Composite control system and method of steam power system

Abstract

The invention provides a compound control system and method of a steam power system, and relates to the technical field of steam power systems. The compound control system comprises a heat source control system and a water supply control system; the heat source control system comprises a first open-loop controller, a first closed-loop controller, a fuel adjusting system, a heat source system and a fuel-to-water ratio solving unit. The water supply control system comprises a second open-loop controller, a second closed-loop controller, a water supply system and a boiler. According to the invention, a compound control strategy combining open and closed loops is adopted for heat source power control and water supply system control, so that the quick response of the water supply flow is facilitated, the problem that the water supply control system and the heat source power control system influence each other is avoided, the water supply regulation time can be greatly shortened, and the dynamic response performance is remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of steam power systems, and in particular to a composite control system and method for a steam power system. Background Art

[0002] The direct-current boiler has low heat and fast dynamic response, and is one of the main types of steam generators in steam power plants. It transfers the heat generated by the heat source to the feed water of the steam-water circulation loop, turning the feed water of the steam-water circulation loop into steam of a certain temperature and pressure.

[0003] Since too low or too high steam pressure will affect the normal operation of subsequent steam-using equipment, especially when the pressure is too high, it will bring operational safety problems; therefore, during operation, the outlet steam pressure of the direct current boiler needs to be controlled within a certain range. In addition, it is also necessary to ensure that the steam dryness at the outlet of the direct current boiler is within a reasonable range to avoid water droplets accompanying the steam at the boiler outlet, or even hot water, which will endanger the safe operation of the steam turbine. During the operation of the steam power system, the combustion rate of the fuel regulating system and the flow regulation of the water supply system are usually used as control means to maintain the direct current boiler pressure within the set range, that is, the steam pressure is maintained by increasing or decreasing the combustion rate of the fuel and the water supply flow of the direct current boiler to prevent the steam pressure from being too high or too low, while taking into account that the steam dryness is not too low.

[0004] At present, the regulation of the feedwater system of the steam power system is mainly achieved by controlling the opening of the regulating valve and changing the speed of the feedwater pump. After receiving the feedwater flow adjustment instruction, the feedwater regulating valve first acts to change the feedwater flow. This process will cause the pressure difference between the direct current boiler feedwater pipe and the steam outlet pipe to change. The controller then gives an instruction to change the speed of the feedwater pump to maintain the pressure difference between the direct current boiler feedwater pipe and the steam outlet pipe at a given value. In this dynamic process, the opening of the feedwater regulating valve is further adjusted to meet the feedwater flow demand. This cycle is repeated to complete the feedwater flow regulation, forming a two-input and two-output coupling process of the feedwater system with the regulating valve opening and the feedwater pump speed as input and the pressure difference between the two ends of the feedwater pipe and the steam outlet pipe and the feedwater flow as output.

[0005] However, in the above-mentioned adjustment process, the changes in the speed of the feedwater pump and the opening of the regulating valve are a process of following each other, which will inevitably cause fluctuations in the feedwater flow, a long adjustment time, and poor dynamic control performance of the direct-current boiler; at the same time, the feedwater adjustment process on the steam-water circulation loop side can affect the heat source side through the heat transfer of the direct-current boiler, which in turn causes the heat source power control system to operate continuously to adapt to the fluctuations in the load of the steam-water circulation loop, forming an implicated response between the heat source and the steam-water circulation loop, and delaying the overall stabilization process of the steam power unit during the variable working condition. Therefore, there is an urgent need for a control system and method that can coordinate the heat source power and overcome the coupling problem of the feedwater system. Summary of the invention

[0006] Based on this, it is necessary to provide a composite control system and method for a steam power system to address the above technical issues, which can coordinate the heat source power and overcome the coupling problem of the water supply system.

[0007] In one aspect, the present invention provides a composite control system for a steam power system, the composite control system comprising a heat source control system and a water supply control system; The heat source control system comprises: A first open-loop controller, configured to receive a working condition instruction in real time and output a first fuel usage rate; a first closed-loop controller, configured to set a standard fuel-to-water ratio, collect the current fuel-to-water ratio in real time, and output a second fuel usage rate based on the standard fuel-to-water ratio and the current fuel-to-water ratio; a fuel regulating system, configured to receive the first fuel usage rate and the second fuel usage rate, obtain a current fuel usage rate, and output a fuel usage rate; Heat source system, used to provide heat to the boiler; A fuel-to-water ratio solving unit, used for collecting the fuel usage rate and the water flow rate, outputting the current fuel-to-water ratio and feeding it back to the first closed-loop controller; The water supply control system comprises: A second open-loop controller is used to receive working condition instructions in real time and output the valve position of the first regulating valve; A second closed-loop controller is used to set a standard boiler outlet pressure, collect the current boiler outlet pressure in real time, and output a second regulating valve position based on the standard boiler outlet pressure and the current boiler outlet pressure; A water supply system, used for receiving the valve position of the first regulating valve and the valve position of the second regulating valve, obtaining the current valve position of the regulating valve, and outputting the water supply flow rate; The boiler is used to heat the water flow output by the water supply system using the heat provided by the heat source system, output the current boiler outlet pressure and feed it back to the second closed-loop controller.

[0008] Furthermore, the operating condition instruction includes an operating point fuel usage rate and an operating point regulating valve position.

[0009] Furthermore, the input information of the first closed-loop controller is: the difference between the standard fuel-to-water ratio and the current fuel-to-water ratio.

[0010] Furthermore, when the standard fuel-to-water ratio is equal to the current fuel-to-water ratio, the first closed-loop controller stops adjusting; conversely, when the standard fuel-to-water ratio deviates from the current fuel-to-water ratio, the first closed-loop controller readjusts.

[0011] Furthermore, the input information of the second closed-loop controller is: the difference between the standard boiler outlet pressure and the current boiler outlet pressure.

[0012] Furthermore, when the standard boiler outlet pressure is equal to the current boiler outlet pressure, the second closed-loop controller stops adjusting; conversely, when the standard boiler outlet pressure deviates from the current boiler outlet pressure, the second closed-loop controller readjusts.

[0013] Furthermore, the current fuel-to-water ratio The calculation formula includes: ; in, Indicates fuel usage rate; Indicates the water flow rate.

[0014] Furthermore, the composite control of the steam power system also includes: By jointly adjusting the first open-loop controller and the first closed-loop controller, the current fuel-to-water ratio reaches the standard fuel-to-water ratio; The current boiler outlet pressure reaches the standard boiler outlet pressure by jointly adjusting the second open-loop controller and the second closed-loop controller.

[0015] Furthermore, The pole of the first closed-loop controller is located in a first set area of ​​the pole distribution plane, and the value of the first set area ensures that the overshoot of the current fuel-to-water ratio does not exceed the first set value and the rise time does not exceed the first time; The pole of the second closed-loop controller is located in a second set area of ​​the pole distribution plane, and the value of the second set area ensures that the overshoot of the current boiler outlet pressure does not exceed the second set value and the rise time does not exceed the second time.

[0016] On the other hand, the present invention also provides a composite control method for a steam power system, the control method comprising: Receiving working condition instructions in real time, and correspondingly outputting a first fuel usage rate and a first regulating valve position; Set a standard fuel-to-water ratio and a standard boiler outlet pressure, collect the current fuel-to-water ratio in real time, and output a second fuel usage rate based on the standard fuel-to-water ratio and the current fuel-to-water ratio; collect the current boiler outlet pressure in real time, and output a second regulating valve position based on the standard boiler outlet pressure and the current boiler outlet pressure; Obtaining a current fuel usage rate based on the first fuel usage rate and the second fuel usage rate, and controlling the first fuel usage rate and the second fuel usage rate so that the current fuel usage rate meets the current fuel-to-water ratio requirement; The current regulating valve position is obtained based on the first regulating valve position and the second regulating valve position; and the current regulating valve position is made to meet the current boiler outlet pressure requirement by controlling the first regulating valve position and the second regulating valve position.

[0017] In general, the present invention provides a composite control system and method for a steam power system, which can achieve the following beneficial effects compared with the prior art: On the one hand, the present invention provides a first open-loop controller and a second open-loop controller, and through the open-loop feedforward of the operating condition, the control of the water supply control system and the control of the heat source control system are coordinated in terms of timing; on the other hand, a first closed-loop controller and a second closed-loop controller are provided, and through closed-loop feedback control, the control accuracy of the water supply control system and the heat source control system is ensured; in addition, the dynamic response time (rise time) of the two closed-loop control processes is constrained in magnitude, thereby avoiding the problems of the two control systems influencing and following each other and having a long stabilization time during the control process, which can greatly shorten the dynamic adjustment time of the water supply control system and the heat source control system, optimize the control process, and realize high-performance coordinated control of the water supply control system and the heat source control system, providing technical support for the high-performance operation of the steam power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 It is a schematic diagram of the system principle of a composite control system and method for a steam power system provided by the present invention; Figure 2 It is a schematic diagram of open-loop control of a heat source control system of a composite control system and method for a steam power system provided by the present invention; Figure 3 It is a closed-loop feedback control schematic diagram of a heat source control system of a composite control system and method for a steam power system provided by the present invention; Figure 4 It is a pole distribution diagram of a composite control system and method for a steam power system provided by the present invention; Figure 5It is a schematic diagram of open-loop control of a water supply control system of a composite control system and method for a steam power system provided by the present invention; Figure 6 It is a closed-loop feedback control schematic diagram of a water supply control system of a composite control system and method for a steam power system provided by the present invention. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in combination with the drawings and embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0021] It should be noted that, in the description of the embodiments of the present invention, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a method, step or system including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such method, step or system. In the absence of further restrictions, an element defined by the sentence "includes a ..." does not exclude the existence of other identical elements in the method, step or system including the element.

[0022] The present invention provides a composite control system and method for a steam power system, which adopts a composite control strategy combining open and closed loops for heat source power control and water supply system control, which is beneficial to the rapid response of the water supply flow itself, and avoids the problem of mutual influence between the water supply control system and the heat source power control system. It can greatly shorten the water supply adjustment time and significantly improve its dynamic response performance.

[0023] like Figure 1 As shown, the composite control system includes a heat source control system and a water supply control system that combine open and closed loops.

[0024] The heat source control system includes a first open-loop controller, a first closed-loop controller, a fuel regulating system, a heat source system and a fuel-to-water ratio solving unit.

[0025] The first open-loop controller is used to receive the operating condition instruction in real time and output a first fuel usage rate.

[0026] The first closed-loop controller is used to set a standard fuel-to-water ratio, collect the current fuel-to-water ratio in real time, and output a second fuel usage rate based on the standard fuel-to-water ratio and the current fuel-to-water ratio.

[0027] The fuel regulating system is used to receive a first fuel usage rate and a second fuel usage rate, obtain a current fuel usage rate, and output a fuel usage rate.

[0028] Heat source system, used to provide heat to the boiler.

[0029] The fuel-to-water ratio solving unit is used to collect the fuel usage rate and the water supply flow rate, output the current fuel-to-water ratio and feed it back to the first closed-loop controller.

[0030] It should be noted that the heat source control system adopts a composite control strategy, including the first open-loop controller C 11 ( s ) and the first closed-loop controller C 12 ( s ).

[0031] More specifically, C 11 ( s ) is the working condition instruction gk, The output information is the first fuel usage rate ; C 12 ( s ) is the standard fuel-water ratio Compared with the current fuel-water ratio The output information is the second fuel usage rate ; The sum of the open-loop and closed-loop output information is the current fuel usage rate , through the fuel regulation system to make the fuel usage rate reach , which makes the current fuel-water ratio Compared with standard fuel water ratio equal.

[0032] That is, when the standard fuel-to-water ratio is equal to the current fuel-to-water ratio, the first closed-loop controller stops adjusting; conversely, when the standard fuel-to-water ratio deviates from the current fuel-to-water ratio, the first closed-loop controller readjusts.

[0033] More specifically, the current fuel-to-water ratio is made to reach the standard fuel-to-water ratio quickly and accurately by jointly adjusting the first open-loop controller and the first closed-loop controller.

[0034] It should be noted that the operating condition instruction includes the operating point fuel usage rate and the operating point control valve position.

[0035] Specifically, a working point fuel usage rate corresponds to a working point control valve position. Determine the working point of the heat source system and water supply system under different working conditions ,in, For working condition instructions The working point, For working condition instructions The corresponding operating point fuel usage rate, For working condition instructions The corresponding working point regulating valve position is also the opening of the water supply regulating valve.

[0036] For the actual steam power system, change the operating conditions of the steam power system and test and determine the instructions for different operating conditions gk The corresponding and For example, assuming there are 15 operating conditions in total, then .

[0037] As an example, Figure 2 As shown, the first open-loop controller C 11 ( s ) includes: according to the working point determined under different working condition instructions Design the first open-loop controller C 11 ( s ), so that in different working conditions the instructions gk The corresponding first open-loop controller C 11 ( s ) The first fuel usage rate output The current fuel usage rate is Approximately equal to the fuel usage rate at the operating point , and then use open-loop control to achieve coarse adjustment of the fuel usage rate.

[0038] As an example, Figure 3 As shown, the first closed-loop controller C 12 ( s ) includes: setting the standard fuel-to-water ratio , the standard fuel to water ratio As a reference command signal for closed-loop control of heat source power, the pole of the first closed-loop controller is located in the first set area of ​​the pole distribution plane. The value of the first set area ensures that the overshoot of the current fuel-to-water ratio does not exceed the first set value and the rise time does not exceed the first time.

[0039] Specifically, the poles of the closed-loop control loop are located in a specific area of ​​the left half plane of the pole distribution plane (s plane), and the damping ratio , natural damping frequency The value of the current fuel-water ratio is selected so that the overshoot does not exceed , the rise time is no greater than , to ensure that the heat source fuel-to-water ratio does not fluctuate significantly and the dynamic response is fast enough. In addition, in order to eliminate the dynamic coupling effect of the water supply control system on the heat source power control process, it is necessary to ensure , that is, the dynamic response process is more than an order of magnitude slower than that of the water supply control system.

[0040] For example, to set the standard fuel-to-water ratio , the standard fuel to water ratio As the reference command signal for the closed-loop control of the heat source power, the pole of the closed-loop control loop is required to be located at Figure 4 The cross-section area of ​​the left half plane of the pole distribution plane (s plane) shown, where ξ is taken as 0.7 and ω n It is taken as 0.018, so that the overshoot of the fuel-to-water ratio does not exceed 5% and the rise time is not greater than 100 seconds, thereby ensuring that the heat source operating parameters are stable and the dynamic response is fast enough.

[0041] The fuel-to-water ratio solving unit is used to collect the fuel usage rate and the water supply flow rate, output the current fuel-to-water ratio and feed it back to the first closed-loop controller.

[0042] As an example, the current fuel-to-water ratio The calculation formula includes: ;in, Indicates fuel usage rate; Indicates the water flow rate.

[0043] The water supply control system includes a second open-loop controller, a second closed-loop controller, a water supply system, a heat source system and a boiler.

[0044] The second open-loop controller is used to receive the working condition instruction in real time and output the valve position of the first regulating valve.

[0045] The second closed-loop controller is used to set the standard boiler outlet pressure, collect the current boiler outlet pressure in real time, and output the second regulating valve position based on the standard boiler outlet pressure and the current boiler outlet pressure.

[0046] The water supply system is used to receive the valve position of the first regulating valve and the valve position of the second regulating valve, obtain the current valve position of the regulating valve, and output the water supply flow.

[0047] The boiler is used to heat the water flow output by the water supply system using the heat provided by the heat source system, output the current boiler outlet pressure and feed it back to the second closed-loop controller.

[0048] It should be noted that the water supply control system also adopts a composite control strategy, including the second open-loop controller C twenty one( s ) and the second closed-loop controller C twenty two( s ).

[0049] More specifically, C twenty one( s ) is the working condition instruction gk, The output information is the valve position of the first regulating valve ; C twenty two( s ) is the standard boiler outlet pressure With the current boiler outlet pressure The output information is the valve position of the second control valve The sum of the open-loop and closed-loop output information is the current control valve position. , the valve position changes the flow output of the water supply system , thereby changing the steam pressure at the outlet of the direct current boiler. , so that the current boiler outlet pressure With standard boiler outlet pressure equal.

[0050] That is, when the standard boiler outlet pressure is equal to the current boiler outlet pressure, the second closed-loop controller stops adjusting; conversely, when the standard boiler outlet pressure deviates from the current boiler outlet pressure, the second closed-loop controller readjusts.

[0051] More specifically, the second open-loop controller and the second closed-loop controller are jointly adjusted to enable the current boiler outlet pressure to quickly and accurately reach the standard boiler outlet pressure.

[0052] As an example, Figure 5 As shown, the second open-loop controller C twenty one( s ) includes: according to the working point determined under different working condition instructions Design the second open-loop controller C twenty one( s ), so that in different working conditions the instructions gk The corresponding second open-loop controller C twenty one( s ) output of the first regulating valve position Under the effect of Approximately equal to the working point control valve position , and then use open-loop control to achieve coarse adjustment of the control valve position.

[0053] As an example, Figure 6 As shown, the second closed-loop controller C twenty two( s ) includes: setting the standard boiler outlet pressure , the standard boiler outlet pressure As a reference command signal for closed-loop control of the water pump speed, the pole of the second closed-loop controller is located in the second set area of ​​the pole distribution plane. The value of the second set area ensures that the overshoot of the current boiler outlet pressure does not exceed the second set value and the rise time does not exceed the second time.

[0054] Specifically, the poles of the closed-loop control loop are located in a specific area of ​​the left half plane of the pole distribution plane (s plane), and the damping ratio , natural damping frequency The value of the boiler outlet pressure is selected so that the overshoot does not exceed , the rise time is no greater than , ensuring that the steam parameters at the boiler outlet are stable and the dynamic response is fast enough. In addition, the feed water system is decoupled in real time during the control period, so that the feed water flow is only affected by the opening of the regulating valve.

[0055] For example, to set the standard boiler outlet pressure , the standard boiler outlet pressure As the reference command signal for the closed-loop control of the water pump speed, the pole of the closed-loop control loop is required to be located at Figure 4 The section line area of ​​the left half plane of the pole distribution plane (s-plane) shown, where ξ is taken as 0.7 and ωn is taken as 0.018, ensuring that the boiler outlet steam parameters are stable and the dynamic response is fast enough.

[0056] In addition, it should be noted that the decoupling method can be: obtaining input parameters and output parameters of the water supply control system; obtaining a first transfer function matrix based on the input parameters and output parameters; obtaining equivalent input parameters of the water supply control system according to the decoupled output parameters, and obtaining a second transfer function matrix based on the equivalent input parameters and output parameters; determining whether the first transfer function matrix is ​​reversible, and obtaining a feedforward matrix based on the inverse matrix of the first transfer function matrix and the second transfer function matrix; applying the feedforward matrix to the water supply system to be decoupled, thereby realizing decoupling control of the water supply flow.

[0057] In order to solve the coupling problem between the pressure difference between the feed water header and the steam header and the feed water flow rate under the combined effect of the feed water valve opening and the feed water pump speed in the feed water control system, a decoupling control module is connected in series in front of the original system to decouple the multi-input and multi-output water supply system, so that the feed water flow rate at the outlet of the regulating valve is only affected by the opening of the equivalent regulating valve, and it can be controlled as a single-input and single-output system.

[0058] In a second aspect, the present invention further provides a composite control method for a steam power system, the control method comprising: Receiving working condition instructions in real time, and correspondingly outputting a first fuel usage rate and a first regulating valve position; Set a standard fuel-to-water ratio and a standard boiler outlet pressure, collect the current fuel-to-water ratio in real time, and output the second fuel usage rate based on the standard fuel-to-water ratio and the current fuel-to-water ratio; collect the current boiler outlet pressure in real time, and output the second regulating valve position based on the standard boiler outlet pressure and the current boiler outlet pressure; Obtaining a current fuel usage rate based on the first fuel usage rate and the second fuel usage rate, and controlling the first fuel usage rate and the second fuel usage rate so that the current fuel usage rate meets the current fuel-to-water ratio requirement; The current regulating valve position is obtained based on the first regulating valve position and the second regulating valve position; the current regulating valve position is made to meet the current boiler outlet pressure requirement by controlling the first regulating valve position and the second regulating valve position.

[0059] Furthermore, the steam power system includes a heat source system and a water supply system, the heat source system includes a first open-loop controller and a first closed-loop controller, and the water supply system includes a second open-loop controller and a second closed-loop controller.

[0060] The first open-loop controller and the second open-loop controller receive operating condition instructions in real time, and correspondingly output a first fuel usage rate and a first regulating valve position; wherein the operating condition instructions include a working point fuel usage rate and a working point regulating valve position.

[0061] A standard fuel-to-water ratio and a standard boiler outlet pressure are set, and the first closed-loop controller collects the current fuel-to-water ratio in real time, and outputs the second fuel usage rate based on the standard fuel-to-water ratio and the current fuel-to-water ratio; the second closed-loop controller collects the current boiler outlet pressure in real time, and outputs the second regulating valve position based on the standard boiler outlet pressure and the current boiler outlet pressure.

[0062] The current fuel usage rate is obtained based on the first fuel usage rate and the second fuel usage rate, and the current regulating valve position is obtained based on the first regulating valve position and the second regulating valve position.

[0063] By jointly adjusting the first open-loop controller and the first closed-loop controller, the current fuel-to-water ratio reaches the standard fuel-to-water ratio. By jointly adjusting the second open-loop controller and the second closed-loop controller, the current boiler outlet pressure reaches the standard boiler outlet pressure, thereby realizing composite control of the steam power system.

[0064] Furthermore, the first closed-loop controller collects the current fuel-to-water ratio in real time, including obtaining the water flow of the water supply system based on the current regulating valve position; based on the fuel utilization rate and the water flow, obtains the current fuel-to-water ratio and feeds it back to the first closed-loop controller.

[0065] Other technical solutions of the control method are consistent with the technical solutions of the above-mentioned control system and will not be described in detail here.

[0066] It should be noted that, for the above-mentioned various embodiments, for the sake of simplicity of description, they are all expressed as a series of action combinations, but those skilled in the art should be aware that the present application is not limited by the described order of actions, and according to the present application, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present application.

[0067] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, please refer to the relevant description of other embodiments. In the several embodiments provided in this application, it should be understood that the disclosed method or system can be implemented in other ways. For example, the embodiments described above are only schematic, such as the division of the units, which is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed.

[0068] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0069] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0070] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable memory. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or the whole or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a memory, including a number of instructions for a computer device (which can be a personal computer, a server or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application.

[0071] Those skilled in the art will appreciate that all or part of the various circuits in the above embodiments may be completed by entering a program to instruct related hardware, and the program may be stored in a computer-readable memory, which may include: a flash drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, etc.

[0072] The above is only an exemplary embodiment of the present disclosure, and the scope of the present disclosure cannot be limited thereto. That is, any equivalent changes and modifications made according to the teachings of the present disclosure are still within the scope of the present disclosure. After considering the specification and practicing the disclosure here, those skilled in the art will easily think of the implementation scheme of the present disclosure. This application is intended to cover any modification, use or adaptation of the present disclosure, which follows the general principles of the present disclosure and includes common knowledge or customary technical means in the technical field not recorded in the present disclosure. The description and examples are regarded as exemplary only, and the scope and spirit of the present disclosure are defined by the claims.

[0073] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. As long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0074] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A composite control system for a steam power system, characterized in that: The composite control system includes a heat source control system and a water supply control system; The heat source control system comprises: A first open-loop controller, configured to receive a working condition instruction in real time and output a first fuel usage rate; a first closed-loop controller, configured to set a standard fuel-to-water ratio, collect the current fuel-to-water ratio in real time, and output a second fuel usage rate based on the standard fuel-to-water ratio and the current fuel-to-water ratio; a fuel regulating system, configured to receive the first fuel usage rate and the second fuel usage rate, obtain a current fuel usage rate, and output a fuel usage rate; Heat source system, used to provide heat to the boiler; A fuel-to-water ratio solving unit, used for collecting the fuel usage rate and the water flow rate, outputting the current fuel-to-water ratio and feeding it back to the first closed-loop controller; The water supply control system comprises: A second open-loop controller is used to receive working condition instructions in real time and output the valve position of the first regulating valve; A second closed-loop controller is used to set a standard boiler outlet pressure, collect the current boiler outlet pressure in real time, and output a second regulating valve position based on the standard boiler outlet pressure and the current boiler outlet pressure; A water supply system, used for receiving the valve position of the first regulating valve and the valve position of the second regulating valve, obtaining the current valve position of the regulating valve, and outputting the water supply flow rate; The boiler is used to heat the water flow output by the water supply system using the heat provided by the heat source system, output the current boiler outlet pressure and feed it back to the second closed-loop controller.

2. A composite control system for a steam power system according to claim 1, characterized in that: The operating condition instruction includes a fuel usage rate at an operating point and a valve position of an operating point regulating valve.

3. The composite control system of a steam power system according to claim 1, characterized in that: The input information of the first closed-loop controller is: the difference between the standard fuel-to-water ratio and the current fuel-to-water ratio.

4. A composite control system for a steam power system according to claim 3, characterized in that: When the standard fuel-to-water ratio is equal to the current fuel-to-water ratio, the first closed-loop controller stops adjusting; conversely, when the standard fuel-to-water ratio deviates from the current fuel-to-water ratio, the first closed-loop controller readjusts.

5. The composite control system of a steam power system according to claim 1, characterized in that: The input information of the second closed-loop controller is: the difference between the standard boiler outlet pressure and the current boiler outlet pressure.

6. A composite control system for a steam power system according to claim 5, characterized in that: When the standard boiler outlet pressure is equal to the current boiler outlet pressure, the second closed-loop controller stops adjusting; otherwise, when the standard boiler outlet pressure deviates from the current boiler outlet pressure, the second closed-loop controller readjusts.

7. The composite control system of a steam power system according to claim 1, characterized in that: The current fuel-to-water ratio The calculation formula include: ； in, Indicates fuel usage rate; Indicates the water flow rate.

8. The composite control system of a steam power system according to claim 1, characterized in that: The composite control of the steam power system also includes: By jointly adjusting the first open-loop controller and the first closed-loop controller, the current fuel-to-water ratio reaches the standard fuel-to-water ratio; The current boiler outlet pressure reaches the standard boiler outlet pressure by jointly adjusting the second open-loop controller and the second closed-loop controller.

9. A composite control system for a steam power system according to claim 1, characterized in that: The pole of the first closed-loop controller is located in a first set area of ​​the pole distribution plane, and the value of the first set area ensures that the overshoot of the current fuel-to-water ratio does not exceed the first set value and the rise time does not exceed the first time; The pole of the second closed-loop controller is located in a second set area of ​​the pole distribution plane, and the value of the second set area ensures that the overshoot of the current boiler outlet pressure does not exceed the second set value and the rise time does not exceed the second time.

10. A composite control method for a steam power system, characterized in that: The control method comprises: Receiving working condition instructions in real time, and correspondingly outputting a first fuel usage rate and a first regulating valve position; Set a standard fuel-to-water ratio and a standard boiler outlet pressure, collect the current fuel-to-water ratio in real time, and output a second fuel usage rate based on the standard fuel-to-water ratio and the current fuel-to-water ratio; collect the current boiler outlet pressure in real time, and output a second regulating valve position based on the standard boiler outlet pressure and the current boiler outlet pressure; Obtaining a current fuel usage rate based on the first fuel usage rate and the second fuel usage rate, and controlling the first fuel usage rate and the second fuel usage rate so that the current fuel usage rate meets the current fuel-to-water ratio requirement; The current regulating valve position is obtained based on the first regulating valve position and the second regulating valve position; and the current regulating valve position is made to meet the current boiler outlet pressure requirement by controlling the first regulating valve position and the second regulating valve position.

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