Drum screen drive and nuclear power plant cold source filtration system

Abstract

The utility model discloses a drum filter screen drive arrangement and nuclear power plant cold source filtering system. Drum filter screen drive arrangement includes horizontal speed reducer, drive long axle, gear, at least two frequency conversion motor, horizontal speed reducer includes opposite first side and second side, and first side is towards drum filter screen, and second side is away from drum filter screen, drive long axle is located first side, and drive long axle includes opposite first end and second end, and first end is connected with horizontal speed reducer, and second end is connected with gear transmission, and gear is used for connecting the big gear ring on drum filter screen, at least two frequency conversion motor all are located second side, and are connected with horizontal speed reducer. Every frequency conversion motor can complete low speed and medium high speed torque output alone. All frequency conversion motor is arranged away from wall body, thereby avoids the interference of high pressure backwashing pipeline's instrument pipeline, is more suitable for nuclear power plant's field arrangement environment, thereby is more convenient for field installation and overhauls.

Description

Technical Field

[0001] This utility model relates to the field of drum filter drive technology for nuclear power plants, and in particular to a drum filter drive device and a cold source filtration system for nuclear power plants. Background Technology

[0002] The drum filter in a nuclear power plant consists of a rotating cylindrical frame structure. Filter plates are installed circumferentially on the frame. Water enters the drum filter from both sides of the end face, is filtered through the mesh of the plates, and then flows to the outside of the drum filter. When the drum filter rotates, the debris collected in the sludge hopper and on the inner side of the mesh is lifted above the operating platform and flushed out by backwash water sprayed from the outside of the mesh into the drainage trough. The drum filter drive mechanism, as the power source for the drum filter in the nuclear power plant, indirectly plays a crucial role in ensuring the removal of reactor heat and the integrity of the reactor core. It is a key piece of equipment in the cold source safety and nuclear safety assurance aspects of the nuclear power plant.

[0003] Existing drum filter drive mechanisms generally employ worm gear vertical reducers, which are conventional dual-shaft input reducers (with two input shafts). The reducer is installed vertically in a cantilever configuration. While this method offers the advantage of a small installation footprint, it suffers from inherently insufficient vibration damping. Furthermore, the reducer's two primary reduction mechanisms are equipped with three motors, resulting in asymmetrical structure, uneven weight distribution, and overall instability, which can easily lead to excessive vibration, abnormal noise, wear, and oil leaks. Additionally, some drum filter drive mechanisms in related technologies utilize horizontal reducers, but these require at least three motors to handle low-speed and medium-to-high-speed outputs respectively. Since the space occupied by the drum filter drive mechanism is limited by other equipment and pipelines, its layout is extremely confined, making on-site installation and maintenance very difficult when three motors are involved. In summary, existing drum filter drive mechanisms suffer from significant equipment vibration and inconvenient on-site installation and maintenance, hindering the long-term stable operation of the drum filter. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide a drum-shaped filter drive device and a nuclear power plant cold source filtration system, addressing at least one of the deficiencies mentioned in the background art.

[0005] The technical solution adopted by this utility model to solve its technical problem is as follows: A drum-shaped filter drive device is constructed for connecting a drum-shaped filter in a nuclear power plant. It includes a horizontal reducer, a long drive shaft, a gear, and at least two variable frequency motors. The horizontal reducer includes a first side and a second side facing each other, with the first side facing the drum-shaped filter and the second side facing away from the drum-shaped filter. The long drive shaft is located on the first side and includes a first end and a second end facing each other. The first end is connected to the horizontal reducer, and the second end is connected to the gear. The gear is used to connect to the large gear ring on the drum-shaped filter. All at least two variable frequency motors are located on the second side and are connected to the horizontal reducer.

[0006] In some embodiments, a vibration measurement unit is further included, which is at least partially disposed on the horizontal reducer.

[0007] In some embodiments, the vibration measurement unit includes a vibration sensor, a data acquisition unit, and a terminal device. The vibration sensor is mounted on the horizontal reducer, and the data acquisition unit is connected between the vibration sensor and the terminal device.

[0008] In some embodiments, the vibration sensor is a magnetic vibration sensor.

[0009] In some embodiments, the horizontal reducer includes a housing and a gear transmission structure disposed inside the housing, the first end of the drive shaft and the variable frequency motor are respectively connected to the gear transmission structure, and the vibration sensor is disposed on the housing.

[0010] In some embodiments, the horizontal reducer includes an output shaft and at least two input shafts, the first end of the drive shaft is connected to the output shaft, and the two variable frequency motors are connected to the at least two input shafts in a one-to-one correspondence.

[0011] In some embodiments, the system further includes an output coupling and at least two input couplings, wherein the first end of the drive shaft and the output shaft are connected via the output coupling, and the at least two variable frequency motors and the at least two input shafts are connected one-to-one via the at least two input couplings.

[0012] In some embodiments, the central axis extension directions of both the output shaft and the input shaft are consistent with the central axis extension direction of the drum-shaped filter.

[0013] In some embodiments, the number of variable frequency motors is two.

[0014] This utility model also provides a nuclear power plant cold source filtration system, which includes a drum-shaped filter and a drum-shaped filter drive device as described in any of the above. A wall is provided between the drum-shaped filter and the drum-shaped filter drive device, with the first side facing the wall and the second side facing away from the wall. The drum-shaped filter and the drum-shaped filter drive device are connected by a drive shaft, which passes through the wall.

[0015] This invention offers at least the following advantages: It replaces the existing vertical reducer with a horizontal reducer, which has a lower and more stable center of gravity, reducing risks such as vibration, noise, wear, and oil leakage; it employs at least two variable frequency motors, each capable of independently outputting torque at low and medium-high speeds. The two motors serve as backups for each other, meeting the redundancy design requirements of nuclear power plants; and because all the variable frequency motors are located on the second side away from the wall, i.e., all motors are arranged away from the wall, interference from the instrument lines of the high-pressure backwashing pipeline is avoided. This allows personnel to install and maintain all the motors from this side away from the wall, making it more suitable for the on-site layout environment of nuclear power plants and facilitating on-site installation and maintenance. Attached Figure Description

[0016] To more clearly illustrate the technical solution of this utility model, the following will further describe this utility model in conjunction with the accompanying drawings and embodiments. In the drawings:

[0017] Figure 1 This is a schematic diagram of the structure of a drum-shaped filter drive mechanism as described in the background art;

[0018] Figure 2 This is a schematic diagram of the planar layout of a nuclear power plant cold source filtration system in some embodiments of this utility model;

[0019] Figure 3 yes Figure 2 Enlarged structural diagram of section A. Detailed Implementation

[0020] To provide a clearer understanding of the technical features, objectives, and effects of this utility model, the specific embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0021] Please see Figure 1As described in the background section, although the drum filter drive mechanism in the related technology uses a horizontal reducer 10, this horizontal reducer 10 requires at least three motors 11 to handle low-speed output and medium-to-high-speed output respectively. This drum filter drive mechanism is located in the plant where the high-pressure backwashing pipeline is situated, and is positioned close to the high-pressure backwashing pipeline. The plant where the drum filter drive mechanism is located contains supports for the high-pressure backwashing pipeline and instrument lines 12. When there are three motors 11, one of them can only be placed against the wall, and the space around the motor against the wall is very narrow, making on-site installation and maintenance extremely difficult.

[0022] Please see Figure 2 and Figure 3 This utility model provides a cold source filtration system for a nuclear power plant, comprising a drum-shaped filter 2 and a drum-shaped filter drive device. The drum-shaped filter drive device is located inside the plant building where the high-pressure backwashing pipeline is located. The drum-shaped filter 2 is located outdoors, outside the plant building where the high-pressure backwashing pipeline is located. A wall 4 is provided between the drum-shaped filter 2 and the drum-shaped filter drive device, which is the wall 4 of the plant building where the high-pressure backwashing pipeline is located. The drum-shaped filter 2 and the drum-shaped filter drive device need to be connected by a drive shaft 32, therefore the drive shaft 32 passes through the wall 4.

[0023] Please see Figure 2 and Figure 3 In some embodiments, the drum filter drive device includes a horizontal reducer 31, a drive shaft 32, a gear 33, and two variable frequency motors 34. Compared to a worm gear vertical reducer, the horizontal reducer 31 helps to lower the center of gravity of the device and has better vibration resistance. The horizontal reducer 31 includes a first side 311 and a second side 312 facing each other. The first side 311 faces the drum filter 2, and the second side 312 faces away from the drum filter 2. That is, the first side 311 faces the wall 4, and the second side 312 faces away from the wall 4. The drive shaft 32 is located on the first side 311 and includes a first end 321 and a second end 322 facing each other. The first end 321 is connected to the horizontal reducer 31, and the second end 322 is connected to the gear 33 for transmission. The gear 33 is used to connect to a large gear ring on the drum filter 2. Specifically, the drum filter 2 is provided with a large gear ring extending around its circumference. Gear 33 meshes with the large gear ring on the drum-shaped filter screen 2. In some other embodiments, the number of variable frequency motors 34 may also be two or more. All variable frequency motors 34 are located on the second side 312, that is, all variable frequency motors 34 are located on the second side 312. And they are connected to the horizontal reducer 31. The torque output by the variable frequency motors 34 is transmitted to the horizontal reducer 31, and the horizontal reducer 31 outputs torque to the drive shaft 32. The drive shaft 32 rotates, driving gear 33 to rotate. Gear 33, through its meshing relationship with the large gear ring, drives the drum-shaped filter screen 2 to rotate circumferentially.

[0024] Specifically, the variable frequency motor 34 is a motor capable of continuous operation within a 10% to 100% rated speed range at 100% rated load under standard conditions. The variable frequency motor 34 can be a conventional variable frequency motor. Each variable frequency motor 34 can independently complete low-speed and medium-to-high-speed torque output. The two variable frequency motors 34 serve as backups for each other, meeting the redundancy design requirements of nuclear power plants. According to relevant technical standards for nuclear power plants, under normal operating conditions, the drum filter 2 is activated in low-speed mode when it is slightly clogged; and in medium-speed or high-speed mode when it is severely clogged. The degree of clogging of the drum filter 2 can be determined based on the water level difference. The nominal speed of the drum filter 2 during low-speed operation is 2.5 m / min. The nominal speed of the drum filter 2 during medium-speed operation is 10 m / min. The nominal speed of the drum filter 2 during high-speed operation is 20 m / min. Each variable frequency motor 34 can independently drive the drum filter 2 to operate at low, medium, or high speeds.

[0025] Because this invention uses two variable frequency motors 34, and all of the variable frequency motors 34 are located on the second side 312 away from the wall 4, that is, all the variable frequency motors 34 are arranged away from the wall 4, thus avoiding interference from the instrument pipelines of the high-pressure backwashing pipeline. Personnel can install and maintain all the variable frequency motors 34 on this side away from the wall 4, which is more suitable for the on-site layout environment of a nuclear power plant, thus facilitating on-site installation and maintenance. Furthermore, the space between the first side 311 of the horizontal reducer 31 and the wall 4 can be reduced, meaning the horizontal reducer 31 can be arranged closer to the wall 4, resulting in a more compact on-site space layout. Because the horizontal reducer 31 can be arranged closer to the wall 4, the length of the drive shaft 32 can also be reduced, which helps to reduce construction costs.

[0026] In summary, this utility model has at least the following beneficial effects: It replaces the vertical reducer in the prior art with a horizontal reducer 31, which has a lower and more stable center of gravity, reducing the risks of vibration, abnormal noise, wear, and oil leakage; it uses at least two variable frequency motors 34, each capable of independently completing low-speed and medium-to-high-speed torque output. The at least two variable frequency motors 34 serve as backups for each other, meeting the redundancy design requirements of nuclear power plants; since all the variable frequency motors 34 are located on the second side 312 away from the wall 4, i.e., all the variable frequency motors 34 are arranged away from the wall 4, interference from the instrument lines of the high-pressure backwashing pipeline is avoided. Personnel can install and maintain all the variable frequency motors 34 from this side away from the wall 4, making it more suitable for the on-site layout environment of nuclear power plants and thus more convenient for on-site installation and maintenance.

[0027] like Figure 2As shown, in some embodiments, the drum filter drive device further includes a vibration measurement unit at least partially disposed on the horizontal reducer 31. This vibration measurement unit includes a vibration sensor 51, a data acquisition unit 52, and a terminal device 53. The vibration sensor 51 is disposed on the horizontal reducer 31, and the data acquisition unit 52 is connected between the vibration sensor 51 and the terminal device 53. Specifically, the data acquisition unit 52 and the vibration sensor 51 can be connected via a cable, with the vibration sensor 51 collecting vibration data from the reducer and transmitting it to the data acquisition unit 52. The data acquisition unit 52 and the terminal device 53 can be connected via a cable or wirelessly. For example, a wireless router can be set up between the data acquisition unit 52 and the terminal device 53 for data transmission. The terminal device 53 can be an electronic device such as a computer or mobile phone, equipped with corresponding software for receiving the vibration data collected by the data acquisition unit 52. In other embodiments, the vibration measurement unit may also include a vibration meter disposed on the horizontal reducer 31. The vibration measurement unit can monitor the vibration of the horizontal reducer 31 in real time, providing objective data support for the operation status of the horizontal reducer 31, thereby making the operation status of the drive device visible.

[0028] In some embodiments, the horizontal reducer 31 includes a housing 313 and a gear transmission structure (not shown) disposed inside the housing 313. The first end 321 of the drive shaft 32 and the variable frequency motor 34 are respectively connected to the gear transmission structure. A vibration sensor 51 is disposed on the housing 313. Specifically, the gear transmission structure includes multiple pairs of gears 33. Each pair of gears 33 includes one (i.e., two) meshing reduction gears 33, corresponding to one reduction stage. The gear transmission structure can be a four-stage gear transmission structure or a three-stage gear transmission structure, etc. For example, a four-stage gear transmission structure has four meshing pairs of gears 33, which can achieve four independent reduction stages. For details regarding the specific structure and reduction principle of the gear transmission structure and reducer, please refer to the prior art.

[0029] Furthermore, in some embodiments, the vibration sensor 51 is a magnetic vibration sensor 51. The magnetic vibration sensor 51 can be directly attached to the housing 313 of the horizontal reducer 31, and its position on the horizontal reducer 31 can be easily moved. Of course, the vibration sensor 51 is not limited to a magnetic vibration sensor 51. In other embodiments, the vibration sensor 51 can also be a patch vibration sensor 51 or other forms of vibration sensor 51.

[0030] like Figure 2 and Figure 3As shown, in some embodiments, the horizontal reducer 31 includes an output shaft 314 and at least two input shafts 315. The first end 321 of the drive shaft 32 is connected to the output shaft 314, and at least two variable frequency motors 34 are connected to at least two input shafts 315 in a one-to-one correspondence. Each input shaft 315 and the output shaft 314 is connected to a reduction gear 33. The number of reduction gears 33 can vary depending on the specific design of the reducer and the arrangement of the gears 33, and is not limited here.

[0031] like Figure 2 As shown, in some embodiments, the central axis extension directions of both the output shaft 314 and the input shaft 315 are consistent with the central axis (Y) extension direction of the drum filter 2. This eliminates the need for a commutator between the reducer and the drum filter 2. The two variable frequency motors 34 are directly connected to the two input shafts 315 in a one-to-one correspondence, further eliminating the need for a commutator between the motors and the input shafts 315. Therefore, the entire drive unit can be driven without a commutator, saving components and reducing the risk of single-point failure in the drive unit.

[0032] like Figure 3 As shown, in some embodiments, the drum filter drive device further includes an output coupling 61 and at least two input couplings 62. The first end 321 of the drive shaft 32 and the output shaft 314 are connected via the output coupling 61. At least two variable frequency motors 34 and at least two input shafts 315 are connected one-to-one via at least two input couplings 62. That is, each variable frequency motor 34 and its corresponding input shaft 315 are connected via an input coupling 62. These couplings are used to transmit torque between the motor and the input shaft 315, or between the drive shaft and the output shaft 314, and facilitate the disassembly and assembly of the various motors and drive shafts, thus simplifying equipment maintenance.

[0033] In addition, support structures can be provided between the horizontal reducer 31 and its placement surface (ground), and between the variable frequency motor 34 and its placement surface, to further reduce the vibration of the horizontal reducer 31 and the variable frequency motor 34.

[0034] It is understood that the above embodiments only illustrate preferred embodiments of the present utility model, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present utility model patent. It should be noted that for those skilled in the art, the above technical features can be freely combined, and several modifications and improvements can be made without departing from the concept of the present utility model, all of which fall within the protection scope of the present utility model. Therefore, all equivalent transformations and modifications made within the scope of the claims of the present utility model should fall within the coverage of the claims of the present utility model.

Claims

1. A drum filter drive device for connecting a drum filter (2) in a nuclear power plant, characterized in that, Includes a horizontal reducer (31), a drive shaft (32), a gear (33), and at least two variable frequency motors (34); The horizontal reducer (31) includes a first side (311) and a second side (312) facing each other, the first side (311) facing the drum-shaped filter (2) and the second side (312) facing away from the drum-shaped filter (2); The drive shaft (32) is located on the first side (311). The drive shaft (32) includes a first end (321) and a second end (322) opposite to each other. The first end (321) is connected to the horizontal reducer (31), and the second end (322) is connected to the gear (33) for transmission. The gear (33) is used to connect to the large gear ring on the drum-shaped filter screen (2). The at least two variable frequency motors (34) are all located on the second side (312) and are connected to the horizontal reducer (31).

2. The drum-shaped filter drive device according to claim 1, characterized in that, It also includes a vibration measurement unit, which is at least partially mounted on the horizontal reducer (31).

3. The drum-shaped filter drive device according to claim 2, characterized in that, The vibration measurement unit includes a vibration sensor (51), a data acquisition unit (52), and a terminal device (53). The vibration sensor (51) is mounted on the horizontal reducer (31), and the data acquisition unit (52) is connected between the vibration sensor (51) and the terminal device (53).

4. The drum-shaped filter drive device according to claim 3, characterized in that, The vibration sensor (51) is a magnetic vibration sensor (51).

5. The drum-shaped filter drive device according to claim 3, characterized in that, The horizontal reducer (31) includes a housing (313) and a gear (33) transmission structure disposed inside the housing (313). The first end (321) of the drive shaft (32) and the variable frequency motor (34) are respectively connected to the gear (33) transmission structure. The vibration sensor (51) is disposed on the housing (313).

6. The drum-shaped filter drive device according to claim 1, characterized in that, The horizontal reducer (31) includes an output shaft (314) and at least two input shafts (315). The first end (321) of the drive shaft (32) is connected to the output shaft (314). The two variable frequency motors (34) are connected to the at least two input shafts (315) in a one-to-one correspondence.

7. The drum-shaped filter drive device according to claim 6, characterized in that, It also includes an output coupling (61) and at least two input couplings (62), the first end (321) of the drive shaft (32) and the output shaft (314) are connected by the output coupling (61), and the at least two variable frequency motors (34) and the at least two input shafts (315) are connected one-to-one by the at least two input couplings (62).

8. The drum-shaped filter drive device according to claim 6, characterized in that, The central axis of both the output shaft (314) and the input shaft (315) extends in the same direction as the central axis (Y) of the drum-shaped filter (2).

9. The drum-shaped filter drive device according to claim 1, characterized in that, The number of the variable frequency motors (34) is two.

10. A nuclear power plant cold source filtration system, characterized in that, The device includes a drum-shaped filter (2) and a drum-shaped filter drive device according to any one of claims 1 to 9, wherein a wall (4) is provided between the drum-shaped filter (2) and the drum-shaped filter drive device, the first side (311) faces the wall (4) and the second side (312) faces away from the wall (4), the drum-shaped filter (2) and the drum-shaped filter drive device are connected by the drive shaft (32), and the drive shaft (32) passes through the wall (4).

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