A method for optimizing monitoring of start-stop process of thermal power unit based on curve

Abstract

The application discloses a method for monitoring and controlling the starting and stopping process of a thermal power unit based on curves, and relates to the technical field of power generation. The method for monitoring and controlling the starting and stopping process of a thermal power unit based on curves sets the unit starting and stopping type parameters and the starting and stopping type stages, and displays the data of the unit starting and stopping monitoring task in the form of a curve graph, thereby greatly saving manpower and improving the accuracy of business processing operations. The application is suitable for the change rate of the actual starting and stopping process of various units and the set standard process which needs to be displayed intuitively. The application monitors the parameter conditions of each stage of the starting and stopping process, displays the parameter trends of each stage of the starting and stopping process of the unit in different states, compares the parameter trends, and provides guidance and analysis functions for the starting and stopping operation.

Description

Technical Field

[0001] This invention relates to the field of power generation technology, specifically to a method for optimizing and monitoring the start-up and shutdown process of thermal power units based on curves. Background Technology

[0002] Thermal power generation technology is affected by the grid architecture, increased consumption of renewable energy, and the rise in inter-regional and inter-provincial power transactions. The average number of unit start-ups and shutdowns exceeds 60 per year, covering base load, deep peak-shaving load, and peak-shaving services. Frequent start-ups and shutdowns for peak shaving, short-term standby, and other operations lead to frequent equipment defects and increased operational difficulty, significantly increasing start-up costs and overall operating costs.

[0003] To effectively control unit start-up costs and reduce start-up energy consumption, analyzing the standard and actual curves of the start-up and shutdown processes of thermal power units can effectively improve the company's cost reduction and efficiency improvement capabilities, ensuring that the unit can achieve timely temperature rise, start-up, and grid connection. By configuring parameter measurement points and stage measurement point expressions for the unit equipment, and monitoring the changes in measurement point data and whether the expressions meet the stage conditions, it is possible to intuitively see whether the actual curves of real-time parameter changes during the start-up and shutdown process conform to the standard start-up and shutdown curves. This method includes monitoring of the start-up process and the post-shutdown process, providing an intuitive reference for the main parameters and their rate of change during the start-up and shutdown of thermal power units. This facilitates human intervention to optimize operation, ensuring a scientific evaluation of the start-up and shutdown performance, thereby guaranteeing the safety and reliability of unit start-up and shutdown.

[0004] Currently, a common method for determining the start-up and shutdown status of generating units is to obtain the unit's start-up and shutdown status from the unit's equipment maintenance checklist. However, this method only analyzes the unit's status at a specific moment and is too susceptible to external factors. It only provides qualitative analysis and lacks comparative analysis of real-time data changes during unit start-up and shutdown and changes in set standard lines. This prevents operators from intuitively optimizing unit operations based on the current start-up and shutdown process to ensure the unit equipment is in the correct state as accurately as possible. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for optimizing and monitoring the start-up and shutdown process of thermal power units based on curves.

[0006] To achieve the above objectives, the present invention employs the following technical solution:

[0007] A method for optimizing and monitoring the start-up and shutdown process of thermal power units based on curves includes the following steps:

[0008] Step 1: Obtain basic unit information and details of unit start-up and shutdown types;

[0009] Step 2: Obtain the set of monitoring parameters for the unit start-up and shutdown types;

[0010] Step 3: Obtain the monitoring phase set for the unit start-up and shutdown type;

[0011] Step 4: Obtain a random number as the identifier key for the start / stop type task, and destroy the start / stop task when the monitoring screen is closed;

[0012] The unit start-up and shutdown curves are obtained using the identifier Key;

[0013] Step 5: Obtain the real-time curve refresh task cycle, initialize the start / stop task, and start the start / stop task.

[0014] Furthermore, the specific steps in step 1 of obtaining the basic unit information and unit start-up / shutdown type details are as follows:

[0015] Obtain equipment group information from the portal system using equipment codes;

[0016] Retrieve start / stop type data from the database dictionary table;

[0017] The start / stop type data includes: hot start, cold start, extremely hot start / stop, sliding parameter stop, and temperature start;

[0018] Obtain the relevant details of the start-up and shutdown types for the unit.

[0019] Furthermore, the set of monitoring parameters for unit start-up and shutdown types in step 2 specifically includes:

[0020] Step 201: Obtain the set of all parameters for the start / stop type using the start / stop type ID;

[0021] Step 202: Obtain the standard curve of start / stop type parameters;

[0022] Step 203: Take the union of the X-axis time points of all start-stop type parameter standard curves, calculate the corresponding Y-axis values, and use the calculated values ​​as the Y-axis range of the standard curve.

[0023] Furthermore, the specific steps in step 3 of obtaining the monitoring phase set for unit start-up and shutdown types are as follows:

[0024] Retrieve the set of all stages of a start / stop type by start / stop type ID.

[0025] Furthermore, the unit start-up and shutdown monitoring task in step 4 also includes the following steps:

[0026] Step 401: Initialize and run the start / stop phase tasks, and generate an online start / stop report;

[0027] Step 402: Calculate the real-time value of the actual curve, obtain the measurement points for the parameter values, obtain the corresponding real-time values ​​through the measurement points, use the real-time values ​​as the Y-value of the real-time curve, and use the time as the X-axis coordinate of the real-time curve;

[0028] Step 403: If the monitoring task status is in the start monitoring state, proceed to step 404;

[0029] If the monitoring task is in a stopped monitoring state, proceed to step 405;

[0030] Step 404: Statistically determine the standard values ​​of the measured parameters at the measurement points, and simultaneously determine whether the requirements are met during the monitoring phase;

[0031] If the monitoring start condition expression is true, the crew monitoring task has now entered the aforementioned phase state; if the monitoring end condition expression is true, the crew monitoring task has ended the aforementioned phase state.

[0032] Step 405: Move the identifier Key by one cycle, and write the standard curve and actual curve screen data, start / stop type, start / stop parameters and start / stop stage data into the cache. The task waits for the next cycle to execute.

[0033] Furthermore, the generation of online reports for unit start-up and shutdown in step 5 specifically involves:

[0034] Step 501: Start the monitoring phase task;

[0035] Step 502: Create a monitoring phase and write the monitoring phase data into the database;

[0036] Step 503: Obtain the set of all monitoring stages for start / stop types;

[0037] Step 504: Loop through the monitoring phase set and obtain the start and end times of each monitoring phase;

[0038] Step 505: Obtain all monitoring type parameters and create monitoring report details for each stage;

[0039] Step 506: Obtain the average, maximum, minimum, start time interpolation, and end time interpolation within the start and end time ranges of each monitoring stage through the measurement points, and write the monitoring report details into the database;

[0040] Step 507: The monitoring phase task ends, and the process will proceed to step 403 when the next monitoring task cycle begins.

[0041] Furthermore, in step 6, the writing of standard curve and actual curve image data, start-up / stop type, start-up / stop parameters, and start-up / stop phase data into the cache specifically involves:

[0042] Step 601: Obtain the corresponding start / stop monitoring task through the identifier Key. If the task is empty, return empty; if the task is not empty, obtain the real-time time value of the measurement point from the cache as the X-axis coordinate of the real-time curve.

[0043] Step 602: Retrieve the monitoring task from the cache. If the monitoring state has started, set the current standard time (hours, minutes, seconds) to the cursor position of the standard curve, and calculate the corresponding Y value based on the current cursor time by calling the standard curve.

[0044] If the start / stop type at the specified time is in the start / stop parameter stage, obtain the corresponding stage name and stage content;

[0045] Step 603: Obtain the last access time of the task from the cache, and determine whether the task was abnormally interrupted based on the last access time. If it was abnormally interrupted, destroy the running start / stop monitoring task.

[0046] Step 604: Obtain the set of all parameter data under the unit start-up and shutdown type from the cache, loop through the set of parameter data, and calculate the maximum and minimum values ​​of the standard curve corresponding to each parameter;

[0047] If the real-time value of the measured point is greater than the maximum value of the standard curve, then the Y value of the real-time curve is the maximum value of the standard curve; if the real-time value of the measured point is less than the minimum value of the standard curve, then the Y value of the real-time curve is the minimum value of the standard curve; if the real-time value of the measured point is within the range of the minimum and maximum values ​​of the standard curve, then the Y value of the real-time curve is the current real-time value of the parameter.

[0048] The rate of change of the standard curve Y value and the real-time curve Y value for each parameter is obtained by dividing the difference between the current standard curve Y value and the real-time curve Y value by the standard curve Y value.

[0049] When the start / stop parameter type is a fixed limit type, if the Y value of the real-time curve is greater than the configured limit, the alarm status at the current moment is triggered.

[0050] When the start / stop parameter type is a relative standard value type, if the real-time curve Y value is greater than the reference value of the current standard curve Y value, the alarm status at the current moment is triggered.

[0051] Step 605: After all cached parameter sets have been traversed, proceed to step 601.

[0052] Furthermore, the standard curve and actual curve screen data in step 7 of the unit start-up and shutdown task are specifically as follows:

[0053] Step 701: Once the unit equipment has been started up, the trend of the real-time curve will begin to be drawn as a straight line based on the value at the time of start-up completion;

[0054] Step 702: After closing the start / stop parameter monitoring screen, destroy the start / stop type task. Compared with the prior art, the present invention has the following beneficial effects:

[0055] This invention presents a curve-based method for optimizing and monitoring the start-up and shutdown process of thermal power units. By setting parameters for the start-up and shutdown type and the stages of the start-up and shutdown, the data from the unit's start-up and shutdown monitoring task is displayed graphically, significantly saving manpower and improving the accuracy of operational processes. This invention is adaptable to various situations requiring intuitive display of the actual start-up and shutdown processes of units and the rate of change of set standard processes. By monitoring the parameter status at each stage of the start-up and shutdown, this invention enables the unit to display and compare the parameter trends at each stage of the start-up and shutdown process under different states, providing guidance and analysis for start-up and shutdown operations. To further improve the professional skills of centralized control personnel and enable operators to grasp the main points, the start-up and shutdown monitoring system can summarize and analyze the control and operation of key parameters during the unit startup process. Attached Figure Description

[0056] Figure 1 This is a flowchart of the method for optimizing and monitoring the start-up and shutdown process of thermal power units based on curves according to the present invention;

[0057] Figure 2 This is a flowchart of the start / stop task execution process of the present invention;

[0058] Figure 3 The following is a display result of the main parameters of the unit startup process in the example. Detailed Implementation

[0059] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0060] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0061] The present invention will now be described in further detail with reference to the accompanying drawings:

[0062] See Figure 1 , Figure 1 The flowchart shows a method for optimizing and monitoring the start-up and shutdown process of thermal power units based on curves. The method of the present invention includes the following steps:

[0063] Step 1: Configure start / stop parameters

[0064] 1.1 Obtain unit instances based on business scenario types and set basic start / stop type information for them. Each start / stop type has multiple start / stop parameters.

[0065] Specifically, the main parameters for hot start-up include: unit load, main steam temperature, speed, main steam pressure, primary reheat steam pressure, reheat steam temperature, and secondary reheat steam pressure. For each start / stop parameter, you can set the measurement points, standard change curve, alarm mode (divided into fixed value and relative standard value), where fixed value corresponds to over-limit values, and relative standard value corresponds to the floating percentage, data accuracy, and curve color.

[0066] 1.2 Simultaneously set multiple stage parameters for each start-up and shutdown type, such as boiler ignition and pressurization, turbine start-up, and grid connection with load. Each start-up and shutdown stage is configured with a stage name, start stage conditions, end stage conditions, and stage content.

[0067] Step 2, Start and stop the task execution process, see [link / reference] Figure 2 ,include:

[0068] 2.1. Based on the union of the X-axis of all parameter standard curves under the unit start-up / shutdown type, the range of the actual curve X-axis is set. Specifically, when the start-up / shutdown task is initiated, the real-time values ​​of the measuring points are acquired, and compared with the values ​​of the standard curves at that time to set the Y-value of the actual curve. When the unit start-up / shutdown type reaches the preset state at a certain time, the actual curve starts to draw a straight line with the value of the last time.

[0069] 2.2 If the start / stop task is under monitoring, calculate the standard value of the standard curve at this moment, and count whether the start / stop type meets the phase start condition or phase end condition.

[0070] If the start / stop task is not under monitoring, proceed to step 2.3;

[0071] 2.3 Write the start / stop type data collected in the task into the cache for use by the front-end start / stop monitoring curve, and the task waits for the next cycle to continue execution.

[0072] Example

[0073] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0074] As attached Figure 1 , 2 As shown, the present invention provides a method for optimizing and monitoring the start-up and shutdown process of a generating unit based on curves, comprising the following steps:

[0075] Step 1: Obtain basic information and start / stop type details for the unit equipment instance. Taking the cold start type of Unit #1 as an example, cold start mainly includes the following configuration information, as shown in Table 1:

[0076] Table 1

[0077]

[0078] Step 2: Obtain the start-up and shutdown parameters for Unit #1 under cold start conditions. These parameters mainly include generator power, coal mill feed rate, main hot steam temperature and pressure, reheat steam temperature and pressure, and turbine speed, as shown in Table 2.

[0079] Table 2

[0080] Parameter name unit measuring point Alarm methods Exceeding the limit Show or not? generator power mw N1DCS.MW Fixed value 5 yes Coal feed ton N1DCS.30NT Fixed value 5 yes Main hot steam temperature ℃ N1DCS.TFSHO relative standard value 5 yes Main hot steam pressure kPa N1DCS.MSP relative standard value 5 yes Reheat steam temperature ℃ N1DCS.HRHOTL Fixed value 2 yes Reheat steam pressure kPa N1DCS.PLRH Fixed value 0.5 yes Steam turbine speed rpm N1DCS.NTR Fixed value 100 yes

[0081] Table 2 shows that alarm methods are divided into two types: fixed value and relative standard value. Fixed value is a more traditional alarm mode, representing a limit value. If the actual value curve changes beyond this value, an alarm will be triggered. Relative standard value represents a range based on a ratio. If the actual value curve changes beyond the set standard value range, an alarm will be triggered. For example, if the set floating standard is 10% and the tag value is 100, the limit will be 90-110. Therefore, if the actual value is lower than 90 or higher than 110, it will exceed the limit.

[0082] The start-up and shutdown parameters also include "standard variation curves," such as the standard variation curve under ideal conditions simulating the unit's start-up process. A standard curve is a curve showing the change of monitored parameters over time during the start-up and shutdown process, based on the parameter characteristics. Taking generator power as an example, its variation pattern during cold start-up is as follows:

[0083] The initial time is marked as 0, and the generator power is 0.

[0084] Two minutes later, the generator power is 10; (00:02, 10)

[0085] Four minutes later, the generator power is 50; (00:04, 50)

[0086] Five minutes later, the generator power is 100; (00:05, 100)

[0087] After 15 minutes, the generator power is 150; (00:15, 150)

[0088] After 18 minutes, the generator power is 250; (00:18, 250) ...

[0090] Finally, the standard variation curve of the generator is defined as:

[0091] (00:02,10),(00:04,50),(00:05,100),(00:15,150),(00:18,250)....

[0092] This is a standard curve for parameters. Multiple parameters can be adjusted and set according to this principle, such as generator power, coal mill feed rate, main and reheat steam temperature and pressure, and turbine speed.

[0093] Step 3: Obtain the start-up and shutdown phase of Unit #1 in cold start condition.

[0094]

[0095]

[0096] like Figure 3As shown, when the start-up and shutdown parameters of Unit #1 in the cold start type—main steam temperature, coal feed rate, and main steam pressure—meet the start-up and shutdown stage conditions for grid connection (as indicated by the stage name): 'Main steam temperature' >= 100, 'Coal feed rate' > 0, and 'Main steam pressure' > 1, it indicates that Unit #1 is currently in grid connection mode. The start and end times for other stages are similar.

[0097] Steps 4 and 5, as follows Figure 3 As shown, the graph of the monitoring process can only be displayed after the monitoring parameters and monitoring stages are configured.

[0098] Actual cursor position: The actual location of the curved cursor, refreshed every 10 seconds.

[0099] Standard cursor position: The location of the cursor on the standard curve. Clicking the mouse on the standard curve allows you to specify the standard cursor position, or you can manually set the cursor value in reverse. Click "OK" to set the cursor position.

[0100] During unit start-up and shutdown monitoring, the system will mark a parameter exceeding the limit in red. When entering a preset monitoring phase, the system will mark it in blue and display the monitoring phase's content in a scrolling manner. The monitoring task will automatically refresh the rate of change of the monitored parameters. The rate of change is calculated as: (actual value - previous actual value) / previous actual value. The parameters displayed in red are the parameters in the alarm.

[0101] Once the unit start-up and shutdown process is complete, a start-up and shutdown report record will be automatically generated, as shown in Table 4:

[0102] Table 4

[0103]

[0104]

[0105] 1. Report Start-up / Stop Type: Cold Start Stage Name: Grid Connection

[0106] Stage start conditions: 'Main steam temperature' >= 100, 'Coal feed rate' > 0, 'Main steam pressure' > 1

[0107] Stage End Conditions: 'Main Steam Temperature' >= 200°C, 'Coal Feed Rate' > 0, 'Main Steam Pressure' > 1. Stage Start Time: 2020-05-11 05:17:45

[0108] Phase End Time: 2020-05-11 06:17:47

[0109]

[0110] 2. Stage Name: Temperature and Pressure Increase

[0111] Phase start conditions: 'Main steam temperature' >= 200 && 'Turbine speed' > 20

[0112] Stage termination conditions: 'Main steam temperature' >= 400 && 'Turbine speed' > 20 ...

[0114] 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 to the technical solution 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 method for optimizing and monitoring the start-up and shutdown process of thermal power units based on curves, characterized in that, Includes the following steps: Step 1: Obtain basic unit information and details of unit start-up and shutdown types; Step 2: Obtain the set of monitoring parameters for the unit start-up and shutdown types; Step 3: Obtain the monitoring phase set for the unit start-up and shutdown type; Step 4: Obtain a random number as the identifier key for the start / stop type task, and destroy the start / stop task when the monitoring screen is turned off; The unit start-up and shutdown curves are obtained using the identifier Key; Step 5: Obtain the real-time curve refresh task cycle, initialize the start / stop task, and start the start / stop task; The specific set of monitoring parameters for unit start-up and shutdown types in step 2 is as follows: Step 201: Obtain the set of all parameters for the start / stop type using the start / stop type ID; Step 202: Obtain the standard curve of start / stop type parameters; Step 203: Take the union of the X-axis time points of the standard curve for all start-stop type parameters, calculate the corresponding Y-axis value, and use the calculated value as the Y-axis range of the standard curve; Step 4 also includes the following steps: Step 401: Initialize and run the start / stop phase tasks, and generate an online start / stop report; Step 402: Calculate the real-time value of the actual curve, obtain the measurement points for the parameter values, obtain the corresponding real-time values ​​through the measurement points, use the real-time values ​​as the Y-value of the real-time curve, and use the time as the X-axis coordinate of the real-time curve; Step 403: If the monitoring task status is in the start monitoring state, proceed to step 404; If the monitoring task is in a stopped monitoring state, proceed to step 405; Step 404: Statistically determine the standard values ​​of the measured parameters at the measurement points, and simultaneously determine whether the requirements are met during the monitoring phase; If the monitoring start condition expression is true, the crew monitoring task has now entered the phase state; if the monitoring end condition expression is true, the crew monitoring task has ended the phase state. Step 405: Move the identifier Key by one cycle, and write the standard curve and actual curve screen data, start / stop type, start / stop parameters and start / stop stage data into the cache. The task waits for the next cycle to execute. In step 405, the standard curve and actual curve image data, start / stop type, start / stop parameters, and start / stop phase data in the unit start / stop task are written into the cache specifically as follows: Step 601: Obtain the corresponding start / stop monitoring task through the identifier Key. If the task is empty, return empty; if the task is not empty, obtain the real-time time value of the measurement point from the cache as the X-axis coordinate of the real-time curve. Step 602: Retrieve the monitoring task from the cache. If the monitoring state has started, set the current standard time (hours, minutes, seconds) to the cursor position of the standard curve, and calculate the corresponding Y value based on the current cursor time by calling the standard curve. If the start / stop type at the cursor moment is in the start / stop parameter stage, obtain the corresponding stage name and stage content; Step 603: Obtain the last access time of the task from the cache, and determine whether the task was abnormally interrupted based on the last access time. If it was abnormally interrupted, destroy the running start / stop monitoring task. Step 604: Obtain the set of all parameter data under the unit start-up and shutdown type from the cache, loop through the set of parameter data, and calculate the maximum and minimum values ​​of the standard curve corresponding to each parameter; If the real-time value of the measured point is greater than the maximum value of the standard curve, then the Y value of the real-time curve is the maximum value of the standard curve; if the real-time value of the measured point is less than the minimum value of the standard curve, then the Y value of the real-time curve is the minimum value of the standard curve; if the real-time value of the measured point is within the range of the minimum and maximum values ​​of the standard curve, then the Y value of the real-time curve is the current real-time value of the parameter. The rate of change of the standard curve Y value and the real-time curve Y value for each parameter is obtained by dividing the difference between the current standard curve Y value and the real-time curve Y value by the standard curve Y value. When the start / stop parameter type is a fixed limit type, if the Y value of the real-time curve is greater than the configured limit, the alarm status at the current moment is triggered. When the start / stop parameter type is a relative standard value type, if the real-time curve Y value is greater than the reference value of the current standard curve Y value, the alarm status at the current moment is triggered. Step 605: After all cached parameter sets have been traversed, proceed to step 601.

2. The method for optimizing and monitoring the start-up and shutdown process of thermal power units based on curves according to claim 1, characterized in that, The specific steps for obtaining basic unit information and unit start-up / shutdown type details in step 1 are as follows: Obtain equipment group information from the portal system using equipment codes; Retrieve start / stop type data from the database dictionary table; The start / stop type data includes: hot start, cold start, extremely hot start / stop, sliding parameter stop, and temperature start; Obtain the relevant details of the start-up and shutdown types for the unit.

3. The method for optimizing and monitoring the start-up and shutdown process of thermal power units based on curves according to claim 1, characterized in that, The specific steps for obtaining the monitoring phase set of unit start-up and shutdown types in step 3 are as follows: Retrieve the set of all stages of a start / stop type by start / stop type ID.

4. The method for optimizing and monitoring the start-up and shutdown process of thermal power units based on curves according to claim 1, characterized in that, The generation of online reports for unit start-up and shutdown in step 401 specifically involves: Step 501: Start the monitoring phase task; Step 502: Create a monitoring phase and write the monitoring phase data into the database; Step 503: Obtain the set of all monitoring stages for start / stop types; Step 504: Loop through the monitoring phase set and obtain the start and end times of each monitoring phase; Step 505: Obtain all monitoring type parameters and create monitoring report details for each stage; Step 506: Obtain the average, maximum, minimum, start time interpolation, and end time interpolation within the start and end time ranges of each monitoring stage through the measurement points, and write the monitoring report details into the database; Step 507: The monitoring phase task ends, and the process will proceed to step 403 when the next monitoring task cycle begins.

5. The method for optimizing and monitoring the start-up and shutdown process of thermal power units based on curves according to claim 1, characterized in that, The specific data for the standard curve and actual curve in the unit start-up and shutdown task in step 405 are as follows: Step 701: Once the unit equipment has been started up, the trend of the real-time curve will begin to be drawn as a straight line based on the value at the time of start-up completion; Step 702: After closing the start / stop parameter monitoring screen, destroy the start / stop type task.

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