching the combustion air source from high-temperature exhaust gas to standby ambient temperature air within seconds. Simultaneously, the intelligent decision-making and control module interrupts the PID control output and sends a preset, fixed control signal to the gas electric regulating valve. This preset value corresponds to a specific valve opening, which is pre-calculated and set based on the amount of fuel required to maintain stable ignition under normal temperature air combustion conditions. Because the enthalpy of normal temperature air is much lower than that of high temperature exhaust gas, more fuel needs to be supplied to maintain combustion, and this preset value is set for this purpose.

[0095] Through the above structure and working method, this combustion execution and safety assurance module constitutes the physical execution layer and safety barrier of the entire system. It not only executes energy-saving combustion control commands under normal operating conditions, but more importantly, through its internally integrated air source switching function and fuel supply mode switching function, it ensures that in abnormal operating conditions where the main heat source fails, the ignition process can automatically and quickly switch to the backup scheme, thereby avoiding production interruption and ensuring the continuity and stability of the entire sintering process.

[0096] A hot air coordinated distribution module is located downstream of the waste heat capture and transport module and is used to distribute high-temperature waste gas to the ignition furnace and at least one other heat-using device according to a preset strategy.

[0097] The intelligent decision-making and control module also has a built-in collaborative allocation algorithm to generate control commands for the hot air collaborative allocation module;

[0098] In an optional embodiment of the present invention, for some sintering production lines that not only need to use the waste heat from the annular cooler for ignition and combustion, but also have other heat demands such as using hot air to preheat the sintering material surface, a technical problem arises as to how to effectively allocate limited high-temperature waste heat resources among multiple heat-consuming points. The present invention provides a hot air collaborative allocation module. The function of this module is that, when the total hot air volume provided by the waste heat capture and conveying module is excessive, it can allocate the remaining hot air to other heat-consuming equipment according to a preset strategy, while ensuring priority heat use by the ignition furnace, thereby achieving tiered utilization of heat resources and optimization of the overall system energy efficiency.

[0099] The hot air coordinated distribution module has the following structure and working method.

[0100] This module is physically located downstream of the waste heat capture and transport module and is a piping distribution system connecting the main hot air source and multiple hot spots. Its structure includes a tee or multi-way branch fitting installed on the main hot air transport duct, which branches the main duct into at least two parallel branch ducts.

[0101] The first branch pipe connects to the combustion execution and safety module, and is dedicated to supplying high-temperature combustion air to the ignition furnace. The other (one or more) branch pipes are connected to one or more other heat-using devices, such as the hot air sintering preheating box above the sintering machine trolley.

[0102] To achieve independent and precise control of the flow rate in each branch, a flow regulating valve is installed on each branch pipeline. These regulating valves are preferably electric regulating valves with positioners, and their electric actuators are electrically connected to the output channel of the intelligent decision and control module to receive and execute continuous regulation commands from the module.

[0103] The operation of this module is centrally controlled by the collaborative allocation algorithm built into the intelligent decision-making and control module. The core of this algorithm is an allocation logic based on heat usage priority. Its design goal is to first unconditionally meet the heat usage requirements of the ignition furnace, which is crucial to the entire sintering process, and then consider other auxiliary heat usage requirements.

[0104] The execution process of this collaborative allocation algorithm is as follows:

[0105] The central controller of the intelligent decision-making and control module first needs to obtain two key parameters: the total available hot air flow rate F of the system. total And the rated process flow rate F of the ignition furnace. igm_req Among them, F ign_req It is a preset value based on the ignition process requirements.

[0106] F totalThe flow rate can be measured in real time by a flow meter installed on the main hot air delivery pipeline, or indirectly estimated based on the performance curve, speed, and pipeline resistance of the high-temperature induced draft fan.

[0107] After acquiring the parameters, the central controller performs the following judgments and calculations in each control cycle:

[0108] First, the target flow rate F allocated to the first branch pipe (leading to the ignition furnace) ign The calculations are performed according to the following priority principles:

[0109]

[0110] Where: when the total available flow F total The flow rate F required by the ignition furnace is less than or equal to the flow rate required by the ignition furnace. ign_req At that time, all available flow is allocated to the ignition furnace, i.e., F ign =F total When the total available flow rate exceeds the flow rate required by the ignition furnace, it will be allocated in full according to the required flow rate, i.e., F ign =F ign_req .

[0111] Next, calculate the total target flow rate F allocated to other branch pipes (leading to other heat-consuming equipment). secondary The calculation formula is as follows:

[0112] F secondary =F total -F ign ;

[0113] This ensures that only after the ignition furnace's demand is fully met will any remaining flow be allocated to secondary heating equipment. If the ignition furnace has consumed all available flow, then zero flow will be allocated to the secondary equipment.

[0114] After calculating the target flow rate for each branch, the central controller uses these flow rate values ​​and the flow characteristic curves of each regulating valve to calculate the required opening percentage for each flow regulating valve. Finally, the controller sends corresponding control signals to the flow regulating valves on the downstream branch pipes through its analog output channel, driving them to adjust to the target opening, thereby achieving dynamic and automated distribution of the total hot air flow rate in accordance with the preset distribution strategy.

[0115] By setting up the hot air coordinated distribution module and its control logic, this invention establishes an orderly resource allocation mechanism based on process importance and prioritization between a single heat source and multiple heat sources, ensuring the heat stability of key process points and making full use of surplus waste heat resources.

[0116] Please see the appendix Figure 1-2A method for increasing ignition temperature and saving gas by utilizing sintering waste heat includes the following steps:

[0117] Waste heat combustion-assisted step: High-temperature waste gas is drawn from the annular cooler and sent into the ignition furnace as combustion-assisted air, where it is mixed with fuel for combustion;

[0118] Status awareness step: Real-time monitoring of at least one of the following operating parameters: combustion air temperature, furnace temperature of the ignition furnace, and operating status of the induced draft fan used to extract high-temperature exhaust gas;

[0119] Intelligent decision-making and closed-loop control steps: Based on the deviation between the monitored furnace temperature and the preset target temperature, the fuel supply is dynamically adjusted through a closed-loop control algorithm to stabilize the ignition temperature.

[0120] Safety switching procedure: When the monitored operating parameters meet the preset fault conditions, the combustion air is automatically switched from high-temperature exhaust gas to standby ambient temperature air, and the fuel supply is adjusted simultaneously to maintain ignition.

[0121] In this embodiment, the method is executed through the aforementioned system that utilizes sintering waste heat to increase the ignition temperature and save gas. Its operational logic is embedded in the central controller of the intelligent decision-making and control module. The specific execution flow of this method is as follows.

[0122] The method first executes a waste heat-assisted combustion step. After the system starts up and enters normal operation, the high-temperature induced draft fan in the waste heat capture and transport module starts running, actively drawing high-temperature waste gas from the sintering ring cooler. This high-temperature waste gas is stably transported to the combustion execution and safety assurance module via the waste heat extraction pipeline and the hot air transport main pipeline. Finally, this high-temperature waste gas, as preheated combustion air, enters the combustion zone of the ignition furnace, mixes with and burns the fuel (such as coal gas) supplied by the gas supply and regulation system, thereby realizing the use of waste heat to assist combustion in the ignition process.

[0123] While the waste heat combustion process is underway, the system continuously executes a status sensing step. Status sensing modules installed in the system's pipelines and equipment continuously monitor key operating parameters of the entire system in real time. Specifically, a combustion air temperature sensor installed on the combustion air duct before the ignition furnace continuously measures the actual inlet temperature of the combustion air; a furnace temperature sensor inside the ignition furnace acquires the combustion temperature within the furnace in real time; and an induced draft fan status monitor associated with the high-temperature induced draft fan is responsible for monitoring the normal operation of this core power unit. All these parameters acquired through sensors and monitors are continuously transmitted as electrical signals to the central controller of the intelligent decision-making and control module, serving as the data basis for subsequent decision-making and control.

[0124] Upon receiving real-time operating parameters, the intelligent decision-making and control module executes intelligent decision-making and closed-loop control steps. Under normal waste heat source operation, the central controller continuously compares the monitored real-time furnace temperature with the pre-set process target temperature value within the controller, thus obtaining an error signal representing the current temperature deviation. This error signal is then input into a built-in closed-loop control algorithm, preferably a proportional-integral-derivative (PID) control algorithm. Based on the current and historical temperature deviations, this algorithm calculates a precise adjustment amount and generates a dynamic control command signal, which is output to the gas-electric regulating valve in the combustion execution and safety assurance module. The regulating valve automatically adjusts its opening according to this command signal, thereby precisely controlling the fuel supply to the ignition furnace. This continuous closed-loop negative feedback regulation process actively overcomes external disturbances such as changes in combustion air temperature caused by fluctuations in the annular cooler's operating conditions, stabilizing the furnace temperature within the preset target range.

[0125] Throughout the operation, the system executes safety switching procedures in parallel. The central controller continuously determines whether preset fault conditions have been triggered based on parameters obtained from the status awareness step. These fault conditions include, for example, a report from the induced draft fan status monitor indicating a fan malfunction, or a combustion air temperature sensor reading below a preset minimum safe temperature threshold for a given period. Once any fault condition is met, the central controller immediately determines that the waste heat combustion system has failed and automatically initiates the safety protection program. The program first sends a switching command to the air source switching device, driving it to quickly switch the combustion air source from the high-temperature exhaust gas duct to the backup ambient temperature air path. Simultaneously, the controller temporarily suspends the aforementioned closed-loop control algorithm and sends a preset emergency opening command to the gas-fired electric regulating valve, matching the ambient temperature air combustion conditions. This series of synchronously executed switching and adjustment operations ensures a seamless transition to backup mode during waste heat source failures, preventing production stoppages due to ignition interruptions and guaranteeing the continuity and safety of the entire sintering production operation.

[0126] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A system for increasing ignition temperature and saving coal gas by utilizing sintering waste heat, characterized in that, include: A waste heat capture and transport module is used to extract high-temperature waste gas from the annular cooler and transport it as combustion air. A status sensing module is used to monitor the temperature of the combustion air and / or the furnace temperature of the ignition furnace in real time. The intelligent decision-making and control module is electrically connected to the state perception module and is used to generate control commands for the fuel supply to the ignition furnace based on the monitored temperature information. The combustion execution and safety assurance module is connected to the waste heat capture and delivery module and the intelligent decision and control module. It is used to receive the combustion air and fuel and execute combustion operations according to the control instructions. The module also includes a backup ambient temperature air path and an air source switching device controlled by the intelligent decision and control module, which is used to switch the combustion air source under preset conditions. A hot air coordinated distribution module is located downstream of the waste heat capture and conveying module, and is used to distribute the high-temperature waste gas to the ignition furnace and at least one other heat-using device according to a preset strategy. The intelligent decision-making and control module also has a built-in collaborative allocation algorithm for generating control commands for the hot air collaborative allocation module.

2. The system for increasing ignition temperature and saving coal gas by utilizing sintering waste heat according to claim 1, characterized in that, The waste heat capture and transport module includes: One end is connected to the waste heat outlet pipe in the high-temperature zone of the annular cooler; A high-temperature resistant induced draft fan, the inlet of which is connected to the waste heat outlet pipe; The hot air delivery pipe has its inlet connected to the outlet of the high-temperature induced draft fan, and its outlet connected to the air source switching device of the combustion execution and safety assurance module.

3. The system for increasing ignition temperature and saving coal gas by utilizing sintering waste heat according to claim 2, characterized in that, The status perception module also includes an induced draft fan status monitor, which is used to monitor the operating status of the high-temperature induced draft fan and send the status signal to the intelligent decision and control module.

4. The system for increasing ignition temperature and saving coal gas by utilizing sintering waste heat according to claim 1, characterized in that, The intelligent decision-making and control module has a built-in safety switching logic. The preset conditions include: the induced draft fan status monitor detects a malfunction in the induced draft fan, or the temperature of the combustion air is lower than a preset temperature threshold.

5. A system for increasing ignition temperature and saving coal gas by utilizing sintering waste heat according to claim 1, characterized in that, The intelligent decision-making and control module has a built-in ignition temperature closed-loop control algorithm. This algorithm generates the control command based on the deviation between the furnace temperature monitored by the state perception module and a preset target ignition temperature.

6. A system for increasing ignition temperature and saving coal gas by utilizing sintering waste heat according to claim 5, characterized in that, The ignition temperature closed-loop control algorithm is a proportional-integral-derivative control algorithm.

7. A system for increasing ignition temperature and saving coal gas by utilizing sintering waste heat according to claim 1, characterized in that, The air source switching device in the combustion execution and safety assurance module can switch between the high-temperature exhaust gas combustion air path and the backup ambient temperature air path when it receives a switching command from the intelligent decision and control module.

8. A system for increasing ignition temperature and saving coal gas by utilizing sintering waste heat according to claim 1, characterized in that, The hot air coordinated distribution module includes flow regulating valves installed on branch pipes leading to the ignition furnace and other heat-using equipment, and the flow regulating valves are controlled by the intelligent decision and control module.

9. A method for saving coal gas by utilizing sintering waste heat to increase ignition temperature, used in the system for saving coal gas by utilizing sintering waste heat to increase ignition temperature according to any one of claims 1-8, characterized in that, Includes the following steps: Waste heat combustion-assisted step: High-temperature waste gas is drawn from the annular cooler and sent into the ignition furnace as combustion-assisted air, where it is mixed with fuel for combustion; Status awareness step: Real-time monitoring of at least one of the following operating parameters: the temperature of the combustion air, the furnace temperature of the ignition furnace, and the operating status of the induced draft fan used to extract high-temperature exhaust gas; Intelligent decision-making and closed-loop control steps: Based on the deviation between the monitored furnace temperature and the preset target temperature, the fuel supply is dynamically adjusted through a closed-loop control algorithm to stabilize the ignition temperature. Safety switching procedure: When the monitored operating parameters meet the preset fault conditions, the combustion air is automatically switched from the high-temperature exhaust gas to the backup ambient temperature air, and the fuel supply is adjusted simultaneously to maintain ignition.

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