Control method and system for high bypass participation in steam extraction based on high pressure difference optimization

Abstract

This invention discloses a control method and system for high-pressure bypass steam extraction based on high-pressure differential pressure optimization, belonging to the field of intelligent control technology for thermal power units. It includes a first function module, a second function module, a third function module, a first subtraction module, a first greater than comparison module, a first less than comparison module, a second greater than comparison module, a first AND module, a first inertial function module, a first constant module, a first switching module, a second subtraction module, and a first feedforward module. Based on load command deviation, this invention constructs a feedforward loop for the high-pressure bypass opening, employing a fast-acting, slow-return method to achieve rapid response of the high-pressure bypass feedforward command to load changes. Based on changes in high-pressure differential pressure, high-pressure temperature, and high-pressure check valve opening, it estimates the margin for maintaining the industrial extraction steam pressure required to meet demand, limiting the amplitude of the high-pressure bypass opening until it forces a reduction in the high-pressure bypass opening.

Description

Technical Field

[0001] This invention belongs to the field of intelligent control technology for thermal power units, specifically relating to a control method and system for high-pressure bypass steam extraction based on high-pressure differential optimization. Background Technology

[0002] Currently, some industrial steam extraction requires higher steam pressure, and the steam source is generally drawn from the exhaust of the high-pressure cylinder of the steam turbine. As the unit load decreases, the exhaust pressure of the high-pressure cylinder drops to the minimum limit for industrial steam extraction. In order to meet the needs of industrial steam extraction users, it is necessary to limit the unit load to a further reduction. If the unit load cannot be reduced, it will significantly increase the grid's deep dispatch assessment.

[0003] In order to balance the minimum steam source pressure of industrial extraction steam and the potential of the unit to reduce the minimum load, a heating bypass and desuperheating system are added to the main steam pipeline. When the industrial extraction steam pressure is insufficient, the heating bypass is opened and connected to the industrial extraction steam system after pressure reduction and desuperheating, so as to stabilize the industrial extraction steam source and further reduce the unit load.

[0004] As the high-pressure bypass system is put into operation and the unit load continues to decrease, the exhaust pressure of the high-pressure cylinder will gradually approach or even equal the steam pressure after the high-pressure bypass. Under this condition, the check valve installed on the high-pressure cylinder exhaust to reheat pipeline will experience a decrease in flow capacity due to the reduced pressure difference across the high-pressure cylinder (hereinafter referred to as high-pressure exhaust pressure difference). The high-speed rotation of the high-pressure cylinder blades will generate a blower-like temperature rise, causing the high-pressure cylinder exhaust temperature to rise rapidly, thus affecting the safe operation of the unit. Therefore, it is necessary to optimize the maximum opening of the high-pressure bypass and the lower limit of unit load reduction based on the change in the high-pressure exhaust pressure difference. Summary of the Invention

[0005] To address the aforementioned problems, the present invention aims to provide a control method and system for high-pressure bypass participation in steam extraction based on high-pressure differential pressure optimization. Its main functions include: constructing a feedforward loop for the high-pressure bypass opening based on load command deviation, and employing a fast-acting, slow-return method to achieve rapid response of the high-pressure bypass feedforward command to load changes; estimating the margin for maintaining the industrial extraction steam pressure demand based on changes in high-pressure differential pressure, high-pressure temperature, and high-pressure check valve opening, limiting the amplitude of the high-pressure bypass opening until it is forced to decrease; and rapidly increasing the minimum opening of the high-pressure bypass based on changes in high-pressure differential pressure and the industrial extraction steam opening margin, achieving a good atomization effect of superheated steam at a small opening and stabilizing the stability of the high-pressure bypass desuperheating water regulation.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: The control system based on high exhaust pressure difference optimization with high bypass participation in steam extraction includes a first function module, a second function module, a third function module, a first subtraction module, a first greater than comparison module, a first less than comparison module, a second greater than comparison module, a first AND module, a first inertial function module, a first constant module, a first switching module, a second subtraction module, and a first feedforward module. The outputs of the second function module and the third function module are both connected to the first inertial function module; the output of the first subtraction module is connected to the second greater than comparison module, and the outputs of the second greater than comparison module, the first greater than comparison module, and the first less than comparison module are all connected to the first AND module; the outputs of the first AND module, the first inertial function module, and the first constant module are respectively connected to the enable trigger terminal, the "Y" terminal, and the "N" terminal of the first switching module; the outputs of the first function module and the first switching module are both connected to the second subtraction module, and the output of the second subtraction module is connected to the first feedforward module.

[0007] A further improvement of the present invention is that the target load command issued by the power grid load command is connected to the first function module; the deviation values ​​of the target load and the rate-based load command are respectively connected to the second function module and the third function module.

[0008] A further improvement of the present invention is that the pressure of the high-pressure cylinder exhaust steam and the steam pressure after the heating high-pressure bypass valve are both connected to the first phase subtraction module.

[0009] A further improvement of the present invention is that the temperature of the exhaust steam from the high-pressure cylinder is connected to the first greater than comparison module, and the feedback of the industrial extraction steam regulating valve is connected to the first less than comparison module.

[0010] A further improvement of the present invention is that the feedback of the high-pressure bypass valve for heating ≥5% and the feedback of the high-pressure check valve opening are both connected to the first module.

[0011] A further improvement of the present invention is that it also includes a third subtraction module, a fourth function module, a third greater than comparison module, a fourth subtraction module, a fourth greater than comparison module, a first NOT module, a first OR module, a second AND module, a second less than comparison module, a fifth greater than comparison module, a first PID module, a third AND module, a second constant module, a third constant module, a second switching module, a first large selection module, a first small selection module, and a third switching module; The output of the third subtraction module is connected to the fourth function module; the output of the fourth subtraction module is connected to the fourth greater than comparison module; the outputs of the third greater than comparison module, the fourth greater than comparison module, and the first NOT module are all connected to the first OR module; the output of the first OR module is connected to the second AND module; the outputs of the fourth function module and the second AND module are connected to the "in" terminal and the "||" terminal of the first PID module in sequence. The outputs of the second less-than comparison module and the fifth greater-than comparison module are both connected to the third AND module; the outputs of the third AND module, the second constant module, and the third constant module are respectively connected to the enable trigger terminal, the "Y" terminal, and the "N" terminal of the second switching module; the outputs of the first PID module and the second switching module are both connected to the first large selection module; the outputs of the second AND module, the third switching module, and the first small selection module are respectively connected to the enable trigger terminal, the "Y" terminal, and the "N" terminal of the third switching module; the outputs of the first large selection module and the third switching module are both connected to the first small selection module, and the output of the first small selection module is connected to the control command for high-pressure bypass participation in steam extraction based on high-pressure differential optimization.

[0012] A further improvement of the present invention is that the desired pressure value of industrial extraction steam and the steam pressure after the high-pressure bypass valve of heating are both connected to the third phase subtraction module, and the pressure of high-pressure cylinder exhaust steam and the steam pressure after the high-pressure bypass valve of heating are both connected to the fourth phase subtraction module.

[0013] A further improvement of the present invention is that the high-pressure check valve is connected to the first non-module with feedback, the output terminal of the high-pressure bypass valve with feedback ≥5% is connected to the second module, and the steam pressure after the high-pressure bypass valve is connected to the "F" terminal of the first PID module.

[0014] A further improvement of the present invention is that the temperature of the exhaust steam from the high-pressure cylinder is connected to the third greater than comparison module, the load command after the target load command passes through the load high and low limit limits and the load change rate is connected to the second less than comparison module, and the feedback of the industrial extraction steam regulating valve is connected to the fifth greater than comparison module.

[0015] Control methods based on high exhaust pressure differential optimization with high bypass steam extraction participation include: The deviation values ​​of the target load and rate-based load commands are calculated by the second function module and output as the opening value. The deviation values ​​are also calculated by the third function module and output as the inertia time, which are then applied to the first inertia function module. The pressure of the high-pressure cylinder exhaust steam and the steam pressure after the heating high-pressure bypass valve are calculated by the first subtraction module and compared with the built-in constant "0" of the second greater than comparison module. The temperature of the high-pressure cylinder exhaust steam is compared with the built-in constant "385" of the first greater than comparison module. The feedback from the industrial extraction steam regulating valve is compared with the first small... The comparison module's built-in constant "45" is used for comparison. If the feedback from the high-pressure bypass valve of the heating system is ≥5%, the second greater than comparison module, the feedback from the high-pressure check valve that is open, the first greater than comparison module, and the first less than comparison module all output "1", then the output of the first switching module is the output value of the first inertial function module. Otherwise, the output of the built-in constant "0" of the first constant module is used. The target load command sent from the power grid load command is calculated by the first function module into a rate-based load command and output as an opening value. At the same time, it is calculated by the second subtraction module with the output value of the first switching module to obtain the first feedforward module. The expected industrial extraction steam pressure and the steam pressure after the high-pressure bypass valve are subtracted by the third subtraction module and then calculated by the fourth function module to obtain the deviation between the expected and actual industrial extraction steam pressure, which is output as a pressure deviation value with dead zone. The temperature of the high-pressure cylinder exhaust steam is compared with the built-in constant "390" of the third greater than comparison module. The pressure of the high-pressure cylinder exhaust steam and the steam pressure after the high-pressure bypass valve are calculated by the fourth subtraction module and compared with the built-in constant "0" of the fourth greater than comparison module. The feedback that the high-pressure exhaust check valve is open is negated by the first NOT module. When the output value of the third greater than comparison module, the fourth greater than comparison module, or the first NOT module is "1", and the feedback of the high-pressure bypass valve is ≥5% and "1", then the output of the second AND module is "1". The output of the fourth function module, the steam pressure after the high-pressure bypass valve, and the output of the second AND module are sequentially connected to the first PID module. The "in", "F", and "||" terminals of the block; the target load command after passing through the load high and low limit limits and the load rate change is compared with the built-in constant of the second less than comparison module, and the feedback of the industrial extraction steam regulating valve is compared with the built-in constant of the fifth greater than comparison module. If both outputs are "1", then the third AND module outputs "1", and the second switching module outputs the built-in constant of the second constant module "10". Otherwise, the built-in constant of the third constant module is "0". The output value of the first PID module is compared with the output value of the second switching module through the first selection module. When the output of the second AND module is "1", the third switching module outputs its previous value. Otherwise, it outputs the output value of the first small selection module. After the output value of the first selection module and the output value of the third switching module are compared through the first small selection module, the final output is the control command for high bypass participation in steam extraction based on high exhaust pressure difference optimization.

[0016] Compared with the prior art, the present invention has at least the following beneficial technical effects: This invention provides a control system based on high exhaust pressure differential optimization with high bypass participation in steam extraction. It is implemented by relying on a high bypass participation in steam extraction coordinated control system. The system integrates a data acquisition unit, a logic operation unit, an execution control unit, and a safety monitoring unit. The functions of each unit work together to ensure the accurate execution of the control logic.

[0017] This invention provides a control method for high-pressure bypass participation in steam extraction based on high-pressure differential pressure optimization. Based on key parameters such as unit load command changes, high-pressure differential pressure, high-pressure temperature, check valve status, and industrial extraction steam regulating valve opening, the method achieves precise and dynamic adjustment of the high-pressure bypass opening for heating.

[0018] In summary, the control method and system for high-pressure bypass steam extraction based on high-pressure differential pressure optimization of the present invention predicts the high-pressure bypass opening command in advance based on the change in high-pressure differential pressure and the direction and step amount of the unit load command change. It limits the lower limit and maximum upper limit of the high-pressure bypass opening based on the high-pressure check valve status signal and the opening of the industrial extraction steam regulating valve. Based on the changes in high-pressure cylinder exhaust temperature and the pressure difference before and after the high-pressure exhaust, it limits and reduces the upper limit of the high-pressure bypass valve command, thereby achieving the goal of stabilizing the industrial extraction steam pressure during the reduction of the unit load command. Attached Figure Description

[0019] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 This is a system diagram of the control system for high-pressure bypass steam extraction based on high exhaust pressure differential optimization according to the present invention.

[0021] Figure 2 This is a schematic diagram of the control system for high-pressure bypass steam extraction based on high exhaust pressure differential optimization according to the present invention.

[0022] Figure 3 This is a schematic diagram of the control system for high-pressure bypass steam extraction based on high exhaust pressure differential optimization according to the present invention.

[0023] Figure 4 This is a rendering of an embodiment of the present invention.

[0024] Explanation of reference numerals in the attached figures: 001. Heating high-pressure bypass valve; 002. Desuperheating water regulating valve; 003. High-pressure exhaust check valve; 004. Industrial extraction steam regulating valve; 005. Main steam valve; 006. High-pressure cylinder; 007. Superheated steam; 008. Cold reheat steam; 009. Temperature T1; 010. High-pressure exhaust steam pressure P1; 011. Pressure P2 after pressure reduction and desuperheating of the heating high-pressure bypass valve; 012. Target load command issued from the power grid load command; 013. Deviation between the target load and the rate-based load command; 014. Heating high-pressure bypass valve Door feedback ≥5%; 015, High-pressure cylinder exhaust pressure; 016, Steam pressure after the heating high-pressure bypass valve; 017, High-pressure exhaust check valve open feedback; 018, High-pressure cylinder exhaust temperature; 019, Industrial extraction steam regulating valve feedback; 020, First function module; 021, Second function module; 022, Third function module; 023, First subtraction module; 024, First greater than comparison module; 025, First less than comparison module; 026, Second greater than comparison module; 027, First AND module Block; 028, First Inertia Function Module; 029, First Constant Module; 030, First Switching Module; 031, Second Subtraction Module; 032, First Feedforward Module; 033, Expected Pressure Value of Industrial Extraction Steam; 034, Load Command after Target Load Command has passed through Load High and Low Limits and Variable Load Rate; 035, Third Subtraction Module; 036, Fourth Function Module; 037, Third Greater Than Comparison Module; 038, Fourth Subtraction Module; 039, Fourth Greater Than Comparison Module; 040 041. First NOT module; 042. First OR module; 043. Second AND module; 044. Second less than comparison module; 045. Fifth greater than comparison module; 046. First PID module; 047. Third AND module; 048. Second constant module; 049. Third constant module; 050. Second switching module; 051. First large selection module; 052. First small selection module; 053. Third switching module; 054. Control command for high-pressure bypass participation in steam extraction based on high-pressure differential optimization. Detailed Implementation

[0025] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0026] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0027] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0028] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0029] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0030] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0031] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0032] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0033] The accompanying drawings illustrate various structural schematic diagrams according to embodiments disclosed in this invention. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0034] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0035] The Figure 1 The present invention provides a system diagram of a control system for high-pressure bypass steam extraction based on high exhaust pressure differential optimization.

[0036] Specifically, it includes: heating high-pressure bypass valve 001, desuperheating water regulating valve 002, high-pressure exhaust check valve 003, industrial extraction steam regulating valve 004, main steam valve 005, high-pressure cylinder 006, superheated steam 007, cold reheated steam 008, temperature T1009, high-pressure exhaust steam pressure P1010, and pressure after pressure reduction and desuperheating of heating high-pressure bypass valve P2011.

[0037] Example 1 The present invention provides a control system based on high exhaust pressure differential optimization with high bypass participation in steam extraction. Figure 2 The present invention is based on the schematic diagram of a control system for high-pressure bypass steam extraction under high exhaust pressure differential optimization.

[0038] Specifically, it includes: target load command issued by the power grid load command 012, deviation value between target load and rate-based load command 013, feedback of ≥5% from the high-pressure bypass valve of the heating system 014, pressure of exhaust steam from the high-pressure cylinder 015, steam pressure after the high-pressure bypass regulating valve of the heating system 016, feedback that the high-pressure exhaust check valve is open 017, temperature of exhaust steam from the high-pressure cylinder 018, feedback from the industrial extraction steam regulating valve 019, first function module 020, second function module 021, third function module 022, first subtraction module 023, first greater than comparison module 024, first less than comparison module 025, second greater than comparison module 026, first AND module 027, first inertia function module 028, first constant module 029, first switching module 030, second subtraction module 031, and first feedforward module 032.

[0039] The Figure 3 This is a schematic diagram of the control system for high-pressure bypass steam extraction based on high exhaust pressure differential optimization according to the present invention.

[0040] Specifically, it includes: feedback from the high-pressure bypass valve (≥5%) 014, pressure of high-pressure cylinder exhaust steam 015, steam pressure after the high-pressure bypass regulating valve 016, feedback that the high-pressure exhaust check valve is open 017, temperature of high-pressure cylinder exhaust steam 018, feedback from the industrial extraction steam regulating valve 019, first feedforward module 032, expected pressure value of industrial extraction steam 033, target load command after passing through load high and low limits and load change rate 034, third phase subtraction module 035, fourth function module 036, third greater than comparison module 037, fourth phase Subtraction module 038, Fourth greater than comparison module 039, First NOT module 040, First OR module 041, Second AND module 042, Second less than comparison module 043, Fifth greater than comparison module 044, First PID module 045, Third AND module 046, Second constant module 047, Third constant module 048, Second switching module 049, First large selection module 050, First small selection module 051, Third switching module 052, Control command for high-pressure bypass participation in steam extraction based on high-pressure differential optimization 053.

[0041] Figure 1 The system diagram includes the following parts: based on Figure 1The system includes a heating high-pressure bypass valve (001), a desuperheating water regulating valve (002), a high-pressure exhaust check valve (003), an industrial extraction steam regulating valve (004), a main steam valve (005), a high-pressure cylinder (006), superheated steam (007), cold reheat steam (008), a temperature (T1009), high-pressure exhaust steam pressure (P1010), and a high-pressure bypass pressure after depressurization and desuperheating (P2011). This control method and system, based on changes in the high-pressure exhaust pressure difference and according to the direction and step size of the unit load command, predicts the heating high-pressure bypass opening command in advance. Based on the status signal of the high-pressure exhaust check valve and the opening of the industrial extraction steam regulating valve, it limits the lower and upper limits of the heating high-pressure bypass opening. Based on changes in the high-pressure cylinder exhaust temperature and the pressure difference before and after the high-pressure exhaust, it limits and forces the reduction of the high-pressure bypass valve command, achieving the goal of stabilizing the industrial extraction steam pressure during the reduction of the unit load command.

[0042] Figure 2 The control strategy logic diagram includes the following parts: The target load command 012, issued by the power grid load command, is connected to the first function module 020; the deviation value 013 between the target load and the rate-based load command is connected to the second function module 021 and the third function module 022, respectively. The outputs of the second function module 021 and the third function module 022 are both connected to the first inertial function module 028; the pressure 015 of the high-pressure cylinder exhaust and the steam pressure 016 after the heating high-pressure bypass valve are both connected to the first subtraction module 023. The output of the first subtraction module 023 is connected to the second greater than comparison module 026; the temperature 018 of the high-pressure cylinder exhaust is connected to the first greater than comparison module 024; and the feedback 019 of the industrial extraction steam regulating valve is connected to the first less than comparison module 026. Compared to module 025, the output terminals of the heating high-voltage bypass valve feedback ≥5% 014, the second greater than comparison module 026, the high-voltage check valve open feedback 017, the first greater than comparison module 024, and the first less than comparison module 025 are all connected to the first AND module 027; the output terminals of the first AND module 027, the first inertial function module 028, and the first constant module 029 are respectively connected to the enable trigger terminal, the "Y" terminal, and the "N" terminal of the first switching module 030; the output terminals of the first function module 020 and the first switching module 030 are both connected to the second subtraction module 031, and the output terminal of the second subtraction module 031 is connected to the first feedforward module 032.

[0043] Figure 3 The control strategy logic diagram includes the following parts: The desired industrial extraction steam pressure (033) and the steam pressure (016) after the high-pressure bypass valve for heating are both connected to the third subtraction module (035), and the output of the third subtraction module (035) is connected to the fourth function module (036). The temperature (018) of the high-pressure cylinder exhaust is connected to the third greater than comparison module (037), and the pressure (015) of the high-pressure cylinder exhaust and the steam pressure (016) after the high-pressure bypass valve for heating are both connected to the fourth subtraction module (038). The output of the fourth subtraction module (038) is connected to the fourth greater than comparison module (039), and the feedback (017) indicating that the high-pressure exhaust check valve is open is connected to the first non-mode module. Block 040, the output terminals of the third greater than comparison module 037, the fourth greater than comparison module 039, and the first non-module 040 are all connected to the first OR module 041; the output terminals of the first OR module 041 and the output terminal of the heating high bypass valve feedback ≥5% 014 are all connected to the second AND module 042; the output terminals of the fourth function module 036, the steam pressure after the heating high bypass valve 016, and the output terminal of the second AND module 042 are sequentially connected to the "in", "F", and "||" terminals of the first PID module 045.

[0044] The target load command, after passing through load high and low limits and variable load rate, is connected to the second less-than comparison module 043. The industrial extraction steam regulating valve feedback 019 is connected to the fifth greater-than comparison module 044. The outputs of both the second less-than comparison module 043 and the fifth greater-than comparison module 044 are connected to the third AND module 046. The output of the third AND module 046, the second constant module 047, and the third constant module 048 are respectively connected to the enable trigger terminal, the "Y" terminal, and the "N" terminal of the second switching module 049. The first PID module 0... The output terminals of 45 and the second switching module 049 are both connected to the first large selection module 050; the output terminals of the second and third switching modules 042, the third switching module 052, and the first small selection module 051 are respectively connected to the enable trigger terminal, the "Y" terminal, and the "N" terminal of the third switching module 052; the output terminals of the first large selection module 050 and the third switching module 052 are both connected to the first small selection module 051, and the output terminal of the first small selection module 051 is connected to the control command 053 for high-pressure bypass participation in steam extraction based on high-pressure differential optimization.

[0045] Example 2 The control method for high-pressure bypass steam extraction based on high exhaust pressure differential optimization provided by this invention needs to be divided into the following steps: (1) The deviation value 013 of the target load and the rate after the load command is calculated by the second function module 021 and output as the opening value. After being calculated by the third function module 022, the deviation value of the target load and the rate after the load command is output as the inertial time, which is respectively applied to the first inertial function module 028. The pressure 015 of the high-pressure cylinder exhaust and the steam pressure 016 after the heating high bypass valve are calculated by the first subtraction module 023 and compared with the built-in constant "0" of the second greater than comparison module 026. The temperature 018 of the high-pressure cylinder exhaust is compared with the built-in constant "385" of the first greater than comparison module 024. The feedback 019 of the industrial extraction steam regulating valve is compared with the first less than comparison module. Comparing the built-in constant "45" of module 025, if the feedback from the high-pressure bypass valve ≥5% 014, the second greater than comparison module 026, the feedback from the high-pressure check valve already open 017, the first greater than comparison module 024, and the first less than comparison module 025 all output "1", then the output of the first switching module 030 is the output value of the first inertia function module 028; otherwise, the built-in constant "0" of the first constant module 029 is output. The target load command 012 sent from the power grid load command is calculated by the first function module 020 into a rate-based load command and output as an opening value. At the same time, it is calculated by the second subtraction module 031 with the output value of the first switching module to obtain the first feedforward module 032.

[0046] (2) The expected industrial extraction steam pressure 033 and the steam pressure 016 after the high-pressure bypass valve of the heating system are subtracted by the third subtraction module 035 and calculated by the fourth function module 036. The result is the deviation between the expected and actual industrial extraction steam pressure and the output is the pressure deviation value with dead zone. The temperature 018 of the high-pressure cylinder exhaust is compared with the built-in constant "390" of the third greater than comparison module 037. The pressure 015 of the high-pressure cylinder exhaust and the steam pressure 016 after the high-pressure bypass valve of the heating system are calculated by the fourth subtraction module 038 and compared with the built-in constant "0" of the fourth greater than comparison module 039. The feedback 017 of the high-pressure exhaust check valve being open is not calculated by the first non module 040. When the output value of the third greater than comparison module 037 or the fourth greater than comparison module 039 or the first non module 040 is "1", and the feedback of the high-pressure bypass valve of the heating system is ≥5% 014 and is "1", then the output of the second AND module 042 is "1". The output terminals of the fourth function module 036, the steam pressure 016 after the high-pressure bypass valve, and the output terminal of the second AND module 042 are sequentially connected to the "in", "F", and "||" terminals of the first PID module 045. The target load command, after passing through high and low load limits and varying load rates, is compared with the built-in constant of the second less-than comparison module 043. The feedback from the industrial extraction steam regulating valve 019 is compared with the built-in constant of the fifth greater-than comparison module 044. If both outputs are "1", then the third AND module 046 outputs "1", and the second switching module 049 outputs the built-in constant "10" of the second constant module 047; otherwise, the built-in constant "0" of the third constant module 048 is "0". The output values ​​of the first PID module 045 and the second switching module 049 are compared by the first selection module 050. When the second AND module 042 outputs "1", the third switching module 052 outputs its previous value; otherwise, it outputs the value of the first smaller selection module 051. After the output value of the first selection module 050 and the output value of the third switching module 052 are compared by the first sub-select module 051, the final output is the control command 053 based on the high-pressure differential pressure optimization of the high-pressure bypass steam extraction.

[0047] (3) Main functions: In the event of changes in unit load command, the flow function is calculated based on the load command after the rate and the direction and amplitude function of the load change. The changes in the opening degree of the high-pressure bypass are predicted in advance to make up for the impact of the high-pressure cylinder exhaust steam change on the industrial extraction steam pressure fluctuation. The high-pressure bypass is limited to be effective only under the following safety boundaries: the high-pressure bypass is not closed, the high-pressure exhaust check valve is fully open and the pressure difference before and after it is positive, the high-pressure cylinder exhaust steam temperature is not higher than the alarm value and the industrial extraction steam regulating valve has insufficient opening margin. The high-pressure bypass PID control loop is constructed based on the stable constant industrial extraction steam pressure. When the unit load command is lower than the limit and the opening degree of the industrial extraction steam regulating valve is greater than the limit, the minimum opening degree of the high-pressure bypass is limited. When approaching the safety boundary of the high-pressure bypass, the maximum opening degree of the high-pressure bypass is limited first. If the high-pressure exhaust pressure difference continues to decrease, the high-pressure bypass is forcibly closed or even fully closed.

[0048] Example 3 like Figure 4 As shown, through the implementation and application of the technology of this invention, in the deep adjustment mode of the unit's coordinated control process, the unit load is between 105MW and 145MW, and the load change rate is 2.2%Pe / min. This includes: 1. Target load setting (60-300MW); 2. Unit load command (60-300MW); 3. Actual unit power generation (60-300MW); 4. Set main steam pressure (0-28MPa); 5. Actual main steam pressure (0-28MPa); 6. Main steam temperature (0-580℃); 7. Reheat steam temperature (0-580℃); 8. Intermediate point temperature setting (320-620℃); 9. Actual intermediate point temperature (320-620℃). When the industrial extraction steam reaches the design level, during the non-heating season, a single unit meets a total industrial extraction steam flow of not less than 600t / h for both primary and secondary units, of which the primary industrial extraction steam flow is not less than 40t / h, and the unit's peak-shaving target load reaches 30%Pe demand. The unit's primary frequency regulation and AGC control can be continuously activated, all parameters are under safe control, all protection functions of the main and auxiliary units are in normal operation, and environmental protection indicators meet emission requirements.

[0049] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the scope of the invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0050] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that can be understood by those skilled in the art. The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A control system based on high exhaust pressure differential optimization with high bypass steam extraction, characterized in that, It includes a first function module (020), a second function module (021), a third function module (022), a first subtraction module (023), a first greater than comparison module (024), a first less than comparison module (025), a second greater than comparison module (026), a first AND module (027), a first inertial function module (028), a first constant module (029), a first switching module (030), a second subtraction module (031), and a first feedforward module (032); The output terminals of the second function module (021) and the third function module (022) are both connected to the first inertial function module (028); the output terminal of the first subtraction module (023) is connected to the second greater than comparison module (026), and the output terminals of the second greater than comparison module (026), the first greater than comparison module (024), and the first less than comparison module (025) are all connected to the first AND module (027); the output terminals of the first AND module (027), the first inertial function module (028), and the first constant module (029) are respectively connected to the enable trigger terminal, the "Y" terminal, and the "N" terminal of the first switching module (030); the output terminals of the first function module (020) and the first switching module (030) are both connected to the second subtraction module (031), and the output terminal of the second subtraction module (031) is connected to the first feedforward module (032).

2. The control system based on high exhaust pressure differential optimization with high bypass steam extraction as described in claim 1, characterized in that, The target load command (012) issued by the power grid load command is connected to the first function module (020); the deviation value (013) between the target load and the rate-following load command is connected to the second function module (021) and the third function module (022), respectively.

3. The control system based on high exhaust pressure differential optimization with high bypass steam extraction as described in claim 2, characterized in that, The pressure of the high-pressure cylinder exhaust (015) and the steam pressure after the heating high bypass valve (016) are both connected to the first subtraction module (023).

4. The control system based on high exhaust pressure differential optimization with high bypass steam extraction as described in claim 3, characterized in that, The temperature of the high-pressure cylinder exhaust steam (018) is connected to the first greater than comparison module (024), and the feedback of the industrial extraction steam regulating valve (019) is connected to the first less than comparison module (025).

5. The control system based on high exhaust pressure differential optimization with high bypass steam extraction as described in claim 4, characterized in that, The feedback of the high-pressure bypass valve for heating ≥5% (014) and the feedback of the high-pressure check valve being open (017) are both connected to the first AND module (027).

6. The control system based on high exhaust pressure differential optimization with high bypass steam extraction as described in claim 5, characterized in that, It also includes a third subtraction module (035), a fourth function module (036), a third greater than comparison module (037), a fourth subtraction module (038), a fourth greater than comparison module (039), a first NOT module (040), a first OR module (041), a second AND module (042), a second less than comparison module (043), a fifth greater than comparison module (044), a first PID module (045), a third AND module (046), a second constant module (047), a third constant module (048), a second switching module (049), a first large selection module (050), a first small selection module (051), and a third switching module (052). The output of the third subtraction module (035) is connected to the fourth function module (036); the output of the fourth subtraction module (038) is connected to the fourth greater than comparison module (039); the outputs of the third greater than comparison module (037), the fourth greater than comparison module (039), and the first NOT module (040) are all connected to the first OR module (041); the output of the first OR module (041) is connected to the second AND module (042); the outputs of the fourth function module (036) and the second AND module (042) are connected sequentially to the "in" terminal and the "||" terminal of the first PID module (045); The output terminals of the second less than comparison module (043) and the fifth greater than comparison module (044) are both connected to the third AND module (046); the output terminals of the third AND module (046), the second constant module (047), and the third constant module (048) are respectively connected to the enable trigger terminal, the "Y" terminal, and the "N" terminal of the second switching module (049); the output terminals of the first PID module (045) and the second switching module (049) are both connected to the first large selection module (050); the output terminals of the second AND module (042), the third switching module (052), and the first small selection module (051) are respectively connected to the enable trigger terminal, the "Y" terminal, and the "N" terminal of the third switching module (052); the output terminals of the first large selection module (050) and the third switching module (052) are both connected to the first small selection module (051), and the output terminal of the first small selection module (051) is connected to the control command (053) for high-pressure bypass participation in steam extraction based on high-pressure differential optimization.

7. The control system based on high exhaust pressure differential optimization with high bypass steam extraction as described in claim 6, characterized in that, The desired industrial extraction steam pressure (033) and the steam pressure after the high-pressure bypass valve for heating (016) are both connected to the third phase subtraction module (035), and the exhaust steam pressure of the high-pressure cylinder (015) and the steam pressure after the high-pressure bypass valve for heating (016) are both connected to the fourth phase subtraction module (038).

8. The control system based on high exhaust pressure differential optimization with high bypass steam extraction as described in claim 7, characterized in that, The feedback (017) of the high-pressure check valve being opened is connected to the first non-module (040), the output of the feedback (014) of the high-pressure bypass valve is connected to the second module (042), and the steam pressure (016) after the high-pressure bypass valve is connected to the "F" terminal of the first PID module (045).

9. The control system based on high exhaust pressure differential optimization with high bypass steam extraction as described in claim 8, characterized in that, The temperature of the high-pressure cylinder exhaust steam (018) is connected to the third greater than comparison module (037), the target load command after passing through the load high and low limit limits and the load change rate (034) is connected to the second less than comparison module (043), and the industrial extraction steam regulating valve feedback (019) is connected to the fifth greater than comparison module (044).

10. A control method for high-pressure bypass steam extraction based on high-pressure differential optimization, characterized in that, This method, based on the control system of high-pressure bypass participation in steam extraction under high exhaust pressure differential optimization as described in claim 9, includes: The deviation value (013) between the target load and the rate-based load command is calculated by the second function module (021) and output as the opening value. The deviation value is also calculated by the third function module (022) and output as the inertial time. These values ​​are then applied to the first inertial function module (028). The pressure (015) of the high-pressure cylinder exhaust and the steam pressure (016) after the heating high-pressure bypass valve are calculated by the first subtraction module (023) and compared with the built-in constant "0" of the second greater than comparison module (026). The temperature (018) of the high-pressure cylinder exhaust is compared with the built-in constant "385" of the first greater than comparison module (024). The feedback (019) of the industrial extraction steam regulating valve is compared with the first less than comparison module. (025) Compare the built-in constant "45". If the feedback of the high-pressure bypass valve of the heating system is ≥5% (014), the second greater than comparison module (026), the feedback of the high-pressure check valve being open (017), the first greater than comparison module (024), and the first less than comparison module (025) all output "1", then the output of the first switching module (030) is the output value of the first inertial function module (028). Otherwise, the built-in constant "0" of the first constant module (029) is output. The target load command (012) sent by the power grid load command is calculated by the first function module (020) and becomes the rate load command and is output as the opening value. At the same time, it is calculated by the second subtraction module (031) with the output value of the first switching module to obtain the first feedforward module (032). The expected industrial extraction steam pressure (033) and the steam pressure (016) after the high-pressure bypass valve are subtracted by the third subtraction module (035), and then calculated by the fourth function module (036) to be the deviation between the expected and actual industrial extraction steam pressure, which is output as a pressure deviation value with dead zone. The temperature (018) of the high-pressure cylinder exhaust is compared with the built-in constant "390" of the third greater than comparison module (037). The pressure (015) of the high-pressure cylinder exhaust and the steam pressure (016) after the high-pressure bypass valve are calculated by the fourth subtraction module (038) and compared with the value of the fourth greater than comparison module (037). 039) The built-in constant "0" is used for comparison. The feedback of the high-pressure check valve being open (017) is not calculated by the first non-module (040). When the output value of the third greater than comparison module (037) or the fourth greater than comparison module (039) or the output value of the first non-module (040) is "1", and at the same time the feedback of the high-pressure bypass valve is ≥5% (014) and is "1", then the output of the second AND module (042) is "1". The output of the fourth function module (036), the steam pressure after the high-pressure bypass valve (016) and the output of the second AND module (042) are connected in sequence to the first P The "in", "F", and "||" terminals of the ID module (045); the load command (034) after the target load command passes through the load high and low limit limits and the variable load rate is compared with the built-in constant of the second less than comparison module (043), and the feedback of the industrial extraction steam regulating valve (019) is compared with the built-in constant of the fifth greater than comparison module (044). If both output "1", then the output of the third AND module (046) is "1", then the output of the second switching module (049) is the built-in constant "10" of the second constant module (047). Otherwise, the output of the third constant module (048) is "10". Set constant "0"; compare the output value of the first PID module (045) with the output value of the second switching module (049) through the first selection module (050); when the output of the second AND module (042) is "1", the output of the third switching module (052) is its previous value, otherwise, the output value of the first small selection module (051) is output; after the output value of the first selection module (050) and the output value of the third switching module (052) are compared through the first small selection module (051), its final output is the control command (053) based on the high-pressure differential optimization of the high-pressure differential and the high-pressure auxiliary steam extraction.

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