A rotating machine rotor counterweight adjustment device and adjustment method

Abstract

The application discloses a rotating machine rotor counterweight adjusting device and adjusting method, which comprises a rotor, a counterweight, a speed detection unit, a counterweight adjusting unit and a control unit; the rotor is provided with the counterweight; the speed detection unit is used for detecting the rotor speed; the counterweight adjusting unit comprises an electromagnetic fixing ring and electromagnets; the rotor penetrates through the electromagnetic fixing ring; the electromagnetic fixing ring is uniformly provided with n electromagnets in the circumferential direction; the electromagnets are arranged towards the counterweight; and the control unit is electrically connected with the speed detection unit and the electromagnets. The application has the advantages that the control unit controls the power supply of the electromagnets which are symmetric with the i-th electromagnet along the rotor center; the pulling force generated by the counterweight is used to offset the attraction force between the counterweight and the i-th electromagnet; the centrifugal force generated when the rotor rotates is offset; the rotating machine can have excellent dynamic balance characteristics at any rotating speed; and the operation safety of the equipment is ensured.

Description

Technical Field

[0001] This invention relates to the field of dynamic balancing technology for rotating machinery, specifically to a rotor counterweight adjustment device and adjustment method for rotating machinery. Background Technology

[0002] Modern coal-fired power plants contain large rotating machinery with various power sources, including fans and pumps, such as steam-powered, hydraulic-powered, and electric-powered machines. Because the rotors of these large rotating machines have multiple stages of blades of different specifications, when connected to other equipment rotors via couplings, their dynamic balance often becomes abnormal due to machining or installation precision issues during synchronous rotation. This manifests as increased vibration of the rotor bearings, affecting the safe operation of the equipment.

[0003] The current common solution is to conduct on-site dynamic balancing tests, which involves collecting vibration data and performing vibration spectrum analysis on-site, and then attempting to add appropriate counterweights to the rotor. However, this approach has the following drawbacks:

[0004] 1. Low success rate on the first attempt. The weight and position of the counterweight are difficult to achieve in one go. Usually, after the first installation, actual operation is required for testing. If the vibration is still not ideal, the machine needs to be stopped and the counterweight readjusted. In actual field practice, it is often necessary to repeatedly start and stop the equipment to find and adjust the size of the counterweight.

[0005] 2. Inability to meet the different counterweight requirements across the entire speed range. The rotors of some large rotating machinery exhibit varying rigidity at low, medium, and high speeds, resulting in different shaft vibration characteristics and thus different requirements for counterweight size. Existing counterweight installation methods lack online adjustability, and can only consider the vibration reduction effect across the entire speed range during installation, rather than achieving optimal shaft vibration at each speed range.

[0006] Chinese invention patent document CN113432789A discloses an online counterweight detection device. By detecting and adjusting electromagnetic force, it derives patterns to guide the addition of counterweights, thereby significantly reducing the number of tests and improving the efficiency of successful counterweight installation. However, this invention overlooks an important fact: the vibration of rotating machinery is not static. A suitable counterweight added at a certain speed may become unsuitable when operating conditions change (including two scenarios: constant load with changing speed, or constant speed with changing load). For example, the rated speed of a steam turbine in a thermal power plant (coaxially connected to the generator) is 3000 r / min. During the turbine's initial startup, there exists a "critical speed" (when the excitation force frequency equals the rotor's transverse natural frequency, the rotor resonates, and the amplitude increases sharply; this speed is the rotor's critical speed), at which point the vibration condition changes drastically. Furthermore, the vibration characteristics of a steam turbine rotor will typically change to varying degrees when subjected to different loads at speeds of 0-1000 r / min, 1000-2000 r / min, 2000-3000 r / min, and a constant speed of 3000 r / min. If the added fixed counterweight can only guarantee the balance effect under a certain operating condition, it cannot cover the full speed operating conditions of the equipment, and cannot guarantee that the rotating machinery will have excellent dynamic balance characteristics at any speed, thus failing to guarantee the safe operation of the equipment. Summary of the Invention

[0007] The technical problem to be solved by this invention is how to ensure that rotating machinery has excellent dynamic balance characteristics at any speed and ensure the safe operation of the equipment.

[0008] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0009] A counterweight adjustment device for a rotating machinery rotor includes a rotor, a counterweight block, a speed detection unit, a counterweight adjustment unit, and a control unit; the rotor is provided with a counterweight block, and the speed detection unit is used to detect the rotor speed.

[0010] The counterweight adjustment unit includes an electromagnetic fixing ring and an electromagnet. The rotor passes through the electromagnetic fixing ring. n electromagnets are evenly distributed on the electromagnetic fixing ring along the circumferential direction, and the electromagnets are arranged towards the counterweight blocks.

[0011] The control unit is electrically connected to the speed detection unit and the electromagnet;

[0012] When the counterweight rotates to the i-th electromagnet, it generates an attractive force. The control unit controls the ii-th magnet, which is symmetrical to the i-th magnet along the rotor center, to be energized, generating a pulling force on the counterweight to counteract the attractive force between the counterweight and the i-th electromagnet.

[0013] By controlling the ii magnet, which is symmetrical to the i magnet along the rotor center, to be energized by the control unit, a pulling force is generated on the counterweight to counteract the attraction between the counterweight and the i electromagnet, thereby counteracting the centrifugal force generated when the rotor rotates, ensuring that the rotating machinery has excellent dynamic balance characteristics at any speed, and ensuring the safe operation of the equipment.

[0014] Preferably, the speed detection unit includes a gear and a speedometer. The gear is coaxially fixed on the rotor, and the speedometer is positioned towards the gear to detect the gear speed. The speedometer is electrically connected to the control unit.

[0015] Preferably, the velocimeter is an ultrasonic or laser velocimeter.

[0016] Preferably, the counterweight adjustment unit further includes a tension sensor, with each electromagnet equipped with a tension sensor, and the tension sensor is electrically connected to the control unit.

[0017] Preferably, the electromagnetic retaining ring is fixed by a fixing seat, so that the electromagnetic retaining ring is coaxially arranged with the rotor.

[0018] Preferably, the rotor is provided with a mounting groove, and the counterweight is fixed in the mounting groove.

[0019] Preferably, the present invention also provides an adjustment method for a rotor counterweight adjustment device for rotating machinery, comprising the following steps:

[0020] The rated speed of the rotor is R n The rotor speed is divided into N speed ranges, namely 0-R. n / N、R n / N-2R n / N……(N-1)R n / NR n It includes the following steps:

[0021] Step 1: Start the rotor and simultaneously measure the rotor speed through the speed detection unit. The rotor speed gradually increases from 0 to the end of the first interval. During this process, the control unit supplies detection current to all electromagnets. When the counterweight rotates to the corresponding electromagnet, it generates an attractive force. The attractive force signal received by the electromagnet is transmitted to the control unit.

[0022] Step 2: The control unit plots the 0-R curve based on the rotor speed signal and the electromagnet attraction signal. n Vibration characteristic curves (angle-tension curves) in the / N speed range.

[0023] Step 3: At speeds of 0-R nWhen / N, the attractive force vibration characteristic curve of the counterweight and the corresponding i-th electromagnet is expressed in terms of angle and tension as (α). i °, A), the ii magnet is symmetrical about the i magnet along the rotor center. The ii magnet is energized by the control unit to generate a pulling force A on the counterweight to counteract the attraction between the counterweight and the i electromagnet.

[0024] The specific calculation for ii is as follows:

[0025] If 0≤α i ≤180°, α ii =α i +180°;

[0026] If 180° < α i If ≤360°, then α ii =α i -180°;

[0027] ii=α ii / (360° / n)

[0028] Step 4: Repeat the above steps to plot the vibration characteristic curves (angle-tension curves) for other speed ranges, and calculate the control sequence of the i-th electromagnet and the ii-th magnet for other speed ranges.

[0029] Compared with the prior art, the beneficial effects of the present invention are:

[0030] By controlling the ii magnet, which is symmetrical to the i magnet along the rotor center, to be energized by the control unit, a pulling force is generated on the counterweight to counteract the attraction between the counterweight and the i electromagnet, thereby counteracting the centrifugal force generated when the rotor rotates, ensuring that the rotating machinery has excellent dynamic balance characteristics at any speed, and ensuring the safe operation of the equipment. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the structure of an embodiment of the present invention;

[0032] Figure 2 This is a vibration characteristic curve of an embodiment of the present invention. Detailed Implementation

[0033] To facilitate understanding of the technical solution of the present invention by those skilled in the art, the technical solution of the present invention will now be further described in conjunction with the accompanying drawings.

[0034] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0035] In this application, unless otherwise expressly specified and limited, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying 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. In the description of this application, "multiple" means two or more, unless otherwise expressly and specifically limited.

[0036] See Figure 1 This embodiment discloses a counterweight adjustment device for a rotating machinery rotor, including a rotor 1, a counterweight block 2, a speed detection unit 3, a counterweight adjustment unit 4, and a control unit 5; the rotor 1 is provided with an installation groove (not shown in the figure), and the counterweight block 2 is fixed in the installation groove.

[0037] The speed detection unit 3 includes a gear 31 and a speedometer 32. The gear 32 is coaxially fixed on the rotor 1 and rotates synchronously with the rotor 1. The speedometer 32 is set towards the gear 31 to detect the rotational speed of the gear 31, and thus detect the rotational speed of the rotor 1. The speedometer 32 is electrically connected to the control unit 5.

[0038] The speedometer 32 is an ultrasonic or laser speedometer. It achieves signal blocking and reception by calculating the gap between the teeth of the gear 31, and finally calculates the accurate rotational speed of the rotor 1.

[0039] The counterweight adjustment unit 4 includes an electromagnetic fixing base 41, a fixing ring 42, an electromagnet 43, and a tension sensor (not shown in the figure). The fixing ring 42 is fixed on the electromagnetic fixing base 41 and is coaxially arranged with the rotor 1. n electromagnets are evenly distributed along the circumferential direction on the fixing ring 42. The electromagnets 43 are arranged towards the counterweight 2. A tension sensor is also provided on the electromagnets 43. Both the electromagnets 43 and the tension sensor are electrically connected to the control unit 5. The control unit 5 energizes the electromagnets 43, causing them to attract the counterweight 2. Specifically, when the counterweight 2 rotates to the i-th electromagnet, it generates an attraction. The control unit 5 controls the ii-th electromagnet, which is symmetrical to the i-th electromagnet along the center of the rotor 1, to be energized, generating a tension force on the counterweight 2 to counteract the attraction force between the counterweight 2 and the i-th electromagnet. This counteracts the centrifugal force generated when the rotor 1 rotates, ensuring that the rotating machinery has excellent dynamic balance characteristics at any speed and guaranteeing the safe operation of the equipment.

[0040] This embodiment also provides an adjustment method for a rotor counterweight adjustment device for rotating machinery, including the following steps:

[0041] The rated speed of the rotor is R. n The rotor speed is divided into three speed ranges: 0-R. n / 3、R n / 3-2R n / 3、2R n / 3-R n .

[0042] Step 1: Start rotor 1, and simultaneously measure the speed of rotor 1 using tachometer 32. The rotational speed of rotor 1 is gradually increased from 0 to R. n / 3. During this process, the control unit 5 supplies detection current to all electromagnets 43. When the counterweight 2 rotates to the corresponding electromagnet 43, it generates an attractive force. The attractive force signal received by the electromagnet 43 is transmitted to the control unit 5.

[0043] Step 2: As Figure 2 As shown, the control unit 5 plots the 0-R curve based on the rotor speed signal and the attraction force signal generated by the electromagnet 43. n Vibration characteristic curves (angle-tension curves) in the / 3 speed range.

[0044] Step 3: At speeds of 0-R n When / 3, the attractive force vibration characteristic curve of the counterweight 2 and the corresponding i-th electromagnet is expressed in terms of angle and tension as (α). i(°, A) Along the circumference of the i-th magnet, symmetrical to the i-th magnet around the center of rotor 1, is the ii-th magnet. Control unit 5 controls the ii-th magnet to be energized, generating a pulling force A on the counterweight 2 to counteract the attractive force between the counterweight and the i-th electromagnet, thereby counteracting the centrifugal force generated when the rotor 1 rotates.

[0045] The specific calculation for ii is as follows:

[0046] If 0≤α i ≤180°, α ii =α i +180°;

[0047] If 180° < α i If ≤360°, then α ii =α i -180°;

[0048] ii=α ii / (360° / n)

[0049] Step 4: Repeat the above steps to plot R. n / 3-2R n / 3、2R n / 3-R n Vibration characteristic curves (angle-tension curves) within the rotational speed range, and calculation of R. n / 3-2R n / 3、2R n / 3-R n The control sequence of the i-th electromagnet and the ii-th magnet within the rotational speed range.

[0050] 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 illustrative and non-limiting in all respects, 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, and no reference numerals in the claims should be construed as limiting the scope of the claims.

[0051] The above embodiments are merely examples of implementation methods of the invention. The scope of protection of the present invention is not limited to the above embodiments. For those skilled in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all fall within the scope of protection of the present invention.

Claims

1. A rotating machine rotor balance weight adjustment device characterized by: The application relates to a rotor, a counterweight, a speed detection unit, a counterweight adjusting unit and a control unit; the rotor is provided with the counterweight; the speed detection unit is used for detecting the rotating speed of the rotor; The counterweight adjusting unit comprises an electromagnetic fixing ring and electromagnets, the rotor penetrates through the electromagnetic fixing ring, n electromagnets are uniformly distributed on the electromagnetic fixing ring in the circumferential direction, and the electromagnets are arranged towards the counterweight; The control unit is electrically connected with the speed detection unit and the electromagnets; When the counterweight rotates to the i-th electromagnet, an attractive force is generated, the control unit controls the ii-th electromagnet which is symmetric to the i-th electromagnet along the center of the rotor to be electrified, a pulling force is generated on the counterweight to offset the attractive force generated between the counterweight and the i-th electromagnet.

2. A rotating machine rotor counterweight adjustment device according to claim 1, characterized by: The speed detection unit comprises a gear and a speed meter, the gear is coaxially fixed on the rotor, the speed meter is arranged towards the gear and is used for detecting the rotating speed of the gear, and the speed meter is electrically connected with the control unit.

3. A rotating machine rotor balance weight adjustment device according to claim 2, wherein: The speed meter is an ultrasonic speed meter or a laser speed meter.

4. A rotating machine rotor balance weight adjustment device according to claim 1, characterized by: The counterweight adjusting unit further comprises a pulling force sensor, the pulling force sensor is arranged on each electromagnet, and the pulling force sensor is electrically connected with the control unit.

5. A rotating machine rotor balance weight adjustment device according to claim 1, wherein: The electromagnetic fixing ring is fixed through a fixing base, so that the electromagnetic fixing ring is coaxially arranged with the rotor.

6. A rotating machine rotor balance weight adjustment device according to claim 1, wherein: The rotor is provided with a mounting groove, and the counterweight is fixed in the mounting groove.

7. A method of adjusting a rotating machine rotor balance weight adjustment device according to any one of claims 1 to 6, characterized in that: The rated rotating speed of the rotor is R n The rotating speed of the rotor is divided into N rotating speed intervals, respectively 0-R n / N, R n / N-2R n / N...(N-1)R n / N-R n The method comprises the following steps: Step 1: start the rotor, meanwhile, the rotating speed of the rotor is detected through the speed detection unit, the rotating speed of the rotor is gradually increased from 0 to the rotating speed at the end of the first interval, in the process, the control unit supplies detection current to all the electromagnets, when the counterweight rotates to a corresponding electromagnet, an attractive force is generated, the attractive force signal of the electromagnet is transmitted to the control unit; Step 2: The control unit draws the vibration characteristic curve (angle-tension curve) of 0-R n / N rotation interval according to the signal of the rotor rotation value and the signal of the electromagnetic attraction value. Step 3: When the rotation speed is 0-R n / N, the counterweight and the corresponding ith electromagnet generate an attractive force. The vibration characteristic curve coordinates are expressed as (α i °, A), and the ii th electromagnet is symmetric to the ith electromagnet along the rotor center. The ii th electromagnet is controlled by the control unit to generate a pulling force A on the counterweight to offset the attractive force generated between the counterweight and the ith electromagnet. The calculation of the specific ii is as follows: if0≤a i ≤180°,a ii =a i +180°; if 180° < a i ≤ 360°, then a ii = a i - 180°; ii = a ii / (360° / n); Step 4: repeat the above steps to draw the vibration characteristic curves (angle-pulling force curves) of other rotating speed intervals, and calculate the control sequence of the i-th electromagnet and the ii-th magnet in other rotating speed intervals.

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