JPH0776526B2 - Steam temperature reducing pressure reducing control valve - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steam temperature reducing / pressure reducing control valve for reducing the temperature of high temperature high pressure steam in a turbine bypass system of a commercial boiler.

[0002]

2. Description of the Related Art Conventionally, as the temperature reducing / reducing pressure control valve, there is one described in Japanese Patent Publication No. 61-35361. This prior art is a vapor dehumidification having a valve casing having an inlet flow passage and an outlet flow passage, a valve seat formed in the valve casing, and a valve element movable in a direction to move toward and away from the valve seat. In the pressure reducing control valve, a cage is provided around the valve rod, a mixing chamber is provided between the cage and the valve rod guide, and a valve shutoff formed between the valve body provided at the lower end of the valve rod and the valve seat. Mixing the inlet steam flowing into the lower region of the mixing chamber with the cooling water supplied to the upper region of the mixing chamber from the cooling water supply path formed between the upper end of the cage and the upper end of the valve rod guide. Mix indoors. As a result, the high-temperature and high-pressure inlet steam is decompressed in the throttle portion between the valve body and the valve seat, and is cooled by being mixed with the cooling water. Is discharged.

[0003]

However, the following problems are expected in the prior art.

There is a sealing surface for the valve element and the valve seat in the mixing chamber of steam and cooling water, and the cooling water supplied from the cooling water supply path into the mixing chamber collides with both sealing surfaces in the transient state of flow rate change. Since the structure is obtained, both seal surfaces are easily subjected to thermal shock, and the hardened layer portions of both seal surfaces may be cracked to impair the valve shutoff property.

With respect to the position where the inlet steam flows into the mixing chamber,
Since the opening position of the cooling water supply path to the mixing chamber is remote and the cooling water is not mixed immediately with the high temperature inlet steam jet immediately after flowing into the mixing chamber, a perfect mixing state is obtained in the small flow range. I can't. This improper mixing means that the coarse water particles pass through the cage and are discharged to the side of the outlet flow path, and as a result, the coarse water particles colliding with the valve casing give a large thermal shock to the casing and cause erosion. There is a risk that the life of the casing will be impaired due to heat stress.

The inlet steam flows out to the mixing chamber side from the wide-opened valve throttle portion formed between the valve body and the valve seat, and the flow is likely to be uneven around the valve body, It causes vibration and noise.

In the above, the valve seat, which is prone to cracking, is formed integrally with the valve casing, so that repair is difficult and maintainability is poor.

An object of the present invention is to ensure a stable depressurization operation at a low temperature without causing thermal damage to valve components.

An object of the present invention is to improve maintainability.

[0010]

The present invention according to claim 1 provides a valve casing having an inlet passage and an outlet passage, a valve seat formed in the valve casing, and a contacting / separating portion with respect to the valve seat. In a steam temperature reducing / pressure reducing control valve having a valve body that can move in the same direction, it is arranged so as to slide around the outer circumference of the valve body to partition the inlet flow passage and the outlet flow passage together with the valve body, and is opened and closed by the valve body. And an inner cage having a plurality of small holes that allow the inlet flow path and the outlet flow path to communicate with each other, and is arranged around the valve body and the inner cage, and a mixing chamber is provided between the valve body and the inner cage. An outer cage provided with a plurality of small holes that allow the mixing chamber and the outlet channel to communicate with each other, a cooling water supply path extending to the valve body surrounding member, and a cooling water supply path communicating with the cooling water supply path. The cooling water is supplied to the side of the mixing chamber by opening the valve member surrounding member facing the mixing chamber. A water bypass hole that opens from the seat surface of the valve body and the valve seat of the valve body to the side of the inlet flow path, and a steam bypass path that extends in the valve body, and can communicate with the mixing chamber by communicating with the steam bypass path. And a steam ejection hole that opens to the outer peripheral portion of the valve body, and a water injection path from the water injection hole and a steam ejection path from the steam ejection hole are provided in the immediate vicinity.

According to a second aspect of the present invention, in the steam temperature reducing / pressure reducing valve according to the first aspect, a steam jetting path is further provided between the inner cage and the valve body surrounding member, and the water injection hole is provided. Is opened around the outlet of the steam ejection path.

According to a third aspect of the present invention, in the steam temperature reducing / pressure reducing valve according to the first aspect, a steam jetting path is further provided between the inner cage and the valve body surrounding member, and the water injection hole is provided. The opening is made in the steam ejection path.

The present invention according to claim 4 provides the invention according to claims 1 to 3.
In the steam temperature reducing / reducing pressure control valve according to any one of items 1 to 3, the steam ejection hole can be opened and closed by an inner cage as the valve body moves, and the steam passage of the steam ejection hole increases as the valve opening increases. The area is increased.

The present invention according to claim 5 provides claims 1 to 4.
In the steam temperature reducing / pressure reducing control valve according to any one of 1 to 3, further, a partition having a plurality of small holes is provided between the inner cage and the outer cage, and the mixing chamber is divided into a plurality of mixing chambers. .

The present invention according to claim 6 provides the invention according to claims 1 to 5.
In the steam decompression / decompression control valve according to any one of items 1 to 3, the valve seat is closer to the inlet flow path side than the seat surface of the valve body, and has a diameter smaller than the valve seat inner diameter portion and is minute between the valve seat inner diameter portion. Providing an overhanging portion capable of forming a gap and having a steam rectifying surface projecting from the overhanging edge portion of the overhanging portion toward the inlet flow path in a reduced diameter state that is concave around the valve body axis Is.

According to a seventh aspect of the present invention, in the steam temperature reducing / pressure reducing valve according to the sixth aspect, the small hole of the inner cage is inclined with respect to the valve body axis. The steam streamlines
The valve body is provided in a direction along the steam rectifying surface.

The present invention according to claim 8 provides the invention according to any one of claims 1 to 7.
In the steam temperature reducing / pressure reducing valve according to any one of the above, a labyrinth groove is further provided in a portion of the outer peripheral portion of the valve body which is slidably contacted and guided.

The present invention according to claim 9 is directed to claims 1 to 8.
In the steam temperature reducing / pressure reducing control valve according to any one of (1) to (4), further, a valve seat ring having the valve seat is exchangeably coupled to a valve casing.

[0019]

According to the present invention described in claims 1 and 2, the following
There are (1) to (5).

(1) The cooling water supplied from the cooling water supply path provided in the valve body surrounding member is supplied to the mixing chamber between the inner cage covering the seat surface of the valve body and the valve seat, and the outer cage. It Therefore, the cooling water supplied to the mixing chamber does not fall on the seat surface of the valve body or the valve seat, and cracks may occur on the seat surface of the valve body or the hardened surface layer of the valve seat due to erosion or thermal stress. Secure high valve shutoff.

The cooling water supplied from the cooling water supply passage provided in the valve body surrounding member can be completely contactless to the valve rod side portion of the valve body, so that the entire valve body is thermally heated. Reliable protection from damage.

(2) The opening position of the cooling water supply path defined by the water injection hole of the valve member surrounding member to the mixing chamber is located close to the inlet steam inflow position into the mixing chamber defined by the small hole of the inner cage. You can also Then, in that case, the cooling water can be immediately mixed with the high-speed inlet steam jet immediately after flowing into the mixing chamber, and the mixing and atomization is completed. Therefore, the coarse water particles do not pass through the outer cage and are discharged to the side of the outlet flow path, and as a result, the coarse water particles do not collide with the valve casing and give a large thermal shock, so that the valve casing The lifetime of is not impaired by erosion or thermal stress.

(3) The cooling water supplied to the mixing chamber side from the water injection hole communicating with the cooling water supply passage is mixed with the steam ejected at a high flow rate from the steam ejection hole communicating with the steam bypass passage of the valve body. It is heated, atomized, and supplied to the mixing chamber in a state where it is boiled and evaporated, and is mixed with the inlet steam supplied to the mixing chamber from the small holes of the inner cage. Therefore, the mixing of the inlet steam and the cooling water in the mixing chamber is better, the coarse water particles pass through the outer cage and are not easily discharged to the outlet flow path side, and the water particles give a thermal shock to the valve casing. Can be reliably prevented, and the reduced-temperature reduced pressure steam that has been uniformly reduced in temperature can be discharged to the outlet passage.

Incidentally, in the steam temperature reducing / pressure reducing valve, when the valve is used in a slightly opened state, the flow velocity of the steam is low and the amount of cooling water to be supplied is also reduced. Have difficulty. However, according to the present invention, the above (3)
As a result, even when the valve is slightly opened, it is possible to improve the performance of mixing and atomizing the cooling water with the steam.

(4) By thoroughly mixing the inlet steam and the cooling water in the above (3), the temperature distribution of the outlet steam becomes uniform, and the steam temperature reduction controllability is improved.

(5) The inlet steam flows out from the small holes of the inner cage around the valve body to the side of the mixing chamber, and the flow can be divided into subdivided parts around the valve body and equalized, resulting in fluid energy. It is possible to obtain a large decompression effect due to the friction loss and to prevent vibration and noise due to self-excited vibration due to generation of large vortices and separation.

According to the present invention described in claim 3, the following (6)
Has the effect of.

(6) The cooling water supplied from the water injection hole is given a high atomization effect due to the Venturi effect of the steam jetting path with a narrow steam between the inner cage and the valve member, and a high steam flow velocity. It is more effectively mixed and atomized with the steam flowing through the jet path.

According to the present invention described in claim 4,
There is an action of (7).

(7) The opening area (steam passage area) of the steam injection hole can be increased or decreased depending on the opening degree (valve opening degree) of the valve body with respect to the valve seat. Therefore, as compared with the case where a constant steam flow rate flows through the steam bypass path at the same time when the valve opens, the maximum flow rate / minimum controllable flow rate (range availability) of the valve does not decrease and The atomizing action of cooling water can be promoted.

According to the present invention described in claim 5,
It has the effects of (8) and (9).

(8) The inlet steam flowing out from the small hole of the inner gauge and the cooling water supplied from the water injection hole of the valve member surrounding member collide coaxially in the mixing chamber to perform mixed atomization. By providing a plurality of mixing chambers between the inner gauge and the outer gauge, atomization and mixing of steam and cooling water can be performed in stages, and a uniform steam temperature state can be obtained.

(9) By providing a plurality of mixing chambers, the pressure can be reduced stepwise and the noise reduction effect can be obtained. Further, according to the present invention, a plurality of mixing chambers are provided inside the valve casing, as compared with the conventional one in which a plurality of orifice plates are provided on the outlet side of the valve casing to reduce the pressure and reduce the pressure. As a result, the same decompression effect as the conventional one can be obtained, and the number of orifice plates to be provided on the outlet side of the valve casing can be reduced to one.

According to the present invention of claim 6, the following (1
There is an action of 0).

(10) The foreign matter in the steam moves with the flow of steam along the steam straightening surface of the valve body, and due to the presence of the overhanging portion, it is allowed to flow down to the small hole side of the inner cage without colliding with the valve body seat surface. To be Also, when closing the valve body from the open position,
As a result of the foreign matter flowing in around the valve seat being captured by the overhanging portion of the valve body, the foreign matter is not caught between the seat surface of the valve body and the valve seat. This prevents damage to the seat surface of the valve body and the valve seat.

According to the present invention of claim 7, the following (1
It has the effect of 1).

(11) The inlet steam smoothly flows into the small holes of the inner cage from the steam rectifying surface of the valve body, and there is no sudden change in the steam flow direction around the valve body. Vibration and noise can be prevented.

According to the present invention of claim 8, the following (1
There is a function of 2).

(12) Steam flowing in the gap between the outer peripheral portion of the valve body and the inner cage generates self-excited vibration due to vortex generation and separation due to the nonuniformity of the gap between the outer peripheral portion of the valve body and the inner cage during valve assembly. When there is a risk of causing the flow of steam, the steam flow is retained in the labyrinth groove, and the dynamic pressure is converted to a high static pressure. The self-excited vibration of the valve body can be prevented by adjusting the center of the valve body.

According to the invention of claim 9, the following (1
There is a function of 3).

(13) Maintainability can be improved by making the valve seat ring freely replaceable with respect to the valve casing.

[0042]

1 is a sectional view showing a first embodiment of a steam temperature reducing / pressure reducing valve according to the present invention, FIG. 2 is a sectional view taken along line II-II of FIG. 1, and FIG. 3 is a schematic view showing the valve closed state of FIG. 3, FIG. 3 (B) is a schematic view showing the valve opened state of FIG. 1, FIG. 4 is a sectional view showing the second embodiment of the present invention, and FIG. 5 is a third embodiment of the present invention. 6 is a sectional view showing a fourth embodiment of the present invention, FIG. 7 is a sectional view showing a fifth embodiment of the present invention, and FIG. 8 is a sectional view showing a sixth embodiment of the present invention. 9 is a sectional view showing a seventh embodiment of the present invention, and FIG. 10 is a sectional view showing an eighth embodiment of the present invention.

(First Embodiment) (See FIGS. 1 to 3) The steam temperature reducing / pressure reducing valve 10 includes an inlet passage 11 and an outlet passage 1.
It has a valve casing 13 with two. An upper valve body guide 14 and a lower valve body guide 15 are fixedly arranged in the valve casing 13.

The lower valve body guide 15 has a valve seat 16 which connects the inlet passage 11 and the outlet passage 12.

The upper valve body guide 14 slidably supports the valve rod 17, and the lower valve body guide 15 is a valve body 18 integral with the valve rod 17.
Is slidably supported. The valve body 18 is arranged so as to face the valve seat 16, moves upward with the valve seat 16 as a base point, and brings the seat surface 18A provided on the valve body 18 into contact with and separates from the valve seat 16.

The upper valve body guide 14 is the valve casing 1
The gasket 100 is sandwiched between the fitting portion 3 and the valve rod 17
A packing 101 is provided around it. Packing 101
Is held by a packing retainer 103 which is tightened to the upper valve body guide 14 by a bolt 102, and the valve casing 1
Prevents steam from leaking.

The lower valve body guide 15 functions as a valve seat ring having the valve seat 16 as described above, and the retainer 104 screwed to the valve casing 13 allows the lower valve body guide 15 to be freely exchanged with the valve casing 13. Fitted and fixed.

The portion of the lower valve body guide 15 which slidably supports the valve body 18 is an inner cage 21 having a cylindrical shape. In addition, the bolt 10
5, the skirt sleeve 106 and the tubular outer cage 2
3 are coaxially arranged around the inner cage 21 and the valve body 18. The skirt sleeve 106 is hung from the entire circumference of the lower end of the upper valve body guide 14 to the entire circumference of the upper end of the inner cage 21, and together with the upper valve body guide 14 and the inner cage 21, surrounds the circumference of the valve rod 17 and the valve body 18 substantially completely. Siege. The outer cage 23 forms an annular mixing chamber 22 between the inner cage 21 and the skirt sleeve 106.

That is, the inner cage 21 is arranged so as to be slidably contacted around the outer peripheral portion of the valve body 18 so as to partition the inlet passage 11 and the outlet passage 12 together with the valve body 18, and is opened and closed by the valve body 18 to open the inlet. A large number of small holes 24 that allow the flow passage 11 and the mixing chamber 22 to communicate with each other, and thus the inlet flow passage 11 and the outlet flow passage 12.
Is equipped with.

The outer cage 23 is arranged further outside the inner cage 21 and the skirt sleeve 106 surrounding the valve body 18, and forms the above-mentioned mixing chamber 22 between the inner cage 21 and the skirt sleeve 106. With
It has a large number of small holes 25 that allow the mixing chamber 22 and the outlet channel 12 to communicate with each other.

At this time, the outer cage 23 is provided with a plurality of small holes 25 in the circumferential direction at each of a plurality of step positions in the vertical axis direction, and the steam flow line direction θ of each small hole 25 is set to the radial line of the outer cage 23. Alternatively, the acting force exerted on the casing 13 by the steam line ejected from the small hole 25 and colliding with the casing 13 may be relaxed. Then, between the vertically adjacent small holes 25, the steam streamline direction θA imparted to the upper stage small hole 25A and the steam streamline direction θB imparted to the lower stage small hole 25B are defined by the radius line of the outer cage 23. The opposite directions to each other so that the moments of reaction forces exerted on the outer cage 23 by the steam flows ejected from the upper and lower small holes 25A and 25B cancel each other out so that the rotating force due to the steam flow is not generated in the outer cage 23. You can also

A cooling water supply passage 31 is provided inside the upper valve body guide 14 and the skirt sleeve 106. The cooling water supply path 31 includes a cooling water supply pipe 32 connected to the upper valve body guide 14 and an annular water storage space 33 provided at the upper end of the skirt sleeve 106 and communicating with the cooling water supply pipe 32. .

In the skirt sleeve 106, a large number of water injection holes 39 for supplying cooling water to the mixing chamber 22 are opened, which are open to a portion of the cooling water supply passage 31 which communicates with the annular water storage space 33 and faces the mixing chamber 22. is doing.

On the other hand, the valve body 18 has a steam bypass path 41.
Is extended, and the steam bypass path 41 opens from the seat surface 18A with the valve seat 16 of the valve body 18 to the side opposite to the inlet flow path 11. In addition, the valve body 18 has a steam bypass path 41.
Has a steam ejection hole 42 that is open to the outer peripheral portion of the valve body 18 and is capable of communicating with the mixing chamber 22.

A water injection path from the water injection hole 39 and a steam injection path from the steam injection hole 42 are provided in the immediate vicinity.

Here, in the first embodiment, the inner cage 2
1 and the skirt sleeve 106 between the steam ejection path 43
Is provided, and the water injection hole 39 is opened around the outlet of the steam ejection path 43.

Since the steam bypass path 41 provided in the valve body 18 is provided on the side of the seat surface 18A of the valve body 18 opposite to the inlet passage 11 side, as described above, the valve body 18 has the valve seat 1
When the valve in contact with 6 is fully closed, a reliable valve shutoff is possible without using any means for closing the opening. When the valve is opened, the steam bypass path 41 communicates with the inlet passage 11 and can introduce high-temperature, high-pressure inlet steam.

Further, the valve body 18 has a diameter smaller than the inner diameter portion of the valve seat 16 on the side of the inlet passage 11 from the seat surface 18A so that a minute gap can be formed between the valve body 18 and the inner diameter portion of the valve seat 16 when the valve is closed. The steam rectifying surface 18C is provided with the projecting portion 18B, and the steam rectifying surface 18C is provided so as to project from the projecting edge portion of the projecting portion 18B toward the inlet passage 11 in a reduced diameter state that is concave around the valve body axis.

At this time, the small hole 24 of the inner cage 21 is inclined with respect to the valve body axis, and the steam flow line of the small hole 24 is provided in the direction along the steam rectifying surface 18C of the valve body 18. .

Further, the valve body 18 has an inner cage 21 at the outer peripheral portion.
A labyrinth groove 18D is provided in a portion which is slidably contacted with and guided.

In FIG. 1, reference numeral 60 is an orifice plate provided in the outlet passage 12.

Next, the operation of the above embodiment will be described.

In the steam temperature reducing / pressure reducing control valve 10, the flow rate of the steam flowing into the inlet passage 11 is controlled and the pressure is reduced in the small hole 24 of the inner cage 21 which is not blocked by the valve body 18. It spouts into the mixing chamber 22.

On the other hand, the cooling water supplied from the cooling water supply path 31 is jetted from the water injection hole 39 to the mixing chamber 22, and the steam supplied from the inlet flow path 11 via the steam bypass path 41 is steamed from the steam injection hole 42. Mixing chamber 22 through ejection path 43
Gushes into. As a result, the cooling water ejected from the water injection hole 39 to the mixing chamber 22 is mixed with the steam ejected from the steam ejection hole 42 to the mixing chamber 22 and is heated and atomized into fine particles inside the mixing chamber 22. spread.

The steam ejected from the small holes 24 of the inner cage 21 and the cooling water ejected from the water injection holes 39 and widely sprayed in the mixing chamber 22 as described above are the mixing chamber 2
Collision and mixing occur in 2 to reduce the steam temperature uniformly. This steam is rectified by the small holes 25 of the outer cage 23 and discharged from the outlet passage 12.

However, according to the above embodiment, the following (1)
It has the function of (10).

(1) The cooling water supplied from the cooling water supply passage 31 provided in the upper valve body guide 14 and the skirt sleeve 106 is supplied with the inner cage 21 that covers the seat surface 18A of the valve body 18 and the valve seat 16, and the outer cage. 23 to the mixing chamber 22. Therefore, the cooling water supplied to the mixing chamber 22 does not fall on the seat surface 18A of the valve body 18 or the valve seat 16, and the seat surface 1 of the valve body 18 is caused by erosion or thermal stress.
8A and the hardened surface portion of the valve seat 16 are not cracked, and a high valve shutoff property is secured.

The cooling water supplied from the cooling water supply passage 31 provided on the skirt sleeve 106 can be completely contactless to the valve rod 17 side portion of the valve body 18, so that the entire valve body 18 is in contact. Can be surely protected from thermal damage.

(2) Opening position of the cooling water supply passage 31 defined by the water injection hole 39 of the skirt sleeve 106 to the mixing chamber 22 with respect to the inlet steam inlet position into the mixing chamber 22 defined by the small hole 24 of the inner cage 21. Can be placed close together. Therefore, the cooling water can be immediately mixed with the high speed inlet steam jet immediately after flowing into the mixing chamber 22, and the mixing and atomization is completed. Therefore,
The coarse water particles do not pass through the outer cage 23 and are discharged to the side of the outlet flow path 12, and as a result, the coarse water particles do not collide with the valve casing 13 and give a large thermal shock. The life of the casing 13 is not impaired by erosion or thermal stress.

(3) The cooling water supplied from the water injection hole 39 communicating with the cooling water supply path 31 to the mixing chamber 22 side is the valve body 18
From the steam ejection hole 42 communicating with the steam bypass path 41, the steam is mixed with the steam ejected at a high flow rate, heated, atomized, and supplied to the mixing chamber 22 in a state of boiling and evaporation, and the small hole 24 of the inner cage 21 is supplied. From the inlet steam supplied to the mixing chamber 22 from. Therefore, the mixing of the inlet steam and the cooling water in the mixing chamber 22 is even better, the coarse water particles hardly pass through the outer cage 23 and are discharged to the outlet passage 12 side, and the water particles enter the valve casing 13. It is possible to reliably prevent the thermal shock and to discharge the depressurized decompressed steam that has been uniformly dehumidified to the outlet passage 12.

Incidentally, in the steam temperature reducing / pressure reducing control valve 10, when the valve is used in a slightly opened state, the steam flow velocity is low and the amount of supplied cooling water is also reduced. Is difficult. However, according to the present invention, the above
Due to (3), even when the valve is used in a slightly opened state, it is possible to improve the mixing and atomizing performance with the cooling water vapor.

(4) By thoroughly mixing the inlet steam and the cooling water in the above (3), the temperature distribution of the outlet steam becomes uniform and the steam temperature reduction controllability is improved.

(5) The inlet steam flows out from the small holes 24 of the inner cage 21 around the valve body 18 toward the mixing chamber 22 side, and the flow is divided into subdivided parts around the valve body 18 to equalize them. As a result, it is possible to obtain a pressure reducing effect due to friction loss of fluid energy, and it is possible to prevent vibration and noise due to self-excited vibration due to generation of large vortices and separation.

(6) Foreign matter in the steam moves with the flow of steam along the steam rectifying surface 18C of the valve body 18, and the overhanging portion 18B.
Due to the existence of the above, the flow is made to flow down to the small hole 24 side of the inner cage 21 without colliding with the valve body seat surface 18A. Also,
When the valve body 18 is closed from the open position, the overhanging portion 18B of the valve body 18 captures the foreign matter flowing around the valve seat 16, so that the foreign matter is caught between the seat surface 18A of the valve body 18 and the valve seat 16. It's never crowded. Thereby, the seat surface 18A of the valve body 18 and the valve seat 16 can be prevented from being damaged.

(7) The inlet steam is the steam rectifying surface 18 of the valve body 18.
Since it smoothly flows into the small hole 24 of the inner cage 21 from C and there is no sudden change in the steam flow direction around the valve body 18,
Vibration and noise due to self-excited vibration due to turbulence of the steam flow can be prevented.

(8) The steam flowing through the gap between the outer peripheral portion of the valve body 18 and the inner cage 21 generates and separates vortices based on the nonuniformity of the gap between the outer peripheral portion of the valve body 18 and the inner cage 21 during valve assembly. When there is a risk of causing self-excited vibration due to, the steam flow is stagnated in the labyrinth groove 18D, and the dynamic pressure is converted into a high static pressure. By aligning the body 18 with the inner cage 21, self-excited vibration of the valve body 18 can be prevented.

(9) Lower valve disc guide 15 as a valve seat ring
Since the valve casing 13 is freely exchangeable, the maintainability can be improved.

The steam temperature reducing / pressure reducing valve 10 is in a flow direction in which the steam supplied from the inlet passage 11 pushes up the valve body 18, and constitutes a so-called flow open structure (normal plug structure). Therefore, the reduced pressure steam is provided on the downstream side of the valve cutoff portion, and the thickness of the casing on the outlet flow passage side can be reduced. Therefore, the generation of thermal stress due to the temperature difference between the inner and outer surfaces of the casing can be alleviated, and the life of the valve can be extended.

(Second Embodiment) (See FIG. 4) The difference between the steam temperature reducing / pressure reducing control valve 10 of FIG. 4 and the steam temperature reducing / pressure reducing control valve 10 of the first embodiment (FIG. 1) is as follows. Is.

That is, in this steam temperature reducing / pressure reducing control valve 10, the steam jet hole 42 provided in the valve body 18 can be opened and closed by the inner cage 21 as the valve body 18 moves, and the valve opening degree can be adjusted. The steam passage area of the steam ejection holes 42 is increased as the number thereof increases.

According to the second embodiment, in addition to the functions (1) to (9) described above in the first embodiment, there is the following function (10).

(10) The opening area (steam passage area) of the steam ejection hole 42 can be increased or decreased depending on the opening degree (valve opening degree) of the valve body 18 with respect to the valve seat 16. Therefore, the maximum flow rate / minimum controllable flow rate (range avility) of the valve is set to a value higher than that of the one in which a constant steam flow rate flows through the steam bypass path 41 at the same time when the valve opens (the first embodiment). The atomizing action of the cooling water by the above-mentioned steam can be realized without lowering it.

(Third Embodiment) (See FIG. 5) The difference between the steam temperature reduction / pressure reduction control valve 10 of FIG. 5 and the steam temperature reduction / pressure reduction control valve 10 of the first embodiment (FIG. 1) is as follows. Is.

That is, in the steam temperature reducing / pressure reducing valve 10, the steam jetting path 43 is provided between the inner cage 21 and the skirt sleeve 106, and the water injection hole 39 is opened in the middle portion of the steam jetting path 43. It was done.

According to the third embodiment, in addition to the functions (1) to (9) described above in the first embodiment, there is the following function (11).

(11) The cooling water supplied from the water injection hole 39 is
Narrow between the inner cage 21 and the skirt sleeve 106,
A high atomization effect is imparted by the Venturi effect of the steam jet path 43 having a high steam flow velocity, and the steam flowing through the steam jet path 43 is more effectively mixed and atomized.

(Fourth Embodiment) (See FIG. 6) The difference between the steam temperature reducing / pressure reducing control valve 10 of FIG. 6 and the steam temperature reducing / pressure reducing control valve 10 of the second embodiment (FIG. 4) is as follows. Is.

That is, in the steam temperature reducing / reducing control valve 10, the steam jetting path 43 is provided between the inner cage 21 and the skirt sleeve 106, and the water injection hole 39 is opened in the middle portion of the steam jetting path 43. It was done.

According to the fourth embodiment, in addition to the actions (1) to (10) described above in the second embodiment, there is the action (11) described above in the third embodiment.

(Fifth Embodiment) (See FIG. 7) The difference between the steam temperature reducing / pressure reducing control valve 10 of FIG. 7 and the steam temperature reducing / pressure reducing control valve 10 of the first embodiment (FIG. 1) is as follows. Is.

That is, in the steam temperature reducing / pressure reducing control valve 10, a partition wall 70 having a plurality of small holes 71 is provided between the inner cage 21 and the outer cage 23, and the mixing chamber 22 has two mixing chambers. It is divided into 22A and 22B. The partition wall 70 is arranged coaxially with the inner cage 21 and the outer cage 23.

According to the fifth embodiment, in addition to the operations (1) to (9) described above in the first embodiment, the following (12),
It has the function of (13).

(12) The inlet steam flowing out from the small hole 24 of the inner gauge 21 and the cooling water supplied from the water injection hole 39 of the skirt sleeve 106 collide with each other in the mixing chamber 22,
Mixed atomization is performed, but inner gauge 21 and outer gauge 23
By providing a plurality of mixing chambers 22A and 22B in the middle of the above, the steam and the cooling water are atomized and mixed in stages, and a more uniform steam temperature state is obtained.

(13) By providing the plurality of mixing chambers 22A and 22B, the pressure is gradually reduced, and the noise reducing effect is obtained. Further, in order to reduce noise of the conventional valve, a plurality of orifice plates 6 are provided on the outlet side of the valve casing 13.
The valve casing 13 is
By providing a plurality of mixing chambers 22A and 22B inside, the same effect can be obtained, and the number of orifice plates 60 provided on the outlet side of the valve casing 13 can be reduced to, for example, one.

(Sixth Embodiment) (See FIG. 8) The difference between the steam temperature reducing / pressure reducing control valve 10 of FIG. 8 and the steam temperature reducing / pressure reducing control valve 10 of the third embodiment (FIG. 5) is as follows. Is.

That is, in this steam temperature reducing / pressure reducing valve 10, a partition wall 70 having a plurality of small holes 71 is provided between the inner cage 21 and the outer cage 23, and the mixing chamber 22 has two mixing chambers. It is divided into 22A and 22B. The partition wall 70 is arranged coaxially with the inner cage 21 and the outer cage 23.

According to the sixth embodiment, in addition to the functions (1) to (9) and (11) described above in the third embodiment, (12) and (13) described in the fifth embodiment are used. ) Has the effect.

(Seventh Embodiment) (See FIG. 9) The difference between the steam temperature reduction / pressure reduction control valve 10 of FIG. 9 and the steam temperature reduction / pressure reduction control valve 10 of the second embodiment (FIG. 4) is as follows. Is.

That is, in the steam temperature reducing / pressure reducing control valve 10, a partition wall 80 having a plurality of small holes 81 is provided between the inner cage 21 and the outer cage 23, and the mixing chamber 22 has two mixing chambers. It is divided into 22A and 22B. The partition wall 80 is arranged substantially orthogonally from the lower end of the skirt sleeve 106 toward the outer cage 23.

According to the seventh embodiment, in addition to the operations (1) to (10) described above in the second embodiment, the fifth embodiment
In the embodiment, there are the actions (12) and (13) described above.

(Eighth Embodiment) (See FIG. 10) The difference between the steam temperature reduction / pressure reduction control valve 10 of FIG. 10 and the steam temperature reduction / pressure reduction control valve 10 of the fourth embodiment (FIG. 6) is as follows. Is.

That is, in this steam temperature reducing pressure reducing valve 10, a plurality of small holes 8 are provided between the inner cage 21 and the outer cage 23.
A partition 80 having No. 1 is provided, and the mixing chamber 22 is divided into two mixing chambers 22A and 22B. The partition wall 80 is arranged substantially orthogonally from the cargo-carrying portion of the skirt sleeve 106 toward the outer cage 23.

According to the eighth embodiment, in addition to the operations (1) to (11) described above in the fourth embodiment, the fifth embodiment
In the embodiment, there are the actions (12) and (13) described above.

[0104]

As described above, according to the present invention, it is possible to secure a stable temperature-reducing / decompressing operation without causing thermal damage to the valve components.

Further, according to the present invention, maintainability can be improved.

[Brief description of drawings]

FIG. 1 is a first diagram of a steam temperature reducing / pressure reducing control valve according to the present invention.
It is sectional drawing which shows an Example.

FIG. 2 is a sectional view taken along the line II-II in FIG.

FIG. 3 (A) is a schematic diagram showing a valve closed state of FIG. 1,
FIG. 3B is a schematic diagram showing the valve open state of FIG.

FIG. 4 is a sectional view showing a second embodiment of the present invention.

FIG. 5 is a sectional view showing a third embodiment of the present invention.

FIG. 6 is a sectional view showing a fourth embodiment of the present invention.

FIG. 7 is a sectional view showing a fifth embodiment of the present invention.

FIG. 8 is a sectional view showing a sixth embodiment of the present invention.

FIG. 9 is a sectional view showing a seventh embodiment of the present invention.

FIG. 10 is a sectional view showing an eighth embodiment of the present invention.

[Explanation of symbols]

 10 Steam Dehumidifying / Decompressing Control Valve 11 Inlet Flow Path 12 Outlet Flow Path 13 Valve Casing 14 Upper Valve Body Guide 15 Lower Valve Body Guide 16 Valve Seat 17 Valve Rod 18 Valve Body 18A Seat Surface 18B Overhanging Portion 18C Steam Rectifying Surface 18D Labyrinth Groove 21 Inner cage 22 Mixing chamber 23 Outer cage 24, 25 ... Small hole 31 Cooling water supply path 39 Water injection hole 41 Steam bypass path 42 Steam ejection hole 43 Steam ejection path 70, 80 Partition wall 71, 81 Small hole

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Naoki Hanao 1-14 Nakamachi, Moji-ku, Kitakyushu, Fukuoka Prefecture, Okano Valve Manufacturing Co., Ltd. (56) References: 1-97002 (JP, U)

Claims (9)

[Claims] 1. A steam dehumidifying system having a valve casing having an inlet passage and an outlet passage, a valve seat formed in the valve casing, and a valve element movable in a direction toward and away from the valve seat. In the pressure reducing control valve, it is arranged so as to slide around the outer periphery of the valve body so as to partition the inlet flow path and the outlet flow path together with the valve body, and can be opened and closed by the valve body to allow communication between the inlet flow path and the outlet flow path. Is arranged around the valve body and the inner cage having a plurality of small holes to form a mixing chamber between the valve body and the inner cage, and the communication between the mixing chamber and the outlet channel is possible. An outer cage having a plurality of small holes, a cooling water supply path extending to the valve body surrounding member, and a cooling water supply path communicating with the cooling water supply path and opening to the valve body surrounding member facing the mixing chamber, From the seating surface of the valve seat and the water injection hole that supplies water to the mixing chamber side It has a steam bypass path that is open to the side opposite to the inlet flow path and that extends to the valve body, and a steam ejection hole that is open to the outer peripheral portion of the valve body that is in communication with the steam bypass path and is capable of communicating with the mixing chamber. A steam temperature reducing / pressure reducing valve characterized in that a water injection path from a water injection hole and a steam injection path from a steam injection hole are provided in the immediate vicinity. 2. The steam temperature reducing / pressure reducing control valve according to claim 1, wherein a steam jetting path is provided between the inner cage and the valve body surrounding member, and the water injection hole is opened around an outlet of the steam jetting path. 3. The steam temperature reducing / pressure reducing control valve according to claim 1, wherein a steam jetting path is provided between the inner cage and the valve member surrounding member, and the water injection hole is opened to the steam jetting path. 4. The steam ejection hole, according to the movement of the valve body,
The steam temperature reducing / reducing pressure control valve according to any one of claims 1 to 3, which can be opened and closed by an inner cage, and a steam passage area of the steam injection hole increases as the valve opening degree increases. 5. The steam temperature reducing system according to claim 1, wherein a partition having a plurality of small holes is provided between the inner cage and the outer cage, and the mixing chamber is divided into a plurality of mixing chambers. Pressure reducing control valve. 6. An overhanging portion, which has a smaller diameter than the inner diameter portion of the valve seat and can form a minute gap with the inner diameter portion of the valve seat, is provided on the inlet flow path side from the seat surface of the valve body with the valve seat, Further, the steam rectifying surface is provided so as to project from the overhanging edge portion of the overhanging portion to the inlet passage side in a reduced diameter state which is concave around the valve body axis.
5. A steam temperature reducing / pressure reducing control valve according to any one of 1. 7. The small hole of the inner cage is inclined with respect to the valve body axis, and the steam flow line of the small hole is provided in a direction along a steam rectifying surface of the valve body. Steam temperature reduction pressure reducing control valve. 8. The steam temperature reducing / pressure reducing control valve according to claim 1, wherein a labyrinth groove is provided in a portion of the outer peripheral portion of the valve body which is slidably guided by the inner cage. 9. The steam temperature reducing / pressure reducing valve according to claim 1, wherein the valve seat ring having the valve seat is exchangeably coupled to a valve casing.