JPH0315411B2 - - Google Patents

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to a large-capacity turbine generator, in particular, in order to prevent internal cooling medium from leaking from the shaft seal to the outside. This invention relates to an improvement of a shaft sealing oil supply device that supplies sealing oil.

[Technical Background of the Invention] Generally, in a turbine generator that performs cooling by sealing a cooling medium such as hydrogen gas inside the machine, a shaft seal is used to prevent hydrogen gas from leaking into the atmosphere from the shaft penetrating portion. A shaft sealing section is provided, and shaft sealing oil is supplied to this shaft sealing section to seal hydrogen gas. Conventionally, a shaft seal oil supply device has been used to supply such shaft seal oil. This shaft seal oil supply device is equipped with a regular shaft seal oil pump, an emergency shaft seal oil pump, a vacuum pump, a vacuum tank, etc. The vacuum tank is equipped with a peephole to prevent oil circulation and bubbles inside the tank. It is possible to monitor the status of Additionally, in order to improve the quality of the oil in the vacuum tank through vacuum treatment, it can be dehydrated and degassed using a vacuum pump.

By the way, in this type of shaft seal oil supply device, when evacuation inside the generator is started from its normal operating state, the vacuum pump sucks in a large amount of hydrogen gas or air, and many bubbles are generated in the vacuum chamber. If you operate in this condition, the oil will be sucked into the regular shaft seal pump and this will cause cavitation.
This will lead to a decline in operational performance and failure of the regular shaft seal oil pump.

[Problems in the Background Art] Therefore, in order to prevent such cavitation, the internal vacuum valve is manually slightly opened to reduce bubbling in the vacuum chamber and to prevent cavitation from occurring in the regular shaft-sealed oil pump. What you haven't done
The inside of the generator is being evacuated while checking through the peephole. For this reason, automatic operation cannot be performed, and on-site monitoring and slight opening and closing of the manual vacuum valve inside the machine are repeated over a period of 3 to 4 hours. Therefore, automatic operation is performed from the central control room. It is impossible.

[Object of the Invention] The object of the present invention is to automatically prevent cavitation of a regular shaft seal oil pump while automatically evacuating the inside of the generator, and to apply high quality shaft seal oil to the shaft seal part even when the inside of the machine is evacuated. An object of the present invention is to provide a shaft seal oil supply device for a turbine generator that can supply oil to the shaft of a turbine generator.

[Summary of the Invention] In order to achieve the above object, the present invention includes a shaft seal that performs cooling by sealing a cooling medium such as hydrogen gas inside the machine and prevents the cooling medium from leaking to the outside at the shaft penetrating portion. In a device for supplying shaft seal oil to a shaft seal portion of a turbine generator comprising:
Shaft sealing oil is stored inside and communicates with the shaft seal part through an oil drain pipe, and a vacuum chamber that communicates with the inside of the turbine generator through in-machine vacuum piping, and shaft sealing oil introduced from the vacuum chamber through a suction pipe. A shaft sealing oil pump that supplies oil to the shaft seal via an oil guide pipe, an automatic vacuum control valve installed at the inlet of the in-machine vacuum piping, and an automatic vacuum control valve installed in a vacuum chamber to control the shaft sealing oil in the vacuum chamber. It is equipped with a conductivity measurement sensor that detects concentration changes, and is installed in the vacuum piping that communicates with the vacuum chamber in response to the detection signal from the conductivity measurement sensor when the inside of the turbine generator is evacuated. The automatic vacuum control valve is opened and closed.

[Embodiment of the Invention] Hereinafter, an embodiment of the present invention shown in the drawings will be described.

The figure is a diagram showing an example of the overall configuration of a shaft seal oil supply device for a turbine generator according to the present invention. In the figure, a shaft penetrating portion of a turbine generator 1 that seals hydrogen gas inside for cooling is installed with a shaft seal to prevent hydrogen gas from leaking into the atmosphere from the shaft penetrating portion. Sections 2 and 3 are provided. On the other hand, 4 is a regular shaft seal oil pump, and 5 is an emergency shaft seal oil pump installed in parallel with this regular shaft oil pump 4, with relief valves 6a, 6b and check valves 7a, 7, respectively.
Separately through b, the oil guide pipe 8 connects the seal portion 2,
Shaft sealing oil is supplied to 3. Further, the oil guide pipe 8 is provided with a regulating valve 9, which detects the pressure difference between the hydrogen gas pressure inside the turbine generator 1 and the shaft seal oil pressure of the shaft seal parts 2 and 3, and adjusts the pressure difference to the hydrogen gas pressure. The system automatically controls the value necessary to prevent leakage.

On the other hand, 10 is a vacuum tank containing shaft seal oil, which is connected to the regular shaft seal oil pump 4 through a suction pipe 11, and into the turbine generator 1 through an in-machine vacuum exhaust pipe 12.
They communicate with each other. A float valve 13 is provided within the vacuum chamber 10 to maintain the shaft sealing oil at a predetermined level, and a viewing window 14 is provided on the side surface of the float valve 13.

On the other hand, 15 is a vacuum pump connected to the vacuum chamber 10 through a vacuum pump inlet valve 16, and is designed to be able to dehydrate and degas the shaft seal oil in the vacuum chamber 10 in order to improve its quality through vacuum treatment. There is. Reference numeral 17 denotes a conductivity measuring sensor movably mounted within the vacuum chamber 10, which detects changes in the concentration of shaft seal oil within the vacuum chamber 10. Furthermore, 18 is a converter that converts the concentration value detected by the conductivity measurement sensor 17 into a corresponding current value, and 19 is a positioner that has an electropneumatic converter that converts the electric signal from the converter 18 into an air signal. in,
Depending on the magnitude of this air signal, an automatic vacuum control valve 20 provided in the in-machine vacuum piping 12 is opened and closed using air. Here, when the resistance value detected by the conductivity measuring sensor 17 is high, the automatic evacuation valve 20 is operated in the closing direction, and conversely, when it is low, it is similarly operated in the opening direction.

Furthermore, the shaft seal parts 2 and 3 are connected to the exhaust pipe 21.
This allows communication with the emergency shaft seal oil pump 5 and the vacuum tank 10 via the check valve 22.

Next, in the shaft seal oil supply device configured as described above, the operation when vacuuming the inside of the turbine generator 1 from the normal operating state will be described.

First, before the vacuum pump 15 is started, the shaft sealing oil in the vacuum chamber 10 is normally maintained at a predetermined level by the float valve 13. On the other hand, a conductivity measuring sensor 17 is attached near the top surface of this shaft seal oil. Therefore, from this state, the vacuum pump 15 and the regular shaft seal oil pump 4
After the oil level in the vacuum chamber 10 is stabilized,
The automatic evacuation control valve 20 provided at the inlet of the evacuation piping 12 installed from inside the turbine generator 1 is connected to the converter 1 by the conductivity measurement sensor 17.
The turbine generator 1 is evacuated under control by a positioner 19 based on an electric signal obtained through the vacuum pump 8 while limiting the displacement of the vacuum pump 15. That is, when the resistance value detected by the conductivity measuring sensor 17 is high, the automatic evacuation control valve 20 is operated in the closing direction, and conversely, when it is low, it is operated in the opening direction. Therefore, the regular shaft seal oil pump 4 does not cause cavitation.
The degree of vacuum inside the turbine generator 1 is set to an absolute pressure of 20 mm.
By reaching Hgabs, the inside of the turbine generator 1 is vacuum replaced from hydrogen gas to air, or from air to hydrogen gas.

Further, in the above, the inside of the vacuum tank 10 while the turbine generator 1 is being evacuated is maintained at a higher degree of vacuum than the inside vacuum by the vacuum pump 15. Therefore, the shaft seal oil in the vacuum chamber 10 is subjected to vacuum treatment such as deaeration and dehydration here to obtain high quality shaft seal oil, so even when the machine is vacuumed, high quality shaft seal oil can be obtained. However, the shaft seal parts 2 and 3 of the turbine generator 1 are connected from the regular shaft seal oil pump 4 to the shaft seal parts 2 and 3 of the turbine generator 1 via the conductive pipe 8.
This will prevent gas leakage from the shaft penetrating portion.

As mentioned above, in this embodiment, cooling is performed by sealing a cooling medium such as hydrogen gas inside the machine, and shaft seals 2 and 3 are provided at the shaft penetrating portion to prevent the cooling medium from leaking to the outside. A device for supplying shaft seal oil to the shaft seal parts 2 and 3 of the turbine generator 1, which is constructed of a turbine generator 1, is configured such that the shaft seal oil is stored inside and is connected to the shaft seal parts 2 and 3 through an oil drain pipe 21, and is connected to an in-machine vacuum piping. A vacuum tank 10 communicates with the inside of the turbine generator 1 by 12, and a shaft seal oil that supplies shaft seal oil introduced from the vacuum tank 10 through a suction pipe 11 to the shaft seal parts 2 and 3 via an oil guide pipe 8. The pumps 4 and 5, the automatic evacuation control valve 20 provided at the inlet of the in-machine evacuation piping 12, and the conductivity measurement provided in the vacuum chamber 10 to detect changes in the concentration of shaft sealing oil in the vacuum chamber 10. When the inside of the turbine generator 1 is evacuated, the conductivity measurement sensor 17 communicates with the vacuum chamber 10 via a converter 18 and a positioner 19 in response to a detection signal from the conductivity measurement sensor 17. An automatic evacuation control valve 20 provided at the inlet of the in-machine evacuation piping 12 is opened and closed.

Therefore, when the turbine generator 1 is evacuated, a change in the bubbles that occur rapidly and in large quantities in the vacuum chamber 10, that is, a change in the concentration of the shaft sealing oil, is detected as a resistance change, and based on this, automatic evacuation is performed. Since the displacement of the vacuum pump 15 is automatically controlled by the control valve 20, the status of the shaft seal oil in the vacuum chamber 10 and the cavitation occurrence state of the regular shaft seal oil pump 4 can be visually monitored as in the conventional case. While preventing the occurrence of cavitation in the regular shaft seal oil pump 4, the vacuum level inside the turbine generator 1 reaches an absolute pressure of about 20 mmHgabs from atmospheric pressure, and the inside of the turbine generator 1 is purged from air to hydrogen. Automatic vacuum replacement from gas or hydrogen gas to air becomes possible. In addition, for the above-mentioned reasons, there is no longer a need for on-site monitoring and manual operation of the manual vacuum valve in the machine, which makes it possible to save labor and almost eliminate maintenance errors. It can also be operated automatically from the central control room. Furthermore, for the above-mentioned reasons, even when the machine is being evacuated, extremely high-quality shaft seal oil can be supplied from the vacuum chamber 10 to the shaft seal portion 23 of the turbine generator 1, and hydrogen gas from the shaft penetrating portion can be supplied. This makes it possible to reliably prevent leakage.

[Effects of the Invention] As explained above, according to the present invention, cavitation of the regular shaft seal oil pump is automatically prevented, and the inside of the turbine generator is automatically evacuated. An extremely reliable shaft seal oil supply device for a turbine generator that can supply seal oil to the shaft seal portion can be provided.

[Brief explanation of the drawing]

The figure is a configuration diagram showing an embodiment of a shaft seal oil supply device for a turbine generator according to the present invention. DESCRIPTION OF SYMBOLS 1... Turbine generator, 2, 3... Shaft seal part, 4... Regular shaft seal oil pump, 5... Emergency shaft seal oil pump, 6a, 6b... Relief valve, 7a, 7
b, 22... Check valve, 8... Oil guide pipe, 9... Adjustment valve, 10... Vacuum tank,... Suction pipe, 12... In-machine vacuum piping, 13... Float valve, 14... Peephole , 15... Vacuum pump, 16... Inlet valve of vacuum pump 15, 17... Sensor for measuring conductivity, 1
8...Converter, 19...Positioner, 20...
Automatic vacuum control valve, 21...oil drain pipe.

Claims (1)

[Scope of Claims] 1. A turbine generator which performs cooling by sealing a cooling medium such as hydrogen gas inside the machine, and which is provided with a shaft seal portion in the shaft penetrating portion to prevent leakage of the cooling medium to the outside. In the device for supplying shaft seal oil to the shaft seal portion, the shaft seal oil is stored inside, and is communicated with the shaft seal portion through an oil drain pipe, and also communicates with the inside of the turbine generator through an in-machine vacuum piping. a shaft sealing oil pump that supplies shaft sealing oil introduced from the vacuum tank through an absorption pipe to the shaft seal portion via an oil guide pipe; and an automatic vacuum control provided at the inlet of the in-machine vacuum piping. a valve, and a conductivity measurement sensor provided in the vacuum chamber to detect a change in the concentration of shaft seal oil in the vacuum chamber, and when the inside of the turbine generator is evacuated, the conductivity A shaft sealing oil supply device for a turbine generator, characterized in that an automatic vacuum control valve provided in an in-machine vacuum piping communicating with the vacuum chamber is opened and closed in response to a detection signal from a measurement sensor. .