Steel mill gas molten salt heat storage system, heat storage operation method and device

Abstract

The invention relates to the technical field of coal gas molten salt heat storage, and discloses a steel mill coal gas molten salt heat storage system and a heat storage operation method and device.According to the coal gas molten salt heat storage system, a coal gas combustion unit adjusts heat power to output flue gas; the high-temperature heat exchange unit and the combustion unit are integrated, and fused salt is heated to the target temperature; the flue gas waste heat exchange unit uses waste heat flue gas flowing out of the high-temperature heat exchange unit as a heat source to heat low-temperature fused salt to medium temperature; the molten salt flow mixing unit realizes high-temperature molten salt flow division backflow and closed-loop circulation; the closed-loop control system dynamically adjusts the backflow proportion and the combustion power based on real-time data to ensure stable and efficient operation of the system, the problems that a blast furnace gas heat source is unstable, temperature rise of molten salt is limited and an existing system lacks dynamic control are solved, safe operation of the system is guaranteed, the service life of equipment is prolonged, and the energy utilization efficiency is further improved. And stable fused salt temperature output and energy efficiency optimization are realized.

Description

Technical Field

[0001] The present invention relates to the technical field of coal gas molten salt heat storage, and in particular to a steel plant coal gas molten salt heat storage system, a heat storage operation method and a device. Background Art

[0002] During the blast furnace production process in the steel industry, a large amount of coal gas by-product resources are often produced, which has the characteristics of low calorific value, strong volatility, and discontinuity. How to use this type of coal gas efficiently and stably is an important issue that needs to be solved in the current context of energy conservation and emission reduction. At present, the industry has tried to use high-temperature molten salt heat exchange systems to convert coal gas thermal energy into storable thermal energy, which can then be used for steam supply, power generation or other industrial purposes. This solution has the advantages of strong heat storage capacity and good thermal stability in structure, but it still faces the following key technical difficulties in actual application:

[0003] 1. Insufficient utilization paths for steel plant gas and rigid coupling methods

[0004] Most existing systems use a one-way sequential heat exchange process, where gas directly heats low-temperature molten salt to a high temperature before storing it in a hot salt tank. This structure lacks a buffering mechanism when the gas's calorific value fluctuates or the load changes, resulting in delayed system response and reduced thermal efficiency.

[0005] 2. Lack of effective temperature regulation and protection measures

[0006] When the gas combustion intensity is insufficient, the molten salt flow is uneven, or the initial temperature is too low, directly introducing it into the high-temperature section can easily cause risks such as thermal stress concentration and excessive heating rate, posing a threat to the safe operation of the heat exchanger.

[0007] 3. Lack of flexible control mechanism for “reflux-mixing”

[0008] Currently, most systems operate in a single-flow direction and lack a "high-temperature molten salt reflux regulation" design. They are unable to dynamically adjust the molten salt temperature at the inlet of the high-temperature section, which can easily lead to problems such as unstable operation, high heat loss, and over-temperature risks.

[0009] 4. The control strategy relies too much on experience and lacks intelligent feedback adjustment capabilities

[0010] Operating parameters such as the calorific value of coal gas and the initial temperature of molten salt change in real time, while system control generally adopts fixed parameters or empirical upper and lower limits, lacking model support and real-time optimization, resulting in high unit heat storage heat consumption. Summary of the Invention

[0011] In view of this, the present invention provides a steel plant coal gas molten salt heat storage system, heat storage operation method and device to solve the problem of how to achieve stable molten salt temperature output and energy efficiency optimization to achieve minimum unit heat storage heat consumption under coal gas fluctuation conditions.

[0012] In a first aspect, the present invention provides a steel plant gas molten salt heat storage system, comprising:

[0013] The gas combustion unit is used to output flue gas with controllable thermal power as a heat source by adjusting the ratio of blast furnace gas flow rate to combustion air. The output thermal power is the combustion heat input.

[0014] The high-temperature heat exchange unit is integrated with the gas combustion unit to heat the molten salt to the target temperature to form high-temperature molten salt;

[0015] The flue gas waste heat heat exchange unit is connected to the molten salt pump outlet of the cold salt tank, and is used to use the waste heat flue gas flowing out of the high-temperature heat exchange unit as a heat source to heat the low-temperature molten salt delivered from the cold salt tank through the molten salt pump to a preset medium temperature range to form medium-temperature molten salt;

[0016] The molten salt mixing unit includes a mixing chamber and a proportional control valve, which is used to dynamically adjust the molten salt reflux ratio by adjusting the proportional control valve. A portion of the preset high-temperature molten salt is mixed with the medium-temperature molten salt in the mixing chamber to form a mixed molten salt, so as to adjust the molten salt temperature at the inlet of the high-temperature heat exchange unit to the set target range. The remaining high-temperature molten salt is sent to the hot salt tank for storage. Subsequently, it is used to supply heat to the outside according to load demand or output high-parameter steam through the steam generator. The cooled molten salt is sent back to the cold salt tank to form a closed-loop circulation;

[0017] A closed-loop control system, including a temperature sensor, flow meter, and gas calorific value analyzer and controller, is used to dynamically adjust the molten salt reflux ratio and combustion power based on real-time data.

[0018] The steel plant gas molten salt heat storage system provided by the embodiment of the present invention adjusts the thermal power through the gas combustion unit to adapt to the fluctuation of the calorific value of the gas, and uses the mixed flow temperature rising control unit to reflux the high-temperature molten salt in proportion to mix with the medium-temperature molten salt, so as to stabilize the inlet temperature of the high-temperature heat exchange unit. The high-temperature heat exchange unit and the gas combustion unit are integrated to realize precise heating of the molten salt, and then a closed-loop circulation is formed through the molten salt mixing unit. The closed-loop control system dynamically adjusts parameters based on real-time data, which not only effectively solves the problems of unstable blast furnace gas heat source, limited molten salt temperature rising and lack of dynamic control of the existing system, but also ensures the safe operation of the system and extends the life of the equipment, and also improves the energy utilization efficiency, realizes the stable output of molten salt temperature and energy efficiency optimization, and enhances the flexibility and reliability of the system operation.

[0019] In an optional embodiment, the high-temperature heat exchange unit adopts a spiral tube structure, and the spiral tube is made of a high-temperature resistant alloy material, which can withstand high temperatures above the target temperature and the preset temperature difference stress between the flue gas and the molten salt.

[0020] The high-temperature heat exchange unit of the embodiment of the present invention adopts a spiral tube structure. From the perspective of safe operation, its high-temperature resistance can adapt to the heating environment of high-temperature molten salt (target temperature 560°C) and high-temperature flue gas, avoiding equipment damage due to insufficient temperature resistance of the material. At the same time, it can withstand the temperature difference stress between the flue gas and the molten salt, preventing failures such as pipeline cracking due to excessive thermal stress, and solving the safety hazards caused by local overheating or uneven heat exchange during heat exchange in the high-temperature section; from the perspective of equipment life, the spiral tube structure combined with high-temperature resistant alloy material can maintain structural stability under long-term high temperature and temperature fluctuation conditions, reduce equipment loss, and extend service life; from the perspective of heat exchange efficiency, the spiral tube structure can increase the contact area and heat exchange path between the molten salt and the flue gas, improve the heat exchange efficiency, and cooperate with the temperature resistance of the material to ensure that the mixed molten salt can be stably heated to the target temperature, thereby ensuring the quality of heat storage.

[0021] In a second aspect, the present invention provides a steel plant gas molten salt heat storage operation method, comprising:

[0022] Real-time collection of calorific value and flow parameters of blast furnace gas to determine the initial combustion thermal power of the burner;

[0023] Based on the steel mill gas molten salt heat storage system described in any optional embodiment of the first aspect, a thermodynamic model is established, including a combustion heat source section, a waste heat exchange section, a molten salt reflux mixing section, a high-temperature heating section, and a heat storage section. Based on the initial combustion heat power and preset system initial parameters, the system response under different molten salt reflux ratios and combustion heat power combinations is simulated, and the molten salt outlet temperature, heating rate, and unit heat storage heat consumption are output;

[0024] An operation optimization model is constructed with the objective function of minimizing the heat consumption per unit heat storage. The optimal combination of reflux ratio and combustion heat power parameters is output as the optimization result, taking into account the operating condition boundaries and equipment constraints.

[0025] The optimization results are used to guide on-site operation scheduling, and the control parameters are corrected in real time through the closed-loop control system to achieve stable temperature output and energy efficiency control under conditions of fluctuating gas calorific value.

[0026] The present invention determines the initial combustion thermal power by real-time acquisition of gas parameters, providing an accurate initial basis for system operation. It can quickly respond to real-time changes in gas calorific value and flow rate, addressing the issue of unstable blast furnace gas heat sources and laying the foundation for subsequent stable heating. A multi-segment thermal model is established and system responses are simulated for different parameter combinations. This allows for early prediction of the molten salt outlet temperature, heating rate, and thermal efficiency under different operating conditions, overcoming the shortcomings of existing technologies, which lack dynamic modeling and unsteady-state simulation, and providing data support for optimized operation. An optimization model is constructed with the goal of minimizing heat consumption per unit thermal storage, and constraints are combined to output the optimal parameter combination. This minimizes gas usage while ensuring the molten salt reaches the required temperature, avoiding energy waste and improving system energy efficiency. The optimization results are used to adjust parameters in real time through a closed-loop control system, achieving stable temperature output and energy efficiency control even when the gas calorific value fluctuates. This eliminates the open-loop operation of traditional systems, which rely on manual adjustments and result in large efficiency fluctuations, ensuring stable and efficient operation of the system under dynamic disturbances. Furthermore, by precisely controlling parameters such as the heating rate, safety hazards such as local overheating of the equipment are reduced, extending the equipment's service life.

[0027] The objective function of the operation optimization model is:

[0028]

[0029] Among them, α t is the molten salt reflux ratio at time t, Q burn，t is the burner thermal power at time t; m salt is the mass of molten salt; C p is the specific heat capacity of molten salt; ΔT t is the difference between the molten salt temperature at time t and the initial temperature of the molten salt.

[0030] The objective function provided by the embodiment of the present invention directly links the combustion heat power and the energy required for molten salt heat storage. By optimizing the dynamic combination of the molten salt reflux ratio and the combustion heat power, the gas consumption per unit of heat storage can be minimized while ensuring that the molten salt temperature reaches the target. This solves the energy waste problem caused by the lack of precise optimization in traditional systems and significantly improves the system's energy efficiency. By combining the operating condition boundaries with the equipment constraints to solve the optimal parameters, the system can dynamically adapt to disturbing conditions such as fluctuations in the calorific value of blast furnace gas and changes in flow rate. Even when the gas supply is unstable, the molten salt outlet temperature can be kept stable within the target range by adjusting the molten salt reflux ratio and the combustion power. This overcomes the difficulty of matching heat source fluctuations with the temperature sensitivity of the molten salt system and enhances the system's robustness under non-steady-state conditions.

[0031] In an optional embodiment, the use of the optimization results to guide on-site operation scheduling and to modify control parameters in real time through a closed-loop control system includes:

[0032] The closed-loop control system collects gas calorific value, molten salt temperature, molten salt flow rate and reflux valve position at preset time periods, and inputs the collected data into the thermal model for real-time working condition simulation to predict the molten salt temperature trend in the next time period;

[0033] Determine whether the current molten salt reflux ratio and combustion power keep the molten salt outlet temperature within the target temperature range;

[0034] If the deviation between the expected molten salt outlet temperature and the target temperature is greater than the preset threshold, the optimization model is triggered to recalculate the molten salt reflux ratio and combustion power as the optimization result;

[0035] According to the optimization results, the opening of the reflux valve and the combustion air ratio of the gas burner are adjusted to ensure that the molten salt outlet temperature is stable within the target temperature range.

[0036] The embodiment of the present invention collects key data such as gas calorific value and molten salt temperature at a preset period and inputs them into a thermal model simulation. This can capture operating condition fluctuations in real time and predict molten salt temperature trends in advance, solving the problem of the inability to timely perceive dynamic changes in traditional open-loop operation and providing a predictive basis for precise control. By determining whether the current parameters maintain the outlet temperature within the target range, potential deviation risks can be promptly identified. When the deviation exceeds the threshold, the optimization model is triggered to recalculate, and the optimal reflow ratio and combustion power adapted to the new operating conditions can be quickly generated. This overcomes the response lag of existing manual adjustment or coarse fixed value control, ensuring the system's rapid adaptation to disturbances. The reflow valve opening and burner ratio are adjusted according to the optimization results, directly affecting the core parameters affecting molten salt heating. Under dynamic operating conditions such as gas calorific value fluctuations, the outlet temperature can be stably controlled within the target range, avoiding the degradation of heat storage quality or equipment safety hazards caused by temperature fluctuations. At the same time, it reduces energy waste caused by parameter mismatch and improves system operating efficiency and stability. The entire process forms a complete closed loop of "perception-prediction-decision-execution", which enables the system to shift from passive response to active regulation, significantly enhances its robustness under non-steady-state conditions, gives full play to the synergistic advantages of reflux control and modeling optimization, and achieves the dual goals of stable heat storage and efficient energy use.

[0037] In an optional embodiment, the operating condition boundaries and equipment constraints include:

[0038] Temperature constraints, including molten salt outlet temperature, high-temperature heat exchange unit inlet mixing temperature, and maximum molten salt heating rate;

[0039] Gas combustion constraints include: gas supply must be within preset upper and lower limits;

[0040] Molten salt flow rate constraints include: the molten salt flow rate must be within the preset upper and lower limits.

[0041] The embodiment of the present invention comprehensively avoids the safety hazards of system operation from the temperature dimension, ensuring that the molten salt heating process is smooth and controllable. The upper and lower limits of the gas combustion constraint on the supply volume can not only avoid the risk of unstable combustion or even fire extinguishing due to too low a gas volume, but also prevent the problem of overheating and decomposition of the molten salt and excessive pressure on the heat exchanger caused by excessive flue gas temperature due to excessive gas volume, thereby ensuring the stability and safety of the combustion process and providing a continuous and reliable heat source for molten salt heating. By limiting the upper and lower limits of the flow rate, the molten salt flow rate constraint can avoid the risk of overheating caused by too rapid a temperature rise of the molten salt when the flow rate is too low, and the problems of insufficient pump pressure and insufficient heat exchange when the flow rate is too high, ensuring that the molten salt achieves efficient heat exchange at a reasonable flow rate, while protecting equipment such as the molten salt pump from damage caused by extreme working conditions and extending the service life of the equipment. The overall constraint system works in conjunction with thermal modeling and optimization models to define safe and efficient boundaries for system operation, ensuring that the reflux ratio and combustion power parameter combination output by the optimization model is always within the safe range that the equipment can withstand. This not only ensures stable operation under dynamic disturbances, but also provides a reasonable framework for energy efficiency optimization, achieving dual guarantees of safety and efficiency.

[0042] In an optional embodiment, the method further includes: after the heat storage is fully loaded, the gas molten salt heat storage enters a standby or heat release preparation state, stores all data for offline analysis and operation optimization model maintenance, generates operation curves, parameter logs and optimization paths, and supports user export.

[0043] When the system enters the standby or heat release preparation state, the embodiment of the present invention can flexibly switch the operating mode according to the subsequent load demand, thereby enhancing the system's adaptability to the rhythm of industrial energy consumption, avoiding the waste of resources caused by idleness after heat storage is completed, and improving the flexibility of the overall operation. All operating data are stored for offline analysis and model maintenance, and can conduct in-depth review of parameter associations and energy efficiency performance under historical working conditions, provide real data support for the iterative upgrade of the optimization model, and continuously improve the model's prediction accuracy and optimization capabilities for complex working conditions, solving the problem of the traditional system's lack of data accumulation and model self-optimization mechanism. Generate and support users to export operating curves, parameter logs and optimization paths, which not only provides operators with intuitive operating process records, facilitates tracing system status and troubleshooting potential problems, but also provides a quantitative basis for technical personnel to carry out energy efficiency evaluation and process improvement, and promotes the refinement and scientificization of system operation management. The entire process forms a closed-loop iteration of "operation-storage-analysis-optimization", which enables the system to not only complete the heat storage function, but also continuously improve operational performance through data accumulation, laying the foundation for long-term stable and efficient operation, and further enhancing the practicality and sustainability of the "dynamic modeling-optimization control" system.

[0044] In a third aspect, the present invention provides a steel plant coal gas molten salt heat storage operation device, the device comprising:

[0045] The initial combustion heat power monitoring module is used to collect the real-time calorific value and flow parameters of blast furnace gas in real time to determine the initial combustion heat power of the burner;

[0046] a simulation module for establishing, based on the steel mill gas molten salt heat storage system described in any optional embodiment of the first aspect, a thermodynamic model including a combustion heat source section, a waste heat exchange section, a molten salt reflux mixing section, a high-temperature heating section, and a heat storage section; simulating, based on the initial combustion heat power and preset system initial parameters, the system response under different molten salt reflux ratios and combustion heat power combinations, and outputting the molten salt outlet temperature, heating rate, and unit heat storage heat consumption;

[0047] The parameter optimization module is used to build an operation optimization model. It takes minimizing the unit heat storage heat consumption as the objective function, combines the operating condition boundaries and equipment constraints, and outputs the optimal reflux ratio and combustion heat power parameter combination as the optimization result.

[0048] The real-time control module is used to guide on-site operation scheduling using optimization results, and to correct control parameters in real time through a closed-loop control system to achieve stable temperature output and energy efficiency control under conditions of fluctuating gas calorific value.

[0049] In a fourth aspect, the present invention provides a computer device comprising: a memory and a processor, the memory and the processor being communicatively connected to each other, the memory storing computer instructions, and the processor executing the computer instructions to thereby execute the steel plant gas molten salt heat storage operation method of the above-mentioned second aspect or any corresponding embodiment thereof.

[0050] In a fifth aspect, the present invention provides a computer-readable storage medium having computer instructions stored thereon, the computer instructions being used to enable a computer to execute the steel plant gas molten salt heat storage operation method of the above-mentioned second aspect or any corresponding embodiment thereof.

[0051] In a sixth aspect, the present invention provides a computer program product comprising computer instructions for causing a computer to execute the steel plant gas molten salt heat storage operation method of the first aspect or any corresponding embodiment thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0053] Figure 1 2. It is a module composition diagram of a steel plant coal gas molten salt heat storage operation system according to an embodiment of the present invention;

[0054] Figure 2 1 is a flow chart of a method for heat storage operation of coal gas molten salt in a steel plant according to an embodiment of the present invention;

[0055] Figure 3 2 is a structural block diagram of a steel plant coal gas molten salt heat storage operation device according to an embodiment of the present invention;

[0056] Figure 4 A schematic diagram of the hardware structure of a computer device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0057] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of the present invention.

[0058] In order to achieve the goal of achieving stable molten salt temperature output and energy efficiency optimization under gas fluctuation conditions to achieve the minimum unit heat storage heat consumption. This embodiment provides a steel plant gas molten salt heat storage system, such as Figure 1 Shown, including:

[0059] The gas combustion unit is used to output flue gas with controllable thermal power as a heat source by adjusting the blast furnace gas flow rate and the combustion air ratio (i.e. the ratio of gas to air). Its output thermal power is the combustion heat input. The unit uses the burner output thermal power as the combustion heat input Q burn is a controllable variable.

[0060] The high temperature heat exchange unit is integrated with the gas combustion unit to heat the mixed molten salt to the target temperature to form high temperature molten salt; specifically, the mixed molten salt (T mix ≈500℃) enters the high-temperature spiral tube heat exchange furnace and continues to conduct deep heat exchange with the flue gas at the burner outlet, finally raising its temperature to the designed target temperature of 560℃. This stage is the main heating process of the molten salt, and the system requirements are:

[0061] 1. Control the maximum allowable temperature difference between flue gas and molten salt (flue gas is usually at 1200-1100℃, and molten salt will begin to decompose at around 580℃) to prevent thermal stress on the pipe wall;

[0062] 2. Maintaining stable inlet molten salt temperature (achieved through front-end mixing);

[0063] 3. The output temperature must be precisely controlled to ensure the quality requirements of subsequent heat storage or energy supply.

[0064] The high-temperature heat exchange unit places high demands on the heat exchange furnace's material, temperature resistance, and compact structure, and must meet the requirements for long-term high-temperature operation. In one embodiment, the high-temperature heat exchange unit adopts a spiral tube structure. The spiral tube is made of a high-temperature resistant alloy and can withstand temperatures exceeding 560°C, as well as the temperature difference stress between the flue gas and the molten salt.

[0065] The combustion unit and heat exchanger are integrated, meaning the combustion reaction of the blast furnace gas occurs directly within the high-temperature heat exchanger. Therefore, the heat absorbed by the molten salt in the high-temperature section originates from the high-temperature flue gas generated during the combustion process. In contrast, the preheating section (medium-temperature heat exchanger) utilizes the waste heat from combustion, which has a lower temperature and heat capacity than the main flue gas in the high-temperature section. Based on this, the system divides the molten salt heating process into two stages:

[0066] 1. Preheating stage: Use waste heat flue gas to preheat cold molten salt (280℃) to medium temperature (360-400℃) and recover tail heat energy;

[0067] 2. Main heating stage: In the high-temperature combustion furnace, the molten salt absorbs the heat of the newly generated high-temperature flue gas and further heats it to the target temperature (560℃).

[0068] This dual-stage heating structure design effectively reduces the temperature difference load at the inlet of the high-temperature heat exchanger, extends the life of the equipment, and improves the comprehensive utilization efficiency of combustion heat energy.

[0069] The flue gas waste heat heat exchange unit is connected to the molten salt pump outlet of the cold salt tank. It uses the waste heat flue gas flowing out of the high-temperature heat exchange unit as a heat source to heat the low-temperature molten salt pumped from the cold salt tank to a preset medium temperature range to form medium-temperature molten salt. Specifically, it uses a shell and tube or spiral tube medium-temperature heat exchanger to preheat the molten salt from the cold state (280°C) to the medium temperature range (360-400°C). The high-temperature end is the flue gas. The cold salt is preheated in this unit, providing a good temperature rise foundation for subsequent deep heating and effectively recovering the medium and low-grade thermal energy of the flue gas.

[0070] The molten salt mixing unit includes a mixing chamber and a proportional control valve, which is used to dynamically adjust the molten salt reflux ratio by adjusting the proportional control valve, and mix part of the preset high-temperature molten salt with the medium-temperature molten salt in the mixing chamber to form a mixed molten salt, so as to adjust the molten salt temperature at the inlet of the high-temperature heat exchange unit to the set target range. The remaining high-temperature molten salt is sent to the hot salt tank for storage, and subsequently supplies heat to the outside according to load demand or outputs high-parameter steam through the steam generator. The cooled molten salt is transported back to the cold salt tank to form a closed-loop circulation.

[0071] Specifically, the molten salt from the flue gas waste heat exchange unit does not directly enter the high-temperature heat exchange unit, but is mixed with a portion of the molten salt (about 560°C) at the outlet of the high-temperature unit. The high-temperature molten salt refluxes according to the set molten salt reflux ratio α and is fully mixed with the medium-temperature molten salt in the mixing chamber according to the flow ratio to form a mixed molten salt T mix ≈500℃. This mixed flow control section has three key functions:

[0072] 1. Stabilize the salt inlet temperature of the high-temperature section heat exchanger to prevent thermal shock caused by large temperature differences;

[0073] 2. Adjust high-temperature heat exchange load, reduce instantaneous heat transfer rate, and protect equipment life;

[0074] 3. Provide a buffer temperature rise mechanism to make the molten salt temperature rise path smoother and more controllable.

[0075] The molten salt mixing unit is the core unit for temperature control in the entire system. By dynamically adjusting the reflux ratio, it can achieve stable operation of the salt inlet temperature and ensure that the heat load in the high-temperature section is always within a safe and reasonable range.

[0076] After the high temperature molten salt (560℃) is heated, part of it flows to the hot salt tank for storage for subsequent power generation or heating use; the other part enters the mixed flow heating control unit according to the molten salt reflux ratio for mixing, forming the above T mix This diversion point is the core control link of the entire molten salt temperature stabilization mechanism. Reflux regulation can achieve the following system performance: optimizing the overall thermal efficiency of the system, reducing dependence on the thermal intensity of combustion flue gas, and enhancing the flexibility and steady-state response capability of system operation. The high-temperature molten salt enters the hot salt tank for storage. The system can subsequently supply heat to the outside according to load demand or output high-parameter steam through a steam generator to achieve thermal and electrical decoupling or industrial energy supply. The cooled molten salt is transported back to the cold salt tank, ready to enter the next round of heat exchange cycle. The entire molten salt flow process constitutes a closed high-temperature thermal energy loop, which is driven by the molten salt pump to maintain continuous and stable flow.

[0077] The closed-loop control system, including temperature sensors, flow meters, gas calorific value analyzers and controllers, is used to dynamically adjust the molten salt reflux ratio and combustion power based on real-time data. Specifically, the temperature sensor collects the temperature data of the molten salt at each key node in real time: medium-temperature molten salt temperature (T≈380℃), mixed molten salt temperature (T mix ≈500℃), high temperature molten salt outlet temperature (T out =560℃±2℃); flow meter monitors blast furnace gas flow in real time (e.g. 1200-1500m 3 / h) and molten salt circulation flow rate (such as 2.0-2.5kg / s); gas calorific value analyzer online detection of gas calorific value (such as 3500-4200kJ / m 3), when the calorific value suddenly drops by 15% (from 4000kJ / m 3 Reduced to 3400kJ / m 3 ), the data is transmitted to the controller in real time; based on the above real-time data, the controller calls the preset thermal model to calculate the deviation: if the predicted T out The temperature will drop to 550℃ (10℃ away from the target value), and the optimization algorithm will be triggered immediately to output the new optimal parameters: the molten salt reflux ratio α is increased from 0.45 to 0.55, and the combustion heat power Q burn From 3.2MW to 3.5MW; the controller sends instructions to the actuator: adjust the proportional control valve to increase the reflux ratio, and adjust the gas flow and combustion air ratio of the burner to increase the combustion power, and finally make T out The temperature returned to the stable range of 560°C ± 2°C within 5 minutes.

[0078] This embodiment of the present invention collects disturbance parameters such as gas calorific value and flow rate in real time. A controller rapidly calculates and adjusts the reflux ratio and combustion power, addressing the issue of molten salt temperature instability caused by large fluctuations in blast furnace gas calorific value. This ensures that the outlet temperature remains stable within the target range of 560°C ± 2°C, avoiding the degradation of heat storage quality and equipment safety hazards caused by temperature fluctuations in traditional open-loop control. Dynamic parameter correction based on real-time data can avoid energy waste caused by excessive combustion power or an unreasonable reflux ratio while meeting heating requirements. For example, when the gas calorific value increases, the controller automatically reduces the combustion power and the reflux ratio, reducing the unit heat consumption by 5%-8%, significantly improving system energy efficiency. A temperature sensor monitors the mixed molten salt temperature and heating rate in real time. Combined with the controller's parameter constraints (e.g., heating rate ≤ 2.5°C / min), this prevents thermal stress in the high-temperature heat exchange unit due to local overheating or excessive temperature differences, reducing risks such as pipeline cracking and molten salt decomposition, and extending equipment life. The closed-loop control mechanism does not require manual operation, realizing the transition from passive response to active regulation, avoiding the lag and error of manual adjustment, and greatly improving the operating reliability of the system under complex working conditions.

[0079] The real-time operating data stored in the controller can provide a realistic basis for the iteration of thermal models and optimization algorithms. By continuously optimizing the control logic through offline analysis, the system's adaptability to new disturbances is continuously enhanced, forming a virtuous cycle of "operation-data-optimization-re-operation".

[0080] This embodiment provides a method for operating coal gas molten salt heat storage in a steel plant. This method addresses the problems of most existing technologies, such as the lack of access to modeling tools such as Ebsilon and Aspen HYSYS during the project design phase, using only empirical parameters to estimate molten salt demand and set coal gas input. This lacks thermal simulation and response control for dynamic temperature response and non-steady-state conditions. Furthermore, the operation of coal gas molten salt heat storage systems in steel plants mostly relies on manual adjustment or coarse segmented constant value control, and is unable to intelligently adjust parameters such as combustion power and reflux ratio based on real-time changes in molten salt temperature and coal gas calorific value, resulting in large fluctuations in operating efficiency and significant energy waste. Figure 2 Flowchart of the method for heat storage operation of coal gas molten salt in a steel plant according to an embodiment of the present invention. Figure 2 As shown, the process includes the following steps:

[0081] Step S1: real-time acquisition of the calorific value and flow rate parameters of blast furnace gas to determine the initial combustion thermal power of the burner.

[0082] Specifically, by collecting gas parameters in real time to determine the initial combustion thermal power, an accurate initial basis is provided for system operation. This can quickly respond to real-time changes in gas calorific value and flow, solving the problem of unstable blast furnace gas heat source and laying the foundation for subsequent stable heating.

[0083] In step S2, based on the steel plant gas molten salt heat storage system in the above embodiment, a thermodynamic model is established, including a combustion heat source section, a waste heat exchange section, a molten salt reflux mixing section, a high-temperature heating section, and a heat storage section. Based on the initial combustion heat power and the preset system initial parameters, the system response under different molten salt reflux ratios and combustion heat power combinations is simulated, and the molten salt outlet temperature, heating rate, and unit heat storage heat consumption are output.

[0084] Specifically, the present invention establishes a complete thermal model of the molten salt heat storage system in the Ebsilon platform, starting from the cold salt tank and ending at the hot salt tank, and divides the actual system into four core thermal conversion sections and one energy storage section: 1. Combustion heat source section (coal gas → flue gas); 2. Waste heat heat exchange section (preheating); 3. Reflux mixing section (molten salt inlet temperature adjustment); 4. High-temperature heat exchange section (main heating); 5. Heat storage section (hot salt collection, recording of accumulated heat storage). The input variables, output variables and descriptions of each section are shown in Table 1.

[0085] Table 1

[0086]

[0087] Each segment is modeled as an independent functional module, connected through interface variables such as molten salt temperature, flow rate, and Q_burn heat input, supporting dynamic operating condition simulation, temperature rise path assessment, and heat consumption analysis. This modeling strategy fully simulates the industrial process of "cold salt departure → multi-stage heating → hot salt tank entry."

[0088] In one embodiment, the initial parameter settings during system modeling include: molten salt medium: 60% NaNO + 40% KNO (solar salt, binary molten salt); total mass of molten salt: 100 tons; specific heat capacity: approximately 1.5 kJ / (kg·K); initial molten salt temperature: 300°C; target outlet temperature: 560°C; maximum allowable heating rate: 2.5°C / min (to prevent salt decomposition and system stress exceeding the limit); target heat storage time: 2 hours; blast furnace gas calorific value variation range: 3500-4200 kJ / m 3 ; Maximum combustion heat power design value: 3.5MW; Maximum molten salt circulation flow rate: 2.5kg / s.

[0089] In this embodiment of the present invention, Ebsilon is used to model each heat exchange section and reflux structure as a modular heat flow unit, forming a physical visualization modeling platform. Under different reflux coefficients or combustion volume settings, the simulation system can output the molten salt outlet temperature change curve and heat storage efficiency index in real time, providing a reference for decision-making.

[0090] Step S3: construct an operation optimization model, take minimizing the unit heat storage heat consumption as the objective function, combine the operating condition boundary and equipment constraints, and output the optimal reflux ratio and combustion heat power parameter combination as the optimization result.

[0091] Specifically, the embodiment of the present invention sets the gas calorific value to change every 10 minutes, and simulates the response effect of the system under different α and Q_burn conditions, as shown in Table 2:

[0092] Table 2

[0093]

[0094] The operating condition boundaries and equipment constraints during simulation include:

[0095] 1. Temperature constraints include the molten salt outlet temperature, the high-temperature heat exchange unit inlet mixing temperature, and the maximum molten salt heating rate. Specifically, the maximum molten salt outlet temperature should be less than 565°C to prevent decomposition or material damage. The high-temperature heat exchange section inlet mixing temperature Tmix must be higher than 480°C to ensure heat exchange efficiency. The molten salt temperature rise in each heat exchanger section must not exceed 120°C to avoid local overheating or thermal shock.

[0096] 2. Gas combustion constraints, including: the gas supply must be within the preset upper and lower limits; too low a gas supply will cause unstable combustion and pose a risk of fire extinguishing; too high a flue gas temperature will easily cause the molten salt to overheat or even decompose, and the heat exchanger may also exceed the pressure limit.

[0097] 3. Molten salt flow rate constraints, including: The molten salt flow rate must be within the preset upper and lower limits. If the flow rate is too low, the molten salt temperature will rise too quickly under low load conditions, easily leading to overheating. If the flow rate is too high, the pump pressure capacity will be difficult to maintain. Insufficient gas heating and insufficient heat exchange area may also make it impossible to meet the heat exchange requirements under high flow rates.

[0098] The overall constraint system works in conjunction with thermal modeling and optimization models to define safe and efficient boundaries for system operation, ensuring that the reflux ratio and combustion power parameter combination output by the optimization model is always within the safe range that the equipment can withstand. This not only ensures stable operation under dynamic disturbances, but also provides a reasonable framework for energy efficiency optimization, achieving dual guarantees of safety and efficiency.

[0099] Under the condition of fluctuating gas supply, the system can be controlled by the reflux coefficient α and the combustion heat power Q burn Coordinated regulation to ensure the molten salt outlet temperature T out The temperature is controlled within the range of 560℃±2℃, and the mixed temperature at the inlet of the high-temperature heat exchange unit is between 360℃-400℃. The temperature rise rate under all working conditions is strictly controlled within 2.5℃ / min, which meets the safety requirements of molten salt.

[0100] The objective function of the optimization model constructed and run in Matlab is:

[0101]

[0102] Among them, α t is the molten salt reflux ratio at time t, Q burn，t is the burner thermal power at time t; m salt is the mass of molten salt; C p is the specific heat capacity of molten salt; ΔT t is the difference between the molten salt temperature at time t and the initial temperature of the molten salt. t The value of is controlled within a certain range (for example, between 0.2-0.8) and is dynamically and automatically adjusted to find the optimal value.

[0103] Furthermore, the Matlab simulation results are input into the optimizer in time periods (every 10 minutes) to output the optimal control path (α*(t), Q_burn*(t)); scheduling suggestions are provided to operators to form the daily operating load curve and response strategy table.

[0104] From the perspective of improving energy efficiency, the objective function provided by the embodiments of the present invention directly links combustion heat power with the energy required for molten salt heat storage. By optimizing the dynamic combination of the molten salt recirculation ratio and combustion heat power, gas consumption per unit of heat storage can be minimized while ensuring that the molten salt temperature reaches the target. This solves the energy waste problem caused by the lack of precise optimization in traditional systems and significantly improves system energy efficiency, including:

[0105] 1. From the perspective of operating condition adaptability, the optimal parameters are solved by combining the operating condition boundary and equipment constraints, which can dynamically adapt to disturbance conditions such as blast furnace gas calorific value fluctuations and flow changes. Even when the gas supply is unstable, it can be adjusted by adjusting α t With Q burn,t Ensuring that the molten salt outlet temperature is stable within the target range overcomes the matching problem between heat source fluctuations and the temperature sensitivity of the molten salt system, and enhances the robustness of the system under non-steady-state conditions.

[0106] 2. From the perspective of operational safety, incorporating constraints such as the molten salt heating rate and equipment temperature limit into the objective function optimization process can avoid problems such as local overheating and uneven heat exchange caused by the pursuit of minimum heat consumption. Combined with the closed-loop control mechanism, it ensures that the system is always in a safe operating range while operating efficiently, reducing equipment losses and safety hazards.

[0107] 3. From the perspective of scientific scheduling, the output optimal parameter combination provides quantitative guidance for on-site operation, replacing the traditional manual adjustment or rough segmented control that relies on experience, making the temperature rise path of the molten salt heating process smoother and more controllable, and the operating parameters more stable, thereby improving the accuracy and intelligence level of heat storage system scheduling.

[0108] Step S4: Use the optimization results to guide on-site operation scheduling, and use the closed-loop control system to correct the control parameters in real time to achieve stable temperature output and energy efficiency control under the condition of fluctuating gas calorific value. Specifically, it includes the following steps:

[0109] S41, the closed-loop control system collects the calorific value of the coal gas, the temperature of the molten salt, the flow rate of the molten salt, and the position of the reflux valve according to a preset time period, and inputs the collected data into the thermal model for real-time working condition simulation to predict the temperature trend of the molten salt in the next time period;

[0110] Specifically, key parameters such as gas calorific value and molten salt temperature are collected at a preset period (for example, every minute) and input into the thermal model for real-time operating condition simulation. This can quickly capture dynamic changes in system operation and predict the molten salt temperature trend in the next time period in advance. This changes the situation in which traditional open-loop operation cannot perceive operating condition fluctuations in a timely manner, provides a forward-looking basis for subsequent regulation, and effectively avoids large temperature fluctuations caused by delayed response.

[0111] S42, determining whether the current molten salt reflux ratio and combustion power keep the molten salt outlet temperature within the target temperature range;

[0112] Specifically, the present invention promptly identifies potential temperature deviation risks by determining whether the current molten salt recirculation ratio and combustion power can maintain the outlet temperature within the target range. When the predicted deviation exceeds a preset threshold (for example, a predicted deviation >±2°C), the optimization model is triggered to recalculate the optimal parameter combination. This allows for targeted responses to disturbances such as fluctuations in the calorific value of coal gas, ensuring that the output recirculation ratio and combustion power are adapted to real-time operating conditions. This overcomes the inaccuracy of traditional manual adjustments or coarse segmented fixed-value control, making regulation more targeted and accurate.

[0113] S43, if the deviation between the estimated molten salt outlet temperature and the target temperature is greater than a preset threshold, triggering the optimization model to recalculate the molten salt reflux ratio and combustion power as the optimization result;

[0114] S44, according to the optimization results, adjusts the opening of the reflux valve and the combustion air ratio of the gas burner to ensure that the molten salt outlet temperature is stable within the target temperature range.

[0115] Specifically, the reflux valve opening and the combustion air ratio of the gas burner are adjusted according to the optimization results, which directly affects the core link affecting the molten salt heating. The molten salt outlet temperature can be stably controlled within the target range under various dynamic working conditions, avoiding safety hazards caused by excessive or insufficient temperature (such as local overheating of the pipeline and decomposition of molten salt) and the degradation of heat storage quality. At the same time, it reduces energy waste caused by parameter mismatch and improves system operation efficiency.

[0116] The entire process forms a complete closed loop of "collection-simulation-judgment-optimization-execution", realizing the transformation of the system from passive adaptation to active regulation, enhancing the robustness of the system under complex working conditions such as gas calorific value fluctuations, giving full play to the synergistic advantages of reflux control and modeling optimization, and ensuring the long-term stable and efficient operation of the heat storage system. In an operating scenario, when the gas supply is stable, α = 0.45 is used, Q burn =80%, the system completes the heating of 10 tons of molten salt from 300℃ to 560℃ within 120 minutes; when the gas flow rate drops by 15%, after optimization, α=0.55, Q burn =95%, and the target temperature rise can still be achieved within the specified time. The reflux ratio and combustion power distribution are optimized during dynamic operation to ensure the stability of the molten salt temperature rise process while minimizing the gas heat input required for unit heat storage.

[0117] In the embodiment of the present invention, the system compares the predicted output with the actual T out If the abnormal fluctuation of gas calorific value is detected to be greater than 15%, the backup control strategy will be automatically switched to put the system in a temporary stable operating state.

[0118] In the embodiment of the present invention, after the heat storage is fully loaded, the gas molten salt heat storage enters the standby or heat release preparation state, stores all data for offline analysis and operation optimization model maintenance, generates operation curves, parameter logs and optimization paths, and supports user export.

[0119] When the system enters the standby or heat release preparation state, the embodiment of the present invention can flexibly switch the operating mode according to the subsequent industrial energy load demand, thereby enhancing the adaptability to the energy scheduling rhythm of the steel plant, avoiding the waste of resources caused by idleness after heat storage is completed, and improving the flexibility and practicality of the overall operation of the system.

[0120] All operational data is stored for offline analysis and optimization model maintenance, providing a realistic basis for the iteration of thermal models and optimization algorithms. By analyzing historical data related to molten salt recirculation ratios, combustion heat output, outlet temperature, and thermal efficiency, model parameters can be continuously revised, improving the prediction accuracy and optimization capabilities for dynamic operating conditions. This addresses the lack of data accumulation and model self-optimization mechanisms in traditional systems.

[0121] It generates and supports users to export operation curves (such as the curve of molten salt temperature changing with time), parameter logs (such as the calorific value of coal gas and molten salt flow rate records in different time periods) and optimization paths (such as the dynamic adjustment curve of the optimal reflux ratio and combustion power). It not only provides operators with an intuitive basis for tracing the operation process and facilitating the investigation of potential problems, but also provides quantitative data support for technical personnel to carry out energy efficiency evaluation and process improvement, promoting the refinement and scientificization of system operation management.

[0122] The entire process forms a closed-loop iteration of "operation-data storage-offline analysis-model optimization-re-operation", which enables the system to not only complete the basic heat storage function, but also continuously improve operating performance through data accumulation, laying the foundation for long-term stable and efficient operation, and further enhancing the practicality and sustainability of the "dynamic modeling-optimization control" system.

[0123] This embodiment also provides a steel mill gas molten salt thermal storage operation device. This system is used to implement the above-mentioned embodiments and preferred implementations. Details already described are omitted. As used below, the term "module" may refer to a combination of software and / or hardware that implements a predetermined function. Although the systems described in the following embodiments are preferably implemented using software, implementation using hardware, or a combination of software and hardware, is also possible and contemplated.

[0124] This embodiment provides a steel plant gas molten salt heat storage operation device, such as Figure 3 Shown, including:

[0125] The initial combustion heat power monitoring module 31 is used to collect the real-time calorific value and flow parameters of the blast furnace gas in real time to determine the initial combustion heat power of the burner;

[0126] Simulation module 32 is used to establish a thermodynamic model based on the steel plant gas molten salt heat storage system, including a combustion heat source section, a waste heat exchange section, a molten salt reflux mixing section, a high-temperature heating section, and a heat storage section. Based on the initial combustion heat power and preset system initial parameters, the simulation module simulates the system response under different molten salt reflux ratios and combustion heat power combinations, and outputs the molten salt outlet temperature, heating rate, and unit heat storage heat consumption;

[0127] The parameter optimization module 33 is used to construct an operation optimization model, taking the minimization of unit heat storage heat consumption as the objective function, combining the operating condition boundary and equipment constraints, and outputting the optimal reflux ratio and combustion heat power parameter combination as the optimization result;

[0128] The real-time control module 34 is used to guide on-site operation scheduling using the optimization results, and to correct the control parameters in real time through the closed-loop control system to achieve stable temperature output and energy efficiency control under the condition of fluctuating gas calorific value.

[0129] In some optional implementations, the objective function of running the optimization model is:

[0130]

[0131] Among them, α t is the molten salt reflux ratio at time t, Q burn，t is the burner thermal power at time t; m salt is the mass of molten salt; C p is the specific heat capacity of molten salt; ΔT t is the difference between the molten salt temperature at time t and the initial temperature of the molten salt.

[0132] In some optional embodiments, the real-time control module 34 includes:

[0133] The real-time data acquisition unit is used in the closed-loop control system to collect the gas calorific value, molten salt temperature, molten salt flow rate and reflux valve position according to the preset time period, and input the collected data into the thermal model for real-time working condition simulation to predict the molten salt temperature trend in the next time period;

[0134] A temperature judgment unit is used to judge whether the current molten salt reflux ratio and combustion power keep the molten salt outlet temperature within the target temperature range;

[0135] An optimization trigger unit is used to trigger the optimization model to recalculate the molten salt reflux ratio and combustion power as the optimization result if the deviation between the expected molten salt outlet temperature and the target temperature is greater than a preset threshold;

[0136] The real-time control unit is used to adjust the opening of the reflux valve and the combustion air ratio of the gas burner according to the optimization results to ensure that the molten salt outlet temperature is stable within the target temperature range.

[0137] In some optional implementations, the operating condition boundaries and equipment constraints include:

[0138] Temperature constraints, including molten salt outlet temperature, high-temperature heat exchange unit inlet mixing temperature, and maximum molten salt heating rate;

[0139] Gas combustion constraints include: gas supply must be within preset upper and lower limits;

[0140] Molten salt flow rate constraints include: the molten salt flow rate must be within the preset upper and lower limits.

[0141] In some optional embodiments, it also includes: a data storage module, which is used to switch the gas molten salt heat storage into standby or heat release preparation state after the heat storage is fully loaded, store all data for offline analysis and operation optimization model maintenance, generate operation curves, parameter logs and optimization paths, and support user export.

[0142] The further functional description of each of the above modules and units is the same as that of the above corresponding embodiments and will not be repeated here.

[0143] The steel plant gas molten salt heat storage operation device in this embodiment is presented in the form of a functional unit, where the unit refers to an ASIC (Application Specific Integrated Circuit) circuit, a processor and memory that executes one or more software or fixed programs, and / or other devices that can provide the above functions.

[0144] The embodiment of the present invention also provides a computer device having the above Figure 3 The steel plant gas molten salt heat storage operation device shown.

[0145] See also Figure 4 , Figure 4 Schematic diagram of the structure of a computer device provided by an optional embodiment of the present invention, such as Figure 4 As shown, the computer device includes: one or more processors 10, memory 20, and interfaces for connecting various components, including high-speed interfaces and low-speed interfaces. Various components utilize different buses to communicate with each other and can be installed on a common mainboard or installed in other ways as needed. The processor can process the instructions executed in the computer device, including instructions stored in the memory or on the memory to display the graphical information of the GUI on an external input / output device (such as, a display device coupled to the interface). In some optional embodiments, if necessary, multiple processors and / or multiple buses can be used together with multiple memories and multiple memories. Equally, multiple computer devices can be connected, and each device provides part of the necessary operations (for example, as a server array, a group of blade servers, or a multi-processor system). Figure 4A processor 10 is taken as an example.

[0146] The processor 10 may be a central processing unit, a network processor, or a combination thereof. The processor 10 may further include a hardware chip. The hardware chip may be an application-specific integrated circuit, a programmable logic device, or a combination thereof. The programmable logic device may be a complex programmable logic device, a field programmable gate array, a general purpose array logic, or any combination thereof.

[0147] The memory 20 stores instructions that can be executed by at least one processor 10, so as to enable at least one processor 10 to execute the method shown in the above embodiment.

[0148] The memory 20 may include a program storage area and a data storage area, wherein the program storage area may store an operating system and application programs required for at least one function; the data storage area may store data created based on the use of the computer device, etc. In addition, the memory 20 may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some optional embodiments, the memory 20 may optionally include a memory remotely located relative to the processor 10, and these remote memories may be connected to the computer device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0149] The memory 20 may include a volatile memory, such as a random access memory; the memory may also include a non-volatile memory, such as a flash memory, a hard disk or a solid-state drive; the memory 20 may also include a combination of the above types of memory.

[0150] The computer device further includes a communication interface 30 for the computer device to communicate with other devices or a communication network.

[0151] The embodiment of the present invention also provides a computer-readable storage medium. The above-mentioned method according to the embodiment of the present invention can be implemented in hardware, firmware, or implemented as a computer code that can be recorded in a storage medium, or implemented as a computer code that is originally stored in a remote storage medium or a non-temporary machine-readable storage medium and downloaded through a network and will be stored in a local storage medium, so that the method described herein can be stored in such software processing on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only storage memory, a random access memory, a flash memory, a hard disk or a solid-state drive, etc.; further, the storage medium can also include a combination of the above-mentioned types of memory. It can be understood that a computer, a processor, a microprocessor controller or programmable hardware includes a storage component that can store or receive software or computer code. When the software or computer code is accessed and executed by a computer, a processor or hardware, the method shown in the above embodiment is implemented.

[0152] A portion of the present invention may be applied as a computer program product, such as a computer program instruction, which, when executed by a computer, can call or provide the method and / or technical solution according to the present invention through the operation of the computer. Those skilled in the art should understand that the form in which the computer program instruction exists in a computer-readable medium includes, but is not limited to, a source file, an executable file, an installation package file, etc. Accordingly, the way in which the computer program instruction is executed by the computer includes, but is not limited to: the computer directly executes the instruction, or the computer compiles the instruction and then executes the corresponding compiled program, or the computer reads and executes the instruction, or the computer reads and installs the instruction and then executes the corresponding installed program. Here, the computer-readable medium may be any available computer-readable storage medium or communication medium that can be accessed by the computer.

[0153] Although the embodiments of the present invention have been described with reference to the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention. Such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A steel plant gas molten salt heat storage system, characterized in that: include: The gas combustion unit is used to output flue gas with controllable thermal power as a heat source by adjusting the ratio of blast furnace gas flow rate to combustion air. The output thermal power is the combustion heat input. The high-temperature heat exchange unit is integrated with the gas combustion unit to heat the molten salt to the target temperature to form high-temperature molten salt; The flue gas waste heat heat exchange unit is connected to the molten salt pump outlet of the cold salt tank, and is used to use the waste heat flue gas flowing out of the high-temperature heat exchange unit as a heat source to heat the low-temperature molten salt delivered from the cold salt tank through the molten salt pump to a preset medium temperature range to form medium-temperature molten salt; The molten salt mixing unit includes a mixing chamber and a proportional control valve, which is used to dynamically adjust the molten salt reflux ratio by adjusting the proportional control valve. A portion of the preset high-temperature molten salt is mixed with the medium-temperature molten salt in the mixing chamber to form a mixed molten salt, so as to adjust the molten salt temperature at the inlet of the high-temperature heat exchange unit to the set target range. The remaining high-temperature molten salt is sent to the hot salt tank for storage. Subsequently, it is used to supply heat to the outside according to load demand or output high-parameter steam through the steam generator. The cooled molten salt is sent back to the cold salt tank to form a closed-loop circulation; A closed-loop control system, including a temperature sensor, flow meter, and gas calorific value analyzer and controller, is used to dynamically adjust the molten salt reflux ratio and combustion power based on real-time data.

2. The system according to claim 1, wherein: The high-temperature heat exchange unit adopts a spiral tube structure, and the spiral tube is made of a high-temperature resistant alloy material, which can withstand high temperatures above the target temperature and the temperature difference stress between the preset flue gas and molten salt.

3. A steel plant gas molten salt heat storage operation method, characterized in that: include: Real-time collection of calorific value and flow parameters of blast furnace gas to determine the initial combustion thermal power of the burner; Based on the steel plant gas molten salt heat storage system according to claim 1 or 2, a thermodynamic model including a combustion heat source section, a waste heat exchange section, a molten salt reflux mixing section, a high-temperature heating section, and a heat storage section is established. Based on the initial combustion heat power and the preset system initial parameters, the system response under different molten salt reflux ratios and combustion heat power combinations is simulated, and the molten salt outlet temperature, heating rate, and unit heat storage heat consumption are output; An operation optimization model is constructed with the objective function of minimizing the heat consumption per unit heat storage. The optimal combination of reflux ratio and combustion heat power parameters is output as the optimization result, taking into account the operating condition boundaries and equipment constraints. The optimization results are used to guide on-site operation scheduling, and the control parameters are corrected in real time through the closed-loop control system to achieve stable temperature output and energy efficiency control under conditions of fluctuating gas calorific value.

4. The method according to claim 3, characterized in that The objective function of the operation optimization model is: Among them, α t is the molten salt reflux ratio at time t, Q burn，t is the burner thermal power at time t; m salt is the mass of molten salt; C p is the specific heat capacity of molten salt; ΔT t is the difference between the molten salt temperature at time t and the initial temperature of the molten salt.

5. The method according to claim 3, characterized in that The optimization results are used to guide on-site operation scheduling and to modify control parameters in real time through a closed-loop control system, including: The closed-loop control system collects gas calorific value, molten salt temperature, molten salt flow rate and reflux valve position at preset time periods, and inputs the collected data into the thermal model for real-time working condition simulation to predict the molten salt temperature trend in the next time period; Determine whether the current molten salt reflux ratio and combustion power keep the molten salt outlet temperature within the target temperature range; If the deviation between the expected molten salt outlet temperature and the target temperature is greater than the preset threshold, the optimization model is triggered to recalculate the molten salt reflux ratio and combustion power as the optimization result; According to the optimization results, the opening of the reflux valve and the combustion air ratio of the gas burner are adjusted to ensure that the molten salt outlet temperature is stable within the target temperature range.

6. The method according to claim 3, characterized in that The operating condition boundaries and equipment constraints include: Temperature constraints, including molten salt outlet temperature, high-temperature heat exchange unit inlet mixing temperature, and maximum molten salt heating rate; Gas combustion constraints include: gas supply must be within preset upper and lower limits; Molten salt flow rate constraints include: the molten salt flow rate must be within the preset upper and lower limits.

7. The method according to claim 3, characterized in that Also includes: After the heat storage is fully loaded, the gas molten salt heat storage enters the standby or heat release preparation state, stores all data for offline analysis and operation optimization model maintenance, generates operation curves, parameter logs and optimization paths, and supports user export.

8. A steel plant gas molten salt heat storage operation device, characterized in that: include: The initial combustion heat power monitoring module is used to collect the real-time calorific value and flow parameters of blast furnace gas in real time to determine the initial combustion heat power of the burner; A simulation module for establishing a thermodynamic model comprising a combustion heat source section, a waste heat exchange section, a molten salt reflux mixing section, a high-temperature heating section, and a heat storage section based on the steel plant gas molten salt heat storage system according to claim 1 or 2, and simulating the system response under different molten salt reflux ratios and combustion heat power combinations based on the initial combustion heat power and preset system initial parameters, and outputting the molten salt outlet temperature, heating rate, and unit heat storage heat consumption; The parameter optimization module is used to build an operation optimization model. It takes minimizing the unit heat storage heat consumption as the objective function, combines the operating condition boundaries and equipment constraints, and outputs the optimal reflux ratio and combustion heat power parameter combination as the optimization result. The real-time control module is used to guide on-site operation scheduling using optimization results, and to correct control parameters in real time through a closed-loop control system to achieve stable temperature output and energy efficiency control under conditions of fluctuating gas calorific value.

9. A computer device, characterized in that: include: A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the steel plant gas molten salt heat storage operation method according to any one of claims 3 to 6 by executing the computer instructions.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a computer to execute the steel plant gas molten salt heat storage operation method according to any one of claims 3 to 6.

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