JPH0893623A - Forced-air-cooled bearing of vertical water turbine - Google Patents

Abstract

PURPOSE: To prevent any performance drop through all seasons by inserting one end of plural cooling fins in the hollow hole of the stay vane of a vertical spindle water mill and arranging plural cold air pipes so that the other end can be positioned beneath a bearing oil tank and arranging an exhaust fan for generating an air current flowing from downward to upward on the periphery of the bearing oil tank. CONSTITUTION: The bearing is improved to an air cooling structure in which a cooling area is increased by the installation of plural cooling fins 30 on the outer periphery of a bearing oil tank 19. One end of a cold air pipe 31 bent to a right angle at its intermediate part is inserted in the hollow hole of a stay vane 21 and also an inhaled cold air is blowed out by arranging the other end so as to position beneath the bearing oil tank 19 in order to inhale the cold air, which is the cooling medium of the bearing oil tank 19, on the periphery of a draft tube 25 and near the entrance valve of a water mill 10. Further, an exhaust fan 32 is installed on the upward and outer periphery of the bearing part 13a of a water main spindle 13 in order to discharge an air warmed by the cooling of the bearing oil tank 19. Therefore, cooling efficiency can be improved through all seasons.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a cooling structure for a bearing of a vertical turbine used for power generation, etc., and more particularly to a vertical turbine for cooling the bearing by cold air around the upper portion of the turbine or around the draft tube. Regarding air-cooled bearings.

[0002]

2. Description of the Related Art Generally, in a hydroelectric power plant, a vertical shaft turbine (hereinafter referred to as "turbine") has a flange in which a rotor spindle is provided on each spindle above a turbine spindle mounted on the turbine runner. A rotor of a water turbine generator (hereinafter, referred to as a generator) that is integrally connected via a rotor is rotationally driven to generate electric power.

By the way, as described above, the lower turbine runner and the upper generator rotor, which are integrally connected via the turbine main shaft and the rotor main shaft, are usually provided on the upper rotor main shaft. Two bearings, a thrust bearing and a guide bearing provided on the lower turbine main shaft, are supported as main bearings.

That is, the thrust bearing provided on the upper rotor main shaft suspends the rotor of the generator and the runner of the water turbine, which are integrally connected to each other through the main shaft, to suspend the total weight of both. The guide bearing that is supported and provided on the lower turbine main shaft has a function of suppressing lateral shake that occurs due to the rotation of both. Needless to say, a guide bearing is also provided on the rotor main shaft of the generator, if necessary.

As described above, the rotating part of the generator and the turbine, which are integrated, is supported by the thrust bearing and the guide bearing, but the subject of the present invention is the cooling structure for the guide bearing provided on the turbine main shaft. A vertical shaft turbine having this guide bearing will be described below with reference to the drawings.

FIG. 2 is a schematic vertical sectional view taken along the center line of a conventional vertical shaft turbine for power generation.

In FIG. 2, reference numeral 10 denotes a water turbine, which is generally installed in a water turbine pit 10a provided inside a power plant building. Reference numeral 11 denotes a water wheel runner of the water wheel 10, a part of which is arranged at the center of the spiral casing 12 shown in the drawing. Pressure water for rotationally driving the water turbine runner 11 is introduced into the spiral casing 12 from a water hydraulic line (not shown) via a water turbine inlet valve (not shown). Reference numeral 13 denotes a water turbine main shaft, which is integrally attached to the water turbine runner 11 by a plurality of bolts (not shown), and has a flange 13 at its upper end.
a is provided.

Reference numeral 14 is a rotor main shaft of a water turbine generator (not shown) installed above the water turbine 10, and a flange 14a is provided at the lower end thereof. And the water turbine main shaft 13
And the rotor main shaft 14 are these flanges 13a and 14
and a are integrally connected by a plurality of bolts (not shown).

Reference numeral 15 is an upper cover that covers the upper surface of the water turbine runner 11, and 16 is a lower cover that covers the lower surface. A guide bearing 18 is supported above the upper cover 15 by a bearing stand 17, and the guide bearing 18 allows the water turbine main shaft 1 to be supported.
The outer peripheral surface of the third bearing portion 13b is supported.

A donut-shaped bearing oil tank 19 is provided below the bearing portion 13b of the turbine main shaft 13 and has a central hole through which the turbine main shaft 13 penetrates. It is filled with oil 19a.
19b is the oil surface of the lubricating oil 19a, and the lower parts of the bearing portion 13b of the turbine main shaft 13 and the guide bearing 18 are immersed in the lubricating oil 19a and lubricated by the lubricating oil 19a, as is apparent from the figure. It is configured to be cooled at the same time.

Reference numeral 20 denotes a cooling water pipe which is arranged in the bearing oil tank 19 and through which cooling water taken from an unillustrated water intake is passed, and cooling for cooling the filled lubricating oil 19a. It is a device.

Reference numeral 21 is a stay vane which determines the inflow direction of the pressure water introduced into the spiral casing 12 from a hydraulic conduit (not shown) and further flowing into the water turbine runner 11. Reference numeral 22 denotes a guide vane that controls the flow rate of the pressure water flowing into the water turbine runner 11 by adjusting the opening degree, and the opening degree is adjusted by connecting the upper end of the guide vane shaft 22a extending above the guide vane 22 to the link mechanism. This is performed by connecting the guide ring 24 via 23 and rotating the guide ring 24 by using a servo mechanism (not shown).

Reference numeral 25 is a draft tube connected to the lower part of the water turbine 10, which flows into the water turbine runner 11 and rotationally drives it to discharge the pressure water, which has completed the work, to the discharge channel. In addition, 26 is a water seal for suppressing a leak of a part of the pressure water flowing in during the operation of the water turbine 10 through the gap between the water wheel runner 11 and the upper cover 15 to the upper surface of the upper cover 15. It is a device.

When the vertical shaft turbine 10 having the above-mentioned structure is started and put into an operating state, the turbine runner 11 (the turbine main shaft 13) rotates at the rated rotation speed, but during the operation period, the turbine main shaft 13 has its bearing portion 13b. The guide bearing 18 keeps rotating while suppressing lateral vibration thereof. And the turbine main shaft 1
Since the bearing portion 13b of No. 3 and the guide bearing 18 are immersed in the lubricating oil 19a, a coating film of the lubricating oil 19a is formed between them and the two are sufficiently lubricated. It is impossible to completely suppress the frictional heat generated in the.

Therefore, the lubricating oil 19 is generated by this frictional heat.
The temperature of “a” gradually rises, and eventually exceeds the allowable temperature, which hinders the continued operation of the water turbine 10.
Therefore, usually, a cooling water pipe 20 for cooling the lubricating oil 19a is provided in the bearing oil tank 19, cooling water is taken in through an intake port (not shown), and water is passed through the cooling water pipe 20 to cool the lubricating oil 19a. However, the temperature of the lubricating oil 19a is prevented from exceeding its allowable temperature.

[0016]

However, when the cooling water is passed through the cooling water pipe 20, the lubricating oil 19a is provided.
In the conventional cooling device for cooling the water, the cooling water pipe 20
When the temperature of the lubricating oil 19a rises due to a malfunction of the cooling water device due to the inclusion of foreign matter in the cooling water at the cooling water intake port, or a deterioration of the cooling capacity due to corrosion deterioration of the cooling water pipe 20 or the like. , The performance of the guide bearings 18 is deteriorated, so although not shown, when a monitoring device is provided and each of the above-mentioned problems occurs, these are detected to detect them.
0 was stopped.

In addition, in a hydroelectric power plant under a special environment called Japan, foreign matters are mixed into the cooling water to be taken in various ways due to changes in the climate (four seasons). There is a problem that it is easy to do.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a wind-cooled bearing for a vertical turbine that does not cause deterioration in performance throughout the four seasons.

[0019]

In order to achieve the above-mentioned object, the present invention provides that the bearing portion of the turbine main shaft is supported by a guide bearing supported by a bearing stand, and the bearing portion and the guide bearing are In a bearing of a vertical axis turbine whose lower part is immersed in lubricating oil in a bearing oil tank whose center hole is penetrated by the turbine main shaft, a plurality of cooling fins attached to an outer peripheral surface of the bearing oil tank and an intermediate portion thereof. At a substantially right angle, and one end of which is inserted into the hollow hole of the stay vane of the vertical turbine and the other end of which is arranged below the bearing oil tank to which the plurality of cooling fins are attached. A cold air pipe, and an exhaust fan that is attached to the outer peripheral surface of the turbine main shaft above the bearing portion and that is rotated by the rotation of the turbine main shaft to generate an airflow that goes upward from below around the bearing oil tank, Characterized in that it et configuration.

[0020]

The bearing oil tank filled with lubricating oil has a plurality of cooling fins mounted on the outer peripheral surface of the bearing oil tank to increase the cooling area to form an air-cooling structure. One end communicates with the cool air below the turbine through the hollow hole in the stay vane of the turbine, and the other end is located below the bearing oil tank with an air-cooled structure, and the exhaust fan is located above the bearing of the turbine main shaft. Since the rotation of the main shaft of the water turbine was made to rotate so as to generate an air flow in the vicinity of the bearing oil tank, the cold air below the water turbine was sucked in from a plurality of cold air pipes and discharged below the bearing oil tank. The lubricating oil in the bearing oil tank is efficiently cooled by this cold air.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 is a schematic vertical sectional view taken along the center line of a vertical axis turbine for power generation showing an embodiment of the present invention, and the same parts as those in FIG. 2 are designated by the same reference numerals and their detailed description will be omitted. To do.

In FIG. 1, 10 is a water wheel, 10a is a water wheel pit, 11 is a water wheel runner, 12 is a spiral casing, 1
3 is a turbine main shaft, 13 a is a flange of the turbine main shaft 13, 13 a
Reference numeral b is a bearing portion, 14 is a rotor main shaft of a water turbine generator (not shown), 14a is a flange of the rotor main shaft 14, and 15 is a water turbine 1.
0 upper cover, 16 lower cover, 17 bearing stand, 18 guide bearing, 19 bearing oil tank, 19a lubricating oil, 19b
Is an oil surface of the lubricating oil 19a, 21 is a stay vane, 22 is a guide vane, 22a is a guide vane shaft, 23 is a link mechanism, 24 is a guide ring, 25 is a draft tube, 2
Reference numeral 6 is a water sealing device, which is the same as that shown in FIG.

Next, a configuration of the present invention different from that of FIG. 2 will be described.

First, the cooling water pipe 20 for cooling the lubricating oil 19a arranged in the bearing oil tank 19 in FIG. 2 is omitted. Then, the bearing oil tank 19 is modified into an air-cooled structure in which a plurality of cooling fins 30 are attached to the outer peripheral surface of the bearing oil tank 19 to increase the cooling area.

Further, in order to suck in cool air around the draft tube 25 serving as a cooling medium of the bearing oil tank 19 and in the vicinity of a water turbine inlet valve (not shown), one end of the cold air pipe 31 bent substantially at a middle portion ( (The lower part in the figure) is inserted into the hollow hole of the stay vane 21, and
The other end (the left portion in the drawing) is arranged so as to be located below the bearing oil tank 19 to which the cooling fin 30 is attached, and the sucked cool air is blown out. Needless to say,
It is preferable that a plurality of the cold air pipes 31 are provided along the entire circumference of the stay vane portion of the spiral casing 12, and the tip end thereof is enlarged in a trumpet shape as shown in the drawing.

Further, in order to discharge the above-mentioned cold air (air) which has been warmed by cooling the bearing oil tank 19, an exhaust fan 32 is attached to the outer peripheral surface above the bearing portion 13a of the water turbine main shaft 13, and the above-mentioned cold air pipe is provided. In order to suck the cool air from the cool air 31 and discharge the warm cold air, that is, to distribute the cool air more efficiently, the exhaust fan 32 is provided with a cover 33 whose inner circumferential surface of the central circular hole is close to the water turbine. Pit 1
Attach to the side wall of 0a.

The air-cooled guide bearing 1 according to the present invention having the above structure.
When the water turbine 10 equipped with the water turbine 8 is driven, the exhaust fan 32 attached thereto also rotates due to the rotation of the runner main shaft 13 accompanying the rotation of the water turbine runner 11. The water turbine pit 10 partitioned by the cover 33 by the rotation of the exhaust fan 32
The air in the upper space of the water turbine 10a is discharged upward in the drawing, so that the inside of the water turbine pit 10a has a negative pressure.

Therefore, the cold air around the draft tube 25 and in the vicinity of the water turbine inlet valve (not shown) are sucked in from the lower (opening) ends of the plurality of cold air pipes 31 and open near the lower outer peripheral surface of the donut-shaped bearing oil tank 19. Is discharged from the left end in the figure. The discharged cool air is exhausted by the exhaust fan 32.
Due to the exhaust action, the air current rises in the direction of the runner main shaft 13, that is, toward the center of the water turbine 10 and is discharged into the upper space of the cover 33. Then, the discharged cool air, in the process of rising toward the center of the water turbine 10, has a plurality of cooling fins 30 added thereto to increase the cooling area, and the lubricating oil 19a in the bearing oil tank 19 which has been modified into an air-cooled structure.
The lubricating oil 19a is continuously cooled during the operation period of the water turbine 10.

In this way, the lubricating oil 19a in the bearing oil tank 19 is cooled by the cold air which is always kept at a low temperature around the draft tube 25 and in the vicinity of the water turbine inlet valve (not shown). The temperature rise above the permissible temperature is suppressed. Therefore, the guide bearing 18 does not deteriorate its performance throughout the four seasons, and the stable performance is always maintained.

[0030]

As described above, the present invention has been described in detail. According to the present invention, the cooling of the lubricating oil in the bearing oil tank is omitted by omitting the cooling water piping in the conventional bearing oil tank. Since multiple cooling fins were attached to the air conditioner to modify it to an air-cooled structure with an increased cooling area, and the cooling air around the draft tube and in the vicinity of the turbine inlet valve was always used for cooling, no cooling water device was required. It is possible to solve all problems of water and oil generated by passing the cooling water pipe through the lubricating oil and to simplify the cooling equipment.

Further, since the temperature difference between the cool air around the draft tube and the air near the turbine inlet valve and the air around the turbine guide bearing can always be ensured, the cooling efficiency can be improved and the performance deteriorates throughout the four seasons. You can get the vertical cooling turbine air cooling bearing without any.

[Brief description of drawings]

FIG. 1 is a schematic vertical sectional view taken along the center line of a vertical axis turbine for power generation showing an embodiment of the present invention.

FIG. 2 is a schematic vertical sectional view taken along the center line of a conventional vertical turbine for power generation.

[Explanation of symbols]

 10 Turbine 10a Turbine Pit 11 Turbine Runner 12 Vortex Casing 13 Turbine Main Spindle 13a Turbine Main Spindle Flange 13b Bearing 14 Turbine Generator Rotor Main Spindle 14a Rotor Main Spindle 15 Turbine Top Cover 16 Water Turbine Bottom Cover 17 Bearing Stand 18 Guide bearing 19 Bearing oil tank 19a Lubricating oil 19b Oil surface of lubricating oil 20 Cooling water pipe 21 Stay vane 22 Guide vane 22a Guide vane shaft 23 Link mechanism 24 Guide ring 25 Draft tube 26 Sealing device 30 Bearing oil tank cooling fin 31 Cold air pipe 32 Exhaust fan 33 cover

Claims (1)

[Claims] 1. A bearing oil tank in which a bearing portion of a turbine main shaft is supported by a guide bearing supported by a bearing stand, and lower portions of the bearing portion and the guide bearing are penetrated by a central hole of the turbine main shaft. In a vertical axis turbine bearing immersed in a lubricating oil therein, a plurality of cooling fins attached to the outer peripheral surface of the bearing oil tank and an intermediate portion thereof are bent at substantially right angles, and one end of the cooling fin is a stay vane of the vertical axis turbine. A plurality of cold air pipes, which are inserted into the hollow holes of the turbine and have the other end located below the bearing oil tank to which the plurality of cooling fins are attached, and the outer peripheral surface of the turbine main shaft above the bearing portion. An air-cooling bearing for a vertical-axis water turbine, which is attached to the exhaust turbine and is rotated by the rotation of the main shaft of the water turbine to generate an airflow around the bearing oil tank from below to above.