Anti-condensation structure of hydropower station bubble head vertical shaft

Abstract

An anti-condensation structure of a hydropower station bubble head vertical shaft comprises a vertical shaft, a busbar of a generator arranged in the vertical shaft, a ventilation pipeline and a manhole cover plate located at the bottom of the vertical shaft, a metal layer is arranged on the inner wall of the vertical shaft, a heat preservation and insulation layer is arranged between the metal layer and the wall of the vertical shaft, and the thickness of the heat preservation and insulation layer is 60-80 mm; the ventilation pipeline comprises an exhaust pipe and an air supply pipe, an air inlet of the exhaust pipe extends to the position above an oil-supply head platform in the bulb head, an air outlet of the exhaust pipe is used for being connected with an exhaust fan, and an air outlet of the air supply pipe is located in the upper portion of the vertical shaft, so that the position of the air outlet of the air supply pipe is higher than the air inlet of the exhaust pipe. An air inlet of the air supply pipe is used for being connected with an air blower. A busbar of the generator is fixed on a busbar mounting frame, a plurality of fixing plates for fixing the busbar are arranged on the busbar mounting frame, and each fixing plate is of a big-end-down trapezoidal structure, so that water drops cannot be gathered on the fixing plates; and a plurality of vent holes are formed in the manhole cover plate.

Description

Technical Field

[0001] The utility model relates to the technical field of anti-condensation, in particular to an anti-condensation structure of a bubble head shaft of a hydropower station. Background Art

[0002] The bulb-shaped tubular turbine of a hydroelectric power station is an efficient and reliable hydroelectric generating equipment. The generator of this turbine is installed in a bulb-shaped shell, which is usually called a bubble head. Water flows through the outside of the bubble head, driving the turbine blades at the downstream end of the bubble head to rotate and drive the generator to generate electricity. A vertical shaft is provided at the upper end of the bubble head, which is used to install equipment and provide a passage for workers to enter and exit for maintenance. The busbar of the generator is installed in the shaft.

[0003] Since the outer wall of the bubble head and the outer wall of the shaft are in direct contact with the river water, the temperature of the river water is low, and the generator generates heat when running in the bubble head, making the temperature of the bubble head and the shaft higher. Since the inner wall of the shaft is provided with a metal layer, the thermal conductivity is higher than that of the surrounding non-metallic materials. The lower water temperature outside the shaft is transferred to the inner wall, causing the temperature of the metal inner wall of the shaft to be lower than the water vapor dew point temperature, thereby quickly forming condensation on the metal surface of the inner wall of the shaft, resulting in condensation and water accumulation in the shaft. The condensed water formed by the condensation easily drips onto the busbar at the outlet of the unit, reducing the insulation of the busbar, thereby generating arc discharge at the busbar insulation support or the horizontal section of the generator outlet lead wire. After condensation appears on the inner wall of the shaft, moisture appears around the busbar, resulting in insulation degradation and even grounding short circuit failure, which seriously threatens the safe operation of the unit and affects the power generation efficiency. However, there has been no good way to solve the condensation problem in the shaft of a hydroelectric power station for a long time. Summary of the invention

[0004] The utility model aims to solve the problems existing in the prior art and proposes an anti-condensation structure for a bubble head shaft of a hydropower station. The structure provides a heat-insulating layer between the inner wall of the shaft and the metal layer, multiple exhaust pipes and air supply pipes are arranged in the shaft, a fixing plate of the busbar is arranged as a trapezoidal structure with a small upper part and a large lower part, and a plurality of ventilation holes are arranged on the manhole cover plate, thereby enhancing the exchange efficiency of hot and cold air in the bubble head, greatly reducing the temperature difference and humidity between the inner and outer walls of the shaft, and avoiding condensation.

[0005] The purpose of the utility model is achieved in this way.

[0006] A condensation prevention structure for a bubble head shaft of a hydropower station comprises a shaft arranged above the bubble head, a busbar of a generator arranged in the shaft, a ventilation duct and a manhole cover at the bottom of the shaft, a metal layer is arranged on the inner wall of the shaft, a heat preservation and heat insulation layer is arranged between the metal layer and the shaft wall, and the thickness of the heat preservation and heat insulation layer is 60 to 80 mm; the ventilation duct comprises an exhaust pipe and an air supply pipe, the air inlet of the exhaust pipe extends to the upper side of the oil receiving platform in the bubble head, and the air outlet of the exhaust pipe is used to connect An exhaust fan, the air outlet of the air supply pipe is located in the upper part of the vertical shaft, so that the position of the air outlet of the air supply pipe is higher than the air inlet of the exhaust pipe, and the air inlet of the air supply pipe is used to connect the blower; the busbar of the generator is fixed on the busbar mounting frame, and the busbar mounting frame is provided with a plurality of fixing plates for fixing the busbar, and the fixing plates are in a trapezoidal structure with the upper part being small and the lower part being large, so that water droplets cannot gather on the fixing plates; a plurality of ventilation holes are arranged on the manhole cover plate, so that the hot air in the bubble head can pass through the manhole cover plate to dissipate heat.

[0007] Furthermore, the thermal insulation layer is divided into multiple layers, and the multiple thermal insulation layers are bonded together by adhesive.

[0008] Furthermore, the thermal insulation layer is divided into three layers, wherein the thermal insulation layer close to the metal layer has a thickness of 10 mm, and the thicknesses of the other two thermal insulation layers are both 30 mm.

[0009] Furthermore, the thermal insulation layer is made of polyethylene foam plastic board.

[0010] Furthermore, the metal layer is an aluminum alloy plate.

[0011] Furthermore, two air supply pipes are provided, and one air exhaust pipe is provided.

[0012] Furthermore, the height difference between the air outlet of the air supply pipe and the air inlet of the exhaust pipe is 8 to 10 meters.

[0013] Furthermore, the manhole cover plate is supported above the manhole by a bracket, so that a heat dissipation channel is formed between the manhole cover plate and the manhole.

[0014] Furthermore, the width of the upper end of the fixing plate is the same as the width of each busbar when placed side by side, the width of the lower end of the fixing plate is greater than the width of the upper end, and both sides of the fixing plate are inclined surfaces.

[0015] The anti-condensation structure of the bubble head shaft of the hydropower station of the utility model, the exhaust pipe and the air supply pipe, and the arrangement of the vents on the manhole cover effectively improve the exchange efficiency of the cold and hot air in the bubble head, and a large amount of moisture will be taken away when the hot air is discharged, thereby greatly reducing the humidity of the air in the bubble head; the arrangement of the thermal insulation layer reduces the temperature difference between the inner and outer walls of the shaft, thereby avoiding the formation of condensation on the inner wall of the shaft; the shape of the busbar fixing plate is set to a trapezoidal structure with a small top and a large bottom, so that the condensation on the busbar fixing plate can slide down without forming water accumulation, thereby greatly avoiding the short circuit of the three-phase busbar. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the utility model.

[0017] Figure 2 It is the assembly diagram of busbar, fixing plate and busbar mounting frame.

[0018] Figure 3 It is a schematic diagram of the structure of the manhole cover.

[0019] Explanation of the reference numerals: bubble head 1, vertical shaft 2, busbar 3, manhole cover 4, metal layer 5, thermal insulation layer 6, manhole 7, exhaust pipe 8, air supply pipe 9, busbar mounting frame 10, fixing plate 11, vent 12, bracket 13. DETAILED DESCRIPTION

[0020] See also Figure 1 , an anti-condensation structure of a bubble head shaft of a hydropower station, comprising a shaft 2 arranged above the bubble head 1, and a busbar 3 of a generator arranged in the shaft 2, a ventilation duct and a manhole cover 4 at the bottom of the shaft. A metal layer 5 is provided on the inner wall of the shaft 2, and a thermal insulation layer 6 is provided between the metal layer 5 and the wall of the shaft 2, and the thickness of the thermal insulation layer 6 is 60 to 80 mm; the thermal insulation layer 6 is divided into multiple layers, and the multiple thermal insulation layers 6 are bonded by an adhesive. In this embodiment, the thermal insulation layer 6 is divided into three layers, wherein the thickness of the thermal insulation layer close to the metal layer 5 is 10 mm, and the thickness of the remaining two thermal insulation layers is 30 mm. The thermal insulation layer 6 is made of a polyethylene foam plastic board, and the thermal insulation layer 6 can greatly slow down the heat transfer between the inner and outer walls of the shaft 2, reduce the temperature difference between the inner and outer walls of the shaft 2, and avoid the generation of condensation on the inner wall of the shaft 2. The metal layer 5 is an aluminum alloy plate, and the purpose of providing the aluminum alloy plate is to enhance thermal insulation and improve aesthetics.

[0021] See also Figure 1The ventilation duct includes an exhaust pipe 8 and an air supply pipe 9. The exhaust pipe 8 is used to extract the hot air in the bubble head 1, and the air supply pipe 9 is used to send cold air into the shaft 2 and the bubble head 1. The air inlet of the exhaust pipe 8 extends to the upper part of the oil receiving platform in the bubble head 1, and the air outlet of the exhaust pipe 8 is used to connect the exhaust fan. Since the higher the air temperature, the stronger its ability to carry water vapor, the exhaust pipe 8 extracts the hot air at the heat source of the bubble head 1 and also takes away a large amount of moisture therein, which is beneficial to reduce the humidity of the air in the bubble head 1 and avoid the formation of condensation on the inner wall of the shaft 2. The air outlet of the air supply pipe 9 is located in the upper part of the shaft 2, so that the position of the air outlet of the air supply pipe 9 is higher than the air inlet of the exhaust pipe 8, and the air inlet of the air supply pipe 9 is used to connect the blower; two air supply pipes 9 are provided, and one exhaust pipe 8 is provided. The height difference between the air outlet of the air supply pipe 9 and the air inlet of the exhaust pipe 8 is 8 to 10 meters. The exhaust pipe 8 and the air supply pipe 9 form a circulation convection of cold and hot air, reduce the temperature difference, and avoid the generation of condensation on the inner wall of the shaft 2.

[0022] See also Figure 2 The busbar 3 of the generator is fixed on a busbar mounting frame 10, and a plurality of fixing plates 11 for fixing the busbar are provided on the busbar mounting frame 10. The fixing plates 11 are in a trapezoidal structure with a small top and a large bottom, so that water droplets cannot gather on the fixing plates 11; in this embodiment, the width of the upper end of the fixing plate 11 is the same as the width of each busbar 3 when arranged side by side, and the width of the lower end of the fixing plate 11 is greater than the width of the upper end. The two sides of the fixing plate 11 are inclined surfaces, which facilitates the sliding of accumulated water formed by condensation to avoid short circuit of the three-phase busbar 3.

[0023] See also Figure 3 The manhole cover plate 4 is provided with a plurality of vents 12, so that the hot air in the bubble head 1 can be dissipated through the manhole cover plate 4. In this embodiment, the manhole cover plate 4 is provided with 550 φ18mm vents 12; the manhole cover plate 4 is supported above the manhole 7 by a bracket 13, so that a heat dissipation channel is formed between the manhole cover plate 4 and the manhole 7. The applicant has calculated and verified that the heat dissipation area of ​​the vent 12 is about 0.14m 2 The original manhole area is about 0.3m 2 The area of ​​the heat dissipation channel formed by the heightening of the manhole cover plate 4 is 0.94m 2 , the total heat dissipation area increases to 1.38m 2 , which is 4.6 times the original area. At the same time, a more powerful dehumidifier is set in the bubble head 1, and the dehumidification capacity is 138 liters / day, which greatly increases the dehumidification effect.

[0024] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification made to the present invention by those skilled in the art without departing from the spirit of the present invention shall fall within the protection scope of the present invention.

Claims

1. A condensation prevention structure for a vertical shaft of a hydropower station, comprising a vertical shaft (2) arranged above a bubble head (1), and a busbar (3) of a generator arranged in the vertical shaft (2), a ventilation duct and a manhole cover (4) at the bottom of the vertical shaft, characterized in that: The inner wall of the vertical shaft (2) is provided with a metal layer (5), and a heat-insulating layer (6) is provided between the metal layer (5) and the wall of the vertical shaft (2), and the thickness of the heat-insulating layer (6) is 60 to 80 mm; the ventilation duct comprises an exhaust pipe (8) and an air supply pipe (9), the air inlet of the exhaust pipe (8) extends to the upper part of the oil receiving platform in the bubble head (1), the air outlet of the exhaust pipe (8) is used to connect to the exhaust fan, and the air outlet of the air supply pipe (9) is located in the upper part of the vertical shaft (2), so that the position of the air outlet of the air supply pipe (9) is The manhole cover (4) is provided with a plurality of vent holes (12) so that the hot air in the bubble head (1) can pass through the manhole cover (4) to dissipate heat.

2. The anti-condensation structure of the bubble head shaft of a hydropower station according to claim 1, characterized in that: The thermal insulation layer (6) is divided into multiple layers, and the multiple layers of thermal insulation layer (6) are bonded together by an adhesive.

3. The anti-condensation structure of the bubble head shaft of a hydropower station according to claim 2, characterized in that: The thermal insulation layer (6) is divided into three layers, wherein the thermal insulation layer close to the metal layer (5) has a thickness of 10 mm, and the thicknesses of the other two thermal insulation layers are both 30 mm.

4. The anti-condensation structure of the bubble head shaft of a hydropower station according to any one of claims 1 to 3, characterized in that: The thermal insulation layer (6) is made of polyethylene foam plastic board.

5. The anti-condensation structure of the bubble head shaft of a hydropower station according to claim 1, characterized in that: The metal layer (5) is an aluminum alloy plate.

6. The anti-condensation structure of the bubble head shaft of a hydropower station according to claim 1, characterized in that: Two air supply pipes (9) are provided, and one air exhaust pipe (8) is provided.

7. The anti-condensation structure of the bubble head shaft of a hydropower station according to claim 1 or 6, characterized in that: The height difference between the air outlet of the air supply pipe (9) and the air inlet of the air exhaust pipe (8) is 8 to 10 m.

8. The anti-condensation structure of the bubble head shaft of a hydropower station according to claim 1, characterized in that: The manhole cover plate (4) is supported above the manhole (7) by a bracket (13), so that a heat dissipation channel is formed between the manhole cover plate (4) and the manhole (7).

9. The anti-condensation structure of the bubble head shaft of a hydropower station according to claim 1, characterized in that: The width of the upper end of the fixing plate (11) is the same as the width of each busbar (3) when arranged side by side, the width of the lower end of the fixing plate (11) is greater than the width of the upper end, and both sides of the fixing plate (11) are inclined surfaces.

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