Steam turbine type steam extraction energy storage type fused salt heat storage system

Abstract

The invention discloses a steam turbine type steam extraction energy storage type fused salt heat storage system, and relates to the technical field of heat storage management. The data comprises a total power demand value determined by a power grid dispatching instruction or a power market clearing signal, a controllable state value, a rated heat storage capacity, a real-time heat storage state value and a real-time heat release state value of each fused salt heat storage unit, and maximum allowable heat charging power and maximum allowable heat release power dynamically calculated based on real-time fused salt temperature and flow; meanwhile, real-time steam extraction parameters and heat supply load requirements of the cogeneration unit are collected; by introducing a multi-mode dynamic switching and multi-objective optimization algorithm, an intelligent cooperation mechanism of a heat storage system and a cogeneration host is constructed, the operation constraint that electricity is determined by heat is effectively broken through, the unit can flexibly and economically participate in electricity market regulation while heat supply stability is guaranteed, and the power market regulation efficiency is improved. And the peak regulation capability and the comprehensive benefit of the system are obviously improved.

Description

Technical Field

[0001] This invention relates to the field of thermal energy storage management technology, and in particular to a steam turbine extraction energy storage molten salt thermal energy storage system. Background Technology

[0002] With the transformation of the energy structure and the advancement of the "dual carbon" target, the integration of a high proportion of new energy sources into the power grid has become an inevitable trend. Against this backdrop, the power grid's need for flexible resource regulation is increasingly urgent. Combined heat and power (CHP) units, as a highly efficient form of energy utilization, not only provide stable heating but also undertake important power generation functions. However, the traditional operating mode of CHP units typically follows the principle of "heat-driven power generation," and their power generation capacity is severely constrained by the heating load. During the heating season, to meet users' heating demands, the units must maintain a high steam extraction flow rate, resulting in an inability to significantly reduce their power generation output and a severe deficiency in peak-shaving capacity. Conversely, when peak power generation is needed, the unit's power generation capacity may be limited by the boiler's maximum output and heating parameters, making further increases difficult. This operational rigidity makes it difficult for CHP units to flexibly adjust their power generation strategies according to electricity price signals in the electricity spot market, leading not only to huge trading losses but also affecting the grid's ability to absorb intermittent new energy sources such as wind and solar power due to their inflexible regulation characteristics.

[0003] To break the "heat-driven power generation" dilemma, introducing molten salt thermal energy storage technology into combined heat and power (CHP) systems is considered an effective solution. Specifically, a turbine-type extraction steam storage molten salt thermal energy storage system is employed. By coupling molten salt thermal energy storage devices to the unit's extraction steam pipeline, surplus steam heat that would otherwise be used for heating can be stored in molten salt during periods of low electricity demand or high renewable energy generation, reducing power generation output. During periods of high electricity demand or insufficient renewable energy output, the stored heat can be released for heating or power generation, thereby increasing the unit's power output. Theoretically, this technological approach can decouple heat and electricity production, enhancing the unit's operational flexibility.

[0004] However, existing energy management methods for molten salt thermal energy storage systems still have significant limitations. These methods often employ simple power allocation strategies, failing to fully consider the system's optimal operating objectives under different scenarios. For example, during periods of high electricity spot market prices, the system should aim to maximize power generation revenue; during grid frequency fluctuations, the goal should be rapid response to frequency regulation commands; and during periods of tight heating demand, ensuring safe and stable heating supply should be the primary task. A single control strategy cannot adapt to these complex and ever-changing needs. Summary of the Invention

[0005] To address the aforementioned technical problems, the present invention provides a steam turbine-type extraction steam storage molten salt thermal energy storage system, comprising: The system collects real-time operating data, including: total power demand determined by grid dispatch instructions or electricity market clearing signals; controllable state values ​​of each molten salt thermal storage unit; rated thermal storage capacity; real-time thermal storage state value; real-time heat release state value; and maximum allowable heat charging power and maximum allowable heat release power dynamically calculated based on real-time molten salt temperature and flow rate. Simultaneously, it collects real-time extraction steam parameters and heating load demand of the cogeneration unit. Based on the total power demand and the heating load demand, the system's operating mode is dynamically determined and selected. The operating modes include at least the power generation priority mode, the heating guarantee mode, and the frequency regulation mode. Based on the selected operating mode, the weighted heat charging or heat releasing ratio characteristic value of each molten salt thermal storage unit in the current mode is calculated. Based on the weighted heat charging or heat releasing ratio characteristic value and the real-time heat storage state value of each unit, a multi-objective optimization algorithm considering state equilibrium is adopted to calculate the initial power command value of each molten salt heat storage unit, so as to achieve the optimal overall system operating efficiency and the heat storage state of each unit tends to be consistent. The initial power command value of each molten salt thermal storage unit is compared with its dynamically calculated maximum allowable heat charging or releasing power. If the limit is exceeded, a power redistribution algorithm based on priority sorting is initiated for online correction. The priority is jointly determined by the operating mode, unit health and economic coefficient. The modified power command values ​​of each molten salt thermal storage unit are integrated with the steam extraction regulation command of the cogeneration unit to generate and output the overall system control command, thereby realizing the coordinated control of flexible adjustment of power generation output and stable heating of the cogeneration unit.

[0006] Preferably, the dynamic determination and selection of the system's operating mode includes: When the total power demand is positive and higher than the set threshold, or when the grid frequency is lower than the rated value, the power generation priority mode is entered. In this mode, the power generation revenue coefficient is introduced for weighting when calculating the heat release ratio characteristic value. When the heating load demand approaches the upper limit of the system's heating capacity, the system enters the heating guarantee mode. In this mode, a heating stability weight is introduced when calculating the characteristic value of the heat charging / heat releasing ratio to prioritize the stability of steam extraction heating. When a high-frequency regulation command is received from the power grid, the system enters the frequency regulation mode. In this mode, the calculation of the multiplier characteristic value focuses on the unit's response speed factor to achieve rapid bidirectional power regulation.

[0007] Preferably, a multi-objective optimization algorithm considering state equilibrium is adopted to construct an objective function (α·F1+β·F2), where: F1 is the square of the total power tracking deviation of the system, F2 is the sum of squares of the deviations between the thermal state values ​​of each molten salt thermal storage unit and the average thermal state value, and α and β are weighting coefficients, whose values ​​are dynamically adjusted by the current operating mode. By solving for the optimal solution under this objective function, the initial power command value of each molten salt thermal storage unit is obtained.

[0008] Preferably, the priority-based power redistribution algorithm is corrected online, including: Identify all molten salt thermal storage units whose initial power command values ​​exceed the limits, and temporarily clamp their power to their maximum allowable value; The difference between the total power demand and the sum of the power of all clamped units is calculated to obtain the power to be allocated; Calculate the dynamic allocation priority P for molten salt thermal storage units that have not exceeded the limits. i ; The power to be allocated is distributed to the units that have not exceeded their power limits in descending order of priority, until the allocation is completed or all units have reached their power limits.

[0009] Preferably, the dynamic allocation priority P i Calculate using the following formula: P i =w1·SOH i +w2·R i +w3·E i ,in: SOH i The health status of unit i is a normalized value between 0 and 1; R i R is the response performance score of unit i in the current operating mode. i ; E i The energy efficiency coefficient for charging and discharging of unit i is based on real-time or predicted electricity prices; w1, w2, and w3 are weighting coefficients related to the operating mode.

[0010] Preferably, the response performance score R i The method for determining it is as follows: In the power generation priority mode or frequency regulation mode, R i It is mainly negatively correlated with the historical average power response delay time of the unit; the shorter the delay, the higher the score. Under the aforementioned heating guarantee mode, R i The score is mainly negatively correlated with the fluctuation range of the unit's steam extraction parameters caused by the unit during the heat charging and discharging process; the smaller the fluctuation, the higher the score.

[0011] Preferably, the coordinated integration with the extraction steam regulation command of the cogeneration unit is achieved by establishing and solving a coupling relationship model of power-extraction steam flow-power generation of the molten salt thermal storage system, and then solving the optimal extraction steam regulation amount in reverse based on the sum of the final power command values ​​of the molten salt thermal storage unit, so that the rate of change of the unit's power generation heat consumption remains within a preset stable range.

[0012] The present invention has at least the following beneficial effects: 1. By introducing a multi-mode dynamic switching mechanism, the system can intelligently identify operating scenarios and switch core objectives. During periods of high electricity spot market prices, the system prioritizes discharging to maximize power generation revenue; when the grid frequency is unstable, it quickly enters frequency regulation mode to provide ancillary services; and when heating demand is tight, ensuring heating safety becomes the primary task.

[0013] 2. It achieves a higher level of optimization. It not only accurately tracks grid power demand but also dynamically adjusts its target convergence, preventing overuse or idleness of some units and preparing them for future market opportunities. Simultaneously, when allocating power, it comprehensively considers unit health status, response speed, and economic efficiency, ensuring that the power allocation strategy meets immediate needs while extending the overall system lifespan and maximizing the economic benefits of each charging and discharging operation.

[0014] 3. By establishing and updating an online coupling model of the molten salt thermal storage system's power, steam extraction flow, and power generation, the system's operation is deeply integrated with the main generator's operating status. The system output is no longer an isolated thermal storage power command, but a globally optimal command integrated with the main generator's steam extraction regulation. This allows the unit's core parameters to remain within a stable range even when significantly adjusting power generation, effectively avoiding unit efficiency decline and accelerated equipment fatigue caused by drastic fluctuations in steam extraction. It fundamentally resolves the contradiction between flexible peak shaving and the safe and stable operation of the main generator, providing the power grid with truly reliable and sustainable flexible regulation capabilities. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a flow chart of a steam turbine extraction energy storage molten salt thermal energy storage system provided in Embodiment 1 of the present invention. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or server that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or devices.

[0019] Example 1

[0020] This embodiment provides a steam turbine extraction energy storage molten salt thermal energy storage system, the system including as follows: Figure 1 As shown: (i) Real-time acquisition of system operation data, including: total power demand value determined by power grid dispatch instructions or power market clearing signals, controllable status value of each molten salt thermal storage unit, rated thermal storage capacity, real-time thermal storage status value, real-time heat release status value, maximum allowable heat charging power and maximum allowable heat release power dynamically calculated based on real-time molten salt temperature and flow rate; at the same time, real-time extraction steam parameters and heating load demand of cogeneration units are acquired. Specifically, firstly, regarding grid and market data, the system receives AGC (Automatic Generation Control) commands issued by the grid dispatch system or spot market clearing signals issued by the power trading platform in real time through a data gateway deployed in the dispatch center. After verification and format conversion, these signals are parsed into a clear total power demand value (unit: MW). When the value is positive, it indicates that the system needs to increase power generation output, and when it is negative, it indicates that it needs to absorb electrical energy for thermal storage.

[0021] Secondly, regarding the data of the molten salt thermal storage unit itself, each unit is equipped with a local control unit. This unit uploads fixed parameters such as its controllable status ("1" for available, "0" for fault or maintenance), rated thermal storage capacity (MWh), and dynamic parameters such as real-time thermal storage status value (SoC, calculated by measuring molten salt level and temperature) and heat release status value (reflecting heat release capacity) to the central energy management system via an industrial bus network (such as PROFIBUS-DP or Modbus TCP). Crucially, the system dynamically calculates the maximum allowable charging / releasing power, which is not a fixed value. The system collects real-time temperature, pressure, and flow data of the high-temperature and low-temperature molten salt in each unit, inputting these real-time operating parameters into a preset thermal-hydraulic calculation model. This model comprehensively considers the heat transfer limits of the heat exchanger, the mechanical limits of the pumps and valves, and the solidification risk of the molten salt, dynamically calculating the maximum allowable power for safe operation of the unit at the current moment. This ensures that the command is physically feasible and safe after it is issued.

[0022] Finally, for the data from the cogeneration unit, the system needs to establish a data link with the unit's DCS (distributed control system) to read key parameters such as pressure, temperature, and flow rate on the extraction steam pipeline in real time, as well as the external heating load demand.

[0023] (ii) Based on the total power demand and heating load demand, dynamically determine and select the system operation mode. The operation mode shall include at least the power generation priority mode, the heating guarantee mode and the frequency regulation mode. Based on the selected operation mode, calculate the weighted heat charging or heat releasing ratio characteristic value of each molten salt thermal storage unit under the current mode. The dynamic determination and selection of the system's operating mode in the above embodiments includes: When the total power demand is positive and higher than the set threshold, or when the grid frequency is lower than the rated value, the power generation priority mode is entered. In this mode, the power generation revenue coefficient is introduced for weighting when calculating the heat release ratio characteristic value. When the heating load demand approaches the upper limit of the system's heating capacity, the system enters the heating guarantee mode. In this mode, a heating stability weight is introduced when calculating the characteristic value of the heat charging / heat releasing ratio to prioritize the stability of steam extraction heating. When a high-frequency regulation command is received from the power grid, the system enters the frequency regulation mode. In this mode, the calculation of the multiplier characteristic value focuses on the unit's response speed factor to achieve rapid bidirectional power regulation.

[0024] In the detailed embodiments described above, 1. Power generation priority mode, its implementation mechanism: There are two triggering conditions for this mode, and it can be activated if either one is met.

[0025] Condition 1: The system compares the total power demand value received in real time with a set threshold (this threshold can be dynamically adjusted according to market electricity prices, for example, set to 50MW). When the demand value is positive and higher than the threshold, it means that increasing power generation output at this time has significant economic benefits.

[0026] Condition 2: Real-time monitoring of the power grid frequency. When the frequency is below 49.8Hz (the rated frequency in my country is 50Hz), it indicates that there is a power shortage in the power grid and active power support needs to be provided immediately.

[0027] Once in this mode, the heat release ratio characteristic value of each molten salt thermal storage unit is multiplied by a power generation benefit factor (e.g., 1.2 to 1.5). This means that even if two units have the same basic performance, the system will tend to command the unit that generates higher benefits to discharge more.

[0028] During peak hours in the electricity spot market, when electricity prices climb to high levels, the grid dispatch center issues an order requiring the thermal power plant to provide an additional 60MW of generating capacity (total power demand +60MW). This value exceeds the system's set economic threshold of 50MW, and the decision-maker immediately determines to enter the generation priority mode. Subsequently, when allocating this 60MW of power, a molten salt unit with good thermal storage and a higher generation revenue coefficient due to its geographical location which reduces line losses will be assigned a larger power task than usual, thereby maximizing the power plant's overall market revenue.

[0029] 2. Heating Supply Guarantee Mode and its Implementation Mechanism: The core of this mode is to ensure heating safety. Its trigger condition is that the heating load demand approaches the upper limit of the system's heating capacity (e.g., reaching more than 85% of the design capacity). The system determines this by real-time monitoring of steam extraction flow and pressure and comparing them with the set safety upper limit.

[0030] In this mode, a heating stability weight is introduced when calculating the characteristic value of the heat charging or releasing ratio. This weight is usually a penalty factor. For example, if the heat charging or releasing behavior of a certain thermal storage unit causes drastic fluctuations in the extraction steam parameters, its ratio characteristic value will be multiplied by a weight less than 1, thereby being "suppressed" during power allocation to reduce interference with the main unit's heating extraction steam.

[0031] In severe cold weather, when urban heating demand surges and the unit's extraction steam flow reaches 90% of its rated value, the system is at full heating capacity. At this point, even if the grid has a power demand of +30MW, the energy management system's decision-maker will prioritize entering the heating security mode. When calculating power allocation, a molten salt unit with a fast response but significant impact on extraction steam pressure will have its ratio characteristic value reduced by multiplying it by a heating stability weight of 0.7; conversely, a unit with a smooth response and minimal impact on the heating system may have a weight of 1.0. In this way, the system meets some of the power generation demand while maximizing the stability and security of heating.

[0032] 3. Frequency regulation mode, its implementation mechanism: This mode is directly triggered by the high-frequency frequency regulation command of the power grid. These commands are usually issued continuously at a cycle of seconds or minutes, requiring the generating units to adjust their output quickly and accurately.

[0033] In this mode, speed is the top priority. The calculation of the rate characteristic value will focus on the unit's response speed factor. This factor is negatively correlated with the response delay time from receiving the command to reaching the target power; the shorter the delay, the higher the factor value. The system will prioritize assigning fast, small-range power adjustment tasks to the fastest-responding units.

[0034] When a large generating unit in the power grid suddenly trips, causing a sharp drop in frequency, the grid will issue a series of rapidly changing power commands to power plants with frequency regulation capabilities. Upon receiving these commands, this system immediately switches to frequency regulation mode. When allocating commands, the system queries the historical response data of each molten salt unit. A unit that can reach 90% of the target power within 10 seconds will have a much higher response speed factor than a unit that requires 60 seconds. Therefore, the vast majority of rapid, fluctuating frequency regulation power will be handled by the fastest-responding unit, ensuring the system can track grid commands with high quality and support grid stability.

[0035] (III) Based on the weighted heat charging or heat release ratio characteristic value and the real-time heat storage state value of each unit, a multi-objective optimization algorithm considering state equilibrium is adopted to calculate the initial power command value of each molten salt heat storage unit, so as to achieve the optimal overall system operating efficiency and the heat storage state of each unit tends to be consistent. The above adopts a multi-objective optimization algorithm that considers state equilibrium to construct the objective function (α·F1+β·F2), where: F1 is the square of the total power tracking deviation of the system, F2 is the sum of the squares of the deviations between the thermal state value of each molten salt thermal storage unit and the average thermal state value, and α and β are weighting coefficients, whose values ​​are dynamically adjusted by the current operating mode. By solving for the optimal solution under this objective function, the initial power command value of each molten salt thermal storage unit is obtained.

[0036] Specifically, this involves solving optimization problems using mathematical tools. The goal is to intelligently manage the health status of each thermal storage unit while accurately tracking the power demand of the power grid, preventing some units from being overused or idle, thereby achieving a balance between long-term stable system operation and short-term economic benefits.

[0037] (iv) Compare the initial power command value of each molten salt thermal storage unit with its dynamically calculated maximum allowable heat charging or releasing power. If there is an over-limit, start the power redistribution algorithm based on priority sorting for online correction. The priority is determined by the operating mode, unit health and economic coefficient. The above priority-based power redistribution algorithm is corrected online, including: Identify all molten salt thermal storage units whose initial power command values ​​exceed the limits, and temporarily clamp their power to their maximum allowable value; The difference between the total power demand and the sum of the power of all clamped units is calculated to obtain the power to be allocated; Calculate the dynamic allocation priority P for molten salt thermal storage units that have not exceeded the limits. i ; The power to be allocated is distributed to the units that have not exceeded their limits in descending order of priority, until the allocation is completed or all units have reached their power limits.

[0038] Furthermore, dynamically allocate priority P i Calculate using the following formula: P i =w1·SOH i +w2·R i +w3·E i ,in: SOH i The health status of unit i is a normalized value between 0 and 1; R i R is the response performance score of unit i in the current operating mode. i ; E i The energy efficiency coefficient for charging and discharging of unit i is based on real-time or predicted electricity prices; w1, w2, and w3 are weighting coefficients related to the operating mode.

[0039] Secondly, the response performance score R i The method for determining it is as follows: In power generation priority mode or frequency regulation mode, R i It is mainly negatively correlated with the historical average power response delay time of the unit; the shorter the delay, the higher the score. Under the heating supply guarantee model, R i The score is mainly negatively correlated with the fluctuation range of the unit's steam extraction parameters caused by the unit during the heat charging and discharging process; the smaller the fluctuation, the higher the score.

[0040] Specifically, the calculated initial power command value for each unit is compared one by one with its dynamically calculated maximum allowable power. Once a unit's command value is found to exceed its physical limit, the algorithm immediately activates. All units exceeding the limit are immediately identified, and their power command values ​​are temporarily forced (clamped) to their maximum allowable value. This is a "safety net" operation, ensuring that no unit receives a dangerous over-limit command.

[0041] Secondly, all units exceeding the limits will be immediately identified, and their power command values ​​will be temporarily forced (clamped) to their maximum allowable value. This is a "safety net" operation, ensuring that no unit receives a dangerous over-limit command.

[0042] Furthermore, all non-limited units are calculated according to P. i The values ​​are sorted from highest to lowest. The system allocates the power to be allocated like cutting a cake, prioritizing the highest priority unit until it reaches its own power limit, and then continues to allocate it to the next unit until all the power to be allocated is allocated or all units have reached their limits.

[0043] (v) The modified power command values ​​of each molten salt thermal storage unit are integrated with the steam extraction regulation command of the cogeneration unit to generate a system general control command and output it, so as to realize the flexible adjustment of the power generation output of the cogeneration unit and the coordinated control of the heating stability.

[0044] The above-mentioned coordination and integration with the extraction steam regulation command of the cogeneration unit is achieved by establishing and solving the coupling relationship model of power-extraction steam flow-power generation of the molten salt thermal storage system. Based on the sum of the final power command values ​​of the molten salt thermal storage unit, the optimal extraction steam regulation is solved in reverse, so that the rate of change of the unit's power generation heat consumption is maintained within the preset stable range.

[0045] Specifically, the coupling model clearly describes the quantitative relationship between "steam extraction flow rate," "power generation," and "heat storage / release power." Its core physical principle is that the steam extracted from a combined heat and power (CHP) unit is a portion of the steam that has already done work, drawn from the turbine. When the amount of extracted steam is increased for heating or driving thermal storage, the power generation of the subsequent turbine stage will decrease accordingly; conversely, reducing the amount of extracted steam will allow more steam to be used for power generation, thereby increasing the power generation. The molten salt thermal storage system plays the role of a "virtual power plant" here: during thermal storage, it stores heat energy by consuming extracted steam, equivalent to increasing a heat load and reducing power generation; during heat release, it replaces part of the extracted steam for heating, equivalent to reducing a heat load and increasing power generation. The mathematical model digitizes this dynamic coupling relationship; for example, it can be expressed as: , where: ΔP electric It is the change in power generation, ΔGextraction It is the change in steam extraction flow rate, K is the electrothermal conversion coefficient of the unit, η is the overall efficiency of the thermal storage system, and P thermal-storage It is the power of the thermal storage system (positive for heat absorption, negative for heat release).

[0046] Then, after obtaining the "sum of corrected power command values ​​for each molten salt thermal storage unit" (i.e., the total power required for thermal storage or release by the system), the control center substitutes this value into the aforementioned coupled model for inverse calculation. The goal of the solution is to find an optimal extraction steam regulation (ΔG_extraction) that, while meeting the new thermal storage / release power demand, keeps the unit's "rate of change in power generation heat consumption" within a preset stable range. The rate of change in power generation heat consumption is a key indicator for measuring the unit's operational stability; excessive variation means the unit has deviated from its optimal operating conditions, resulting in reduced efficiency and increased wear. Through the model's inverse calculation, the system can predict in advance the extent to which the extraction steam valves need to be adjusted to execute a specific thermal storage command, and the impact of this adjustment on power generation, thereby ensuring that the entire regulation process is smooth and controlled.

[0047] This embodiment introduces a multi-mode dynamic switching mechanism, enabling the system to intelligently identify operating scenarios and switch core objectives. During periods of high electricity spot market prices, the system prioritizes discharge to maximize power generation revenue; when the grid frequency is unstable, it quickly enters frequency regulation mode to provide auxiliary services; and when heating demand is tight, ensuring heating safety becomes the primary task. Secondly, it achieves a higher level of optimization. It not only accurately tracks grid power demand but also dynamically adjusts its target convergence, preventing overuse or idleness of some units and preparing for participation in subsequent market opportunities. Simultaneously, when allocating power, it comprehensively considers unit health status, response speed, and economic coefficients, ensuring that the power allocation strategy meets immediate needs while extending the overall system lifespan and maximizing the economic benefits of each charging and discharging operation. Furthermore, by establishing and updating an online coupling model of the molten salt thermal storage system's power-extraction steam flow-power generation, the system's actions are deeply integrated with the host's operating status. The system output is no longer an isolated thermal storage power command but a globally optimal command integrated with the host's extraction steam regulation. This allows the core parameters of the unit to remain within a stable range when the power generation is adjusted significantly, effectively avoiding the decrease in unit efficiency and accelerated equipment fatigue caused by drastic fluctuations in steam extraction. It fundamentally solves the contradiction between flexible peak shaving and the safe and stable operation of the main unit, providing the power grid with a truly reliable and sustainable flexible adjustment capability.

[0048] Example 2

[0049] This invention provides a non-transitory computer-readable storage medium storing at least one instruction or at least one program segment, which is loaded and executed by a processor to implement the following steps: The system collects real-time operational data, including: total power demand as determined by grid dispatch instructions or electricity market clearing signals; controllable status values ​​of each molten salt thermal storage unit; rated thermal storage capacity; real-time thermal storage status values; real-time heat release status values; and maximum allowable charging power and maximum allowable heat release power dynamically calculated based on real-time molten salt temperature and flow rate. Simultaneously, it collects real-time extraction steam parameters and heating load demand from combined heat and power (CHP) units. Based on the total power demand and heating load demand, the system's operating mode is dynamically determined and selected. The operating modes include at least the power generation priority mode, the heating guarantee mode, and the frequency regulation mode. Based on the selected operating mode, the weighted heat charging or heat releasing ratio characteristic value of each molten salt thermal storage unit under the current mode is calculated. Based on the weighted heat charging or heat releasing ratio characteristic value and the real-time heat storage state value of each unit, a multi-objective optimization algorithm considering state equilibrium is adopted to calculate the initial power command value of each molten salt heat storage unit, so as to achieve the optimal overall system operating efficiency and the heat storage state of each unit tends to be consistent. The initial power command value of each molten salt thermal storage unit is compared with its dynamically calculated maximum allowable heat charging or releasing power. If the limit is exceeded, a power redistribution algorithm based on priority sorting is initiated for online correction. The priority is determined by the operating mode, unit health and economic coefficient. The modified power command values ​​of each molten salt thermal storage unit are integrated with the steam extraction regulation command of the cogeneration unit to generate and output the overall system control command, thereby realizing the coordinated control of flexible adjustment of power generation output and stable heating of the cogeneration unit.

[0050] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), Rambus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0051] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is used as an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above.

[0052] Example 3

[0053] This invention provides an electronic device, including a processor and a memory, wherein the memory stores at least one instruction or at least one program segment, and the at least one instruction or the at least one program segment is loaded and executed by the processor to implement the following steps: The system collects real-time operational data, including: total power demand as determined by grid dispatch instructions or electricity market clearing signals; controllable status values ​​of each molten salt thermal storage unit; rated thermal storage capacity; real-time thermal storage status values; real-time heat release status values; and maximum allowable charging power and maximum allowable heat release power dynamically calculated based on real-time molten salt temperature and flow rate. Simultaneously, it collects real-time extraction steam parameters and heating load demand from combined heat and power (CHP) units. Based on the total power demand and heating load demand, the system's operating mode is dynamically determined and selected. The operating modes include at least the power generation priority mode, the heating guarantee mode, and the frequency regulation mode. Based on the selected operating mode, the weighted heat charging or heat releasing ratio characteristic value of each molten salt thermal storage unit under the current mode is calculated. Based on the weighted heat charging or heat releasing ratio characteristic value and the real-time heat storage state value of each unit, a multi-objective optimization algorithm considering state equilibrium is adopted to calculate the initial power command value of each molten salt heat storage unit, so as to achieve the optimal overall system operating efficiency and the heat storage state of each unit tends to be consistent. The initial power command value of each molten salt thermal storage unit is compared with its dynamically calculated maximum allowable heat charging or releasing power. If the limit is exceeded, a power redistribution algorithm based on priority sorting is initiated for online correction. The priority is determined by the operating mode, unit health and economic coefficient. The modified power command values ​​of each molten salt thermal storage unit are integrated with the steam extraction regulation command of the cogeneration unit to generate and output the overall system control command, thereby realizing the coordinated control of flexible adjustment of power generation output and stable heating of the cogeneration unit.

[0054] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A steam turbine-type extraction steam storage molten salt thermal energy storage system, characterized in that, include: The system collects real-time operating data, including: total power demand determined by grid dispatch instructions or electricity market clearing signals; controllable state values ​​of each molten salt thermal storage unit; rated thermal storage capacity; real-time thermal storage state value; real-time heat release state value; and maximum allowable heat charging power and maximum allowable heat release power dynamically calculated based on real-time molten salt temperature and flow rate. Simultaneously, it collects real-time extraction steam parameters and heating load demand of the cogeneration unit. Based on the total power demand and the heating load demand, the system's operating mode is dynamically determined and selected. The operating modes include at least the power generation priority mode, the heating guarantee mode, and the frequency regulation mode. Based on the selected operating mode, the weighted heat charging or heat releasing ratio characteristic value of each molten salt thermal storage unit in the current mode is calculated. Based on the weighted heat charging or heat releasing ratio characteristic value and the real-time heat storage state value of each unit, a multi-objective optimization algorithm considering state equilibrium is adopted to calculate the initial power command value of each molten salt heat storage unit, so as to achieve the optimal overall system operating efficiency and the heat storage state of each unit tends to be consistent. The initial power command value of each molten salt thermal storage unit is compared with its dynamically calculated maximum allowable heat charging or releasing power. If the limit is exceeded, a power redistribution algorithm based on priority sorting is initiated for online correction. The priority is jointly determined by the operating mode, unit health and economic coefficient. The modified power command values ​​of each molten salt thermal storage unit are integrated with the steam extraction regulation command of the cogeneration unit to generate and output the overall system control command, thereby realizing the coordinated control of flexible adjustment of power generation output and stable heating of the cogeneration unit.

2. The steam turbine extraction energy storage molten salt thermal energy storage system according to claim 1, characterized in that, The dynamic determination and selection of the system's operating mode includes: When the total power demand is positive and higher than the set threshold, or when the grid frequency is lower than the rated value, the power generation priority mode is entered. In this mode, the power generation revenue coefficient is introduced for weighting when calculating the heat release ratio characteristic value. When the heating load demand approaches the upper limit of the system's heating capacity, the system enters the heating guarantee mode. In this mode, a heating stability weight is introduced when calculating the characteristic value of the heat charging / heat releasing ratio to prioritize the stability of steam extraction heating. When a high-frequency regulation command is received from the power grid, the system enters the frequency regulation mode. In this mode, the calculation of the multiplier characteristic value focuses on the unit's response speed factor to achieve rapid bidirectional power regulation.

3. The steam turbine extraction energy storage molten salt thermal energy storage system according to claim 1, characterized in that, The multi-objective optimization algorithm considering state equilibrium is used to construct the objective function (α·F1+β·F2), where: F1 is the square of the total power tracking deviation of the system, F2 is the sum of the squares of the deviations between the thermal state value of each molten salt thermal storage unit and the average thermal state value, and α and β are weighting coefficients, whose values ​​are dynamically adjusted by the current operating mode. By solving for the optimal solution under this objective function, the initial power command value of each molten salt thermal storage unit is obtained.

4. The steam turbine extraction energy storage molten salt thermal energy storage system according to claim 1, characterized in that, The priority-based power redistribution algorithm is corrected online, including: Identify all molten salt thermal storage units whose initial power command values ​​exceed the limits, and temporarily clamp their power to their maximum allowable value; The difference between the total power demand and the sum of the power of all clamped units is calculated to obtain the power to be allocated; Calculate the dynamic allocation priority P for molten salt thermal storage units that have not exceeded the limits. i ; The power to be allocated is distributed to the units that have not exceeded their power limits in descending order of priority, until the allocation is completed or all units have reached their power limits.

5. A steam turbine extraction energy storage molten salt thermal energy storage system according to claim 4, characterized in that, The dynamic allocation priority P i Calculate using the following formula: P i =w1·SOH i +w2·R i +w3·E i ,in: SOH i The health status of unit i is a normalized value between 0 and 1; R i R is the response performance score of unit i in the current operating mode. i ; E i The energy efficiency coefficient for charging and discharging of unit i is based on real-time or predicted electricity prices; w1, w2, and w3 are weighting coefficients related to the operating mode.

6. A steam turbine extraction energy storage molten salt thermal energy storage system according to claim 5, characterized in that, The response performance score R i The method for determining it is as follows: In the power generation priority mode or frequency regulation mode, R i It is mainly negatively correlated with the historical average power response delay time of the unit; the shorter the delay, the higher the score. Under the aforementioned heating guarantee mode, R i The score is mainly negatively correlated with the fluctuation range of the unit's steam extraction parameters caused by the unit during the heat charging and discharging process; the smaller the fluctuation, the higher the score.

7. A steam turbine extraction energy storage molten salt thermal energy storage system according to claim 1, characterized in that, The coordinated integration with the extraction steam regulation command of the cogeneration unit is achieved by establishing and solving a coupling relationship model of power-extraction steam flow-power generation of the molten salt thermal storage system. Based on the sum of the final power command values ​​of the molten salt thermal storage unit, the optimal extraction steam regulation is solved in reverse, so that the rate of change of the unit's power generation heat consumption is maintained within a preset stable range.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the steps of the steam turbine extraction energy storage molten salt thermal energy storage system according to any one of claims 1 to 7.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the computer program implements the steps of the steam turbine extraction energy storage molten salt thermal energy storage system as described in any one of claims 1 to 7.

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