JPH1169720A - Bearing lubricator for generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure the quantity of lubricant being returned back to a shaft sealing oil supply by preventing reverse flow of shaft sealing discharge oil into bearing lubrication piping from the outside of machine during single operation of the shaft sealing oil supply. SOLUTION: The bearing lubricator for generator comprises a shaft sealing section 4 for preventing leakage of cooling gas to the outside of a generator 1 by pressure lubrication from a shaft sealing oil supply 8, and a bearing 3 subjected to forced lubrication from the outside of the generator through bearing lubrication piping 10 wherein the shaft sealing section 4 is disposed closely to the bearing 3 and a reverse oil flow preventer 20 is disposed closely to the inlet of the bearing lubrication piping 10 to the bearing 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing lubrication system and method for a generator in which a cooling gas is sealed, such as a hydrogen gas-cooled turbine generator.

[0002]

2. Description of the Related Art Conventionally, in a large generator, hydrogen gas is used as a cooling gas in the machine, and in order to seal the hydrogen gas in the machine, a gas is supplied from a shaft sealing oil supply device installed outside the machine. It is generally known to have a shaft seal to which pressurized oil is supplied.

FIG. 5 is a system diagram showing a state during normal operation in a conventional bearing oil supply device for a generator, FIG. 6 is an explanatory view showing a state in which oil is supplied to a bearing gap during normal operation, and FIG.
FIG. 8 is a system diagram showing a state in which a shaft oil supply device is operated alone in a conventional bearing oil supply device of a generator. FIG. It is explanatory drawing which shows a mode that bearing oil flows into a hole and flows backward.

As shown in FIG. 5, both ends of a rotor 2 of a generator 1 are supported by bearings 3, and a cooling gas such as hydrogen gas sealed inside the generator 1 is distributed near the bearings 3. The provided shaft seal portion 4 prevents leakage to the outside of the machine.

[0005] First, the normal operation of a conventional bearing lubricating device for a generator will be described with reference to FIGS. 5 and 6.

The bearing 3 is supplied with oil usually pressurized to 1 to ² kg / cm ² by a bearing oil pump from a bearing oil tank (not shown). As shown in FIG. 6, the oil supplied to the bearing 3 is guided to the bearing gap 7 from the bearing oil supply hole 6 of the horizontal bearing division surface 5. On the other hand, the shaft sealing oil supply device 8 is supplied with oil to a vacuum tank 12 in the shaft sealing oil supply device 8 by an oil supply pipe 11 branched from a bearing oil supply pipe 10 through a bearing oil supply mother pipe 9 as shown in FIG. You. The vacuum tank 12 is maintained at a vacuum by a vacuum pump 13 in order to ensure the cleanliness of oil.

[0007] The oil supplied to the shaft sealing oil supply device 8 is pressurized to an appropriate value by a shaft sealing oil supply pump 14 and a pressure regulating valve 15 installed in the shaft sealing oil supply device 8, and the shaft sealing oil is supplied. It is supplied to the shaft sealing part 4 in the generator 1 via the supply pipe 8a. The oil drained from the shaft seal 4 to the outside of the machine joins the bearing oil drained from the bearing 3 and is discharged to the air extraction tank 16. The oil drained from the shaft sealing portion 4 to the inside of the machine is discharged to the air extraction tank 16 through the expansion tank 17 and the float trap 18.

Here, the oil discharged to the air extraction tank 16 is disposed below the air extraction tank 16 due to the pressure effect because the oil is supplied from the bearing oil supply system to the vacuum tank 12. After passing through the U-shaped tube portion 19, it returns to a bearing oil tank (not shown).

On the other hand, the generator 1 has several operation modes other than the normal operation. When the plant is shut down for a relatively short period of time, the bearing oil pump and other auxiliary power consumption are reduced, bearing lubrication is stopped to simplify maintenance, and the generator 1 is installed inside the generator 1 to reduce in-machine hydrogen gas consumption. Hydrogen gas may be left sealed.

In this case, the shaft sealing oil supply device 8 alone supplies the shaft sealing oil while the bearing oil supply is stopped.

The operation of the shaft sealing oil supply device 8 at the time of independent operation will be described with reference to FIG. The supply of the shaft sealing oil from the shaft sealing oil supply device 8 to the shaft sealing portion 4 and the subsequent flow of oil draining outside and inside the machine are the same as those in the normal operation. However, in this case, since the outer-side shaft sealing oil and the inner-side shaft sealing oil discharged into the air extraction tank 16 do not supply oil to the vacuum tank 12 from the bearing oil supply system, the pressure effect causes the air extraction tank 16 to drain. To the vacuum tank 12. Thus, the discharge and return from the shaft sealing oil supply device 8 are balanced.

[0012]

However, when the shaft sealing oil supply device 8 is operated alone as described above, outside oil from the shaft sealing portion 4 flows into the bearing oil supply pipe 10,
In some cases, the shaft seal oil supply device 8 does not return.

The oil flow at this time will be described with reference to FIG. As shown in FIG. 8, the oil discharged from the shaft seal portion 4 to the outside of the machine flows on the surface of the rotor 2 of the generator 1, and since the supply of the bearing is stopped, the bearing of the bearing 3 located in the vicinity is stopped. It flows into the gap 7. Further, the oil flowing into the bearing gap 7 is
The bearing lubrication pipe 10 extends from the bearing lubrication hole 6 in the bearing horizontal division surface 5.
And flows back through the bearing oil supply pipe 10 to return to a bearing oil supply system such as a bearing oil pump and a bearing oil tank (not shown).

Therefore, the amount of return from the shaft sealing oil supply device 8 is insufficient with respect to the discharge amount, and the oil level of the vacuum tank 12 in the shaft sealing oil supply device 8 can be maintained at a constant level. However, there is a problem that the reliability as a bearing lubrication device is low.

The present invention has been made in consideration of the above-described circumstances, and prevents the shaft-sealing oil supply device from reversely flowing into the bearing oil supply pipe when the shaft-sealing oil supply device is operated alone to prevent shaft sealing. An object of the present invention is to provide a reliable bearing oil supply device for a generator by ensuring a return oil amount to an oil supply device.

[0016]

In order to solve the above-mentioned problems, a first aspect of the present invention is a shaft sealing oil supply device for preventing leakage of a cooling gas outside a generator in which a cooling gas is sealed. The bearing lubricating device of a generator having a shaft seal portion prevented by pressurized lubrication from outside and a bearing forcibly lubricated from outside the machine via a bearing lubrication pipe, and the shaft seal portion is installed near the bearing. An oil backflow prevention device is provided near an inlet of the bearing in the bearing oil supply pipe.

According to a second aspect of the present invention, the oil backflow prevention device provided on the bearing oil supply pipe according to the first aspect is a check valve.

A third aspect of the invention is characterized in that the oil backflow prevention device provided on the bearing oil supply pipe according to the first aspect is a manual valve.

According to a fourth aspect of the present invention, in the bearing lubrication system for a generator according to the first aspect, the oil backflow prevention device provided on the bearing lubrication pipe is an automatic valve, and the automatic valve is opened and closed by remote control. A device is provided.

According to a fifth aspect of the present invention, in the bearing lubrication system for a generator according to the fourth aspect, the valve opening / closing device is controlled based on the generator operation mode, and a detection unit for detecting the generator operation mode is provided. It is characterized by.

According to a sixth aspect of the present invention, in the bearing lubricating device for a generator according to the fifth aspect, the detecting section detects a first detecting section for detecting a bearing lubricating pressure and a gas pressure in the generator or a shaft sealing lubricating lubricating pressure. And a second detection unit for detecting
And a calculating unit for calculating the generator operation mode based on the bearing oil supply pressure detected by the detection unit and the gas pressure in the generator or the shaft sealing oil supply pressure detected by the second detection unit. Features.

According to a seventh aspect of the present invention, in the bearing lubricating apparatus for a generator according to the first aspect, the bearing lubrication pipe is provided near a bearing inlet portion.
A high position portion higher than the generator center position is provided.

According to an eighth aspect of the present invention, in the bearing oil supply device for a generator according to the first aspect, the shaft seal oil supply device is supplied with oil from a bearing oil supply system, and an oil supply pipe and a bearing oil supply pipe to the shaft seal oil supply device are provided. A reverse slope portion is provided on a bearing oil supply mother pipe between the branch portion of the bearing oil supply system and a bearing oil tank and a bearing oil supply pump on the bearing oil supply system.

[0024]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a system diagram showing a bearing oil supply device for a generator according to a first embodiment of the present invention. Parts that are the same as or correspond to those of the conventional configuration will be described using the same reference numerals as in FIGS.

As shown in FIG. 1, both ends of the rotor 2 of the generator 1 are supported by bearings 3, and a cooling gas such as hydrogen gas sealed in the generator 1 is distributed near the bearing 3. The provided shaft seal portion 4 prevents leakage to the outside of the machine.

The bearing 3 is forcibly supplied with oil pressurized by a bearing oil pump from a bearing oil tank, which is a bearing oil supply system (not shown). Further, the vacuum tank 1 in the shaft sealing oil supply device 8 is connected to the shaft sealing oil supply device 8 by an oil supply pipe 11 branched from a bearing oil supply pipe 10 via a bearing oil supply mother pipe 9.
2 is refueled. The vacuum tank 12 is maintained at a vacuum by vacuum degassing hydrogen gas, air, and the like with a vacuum pump 13 in order to ensure the cleanliness of oil.

Further, the oil supplied to the shaft sealing oil supply device 8 is pressurized to an appropriate value by a shaft sealing oil supply pump 14 and a pressure regulating valve 15 installed in the shaft sealing oil supply device 8. The oil is supplied to the shaft sealing portion 4 in the generator 1 through the oil supply pipe 8a. The oil drained from the shaft seal 4 to the outside of the machine (air side)
It merges with the bearing oil drained from the bearing 3 and is discharged to the air extraction tank 16. Further, the oil drained from the shaft sealing portion 4 to the inside of the machine (the hydrogen gas side) is discharged to the air extraction tank 16 through the expansion tank 17 and the float trap 18.

Here, the oil discharged to the air extraction tank 16 is supplied from the bearing oil supply system to the vacuum tank 12. It returns to the bearing oil tank (not shown) through the pipe section 19.

In the present embodiment, an oil backflow prevention device 20 is provided near the inlet of the bearing 3 of the bearing oil supply pipe 10. As the oil backflow prevention device 20, for example, a check valve 20a or a manual valve 20b is selected.

Next, the operation of the present embodiment will be described.

When lubrication to the bearing 3 is stopped, the bearing 3
The shaft sealing and draining oil on the outer side of the machine that has flowed back through the bearing oil supply pipe 10 through the bearing oil supply hole 6 of the bearing horizontal division surface 5 is blocked by the oil backflow prevention device 20 (the check valve 20a or the manual valve 20b). . At this time, when the manual valve 20b is adopted, it is closed.

As described above, according to the present embodiment, when the oil supply to the bearing 3 is stopped, the outside shaft sealing oil discharged through the bearing oil supply pipe 10 flows back to the unillustrated bearing oil pump and the bearing oil tank. Therefore, it is possible to ensure the same return amount as the amount discharged from the shaft sealing oil supply device 8.

Here, when the check valve 20a is adopted,
It can be used irrespective of the generator operation mode such as the operation or stop of bearing refueling. However, when the manual valve 20b is employed, it is necessary to open the bearing lubrication during operation and close it during stop lubrication. However, in this case, the check valve 20a
There is an advantage that opening and closing of the bearing oil supply pipe 10 is more reliable than the case where is adopted.

FIG. 2 is a system diagram showing a bearing oil supply device for a generator according to a second embodiment of the present invention. The same parts as those in the first embodiment will be described with the same reference numerals.
The same applies to the following embodiments.

In the second embodiment, as shown in FIG. 2, an automatic valve 21 is provided near the inlet of the bearing 3 of the bearing oil supply pipe 10 as an oil backflow prevention device. The bearing oil supply pipe 10 is provided with a detector 22a as a first detector for detecting the bearing oil supply pressure.
A detection unit 22b as a second detection unit for detecting the gas pressure inside the generator 1 or the shaft sealing oil supply pressure is attached to a.

Further, the generator operation mode is calculated by the calculation unit 23 based on the bearing oil supply pressure detected by the detection unit 22a and the gas pressure in the generator or the shaft sealing oil supply pressure detected by the detection unit 22b. You. This operation unit 2
The generator operation mode calculated in 3 is sent to the valve opening / closing device section 24, and the valve opening / closing device section 24 is configured to remotely output an open / close signal of the automatic valve 21 according to the generator operation mode. .

Next, the operation of the present embodiment will be described.

Based on the bearing oil supply pressure detected by the two detectors 22a and 22b and the gas pressure in the generator or the shaft oil supply oil pressure, the operation mode of the operation of the operation of the operation of the operation of the operation of the operation of the operation, the operation of the operation of the oil supply of the shaft, and the operation of the operation of the operation. The arithmetic unit 23 detects whether or not the oil is discharged from the outer side of the shaft and flows back through the bearing oil supply pipe 10 through the bearing oil supply hole 6 of the bearing horizontal division surface 5 of the bearing 3. The valve opening / closing device 24 sends an output signal to the automatic valve 21 based on the calculation result, and the automatic valve 21 performs an opening / closing operation. Therefore, the shaft sealing and draining oil that flows back through the bearing oil supply pipe 10 through the bearing oil supply hole 6 of the horizontal bearing division surface 5 when the bearing oil supply is stopped is blocked by the automatic valve 21.

That is, when the bearing oil supply pressure is low and the gas pressure in the generator or the shaft seal oil supply pressure is high, the bearing oil supply is stopped and the shaft seal oil supply is in operation. It is determined that the state is such that the bearing oil supply pipe 10 flows backward through the bearing oil supply hole 6 of the bearing horizontal division surface 5 and the automatic valve 21 is closed. In any other state, it is determined that the outside shaft sealing and draining oil is not in a backflow state, and the automatic valve 2
1 is open.

As described above, according to the present embodiment, the operation mode of the generator relating to the operation and stop of the bearing lubrication and the shaft sealing lubrication is reliably detected, and the opening and closing of the bearing lubrication pipe 10 is automatically performed by remote control. Therefore, the same return amount as the discharge amount from the shaft sealing oil supply device 8 can be secured.

FIG. 3 is a system diagram showing a bearing lubrication device for a generator according to a third embodiment of the present invention. In the third embodiment, between the bearing oil supply mother pipe 9 and the bearing 3 inlet,
In the vicinity of the bearing inlet portion of the bearing oil supply pipe 10, a high position portion 25 higher than the center position of the generator 1 is provided.

Next, the operation of the present embodiment will be described.

When the bearing lubrication is stopped, the bearing lubrication pipe 10 passes through the bearing lubrication hole 6 of the bearing horizontal division surface 5 of the bearing 3.
Since the outer-side shaft sealing oil that has flowed back flows due to its potential energy, it cannot flow past the high position portion 25 that is higher than the bearing horizontal division surface 5, and is blocked at this high position portion 25. Can be

As described above, according to the present embodiment, if there is a slight pressurization, the gas can flow in the forward direction beyond the high position portion 25. Therefore, the same operation as in the above-described embodiment in which the bearing oil supply pipe 10 is opened and closed can be performed, and the same return amount as the amount discharged from the shaft sealing oil supply device 8 can be secured.

FIG. 4 is a system diagram showing a bearing lubrication device for a generator according to a fourth embodiment of the present invention. In the fourth embodiment, a branch portion 26 of the bearing oil supply pipe 10 to the bearing 3 and the oil supply pipe 11 to the shaft sealing oil supply device 8 on the bearing oil supply mother pipe 5, a bearing oil pump and a bearing oil (not shown) A reverse slope 27 is provided on the bearing oil supply mother pipe 9 between the bearing oil supply system such as a tank.

Next, the operation of the present embodiment will be described.

When the bearing lubrication is stopped, the bearing lubrication pipe 10 passes through the bearing lubrication hole 6 of the bearing horizontal division surface 5 of the bearing 3.
The outside shaft seal drainage oil which has flowed back flows through the potential energy, and therefore does not exceed it in the reverse slope portion 27,
The operation returns to the shaft sealing oil supply device 8.

As described above, according to the present embodiment, when the bearing lubrication is stopped, the outer shaft sealing and draining oil is discharged from the bearing lubrication pipe 10.
Does not flow into the bearing oil supply system and returns to the shaft sealing oil supply device 8, so that the same amount of return as the amount discharged from the shaft sealing oil supply device 8 is achieved without complicating the structure. Quantity can be secured.

[0050]

As described above, according to the first aspect of the present invention,
According to the above, the leakage of the cooling gas to the outside of the generator with the cooling gas sealed inside is prevented by pressurized lubrication from the shaft sealing oil supply device, and the bearing is forced through the bearing oil supply pipe from outside the machine A bearing lubricating device for a generator having a lubricated bearing and a shaft sealing portion installed near the bearing, wherein an oil backflow prevention device is provided near an inlet of the bearing of the bearing lubrication pipe. In the state where lubrication is stopped and shaft seal lubrication is in operation, even if the outside shaft seal draining oil from the shaft seal part flows into the bearing lubrication hole on the horizontal split surface of the bearing, backflow to the bearing lubrication system is prevented. Therefore, the same return amount as the discharge amount from the shaft sealing oil supply device can be secured. As a result, the oil level of the vacuum tank in the shaft sealing oil supply device can be kept constant, and a highly reliable bearing oil supply device for a generator can be obtained.

According to the second aspect, the oil reverse flow prevention device provided on the bearing oil supply pipe according to the first aspect is a check valve, so that the same effect as the first aspect is obtained.

According to the third aspect, the oil backflow prevention device provided on the bearing oil supply pipe according to the first aspect is a manual valve. More sure.

According to a fourth aspect of the present invention, in the bearing oil supply device for a generator according to the first aspect, the oil backflow prevention device provided on the bearing oil supply pipe is an automatic valve, and the automatic valve is opened and closed by remote control. By providing the valve opening / closing device, in addition to the effect of claim 1, it is possible to automatically open and close the bearing oil supply pipe by remote control.

According to a fifth aspect of the present invention, in the bearing lubricating device for a generator according to the fourth aspect, the valve opening / closing device is controlled based on the generator operation mode, and provided with a detection unit for detecting the generator operation mode. Thus, it is possible to reliably detect the operation mode of the generator related to the operation and stop of the bearing lubrication and the shaft sealing lubrication.

According to a sixth aspect of the present invention, in the bearing lubricating device for a generator according to the fifth aspect, the detecting section includes a first detecting section for detecting a bearing lubricating pressure, and a gas pressure in the generator or a shaft sealing oil lubricating. And a second detection unit for detecting pressure, based on the bearing oil supply pressure detected by the first detection unit and the gas pressure in the generator or the shaft sealing oil supply pressure detected by the second detection unit. The same effect as in claim 5 can be obtained by providing a calculation unit for calculating the generator operation mode.

According to a seventh aspect of the present invention, in the bearing lubricating device for a generator according to the first aspect, a high position portion higher than the center position of the generator is provided near the bearing inlet of the bearing lubrication pipe. The same operation as that for opening and closing the bearing oil supply pipe can be performed without depending on the generator operation mode such as operation or stop of oil supply.

According to an eighth aspect of the present invention, in the bearing oil supply device for a generator according to the first aspect, oil is supplied to the shaft sealing oil supply device from a bearing oil supply system, and an oil supply pipe and a bearing oil supply pipe to the shaft seal oil supply device are provided. The structure can be simplified by providing the reverse slope portion on the bearing oil supply mother pipe between the branch portion of the bearing oil tank and the bearing oil supply pump on the bearing oil supply system.

[Brief description of the drawings]

FIG. 1 is a system diagram showing a bearing oil supply device for a generator according to a first embodiment of the present invention.

FIG. 2 is a system diagram showing a bearing lubrication device for a generator according to a second embodiment of the present invention.

FIG. 3 is a system diagram showing a bearing lubrication device for a generator according to a third embodiment of the present invention.

FIG. 4 is a system diagram showing a bearing lubrication device for a generator according to a fourth embodiment of the present invention.

FIG. 5 is a system diagram showing a state during normal operation in a conventional bearing oil supply device for a generator.

FIG. 6 is an explanatory diagram showing a state in which oil is supplied to a bearing gap during normal operation.

FIG. 7 is a system diagram showing a state in which a shaft sealing oil supply device is operated alone in a conventional bearing oil supply device for a generator.

FIG. 8 is an explanatory view showing a state in which when the bearing lubrication is stopped, the outer-side shaft sealing and draining oil flows into the lubrication hole in the horizontal split surface of the bearing and flows back through the bearing lubrication.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Generator 2 Rotor 3 Bearing 4 Shaft sealing part 5 Bearing horizontal division surface 6 Bearing oil supply hole 7 Bearing gap 8 Shaft sealing oil supply device 9 Bearing oil supply mother pipe 10 Bearing oil supply pipe 11 Oil supply pipe 12 Vacuum tank 13 Vacuum pump 14 Shaft sealing oil supply pump 15 Pressure adjusting valve 16 Air extraction tank 17 Expansion tank 18 Float trap 19 U-shaped pipe section 20 Oil backflow prevention device 20a Check valve (Oil backflow prevention device) 20b Manual valve (Oil backflow prevention device) 21 Automatic Valve (oil backflow prevention device) 22a Detector (first detector) 22b Detector (second detector) 23 Arithmetic unit 24 Valve opening / closing unit 25 High position unit 26 Branch unit 27 Reverse slope unit

Claims (8)

[Claims] 1. A shaft sealing portion for preventing leakage of a cooling gas to the outside of a generator having a cooling gas sealed therein by pressurized oil supply from a shaft sealing oil supply device, and a bearing oil supply pipe from outside the machine. A bearing that is forcibly lubricated, and in a bearing lubrication device for a generator in which the shaft sealing portion is installed near the bearing, an oil backflow prevention device is provided near an inlet of the bearing in the bearing lubrication pipe. A bearing lubrication device for a generator. 2. The bearing oil supply device for a generator according to claim 1, wherein the oil backflow prevention device provided on the bearing oil supply pipe is a check valve. 3. The bearing oil supply device for a generator according to claim 1, wherein the oil backflow prevention device provided on the bearing oil supply pipe is a manual valve. 4. The bearing lubricating device for a generator according to claim 1, wherein the oil backflow prevention device provided on the bearing lubricating pipe is an automatic valve, and a valve opening / closing device for opening / closing the automatic valve by remote control is provided. A bearing lubrication system for a generator. 5. The bearing lubricating device for a generator according to claim 4, wherein the valve opening / closing device is controlled based on the generator operation mode, and further includes a detection unit for detecting the generator operation mode. Generator bearing lubrication system. 6. The bearing lubricating device for a generator according to claim 5, wherein the detecting unit detects a bearing lubricating pressure, and detects a gas pressure in the generator or a shaft sealing lubricating lubricating pressure. And a detector oil supply pressure detected by the first detector and a gas pressure in the generator or a shaft seal oil supply pressure detected by the second detector. A bearing lubrication device for a generator, comprising a calculation unit for calculating an operation mode. 7. The bearing for a generator according to claim 1, wherein a high position higher than a center position of the generator is provided near a bearing inlet of the bearing oil supply pipe. Refueling equipment. 8. The bearing lubrication device for a generator according to claim 1, wherein the shaft sealing oil supply device is lubricated from a bearing oil supply system, and a branch portion between an oil supply pipe to the shaft sealing oil supply device and a bearing oil supply pipe. A bearing lubrication device for a generator, wherein a reverse slope portion is provided on a bearing lubrication mother pipe between the bearing lubrication tank and the bearing lubrication pump on the bearing lubrication system.