Locked-rotor detection mechanism of power plant rotor

Abstract

The utility model discloses a power plant rotating machine locked-rotor detection mechanism which comprises an NPN type proximity sensor and an induction iron piece, the NPN type proximity sensor is arranged on the inner side of a shell behind a rotating shaft of a rotating machine, and the induction iron piece comprises an L-shaped rotating shaft connecting part and an arc-shaped sensor triggering part. The shaft bottom parallel section of the rotating shaft connecting part is connected with the rear end of the rotating shaft of the rotating machine through a bolt, and the sensor triggering part is arranged at the rear end of the shell parallel section of the rotating shaft connecting part. The problem that the operation state of a rotating machine cannot be detected due to too narrow width of an existing trigger iron sheet is solved.

Description

Technical Field

[0001] The utility model relates to the field of a rotor jam detection mechanism, in particular to a rotor jam detection mechanism for a power plant. Background Art

[0002] In the long-term operation of power plants, proximity sensors are widely used according to the characteristics of the system, equipment, and production process. Proximity sensors are indispensable in the desulfurization vacuum belt conveyor speed reduction mechanism, limestone bucket elevator, dry slag bucket elevator chain break protection, slag crusher blocking and reversing interlock control, etc. The tightness of the mounting bracket, the form of the trigger device, the installation distance, etc. have a significant impact on whether the proximity sensor can work properly.

[0003] In the control circuit of the existing NPN proximity sensor, KA is a relay with a working voltage of 24VDC. When the proximity sensor approaches or moves away from the trigger iron sheet, the intermediate relay coil is energized or de-energized, thus sending the contacts of the intermediate relay to the DCS control system switch input module, and interlock protection is achieved by using delayed on / off logic judgment in the motor stall detection control logic.

[0004] In actual use, the DCS system may be unable to detect the trigger signal and the transfer operation status. At this time, the chain break interlock protection logic will trigger a motor trip command, affecting the normal operation of the limestone bucket elevator and dewatering belt conveyor of the desulfurization system.

[0005] This is mainly because the NPN proximity sensor is in the form of an intermediate relay driven by a 24V DC power supply. The trigger iron sheet is too narrow, measuring approximately 3cm. The crusher motor runs at 52r / min, and the trigger device radius is 6cm. According to the speed formula, the linear speed in cm / s = / 2*3.14*circular radius (6cm)*52 / 60 (s) = 32.7cm / s. The factory-provided trigger device width is 3cm. The effective triggering time of the proximity sensor is t = width (3cm) / linear speed (32.7 cm / s) = 0.09s. The excessively short triggering time is combined with the action delay of the intermediate relay. Considering the Hollysys MA6 model K-DI11 digital input module, the channel software filtering time is generally 200ms. As a result, a large number of pulse signals will be missed in the actual process, which directly leads to the failure of the slag crusher forward and reverse interlocking and tripping protection functions.

[0006] In order to solve the above problems, it is necessary to improve the existing detection structure. Utility Model Content

[0007] The utility model aims to provide a power plant transfer machine stall detection mechanism to solve the problem that the width of the existing trigger iron piece is too narrow and thus the transfer machine operation status cannot be detected.

[0008] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0009] A power plant rotor jam detection mechanism includes an NPN proximity sensor and an inductive iron piece. The NPN proximity sensor is arranged on the inner side of a housing behind the rotor shaft. The inductive iron piece includes an "L"-shaped shaft connection portion and an arc-shaped sensor trigger portion. The shaft bottom parallel section of the shaft connection portion is connected to the rear end of the rotor shaft by a bolt, and the sensor trigger portion is arranged at the rear end of the housing parallel section of the shaft connection portion.

[0010] The original "planar" trigger shape was changed to a "circular" trigger, and the trigger area was increased to 29 cm. Based on the linear velocity of 32.7 cm / s calculated above, the effective trigger time t=29 / 32.7=0.88s. The trigger time is greater than the channel software filtering time of 200ms, and the margin is extremely large, which effectively avoids the occurrence of the above situation.

[0011] As a further preferred embodiment of the present invention, the shell parallel section of the rotating shaft connecting portion is a telescopic structure.

[0012] It is convenient to adjust the length of the shell parallel section of the rotating shaft connecting part according to the location where the NPN type proximity sensor is set.

[0013] As a further preference of the present invention, the parallel section of the shell of the rotating shaft connecting part includes a fixed section and an extension section, a positioning screw is provided on the back of the fixed section, and a sliding opening is provided in the middle of the extension section. The positioning screw passes through the sliding opening outward, and a positioning nut is provided at the outer end of the positioning screw.

[0014] By turning the positioning nut outward, the extension section can be pulled outward or slid inward, so that the length of the shell parallel section of the shaft connection can be adjusted. After adjustment, turn the positioning nut inward to press the extension section to complete the positioning work.

[0015] As a further preferred embodiment of the present invention, the curvature of the sensor trigger portion is the same as the curvature of the inner cavity of the housing behind the rotating shaft of the turntable.

[0016] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0017] 1. The original "planar" trigger shape was changed to a "circular" trigger, and the trigger area was increased to 29 cm. Based on the linear velocity of 32.7 cm / s calculated above, the effective trigger time t=29 / 32.7=0.88s. The trigger time is longer than the channel software filter time of 200ms, and the margin is extremely large, which effectively avoids the occurrence of the above situation.

[0018] 2. It is convenient to adjust the length of the shell parallel section of the shaft connection part according to the location of the NPN proximity sensor.

[0019] 3. The length of the parallel section of the shell at the shaft connection is easy to adjust. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural diagram of the present utility model.

[0021] Figure 2 It is a structural schematic diagram of the shell parallel section of the rotating shaft connecting part of the utility model. DETAILED DESCRIPTION

[0022] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0023] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but rather merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by a person of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0024] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0025] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0026] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," "outer," and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the product of the present invention is typically placed when in use, or are the orientations or positional relationships commonly understood by those skilled in the art. These terms are intended solely to facilitate the description of the present invention and to simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like are used solely to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0027] It should also be noted that, in the description of this utility model, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; direct connections, indirect connections through an intermediate medium, and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances. Specific embodiment 1:

[0029] Figure 1 、 Figure 2 A power plant rotor jam detection mechanism is shown, including an NPN proximity sensor 1 and an inductive iron member 2. The NPN proximity sensor 1 is arranged on the inner side of a housing behind the rotor shaft. The inductive iron member 2 includes an "L"-shaped shaft connection portion 21 and an arc-shaped sensor trigger portion 22. The shaft bottom parallel section 211 of the shaft connection portion 21 is connected to the rear end of the rotor shaft by a bolt 3, and the sensor trigger portion 22 is arranged at the rear end of the housing parallel section 212 of the shaft connection portion 21.

[0030] The original "planar" trigger shape was changed to a "circular" trigger, and the trigger area was increased to 29 cm. Based on the linear velocity of 32.7 cm / s calculated above, the effective trigger time t=29 / 32.7=0.88s. The trigger time is greater than the channel software filtering time of 200ms, and the margin is extremely large, which effectively avoids the occurrence of the above situation. Specific embodiment 2:

[0032] This embodiment further illustrates the shaft connection portion 21 based on the specific embodiment 1. The housing parallel section 212 of the shaft connection portion 21 is a telescopic structure.

[0033] It is convenient to adjust the length of the shell parallel section of the rotating shaft connecting part according to the location where the NPN type proximity sensor is set. Specific embodiment 3:

[0035] This embodiment further explains the rotating shaft connecting part 21 on the basis of the specific embodiment 2. The shell parallel section 212 of the rotating shaft connecting part 21 includes a fixed section 2121 and an extension section 2122. A positioning screw 4 is provided on the back of the fixed section 2121, and a sliding opening 5 is provided in the middle of the extension section 2122. The positioning screw 4 passes through the sliding opening 5 outward, and a positioning nut 6 is provided at the outer end of the positioning screw 4.

[0036] By turning the positioning nut outward, the extension section can be pulled outward or slid inward, so that the length of the shell parallel section of the shaft connection can be adjusted. After adjustment, turn the positioning nut inward to press the extension section to complete the positioning work. Specific embodiment 4:

[0038] This embodiment further illustrates the sensor triggering portion 22 based on the specific embodiment 1. The curvature of the sensor triggering portion 22 is the same as the curvature of the inner cavity of the housing behind the rotating shaft of the rotary machine.

[0039] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments, or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A power plant rotor jam detection mechanism, comprising an NPN proximity sensor (1) and an inductive iron member (2), characterized in that: The NPN type proximity sensor (1) is arranged on the inner side of the housing behind the rotating shaft of the rotating machine. The inductive iron member (2) comprises an L-shaped rotating shaft connecting portion (21) and an arc-shaped sensor triggering portion (22). The shaft bottom parallel section (211) of the rotating shaft connecting portion (21) is connected to the rear end of the rotating shaft of the rotating machine via a bolt (3). The sensor triggering portion (22) is arranged at the rear end of the housing parallel section (212) of the rotating shaft connecting portion (21).

2. The power plant stall detection mechanism according to claim 1, characterized in that: The shell parallel section (212) of the rotating shaft connecting portion (21) is a telescopic structure.

3. The power plant rotor jam detection mechanism according to claim 2, characterized in that: The shell parallel section (212) of the rotating shaft connecting portion (21) includes a fixed section (2121) and an extension section (2122). A positioning screw (4) is provided on the back of the fixed section (2121), and a sliding opening (5) is provided in the middle of the extension section (2122). The positioning screw (4) passes through the sliding opening (5) outward, and a positioning nut (6) is provided at the outer end of the positioning screw (4).

4. The power plant rotor jam detection mechanism according to claim 1, characterized in that: The curvature of the sensor trigger portion (22) is the same as the curvature of the inner cavity of the housing behind the rotating shaft of the turntable.

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