A feedforward predictive control method and device for a wide-load denitrification combined hot water recirculation system

Abstract

This invention discloses a feedforward predictive control method and apparatus for a wide-load denitrification combined hot water recirculation system. The method includes: determining the boiler's operating condition mode based on the acquired real-time boiler load and critical load; determining the working fluid flow direction of the economizer bypass pipe and the hot water recirculation bypass pipe in the combined hot water recirculation system under the operating condition mode to construct an operating condition model; and coordinating the control of the inlet flue gas temperature and economizer outlet subcooling of the combined hot water recirculation denitrification system based on the boiler real-time load, water-cooled wall inlet temperature, economizer bypass pipe water flow rate and hot water recirculation bypass water flow rate in the operating condition model, and the feedforward predictive control model. This technical solution can improve the accuracy and flexibility of inlet flue gas temperature regulation in a wide-load denitrification combined hot water recirculation denitrification system under deep peak shaving, thereby improving the safety and stability of the unit during deep peak shaving, as well as the system operating efficiency, and reducing the difficulty of control operation.

Description

Technical Field

[0001] This invention relates to the field of energy system control technology, and in particular to a feedforward predictive control method and device for a wide-load denitrification combined hot water recirculation system. Background Technology

[0002] Coal-fired power generation is a major form of energy, and coal-fired units are developing towards larger capacity and higher parameters, with supercritical units becoming the mainstream form of future units. In recent years, with the increasing proportion of installed capacity of new energy and other renewable energy sources, their volatility and uncertainty have adversely affected the safe and stable operation of the power grid. Traditional coal-fired units are increasingly shifting from a basic energy source to a regulating energy source, requiring traditional thermal power generating units to have deep peak-shaving capabilities. On the other hand, during deep peak-shaving, the units operate at low loads for extended periods, causing a series of problems, such as: the inability of the denitrification system to operate normally, unstable combustion, inability to guarantee hydrodynamic safety, and limited heating. Among these, the denitrification system has strict temperature requirements, and when the unit operates at low loads, the flue gas temperature cannot adequately meet the temperature window of the denitrification system catalyst, resulting in problems such as the inability of the denitrification system to operate, excessive emissions, and even unit shutdowns, seriously affecting the safe, economical, and stable operation of thermal power units.

[0003] Currently, most research on supercritical unit combined hot water recirculation technology under deep peak shaving focuses on its regulation depth and system flow design, with little research on its control logic. Most studies rely on manual adjustment of flue gas temperature based on operator experience, resulting in high control difficulty and low regulation efficiency. Furthermore, current research often neglects the nonlinearity, delay, and constraints inherent in the coordinated control of economizer water bypass and hot water recirculation bypass in actual flue gas temperature control. Therefore, a feedforward predictive control scheme for supercritical unit combined hot water recirculation is urgently needed to address these technical problems. Summary of the Invention

[0004] In view of this, the present invention provides a feedforward predictive control method and device for a wide-load denitrification combined hot water recirculation system, which can improve the automation level of wide-load denitrification retrofit technology and enhance the accuracy and flexibility of inlet flue gas temperature regulation of the wide-load denitrification combined hot water recirculation denitrification system under deep peak shaving, thereby improving the safety and stability of the unit during deep peak shaving, as well as the system operating efficiency and reducing the difficulty of control operation.

[0005] According to one aspect of the present invention, an embodiment of the present invention provides a feedforward predictive control method for a wide-load denitrification combined hot water recirculation system, the method comprising:

[0006] Obtain the real-time boiler load of the selected supercritical unit, as well as the critical load corresponding to the dry-wet switching condition;

[0007] The operating mode of the boiler is determined based on the real-time load and the critical load, so as to automatically switch the operating mode; wherein, the operating mode includes: dry operation mode and wet operation mode;

[0008] The working fluid flow direction in the economizer bypass pipeline and the hot water recirculation bypass pipeline of the composite hot water recirculation system under the aforementioned operating conditions is determined in order to construct the corresponding operating condition model.

[0009] The inlet temperature of the water-cooled wall is obtained, and based on the real-time load of the boiler, the inlet temperature of the water-cooled wall, the water flow rate of the economizer bypass pipeline and the water flow rate of the hot water recirculation bypass pipeline in the operating condition model, and the pre-built feedforward predictive control model, the inlet flue gas temperature of the composite hot water recirculation denitrification system and the subcooling of the economizer outlet are controlled in a coordinated manner.

[0010] The feedforward predictive control model is constructed based on the working fluid flow direction in the economizer bypass pipeline and the hot water recirculation bypass pipeline corresponding to the operating condition model, as well as the water flow rate in the economizer bypass pipeline and the hot water recirculation bypass pipeline under the working fluid flow direction, through closed-loop simulation experiments.

[0011] According to another aspect of the present invention, embodiments of the present invention also provide a feedforward predictive control device for a wide-load denitrification combined hot water recirculation system, the device comprising:

[0012] The information acquisition module is used to acquire the real-time load of the boiler of the selected supercritical unit, as well as the critical load corresponding to the dry-wet switching condition.

[0013] The operating condition determination module is used to determine the operating condition mode of the boiler based on the real-time load and the critical load of the boiler, so as to automatically switch the operating condition mode; wherein, the operating condition mode includes: dry operating mode and wet operating mode;

[0014] The operation model construction module is used to determine the working fluid flow direction in the economizer bypass pipeline and the hot water recirculation bypass pipeline of the composite hot water recirculation system under the operation mode, so as to construct the corresponding operation mode model.

[0015] The control module is used to acquire the water-cooled wall inlet temperature and, based on the real-time boiler load, the water-cooled wall inlet temperature, the economizer bypass pipeline water flow rate and the hot water recirculation bypass water flow rate in the operating condition model, as well as the pre-built feedforward predictive control model, collaboratively control the inlet flue gas temperature and economizer outlet subcooling of the composite hot water recirculation denitrification system.

[0016] The feedforward predictive control model is constructed based on the working fluid flow direction in the economizer bypass pipeline and the hot water recirculation bypass pipeline corresponding to the operating condition model, as well as the water flow rate in the economizer bypass pipeline and the hot water recirculation bypass pipeline under the working fluid flow direction, through closed-loop simulation experiments.

[0017] According to another aspect of the present invention, embodiments of the present invention also provide an electronic device, the electronic device comprising:

[0018] At least one processor; and

[0019] A memory communicatively connected to the at least one processor; wherein,

[0020] The memory stores a computer program that can be executed by the at least one processor, which enables the at least one processor to perform the feedforward predictive control method for the wide-load denitrification combined hot water recirculation system according to any embodiment of the present invention.

[0021] According to another aspect of the present invention, embodiments of the present invention also provide a computer-readable storage medium storing computer instructions for causing a processor to execute and implement the feedforward predictive control method for a wide-load denitrification combined hot water recirculation system according to any embodiment of the present invention.

[0022] According to another aspect of the present invention, embodiments of the present invention also provide a computer program product, characterized in that the computer program product includes a computer program, which, when executed by a processor, implements the feedforward predictive control method for a wide-load denitrification combined hot water recirculation system as described in any embodiment of the present invention.

[0023] The technical solution described above in this invention determines the boiler's operating condition mode by acquiring the boiler's real-time load and critical load. This determines the working fluid flow direction in the economizer bypass pipe and hot water recirculation bypass pipe of the composite hot water recirculation system under the operating condition mode, and constructs a corresponding operating condition model. Based on the boiler's real-time load, water-cooled wall inlet temperature, economizer bypass pipe water flow rate and hot water recirculation bypass water flow rate in the operating condition model, and a pre-constructed feedforward predictive control model, the inlet flue gas temperature of the composite hot water recirculation denitrification system and the economizer outlet subcooling are coordinated and controlled. This improves the automation level of wide-load denitrification retrofit technology and enhances the accuracy and flexibility of inlet flue gas temperature regulation in the composite hot water recirculation denitrification system under deep peak shaving, thereby improving the safety and stability of the unit during deep peak shaving, as well as system operating efficiency and reducing the difficulty of control operation.

[0024] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0025] 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.

[0026] Figure 1 A flowchart illustrating a feedforward predictive control method for a wide-load denitrification combined hot water recirculation system according to an embodiment of the present invention;

[0027] Figure 2 A flowchart of another feedforward predictive control method for a wide-load denitrification combined hot water recirculation system provided in an embodiment of the present invention;

[0028] Figure 3 This is a schematic diagram of a supercritical unit's composite hot water recirculation system operating in a wet state, according to an embodiment of the present invention.

[0029] Figure 4 This is a schematic diagram of a supercritical unit operating in dry state with combined hot water recirculation, according to an embodiment of the present invention.

[0030] Figure 5 This is a schematic diagram of the architecture of a feedforward predictive control system for a wide-load denitrification combined hot water recirculation system according to an embodiment of the present invention.

[0031] Figure 6 This is a schematic diagram of a feedforward predictive control method for a wide-load denitrification combined hot water recirculation system according to an embodiment of the present invention;

[0032] Figure 7 This is a structural block diagram of a feedforward predictive control device for a wide-load denitrification combined hot water recirculation system provided in an embodiment of the present invention;

[0033] Figure 8 A schematic diagram of the structure of an electronic device provided for implementing embodiments of the present invention. Detailed Implementation

[0034] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. 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 should fall within the scope of protection of the present invention.

[0035] 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 apparatus that comprises 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 apparatus.

[0036] In one embodiment, Figure 1 This is a flowchart of a feedforward predictive control method for a wide-load denitrification combined hot water recirculation system according to an embodiment of the present invention. This embodiment is applicable to the case of feedforward predictive control of a wide-load denitrification combined hot water recirculation system. The method can be executed by a feedforward predictive control device for the wide-load denitrification combined hot water recirculation system, which can be implemented in hardware and / or software.

[0037] like Figure 1 As shown, the method includes:

[0038] S110: Obtain the real-time boiler load of the selected supercritical unit, as well as the critical load corresponding to the dry-wet switching condition.

[0039] The dry-wet switching condition refers to the situation when switching to either a dry or wet operating condition. In this embodiment, the dry-wet switching condition can be determined based on the critical load corresponding to the boiler's dry-wet switching condition, which determines whether it is in dry or wet operation mode. The critical load can be understood as the critical load value for switching between dry and wet operating conditions. This critical load can be given by the boiler's design documents, i.e., it is the boiler's inherent critical load value.

[0040] In this embodiment, the boiler parameters of the selected supercritical unit may include, but are not limited to, the boiler's rated operating conditions and the unit's steam parameters. Since the water-cooled wall temperature may exceed the limit during regulation, to prevent this and ensure the system operates within a safe range—which is the stable operating condition under normal conditions or the design operating condition—this safe range may include, but is not limited to, the optimal reaction temperature range threshold of the denitrification system catalyst, and the minimum and maximum values ​​of the economizer outlet subcooling, used to constrain the economizer outlet subcooling during flue gas temperature control. For example, the optimal reaction temperature range of the unit's denitrification system catalyst can be expressed as: T op.min ≤T op ≤T op.max Among them, T op.min It is the lowest temperature at which the denitrification catalyst can be added to the reaction; T op.max It is the highest temperature at which the denitrification catalyst can be added to the reaction; T op This is the actual operating temperature of the denitrification catalyst. The minimum and maximum constraints of the economizer outlet subcooling can be expressed as δ. min ≤δ≤δ max , where δ min It is the minimum subcooling at the economizer outlet; δ max δ is the maximum value of the economizer outlet subcooling; δ is the actual value of the economizer outlet subcooling during operation. In this embodiment, the economizer is a device installed at the bottom of the boiler tail flue to recover the waste heat of the exhaust gas. The water-cooled wall is the main heat-receiving part of the boiler, which consists of several rows of steel pipes distributed around the boiler furnace.

[0041] In this embodiment, sensors pre-installed at multiple parameter detection points can be used to obtain the real-time load of the selected supercritical unit's boiler. By obtaining the critical load corresponding to the dry-wet switching condition, the operating mode of the boiler can be determined based on the real-time load of the selected supercritical unit's boiler and the critical load corresponding to the dry-wet switching condition.

[0042] S120. Determine the operating mode of the boiler based on the real-time load and critical load of the boiler, and automatically switch the operating mode.

[0043] The operating modes include: dry operating mode and wet operating mode.

[0044] In this embodiment, the boiler's operating mode can be determined by the real-time load of the selected supercritical unit and the critical load corresponding to the dry-wet switching condition, and the operating mode can be automatically switched. In some embodiments, the dry / wet mode can be judged and switched based on the relative magnitude of the critical load corresponding to the dry-wet switching condition and the real-time load signal of the boiler, so as to automatically switch the operating mode. Specifically, the real-time load and critical load of the boiler can be compared to obtain a comparison result, and the operating mode of the boiler can be determined based on the comparison result to automatically switch the operating mode. This can be understood as follows: for a supercritical unit, when the unit is above the critical load to ensure a certain superheat, the unit is in dry operating mode; when the unit is below the critical load, the unit is in wet operating mode. For example, Among them, Q c Represented as critical load; Q r This represents the real-time load of the boiler.

[0045] S130. Determine the working fluid flow direction in the economizer bypass pipeline and the hot water recirculation bypass pipeline of the composite hot water recirculation system under the operating condition mode, so as to construct the corresponding operating condition model.

[0046] In this embodiment, the operating condition model can be understood as a mechanism model under wet or dry operation. This mechanism model includes the working fluid flow directions in the economizer bypass pipe and hot water recirculation bypass pipe of the composite hot water recirculation system under wet operation mode, and the working fluid flow directions in the economizer bypass pipe and hot water recirculation bypass pipe of the composite hot water recirculation system under dry operation mode. It should be noted that the working fluid flow directions in the economizer bypass pipe and hot water recirculation bypass pipe of the composite hot water recirculation system are different under different operating conditions.

[0047] In this embodiment, after determining the boiler's operating mode, the boiler automatically switches to either a dry or wet operating mode. Since the working fluid flow direction differs under different operating modes, a dry operating mode model and a wet operating mode model can be constructed. In this embodiment, the working fluid flow direction in the pipeline differs under different states (dry and wet operation), so it is necessary to first determine whether it is a dry or wet operating state, and then design specific predictive control based on the specific mode.

[0048] In this embodiment, during wet operation, the water flow rate in the economizer water bypass pipeline is regulated by the economizer bypass regulating valve. Hot water in the hot water recirculation bypass pipeline flows out from the steam-water separator storage tank and into the economizer inlet for recirculation. During dry operation, the water flow rate in the economizer water bypass pipeline is regulated by the economizer bypass regulating valve. A dry circulation pipeline is added between the economizer outlet pipeline and the economizer inlet pipeline. A corresponding new economizer regulating valve is added to the dry circulation pipeline. The working fluid flow rate in dry operation mode is regulated by the economizer bypass regulating valve and the new economizer regulating valve. Thus, a mechanism model for wet or dry operation can be constructed based on the working fluid flow direction in the pipeline under different operating conditions.

[0049] S140. Obtain the inlet temperature of the water-cooled wall, and based on the real-time boiler load, the inlet temperature of the water-cooled wall, the water flow rate of the economizer bypass pipe and the hot water recirculation bypass pipe in the operating model, and the pre-built feedforward predictive control model, coordinately control the inlet flue gas temperature of the composite hot water recirculation denitrification system and the subcooling of the economizer outlet.

[0050] The flow rates of the economizer bypass pipeline and the hot water recirculation bypass pipeline are controlled by the economizer bypass regulating valve and the hot water recirculation bypass regulating valve, respectively.

[0051] In this embodiment, the feedforward predictive control model is constructed based on the working fluid flow direction in the economizer bypass pipe and hot water recirculation bypass pipe corresponding to the operating condition model, as well as the water flow rates in the economizer bypass pipe and hot water recirculation bypass pipe under the working fluid flow direction, through closed-loop simulation experiments. This can be understood as follows: the feedforward predictive control model obtains closed-loop operating data of the hot water recirculation SCR denitrification system by conducting closed-loop simulation experiments on the hot water recirculation system using the working fluid flow direction corresponding to the dry-state operating model and the wet-state operating model, as well as the water flow rates in the economizer bypass pipe and hot water recirculation bypass pipe under the working fluid flow direction. This closed-loop operating data is then used to construct the feedforward predictive control model, which is used to control the inlet flue gas temperature and economizer outlet subcooling of the composite hot water recirculation denitrification system. It should be noted that in this embodiment, the boiler's operating mode can be adjusted according to the real-time boiler load, and the working fluid flow direction in the economizer bypass pipe and hot water recirculation bypass pipe of the composite hot water recirculation system under the operating mode can be considered. The real-time boiler load and water-cooled wall inlet temperature are used as feedforward disturbance signals to correct the feedforward predictive control model in real time, thereby increasing the accuracy of the feedforward predictive control model. This can be understood as follows: during the wide-load denitrification control process, the boiler operating mode and composite hot water recirculation operating status need to be adjusted accordingly based on the real-time boiler load signal. Simultaneously, the water-cooled wall inlet temperature cannot be too high or too low during the adjustment process. The real-time boiler load and water-cooled wall inlet temperature are considered as measurable disturbances, which can be used to subsequently correct the feedforward predictive model in real time to increase its accuracy. Specifically, the feedforward disturbance signal is expressed as: v = f(ν s Q r ), where ν s This represents the water-cooled wall inlet temperature disturbance, Q. r This represents the real-time load disturbance of the boiler, where f is represented by ν. s With Q r The mapping relationship between them.

[0052] In some embodiments, a state-space dynamic model corresponding to the hot water recirculation system can be identified using subspace identification methods and closed-loop operation data. This model is used to predict the future behavior of the system. At the current time step, predictions are made using the system model and the current state to obtain the predicted value of the future state. Based on the predicted future state, an optimization problem is constructed, performance indicators and constraints are defined, and numerical optimization methods are used to solve the established optimization problem to obtain the optimal control input sequence. The analytical results of the optimization problem are applied to the system, the first input value of the control input sequence is executed, and the system state is updated to the measurement value of the next time step. The control strategy is continuously updated to achieve optimized control of the system state.

[0053] In this embodiment, the feedforward control model can calculate corresponding control measures by predicting upcoming disturbances. Based on the predicted disturbances or changes in system input, the feedforward controller adjusts the control input to counteract these changes, thereby maintaining the stability of the system output. In this embodiment, the water-cooled wall inlet temperature and the boiler's real-time load are used as feedforward disturbance signals for the feedforward predictive controller. The hot water recirculation loop flow rate and economizer bypass flow rate in the dry-state operating model or the wet-state operating model are transmitted to the feedforward predictive control actuator in the form of commands to coordinate the control of the denitrification system inlet flue gas temperature and the economizer outlet subcooling. This can be understood as follows: the acquired signal, after noise removal and data cleaning, is used as a feedforward measurable disturbance and fed into the predictive control model to correct the composite hot water recirculation model in real time. Then, the hot water recirculation loop flow rate and economizer bypass flow rate under dry conditions, or the hot water recirculation loop flow rate and economizer bypass flow rate under wet conditions, are used as input control quantities and fed into the feedforward predictive control model in the form of instructions for rolling optimization of the input control quantities until the SCR inlet temperature setpoint corresponding to the hot water recirculation loop flow rate and the economizer bypass flow rate are reached. The difference between the economizer outlet subcooling setpoint and the SCR inlet temperature and economizer outlet subcooling output by the feedforward predictive control model is within a preset range. This achieves coordinated control of the inlet flue gas temperature and economizer outlet subcooling of the denitrification system. It can be understood that, given the boiler load, hot water recirculation loop flow rate, and economizer bypass flow rate, the system automatically adjusts the economizer bypass pipe water flow rate and the hot water recirculation bypass water flow rate in the operating condition model, so that the flue gas temperature of the denitrification system can reach above 300℃, enabling the denitrification system to operate stably.

[0054] The technical solution described above in this invention determines the boiler's operating condition mode by acquiring the boiler's real-time load and critical load. This determines the working fluid flow direction in the economizer bypass pipe and hot water recirculation bypass pipe of the composite hot water recirculation system under the operating condition mode, and constructs a corresponding operating condition model. Based on the boiler's real-time load, water-cooled wall inlet temperature, economizer bypass pipe water flow rate and hot water recirculation bypass water flow rate in the operating condition model, and a pre-constructed feedforward predictive control model, the inlet flue gas temperature of the composite hot water recirculation denitrification system and the economizer outlet subcooling are coordinated and controlled. This improves the automation level of wide-load denitrification retrofit technology and enhances the accuracy and flexibility of inlet flue gas temperature regulation in the composite hot water recirculation denitrification system under deep peak shaving, thereby improving the safety and stability of the unit during deep peak shaving, as well as system operating efficiency and reducing the difficulty of control operation.

[0055] In one embodiment, Figure 2This is a flowchart of another feedforward predictive control method for a wide-load denitrification combined hot water recirculation system provided by an embodiment of the present invention. Based on the above embodiments, this embodiment further refines the following: determining the boiler's operating mode according to the boiler's real-time load and critical load to automatically switch the operating mode; determining the working fluid flow direction in the economizer bypass pipe and hot water recirculation bypass pipe of the combined hot water recirculation system under the operating mode to construct a corresponding operating mode model; and further refining the collaborative control of the inlet flue gas temperature and economizer outlet subcooling of the combined hot water recirculation denitrification system based on the boiler's real-time load, water-cooled wall inlet temperature, economizer bypass pipe water flow rate and hot water recirculation bypass water flow rate in the operating mode model, and the pre-constructed feedforward predictive control model.

[0056] like Figure 2 As shown, the feedforward predictive control method for the wide-load denitrification combined hot water recirculation system in this embodiment may specifically include the following steps:

[0057] S210: Obtain the real-time boiler load of the selected supercritical unit, as well as the critical load corresponding to the dry-wet switching condition.

[0058] S220, under the boiler real-time load Q r Less than the critical load Q c In this case, if the boiler is determined to be in wet operation mode, it will automatically switch to wet operation.

[0059] In this embodiment, the boiler's real-time load is compared with the critical load. If the real-time load is less than the critical load, the boiler's operating mode is determined to be wet operation mode, and it automatically switches to wet operation. That is, at the critical load Q... c Greater than the boiler real-time load signal Q r In certain situations, it will automatically switch to wet operation mode.

[0060] S230. When the boiler's real-time load is greater than or equal to the critical load, determine that the boiler's operating condition mode is dry operation mode and automatically switch to dry operation.

[0061] In this embodiment, when the boiler's real-time load is greater than or equal to the critical load, the boiler's operating mode is determined to be dry operation mode, and it automatically switches to dry operation, i.e., at the critical load Q. c Less than or equal to the boiler real-time load signal Q r In such cases, it will automatically switch to dry operation mode.

[0062] S240. In wet operation mode, the water flow rate of the economizer water bypass pipeline is regulated by the economizer bypass regulating valve. Hot water in the hot water recirculation bypass pipeline flows out from the water storage tank of the steam-water separator and flows into the economizer inlet for recirculation. The working fluid flow direction in wet operation mode forms a wet operation condition model.

[0063] In this embodiment, during wet operation, the water flow rate in the economizer bypass pipeline is regulated by the economizer bypass regulating valve. Hot water in the hot water recirculation bypass pipeline flows out from the steam-water separator storage tank and into the economizer inlet for recirculation. This constitutes the working fluid flow direction in the wet operation mode, forming the wet operating condition model. This can be understood as follows: during boiler wet operation, the bypass water flow rate is regulated by the bypass regulating valve, and hot water in the recirculation pipeline flows out from the steam-water separator storage tank and into the economizer inlet for circulation, increasing the economizer inlet water temperature, reducing the heat exchange of flue gas in the economizer, and increasing the inlet flue gas temperature of the denitrification system.

[0064] In this embodiment, to facilitate a better understanding of the wet operation mode, Figure 3 This is a schematic diagram of a supercritical unit's composite hot water recirculation system operating in a wet state, according to an embodiment of the present invention. Figure 3 The text omits equipment such as flow meters and check valves on the pipeline. Figure 3 The blue and orange dashed lines represent the working fluid flow directions of the economizer water bypass and hot water circulation bypass, respectively. It's worth noting that during wet boiler operation, the bypass water flow rate is regulated by a bypass regulating valve. Hot water in the recirculation pipeline flows from the steam-water separator storage tank into the economizer inlet for circulation, increasing the economizer inlet water temperature. This reduces the heat exchange of flue gas in the economizer and increases the inlet flue gas temperature of the denitrification system.

[0065] In this embodiment, the flow direction of the simple water bypass is the same in both dry and wet states. However, the flow direction is different for the hot water recirculation boiler. In the wet state, the hot water in the recirculation pipeline flows out from the water storage tank of the steam-water separator. In the dry state, an additional dry circulation pipeline is added, which connects to the economizer inlet pipeline from the economizer outlet pipeline.

[0066] S250. In dry operation mode, the water flow rate of the economizer water bypass pipeline is regulated by the economizer bypass regulating valve. A dry circulation pipeline is added between the economizer outlet pipeline and the economizer inlet pipeline. A corresponding new economizer regulating valve is added to the dry circulation pipeline. The working fluid flow rate in dry operation mode is regulated by the economizer bypass regulating valve and the new economizer regulating valve. The working fluid flow direction in dry operation mode is used to form a dry operation condition model.

[0067] In this embodiment, under dry operation mode, the water flow rate in the economizer bypass pipeline is regulated by the economizer bypass regulating valve. A dry circulation pipeline is added between the economizer outlet pipeline and the economizer inlet pipeline, and a corresponding new economizer regulating valve is added to the dry circulation pipeline. The working fluid flow rate under dry operation mode is regulated by the economizer bypass regulating valve and the new economizer regulating valve, and the working fluid flow direction under dry operation mode forms a dry operating condition model. This can be understood as follows: when the boiler is operating in dry mode, due to the change in the working fluid flow state, the recirculation pipeline differs from the wet recirculation pipeline. Therefore, an additional dry circulation pipeline needs to be added from the economizer outlet pipeline to the economizer inlet pipeline. A corresponding regulating valve needs to be added to the newly added pipeline to regulate the working fluid flow rate under dry conditions, while the economizer bypass pipeline does not require significant modification.

[0068] In this embodiment, to facilitate a better understanding of the wet operation mode, Figure 4 This is a schematic diagram of a supercritical unit operating in dry state with combined hot water recirculation, according to an embodiment of the present invention. Figure 4 Similarly, flow meters, check valves, and other equipment on the pipeline are omitted. The blue and orange dashed lines represent the working fluid flow directions of the economizer water bypass and hot water circulation bypass, respectively. When the boiler is running in dry state, due to the change in the working fluid flow state, the recirculation pipeline is different from the wet recirculation pipeline. It is necessary to add a dry circulation pipeline from the economizer outlet pipeline to the economizer inlet pipeline. In the newly added pipeline, a corresponding regulating valve needs to be added to regulate the working fluid flow in the dry state. The economizer bypass pipeline does not need much modification.

[0069] S260. Obtain the water-cooled wall inlet temperature and use the real-time boiler load and water-cooled wall inlet temperature as the feedforward disturbance signal of the feedforward predictive control model.

[0070] In this embodiment, the water-cooled wall inlet temperature is acquired, and the real-time boiler load and water-cooled wall inlet temperature are used as feedforward perturbation signals input to the feedforward predictive control model. The feedforward perturbation signal is expressed as: v = f(ν) s Q r ), where ν s This represents the water-cooled wall inlet temperature disturbance, Q. r This represents the real-time load disturbance of the boiler, where f is represented by ν. s With Q r The mapping relationship between them. In this embodiment, during the boiler wide-load denitrification control process, it is necessary to base the real-time load signal Q of the boiler on the mapping relationship between them. rThe boiler operation mode and the combined hot water recirculation operation status are adjusted accordingly. At the same time, the water-cooled wall inlet temperature should not be too high or too low during the adjustment process. This control strategy regards the water-cooled wall inlet temperature and the real-time load signal of the boiler as measurable disturbances, which are used to correct the feedforward prediction model in real time to increase the accuracy of the prediction model.

[0071] S270. The hot water recirculation loop flow rate and economizer bypass flow rate in the dry-state operating model or the wet-state operating model are used as input control quantities and sent to the feedforward predictive control model in the form of instructions for rolling optimization of input control quantities until the difference between the SCR inlet temperature setpoint corresponding to the hot water recirculation loop flow rate and the economizer outlet subcooling setpoint corresponding to the economizer bypass flow rate and the SCR inlet temperature and economizer outlet subcooling output by the feedforward predictive control model is within the preset range, thereby achieving coordinated control of the inlet flue gas temperature and economizer outlet subcooling of the denitrification system.

[0072] The operating condition model includes a dry operating condition model and a wet operating condition model.

[0073] In this embodiment, the real-time boiler load and water-cooled wall inlet temperature are used as feedforward disturbance signals for the feedforward predictive control model, which are output to the feedforward predictive control module for correction. The hot water recirculation loop flow rate and economizer bypass flow rate in the dry-state operating model are used as input control quantities, or the hot water recirculation loop flow rate and economizer bypass flow rate in the wet-state operating model are used as input control quantities, which are sent to the feedforward predictive control model in the form of instructions for rolling optimization of input control quantities until the difference between the SCR inlet temperature setpoint corresponding to the hot water recirculation loop flow rate and the economizer outlet subcooling setpoint corresponding to the economizer bypass flow rate and the SCR inlet temperature and economizer outlet subcooling output by the feedforward predictive control model is within a preset range, thereby achieving coordinated control of the inlet flue gas temperature and economizer outlet subcooling of the denitrification system.

[0074] In this embodiment, the construction of the feedforward predictive control model includes: obtaining closed-loop operation data of the hot water recirculation SCR denitrification system by conducting closed-loop simulation experiments based on the working fluid flow direction in the economizer bypass pipeline and the hot water recirculation bypass pipeline corresponding to the dry-state operation model and the wet-state operation model included in the operating condition model, as well as the water flow rate in the economizer bypass pipeline and the water flow rate in the hot water recirculation bypass pipeline under the working fluid flow direction; initializing the inlet flue gas temperature and economizer outlet subcooling of the hot water recirculation SCR denitrification system, and constructing a feedforward predictive control model based on the inlet flue gas temperature, economizer outlet subcooling, and closed-loop operation data of the hot water recirculation SCR denitrification system.

[0075] More specifically, a feedforward predictive control model is constructed based on the inlet flue gas temperature of the SCR denitrification system, the economizer outlet subcooling, and closed-loop operation data. This includes: identifying the state-space dynamic model corresponding to the hot water recirculation system using a subspace identification method and closed-loop operation data; obtaining the incremental model corresponding to the hot water recirculation system based on a predefined control increment and the state-space dynamic model; acquiring the characteristic matrix coefficients corresponding to the hot water recirculation system and constructing an augmented model corresponding to the hot water recirculation system based on the incremental model and the characteristic matrix coefficients; setting the prediction step size as p and the control step size as m, and deriving the target state variables and target output variables of the hot water recirculation SCR denitrification system using the augmented model; wherein the prediction step size is greater than the control step size; constructing an optimization objective function for the target optimization problem based on the target state variables and target output variables; optimizing the optimization objective function using a rolling optimization method to obtain the optimized feedforward predictive control function, which is then used as the feedforward predictive control model.

[0076] In this embodiment, the subspace identification method is a subspace identification algorithm in the prior art, which mainly includes three steps. The first step is to calculate the row space projection of the input and output data matrix. The typical approach to this step is to perform QR decomposition. The second step is to perform singular value decomposition on the projection result to obtain the system order, observable matrix and Kalman estimation under the state sequence. Finally, the characteristic matrix coefficients A, B, C, D and the noise covariance matrix corresponding to the hot water recirculation system are determined through the observable matrix and Kalman estimation under the state sequence.

[0077] In this embodiment, conducting a closed-loop simulation experiment can be understood as a learning process, adjusting the bypass pipe flow rate W through experiments. e and recirculation pipeline flow rate W r One or two of them are used to observe the economizer outlet subcooling δ and the denitrification inlet flue gas temperature T. e The process involves monitoring increases or decreases in the bypass flow rate W and analyzing the correlation between them. This can be understood as allowing the feedforward predictive control model to learn, after which it can be directly applied to automatically and appropriately adjust the bypass flow rate W based on the situation. e and recirculation pipeline flow rate W r The proportion in the middle ensures that the controlled quantity meets the requirements.

[0078] In one embodiment, the state-space dynamic model is expressed by the formula: Wherein, λ(k) represents the state variable of the hot water recirculation denitrification system at time k, and λ(k+1) represents the state variable of the hot water recirculation denitrification system at time k+1; u(k) represents the input variable of the hot water recirculation denitrification system at time k, which is characterized by the hot water recirculation bypass water flow rate and the economizer bypass pipeline water flow rate; y(k) represents the output variable of the hot water recirculation denitrification system at time k, which is characterized by the inlet flue gas temperature of the hot water recirculation denitrification system and the economizer outlet subcooling degree; v(k) represents the feedforward disturbance signal at time k, which is characterized by the real-time boiler load and the water-cooled wall inlet temperature; A, B, C, and D all represent the characteristic matrix coefficients corresponding to the hot water recirculation system.

[0079] In one embodiment, the predefined control increment formula is expressed as: Where Δλ(k+1) represents the incremental form of the defined λ(k+1); Δu(k) represents the incremental form of the defined u(k), u(k-1) represents the input variable of the hot water recirculation denitrification system at time k-1; Δv(k) represents the incremental form of the defined v(k), v(k-1) represents the feedforward disturbance signal at time k-1; the incremental model is expressed by the formula: Where Δλ(k+1) represents the incremental state variable of the hot water recirculation denitrification system at time k+1; Δy(k) represents the incremental output variable of the hot water recirculation denitrification system at time k, and the output variable is characterized by the inlet flue gas temperature and the economizer outlet subcooling of the hot water recirculation denitrification system; the augmented model is expressed by the formula: In the formula, Let y(k) represent the augmented state variable of the hot water recirculation denitrification system at time k+1, and let y(k) represent the augmented output variable of the hot water recirculation denitrification system at time k. in, and These represent the augmented coefficients of the characteristic matrix coefficients A, B, C, and D, respectively; O represents the all-zero matrix, and I represents the identity matrix; Let k represent the augmented state variable of the hot water recirculation denitrification system at time k; the relationship between the target output variable and the target state variable is expressed by the formula: Where y(k+p) represents the output variable of the hot water recirculation denitrification system at time k+p, and p represents the prediction step size; ΔU represents the input increment sequence of the hot water recirculation denitrification system. These are respectively represented as the matrix coefficients in the target output variables, where, m represents the control step size, p represents the prediction step size, and i represents a variable.

[0080] In one embodiment, the objective function aims to minimize the errors between the SCR denitrification system inlet temperature setpoint and the economizer outlet subcooling setpoint and the SCR inlet temperature and economizer outlet subcooling output by the feedforward predictive controller model, respectively. The constraints corresponding to the objective function include at least: controlled variable constraints and control variable constraints. The controlled variable constraints include: upper and lower limit constraints on the flue gas inlet temperature of the denitrification system and upper and lower limit constraints on the economizer outlet subcooling. The control variable constraints include: working fluid flow constraints in the hot water recirculation loop and economizer bypass water flow constraints.

[0081] The optimization objective function in this embodiment is expressed by the formula: J = (Y o -Y k ) T Q f (Y o -Y k )+ΔU T R f ΔU, where Y o The setpoint matrix represents the controlled variable matrix, which is a matrix of flue gas inlet temperature setpoint and economizer outlet subcooling setpoint for the denitrification system; Y k Let ΔU represent the sequence of output variables under the prediction step size, where the output variables represent the inlet flue gas temperature of the hot water recirculation denitrification system and the outlet subcooling of the economizer; let ΔU represent the sequence of input increments of the hot water recirculation denitrification system, where the input variables represent the working fluid flow rate of the hot water recirculation loop and the economizer bypass water flow rate; ΔU T Let Q be the transpose of ΔU. f R represents the error weight matrix; f Here is the control weight matrix; the constraints of the objective function are expressed as follows: Where, Δu min and Δu max Let u represent the minimum and maximum increments of the hot water recirculation bypass water flow and the economizer bypass water flow, respectively. min and u max Let y represent the minimum and maximum values ​​of the hot water recirculation bypass water flow rate and the economizer bypass water flow rate, respectively. min and y max These represent the minimum and maximum values ​​of the inlet flue gas temperature and the economizer outlet subcooling of the hot water recirculation denitrification system, respectively.

[0082] In actual operation and control, flow regulation is achieved through valve opening. When controlling the inlet flue gas temperature and economizer outlet superheat by adjusting the recirculation pipeline flow and economizer water bypass flow, a certain delay effect occurs due to the time required for heat exchange between the working fluid and flue gas. Therefore, valve opening cannot be changed frequently or rapidly. Simultaneously, upper and lower limit constraints need to be set for the bypass water flow and recirculation loop water flow in the controlled variables, and for the controlled variables, the inlet temperature and subcooling of the denitrification system flue gas, to ensure the safe and stable operation of the actual system.

[0083] The above-mentioned technical solution in this embodiment uses the real-time boiler load and water-cooled wall inlet temperature as feedforward disturbance signals for the feedforward predictive control model, and the hot water recirculation loop flow rate and economizer bypass flow rate as input control quantities. These are then transmitted to the feedforward predictive control model in the form of instructions for rolling optimization of the input control quantities until the difference between the SCR inlet temperature setpoint corresponding to the hot water recirculation loop flow rate and the economizer outlet subcooling setpoint corresponding to the economizer bypass flow rate and the SCR inlet temperature and economizer outlet subcooling output by the feedforward predictive control model is within a preset range. This achieves coordinated control of the inlet flue gas temperature and economizer outlet subcooling of the denitrification system, which can further improve the automation level of wide-load denitrification retrofit technology and enhance the accuracy and flexibility of inlet flue gas temperature regulation of the wide-load denitrification composite hot water recirculation denitrification system under deep peak shaving. This improves the safety and stability of the unit during deep peak shaving, as well as the system operating efficiency and reduces the difficulty of control operation.

[0084] In one embodiment, to facilitate a better understanding of the feedforward predictive control method for a wide-load denitrification combined hot water recirculation system, Figure 5 This is a schematic diagram of the feedforward predictive control architecture of a wide-load denitrification combined hot water recirculation system according to an embodiment of the present invention.

[0085] In this embodiment, both dry and wet operation essentially regulate the flue gas temperature of the SCR system and the subcooling at the economizer outlet through the flow rates in the hot circulation pipeline and the economizer bypass. The difference lies in the different states of the working fluid and the different corresponding circulation loop pipelines in the two situations. The physical meanings of the relevant variables corresponding to the control strategy are detailed in Table 1.

[0086] like Figure 5 As shown, the real-time load Q of the boiler is... r and the water-cooled wall inlet temperature T w As a disturbance signal for the feedforward predictive control model, the bypass pipe flow rate W is adjusted. e and recirculation pipeline flow rate W r This makes the inlet smoke temperature T e Above 300.

[0087] In this embodiment, the setpoints for the SCR denitrification inlet flue gas temperature and the economizer inlet subcooling can be understood as stable values ​​within a safe range. These values ​​need to be adjusted, for example, when a power plant reduces load, the real-time temperature will differ from the setpoint temperature. Figure 5 In this system, the feedforward predictive controller is followed by an inlet temperature and an outlet subcooling, both of which are real-time. The setpoints for the SCR denitrification inlet flue gas temperature and the economizer inlet subcooling are also real-time. To minimize the difference between the real-time values ​​and the setpoints, the feedforward predictive controller is needed to control the inlet temperature and outlet subcooling to a reasonable range, meaning the deviation between the setpoints and the outlet subcooling should gradually decrease. The control method involves using the boiler's real-time load and the water-cooled wall inlet temperature as feedforward disturbance signals for the feedforward predictive control model. The economizer bypass water flow and the recirculation loop water flow are input to the feedforward predictive controller in an actuated form to adjust these flow rates, minimizing the difference. For example... Figure 4 Dry operation: We is the flow rate of the simple water bypass. The essential method is to regulate the opening θ of the economizer bypass valve via the blue valve. e The flow rate is controlled by adjusting the valves; (for example, reducing the flow rate will cause the economizer to absorb some heat and the temperature to rise), and the recirculation pipeline flow rate W r .

[0088] Table 1: Physical meaning of the relevant variables corresponding to the control strategy

[0089]

[0090] In one embodiment, to facilitate a better understanding of the feedforward predictive control method for a wide-load denitrification combined hot water recirculation system, Figure 6 This is a schematic diagram of a feedforward predictive control method for a wide-load denitrification combined hot water recirculation system provided in an embodiment of the present invention.

[0091] like Figure 6 As shown, the specific feedforward predictive control method for a wide-load denitrification combined hot water recirculation system includes the following steps:

[0092] a1. Obtain initial unit parameters and unit operation constraint parameters.

[0093] The initial unit parameters include the critical load Q corresponding to the boiler's dry-wet switching condition. cThe constraints for unit operation include at least the following: the economizer outlet subcooling threshold, which includes the minimum and maximum economizer outlet subcooling values; the denitrification system inlet flue gas temperature threshold, which includes the minimum and maximum temperatures at which the denitrification catalyst can be introduced into the reaction; the minimum and maximum values ​​corresponding to the hot water recirculation bypass water flow rate and the economizer bypass water flow rate, respectively; and the minimum and maximum increment values ​​corresponding to the hot water recirculation bypass water flow rate and the economizer bypass water flow rate, respectively.

[0094] a2. Obtain the real-time boiler load Q r Based on the real-time load of the boiler, the dry / wet mode of the boiler is determined, and the boiler state is automatically switched in real time to build a dry / wet system model.

[0095] a3. During dry / wet operation, the dry / wet thermal circulation pipeline is automatically switched, the dry / wet thermal circulation pipeline is put into operation, the economizer bypass pipeline is put into operation, and a dry / wet mechanism model is constructed.

[0096] a4. Based on the working fluid flow direction corresponding to the dry / wet mechanism model, and the water flow rate of the economizer bypass pipeline and the hot water recirculation bypass pipeline under the working fluid flow direction, a closed-loop simulation experiment was conducted on the hot water recirculation system to obtain the closed-loop operation data of the hot water recirculation SCR denitrification system.

[0097] a5. Initialize the inlet flue gas temperature and economizer outlet subcooling of the hot water recirculation SCR denitrification system, and construct a feedforward predictive control model based on the inlet flue gas temperature, economizer outlet subcooling, and closed-loop operation data of the hot water recirculation SCR denitrification system.

[0098] a6. Obtain the water-cooled wall inlet temperature, and use the water-cooled wall inlet temperature and the boiler real-time load signal as feedforward to the prediction model. Send the hot water recirculation loop flow and the economizer bypass flow in the form of instructions to the feedforward predictive control actuator to coordinate the control of the inlet flue gas temperature of the denitrification system and the subcooling of the economizer outlet.

[0099] In this embodiment, a feedforward control strategy for composite hot water recirculation under deep regulation of supercritical units is considered. By taking into account factors such as water-cooled wall inlet temperature fluctuations and real-time boiler heat load during actual operation, these are treated as measurable disturbances and used as feedforwards to correct the prediction model in real time, thereby improving the model accuracy. By controlling the economizer bypass regulating valve and the hot water circulation bypass regulating valve to change the water bypass and circulation bypass water flow, the automatic regulation of the flue gas temperature at the denitrification system inlet and the subcooling at the economizer outlet is achieved by utilizing the coupling relationship between them, thereby improving the overall automation level of the system. This has profound significance for achieving deep peak shaving and safe and stable operation of supercritical units.

[0100] In one embodiment, Figure 7 This is a structural block diagram of a feedforward predictive control device for a wide-load denitrification combined hot water recirculation system according to an embodiment of the present invention. This device is suitable for feedforward predictive control of a wide-load denitrification combined hot water recirculation system and can be implemented in hardware or software. Figure 7 As shown, the device includes: an information acquisition module 710, a working condition determination module 720, an operation model construction module 730, and a control module 740.

[0101] The information acquisition module 710 is used to acquire the real-time load of the selected supercritical unit's boiler and the critical load corresponding to the dry-wet switching condition.

[0102] The operating condition determination module 720 is used to determine the operating condition mode of the boiler based on the real-time load and the critical load of the boiler, so as to automatically switch the operating condition mode; wherein, the operating condition mode includes: dry operating mode and wet operating mode.

[0103] The operation model construction module 730 is used to determine the working fluid flow direction in the economizer bypass pipeline and the hot water recirculation bypass pipeline in the composite hot water recirculation system under the operation mode, so as to construct the corresponding operation mode model.

[0104] The control module 740 is used to acquire the water-cooled wall inlet temperature and, based on the real-time boiler load, the water-cooled wall inlet temperature, the economizer bypass pipeline water flow rate and the hot water recirculation bypass water flow rate in the operating condition model, and the pre-built feedforward predictive control model, collaboratively control the inlet flue gas temperature and economizer outlet subcooling of the composite hot water recirculation denitrification system.

[0105] The feedforward predictive control model is constructed based on the working fluid flow direction in the economizer bypass pipeline and the hot water recirculation bypass pipeline corresponding to the operating condition model, as well as the water flow rate in the economizer bypass pipeline and the hot water recirculation bypass pipeline under the working fluid flow direction, through closed-loop simulation experiments.

[0106] In this embodiment, the operating model construction module constructs a corresponding operating model based on the working fluid flow direction of the economizer bypass pipe and the hot water recirculation bypass pipe in the composite hot water recirculation system under the operating condition mode. Therefore, the control module, based on the boiler's real-time load, water-cooled wall inlet temperature, economizer bypass pipe water flow rate and hot water recirculation bypass water flow rate in the operating model, and the feedforward predictive control model, collaboratively controls the inlet flue gas temperature and economizer outlet subcooling of the composite hot water recirculation denitrification system. This improves the automation level of the wide-load denitrification retrofit technology and enhances the accuracy and flexibility of inlet flue gas temperature regulation in the composite hot water recirculation denitrification system under deep peak shaving, thereby improving the safety and stability of the unit during deep peak shaving, as well as system operating efficiency, and reducing the difficulty of control operation.

[0107] In one embodiment, the operating condition determination module 720 includes:

[0108] The wet operation unit is used to determine that the boiler is in a wet operation mode when the real-time load of the boiler is less than the critical load, and automatically switch to wet operation.

[0109] The dry operation unit is used to determine that the boiler is in a dry operation mode when the real-time load of the boiler is greater than or equal to the critical load, and to automatically switch to dry operation.

[0110] In one embodiment, the running model building module 730 includes:

[0111] The wet state model construction unit is used to adjust the water flow rate of the economizer water bypass pipeline through the economizer bypass regulating valve during the wet state operation mode. The hot water in the hot water recirculation bypass pipeline flows out from the water storage tank of the steam-water separator and flows into the economizer inlet for recirculation. The working fluid flow direction in the wet state operation mode is used to form a wet state operating condition model.

[0112] The dry-state model construction unit is used to regulate the water flow rate of the economizer water bypass pipeline through the economizer bypass regulating valve under the dry-state operation mode, and to add a dry-state circulation pipeline between the economizer outlet pipeline and the economizer inlet pipeline, add a corresponding new economizer regulating valve to the dry-state circulation pipeline, regulate the working fluid flow rate under the dry-state operation mode through the economizer bypass regulating valve and the new economizer regulating valve, and form a dry-state operating condition model by combining the working fluid flow direction under the dry-state operation mode.

[0113] In one embodiment, the construction of the feedforward predictive control model includes:

[0114] Based on the working fluid flow direction in the economizer bypass pipeline and hot water recirculation bypass pipeline corresponding to the dry and wet operating models included in the operating model, as well as the water flow rate in the economizer bypass pipeline and the water flow rate in the hot water recirculation bypass pipeline under the working fluid flow direction, a closed-loop simulation experiment was conducted to obtain the closed-loop operation data of the hot water recirculation SCR denitrification system.

[0115] Initialize the inlet flue gas temperature and economizer outlet subcooling of the hot water recirculation SCR denitrification system, and construct a feedforward predictive control model based on the inlet flue gas temperature of the hot water recirculation SCR denitrification system, the economizer outlet subcooling, and the closed-loop operation data.

[0116] In one embodiment, the step of constructing a feedforward predictive control model based on the inlet flue gas temperature of the SCR denitrification system, the outlet subcooling of the economizer, and the closed-loop operation data includes:

[0117] The state-space dynamic model of the hot water recirculation system is obtained by using the subspace identification method and closed-loop operation data.

[0118] Based on the predefined control incremental formula and the state-space dynamic model, the incremental model corresponding to the hot water recirculation system is obtained;

[0119] Obtain the characteristic matrix coefficients corresponding to the hot water recirculation system, and construct an augmented model corresponding to the hot water recirculation system based on the incremental model and the characteristic matrix coefficients;

[0120] The prediction step size is set to p, and the control step size is set to m. The target state variables and target output variables of the hot water recirculation SCR denitrification system are derived using the augmented model. The prediction step size is greater than the control step size.

[0121] An optimization objective function is constructed based on the target state variables and the target output variables to address the target optimization problem. The objective function aims to minimize the errors between the SCR denitrification system inlet temperature setpoint and the economizer outlet subcooling setpoint and the SCR inlet temperature and economizer outlet subcooling output by the feedforward predictive controller model, respectively. The constraints corresponding to the objective function include at least: controlled variable constraints and control variable constraints. The controlled variable constraints include: upper and lower limits of the denitrification system flue gas inlet temperature and upper and lower limits of the economizer outlet subcooling. The control variable constraints include: working fluid flow rate constraints in the hot water recirculation loop and economizer bypass water flow rate constraints.

[0122] The objective function is optimized using a rolling optimization method to obtain the optimized feedforward predictive control function, which is then used as the feedforward predictive control model.

[0123] In one embodiment, the state-space dynamic model is expressed by the formula: Wherein, λ(k) represents the state variable of the hot water recirculation denitrification system at time k, and λ(k+1) represents the state variable of the hot water recirculation denitrification system at time k+1; u(k) represents the input variable of the hot water recirculation denitrification system at time k, which is characterized by the hot water recirculation bypass water flow rate and the economizer bypass pipeline water flow rate; y(k) represents the output variable of the hot water recirculation denitrification system at time k, which is characterized by the inlet flue gas temperature of the hot water recirculation denitrification system and the economizer outlet subcooling degree; v(k) represents the feedforward disturbance signal at time k, which is characterized by the real-time boiler load and the water-cooled wall inlet temperature; A, B, C, and D all represent the characteristic matrix coefficients corresponding to the hot water recirculation system;

[0124] The predefined control increment formula is expressed as follows: Wherein, Δλ(k+1) represents the incremental form of the defined λ(k+1); Δu(k) represents the incremental form of the defined u(k), u(k-1) represents the input variable of the hot water recirculation denitrification system at time k-1; Δv(k) represents the incremental form of the defined v(k), v(k-1) represents the feedforward disturbance signal at time k-1;

[0125] The incremental model is expressed by the formula: Wherein, Δλ(k+1) represents the incremental state variable of the hot water recirculation denitrification system at time k+1; Δy(k) represents the incremental output variable of the hot water recirculation denitrification system at time k, and the output variable is characterized by the inlet flue gas temperature and the economizer outlet subcooling of the hot water recirculation denitrification system.

[0126] The augmentation model is expressed by the following formula: In the formula, Let y(k) represent the augmented state variable of the hot water recirculation denitrification system at time k+1, and let y(k) represent the augmented output variable of the hot water recirculation denitrification system at time k. in, and These represent the augmented coefficients of the characteristic matrix coefficients A, B, C, and D, respectively; O represents the all-zero matrix, and I represents the identity matrix; Let k be the augmented state variable of the hot water recirculation denitrification system at time k;

[0127] The relationship between the target output variable and the target state variable is expressed by the formula: Where y(k+p) represents the output variable of the hot water recirculation denitrification system at time k+p, and p represents the prediction step size; ΔU represents the input increment sequence of the hot water recirculation denitrification system. These are respectively represented as the matrix coefficients in the target output variables, where, m represents the control step size, p represents the prediction step size, and i represents a variable.

[0128] In one embodiment, the optimization objective function is expressed by the formula:

[0129] J = (Y o -Y k ) T Q f (Y o -Y k )+ΔU T R f ΔU, where Y o The setpoint matrix represents the controlled variable matrix, which is a matrix of flue gas inlet temperature setpoint and economizer outlet subcooling setpoint for the denitrification system; Y k ΔU represents the sequence of output variables under the prediction step size, where the output variables represent the inlet flue gas temperature of the hot water recirculation denitrification system and the subcooling at the economizer outlet; ΔU represents the sequence of input increments of the hot water recirculation denitrification system, where the input variables represent the working fluid flow rate of the hot water recirculation loop and the economizer bypass water flow rate; ΔU T Let Q be the transpose of ΔU. f R represents the error weight matrix; f The control weight matrix;

[0130] The constraints of the optimization objective function are expressed as follows: Where, Δu min and Δu max Let u represent the minimum and maximum increments of the hot water recirculation bypass water flow and the economizer bypass water flow, respectively. min and u max Let y represent the minimum and maximum values ​​of the hot water recirculation bypass water flow rate and the economizer bypass water flow rate, respectively. min and y max These represent the minimum and maximum values ​​of the inlet flue gas temperature and the economizer outlet subcooling of the hot water recirculation denitrification system, respectively.

[0131] In one embodiment, the control module 740 includes:

[0132] The disturbance signal determination unit is used to take the real-time load of the boiler and the inlet temperature of the water-cooled wall as the feedforward disturbance signal of the feedforward predictive control model.

[0133] The control unit is used to take the hot water recirculation loop flow rate and economizer bypass flow rate in the dry-state operating model or the wet-state operating model as input control quantities, and send them to the feedforward predictive control model in the form of instructions for rolling optimization of the input control quantities until the difference between the SCR inlet temperature setpoint corresponding to the hot water recirculation loop flow rate and the economizer outlet subcooling setpoint corresponding to the economizer bypass flow rate and the SCR inlet temperature and economizer outlet subcooling output by the feedforward predictive control model is within a preset range, thereby achieving coordinated control of the inlet flue gas temperature and economizer outlet subcooling of the denitrification system.

[0134] In one embodiment, the feedforward perturbation signal is expressed as: v = f(ν) s Q r ), where ν s This represents the water-cooled wall inlet temperature disturbance, Q. r This represents the real-time load disturbance of the boiler, where f is represented by ν. s With Q r The mapping relationship between them.

[0135] The feedforward predictive control device for the wide-load denitrification combined hot water recirculation system provided in the embodiments of the present invention can execute the feedforward predictive control method for the wide-load denitrification combined hot water recirculation system provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the execution method.

[0136] In one embodiment, Figure 8 This is a schematic diagram of an electronic device provided for implementing embodiments of the present invention. The electronic device 10 is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device may also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices (e.g., helmets, glasses, watches, etc.), and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the invention described and / or claimed herein.

[0137] like Figure 8As shown, the electronic device 10 includes at least one processor 11 and a memory, such as a read-only memory (ROM) 12 or a random access memory (RAM) 13, communicatively connected to the at least one processor 11. The memory stores computer programs executable by the at least one processor. The processor 11 can perform various appropriate actions and processes based on the computer program stored in the ROM 12 or loaded from storage unit 18 into the RAM 13. The RAM 13 may also store various programs and data required for the operation of the electronic device 10. The processor 11, ROM 12, and RAM 13 are interconnected via a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0138] Multiple components in electronic device 10 are connected to I / O interface 15, including: input unit 16, such as keyboard, mouse, etc.; output unit 17, such as various types of displays, speakers, etc.; storage unit 18, such as disk, optical disk, etc.; and communication unit 19, such as network card, modem, wireless transceiver, etc. Communication unit 19 allows electronic device 10 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0139] Processor 11 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, digital signal processors (DSPs), and any suitable processor, controller, microcontroller, etc. Processor 11 performs the various methods and processes described above, such as the feedforward predictive control method for a wide-load denitrification combined hot water recirculation system.

[0140] In some embodiments, the feedforward predictive control method for a wide-load denitrification combined hot water recirculation system can be implemented as a computer program tangibly contained in a computer-readable storage medium, such as storage unit 18. In some embodiments, part or all of the computer program can be loaded and / or installed on electronic device 10 via ROM 12 and / or communication unit 19. When the computer program is loaded into RAM 13 and executed by processor 11, one or more steps of the feedforward predictive control method for the wide-load denitrification combined hot water recirculation system described above can be performed. Alternatively, in other embodiments, processor 11 can be configured to perform the feedforward predictive control method for the wide-load denitrification combined hot water recirculation system by any other suitable means (e.g., by means of firmware).

[0141] Various embodiments of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SoCs), payload-programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, the at least one input device, and the at least one output device.

[0142] Computer programs used to implement the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when executed by the processor, the computer programs cause the functions / operations specified in the flowcharts and / or block diagrams to be performed. The computer programs may be executed entirely on a machine, partially on a machine, or as a standalone software package, partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0143] In the context of this invention, a computer-readable storage medium can be a tangible medium that may contain or store a computer program for use by or in conjunction with an instruction execution system, apparatus, or device. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination thereof. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0144] To provide interaction with a user, the systems and techniques described herein can be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user provides input to the electronic device. Other types of devices can also be used to provide interaction with the user; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including sound input, voice input, or tactile input).

[0145] The systems and technologies described herein can be implemented in computing systems that include backend components (e.g., as data servers), or computing systems that include middleware components (e.g., application servers), or computing systems that include frontend components (e.g., user computers with graphical user interfaces or web browsers through which users can interact with implementations of the systems and technologies described herein), or any combination of such backend, middleware, or frontend components. The components of the system can be interconnected via digital data communication of any form or medium (e.g., communication networks). Examples of communication networks include local area networks (LANs), wide area networks (WANs), blockchain networks, and the Internet.

[0146] A computing system can include clients and servers. Clients and servers are generally located far apart and typically interact through communication networks. The client-server relationship is created by computer programs running on the respective computers and having a client-server relationship with each other. The server can be a cloud server, also known as a cloud computing server or cloud host, which is a hosting product within the cloud computing service system to address the shortcomings of traditional physical hosts and VPS services, such as high management difficulty and weak business scalability.

[0147] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0148] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A feedforward predictive control method for a wide-load denitrification combined hot water recirculation system, characterized in that, The method includes: Obtain the real-time boiler load of the selected supercritical unit, as well as the critical load corresponding to the dry-wet switching condition; The operating mode of the boiler is determined based on the real-time load and the critical load, so as to automatically switch the operating mode; wherein, the operating mode includes: dry operation mode and wet operation mode; The working fluid flow direction in the economizer bypass pipeline and the hot water recirculation bypass pipeline of the composite hot water recirculation system under the aforementioned operating conditions is determined in order to construct the corresponding operating condition model; the operating condition model includes a dry operating condition model and a wet operating condition model. The inlet temperature of the water-cooled wall is obtained, and based on the real-time boiler load, the inlet temperature of the water-cooled wall, the economizer bypass pipe water flow rate and the hot water recirculation bypass water flow rate in the operating condition model, and a pre-built feedforward predictive control model, the inlet flue gas temperature and economizer outlet subcooling of the composite hot water recirculation denitrification system are coordinated and controlled, including: The real-time load of the boiler and the inlet temperature of the water-cooled wall are used as the feedforward perturbation signals for the feedforward predictive control model. The hot water recirculation loop flow rate and economizer bypass flow rate in the dry-state operating model or the wet-state operating model are used as input control quantities. These are then sent to the feedforward predictive control model in the form of instructions for rolling optimization of the input control quantities. This process continues until the difference between the SCR denitrification system inlet flue gas temperature setpoint corresponding to the hot water recirculation loop flow rate and the economizer outlet subcooling setpoint corresponding to the economizer bypass flow rate and the SCR denitrification system inlet flue gas temperature and economizer outlet subcooling output by the feedforward predictive control model is within a preset range. This achieves coordinated control of the inlet flue gas temperature and economizer outlet subcooling of the composite hot water recirculation SCR denitrification system. The feedforward predictive control model is constructed based on the working fluid flow direction in the economizer bypass pipe and hot water recirculation bypass pipe corresponding to the operating condition model, as well as the water flow rate in the economizer bypass pipe and hot water recirculation bypass pipe under the working fluid flow direction, through closed-loop simulation experiments. The construction of the feedforward predictive control model includes: Based on the working fluid flow direction in the economizer bypass pipeline and hot water recirculation bypass pipeline corresponding to the dry and wet operating models included in the operating model, as well as the water flow rate in the economizer bypass pipeline and the water flow rate in the hot water recirculation bypass pipeline under the working fluid flow direction, a closed-loop simulation experiment was conducted to obtain the closed-loop operation data of the composite hot water recirculation SCR denitrification system. Initialize the inlet flue gas temperature and economizer outlet subcooling of the combined hot water recirculation SCR denitrification system; identify the state-space dynamic model corresponding to the combined hot water recirculation system using subspace identification method and closed-loop operation data; obtain the incremental model corresponding to the combined hot water recirculation system based on the predefined control increment formula and the state-space dynamic model; obtain the characteristic matrix coefficients corresponding to the combined hot water recirculation system, and construct the augmented model corresponding to the combined hot water recirculation system based on the incremental model and the characteristic matrix coefficients; set the prediction step size as p and the control step size as m, and derive the combined hot water recirculation SCR denitrification system using the augmented model. The target state variables and target output variables of the SCR denitrification system are defined; wherein the prediction step size is larger than the control step size; an optimization objective function for the target optimization problem is constructed based on the target state variables and target output variables; the optimization objective function aims to minimize the errors between the inlet temperature setpoint and the economizer outlet subcooling setpoint of the SCR denitrification system and the inlet flue gas temperature and the economizer outlet subcooling output by the feedforward predictive controller model, respectively; the optimization objective function is optimized using a rolling optimization method to obtain the optimized feedforward predictive control function, and the feedforward predictive control function is used as the feedforward predictive control model.

2. The method according to claim 1, characterized in that, The step of determining the boiler's operating mode based on the boiler's real-time load and critical load, and automatically switching the operating mode, includes: When the real-time load of the boiler is less than the critical load, the operating mode of the boiler is determined to be wet operation mode, and the boiler is automatically switched to wet operation mode. When the real-time load of the boiler is greater than or equal to the critical load, the operating mode of the boiler is determined to be dry operation mode, and the boiler is automatically switched to dry operation.

3. The method according to claim 1, characterized in that, The process of determining the working fluid flow direction in the economizer bypass pipeline and the hot water recirculation bypass pipeline of the composite hot water recirculation system under the operating condition mode, in order to construct the corresponding operating condition model, includes: In the wet operation mode, the water flow rate of the economizer water bypass pipeline is regulated by the economizer bypass regulating valve. The hot water in the hot water recirculation bypass pipeline flows out from the water storage tank of the steam-water separator and flows into the economizer inlet for recirculation. The working fluid flow direction in the wet operation mode forms a wet operating condition model. In the dry operation mode, the water flow rate of the economizer water bypass pipeline is regulated by the economizer bypass regulating valve, and a dry circulation pipeline is added between the economizer outlet pipeline and the economizer inlet pipeline. A corresponding new economizer regulating valve is added to the dry circulation pipeline. The working fluid flow rate in the dry operation mode is regulated by the economizer bypass regulating valve and the new economizer regulating valve, and the working fluid flow direction in the dry operation mode forms a dry operating condition model.

4. The method according to claim 1, characterized in that, The state-space dynamic model is expressed by the following formula: ,in, This represents the state variables of the hot water recirculation denitrification system at time k. This represents the state variables of the hot water recirculation denitrification system at time k+1; The input variables of the hot water recirculation denitrification system at time k are represented by the hot water recirculation bypass water flow rate and the economizer bypass pipeline water flow rate. The output variable of the hot water recirculation denitrification system at time k is represented by the inlet flue gas temperature and the outlet subcooling of the economizer. The feedforward disturbance signal at time k represents the real-time boiler load and water-cooled wall inlet temperature; A, B, C, and D all represent the characteristic matrix coefficients corresponding to the hot water recirculation system. The predefined control increment formula is expressed as follows: ,in, Represented as defined Incremental form; Represented as defined Incremental, Let these be the input variables of the hot water recirculation denitrification system at time k-1; Represented as defined Incremental, This is represented as the feedforward perturbation signal at time k-1; The incremental model is expressed by the formula: ;in, This is represented as the incremental state variable of the hot water recirculation denitrification system at time k+1; The output variable of the hot water recirculation denitrification system at time k is represented by the inlet flue gas temperature and the outlet subcooling of the economizer. The augmentation model is expressed by the following formula: In the formula, Let the augmented state variables of the hot water recirculation denitrification system at time k+1 be represented. This represents the augmented output variable of the hot water recirculation denitrification system at time k; , , , ;in, , , and These are respectively represented as the augmentation coefficients of the characteristic matrix coefficients A, B, C, and D; Represented as a matrix of all zeros, Represented as an identity matrix; Let k be the augmented state variable of the hot water recirculation denitrification system at time k; The relationship between the target output variable and the target state variable is expressed by the formula: ,in, Let be the output variable of the hot water recirculation denitrification system at time k+p, and p be the prediction step size; This is represented as the input increment sequence of the hot water recirculation denitrification system. , , , These are respectively represented as the matrix coefficients in the target output variables, where, , , m is the control step size, p is the prediction step size, and i is a variable.

5. The method according to claim 1, characterized in that, The constraints corresponding to the optimization objective function include at least: controlled variable constraints and control variable constraints; the controlled variable constraints include: upper and lower limit constraints on the flue gas inlet temperature of the denitrification system and upper and lower limit constraints on the subcooling of the economizer outlet; the control variable constraints include: working fluid flow constraints in the hot water recirculation loop and economizer bypass water flow constraints.

6. The method according to claim 1, characterized in that, The optimization objective function is expressed by the following formula: In the formula, This represents the setpoint matrix of the controlled variables, which is characterized as the setpoint matrix of flue gas inlet temperature of the denitrification system and the setpoint matrix of subcooling at the economizer outlet. It is represented as a sequence of output variables under the prediction step size, wherein the output variables characterize the inlet flue gas temperature of the hot water recirculation denitrification system and the subcooling at the economizer outlet; The sequence of input increments for the hot water recirculation denitrification system is represented by the hot water recirculation loop working fluid flow rate and the economizer bypass water flow rate. Represented as transpose, Represents the error weight matrix; The control weight matrix; The constraints of the optimization objective function are expressed as follows: ;in, and These represent the minimum and maximum increments of the hot water recirculation bypass water flow rate and the economizer bypass water flow rate, respectively. and These represent the minimum and maximum values ​​of the hot water recirculation bypass water flow rate and the economizer bypass water flow rate, respectively. and These represent the minimum and maximum values ​​of the inlet flue gas temperature and the economizer outlet subcooling of the hot water recirculation denitrification system, respectively.

7. The method according to claim 1, characterized in that, The feedforward perturbation signal is represented as: ,in, This represents the water-cooled wall inlet temperature disturbance. This represents the real-time load disturbance of the boiler. Represented as and The mapping relationship between them.

8. A feedforward predictive control device for a wide-load denitrification combined hot water recirculation system, characterized in that, The device includes: The information acquisition module is used to acquire the real-time load of the boiler of the selected supercritical unit, as well as the critical load corresponding to the dry-wet switching condition. The operating condition determination module is used to determine the operating condition mode of the boiler based on the real-time load and the critical load of the boiler, so as to automatically switch the operating condition mode; wherein, the operating condition mode includes: dry operating mode and wet operating mode; The operation model construction module is used to determine the working fluid flow direction in the economizer bypass pipeline and the hot water recirculation bypass pipeline of the composite hot water recirculation system under the operation mode, so as to construct the corresponding operation mode operation model; the operation mode operation model includes a dry operation mode operation model and a wet operation mode operation model. The control module is used to acquire the water-cooled wall inlet temperature and, based on the real-time boiler load, the water-cooled wall inlet temperature, the economizer bypass pipeline water flow rate and the hot water recirculation bypass water flow rate in the operating condition model, as well as the pre-built feedforward predictive control model, collaboratively control the inlet flue gas temperature and economizer outlet subcooling of the composite hot water recirculation denitrification system. The feedforward predictive control model is constructed based on the working fluid flow direction in the economizer bypass pipe and hot water recirculation bypass pipe corresponding to the operating condition model, as well as the water flow rate in the economizer bypass pipe and hot water recirculation bypass pipe under the working fluid flow direction, through closed-loop simulation experiments. The construction of the feedforward predictive control model includes: obtaining closed-loop operation data of the composite hot water recirculation SCR denitrification system by conducting closed-loop simulation experiments based on the working fluid flow direction in the economizer bypass pipeline and hot water recirculation bypass pipeline corresponding to the dry-state operation model and wet-state operation model included in the operating condition model, as well as the water flow rate in the economizer bypass pipeline and hot water recirculation bypass pipeline under the working fluid flow direction; initializing the inlet flue gas temperature and economizer outlet subcooling of the composite hot water recirculation SCR denitrification system; identifying the state-space dynamic model corresponding to the composite hot water recirculation system using the subspace identification method and closed-loop operation data; obtaining the incremental model corresponding to the composite hot water recirculation system based on the predefined control incremental formula and the state-space dynamic model; obtaining the characteristic matrix coefficients corresponding to the composite hot water recirculation system, and based on the... An augmented model corresponding to the composite hot water recirculation system is constructed using the incremental model and the coefficients of the characteristic matrix. The prediction step size is set to p, and the control step size to m. The target state variables and target output variables of the composite hot water recirculation SCR denitrification system are derived using the augmented model. The prediction step size is greater than the control step size. An optimization objective function is constructed based on the target state variables and the target output variables. The optimization objective function aims to minimize the errors between the SCR denitrification system inlet temperature setpoint and the economizer outlet subcooling setpoint and the SCR denitrification system inlet flue gas temperature and economizer outlet subcooling output by the feedforward predictive controller model. The optimization objective function is optimized using a rolling optimization method to obtain the optimized feedforward predictive control function, which is then used as the feedforward predictive control model. The control module includes: The disturbance signal determination unit is used to take the real-time load of the boiler and the inlet temperature of the water-cooled wall as the feedforward disturbance signal of the feedforward predictive control model. The control unit is used to take the hot water recirculation loop flow rate and economizer bypass flow rate in the dry-state operating model or the wet-state operating model as input control quantities, and send them to the feedforward predictive control model in the form of instructions for rolling optimization of the input control quantities until the difference between the SCR denitrification system inlet flue gas temperature setpoint corresponding to the hot water recirculation loop flow rate and the economizer outlet subcooling setpoint corresponding to the economizer bypass flow rate and the SCR denitrification system inlet flue gas temperature and economizer outlet subcooling output by the feedforward predictive control model is within a preset range, thereby realizing the coordinated control of the composite hot water recirculation SCR denitrification system inlet flue gas temperature and economizer outlet subcooling.

9. An electronic device, characterized in that, The electronic device includes: At least one processor; and A memory communicatively connected to the at least one processor; wherein, The memory stores a computer program that can be executed by the at least one processor, the computer program being executed by the at least one processor to enable the at least one processor to perform the feedforward predictive control method for the wide-load denitrification combined hot water recirculation system according to any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions that cause a processor to execute the feedforward predictive control method for the wide-load denitrification combined hot water recirculation system according to any one of claims 1-7.

11. A computer program product, characterized in that, The computer program product includes a computer program that, when executed by a processor, implements the feedforward predictive control method for a wide-load denitrification combined hot water recirculation system according to any one of claims 1-7.

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