Optimal circulation volume optimization operation method and system of slurry circulating pump, storage medium and program product

Abstract

The invention provides an optimal circulation quantity optimization operation method and system of a slurry circulating pump, a storage medium and a program product, and relates to the technical field of flue gas desulfurization. The method comprises the steps that real-time operation working condition parameters of a wet desulphurization system are input into a preset working condition matching model, matching a target circulation flow and a target operation combination mode corresponding to the real-time operation working condition parameters from the optimal circulation flow working condition library; determining a commissioning slurry circulating pump according to the target operation combination mode, and obtaining a performance curve of the commissioning slurry circulating pump at a plurality of preset rotating speeds and a pipe resistance characteristic curve of an outlet pipeline at a plurality of preset valve opening degrees; and according to the target circulating flow, the performance curve and the pipe resistance characteristic curve, target two-parameter coupling regulation and control operation is executed on the slurry circulating pump put into operation and the flow and pressure regulating valve put into operation, so that the actual circulating flow reaches the target circulating flow, and the nozzle inlet pressure is maintained within the preset atomization pressure interval.

Description

Technical Field

[0001] This application relates to the field of flue gas desulfurization technology, and in particular to a method, system, storage medium and program product for optimizing the operation of a slurry circulation pump with optimal circulation volume. Background Technology

[0002] With the continuous improvement of environmental protection standards and the in-depth advancement of flexible retrofitting of thermal power units, coal-fired power plants have placed higher demands on the operation and control of wet desulfurization systems. In wet desulfurization systems, the desulfurization slurry circulation pump is responsible for transporting the circulating slurry from the bottom of the desulfurization tower to each spray layer, and is a key piece of equipment to ensure desulfurization efficiency.

[0003] In related technologies, the operation and control of desulfurization slurry circulation pumps typically adopts a power frequency operation mode. This involves adjusting the liquid-to-gas ratio of the desulfurization tower by starting and stopping different numbers of slurry circulation pumps to meet the desulfurization requirements under different operating conditions. Since the nozzles in the spray layer inside the desulfurization tower have strict requirements for inlet pressure, and the nozzle inlet pressure must be maintained within a specific range to ensure that the atomized particle size and spray coverage area meet the desulfurization efficiency requirements, the stability of the nozzle inlet pressure must be considered while adjusting the circulation flow rate.

[0004] However, the flow regulation of the slurry circulation pump is discontinuous under the power frequency operation mode. When the unit load changes or the sulfur content of the coal fluctuates, starting and stopping the slurry circulation pump will cause a step change in the circulation flow rate, and at the same time cause a large fluctuation in the nozzle inlet pressure. It is difficult to stabilize the circulation flow rate and the nozzle inlet pressure within the corresponding range at the same time, which leads to poor coordinated control effect of circulation flow rate and nozzle inlet pressure in related technologies. Summary of the Invention

[0005] This application provides a method, system, storage medium, and program product for optimizing the operation of a slurry circulation pump to improve the synergistic control effect between circulation flow and nozzle inlet pressure.

[0006] Firstly, this application provides a method for optimizing the operation of a slurry circulation pump, applied to a wet desulfurization system. The wet desulfurization system includes a desulfurization tower, multiple slurry circulation pumps, flow regulating and pressure regulating valves installed on the outlet pipeline of each slurry circulation pump, and multiple spray layers. The slurry circulation pumps are correspondingly connected to the spray layers. The method includes: upon obtaining the real-time operating condition parameters of the wet desulfurization system, inputting the real-time operating condition parameters into a preset operating condition matching model, and using the preset operating condition matching model to match a target circulation flow rate and a target operating combination corresponding to the real-time operating condition parameters from an optimal circulation volume operating condition library. The method involves determining the slurry circulation pump to be put into operation from multiple slurry circulation pumps based on the target operating combination, and obtaining the performance curves of the slurry circulation pump at multiple preset speeds and the pipe resistance characteristic curves of the outlet pipeline of the slurry circulation pump at multiple preset valve openings. Based on the target circulation flow rate, performance curves, and pipe resistance characteristic curves, the target dual-parameter coupled control operation is performed on the slurry circulation pump and the corresponding flow regulating and pressure regulating valve to ensure that the actual circulation flow rate of the desulfurization tower reaches the target circulation flow rate, and that the nozzle inlet pressure of the spray layer corresponding to the slurry circulation pump is maintained within the preset atomization pressure range.

[0007] By adopting the above technical solution, real-time operating parameters are input into a preset operating condition matching model for operating condition matching. This allows for the rapid acquisition of the target circulating flow rate and target operating combination mode that are compatible with the current operating condition from the optimal circulating flow rate operating condition library. This enables precise adaptation of the circulating flow rate setpoint to dynamic changes in operating conditions, avoiding energy waste or insufficient desulfurization efficiency caused by a fixed circulating flow rate. By acquiring the performance curves of the slurry circulating pump at multiple preset speeds and the pipe resistance characteristic curves of the outlet pipeline of the slurry circulating pump at multiple preset valve openings, and performing target dual-parameter coupled control operations on the slurry circulating pump and the flow regulating and pressure regulating valve based on the target circulating flow rate, performance curves, and pipe resistance characteristic curves, the coordinated adjustment of pump speed and valve opening is achieved. This ensures that the actual circulating flow rate of the desulfurization tower can accurately reach the target circulating flow rate, while the nozzle inlet pressure of the spray layer corresponding to the slurry circulating pump can also be maintained within the preset atomization pressure range. This ensures that the atomization particle size of the nozzle and the spray coverage area meet the desulfurization efficiency requirements. This solves the technical problem of poor coordinated control of circulating flow and nozzle inlet pressure in related technologies, and achieves a better coordinated control effect between circulating flow and nozzle inlet pressure.

[0008] Optionally, the target dual-parameter coupled control operation includes: performing a first cross-matching analysis on the performance curve and the pipe resistance characteristic curve in the flow-head coordinate system to obtain multiple candidate operating points. Each candidate operating point corresponds to a combination of a preset rotational speed and a preset valve opening, and each candidate operating point includes a candidate flow rate value and a candidate head value; selecting flow matching operating points from the multiple candidate operating points whose flow deviation between the candidate flow rate value and the target circulating flow rate is within a preset flow deviation range; determining the estimated nozzle inlet pressure of the flow matching operating point based on the candidate head value corresponding to the flow matching operating point and the pipeline resistance loss corresponding to the pipe resistance characteristic curve; selecting flow pressure matching operating points from the flow matching operating points whose estimated nozzle inlet pressure is within a preset atomization pressure range; and performing coordinated control operations on the commissioned slurry circulation pump and the commissioned flow and pressure regulating valve based on the flow and pressure matching operating points.

[0009] By adopting the above technical solution, the performance curve and the pipe resistance characteristic curve are subjected to a first cross-matching analysis in the flow-head coordinate system to obtain multiple candidate operating points. Then, the range of candidate operating points is gradually narrowed through flow deviation screening and nozzle inlet pressure screening. Finally, a flow-pressure matching operating point that simultaneously meets the flow and pressure requirements is obtained. Based on the flow-pressure matching operating point, the commissioned slurry circulation pump and the commissioned flow-regulating and pressure-regulating valve are subjected to coordinated regulation operations. This enables the systematic search for the optimal operating point in the combination space composed of multiple preset speeds and multiple preset valve openings, ensuring the accuracy and reliability of the target dual-parameter coupled control operation.

[0010] Optionally, the coordinated adjustment operation includes: determining the pump operating efficiency at the flow-pressure matching working point based on the flow-efficiency correspondence in the performance curve, and determining the flow-pressure matching working point corresponding to the pump operating efficiency not less than a preset efficiency threshold as the target working point; sorting the target working points in ascending order based on the operating power of the slurry circulation pump at the target working point, and taking the preset speed corresponding to the first target working point after sorting as the target speed, and taking the preset valve opening corresponding to the first target working point after sorting as the initial valve opening of the flow-regulating and pressure-regulating valve; adjusting the speed of the slurry circulation pump to the target speed, and adjusting the valve opening of the flow-regulating and pressure-regulating valve to the initial valve opening; during the operation of the slurry circulation pump at the target speed, measuring the nozzle inlet pressure of the spray layer corresponding to the slurry circulation pump in real time, and performing pressure deviation analysis between the nozzle inlet pressure and the preset atomization pressure range to obtain the pressure deviation value; and performing dynamic correction operation on the slurry circulation pump and the flow-regulating and pressure-regulating valve based on the pressure deviation value.

[0011] By adopting the above technical solution, based on the flow-efficiency correspondence in the performance curve, the flow-pressure matching operating point with a pump operating efficiency not less than a preset efficiency threshold is selected as the target operating point. This ensures that the slurry circulation pump operates within the high-efficiency range, avoiding energy waste caused by low-efficiency operation. By sorting the target operating points in ascending order according to their operating power and selecting the preset speed and preset valve opening corresponding to the first target operating point after sorting, the operating point with the lowest operating power is selected while meeting the flow, pressure, and efficiency requirements, further reducing the operating energy consumption of the slurry circulation pump. In addition, by measuring the nozzle inlet pressure in real time and performing pressure deviation analysis during the operation of the slurry circulation pump at the target speed, and performing dynamic correction operations based on the pressure deviation value, closed-loop control of the nozzle inlet pressure is achieved, ensuring that the nozzle inlet pressure is continuously maintained within the preset atomization pressure range during actual operation.

[0012] Optionally, the dynamic correction operation includes: when the pressure deviation value exceeds the preset allowable deviation range, using a preset control algorithm to perform feedback calculation on the pressure deviation value to obtain an opening correction compensation value; superimposing the opening correction compensation value with the initial valve opening to obtain the corrected valve opening; when the corrected valve opening is within a preset safe range, determining the corrected pipeline resistance loss corresponding to the corrected valve opening based on the pipeline resistance characteristic curve; performing a second cross-matching analysis between the corrected pipeline resistance loss and the performance curve of the commissioned slurry circulation pump at the target speed to obtain the corrected working flow rate; when the flow deviation value between the corrected working flow rate and the target circulation flow rate is within the preset flow deviation range, adjusting the opening of the commissioned flow regulating and pressure regulating valve according to the corrected valve opening, and updating the corrected valve opening to the initial valve opening.

[0013] By adopting the above technical solution, the pressure deviation value is processed by a preset control algorithm to obtain the opening correction compensation value. The opening correction compensation value is then superimposed with the initial valve opening to obtain the corrected valve opening, thus achieving adaptive adjustment of the valve opening based on the pressure deviation. When the corrected valve opening is within a preset safe range, the corrected pipeline resistance loss corresponding to the corrected valve opening is determined according to the pipeline resistance characteristic curve. The corrected pipeline resistance loss is then compared with the performance curve of the slurry circulation pump at the target speed, and a second cross-matching analysis is performed to obtain the corrected working flow rate. The flow deviation between the corrected working flow rate and the target circulation flow rate is then verified to ensure that the actual circulation flow rate does not deviate from the target circulation flow rate while adjusting the valve opening to correct the nozzle inlet pressure, thereby achieving dynamic coordinated stability between the circulation flow rate and the nozzle inlet pressure.

[0014] Optionally, before matching the target circulating flow rate and target operating combination mode corresponding to the real-time operating condition parameters from the optimal circulating flow rate operating condition library using the preset operating condition matching model, the method further includes: obtaining the rated flue gas treatment capacity of the wet desulfurization system, and determining multiple flue gas volume ranges based on the rated flue gas treatment capacity; sequentially traversing each flue gas volume range in the multiple flue gas volume ranges, and performing the following operating condition calibration operation on the currently traversed flue gas volume range: selecting multiple test flue gas volumes from the target flue gas volume range, and selecting multiple test circulating flow rates from the preset circulating flow rate range, where the target flue gas volume range is the currently traversed flue gas volume range; determining N candidate operating combinations of multiple slurry circulating pumps based on the multiple test circulating flow rates, the spatial distribution of the spray layer corresponding to each slurry circulating pump in the desulfurization tower, and the spray coverage characteristics, where N is a positive integer; under each test flue gas volume, using each In the candidate operating combinations, the performance curves and pipe resistance characteristic curves of each slurry circulation pump are subjected to the first dual-parameter coupling control operation to ensure that the actual circulation flow rate of the desulfurization tower reaches the corresponding test circulation flow rate, and the nozzle inlet pressure of the spray layer corresponding to each slurry circulation pump is within the preset atomization pressure range. After the first dual-parameter coupling control operation is completed and the wet desulfurization system reaches a stable operating state, the desulfurization efficiency of each candidate operating combination is tested to obtain the test desulfurization efficiency, test nozzle inlet pressure, and test operating power of each candidate operating combination. Based on the test desulfurization efficiency, test nozzle inlet pressure, and test operating power, the first operating combination and the first circulation flow rate corresponding to the target flue gas volume range are determined from the N candidate operating combinations. The target flue gas volume range, the first operating combination, and the first circulation flow rate are associated and stored in the optimal circulation volume operating condition library.

[0015] By adopting the above technical solution, multiple flue gas volume ranges are determined based on the rated flue gas treatment capacity of the wet desulfurization system, and operating condition calibration is performed on each flue gas volume range to achieve systematic coverage of the entire operating range. Under each test flue gas volume, the first dual-parameter coupling control operation is performed using the performance curves and pipe resistance characteristic curves of each slurry circulation pump in each candidate operating combination. After the wet desulfurization system reaches a stable operating state, the desulfurization efficiency is tested to obtain the test desulfurization efficiency, test nozzle inlet pressure, and test operating power, thereby achieving a comprehensive evaluation of the operating effect of each candidate operating combination under different flue gas volumes. In addition, based on the test desulfurization efficiency, test nozzle inlet pressure, and test operating power, the first operating combination mode and the first circulation flow rate corresponding to the target flue gas volume range are determined from the candidate operating combinations and associated and stored in the optimal circulation volume operating condition library, providing a scientific and reliable data foundation for subsequent real-time operating condition matching.

[0016] Optionally, based on the tested desulfurization efficiency, tested nozzle inlet pressure, and tested operating power, a first operating combination mode and a first circulation flow rate corresponding to the target flue gas volume range are determined from N candidate operating combinations. This includes: selecting M compliant operating combinations from the N candidate operating combinations where the tested desulfurization efficiency is not less than a preset desulfurization efficiency threshold and the tested nozzle inlet pressure is within a preset atomization pressure range, where M is a positive integer less than or equal to N; obtaining the installation elevation of the spray layer corresponding to each operational slurry circulation pump in each compliant operating combination mode, and determining the installation elevation of each compliant operating combination mode based on the installation elevation. The static head energy consumption penalty coefficient for the standard operating combination mode is calculated, where the installation elevation is positively correlated with the static head energy consumption penalty coefficient. The test operating power of each compliant operating combination mode is weighted and corrected according to the static head energy consumption penalty coefficient to obtain the equivalent evaluation energy consumption of each compliant operating combination mode. The M compliant operating combination modes are sorted in a second ascending order according to the equivalent evaluation energy consumption, and the compliant operating combination mode that ranks first after sorting is taken as the first operating combination mode in the target flue gas volume range, and the test circulation flow rate corresponding to the first operating combination mode is taken as the first circulation flow rate.

[0017] By adopting the above technical solution, qualified operating combinations are selected from candidate operating combinations, ensuring that the desulfurization efficiency is not less than the preset desulfurization efficiency threshold and the nozzle inlet pressure is within the preset atomization pressure range. This ensures that all selected operating combinations meet the basic requirements of desulfurization efficiency and nozzle atomization pressure. By obtaining the installation elevation of the spray layer corresponding to each slurry circulation pump in each qualified operating combination, and determining the static head energy consumption penalty coefficient based on the installation elevation, the test operating power is weighted and corrected to obtain the equivalent evaluation energy consumption. The influence of the spray layer installation elevation on the pump group energy consumption is incorporated into the evaluation system, avoiding evaluation bias caused by ignoring the static head difference while using only the test operating power as the energy consumption evaluation index. In addition, by sorting the qualified operating combinations in a second ascending order according to the equivalent evaluation energy consumption and selecting the qualified operating combination at the top of the sort as the first operating combination, the operating combination with the lowest equivalent evaluation energy consumption is selected under the premise of meeting the desulfurization efficiency and nozzle inlet pressure requirements, further improving the economic efficiency of slurry circulation pump operation.

[0018] Optionally, after determining the slurry circulation pump to be put into operation from multiple slurry circulation pumps according to the target operating combination, the method further includes: obtaining the current actual operating combination of the wet desulfurization system; if the actual operating combination differs from the target operating combination, performing a difference comparison analysis between the actual and target operating combinations to identify slurry circulation pumps to be started that are not present in the target operating combination, and slurry circulation pumps to be stopped that are not present in the target operating combination; obtaining the current inlet flue gas volume of the desulfurization tower, and determining the total flow stability constraint condition during the pump group switching transition period based on the inlet flue gas volume; determining the load increase operating trajectory of the slurry circulation pump to be started and the load decrease operating trajectory of the slurry circulation pump to be stopped based on the total flow stability constraint condition; starting the slurry circulation pump to be started... The slurry circulation pump is activated to allow the slurry circulation pump to be started and the slurry circulation pump to be stopped to enter the pump set switching transition period. During the pump set switching transition period, the slurry circulation pump to be started is controlled to perform load increase adjustment operation according to the load increase operation trajectory, and the slurry circulation pump to be stopped is controlled to perform load decrease adjustment operation according to the load decrease operation trajectory, so that the actual circulation flow of the desulfurization tower continuously meets the total flow stability constraint condition. When the real-time load parameter of the slurry circulation pump to be stopped is detected to drop to the preset safe shutdown threshold, the slurry circulation pump to be stopped is controlled to stop operation. When the slurry circulation pump to be stopped stops operation, and the actual operation combination mode is the same as the target operation combination mode, and the slurry circulation pump in operation is in a stable operation state, the target dual-parameter coupling control operation is performed on the slurry circulation pump in operation, so that the actual circulation flow of the desulfurization tower reaches the target circulation flow.

[0019] By adopting the above technical solution, the actual operating combination mode is compared and analyzed with the target operating combination mode to determine the slurry circulation pump to be started and the slurry circulation pump to be stopped, thus achieving accurate identification of pump group switching. Based on the inlet flue gas volume, the total flow stability constraint condition during the pump group switching transition period is determined, and based on the total flow stability constraint condition, the load increase operation trajectory of the slurry circulation pump to be started and the load decrease operation trajectory of the slurry circulation pump to be stopped are determined. During the pump group switching transition period, the slurry circulation pump to be started and the slurry circulation pump to be stopped are synchronously controlled according to the load increase and load decrease operation trajectories. This ensures that the actual circulation flow of the desulfurization tower continuously meets the total flow stability constraint condition during the pump group switching process, avoiding fluctuations in desulfurization efficiency caused by step changes in circulation flow during pump group switching. Furthermore, after the pump group switching is completed and the slurry circulation pump is in a stable operating state, the target dual-parameter coupled control operation is executed to ensure the orderly connection between pump group switching and fine control.

[0020] In a second aspect, embodiments of this application provide a slurry circulation control system, which includes: one or more processors and a memory; the memory is coupled to one or more processors, and the memory is used to store computer program code, the computer program code including computer instructions, and the one or more processors call the computer instructions to cause the slurry circulation control system to perform the method described in the first aspect and any possible implementation thereof.

[0021] Thirdly, embodiments of this application provide a computer-readable storage medium including instructions that, when executed on a slurry circulation control system, cause the slurry circulation control system to perform the method described in the first aspect and any possible implementation thereof.

[0022] Fourthly, embodiments of this application provide a computer program product containing instructions that, when the computer program product is run on a slurry circulation control system, cause the slurry circulation control system to perform the method described in the first aspect and any possible implementation thereof.

[0023] One or more technical solutions provided in the embodiments of this application have at least the following technical effects or advantages:

[0024] 1. Input the real-time operating condition parameters into the preset operating condition matching model for operating condition matching. It can quickly obtain the target circulation flow and target operating combination mode that are suitable for the current operating condition from the optimal circulation flow operating condition library, so as to achieve accurate matching of the circulation flow set value with the dynamic change of operating condition, and avoid energy waste or insufficient desulfurization efficiency caused by fixed circulation flow.

[0025] 2. By acquiring the performance curves of the slurry circulation pump at multiple preset speeds and the pipe resistance characteristic curves of the outlet pipeline of the slurry circulation pump at multiple preset valve openings, and based on the target circulation flow, performance curves, and pipe resistance characteristic curves, the slurry circulation pump and the flow regulating and pressure regulating valve are subjected to target dual-parameter coupled control operations. This achieves coordinated adjustment of pump speed and valve opening, ensuring that the actual circulation flow of the desulfurization tower can accurately reach the target circulation flow, while the nozzle inlet pressure of the spray layer corresponding to the slurry circulation pump can also be maintained within the preset atomization pressure range. This ensures that the atomization particle size of the nozzle and the spray coverage area meet the desulfurization efficiency requirements.

[0026] 3. In the flow-head coordinate system, the performance curve and the pipe resistance characteristic curve are subjected to a first cross-matching analysis to obtain multiple candidate operating points. Then, the range of candidate operating points is gradually narrowed through flow deviation screening and nozzle inlet pressure screening. Finally, the flow-pressure matching operating point that simultaneously meets the flow and pressure requirements is obtained. Based on the flow-pressure matching operating point, the commissioned slurry circulation pump and the commissioned flow and pressure regulating valve are coordinated and adjusted. This realizes the systematic search for the optimal operating point in the combination space composed of multiple preset speeds and multiple preset valve openings, ensuring the accuracy and reliability of the target dual-parameter coupled control operation. Attached Figure Description

[0027] Figure 1 This is a flowchart illustrating an optimal operation method for the slurry circulation pump in an embodiment of this application.

[0028] Figure 2 This is a schematic diagram of the physical device structure of a slurry circulation control system in the embodiments of this application. Detailed Implementation

[0029] The terminology used in the following embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. As used in the specification and appended claims of this application, the singular expressions “a,” “an,” “the,” “the,” “the,” and “this” are intended to include the plural expressions as well, unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used in this application refers to any or all possible combinations including one or more of the listed items.

[0030] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as implying or suggesting relative importance or implicitly indicating 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, and in the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more.

[0031] This application provides a method for optimizing the circulation rate of a slurry circulation pump, applied to a wet desulfurization system. The wet desulfurization system includes a desulfurization tower, multiple slurry circulation pumps, flow regulating and pressure regulating valves installed on the outlet pipeline of each slurry circulation pump, and multiple spray layers. The slurry circulation pumps are correspondingly connected to the spray layers. (See reference...) Figure 1 , Figure 1 This is a flowchart illustrating an optimal circulation rate operation method for a slurry circulation pump according to an embodiment of this application, comprising the following steps:

[0032] Step S101: After obtaining the real-time operating condition parameters of the wet desulfurization system, input the real-time operating condition parameters into the preset operating condition matching model, so as to use the preset operating condition matching model to match the target circulation flow and target operating combination mode corresponding to the real-time operating condition parameters from the optimal circulation flow condition library.

[0033] Step S102: Determine the slurry circulation pump to be put into operation from multiple slurry circulation pumps according to the target operation combination mode, and obtain the performance curve of the slurry circulation pump to be put into operation at multiple preset speeds and the pipe resistance characteristic curve of the outlet pipeline of the slurry circulation pump to be put into operation at multiple preset valve openings.

[0034] Step S103: Based on the target circulation flow rate, performance curve and pipe resistance characteristic curve, perform target dual-parameter coupled control operation on the slurry circulation pump and the corresponding flow and pressure regulating valve to ensure that the actual circulation flow rate of the desulfurization tower reaches the target circulation flow rate, and that the nozzle inlet pressure of the spray layer corresponding to the slurry circulation pump is maintained within the preset atomization pressure range.

[0035] The wet desulfurization system refers to a flue gas desulfurization system employing the limestone-gypsum wet desulfurization process. This system includes a desulfurization tower, multiple slurry circulation pumps, flow regulating and pressure regulating valves on the outlet pipeline of each slurry circulation pump, and multiple spray layers. The desulfurization tower is the tower equipment used for gas-liquid contact reaction between flue gas and desulfurization slurry to remove sulfur dioxide from the flue gas. The slurry circulation pump is the pump equipment that transports the circulating slurry from the bottom of the desulfurization tower to each spray layer; each slurry circulation pump is connected to one spray layer. The flow regulating and pressure regulating valve is an electric valve installed on the outlet pipeline of each slurry circulation pump, used to regulate the slurry flow rate and pressure in the outlet pipeline. The spray layer refers to the slurry spraying device installed inside the desulfurization tower, with multiple nozzles to atomize and spray the desulfurization slurry transported by the slurry circulation pumps, achieving sufficient contact between the flue gas and the desulfurization slurry. Real-time operating parameters refer to the operating status parameters of the wet desulfurization system at the current moment, including but not limited to at least one of the following: real-time flue gas volume, inlet sulfur dioxide concentration, flue gas temperature, flue gas pressure, unit load, and sulfur content of the coal fed into the furnace. The preset operating condition matching model refers to a pre-established model used to match the corresponding target circulation flow rate and target operating combination mode from the optimal circulation flow rate operating condition library based on the real-time operating parameters. The optimal circulation flow rate operating condition library refers to a pre-built database storing the mapping relationships between different flue gas volume ranges and their corresponding optimal circulation flow rates and optimal operating combinations.

[0036] The target circulation flow rate refers to the optimal slurry circulation flow rate that matches the current real-time operating parameters. The target operating combination refers to the optimal start-stop combination scheme of multiple slurry circulation pumps that matches the current real-time operating parameters; this target operating combination specifies which slurry circulation pumps need to be put into operation. The slurry circulation pump in operation refers to the slurry circulation pump that needs to be put into operation according to the target operating combination. The performance curve refers to the flow-head characteristic curve of the in-operation slurry circulation pump at a preset speed, reflecting the correspondence between the output flow rate and output head of the in-operation slurry circulation pump at that preset speed. The pipe resistance characteristic curve refers to the flow-pipeline resistance loss characteristic curve of the outlet pipeline of the in-operation slurry circulation pump at a preset valve opening, reflecting the correspondence between the slurry flow rate and pipeline resistance loss in the pipeline at that preset valve opening. The commissioning flow regulating and pressure regulating valve refers to the flow regulating and pressure regulating valve corresponding to the in-operation slurry circulation pump. The target dual-parameter coupled control operation refers to the coordinated adjustment of the rotational speed of the slurry circulation pump and the valve opening of the flow and pressure regulating valve. The purpose of this operation is to ensure that the actual circulation flow rate of the desulfurization tower reaches the target circulation flow rate, while maintaining the nozzle inlet pressure of the spray layer corresponding to the slurry circulation pump within the preset atomization pressure range. The preset atomization pressure range refers to the inlet pressure range required for the nozzles of the spray layer to achieve good atomization, for example, 0.06 MPa to 0.08 MPa.

[0037] In the above embodiment, a wet flue gas desulfurization system supporting a 600 MW coal-fired unit is taken as an example for illustration. The wet flue gas desulfurization system includes a desulfurization tower, 4 slurry circulation pumps (respectively marked as No. 1 slurry circulation pump, No. 2 slurry circulation pump, No. 3 slurry circulation pump and No. 4 slurry circulation pump), flow regulating and pressure regulating valves (respectively marked as No. 1 flow regulating and pressure regulating valve, No. 2 flow regulating and pressure regulating valve, No. 3 flow regulating and pressure regulating valve and No. 4 flow regulating and pressure regulating valve) arranged on the outlet pipelines of each slurry circulation pump, and 4 spray layers (respectively marked as the first spray layer, the second spray layer, the third spray layer and the fourth spray layer). Among them, the No. 1 slurry circulation pump is correspondingly connected to the first spray layer, the No. 2 slurry circulation pump is correspondingly connected to the second spray layer, the No. 3 slurry circulation pump is correspondingly connected to the third spray layer, and the No. 4 slurry circulation pump is correspondingly connected to the fourth spray layer. The slurry circulation control system collects the real-time operating condition parameters of the wet flue gas desulfurization system in real time. For example, the collected real-time operating condition parameters include: the real-time flue gas volume is 1.8 million Nm³ / h, the inlet sulfur dioxide concentration is 2000 mg / Nm³, the flue gas temperature is 130 °C, and the unit load is 420 MW. The slurry circulation control system inputs the above real-time operating condition parameters into a preset condition matching model. The preset condition matching model performs a matching query in the optimal circulation volume condition library according to the real-time operating condition parameters, and determines that the target circulation flow rate corresponding to the current real-time operating condition parameters is 36000 m³ / h, and the target operating combination mode is that the No. 1 slurry circulation pump + the No. 2 slurry circulation pump + the No. 3 slurry circulation pump are put into operation, and the No. 4 slurry circulation pump stops operating.

[0038] In the above embodiment, the slurry circulation control system determines that the slurry circulation pumps put into operation are the No. 1 slurry circulation pump, the No. 2 slurry circulation pump and the No. 3 slurry circulation pump according to the target operating combination mode, and obtains the performance curves of the No. 1 slurry circulation pump, the No. 2 slurry circulation pump and the No. 3 slurry circulation pump at multiple preset speeds (such as 70%, 80%, 90%, 100% of the rated speed, etc.), and the pipe resistance characteristic curves of the outlet pipelines of the No. 1 slurry circulation pump, the No. 2 slurry circulation pump and the No. 3 slurry circulation pump at multiple preset valve openings (such as 40%, 50%, 60%, 70%, 80%, 90%, 100%, etc.). The slurry circulation control system performs a target dual-parameter coupling regulation operation on the No. 1 slurry circulation pump, the No. 2 slurry circulation pump, the No. 3 slurry circulation pump and the corresponding No. 1 flow regulating and pressure regulating valve, No. 2 flow regulating and pressure regulating valve, and No. 3 flow regulating and pressure regulating valve according to the target circulation flow rate of 36000 m³ / h, the above performance curves and pipe resistance characteristic curves, that is, simultaneously adjusts the speeds of each slurry circulation pump put into operation and the valve openings of each flow regulating and pressure regulating valve put into operation, so that the actual circulation flow rate of the desulfurization tower reaches 36000 m³ / h, and the nozzle inlet pressures of the first spray layer, the second spray layer and the third spray layer are all maintained within a preset atomization pressure range (such as 0.06 MPa to 0.08 MPa, etc.).

[0039] Through the above steps, real-time operating parameters are input into a preset operating condition matching model for operating condition matching. This allows for the rapid acquisition of the target circulating flow rate and target operating combination mode adapted to the current operating condition from the optimal circulating flow rate operating condition library. This enables precise adaptation of the circulating flow rate setpoint to dynamic changes in operating conditions, avoiding energy waste or insufficient desulfurization efficiency caused by a fixed circulating flow rate. By acquiring the performance curves of the slurry circulating pump at multiple preset speeds and the pipe resistance characteristic curves of the outlet pipeline of the slurry circulating pump at multiple preset valve openings, and performing target dual-parameter coupled control operations on the slurry circulating pump and the flow regulating and pressure regulating valve based on the target circulating flow rate, performance curves, and pipe resistance characteristic curves, the pump speed and valve opening are coordinated and adjusted. This ensures that the actual circulating flow rate of the desulfurization tower can accurately reach the target circulating flow rate, while the nozzle inlet pressure of the spray layer corresponding to the slurry circulating pump can also be maintained within the preset atomization pressure range. This guarantees that the atomization particle size of the nozzle and the spray coverage area meet the desulfurization efficiency requirements. This solves the technical problem of poor coordinated control of circulating flow and nozzle inlet pressure in related technologies, and achieves a better coordinated control effect between circulating flow and nozzle inlet pressure.

[0040] The executing entity for the above steps can be a slurry circulation control system, a controller or processor within the slurry circulation control system, a standalone controller or processor, or other processing equipment or units with similar processing functions, but is not limited to these. It should be noted that the wet desulfurization system in this application and the aforementioned executing entity have a controlled object and control system relationship. Specifically, the wet desulfurization system is the physical process system applied to the optimal circulation rate optimization operation method of the slurry circulation pump. The aforementioned executing entity interacts with the various process equipment and sensors in the wet desulfurization system through a communication interface. The aforementioned actuator collects real-time operating parameters (e.g., real-time flue gas volume, inlet sulfur dioxide concentration, flue gas temperature, flue gas pressure, unit load, nozzle inlet pressure, slurry circulation pump speed and flow rate, etc.) from sensors in the wet desulfurization system. Based on the collected real-time operating parameters, it executes control logic such as operating condition matching, target dual-parameter coupling control operation, and pump group switching in the optimal circulation volume optimization operation method of the slurry circulation pump described in this application. It then issues speed adjustment commands and valve opening adjustment commands to the slurry circulation pump and flow regulating valve in the wet desulfurization system to achieve optimized control of the slurry circulation pump's operating status. The aforementioned actuator can communicate with each process device and sensor in the wet desulfurization system through a DCS (Distributed Control System), or it can function as an independent control system communicating with each process device and sensor in the wet desulfurization system through an industrial communication bus or network interface.

[0041] In an optional embodiment, the target dual-parameter coupled control operation includes: performing a first cross-matching analysis on the performance curve and the pipe resistance characteristic curve in the flow-head coordinate system to obtain multiple candidate operating points. Each candidate operating point corresponds to a combination of a preset rotational speed and a preset valve opening, and each candidate operating point includes a candidate flow rate value and a candidate head value; selecting flow matching operating points from the multiple candidate operating points whose flow deviation between the candidate flow rate value and the target circulating flow rate is within a preset flow deviation range; determining the estimated nozzle inlet pressure of the flow matching operating point based on the candidate head value corresponding to the flow matching operating point and the pipeline resistance loss corresponding to the pipe resistance characteristic curve; selecting flow pressure matching operating points from the flow matching operating points whose estimated nozzle inlet pressure is within a preset atomization pressure range; and performing coordinated control operations on the commissioned slurry circulation pump and the commissioned flow and pressure regulating valve based on the flow and pressure matching operating points.

[0042] The flow-head coordinate system refers to a two-dimensional coordinate system established with slurry flow rate as the horizontal axis and head as the vertical axis. The first cross-matching analysis refers to the process of finding the intersection points of the performance curves of the slurry circulation pump at multiple preset speeds and the pipe resistance characteristic curves of the pump's outlet pipeline at multiple preset valve openings within the flow-head coordinate system. The intersection point of each performance curve and each pipe resistance characteristic curve is a candidate operating point. A candidate operating point is the intersection point of the performance curve and the pipe resistance characteristic curve in the flow-head coordinate system. This intersection point represents the steady-state operating point of the slurry circulation pump under the corresponding preset speed and preset valve opening combination. Each candidate operating point includes a candidate flow rate value and a candidate head value. The candidate flow rate value is the flow rate coordinate value corresponding to the candidate operating point in the flow-head coordinate system. The candidate head value is the head coordinate value corresponding to the candidate operating point in the flow-head coordinate system.

[0043] Among them, the flow deviation refers to the absolute value of the difference between the candidate flow value and the target circulating flow. The preset flow deviation range refers to the preset allowable flow deviation range, such as ±5% of the target circulating flow. The flow matching operating point refers to the candidate operating point where the flow deviation between the candidate flow value and the target circulating flow is within the preset flow deviation range. The pipeline resistance loss refers to the pressure loss generated by factors such as pipeline friction and local resistance when the slurry flows in the outlet pipeline of the operating slurry circulation pump. The estimated nozzle inlet pressure refers to the pressure value at the inlet of the spray layer nozzle estimated by subtracting the pipeline resistance loss corresponding to the pipeline resistance characteristic curve from the candidate head value corresponding to the flow matching operating point. The flow-pressure matching operating point refers to the flow matching operating point where the estimated nozzle inlet pressure is within the preset atomization pressure range, that is, the operating point that simultaneously meets the flow requirement and the nozzle inlet pressure requirement. The coordinated adjustment operation refers to the operation of synchronously adjusting the speed of the operating slurry circulation pump and the valve opening of the operating flow regulating and pressure regulating valve according to the preset speed and preset valve opening corresponding to the flow-pressure matching operating point.

[0044] In the above embodiment, taking the wet flue gas desulfurization system supporting the above 600MW coal-fired unit as an example, taking the No. 1 slurry circulation pump and the No. 1 flow regulating and pressure regulating valve as examples to illustrate the specific process of the target dual-parameter coupling regulation operation. In the flow-head coordinate system of the slurry circulation control system, the first cross-matching analysis is carried out on the four performance curves of the No. 1 slurry circulation pump at 4 preset speeds (70%, 80%, 90%, 100% of the rated speed) and the 7 pipeline resistance characteristic curves of the outlet pipeline of the No. 1 slurry circulation pump at 7 preset valve openings (40%, 50%, 60%, 70%, 80%, 90%, 100%). Each performance curve and each pipeline resistance characteristic curve have an intersection point in the flow-head coordinate system, so a total of 4×7 = 28 candidate operating points are obtained. Each candidate operating point corresponds to a combination of a preset speed and a preset valve opening, and each candidate operating point includes a candidate flow value and a candidate head value. For example, the candidate flow value of the candidate operating point corresponding to the preset speed of 90% of the rated speed and the preset valve opening of 70% is 12200 m³ / h, and the candidate head value is 32 m. Assuming that the target circulating flow assigned to the No. 1 slurry circulation pump is 12000 m³ / h and the preset flow deviation range is ±5% of the target circulating flow (that is, 11400 m³ / h to 12600 m³ / h), the slurry circulation control system screens the candidate operating points with candidate flow values within the range of 11400 m³ / h to 12600 m³ / h from the 28 candidate operating points as the flow matching operating points. For example, 8 flow matching operating points are obtained through screening.

[0045] In the above embodiments, the slurry circulation control system determines the estimated nozzle inlet pressure for each flow matching operating point based on the candidate head value and the pipeline resistance loss corresponding to the pipeline resistance characteristic curve. Specifically, the estimated nozzle inlet pressure is equal to the pressure value corresponding to the candidate head value minus the pressure value corresponding to the pipeline resistance loss. For example, if the candidate head value for a certain flow matching operating point is 32m (corresponding to a pressure of approximately 0.314MPa) and the corresponding pipeline resistance loss is 24m (corresponding to a pressure of approximately 0.235MPa), then the estimated nozzle inlet pressure for this flow matching operating point is approximately 0.314MPa - 0.235MPa = 0.079MPa. As another example, if the candidate head value for another flow matching operating point is 28m (corresponding to a pressure of approximately 0.275MPa) and the corresponding pipeline resistance loss is 23m (corresponding to a pressure of approximately 0.226MPa), then the estimated nozzle inlet pressure for this flow matching operating point is approximately 0.275MPa - 0.226MPa = 0.049MPa.

[0046] In the above embodiment, the slurry circulation control system selects flow-pressure matching working points from the above 8 flow matching working points whose estimated nozzle inlet pressure is within a preset atomization pressure range (0.06MPa to 0.08MPa). For example, the flow-pressure matching working point with an estimated nozzle inlet pressure of 0.079MPa is within the preset atomization pressure range and is therefore a flow-pressure matching working point; while the flow-pressure matching working point with an estimated nozzle inlet pressure of 0.049MPa is not within the preset atomization pressure range and is therefore not a flow-pressure matching working point. After screening, 5 flow-pressure matching working points are obtained. The slurry circulation control system performs coordinated adjustment operations on the No. 1 slurry circulation pump and the No. 1 flow-regulating and pressure-regulating valve according to the above 5 flow-pressure matching working points, that is, it selects the optimal working point from the 5 flow-pressure matching working points, adjusts the speed of the No. 1 slurry circulation pump to the preset speed corresponding to the working point, and adjusts the valve opening of the No. 1 flow-regulating and pressure-regulating valve to the preset valve opening corresponding to the working point. The same target dual-parameter coupled control operation was also performed on the No. 2 slurry circulation pump and the No. 2 flow regulating and pressure regulating valve, as well as the No. 3 slurry circulation pump and the No. 3 flow regulating and pressure regulating valve.

[0047] In an optional embodiment, the coordinated adjustment operation includes: determining the pump operating efficiency of the flow-pressure matching working point based on the flow-efficiency correspondence in the performance curve, and determining the flow-pressure matching working point corresponding to the pump operating efficiency not less than a preset efficiency threshold as the target working point; sorting the target working points in a first ascending order based on the operating power of the slurry circulation pump at the target working point, and taking the preset speed corresponding to the first target working point after sorting as the target speed, and taking the preset valve opening corresponding to the first target working point after sorting as the initial valve opening of the flow-regulating and pressure-regulating valve; adjusting the speed of the slurry circulation pump to the target speed, and adjusting the valve opening of the flow-regulating and pressure-regulating valve to the initial valve opening; during the operation of the slurry circulation pump at the target speed, measuring the nozzle inlet pressure of the spray layer corresponding to the slurry circulation pump in real time, and performing pressure deviation analysis between the nozzle inlet pressure and the preset atomization pressure range to obtain the pressure deviation value; and performing dynamic correction operation on the slurry circulation pump and the flow-regulating and pressure-regulating valve based on the pressure deviation value.

[0048] The flow-efficiency correspondence refers to the relationship between flow rate and pump operating efficiency contained in the performance curve of the slurry circulation pump, that is, the operating efficiency value corresponding to different flow rates output by the slurry circulation pump at a certain preset speed. Pump operating efficiency refers to the percentage of input power converted into effective hydraulic power by the slurry circulation pump at a certain operating point. The preset efficiency threshold is the minimum allowable operating efficiency value for the slurry circulation pump, such as 75%, set in advance to ensure that the pump operates within a high-efficiency range. The target operating point is the flow-pressure matching operating point where the pump operating efficiency is not less than the preset efficiency threshold. Operating power refers to the electrical power consumed by the slurry circulation pump when operating at a certain target operating point. The first ascending order sorting process refers to the process of sorting multiple target operating points in ascending order of operating power. The target speed refers to the preset speed corresponding to the target operating point that ranks first after the first ascending order sorting process, that is, the preset speed corresponding to the target operating point with the lowest operating power. The initial valve opening refers to the preset valve opening corresponding to the target operating point that ranks first after the first ascending order sorting process, i.e., the preset valve opening corresponding to the target operating point with the lowest operating power. The pressure deviation value refers to the difference between the real-time nozzle inlet pressure of the spray layer corresponding to the slurry circulation pump and the median of the preset atomization pressure range, or the deviation between the real-time nozzle inlet pressure and the upper or lower limit of the preset atomization pressure range. Dynamic correction operation refers to the operation of dynamically adjusting and correcting the speed of the slurry circulation pump and the valve opening of the flow regulating and pressure regulating valve based on the pressure deviation value, so that the nozzle inlet pressure returns to the preset atomization pressure range.

[0049] In the above embodiment, the specific process of coordinated regulation operation is further illustrated using No. 1 slurry circulation pump and No. 1 flow and pressure regulating valve as examples. The slurry circulation control system determines the pump operating efficiency of each of the five flow-pressure matching operating points obtained from the screening based on the flow-efficiency correspondence in the performance curve of No. 1 slurry circulation pump. For example, the pump operating efficiencies of the five flow-pressure matching operating points are 78%, 82%, 74%, 80%, and 76%, respectively. The slurry circulation control system determines the flow-pressure matching operating points with pump operating efficiencies not less than a preset efficiency threshold (e.g., 75%) as target operating points. The flow-pressure matching operating point with a pump operating efficiency of 74% is lower than the preset efficiency threshold of 75% and is therefore excluded. Four target operating points are obtained after screening, with pump operating efficiencies of 78%, 82%, 80%, and 76%, respectively. The slurry circulation control system performs a first ascending order sorting process on the four target operating points based on the operating power of No. 1 slurry circulation pump at the above four target operating points. For example, if the operating power of four target operating points is 850kW, 820kW, 880kW, and 900kW, the sorted order is: target operating point with an operating power of 820kW (first in the sorted order), target operating point with an operating power of 850kW, target operating point with an operating power of 880kW, and target operating point with an operating power of 900kW. The slurry circulation control system uses the preset speed corresponding to the target operating point that is first in the sorted order as the target speed (e.g., 88% of the rated speed), and uses the preset valve opening corresponding to the target operating point that is first in the sorted order as the initial valve opening of the No. 1 flow regulating and pressure regulating valve (e.g., 72%).

[0050] In the above embodiment, the slurry circulation control system adjusts the rotational speed of slurry circulation pump No. 1 to the target rotational speed (88% of the rated speed) and adjusts the valve opening of flow regulating valve No. 1 to the initial valve opening (72%). While slurry circulation pump No. 1 operates at the target rotational speed, the slurry circulation control system measures the nozzle inlet pressure of the first spray layer corresponding to slurry circulation pump No. 1 in real time. For example, the real-time measured nozzle inlet pressure is 0.073 MPa, the preset atomization pressure range is 0.06 MPa to 0.08 MPa, and the median of the preset atomization pressure range is 0.07 MPa. The slurry circulation control system performs pressure deviation analysis on the nozzle inlet pressure of 0.073 MPa and the median of the preset atomization pressure range of 0.07 MPa, obtaining a pressure deviation value of +0.003 MPa. The slurry circulation control system performs dynamic correction operations on slurry circulation pump No. 1 and flow regulating valve No. 1 based on the pressure deviation value of +0.003 MPa. For example, if the pressure deviation of +0.003 MPa is within the preset allowable deviation range (e.g., ±0.005 MPa), no dynamic correction operation is required, and the No. 1 slurry circulation pump continues to operate at the target speed, while the No. 1 flow regulating and pressure regulating valve maintains its initial valve opening. If the nozzle inlet pressure measured in real time changes during subsequent operation, causing the pressure deviation to exceed the preset allowable deviation range, the slurry circulation control system will perform a dynamic correction operation to adjust the valve opening of the No. 1 flow regulating and pressure regulating valve.

[0051] In an optional embodiment, the dynamic correction operation includes: when the pressure deviation value exceeds a preset allowable deviation range, performing feedback calculation on the pressure deviation value using a preset control algorithm to obtain an opening correction compensation value; superimposing the opening correction compensation value with the initial valve opening to obtain a corrected valve opening; when the corrected valve opening is within a preset safe range, determining the corrected pipeline resistance loss corresponding to the corrected valve opening based on the pipeline resistance characteristic curve; performing a second cross-matching analysis on the corrected pipeline resistance loss and the performance curve of the commissioned slurry circulation pump at the target speed to obtain the corrected working flow rate; when the flow deviation value between the corrected working flow rate and the target circulation flow rate is within a preset flow deviation range, adjusting the opening of the commissioned flow regulating and pressure regulating valve according to the corrected valve opening, and updating the corrected valve opening to the initial valve opening.

[0052] The preset deviation allowable range refers to the pre-set allowable nozzle inlet pressure deviation range within which no correction adjustment of the valve opening of the flow regulating valve is required, for example, ±0.005MPa. The preset control algorithm refers to the pre-set feedback control algorithm used to calculate the valve opening correction amount based on the pressure deviation value, such as a PID (Proportional-Integral-Derivative) control algorithm. Feedback calculation processing refers to the process of performing proportional, integral, and derivative calculations on the pressure deviation value using the preset control algorithm. The opening correction compensation value refers to the valve opening adjustment amount obtained after feedback calculation processing of the pressure deviation value using the preset control algorithm. This adjustment amount is used to correct the initial valve opening of the flow regulating valve. Corrected valve opening refers to the new valve opening value obtained by superimposing the opening correction compensation value and the initial valve opening. The preset safety range refers to the safe operating range of the valve opening of the flow regulating valve, for example, 30% to 100%. Exceeding this range may lead to cavitation or flow control failure in the flow regulating valve. Corrected pipeline resistance loss refers to the pipeline resistance loss value in the outlet pipeline of the slurry circulation pump, determined based on the pipeline resistance characteristic curve under corrected valve opening. The second cross-matching analysis is the process of finding the intersection point between the pipeline resistance characteristic curve corresponding to the corrected pipeline resistance loss and the performance curve of the slurry circulation pump at the target speed in a flow-head coordinate system. Corrected operating flow rate refers to the actual slurry flow rate output by the slurry circulation pump under the corrected valve opening and target speed, obtained through the second cross-matching analysis.

[0053] In the above embodiment, the specific process of dynamic correction operation will continue to be illustrated using the No. 1 slurry circulation pump and the No. 1 flow regulating and pressure regulating valve as examples. Assume that during the operation of the No. 1 slurry circulation pump at the target speed (88% of the rated speed), due to factors such as changes in slurry density or pipe scaling, the nozzle inlet pressure of the first spray layer, measured in real time by the slurry circulation control system, becomes 0.056 MPa. The pressure deviation between this pressure and the median of the preset atomization pressure range (0.06 MPa to 0.08 MPa), 0.07 MPa, is -0.014 MPa. The slurry circulation control system determines that the pressure deviation of -0.014 MPa exceeds the preset allowable deviation range of ±0.005 MPa, therefore, dynamic correction operation is required. The slurry circulation control system uses a preset control algorithm (e.g., a PID control algorithm) to perform feedback calculations on the pressure deviation of -0.014 MPa to obtain the opening correction compensation value. Specifically, the PID control algorithm performs comprehensive calculations based on the proportional, integral, and derivative terms of the pressure deviation value. In this embodiment, since the nozzle inlet pressure of 0.056 MPa is lower than the lower limit of the preset atomization pressure range of 0.06 MPa, the pressure deviation value is negative (-0.014 MPa), indicating that the current nozzle inlet pressure is too low and needs to be increased. Based on the physical characteristics of the pipeline system, increasing the valve opening of the flow regulating and pressure regulating valve can reduce pipeline resistance loss. With the pump speed remaining constant, the reduced pipeline resistance loss will allow more pressure to be transmitted to the nozzle inlet, thereby increasing the nozzle inlet pressure. Therefore, the opening correction compensation value output by the PID control algorithm is +5% (a positive value indicates an increase in valve opening).

[0054] In the above embodiment, the slurry circulation control system superimposes the opening correction compensation value +5% with the initial valve opening of 72%, resulting in a corrected valve opening of 72% + 5% = 77%. The slurry circulation control system determines that the corrected valve opening of 77% is within a preset safe range (30% to 100%), and therefore determines the corrected pipeline resistance loss corresponding to the corrected valve opening of 77% based on the pipe resistance characteristic curve. For example, according to the pipe resistance characteristic curve, the corrected pipeline resistance loss at a flow rate of 12000 m³ / h with a valve opening of 77% is found to be 22.5 m. The slurry circulation control system performs a second cross-matching analysis between the pipe resistance characteristic curve corresponding to the corrected pipeline resistance loss of 22.5 m and the performance curve of the No. 1 slurry circulation pump at the target speed (88% of the rated speed), and finds the intersection of the two curves in the flow rate-head coordinate system, obtaining a corrected working flow rate of 12150 m³ / h. The slurry circulation control system determined that the flow deviation between the corrected working flow rate of 12150 m³ / h and the target circulation flow rate of 12000 m³ / h was 150 m³ / h, accounting for 1.25% of the target circulation flow rate, which is within the preset flow deviation range (±5%). Therefore, the slurry circulation control system adjusted the opening of the No. 1 flow regulating and pressure regulating valve based on the corrected valve opening of 77%, adjusting the valve opening from 72% to 77%, and updating the corrected valve opening of 77% to the initial valve opening as the reference opening for subsequent dynamic correction operations. Afterward, the slurry circulation control system continued to measure the nozzle inlet pressure of the first spray layer in real time and repeated the above dynamic correction operation process to continuously maintain the nozzle inlet pressure within the preset atomization pressure range and keep the actual circulation flow rate near the target circulation flow rate.

[0055] In an optional embodiment, before matching the target circulating flow rate and target operating combination mode corresponding to the real-time operating condition parameters from the optimal circulating flow rate operating condition library using a preset operating condition matching model, the method further includes: obtaining the rated flue gas treatment capacity of the wet desulfurization system, and determining multiple flue gas volume intervals based on the rated flue gas treatment capacity; sequentially traversing each flue gas volume interval in the multiple flue gas volume intervals, and performing the following operating condition calibration operation on the currently traversed flue gas volume interval: selecting multiple test flue gas volumes from the target flue gas volume interval, and selecting multiple test circulating flow rates from the preset circulating flow rate range, where the target flue gas volume interval is the currently traversed flue gas volume interval; determining N candidate operating combination modes for multiple slurry circulating pumps based on the multiple test circulating flow rates, the spatial distribution of the spray layer corresponding to each slurry circulating pump in the desulfurization tower, and the spray coverage characteristics, where N is a positive integer; under each test flue gas volume, using... The first dual-parameter coupling control operation is performed using the performance curves and pipe resistance characteristic curves of each slurry circulation pump in each candidate operating combination to ensure that the actual circulation flow rate of the desulfurization tower reaches the corresponding test circulation flow rate, and that the nozzle inlet pressure of the spray layer corresponding to each slurry circulation pump is within the preset atomization pressure range. After the first dual-parameter coupling control operation is completed and the wet desulfurization system reaches a stable operating state, the desulfurization efficiency of each candidate operating combination is tested to obtain the test desulfurization efficiency, test nozzle inlet pressure, and test operating power of each candidate operating combination. Based on the test desulfurization efficiency, test nozzle inlet pressure, and test operating power, the first operating combination and the first circulation flow rate corresponding to the target flue gas volume range are determined from the N candidate operating combinations. The target flue gas volume range, the first operating combination, and the first circulation flow rate are associated and stored in the optimal circulation volume operating condition library.

[0056] Rated flue gas capacity refers to the maximum flue gas volume that the wet desulfurization system can handle under rated operating conditions, as determined during the system's design. Flue gas volume range refers to different flue gas volume ranges divided based on the rated flue gas capacity. Each range corresponds to an upper and lower limit value for the flue gas volume. For example, the rated flue gas capacity can be divided into five ranges: 60%-70%, 70%-80%, 80%-90%, 90%-100%, and 100%-110%. Operating condition calibration refers to the testing and evaluation operations performed on the currently traversed flue gas volume range to determine the optimal circulating flow rate and optimal operating combination for that range. The target flue gas volume range refers to the currently traversed flue gas volume range. The test flue gas volume refers to the flue gas volume value selected from the target flue gas volume range for operating condition calibration testing. The test circulating flow rate refers to the circulating flow rate value selected from a preset circulating flow rate range for operating condition calibration testing. The preset circulation flow range refers to the pre-defined adjustment range of the slurry circulation flow rate, such as 30% to 100% of the design circulation flow rate of a wet desulfurization system. Spatial distribution refers to the installation position of the spray layer corresponding to each slurry circulation pump along the height direction inside the desulfurization tower. Spray coverage characteristics refer to the arrangement of nozzles on the spray layer corresponding to each slurry circulation pump, as well as its spray coverage area and uniformity.

[0057] The candidate operating combinations refer to the possible start-up and shutdown combinations of multiple slurry circulation pumps determined based on multiple test circulation flow rates, the spatial distribution of the spray layer within the desulfurization tower, and the spray coverage characteristics. Each candidate operating combination specifies which slurry circulation pumps are put into operation and the allocated flow rate for each pump. N represents the total number of candidate operating combinations. The first dual-parameter coupled control operation refers to the coordinated adjustment of the rotational speed of each slurry circulation pump and the valve opening of the corresponding flow and pressure regulating valves in each candidate operating combination during the operating condition calibration test. This ensures that the actual circulation flow rate of the desulfurization tower reaches the corresponding test circulation flow rate, and the nozzle inlet pressure of the spray layer corresponding to each slurry circulation pump is within the preset atomization pressure range. Stable operating state refers to the state where the operating parameters of the wet desulfurization system tend to stabilize and no longer fluctuate significantly after the first dual-parameter coupled control operation is performed. Test desulfurization efficiency refers to the percentage of desulfurization efficiency of the wet desulfurization system measured under stable operating conditions. Test nozzle inlet pressure refers to the nozzle inlet pressure value of the spray layer corresponding to each operating slurry circulation pump measured under stable operating conditions. Test operating power refers to the total operating electrical power of all commissioned slurry circulation pumps measured under stable operating conditions. The first operating combination mode refers to the optimal operating combination mode corresponding to the target flue gas volume range, determined after evaluation and screening. The first circulation flow rate refers to the optimal circulation flow rate corresponding to the first operating combination mode.

[0058] In the above embodiments, taking the wet flue gas desulfurization system supporting the 600MW coal-fired unit as an example, the construction process of the optimal circulation volume working condition library is described below. The slurry circulation control system obtains the rated flue gas treatment volume of the wet flue gas desulfurization system, such as 2.4 million Nm³ / h. The slurry circulation control system determines multiple flue gas volume intervals according to the rated flue gas treatment volume of 2.4 million Nm³ / h. For example, the rated flue gas treatment volume is divided into 60%-70%, 70%-80%, 80%-90%, 90%-100%, and 100%-110% to obtain 5 flue gas volume intervals, namely: the first flue gas volume interval (1.44 million - 1.68 million Nm³ / h), the second flue gas volume interval (1.68 million - 1.92 million Nm³ / h), the third flue gas volume interval (1.92 million - 2.16 million Nm³ / h), the fourth flue gas volume interval (2.16 million - 2.4 million Nm³ / h), and the fifth flue gas volume interval (2.4 million - 2.64 million Nm³ / h). The slurry circulation control system traverses the above 5 flue gas volume intervals in sequence. Taking the second flue gas volume interval (1.68 million - 1.92 million Nm³ / h) as the target flue gas volume interval currently traversed, the specific process of the working condition calibration operation is described as follows: The slurry circulation control system selects multiple test flue gas volumes from the target flue gas volume interval (1.68 million - 1.92 million Nm³ / h), such as 5 test flue gas volumes of 1.7 million Nm³ / h, 1.75 million Nm³ / h, 1.8 million Nm³ / h, 1.85 million Nm³ / h, and 1.9 million Nm³ / h. The slurry circulation control system selects multiple test circulation flows from the preset circulation flow range (such as 30% to 100% of the designed circulation flow, that is, 14,400 m³ / h to 48,000 m³ / h), such as 4 test circulation flows of 24,000 m³ / h, 30,000 m³ / h, 36,000 m³ / h, and 42,000 m³ / h.

[0059] In the above embodiment, the slurry circulation control system determines N candidate operating combinations of the four slurry circulation pumps based on the four test circulation flow rates, the spatial distribution of the spray layers corresponding to the four slurry circulation pumps within the desulfurization tower (e.g., the installation elevation of the first spray layer is 12m, the second spray layer is 15m, the third spray layer is 18m, and the fourth spray layer is 21m), and the spray coverage characteristics. For example, the candidate operating combinations include: combination A (slurry circulation pump 1 + slurry circulation pump 2), combination B (slurry circulation pump 1 + slurry circulation pump 3), combination C (slurry circulation pump 2 + slurry circulation pump 3), combination D (slurry circulation pump 1 + slurry circulation pump 2 + slurry circulation pump 3), and combination E (slurry circulation pump 1 + slurry circulation pump 2 + slurry circulation pump 4), etc., for a total of N=10 candidate operating combinations. Under each test flue gas volume, the slurry circulation control system performs the first dual-parameter coupled control operation using the performance curves and pipe resistance characteristic curves of each slurry circulation pump in each candidate operating combination. For example, under the condition of a test flue gas volume of 1.8 million Nm³ / h, for candidate operating combination D (slurry circulation pump No. 1 + slurry circulation pump No. 2 + slurry circulation pump No. 3 in operation), the slurry circulation control system adjusts the speed of slurry circulation pump No. 1, slurry circulation pump No. 2, and slurry circulation pump No. 3, as well as the valve opening of flow regulating valves No. 1, No. 2, and No. 3, so that the actual circulation flow of the desulfurization tower reaches the test circulation flow of 36,000 m³ / h, and the nozzle inlet pressure of the first spray layer, the second spray layer, and the third spray layer are all within the preset atomization pressure range (0.06 MPa to 0.08 MPa).

[0060] In the above embodiments, after the first dual-parameter coupling control operation is completed and the wet desulfurization system reaches a stable operating state, the slurry circulation control system tests the desulfurization efficiency of each candidate operating combination, obtaining the test desulfurization efficiency, test nozzle inlet pressure, and test operating power for each candidate operating combination. For example, under the conditions of a test flue gas volume of 1.8 million Nm³ / h and a test circulation flow rate of 36,000 m³ / h, candidate operating combination D has a measured test desulfurization efficiency of 99.3%, test nozzle inlet pressures of 0.072 MPa, 0.069 MPa, and 0.071 MPa, and a test operating power of 2460 kW. Based on the test desulfurization efficiency, test nozzle inlet pressure, and test operating power, the slurry circulation control system determines the first operating combination and the first circulation flow rate corresponding to the target flue gas volume range (1.68 million-1.92 million Nm³ / h) from the 10 candidate operating combinations. For example, after comprehensive evaluation, the first operating combination mode was determined to be candidate operating combination mode D (slurry circulation pump No. 1 + slurry circulation pump No. 2 + slurry circulation pump No. 3 in operation), with a first circulation flow rate of 36,000 m³ / h. The slurry circulation control system associated and stored the target flue gas volume range (1.68 million - 1.92 million Nm³ / h), the first operating combination mode (candidate operating combination mode D), and the first circulation flow rate (36,000 m³ / h) in the optimal circulation volume operating condition library. The slurry circulation control system also performed the same operating condition calibration operation on the other four flue gas volume ranges, ultimately constructing an optimal circulation volume operating condition library covering the entire operating condition range.

[0061] In an optional embodiment, based on the tested desulfurization efficiency, the tested nozzle inlet pressure, and the tested operating power, a first operating combination mode and a first circulation flow rate corresponding to the target flue gas volume range are determined from N candidate operating combinations. This includes: selecting M compliant operating combinations from the N candidate operating combinations where the tested desulfurization efficiency is not less than a preset desulfurization efficiency threshold and the tested nozzle inlet pressure is within a preset atomization pressure range, where M is a positive integer less than or equal to N; obtaining the installation elevation of the spray layer corresponding to each operational slurry circulation pump in each compliant operating combination mode, and determining the installation elevation based on the installation elevation. A static head energy consumption penalty coefficient is determined for each compliant operation combination mode, wherein the installation elevation is positively correlated with the static head energy consumption penalty coefficient; the test operation power of each compliant operation combination mode is weighted and corrected according to the static head energy consumption penalty coefficient to obtain the equivalent evaluation energy consumption of each compliant operation combination mode; the M compliant operation combinations mode are sorted in a second ascending order according to the equivalent evaluation energy consumption, and the compliant operation combination mode ranked first after sorting is taken as the first operation combination mode in the target flue gas volume range, and the test circulation flow rate corresponding to the first operation combination mode is taken as the first circulation flow rate.

[0062] The preset desulfurization efficiency threshold refers to the minimum desulfurization efficiency value that the wet desulfurization system must achieve, such as 99%. The compliant operation combination refers to the candidate operation combination selected from N candidate operation combinations, where the test desulfurization efficiency is not less than the preset desulfurization efficiency threshold and the test nozzle inlet pressure is within the preset atomization pressure range. M is the number of compliant operation combinations, where M is a positive integer less than or equal to N. Installation elevation refers to the vertical installation height of the spray layer corresponding to each operational slurry circulation pump in each compliant operation combination relative to the reference plane within the desulfurization tower. The static head energy consumption penalty coefficient is a weighted coefficient determined based on the installation elevation to correct the test operating power. A higher installation elevation requires the slurry circulation pump to overcome a greater static head, resulting in higher operating energy consumption; therefore, the installation elevation and the static head energy consumption penalty coefficient are positively correlated. Equivalent evaluation energy consumption refers to the comprehensive energy consumption evaluation value obtained by weighting and correcting the test operating power using the static head energy consumption penalty coefficient. This equivalent evaluation energy consumption incorporates the impact of the sprinkler layer installation elevation on energy consumption into the evaluation system, and can more objectively reflect the actual energy consumption level of different compliant operating combinations. The second ascending order sorting process refers to the process of sorting the M compliant operating combinations in ascending order of equivalent evaluation energy consumption. The first operating combination refers to the compliant operating combination that ranks first after the second ascending order sorting process, i.e., the compliant operating combination with the lowest equivalent evaluation energy consumption. The first circulation flow rate refers to the test circulation flow rate corresponding to the first operating combination in the operating condition calibration test.

[0063] In the above embodiments, continuing with the wet flue gas desulfurization system supporting the above 600 MW coal-fired unit as an example, taking the target flue gas volume range as the second flue gas volume range (1.68 million - 1.92 million Nm³ / h) as an example, the specific process of determining the first operation combination mode and the first recycle flow rate from the candidate operation combination modes is illustrated. Assuming that after the working condition calibration operation, under the conditions of a test flue gas volume of 1.8 million Nm³ / h and a test recycle flow rate of 36,000 m³ / h, the test results of 10 candidate operation combination modes are as follows (only partial examples are listed): Candidate operation combination mode A (No. 1 slurry recycle pump + No. 2 slurry recycle pump are put into operation): The test desulfurization efficiency is 98.5%, the test nozzle inlet pressure is 0.073 MPa and 0.071 MPa, and the test operation power is 1850 kW. Candidate operation combination mode C (No. 2 slurry recycle pump + No. 3 slurry recycle pump are put into operation): The test desulfurization efficiency is 99.1%, the test nozzle inlet pressure is 0.070 MPa and 0.068 MPa, and the test operation power is 1920 kW. Candidate operation combination mode D (No. 1 slurry recycle pump + No. 2 slurry recycle pump + No. 3 slurry recycle pump are put into operation): The test desulfurization efficiency is 99.3%, the test nozzle inlet pressure is 0.072 MPa, 0.069 MPa and 0.071 MPa, and the test operation power is 2460 kW. Candidate operation combination mode E (No. 1 slurry recycle pump + No. 2 slurry recycle pump + No. 4 slurry recycle pump are put into operation): The test desulfurization efficiency is 99.2%, the test nozzle inlet pressure is 0.074 MPa, 0.070 MPa and 0.065 MPa, and the test operation power is 2580 kW.

[0064] In the above embodiment, the slurry circulation control system selects compliant operating combinations from 10 candidate operating combinations, ensuring that the tested desulfurization efficiency is not less than a preset desulfurization efficiency threshold (99%) and the test nozzle inlet pressure is within a preset atomization pressure range (0.06MPa to 0.08MPa). Candidate operating combination A has a tested desulfurization efficiency of 98.5%, which is lower than the preset desulfurization efficiency threshold of 99%, and is therefore excluded. Candidate operating combinations C, D, and E all meet the conditions. Assume that a total of M=6 compliant operating combinations are obtained after screening. The slurry circulation control system obtains the installation elevation of the spray layer corresponding to each operating slurry circulation pump in each compliant operating combination and determines the static head energy consumption penalty coefficient for each compliant operating combination based on the installation elevation. For example, the installation elevation of the first spray layer is 12m, the second spray layer is 15m, the third spray layer is 18m, and the fourth spray layer is 21m. For candidate operation combination C (Pumps 2 and 3 are in operation, corresponding to the second and third spray layers), the installation elevations of the spray layers corresponding to each pump are 15m and 18m, respectively, with an average installation elevation of 16.5m. For candidate operation combination D (Pumps 1, 2, and 3 are in operation, corresponding to the first, second, and third spray layers), the installation elevations of the spray layers corresponding to each pump are 12m, 15m, and 18m, respectively, with an average installation elevation of 15m. For candidate operation combination E (Pumps 1, 2, and 4 are in operation, corresponding to the first, second, and fourth spray layers), the installation elevations of the spray layers corresponding to each pump are 12m, 15m, and 21m, respectively, with an average installation elevation of 16m.

[0065] In the above embodiments, the slurry circulation control system determines the static head energy consumption penalty coefficient for each compliant operating combination mode based on the average installation elevation. For example, using the ratio of the average installation elevation to the reference elevation (e.g., 12m) as the static head energy consumption penalty coefficient, the static head energy consumption penalty coefficient for candidate operating combination mode C is 16.5 / 12 = 1.375, the static head energy consumption penalty coefficient for candidate operating combination mode D is 15 / 12 = 1.25, and the static head energy consumption penalty coefficient for candidate operating combination mode E is 16 / 12 = 1.333. The slurry circulation control system performs a weighted correction on the test operating power of each compliant operating combination mode based on the static head energy consumption penalty coefficient to obtain the equivalent evaluation energy consumption of each compliant operating combination mode. For example, the equivalent evaluation energy consumption of candidate operating combination mode C is 1920kW × 1.375 = 2640kW, the equivalent evaluation energy consumption of candidate operating combination mode D is 2460kW × 1.25 = 3075kW, and the equivalent evaluation energy consumption of candidate operating combination mode E is 2580kW × 1.333 = 3439.14kW. The slurry circulation control system sorts the six compliant operating combinations in ascending order according to their equivalent evaluation energy consumption. Assuming that after sorting, the equivalent evaluation energy consumption of candidate operating combination mode C, 2640kW, is ranked first, the slurry circulation control system will use candidate operating combination mode C, ranked first, as the first operating combination mode in the target flue gas volume range (1.68 million - 1.92 million Nm³ / h), and will use the test circulation flow rate of 36000m³ / h corresponding to candidate operating combination mode C as the first circulation flow rate.

[0066] In an optional embodiment, after determining the slurry circulation pump to be put into operation from multiple slurry circulation pumps according to the target operating combination, the method further includes: obtaining the current actual operating combination of the wet desulfurization system; if the actual operating combination differs from the target operating combination, performing a difference comparison analysis between the actual operating combination and the target operating combination to determine the slurry circulation pump to be started that is not present in the target operating combination, and the slurry circulation pump to be stopped that is not present in the target operating combination; obtaining the current inlet flue gas volume of the desulfurization tower, and determining the total flow stability constraint condition during the pump group switching transition period based on the inlet flue gas volume; determining the load increase operating trajectory of the slurry circulation pump to be started and the load decrease operating trajectory of the slurry circulation pump to be stopped based on the total flow stability constraint condition; starting... The slurry circulation pump to be started is activated to allow the slurry circulation pump to be started and the slurry circulation pump to be stopped to enter the pump set switching transition period. During the pump set switching transition period, the slurry circulation pump to be started is controlled to perform load increase adjustment operation according to the load increase operation trajectory, and the slurry circulation pump to be stopped is controlled to perform load decrease adjustment operation according to the load decrease operation trajectory, so that the actual circulation flow of the desulfurization tower continuously meets the total flow stability constraint condition. When the real-time load parameter of the slurry circulation pump to be stopped is detected to drop to the preset safe shutdown threshold, the slurry circulation pump to be stopped is controlled to stop operation. When the slurry circulation pump to be stopped stops operation, and the actual operation combination mode is the same as the target operation combination mode, and the slurry circulation pump in operation is in a stable operation state, the target dual-parameter coupling control operation is performed on the slurry circulation pump in operation, so that the actual circulation flow of the desulfurization tower reaches the target circulation flow.

[0067] The actual operating combination refers to the start-up and shutdown combination schemes of multiple slurry circulation pumps currently in operation in the wet desulfurization system. The difference comparison analysis refers to the process of comparing the actual operating combination with the target operating combination one by one to identify the differences between the two. The slurry circulation pump to be started refers to the slurry circulation pump that needs to be put into operation in the target operating combination but is not in operation in the actual operating combination; that is, the slurry circulation pump that needs to be switched from a stopped state to an operating state. The slurry circulation pump to be stopped refers to the slurry circulation pump that is currently operating in the actual operating combination but does not need to be put into operation in the target operating combination; that is, the slurry circulation pump that needs to be switched from an operating state to a stopped state. The inlet flue gas volume refers to the real-time flue gas volume at the current inlet of the desulfurization tower. The pump set switching transition period refers to the time period from the start-up of the slurry circulation pump to the complete shutdown of the slurry circulation pump to be stopped; during this time period, both the slurry circulation pump to be started and the slurry circulation pump to be stopped are in operation simultaneously. The total flow stability constraint means that during the pump set switching transition period, the change in the actual circulating flow of the desulfurization tower must be maintained within the allowable fluctuation range to ensure that the desulfurization efficiency is not significantly affected.

[0068] Among them, the load increasing operation trajectory refers to the operation path of the to-be-started slurry circulating pump gradually increasing from a low load to the target load during the pump group switching transition period, including the curve of the rotational speed of the to-be-started slurry circulating pump changing with time. The load decreasing operation trajectory refers to the operation path of the to-be-stopped slurry circulating pump gradually decreasing from the current load to the load level at which it can be safely shut down during the pump group switching transition period, including the curve of the rotational speed of the to-be-stopped slurry circulating pump changing with time. The load increasing adjustment operation refers to the adjustment operation of gradually increasing the rotational speed and flow rate of the to-be-started slurry circulating pump according to the load increasing operation trajectory. The load decreasing adjustment operation refers to the adjustment operation of gradually decreasing the rotational speed and flow rate of the to-be-stopped slurry circulating pump according to the load decreasing operation trajectory. The real-time load parameter refers to the current operation load parameter of the to-be-stopped slurry circulating pump, including at least one of rotational speed, current and output flow rate. The preset safe shutdown threshold refers to the lowest load parameter value preset for the slurry circulating pump to be able to safely shut down. When the real-time load parameter of the to-be-stopped slurry circulating pump drops to the preset safe shutdown threshold, it indicates that the slurry circulating pump can be safely shut down.

[0069] In the above embodiment, taking the wet flue gas desulfurization system supporting the above 600MW coal-fired unit as an example, the specific process of pump group switching transition control is described. It is assumed that the slurry circulating control system determines that the slurry circulating pumps to be put into operation are No. 1 slurry circulating pump, No. 2 slurry circulating pump and No. 3 slurry circulating pump according to the target operation combination mode (that is, the target operation combination mode is that No. 1 slurry circulating pump + No. 2 slurry circulating pump + No. 3 slurry circulating pump are put into operation). The slurry circulating control system obtains the current actual operation combination mode of the wet flue gas desulfurization system. For example, the current actual operation combination mode of the wet flue gas desulfurization system is that No. 1 slurry circulating pump + No. 2 slurry circulating pump + No. 4 slurry circulating pump are put into operation. The slurry circulating control system determines that the actual operation combination mode (No. 1 slurry circulating pump + No. 2 slurry circulating pump + No. 4 slurry circulating pump are put into operation) is different from the target operation combination mode (No. 1 slurry circulating pump + No. 2 slurry circulating pump + No. 3 slurry circulating pump are put into operation), so the actual operation combination mode and the target operation combination mode are compared and analyzed for differences. Through the difference comparison and analysis, the slurry circulating control system determines that the to-be-started slurry circulating pump that exists in the target operation combination mode but does not exist in the actual operation combination mode is No. 3 slurry circulating pump; the to-be-stopped slurry circulating pump that exists in the actual operation combination mode but does not exist in the target operation combination mode is No. 4 slurry circulating pump. No. 1 slurry circulating pump and No. 2 slurry circulating pump exist in both the actual operation combination mode and the target operation combination mode, and no start-stop switching is required.

[0070] In the above embodiment, the slurry circulation control system obtains the current inlet flue gas volume of the desulfurization tower, for example, 1.8 million Nm³ / h, and determines the total flow stability constraint condition during the pump group switching transition period based on the inlet flue gas volume of 1.8 million Nm³ / h. For example, the total flow stability constraint condition is: during the pump group switching transition period, the fluctuation range of the actual circulation flow of the desulfurization tower shall not exceed ±8% of the target circulation flow of 36,000 m³ / h, that is, the actual circulation flow needs to be maintained within the range of 33,120 m³ / h to 38,880 m³ / h. The slurry circulation control system determines the load increase operation trajectory of the slurry circulation pump to be started (slurry circulation pump No. 3) and the load decrease operation trajectory of the slurry circulation pump to be stopped (slurry circulation pump No. 4) based on the total flow stability constraint condition. For example, the load increase trajectory of slurry circulation pump No. 3 is as follows: within 120 seconds, the speed of slurry circulation pump No. 3 is linearly increased from 30% of the rated speed to 88% of the rated speed, corresponding to a gradual increase in output flow rate from 4000 m³ / h to 12000 m³ / h. The load decrease trajectory of slurry circulation pump No. 4 is as follows: within 120 seconds, the speed of slurry circulation pump No. 4 is linearly decreased from 85% of the current rated speed to 30% of the rated speed, corresponding to a gradual decrease in output flow rate from 11500 m³ / h to 4000 m³ / h. The load increase trajectory of slurry circulation pump No. 3 and the load decrease trajectory of slurry circulation pump No. 4 are executed synchronously in time, ensuring that at any given moment, the increase in flow rate of slurry circulation pump No. 3 is approximately equal to the decrease in flow rate of slurry circulation pump No. 4, thereby guaranteeing that the actual circulating flow rate of the desulfurization tower continuously meets the total flow stability constraint.

[0071] In the above embodiment, the slurry circulation control system starts slurry circulation pump No. 3, initiating a pump set switching transition period between slurry circulation pump No. 3 and slurry circulation pump No. 4. During this transition period, the slurry circulation control system controls slurry circulation pump No. 3 to perform load increase adjustment operations according to the load increase trajectory, i.e., gradually increasing the speed of slurry circulation pump No. 3; simultaneously, the slurry circulation control system controls slurry circulation pump No. 4 to perform load decrease adjustment operations according to the load decrease trajectory, i.e., gradually decreasing the speed of slurry circulation pump No. 4. During this process, the actual circulation flow rate of the desulfurization tower continuously meets the total flow rate stability constraint condition (33120 m³ / h to 38880 m³ / h). The slurry circulation control system monitors the real-time load parameters (e.g., speed and output flow rate) of slurry circulation pump No. 4 in real time. When the slurry circulation control system detects that the real-time load parameters of slurry circulation pump No. 4 have dropped to the preset safe shutdown threshold (e.g., the speed drops below 30% of the rated speed, and the output flow rate drops below 4000 m³ / h), the slurry circulation control system controls slurry circulation pump No. 4 to stop operating and closes the No. 4 flow regulating and pressure regulating valve. After slurry circulation pump No. 4 stops operating, the current actual operating combination becomes "slurry circulation pump No. 1 + slurry circulation pump No. 2 + slurry circulation pump No. 3 are put into operation", which is the same as the target operating combination. After the slurry circulation control system waits for slurry circulation pumps No. 1, No. 2, and No. 3 to be in stable operation, it performs a target dual-parameter coupled control operation on slurry circulation pumps No. 1, No. 2, and No. 3. That is, it adjusts the speed of each slurry circulation pump and the valve opening of each flow regulating and pressure regulating valve to make the actual circulation flow of the desulfurization tower reach the target circulation flow of 36,000 m³ / h, and the nozzle inlet pressure of the first spray layer, the second spray layer, and the third spray layer are all maintained within the preset atomization pressure range (0.06 MPa to 0.08 MPa).

[0072] It should be noted that the embodiments described above are only some embodiments of this application, and not all embodiments. The present application will be described in detail below with reference to specific embodiments.

[0073] Through the embodiments of this application, an optimal circulation volume operating condition library is constructed and a preset operating condition matching model is used for real-time operating condition matching. This achieves precise adaptation of the target circulation flow rate and target operating combination mode of the slurry circulation pump to the dynamic changes of operating conditions, avoiding the energy waste caused by the continuous operation of a single high-power pump or the simple start-stop of a fixed pump group. Target dual-parameter coupled control operation is performed on the rotational speed of the slurry circulation pump and the valve opening of the flow regulating and pressure regulating valve. The optimal operating point is systematically searched in the combination space formed by the performance curve and the pipe resistance characteristic curve, and optimized by combining pump operating efficiency and operating power. This achieves efficient coordinated control of circulation flow rate and nozzle inlet pressure while meeting desulfurization efficiency requirements. In addition, during the pump group switching transition period, the slurry circulation pump to be started and the slurry circulation pump to be stopped are synchronously controlled according to the load increase and load decrease operating trajectories. This ensures that the actual circulation flow rate of the desulfurization tower remains stable during the pump group switching process, avoiding fluctuations in desulfurization efficiency and large fluctuations in nozzle inlet pressure caused by step changes in circulation flow rate.

[0074] The slurry circulation control system in the embodiments of this invention is described below from the perspective of hardware processing. (See attached document.) Figure 2 , Figure 2 This is a schematic diagram of the physical device structure of a slurry circulation control system in the embodiments of this application.

[0075] It should be noted that, Figure 2 The structure of the slurry circulation control system shown is merely an example and should not impose any limitations on the functionality and scope of use of the embodiments of the present invention.

[0076] like Figure 2 As shown, the slurry circulation control system includes a central processing unit (CPU) 201, which can perform various appropriate actions and processes according to a program stored in read-only memory (ROM) 202 or a program loaded from storage section 208 into random access memory (RAM) 203, such as performing the methods described in the above embodiments. The RAM 203 also stores...

[0077] The system contains various programs and data required for operation. The CPU 201, ROM 202, and RAM 203 are interconnected via bus 204. Input / output (I / O) interface 205 is also connected to bus 204. The following components are connected to I / O interface 205: input section 206, including audio input devices, push-button switches, etc.; output section 207, including a Liquid Crystal Display (LCD), audio output devices, indicator lights, etc.; storage section 208, including a hard disk, etc.; and communication section 209, including a network interface card such as a LAN (Local Area Network) card, modem, etc. Communication section 209 performs communication processing via a network such as the Internet. Drive 210 is also connected to I / O interface 205 as needed. Removable media 211, such as a disk, optical disk, magneto-optical disk, semiconductor memory, etc., are installed on drive 210 as needed so that computer programs read from them can be installed into storage section 208 as needed.

[0078] In particular, according to embodiments of the present invention, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of the present invention include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing computer programs for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via communication section 209, and / or installed from removable medium 211. When the computer program is executed by central processing unit (CPU) 201, it performs the various functions defined in the present invention.

[0079] It should be noted that specific examples of computer-readable storage media may include, but are not limited to: electrical connections having one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM), flash memory, optical fiber, portable compact disc read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In this invention, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0080] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. Each block in a flowchart or block diagram may represent a module, program segment, or portion of code, which contains one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those shown in the drawings.

[0081] Specifically, the slurry circulation control system of this embodiment includes a processor and a memory. The memory stores a computer program. When the computer program is executed by the processor, it implements the optimal circulation rate optimization operation method of the slurry circulation pump provided in the above embodiment.

[0082] In another aspect, the present invention also provides a computer-readable storage medium, which may be included in the slurry circulation control system described in the above embodiments; or it may exist independently and not assembled into the slurry circulation control system. The storage medium carries one or more computer programs that, when executed by a processor of the slurry circulation control system, cause the slurry circulation control system to implement the optimal circulation rate operation method for the slurry circulation pump provided in the above embodiments.

[0083] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit it. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

[0084] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. This program can be stored in a computer-readable storage medium, and when executed, it can include the processes described in the above method embodiments. The aforementioned storage medium includes various media capable of storing program code, such as ROM or random access memory (RAM), magnetic disks, or optical disks.

Claims

1. A method for optimizing the circulation rate of a slurry circulating pump, characterized in that, The method is applied to a wet desulfurization system, which includes a desulfurization tower, multiple slurry circulation pumps, flow regulating and pressure regulating valves installed on the outlet pipeline of each slurry circulation pump, and multiple spray layers. The slurry circulation pumps are correspondingly connected to the spray layers. When the real-time operating condition parameters of the wet desulfurization system are obtained, the real-time operating condition parameters are input into the preset operating condition matching model, so as to use the preset operating condition matching model to match the target circulation flow and target operating combination mode corresponding to the real-time operating condition parameters from the optimal circulation flow condition library. Based on the target operating combination, the slurry circulation pump to be put into operation is determined from the plurality of slurry circulation pumps, and the performance curves of the slurry circulation pump to be put into operation at multiple preset speeds and the pipe resistance characteristic curves of the outlet pipeline of the slurry circulation pump to be put into operation at multiple preset valve openings are obtained. Based on the target circulation flow rate, the performance curve, and the pipe resistance characteristic curve, a target dual-parameter coupled control operation is performed on the commissioning slurry circulation pump and the commissioning flow regulating and pressure regulating valve corresponding to the commissioning slurry circulation pump, so that the actual circulation flow rate of the desulfurization tower reaches the target circulation flow rate, and the nozzle inlet pressure of the spray layer corresponding to the commissioning slurry circulation pump is maintained within the preset atomization pressure range.

2. The method according to claim 1, characterized in that, The target dual-parameter coupled control operation includes: In the flow rate and head coordinate system, the performance curve and the pipe resistance characteristic curve are subjected to a first cross-matching analysis to obtain multiple candidate operating points. Each candidate operating point corresponds to a combination of a preset rotation speed and a preset valve opening. Each candidate operating point includes a candidate flow rate value and a candidate head value. From the plurality of candidate working points, select the flow matching working points whose flow deviation between the candidate flow value and the target circulating flow is within a preset flow deviation range; The estimated nozzle inlet pressure of the flow matching operating point is determined based on the candidate head value corresponding to the flow matching operating point and the pipeline resistance loss corresponding to the pipeline resistance characteristic curve. Select flow pressure matching working points from the flow matching working points where the estimated nozzle inlet pressure is within the preset atomization pressure range; The commissioning of the slurry circulation pump and the commissioning of the flow and pressure regulating valve are coordinated and adjusted according to the flow and pressure matching operating point.

3. The method according to claim 2, characterized in that, The coordinated adjustment operation includes: The pump operating efficiency at the flow-pressure matching working point is determined based on the flow-efficiency correspondence in the performance curve, and the flow-pressure matching working point corresponding to the pump operating efficiency that is not less than the preset efficiency threshold is determined as the target working point. Based on the operating power of the slurry circulation pump at the target working point, the target working points are sorted in ascending order, and the preset speed corresponding to the first target working point after sorting is taken as the target speed, and the preset valve opening corresponding to the first target working point after sorting is taken as the initial valve opening of the flow regulating and pressure regulating valve. Adjust the rotation speed of the slurry circulation pump to the target rotation speed, and adjust the valve opening of the flow regulating and pressure regulating valve to the initial valve opening; During the operation of the slurry circulation pump at the target speed, the nozzle inlet pressure of the spray layer corresponding to the slurry circulation pump is measured in real time, and the pressure deviation between the nozzle inlet pressure and the preset atomization pressure range is analyzed to obtain the pressure deviation value. Dynamic correction operations are performed on the commissioned slurry circulation pump and the commissioned flow and pressure regulating valve based on the pressure deviation value.

4. The method according to claim 3, characterized in that, The dynamic correction operation includes: When the pressure deviation value exceeds the preset allowable deviation range, the preset control algorithm is used to perform feedback calculation on the pressure deviation value to obtain the opening correction compensation value. The corrected valve opening is obtained by superimposing the opening correction compensation value with the initial valve opening. When the opening degree of the corrected valve is within a preset safe range, the corrected pipeline resistance loss corresponding to the opening degree of the corrected valve is determined according to the pipeline resistance characteristic curve. A second cross-matching analysis is performed between the corrected pipeline resistance loss and the performance curve of the commissioned slurry circulation pump at the target speed to obtain the corrected working flow rate. When the flow deviation between the corrected working flow rate and the target circulating flow rate is within the preset flow deviation range, the opening of the commissioning flow regulating and pressure regulating valve is adjusted according to the corrected valve opening, and the corrected valve opening is updated to the initial valve opening.

5. The method according to claim 1, characterized in that, Before matching the target circulation flow and target operating combination mode corresponding to the real-time operating condition parameters from the optimal circulation flow condition library using the preset operating condition matching model, the method further includes: Obtain the rated flue gas treatment capacity of the wet desulfurization system, and determine multiple flue gas volume ranges based on the rated flue gas treatment capacity; Iterate through each of the multiple flue gas volume intervals in sequence, and perform the following operating condition calibration operation on the currently traversed flue gas volume interval: Multiple test flue gas volumes are selected from the target flue gas volume range, and multiple test circulating flow rates are selected from the preset circulating flow rate range, wherein the target flue gas volume range is the flue gas volume range currently being traversed. Based on the multiple test circulation flow rates, the spatial distribution of the spray layer corresponding to each slurry circulation pump within the desulfurization tower, and the spray coverage characteristics, N candidate operating combinations of the multiple slurry circulation pumps are determined, where N is a positive integer; Under each test flue gas volume, the first dual-parameter coupling control operation is performed using the performance curve and pipe resistance characteristic curve of each slurry circulation pump in each candidate operation combination mode, so that the actual circulation flow of the desulfurization tower reaches the corresponding test circulation flow, and the nozzle inlet pressure of the spray layer corresponding to each slurry circulation pump is within the preset atomization pressure range. After the first dual-parameter coupling control operation is completed and the wet desulfurization system reaches a stable operating state, the desulfurization efficiency of each candidate operating combination is tested to obtain the test desulfurization efficiency, test nozzle inlet pressure and test operating power of each candidate operating combination. Based on the test desulfurization efficiency, the test nozzle inlet pressure, and the test operating power, a first operating combination mode and a first circulation flow rate corresponding to the target flue gas volume range are determined from the N candidate operating combination modes. The target flue gas volume range, the first operating combination mode, and the first circulation flow rate are associated and stored in the optimal circulation volume operating condition library.

6. The method according to claim 5, characterized in that, The step of determining the first operating combination mode and the first circulation flow rate corresponding to the target flue gas volume range from the N candidate operating combinations based on the tested desulfurization efficiency, the tested nozzle inlet pressure, and the tested operating power includes: From the N candidate operating combinations, select M compliant operating combinations where the test desulfurization efficiency is not less than the preset desulfurization efficiency threshold and the test nozzle inlet pressure is within the preset atomization pressure range, where M is a positive integer less than or equal to N; Obtain the installation elevation of the spray layer corresponding to each slurry circulation pump in each of the above-mentioned compliant operation combination modes, and determine the static head energy consumption penalty coefficient of each of the above-mentioned compliant operation combination modes based on the installation elevation, wherein the installation elevation is positively correlated with the static head energy consumption penalty coefficient; The test operating power of each of the compliant operating combinations is weighted and corrected according to the static head energy consumption penalty coefficient to obtain the equivalent evaluation energy consumption of each of the compliant operating combinations. The M compliant operation combinations are sorted in a second ascending order according to the equivalent evaluation energy consumption, and the compliant operation combination that ranks first after sorting is taken as the first operation combination of the target flue gas volume range, and the test circulation flow rate corresponding to the first operation combination is taken as the first circulation flow rate.

7. The method according to claim 1, characterized in that, After determining the slurry circulation pump to be put into operation from the plurality of slurry circulation pumps according to the target operating combination, the method further includes: Obtain the current actual operating configuration of the wet desulfurization system; When the actual operating combination mode is different from the target operating combination mode, a difference comparison analysis is performed between the actual operating combination mode and the target operating combination mode to identify the slurry circulation pumps to be started that are not present in the actual operating combination mode from the target operating combination mode, and to identify the slurry circulation pumps to be stopped that are not present in the target operating combination mode from the actual operating combination mode. Obtain the current inlet flue gas volume of the desulfurization tower, and determine the total flow stability constraint condition during the pump group switching transition period based on the inlet flue gas volume; The load increase trajectory of the slurry circulation pump to be started and the load decrease trajectory of the slurry circulation pump to be stopped are determined based on the total flow stability constraint condition. Start the slurry circulation pump to be started, so that the slurry circulation pump to be started and the slurry circulation pump to be stopped enter the pump set switching transition period; During the pump set switching transition period, the slurry circulation pump to be started is controlled to perform load increase adjustment operation according to the load increase operation trajectory, and the slurry circulation pump to be stopped is controlled to perform load decrease adjustment operation according to the load decrease operation trajectory, so as to ensure that the actual circulation flow of the desulfurization tower continuously meets the total flow stability constraint condition. If the real-time load parameter of the slurry circulation pump to be stopped drops to a preset safe shutdown threshold, the pump will be controlled to stop operating. When the slurry circulation pump to be stopped stops operating, and the actual operating combination is the same as the target operating combination, and the slurry circulation pump in operation is in a stable operating state, the target dual-parameter coupling control operation is performed on the slurry circulation pump in operation so that the actual circulation flow rate of the desulfurization tower reaches the target circulation flow rate.

8. A slurry circulation control system, characterized in that, The slurry circulation control system includes: one or more processors and a memory; the memory is coupled to the one or more processors, the memory is used to store computer program code, the computer program code including computer instructions, and the one or more processors call the computer instructions to cause the slurry circulation control system to perform the method as described in any one of claims 1-7.

9. A computer-readable storage medium comprising program instructions, characterized in that, When the program instructions are run on the slurry circulation control system, the slurry circulation control system performs the method as described in any one of claims 1-7.

10. A computer program product, characterized in that, When the computer program product is run on the slurry circulation control system, the slurry circulation control system performs the method as described in any one of claims 1-7.

Images