JPH06281366A - Controller for gas extractor - Google Patents

Abstract

PURPOSE:To ensure an amount of gas required for the operation of a gas extractor by a method wherein a changeover operation of suction of the atmospheric air to recirculation of a portion of non-condensing gas to a condenser is carried out at the start-up time and during loading operation of a steam turbine. CONSTITUTION:At the start-up time of a steam turbine 1, a start-up ejector 4 is operated to increase the vacuum pressure of a condenser 5, and air suction of a gas extractor 3 which is coaxially connected to the steam turbine 1 is controlled. And, when the load of the steam turbine 1 increases, an air suction valve is closed in response to a loading signal and a portion of delivered gas from the gas extractor 3 is recirculated to the condenser 5 via a gas recirculation pipe 10 and a gas recirculation control valve 17. Thereby, an amount of gas required for the operation of the gas extractor 3 can be ensured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas extractor device for extracting a non-condensable gas from a condenser in a geothermal power plant and maintaining a condenser vacuum degree, and particularly to starting and loading of the gas extractor device. The present invention relates to control of a gas extractor when the amount of non-condensed gas decreases during operation.

[0002]

2. Description of the Related Art FIG. 3 is a system diagram showing a configuration of a conventional gas extractor device of this type, in which exhaust steam from a steam turbine 1 flows into a condenser 5. Bowl 5
The steam condenses due to heat exchange between the steam and cooling water (not shown). On the other hand, the non-condensable gas contained in the steam is sucked by the gas extractor 3 from the gas extractor inlet valve 12 and the gas extractor inlet pipe 13, and is discharged by the gas extractor discharge pipe 6 and the check valve 8.
And it is released to the atmosphere through the gas release pipe 9.

To start the steam turbine 1, steam is introduced into the starting ejector 4 from the starting ejector actuating steam pipe 23 and the stop valve 26, and the air in the condenser 5 is started.
It is sucked through 11 and discharged to the atmosphere to raise the vacuum degree of the condenser 5 and then started. By this activation, the generator 2 and the gas extractor 3 that are coupled to one shaft also rotate up. At this time, the amount of gas in the condenser 5 is small and the minimum amount of gas required to operate the gas extractor 3 cannot be maintained. Therefore, the gas extractor gas inlet valve 12 is closed and the air suction pipe 16 and air Air is sucked from the volume control valve 15 and the air pipe 14, and the gas extractor 3
To ensure the minimum amount of gas needed to operate the. When the load on the steam turbine 1 increases, the gas extractor gas inlet valve 12
Is opened, the starting ejector gas inlet valve 11 and the stop valve 26 are closed, and the starting ejector 4 is stopped. When the amount of non-condensable gas from the condenser 5 decreases, the amount of gas required to operate the gas extractor 3 is adjusted by the orifice 7, the flow rate detector 21, and the converter 25 installed in the gas extractor discharge pipe 6. The air amount control valve 15 is controlled so that

[0004]

However, in the conventional gas extractor control device described above, the amount of gas contained in the steam of the geothermal power plant often decreases when the gas extractor 3 is operated for a long time. When the amount of non-condensed gas decreases and the amount of gas required to operate the gas extractor 3 cannot be secured, the gas extractor 3 is operated by sucking air from the atmosphere, and the gas having a larger molecular weight than the gas is used. There is a problem that the operation becomes long and the shaft power of the gas extractor becomes large.

The present invention has been made in view of the above situation, and when the steam turbine is started, the vacuum degree of the condenser is raised by the operation of the starter ejector, and the gas extractor connected to the single shaft is exposed to the atmosphere. When the suction control of air is performed and the steam turbine load rises, the gas flow rate detected by the gas extractor is used to recirculate a part of the gas amount from the gas extractor discharge to the condenser, and the gas required to operate the gas extractor is recirculated. An object of the present invention is to provide a gas extractor control device capable of switching and controlling air suction and gas amount recirculation so as to secure a sufficient amount.

[0006]

Means for Solving the Problems As a means for achieving the above object, the present invention increases the degree of vacuum of a condenser by operating a starter ejector at the time of starting a steam turbine, so that the gas is uniaxially connected. Suction control of air into the extractor,
When the steam turbine load increases, the load signal closes the air intake valve, and the discharge amount of the gas extractor changes the amount of gas that is recirculated to the condenser. And a control mechanism for controlling so that

[0007]

In the gas extractor control device according to the present invention, the suction of the gas extractor is provided with the air pipe for controlling the intake of air and the air amount control valve, and the discharge of the gas extractor is provided with the gas extractor. Gas recirculation pipe for controlling the amount recirculation,
A gas recirculation amount control valve is provided. At the time of starting the steam turbine, the starter ejector is operated to raise the vacuum degree of the condenser, and the gas extractor connected to the single shaft has the atmospheric pressure to ensure the minimum amount necessary for operating the gas extractor. Suction control of air by the air pipe and air amount control valve, when the steam turbine load rises, the load signal closes the air amount control valve of atmospheric air and switches to the gas recirculation amount control valve. By recirculating a part of the gas amount to the condenser with the gas recirculation pipe and the gas recirculation amount control valve in order to secure the gas amount necessary for the operation of the gas extractor,
It becomes possible to control to secure the amount of gas required for operating the gas extractor.

[0008]

1 is a system diagram showing a gas extractor control device according to a first embodiment of the present invention. In the figure, exhaust steam from a steam turbine 1 flows into a condenser 5. The steam is condensed by the heat exchange between the steam and the cooling water (not shown) in the condenser 5. On the other hand, the non-condensable gas contained in the steam is the gas extractor inlet valve 12, the gas extractor inlet pipe.
The gas is sucked in by the gas extractor 3 from 13 and is discharged to the atmosphere through the gas extractor discharge pipe 6, the check valve 8 and the gas discharge pipe 9. To start the steam turbine 1, steam is introduced into the starter ejector 4 through the starter ejector actuating steam pipe 23 and the stop valve 26, and the air in the condenser 5 is sucked through the starter ejector gas inlet valve 11 and released to the atmosphere. After the vacuum degree of the condenser 5 is increased, the condenser 5 is started. By this activation, the generator 2 and the gas extractor 3 which are connected to the single shaft also rotate up. At this time,
Since the amount of gas in the condenser 5 is small and the minimum amount of gas required to operate the gas extractor 3 cannot be maintained, the gas extractor gas inlet valve 12 is closed, the air suction pipe 16, the air amount control valve.
Air is sucked from 15 and the air pipe 14 to secure the minimum amount of gas required to operate the gas extractor 3. When the load of the steam turbine 1 increases, the gas extractor gas inlet valve 12 is opened, the starter ejector gas inlet valve 11 and the stop valve 26 are closed, and the starter esector 4 is stopped. When the amount of non-condensable gas from the condenser 5 decreases, the amount of gas required to operate the gas extractor 3 is adjusted by the orifice 7, the flow rate detector 21, and the converter 25 installed in the gas extractor discharge pipe 6. The air amount control valve 15 is controlled so that When the load on the steam turbine 1 increases, the electromagnetic valve 18 is closed and the electromagnetic valve 19 is opened by the generator outlet signal 20 and the converter 22. By this control, the air amount control valve 15 is closed. On the other hand, the gas recirculation amount control valve 17 opens the solenoid valve 19 in response to signals from the orifice 7, the flow rate detector 21, and the converter 25 installed in the discharge pipe 6 of the gas extractor to perform switching control. When the discharge amount decreases, a part of the gas amount is supplied to the condenser 5 by the gas recirculation pipe 10 and the gas recirculation amount control valve 17 in order to secure the gas amount necessary for the operation of the gas extractor 3. By recirculating, it is controlled to secure the amount of gas required for the operation of the gas extractor.

FIG. 2 is a system diagram showing a second embodiment of the present invention, in which the gas extractor is driven by a separate motor. That is, the exhaust steam from the steam turbine 1 flows into the condenser 5, and the steam and the cooling water (not shown) exchange heat in the condenser 5 to condense the steam. On the other hand, the non-condensable gas contained in the steam is sucked by the gas extractor 3 from the gas extractor inlet valve 12 and the gas extractor inlet pipe 13, and the gas extractor discharge pipe 6, the check valve 8 and the gas discharge pipe. It is released to the atmosphere from 9.

When the steam turbine 1 is started, steam is introduced into the starter ejector 4 from the starter ejector actuating steam pipe 23 and the stop valve 26, and the air in the condenser 5 is started.
It is sucked through 11 and discharged to the atmosphere to raise the vacuum degree of the condenser 5 and then started. At this time, since the amount of gas in the condenser 5 is small and the minimum amount of gas required to operate the gas extractor 3 cannot be maintained, the gas extractor gas inlet valve 12 is closed and the air suction pipe 16, air Air is sucked from the amount control valve 15 and the air pipe 14 to secure the minimum amount of gas required to operate the gas extractor 3. When the load on the steam turbine 1 increases, the gas extractor gas inlet valve 12 is opened, the starter ejector gas inlet valve 11 and the stop valve 16 are closed, and the starter ejector 4 is stopped. When the amount of non-condensable gas from the condenser 5 decreases, the amount of gas required to operate the gas extractor 3 is adjusted by the orifice 7, the flow rate detector 21, and the converter 25 installed in the gas extractor discharge pipe 6. The air amount control valve 15 is controlled so that When the load on the steam turbine 1 rises, the generator output signal
20, the solenoid 22 is closed by the converter 22, and the solenoid valve 19 is opened. By this control, the air amount control valve 15 is closed. On the other hand, the gas recirculation amount control valve 17 opens the solenoid valve 19 in response to signals from the orifice 7, the flow rate detector 21, and the converter 25 installed in the discharge pipe 6 of the gas extractor to perform switching control. When the discharge amount decreases, a part of the gas amount is supplied to the condenser 5 by the gas recirculation pipe 10 and the gas recirculation amount control valve 17 in order to secure the gas amount necessary for the operation of the gas extractor 3. By recirculating, it is controlled to secure the amount of gas required for the operation of the gas extractor.

[0011]

As described above, according to the present invention, when the steam turbine is started, the vacuum degree of the condenser is increased by the operation of the starter ejector, the gas extractor controls the intake of air, and the steam turbine is controlled. When the load rises, the load signal switches to close the atmospheric air intake valve and control the gas recirculation valve. When the gas extractor discharge decreases, part of the gas is recirculated to the condenser. By controlling so that the amount of gas required for the operation of the gas extractor is reduced, by recirculating a part of the discharge amount of the gas extractor to the condenser against the decrease in the amount of non-condensable gas during operation. Since the recirculation operation can be performed with a gas having a smaller molecular weight than that of air, the shaft power of the gas extractor can be reduced, and the amount of main steam of the geothermal power plant or the amount of power in the plant can be reduced.

[Brief description of drawings]

FIG. 1 is a system diagram showing a gas extractor control device according to a first embodiment of the present invention.

FIG. 2 is a system diagram showing a gas extractor control device according to a second embodiment of the present invention.

FIG. 3 is a system diagram showing a conventional gas extractor device.

[Explanation of symbols]

 1 ... Steam turbine 2 ... Generator 3 ... Gas extractor 4 ... Start-up ejector 5 ... Condenser 6 ... Gas extractor gas discharge pipe 7 ... Orifice 8 ... Check valve 9 ... Gas discharge pipe 10 ... Gas recirculation 11 ... Start-up ejector Gas inlet valve 12 ... Gas extractor gas inlet valve 13 ... Gas extractor gas inlet pipe 14 ... Air pipe 15 ... Air amount control valve 16 ... Air suction pipe 17 ... Gas recirculation amount control valve 18 ... Solenoid valve 19 ... Solenoid valve 20 ... Generator output signal 21 ... Flow rate detector 22 ... Converter 23 ... Start-up ejector actuation steam pipe 24 ... Motor 25 ... Converter 26 ... Stop valve

Claims (1)

[Claims] 1. In a gas extractor for extracting non-condensable gas from a condenser and maintaining the degree of vacuum of the condenser, a mechanism for sucking air into a gas extractor suction path and a condensate from a gas extractor discharge path. Equipped with a mechanism that recirculates a portion of the non-condensable gas to the condenser, switching operation that sucks in atmospheric air and recirculates a portion of the non-condensable gas to the condenser during steam turbine startup and load operation A gas extractor control device characterized by: