JPH07217524A - Lubricating oil cooling device for francis turbine - Google Patents

Abstract

PURPOSE:To improve cooling performance by cooling the lubricating oil in an oil tank, in which a main shaft skirt and a bearing for supporting this main shaft skirt are submerged, by air sucked into a clearance between a labyrinth and a runner boss in a water sealing part at the rotating time of a turbine shaft, through an outer side wall provided with a cooling fin, and the like. CONSTITUTION:An external wall with the upper part connected to the bottom part of a bearing support 6 and with the lower part connected to a labyrinth 11 fitted to an upper cover 10 is provided to surround the outer side wall 7a of an oil tank 7, and an internal wall 14 extended from the bottom plate 7b of the oil tank 7 and facing the shoulder face of a runner boss 2 with a micro clearance is provided in such a way as to surround a turbine shaft 1. A cooling chamber 16 is formed by both internal and external walls 14, 13. At the rotating time of a runner 3, the pressure in a space near a runner boss 2 between the upper cover 10 and the runner 3 becomes negative, so that more air is sucked into an intake pipe 18, and this air is let flow along a cooling fin 17 in the cooling chamber 16 so as to cool lubricating oil, rising in the temperature by the rotation at a bearing 5, through the side wall 7a provided with the cooling fin 17 and the bottom plate 7b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a Francis turbine lubricating oil cooling device for cooling lubricating oil for bearings of a vertical Francis turbine.

[0002]

2. Description of the Related Art A vertical shaft of a Francis turbine is supported by a bearing through a main shaft skirt provided on the hydraulic shaft, and the main shaft skirt and the bearing are immersed in lubricating oil in an oil tank to rotate the water turbine shaft. At this time, the lubricating oil lubricates the rotating portion of the bearing of the main shaft skirt. A vertical Francis turbine equipped with this type of oil tank is known as shown in FIG. In FIG. 3, a vertical turbine shaft 1 is provided with a runner 3 attached to a lower portion by a runner boss 2. A main shaft skirt 4 is provided on the water turbine shaft 1, and the water turbine shaft 1 is supported by bearings 5 via the main shaft skirt 4. The main shaft skirt 4 and the bearing 5 are inserted into an annular oil tank 7 surrounding the water turbine shaft 1 supported by the bearing support 6 and immersed in the lubricating oil 8 in the oil tank 7. A serpentine cooling water pipe 9 through which cooling water flows is arranged in the oil tank 7. A cooling water supply / discharge pipe and a water supply pump (not shown) are connected to the cooling water pipe 9. The runner 3 is covered with an upper cover 10 that surrounds the runner boss 2, and a water sealing portion in which the labyrinth 11 is attached to the upper cover 10 is formed at a penetrating portion where the runner boss 2 penetrates the upper cover 10.

With such a structure, when the water turbine shaft 1 of the vertical Francis turbine is supported by the bearing 5 and rotated by the water flowing through the runner 3, it is lubricated by the lubricating oil 8 in the oil tank 7. At this time, the lubricating oil that rises in temperature in the oil tank 7 due to the rotation of the water wheel shaft 1 is supplied to and discharged from the cooling water supply / discharge pipe by the water supply pump and cooled by the cooling water flowing through the cooling water pipe 9.

Further, when the water wheel shaft 1 rotates, the space in the vicinity of the runner boss 2 between the rotating runner 3 and the upper cover 10 becomes negative pressure, so that the space between the labyrinth 11 and the runner boss 2 in the water sealing part is reduced. Air is taken into the runner 3 through the gap.

[0005]

The lubricating oil 8 in the oil tank 7 which is heated by the rotation of the water wheel shaft 1 is cooled by the cooling water flowing through the cooling water pipe 9. In this case, it is necessary to provide a water supply device in which the cooling water pipe 9 and the cooling water supply / discharge pipe are laid and a water supply pump or the like is arranged, which causes a problem that the facility cost becomes high and the maintenance work becomes long.

An object of the present invention is to provide a lubricating oil cooling device for a vertical Francis turbine capable of reducing the facility cost and omitting maintenance by using the cooling medium instead of the cooling water as the lubricating oil in the oil tank. It is to be.

[0007]

In order to solve the above-mentioned problems, according to the present invention, a main shaft skirt provided on a vertical water wheel shaft and a bearing for supporting the main shaft skirt are inserted, and the main shaft skirt bearing is inserted. The annular oil tank that encloses the turbine axle that is filled with lubricating oil that lubricates the rotating part of the engine, and the runner that is attached to the lower portion of the turbine axle by the runner boss and that surrounds the runner boss. In a lubricating oil cooling device for a Francis turbine, which cools the lubricating oil in the oil tank of the Francis turbine provided with a water seal portion provided with, an opening between an upper part of an outer side wall of the oil tank and the outer side wall is closed. In addition to surrounding, the outer wall that is attached to the upper cover by surrounding the turbine shaft with the gap of the sealing part inside and the outer shaft that extends from the bottom plate of the oil tank surrounds the turbine shaft, and has a minute gap on the shoulder surface of the runner boss. A cooling chamber formed from an inner wall facing to the cooling chamber of the outer wall upper portion air sucked air inlet provided, intended to comprise a plurality of cooling fins provided on the outer sidewall of the oil tank in the cooling chamber.

In the above-described Francis turbine lubricating oil cooling device, the runner boss is projected from the upper cover, and a row of blades of an axial fan is arranged on the outer peripheral surface of the projected runner boss so as to face the water sealing portion. Shall be installed.

[0009]

The main shaft skirt provided on the water wheel shaft and the bearing supporting the water wheel shaft are immersed in the lubricating oil in the annular oil tank surrounding the water wheel shaft, and this lubricating oil lubricates the rotating part of the main shaft skirt bearing. ing. In this case, the opening between the upper part of the outer side wall of the oil tank is closed to surround the outer side wall, and the water turbine shaft is surrounded with the gap of the water sealing part having the labyrinth inside, and the lower end part covers the runner. A cooling chamber formed of an outer wall attached to the upper cover surrounding the runner boss and an inner wall extending from the bottom plate of the oil tank and surrounding the water turbine shaft facing the shoulder surface of the runner boss surrounded by the upper cover with a minute gap. By providing an intake port for sucking air in the upper part of the outer wall of the cooling chamber and a plurality of cooling fins on the outer wall of the oil chamber in the cooling chamber, when water flows through the runner and the water wheel shaft and runner rotate, Since the pressure in the space near the runner boss between the runner and the upper cover becomes a negative pressure, the air is sucked from the intake port of the cooling chamber and flows in the cooling chamber along the outer side wall with the cooling fins of the oil tank, and the labyrinth. From the gap of the seal water portion provided flowing into the runner part.

Therefore, due to the air flowing through the cooling chamber,
Lubricating oil in the oil tank whose temperature is raised by the rotation of the water wheel shaft is cooled via an outer side wall of the oil tank provided with a plurality of cooling fins for improving heat transfer. Further, in the above lubricating oil cooling device, the blade row composed of the blades of the axial fan is disposed on the outer peripheral surface of the runner boss portion protruding from the upper cover so as to face the water sealing portion, so that the shaft accompanying the rotation of the water turbine shaft is rotated. A larger amount of air is taken in through the intake port of the cooling chamber by the fan action due to the rotation of the flow fan, so that the cooling performance is further improved.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a partial sectional view of a vertical Francis turbine equipped with a lubricating oil cooling device according to the first embodiment of the present invention. In FIG. 1 and FIG. 2 described later, the same parts as those of the conventional example of FIG. 1 is different from the conventional example as follows.

An outer side wall 7a of the oil tank 7 is surrounded by an outer side wall 7a of the oil tank 7, and an upper portion thereof is connected to a bottom portion of the bearing support 6, while a lower portion thereof is connected to a labyrinth 11 mounted on an upper cover 10.
a and an outer wall 13 that surrounds the water turbine shaft 1 and a cooling chamber 1 that extends from the bottom plate 7b of the oil tank 7 and that faces the shoulder surface of the runner boss 2 with a minute gap and that surrounds the water turbine shaft 1
6 is provided. In addition, the intake port 1 is provided on the outer wall of the cooling chamber 16.
5 is provided.

Further, on the outer side wall 7a of the oil tank 7, a plurality of rows of cooling fins 17 composed of a plurality of heat transfer plates are provided around the outer side wall 7a. An intake pipe 18 is connected to the intake port 15 and provided. With such a configuration, when water flows into the runner 3 and the water wheel shaft 1 and the runner 3 rotate,
Since the space in the vicinity of the runner boss 2 between the upper cover 10 and the runner 3 has a negative pressure, air is taken in from the intake port 15 via the intake pipe 18. Then, the air taken in is cooled by the cooling chamber 16
It flows inside along the cooling fins 17, and flows into the runner 3 part from the gap between the labyrinth 11 and the runner boss 2 in the water sealing part. Therefore, the lubricating oil whose temperature rises due to the rotation of the bearing 5 of the main shaft skirt 4 of the water turbine shaft 1 by the air flowing in the cooling chamber 16 passes through the outer side wall 7 a provided with the cooling fins 17 of the oil tank 7 and the bottom plate 7 b. To be cooled.

FIG. 2 is a partial sectional view of a vertical Francis turbine equipped with a lubricating oil cooling device according to a second embodiment of the present invention. 2 is the same as FIG. 1 except that a blade row composed of blades 20 of an axial flow fan is arranged on the outer peripheral surface of the runner boss 2 above the labyrinth 11 in FIG. With such a configuration, when water flows into the runner 3 and the water wheel shaft 1 and the runner 3 rotate, the axial fan having the blade row of the blades 20 rotates, and a large amount of air is generated by the fan action. 1 through the intake pipe 18 shown in FIG.
Since it is sucked into the cooling chamber 16 from 5, the cooling performance for cooling the lubricating oil is improved. Therefore, the lubricating oil in the oil tank 7 that lubricates the rotating portion of the bearing 5 of the main shaft skirt 4 of the water turbine shaft 1 is cooled more sufficiently.

[0015]

As is apparent from the above description, according to the first aspect of the present invention, when the water turbine shaft is rotated by the above-mentioned structure,
The air sucked into the gap between the runner boss and the labyrinth of the water sealing part flows in the cooling chamber along the cooling fins attached to the outer side wall of the oil tank, so the water wheel axle is provided via the outer side wall equipped with the cooling fins. The main shaft skirt and the bearing supporting the main shaft skirt are cooled to cool the lubricating oil in the oil tank.

According to the second aspect of the present invention, since the blade rows of the axial fan are arranged on the outer periphery of the runner boss projecting from the upper cover which covers the runner, the fan action of the axial fan due to the rotation of the water turbine shaft is The amount of air taken into the cooling chamber is increased, so that the cooling performance is further improved and the lubricating oil is cooled more sufficiently. As described above, in both claims 1 and 2, the cooling of the lubricating oil is performed by the air taken in, so that maintenance of the cooling device can be omitted and the facility cost can be reduced.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of a vertical Francis turbine equipped with a lubricating oil cooling device according to an embodiment of the present invention.

FIG. 2 is a partial sectional view of a vertical Francis turbine equipped with a lubricating oil cooling device according to an embodiment of claim 2 of the present invention.

FIG. 3 is a partial cross-sectional view of a vertical Francis turbine equipped with a conventional lubricating oil cooling device.

[Explanation of symbols]

 1 Water Turbine Shaft 2 Runner Boss 3 Runner 4 Spindle Skirt 5 Bearing 7 Oil Tank 7a Outer Side Wall 7b Bottom Plate 8 Lubricating Oil 10 Top Cover 11 Labyrinth 13 Outer Wall 14 Inner Wall 15 Inlet 16 Cooling Room 17 Cooling Fin 20 Wing

Claims (2)

[Claims] 1. A main shaft skirt provided on a vertical water wheel shaft and a bearing for supporting the main shaft skirt are inserted to surround a water turbine shaft filled with a lubricating oil for lubricating a rotating portion of the main shaft skirt bearing. Lubrication in the oil tank of the Francis turbine, which includes an annular oil tank and a water seal part provided with a labyrinth in the gap between the runner boss and an upper cover surrounding the runner boss that is attached to the runner boss at the lower part of the water turbine shaft. In a Francis turbine lubricating oil cooling device that cools oil, the opening between the upper part of the outer side wall of the oil tank is closed to enclose the outer side wall, and the gap of the water sealing part is placed inside to enclose the water wheel shaft. A cooling chamber formed by an outer wall attached to the upper cover, an inner wall extending from the bottom plate of the oil tank to surround the water wheel shaft and facing the shoulder surface of the runner boss with a minute gap, and an upper portion of the outer wall of the cooling chamber An intake port for sucking air is provided, lubrication oil cooling apparatus Francis turbine, characterized in that a plurality of cooling fins provided on the outer sidewall of the oil tank in the cooling chamber. 2. The runner boss according to claim 1, wherein the runner boss is projected from the upper cover, and a row of blades of an axial fan is disposed on the outer peripheral surface of the projecting runner boss so as to face the sealing portion. Francis turbine lubricating oil cooling device characterized by.