Method for shortening response time of energy storage system for rapid peak shaving of coal-fired unit

Abstract

The application discloses a method for shortening the response time of an energy storage system for rapid peak regulation of a coal-fired unit, and belongs to the technical field of coal-fired units and thermochemical energy storage. The method comprises the following steps: S1, determining a target output curve of a rapid peak regulation stage; S2, quantifying factors affecting the target duration t1 of the rapid peak regulation stage into a supply-side response time parameter and a response-side time parameter; S3, obtaining the calcium carbonate particle mass flow and the inlet carbon dioxide mass flow required for shortening the target duration t1 of the rapid peak regulation stage; S4, making the electric heating output power reach the required power for peak regulation; and S5, performing online real-time correction according to the temperature rising state and the reaction state. The application realizes the quantifiable improvement of the rapid peak regulation capacity, realizes the rapid ramping of the heat storage power and the on-demand establishment, improves the instant improvement capacity of the unit load reduction rate, and can maintain the operation stability and safety margin of the heat storage reactor while improving the rapid response capacity.

Description

Technical Field

[0001] This invention belongs to the field of coal-fired power units and thermochemical energy storage technology, specifically relating to a method for shortening the response time of an energy storage system for rapid peak shaving in coal-fired power units. Background Technology

[0002] With the large-scale integration of renewable energy into the grid, the power system's demand for peak shaving, frequency regulation, and reserve capabilities has increased significantly. Coal-fired units are gradually transforming from traditional baseload power sources into flexible regulating power sources capable of deep peak shaving and rapid ramp-up. Their minimum stable load, load change rate, and start-up / shutdown frequency have become crucial factors restricting the grid's absorption of renewable energy. Existing coal-fired units typically improve flexibility through combustion organization optimization, boiler low-load stable combustion technology, turbine sliding parameter operation, and the configuration of electrochemical energy storage or electric boilers. However, problems such as difficulty in reducing minimum load, limited peak shaving rate, and significant decrease in thermal efficiency still exist.

[0003] Thermochemical energy storage utilizes reversible chemical reactions to absorb and release energy, offering advantages such as high energy density, suitability for long-term storage, low self-heating loss, and flexible temperature level matching. It is suitable for coupling with coal-fired power units to achieve equivalent regulation of electric power. Calcium-based thermochemical energy storage, represented by the calcium carbonate / calcium oxide system, can achieve heat storage through decomposition reactions under high-temperature conditions, possessing application potential for coupling with the boiler side or electric heating side. However, in engineering applications for rapid peak shaving of coal-fired power units, existing technologies still generally have the following shortcomings: First, most solutions focus on matching thermal storage capacity with steady-state power levels, lacking dynamic performance indicators centered on the "target duration of the rapid peak shaving phase," making it difficult to answer how quickly the energy storage system needs to establish effective thermal storage power under a given peak shaving target time. Second, existing control strategies are mostly focused on temperature or local power stability, lacking a unified framework for quantifiable decomposition of system response lag sources, making it difficult to identify and specifically eliminate bottlenecks that limit rapid peak shaving. Third, the linkage control between the energy storage system and the unit often remains at the power or temperature tracking level, failing to incorporate the time scales of solid feeding, gas supply, electric heating output, and reactor heating and reaction establishment into the same optimization objective, affecting the immediate improvement effect of the unit's load reduction rate.

[0004] Therefore, there is an urgent need for a technical solution that can quantify and decompose the key links affecting the system response by taking the target duration of the rapid peak shaving phase as the guide, and shorten the response time based on bottleneck identification and online correction, so as to improve the effective power building capability of thermochemical energy storage system during the rapid peak shaving phase, enable the load reduction rate of coal-fired units to reach the target improvement value as soon as possible, and take into account the safe and stable operation of the reactor. Summary of the Invention

[0005] The technical problem solved by this invention is to provide a method for shortening the response time of an energy storage system for rapid peak shaving of coal-fired power units, so that the thermochemical energy storage system can quickly establish effective thermal storage power during the rapid peak shaving phase, shorten the target duration of the rapid peak shaving phase, and enable the coal-fired power unit to reach the target increase value as soon as possible, while ensuring the safe and stable operation of the thermal storage reactor.

[0006] Technical Solution: To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] A method for shortening the response time of an energy storage system for rapid peak shaving in coal-fired power units includes the following steps:

[0008] S1. Obtain the operating parameters of the coal-fired unit, including rated load, minimum stable load, original load change rate and target duration t1 of the rapid peak shaving phase, and determine the target output curve of the rapid peak shaving phase.

[0009] S2. Quantify the factors affecting the target duration t1 of the rapid peak-shaving phase into the supply-side response time parameter t. a t b t c and the response-side time parameter t d t e , where t a For solid feeding time, t b For the gas supply time, t c For electric heating time, t d For the heating time, t e The reaction time is determined, and the constraint relationship between the time parameter and the target duration t1 of the rapid peak-shaving phase is established.

[0010] S3, for solid feed time t a and gas supply time t b Based on the analytical relationship between the input power of the thermal storage system and the required mass flow rate of calcium carbonate particles and the mass flow rate of inlet carbon dioxide, the mass flow rate of calcium carbonate particles and the mass flow rate of inlet carbon dioxide required to shorten the target duration t1 of the rapid peak shaving stage are obtained.

[0011] S4, Regarding the electric heating time t c The electric heating arrangement strategy is selected based on the rated power of the electric heater to ensure that the output power of the electric heater reaches the power required for peak shaving.

[0012] S5, regarding the heating time t d and reaction time t e During the rapid peak shaving phase, the temperature, pressure, and reaction conversion rate at various points in the thermal storage reactor bed are monitored in real time, and online real-time corrections are made based on the heating and reaction status.

[0013] Preferably, S1 specifically includes: collecting the rated load, minimum stable load, original load change rate, and target duration t1 of the rapid peak shaving phase of the coal-fired unit, and identifying typical rapid load reduction conditions of the unit in combination with grid dispatch instructions or historical operating data of the unit.

[0014] Based on the identified rapid load reduction conditions, the start and end times, load reduction magnitude, and target equivalent load reduction rate of the rapid peak shaving phase are determined, thereby constructing the target output curve for the rapid peak shaving phase and providing target constraints for subsequently shortening the target duration t1 of the rapid peak shaving phase.

[0015] Preferably, the specific process of determining the target output curve for the rapid peak-shaving phase in S1 includes:

[0016] Using the unit's rated load as the starting output for the rapid peak-shaving phase and the target minimum output for the rapid peak-shaving phase as the ending output, the duration of the target output curve and the target load reduction rate are determined based on the target duration t1 of the rapid peak-shaving phase, in order to subsequently shorten the solid feed time t. a Gas supply time t b Electric heating time t c Heating time t d and reaction time t e Provide target constraints.

[0017] Preferably, S2 further includes:

[0018] Determine the solid feeding time t respectively a Gas supply time t b Electric heating time t c Heating time t d and reaction time t e The acquisition or characterization method is used as a constraint on the rate of thermal storage power establishment during the rapid peak shaving phase.

[0019] Based on the aforementioned constraints, the target duration t1 of the rapid peak shaving phase and the solid feeding time t are established. a Gas supply time t b Electric heating time t c Heating time t d and reaction time t e The constraint relationship between them is used to identify the bottleneck time parameter that limits the shortening of the target duration t1 during the rapid peak shaving phase and serves as the basis for subsequent control strategies;

[0020] The establishment of the target duration t1 of the rapid peak shaving phase and the solid feeding time t a Gas supply time t b Electric heating time t cHeating time t d and reaction time t e The specific process of establishing the constraint relationship between them includes:

[0021] Using solid feeding time t a Gas supply time t b and electric heating time t c As a supply-side constraint, the maximum achievable ramp rate for calcium carbonate mass flow rate, inlet carbon dioxide mass flow rate, and electric heating output power to reach the target value from the current value is limited.

[0022] With heating time t d and reaction time t e As a response-side constraint, it limits the time required for the bed temperature of the thermal storage reactor to enter the decomposition temperature range and for the decomposition reaction to reach the target rate or target conversion rate.

[0023] By considering both supply-side and response-side constraints, feasible conditions are determined for the thermal storage power to reach the target ramp-up speed during the rapid peak-shaving phase. The maximum time parameter limiting the target ramp-up speed is identified as the bottleneck term, thus obtaining the solid feed time t for the target duration t1 of the rapid peak-shaving phase. a Gas supply time t b Electric heating time t c Heating time t d and reaction time t e A relationship of mutual constraints.

[0024] Preferably, in step S3, the specific process of obtaining the calcium carbonate particle mass flow rate and inlet carbon dioxide mass flow rate required to shorten the target duration t1 of the rapid peak-shaving phase includes:

[0025] Based on the target output curve determined by S1, the demand curve of the equivalent thermal power required by the thermochemical energy storage system during the rapid peak-shaving phase as a function of time is calculated. Using the analytical relationship between the system input power and the required mass flow rates of calcium carbonate particles and inlet carbon dioxide during the thermal storage process, the system input power demand curve is mapped to the target curves of the calcium carbonate particle mass flow rate and the inlet carbon dioxide mass flow rate. The analytical relationship is as follows:

[0026]

[0027]

[0028] In the formula, P el The input power of the thermal storage reactor, This represents the mass flow rate of calcium carbonate particles. The temperature at which calcium carbonate particles enter the thermal storage reactor. The temperature of the bed in the thermal storage reactor. (T) represents the isobaric specific heat capacity of calcium carbonate at temperature T, X represents the conversion rate of the heat storage reaction, and ΔH represents... Enthalpy of reaction at temperature This represents the mass flow rate of carbon dioxide. (T) represents the isobaric specific heat capacity of carbon dioxide at temperature T. This represents the apparent density of calcium carbonate particles within the thermal storage reactor. for The density of carbon dioxide at temperature A, where A is the effective cross-sectional area of ​​the thermal storage reactor, and R is the gas constant. This is the molar mass of calcium carbonate. The fluidization rate of carbon dioxide within the thermal storage reactor. This represents the pressure inside the thermal storage reactor.

[0029] Preferably, in step S4, the specific process of making the electric heating output power reach the power required for peak shaving includes:

[0030] Based on the target output curve determined by S1 and the rapid peak-shaving target t1, the required electric heating power and its power ramp-up rate for the thermochemical energy storage system during the rapid peak-shaving phase are determined, and the target electric heating power curve P is established. el (t), and the electric heating time t c To constrain the process, determine the electric heating device's heating time t. c Achievable power ramping capability under constraints;

[0031] Based on the rated power and power regulation capability of the electric heater, a layout strategy for the electric heating device is selected. This strategy includes zoned layout and multi-level power module combinations to reduce the power response lag of a single electric heating unit and shorten the electric heating time t. c ;

[0032] During the rapid peak-shaving phase, the power allocation and power enhancement strategies for each electric heating zone are controlled to ensure that the electric heating output power reaches the target level according to the required electric heating power, thereby preparing for subsequent heating during the heating time t. d and reaction time t e Under constraints, the establishment of effective thermal storage power provides power guarantee for the electric heating side.

[0033] Preferably, in step S5, the specific process of online real-time correction includes:

[0034] Based on real-time monitoring of temperature, pressure, and reaction conversion rate parameters at various points in the thermal storage reactor bed, and combined with the deviation between the actual and target output curves of the coal-fired unit, the target curves for calcium carbonate particle mass flow rate (S3), inlet carbon dioxide mass flow rate (S4), and electric heating power (S4) are corrected online to shorten the heating time t.d and reaction time t e ;

[0035] Closed-loop control is used to dynamically adjust the output of the solid feeding device, gas regulating valve and electric heating device, so that the actual mass flow rate of calcium carbonate particles, the actual inlet carbon dioxide mass flow rate and the actual electric heating output power track the target curve.

[0036] Preferably, in step S5, the online real-time correction further includes adjusting the heating time t. d and reaction time t e Quantitative criteria and judgment process:

[0037] Heating time t d The determination is made by the first criterion that the temperature of each point in the bed of the thermal storage reactor enters the decomposition temperature range and meets the temperature stability requirements. The first criterion includes at least one of the following: the temperature of the representative measuring point of the bed reaches the target temperature threshold, the temperature fluctuation amplitude is less than the set threshold, and the temperature gradient of the upper, middle and lower parts of the bed is less than the set threshold.

[0038] Reaction time t e The determination is made by a second criterion that the reaction conversion rate reaches the target level. The second criterion includes at least one of the following conditions: the conversion rate reaches and remains at the target threshold due to changes in the composition of the outlet gas, characteristic parameters of the reaction product gas, or material balance back-calculation.

[0039] The heating time t is calculated online based on the first criterion and the second criterion. d and reaction time t e and the heating time t d and reaction time t e The changing trend serves as the basis for parameter adjustment of the feed controller, gas supply controller, and electric heating power controller: when the heating time t d or reaction time t e When the estimated value deviates from the target range, the closed-loop control parameters of the solid feeder, gas regulating valve, and electric heater are adjusted online under safety constraints; the safety constraints include the upper limit of bed temperature. Upper limit of bed pressure The rated power and current limit of the electric heater, as well as the maximum ramp rate and minimum stable flow constraints for solid feed and gas supply.

[0040] Preferably, in step S5, when the heating process is limited, resulting in a heating time t... d When increasing the power, prioritize increasing the electric heating power under safety constraints and coordinate the mass flow rate of calcium carbonate particles and the mass flow rate of inlet carbon dioxide to accelerate the bed into the decomposition temperature range and improve temperature stability.

[0041] When reaction establishment is limited, resulting in reaction time t e When the reaction rate is increased, the mass flow rate of calcium carbonate particles, the mass flow rate of inlet carbon dioxide, and the electric heating power are synergistically corrected based on the reaction conversion rate or the characteristic parameters of the outlet gas, so that the reaction can reach the target conversion level more quickly.

[0042] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0043] 1. This invention quantifies the key factors affecting the target duration t1 of the rapid peak-shaving phase into a unified supply-side time parameter: solid feeding time t. a Gas supply time t b and electric heating time t c And the response-side time parameter: heating time t d and reaction time t e This transforms the existing peak-shaving lag into a measurable, estimable, and optimizable system. Compared to schemes that only use temperature or power steady state as control targets, this invention can clearly identify the bottlenecks that limit rapid peak shaving and specifically shorten the bottleneck time, achieving a quantifiable improvement in rapid peak-shaving capability.

[0044] 2. This invention constructs the target output curve and equivalent power demand for the rapid peak shaving phase, and combines the analytical relationship between the input power of the thermal storage system and the mass flow rate of calcium carbonate particles and the inlet carbon dioxide mass flow rate to obtain the control targets for calcium carbonate particles and gas flow rates required to shorten the target duration t1 of the rapid peak shaving phase. Furthermore, by selecting a suitable electric heating arrangement strategy, the electric heating output power can quickly reach the power required for peak shaving, thereby realizing the rapid ramp-up and on-demand establishment of thermal storage power and improving the unit's ability to instantly increase the load reduction rate.

[0045] 3. This invention monitors parameters such as temperature, pressure, and reaction conversion rate at various points in the bed during the rapid peak shaving stage, and makes real-time corrections based on the heating and reaction status, effectively avoiding problems such as calcium carbonate particle sintering, bed fluidization deterioration, and incomplete reaction caused by local overheating. Compared with open-loop or single-variable control that lacks process status feedback, this invention can maintain the operational stability and safety margin of the thermal storage reactor while improving rapid response capability, thereby enhancing the reliability and engineering feasibility of the rapid peak shaving process of coal-fired units. Attached Figure Description

[0046] Figure 1 This is a schematic diagram of the output-time relationship of a coal-fired power unit during the rapid load reduction phase according to an embodiment of the present invention, where the horizontal axis represents time. The unit is min, and the vertical axis represents the output of the coal-fired power unit. The unit is MW;

[0047] Figure 2This is a schematic diagram of the overall process of the method of the present invention;

[0048] Figure 3 This is a schematic diagram illustrating the specific method for controlling the solid feeding time in the embodiment;

[0049] Figure 4 This is a schematic diagram illustrating the specific method for controlling the gas supply time in the embodiment;

[0050] Figure 5 This is a schematic diagram illustrating the specific method for controlling the electric heating time in the embodiment;

[0051] Figure 6 This is a schematic diagram illustrating the specific method for controlling the heating time in the embodiment;

[0052] Figure 7 This is a schematic diagram illustrating the specific method for controlling the reaction time in the embodiment. Detailed Implementation

[0053] The present invention will be further illustrated below with reference to specific embodiments. These embodiments are implemented based on the technical solutions of the present invention, and it should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention.

[0054] Example 1

[0055] Figure 1 middle, This indicates the initial maximum load reduction of the coal-fired power unit, in MW; This indicates the additional load reduction that a coal-fired power unit can achieve after coupling a thermochemical energy storage system, expressed in MW. This indicates the original permissible rate of change of load for coal-fired power units, expressed in %Pe / min. This represents the target load change rate of the coal-fired unit after coupling the thermochemical energy storage system, expressed in %Pe / min. Indicates the start time of the rapid load reduction process; The target duration for the rapid peak shaving phase is expressed in minutes. The unit's rapid load reduction ends after coupling the thermochemical energy storage system, in minutes; This indicates the end time of the low-load maintenance phase, in minutes.

[0056] like Figures 1-7 As shown in the figure, this embodiment provides a method for shortening the response time of an energy storage system for rapid peak shaving of coal-fired power units, including the following steps:

[0057] S1. Obtain the operating parameters of the coal-fired unit, including rated load, minimum stable load, original load change rate and target duration t1 of the rapid peak shaving phase, and determine the target output curve of the rapid peak shaving phase.

[0058] Specifically, this includes: collecting the rated load, minimum stable load and original load change rate of the coal-fired unit; giving the target duration t1 of the rapid peak shaving phase of the unit after the coupled thermochemical energy storage system; and combining the grid dispatch instructions or historical operating data of the unit to obtain the rapid load reduction condition based on the unit's load reduction curve.

[0059] Based on the obtained rapid load reduction conditions, the start and end times, load reduction magnitude, and target equivalent load reduction rate of the rapid peak shaving phase are determined, and the target output curve of the rapid peak shaving phase is constructed to provide constraints for the target duration t1 of the subsequent rapid peak shaving phase.

[0060] The specific process of constructing the target output curve for the rapid peak-shaving phase includes:

[0061] Using the unit's rated load as the starting output for the rapid peak shaving phase and the target minimum output for the rapid peak shaving phase as the ending output, the target load reduction rate r1 is obtained based on the target duration t1 of the rapid peak shaving phase, which is then used to shorten the subsequent solid feed time t. a Gas supply time t b Electric heating time t c Heating time t d and reaction time t e Provide target constraints.

[0062] S2. Quantify the factors affecting the target duration t1 of the rapid peak-shaving phase into the supply-side response time parameter t. a t b t c and the response-side time parameter t d t e , where t a For solid feeding time, t b For the gas supply time, t c For electric heating time, t d For the heating time, t e To determine the reaction time, and to establish the constraint relationship between the time parameters and the target duration t1 of the rapid peak-shaving phase;

[0063] Also includes:

[0064] Determine the solid feeding time t respectively a Gas supply time t b Electric heating time t c Heating time t d and reaction time t e The acquisition or characterization method is used as a constraint on the rate of thermal storage power establishment during the rapid peak shaving phase.

[0065] Based on the aforementioned constraints, the target duration t1 of the rapid peak shaving phase and the solid feeding time t are established. a Gas supply time t b Electric heating time t c Heating time t d and reaction time t e The constraint relationship between them is used to identify the bottleneck time parameter that limits the shortening of the target duration t1 during the rapid peak shaving phase and serves as the basis for subsequent control strategies;

[0066] The establishment of the target duration t1 of the rapid peak shaving phase and the solid feeding time t a Gas supply time t b Electric heating time t c Heating time t d and reaction time t e The specific process of establishing the constraint relationship between them includes:

[0067] Using solid feeding time t a Gas supply time t b and electric heating time t c As a supply-side constraint, the maximum achievable ramp rate for calcium carbonate mass flow rate, inlet carbon dioxide mass flow rate, and electric heating output power to reach the target value from the current value is limited.

[0068] With heating time t d and reaction time t e As a response-side constraint, it limits the time required for the bed temperature of the thermal storage reactor to enter the decomposition temperature range and for the decomposition reaction to reach the target rate or target conversion rate.

[0069] Integrating supply-side and response-side constraints, at the start of the rapid peak-shaving phase, the maximum achievable ramp-up rate is simultaneously increased based on the supply-side constraints, which determine the mass flow rate of calcium carbonate particles, the inlet carbon dioxide mass flow rate, and the electric heating output power. Simultaneously, based on the response-side constraints, the heating time t required for the bed temperature to enter the decomposition temperature range and for the decomposition reaction to reach the target rate or conversion rate is calculated. d With reaction time t e The feasible conditions for the thermal storage power to reach the target ramp-up speed during the rapid peak-shaving phase were determined, and the maximum time parameter limiting the target ramp-up speed was identified as the bottleneck term. Thus, the target duration t1 of the rapid peak-shaving phase was obtained, along with the solid feed time t. a Gas supply time t b Electric heating time t c Heating time t d and reaction time t e A relationship of mutual constraints.

[0070] S3, for solid feed time ta and gas supply time t b Based on the analytical relationship between the input power of the thermal storage system and the required mass flow rate of calcium carbonate particles and the mass flow rate of inlet carbon dioxide, the mass flow rate of calcium carbonate particles and the mass flow rate of inlet carbon dioxide required to shorten the target duration t1 of the rapid peak shaving stage are obtained.

[0071] The specific process for obtaining the required mass flow rates of calcium carbonate particles and inlet carbon dioxide to shorten the target duration t1 of the rapid peak-shaving phase includes:

[0072] Based on the target output curve determined by S1, the demand curve of the equivalent thermal storage power required by the thermochemical energy storage system during the rapid peak-shaving phase is calculated as a function of time. Using the analytical relationship between the input power of the thermochemical energy storage system during the thermal storage process and the required mass flow rates of calcium carbonate particles and inlet carbon dioxide, the input power demand curve of the thermochemical energy storage system is mapped to the target curves of the calcium carbonate particle mass flow rate and the inlet carbon dioxide mass flow rate. The analytical relationship is as follows:

[0073]

[0074]

[0075] In the formula, P el The input power of the thermal storage reactor, This represents the mass flow rate of calcium carbonate particles. The temperature at which carbon dioxide enters the thermal storage reactor. The temperature at which calcium carbonate particles enter the thermal storage reactor. The temperature of the bed in the thermal storage reactor. (T) represents the isobaric specific heat capacity of calcium carbonate at temperature T, X represents the conversion rate of the heat storage reaction, and ΔH represents... Enthalpy of reaction at temperature This represents the inlet carbon dioxide mass flow rate. (T) represents the isobaric specific heat capacity of carbon dioxide at temperature T. This represents the apparent density of calcium carbonate particles within the thermal storage reactor. for The density of carbon dioxide at temperature A, where A is the effective cross-sectional area of ​​the thermal storage reactor, and R is the gas constant. is the molar mass of calcium carbonate; The fluidization rate of carbon dioxide within the thermal storage reactor. This represents the pressure inside the thermal storage reactor.

[0076] S4, Regarding the electric heating time t c The electric heating arrangement strategy is selected based on the rated power of the electric heater to ensure that the output power of the electric heater reaches the power required for peak shaving.

[0077] The specific process of making the electric heating output power reach the power required for peak shaving includes:

[0078] Based on the target output curve determined by S1 and the target duration t1 of the rapid peak shaving phase, the required electric heating power and its power ramp-up rate for the thermochemical energy storage system during the rapid peak shaving phase are determined, and the target electric heating power curve, i.e., the actual electric heating output power P, is established. el (t), and the electric heating time t c To constrain the process, determine the electric heater's heating time t. c Achievable power ramping capability under constraints;

[0079] Based on the rated power and power adjustment capability of the electric heater, a layout strategy for the electric heating device is selected. The layout strategy includes zoned layout and multi-level power module combination. Zoned layout involves dividing the bed of the thermal storage reactor into M electric heating zones axially (e.g., upper preheating zone, middle reaction zone, lower compensation zone) and / or radially into inner and outer ring zones. Each electric heating zone is equipped with an independent power supply circuit and temperature measuring point, allowing independent adjustment of the electric heating power of each zone. Multi-level power module combination involves each electric heating zone consisting of K parallel electric heating units, each electric heating unit composed of several power modules to form multi-level adjustable power. Through parallel connection and phased switching of multiple modules, the power response lag of a single electric heating unit is reduced, and the electric heating time t is shortened. c ;

[0080] During the rapid peak-shaving phase, the power distribution of each electric heating zone is controlled to ensure that the electric heating output power reaches the target level according to the electric heating power demand, thereby preparing for subsequent heating during the heating time t. d and reaction time t e Under constraints, the establishment of effective thermal storage power provides power guarantee for the electric heating side.

[0081] S5, regarding the heating time t d and reaction time t e During the rapid peak shaving phase, the temperature, pressure and reaction conversion rate at each point in the thermal storage reactor bed are monitored in real time, and online real-time corrections are made based on the heating state and reaction state.

[0082] The specific process of online real-time correction includes:

[0083] Based on real-time monitoring of temperature, pressure, and reaction conversion rate parameters at various points in the thermal storage reactor bed, and combined with the deviation between the actual and target output curves of the coal-fired unit, the target curves for calcium carbonate particle mass flow rate (S3), inlet carbon dioxide mass flow rate (S4), and electric heating power (S4) are corrected online to shorten the heating time t.d and reaction time t e Online correction includes: obtaining the power deviation based on the actual output and target output curves, and obtaining the reaction-side deviation based on the bed temperature deviation and conversion rate deviation; and incrementally correcting the electric heating power setting, solid feed setting, and gas supply setting based on the deviation, provided that the rated upper limit, ramp rate upper limit, and safety constraints of each execution quantity are met. Safety constraints include the upper limit of bed temperature. Upper limit of bed pressure The rated power and current limit of the electric heater, as well as the maximum ramp rate and minimum stable flow constraints for solid feed and gas supply, are determined. The corrections are superimposed onto the target curve to obtain an updated setpoint curve. Closed-loop control is then used to dynamically adjust the execution quantities of the solid feed device, gas regulating valve, and electric heater, ensuring that the actual calcium carbonate particle mass flow rate, actual inlet carbon dioxide mass flow rate, and actual electric heater output power track the updated target curve, thereby shortening the heating time. d With reaction time t e ;

[0084] Online real-time correction also includes adjustments to the heating time t. d and reaction time t e Quantitative criteria and judgment process:

[0085] Heating time t d The determination is made based on a first criterion that the temperature at various points in the thermal storage reactor bed enters the decomposition temperature range and meets the temperature stability requirements. The first criterion includes at least one of the following: the temperature at a representative measuring point in the bed reaches the target temperature threshold. Temperature fluctuation amplitude is less than the set threshold And the temperature gradient between the upper, middle and lower layers of the bed is less than the set threshold. ;

[0086] Reaction time t e The determination is made based on a second criterion that the reaction conversion rate reaches the target level. The second criterion includes at least one of the following: changes in outlet gas composition parameters (including outlet carbon dioxide volume fraction) obtained from an online gas analyzer. The rate of carbon dioxide generation (or consumption) reaches and remains at a threshold based on the material balance of inlet / outlet gas flow rate and composition. Reaching and maintaining a threshold and based on reaction conversion rate Reach the target conversion rate threshold And maintain;

[0087] The heating time t is calculated online based on the first and second criteria. d and reaction time t e and the heating time t d and reaction time te The changing trend serves as the basis for parameter adjustment of the feed controller, gas supply controller, and electric heating power controller: when the heating time t d or reaction time t e When the estimated value deviates from the target range, the closed-loop control parameters of the solid feeder, gas regulating valve and electric heater are adjusted online under safety constraints;

[0088] When the heating process is limited, the heating time t is reduced. d When increasing the power, prioritize increasing the electric heating power under safe constraints, and coordinate the mass flow rate of calcium carbonate particles and the mass flow rate of inlet carbon dioxide: including prioritizing the allocation of electric heating power to the low temperature zone, temporarily reducing or partially restoring solid feed to reduce the sensible heat and endothermic heat load of the bed, and adjusting the gas flow rate to the minimum stable value that meets the fluidization and pressure drop requirements or dividing the gas according to the temperature deviation, thereby accelerating the bed to enter the decomposition temperature range and improving temperature stability;

[0089] When reaction establishment is limited, resulting in reaction time t e When increasing the concentration, the mass flow rate of calcium carbonate particles, the mass flow rate of inlet carbon dioxide, and the electric heating power are synergistically corrected based on the reaction conversion rate or outlet gas characteristic parameters. This includes increasing the heat input of the effective reaction zone at rated power, changing the reactant partial pressure and mass transfer driving force by adjusting the inlet / outlet gas flow rate and valve position, and adopting segmented feeding or correction based on conversion rate deviation for solid feed, so that the reaction can reach the target conversion rate threshold more quickly. And maintain this state, thereby shortening the time required to reach the target reaction state.

[0090] In specific implementation: (The following five types of closed-loop control schemes are the specific schemes modified in steps S3-S5.)

[0091] like Figure 3 As shown, for the solid feeding time t a A closed-loop feedback control based on particle mass flow rate is employed to achieve rapid response and stable tracking of solid feed. First, based on the target calcium carbonate particle mass flow rate curve obtained in step S3, which requires shortening the target duration t1 of the rapid peak-shaving phase, a particle mass flow rate setpoint is generated. Set value The actual particle mass flow rate obtained from the particle mass flow rate measurement unit The flow deviation is obtained by comparison. = - , This indicates the particle mass flow rate deviation, and this deviation is input to the feed PID controller. The feed PID controller outputs a control quantity for the particle feeding mechanism based on the particle mass flow rate deviation, ensuring the actual particle mass flow rate... Approaching and tracking quickly Through the closed-loop control method described above, this embodiment can quickly achieve the required particle mass flow rate during the rapid peak shaving phase, providing stable solid feed conditions.

[0092] like Figure 4 As shown, for the gas supply time t b A closed-loop feedback control of the inlet carbon dioxide mass flow rate is employed to achieve rapid response and stable tracking of the gas supply. First, based on the target curve of the inlet carbon dioxide mass flow rate required to shorten the target duration t1 of the rapid peak-shaving phase obtained in step S3, an inlet carbon dioxide mass flow rate setpoint is generated. The set value is compared with the actual inlet carbon dioxide mass flow rate obtained by the gas mass flow rate measurement unit. The flow deviation is obtained by comparison. = - , This indicates the gas mass flow rate deviation, which is then input into the gas supply PID controller. The gas supply PID controller outputs control signals to the gas supply mechanism based on the gas mass flow rate deviation. These signals are used to adjust the control valve opening, the speed of the variable frequency blower or compressor, and other actuators to ensure the actual inlet carbon dioxide mass flow rate... Approaching and tracking quickly Through the closed-loop control method described above, this embodiment can rapidly achieve and maintain a stable inlet carbon dioxide mass flow rate at the required level during the rapid peak-shaving phase, thereby shortening the time required for peak shaving. b It provides stable gas-solid contact and bed fluidization conditions.

[0093] like Figure 5 As shown, for the electric heating time t c A closed-loop feedback control of the electric heating output power is adopted to achieve rapid establishment and stable tracking of the electric heating power. Based on the power demand required for peak shaving during the rapid peak shaving phase determined in step S4, a setpoint for the electric heating output power is generated. Set the electric heating output power value. The actual electric heating output power obtained by the electric power measurement unit The deviation in electric heating output power is obtained by comparison. = - , This indicates the deviation in electric heating output power, and this deviation is input to the electric heating power controller. The electric heating power controller outputs a control signal to the power adjustment unit based on the deviation, adjusting the actual electric heating output power... Approaching and tracking quickly Through the aforementioned closed-loop control, this embodiment can achieve rapid arrival and stable output of electric heating power during the rapid peak-shaving phase, thereby shortening the response-side heating time t. d With reaction time t e Providing sufficient and rapidly adjustable heat source support helps to shorten the target duration t1 of the rapid peak shaving phase and enable the coal-fired unit to reach the target increase value as soon as possible.

[0094] like Figure 6 As shown, for the heating time t d A closed-loop temperature control strategy, using multi-point temperature feedback in the reactor bed, is employed to ensure the bed temperature quickly enters and stabilizes within the decomposition temperature window. The lowest temperature is then extracted. With the highest temperature This serves as a key criterion for temperature control. Using the target decomposition temperature window as a constraint, the bed temperature control range is set as follows: and This is used to characterize whether the bed has achieved effective heating and whether there is a risk of localized overheating. When detected... When the setpoints are too low or there are underheated areas in the bed, the three types of controllable setpoints are corrected according to priority:

[0095] Increase the electric heating output power setting value This is then achieved through closed-loop feedback control of the electric heating output power (such as...). Figure 5 (As shown) Adjustment This increases the overall heating rate of the bed.

[0096] Increase the inlet carbon dioxide mass flow rate setpoint To enhance bed mixing and gas-solid heat exchange, and then through closed-loop feedback control of the inlet carbon dioxide mass flow rate (e.g.) Figure 4 (As shown) Adjust the actual inlet carbon dioxide mass flow rate This reduces the bed temperature gradient and shortens the heating lag in the underheated area;

[0097] Reduce the set value of calcium carbonate granule mass flow rate To reduce the solid temperature rise load entering the bed per unit time and effectively increase the particle residence time, closed-loop feedback control of particle mass flow rate (e.g.) is then implemented. Figure 3 (As shown) Adjust the actual particle mass flow rate This promotes faster bed temperature to reach the target window.

[0098] Through the above control strategy, this embodiment can quickly eliminate underheated areas while avoiding local overheating during the rapid peak shaving stage, improve the uniformity of the bed temperature field, and establish a stable temperature field.

[0099] like Figure 7 As shown, for reaction time te A closed-loop control strategy with the reaction conversion rate as the core feedback variable is adopted to ensure that the conversion rate of the calcium carbonate decomposition reaction can reach the target level as quickly as possible and remain stable, thereby shortening the reaction time t. e The reaction conversion rate target is set based on the requirements for establishing effective thermal storage power during the rapid peak-shaving phase. In actual operation, the reaction conversion rate at the current moment is obtained through real-time measurement or based on material balance. , = - Based on the deviation of reaction conversion rate This serves as the input signal for the outer loop control of the reaction. When an excessive deviation in the reaction conversion rate is detected, i.e., exceeding the preset deviation value, it is considered an input signal. ,satisfy At that time, the energy storage parameter control system corrects the three types of controllable setpoints in real time according to priority:

[0100] Increase the electric heating output power setting value This is then achieved through closed-loop feedback control of the electric heating output power (such as...). Figure 5 (As shown) Adjustment By increasing the heat input to the effective reaction zone of the bed, the reaction temperature stability is improved and the reaction rate is accelerated, thereby promoting the conversion rate. Approaching faster And shorten reaction time ;

[0101] Increase the inlet carbon dioxide mass flow rate setpoint To enhance bed mixing and gas-solid heat exchange, and then through closed-loop feedback control of the inlet carbon dioxide mass flow rate (e.g.) Figure 4 (As shown) Adjust the actual inlet carbon dioxide mass flow rate By altering the bed mixing intensity, gas-solid heat and mass transfer conditions, and reactant partial pressure environment, the effective reaction rate can be increased, enabling the conversion rate to reach the target level more quickly, thereby shortening the reaction time. ;

[0102] Reduce the set value of calcium carbonate granule mass flow rate To reduce the solid temperature rise load entering the bed per unit time and effectively increase the particle residence time, closed-loop feedback control of particle mass flow rate (e.g.) is then implemented. Figure 3 (As shown) Adjust the actual particle mass flow rate This promotes faster bed temperature entry into the target reaction window by reducing the sensible heat and endothermic heat load of the solids entering the bed per unit time, effectively extending the effective residence time of particles, and reducing bed temperature fluctuations. This allows the bed to enter and maintain the target reaction window more quickly, thereby improving conversion rate and shortening reaction time. .

[0103] The above control strategy can accelerate the reaction setup process during the rapid peak-shaving phase, enabling the reaction conversion rate to quickly reach the set target and remain stable, thereby effectively shortening the reaction time t. e This will enable the coal-fired power units to reach the target load reduction rate as quickly as possible.

[0104] In summary, this invention decomposes the target duration t1 of the rapid peak shaving phase into the solid feeding time t. a Gas supply time t b Electric heating time t c Heating time t d and reaction time t e Each of the five types of loops is controlled and corrected online to enable the thermochemical energy storage system to quickly establish and stably track the thermal power required for the rapid peak shaving phase, thereby shortening the target duration t1 of the rapid peak shaving phase and enabling the coal-fired unit to reach the target increase value as soon as possible.

[0105] In this embodiment, the relevant components and structure of the coal-fired power unit and the thermochemical energy storage system are described as follows:

[0106] The coal-fired units utilize existing subcritical, supercritical, or ultra-supercritical coal-fired generator sets, with capacities ranging from tens of MW to thousands of MW. These units include, but are not limited to: boiler systems (furnace, drum / once-through boiler heating surfaces, superheater, reheater, economizer, air preheater, etc.), turbine systems (high / medium / low-pressure cylinders), generators, condensers and condensate systems, feedwater systems (deaerator, high and low-pressure heaters, feedwater pumps), and output control systems related to unit output regulation. The target duration of the rapid peak-shaving phase in this embodiment... The target time window given for the peak shaving task of coal-fired power units is used to characterize the allowable duration from the start of peak shaving to reaching the target output.

[0107] The CaCO3 / CaO thermochemical energy storage system employs a reversible reaction. Using the enthalpy of reaction as the energy storage medium, the process can be a single-reactor or dual-reactor structure; reactor types include, but are not limited to, fixed-bed, bubbling-bed, and fluidized-bed reactors; material conveying methods include, but are not limited to, screw feeders and pneumatic conveyors. Thermochemical energy storage systems include, but are not limited to: thermal storage reactors (used to complete endothermic decomposition or thermal storage processes), exothermic reactors (used to complete exothermic reactions or exothermic processes, optional), solid feeding and discharging systems, gas supply and regulation systems, electric heating systems, and energy storage parameter control systems.

[0108] Coal-fired power units and thermochemical energy storage systems can achieve rapid peak shaving through heat and power matching: During the rapid peak shaving phase, the heat storage power of the thermochemical energy storage system is matched with the output change demand of the unit, and the target duration t1 of the rapid peak shaving phase is shortened under the constraints of the supply side (solid feed, gas supply, electric heating) and the response side (bed heating, reaction establishment).

[0109] The key devices and functions involved in this embodiment are as follows:

[0110] Thermal storage reactor: used to contain a bed of thermochemical energy storage materials and complete the target thermochemical reaction; the reactor is equipped with a bed space, gas distribution components and necessary support / insulation structures to ensure gas-solid contact and temperature field stability;

[0111] Bed temperature and pressure measurement unit: used to collect temperature, pressure and other state parameters at representative locations in the bed in real time, and generate a heating time t. d With reaction time t e The criteria input is used to determine safety constraints such as temperature stability and pressure upper limit;

[0112] Electric heaters: used to provide adjustable heat input to the reactor bed or effective reaction zones of the reactor; electric heaters include resistance heating tubes / rods, embedded heating elements, heating belts, or other equivalent electric heating components; their arrangement can be zoned and / or multi-module combinations to improve power build-up speed and shorten electric heating time. ;

[0113] Electric heating power controller: used for closed-loop regulation of the electric heater's output power; sets the electric heating power value. Compared with the measured actual power The deviation is compared and a control signal is output to the power regulation unit;

[0114] Power regulation unit: used to perform electric heating power regulation, including controllable power / voltage regulation unit, frequency converter, module switching unit, etc.; converts the control signal output by the electric heating power controller into voltage / current / module switching commands for the electric heater, realizing rapid power ramp-up and stable tracking;

[0115] Solid feeding devices: used to continuously or segmentally convey solid particles (such as calcium carbonate particles) to thermal storage reactors, including screw feeders, star valves and vibrating feeders, etc.

[0116] Feed PID controller: used for closed-loop control of solid mass flow rate; sets the solid mass flow rate. Compared with the measured actual solid mass flow rate The deviation is compared and the control quantity is output to the solid feed actuator.

[0117] Solid feeding actuator: used to perform feeding adjustment actions, including adjusting motor speed, valve opening, feeding frequency, etc., to ensure that the solid mass flow rate quickly reaches and tracks the target curve;

[0118] Particle mass flow rate measurement unit: Used for online measurement of the mass flow rate of calcium carbonate particles entering the thermal storage reactor, and outputs the actual solid mass flow rate. As a feedback quantity for the closed-loop control of feeding, it enables the solid feed mass flow rate to quickly ramp up and stably track the solid feed target curve.

[0119] Gas regulating valve: used to regulate the inlet carbon dioxide gas flow rate or pressure to quickly establish the gas supply target curve;

[0120] Gas supply PID controller: used for closed-loop control of inlet gas mass flow rate; sets the inlet gas mass flow rate setpoint. Compared with the measured actual inlet gas mass flow rate The deviation is compared and the control quantity is output to the gas supply actuator;

[0121] Gas supply actuator: used to perform gas supply regulation actions, including regulating valve opening, variable frequency blower speed, compressor speed, etc., to achieve rapid ramp-up and stabilization of inlet gas flow;

[0122] Gas mass flow measurement unit: Used for online measurement of the mass flow rate of carbon dioxide gas entering the thermal storage reactor, and outputs the actual inlet gas mass flow rate. As feedback quantity for closed-loop control of gas supply; the gas mass flow measurement unit includes, but is not limited to, Coriolis mass flow meter, thermal mass flow meter, differential pressure flow meter, etc.

[0123] Online gas analyzer: used to perform online analysis of the gas components at the outlet of the thermal storage reactor, and to obtain the volume fraction of carbon dioxide at the outlet and its rate of change as input signals for reaction state identification and conversion rate estimation; online gas analyzers include, but are not limited to, one or a combination of infrared gas analyzers, mass spectrometers, gas chromatographs or laser absorption spectrometers.

[0124] Example 2

[0125] The following uses a 600MW coal-fired unit and a CaCO3 / CaO thermochemical energy storage system as an example to explain in detail the process by which the method of the present invention compresses the actual response time of the system to the target duration t1 of the rapid peak shaving phase.

[0126] In this embodiment, the target duration of the rapid peak shaving phase is set to t1 = 12 minutes. The rapid peak shaving phase requires the thermochemical energy storage system to establish effective thermal storage power within the target duration t1. MW and remain stable. The criterion for the bed temperature to enter the reaction temperature window is: the temperature at the representative temperature measurement point in the bed reaches the temperature threshold. Furthermore, both the temperature fluctuation amplitude and the bed temperature gradient are less than the set threshold. The criterion for achieving the reaction target is: reaction conversion rate. (Example) The enthalpy of the decomposition reaction of CaCO3 is... MJ / kg, then establish The required CaCO3 decomposition mass flow rate for MW thermal storage power is approximately kg / s t / h, corresponding to CO2 production kg / s.

[0127] In the original design of this unit, the existing technology uses a single high-power electric heating unit without partitioning, and only monitors the reaction state without online real-time correction. The key time parameter obtained from the experiment is: solid feed time t. a =160s, gas supply time t b =120s, electric heating time t c =240s, heating time t d =520s, reaction time t e =520s. The time for the supply side to reach its target is... s; the time for the response side to reach the target is s (approximately 17.3 min); therefore, the actual peak-shaving duration to meet the requirements of temperature, conversion rate, and power is s The timeframe of 17.3 minutes is insufficient to meet the target duration of t1 = 12 minutes, indicating that the bottleneck lies on the response side. ).

[0128] After adopting the method of the present invention, the target duration t1 of the rapid peak shaving stage and the solid feeding time t are first established according to step S3. a Gas supply time t b Electric heating time t c Heating time t d and reaction time t eThe constraints were identified, and the response side was identified as the bottleneck. Secondly, based on step S4, an electric heating zone arrangement and a multi-stage power module combination were adopted to improve power ramp-up capability and bed temperature uniformity. Thirdly, based on step S5, an online collaborative correction of the "conversion rate outer loop + power / flow rate inner loop" was introduced to real-time correct the solid feed, gas supply, and electric heating power setting curves, accelerating the heating and reaction establishment process. The key time parameter obtained from the experiment is: solid feed time t. a =60s, gas supply time t b =55s, electric heating time t c =80s, heating time t d =300s, reaction time t e =420s. The time t for the supply side to reach its target is at this point. s =max(t) a , t b , t c =80s; Time for the response side to reach the target s=12min; therefore, the actual shortest duration s The response time is 12 minutes, which satisfies the constraint of the target duration t1 during the rapid peak shaving phase, thus shortening the response time during the rapid peak shaving phase.

[0129] Furthermore, taking the 6th minute of the rapid peak-shaving process as an example, the bed temperature has entered the target temperature window, but the conversion rate deviation meets the requirements. If the response is determined to be delayed, the control system will coordinately correct the three types of controllable setpoints according to priority, and execute the operation with limited amplitude and speed under safety constraints such as rated power, upper limit of bed pressure, and ramp rate: the electric heating power setpoint will be adjusted accordingly. Increase and prioritize allocation to the main reaction zone to improve the effective heat input and temperature stability of the reaction zone; adjust the inlet gas mass flow rate setpoint. Increase the setpoint to improve gas-solid contact and heat and mass transfer conditions; increase the setpoint for solid feed mass flow rate. The heat load per unit time is appropriately reduced to effectively extend the particle residence time. Through the above online collaborative correction, the conversion rate... Reach and maintain target conversion rate thresholds faster This shortens the reaction time t e This ensures that the overall response time of the thermochemical energy storage system meets the rapid peak shaving requirement for the target duration t1 of the rapid peak shaving phase.

[0130] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for shortening the response time of an energy storage system for rapid peak shaving in coal-fired power units, characterized in that, Includes the following steps: S1. Obtain the operating parameters of the coal-fired unit, including rated load, minimum stable load, original load change rate and target duration t1 of the rapid peak shaving phase, and determine the target output curve of the rapid peak shaving phase. S2. Quantify the factors affecting the target duration t1 of the rapid peak-shaving phase into the supply-side response time parameter t. a t b t c and the response-side time parameter t d t e , where t a For solid feeding time, t b For the gas supply time, t c For electric heating time, t d For the heating time, t e The reaction time is determined, and the constraint relationship between the time parameter and the target duration t1 of the rapid peak-shaving phase is established. S3, for solid feed time t a and gas supply time t b Based on the analytical relationship between the input power of the thermal storage system and the required mass flow rate of calcium carbonate particles and the mass flow rate of inlet carbon dioxide, the mass flow rate of calcium carbonate particles and the mass flow rate of inlet carbon dioxide required to shorten the target duration t1 of the rapid peak shaving stage are obtained. S4, Regarding the electric heating time t c The electric heating arrangement strategy is selected based on the rated power of the electric heater to ensure that the output power of the electric heater reaches the power required for peak shaving. S5, regarding the heating time t d and reaction time t e During the rapid peak shaving phase, the temperature, pressure, and reaction conversion rate at various points in the thermal storage reactor bed are monitored in real time, and online real-time corrections are made based on the heating and reaction status.

2. The method for shortening the response time of an energy storage system for rapid peak shaving of coal-fired power units according to claim 1, characterized in that, S1 specifically includes: collecting the rated load, minimum stable load, original load change rate and target duration t1 of the rapid peak shaving phase of the coal-fired unit, and identifying typical rapid load reduction conditions of the unit by combining grid dispatch instructions or historical operating data of the unit. Based on the identified rapid load reduction conditions, the start and end times, load reduction magnitude, and target equivalent load reduction rate of the rapid peak shaving phase are determined, thereby constructing the target output curve for the rapid peak shaving phase and providing target constraints for subsequently shortening the target duration t1 of the rapid peak shaving phase.

3. The method for shortening the response time of an energy storage system for rapid peak shaving of coal-fired power units according to claim 2, characterized in that, The specific process for determining the target output curve during the rapid peak-shaving phase in S1 includes: Using the unit's rated load as the starting output for the rapid peak-shaving phase and the target minimum output for the rapid peak-shaving phase as the ending output, the duration of the target output curve and the target load reduction rate are determined based on the target duration t1 of the rapid peak-shaving phase, in order to subsequently shorten the solid feed time t. a Gas supply time t b Electric heating time t c Heating time t d and reaction time t e Provide target constraints.

4. The method for shortening the response time of an energy storage system for rapid peak shaving of coal-fired power units according to claim 2, characterized in that, S2 further includes: Determine the solid feeding time t respectively a Gas supply time t b Electric heating time t c Heating time t d and reaction time t e The acquisition or characterization method is used as a constraint on the rate of thermal storage power establishment during the rapid peak shaving phase. Based on the aforementioned constraints, the target duration t1 of the rapid peak shaving phase and the solid feeding time t are established. a Gas supply time t b Electric heating time t c Heating time t d and reaction time t e The constraint relationship between them is used to identify the bottleneck time parameter that limits the shortening of the target duration t1 during the rapid peak shaving phase and serves as the basis for subsequent control strategies; The establishment of the target duration t1 of the rapid peak shaving phase and the solid feeding time t a Gas supply time t b Electric heating time t c Heating time t d and reaction time t e The specific process of establishing the constraint relationship between them includes: Using solid feeding time t a Gas supply time t b and electric heating time t c As a supply-side constraint, the maximum achievable ramp rate for calcium carbonate mass flow rate, inlet carbon dioxide mass flow rate, and electric heating output power to reach the target value from the current value is limited. With heating time t d and reaction time t e As a response-side constraint, it limits the time required for the bed temperature of the thermal storage reactor to enter the decomposition temperature range and for the decomposition reaction to reach the target rate or target conversion rate. By considering both supply-side and response-side constraints, feasible conditions are determined for the thermal storage power to reach the target ramp-up speed during the rapid peak-shaving phase. The maximum time parameter limiting the target ramp-up speed is identified as the bottleneck term, thus obtaining the solid feed time t for the target duration t1 of the rapid peak-shaving phase. a Gas supply time t b Electric heating time t c Heating time t d and reaction time t e A relationship of mutual constraints.

5. The method for shortening the response time of an energy storage system for rapid peak shaving of coal-fired power units according to claim 1, characterized in that, In step S3, the specific process for obtaining the calcium carbonate particle mass flow rate and inlet carbon dioxide mass flow rate required to shorten the target duration t1 of the rapid peak-shaving phase includes: Based on the target output curve determined by S1, the demand curve of the equivalent thermal power required by the thermochemical energy storage system during the rapid peak-shaving phase as a function of time is calculated. Using the analytical relationship between the system input power and the required mass flow rates of calcium carbonate particles and inlet carbon dioxide during the thermal storage process, the system input power demand curve is mapped to the target curves of the calcium carbonate particle mass flow rate and the inlet carbon dioxide mass flow rate. The analytical relationship is as follows: ； ； In the formula, P el The input power of the thermal storage reactor, This represents the mass flow rate of calcium carbonate particles. The temperature at which calcium carbonate particles enter the thermal storage reactor. The temperature of the bed in the thermal storage reactor. (T) represents the isobaric specific heat capacity of calcium carbonate at temperature T, X represents the conversion rate of the heat storage reaction, and ΔH represents... Enthalpy of reaction at temperature This represents the mass flow rate of carbon dioxide. (T) represents the isobaric specific heat capacity of carbon dioxide at temperature T. This represents the apparent density of calcium carbonate particles within the thermal storage reactor. for The density of carbon dioxide at temperature A, where A is the effective cross-sectional area of ​​the thermal storage reactor, and R is the gas constant. This is the molar mass of calcium carbonate. The fluidization rate of carbon dioxide within the thermal storage reactor. This represents the pressure inside the thermal storage reactor.

6. The method for shortening the response time of an energy storage system for rapid peak shaving of coal-fired power units according to claim 1, characterized in that, In step S4, the specific process of making the electric heating output power reach the power required for peak shaving includes: Based on the target output curve determined by S1 and the rapid peak-shaving target t1, the required electric heating power and its power ramp-up rate for the thermochemical energy storage system during the rapid peak-shaving phase are determined, and the target electric heating power curve P is established. el (t), and the electric heating time t c To constrain the process, determine the electric heating device's heating time t. c Achievable power ramping capability under constraints; Based on the rated power and power regulation capability of the electric heater, a layout strategy for the electric heating device is selected. This strategy includes zoned layout and multi-level power module combinations to reduce the power response lag of a single electric heating unit and shorten the electric heating time t. c ; During the rapid peak-shaving phase, the power allocation and power enhancement strategies for each electric heating zone are controlled to ensure that the electric heating output power reaches the target level according to the required electric heating power, thereby preparing for subsequent heating during the heating time t. d and reaction time t e Under constraints, the establishment of effective thermal storage power provides power guarantee for the electric heating side.

7. The method for shortening the response time of an energy storage system for rapid peak shaving in coal-fired power units according to claim 1, characterized in that, In step S5, the specific process of online real-time correction includes: Based on real-time monitoring of temperature, pressure, and reaction conversion rate parameters at various points in the thermal storage reactor bed, and combined with the deviation between the actual and target output curves of the coal-fired unit, the target curves for calcium carbonate particle mass flow rate (S3), inlet carbon dioxide mass flow rate (S4), and electric heating power (S4) are corrected online to shorten the heating time t. d and reaction time t e ; Closed-loop control is used to dynamically adjust the output of the solid feeding device, gas regulating valve and electric heating device, so that the actual mass flow rate of calcium carbonate particles, the actual inlet carbon dioxide mass flow rate and the actual electric heating output power track the target curve.

8. The method for shortening the response time of an energy storage system for rapid peak shaving of coal-fired power units according to claim 1, characterized in that, In step S5, the online real-time correction further includes adjusting the heating time t. d and reaction time t e Quantitative criteria and judgment process: Heating time t d The determination is made by the first criterion that the temperature of each point in the bed of the thermal storage reactor enters the decomposition temperature range and meets the temperature stability requirements. The first criterion includes at least one of the following: the temperature of the representative measuring point of the bed reaches the target temperature threshold, the temperature fluctuation amplitude is less than the set threshold, and the temperature gradient of the upper, middle and lower parts of the bed is less than the set threshold. Reaction time t e The determination is made by a second criterion that the reaction conversion rate reaches the target level. The second criterion includes at least one of the following conditions: the conversion rate reaches and remains at the target threshold due to changes in the composition of the outlet gas, characteristic parameters of the reaction product gas, or material balance back-calculation. The heating time t is calculated online based on the first criterion and the second criterion. d and reaction time t e and the heating time t d and reaction time t e The changing trend serves as the basis for parameter adjustment of the feed controller, gas supply controller, and electric heating power controller: when the heating time t d Or reaction time t e When the estimated value deviates from the target range, the closed-loop control parameters of the solid feeder, gas regulating valve, and electric heater are adjusted online under safety constraints; the safety constraints include the upper limit of bed temperature. Upper limit of bed pressure The rated power and current limit of the electric heater, as well as the maximum ramp rate and minimum stable flow constraints for solid feed and gas supply.

9. The method for shortening the response time of an energy storage system for rapid peak shaving of coal-fired power units according to claim 8, characterized in that, In S5, when the heating process is limited, resulting in a heating time t d When increasing the power, prioritize increasing the electric heating power under safety constraints and coordinate the mass flow rate of calcium carbonate particles and the mass flow rate of inlet carbon dioxide to accelerate the bed into the decomposition temperature range and improve temperature stability. When reaction establishment is limited, resulting in reaction time t e When the reaction rate is increased, the mass flow rate of calcium carbonate particles, the mass flow rate of inlet carbon dioxide, and the electric heating power are synergistically corrected based on the reaction conversion rate or the characteristic parameters of the outlet gas, so that the reaction can reach the target conversion level more quickly.

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