Switching device

Abstract

To further improve the cooling performance of a valve plate in a valve device.SOLUTION: A valve device is equipped with a housing H provided in a fluid supply path 10, a valve body 20 that is provided in the housing H to open / close the fluid supply path 10, a refrigerant passage 32 that is provided in the valve body 20 and in which a refrigerant supplied from the outside of the housing H circulates, a first cooling gas supply portion 40 that supplies cooling gas supplied from the outside of the housing H into the housing H through a first opening 44 provided at a valve seat 45 on which a peripheral edge portion of the valve body 20 in a closing-valve state abuts on, and a second cooling gas supply portion 50 that supplies cooling gas supplied from the outside of the housing H into the housing H through a second opening 52 opposing to the valve body 20 in the closing-valve state or the opening-valve state at an interval.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] This invention relates to a valve device provided in a high-temperature fluid supply passage.

Background Art

[0002] As a valve device provided in a high-temperature fluid supply passage, for example, there is one described in Patent Document 1. This valve device is a partition valve having a cooling structure, and a valve body for opening and closing a flow path is attached to be vertically movable inside a housing composed of a valve box and a bonnet (described as a cap portion in Patent Document 1) provided on the upper part thereof. The bonnet serves as a housing space for the valve body in the valve opening position.

[0003] The valve body is formed by connecting two disc-shaped valve plates made of steel plates with a pair of spiral plates that form a cooling water flow path from the center to the outer peripheral edge. An annular sheet ring is attached to the outer peripheral edge of the connected valve plates by welding.

[0004] On the peripheral wall of the sheet ring, a water inlet and a drain outlet for the cooling water supplied to the cooling water flow path are provided, and a pair of hollow valve rods are connected in parallel to the water inlet and the drain outlet. At the upper part of the valve rod, an inlet and an outlet for the cooling water are respectively provided. The cooling water is supplied from the inlet, passes through the inside of the valve rod, enters the spiral cooling water flow path inside the sheet ring from the water inlet, passes through the center part of the valve body, passes through the inside of the valve rod from the drain outlet, and is discharged from the outlet. Thereby, the entire valve body is uniformly cooled.

[0005] Also, the valve device described in Patent Document 2 is also known. This valve device opens and closes a hot air pipeline leading to a blast furnace, includes a vertically movable valve plate inside a housing composed of a valve box and a bonnet, and is provided with an annular air cooling passage adjacent to a sealing valve seat where the valve plate comes into contact with and separates from. The air cooling passage is connected to a cooling air source. The cooling air supplied from the cooling air source passes through the air cooling passage and is supplied from a cooling gap opening to the sealing surface of the sealing valve seat into the housing internal space.

[0006] In the closed valve state, the cooling gap of the sealing valve seat is closed by the valve plate. Therefore, the inflow of cooling air into the internal space of the housing is interrupted, and it is said that the sealing valve seat can be cooled (see the first to eighth lines from the bottom left on page 2 of Patent Document 2). Note that in the closed valve state, since the valve body shields the hot fluid, the necessity of cooling the sealing valve seat is considered to be relatively low. On the other hand, in the open valve state, since the valve plate is pulled up by the bonnet provided at the upper part of the valve box, cooling air flows into the internal space of the housing from the cooling gap. Thereby, not only the sealing valve seat but also the internal space of the housing is said to be cooled (see the 15th line from the upper right to the first line from the bottom left on page 2 of Patent Document 2).

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0008] In the valve device of Patent Document 2, in the open valve state, since the valve body (valve plate) is separated from the sealing valve seat, the cooling gap is opened and cooling air flows into the housing. At this time, since the valve body is pulled up inside the bonnet (cover) provided at the upper part of the valve box, the cooling air ejected from the cooling gap is not directly applied to the valve body.

[0009] However, depending on the type of fluid handled in the hot air pipeline and the specifications of the facility, there is a demand to further enhance the cooling effect on the valve body. For this reason, in each of the closed valve state and the open valve state, it is required to cool the valve body more efficiently.

[0010] Therefore, an object of the present invention is to further improve the cooling performance of a valve body in a valve device provided in a high-temperature fluid supply passage.

Means for Solving the Problems

[0011] In order to solve the above problems, the present invention provides a valve device including a housing provided in a fluid supply passage, a valve body provided in the housing for opening and closing the fluid supply passage, a refrigerant passage provided in the valve body through which refrigerant supplied from outside the housing flows, a first cooling gas supply unit for supplying cooling gas supplied from outside the housing into the housing through a first opening provided at a valve seat with which a peripheral edge portion of the valve body in a closed valve state abuts, and a second cooling gas supply unit for supplying cooling gas supplied from outside the housing into the housing through a second opening facing the valve body in a closed valve state or an open valve state with a gap.

[0012] Here, the valve body is supported by a valve rod, and closes the valve by moving the valve rod axially in one direction and opens the valve by moving it in the other direction. The second opening may adopt a configuration including a valve box side opening facing an end portion on the other side of the valve body in a closed valve state with a gap and a bonnet side opening facing an end portion on the other side of the valve body in an open valve state with a gap.

[0013] Further, the second cooling gas supply unit may adopt a configuration including a chamber having a cross-sectional area larger than that of the second opening adjacent to the second opening.

[0014] Further, the first cooling gas supply unit and the second cooling gas supply unit may adopt a configuration in which the cooling gas is supplied from a common gas supply source.

[0015] In each of these aspects, the second opening may adopt a configuration arranged on the downstream side of the fluid supply passage with respect to the valve body.

[0016] The valve body is provided with a heat pipe having a function of transferring the heat absorbed at the high-temperature part to a low-temperature part having a lower temperature than the high-temperature part, and a configuration can be adopted in which the low-temperature part of the heat pipe in the valve body in the closed valve state faces the second opening.

[0017] Further, the valve body is provided with a heat pipe having a function of transferring the heat absorbed at the high-temperature part to a low-temperature part having a lower temperature than the high-temperature part, and a configuration can be adopted in which the low-temperature part of the heat pipe in the valve body in the open valve state faces the second opening or is exposed outside the housing.

Advantages of the Invention

[0018] In this invention, in a valve device provided in a high-temperature fluid supply path, the cooling performance of the valve body can be further enhanced.

Brief Description of the Drawings

[0019]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0020] Embodiments of this invention will be described based on FIGS. 1 to 7. In this embodiment, the configuration of this invention will be described by taking as an example a valve device 1 provided in a pipeline 10 for supplying a hot fluid leading to a blast furnace (hereinafter referred to as the fluid supply path 10).

[0021] The configuration of the valve device 1 is of a partition valve type in which a valve box 2 is provided in the middle of the fluid supply passage 10, and a valve body 20 that can move forward and backward is provided in the valve box 2. By the forward and backward movement of the valve body 20 within the valve box 2, the fluid supply passage 10 is opened and closed. On the upstream side of the valve body 20 within the valve box 2, a valve box valve seat 45 that contacts and separates from a valve body valve seat portion 34 provided at the peripheral edge of the valve body 20 is provided. The valve box valve seat 45 is provided only on the upstream side of the valve body 20. The valve body valve seat portion 34 on the valve body side and the valve box valve seat 45 on the valve box side (hereinafter simply referred to as the valve seat 45) are each provided in an annular shape and are in contact with each other over the entire circumference in the closed valve state.

[0022] A valve body ring 27 that contacts and separates from a guide ring 7 is provided at the peripheral edge of the valve body 20. The guide ring 7 and the valve body ring 27 are each provided in an annular shape. The guide ring 7 and the valve body ring 27 are each made of metal, similar to the valve body valve seat portion 34 and the valve seat 45, and have a metal touch structure in which the metals rub against each other in the closed valve state.

[0023] The peripheral edge of the valve body 20 is pressed against the valve seat 45 by the force from the downstream side where the pressure is relatively high in the closed valve state. Therefore, a single-side valve seat type with the valve seat 45 provided only on the upstream side can be adopted. Also, when the valve body 20 opens and closes, on the downstream side surface of the valve body 20 where the valve seat 45 is not provided, the guide ring 7 and the valve body ring 27 rub against each other, so that the refractory materials 14 and 22 described later do not obstruct the operation of the valve body 20.

[0024] The inner surface of the fluid supply passage 10 within the valve box 2 is covered with refractory materials 13 and 14 made of a material that can withstand high heat and has heat insulation performance, excluding the space into which the valve body 20 enters. The refractory material 13 is disposed on the inner surface of the upstream flow passage 11 with respect to the valve body 20, and the refractory material 14 is disposed on the inner surface of the downstream flow passage 12. A recess 8 into which the valve body 20 enters is provided between the upstream flow passage 11 and the downstream flow passage 12. The inner surface of the recess 8 is covered with a similar refractory material 15. The reference numeral 9 shown in FIGS. 1 to 3 is a drain, and the reference numeral 46 shown in FIGS. 2 and 3 is a drain valve.

[0025] The valve box 2 is provided with a hollow mounting portion 3 that protrudes outward from the outer surface of the cylindrical body forming the fluid supply passage 10 at its upper part. Further, a lid member 4 is attached to the upper part of the mounting portion 3 via flanges 3a and 4a. The valve box 2 (including the mounting portion 3) and the lid member 4 constitute the housing H. Also, the interior of the mounting portion 3 and the lid member 4 functions as a bonnet 5 for accommodating the valve body 20 in the open valve state, and the inner surfaces of the mounting portion 3 and the lid member 4 are also covered with a refractory 16 similar to that in the fluid supply passage 10. Hereinafter, the valve box 2 and the lid member 4 together are referred to as the housing H.

[0026] A valve rod 6 is attached to the valve body 20. The valve rod 6 extends upward within the bonnet 5 and is drawn out outside the housing H. The valve rod 6 is driven by a driving device to move forward and backward in the axial direction of the valve rod 6, and the valve body 20 moves forward and backward in the same direction together with the valve rod 6. That is, the valve body 20 closes when the valve rod 6 moves (descends) to one side along the axial direction of the valve rod 6, and opens when the valve rod 6 moves (ascends) to the other side along the axial direction of the valve rod 6.

[0027] A refrigerant passage 32 through which refrigerant supplied from outside the housing H flows is provided in the valve body 20. As shown in FIG. 1, the valve body 20 includes front and rear two metal (steel) valve plates 24 and 25 that sandwich the refrigerant passage 32 disposed at the central portion in the thickness direction. A heat pipe 23 is disposed outside the downstream valve plate 25, and the outside thereof is further covered with a refractory 22. Also, the outside of the upstream valve plate 24 is covered with a refractory 21. An annular sheet ring is attached to the outer peripheral edge of the valve body 20 to form a valve body valve seat 34. The outer periphery of the sheet ring is also covered with a refractory 28 on the side facing the recess 8.

[0028] As shown in FIG. 1, a pair of spiral plates are disposed in the disk-shaped space sandwiched between the valve plates 24 and 25 and the sheet ring, as shown in FIG. 2. The spiral plates form a single refrigerant passage 32 that extends from the supply port provided at the outer peripheral edge of the valve plates 24 and 25 toward the center, and then from the center to the discharge port provided at the outer peripheral edge.

[0029] At the supply port and the discharge port, a pair of refrigerant passages 31 respectively provided in two valve rods 6 are connected. The pair of refrigerant passages 31 communicate with a refrigerant supply source (not shown). The refrigerant supplied from the refrigerant supply source enters the refrigerant passage 32 from the supply port through the refrigerant passage 31 inside one of the valve rods 6, passes through the central portion of the valve body 20, and then returns to the refrigerant supply source through the refrigerant passage 31 inside the other valve rod 6 from the discharge port, constituting a refrigerant supply unit 30. The valve body 20 is cooled by this refrigerant supply unit 30. In this embodiment, air is adopted as the refrigerant handled by the refrigerant supply unit 30, but it may be a refrigerant composed of other gases other than air or a refrigerant composed of a liquid.

[0030] In addition, the valve device 1 includes a first cooling gas supply unit 40 that supplies cooling gas supplied from a gas supply source 54 provided outside the valve box 2 and the bonnet 5, that is, outside the housing H, into the valve box 2 through a first opening (cooling gap) 44 provided in the valve seat 45. As shown in FIGS. 1 to 3, the first cooling gas supply unit 40 is connected to the gas supply source 54 via a communication passage 53, and includes an outer annular passage 41 of the valve box surrounding the fluid supply passage 10, an inner annular passage of the valve box (air-cooling circulation annular pipe for the valve body) 43 formed in the valve seat 45, and a plurality of connecting passages 42 extending radially connecting the outer annular passage 41 of the valve box and the inner annular passage 43 of the valve box. The valve seat 45 is formed of a hollow annular member, and its interior serves as a passage for the cooling gas.

[0031] Thus, by providing the first cooling gas supply unit 40 having the first opening 44, the metal surface of the valve seat 45 can be efficiently cooled as compared with a simple circulation type cooling device without the first opening 44.

[0032] Both the outer annular passage 41 of the valve box and the inner annular passage 43 of the valve box are located on the upstream side of the housing H, and the hot air is blocked by the valve seat 45 in this upstream position in the closed valve state. Therefore, the thermal influence from the downstream side, which is at high temperature and high pressure, is reduced. In this embodiment, air is adopted as the cooling gas, but other gases other than air may also be used.

[0033] Furthermore, the valve device 1 includes a second cooling gas supply unit 50 that supplies cooling gas supplied from outside the housing H into the housing H through a second opening (cooling gap) 52 provided in the housing H. As shown in FIGS. 2 and 3, the second cooling gas supply unit 50 includes a chamber (air reservoir) 51 connected to a gas supply source 54 via a communication path 53. The chamber 51 is made of a hollow member, and its interior serves as a reservoir portion for cooling gas having a cross-section larger than the cross-sectional area of the second opening 52 that communicates with the space inside the housing H. In this embodiment, two chambers 51 are provided in the housing H along the opening and closing direction of the valve body 20. Here, the chamber 51 on one side (the lower side in this embodiment) along the axial direction of the valve stem 6 is referred to as the valve box side chamber 51a, and the chamber 51 on the other side (the upper side in this embodiment) along the axial direction of the valve stem 6 is referred to as the bonnet side chamber 51b. Also, the second opening 52 of the valve box side chamber 51a is referred to as the valve box side opening 52a, and the second opening 52 of the bonnet side chamber 51b is referred to as the bonnet side opening 52b.

[0034] In the closed valve state shown in FIG. 1, the valve box side opening 52a faces the other end (peripheral edge portion) of the valve body 20 with a gap. In the closed valve state, the valve body 20 becomes particularly hot due to the heat received from the hot fluid. At this time, since the upper part of the valve body 20 enters the mounting portion 3 outside the fluid supply path 10, the portion that has entered the mounting portion 3 can be cooled by the cooling air discharged from the valve box side opening 52a. In this closed valve state, since the bonnet side opening 52b does not face the valve body 20, the discharge of the cooling air from the bonnet side opening 52b does not significantly affect the cooling of the valve body 20. Therefore, by providing an on-off valve in the communication path 53 or the like leading to the bonnet side chamber 51b, the discharge of the cooling air from the bonnet side opening 52b may be stopped in the closed valve state.

[0035] Also, in the valve opening state shown in FIG. 7, the bonnet-side opening 52b faces the other end (peripheral edge) of the valve body 20 with a gap. Thereby, the end of the valve body 20 far from the fluid supply passage 10 can be cooled by the cooling air discharged from the bonnet-side opening 52b. Note that, by providing an on-off valve in the communication passage 53 or the like leading to the valve box-side chamber 51a, the discharge of the cooling air from the valve box-side opening 52a may be stopped in the valve opening state.

[0036] Since both the valve box-side opening 52a and the bonnet-side opening 52b are arranged on the downstream side of the fluid supply passage 10 with respect to the valve body 20, a higher cooling effect can be expected in an environment where the relatively downstream side of both the front and back surfaces of the valve body 20 is the high-temperature side.

[0037] In the above-described embodiment, the first cooling gas supply unit 40 and the second cooling gas supply unit 50 are configured such that the cooling gas is supplied from a common gas supply source 54, but they may be supplied from separate gas supply sources.

[0038] Furthermore, in this embodiment, the valve body 20 is provided with a heat pipe 23 having a function of transferring the heat absorbed in the high-temperature portion to a low-temperature portion having a lower temperature than the high-temperature portion. An example of the arrangement location of the heat pipe 23 is shown in FIG. 4.

[0039] Generally, a heat pipe is a device in which a working fluid is sealed in a sealed container and the container is provided with a capillary structure. When a part of the container is heated to generate a high-temperature portion, the working fluid absorbs heat and evaporates at the high-temperature portion. The vapor moves toward the low-temperature portion in the same container, and at the low-temperature portion, the vapor condenses and heat is released. The condensed working fluid returns to the high-temperature portion by capillary action. By repeating this process, heat transfer from the high-temperature portion to the low-temperature portion is performed.

[0040] In the closed valve state, the portion of the valve body 20 that enters the fluid supply passage 10 corresponds to the high-temperature portion of the heat pipe 23. On the other hand, the upper portion of the valve body 20, that is, the portion that enters the mounting portion 3 outside the fluid supply passage 10, corresponds to the low-temperature portion of the heat pipe 23 that has a relatively lower temperature than the high-temperature portion because it is less affected by the heat from the hot fluid. For this reason, as shown in FIG. 5, the heat pipe 23 transfers heat in the direction of arrow a from the high-temperature portion (lower portion 23a) in the fluid supply passage 10 to the low-temperature portion (upper portion 23b) in the bonnet 5. Thereby, the valve body 20 is cooled. Since the cooling is performed in the bonnet 5, it does not affect the temperature of the hot fluid in the fluid supply passage 10.

[0041] Also, in this closed valve state, the low-temperature portion (upper portion 23b) of the heat pipe 23 faces the valve box side opening 52a. For this reason, the heat that has moved from the high-temperature portion (lower portion 23a) to the low-temperature portion (upper portion 23b) is quickly cooled by the cooling air (see arrow b) discharged from the valve box side opening 52a. Thereby, the low-temperature portion can continuously release the heat that has moved from the high-temperature portion. At this time, the discharge of the cooling air from the bonnet side opening 52b may be stopped.

[0042] Also, in the open valve state, the heat pipe 23 in the valve body 20 is entirely housed in the mounting portion 3 and the bonnet 5 outside the fluid supply passage 10. Also in this case, the lower portion 23a, which is the side of the valve body 20 closer to the fluid supply passage 10, corresponds to the high-temperature portion. On the other hand, the upper portion 23b of the valve body 20 corresponds to the low-temperature portion that has a relatively lower temperature than the high-temperature portion because it is far from the hot fluid in the fluid supply passage 10. For this reason, as shown in FIG. 6, the heat pipe 23 transfers heat in the direction of arrow a from the lower portion 23a to the upper portion 23b of the valve body 20.

[0043] In this open valve state, the low-temperature part (upper part 23b) of the heat pipe 23 faces the bonnet-side opening 52b. Therefore, the heat that has moved from the high-temperature part (lower part 23a) to the low-temperature part (upper part 23b) is quickly cooled by the cooling air (see arrow c) discharged from the bonnet-side opening 52b. As a result, the low-temperature part can continuously release the heat transferred from the high-temperature part. At this time, the discharge of the cooling air from the valve box-side opening 52a may be stopped.

[0044] FIG. 7 shows a modified example of this embodiment. In this example, in the open valve state, the upper end of the heat pipe 23 in the valve body 20 is exposed to the atmosphere outside the bonnet 5 through a through hole provided in the upper part of the bonnet 5. Therefore, the lower part 23a, which is the side of the valve body 20 closer to the fluid supply passage 10, corresponds to the high-temperature part, and the upper part 23b of the valve body 20 is cooled by the atmosphere at the position indicated by arrow d and corresponds to the low-temperature part with a relatively lower temperature than the high-temperature part. For this reason, a large temperature difference between the high-temperature part and the low-temperature part can be ensured, so it can be said that the cooling effect is higher. At this time, the installation of the bonnet-side opening 52b and the bonnet-side chamber 51b may be omitted. Also, when the valve body 20 shifts to the closed valve state, it is desirable to block the through hole so that the space inside the bonnet 5 does not communicate with the atmosphere.

[0045] Note that since the installation of the heat pipe 23 is optional, when the cooling function of the valve body 20 by the refrigerant supply unit 30, the first cooling gas supply unit 40, and the second cooling gas supply unit 50 is sufficient, its installation can also be omitted.

[0046] The valve device 1 of the present invention can be applied to various fluid supply passages 10 that handle high-temperature heat fluids. For example, in addition to the burner shut-off valve provided in the fluid supply passage 10 connecting between the hot blast stove that supplies hot air to the blast furnace and the burner that is its heat source, the valve device 1 of the present invention can also be applied to the hot air valve provided in the fluid supply passage 10 connecting between the hot blast stove and the blast furnace.

Explanation of Reference Numerals

[0047] 1 Valve device 2 Valve box 5 Bonnet 10 Fluid supply path (hot air duct) 20 Valve body 23 Heat pipe 30 Refrigerant supply section 32 Refrigerant passage 40 First cooling gas supply section 44 First opening 45 Valve box valve seat (valve seat) 50 Second cooling gas supply section 52 Second opening 54 Gas supply source

Claims

1. A housing (H) provided in a fluid supply passage (10); A valve body (20) provided in the housing (H) for opening and closing the fluid supply passage (10); A refrigerant passage (32) provided in the valve body (20) through which refrigerant supplied from outside the housing (H) flows; A first cooling gas supply unit (40) that supplies cooling gas supplied from outside the housing (H) into the housing (H) through a first opening (44) provided in a valve seat (45) with which the peripheral edge of the valve body (20) in the closed valve state abuts; A second cooling gas supply unit (50) that supplies cooling gas supplied from outside the housing (H) into the housing (H) through a second opening (52) that faces the valve body (20) in the closed valve state or the open valve state with a gap, the valve device comprising: The valve body (20) is supported by a valve rod (6), and closes by moving the valve rod (6) axially in one direction and opens by moving in the other direction; The second opening (52) includes a valve box side opening (52a) that faces the other end of the valve body (20) in the closed valve state with a gap, and a bonnet side opening (52b) that faces the other end of the valve body (20) in the open valve state with a gap.

2. The valve device according to claim 1, wherein the second cooling gas supply unit (50) includes a chamber (51) having a cross-section larger than the cross-sectional area of the second opening (52), adjacent to the second opening (52).

3. The valve device according to claim 1 or 2, wherein the cooling gas is supplied to the first cooling gas supply unit (40) and the second cooling gas supply unit (50) from a common gas supply source (54).

4. A housing (H) provided in a fluid supply passage (10); A valve body (20) provided in the housing (H) for opening and closing the fluid supply passage (10); A refrigerant passage (32) provided in the valve body (20) through which refrigerant supplied from outside the housing (H) flows; A first cooling gas supply unit (40) that supplies cooling gas supplied from outside the housing (H) into the housing (H) through a first opening (44) provided in a valve seat (45) with which the peripheral edge of the valve body (20) in the closed valve state abuts; A second cooling gas supply unit (50) that supplies cooling gas supplied from outside the housing (H) into the housing (H) through a second opening (52) that faces the valve body (20) with a gap in a closed valve state or an open valve state. The second opening (52) is a valve device disposed on the downstream side of the fluid supply passage (10) with respect to the valve body (20).

5. A housing (H) provided in the fluid supply passage (10). A valve body (20) provided in the housing (H) for opening and closing the fluid supply passage (10). A refrigerant passage (32) provided in the valve body (20) through which refrigerant supplied from outside the housing (H) flows. A first cooling gas supply unit (40) that supplies cooling gas supplied from outside the housing (H) into the housing (H) through a first opening (44) provided in a valve seat (45) with which the peripheral edge of the valve body (20) in a closed valve state abuts. A second cooling gas supply unit (50) that supplies cooling gas supplied from outside the housing (H) into the housing (H) through a second opening (52) that faces the valve body (20) with a gap in a closed valve state or an open valve state. The valve body (20) is provided with a heat pipe (23) having a function of transferring heat absorbed at a high temperature portion to a low temperature portion having a lower temperature than the high temperature portion. A valve device in which the low temperature portion of the heat pipe (23) in the valve body (20) in a closed valve state faces the second opening (52).

6. A housing (H) provided in the fluid supply passage (10). A valve body (20) provided in the housing (H) for opening and closing the fluid supply passage (10). A refrigerant passage (32) provided in the valve body (20) through which refrigerant supplied from outside the housing (H) flows. A first cooling gas supply unit (40) that supplies cooling gas supplied from outside the housing (H) into the housing (H) through a first opening (44) provided in a valve seat (45) with which the peripheral edge of the valve body (20) in a closed valve state abuts. A second cooling gas supply unit (50) that supplies cooling gas supplied from outside the housing (H) into the housing (H) through a second opening (52) that faces the valve body (20) with a gap in a closed valve state or an open valve state. The valve body (20) is provided with a heat pipe (23) having a function of transferring heat absorbed at a high temperature portion to a low temperature portion having a lower temperature than the high temperature portion. A valve device in which a low-temperature portion of the heat pipe (23) in the valve body (20) in the open state faces the second opening (52) or is exposed outside the housing (H).

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