Low-energy-consumption high-efficiency steel smelting furnace bottom heat exchange system

Abstract

The invention discloses a low-energy-consumption high-efficiency steel smelting furnace bottom heat exchange system, which belongs to the technical field of steel smelting and comprises a heat collection module, a heat exchange processing module, an intelligent control module and a feedback regulation module. The heat collection module collects heat and temperature data through an efficient heat conduction pipeline surrounding the bottom of the smelting furnace and a temperature sensor. The heat exchange treatment module realizes efficient heat exchange by using a reverse flow type heat exchanger and multiple layers of heat exchange fins, and recovered heat is used for preheating raw materials; the intelligent control module adjusts the flow and flow velocity parameters of a heat exchange medium by using a control algorithm according to the temperature data, and precisely controls the bottom temperature of the smelting furnace; the feedback adjusting module feeds back the operation effect of the heat exchange processing module to the intelligent control module, and system closed-loop control is achieved. The device is high in heat exchange efficiency, low in energy consumption, accurate in temperature control, simple in structure and convenient to maintain, and the production efficiency and the product quality of steel smelting are effectively improved.

Description

Technical Field

[0001] The invention relates to the technical field of steel smelting, and in particular to a low-energy-consumption and high-efficiency heat exchange system at the bottom of a steel smelting furnace. Background Art

[0002] In the steelmaking process, energy consumption and thermal management have always been key factors affecting production efficiency and cost. As a core equipment, the steelmaking furnace generates a lot of heat during operation, especially in the bottom area of ​​the furnace. How to efficiently recover and utilize this heat has become an important issue that needs to be solved in the steel industry.

[0003] The traditional heat exchange system at the bottom of the steel smelting furnace has many shortcomings. On the one hand, the heat exchange efficiency is low. The early heat exchanger design is often relatively simple, using downstream or cross-flow heat exchange methods. The temperature difference driving force between the cold and hot media is not fully utilized, resulting in insufficient heat transfer and a large amount of heat energy being wasted. For example, the heat exchange efficiency of some old heat exchangers can only reach 60% - 70%, which means that a considerable part of the heat cannot be effectively recycled and is directly discharged into the environment, which not only causes energy waste, but also increases the production cost of the enterprise.

[0004] On the other hand, energy consumption is too high. In order to achieve a certain heat exchange effect, some heat exchange systems have to rely on a large number of power equipment to maintain the flow and flow rate of the medium, resulting in huge energy consumption. For example, some systems use high-power pumps to transport cold media. Although this can improve the heat exchange efficiency to a certain extent, it also brings high electricity consumption. Moreover, the traditional system lacks precision in control and cannot adjust the operating parameters in real time according to the actual heat generation and heat exchange requirements of the smelting furnace, further exacerbating the waste of energy.

[0005] In addition, the traditional heat exchange system has a low level of intelligence. There is a lack of effective real-time monitoring and feedback mechanisms for key parameters in the heat exchange process, such as the temperature and flow of hot and cold media. Operators can only rely on experience and regular manual inspections to judge the operating status of the system, and it is difficult to discover and solve potential problems in a timely manner. When the operating conditions of the smelting furnace change, the system cannot respond quickly, resulting in unstable heat exchange effects, affecting the quality and production efficiency of steel smelting.

[0006] As the steel industry's requirements for energy conservation, emission reduction and intelligent production are increasing, the development of a heat exchange system at the bottom of a steel smelting furnace with low energy consumption, high efficiency and intelligent control function has important practical significance. The present invention aims to solve the above problems in the prior art, and through innovative system design, advanced heat exchange technology and intelligent control strategy, achieve efficient recovery and utilization of heat at the bottom of a steel smelting furnace, reduce energy consumption, and improve production efficiency and product quality. Summary of the Invention

[0007] The object of the present invention is to provide a bottom heat exchange system for a steel smelting furnace with low energy consumption and high efficiency. Through innovative high-efficiency heat conduction pipe design, advanced countercurrent heat exchange technology and intelligent feedback control strategy, it overcomes the disadvantages of traditional heat exchange systems such as low heat exchange efficiency, high energy consumption and low intelligence level. Thus, it greatly improves the heat exchange efficiency, reduces energy consumption and enhances the intelligence level of the system. It is especially suitable for large steel smelting plants with extremely high requirements for energy utilization efficiency and production stability, providing a reliable solution for efficient heat management and energy conservation and emission reduction in the steel smelting process, and effectively ensuring the efficient and stable operation of steel production.

[0008] To achieve the above object, the present invention provides a bottom heat exchange system for a steel smelting furnace with low energy consumption and high efficiency, including a heat collection module, a heat exchange processing module, an intelligent control module and a feedback adjustment module; The heat collection module consists of high-efficiency heat conduction pipes surrounding the bottom of the smelting furnace and temperature sensors evenly distributed on the pipes, and is used to collect the heat at the bottom of the smelting furnace and monitor the temperature of the heat medium in the pipes; The heat exchange processing module uses a countercurrent heat exchanger with multiple layers of heat exchange fins inside, and is used to receive the heat carried by the hot medium in the high-efficiency heat conduction pipes and conduct heat exchange, that is, transfer the heat of the hot medium to the cold medium; The intelligent control module receives the temperature data of the hot medium, and according to the preset target temperature, adjusts the flow control valve through a control algorithm to regulate the flow rate and flow velocity of the cold medium in the heat exchange of the heat exchange processing module; The feedback adjustment module calculates the heat exchange efficiency of the heat exchange processing module according to the temperature of the hot medium and the temperature of the cold medium, and feeds it back to the intelligent control module for optimizing the control algorithm of the intelligent control module.

[0009] Furthermore, the high-efficiency heat conduction pipes are made of copper alloy material with a silicon carbide coating.

[0010] Furthermore, the temperature sensors are equipped with wireless communication modules to transmit the temperature of the hot medium to the intelligent control module.

[0011] Furthermore, in the heat exchange processing module, the heat exchange fins inside the countercurrent heat exchanger are made of stainless steel, with 5 layers, the thickness of each layer of fins is 0.5 mm, and the fin spacing is 2 mm.

[0012] Furthermore, the intelligent control module uses an STM32F407 microcontroller as the core processor to process the temperature data of the hot medium, execute the control algorithm, and accurately output the control signal to the flow control valve to regulate the flow rate and flow velocity of the cold medium.

[0013] Furthermore, the control algorithm is an improved PID control algorithm, which adds an integral separation link on the basis of the traditional PID algorithm, and its control formula is: Wherein, is the output of the controller, that is, the adjustment amount of the flow rate and velocity of the cold medium in the heat exchange; is the proportional coefficient, is the integral time constant, and the integral term represents the definite integral of the error function on the interval [0, t], is the differential time constant; is the deviation between the target temperature and the actual temperature, is the integral separation threshold, and t represents the time point.

[0014] Furthermore, in the feedback adjustment module, the monitoring of the heat exchange efficiency is calculated by measuring the temperatures and flow rates of the hot medium and the cold medium before and after the heat exchange, and the calculation formula is: Wherein, is the heat exchange efficiency, is the effective heat transfer amount, is the specific heat capacity of the cold medium, is the mass flow rate of the cold medium, representing the mass of the cold medium participating in the heat exchange per unit time, is the temperature of the cold medium leaving the heat exchanger after absorbing heat, is the initial temperature when the cold medium enters the heat exchanger; is the total heat, is the specific heat capacity of the hot medium, is the mass flow rate of the hot medium, is the temperature of the hot medium entering the heat exchanger, is the temperature of the hot medium leaving the heat exchanger; when the heat exchange efficiency is lower than 80%, the intelligent control module is triggered to adjust the flow rate and velocity of the heat exchange medium.

[0015] Furthermore, the intelligent control module adjusts the parameters of the improved PID control algorithm according to the feedback of the feedback adjustment module: When the gap between the actual heat exchange efficiency and the target value exceeds the preset threshold, the intelligent control module will increase the proportional coefficient ; Increasing makes the controller more sensitive to the temperature deviation, makes the control quantity change rapidly, and thus speeds up the adjustment speed; when the gap between the actual heat exchange efficiency and the target value is lower than the preset threshold, the intelligent control module will decrease the proportional coefficient ; When the gap between the actual temperature and the target temperature of the hot medium exceeds the preset threshold, the intelligent control module shortens the integral time constant to accelerate the integral action, eliminate the steady-state error, and make the output of the system approach the target value; when the gap between the actual temperature and the target temperature of the hot medium is less than the threshold, the intelligent control module will extend the integral time constant to reduce the integral action.

[0016] Compared with the prior art, the advantages of the present invention are as follows: (1) Innovative heat exchange structure and efficient heat transfer: The present invention adopts a countercurrent heat exchanger with multiple layers of stainless steel heat exchange fins, which greatly increases the heat exchange area, makes full use of the temperature difference driving force, and realizes the efficient recovery and utilization of heat.

[0017] (2) Precise energy consumption control and energy-saving design: The intelligent control module accurately regulates the flow rate and velocity of the cold medium, abandons the excessive use of traditional high-power pumps, and avoids energy waste. While ensuring the heat exchange effect, it significantly reduces the system energy consumption and saves a large amount of production costs for steel enterprises.

[0018] (3) Intelligent real-time control and dynamic regulation: The intelligent control module takes the STM32F407 microcontroller as the core, combines the improved PID control algorithm with the feedback regulation module, and monitors the heat exchange efficiency and the medium temperature in real time. Different from the traditional system that relies on manual experience judgment, it can quickly and automatically adjust the operating parameters according to the real-time working conditions of the smelting furnace to ensure that the heat exchange process is always efficient and stable.

[0019] (4) High stability and adaptability to complex working conditions: The heat exchanger shell is made of Q345R pressure vessel steel, which can operate stably under complex working conditions such as high pressure. And the components of the system are coordinated and optimized to adapt to different working states of the smelting furnace, with stronger stability and adaptability than the traditional system. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0021] Figure 1 is the system module diagram of the present invention; Figure 2 is the structure diagram of the deep learning model construction module of the present invention; Figure 3 is the structure diagram of the dynamic feedback regulation module of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts fall within the scope of protection of the present application.

[0023] Embodiment 1: Please refer to Figure 1 As shown, a bottom heat exchange system for a low-energy consumption and high-efficiency steel smelting furnace in this embodiment includes a heat collection module, a heat exchange processing module, an intelligent control module, and a feedback adjustment module; The heat collection module is composed of highly efficient heat conduction pipes surrounding the bottom of the smelting furnace and temperature sensors evenly distributed on the pipes, and is used to collect the heat at the bottom of the smelting furnace and monitor the temperature of the heat medium in the pipes; The highly efficient heat conduction pipes are made of copper alloy materials with a silicon carbide coating; the temperature sensors are equipped with wireless communication modules to transmit the temperature of the heat medium to the intelligent control module; The working process and details of the heat collection module: Heat absorption process: The highly efficient heat conduction pipes surrounding the bottom of the smelting furnace are made of copper alloy with a silicon carbide coating. The excellent heat conduction performance enables the pipes to quickly and efficiently absorb the heat dissipated from the furnace bottom. In actual operation, the high-temperature furnace bottom is in close contact with the heat conduction pipes, and the heat is quickly transferred from the furnace bottom to the pipes through heat conduction; since the pipes are tightly wound around the furnace bottom in a ring shape, it ensures that the heat in all parts of the furnace bottom can be fully absorbed, achieving a comprehensive collection of the heat at the furnace bottom.

[0024] Temperature sensor data acquisition: Platinum resistance temperature sensors PT100 evenly distributed on the pipes play a key role in temperature monitoring throughout the heat collection process. When the heat conduction pipes absorb heat, the temperature of the heat medium (heat-conducting oil) in the pipes will increase accordingly; the temperature sensors PT100 have extremely high temperature sensitivity and can accurately and real-time sense the change in the temperature of the heat-conducting oil. Every 3 seconds, the sensors will perform a temperature data acquisition; during the acquisition process, the platinum resistance inside the sensors will change its own resistance value with the change in temperature. According to the resistance-temperature characteristic curve of the platinum resistance, the resistance value can be converted into the corresponding temperature value, thereby obtaining accurate temperature data.

[0025] Data transmission to the intelligent control module: The temperature sensor PT100 outputs the collected temperature data in the form of an electrical signal. To ensure the stability and accuracy of data transmission, the RS485 communication protocol is used for data transmission to the intelligent control module, providing an important basis for the precise control of the subsequent heat exchange process.

[0026] The heat exchange processing module uses a countercurrent heat exchanger with multiple layers of heat exchange fins inside, which is used to receive the heat carried by the hot medium in the high-efficiency heat-conducting pipeline and conduct heat exchange, that is, transfer the heat of the hot medium to the cold medium. The detailed working process of the heat exchange processing module: Heat exchanger structure and material: The shell of the heat exchanger is made of Q345R pressure vessel steel, which has good strength and toughness to ensure stable operation in a complex industrial environment. The internal multiple layers of heat exchange fins are made of stainless steel, with a thickness of only 0.5 mm and a spacing of 2 mm. Inflow of hot medium and heat transfer: The high-temperature heat-conducting oil (hot medium) flowing out of the heat collection module enters the countercurrent heat exchanger at a certain flow rate. After the hot medium enters the heat exchanger, the large amount of heat it carries begins to contact the heat exchange fins; due to the high heat conductivity of the heat exchange fins, the heat quickly transfers from the hot medium to the fin surface; in this process, heat conduction follows Fourier's law, that is, the heat flux per unit time through a unit area is proportional to the temperature gradient; the greater the temperature difference between the hot medium and the fins, the faster the heat transfer rate. Inflow of cold medium and countercurrent design: The cold medium (cooling water) introduced from the outside flows into the heat exchanger from the bottom at a lower temperature, forming a countercurrent flow state with the hot medium; at the inlet of the heat exchanger, the temperature of the hot medium is higher than that of the cold medium, and there is a temperature difference between them, so the heat transfer rate is fast; as the heat exchange process progresses, at the outlet of the heat exchanger, although the temperature of the hot medium decreases and the temperature of the cold medium increases, due to the countercurrent design, there is still a certain temperature difference between them, and heat transfer continues. Enhancing effect of multiple layers of heat exchange fins: When the hot medium and the cold medium flow between the fins, the boundary layer of the fluid is continuously destroyed and updated, reducing the thermal resistance and promoting the rapid transfer of heat. The heat transfer amount in the heat exchange process can be calculated by the formula where is the heat transfer amount, is the comprehensive thermal conductivity between the hot and cold media, is the heat exchange area, is the average temperature difference between the hot and cold media, is the length of the heat conduction path.

[0027] The intelligent control module refers to Figure 2As shown, receive the temperature data of the hot medium, and according to the preset target temperature, adjust the flow regulating valve through a control algorithm to regulate the flow rate and velocity of the cold medium in the heat exchange process module during heat exchange; The intelligent control module uses the STM32F407 microcontroller as the core processor to process the temperature data of the hot medium, execute the control algorithm, and accurately output the control signal to the flow regulating valve to regulate the flow rate and velocity of the cold medium; The control algorithm is an improved PID control algorithm, which adds an integral separation link on the basis of the traditional PID algorithm. Its control formula is: Wherein, is the output of the controller, that is, the adjustment amount of the flow rate and velocity of the cold medium in the heat exchange; is the proportional coefficient, is the integral time constant, and the integral term represents the definite integral of the error function on the interval [0, t], is the differential time constant; is the deviation between the target temperature and the actual temperature, is the integral separation threshold, and t represents the time point.

[0028] The feedback adjustment module, referring to Figure 3 as shown, calculates the heat exchange efficiency of the heat exchange process module according to the temperature of the hot medium and the temperature of the cold medium, and feeds it back to the intelligent control module for optimizing the control algorithm of the intelligent control module.

[0029] In the feedback adjustment module, the monitoring of the heat exchange efficiency is calculated by measuring the temperatures and flow rates of the hot medium and the cold medium before and after heat exchange. The calculation formula is: Wherein, is the heat exchange efficiency, is the effective heat transfer amount, is the specific heat capacity of the cold medium, is the mass flow rate of the cold medium, representing the mass of the cold medium participating in heat exchange per unit time, is the temperature of the cold medium leaving the heat exchanger after absorbing heat, is the initial temperature of the cold medium when it enters the heat exchanger; is the total heat, is the specific heat capacity of the hot medium, is the mass flow rate of the hot medium, is the temperature of the hot medium entering the heat exchanger, is the temperature at which the heat medium leaves the heat exchanger; when the heat exchange efficiency is lower than 80%, the intelligent control module is triggered to adjust the flow rate and velocity of the heat exchange medium.

[0030] The intelligent control module adjusts the parameters of the improved PID control algorithm according to the feedback from the feedback adjustment module: When the gap between the actual heat exchange efficiency and the target value exceeds the preset threshold, the intelligent control module will increase the proportionality coefficient ; Increasing makes the controller more sensitive to temperature deviation, causing the control quantity to change rapidly, thereby accelerating the adjustment speed; when the gap between the actual heat exchange efficiency and the target value is lower than the preset threshold, the intelligent control module will decrease the proportionality coefficient ; When the gap between the actual temperature of the heat medium and the target temperature exceeds the preset threshold, the intelligent control module shortens the integral time constant , accelerating the integral action, eliminating the steady-state error, and making the output of the system approach the target value; when the gap between the actual temperature of the heat medium and the target temperature is less than the threshold, the intelligent control module will extend the integral time constant , reducing the integral action.

[0031] The above formulas are all in dimensionless form and only use numerical values for calculation. These formulas are based on a large amount of data and obtained through software simulation, aiming to be as close to the actual situation as possible. The preset parameters in the formulas can be adjusted by those skilled in the art according to specific requirements.

[0032] In the description of this specification, the description referring to terms such as "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in connection with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0033] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the present invention to only the specific implementation manners. Obviously, many modifications and variations can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art in the relevant technical field can understand and utilize the present invention well. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. A bottom heat exchange system for a low-energy-consumption and high-efficiency steel smelting furnace, characterized in that, The system includes: A heat collection module, which consists of highly efficient heat-conducting pipes surrounding the bottom of the smelting furnace and temperature sensors evenly distributed on the pipes, and is used to collect the heat at the bottom of the smelting furnace and monitor the temperatures of the hot medium and cold medium in the pipes; A heat exchange processing module, which uses a countercurrent heat exchanger with multiple layers of heat exchange fins inside, and is used to receive the heat carried by the hot medium in the highly efficient heat-conducting pipes and conduct heat exchange, where the heat exchange is to transfer the heat of the hot medium to the cold medium; An intelligent control module, which receives the temperature data of the hot medium, and according to the preset target temperature, through a control algorithm, adjusts the flow regulating valve to control the flow rate and flow velocity of the cold medium in the heat exchange in the heat exchange processing module; A feedback regulation module, which calculates the heat exchange efficiency of the heat exchange processing module based on the temperature of the hot medium and the temperature of the cold medium, and feeds it back to the intelligent control module for optimizing the control algorithm of the intelligent control module.

2. The system according to claim 1, wherein The highly efficient heat-conducting pipes are made of a copper alloy material with a silicon carbide coating.

3. The system according to claim 2, wherein , The temperature sensor is equipped with a wireless communication module to transmit the temperature of the hot medium to the intelligent control module.

4. The system according to claim 1, wherein In the heat exchange processing module, the heat exchange fins inside the countercurrent heat exchanger are made of stainless steel, with 5 layers, the thickness of each layer of fins is 0.5 mm, and the fin pitch is 2 mm.

5. The system according to claim 1, wherein The intelligent control module uses an STM32F407 microcontroller as the core processor to process the temperature data of the hot medium, execute the control algorithm, and accurately output the control signal to the flow regulating valve to control the flow rate and flow velocity of the cold medium.

6. The system according to claim 5, wherein The control algorithm is an improved PID control algorithm, which adds an integral separation link on the basis of the traditional PID algorithm, and its control formula is: wherein, is the output of the controller, i.e., the adjustment amount of the flow rate and velocity of the cold medium in the heat exchange; is the proportionality coefficient, is the integral time constant, and the integral term represents the definite integral of the error function over the interval [0, t], is the differential time constant; is the deviation between the target temperature and the actual temperature, is the integral separation threshold, and t represents the time point.

7. The system according to claim 1, wherein In the feedback regulation module, the monitoring of the heat exchange efficiency is calculated by measuring the temperatures and flow rates of the hot medium and cold medium before and after the heat exchange, and the calculation formula is: Among them, is the heat exchange efficiency, is the effective heat transfer amount, is the specific heat capacity of the cold medium, is the mass flow rate of the cold medium, representing the mass of the cold medium participating in heat exchange per unit time, is the temperature of the cold medium leaving the heat exchanger after absorbing heat, is the initial temperature of the cold medium when entering the heat exchanger; is the total heat amount, is the specific heat capacity of the hot medium, is the mass flow rate of the hot medium, is the temperature of the hot medium entering the heat exchanger, is the temperature of the hot medium leaving the heat exchanger; when the heat exchange efficiency is lower than 80%, the intelligent control module is triggered to adjust the flow rate and velocity of the heat exchange medium.

8. The system according to claim 7, wherein The intelligent control module adjusts the parameters of the improved PID control algorithm according to the feedback from the feedback regulation module: When the gap between the actual heat exchange efficiency and the target value exceeds the preset threshold, the intelligent control module will increase the proportionality coefficient ; Increasing makes the controller more sensitive to temperature deviation, causing the control quantity to change rapidly, thereby accelerating the adjustment speed; when the gap between the actual heat exchange efficiency and the target value is lower than the preset threshold, the intelligent control module will decrease the proportionality coefficient ; When the difference between the actual temperature and the target temperature of the heat medium exceeds the preset threshold, the intelligent control module shortens the integral time constant , speeds up the integral action, eliminates the steady-state error, and makes the output of the system approach the target value; when the difference between the actual temperature and the target temperature of the heat medium is less than the threshold, the intelligent control module will extend the integral time constant , reducing the integral action.

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