JPH0160733B2 - - Google Patents

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a gas supply device such as a gas turbine control device that controls the output of a gas turbine by adjusting the flow rate of fuel gas. In particular, the present invention relates to a leakage gas discharge device for discharging the leaked fuel gas.

(Prior Art) First, the aforementioned gas turbine control device will be explained with reference to FIG.

A compressor 1 that compresses intake air is driven by an output shaft 3 of a gas turbine 2, and the air compressed within the compressor 1 is guided to a combustor 5 via a pipe 4. ing. On the other hand, this combustor 5 includes a strainer 6,
A pipe line 9 in which an on-off valve 7 and a control valve 8 are respectively installed.
Gaseous fuel is supplied through the system, mixed with air, and combusted. The high temperature gas generated by the combustion of the gas fuel in the combustor 5 is transferred to the pipe 10.
The gas is supplied to the gas turbine 2 via the gas turbine 2, rotates turbine blades (not shown), and generates electricity by a coaxially arranged generator 11.

The rotation speed of the output shaft 3 is determined by the rotation speed pick-up 1.
This measured value is fed back to the control device 13, which controls the on-off valve 7 and the control valve 8, and calculates the load on the compressor 1 from the output of the gas turbine 2. Gas fuel is supplied to the combustor 5 in an amount corresponding to the load of the generator 11 determined by subtraction.

By the way, the on-off valve 7 and the control valve 8 have movable parts, and there is a possibility that flammable fuel gas may leak from the ground part. If the on-off valve 7 and the control valve 8 are installed outdoors or in a well-ventilated place, there is no problem because even if flammable gas leaks from the gland, it will not accumulate, but this is especially true for large power generation plants such as combined cycle. In general, the gas turbine is usually installed inside a building, and in order to improve the gas turbine load followability and prevent overspeed, it is generally necessary to install the control valve 8 etc. near the gas turbine 2. It is difficult to install it outside the building. In this case, the entire building must be well ventilated to prevent flammable gas from accumulating in the event of a leak. Additionally, if the building has poor ventilation, it will be necessary to make the electrical equipment throughout the building explosion-proof.
This is extremely difficult both technically and cost-wise.

In addition, in gas handling equipment that handles flammable gases and harmful gases, which have been known in the past,
Some of them are described in Japanese Utility Model Publication No. 56-43647. The former bulletin uses a blower to forcibly discharge explosive gases heavier than air, such as gasoline or propane, that have leaked into the gasoline pump room of a gas station, and the latter The dust and harmful gases flowing along the ceiling are passed through conduits to the outside of the structure, and are forcibly exhausted by exhaust fans.

(Problems to be Solved by the Invention) In conventional gas handling devices used for ventilation in pump rooms of gas stations and indoor structures, explosive gases such as gasoline, which are to be exhausted, are heavier than air. , because it handles gases that are lighter than air, such as harmful gases, centrally.
There are no particular difficulties in the exhaust structure for explosive or harmful gases.

However, in gas turbine combustors, LNG (liquefied natural gas), which is lighter than air, and LPG (liquefied propane gas), which is heavier than air, are selectively used as fuel, and these two conflicting types of fuel are used. In a gas supply device that handles gas, it is necessary to install an independent leakage gas exhaust device for each fuel gas, and each time the fuel gas is changed, it is necessary to install a new leakage gas exhaust device or modify the leakage gas exhaust device.

The present invention has been made in consideration of the above-mentioned circumstances, and even when two types of conflicting flammable gases are handled, leaked flammable gas can be actively and efficiently discharged to the outside using a single leakage gas discharge device. It is an object of the present invention to provide a leakage gas exhaust device in a gas supply device that can perform the following steps.

[Structure of the Invention] (Means for Solving the Problems) In order to solve the above-mentioned problems, a leakage gas discharge device in a gas supply device according to the present invention includes a valve, a strainer, etc. in a pipe line for supplying flammable gas. In a gas supply device equipped with a device, the device is surrounded by a box having a sloped top wall and a bottom wall, and the box has a wall near the top of the slope top wall and a bottom near the bottom of the slope bottom wall. The end opening of the leaked gas suction pipe is faced, and the gas suction pipe is connected to the gas exhaust machine, and a switching valve is provided in the gas suction pipe to connect either one of the end openings to the gas exhaust machine. be.

(Function) Since the leakage gas discharge device in this gas supply device has the above-described configuration, leakage gas lighter than air is discharged from the tip opening near the top of the inclined top wall, and leakage gas heavier than air is discharged from the tip opening near the top of the inclined top wall. It can be effectively and efficiently discharged from the tip opening near the bottom of the wall by operating the switching valve, and even if two types of conflicting flammable gases are used, a single leakage gas discharge device can be used. This allows efficient forced exhaust, and even if the type of combustible gas is changed, there is no need to install or modify a leakage gas exhaust device.

(Example) Hereinafter, the present invention will be explained using examples shown in the drawings.

FIG. 2 shows a first embodiment of the present invention, and in FIG. 2, a strainer 6, an on-off valve 7, a control valve 8, and an oil cylinder (not shown) installed in a flammable gas pipe 9 are shown. , a spring box, a differential transformer, a solenoid valve, a pressure transmitter, a pressure switch, and other devices are surrounded by a box 14.
The top wall 14a and the bottom wall 14b of No. 4 are inclined. Further, a gas ejector 15 consisting of a pump is installed on the bottom wall 14b of the box body 14, and this ejector 15 is connected to a leakage gas suction pipe 16 via a flange 17.

The gas suction pipe 16 is branched from the middle, one directly below the top of the top wall 14a, and the other directly below the bottom wall 1.
4b, each has a tip opening 16 immediately above the lowest point.
A and 16b are arranged so as to face each other. Also,
The tip opening 16 is located in the branch portion of this suction pipe 16.
Only one of a and 16b is the gas discharger 15
A switching valve 21 is provided so as to communicate with the.
Furthermore, air inlets 20, 20a are formed at the lower and upper ends of each side wall 14c of the box body 14, respectively, and the air inlets 20, 20a are switched so that only one of them is opened. It is becoming more and more common.

The gas discharger 15 also has a tip opening 18a.
is connected to a blow-off pipe 18 which is outside the box body 14 and faces the outside of the building (not shown). Note that the gas exhaust device 15 may be installed outside the box 14, but this gas exhaust device 15 also has a ground portion, and there is a risk of flammable gas leaking into the building installed outside the box 14. Therefore, in this embodiment, it is installed inside the box body 14.

Each flange portion 7 of the on-off valve 7 and control valve 8
Since flammable gas is likely to leak from the flanges 7a and 8a, there are conduits 1 communicating with the suction pipe 16 at positions closer to the conduit 9 than the flange portions 7a and 8a, respectively.
9 is connected to the flammable gas directly inhaling pipe 1.
It is designed to suck in 6. Furthermore, air inlet ports 20 are formed at the lower ends of the side walls 14c of the box body 14, respectively.

According to the above-described configuration, even if flammable gas leaks from the strainer 6, the on-off valve 7, the control valve 8, etc., if this flammable gas is lighter than air, the switching valve 21 is operated to remove the upper tip. Opening 16a
What is necessary is to communicate with the gas discharger 15 and open the lower air inlet 20. In addition, if the flammable gas is heavier than air, the lower tip opening 1
6b with the gas discharger 15 and open the upper air inlet 20a. This makes it possible to effectively capture and effectively discharge both combustible gases that are lighter than air and combustible gases that are heavier than air.

FIG. 3 shows an embodiment in which air is introduced into the box body 14 through a conduit 22 instead of the air inlets 20, 20a in the embodiment shown in FIG. Since the control valve 8 and the control valve 8 are the same as those shown in FIG. 2, illustration thereof is omitted.

The conduit 22 has an inlet port 22a facing outside the box body 14.
and discharge ports 22b and 22c facing the upper and lower ends of the box body 14, respectively, and the inside has a hole such that only one of the discharge ports 22b and 22c communicates with the suction port 22a. A switching valve 23 is provided.

With this configuration, as in the embodiment shown in FIG. 4, both combustible gases lighter than air and combustible gases heavier than air can be forcibly discharged.

It goes without saying that the present invention can also be applied to devices other than the turbine control device described above.

〔Effect of the invention〕

As explained above, in the leakage gas discharge device in the gas supply device according to the present invention, devices such as valves and strainers are surrounded by a box having an inclined top wall and a bottom wall, and the box has an inclined top wall. The tip opening of the leaked gas suction pipe is faced near the top of the top and the bottom of the inclined bottom wall, and the gas suction pipe is connected to the gas exhaust machine, while either of the tip openings is placed inside the gas suction pipe. Since we have installed a switching valve that communicates with the gas discharger, even if flammable gas leaks from equipment such as valves or strainers, even if the leaked flammable gas is heavier than air or lighter than air, the switching valve will The switching operation and the sloping top and bottom walls can effectively capture flammable gas, forcefully and effectively exhaust leaking gas outside the building, and prevent explosions due to flammable gas leaks. .

In addition, even if two types of conflicting flammable gases are used, this leakage gas exhaust device can take measures against leakage gas by switching the switching valve. However, this has the effect of eliminating the need for new installation or modification of a leakage gas exhaust device.

[Brief explanation of drawings]

FIG. 1 is a pipeline diagram showing a general turbine control device, and FIGS. 2 and 3 are sectional views showing respective embodiments of a leakage gas exhaust device in a gas supply device according to the present invention. 1... Compressor, 2... Turbine, 6...
Strainer, 7... Open/close valve, 8... Control valve, 9...
...Pipe line, 11... Generator, 14... Box body, 15...
...Gas exhaust machine, 16...Gas suction pipe, 18...Gas discharge pipe, 20, 20a...Air inlet, 21,
23...Switching valve, 22...Conduit.

Claims (1)

[Scope of Claims] 1. In a gas supply device in which equipment such as a valve and a strainer is interposed in a pipe line for supplying flammable gas, the equipment is surrounded by a box having an inclined top wall and a bottom wall, and the above-mentioned The top opening of the leaked gas suction pipe is placed in the box body near the top of the sloped top wall and near the bottom of the sloped bottom wall, and the gas suction pipe is connected to the gas exhaust machine. A leakage gas exhaust device in a gas supply device, characterized in that a switching valve is provided that connects either one of the tip openings to a gas exhaust device. 2. The box body is provided with a conduit for introducing air into its interior, and this conduit has an inlet facing the outside of the box body, and an outlet facing the upper and lower ends of the box body; The leakage gas exhaust device in the gas supply device according to claim 1, wherein either one of the two exhaust ports is configured to communicate with the suction port via a switching valve.