JPS5832470Y2 - Sealing oil supply device for turbine generator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a sealing oil supply device for a hydrogen-cooled turbine generator.

The conventional technology will be explained using the device system shown in FIG.

Shaft seals 2 and 3 are provided in the shaft penetrating portion of the turbine generator 1 which is cooled with hydrogen gas.

Sealing oil is supplied to each of the shaft seals 2 and 3, and hydrogen gas is sealed by the differential pressure between the pressure of this sealing oil and the in-machine gas pressure.

When the regular seal oil pump 4 incorporated in this device is operated, seal oil is sent from an oil supply pipe 5 connected to an oil tank equipped with a cooler (not shown), branched into three directions from the middle, and one side is vacuumed via a pipe 5a. The oil flows into the tank 6, and the other side communicates with the suction side of an emergency seal oil pump 11, which will be described later, via a pipe 5b.

The oil from which hydrogen and other gases have been degassed in the vacuum tank is pumped through a check valve 7 and a differential pressure regulating valve 9 by a regular sealed oil pump 4.

and is supplied to the shaft seal parts 2 and 3.

Furthermore, an emergency sealing oil pump 11 is connected in parallel to this device in order to cope with loss of A-C power supply or failure of the regular sealing oil pump 4.

This emergency sealing oil pump 11 communicates with the aforementioned oil tank (not shown) and supplies pressure oil to the oil supply side pipe line of the regular sealing oil pump 4.

Relief valves 14 and 19 are provided on the discharge sides of these pumps 4 and 11, respectively, to provide oil return circuits.

The reason for this is to prepare for the situation where a large amount of sealing oil is required due to a problem with the seal ring due to the gap between the shaft seal part 2 and the rotating shaft becoming larger, and in general, approximately twice the amount of sealing oil required under normal conditions is discharged. This is because it has a capacity.

The details of the feedback circuit for both pumps 4 and 110 are as follows:
The return circuit of the regular sealed oil pump 4 adjusts the hydraulic control mechanism of the IJ valve 14 connected to its discharge side to maintain the oil pressure of the oil supply circuit at a predetermined value, and drains excess oil into the vacuum tank 6.
It is set to return to normal.

Therefore, the regular sealed oil pump 4 is supplied with cold oil that is mixed with the cold oil in the vacuum tank.

On the other hand, the feedback circuit 15 of the emergency sealing oil pump 11 is connected to the suction side of the pump 11, that is, the pipe 5b of the oil tank described above, via a relief valve 19 connected to its discharge side.

Therefore, when the emergency seal oil pump 11 is operated while the turbine generator is in operation, although there is an amount of circulating oil that passes through the feedback circuit, only the predetermined amount of oil supplied to the shaft seals 2 and 3 is drawn from the oil tank. Since the cold oil is mixed, the emergency seal oil pump 11 will not overheat.

This device is used to seal hydrogen gas even when the turbine generator is not in operation 1. For example, during slow speed operation of 5 to 10 rpm to prevent rotor deformation, that is, turning operation, or even when the turbine generator is stopped. being driven.

At this time, the amount of sealing oil supplied to the shaft seal is proportional to the rotation speed of the shaft, so it is much smaller than when the turbine generator is operated at the rated speed (generally 3000 to 3600 rpm). Only a small amount flows.

Therefore, when the regular seal oil pump 4 is operated, there is no problem because cold oil is supplied as described above, but when the emergency seal oil pump 11 is operated, most of the oil discharged is from the relief valve 19. It returns to the suction side of the pump from the feedback circuit 15 via.

As a result, the temperature of the sealing oil becomes abnormally high due to stirring heat due to circulation by the pump and heat loss from the pump driving motor, resulting in the following drawbacks.

(1) The temperature of the seal oil exceeds the operating limit temperature of the shaft seal of the emergency seal oil pump.

(2) Abnormal thermal deformation occurs in the shaft seal.

(3) Seal oil deteriorates faster.

SUMMARY OF THE INVENTION An object of the present invention is to provide a sealing oil supply system for a turbine generator, which is configured to supply cold oil to an emergency sealing oil pump while the turbine generator is in slow operation or stopped.

An embodiment of the present invention will be described below with reference to FIG.

The system for supplying sealing oil to the shaft seal portions 2 and 3 provided in the turbine generator 1 is as follows.

Cold oil is supplied to the oil supply pipe 5 from an oil tank equipped with a cooler (not shown).
It is pumped by

This oil supply pipe 5 branches into three directions in the middle, and one pipe 5a is communicated with a vacuum tank 6.

This vacuum tank 6 has a built-in float valve 18 to remove hydrogen gas from oil, so that the cold oil sent from the pipe 5a maintains the oil level in the vacuum tank 6 at a predetermined position. ing.

The other branched pipe 5b is an emergency sealed oil pump 1 which will be described later.
1 is connected.

The regular sealing oil pump 4 communicates with the vacuum tank 6 and is supplied with cold sealing oil.

The discharge side of the regular sealed oil pump 4 has a check valve 7 and a differential pressure regulating valve 9.
The shaft seals 2 and 3 are connected to each other through the shaft seals 2 and 3, respectively.

This differential pressure regulating valve 3 measures the hydrogen gas pressure inside the machine and automatically adjusts the difference between the hydrogen pressure inside the machine and the oil pressure supplied to the shaft seal part to a predetermined value based on the measured value. It is something.

An emergency seal oil pump 11 is connected in parallel to the oil supply system of the regular seal oil pump 4 in case the pump 4 is unable to operate.

This emergency sealing oil pump 11 communicates with the aforementioned branch pipe 5b and is supplied with cold oil.

The output side thereof is communicated via the check valve 12 between the check valve 7 of the regular oil supply system and the differential pressure regulating valve 9.

Now, these two imperial oil pumps 4 and 11 each have a return circuit for excess oil.

The discharge of the regular sealed oil pump 4 is communicated with the vacuum tank 6 via the relief valve 14.

On the other hand, the discharge side of the emergency seal oil pump 11 is provided with a relief valve 19.
A return circuit is formed by communicating with an air extraction tank 16, which will be described later, through a pipe 20.

Next, the oil drain side of this system will be explained.

The oil drain portions of the shaft seals 2 and 3 communicate with an air extraction tank 16 installed at the bottom of the turbine generator, respectively.

This air extraction tank 16 is for separating air dissolved in oil, and its oil drain side communicates with the aforementioned oil tank (not shown) through an oil drain pipe 21.

Note that a circuit is provided that communicates the air extraction tank 16 and the oil supply pipe 5 via a check valve 17.

In this circuit, when oil supply from the oil supply pipe 5 is stopped due to an accident, the oil stored in the air extraction tank 16 is reversely supplied to the both oil pump circuits and sent to the shaft seal parts 2 and 3. This is to prevent the situation where the seal oil is immediately stopped.

The effect will be explained.

While the turbine generator 1 is operating slowly or stopped,
When the regular sealed oil pump 4 is operated, cold oil is supplied to the pump, so there is no problem of overheating, which is the same as in the prior art device.

On the other hand, when the emergency sealed oil pump 11 is operated, only cold oil is supplied from the oil tank to the suction side of the pump 11.
Excess oil flows through the return circuit of the pump 11, enters the air extraction tank 16, and is discharged to the oil tank.

Therefore, the total amount of oil flowing into the suction side of the emergency sealing oil pump 11 is cold oil supplied from the oil tank.

In this way, the emergency sealed oil pump 11 has no circulating oil that directly flows in via the feedback circuit, so the overheating phenomenon is eliminated.
The rubber gasket used for the shaft seal of the pump 11 will not deteriorate prematurely.

Furthermore, since the shaft seal portions 2 and 3 of one generator are also supplied with cold oil, it is possible to prevent the seal ring from being thermally deformed and coming into contact with the rotating shaft.

Furthermore, since deterioration of the sealing oil due to high temperatures is prevented, the life of the sealing oil can be extended.

Incidentally, in the above embodiment, it is communicated with the air extraction tank 16 which is a feedback circuit of the emergency sealed oil pump 11.

Even if it communicates with the oil drain pipe 21 of the air extraction tank 16, the same effects as in the above embodiment can be obtained.

As explained above, according to the present invention, it is possible to supply cold oil to the emergency seal oil pump while the turbine generator is operating at a slow speed or when the turbine generator is stopped, which has the effect of providing a seal oil supply device that does not overheat. .

[Brief explanation of drawings]

FIG. 1 is a system diagram showing a conventional sealing oil supply device. FIG. 2 is a system diagram of a sealing oil supply device for a turbine generator showing an embodiment of the present invention. 1... Turbine generator, 2, 3... Shaft seal section. 4... Regular sealed oil pump, 5... Oil tank oil supply pipe, 6... Vacuum tank, 9...
Differential pressure regulating valve, 11...Emergency seal oil pump, 1
4... Relief valve, 16... Air extraction tank, 19... IJ IJ-f valve.

Claims (1)

[Scope of utility model registration request] An oil tank equipped with a cooler for supplying sealing oil to the shaft seal of the turbine generator, a vacuum tank for deaerating the sealing oil sent from this oil tank, and a pipe from this vacuum tank to the shaft seal. A regular sealed oil pump that supplies pressure oil through a channel;
A feedback circuit that communicates the discharge side of the normal seal oil pump with the vacuum tank via a relief valve, an emergency seal oil pump installed in a pipe line parallel to the normal seal oil pump line, and A sealing oil for a turbine generator, characterized in that the discharge side of a sealing oil pump for use in a turbine generator is provided with a return passage communicating through a relief valve with an oil drainage passage that returns waste oil from the shaft seal portion to the oil tank. Feeding device.