Coal-fired unit dry and wet state automatic conversion control method and system based on prediction model

Abstract

The invention discloses a coal-fired unit dry and wet state automatic conversion control method and system based on a prediction model. The system comprises a first function module, a first function module, a second function module and the like. The method comprises the following steps: when actual power of a generator meets a built-in constant of a first greater module and an output value of an intermediate point superheat degree prediction model meets a built-in constant of a first less module, triggering a wet state to be 1, and otherwise, triggering a dry state; when the actual power of the generator is second larger than the built-in constant of the module, the output value of the intermediate point superheat degree prediction model meets the third larger than the built-in constant of the module, and the water level selection value of the water storage tank meets the second smaller than the built-in constant of the module; and when the control instruction of the water storage tank water level pneumatic control valve 1 and the control instruction of the water storage tank water level pneumatic control valve 2 meet the condition that the closing state of the fourth smaller module or the inlet electric valve of the water storage tank water level control valve is 1, the first SR module is triggered, the output of the first SR module is zero forever, the wet state is zero, and the dry state is 1 at the moment.

Description

Technical Field

[0001] The present invention belongs to the field of intelligent control of power generation units, and in particular relates to a method and system for automatic dry-wet state conversion control of a coal-fired unit based on a prediction model. Background Art

[0002] During operation, coal-fired units will undergo a conversion process from wet to dry or dry to wet, especially during the startup, variable load, and low load stages. This process involves complex thermal and hydraulic changes, which places high demands on the control system. Traditional control methods often find it difficult to accurately respond to these changes, resulting in large parameter fluctuations and poor stability during the conversion process. Therefore, it is urgent to develop a control method and system for automatic dry-wet state conversion of coal-fired units based on a predictive model to solve such phenomena and problems of coal-fired units and achieve the goal of stable, safe, and efficient operation of coal-fired units. Summary of the invention

[0003] The purpose of the present invention is to provide a control method and system for automatic dry-wet state conversion of a coal-fired unit based on a prediction model. In order to improve the control accuracy and stability of the dry-wet state conversion, a control method based on a prediction model is introduced. This method uses advanced data analysis technology and artificial intelligence algorithms to monitor and predict key parameters in the boiler operation process in real time, so as to adjust the control strategy in advance and ensure the smooth progress of the conversion process.

[0004] In order to achieve the above object, the present invention adopts the following technical solution: A dry-wet state automatic conversion control system for a coal-fired unit based on a prediction model comprises a first greater than module, a first function module, a second function module, a first delay module, a first less than module, a second greater than module, a third greater than module, a second less than module, a first large selection module, a first not module, a first and module, a third less than module, a second delay module, a fourth less than module, a second and module, a third delay module, a first or module, a second or module, a third and module, a fourth delay module, a first SR module, a first off-delay module and a second not module; The output end of the first greater than module is connected to the input end of the first delay module, the output end of the first function module is connected to the assignment end of the first delay module, the output end of the first delay module and the output end of the first less than module are both connected to the input end of the first and module, the output end of the third less than module is connected to the third delay module, and the output end of the first and module and the output end of the third delay module are both connected to the second or module; the output end of the third greater than module is connected to the input end of the second delay module, the output end of the second function module is connected to the assignment end of the second delay module, the output end of the first large selection module is connected to the fourth less than module, the output end of the first not module is connected to the second and module, the output end of the fourth less than module and the output end of the second and module are both connected to the first or module, the output end of the first or module is connected to the fourth delay module, the output end of the second greater than module, the output end of the second delay module, the output end of the second less than module and the fourth delay module are all connected to the third and module; the output end of the second or module and the output end of the third and module are respectively connected to the "S" end and the "R" end of the first SR module, the output end of the first SR module is connected to the first off-delay module, and the first off-delay module is connected to the second not module.

[0005] A further improvement of the present invention is that the actual power generated by the generator is connected to the second larger than module and the third smaller than module respectively.

[0006] A further improvement of the present invention is that the output value distribution of the intermediate point superheat prediction model is connected to the second function module, the first less than module and the third greater than module.

[0007] A further improvement of the present invention is that the water level selection value of the water storage tank is respectively connected to the first greater than module, the first function module and the second less than module.

[0008] A further improvement of the present invention is that the first water tank water level pneumatic regulating valve control instruction and the second water tank water level pneumatic regulating valve control instruction are both connected to the first large value selection module.

[0009] A further improvement of the present invention is that the inlet electric valve of the water level regulating valve of the water storage tank is connected to the first non-module in an open state.

[0010] A further improvement of the present invention is that the electric valve at the inlet of the water level regulating valve of the water storage tank is connected to the second module in a closed state.

[0011] A further improvement of the present invention is that the output end of the first off-delay module is connected to the wet state.

[0012] A further improvement of the present invention is that the output terminal of the second non-module is connected to a dry state.

[0013] A method for automatic dry-wet state conversion control of a coal-fired unit based on a prediction model, the method is based on the automatic dry-wet state conversion control system of a coal-fired unit based on a prediction model, including: when the actual power of the generator satisfies the built-in constant of the first greater than module, and the output value of the intermediate point superheat prediction model satisfies the built-in constant of the first less than module, the wet state is triggered to be 1, otherwise the dry state is triggered; when the actual power of the generator is greater than the built-in constant of the second greater than module, and the output value of the intermediate point superheat prediction model satisfies the built-in constant of the third greater than module, and the water level selection value of the water tank satisfies the built-in constant of the second less than module, and the control instruction of the water tank water level pneumatic regulating valve 1 and the control instruction of the water tank water level pneumatic regulating valve 2 meet the fourth less than module or the closed state of the water tank water level regulating valve inlet electric valve is 1, the first SR module is triggered, and the output of the first SR module is always 0, then the wet state is 0 and the dry state is 1.

[0014] Compared with the prior art, the present invention has at least the following beneficial technical effects: The present invention provides a control system for automatic dry-wet state conversion of coal-fired units based on a prediction model. The control system based on the prediction model should include multiple subsystems such as an intermediate point enthalpy control system, a water level control system, and a circulation flow control system. These subsystems work together to realize the automatic control of the dry-wet state conversion process. At the same time, a reasonable controller switching logic is designed to ensure that the optimal control strategy can be selected under different working conditions.

[0015] The automatic dry-wet state conversion control method for a coal-fired unit based on a prediction model provided by the present invention monitors changes in key parameters such as working fluid flow rate, coal feed rate, water level in a water storage tank, and intermediate point enthalpy value during the dry-wet state conversion process. The prediction model can be used to deeply analyze the mutual influence and change trends of various parameters, thereby achieving precise regulation of the control method.

[0016] In summary, the present invention describes a method and system for automatic dry-wet state conversion control of a coal-fired unit based on a prediction model. The control system based on the prediction model is applied to an actual coal-fired unit, and its performance is evaluated through on-site debugging and simulation verification. The verification results show that the system can significantly improve the stability and speed of the dry-wet state conversion process and reduce the difficulty and risk of operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1This is the schematic diagram of the automatic dry-wet conversion control system for coal-fired units based on the prediction model.

[0019] Figure 2 This is a rendering of an embodiment of the present invention.

[0020] Description of reference numerals: 001, actual power of generator, 002, output value of intermediate point superheat prediction model, 003, water level selection value of water tank, 004, control instruction of first water tank water level pneumatic regulating valve, 005, control instruction of second water tank water level pneumatic regulating valve, 006, open state of inlet electric valve of water tank water level regulating valve, 007, closed state of inlet electric valve of water tank water level regulating valve, 008, first greater than module, 009, first function module, 010, second function module, 011, first delay module, 012, first less than module, 013, second greater than module, 0 14. The third greater than module, 015. The second less than module, 016. The first large selection module, 017. The first not module, 018. The first and module, 019. The third less than module, 020. The second delay module, 021. The fourth less than module, 022. The second and module, 023. The third delay module, 024. The first or module, 025. The second or module, 026. The third and module, 027. The fourth delay module, 028. The first SR module, 029. The first off-delay module, 030. The second not module, 031. The wet state, 032. The dry state. DETAILED DESCRIPTION

[0021] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0022] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0023] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0024] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0025] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0026] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0027] It should also be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0028] It should be further understood that the term "and / or" used in the present description and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0029] Various structural schematic diagrams of the embodiments disclosed in the present invention are shown in the accompanying drawings. These figures are not drawn to scale, and some details are magnified and some details may be omitted for the purpose of clear expression. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships therebetween are only exemplary, and may deviate in practice due to manufacturing tolerances or technical limitations, and those skilled in the art may additionally design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0030] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0031] Example 1 like Figure 1 As shown, the automatic dry-wet state conversion control system of the coal-fired unit based on the prediction model provided by the present invention specifically includes: the actual power of the generator 001, the output value of the intermediate point superheat prediction model 002, the water level selection value of the water storage tank 003, the first water storage tank water level pneumatic regulating valve control instruction 004, the second water storage tank water level pneumatic regulating valve control instruction 005, the water storage tank water level regulating valve inlet electric valve open state 006, the water storage tank water level regulating valve inlet electric valve closed state 007, the first greater than module 008, the first function module 009, the second function module 010, the first delay module 011 , the first less than module 012, the second greater than module 013, the third greater than module 014, the second less than module 015, the first large selection module 016, the first not module 017, the first and module 018, the third less than module 019, the second delay module 020, the fourth less than module 021, the second and module 022, the third delay module 023, the first or module 024, the second or module 025, the third and module 026, the fourth delay module 027, the first SR module 028, the first off delay module 029, the second not module 030, the wet state 031 and the dry state 032.

[0032] Figure 1 The control strategy logic diagram contains the following parts: The wet state 031 includes: the water level selection value 003 of the water storage tank is connected to the first greater than module 008, the output end of the first greater than module 008 is connected to the input end of the first delay module 011, the water level selection value 003 of the water storage tank is connected to the first function module 009, the output end of the first function module 009 is connected to the assignment end of the first delay module 011, the intermediate point superheat prediction model output value 002 is connected to the input end of the first less than module 012, the output end of the first delay module 011 and the output end of the first less than module 012 are both connected to the input end of the first and module 018, and the actual power of the generator 001 is connected to the third less than module 019, the output end of the third less than module 019 is connected to the third delay module 023, the output end of the first and module 018 and the output end of the third delay module 023 are both connected to the second or module 025; the actual power of the generator 001 is connected to the second greater than module 013, the intermediate point superheat prediction model output value 002 is connected to the third greater than module 014, the output end of the third greater than module 014 is connected to the input end of the second delay module 020, the intermediate point superheat prediction model output value 002 is connected to the second function module 010, and the output end of the second function module 010 is connected to the second delay module 02 0, the water tank water level selection value 003 is connected to the second less than module 015, the first water tank water level pneumatic regulating valve control instruction 004 and the second water tank water level pneumatic regulating valve control instruction 005 are both connected to the first large value module 016, the output end of the first large value module 016 is connected to the fourth less than module 021, the water tank water level regulating valve inlet electric valve open state 006 is connected to the first non-module 017, the output end of the first non-module 017 and the water tank water level regulating valve inlet electric valve closed state 007 are both connected to the second AND module 022, the output end of the fourth less than module 021 and the second AND module 02 2 are all connected to the first OR module 024, the output end of the first OR module 024 is connected to the fourth delay module 027, the output end of the second greater than module 013, the output end of the second delay module 020, the output end of the second less than module 015, and the fourth delay module 027 are all connected to the third AND module 026; the output end of the second OR module 025 and the output end of the third AND module 026 are respectively connected to the "S" end and the "R" end of the first SR module 028, the output end of the first SR module 028 is connected to the first off-delay module 029, and the output end of the first off-delay module 029 is connected to the wet state 031.

[0033] The dry state 032 includes: a first off-delay module 029 connected to a second non-module 030 , and an output end of the second non-module 030 connected to the dry state 032 .

[0034] Example 2 The present invention provides a prediction model-based automatic dry-wet state conversion control method for a coal-fired unit, comprising: (1) Model establishment: The midpoint superheat prediction model is established through mechanism modeling and data identification methods. If the midpoint superheat is too high or too low, it will affect the stable operation of the system. The prediction model can be adjusted in time to avoid overheating or overcooling. The prediction model can help operation and maintenance personnel to find potential problems in time, perform maintenance in advance, and reduce the risk of sudden failures. The data analysis and trend prediction provided by the prediction model can provide scientific decision-making basis for management and help formulate more reasonable production plans and operation strategies. Through long-term monitoring and analysis of the midpoint superheat, the risk of system operation can be evaluated, providing a reference for risk management and the formulation of preventive measures.

[0035] (2) Parameter identification: Adopt one of the judgment criteria based on the intermediate point superheat prediction model, identify the load, main steam pressure, and intermediate point temperature at the same time, and optimize the controller parameters. Through the control logic, realize the automatic judgment of the dry / wet state conversion of the unit, the adaptive adjustment of the feed water flow regulation, and the adaptive control of the control parameters; for the unit using the intermediate point temperature control, integrate the control strategy to realize the automatic conversion of the dry and wet state; use real-time data for trend analysis and predict the best time for the dry-wet state conversion to reduce human intervention and improve the accuracy and efficiency of the conversion.

[0036] (3) Non-disturbance switching control strategy: A non-disturbance switching control strategy for the coordinated control system of coal-fired units during the dry / wet state conversion process is proposed to improve the control logic and realize full automatic control of the dry / wet state conversion process.

[0037] This embodiment specifically includes: when the actual power generated by the generator 001 satisfies the first built-in constant greater than module 008, and the output value 002 of the midpoint superheat prediction model satisfies the first built-in constant less than module 012, the wet state 031 is triggered to be 1, otherwise the dry state 032 is triggered; when the actual power generated by the generator 001 is the second greater than the built-in constant of module 013, and the output value 002 of the midpoint superheat prediction model satisfies the third greater than the built-in constant of module 014, and the water tank water level selection value 003 satisfies the second less than the built-in constant of module 015, and the water tank water level pneumatic regulating valve 1 control instruction 004 and the water tank water level pneumatic regulating valve 2 control instruction 005 satisfy the fourth less than module 021 or the water tank water level regulating valve inlet electric valve closing state 007 is 1, the first SR module 028 is triggered, and the output of the first SR module 028 is always 0, then the wet state 031 is 0 and the dry state 032 is 1.

[0038] Example 3 like Figure 2As shown, through the implementation and application of the technology of the present invention, within the scope of simulation, through simulation debugging and on-site implementation, the effectiveness of the automatic control system is verified, ensuring the smooth transition of the dry-wet state conversion process. In general, the automatic dry-wet state conversion control technology of coal-fired units based on the prediction model uses advanced control algorithms and prediction models to achieve efficient and stable conversion between dry and wet states of coal-fired units. This technology not only improves the operating efficiency and economy of thermal power units, but also enhances its responsiveness to the peak load requirements of the power grid, and has important practical application value and broad development prospects.

[0039] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the attached claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any figure mark in the claims should not be regarded as limiting the claims involved.

[0040] In addition, it should be understood that although this specification is described in accordance with the implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation modes that can be understood by those skilled in the art. The above content is only to illustrate the technical idea of ​​the present invention, and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution according to the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A dry-wet state automatic conversion control system for a coal-fired unit based on a prediction model, characterized in that: It includes a first greater than module (008), a first function module (009), a second function module (010), a first delay module (011), a first less than module (012), a second greater than module (013), a third greater than module (014), a second less than module (015), a first large value selection module (016), a first negation module (017), a first and module (018), a third less than module (019), a second delay module (020), a fourth less than module (021), a second and module (022), a third delay module (023), a first or module (024), a second or module (025), a third and module (026), a fourth delay module (027), a first SR module (028), a first break delay module (029) and a second negation module (030); The output end of the first greater than module (008) is connected to the input end of the first delay module (011), the output end of the first function module (009) is connected to the assignment end of the first delay module (011), the output end of the first delay module (011) and the output end of the first less than module (012) are both connected to the input end of the first AND module (018), the output end of the third less than module (019) is connected to the third delay module (023), the output end of the first AND module (018) and the output end of the third delay module (023) are both connected to the second OR module (025); the output end of the third greater than module (014) is connected to the input end of the second delay module (020), the output end of the second function module (010) is connected to the assignment end of the second delay module (020), and the output end of the first large selection module (016) is connected to the fourth less than module (021). , the output end of the first NOT module (017) is connected to the second AND module (022), the output end of the fourth less than module (021) and the output end of the second AND module (022) are both connected to the first OR module (024), the output end of the first OR module (024) is connected to the fourth delay module (027), the output end of the second greater than module (013), the output end of the second delay module (020), the output end of the second less than module (015) and the fourth delay module (027) are all connected to the third AND module (026); the output end of the second OR module (025) and the output end of the third AND module (026) are respectively connected to the "S" end and the "R" end of the first SR module (028), the output end of the first SR module (028) is connected to the first off-delay module (029), and the first off-delay module (029) is connected to the second NOT module (030).

2. The dry-wet state automatic conversion control system of a coal-fired unit based on a prediction model according to claim 1 is characterized in that: The actual power generated by the generator (001) is connected to the second greater than module (013) and the third less than module (019) respectively.

3. The dry-wet state automatic conversion control system of a coal-fired unit based on a prediction model according to claim 2 is characterized in that: The intermediate point superheat prediction model output value (002) is distributedly connected to the second function module (010), the first less than module (012) and the third greater than module (014).

4. The dry-wet state automatic conversion control system of a coal-fired unit based on a prediction model according to claim 3 is characterized in that: The water level selection value (003) of the water storage tank is respectively connected to the first greater than module (008), the first function module (009) and the second less than module (015).

5. The dry-wet state automatic conversion control system of a coal-fired unit based on a prediction model according to claim 4 is characterized in that: The first water storage tank water level pneumatic regulating valve control instruction (004) and the second water storage tank water level pneumatic regulating valve control instruction (005) are both connected to the first large value selection module (016).

6. The automatic dry-wet state conversion control system for coal-fired units based on a prediction model according to claim 5 is characterized in that: The water tank water level regulating valve inlet electric valve open state (006) is connected to the first non-module (017).

7. The automatic dry-wet state conversion control system for coal-fired units based on a prediction model according to claim 6 is characterized in that: The closed state (007) of the inlet electric valve of the water level regulating valve of the water storage tank is connected to the second AND module (022).

8. The dry-wet state automatic conversion control system of a coal-fired unit based on a prediction model according to claim 7 is characterized in that: The output end of the first off-delay module (029) is connected to the wet state (031).

9. The dry-wet state automatic conversion control system of a coal-fired unit based on a prediction model according to claim 8 is characterized in that: The output terminal of the second non-module (030) is connected to the dry state (032).

10. A method for automatic dry-wet state conversion control of a coal-fired unit based on a prediction model, characterized in that: The method is based on the dry-wet state automatic conversion control system of the coal-fired unit based on the prediction model as described in claim 9, comprising: when the actual power (001) of the generator satisfies the first built-in constant greater than the module (008), and the output value (002) of the midpoint superheat prediction model satisfies the first built-in constant less than the module (012), the wet state (031) is triggered to be 1, otherwise the dry state (032) is triggered; when the actual power (001) of the generator is second greater than the built-in constant of the module (013), and the output value (002) of the midpoint superheat prediction model satisfies the first built-in constant less than the module (012), the wet state (031) is triggered to be 1, otherwise the dry state (032) is triggered; When the third is greater than the built-in constant of the module (014), and the water level selection value (003) of the water storage tank satisfies the built-in constant of the second is less than the module (015), and the water level pneumatic regulating valve 1 control instruction (004) and the water level pneumatic regulating valve 2 control instruction (005) of the water storage tank satisfy the fourth is less than the module (021) or the closed state (007) of the inlet electric valve of the water storage tank water level regulating valve is 1, the first SR module (028) is triggered, and the output of the first SR module (028) is always 0. At this time, the wet state (031) is 0 and the dry state (032) is 1.

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