JPH05236695A - Supplying device for sealing oil - Google Patents

Abstract

PURPOSE:To prevent the purity of cooling gas inside a rotating electric machine from dropping, which is caused by sealing oil whose deairing and dehydration are not enough being supplied to a shaft seal part by an emergency sealing oil pump when a sealing oil pump goes wrong. CONSTITUTION:Two sealing oil pumps 10a and 10b are juxtaposed, and relief valves 14a and 14b, pressure switches 24a and 24b, and check valves 13a and 13b are connected to respective discharge pipes 12a and 12b, and pipes 28a and 28b are branched. Valves 29a and 29b are connected to these pipes 28a and 28b, respectively, and they are connected to a vacuum oil reservoir 6 through a return pipe 19.

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 sealing oil supply device for a rotary electric machine such as a large capacity turbine generator whose inside is cooled by hydrogen gas.

[0002]

2. Description of the Related Art Generally, in a turbine generator in which a cooling medium such as hydrogen gas is enclosed in a machine for cooling, a shaft seal portion is provided to prevent hydrogen gas from leaking to the atmosphere from a shaft penetrating portion. Sealing oil is supplied to the shaft seal portion to seal the hydrogen gas.

Therefore, in the turbine generator described above, a sealing oil pump for supplying the sealing oil, a vacuum oil tank for deaerating and dehydrating the sealing oil, and a relief valve for maintaining the pressure of the supply sealing oil pipeline. A sealing oil supply device including a differential pressure adjusting valve and the like for maintaining the pressure of the supplied sealing oil at a predetermined value higher than the hydrogen gas pressure in the turbine generator.

FIG. 5 is a piping system diagram showing a conventional sealing oil supply device. In the figure, 1 is a rotating electric machine, 2 and 3 are shaft seals, and the bearing oil is normally supplied from a bearing oil supply device (not shown) to the vacuum oil tank 6.
The inside of the vacuum oil tank 6 is degassed and dehydrated by maintaining the inside of the vacuum pump 9 in a vacuum state, and the sealing oil pump 10 supplies high-quality sealing oil to the shaft seal portions 2 and 3. ..

By the way, the vacuum oil tank 6 during normal operation
The seal oil inside is supplied to the shaft seal portions 2 and 3 of the rotary electric machine 1 through the seal oil supply circuit. At this time, the differential pressure adjusting valve 15
Thus, the sealing oil supply amount is adjusted so that the sealing oil supply pressure is always kept higher than the in-machine gas pressure of the rotary electric machine 1 by a predetermined value.

On the other hand, the relief valve 14 allows the sealing oil pump 10
The sealing oil supply circuit pressure is adjusted by returning a part of the discharge oil amount to the vacuum oil tank 6. In addition, the sealing oil discharged from the shaft sealing mechanism of the shaft sealing portions 2 and 3 is the rotating electric machine 1
It is configured to return to a bearing oil supply device (not shown) via the bearing return pipe 5 of FIG. Further, a circulation circuit is formed so that the bearing lubricating oil of substantially the same amount as the amount of sealing oil supplied to the shaft seal portions 2 and 3 is supplied to the vacuum oil tank 6.

A vacuum oil tank 6 is provided by the relief valve 14 described above.
The sealing oil that has been returned to (1) is jetted into the vacuum oil tank 6 through the spray 20 to accelerate deaeration and dehydration of the sealing oil. At this time, the amount of sealing oil obtained by subtracting the amount of sealing oil supplied to the shaft seal portions 2 and 3 from the discharge amount of the sealing oil pump 10 is the vacuum oil tank 6
However, if the amount of the sealing oil is small, the sealing oil in the vacuum oil tank 6 cannot be sufficiently deaerated and dehydrated. Therefore, a recirculation oil pump 16 is provided separately from the sealing oil pump 10, and By connecting to the return pipe 19 of the relief valve 14 described above, the sealing oil in the vacuum oil tank 6 is deaerated and dehydrated.

[0008]

The seal oil pump 10 is usually driven by an AC power supply, and if the discharge pressure of the seal oil pump 10 drops, an emergency seal oil is driven by a DC power supply. The operation is performed by switching to the pump 21, but the operation with the emergency sealing oil pump 21 is for emergency only,
The system is not configured to deaerate and dehydrate the sealing oil.
This is because, assuming an accident around the vacuum oil tank 6, the sealing oil is directly supplied from the oil supply line to the emergency sealing oil pump 21 to improve the reliability. However,
Supplying the sealing oil with insufficient deaeration and dehydration to the shaft seal portions 2 and 3 for a long period of time lowers the in-machine hydrogen gas purity of the rotating electric machine 1. Therefore, the emergency sealing oil pump 21 is operated for a long period of time. Continuation is not a good idea. In the figure, 4
Is a seal oil supply pipe, 5 is a bearing return pipe, 7 is a bearing oil supply pipe,
8 is a float valve, 9a is a vacuum pump suction pipe, 11 is a suction pipe, 12 and 22 are discharge pipes, 12C is a connected discharge pipe, 13 and 25 are check valves, 17 is a recirculation pump suction pipe, and 18 is a recirculation pipe. A pump discharge pipe, and 23 is a control device.

According to the present invention, when the sealing oil pump fails, the emergency sealing oil pump supplies the shaft sealing portion with the sealing oil which is not sufficiently deaerated and dehydrated, so that the purity of the cooling gas in the rotating electric machine is lowered. It is an object of the present invention to provide a sealing oil supply device that prevents the above.

[0010]

According to the present invention, there is provided a sealing oil pump for supplying sealing oil to a shaft seal portion of a rotary electric machine having a cooling gas sealed therein, and a sealing oil pump for deaerating and dehydrating the sealing oil. In a sealed oil supply device comprising a vacuum oil tank and a vacuum pump, a plurality of sealed oil pumps are provided, each of which is provided with a pressure switch, a relief valve and a check valve, and
A pipe line for returning the sealing oil to the vacuum oil tank is provided on the upstream side of the check valve via the valve.

[0011]

With the above construction, while one sealing oil pump is supplying the sealing oil to the shaft seal portion, the other sealing oil pump opens the valve provided in the discharge pipe downstream thereof. It is possible to return all of the discharge amount to the vacuum oil tank, so that it plays the role of a recirculating oil pump in the conventional sealing oil supply device, and should the sealing oil be supplied to the shaft seal part. If the operation of the sealing oil pump is disturbed, the valve that is "open" on the other sealing oil pump side is closed and the sealing oil is supplied to the shaft seal portion.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a piping system diagram of an embodiment of the present invention. As shown in the figure, the present embodiment is largely different from the above-described conventional sealing oil supply device in that a sealing oil pump is provided in parallel and a recirculation pump is not provided. That is, the sealing oil pumps 10a and 10b are arranged side by side, and the respective discharge pipes
12a, 12b, relief valves 14a, 14b, pressure switch 24
a, 24b, check valves 13a, 13b are connected, and a pipe line 28a,
Branch 28b. The pipes 28a, 28b are provided with valves 29a, 29b.
And the vacuum oil tank 6 via the return pipe 19.

Next, the operation of the embodiment configured as described above will be described. First, in normal operation, both the sealing oil pumps 10a and 10b are operating. Here, the sealing oil pump 10a is in normal operation, and the valve 29a is "closed". On the other hand, the sealing oil pump 10b is in standby operation,
The valve 29b is "open". Sealing oil pump during normal operation
Since the valve 29a is "closed" in the line of 10a, as described in the conventional sealing oil supply device, the relief valve 14a is
As a result, a part of the discharged oil amount is transferred via the return pipe 19 to the vacuum oil tank 6
Have been returned to. Since the valve 29b is "open" in the line of the sealing oil pump 10b during the standby operation, the entire amount of the discharged oil is returned to the vacuum oil tank 6 through the return pipe 19. The flow rate and pressure value in this state will be described with a specific example. The pressure of the sealing oil supplied to the shaft seal portions 2 and 3 of the rotary electric machine 1 is set to 6
kgf / cm ² In the device with the sealing oil amount of 300 l / min, the capacity of the sealing oil pumps 10a and 10b is set to about 1.5 to 2 times the sealing oil amount, so it is assumed that the pump of 500 l / min is selected. .. In this state, the sealing oil pumps 10a, 10b
Considering the pressure loss on the downstream side, the pressure at the discharge part of the relief valve 14a, 14b is 8 kgf / cm ² Is set to. When the valve 29b is opened in this state, the discharge pressure of the sealing oil pump 10b is 0.5 kgf / cm ^{2 due} to the valve resistance of the valve 29b and the spray 20 and the line resistance in the middle. It becomes a degree. Due to such a pressure state, the check valve 13a is "open" and the check valve 13b is "closed".
Although the capacity of the sealing oil pump 10b depends on the type of pump, it remains almost 500 l / min when a positive displacement pump is used, so the amount of oil returned from the sealing oil pump 10a is
Total of 200 l / min and the amount of sealing oil of sealing oil pump 10b 7
00 l / min is ejected into the vacuum oil tank 6. If this amount of sealing oil is ejected to the vacuum oil tank 6, the recirculation oil pump 16 employed in the conventional sealing oil supply device becomes unnecessary.

In this state, if any trouble occurs in the operation of the sealing oil pump 10a, it is detected by the pressure switch 24a that the decrease in pump discharge pressure has become less than a set value, and the controller 23 causes an emergency. Sealing oil pump
21 is automatically started. In this case, if a predetermined investigation is performed and it is confirmed that there is no hindrance to the normal operation of the sealing oil pump 10b, the valve 29b is closed and the sealing oil pump 10b discharges the sealing oil. The shaft seal part 2,
3 is supplied, and the emergency sealing oil pump 21 is stopped to put it in a standby state. In this state, the amount of the sealing oil jetted into the vacuum oil tank 6 through the spray 20 is reduced as compared with the normal operating state, but degassing and dehydration are not performed by the emergency sealing oil pump 21 at all. Compared to supplying sealing oil, the effect on lowering the purity of hydrogen gas is sufficiently low. Furthermore, the emergency sealing oil pump 21 is on standby as a backup of the sealing oil pump 10b, and the operation reliability of the device is improved. Can be improved. The equipment changes necessary for embodying the present embodiment include changing the specifications of the pump for the recirculation oil pump and using it as a sealed oil pump, and the installation of valves 29a, 29b and connecting pipes. Initial costs only increase, and operating costs hardly increase.

As described above, the present embodiment (hereinafter, referred to as the first
According to the embodiment), the sealing oil pumps are arranged in parallel, one side always supplies the sealing oil to the shaft seal portion, the other side plays a role of a recirculation pump, and when one side has a trouble, the other side starts from the other side. Since the seal oil is supplied to the shaft seal portion, it is possible to stably supply the clean oil, although the recirculation pump is omitted.

The present invention is not limited to the above-mentioned first embodiment, but can be variously modified and implemented. Figure 2
It is a piping system diagram which shows the structure of other Example (henceforth a 2nd Example) of this invention. As shown in the figure, the second embodiment is different in that automatic valves 30a and 30b are provided instead of the valves 29a and 29b in the first embodiment. The automatic valves 30a and 30b are electrically connected to the control device 23. The automatic valves 30a and 30b are of a type that "closes" when air pressure is lost.

Next, the operation of the second embodiment having the above construction will be described. When the pressure switch 24a detects that the operation of the sealing oil pump 10a has been hindered as a decrease in the discharge pressure, the emergency sealing oil pump 21 is immediately activated, but at the same time, the control device 23 automatically controls the valve. Send a "closed" signal to 30b. If the discharge pressure drop of the sealing oil pump 10a is due to the loss of AC power, the sealing oil pump 10b also stops its operation. However, since the motor and the pump continue to rotate due to inertia until completely stopped, the seal oil is continuously supplied to the shaft seal portions 2 and 3 until the emergency seal oil pump 21 reaches a predetermined pressure. It has an effect of preventing the seals of the shaft seal portions 2 and 3 from breaking.
Further, if the discharge pressure drop of the sealing oil pump 10a is due to a failure of the pump itself, it means that the sealing oil pump 10b has already reached a predetermined rotation speed, and the sealing oil pump 10a should be backed up quickly. It will be possible to fulfill. In this case, the sealing oil pump 10b and the emergency sealing oil pump 21
Parallel operation is performed, but after that, the sealing oil pump 10b
After confirming that the operation of (1) is normally performed, the operation of the emergency sealing oil pump 21 is stopped and put in the standby state. The automatic valves 30a and 30b are automatically closed by the force of the built-in spring when the pressure of the supplied air source is lost due to some trouble. The operation is designed so that it can be continued. In this case, both the sealing oil pumps 10a and 10b are operated, and the sealing oil is supplied to the shaft seal portions 2 and 3 while returning the excess sealing oil from the reliefs 14a and 14b to the vacuum oil tank 6.

As described above, according to the second embodiment,
Compared with the first embodiment described above, it is possible to further improve the excessive pressure drop phenomenon of the sealing oil in the shaft seal portions 2 and 3 when the sealing oil pump is switched due to the decrease in the discharge pressure of the sealing oil pump. Become.

FIG. 3 is a piping system diagram showing the configuration of still another embodiment of the present invention (hereinafter referred to as the third embodiment). As shown in the figure, the third embodiment differs from the second embodiment described above in that primary pressure adjusting valves 31a and 31b are provided in place of the automatic valves 30a and 30b, and relief valves 14a are provided in the discharge pipes 12a and 12b. , 14b are not provided. Here, the primary pressure adjusting valves 31a and 31b have a function of absorbing pressure fluctuations on the primary side and adjusting to a constant pressure. Further, the primary pressure adjusting valves 31a, 31b have the same function as the relief valves 14a, 14b in the above-described first and second embodiments. However, the seal oil pump 10 in standby operation
On the b side primary pressure regulating valve 31b, the control device 23 is "fully opened".
Sent to the signal.

Next, the operation of the third embodiment having the above construction will be described. When the pressure switch 24a detects that the operation of the sealing oil pump 10a has been hindered as a decrease in the discharge pressure, the emergency sealing oil pump 21 is immediately activated, and at the same time, the control device 23 controls the primary pressure. Regulating valve
Switch the "Fully open" signal sent to 31b to "Run". Then, the primary pressure adjusting valve 31b starts adjusting the primary pressure. Due to this action, the same effect as the second embodiment described above can be obtained.

FIG. 4 is a piping system diagram showing the structure of still another embodiment of the present invention (hereinafter referred to as the fourth embodiment). As shown in the figure, the fourth embodiment is different from the above-described third embodiment in that differential pressure adjusting valves 32a and 32b are provided instead of the primary pressure adjusting valves 31a and 31b, and a differential pressure adjusting valve is provided instead of the relief valve 26. The configuration in which the adjusting valve 32c is provided is different. These differential pressure regulating valves 32a, 32b, 32c are connected to conduits so that the gas pressure inside the rotary electric machine 1 and the sealing oil pressure of the shaft seal portions 2 and 3 act, respectively, and are electrically connected to the control device 23. ing. On the other hand, when the sealing oil pump 10a is in normal operation, the sealing oil pump 10b is in standby operation, and the emergency sealing oil pump 21 is in standby, the differential pressure adjusting valve 32a is in the "operation" state,
Differential pressure adjusting valve 32b is "fully open", differential pressure adjusting valve 32c is "fully closed"
In this state, the discharge amount of the sealing oil pump 10b is all returned to the vacuum oil tank 6.

Next, the operation of the fourth embodiment constructed as described above will be explained. When the pressure switch 24a detects that the operation of the sealing oil pump 10a has been hindered as a decrease in the discharge pressure, the control device 23 activates the emergency sealing oil pump 21 and "runs" the differential pressure adjusting valve 32c. State. At the same time, the differential pressure regulating valve 32b is put in the "operating" state. Due to this action, the same effect as the second embodiment described above can be obtained.

[0023]

As described above, according to the present invention, a plurality of sealing oil pumps are provided, each of which is provided with a pressure switch, a relief valve and a check valve, and a valve is provided upstream of the check valve. Since a pipeline for returning the sealing oil to the vacuum oil tank is provided, it is possible to stably supply a clean degassed and dehydrated sealing oil, and when switching from the sealing oil pump to the emergency sealing oil pump. In addition, it is possible to provide a sealing oil supply device that improves transient characteristics of pressure drop at the shaft seal portion and is also economically excellent.

[Brief description of drawings]

FIG. 1 is a piping system diagram showing the configuration of an embodiment of the present invention.

FIG. 2 is a piping system diagram showing the configuration of another embodiment of the present invention.

FIG. 3 is a piping system diagram showing the configuration of still another embodiment of the present invention.

FIG. 4 is a piping system diagram showing the configuration of still another embodiment of the present invention.

FIG. 5 is a piping system diagram showing a configuration of a conventional sealing oil supply device.

[Explanation of symbols]

1 ... Rotating electric machine, 2, 3 ... Shaft seal part, 6 ... Vacuum oil tank, 9
... Vacuum pumps, 10a, 10b ... Sealing oil pumps, 12a, 12b
... Discharge pipe, 13a, 13b, 25 ... Check valve, 14a, 14b ... Relief valve, 15, 32a, 32b, 32c ... Differential pressure adjusting valve, 19 ... Return pipe, 20 ... Spray, 21 ... Emergency sealing oil pump , 23 ... Control device, 24a, 24b ... Pressure switch, 29a, 29b ... Valve, 30
a, 30b ... Automatic valve, 31a, 31b ... Primary pressure adjusting valve.

Claims (1)

[Claims] 1. A seal oil pump for supplying seal oil to a shaft seal portion of a rotary electric machine, in which a cooling gas is sealed, a vacuum oil tank and a vacuum pump for degassing and dehydrating the seal oil. In the sealing oil supply device, a plurality of sealing oil pumps are provided, each of which is provided with a pressure switch, a relief valve and a check valve, and the sealing oil is vacuumed through a valve upstream of the check valve. A sealing oil supply device, characterized in that a pipe line for returning to the oil tank is provided.