A vibration treatment method for a stationary blade adjustable axial flow induced draft fan

Abstract

This invention discloses a vibration control method for an adjustable-blade axial-flow induced draft fan, comprising a center alignment component and an opening measurement component. The beneficial effects of this invention are: by using the center alignment component and the opening measurement component, the center alignment value of the coupling and the opening size of the coupling wheel can be accurately measured, thereby allowing adjustment of the center alignment allowance expansion value and optimization of the coupling wheel opening size based on the values ​​given in the manufacturer's instructions. Furthermore, by conducting a dynamic balancing test on the intermediate shaft and using counterweights to minimize the disturbance effect of the long shaft, the influence of the long intermediate shaft connecting the fan impeller and the motor is eliminated, simultaneously reducing the vibration of the induced draft fan and its motor. This ensures that the vibration of the induced draft fan reaches a qualified level under high-load conditions above 47Hz, improving the safety, reliability, and economic performance of the equipment.

Description

Technical Field

[0001] This invention relates to a vibration control method, specifically a vibration control method for an adjustable axial flow induced draft fan, belonging to the technical field of adjustable axial flow induced draft fans for coal-fired power generating units. Background Technology

[0002] An induced draft fan is a device that generates negative pressure by rotating an impeller, thereby extracting negative pressure from the system. In thermal power plants, induced draft fans are installed in the flue at the tail end of the boiler to extract hot flue gas from the boiler, maintain negative pressure in the boiler, and ensure air circulation. In existing solutions, the majority of the modifications involve combining the booster fan and the induced draft fan into one unit to replace the original booster fan and induced draft fan.

[0003] However, after the modification, due to the longer intermediate shaft connecting the induced draft fan impeller and the motor, resonance easily occurs under high load conditions (above 47Hz in variable frequency operation to mains frequency), leading to excessive horizontal vibration of the motor and fan. Using conventional dynamic balancing tests with counterweights to address this, the fan and motor vibrations exhibit a seesaw-like change: when the fan-side vibration drops to the acceptable range, the motor vibration increases and exceeds the limit. Conversely, reducing the motor-side vibration causes the fan-side vibration to increase, resulting in significant vibration of the induced draft fan under high load conditions above 47Hz in variable frequency operation. The horizontal vibration of the fan and motor reaches a maximum of 12mm / s, severely affecting the safe and stable operation of the unit, as well as its load-bearing capacity and economic performance. Summary of the Invention

[0004] The purpose of this invention is to provide a vibration control method for an adjustable axial flow induced draft fan in order to solve at least one of the above-mentioned technical problems.

[0005] This invention achieves the above objective through the following technical solution: a vibration control method for an adjustable-blade axial flow induced draft fan, comprising the following steps:

[0006] Step 1: Based on the actual flue gas temperature in the working environment of the induced draft fan, align the coupling using the center alignment component, and adjust the reserved expansion value according to the measurement results.

[0007] The center alignment component includes a vertical support rod connected to the active rotating shaft on one side of the coupling and a dial indicator abutting against the surface of the driven rotating shaft on the other side of the coupling. The bottom end of the vertical support rod is connected to the active rotating shaft through an arc-shaped buckle. The dial indicator is installed in the clamping sleeve connected to the bottom end of the L-shaped upright. The upper end of the L-shaped upright is fixedly connected to one end of the horizontal connecting rod, and the other end of the horizontal connecting rod is fixedly connected to the body of the vertical support rod.

[0008] Step 2: Measure the opening size of the coupling pulleys using the opening measurement component. Based on the measurement results, optimize and adjust the values ​​given in the manufacturer's instructions.

[0009] The opening measurement component includes a pointed feeler gauge for insertion into the gap between the coupling wheels. The pointed feeler gauge is fixedly connected to the telescopic end of the elastic telescopic rod, and the elastic telescopic rod is combined and connected with the transverse connecting rod.

[0010] Step 3: Adjust the impeller counterweight. Based on the dynamic balance test of the induced draft fan impeller, conduct a dynamic balance test of the long intermediate shaft system of the induced draft fan. Add counterweights to the intermediate shaft to eliminate the influence of long shaft disturbance.

[0011] As a further aspect of the present invention: the two arc-shaped buckles are arranged symmetrically, and the inner surface of the arc-shaped buckles is embedded with a fixing magnetic strip.

[0012] As a further embodiment of the present invention: a limiting block is connected to the upper end of one side of the two arc-shaped buckles, and a limiting groove is formed at the upper end of the other side.

[0013] As a further embodiment of the present invention: the outer surfaces of the two arc-shaped buckles are integrally connected with a sliding track for holding the slide, and the bottom sides of the slide are respectively embedded with positioning magnetic strips.

[0014] As a further embodiment of the present invention: one end of the transverse connecting rod is connected to a connecting rod fixing sleeve, and the connecting rod fixing sleeve is sleeved on the body of the vertical support rod.

[0015] As a further embodiment of the present invention: the other end of the transverse connecting rod is connected to a vertical pole fixing sleeve, and an L-shaped vertical pole is fitted inside the vertical pole fixing sleeve.

[0016] As a further embodiment of the present invention: a movable sleeve is fixedly connected to the outer side of the elastic telescopic rod, and the movable sleeve is sleeved on the side of the transverse connecting rod.

[0017] The beneficial effects of this invention are as follows: By using a center alignment component and an opening measurement component, the center alignment value of the coupling and the opening size of the coupling wheel can be accurately measured. This allows for adjustment of the center alignment allowance expansion value and optimization of the coupling wheel opening size based on the values ​​given in the manufacturer's instructions. In addition, by conducting a dynamic balancing test on the intermediate shaft and using counterweights to minimize the disturbance of the long shaft, the disturbance of the long intermediate shaft connecting the induced draft fan impeller and the motor is eliminated. This also reduces the vibration of the induced draft fan and its motor, ensuring that the vibration of the induced draft fan reaches a qualified level under high load conditions above 47Hz, thereby improving the safety, reliability, and economic performance of the equipment. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the center alignment component and the opening measurement component of the present invention;

[0019] Figure 2 This is a schematic diagram of the arc-shaped buckle structure of the present invention;

[0020] Figure 3 This is a schematic diagram of the slide structure of the present invention;

[0021] Figure 4 This is a schematic diagram of the L-shaped upright structure of the present invention.

[0022] In the diagram: 1. Arc-shaped buckle, 2. Slide seat, 3. Vertical support rod, 4. Horizontal connecting rod, 5. Connecting rod fixing sleeve, 6. Upright pole fixing sleeve, 7. L-shaped upright pole, 8. Dial indicator, 9. Movable sleeve, 10. Elastic telescopic rod, 11. Pointed angle feeler gauge, 12. Fixed magnetic strip, 13. Sliding track, 14. Limiting block, 15. Limiting groove, 16. Positioning magnetic strip, 17. Clamping sleeve. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Example 1

[0025] like Figures 1 to 4 As shown, a vibration control method for an adjustable-blade axial flow induced draft fan includes the following steps:

[0026] Step 1: Based on the actual flue gas temperature in the working environment of the induced draft fan, align the coupling using the center alignment component, and adjust the reserved expansion value according to the measurement results.

[0027] The center alignment component includes a vertical support rod 3 connected to the active rotating shaft on one side of the coupling and a dial indicator 8 abutting against the surface of the driven rotating shaft on the other side of the coupling. The bottom end of the vertical support rod 3 is connected to the active rotating shaft through an arc-shaped buckle 1. The dial indicator 8 is installed in the clamping sleeve 17 connected to the bottom end of the L-shaped upright rod 7. The upper end of the L-shaped upright rod 7 is fixedly connected to one end of the transverse connecting rod 4, and the other end of the transverse connecting rod 4 is fixedly connected to the body of the vertical support rod 3.

[0028] Step 2: Measure the opening size of the coupling pulleys using the opening measurement component. Based on the measurement results, optimize and adjust the values ​​given in the manufacturer's instructions.

[0029] The opening measurement component includes a pointed feeler gauge 11 for insertion into the gap between the coupling wheels. The pointed feeler gauge 11 is fixedly connected to the telescopic end of the elastic telescopic rod 10, and the elastic telescopic rod 10 is combined and connected with the transverse connecting rod 4.

[0030] Step 3: Adjust the impeller counterweight. Based on the dynamic balance test of the induced draft fan impeller, conduct a dynamic balance test of the long intermediate shaft system of the induced draft fan. Add counterweights to the intermediate shaft to eliminate the influence of long shaft disturbance.

[0031] Two arc-shaped buckles 1 are arranged symmetrically, and a fixing magnetic strip 12 is embedded in the inner side of the arc-shaped buckle 1, so that the two arc-shaped buckles 1 can be attracted and fixed on the shaft of the active rotating shaft, thereby connecting the vertical support rod 3 with the active rotating shaft for easy operation.

[0032] Example 2

[0033] like Figures 1 to 4 As shown, in addition to all the technical features included in Embodiment 1, this embodiment also includes:

[0034] The upper end of one side of the two arc-shaped buckles 1 is connected to a limiting block 14, and the upper end of the other side is provided with a limiting groove 15, so that the two arc-shaped buckles 1 can be aligned and connected by the docking of the limiting block 14 and the limiting groove 15.

[0035] The outer surfaces of the two arc-shaped buckles 1 are integrally connected to a sliding rail 13 for holding the slide block 2, and the bottom sides of the slide block 2 are respectively embedded with positioning magnetic strips 16. The slide block 2 can slide on the sliding rail 13, thereby driving it, and under the action of the positioning magnetic strips 16, the position of the slide block 2 after movement can be positioned, ensuring that the vertical support rod 3 can be stably positioned in the four positions of up, down, left, and right of the active rotating shaft body, thereby achieving accurate measurement.

[0036] Example 3

[0037] like Figures 1 to 4 As shown, in addition to all the technical features included in Embodiment 1, this embodiment also includes:

[0038] One end of the transverse connecting rod 4 is connected to a connecting rod fixing sleeve 5, and the connecting rod fixing sleeve 5 is fitted onto the body of the vertical support rod 3, which facilitates the adjustment of the height of the transverse connecting rod 4, so that the bottom end of the pointed feeler gauge 11 can be inserted into the gap of the coupling wheel under the action of the elastic telescopic rod 10, so as to measure the opening size of the coupling wheel.

[0039] The other end of the transverse connecting rod 4 is connected to the upright fixing sleeve 6, and an L-shaped upright rod 7 is fitted inside the upright fixing sleeve 6. After the transverse connecting rod 4 is fixed in position, the L-shaped upright rod 7 can be moved up and down to adjust the installation height of the dial indicator 8, so that the bottom end of the dial indicator 8 can accurately abut against the shaft of the driven rotating shaft, thereby achieving center alignment.

[0040] Example 4

[0041] like Figures 1 to 4As shown, in addition to all the technical features included in Embodiment 1, this embodiment also includes:

[0042] A movable sleeve 9 is fixedly connected to the outer side of the elastic telescopic rod 10, and the movable sleeve 9 is fitted onto the side of the transverse connecting rod 4. The elastic telescopic rod 10 can be moved left and right to drive the pointed feeler gauge 11 to move, and then it can be suspended directly above the gap of the coupling wheel. The gap can be quickly measured by pulling it down.

[0043] Working principle: Based on the actual flue gas temperature in the working environment of the induced draft fan, the pre-expansion value for center alignment of the coupling is adjusted, and the opening size of the coupling wheel is optimized and adjusted based on the value given in the manufacturer's instructions; the impeller counterweight is adjusted, and based on the dynamic balance test of the induced draft fan impeller, a dynamic balance test of the long intermediate shaft system of the induced draft fan is carried out, and counterweights are added to the intermediate shaft to eliminate the influence of long shaft disturbance.

[0044] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0045] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for vibration control of a stationary vane adjustable axial flow induced draft fan, characterized in that: It comprises the following steps: Step one, according to the actual smoke temperature of the induced draft fan working environment, the center alignment assembly is used to align the center of the coupling, and the reserved expansion value is adjusted according to the measurement result; The center alignment assembly comprises a vertical support rod (3) connected to the driving rotating shaft on one side of the coupling and a dial indicator (8) abutting against the surface of the driven rotating shaft on the other side of the coupling, the bottom end of the vertical support rod (3) is connected to the driving rotating shaft through an arc-shaped buckle (1), the dial indicator (8) is installed in the clamping sleeve (17) connected to the bottom end of the L-shaped vertical rod (7), and the upper end of the L-shaped vertical rod (7) is fixedly connected with one end of the horizontal connecting rod (4), the other end of the horizontal connecting rod (4) is fixedly connected with the rod body of the vertical support rod (3); Step two, the opening size of the coupling pair of wheels is measured by the opening measurement assembly, and the value given in the manufacturer's manual is optimized and adjusted on the basis of the measurement result; The opening measurement assembly comprises a sharp corner plug gauge (11) inserted between the gap of the coupling pair of wheels, the sharp corner plug gauge (11) is fixedly connected to the telescopic end of the elastic telescopic rod (10), and the elastic telescopic rod (10) is combined with the horizontal connecting rod (4) Step three, adjust the impeller weight, on the basis of the induced draft fan impeller dynamic balance test, carry out the induced draft fan long intermediate shaft dynamic balance test, and add weight on the intermediate shaft to eliminate the influence of long shaft disturbance.

2. The vibration control method of a stationary vane-adjustable axial flow draft fan according to claim 1, characterized in that: The two arc-shaped buckles (1) are symmetrically arranged, and the inner side of the arc-shaped buckle (1) is embedded with a fixed magnetic strip (12).

3. The vibration control method of a stationary vane-adjustable axial flow draft fan according to claim 1, characterized in that: The one side upper end of the two arc-shaped buckles (1) is connected with a limiting block (14), and the other side upper end is provided with a limiting groove (15).

4. The vibration control method of a stationary vane-adjustable axial flow draft fan according to claim 1, characterized in that: The outer side of the two arc-shaped buckles (1) is integrally connected with a sliding rail (13) for clamping the sliding seat (2), and the bottom end of the sliding seat (2) is embedded with a positioning magnetic strip (16) on both sides.

5. The vibration control method of a stationary vane adjustable axial flow draft fan according to claim 1, characterized in that: One end of the horizontal connecting rod (4) is connected with a connecting rod fixed sleeve (5), and the connecting rod fixed sleeve (5) is sleeved on the rod body of the vertical support rod (3).

6. The vibration control method of a vane-adjustable axial induced draft fan according to claim 1, characterized in that: The other end of the horizontal connecting rod (4) is connected with a vertical rod fixed sleeve (6), and the vertical rod fixed sleeve (6) is sleeved with an L-shaped vertical rod (7).

7. The vibration control method of a stationary vane adjustable axial flow draft fan according to claim 1, characterized in that: The outer side of the elastic telescopic rod (10) is fixedly connected with a movable sleeve (9), and the movable sleeve (9) is sleeved on the rod body of the horizontal connecting rod (4).

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