A fan anti-stall calculation method and system based on dial parameters

Abstract

The present invention discloses a fan anti-stall calculation method and system based on dial parameters. The method includes: measuring and obtaining the flow rate, total pressure, efficiency and blade angle of the fan during operation, and recording the dial opening and dial pressure difference; obtaining the measured fan total pressure-dial pressure difference; obtaining a comparison result; obtaining the functional relationship between the dial opening and the blade angle marked on the design performance curve of the fan when it leaves the factory; calculating the safe total pressure at each opening; when the calculated dial safety pressure difference value is reached during operation, stopping further increasing the load or reducing the dial pressure difference. The system includes a measurement module, a calibration module, a comparison module, a fitting module, a calculation module and an execution module. The present invention does not add any measuring equipment, but only relies on the dial display value to calculate the dial safety pressure difference value at each opening on the dial as an operation reference, and has strong robustness.

Description

Technical Field

[0001] The present invention belongs to the technical field of online monitoring of fan operating status, and in particular relates to a fan anti-stall calculation method and system based on dial parameters, which is applicable to axial flow fans in power stations. Background Art

[0002] At present, the operation monitoring system of power station fans is generally a DCS system commonly used in power plants. Most fans above 300MW use axial flow fans. Compared with centrifugal fans, axial flow fans have a large stall zone. Improper selection or improper operation can easily cause stall, affecting the safe and stable operation of the unit.

[0003] Most fans do not have anti-stall switches, and the differential pressure stall switches used in some are not very accurate. Stall alarms often occur while the actual operation is normal, and stalls often occur without alarms. Summary of the Invention

[0004] The purpose of the present invention is to provide a fan anti-stall calculation method and system based on dial parameters. By combining on-site testing and dial data display, the safe operating differential pressure at various fan openings is calculated, thereby improving the safety of fan operation and providing convenience for operation monitoring personnel. This method does not add any measuring equipment and only relies on the dial display value to calculate the dial safety pressure differential value at various openings on the dial as an operation reference, and has strong robustness.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A fan anti-stall calculation method based on dial parameters, comprising:

[0007] Calculate the flow rate, total pressure, efficiency and blade angle of the fan, and record the dial opening and dial pressure difference;

[0008] According to the measurement results, the dial pressure difference is calibrated to obtain the measured fan total pressure minus the dial pressure difference;

[0009] The actual measured flow rate and total pressure are marked on the design performance curve of the fan when it leaves the factory. The efficiency and blade angle are marked on the design performance curve of the fan when it leaves the factory. The actual measured efficiency and blade angle are compared with the efficiency and blade angle marked on the design performance curve of the fan when it leaves the factory to obtain the comparison result;

[0010] Based on the comparison results, determine whether the measured performance of the fan is consistent with the design performance curve of the fan when it leaves the factory. When the measured performance of the fan is consistent with the revised design performance curve, obtain the functional relationship between the dial opening and the blade angle marked on the design performance curve of the fan when it leaves the factory;

[0011] On the fan's factory-designed performance curve, find the stall point full pressure corresponding to each angle, leaving a set stall margin, and calculate the safe full pressure at each opening;

[0012] Based on the functional relationship between the measured fan total pressure and dial pressure difference, the dial opening and the blade angle marked on the fan's design performance curve when it leaves the factory, and the safe total pressure at each opening, the dial safety pressure difference value at each opening on the dial is deduced and used as an operating reference. When the measured dial safety pressure difference value is reached during operation, stop increasing the load or reduce the dial pressure difference.

[0013] A further improvement of the present invention is that the flow rate, total pressure, efficiency and blade angle of the fan operation are measured and obtained through on-site testing of the fan.

[0014] A further improvement of the present invention is that when determining whether the actual measured performance of the fan is consistent with the design performance curve of the fan when it leaves the factory, if not, the design performance curve of the fan when it leaves the factory is corrected until the actual measured performance of the fan is consistent with the corrected design performance curve.

[0015] A further improvement of the present invention is that, on the design performance curve of the fan when it leaves the factory, the stall point total pressure P0 corresponding to each angle is found, leaving a set stall margin k, and the safe total pressure P1 at each opening is calculated, and the calculation formula is: P1=(1-k)×P0.

[0016] A further improvement of the present invention is that the industry standard requirement for the stall margin k is at least 1.35.

[0017] A fan anti-stall calculation system based on dial parameters, comprising:

[0018] The measurement module is used to measure the flow rate, total pressure, efficiency and blade angle of the fan operation, and record the dial opening and dial pressure difference;

[0019] The calibration module is used to calibrate the dial pressure difference according to the measurement results to obtain the measured fan total pressure minus the dial pressure difference;

[0020] A comparison module is used to mark the actually measured flow rate and total pressure on the design performance curve of the fan when it leaves the factory. The design performance curve of the fan when it leaves the factory is marked with efficiency and blade angle, and compare the actually measured efficiency and blade angle with the efficiency and blade angle marked on the design performance curve of the fan when it leaves the factory to obtain a comparison result;

[0021] The fitting module is used to determine whether the measured performance of the fan is consistent with the design performance curve of the fan when it leaves the factory based on the comparison results. When the measured performance of the fan is consistent with the corrected design performance curve, the functional relationship between the dial opening and the blade angle marked on the design performance curve of the fan when it leaves the factory is obtained;

[0022] The calculation module is used to find the stall point full pressure corresponding to each angle on the fan's factory design performance curve, leaving a set stall margin, and calculate the safe full pressure at each opening;

[0023] The execution module is used to reversely deduce the dial safety pressure difference value at each opening on the dial based on the obtained functional relationship between the measured fan total pressure and the dial pressure difference, the dial opening and the blade angle marked on the fan's design performance curve when it leaves the factory, and the safe total pressure at each opening. This is used as an operation reference. When the measured dial safety pressure difference value is reached during operation, the load is stopped from being increased, or the dial pressure difference is reduced.

[0024] A further improvement of the present invention is that, in the calculation module, the flow rate, total pressure, efficiency and blade angle of the fan operation are calculated through field tests of the fan.

[0025] A further improvement of the present invention is that, in the fitting module, when judging whether the actual measured performance of the fan is consistent with the design performance curve of the fan when it leaves the factory, if it is not consistent, the design performance curve of the fan when it leaves the factory is corrected until the actual measured performance of the fan is consistent with the corrected design performance curve.

[0026] A further improvement of the present invention is that, in the calculation module, the stall point total pressure P0 corresponding to each angle is found on the design performance curve of the fan when it leaves the factory, leaving a set stall margin k, and the safe total pressure P1 at each opening is calculated, and the calculation formula is: P1=(1-k)×P0.

[0027] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of a wind turbine anti-stall calculation method based on dial parameters.

[0028] Compared with the prior art, the present invention has at least the following beneficial technical effects:

[0029] The present invention provides a dial-based parameter-based fan stall prevention calculation method and system. This method, without any additional measuring equipment, relies solely on the dial display to calculate the safe pressure differential at various dial openings, which serves as a reference for operation. This method maximizes cost savings and eliminates errors in DCS measurement point installation positions and errors between dial openings and actual blade angles, facilitating operation and adjustment by monitoring personnel. By combining field testing with dial display, this method reduces on-site workload and minimizes measurement error limitations. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 The present invention is a flow chart of a fan anti-stall calculation method based on dial parameters.

[0031] Figure 2 The following is a schematic diagram of the performance curve of the induced draft fan of an existing power plant.

[0032] Figure 3 This is a structural block diagram of a fan anti-stall calculation system based on dial parameters of the present invention. DETAILED DESCRIPTION

[0033] Hereinafter, only certain exemplary embodiments are briefly described. As will be appreciated by those skilled in the art, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and description are to be considered as illustrative in nature and not restrictive.

[0034] It will be understood that when used in this specification and the appended claims, the terms “comprises” and “comprising” indicate the presence of described features, integers, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0035] It should also be understood that the terms used in the present specification are only for the purpose of describing particular embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms unless the context clearly indicates otherwise.

[0036] It should be further understood that the term "and / or" used in the present description and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0037] The accompanying drawings illustrate various schematic diagrams of structures according to embodiments disclosed herein. These figures are not drawn to scale; for clarity, some details are exaggerated and some details may be omitted. The shapes of the various regions and layers shown in the figures, as well as their relative sizes and positional relationships, are merely exemplary and may deviate in practice due to manufacturing tolerances or technical limitations. Those skilled in the art may design regions / layers with different shapes, sizes, and relative positions as needed.

[0038] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0039] Example 1

[0040] like Figure 1 As shown, this embodiment provides a fan anti-stall calculation method based on dial parameters, including:

[0041] Calculate the flow rate, total pressure, efficiency and blade angle of the fan, and record the dial opening and dial pressure difference;

[0042] According to the measurement results, the dial pressure difference is calibrated to obtain the measured fan total pressure minus the dial pressure difference;

[0043] The actual measured flow rate and total pressure are marked on the design performance curve of the fan when it leaves the factory. The efficiency and blade angle are marked on the design performance curve of the fan when it leaves the factory. The actual measured efficiency and blade angle are compared with the efficiency and blade angle marked on the design performance curve of the fan when it leaves the factory to obtain the comparison result;

[0044] Based on the comparison results, determine whether the measured performance of the fan is consistent with the design performance curve of the fan when it leaves the factory. When the measured performance of the fan is consistent with the revised design performance curve, obtain the functional relationship between the dial opening and the blade angle marked on the design performance curve of the fan when it leaves the factory;

[0045] On the fan's factory-designed performance curve, find the stall point full pressure corresponding to each angle, leaving a set stall margin, and calculate the safe full pressure at each opening;

[0046] Based on the functional relationship between the measured fan total pressure and dial pressure difference, the dial opening and the blade angle marked on the fan's design performance curve when it leaves the factory, and the safe total pressure at each opening, the dial safety pressure difference value at each opening on the dial is deduced and used as an operating reference. When the measured dial safety pressure difference value is reached during operation, stop increasing the load or reduce the dial pressure difference.

[0047] In this embodiment, the stall point pressure P0 corresponding to each angle is found on the fan's factory-designed performance curve, leaving a set stall margin k. The safe total pressure P1 at each opening is calculated using the following formula: P1 = (1-k) × P0. The industry standard for stall margin k is at least 1.35.

[0048] Example 2

[0049] like Figure 1 As shown, this embodiment provides a fan anti-stall calculation method based on dial parameters, including the following steps:

[0050] 1) Through on-site fan testing, the flow rate, total pressure, efficiency and blade angle of the fan are measured and recorded, and the dial opening and dial pressure difference are recorded;

[0051] 2) Based on the measurement results, the dial pressure difference is calibrated to obtain the measured fan total pressure minus the dial pressure difference;

[0052] 3) Mark the actual measured flow rate and total pressure on the fan's factory design performance curve, which also has efficiency and blade angle marked on it. Compare the actual measured efficiency and blade angle with the efficiency and blade angle marked on the fan's factory design performance curve to obtain a comparison result.

[0053] 4) Based on the comparison results, determine whether the measured performance of the fan is consistent with the design performance curve of the fan when it leaves the factory. If not, revise the design performance curve of the fan when it leaves the factory until the measured performance of the fan is consistent with the revised design performance curve. The functional relationship between the dial opening and the blade angle marked on the design performance curve of the fan when it leaves the factory is obtained.

[0054] 5) On the fan's factory-designed performance curve, find the stall point pressure P0 corresponding to each angle, leaving a set stall margin k, and calculate the safe total pressure P1 = (1-k) × P0 at each opening;

[0055] 6) Based on the functional relationship between the measured fan total pressure and the dial pressure difference, the dial opening and the blade angle marked on the fan's design performance curve at the factory, and the safe total pressure at each opening obtained in steps 2), 4), and 5), the dial safety pressure difference value at each opening on the dial is reversely calculated and used as an operating reference. When the measured dial safety pressure difference value is reached during operation, stop increasing the load or take other measures to reduce the dial pressure difference to prevent the fan from stalling.

[0056] In this embodiment, the industry standard requirement for the stall margin is at least 1.35, and an appropriate stall margin can be selected according to actual operating conditions.

[0057] Example 3

[0058] The induced draft fans of a boiler unit at a domestic thermal power plant frequently experienced draft snags and stalls. These failures occurred suddenly and without warning, making them difficult to detect and preventing early warning. This caused economic losses for the power plant. Testing by technical personnel revealed that the operators were only monitoring the induced draft fan's current, ignoring its inlet and outlet pressures. Current monitoring alone could not accurately determine the fan's actual operating position on the performance curve. Consequently, when the actual operating point was in the low-flow, high-pressure stall zone, the operators failed to receive alarm signals and were unable to make timely adjustments, causing the fan to stall.

[0059] Subsequently, we applied this optimization design method for the measurement installation position of the fan body flow meter and optimized the anti-stall calculation method. When the fan differential pressure reaches the alarm value of the current opening, the operator can make timely adjustments, thereby enhancing the safety and stability of the fan operation. The steps are as follows:

[0060] 1) Through on-site fan testing, calculate the fan flow rate, total pressure, efficiency, blade angle, and medium temperature;

[0061] 2) Based on the measurement results, the pressure and temperature of the dial are calibrated. Since the test measurement point and the dial measurement point are only different in position, after eliminating the influence of pressure loss and temperature drop, the functional relationship between the measured fan total pressure and the dial pressure difference and the measured fan inlet temperature and the dial fan inlet temperature are obtained;

[0062] 3) Mark the actual measured flow rate and total pressure on the fan performance curve, see Figure 2 and compare the actually measured efficiency and blade angle with the values ​​marked on the performance curve;

[0063] 4. According to the comparison results, it is found that the fan is consistent with the performance curve and no correction is required. The subsequent steps can be calculated based on the design point performance curve;

[0064] 5) The functional relationship between the dial opening and the performance curve angle is obtained, which is a first-order relationship;

[0065] 6. Find the stall point corresponding to each angle on the performance curve, leaving a certain stall margin (a 12% pressure margin is selected in this embodiment), and calculate the dial safety pressure difference at each opening;

[0066] 7) Based on the functional relationship between the measured fan total pressure and the dial pressure difference, and the dial opening and the performance curve angle obtained in steps 2) and 5), the dial safety pressure difference value at each dial opening is inferred as a reference for operation (see Table 1).

[0067] Table 1

[0068]

[0069] Example 4

[0070] like Figure 3 As shown, this embodiment provides a fan anti-stall calculation system based on dial parameters, including:

[0071] The measurement module is used to measure the flow rate, total pressure, efficiency and blade angle of the fan operation, and record the dial opening and dial pressure difference;

[0072] The calibration module is used to calibrate the dial pressure difference according to the measurement results to obtain the measured fan total pressure minus the dial pressure difference;

[0073] A comparison module is used to mark the actually measured flow rate and total pressure on the design performance curve of the fan when it leaves the factory. The design performance curve of the fan when it leaves the factory is marked with efficiency and blade angle, and compare the actually measured efficiency and blade angle with the efficiency and blade angle marked on the design performance curve of the fan when it leaves the factory to obtain a comparison result;

[0074] The fitting module is used to determine whether the measured performance of the fan is consistent with the design performance curve of the fan when it leaves the factory based on the comparison results. When the measured performance of the fan is consistent with the corrected design performance curve, the functional relationship between the dial opening and the blade angle marked on the design performance curve of the fan when it leaves the factory is obtained;

[0075] The calculation module is used to find the stall point full pressure corresponding to each angle on the fan's factory design performance curve, leaving a set stall margin, and calculate the safe full pressure at each opening;

[0076] The execution module is used to reversely deduce the dial safety pressure difference value at each opening on the dial based on the obtained functional relationship between the measured fan total pressure and the dial pressure difference, the dial opening and the blade angle marked on the fan's design performance curve when it leaves the factory, and the safe total pressure at each opening. This is used as an operation reference. When the measured dial safety pressure difference value is reached during operation, the load is stopped from being increased, or the dial pressure difference is reduced.

[0077] Example 5

[0078] This embodiment provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, it implements the steps of the wind turbine anti-stall calculation method based on dial parameters.

[0079] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present application may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0080] The present application is described with reference to the flowcharts and / or block diagrams of the methods, systems, and computer program products according to the embodiments of the present application. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 a process or multiple processes and / or boxes Figure 1 A system that specifies the functions of a box or boxes.

[0081] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0082] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0083] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, from all points of view, the embodiments should be regarded as illustrative and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes that fall within the meaning and range of equivalents of the claims are included in the present invention. Any reference signs in the claims should not be construed as limiting the claim to which they relate.

[0084] In addition, it should be understood that although this specification describes the embodiments, not every embodiment contains only one independent technical solution. This description is for clarity only. Those skilled in the art should consider the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art. The above content is only for the purpose of illustrating the technical concept of the present invention and cannot be used to limit the scope of protection of the present invention. Any changes made based on the technical solution in accordance with the technical concept proposed by the present invention fall within the scope of protection of the claims of the present invention.

Claims

1. A fan anti-stall calculation method based on dial parameters, characterized in that: include: Calculate the flow rate, total pressure, efficiency and blade angle of the fan, and record the dial opening and dial pressure difference; According to the measurement results, the dial pressure difference is calibrated to obtain the measured fan total pressure minus the dial pressure difference; The actual measured flow rate and total pressure are marked on the design performance curve of the fan when it leaves the factory. The efficiency and blade angle are marked on the design performance curve of the fan when it leaves the factory. The actual measured efficiency and blade angle are compared with the efficiency and blade angle marked on the design performance curve of the fan when it leaves the factory to obtain the comparison result; Based on the comparison results, determine whether the measured performance of the fan is consistent with the design performance curve of the fan when it leaves the factory. When the measured performance of the fan is consistent with the revised design performance curve, obtain the functional relationship between the dial opening and the blade angle marked on the design performance curve of the fan when it leaves the factory; On the fan's factory-designed performance curve, find the stall point full pressure corresponding to each angle, leaving a set stall margin, and calculate the safe full pressure at each opening; Based on the functional relationship between the measured fan total pressure and dial pressure difference, the dial opening and the blade angle marked on the fan's design performance curve when it leaves the factory, and the safe total pressure at each opening, the dial safety pressure difference value at each opening on the dial is deduced and used as an operating reference. When the measured dial safety pressure difference value is reached during operation, stop increasing the load or reduce the dial pressure difference.

2. A fan anti-stall calculation method based on dial parameters according to claim 1, characterized in that: Through on-site tests of the fan, the flow rate, total pressure, efficiency and blade angle of the fan operation are measured and calculated.

3. A fan anti-stall calculation method based on dial parameters according to claim 1, characterized in that: When judging whether the actual measured performance of the fan is consistent with the design performance curve of the fan when it leaves the factory, if not, the design performance curve of the fan when it leaves the factory is corrected until the actual measured performance of the fan is consistent with the corrected design performance curve.

4. A fan anti-stall calculation method based on dial parameters according to claim 1, characterized in that: On the design performance curve of the fan when it leaves the factory, find the stall point total pressure P0 corresponding to each angle, leave a set stall margin k, and calculate the safe total pressure P1 at each opening. The calculation formula is: P1=(1-k)×P0.

5. A fan anti-stall calculation method based on dial parameters according to claim 4, characterized in that: The industry standard for stall margin, k, is a minimum of 1.

35.

6. A fan anti-stall calculation system based on dial parameters, characterized in that: include: The measurement module is used to measure the flow rate, total pressure, efficiency and blade angle of the fan operation, and record the dial opening and dial pressure difference; The calibration module is used to calibrate the dial pressure difference according to the measurement results to obtain the measured fan total pressure minus the dial pressure difference; A comparison module is used to mark the actually measured flow rate and total pressure on the design performance curve of the fan when it leaves the factory. The design performance curve of the fan when it leaves the factory is marked with efficiency and blade angle, and compare the actually measured efficiency and blade angle with the efficiency and blade angle marked on the design performance curve of the fan when it leaves the factory to obtain a comparison result; The fitting module is used to determine whether the measured performance of the fan is consistent with the design performance curve of the fan when it leaves the factory based on the comparison results. When the measured performance of the fan is consistent with the corrected design performance curve, the functional relationship between the dial opening and the blade angle marked on the design performance curve of the fan when it leaves the factory is obtained; The calculation module is used to find the stall point full pressure corresponding to each angle on the fan's factory design performance curve, leaving a set stall margin, and calculate the safe full pressure at each opening; The execution module is used to reversely deduce the dial safety pressure difference value at each opening on the dial based on the obtained functional relationship between the measured fan total pressure and the dial pressure difference, the dial opening and the blade angle marked on the fan's design performance curve when it leaves the factory, and the safe total pressure at each opening. This is used as an operation reference. When the measured dial safety pressure difference value is reached during operation, the load is stopped from being increased, or the dial pressure difference is reduced.

7. A wind turbine anti-stall calculation system based on dial parameters according to claim 6, characterized in that: In the measurement module, the flow rate, total pressure, efficiency and blade angle of the fan are calculated through on-site tests of the fan.

8. The wind turbine anti-stall calculation system based on dial parameters according to claim 6, characterized in that: In the fitting module, it is determined whether the actual measured performance of the fan is consistent with the design performance curve of the fan when it leaves the factory. If not, the design performance curve of the fan when it leaves the factory is corrected until the actual measured performance of the fan is consistent with the corrected design performance curve.

9. The wind turbine anti-stall calculation system based on dial parameters according to claim 6, characterized in that: In the calculation module, the stall point total pressure P0 corresponding to each angle is found on the design performance curve of the fan when it leaves the factory, leaving a set stall margin k, and the safe total pressure P1 at each opening is calculated. The calculation formula is: P1=(1-k)×P0.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of a wind turbine anti-stall calculation method based on dial parameters according to any one of claims 1 to 5.

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