CN219205120U

CN219205120U - High-altitude high-capacity generator pit electromagnetic shielding structure

Info

Publication number: CN219205120U
Application number: CN202223348626.0U
Authority: CN
Inventors: 张永健; 邓清树; 杨彬; 乐零陵; 刘亚青; 杨杰; 崔磊; 徐则诚; 欧阳友; 郑坤; 林建雄
Original assignee: Tibet Datang Zhala Hydropower Development Co ltd
Current assignee: Tibet Datang Zhala Hydropower Development Co ltd
Priority date: 2022-12-13
Filing date: 2022-12-13
Publication date: 2023-06-16
Anticipated expiration: 2032-12-13

Abstract

The utility model discloses a high-altitude high-capacity generator pit electromagnetic shielding structure, belongs to the technical field of generator pit wall electromagnetic shielding, and aims to solve the problems that a pit wall and an aluminum plate cannot be completely attached, so that civil space is occupied, and lead wires in a main part cannot be compactly arranged. Comprises an aluminum plate and a plurality of conductive members; the plurality of conductive members are embedded on the concrete surface layer of the pit wall at the leading-out side of the main middle lead of the generator, the plurality of bolts penetrate through the aluminum plate and are connected with the plurality of conductive members in one-to-one correspondence, and the aluminum plate is connected with the pit wall through the magnetic paint layer. The pit wall and the aluminum plate are completely attached through the magnetic paint layer, so that the pit wall and the aluminum plate basically occupy no civil space, and are particularly suitable for the requirement of large electric distance under the high-altitude condition.

Description

High-altitude high-capacity generator pit electromagnetic shielding structure

Technical Field

The utility model belongs to the technical field of electromagnetic shielding of generator pit walls, and particularly relates to an electromagnetic shielding structure of a high-altitude high-capacity generator pit.

Background

The hydraulic generator is arranged in a pit wall, and the pit wall is of a reinforced concrete structure. The main middle lead of the generator needs to be led out of the pit wall through a copper bar and a cable. The main mid-lead is passed through the generator rated current, which will create a magnetic field. Due to the fact that the distance between the outgoing line and the machine pit wall steel bars is relatively short, heat dissipation of the steel bars in the machine pit wall is poor, and the like, the alternating magnetic field forms vortex on surrounding metal components including the steel bars in the machine pit wall, and the vortex causes the components to generate heat so as to cause the problems of reduced structural strength, oxidation, accelerated aging and the like of the components, so that safe and stable operation of the whole power station is affected. Therefore, electromagnetic shielding measures are required for the reinforcing bars to suppress the temperature rise thereof.

The electromagnetic shielding measures of the pit wall generally arrange an electromagnetic shielding device on the inner side of the pit wall, and the device has a structure of one layer of aluminum plate or one layer of aluminum plate plus one layer of steel plate, wherein the thickness of the aluminum plate is 6-10 mm, and the thickness of the steel plate is 3-5 mm. A certain interval is arranged between the aluminum plate and the steel plate, and the interval width is 5 mm-15 mm. Along with the unit capacity of technical hydraulic generator is bigger and bigger, the patent of publication No. CN110556959B proposes a new "one deck aluminum plate + multilayer silicon steel sheet" electromagnetic shield structure, including parallel stack laminating multilayer silicon steel sheet and one deck aluminum plate that sets up, stacks fixed connection in proper order forms integrated shielding structure, and this mode can produce better shielding effect.

However, in high altitude areas, the reduction of air pressure and air density causes the reduction of air medium cooling effect, which has serious influence on electric appliances using natural convection, forced ventilation or air heat dissipation as main heat dissipation modes. Relevant plateau study reports indicate that: in the altitude range of 5000m, the average air pressure is reduced by 7.7-10.5 kPa and the temperature rise is increased by 3-10% when the air pressure is increased by 1000 m. Considering ventilation and heat dissipation in the secondary pit, the arrangement of the leading-out wires in the main and the secondary pits is expected to be compact, and the air duct is not influenced; but the more compact the arrangement, the higher the corresponding requirements for shielding of the large current transformer, electromagnetic shielding in the pit and the like. Therefore, in high altitude areas, the requirement for the civil space is higher. By adopting the electromagnetic shielding structure, although a better shielding effect can be generated, the pit wall and the aluminum plate still cannot be completely attached, so that the civil space is occupied, and the arrangement of the lead wires in the main part cannot be compact.

Disclosure of Invention

The utility model aims to provide a high-altitude high-capacity generator pit electromagnetic shielding structure, which solves the problems that a pit wall and an aluminum plate cannot be completely attached, so that the civil space is occupied, and the arrangement of lead wires in a main part cannot be compact. The technical scheme adopted by the utility model is as follows:

an electromagnetic shielding structure of a high-altitude high-capacity generator pit comprises an aluminum plate and a plurality of conductive members; the plurality of conductive members are embedded on the concrete surface layer of the pit wall at the leading-out side of the main middle lead of the generator, the plurality of bolts penetrate through the aluminum plate and are connected with the plurality of conductive members in one-to-one correspondence, and the aluminum plate is connected with the pit wall through the magnetic paint layer.

Further, the conductive member is a steel column, a flange is arranged at the inner end of the steel column, the outer end of the steel column is flush with the pit wall, and a screw hole is formed in the outer end face of the steel column.

Further, the thickness of the magnetic paint layer is 1 mm-3 mm.

Compared with the prior art, the utility model has the beneficial effects that:

1. the pit wall and the aluminum plate are completely attached through the magnetic paint layer, so that the pit wall and the aluminum plate basically occupy no civil space, and are particularly suitable for the requirement of large electric distance under the high-altitude condition.

2. The equivalent relative magnetic permeability of the magnetic paint layer is far greater than that of a non-magnetic conductive material or a steel plate, an ultrahigh magnetic conduction path is constructed in the space range of the magnetic leakage field by utilizing the high magnetic permeability characteristic of the non-magnetic conductive material or the steel plate, and the distribution of the space magnetic field is changed, so that the magnetic leakage flux entering the steel bar originally enters the magnetic paint layer to prevent the steel bar from being heated.

Drawings

FIG. 1 is a schematic diagram of the structure of the present utility model;

FIG. 2 is a schematic structural view of a conductive member;

FIG. 3 is a graph of spatial magnetic field distribution without electromagnetic shielding structure;

FIG. 4 is a spatial magnetic field distribution diagram of an electromagnetic shielding structure of "one layer of aluminum plate+multiple layers of silicon steel sheets";

fig. 5 is a spatial magnetic field profile of the present utility model.

In the figure: 1-aluminum plate, 2-magnetic paint layer, 3-conductive component, 31-flange, 32-screw hole, 4-machine pit wall, 5-shielding device, 6-copper bar and 7-steel bar.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the present utility model more apparent, the present utility model is described below by means of specific embodiments shown in the accompanying drawings. It should be understood that the description is only illustrative and is not intended to limit the scope of the utility model. In addition, in the following description, descriptions of well-known structures and techniques are omitted so as not to unnecessarily obscure the present utility model.

The connection mentioned in the utility model is divided into fixed connection and detachable connection, wherein the fixed connection is a conventional fixed connection mode such as folding connection, rivet connection, bonding connection, welding connection and the like, the detachable connection comprises a conventional detachable mode such as bolt connection, buckle connection, pin connection, hinge connection and the like, and when a specific connection mode is not limited, at least one connection mode can be found in the conventional connection mode by default to realize the function, and the person skilled in the art can select the function according to the needs. For example: the fixed connection is welded connection, and the detachable connection is bolted connection.

The present utility model will be described in further detail below with reference to the accompanying drawings, the following examples being illustrative of the present utility model and the present utility model is not limited to the following examples.

Examples: as shown in fig. 1-5, the pit wall 4 is of a reinforced concrete structure, the pit wall 4 is sequentially provided with a base layer, a bottom layer, a middle layer and a concrete surface layer from inside to outside, steel bars 7 are arranged in the base layer, the pit wall 4 is arranged around the hydraulic generator, and main middle leads of the hydraulic generator are led out of the pit wall 4 through copper bars 6 and cables.

The electromagnetic shielding structure of the high-altitude high-capacity generator pit comprises an aluminum plate 1 and a plurality of conductive members 3; the plurality of conductive members 3 are embedded on a concrete surface layer of the pit wall 4 at the lead-out side of the main middle lead of the generator, the plurality of bolts penetrate through the aluminum plate 1 to be connected with the plurality of conductive members 3 in one-to-one correspondence, and the aluminum plate 1 is connected with the pit wall 4 through the magnetic paint layer 2.

The conductive member 3 is a steel column, the inner end of the steel column is provided with a flange 31, the outer end of the steel column is flush with the pit wall 4, and the outer end face of the steel column is provided with a screw hole 32.

The thickness of the magnetic paint layer 2 is 1 mm-3 mm. The relative permeability is above 100.

Brushing a magnetic paint layer 2 on one side of the aluminum plate 1 close to the inner wall of the pit wall 4, fixing the aluminum plate 1 on a plurality of conductive members 3 pre-buried in the pit wall 4 through bolts, completely attaching the magnetic paint layer 2 to the end face of the aluminum plate 1 and the pit wall 4 after solidification,

the principle of electromagnetic heating of the steel bars 7 in the pit wall 4 is as follows: and a large current flows through the main middle lead, and a leakage magnetic field is formed in the surrounding space. The steel bars in the pit wall are influenced by magnetic leakage to generate vortex so as to generate heat.

The equivalent relative magnetic permeability of the magnetic paint layer 2 is far greater than that of a non-magnetic conductive material or a steel plate, an ultrahigh magnetic conduction path is constructed in the space range of a magnetic leakage field by utilizing the high magnetic permeability characteristic of the non-magnetic conductive material or the steel plate, and the distribution of the space magnetic field is changed, so that the magnetic leakage flux originally entering the reinforcing steel bar 7 enters the magnetic paint layer 2.

Fig. 3 to 5 compare magnetic field space distribution diagrams of an electromagnetic shielding structure without electromagnetic shielding means, "one-layer aluminum plate+multi-layer silicon steel sheet" and an electromagnetic shielding structure of the present utility model. The electromagnetic shielding device is not contained relatively, so that the space magnetic leakage is changed, more magnetic force lines enter the electromagnetic shielding device, and the shielding effect is basically the same as that of a layer of aluminum plate and a plurality of layers of silicon steel sheets. Meanwhile, the magnetic paint layer 2 is directly brushed on one side of the aluminum plate 1, which is close to the pit wall 4, so that the aluminum plate 1 is completely attached to the pit wall 4, the installation is more convenient, the civil engineering area is not occupied, and the requirements of large electric distance under the high altitude condition are met.

The aluminum plate 1, the magnetic paint layer 2 and the plurality of conductive members 3 form a shielding device 5; the shielding device 5 constructs an ultrahigh magnetic conduction path in the space range of the magnetic leakage field, and changes the distribution of the space magnetic field so that the magnetic leakage flux which intentionally enters the reinforcing steel bars 7 enters the magnetic paint layer 2; the magnetic force lines vertically penetrate through the aluminum plate 1 and enter the magnetic paint layer 2, current is induced in the aluminum plate 1, and the induced current also generates reverse magnetic leakage so as to counteract the magnetic leakage generated by the original copper bar 6.

The above embodiments are only illustrative of the present patent and do not limit the protection scope thereof, and those skilled in the art can also change the parts thereof, which are within the protection scope of the present patent without exceeding the spirit of the present patent.

Claims

1. The utility model provides a high altitude high capacity generator pit electromagnetic shield structure which characterized in that: comprises an aluminum plate (1) and a plurality of conductive members (3); the plurality of conductive members (3) are embedded on a concrete surface layer of the pit wall (4) at the lead-out side of the main middle lead of the generator, the plurality of bolts penetrate through the aluminum plate (1) to be connected with the plurality of conductive members (3) in one-to-one correspondence, and the aluminum plate (1) is connected with the pit wall (4) through the magnetic paint layer (2).

2. The high altitude mass power generator pit electromagnetic shielding structure of claim 1, wherein: the conductive member (3) is a steel column, the inner end of the steel column is provided with a flange (31), the outer end of the steel column is flush with the pit wall (4), and the outer end face of the steel column is provided with a screw hole (32).

3. The high-altitude high-capacity generator pit electromagnetic shielding structure according to claim 1 or 2, wherein: the thickness of the magnetic paint layer (2) is 1 mm-3 mm.