A compound control system and method for a steam power system

Abstract

The application provides a compound control system and method of a steam power system, and relates to the technical field of the steam power system; the compound control system comprises a heat source control system and a feedwater 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 and feedwater ratio solving unit; and the feedwater control system comprises a second open-loop controller, a second closed-loop controller, a feedwater system and a boiler. The application adopts a compound control strategy combining open-loop control and closed-loop control for heat source power control and feedwater system control, which is beneficial to the rapid response of the feedwater flow itself, avoids the problem that the feedwater control system and the heat source power control system affect each other, can greatly shorten the feedwater adjusting time, and significantly improves the dynamic response performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of steam power system, and particularly relates to a compound control system and method of steam power system. BACKGROUND

[0002] The once-through boiler is one of the main types of steam generator of the steam power plant, which has small heat and fast dynamic response. The once-through boiler transmits the heat generated by the heat source to the feed water of the steam-water circulation loop, so that the feed water of the steam-water circulation loop becomes steam with certain temperature and pressure.

[0003] The steam pressure is too low or too high, which will affect the normal work of the subsequent steam equipment, especially when the pressure is too high, which will cause the problem of operation safety. Therefore, the outlet steam pressure of the once-through boiler needs to be controlled within a certain range during the operation. In addition, it is also necessary to ensure that the outlet steam dryness of the once-through boiler is within a reasonable range, so as to avoid the steam at the outlet of the boiler accompanied by water droplets, or even hot water, which will endanger the safe operation of the steam turbine. In the operation process of the steam power system, the combustion rate of the fuel regulation system and the flow regulation of the feed water system are usually used as the control means to maintain the pressure of the once-through boiler within the set range, that is, the combustion rate of the fuel and the feed water flow of the once-through boiler are increased or decreased to maintain the steam pressure, so as to prevent the steam pressure from being too high or too low, and at the same time, the steam dryness is not too low.

[0004] At present, the regulation of the feed water system of the steam power system is mainly realized by controlling the opening degree of the regulating valve and changing the rotating speed of the feed water pump. After receiving the feed water flow regulation instruction, the feed water regulating valve first acts to change the feed water flow. This process will cause the pressure difference between the feed water pipe and the steam outlet pipe of the once-through boiler to change, and the controller will then give an instruction to change the rotating speed of the feed water pump to maintain the pressure difference between the feed water pipe and the steam outlet pipe of the once-through boiler to be a given value. In this dynamic process, the opening degree of the feed water regulating valve is further adjusted to meet the demand of the feed water flow. This cycle is repeated to complete the feed water flow regulation, forming a coupling process with two inputs and two outputs, that is, the opening degree of the regulating valve and the rotating speed of the feed water pump as inputs, and the pressure difference between the feed water pipe and the steam outlet pipe and the feed water flow as outputs.

[0005] However, in the above regulation process, the change of the rotating speed of the feed water pump and the opening degree of the regulating valve is a process of following each other. This process will inevitably cause the feed water flow to fluctuate, the regulation time is long, and the dynamic control performance of the once-through boiler is poor. At the same time, the feed water regulation process on the steam-water circulation loop side can affect the heat source side through the heat transfer of the once-through boiler, and then cause the heat source power control system to act constantly to adapt to the fluctuation of the steam-water circulation loop load, forming the interdependent response of the heat source and the steam-water circulation loop, and delaying the overall stability process of the steam power plant in the variable working condition process. Therefore, there is an urgent need for a control system and method which can coordinate the heat source power and overcome the coupling problem of the feed water system. SUMMARY

[0006] Therefore, it is necessary to provide a compound control system and method of steam power system to coordinate heat source power and overcome coupling problem of feedwater system.

[0007] In one aspect, the present application provides a compound control system of steam power system, which comprises a heat source control system and a feedwater control system.

[0008] The heat source control system comprises:

[0009] a first open-loop controller, configured to receive working condition instruction in real time and output a first fuel usage rate;

[0010] a first closed-loop controller, configured to set a standard fuel- feedwater ratio, collect a current fuel- feedwater ratio in real time, and output a second fuel usage rate based on the standard fuel- feedwater ratio and the current fuel- feedwater ratio;

[0011] a fuel adjusting 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;

[0012] a heat source system, configured to provide heat for a boiler;

[0013] a fuel- feedwater ratio solving unit, configured to collect the fuel usage rate and a feedwater flow rate, output a current fuel- feedwater ratio, and feed back to the first closed-loop controller;

[0014] The feedwater control system comprises:

[0015] a second open-loop controller, configured to receive working condition instruction in real time and output a first adjusting valve valve position;

[0016] a second closed-loop controller, configured to set a standard boiler outlet pressure, collect a current boiler outlet pressure in real time, and output a second adjusting valve valve position based on the standard boiler outlet pressure and the current boiler outlet pressure;

[0017] a feedwater system, configured to receive the first adjusting valve valve position and the second adjusting valve valve position, obtain a current adjusting valve valve position, and output a feedwater flow rate;

[0018] a boiler, configured to heat the feedwater flow rate output by the feedwater system by using the heat provided by the heat source system, output a current boiler outlet pressure, and feed back to the second closed-loop controller.

[0019] Further, the working condition instruction comprises a working point fuel usage rate and a working point adjusting valve valve position.

[0020] Further, the input information of the first closed-loop controller is the difference between the standard fuel-feed water ratio and the current fuel-feed water ratio.

[0021] Further, when the standard fuel-feed water ratio is equal to the current fuel-feed water ratio, the first closed-loop controller stops adjusting; otherwise, when the standard fuel-feed water ratio is different from the current fuel-feed water ratio, the first closed-loop controller resumes adjusting.

[0022] Further, the input information of the second closed-loop controller is the difference between the standard boiler outlet pressure and the current boiler outlet pressure.

[0023] Further, 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 is different from the current boiler outlet pressure, the second closed-loop controller resumes adjusting.

[0024] Further, the calculation formula of the current fuel-feed water ratio includes:

[0025] ;

[0026] wherein, represents the fuel usage rate; represents the feed water flow.

[0027] Further, the compound control of the steam power system further includes:

[0028] adjusting the current fuel-feed water ratio to the standard fuel-feed water ratio by jointly adjusting the first open-loop controller and the first closed-loop controller;

[0029] adjusting the current boiler outlet pressure to the standard boiler outlet pressure by jointly adjusting the second open-loop controller and the second closed-loop controller.

[0030] Further,

[0031] the pole of the first closed-loop controller is located in a first set region of a pole distribution plane, and the value of the first set region ensures that the overshoot of the current fuel-feed water ratio does not exceed a first set value and the rise time does not exceed a first time;

[0032] the pole of the second closed-loop controller is located in a second set region of a pole distribution plane, and the value of the second set region ensures that the overshoot of the current boiler outlet pressure does not exceed a second set value and the rise time does not exceed a second time.

[0033] In another aspect, the present application further provides a compound control method of a steam power system, which includes:

[0034] receiving a working condition instruction in real time, and outputting a first fuel usage rate and a first adjusting valve valve position corresponding to the working condition instruction;

[0035] setting a standard fuel feedwater ratio and a standard boiler outlet pressure, collecting the current fuel feedwater ratio in real time, outputting a second fuel usage rate based on the standard fuel feedwater ratio and the current fuel feedwater ratio, collecting the current boiler outlet pressure in real time, and outputting a second adjusting valve valve position based on the standard boiler outlet pressure and the current boiler outlet pressure;

[0036] 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 to make the current fuel usage rate meet the requirement of the current fuel feedwater ratio;

[0037] obtaining a current adjusting valve valve position based on the first adjusting valve valve position and the second adjusting valve valve position, and controlling the first adjusting valve valve position and the second adjusting valve valve position to make the current adjusting valve valve position meet the requirement of the current boiler outlet pressure.

[0038] Overall, the present application provides a compound control system and method of a steam power system, which can achieve the following beneficial effects compared with the prior art:

[0039] On one hand, the present application sets a first open-loop controller and a second open-loop controller, and through working condition open-loop feedforward, the control of the feedwater control system and the control of the heat source control system are coordinated in time sequence; on the other hand, the present application sets a first closed-loop controller and a second closed-loop controller, and through closed-loop feedback control, the control accuracy of the feedwater 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 order of magnitude, which avoids the problem that the two control systems affect and follow each other in the control process and have long stable time, can greatly shorten the dynamic adjustment time of the feedwater control system and the heat source control system, optimizes the control process, and realizes high-performance cooperative control of the feedwater control system and the heat source control system, thereby providing technical support for high-performance operation of the steam power system. BRIEF DESCRIPTION OF DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without any creative effort.

[0041] Figure 1It is a system principle schematic diagram of a compound control system and method of a steam power system provided by the application;

[0042] Figure 2 It is an open loop control schematic diagram of a heat source control system of a compound control system and method of a steam power system provided by the application;

[0043] Figure 3 It is a closed loop feedback control schematic diagram of a heat source control system of a compound control system and method of a steam power system provided by the application;

[0044] Figure 4 It is a pole distribution schematic diagram of a compound control system and method of a steam power system provided by the application;

[0045] Figure 5 It is an open loop control schematic diagram of a feedwater control system of a compound control system and method of a steam power system provided by the application;

[0046] Figure 6 It is a closed loop feedback control schematic diagram of a feedwater control system of a compound control system and method of a steam power system provided by the application. DETAILED DESCRIPTION

[0047] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be described below in connection with the drawings and embodiments in the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0048] It should be noted that, in the description of the embodiments of the present application, the terms “comprise”, “contain” or any other variants thereof are intended to cover non-exclusive inclusion, so that the method, step or system comprising a series of elements not only includes those elements, but also includes other elements not explicitly listed, or includes elements inherent to such method, step or system. Without more limitation, the element defined by the statement “comprising a…” does not exclude the presence of another same element in the method, step or system comprising the element.

[0049] The present application provides a compound control system and method of a steam power system, which adopts a compound control strategy combining open loop and closed loop for heat source power control and feedwater system control, which is beneficial to the rapid response of feedwater flow itself, avoids the problem of mutual influence between the feedwater control system and the heat source power control system, can greatly shorten the feedwater regulation time, and significantly improves the dynamic response performance.

[0050] 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.

[0051] The heat source control system includes a first open-loop controller, a first closed-loop controller, a fuel conditioning system, a heat source system, and a fuel-to-water ratio calculation unit.

[0052] The first open-loop controller is used to receive operating condition commands in real time and output the first fuel usage rate.

[0053] The first closed-loop controller is used to set the standard fuel-water ratio, collect the current fuel-water ratio in real time, and output the second fuel usage rate based on the standard fuel-water ratio and the current fuel-water ratio.

[0054] The fuel regulation system receives a first fuel usage rate and a second fuel usage rate, obtains the current fuel usage rate, and outputs the fuel usage rate.

[0055] A heat source system is used to provide heat to a boiler.

[0056] The fuel-to-water ratio calculation unit is used to collect fuel utilization rate and feedwater flow rate, output the current fuel-to-water ratio and feed it back to the first closed-loop controller.

[0057] It should be noted that the heat source control system adopts a composite control strategy, including a first open-loop controller. C 11 ( s ) and the first closed-loop controller C 12 ( s ).

[0058] More specifically, C 11 ( s The input information is the operating condition command. gk, The output information is the first fuel usage rate. ; C 12 ( s The input information is the standard fuel-to-water ratio. Compared to the current fuel feedwater ratio The difference is output as the second fuel usage rate. The sum of the output information from the open-loop and closed-loop systems represents the current fuel consumption rate. The fuel usage rate is achieved through the fuel regulation system. This leads to the current fuel-to-water ratio Compared with standard fuel feedwater ratio equal.

[0059] That is, when the standard fuel-water ratio is equal to the current fuel-water ratio, the first closed-loop controller stops adjusting; conversely, when there is a deviation between the standard fuel-water ratio and the current fuel-water ratio, the first closed-loop controller readjusts.

[0060] More specifically, by jointly adjusting the first open-loop controller and the first closed-loop controller, the current fuel-water ratio is made to quickly and accurately reach the standard fuel-water ratio.

[0061] It should be noted that the operating condition commands include the fuel usage rate at the operating point and the valve position of the operating point regulating valve.

[0062] Specifically, each operating point fuel usage rate corresponds to a specific operating point regulating valve position. The operating points of the heat source system and water supply system under different operating conditions are determined. ,in, Operating condition command Work location, Operating condition command Corresponding operating point fuel consumption rate Operating condition command The corresponding operating point is the valve position of the regulating valve, which is also the opening degree of the water supply regulating valve.

[0063] For actual steam power systems, the operating conditions of the steam power system are changed, and the commands under different operating conditions are tested and measured. gk Corresponding and For example, assuming there are a total of 15 operating conditions, then .

[0064] As an example, such as Figure 2 As shown, the first open-loop controller C 11 ( s The open-loop control method includes: determining the operating point based on different operating condition commands. Design the first open-loop controller. C 11 ( s ), enabling commands under different operating conditions gk The corresponding first open-loop controller C 11 ( s The first fuel consumption rate output Under the influence of this, the current fuel consumption rate Approximately equal to the operating point fuel consumption rate This allows for coarse adjustment of fuel usage rate using open-loop control.

[0065] As an example, such as Figure 3 As shown, the first closed-loop controller C 12 ( sThe closed-loop feedback control method of the heat source power (e.g., a boiler) includes setting a standard fuel-feedwater ratio The standard fuel-feedwater ratio The pole of the first closed-loop controller is located in a first set region of a pole distribution plane as a reference instruction signal of the heat source power closed-loop control, and the value of the first set region ensures that the overshoot of the current fuel-feedwater ratio does not exceed a first set value and the rise time does not exceed a first time.

[0066] Specifically, the pole of the closed-loop control loop is located in a specific region of the left half of a pole distribution plane (s plane), and the damping ratio and the natural damping frequency are set to ensure that the overshoot of the current fuel-feedwater ratio does not exceed and the rise time is not greater than , so as to ensure that the heat source fuel-feedwater ratio has no large fluctuation and the dynamic response is fast enough. In addition, in order to eliminate the dynamic coupling effect of the feedwater control system on the heat source power control process, it is necessary to ensure that , that is, the dynamic response process is more than one order of magnitude slower than the feedwater control system.

[0067] For example, the standard fuel-feedwater ratio is set to be 0.8, and the standard fuel-feedwater ratio is set to be 0.8, and the pole of the closed-loop control loop is required to be located in the profile region of the left half of a pole distribution plane (s plane) as shown in FIG. 8, wherein the damping ratio n is set to be 0.7 and the natural damping frequency is set to be 0.018, so that the overshoot of the fuel-feedwater 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.

[0068] The fuel-feedwater ratio solving unit is configured to collect the fuel usage rate and the feedwater flow rate, output the current fuel-feedwater ratio, and feed back to the first closed-loop controller.

[0069] As an embodiment, the calculation formula of the current fuel-feedwater ratio includes: ; wherein, represents the fuel usage rate; represents the feedwater flow rate.

[0070] The feedwater control system includes a second open-loop controller, a second closed-loop controller, a feedwater system, a heat source system, and a boiler.

[0071] The second open-loop controller is configured to receive a working condition instruction in real time and output a first regulating valve position.

[0072] 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 valve position of the second regulating valve based on the standard boiler outlet pressure and the current boiler outlet pressure.

[0073] The water supply system is used to receive the valve positions of the first regulating valve and the second regulating valve, obtain the current valve position of the regulating valve, and output the water supply flow rate.

[0074] The boiler is used to heat the water flow output from the feedwater system using heat provided by the heat source system, outputs the current boiler outlet pressure and feeds it back to the second closed-loop controller.

[0075] It should be noted that the water supply control system also employs a composite control strategy, including a second open-loop controller. C twenty one( s ) and second closed-loop controller C twenty two( s ).

[0076] More specifically, C twenty one( s The input information is the operating condition command. gk, The output information is the valve position of the first regulating valve. ; C twenty two( s The input information is the standard boiler outlet pressure. With current boiler outlet pressure The difference is output as the valve position of the second regulating valve. The sum of the open-loop and closed-loop output information is the current valve position of the control valve. The valve position change alters the flow output of the water supply system. This changes the steam pressure at the outlet of the once-through boiler, and consequently alters the current boiler outlet pressure. This results in the current boiler outlet pressure Compared with standard boiler outlet pressure equal.

[0077] 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 there is a deviation between the standard boiler outlet pressure and the current boiler outlet pressure, the second closed-loop controller readjusts.

[0078] More specifically, by jointly adjusting the second open-loop controller and the second closed-loop controller, the current boiler outlet pressure can be quickly and accurately brought to the standard boiler outlet pressure.

[0079] As an example, such as Figure 5 As shown, the second open-loop controller C twenty one( sThe open-loop control method of the boiler includes: determining a working point according to different working conditions Designing a second open-loop controller C 21 s , so that the current regulating valve valve position gk is approximately equal to the working point regulating valve valve position C 21 s under the action of the first regulating valve valve position output by the corresponding second open-loop controller , and then using open-loop control to realize the coarse adjustment of the regulating valve valve position.

[0080] As an embodiment, as shown in the figure, the closed-loop feedback control method of the second closed-loop controller Figure 6 22 C includes: setting a standard boiler outlet pressure s , taking the standard boiler outlet pressure as a reference instruction signal of the water pump speed closed-loop control, the pole of the second closed-loop controller is located in a second set region of the pole distribution plane, and the value of the second set region ensures that the overshoot of the current boiler outlet pressure does not exceed a second set value and the rise time does not exceed a second time.

[0081] Specifically, the pole of the closed-loop control loop is located in a specific region of the left half plane of the pole distribution plane (s plane), and the values of the damping ratio and the natural damping frequency ensure that the overshoot of the current boiler outlet pressure does not exceed and the rise time is not greater than , so as to ensure that the boiler outlet steam parameter is stable and the dynamic response is fast enough. In addition, the feedwater system is decoupled in real time during control, so that the feedwater flow is only affected by the regulating valve opening degree.

[0082] For example, the standard boiler outlet pressure is set, the standard boiler outlet pressure is taken as a reference instruction signal of the water pump speed closed-loop control, and the pole of the closed-loop control loop is required to be located in the profile region of the left half plane of the pole distribution plane (s plane) as shown in the figure, wherein ξ is taken as 0.7 and ωn is taken as 0.018, so as to ensure that the boiler outlet steam parameter is stable and the dynamic response is fast enough. Figure 4

[0083] ​​​Further, it needs to be explained that the decoupling method can be: obtaining input parameters and output parameters of the feedwater control system; obtaining a first transfer function matrix based on the input parameters and the output parameters; obtaining equivalent input parameters of the feedwater control system according to the output parameters after decoupling, and obtaining a second transfer function matrix based on the equivalent input parameters and the 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; and applying the feedforward matrix to the feedwater system to be decoupled, so as to realize decoupling control of the feedwater flow.

[0084] The decoupling method can be: obtaining input parameters and output parameters of the feedwater control system; obtaining a first transfer function matrix based on the input parameters and the output parameters; obtaining equivalent input parameters of the feedwater control system according to the output parameters after decoupling, and obtaining a second transfer function matrix based on the equivalent input parameters and the 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; and applying the feedforward matrix to the feedwater system to be decoupled, so as to realize decoupling control of the feedwater flow.

[0085] In a second aspect, the application further provides a compound control method of a steam power system, the control method comprising:

[0086] receiving a working condition instruction in real time, and outputting a first fuel usage rate and a first adjusting valve valve position in correspondence;

[0087] setting a standard fuel feedwater ratio and a standard boiler outlet pressure, collecting a current fuel feedwater ratio in real time, outputting a second fuel usage rate based on the standard fuel feedwater ratio and the current fuel feedwater ratio, collecting a current boiler outlet pressure in real time, and outputting a second adjusting valve valve position based on the standard boiler outlet pressure and the current boiler outlet pressure;

[0088] 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 to make the current fuel usage rate meet the demand of the current fuel feedwater ratio;

[0089] obtaining a current adjusting valve valve position based on the first adjusting valve valve position and the second adjusting valve valve position, and controlling the first adjusting valve valve position and the second adjusting valve valve position to make the current adjusting valve valve position meet the demand of the current boiler outlet pressure.

[0090] Further, the steam power system comprises a heat source system and a feedwater system, the heat source system comprises a first open-loop controller and a first closed-loop controller, and the feedwater system comprises a second open-loop controller and a second closed-loop controller.

[0091] The first open-loop controller and the second open-loop controller receive a working condition instruction in real time, and output a first fuel usage rate and a first adjusting valve valve position in correspondence; wherein the working condition instruction comprises a working point fuel usage rate and a working point adjusting valve valve position.

[0092] The first closed-loop controller acquires the current fuel feed ratio in real time, and outputs the second fuel usage rate based on the standard fuel feed ratio and the current fuel feed ratio; the second closed-loop controller acquires the current boiler outlet pressure in real time, and outputs the second adjusting valve valve position based on the standard boiler outlet pressure and the current boiler outlet pressure.

[0093] The current fuel usage rate is obtained based on the first fuel usage rate and the second fuel usage rate, and the current adjusting valve valve position is obtained based on the first adjusting valve valve position and the second adjusting valve valve position.

[0094] The first open-loop controller and the first closed-loop controller are jointly adjusted to make the current fuel feed ratio reach the standard fuel feed ratio, and the second open-loop controller and the second closed-loop controller are jointly adjusted to make the current boiler outlet pressure reach the standard boiler outlet pressure, thereby realizing the compound control of the steam power system.

[0095] Further, the first closed-loop controller acquires the current fuel feed ratio in real time, including obtaining the feed water flow of the feed water system based on the current adjusting valve valve position; obtaining the current fuel feed ratio based on the fuel usage rate and the feed water flow, and feeding back to the first closed-loop controller.

[0096] The other technical solutions of the control method are consistent with the technical solutions of the control system described above, and will not be repeated here.

[0097] It should be noted that, for the foregoing various embodiments, in order to simply describe, they are all expressed as a series of action combinations, but those skilled in the art should know that the present application is not limited by the action sequence described, according to the present application, certain steps can be adopted in other order or simultaneously. Secondly, those skilled in the art should know that the embodiments described in the specification all belong to preferred embodiments, and the actions and modules involved are not necessarily necessary for the present application.

[0098] In the above embodiments, the description of each embodiment has its own emphasis, and the parts not described in detail in a certain embodiment can be referred to the related description of other embodiments. In the several embodiments provided in the present application, it should be understood that the disclosed method or system can be implemented in other ways. For example, the above described embodiments are only schematic, for example, the division of the units is only a logical function division, and actual implementation can have another division manner, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed.

[0099] The units described as separate components may or may not be physically separate, and the components displayed as units may or may not be physical units, i.e. may be located in one place, or may be distributed on multiple network units. Part or all of the units may be selected according to actual needs to achieve the purpose of the embodiment.

[0100] In addition, the functional units in each embodiment of the present application can be integrated in one processing unit, or each unit can exist physically, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware or in the form of a software functional unit.

[0101] The integrated unit, if realized in the form of a software functional unit and sold or used as an independent product, can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application essentially or the part of the prior art that contributes to the technical solutions or the whole or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium, and includes a plurality of instructions for causing 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.

[0102] Those of ordinary skill in the art can understand that all or part of the circuits in the above embodiments can be realized by programs instructing related hardware, and the programs can be stored in a computer readable storage medium, which can include a flash disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, etc.

[0103] The above is only exemplary embodiments of the present disclosure, and cannot limit the scope of the present disclosure. That is, any equivalent changes and modifications made in accordance with the teachings of the present disclosure are still within the scope of the present disclosure. Those skilled in the art will easily think of embodiments of the present disclosure after considering the specification and practicing the disclosure herein. The present application is intended to cover any variations, uses or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or conventional techniques in the art that are not described in the present disclosure. The specification and examples are only considered as exemplary, and the scope and spirit of the present disclosure are defined by the claims.

[0104] The technical features of the above embodiments can be combined arbitrarily, and for the sake of brevity, not all possible combinations of the technical features in the above embodiments are described, as long as the combinations of the technical features do not exist. It should be considered that it is within the scope of the present disclosure.

[0105] It is to be understood that the above description is intended to be illustrative and not restrictive. Many other embodiments will be apparent to those of skill in the art upon reading and understanding the above description. The scope of the application should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

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 includes: The first open-loop controller is used to receive operating condition commands in real time and output the first fuel usage rate. The first closed-loop controller is used to set the standard fuel-water ratio, collect the current fuel-water ratio in real time, and output the second fuel usage rate based on the standard fuel-water ratio and the current fuel-water ratio. A fuel regulation system is used to receive the first fuel usage rate and the second fuel usage rate, obtain the current fuel usage rate, and output the current fuel usage rate; The heat source system is used to provide heat to the boiler; The fuel-to-water ratio calculation unit is used to collect the current fuel usage rate and water flow rate, output the current fuel-to-water ratio and feed it back to the first closed-loop controller. The water supply control system includes: The second open-loop controller is used to receive operating condition commands in real time and output the valve position of the first regulating valve. 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 valve position of the second regulating valve based on the standard boiler outlet pressure and the current boiler outlet pressure. The water supply system is used to receive the valve positions of the first regulating valve and the second regulating valve, obtain the current valve position of the regulating valve, and output the water supply flow rate; The boiler is used to heat the water flow rate output by the water supply system using the heat provided by the heat source system, and outputs the current boiler outlet pressure and feeds it back to the second closed-loop controller. The current fuel-water ratio is brought to the standard fuel-water ratio by jointly adjusting the first open-loop controller and the first closed-loop controller. The current boiler outlet pressure is brought to the standard boiler outlet pressure by jointly adjusting the second open-loop controller and the second closed-loop controller.

2. The composite control system for a steam power system according to claim 1, characterized in that, The operating condition commands include the fuel usage rate at the operating point and the valve position of the regulating valve at the operating point.

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

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

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

6. The 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; conversely, when there is a deviation between the standard boiler outlet pressure and the current boiler outlet pressure, the second closed-loop controller readjusts.

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

8. The composite control system for a steam power system according to claim 1, characterized in that, The poles of the first closed-loop controller are located in a first set region of the pole distribution plane. The value of the first set region ensures that the overshoot of the current fuel-water ratio does not exceed the first set value and the rise time does not exceed the first time. The poles of the second closed-loop controller are located in the second set region of the pole distribution plane. The value of the second set region 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.

9. A composite control method for a steam power system, characterized in that, The control method is implemented using the composite control system as described in any one of claims 1-8, the control method comprising: It receives operating condition commands in real time and outputs the first fuel usage rate and the first regulating valve position accordingly. Set the standard fuel-water ratio and standard boiler outlet pressure, collect the current fuel-water ratio in real time, and output the second fuel usage rate based on the standard fuel-water ratio and the current fuel-water ratio; collect the current boiler outlet pressure in real time, and output the valve position of the second regulating valve based on the standard boiler outlet pressure and the current boiler outlet pressure; The current fuel usage rate is obtained based on the first fuel usage rate and the second fuel usage rate, and the current fuel usage rate is output; the current fuel usage rate and water supply flow rate are collected, and the current fuel-to-water ratio is output; the current fuel usage rate is made to meet the requirements of the current fuel-to-water ratio by controlling the first fuel usage rate and the second fuel usage rate. The current regulating valve position is obtained based on the first regulating valve position and the second regulating valve position, and the feedwater flow rate is output; the feedwater flow rate output by the feedwater system is heated by the heat provided by the heat source system, and the current boiler outlet pressure is output; 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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