阅读说明：本技术 一种在离心风机叶轮上加装平衡块的结构和方法 (Structure and method for additionally mounting balance block on centrifugal fan impeller ) 是由 李昊燃 郑金 孙大伟 闫宏 石清鑫 马翔 陈得胜 王伯平 于 2021-10-29 设计创作，主要内容包括：本发明公开了一种在离心风机叶轮上加装平衡块的结构和方法,该结构包括在靠近叶轮后盘(1)一侧的蜗壳(2)上预留的矩形槽(3),通过矩形槽(3)将平衡块安装到叶轮后盘(1)上。该方法包括：根据风机结构确定矩形槽几何中心位置和尺寸；根据振动数据确定平衡块的重量和角度；平衡块的加装和矩形槽的封堵。本发明只需要在计算后规定的位置增加方形小孔即可,该结构安全、简单,不影响风机正常运行。(The invention discloses a structure and a method for additionally arranging a balance block on a centrifugal fan impeller, wherein the structure comprises a rectangular groove (3) reserved on a volute (2) close to one side of an impeller rear disc (1), and the balance block is arranged on the impeller rear disc (1) through the rectangular groove (3). The method comprises the following steps: determining the geometric center position and the size of the rectangular groove according to the fan structure; determining the weight and angle of the balance weight according to the vibration data; the additional installation of balancing piece and the shutoff of rectangular channel. The invention only needs to add the square small hole at the specified position after calculation, and the structure is safe and simple and does not influence the normal operation of the fan.)

1. The utility model provides a structure of adorning the balancing piece additional on centrifugal fan impeller which characterized in that includes on spiral case (2) of being close to impeller back plate (1) one side reserve rectangular channel (3), installs the balancing piece on impeller back plate (1) through rectangular channel (3).

2. A structure for adding balance weight on centrifugal fan impeller according to claim 1, characterized in that the vertical center line (4) of the rectangular groove (3) is parallel to the vertical center line (5) of the impeller.

3. The structure for adding the balance weight on the centrifugal fan impeller according to claim 1, wherein the geometric center (6) of the rectangular groove (3) is coincided with the lowest point (7) of the edge line of the impeller back disk.

4. The structure for adding the balance weight on the centrifugal fan impeller according to claim 1, wherein the length dimension of the rectangular groove (3) is 30mm to 50 mm.

5. The structure for adding the balance weight on the centrifugal fan impeller according to claim 1, wherein the width dimension of the rectangular groove (3) is 20mm to 30 mm.

6. The structure of claim 1, wherein the weight and angle of the balancing mass is determined based on vibration data.

7. A structure for adding a balancing mass to a centrifugal fan impeller according to claim 1, characterized in that the balancing mass is welded to the impeller back disk (1).

8. The structure of claim 1, wherein the rectangular groove is sealed after the centrifugal fan impeller is mounted.

9. A method for additionally arranging a balance block on a centrifugal fan impeller is characterized by comprising the following steps:

1) determining the geometric center position and the size of the rectangular groove according to the structure of the fan, wherein the geometric center position of the rectangular groove (3) is superposed with the lowest point (7) of the edge line of the rear disk of the impeller; in order to facilitate the installation of the balance block and not to influence other work on site, the length and the width of the rectangular groove (3) are respectively 30-50 mm and 20-30 mm according to the actual situation on site;

2) determining the weight and angle of the balance weight according to the vibration data; according to the vibration data and the structural parameters of the fan, after the mass and the adding angle of the balance block are determined, marking the corresponding position of the impeller rear disc;

3) the balancing block is additionally arranged at the mark position of the impeller rear disc through the rectangular groove, and the rectangular groove is blocked after the balancing block is additionally arranged.

Technical Field

The invention relates to the field of rotating machinery of coal-fired thermal power plants, in particular to a structure and a method for additionally arranging a balance block on a centrifugal fan impeller.

Background

Unbalance is the most common cause of failure in rotating machines, accounting for more than about 70% of the total number of vibration failures. The rotor of the rotary machine has many factors causing unbalance, such as raw material defects, asymmetry of the rotor structure, thermal deformation, manufacturing and installation errors and the like. Therefore, the dynamic balance work runs through the whole manufacturing, installation and operation stages of the unit and is an important method for treating the vibration fault of the rotary machine. There are many types of rotating machinery in coal-fired power plants: such as steam turbines, generators, various motors, induced draft fans, primary air fans, air blowers, sealing fans and the like, are important equipment of thermal power plants. The centrifugal fan is widely applied due to simple structure and small range of unstable operation area of the fan.

The dynamic balance of the large-scale rotating machinery comprises four methods of low-speed dynamic balance of a manufacturing plant, on-site low-speed dynamic balance, dynamic balance on a high-speed dynamic balance table and on-site high-speed dynamic balance. The centrifugal fan of the coal-fired thermal power plant generally performs low-speed dynamic balance before leaving a factory, but the centrifugal fan needs to perform high-speed dynamic balance on the site due to installation, construction or abrasion after long-time operation of the centrifugal fan after arriving at the site. Although the on-site dynamic balance and the actual condition goodness of fit of the unit are high, the vibration reduction effect is best, the unit (fan) needs to be started and stopped for multiple times, workers need to enter and exit the fan shell for multiple times through the manhole door and weld balance blocks in a narrow space, time cost, labor cost and on-site workload are relatively high, and therefore the method has important significance for researching the method for reducing the on-site dynamic balance workload and time.

Disclosure of Invention

Aiming at the problems of large workload, long time consumption and the like of the existing centrifugal fan of the coal-fired power plant, and simultaneously considering the conventional structure and the field condition of the centrifugal fan, the invention provides a structure and a method for additionally arranging a balance block on an impeller of the centrifugal fan.

The invention is realized by adopting the following technical scheme:

the utility model provides a structure of adorning the balancing piece additional on centrifugal fan impeller, includes the rectangular channel of reserving on the spiral case near impeller back plate one side, installs the balancing piece on the impeller back plate through the rectangular channel.

A further improvement of the present invention is that the vertical centerline of the rectangular slot is parallel to the vertical centerline of the impeller.

The invention has the further improvement that the geometric center of the rectangular groove is coincided with the lowest point of the edge line of the back disk of the impeller.

The invention is further improved in that the length dimension of the rectangular groove is 30 mm-50 mm.

The invention is further improved in that the width dimension of the rectangular groove is 20-30 mm.

A further improvement of the invention consists in determining the weight and angle of the counterweight from the vibration data.

A further improvement of the invention is that the balance mass is welded to the back disk of the impeller.

The invention has the further improvement that the rectangular groove is plugged after the installation is finished.

A method for adding a balance weight on a centrifugal fan impeller comprises the following steps:

1) determining the geometric center position and the size of the rectangular groove according to the structure of the fan, wherein the geometric center position of the rectangular groove is superposed with the lowest point of the edge line of the rear disc of the impeller; in order to facilitate the installation of the balance block and not influence other field work, the length and the width of the rectangular groove are respectively 30-50 mm and 20-30 mm according to the actual field situation;

2) determining the weight and angle of the balance weight according to the vibration data; according to the vibration data and the structural parameters of the fan, after the mass and the adding angle of the balance block are determined, marking the corresponding position of the impeller rear disc;

3) the balancing block is additionally arranged at the mark position of the impeller rear disc through the rectangular groove, and the rectangular groove is blocked after the balancing block is additionally arranged.

The invention has at least the following beneficial technical effects:

according to the structure for additionally arranging the balance block on the centrifugal fan impeller, only the square small hole is required to be additionally arranged at the specified position after calculation, the structure is safe and simple, and the normal operation of the fan is not influenced.

The method for additionally arranging the balance block on the centrifugal fan impeller provided by the invention has the advantages that the dynamic balance work of the on-site fan is more convenient, the on-site workload and time are reduced by at least half, and the manpower and material resources are greatly saved. Because the normal dynamic balance work of fan all need open access door, staff get into the inside welding jobs that carries out of fan, work load is great on the one hand, and on the other hand carries out welding jobs in sealed space and also has certain safety risk. According to the dynamic balance weight adding calculation method and the result, welding work is not required to be carried out in the fan, the field workload is greatly reduced, and meanwhile, no operation risk exists basically.

Drawings

FIG. 1 is a schematic view of an additional balance weight assembly according to the present invention;

FIG. 2 is a schematic view of a balancing block mounting structure of the centrifugal fan of the present invention.

Description of reference numerals:

1-impeller back plate;

2-a volute;

3-a rectangular groove;

4-vertical centerline;

5-impeller vertical center line;

6-geometric center;

7-lowest point of edge line of back disk of impeller.

Detailed Description

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict. The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

As shown in figures 1 and 2, the structure for additionally arranging the balance weight on the centrifugal fan impeller comprises a rectangular groove 3 reserved on a volute 2 close to one side of an impeller rear disc 1, wherein a vertical central line 4 of the rectangular groove 3 is parallel to a vertical central line 5 of the impeller, and a geometric center 6 of the rectangular groove 3 is superposed with the lowest point 7 of the edge line of the impeller rear disc. And welding the balance weight with the calculated quality and angle to the impeller rear disc through the rectangular groove 3.

The invention provides a method for additionally arranging a balance block on a centrifugal fan impeller, which comprises the following specific implementation method:

1. and determining the geometric center position and the size of the rectangular groove according to the fan structure. As shown in fig. 1, the geometric center position of the rectangular groove 3 coincides with the lowest point 7 of the impeller back disk edge line. In order to facilitate the installation of the balance weight and not influence other field work, the length and the width of the rectangular groove are recommended to be 30-50 mm and 20-30 mm respectively according to the actual field situation.

2. The weight and angle of the counterweight are determined from the vibration data. And according to the vibration data and the structural parameters of the fan, marking the corresponding position of the impeller rear disc after determining the mass and the adding angle of the balance block.

3. The additional installation of balancing piece and the shutoff of rectangular channel. Install the balancing piece additional through the rectangular channel in impeller back plate mark position, install additional and accomplish the back carry out the shutoff to the rectangular channel can.

Examples

Two centrifugal induced draft fans are arranged in a smoke and air system of a certain 200MW domestic unit, and after the induced draft fans are overhauled and started during overhaul, the vibration of the induced draft fans exceeds the standard. After vibration test frequency spectrum analysis, vibration data show that the fan has obvious fan unbalance problem, and the scheme is solved by a method of additionally installing a balance block.

Because the typhoon machine often has dynamic balance problem, the structure and the scheme provided by the invention are decided to be adopted for balance, and the subsequent dynamic balance work is facilitated. The fan balance device is balanced through the rectangular groove structure, the workload of field workers and tools for air inlet and outlet is reduced, the balance working time of the fan, which originally consumes about 8 hours, is reduced to 4 hours, and a very good effect is achieved.

Although the invention has been described in detail hereinabove with respect to a general description and specific embodiments thereof, it will be apparent to those skilled in the art that modifications or improvements may be made thereto based on the invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed.