Thermal power plant bypass control method based on DCS system
Through the bypass control method of the DCS system, the main steam pressure and valve characteristics of the thermal power plant are optimized, and the economic problems during low-load operation are solved, and the efficient and energy-saving effect of sliding pressure operation is achieved.
Patent Information
- Application Number
- CN202510472088.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-16
- Publication Date
- 2025-07-11
AI Technical Summary
When existing thermal power plants operate at low loads, the main steam pressure setting deviates from the actual working conditions, resulting in large throttling of the door, reducing the unit economy, and failing to obtain the optimal operating pressure and valve characteristics through tests, making it difficult to optimize the sliding pressure curve.
The thermal power plant bypass control method based on DCS system, through characteristic analysis, sliding pressure control and control efficiency analysis, the main steam pressure setting and valve characteristics are optimized, and the reasonable sliding pressure curve is re-determined, and the sliding pressure operation is changed to sliding pressure operation to reduce throttling losses and improve economicality.
The efficiency of main steam pressure regulation and the economic efficiency of the unit are improved, reducing throttling losses, improving the working efficiency of the unit and the coal-saving and consumption reduction effect.
Smart Images
Figure CN120295257A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of thermal power plant control, and specifically to a bypass control method for a thermal power plant based on a DCS system. Background Art
[0002] The heat storage capacities of different boilers vary. For boilers with stronger heat storage capacity, when the load changes, the adjustment of the main steam pressure can be relatively gentle, and the heat storage of the boiler is utilized to meet short-term load demands and avoid excessive pressure fluctuations; for example, in units using drum boilers, the water volume of the drum is large and the heat storage capacity is strong, and the change rate of the pressure setting can be appropriately reduced during sliding pressure operation.
[0003] When the existing units operate at low load, the main steam pressure setting is still the rated value, seriously deviating from the actual operating conditions, with large throttle of the control valves, reducing the economy of the units; the optimal operating pressure and valve characteristics of the units cannot be obtained through tests, so that a reasonable sliding pressure curve cannot be re-optimized and determined.
[0004] In view of the above technical defects, a solution is now proposed. Summary of the Invention
[0005] The purpose of the present invention is to solve the above-mentioned problems and propose a bypass control method for a thermal power plant based on a DCS system.
[0006] The purpose of the present invention can be achieved through the following technical solutions: A bypass control method for a thermal power plant based on a DCS system, and the process of the bypass control method is as follows: Characteristic analysis: Perform characteristic analysis on the unit, infer the influence of the current unit operating conditions on the main steam pressure setting based on the unit characteristic analysis, and perform pressure adjustment of the unit through the influence evaluation of the main steam pressure setting; Sliding pressure control: Obtain the optimal operating pressure and valve characteristics of the unit through tests, and at the same time re-optimize and determine a reasonable sliding pressure curve, and change the unit operation mode from constant pressure operation to sliding pressure operation; Control efficiency analysis: Infer whether there is an impact on the operation of the unit through efficiency data analysis, and at the same time be able to infer whether the efficiency of the sliding pressure control meets the requirements of pressure regulation based on the real-time energy consumption analysis of the unit.
[0007] As a preferred implementation manner of the present invention, the process of the characteristic analysis is as follows: Collect the floating span of the throttle steam flow of the unit during the floating of the operating load during the operation of the unit. At the same time, obtain the buffer duration between the floating moment of the operating load and the floating moment of the throttle steam flow of the unit during the operation of the unit, and compare the floating span of the throttle steam flow of the unit during the floating of the operating load during the operation of the unit, and the buffer duration between the floating moment of the operating load and the floating moment of the throttle steam flow of the unit during the operation of the unit with the flow floating span threshold and the buffer duration threshold respectively.
[0008] As a preferred embodiment of the present invention, if the floating span of the throttle steam flow of the unit during the floating of the operating load during the operation of the unit exceeds the flow floating span threshold, or the buffer duration between the floating moment of the operating load and the floating moment of the throttle steam flow of the unit during the operation of the unit does not exceed the buffer duration threshold, then mark the operation process of the current unit as a high-impact process, and perform real-time adjustment of the main steam pressure when the unit load floats during the high-impact process; If the floating span of the throttle steam flow of the unit during the floating of the operating load during the operation of the unit does not exceed the flow floating span threshold, and the buffer duration between the floating moment of the operating load and the floating moment of the throttle steam flow of the unit during the operation of the unit exceeds the buffer duration threshold, then mark the operation process of the current unit as a negative-impact process, and perform adaptive adjustment of the main steam pressure when the unit load floats during the high-impact process.
[0009] As a preferred embodiment of the present invention, the sliding pressure control process is as follows: Collect the operation data of the unit according to the operation process of the unit, where the operation data is represented as the coal consumption of the unit and the real-time power generation at each operation moment; perform numerical ratio calculation according to the coal consumption and power generation to obtain the coal-to-production ratio; And compare according to the coal-to-production ratio at each operation moment during the operation process to obtain the operation pressure value and valve opening degree corresponding to the operation moment when the coal-to-production ratio exceeds the set threshold, and collect the operation pressure value and valve opening degree at each operation moment according to the floating of the coal-to-production ratio to construct a pressure curve and a valve opening curve.
[0010] As a preferred embodiment of the present invention, according to the analysis of the pressure curve, determine the optimal main steam pressure setting value in different load intervals at each operation moment to form an optimized pressure setting curve; at the same time, perform synchronous analysis according to the pressure setting curve and the valve opening curve, and infer whether the current pressure setting curve can be adapted according to the numerical range of the valve opening curve. If not, perform numerical adjustment on the pressure setting curve and construct a curve with the adjusted value, marked as the actual sliding pressure control curve; send the pressure setting curve and the actual sliding pressure control curve to the administrator terminal together, and the administrator terminal performs sliding pressure control on the unit operation after receiving it.
[0011] As a preferred embodiment of the present invention, the control efficiency analysis process is as follows: Obtain the span value of the decrease in the average consumption - production ratio before and after the implementation of sliding - pressure control during the operation of the unit. At the same time, obtain the increase span of the peak power generation corresponding to the coal consumption per unit volume after sliding - pressure control during the operation of the unit. Then compare the span value of the decrease in the average consumption - production ratio before and after the implementation of sliding - pressure control during the operation of the unit and the increase span of the peak power generation corresponding to the coal consumption per unit volume after sliding - pressure control during the operation of the unit with the average - decrease span threshold and the peak - increase span threshold respectively.
[0012] As a preferred embodiment of the present invention, if the span value of the decrease in the average consumption - production ratio before and after the implementation of sliding - pressure control during the operation of the unit does not exceed the average - decrease span threshold, or the increase span of the peak power generation corresponding to the coal consumption per unit volume after sliding - pressure control during the operation of the unit does not exceed the peak - increase span threshold, then lower the current actual sliding - pressure control curve. If the span value of the decrease in the average consumption - production ratio before and after the implementation of sliding - pressure control during the operation of the unit exceeds the average - decrease span threshold, and the increase span of the peak power generation corresponding to the coal consumption per unit volume after sliding - pressure control during the operation of the unit exceeds the peak - increase span threshold, then gradually adjust the current actual sliding - pressure control curve towards the pressure - setting curve, and stop the adjustment when the real - time operating consumption - production ratio increases.
[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: In the present invention, the characteristics of the unit are analyzed. Based on the analysis of the unit characteristics, the influence of the current unit operating conditions on the main steam pressure setting is inferred. Through the evaluation of the influence of the main steam pressure setting, the pressure adjustment of the unit is carried out, and the high efficiency of the main steam pressure regulation is ensured. By conducting tests to obtain the optimal operating pressure and valve characteristics of the unit, and at the same time re - optimizing and determining a reasonable sliding - pressure curve, the unit operation mode is changed from constant - pressure operation to sliding - pressure operation. It can achieve reducing throttling losses and improving the economy of the unit while maintaining relatively high parameters, and further save coal and reduce consumption. By analyzing the efficiency data, it is inferred whether there is an impact on the operation of the unit. At the same time, it can be inferred whether the efficiency of the sliding - pressure control meets the requirements of pressure regulation based on the real - time energy consumption analysis of the unit, so as to improve the working efficiency of the entire unit. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] For the convenience of those skilled in the art to understand, the present invention will be further described below with reference to the accompanying drawings.
[0015] Figure 1 is the flowchart of the method of the present invention; Figure 2 is the flowchart of the sliding - pressure control process of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0016] To enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.
[0017] Referring to "embodiments" herein means that the specific features, structures or characteristics described in connection with the embodiments may be included in at least one embodiment of the present invention. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein may be combined with other embodiments.
[0018] Please refer to Figure 1 As shown, for the bypass control method of a thermal power plant based on a DCS system, the specific bypass control method process is as follows: Characteristic analysis: Analyze the characteristics of the unit, infer the influence of the current unit operating conditions on the main steam pressure setting through the unit characteristic analysis, perform the influence assessment of the main steam pressure setting to adjust the pressure of the unit, and ensure the high efficiency of the main steam pressure regulation; Sliding pressure control: Obtain the optimal operating pressure and valve characteristics of the unit through tests, and at the same time re-optimize and determine a reasonable sliding pressure curve. The unit operating mode is changed from constant pressure operation to sliding pressure operation, which can reduce throttling losses and improve the economy of the unit while maintaining relatively high parameters, and further save coal and reduce consumption; Control efficiency analysis: Infer whether there is an impact on the operation of the unit through the analysis of efficiency data, and at the same time be able to infer whether the efficiency of the sliding pressure control meets the requirements of pressure regulation according to the real-time energy consumption analysis of the unit, so as to improve the working efficiency of the entire unit; The process of characteristic analysis is as follows: Collect the floating span of the throttle flow of the unit during the floating of the operating load during the operation of the unit, and at the same time obtain the buffer duration between the floating moment of the operating load and the floating moment of the throttle flow of the unit during the operation of the unit, and compare the floating span of the throttle flow of the unit during the floating of the operating load during the operation of the unit and the buffer duration between the floating moment of the operating load and the floating moment of the throttle flow of the unit during the operation of the unit with the flow floating span threshold and the buffer duration threshold respectively: If during the operation of the unit, when the operating load fluctuates, the floating span of the throttle steam flow of the unit exceeds the flow floating span threshold, or when the operating load fluctuates during the operation of the unit, the buffer duration between the moment of the operating load fluctuation and the moment of the throttle steam flow fluctuation of the unit does not exceed the buffer duration threshold, it is inferred that the operating characteristics of the unit are affected by high load. Mark the operating process of the current unit as a high-impact process, and perform real-time adjustment of the main steam pressure when the unit load fluctuates during the high-impact process; If during the operation of the unit, when the operating load fluctuates, the floating span of the throttle steam flow of the unit does not exceed the flow floating span threshold, and when the operating load fluctuates during the operation of the unit, the buffer duration between the moment of the operating load fluctuation and the moment of the throttle steam flow fluctuation of the unit exceeds the buffer duration threshold, it is inferred that the operating characteristics of the unit are affected by low load. Mark the operating process of the current unit as a negative-impact process, and perform adaptive adjustment of the main steam pressure when the unit load fluctuates during the high-impact process; among them, real-time adjustment means that after the load fluctuates, real-time adjustment is carried out according to the set adjustment span, and adaptive adjustment is gradually carried out according to the real-time operating state after the load fluctuates; Please refer to Figure 2 As shown in the figure, the sliding pressure control process is as follows: Collect the unit operation data according to the unit operation process, where the operation data is represented as the coal consumption and real-time power generation of the unit at each operation moment; calculate the numerical ratio according to the coal consumption and power generation to obtain the coal-to-production ratio. When calculating the ratio of coal consumption to power generation, only the numerical values are calculated, regardless of the influence of inconsistent units; And compare the coal-to-production ratio at each operation moment during the operation process to obtain the corresponding operation pressure value and valve opening degree at the operation moment when the coal-to-production ratio exceeds the set threshold. Collect the operation pressure value and valve opening degree at each operation moment according to the fluctuation of the coal-to-production ratio, and construct a pressure curve and a valve opening curve; According to the analysis of the pressure curve, determine the optimal main steam pressure setting value in different load intervals at each operation moment to form an optimized pressure setting curve; at the same time, perform synchronous analysis according to the pressure setting curve and the valve opening curve, and infer whether the current pressure setting curve can be adapted according to the numerical range of the valve opening curve. If it is not adapted, adjust the numerical value of the pressure setting curve and construct a curve with the adjusted numerical value, which is marked as the actual sliding pressure control curve; send the pressure setting curve and the actual sliding pressure control curve to the administrator terminal together, and the administrator terminal performs sliding pressure control on the unit operation after receiving it; The control efficiency analysis process is as follows: Obtain the span value of the decrease in the average consumption-production ratio before and after the implementation of sliding pressure control during the operation of the unit. At the same time, obtain the increase span of the peak power generation corresponding to the coal consumption per unit volume after the sliding pressure control during the operation of the unit. Compare the span value of the decrease in the average consumption-production ratio before and after the implementation of sliding pressure control during the operation of the unit and the increase span of the peak power generation corresponding to the coal consumption per unit volume after the sliding pressure control during the operation of the unit with the average decrease span threshold and the peak increase span threshold respectively: If the span value of the decrease in the average consumption-production ratio before and after the implementation of sliding pressure control during the operation of the unit does not exceed the average decrease span threshold, or the increase span of the peak power generation corresponding to the coal consumption per unit volume after the sliding pressure control during the operation of the unit does not exceed the peak increase span threshold, it is inferred that the sliding pressure control efficiency during the operation of the unit is unqualified, and the current actual sliding pressure control curve is lowered; If the span value of the decrease in the average consumption-production ratio before and after the implementation of sliding pressure control during the operation of the unit exceeds the average decrease span threshold, and the increase span of the peak power generation corresponding to the coal consumption per unit volume after the sliding pressure control during the operation of the unit exceeds the peak increase span threshold, it is inferred that the sliding pressure control efficiency during the operation of the unit is qualified, and the current actual sliding pressure control curve is gradually adjusted towards the pressure setting curve, and the adjustment stops when the real-time operating consumption-production ratio increases; When the present invention is in use, characteristic analysis: conduct characteristic analysis on the unit, infer the influence of the current unit operating conditions on the main steam pressure setting according to the unit characteristic analysis, and conduct pressure adjustment of the unit through the influence evaluation of the main steam pressure setting; sliding pressure control: obtain the optimal operating pressure and valve characteristics of the unit through experiments, and at the same time re-optimize and determine a reasonable sliding pressure curve, and change the unit operating mode from constant pressure operation to sliding pressure operation; control efficiency analysis: infer whether there is an influence on the operation of the unit through efficiency data analysis, and at the same time be able to infer whether the efficiency of the sliding pressure control meets the requirements of pressure regulation according to the real-time energy consumption analysis of the unit.
[0019] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the present invention to only the specific implementation manners. Obviously, many modifications and variations can be made according to the content of this specification. These embodiments are selected and specifically described in this specification to better explain the principle and practical application of the present invention, so that those skilled in the relevant technical field can understand and utilize the present invention well. The present invention is only limited by the claims and their full scope and equivalents.
Claims
1. A bypass control method for a thermal power plant based on a DCS system, characterized in that, The bypass control method is as follows: Characteristic analysis: Conduct characteristic analysis on the unit, infer the influence of the current unit operating conditions on the main steam pressure setting based on the unit characteristic analysis, and conduct pressure adjustment of the unit through the influence assessment of the main steam pressure setting. Sliding pressure control: Obtain the optimal operating pressure and valve characteristics of the unit through tests, and re-optimize and determine a reasonable sliding pressure curve at the same time. The unit operating mode is changed from constant pressure operation to sliding pressure operation. Control efficiency analysis: Infer whether there is an impact on the unit operation through efficiency data analysis, and at the same time, infer whether the efficiency of the sliding pressure control meets the requirements of pressure regulation based on the real-time energy consumption analysis of the unit.
2. The bypass control method of a thermal power plant based on a DCS system according to claim 1, wherein The process of characteristic analysis is as follows: Collect the floating span of the throttle steam flow of the unit during the floating of the operating load in the unit operation process, and at the same time obtain the buffer duration between the floating moment of the operating load and the floating moment of the throttle steam flow in the unit operation process. Then compare the floating span of the throttle steam flow of the unit during the floating of the operating load in the unit operation process and the buffer duration between the floating moment of the operating load and the floating moment of the throttle steam flow in the unit operation process with the flow floating span threshold and the buffer duration threshold respectively.
3. The bypass control method for a thermal power plant based on a DCS system according to claim 2, wherein If the floating span of the throttle steam flow of the unit during the floating of the operating load in the unit operation process exceeds the flow floating span threshold, or the buffer duration between the floating moment of the operating load and the floating moment of the throttle steam flow in the unit operation process does not exceed the buffer duration threshold, then mark the operation process of the current unit as a high-impact process, and conduct real-time adjustment of the main steam pressure when the unit load floats in the high-impact process. If the floating span of the throttle steam flow of the unit during the floating of the operating load in the unit operation process does not exceed the flow floating span threshold, and the buffer duration between the floating moment of the operating load and the floating moment of the throttle steam flow in the unit operation process exceeds the buffer duration threshold, then mark the operation process of the current unit as a negative-impact process, and conduct adaptive adjustment of the main steam pressure when the unit load floats in the high-impact process.
4. The bypass control method for a thermal power plant based on the DCS system according to claim 1, wherein The process of sliding pressure control is as follows: Collect unit operation data according to the unit operation process, where the operation data is represented as the coal consumption and real-time power generation of the unit at each operation moment; calculate the numerical ratio according to the coal consumption and power generation to obtain the coal consumption to production ratio. And compare the coal consumption to production ratios at each operation moment during the operation process to obtain the corresponding operation pressure value and valve opening degree at the operation moment when the coal consumption to production ratio exceeds the set threshold. Collect the operation pressure value and valve opening degree at each operation moment according to the floating of the coal consumption to production ratio, and construct a pressure curve and a valve opening curve.
5. The bypass control method for a thermal power plant based on a DCS system according to claim 4, characterized in that, According to the pressure curve analysis, determine the optimal main steam pressure setting value in different load intervals at each operation moment to form an optimized pressure setting curve; at the same time, conduct synchronous analysis according to the pressure setting curve and the valve opening curve, and infer whether the current pressure setting curve can be adapted according to the numerical range of the valve opening curve. If not, adjust the numerical value of the pressure setting curve and construct a curve with the adjusted numerical value, which is marked as the actual sliding pressure control curve; send the pressure setting curve and the actual sliding pressure control curve to the administrator terminal together, and the administrator terminal conducts sliding pressure control on the unit operation after receiving them.
6. The bypass control method for a thermal power plant based on a DCS system according to claim 1, wherein The control efficiency analysis process is as follows: Obtain the mean decline span value of the power consumption - production ratio before and after the implementation of sliding - pressure control during the unit operation. At the same time, obtain the increase span of the power generation peak corresponding to the coal consumption per unit volume after the sliding - pressure control during the unit operation, and compare the mean decline span value of the power consumption - production ratio before and after the implementation of sliding - pressure control during the unit operation and the increase span of the power generation peak corresponding to the coal consumption per unit volume after the sliding - pressure control during the unit operation with the mean decline span threshold and the peak increase span threshold respectively.
7. The bypass control method for a thermal power plant based on a DCS system according to claim 6, wherein If the mean decline span value of the power consumption - production ratio before and after the implementation of sliding - pressure control during the unit operation does not exceed the mean decline span threshold, or the increase span of the power generation peak corresponding to the coal consumption per unit volume after the sliding - pressure control during the unit operation does not exceed the peak increase span threshold, then lower the current actual sliding - pressure control curve. If the mean decline span value of the power consumption - production ratio before and after the implementation of sliding - pressure control during the unit operation exceeds the mean decline span threshold, and the increase span of the power generation peak corresponding to the coal consumption per unit volume after the sliding - pressure control during the unit operation exceeds the peak increase span threshold, then gradually adjust the current actual sliding - pressure control curve towards the pressure - setting curve, and stop the adjustment when the real - time operation power consumption - production ratio increases.