JP2001050008A - Side inlet structure of steam turbine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent loss of steam flow by connecting an opening portion of a steam inlet pipe with a bottom portion of a turbine casing in a tapered manner towards the end, and disposing a central axis of the opening portion such that it extends aslope upward from the bottom. SOLUTION: Outlet sides of steam inlet pipes 1-1, 1-2 are flange-connected with opening portions 1a-1, 1a-2, respectively. The opening portions 1a-1, 1a-2 open in a tapered manner toward the end to be connected with a bottom portion of a turbine casing 51a for introducing steam, and have a trumpet-shape tapering toward the ends. Central axis thereof thus extends slightly upward with respect to the flat direction, allowing the steam to flow from the bottom portion of the turbine casing 51a into a turbine portion in the upward-sloping direction. With this configuration, the steam introduced from the steam inlet pipes into the turbine portion flows through the tapered opening portions 1a-1, 1a-2, expands into the turbine portion in the upward-sloping direction, and flows uniformly around the turbine portion thus preventing deflected steam flow.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a side inlet structure of a steam turbine, and more particularly, to a flow of steam flowing from a steam inlet pipe of a side inlet type structure for allowing steam to flow into a vehicle interior from a side and from a vehicle interior to a condenser. The structure is such that the outflow of the steam flow is prevented from being deviated and the loss of the steam flow is reduced.

[0002]

2. Description of the Related Art FIG. 7 is a sectional view of a conventional side inlet type low pressure steam turbine. Low-pressure steam turbines have a method in which steam flows in from the top.In this method, the steam inlet is located in the upper part of the vehicle compartment, and a heavy inlet and lid must be installed on the upper part. From the viewpoint of operability, a side-inlet type low-pressure steam turbine in which steam flows into the turbine section from the side has been developed.

FIG. 7 is a cross-sectional view of this side inlet type steam turbine, wherein 50a is an outer casing, 51b is an inner casing, and a rotor and blades around the rotor are disposed inside. 52-1 and 52-2 (52-2 are not shown) are moisture separation heaters provided on both left and right sides, and 53-1 and 53-2 are left and right heaters 52-1 and 52-2, respectively.
1, 52-2. 54-1,
Reference numeral 54-2 denotes a steam inlet pipe, each of which has a pipe 53.
-1, 53-2, which penetrates the outer casing 50a, opens to the inner casing 51b, and guides low-pressure steam to the turbine section. Reference numeral 55 denotes a condenser, which is disposed immediately below the turbine and condenses steam that has been expanded and worked in the low-pressure turbine section. Reference numerals 56 and 57 denote low-pressure water heaters.
The feedwater is heated in 5, and the exhaust heat is recovered. Reference numeral 60 denotes a foundation, which supports the outer casing 50a and the inner casing 51b.
62 is also the basis, and the moisture separation heaters 52-1, 52-2.
And other equipment.

In the side inlet structure of the conventional low-pressure steam turbine having the above structure, the steam inlet pipes 54-1, 5
4-2 is arranged horizontally with respect to the surface of the foundation 60,
The flange 70 of the inner casing 51b penetrates the outer casing 50a.
It is connected directly below. Moisture separation heaters 52-1, 52
The main stream of the steam 100 from -2 flows out to the region Z, and a difference is generated between the amount of steam flowing to the regions X and Y around the outlet, so that the inflow of the steam is deflected. Further, the low-temperature steam 200 that expands in the turbine section, returns to the condenser 55 after performing work, flows out of the inner casing 51b from around the turbine section, passes between the outer casing 50a and the inner casing 51b, and flows therethrough. The condenser 5 is disposed immediately below the turbine section through a narrow area W where the flange section 70 of the vehicle compartment is located.
5, the flow is disturbed in this region W, and in the portion where the steam inlet pipes 54-1 and 54-2 are connected, the steam flowing to the condenser 55 wraps around the steam inlet 55. The steam is disturbed by the pipes 54-1 and 54-2, and consequently the outflowing steam is deflected, and the steam flow loss is increased.

[0005]

As described above, in the conventional low-pressure steam turbine employing the side inlet system,
The steam flowing from the steam inlet pipe into the turbine section of the inner casing is not uniformly flowed in a region of the steam flowing straight in the lateral direction from the inlet tube and flowing in the surrounding region, and a drift occurs. In addition, the steam flowing from the turbine section to the condenser through the outer casing and the inner casing flows around the flange of the inner casing and around the steam inlet pipe. Will occur.

Accordingly, the present invention provides a steam turbine having a steam inlet pipe for allowing steam to flow in from a lateral direction.
The structure of the steam inlet pipe has been improved to eliminate the drift of the steam flowing into the turbine section so that the steam flows uniformly around the turbine section from the side, and the steam flowing out to the condenser and the outer casing The object of the present invention is to provide a steam turbine side inlet structure which is arranged so as to uniformly wrap around the inner casing in the circumferential direction and flow out to the condenser, thereby suppressing loss of steam flow. is there.

[0007]

The present invention provides the following means (1) to (6) to solve the above-mentioned problems.

(1) In a steam turbine side inlet structure having a steam inlet pipe for guiding steam from both lateral sides of a vehicle compartment to a turbine section, an opening of the steam inlet pipe is connected to a lower portion of the inner casing in a divergent shape. A central axis of the opening is disposed obliquely upward from below.

(2) The steam inlet pipe is inserted into a hole passing through a lower portion of a foundation supporting the vehicle compartment, and an opening thereof is connected to the inner compartment.
The described steam turbine side inlet structure.

[0010] (3) The steam turbine side inlet structure according to (1) or (2), wherein the central axis of the opening is directed substantially directly above.

(4) The divergent opening is formed integrally with the inner casing, and is connected to the steam inlet pipe (1), (2) or (3). The steam turbine side inlet structure according to the above.

(5) A pair of flow guide plates are provided around the steam inlet pipe in the vehicle cabin so as to cover the circumference from both sides and have a smooth curved surface in an arc shape. The steam turbine side inlet structure according to any one of the above.

(6) The steam turbine side inlet structure according to any one of (1) to (5), wherein a condenser is disposed immediately below the vehicle compartment.

In the invention of (1) of the present invention, the steam flowing from the steam inlet pipes on both sides to the turbine portion passes through the divergent opening, expands obliquely upward and flows into the turbine portion, and flows around the turbine portion. The flow is uniform and the drift of the flow is eliminated. Conventionally, the gas flows horizontally from the horizontal direction into the turbine portion, and a drift occurs in the flow in the horizontal portion and in the vicinity of the opening, and the flow does not become uniform around the portion. Such a drift is eliminated.
In addition, the steam flowing out of the turbine section also flows around the inner casing and flows out to the condenser, but the steam inlet pipe is not arranged directly below the flange of the inner casing. Since the pipe is arranged at the lower part of the inner cabin and is installed diagonally upward, it does not hinder the steam flow in the narrow flow path in this area, and the uniform flow from the inner cabin surroundings condenses Spill into container.

In the invention of (2), since the steam inlet pipe is mounted obliquely upward from the lower portion of the inner casing, a through hole is provided in the foundation, so that the steam inlet pipe can be easily arranged obliquely. In the invention of the above, the opening of the steam inlet pipe is arranged upward and almost directly downward, has a divergent shape, allows the steam to flow in uniformly, and in this case, the steam flowing out of the steam inlet pipe The effect of the invention (1) is further promoted without obstructing the flow of the flow.

In (4) of the present invention, since the opening is formed integrally with the inner casing, the assembling is facilitated and the range of application in design is widened. Since the flow guide plate is provided around the steam inlet pipe, when the flowing steam flows around the steam inlet pipe and flows out to the condenser, it flows along the smooth curved surface of the flow guide plate. There is no turbulence and there is less drift.

According to (6) of the present invention, in the steam turbine of the type in which the condenser is disposed immediately below the vehicle compartment,
Since the inlet structure of (5) can be adopted, an inlet having an optimal structure can be adopted under conditions such as the type, capacity, and structural restrictions, so that the steam flow of the steam turbine is prevented from drifting and pressure loss is reduced. can do.

[0018]

Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a plan view of a steam turbine side inlet structure according to a first embodiment of the present invention. In the figure, reference numerals 50a, 50b, and 50c denote outer casings, which are constituted by three low-pressure turbines in this example. Reference numerals 52-1 and 52-2 denote moisture separation heaters on both sides, and steam is guided to both left and right sides by piping 53-1 and 53-2, respectively. Reference numerals 1-1 and 1-2 denote steam inlet pipes, which penetrate the outer casings 50a, 50b, and 50c, open to the inner casing, and guide the steam to the turbine section, as described later. These steam inlet pipes 1-1,1-
Numeral 2 is arranged so as to guide the steam to the turbine section from the lateral direction, and the outer casings 50a, 50b, 5
0c, and the other configuration is the same as that of the conventional example shown in FIG.

FIG. 2 is a view taken along the line AA in FIG.
In the figure, steam inlet pipes 1-1 and 1-2 are provided with through holes 3-1 and 3-2 in a foundation 62 supporting an outer casing 50a and an outer casing 51a of a turbine, respectively.
Steam inlet pipes 1-1 and 1-2 are inserted and arranged in 1, 3-2, respectively. The through holes 3-1 and 3-1
3-2 shows an example in which the hole is inclined obliquely in the figure, but a hole in a horizontal direction may of course be used. In the inclined hole, the steam inlet pipes 1-1 and 1-2 can be installed obliquely upward. . In the figure, an opening that opens to the inner casing and connects to the steam inlet pipe is not shown.

FIG. 3 is a detailed cross-sectional view of the side inlet structure of the first embodiment described above, and will be described in further detail with reference to FIG. Inner car room 5 is inside outer car room 50a.
1a is supported, and the outer casing 50a is fixed to the foundation 62 by support portions 71 on both sides. As described with reference to FIG. 2, the through holes 3-1 and 3-2 are provided on both sides of the foundation 62 horizontally or obliquely as necessary.

The steam inlet pipes 1-1 and 1-2 are inserted into these through holes 3-1 and 3-2, and the inlet side is provided with a support portion 7.
1 and the outlet side is a pipe 53-
1, 53-2, and connected to a moisture separation heater 52-1 (not shown) to supply steam. Further, the steam inlet pipes 1-1 and 1-2 are supported by the cushion device 2 at the openings of the support portions 71, respectively, so that they can cope with elongation due to thermal stress. The cushion device 2 has a bellows structure or a spring structure, is mounted around the pipe, and absorbs expansion and deformation of the pipe.

Openings 1a-1 and 1a-2 are respectively flange-coupled to the outlet sides of the steam inlet pipes 1-1 and 1-2, and the openings 1a-1 and 1a-2 are widened toward the end. It connects to the lower part of 51a and guide | induces a vapor | steam respectively. Further, the openings 1a-1 and 1a-2 may not be separate bodies but may have a structure integral with the inner casing 51a.

The openings 1a-1 and 1a-2 have a flared flared shape, the center axis of which is mounted slightly upward from the horizontal direction. The steam is directed obliquely upward from both lower sides of the inner casing 51a to the turbine section. Into the tank. The openings 1a-1 and 1a-2 may be arranged so as to flow directly upward instead of obliquely unless there is a structural restriction.

The inner casing 5 of the openings 1a-1 and 1a-2.
As described above, the position of attachment to 1a is set obliquely upward so that the periphery of the opening is lower than the narrow region B where the flange portion 70 is located, and flows out of the turbine portion which has been working and has been cooled. It is arranged in a position where the steam flow is not disturbed by the steam inlet tubes 1-1 and 1-2 in the narrow region B and is not obstructed.

In the first embodiment of the above configuration, the steam inlet pipe 1- 1 is guided through the pipes 53-1 and 53-2.
The steam flowing in from the openings 1 and 1-2 is the openings 1a-1 and 1a.
-2 flows obliquely upward from the inner compartment 51a and 90a,
As shown by 90b and 90c, the gas smoothly flows into the vehicle interior, uniformly flows from both sides in the circumferential direction of the turbine unit, and eliminates drift.

Further, the outer casing 50 is operated by working in the turbine section.
The low-temperature steam 91 flowing between the inner space 51a and the inner casing 51a passes through the narrow region B where the flange portion 70 is present from both sides and flows out to the condenser below. And the steam inlet pipes 1-1 and 1-2 and the openings 1a-1 and 1a-2 are located below, so that the wrap around of the steam in the region B is not disturbed as in the conventional case, and is smooth. Thus, the steam flows more evenly from the surroundings, and the drift of the steam flow is prevented.

FIG. 4 is a sectional view of a steam turbine side inlet structure according to a second embodiment of the present invention. In the figure, the part different from the first embodiment shown in FIG. 3 is that the foundation is dug down and lowered without providing a through hole in the foundation,
The steam inlet tube is arranged, and the other configuration is the same as that of the first embodiment shown in FIG. 3 and will be described in detail below.

In FIG. 4, a base 61 is a surface for supporting the moisture separation heaters 52-1 and 52-2, as in the prior art.
The foundation 63 is deeper than the conventional foundation 60 and the foundation 62 of the first embodiment shown in FIG.
L is lower than the surface. The outer casing 50a is supported on the base 63 by the support portion 72, and the steam inlet pipe 11-
Reference numerals 1 and 11-2 are horizontally supported through the support portion 72 at a portion where the base 61 is lowered.

The steam inlet pipes 1-1 and 1-2 have inlets connected to pipes 53-1 and 53-2, respectively, to which steam is supplied from the moisture separation heaters 52-1 and 52-2, and the outlets are open. The openings 11a-1 and 11a-2 are connected to the lower part of the inner casing 51a in a shape in which the central axis is obliquely upward and divergent as in the example of FIG. To the turbine section.

In the second embodiment having such a configuration, as in the first embodiment, the incoming steam 90 is 90
a, 90b, and 90c, the gas smoothly flows obliquely from the lower portion to eliminate the drift, and the steam 91 flowing out of the turbine portion is also connected to the steam inlet pipes 11-1 and 11-1 from both sides. 11-2 and opening 11a
-1, 11a-2 can smoothly flow down the area B without being disturbed by the area 11a-2, and can evenly flow out to the condenser from the surroundings.

FIG. 5 is a sectional view of a steam turbine side inlet structure according to a third embodiment of the present invention. The feature of the third embodiment is that the opening in the conventional structure shown in FIG. 7 is improved to have a divergent shape, and the other structure is the same as that of FIG.

In FIG. 5, the steam inlet pipe 21-
1, 21-2 are connected to pipes 53-1, 53-2, and steam is supplied from the moisture separation heaters 52-1 and 52-2,
The steam 90 flows from the flared openings 21a-1 and 21a-2, respectively, and the steam 90 flows in the same manner as in the first and second embodiments.
As shown at a, 90b, and 90c, the gas flows into the turbine section from both sides in a divergent manner and uniformly flows into the periphery.

In the third embodiment, the steam flowing from the steam inlet pipes 21-1 and 21-2 into the turbine section has an effect of eliminating the drift, but the steam flowing out of the turbine section has an effect. Is the same as the conventional structure,
Although the effect of eliminating the drift cannot be expected, it is suitable for work to be carried out for small-scale improvement of an existing plant, and has an effect that the flow of the flowing steam can be improved by simple work.

FIGS. 6A and 6B show a steam turbine side inlet structure according to a fourth embodiment of the present invention, wherein FIG. 6A is a sectional view, and FIG. 6B is a sectional view taken along line CC in FIG. In the figure, the feature of the fourth embodiment is that flow guide plates 31-1 and 31-2 are provided around the steam inlet pipes 54-1 and 54-2 having the conventional structure shown in FIG. Other structures are the same as the conventional example of FIG.

In the figure, a steam inlet pipe 54-1,
Steam is supplied to pipes 54-2 from pipes 53-1 and 53-2, and steam inlet pipes 54-1 and 54-2 are supplied in the same manner as in the prior art.
Although it flows into the inner casing 51a, the steam inlet pipe 5
A flow guide plate is mounted around 4-1 and 54-2 in a circular arc shape as shown in FIG. The flow guide plates 31-1 and 31-2 have outer casings 50 on both sides of the plates as shown in FIG.
a, and is fixed by welding or the like along a curved surface outside the inner casing 51a.

In the above-described fourth embodiment, the steam 91 flowing out of the turbine section is supplied to the steam inlet pipes 54-1 and 54-1.
Flow flows in a narrow area where 54-2 exists, but is guided by the flow guide plates 31-1 and 31-2 in this area and smoothly along the smooth arc-shaped curved surfaces of the flow guide plates 31-2 and 31-3. And the water is guided to the lower condenser, so that the flow is not disturbed by the conventional steam inlet pipe, and the pressure loss is reduced without causing drift.

In the fourth embodiment, the flow guide plate 31-1, the flow guide plate 31-1, the conventional example shown in FIG.
Although the example shown in FIG. 3-2 is provided, the flow guide plate may naturally be provided in the structure shown in FIGS. 3 and 4. In this case, the first embodiment shown in FIGS. In the second and third embodiments, it is possible to further surely prevent the steam flowing to the condenser from drifting.

[0038]

According to the steam turbine side inlet structure of the present invention, there is provided (1) a steam turbine side inlet structure having a steam inlet pipe for guiding steam from both lateral sides of a vehicle compartment to a turbine section. Has a divergent shape and is connected to a lower portion of the inner casing, and the basic feature is that the central axis of the opening is disposed obliquely upward from below. With such a structure, the steam flowing from the steam inlet pipe into the turbine section passes through the divergent opening, expands and flows into the turbine section obliquely upward, and flows uniformly around the turbine section. The drift is eliminated. In addition, the steam flowing out of the turbine working around the inner cabin also flows out to the condenser,
The steam inlet pipe is not arranged directly below the flange of the inner casing, and the steam inlet pipe is arranged at the lower part of the inner casing and is installed obliquely upward. The steam does not interfere with the steam flow, and can flow out from the periphery of the inner casing into the condenser as a uniform flow.

In the invention of (2), since the steam inlet pipe is mounted obliquely upward from the lower portion of the inner casing, a through hole is provided in the foundation, so that the steam inlet pipe is easily arranged obliquely. According to the invention of the above, the opening of the steam inlet tube is arranged upward and almost right above, so that the steam can flow in uniformly with the divergent shape, and in this case, the steam flowing out of the steam inlet tube The effect of the invention (1) is further promoted without obstructing the flow.

In (4) of the present invention, since the opening is formed integrally with the inner casing, the assembling is facilitated and the range of application in design is widened. Since the flow guide plate is provided around the steam inlet pipe, when the flowing steam flows around the steam inlet pipe and flows out to the condenser, it flows along the smooth curved surface of the flow guide plate. There is no turbulence and there is less drift.

According to (6) of the present invention, in the steam turbine of the type in which the condenser is disposed immediately below the vehicle compartment,
Since the inlet structure of (5) can be adopted, an inlet having an optimal structure can be adopted under conditions such as the type, capacity, and structural restrictions, so that the steam flow of the steam turbine is prevented from drifting and pressure loss is reduced. can do.

[Brief description of the drawings]

FIG. 1 is a plan view of a steam turbine to which a steam turbine side inlet structure according to a first embodiment of the present invention is applied.

FIG. 2 is a view taken in the direction of arrows AA in FIG.

FIG. 3 is a cross-sectional view of the steam turbine side inlet structure according to the first embodiment of the present invention.

FIG. 4 is a sectional view of a steam turbine side inlet structure according to a second embodiment of the present invention.

FIG. 5 is a sectional view of a steam turbine side inlet structure according to a third embodiment of the present invention.

FIGS. 6A and 6B show a steam turbine side inlet structure according to a fourth embodiment of the present invention, wherein FIG. 6A is a cross-sectional view, and FIG. 6B is a view taken along the line CC in FIG.

FIG. 7 is a sectional view of a conventional side inlet type low pressure steam turbine.

[Explanation of symbols]

1-1, 1-2, 11-1, 11-2 Steam inlet tube 21-1, 21-2 Steam inlet tube 1a-1, 1a-2 Opening 2 Cushion device 3-1, 3-2, 4- 1,4-2 Through-holes 31-1, 31-2 Flow guide plate 50a Outer compartment 51a Inner compartment 53-1, 53-2 Piping 61, 62, 63 Base 70 Flange 71, 72 Support 90, 91 Steam

Claims (6)

[Claims] 1. A steam turbine side inlet structure having a steam inlet pipe for guiding steam from both lateral sides of a vehicle compartment to a turbine section, an opening of the steam inlet pipe is connected to a lower part of an inner casing in a divergent shape, The central axis of the opening is disposed obliquely upward from below. A steam turbine side inlet structure. 2. The steam generator according to claim 1, wherein the steam inlet pipe is inserted into a hole penetrating a lower portion of a foundation supporting the casing, and an opening thereof is connected to the inner casing. Steam turbine side inlet structure. 3. The steam turbine side inlet structure according to claim 1, wherein a center axis of the opening is substantially right above. 4. The steam turbine according to claim 1, wherein the divergent opening has an integral structure with the inner casing and is connected to the steam inlet pipe. Side inlet structure. 5. A pair of flow guide plates provided around the steam inlet pipe in the vehicle cabin so as to cover the circumference from both sides and have a smooth curved surface in an arc shape. A steam turbine side inlet structure according to any of the claims. 6. The steam turbine side inlet structure according to claim 1, wherein a condenser is disposed immediately below the vehicle compartment.