JPH0639068Y2 - Gas turbine blow valve operation detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial field of application) The present invention relates to an operation detecting device for a gas turbine blow valve that detects the open / closed state of a blow valve attached to a gas turbine.

(Prior Art) A gas turbine provided in a combined cycle power generation plant or a gas turbine power generation plant is provided with a plurality of blow-off valves for extracting and releasing the air compressed by a compressor. The blow-off valve opens when the gas turbine is started or stopped and blows air to the compressor to prevent surging of the compressor. As a result, when the gas turbine is started, the gas turbine can be efficiently and smoothly started up while giving an appropriate load to the compressor. When the gas turbine reaches a predetermined rotation speed, the blow-off valve is closed and air compression by the compressor is started.

As shown in FIG. 7, the blow-off valve 1 has a valve stem 2 linked to an electrical limit switch 3 for full opening and closing, and the limit switch 3 detects the open / closed state of the blow-off valve 1. is doing. The limit switch 3 plays an important role in maintaining the safety function of the gas turbine.
The operation of the gas turbine is controlled by detecting the open / closed state of.

On the other hand, the gas turbine is designed to trip due to malfunction or non-operation of the limit switch 3 attached to the blowoff valve 1.
The limit switch 3 is required to be highly reliable and free from malfunctions because it may seriously hinder the stop schedule or interfere with the operation of the power plant.

However, the blowoff valve 1 is installed in the gas turbine compartment 4 in a high temperature atmosphere of, for example, about 200 ° C. and the upper part exceeds 200 ° C. due to heat radiation from the gas turbine combustor, and the limit switch 3 attached to the blower valve is also installed. Exposed to a high temperature atmosphere. Since the gas turbine compartment 4 is an explosion danger area due to high temperature and flammable gas leakage, the electric parts must have heat resistance and must be explosion proof.

(Problems to be solved by the invention) When the gas turbine blow valve 1 is used in a high temperature atmosphere of about 200 ° C., the limit switch 3 attached to the blow valve 1 has heat resistance and pressure resistance. Therefore, the switch structure is provided with a seal packing and a spring.However, repeated start and stop of the gas turbine adversely affects the temperature, which deteriorates the seal packing and changes the spring constant. There is a problem that contact failure occurs, malfunction or non-operation occurs, the reliability of the switch deteriorates due to malfunction, the heat deterioration of the limit switch causes a large deterioration effect, and it is prone to failure, and the open / close state of the blow valve is accurate. There was a problem that it could not be detected.

The present invention has been made in view of the above circumstances, and provides a highly reliable gas turbine blowoff valve operation detection device that accurately and reliably detects the open / closed state of a blowoff valve even in a high temperature atmosphere. With the goal.

[Constitution of device]

(Means for Solving the Problem) An operation detecting device for a gas turbine blowoff valve according to the present invention is opened / closed in association with the opening / closing operation of a blowoff valve attached to a gas turbine in order to solve the above-mentioned problems. Has a fluid type limit valve and a pressure switch that is interlocked with the opening / closing operation of the limit valve and detects the opening / closing operation of the limit valve at a remote position. The pressure switch detects the open / closed state of the blowoff valve. It is a thing.

In addition, in order to solve the above-mentioned problems, the operation detecting device for a gas turbine blow valve of the present invention includes a fluid type limit valve housed in a gas turbine compartment and a pressure switch outside the gas turbine compartment. It is provided separately from the valve.

(Operation) This gas turbine blowoff valve operation detection device is provided with a fluid type limit valve that is interlocked with the opening and closing operation of the blowoff valve, so that the opening and closing operation of this limit valve can be detected from a remote position by a pressure switch, A highly reliable detection device capable of accurately and reliably detecting the open / closed state of a blowoff valve even in a high temperature atmosphere.

In that case, the pressure switch of the operation detection device can be installed separately from the fluid type limit valve, so that the pressure switch can be installed outside the gas turbine compartment. If the pressure switch is installed outside the gas turbine compartment, the pressure switch can be easily adjusted, the detection accuracy is further improved, and the operation detection device is further improved in reliability.

(Embodiment) An embodiment of the operation detecting device for a gas turbine blowoff valve according to the present invention will be described below with reference to the accompanying drawings.

FIG. 2 is a schematic sectional view of a gas turbine 10 provided in a combined cycle power plant or a gas turbine power plant. This gas turbine 10 is a power generation system utilizing the expansion force of gas, and is configured by combining a compressor section 11 as a compressor, a combustor 12 and a turbine section 13, and the air compressed in the compressor section 11 is burned. Was introduced into vessel 12, where
It is mixed with fuel such as LNG and burned. The combustion gas generated by this combustion is guided to the turbine section 13 to perform work, and the gas turbine 10 rotates a generator (not shown) to generate electricity. The exhaust gas that has worked in the turbine section 13 is finally discharged to the outside through the exhaust passage 14. Since the gas turbine 10 can be easily started and stopped, it can be operated immediately in response to changes in power demand, and for example, is operated in the daytime power demand time zone.

The gas turbine 10 has a blow-off valve for extracting compressed air from the middle section of the compressor (compressor section) 11, for example, the 11th section.
A plurality of, for example four, 15 are provided, and this blowoff valve 15
The compressed air extracted by opening the valve bypasses the combustor 12 and the turbine section 13 and is discharged outside the exhaust flow path (exhaust pipe). Due to this blast, the gas turbine 10 can be efficiently started while applying an appropriate load to the compressor 11, for example.

As shown in FIG. 3, the blowoff valve 15 is installed in the gas turbine compartment 16 that receives heat from the gas turbine combustor 12 and has a high temperature atmosphere of, for example, about 200 ° C. or higher, and is used for the control shown in FIG. It is opened and closed by the control air from the compressor 18. The control compressor 18 has, for example, two systems, one of which is for backup. Control air (operating air) of, for example, 7 kg / cm ² G is supplied from the control compressor 18 to the cylinder chamber 20 of the blow-off valve 15 via the control valve 19 by the gas turbine control panel (not shown). The piston 21 in 20 is operated to open it. While the control air is temporarily stored in the receiver as an air reservoir, it has no void and is dehumidified / dust-free clean air.

The blowoff valve 15 has a valve structure shown in FIGS. 1 and 4.
A hemispherical valve body 25 seated on a valve seat 24 is rotatably supported in a valve casing 23 of the blowoff valve 15, and a rotation shaft of the valve body 25.
A valve stem 28 is connected to the valve 26 via a mechanical power transmission means such as a link mechanism 27. A piston 21 that slides in the cylinder chamber 20 is provided at the other end of the valve stem 28.
21 is urged by the spring force of the spring 29 so as to always close the blowoff valve 15.

On the other hand, when the gas turbine 10 is started / stopped, a gas turbine control panel (not shown) is operated to open the control valve 19, and the control air is guided from the control compressor 18 to the cylinder chamber 20 of the blowoff valve 15. . When the control air (operating air) is injected into the cylinder chamber 20, the control air presses the piston 21 against the spring force of the spring 29 and moves the valve stem 28 to move the valve body 25 at a required angle, for example, It is designed to rotate 90 degrees to open the blowoff valve 15.

Further, the blowoff valve 15 is additionally provided with an air type limit valve 30 as a fluid type limit valve. The pneumatic limit valve 30 is a maintenance-free, self-reset type overflow prevention valve that does not use seal packing. The pneumatic limit valve 30 is attached to the blowoff valve 15 via a mounting plate 31.

Specifically, as shown in FIG. 5, the valve stem of the blowoff valve 15
An operating lever 33 is fixed to the lever 28 in a cantilever shape, and an adjusting knob 34 is adjustably attached to the free end side of the operating lever 33. The adjusting knob 34 faces the reset button 35 of the pneumatic limit valve.

The pneumatic limit valve 30 is a known one having a reset button 35 and a magnet inside the valve (both not shown), and when the reset button 35 is pressed, the magnet inside the reset button pushes down the valve internal magnet.
The magnetic force pushes down the poppet portion from the valve seat to open the limit valve 30, and normally the air pressure on the upstream side of the limit valve 30 pushes the poppet portion against the valve seat to close it.

By the way, as shown in FIGS. 5 and 6, the control air from the control compressor 18 is constantly acting on the pneumatic limit valve 30. Specifically, the control compressor
The control air of, for example, 7 kg / cm ² G from 18 is reduced to an easy-to-use pressure of, for example, about 1 kg / cm ² G by the pressure reducing valve 43 via the header 41 and the partition valve 42, and this reduced control air is pneumatic. It acts on the upstream side of the limit valve 30. The limit valve 30 may be supplied with other non-combustible gas such as N ₂ or an inert gas instead of the control air.

A pressure switch 45 interlocking with the limit valve 30 is provided downstream of the pneumatic limit valve 30. This pressure switch 45 is located away from the pneumatic limit valve 30,
Preferably, it is provided outside the gas turbine compartment 16. The pressure switch 45 is preferably located outside the gas turbine compartment 16 and as close to the compartment 16 as possible, for example in the junction box 46. This is to accelerate the operation time of the pressure switch 45. The pressure switch 45 detects the open / closed state of the blowoff valve 15 in conjunction with the opening / closing operation of the pneumatic limit valve 30.

Further, the pressure switch 45 is electrically connected to an alarm device, an operation display device, and a gas turbine control device, which are not shown, and audibly or visually displays the open / closed state of the blowoff valve 15,
The gas turbine 10 is tripped or interlocked by controlling the operation of the gas turbine controller.

Further, a normally open bleed valve 48 is provided in the air flow path branched from the downstream side of the pneumatic limit valve 30, and the bleed valve 48 adjusts the blow amount of control air. The bleed valve 48 plays an auxiliary role when the self-resetting pneumatic limit valve 30 self-returns from the open state to the closed state. In the pneumatic limit valve 30, when the blowoff valve 15 is closed, the operating lever 33 shifts to the closing side, and the reset button 35 becomes free. When the reset button 35 becomes free, the repulsion of both built-in magnets causes the reset button 35 to return to its original position (closed side), and the restraint force of the valve body is released. This valve body is automatically closed by the air pressure acting on the upstream side of the valve body when an air flow rate exceeding a certain flow rate flows. The self-reset type limit valve 30 needs to flow an air flow rate above a certain level in order to automatically close this valve, and a bleed valve 48 is installed to secure this air flow rate. However, since this air amount is small, the operation of the pressure switch 45 is not hindered when the limit valve 30 is opened.

Next, the operation of the operation detecting device for the gas turbine blowoff valve will be described.

Control compressor when starting and stopping the gas turbine
Control air is supplied from 18 to the cylinder chamber 20 of the blowoff valve 15,
The piston 21 is pressed against the spring force of the spring 29.
Due to this pressing, the valve body 25 of the blow-off valve 15 is rotated to switch from the fully closed position to the fully open position.

When the blow-off valve 15 is opened, compressed air is extracted from the compressor 11 of the gas turbine 10, and this extracted air is released to the outside such as the exhaust side of the gas turbine 10 via the blow-off valve 15. As a result, the load on the compressor 11 is reduced, and the gas turbine 10 can be started smoothly while applying an appropriate load. When the gas turbine 10 is started and reaches a predetermined rotation speed, the blowoff valve 15 is closed by the operation control of the gas turbine control panel.

By the way, when the blow-off valve 15 is opened, the actuating lever 33 fixed to the valve stem 28 moves integrally and presses the reset button 35 of the self-resetting type pneumatic limit valve 30. By pressing the reset button 35, the reset button 35 is pushed down to the position shown by the broken line in FIG. Due to this depression, the magnet inside the reset button pushes down the magnet inside the valve, and the magnetic force pushes down the poppet portion from the valve seat to open the limit valve 30.

When this limit valve 30 is opened, control air acts on the pressure switch 45, and for example, an automatic reset type micro switch housed in the pressure switch 45 is operated to activate an alarm device or an operation display device (both not shown). Operate and blow off valve 15
Display the open / close status of. Then, for example, if the blow-off valve 15 is not opened at the time of starting the gas turbine, the turbine is tripped or an alarm is issued if one of the four blow-off valves 15 is not opened.

On the other hand, when the blowoff valve 15 is closed from the open state, the operating lever 35 moves following this closing operation, the reset button 35 of the pneumatic limit valve 30 becomes free, and the reset button 35 repels both magnets. The force automatically returns to the original position (closed position). By this return, the valve internal magnet is also freed, the valve body is automatically closed by the pressure of the control air acting on the upstream side, and the valve body is prepared for the next start or stop of the gas turbine.

In this case, the pneumatic limit valve 30 installed in the gas turbine compartment 16 is a self-reset type and is not an electric part such as a limit switch, and since seal packing is not required, it is not always necessary to use a pressure-proof explosion-proof specification. The limit valve 30 is highly reliable and has little deterioration due to heat. Furthermore, since the pressure switch 45 can be installed remotely from the limit valve 30, when installed in the gas turbine compartment 16,
It can be installed on the lower temperature side, and can be less likely to be adversely affected by heat. Further, when the pressure switch 45 is installed outside the gas turbine compartment 16, the adverse effect of heat can be reliably prevented and the operability can be improved.

This blow-off valve operation detector was installed in a gas turbine of a 165,000 KW class combined cycle power plant and a gas turbine start / stop test was conducted for 9 months. There were no malfunctions such as malfunctions and malfunctions, and it was smooth. By the way, in this test, the gas turbine was started 90 times.

[Effect of device]

As described above, in the operation detecting device for the gas turbine blow valve according to the present invention, the fluid type limit valve interlocking with the opening / closing operation of the blow valve is provided, and the opening / closing operation of this limit valve is separated by the pressure switch. Since it can be detected from the position, the limit valve installed in a high temperature atmosphere does not require mechanical and explosion-proof electrical parts, and can accurately and reliably detect the open / closed state of the blowoff valve, and it is reliable with few failures. It is a highly reliable operation detection device.

Also, because the pressure switch can be installed separately from the fluid limit valve, the pressure switch can be installed outside the gas turbine compartment.
Since the pressure switch is easily adjusted and is not adversely affected by heat, the detection accuracy can be further improved.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of an operation detecting device for a gas turbine blow valve according to the present invention, FIG. 2 is a schematic diagram showing a gas turbine equipped with the present invention, and FIG. 3 is a gas turbine blow valve. FIG. 4 is a schematic view showing a mounting mode of the operation detecting device of FIG.
Fig. 5 is a sectional view taken along line IV-IV, Fig. 5 is an enlarged partial view of an essential part of the present invention, and Fig. 6 is a diagram showing a control system of a gas turbine blow valve operation detecting device according to the present invention. FIG. 7 is a view showing a conventional operation detecting device for a gas turbine blowoff valve. 10 …… Gas turbine, 11 …… Compressor (compressor section), 12 …… Combustor, 13 …… Turbine section, 14 …… Exhaust flow path, 15 …… Blowoff valve, 16 …… Gas turbine compartment, 18 ...... Control compressor, 19 ...... Control valve, 20 ......
Cylinder chamber, 21 …… Piston, 28 …… Valve stem, 30 ……
Pneumatic limit valve (fluid limit valve), 33 ...
… Actuating lever, 34 …… Adjustment knob, 35 …… Reset button, 43 …… Reducing valve, 45 …… Pressure switch, 48 …… Bleed valve.

Claims (2)

[Scope of utility model registration request] 1. A fluid type limit valve that opens and closes in conjunction with the opening and closing operation of a blowoff valve attached to a gas turbine, and a position apart from the opening and closing operation of the limit valve in conjunction with the opening and closing operation of the limit valve. And a pressure switch for detecting the open / closed state of the blowoff valve by the pressure switch. 2. The operation detection of the gas turbine blow-off valve according to claim 1, wherein the fluid type limit valve is housed in the gas turbine compartment, and the pressure switch is provided outside the gas turbine compartment and apart from the fluid type limit valve. apparatus.