JPH0674061A - Method and device for protecting bypass device in power device - Google Patents

Abstract

PURPOSE:To reduce a temperature difference between the low temperature side and the high temperature side and to improve reliability by intercommunicating the low temperature side and the high temperature side and causing fluid for cooling on the low temperature side to flow to the high temperature side, in a bypass device to intercouple the outlet side of a compressor and the inlet side of an expansion turbine. CONSTITUTION:An expansion turbine 2 is driven by means of high temperature gas from a high temperature gas generating device 4. A compressor 1 is driven by means of an expansion turbine 2 and compressed air is fed to the high temperature gas generating device 4. Further, a generator 3 is coupled to the compressor 1 and the expansion turbine 2 through a single shaft. Meanwhile, a bypass device 7 intercouples the outlet side of the compressor 1 and the inlet side of the expansion turbine 2. In this constitution, the low temperature side 78 and the high temperature side 79 of the bypass device 7 are intercoupled through a communicating pipe 80 for cooling having a flow rate control valve 8. By causing fluid on the low temperature side 78 of the bypass device 7 to flow to the high temperature side 79, a temperature difference between the low temperature side 78 and the high temperature side 79 is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a high temperature gas generator,
In a power plant including a compressor, an expansion turbine, etc., a bypass device for bypassing compressed air from the compressor to the expansion turbine without passing through the high temperature gas generator when a trouble occurs in the device or equipment. And a protection device for cooling and protecting the low temperature side of the bypass device by connecting the low temperature side (compressor side) and the high temperature side (expansion turbine side) by a cooling communication means. The present invention relates to a protection method and a protection device suitable for cooling and protecting a bypass device by passing a fluid through a high temperature side to reduce a temperature difference between a low temperature side and a high temperature side of the bypass device.

[0002]

2. Description of the Related Art A conventional power unit equipped with a bypass device will be described with reference to FIGS. In the figure, reference numeral 4 is a high-temperature gas generator that works under atmospheric pressure or higher. In the figure, 2 is an expansion turbine. The expansion turbine 2 includes a first pipe 91 connected to the high temperature gas generator 4.
And is driven by the high temperature gas from the high temperature gas generator 4. In the figure, 1 is a compressor. The compressor 1 is connected to the expansion turbine 2 and is also connected to the high temperature gas generator 4 via a second pipe 92, and is driven by the expansion turbine 2 to drive compressed air into the high temperature gas generator. 4 is to be supplied. In the figure, 3 is the compressor 1 and the expansion turbine 2.
It is a generator that is uniaxially connected with. In the figure, 6
Reference numerals 5 and 5 are a first valve and a second valve respectively installed in the middle of the first pipe 91 and the second pipe 92. In the figure, 7 is a bypass device. This bypass device 7
As shown in FIG. 8, the connection pipe portion 71 on the inflow side (upstream side, that is, the low temperature side) provided on the side portion of the main body 70 and the outflow side (downstream side, that is, the high temperature side) provided on the lower portion of the main body 70. A connecting pipe portion 72, a valve seat 73 provided between the inflow side and the outflow side inside the main body 70, a valve rod 74 that can be advanced and retracted inside the main body 70, and a valve provided at the tip of the valve rod 74. A body 75, an opening / closing operator (for example, a solenoid) 76 that opens and closes the valve body 75 with respect to the valve seat 73 via the valve rod 74, and a heat insulating material 77 stretched over the connection pipe portion 72 on the outflow side. Consists of. In the connecting pipe portion 71 on the inflow side of the bypass device 7,
A second pipe 92 between the outlet side of the compressor 1 and the second valve 5 is connected via a connection pipe 78 on the inflow side. on the other hand,
The first pipe 91 between the inlet side of the expansion turbine 2 and the first valve 6 is connected to the outflow side connection pipe portion 72 of the bypass device 7 via the outflow side connection pipe 79.

The operation of the above power plant will be described below. First, during normal operation, as shown in FIGS. 6 and 8, the first valve 6 and the second valve 5 are opened (fully opened), and the valve body 75 of the bypass device 7 is brought into contact with the valve seat 73 and closed. Keep it (fully closed). Then, the high-temperature gas generated in the high-temperature gas generator 4 that performs work under atmospheric pressure or higher is
It is supplied to the expansion turbine 2 via the first pipe 91 and the first valve 6, and drives the expansion turbine 2. By driving the expansion turbine 2, the compressor 1 is driven, and the compressor 1
The compressed air generated in 2 is supplied to the high temperature gas generator 4 through the second pipe 92 and the second valve 5, and high temperature gas is generated in the high temperature gas generator 4. Hereinafter, the above work cycle is repeated. On the other hand, a generator 3 uniaxially connected to the compressor 1 and the expansion turbine 2.
Drive to do the work of generating electricity. In addition, during the normal operation, the valve body 75 of the bypass device 7 is operated by the valve seat 73.
Since the connecting pipe portion 72 side on the outflow side of the bypass device 7 has a high temperature because it is in contact with and is closed, the heat insulating material 77 stretched on the connecting pipe portion 72 on the outflow side insulates it from the outside. ing. Then, when any one of the high temperature gas generator 4 or the compressor 1, the expansion turbine 2 or the like in the power unit described above is in an abnormal state, that is, at the time of trouble, as shown in FIG. The first valve 6 and the second valve 5 are closed (fully closed) to shut off the compressed air supplied from the compressor 1 to the high temperature generator 4 and supplied from the high temperature gas generator 4 to the expansion turbine 2. Shuts off hot gases. At the same time, the valve body 75 of the bypass device 7 is separated from the valve seat 73 and opened (fully opened). Then, the compressed air from the compressor 1 does not pass through the high-temperature gas generator 4 and the bypass device 7
To the expansion turbine 2 via. That is, the compressed air from the compressor 1 passes through the second pipe 92, the inflow side connection pipe 78, the connection pipe portion 71, the outflow side connection pipe portion 72, the connection pipe 79, and the first pipe 91, and the expansion turbine 2 Bypass to. That is, in the above-described power plant, when the energy balance of these systems is lost, or when a trouble occurs in each device, it becomes a very serious problem. For example, from the high temperature gas generator 4 to the expansion turbine 2
When the energy supply to the expansion turbine 2 increases abnormally, the expansion turbine 2 causes a rapid change in speed or a change in load.
The pipe 91 is provided with the first valve 6, and when an abnormality occurs in the high temperature gas generator 4, the first valve 6 is closed to shut off the energy supply from the high temperature gas generator 4. ing. When the high temperature gas generator 4 itself is abnormal, the high temperature gas generator 4 is driven by the expansion turbine 2 to supply compressed air to the high temperature gas generator 4 and the first gas between the compressor 1 and the high temperature gas generator 4. The second pipe 5 is provided with the second pipe 92, and when an abnormality occurs in the high temperature gas generator 4, the second valve 5 is closed to supply compressed air to the high temperature gas generator 4. Cut off. At this time, if the second valve 5 is closed abruptly, there will be no place for the compressed air to go, so the second pipe 92 connecting the compressor 1 and the high temperature gas generator 4, and the high temperature gas generator 4 and the expansion turbine. First pipe 91 connecting 2
The bypass device 7 for bypassing is installed, the valve body 75 of the bypass device 7 is opened, and the compressed air is bypassed to the expansion turbine 2. As a bypass device in such a power plant, for example, Japanese Patent Laid-Open No. 62-
There is one described in Japanese Patent No. 178731.

[0004]

However, since the bypass device 7 in the above-described power plant is closed during the normal operation of the power plant, the bypass side of the compressor 1 (that is, the bypass side of the bypass device 7 on the inflow side). Between the connection pipe 78 and the low temperature side of the connection pipe part 71) and the inlet side of the expansion turbine 2 (that is, the connection pipe 79 on the outflow side of the bypass device 7 and the high temperature side of the connection pipe part 72). , There is a considerable temperature difference. For example, the low temperature side of the bypass device 7 is about 35
The temperature on the hot side of the bypass device 7 is about 8 while it is 0 °.
The bypass device 7 is always exposed to the low temperature fluid and the high temperature fluid. Therefore, the bypass device 7 is likely to be thermally deformed due to this temperature difference. Further, there is a possibility that thermal stress will be generated locally in the bypass device 7, and the reliability of the bypass device 7 becomes a problem. Further, when thermal deformation occurs, the sealing property of the valve body 5 inside the bypass device 7 deteriorates, and compressed air from the compressor 1 constantly flows into the expansion turbine 2 more than necessary. However, a large amount of leak from the low temperature side to the high temperature side will occur. That is, the efficiency of the expansion turbine 2 is reduced in order to lower the gas temperature at the inlet of the expansion turbine 2.

An object of the present invention is to protect a bypass device in a power plant, in which the temperature difference between the low temperature side and the high temperature side of the bypass device is reduced to obtain a more reliable bypass device. A method and protection device are provided.

[0006]

In order to achieve the above object, the invention according to claim 1 (hereinafter referred to as the first invention) connects the low temperature side and the high temperature side of the bypass device. Then, the cooling fluid on the low temperature side of the bypass device is passed through the high temperature side to reduce the temperature difference between the low temperature side and the high temperature side of the bypass device.

The invention according to claim 2 (hereinafter referred to as the second
Of invention. ) Is characterized in that, when trouble occurs, the gas in the high temperature gas generator is allowed to escape to the expansion turbine side via the bypass device.

In order to achieve the above object, the invention according to claim 3 (hereinafter referred to as the third invention) makes the low temperature side and the high temperature side of the bypass device communicate with each other, and The cooling fluid of the bypass device is provided to pass through the cooling fluid on the high temperature side to reduce the temperature difference between the low temperature side and the high temperature side of the bypass device.

The invention according to claim 5 (hereinafter, referred to as the fourth
Of invention. ) Connected at least one cooling communicating pipe to the second pipe between the high temperature gas generator and the second valve on the low temperature side of the bypass device and the high temperature side pipe of the bypass device, respectively. It is characterized by

[0010]

According to the first aspect of the present invention, when the power unit is in a normal operating state by connecting the low temperature side (compressor side) and the high temperature side (expansion turbine side) of the bypass device (that is,
The first valve and the second valve are in the open state, while the valve body of the bypass device is in the closed state. ), The cooling fluid on the low temperature side of the bypass device can be passed through the high temperature side to constantly perform the purge cooling on the high temperature side of the bypass device. As a result,
Reduce the temperature difference between the low temperature side and high temperature side of the bypass device,
It is possible to prevent thermal deformation and thermal stress from occurring in the bypass device, protect the bypass device from cooling, and improve the reliability of the bypass device.

Further, according to the second aspect of the invention, when the trouble occurs, the fluid in the high temperature gas generator is allowed to escape to the expansion turbine side through the bypass device, so that the compressed air supplied from the compressor to the expansion turbine at the time of trouble is reduced. However, the fluid having a relatively low temperature in the high temperature gas generator can be supplied to the expansion turbine via the bypass device to cool the expansion turbine.

According to a third aspect of the present invention, when the power unit is in a normal operating state, the cooling unit connects the low temperature side (compressor side) and the high temperature side (expansion turbine side) of the bypass device. That is, when the first valve and the second valve are in the open state, while the valve body of the bypass device is in the closed state.), The cooling fluid on the low temperature side of the bypass device is passed to the high temperature side,
The high temperature side of the bypass device can be constantly purged and cooled. As a result, the cooling fluid on the low temperature side of the bypass device is passed to the high temperature side, the temperature difference between the low temperature side and the high temperature side of the bypass device is reduced, and thermal deformation and thermal stress are generated in the bypass device. The bypass device can be prevented, the bypass device can be cooled and protected, and the reliability of the bypass device can be improved.

In a fourth aspect of the invention, at least the second pipe on the low temperature side of the bypass device between the high temperature gas generator and the second valve and the pipe on the high temperature side of the bypass device are respectively connected. In the event of trouble, the fluid in the high-temperature gas generator can be released to the expansion turbine side through the bypass device by one cooling communication pipe, so that the compressed air supplied from the compressor to the expansion turbine decreases when trouble occurs. Also,
The relatively low temperature fluid in the hot gas generator can be supplied to the expansion turbine via the bypass device to cool the expansion turbine.

[0014]

The following is a description of two examples of specific examples of a method for protecting a bypass device in a power plant of the present invention and four examples of embodiments of a device for protecting a bypass device in a power plant of the present invention. The description will be made with reference to FIGS. 1 and 2 show a first embodiment of a protection device for a bypass device in a power plant of the present invention, FIG. 1 is a sectional view of a bypass device equipped with the protection device of the present invention, and FIG.
FIG. 11 is a system explanatory view showing a normal operating state of a power plant having a bypass device equipped with the protection device of the present invention. In the figure, the same symbols as those in FIGS. 6 to 8 indicate the same components. In the figure, reference numeral 80 is a cooling communication pipe as a cooling communication means. Both ends of the cooling communication pipe 80 are connected to the connecting pipe 78 on the low temperature side and the inflow side of the bypass device 7 and the bypass device 7.
Of the bypass device 7 to connect the low temperature side (compressor side) and the high temperature side (expansion turbine side) of the bypass device 7 to each other. In the figure, 8 is a flow control valve provided in the middle of the above-mentioned cooling communication pipe 80. The flow control valve 8 allows the cooling fluid on the low temperature side of the bypass device 7 to pass through the cooling communication pipe 80 and the bypass device 7.
It controls the flow rate supplied to the high temperature side. The protective device for the bypass device in the power plant of the present invention of this embodiment has the above-mentioned configuration, and its operation will be described below together with a specific example of the method for protecting the bypass device in the power plant of the present invention. First, the flow control valve 8 is controlled to an appropriate opening. Then, as shown in FIG. 2, when the power plant is in normal operation, that is, the first valve 6 and the second valve
When the valve 5 is in the open state and the valve body 75 of the bypass device 7 is in the closed state, the cooling fluid on the low temperature side of the bypass device 7 is passed to the high temperature side to constantly purge the high temperature side of the bypass device 7. Can be cooled. As a result, the cooling fluid on the low temperature side of the bypass device 7 is passed to the high temperature side,
The heat of the high-temperature gas flowing from the high-temperature gas generator 4 to the expansion turbine 2 is reduced in heat transfer or heat transfer to the bypass device 7, and a large amount is generated between the low-temperature side and the high-temperature side of the bypass device 7. It is possible to prevent the temperature difference from occurring, and to prevent thermal deformation and thermal stress from occurring in the bypass device 7, protect the bypass device 7 from cooling, and improve the reliability of the bypass device 7.

In particular, in this embodiment, since the flow rate control valve 8 is provided in the middle of the cooling communication pipe 80, the flow rate of the cooling fluid passing through the cooling communication pipe 80 is restricted so that the bypass device 7 has a low temperature. The temperature difference between the hot side and the hot side can be controlled.

FIG. 3 is a second embodiment of the protection device for the bypass device in the power plant of the present invention, and is a system diagram showing the normal operating state of the power plant having the bypass device equipped with the protection device of the present invention. It is a figure. 1 and 2 in the figure
The same reference numerals as those in FIGS. 6 to 8 denote the same components. In the figure, reference numeral 81 is a cooling communication pipe as a cooling communication means. Both ends of this cooling communication pipe 81 are located on the low temperature side of the bypass device 7 and between the second valve 5 and the high-pressure gas generator 4, and on the high temperature side of the bypass device 7 and on the outflow side. To connect the low temperature side (compressor side) and the high temperature side (expansion turbine side) of the bypass device 7 to each other.

The protective device for the bypass device in the power plant of the present invention of this embodiment is constituted as described above, and its operation will be described below together with a specific example of the method for protecting the bypass device in the power plant of the present invention. To do. First, the flow control valve 8 is controlled to an appropriate opening. As shown in FIG. 3, when the power unit is in normal operation, that is, when the first valve 6 and the second valve 5 are in the open state, while the valve body 75 of the bypass device 7 is in the closed state, The cooling fluid on the low temperature side of the bypass device 7 can be passed through the high temperature side to constantly purge and cool the high temperature side of the bypass device 7.
As a result, similar to the above-described embodiment, the bypass device 7 can be cooled and protected, and the reliability of the bypass device 7 can be improved.

In particular, in this embodiment, the second pipe 92 between the high temperature gas generator 4 and the second valve 5 on the low temperature side of the bypass device 7 and the high temperature side of the bypass device 7 on the outflow side. Since the cooling communication pipes 81 are respectively connected to the side connection pipes 79, the first valve 6 and the second valve 5 are closed, and the valve body 75 of the bypass device 7 is opened to compress when the trouble occurs. Even if the compressed air supplied from the machine 1 to the expansion turbine 2 is reduced, the fluid having a relatively low temperature in the high temperature gas generator 4 is passed through the bypass device 7 to the expansion turbine 2
To cool the expansion turbine 2.

An orifice may be provided in place of the flow control valve 8 in the above-described first and second embodiments. Alternatively, the flow rate control valve 8 and the orifice such as the flow rate adjusting means for the cooling fluid may not be provided. Further, in the above-described first and second embodiments, one or more cooling communication pipes 80 and 81 may be provided.

FIG. 4 is a sectional view of a third embodiment of a protection device for a bypass device in a power plant of the present invention, which is a bypass device equipped with the protection device of the present invention. In the figure, the same reference numerals as those in FIGS. 1 to 3 and 6 to 8 indicate the same components. In the figure, reference numeral 82 denotes a cooling communication passage as a cooling communication means which is provided by forming a small through hole in the valve body 75 of the bypass device 7. The cooling communication passage 82 is provided in the bypass device 7.
The connection pipe 78 on the low temperature side and the inflow side communicates with the connection pipe 79 on the high temperature side and the outflow side of the bypass device 7. In the protection device for a bypass device according to the present invention in this embodiment, the cooling fluid on the low temperature side of the bypass device 7 is supplied to the high temperature side of the bypass device 7 via the cooling communication passage 82, and the high temperature side is constantly maintained. Can be purge cooled,
It is possible to achieve the same effect as the first embodiment described above.

FIG. 5 is a cross-sectional view of a fourth embodiment of a protection device for a bypass device in a power plant of the present invention, which is equipped with the protection device of the present invention. In the figure, the same reference numerals as those in FIGS. 1 to 4 and 6 to 8 indicate the same components. In the figure, reference numeral 83 is a cooling communication passage as a cooling communication means provided by forming a small through hole in the valve seat 73 of the bypass device 7. The cooling communication passage 83 is provided in the bypass device 7.
The connection pipe 78 on the low temperature side and the inflow side communicates with the connection pipe 79 on the high temperature side and the outflow side of the bypass device 7. In the protection device for a bypass device according to the present invention in this embodiment, the cooling fluid on the low temperature side of the bypass device 7 is supplied to the high temperature side of the bypass device 7 via the cooling communication passage 83, and the high temperature side is constantly maintained. Can be purge cooled,
It is possible to achieve the same effects as those of the above-described first and third embodiments.

In the third and fourth embodiments described above, one or more cooling communication passages 82 and 83 may be provided.

[0023]

As is apparent from the above, the method and device for protecting the bypass device in the power plant of the present invention are:
Low temperature side (compressor side) and high temperature side (expansion type) of the bypass device
When the power unit is in a normal operating state, the cooling fluid on the low temperature side of the bypass device is passed to the high temperature side, and the high temperature side of the bypass device is constantly purged and cooled. be able to. As a result, it is possible to reduce the temperature difference between the low temperature side and the high temperature side of the bypass device, prevent the thermal deformation and thermal stress from occurring in the bypass device, protect the bypass device from cooling, and protect the bypass device. The reliability can be improved.

Further, the protection method and the protection device for the bypass device in the power plant of the present invention are designed to allow the fluid in the high temperature gas generator to escape to the expansion turbine side through the bypass device at the time of trouble. Even if the compressed air supplied to the expansion turbine decreases, the fluid having a relatively low temperature in the hot gas generator can be supplied to the expansion turbine via the bypass device to cool the expansion turbine.

[Brief description of drawings]

1 is a cross-sectional view of a bypass device equipped with the protection device of the present invention, showing a first embodiment of the protection device of the bypass device in the power plant of the present invention.

FIG. 2 is a system explanatory view showing a normal operation state of a power plant equipped with the bypass device of the present invention in FIG.

FIG. 3 is a system explanatory view showing a second embodiment of the protection device for the bypass device in the power plant of the present invention and showing the normal operating state of the power plant equipped with the protection device of the present invention.

FIG. 4 is a cross-sectional view of a bypass device equipped with the protection device of the present invention, showing a third embodiment of the protection device of the bypass device in the power plant of the present invention.

FIG. 5 is a cross-sectional view of a bypass device equipped with the protection device of the present invention, showing a fourth embodiment of the protection device of the bypass device in the power plant of the present invention.

FIG. 6 is a system explanatory view showing a normal operating state of a power plant equipped with a conventional bypass device.

FIG. 7 is a system explanatory view showing a state of a power plant equipped with a conventional bypass device at the time of trouble.

FIG. 8 is a sectional view of a bypass device in a conventional power plant.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Compressor, 2 ... Expansion turbine, 3 ... Generator, 4 ... High temperature gas generator, 5 ... 2nd valve, 6 ... 1st valve, 7 ... Bypass device, 70 ... Main body, 71 ... Inflow side Connection pipe part (low temperature side), 72 ... Outflow side connection pipe part (high temperature side), 73 valve seat,
74 ... Valve rod, 75 ... Valve body, 76 ... Open / close operation device, 77 ... Heat insulating material, 78 ... Inflow side connecting pipe, 79 ... Outflow side connecting pipe,
8 ... Flow control valves, 80 and 81 ... Cooling communication pipes (cooling communication means), 82 and 83 ... Cooling communication passages (cooling communication means), 91 ... First piping, 92 ... Second piping.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Junshi Shimomura 3-1-1, Saiwaicho, Hitachi-shi, Ibaraki Hitachi Ltd. Hitachi factory (72) Inventor Satoshi Sato 3-sai, Hitachi-shi, Ibaraki 1st-1 Hitachi Ltd. Hitachi Works (72) Inventor Masato Machida 3-1-1 1-1 Saiwaicho, Hitachi City, Ibaraki Hitachi Ltd. Hitachi Works

Claims (10)

[Claims] 1. A high-temperature gas generator that operates under atmospheric pressure or higher, and an expansion turbine that is connected to the high-temperature gas generator through a first pipe and is driven by the high-temperature gas from the high-temperature gas generator. A compressor connected to the expansion turbine and connected to the high temperature gas generation device via a second pipe, and driven by the expansion turbine to supply compressed air to the high temperature gas generation device; The first pipe installed in the first pipe and the second pipe, respectively.
A valve and a second valve, and an outlet side of the compressor and an inlet side of the expansion turbine, respectively, and the compressed air from the compressor is closed by closing the first valve and the second valve when a trouble occurs in the device or equipment. A bypass device that bypasses the expansion turbine to the expansion turbine without passing through the high-temperature gas generator, and connects the low-temperature side and the high-temperature side of the bypass device to cool the low-temperature side of the bypass device. A method for protecting a bypass device in a power plant, wherein a working fluid is passed through the high temperature side to reduce a temperature difference between a low temperature side and a high temperature side of the bypass device. 2. The protection of the bypass device in the power plant according to claim 1, wherein the fluid in the high temperature gas generator is allowed to escape to the expansion turbine side through the bypass device when trouble occurs. Method. 3. A high temperature gas generator that operates under atmospheric pressure or higher, and an expansion turbine that is connected to the high temperature gas generator via a first pipe and is driven by the high temperature gas from the high temperature gas generator. A compressor connected to the expansion turbine and connected to the high temperature gas generation device via a second pipe, and driven by the expansion turbine to supply compressed air to the high temperature gas generation device; The first pipe installed in the first pipe and the second pipe, respectively.
A valve and a second valve, and an outlet side of the compressor and an inlet side of the expansion turbine, respectively, and the compressed air from the compressor is closed by closing the first valve and the second valve when a trouble occurs in the device or equipment. A bypass device that bypasses the expansion turbine to the expansion turbine without passing through the high-temperature gas generator, and connects the low-temperature side and the high-temperature side of the bypass device to cool the low-temperature side of the bypass device. A bypass device protection device in a power plant, comprising: cooling communication means for passing a working fluid through the high temperature side to reduce a temperature difference between a low temperature side and a high temperature side of the bypass device. 4. The cooling communication means according to claim 3, wherein at least one cooling communication pipe is connected to the low temperature side pipe of the bypass device and the high temperature side pipe of the bypass device, respectively. The protection device for a bypass device in a power plant according to claim 3, wherein 5. The cooling communication means according to claim 3, wherein a second pipe on the low temperature side of the bypass device between the high temperature gas generator and the second valve, and a pipe on the high temperature side of the bypass device. ,
4. The protection device for a bypass device in a power plant according to claim 3, which is at least one cooling communication pipe connected to each of the above. 6. A means for adjusting the flow rate of the cooling fluid is installed in the middle of the cooling communication pipe.
Or the protection device for the bypass device in the power plant according to 5. 7. The bypass device protection device for a power plant according to claim 6, wherein the cooling fluid flow rate adjusting means according to claim 6 is a flow rate control valve. 8. The bypass device protection device for a power plant according to claim 6, wherein the cooling fluid flow rate adjusting means according to claim 6 is an orifice. 9. The cooling communication means according to claim 3, wherein at least one cooling communication passage is provided in the valve body inside the bypass device so as to communicate the low temperature side and the high temperature side of the bypass device. The protection device for the bypass device in the power plant according to claim 3, wherein 10. The cooling communication means according to claim 3,
4. The bypass in the power plant according to claim 3, wherein the valve seat inside the bypass device is at least one cooling communication passage provided so as to communicate the low temperature side and the high temperature side of the bypass device. Equipment protection device.