JPS5836574B2 - Fire spread prevention device for turbine generator bearings - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fire spread prevention device for a turbine generator bearing in a thermal power plant.

Generally, lubricating oil to the turbine generator bearings in a thermal power plant is supplied by a main oil pump directly connected to the turbine during continuous operation, and when the discharge pressure drops below the required pressure, an auxiliary oil pump is supplied. Therefore, in the event of an emergency when there is no power in the plant, the emergency oil pump supplies lubricating oil to each bearing, ensuring that a predetermined amount of lubricating oil is always supplied to each bearing, and is designed to prevent damage to each bearing due to lack of lubrication. ing.

In particular, in recent years, as thermal power plants have become larger, countermeasures against bearing damage have come to be fully considered.

However, if a fire occurs in a plant, continuing to supply lubricating oil to each bearing will actually increase the risk of a fire since some lubricating oil will leak from the bearing surface, and this will cause more damage than bearing damage. could also cause much greater damage.

Therefore, questions are beginning to arise as to whether the method of constantly supplying lubricating oil to each bearing portion as described above is not necessarily correct.

Therefore, in the event of an emergency such as a fire occurring in a plant, it may be possible to stop the supply of lubricating oil to the lubricant bearings, but in this case, simply stopping the lubricating oil supply would not cause the turbine to trip immediately after the fire broke out. Since the bearing continues to rotate due to inertia for a considerable period of time, damage to the bearing is inevitable.

In view of these points, it is an object of the present invention to provide a device that sufficiently lubricates a bearing when a fire occurs in a plant, and further prevents the spread of the fire.

Hereinafter, one embodiment of the present invention will be described with reference to the accompanying drawings.

In the figure, reference numeral 1 denotes a steam turbine, and a generator 3 is coupled to a rotating shaft 2 of the steam turbine 10 in a driven manner.

The rotating shaft 2 is supported by a plurality of bearings 4, 4, . The lubricating oil is supplied through the piping 7 and the lubricating oil is returned to the oil tank 10 via the return pipe 8 and the lubricating oil return check valve 9.

An auxiliary oil pump 11 and an emergency oil pump 12 are connected in parallel to the main oil pump 5, which has been disconnected.
The discharge measurement of each pump is also communicated to the oil tank 10 via a fire lubricant return valve 13 button and piping 14.

On the other hand, a fire extinguishing liquid supply connected to a fire extinguishing liquid tank 17 via a fire extinguishing liquid supply pump 16 driven by a fire extinguishing liquid supply valve 15 button and an emergency power supply is provided downstream of the fire lubricating oil stop valve 60 of the piping 7. The pipe 18 is connected to the button, and the return pipe 8 is connected to a drain pipe 20 provided with a fire extinguishing fluid drain valve 19.

In addition, as the fire extinguishing liquid, one whose properties are close to that of lubricating oil is selected.

Next, its operation will be explained.

During steady operation, the fire lubricant stop valve 6 button and the lubricant return check valve 9 are opened, and the other valves 13.1519 are closed.

Therefore, the lubricating oil in the oil tank 10 is supplied to each bearing 4 via the main oil pump 5, the lubricating oil stop valve 6 in case of fire, and the piping 7.
, 4..., and each of the bearings 4, 4... is lubricated.

The oil that has lubricated each bearing is further returned to the oil tank 10 via a return pipe 8 and a lubricating oil return check valve 9.

Therefore, when a fire occurs in the plant, the turbine 1 is tripped, but due to inertia, the main oil pump 5 continues to supply lubricating oil to the bearing 4 because it rotates for a long time in a completely stopped case.

For this reason, in the event of a fire, the operator, at his discretion, presses a pushbutton switch installed in a control room, etc. to close the fire lubricant stop valve 6, fire lubricant return valve 13, and fire extinguishing liquid supply valve 15. At the same time, the fire extinguishing liquid pump 16 is started.

Therefore, the supply of lubricating oil to each bearing 4 is stopped, and instead, fire extinguishing fluid is supplied to each bearing, and the bearings are lubricated by the lubricating performance of the fire extinguishing fluid, thereby preventing damage to the bearings.

In addition, even if the liquid supplied to the bearing leaks, this liquid is not a lubricating oil but a fire extinguishing liquid, so there is no risk of spreading a fire.

Next, most of the lubricating oil already supplied to the bearing 4 is in the oil tank 1.
After the lubricating oil is recovered to zero, the lubricating oil return check valve 9 is closed, and at this point, the extinguishing liquid drain valve 19 is fully opened, and the extinguishing liquid supplied to the bearing 4 is sequentially discharged from the drain pipe 20.

In the above explanation, a fire extinguishing liquid supply pump was installed for one turbine generator, but a fire extinguishing liquid supply pump and a fire extinguishing liquid tank were installed for one turbine generator.
It is also possible to install only a set and connect it to each turbine generator via piping and supply valves.

In addition, if the fire extinguishing fluid is supplied not only to the bearings but also to the main parts of the power plant, it can also function as a fire extinguisher.

Furthermore, it is also possible to mix lubricating oil and fire extinguishing liquid to such an extent that the lubricating oil does not catch fire, so that the bearing lubrication effect is not reduced.

As explained above, in the present invention, lubricating oil is supplied to each bearing part in the same manner as in the conventional case during normal operation, but in the event of a plant fire, a fire extinguishing liquid with properties similar to lubricating oil is supplied instead of lubricating oil. As a result, there is no risk of a fire spreading even if it leaks from the bearing, and the spread of the fire can be reliably prevented.

Moreover, since each bearing is lubricated by the fire extinguishing liquid during this time, damage to the bearing is also prevented.

[Brief explanation of drawings]

The drawing is a schematic system diagram showing one embodiment of the present invention. 1... Turbine, 4... Bearing, 5...
... Main oil pump, 15 ... Fire extinguishing liquid supply valve,
16... Fire extinguishing liquid supply pump, 17...
Fire extinguishing liquid tank.

Claims (1)

[Claims] 1 A lubricating oil stop valve and a lubricating oil return check valve are provided in the piping and return pipes that supply lubricating oil to each bearing of the turbine generator, respectively, and a fire extinguishing liquid supply valve is installed in the piping that supplies the lubricating oil. A fire spread prevention device for a turbine generator bearing, characterized in that a fire extinguishing fluid pump is connected to the lubricating oil return pipe, and a drain pipe equipped with a fire extinguishing fluid drain valve is connected to the lubricating oil return pipe.