JP2002054403A - Intermediate drum and condenser in steam turbine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an intermediate drum and a condenser in a steam turbine capable of preventing backflow of steam from the condenser to the intermediate drum, and improving diffuser effect in the intermediate drum. SOLUTION: Low temperature steam flows from an exhaust chamber 50 into the intermediate drum 51 as illustrated with 70, 71, a heater 54 to be connected to a extraction steam pipe 53 is disposed at a position to interfere with an inflow stream by expanding size of X0 to X1 from a conventional center position. The heater 54 is set to make size of an inlet part of the intermediate drum 51 as X to satisfy X0/X>0.2. With this disposition, flow of steam interferes with the heater 54 to be direction-changed to be expanded outward, and it flows along a wall surface which conventionally has been a flow separation range due to backflow in a range E, thereby backflow is eliminated to improve a diffuser effect, and reduce loss.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intermediate body and a condenser of a steam turbine. The arrangement of a bleed tube and a heater of the intermediate body is improved. The structure is such that loss of the flow of steam flowing into the water vessel is reduced.

[0002]

2. Description of the Related Art FIGS. 6A and 6B show a structure of an intermediate body and a condenser of a conventional steam turbine, wherein FIG. 6A is a front view and FIG. 6B is a side view. In the figure, reference numeral 50 denotes an exhaust chamber, which is an inlet into which low-temperature steam flowing out of the low-pressure turbine flows. Reference numeral 51 denotes an intermediate body, which accommodates a heater 54 through which low-temperature water flows, and a bleed pipe 53 that guides steam for heating the low-temperature water by the heater 54. Reference numeral 52 denotes a condenser, which is not shown, and has a tube group composed of a number of cooling tubes arranged therein, and these tube groups are supported by a number of support plates as described later.

[0003] In the above-described structure, the low-temperature steam exiting the low-pressure steam turbine enters the exhaust chamber 50, where the intermediate cylinder 5 has a low temperature.
1, flows into the condenser 52, is cooled in contact with a number of cooling tubes arranged in the condenser 52, is condensed, accumulates at the lower part, and is again guided to the boiler system. Here, the inside of the intermediate body 51 mainly includes a reinforcing pipe 55, a bleeding pipe 53, a heater 54,
And the like. As described above, the steam flows from the upstream exhaust chamber 50 through the intermediate body 51 between these structures to the downstream condenser 52 as described above. In recent years, the exhaust chamber 5
0, there is a tendency to reduce the size of the intermediate body 51 and the condenser 52, and as the exhaust chamber 50 becomes smaller, the average flow velocity at the inlet of the intermediate body 51 increases. The effect of methane on plant performance has become increasingly negligible. Therefore, while simplifying the reinforcing member inside the intermediate body 51 and securing the flow area, the loss ratio is reduced by increasing the area ratio between the inlet and the outlet of the intermediate body 51 to enhance the diffuser effect in the intermediate body 51. I have. However, since the flow velocity at the entrance of the intermediate cylinder 51 is increasing, the flow flows back along the wall surface as indicated by a two-dot chain line 60 in the drawing at the widening portion of the intermediate cylinder 51, and a reverse flow occurs in the region E. However, the diffuser effect cannot be obtained and the loss inside the intermediate cylinder has not been reduced.

FIG. 7 is a perspective view showing a part of the condenser described above, and shows only the right half of FIG. 6 (a). As shown, a large number of support plates 61 are arranged in parallel inside the condenser 52, and are supported by the condenser main body at the top and bottom as described later. The support plate 61 supports a tube group by penetrating a large number of tubes on each surface. A gap 62 is provided between the lower end of each support plate 61 and the bottom surface of the condenser 52, and a gap 63 is provided between each support plate 61.
However, gaps 64 and 65 also exist between the condenser 52 and the end on the support plate 61 side.
5 communicate with each other.

FIGS. 8A and 8B show the mounting state of the condenser support plate 61, wherein FIG. 8A is a front view and FIG. 8B is a side view. As described in FIG. 7, a large number of support plates 61 are arranged in parallel, the upper portion is suspended at a predetermined pitch by a support material fixed to both ends, and the lower end and both sides are respectively the bottom surface and the side surface of the condenser main body. Are supported and fixed at a predetermined pitch, and the side ends of the central portion are connected to each other at a predetermined pitch. The multiple support plates 61 penetrate and support tubes (not shown) arranged in a horizontal multi-stage arrangement.

[0008] In FIG. 8, low-temperature steam enters the intermediate body 51 from the exhaust chamber 50 and further flows into the condenser 52, as indicated by reference numeral 60. From the support plate 61, through the gap 62 on the bottom surface, above the gaps 64, 65 on both sides, flow backward, and reach the intermediate drum 51. For this reason, the exhaust chamber 5
The flow from 0 spreads along the wall of the intermediate barrel 51,
Although the loss was reduced by recovering the pressure, the flow near the wall of the intermediate drum was pushed away by the backflow, and the flow of the intermediate drum 51 was reduced.
Without the diffuser effect inside, causing an increase in loss,
As a result, the condenser performance is reduced.

[0007]

As described above, in the conventional intermediate body and condenser, the flow of the low-temperature steam flowing from the exhaust chamber 50 into the intermediate body 51 enters the condenser 52, and the bottom of the condenser. Flows backward from the gap 62 through the gaps 64 and 65 on both wall surfaces,
Due to this backflow, the flow near both wall surfaces of the intermediate body 51 is pushed away, eliminating the diffuser effect in the intermediate body 51, increasing the loss of the flow, and resulting in a decrease in the condenser performance. Was desired.

Therefore, the present invention improves the arrangement of the equipment and piping of the intermediate cylinder, and furthermore, the gap between the cooling tube support plates of the condenser, the gap between the support plate and the bottom of the condenser, and the condenser. It is an object of the present invention to provide a steam turbine intermediate body and a condenser having a structure that eliminates or reduces a gap between both side wall surfaces and a support plate, and has a structure that eliminates a backflow generated in the intermediate body. It was done as.

[0009]

The present invention provides the following means (1) to (5) in order to solve the above-mentioned problems.

(1) A bleed pipe and two heater pipes connected to the bleed pipe at the center of the inlet and connected to the exhaust chamber for introducing the low-pressure steam are arranged in parallel in the front-rear direction, and are expanded in a tapered shape downward to reduce the low pressure. An intermediate body and a condenser of a steam turbine comprising an intermediate body for guiding steam downward, and a condenser connected to a lower part of the intermediate body to cool and condense the steam from the intermediate body and the condenser. heater tube, a transfer cylinder inlet transverse dimension that connects to the exhaust chamber X, the distance from the transfer cylinder inlet lateral center to the respective heaters tube center as _{X 1, X 1 / X>} 0.
An intermediate shell and a condenser of a steam turbine, wherein the intermediate shell and the condenser are arranged so as to be two.

(2) An intermediate body connected to an exhaust chamber for introducing low-pressure steam and expanding downward in a tapered lateral direction to guide the low-pressure steam downward, and a condenser connected to a lower portion of the intermediate body. The condenser is configured to support a horizontally arranged tube group with a large number of support plates, and the support plates are vertically erected and arranged at predetermined intervals in the horizontal direction to penetrate the tube group. In the intermediate body and the condenser of the steam turbine configured to support the condenser, a specific one of the support plates arranged in the lateral direction of the condenser is located on the left and right sides, and each of the support plates includes a partition plate. An intermediate body of a steam turbine, which penetrates and supports the pipe group and is in close contact with front and rear side walls and a bottom wall of the inner wall of the condenser to partition between a lateral side end and a center side. And condensers.

(3) The horizontal position of the partition plate is approximately one-third of the distance from the lateral side end face to the center.
(2) The steam turbine intermediate body and the condenser according to (2), wherein the intermediate body and the condenser are arranged so as to have a distance of about １ ／.

(4) The partition plate is in close contact with a bottom wall surface in the condenser and has a predetermined gap between front and rear side walls of the condenser. Steam turbine intermediate shell and condenser.

(5) An intermediate body and a condenser of a steam turbine according to (2), wherein an opening / closing door is provided at a lower corner in both front and rear directions of the partition plate.

In (1) of the present invention, the upper part of the intermediate cylinder is provided.
The two heater tubes are at a distance X from the center ₁Is the middle barrel entrance dimension
And X₁/ X> 0.2
It is arranged to expand to the right side. With such an arrangement
And the downward steam flow from the exhaust chamber and the heater tube dry.
The direction of the flow changes in the direction of spreading outside. This
Flow separation area does not easily occur along the wall of the intermediate barrel
Can increase the diffuser effect in the middle barrel,
By increasing the pressure recovery, the loss can be reduced.
You.

In (2) of the present invention, since the support plate is disposed at predetermined positions on both lateral sides of the condenser, the flow from the bottom surface of the condenser to both lateral sides is blocked by the partition plate. Further, there is no gap at both ends in the front-rear direction, and the flow therebetween is also shut off. Therefore, the flow that has flowed backward through these gaps and reached the intermediate body is interrupted, and the flow from the exhaust chamber flows along the intermediate body wall surface smoothly, and the diffuser effect in the intermediate body can be increased, and the pressure can be increased. By increasing the recovery, the loss can be reduced.

According to (3) of the present invention, the position of the support plate is approximately one of the distance from the lateral end surface to the center.
Since the position is determined and optimized at the position of ３ to ４, the effect of the invention (2) can be reliably obtained.

In (4) of the present invention, there is a gap between the front and rear end portions of the partition plate of the above (2) invention and the front and rear side wall surfaces of the condenser, but the central portion is inside the condenser. Since there is no gap in close contact with the bottom wall surface, the flow through the bottom surface is blocked. With this alone, there is no flow flowing back through the central portion and the bottom surface, so that the performance is lower than that of the above invention (2), but the same effect as that of the invention (2) can be obtained.

Further, in (5) of the present invention, in the above-mentioned invention of (2), since the opening and closing door is provided at the lower corners in both front and rear directions of the partition plate, maintenance and inspection are easy, and the invention of the above-mentioned (2) is provided. The function is further improved.

[0020]

Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 shows an intermediate body and a condenser of a steam turbine according to a first embodiment of the present invention, wherein (a) is a front view and (b) is a side view. In the figure, in the first embodiment, reference numerals 50, 51,
The structure of 52, 53, 54 is basically the same as the conventional structure shown in FIGS. 6 to 8, and in the present invention, the mounting position of the heater 54 is moved to both sides as compared with the conventional one, and steam on both sides flows. The structure has a narrow passage.

[0021] In FIG 1, the heater 54 is conventionally has an arrangement obtained by enlarging what was disposed at a position of X ₀ from the heater centerline and X ₁ (X _1> X _0), on both sides. In the first embodiment of the present invention, the length of the entrance portion of the intermediate body 51 is represented by X and X
_{1 /} X> 0.2 so as to interfere with the downward flow from the exhaust chamber 50. Conventionally, X ₀ / X <0.
In There present invention 2 is made larger than the X ₁ X _0.
Other arrangements in the condenser 52 are the same as those in the related art.

According to the steam turbine intermediate body and the condenser of the first embodiment described above, the downward flow of the low-temperature steam flowing from the exhaust chamber 50 is achieved by disposing the heater 54 on the outside as compared with the conventional case. It just interferes with the heater 54, and the flow direction, which has been going straight ahead in the past, flows in the direction expanding outward and changes direction. Thereby, the steam flows along the wall surface of the intermediate cylinder 51, and the separation area, which has been generated in the conventional area E, is less likely to be generated. Therefore, the diffuser effect in the intermediate cylinder 51 can be enhanced, and the pressure recovery can be improved. By increasing the number, loss can be reduced.

FIG. 2 is a partial perspective view of an intermediate body and a condenser of a steam turbine according to a second embodiment of the present invention. The figure shows one side (the right side of FIG. 1A) of the condenser, and a number of support plates 61 are arranged in the condenser 52, and a tube group composed of a number of tubes arranged horizontally. I support. In the middle of the support plate 61, the partition plate 1 that completely separates the support plates on both sides is provided. The partition plate 1 is attached on both sides in close contact with the inner wall of the condenser 52, and the bottom face is also attached to the condenser 5.
It is configured so as to be closely attached to the bottom surface of 2 and completely close the gap between both sides and the bottom surface.

FIG. 3 shows a second embodiment of the present invention described above.
The arrangement of the partition plate according to the form is shown, (a) is a front view,
(B) is a side view. In the drawing, a preferred arrangement example of the partition plate is shown, and when Z ₁ is a distance from the center and Z ₂ is a distance from an end of the partition plate 1, Z ₂ / Z ₁ = １ ／ to １ ／. This arrangement is the most effective arrangement for preventing the steam flow from flowing back to the intermediate drum 51.
Other structures of the intermediate body 51 and the exhaust chamber 50 are the same as those of the conventional example.

According to the above-described second embodiment, the specific support plate 61 is replaced with a partition plate for eliminating a gap between the inner wall surface of the condenser 52 and the partition plate 1 of the condenser 52. Since the support plate 61 is installed on both sides in place of the support plate 61 at a position about 1/3 to 1/4 from the center, the flow of the steam which has flowed back to the intermediate body 51 in the past is interrupted, and the exhaust gas is exhausted. The flow from the chamber 50 flows smoothly along the wall surface of the intermediate cylinder 51 as indicated by reference numerals 70 and 71 in the figure, and the diffuser effect in the intermediate cylinder 51 can be enhanced. By increasing the pressure recovery, the loss can be reduced. Can be planned.

FIG. 4 shows a steam turbine intermediate body and a condenser according to a third embodiment of the present invention, and is a partial perspective view of the condenser. In the figure, in the third embodiment, FIG.
As in the second embodiment shown in FIG. 4, a partition plate 11 is provided. The partition plate 11 has gaps 66 and 67 (dimension t) on both sides of the inner wall of the condenser 52.
The arrangement is the same as the examples shown in FIGS. This partition plate 1
Numeral 1 has gaps 66 and 67 on both sides, and these gaps are almost the same as gaps 64 and 65 of the support plate 61.
This structure has the function of the support plate 61 and completely closes the gap between the center and the bottom. Other structures are the same as those of the second embodiment.

According to the third embodiment described above, the specific support plate 61 is provided with the gaps 66, 6 between the inner wall surfaces of the condenser.
7, but instead of the partition plate 11 having a structure to reduce the gap, and the arrangement is the same as that of FIG. 3. Can be blocked in the same manner as in the second embodiment, and the flow from the exhaust chamber 50 can smoothly flow along both wall surfaces of the intermediate drum 51, and the diffuser effect in the intermediate drum 51 can be enhanced. The loss can be reduced by increasing the pressure recovery.

FIG. 5 is a perspective view showing an intermediate body and a condenser of a steam turbine according to a fourth embodiment of the present invention, showing a part of the condenser. In the fourth embodiment, doors 12 and 13 are provided at lower portions on both sides of the partition plate 1 in the second embodiment shown in FIG.
This is a partition plate 21 having a structure provided with, and the other structure is the same as that of the second embodiment. By using such a partition plate 21, it becomes possible for a worker to enter and exit by opening the entrance manholes 12, 13 such as opening and closing doors on both sides partitioned by the partition plate 21 during maintenance and inspection of the condenser.
Maintenance and inspection are easy. Of course, during normal operation, the door is closed and both sides are closed. Also in the fourth embodiment, the same effects as in the second embodiment can be obtained.

[0029]

The intermediate body and the condenser of the steam turbine according to the present invention are as follows: (1) About two heater pipes connected to the exhaust chamber for introducing low-pressure steam and connected to the bleed pipe at the center of the inlet. An intermediate cylinder that is arranged in parallel in the direction and expands downward in a tapered shape to guide the low-pressure steam downward, and a condenser that is connected to a lower portion of the intermediate cylinder and cools and condenses steam from the intermediate cylinder. In the steam turbine intermediate shell and condenser, the two heater pipes have an intermediate shell inlet horizontal dimension X connected to the exhaust chamber, and a center from the intermediate shell inlet horizontal direction to the center of each heater pipe. Are arranged so that X ₁ /X>0.2, where X ₁ is the distance of X ₁ .

According to the above configuration, the downward steam flow from the exhaust chamber interferes with the heater tube, and the flow direction changes in a direction to spread outward. As a result, a flow separation region is hardly generated along the wall surface of the intermediate cylinder, the diffuser effect in the intermediate cylinder can be enhanced, and the loss can be reduced by increasing the pressure recovery.

(2) The present invention relates to (2) an intermediate cylinder connected to an exhaust chamber for introducing low-pressure steam and expanding downward in a tapered lateral direction to guide the low-pressure steam downward, and to a lower portion of the intermediate cylinder. It consists of a condenser, the condenser supports a horizontally arranged tube group with a large number of support plates, the support plates are erected vertically and arranged at predetermined intervals in the horizontal direction In the intermediate body and the condenser of the steam turbine configured to penetrate and support the tube group, the support plates arranged in the lateral direction of the condenser each include a specific plate near the left and right sides formed of a partition plate. The partition plate penetrates and supports the tube group and is in close contact with the front and rear side wall surfaces and the bottom wall surface of the condenser inner wall, thereby partitioning between the lateral side end and the center side. .

With the above construction, the flow which has flowed back through these gaps and reached the intermediate body is interrupted, and the flow from the exhaust chamber flows along the intermediate body wall surface smoothly to reduce the diffuser effect in the intermediate body. Can be increased, and the loss can be reduced by increasing the pressure recovery.

According to (3) of the present invention, the position of the partition plate is approximately 1/1 / the distance from the lateral end surface to the center.
Since the position is determined and optimized at the position of 3 to 1/4, the effect of the invention (2) can be surely obtained.

In (4) of the present invention, there is a gap between the front and rear end portions of the partition plate of the above (2) invention and the front and rear side wall surfaces of the condenser, but the bottom surface is the inner bottom wall surface of the condenser. And there is no gap, so that the flow through the bottom surface is blocked. This alone eliminates the flow that flows back through the bottom surface.
Although the performance is lower than that of the invention of (2), the same effect as the invention of (2) can be obtained.

Further, in (5) of the present invention, in the above-mentioned invention of (2), since the opening and closing door is provided at the lower corners in both front and rear directions of the partition plate, maintenance and inspection are easy, and the above-mentioned invention of (2) is provided. The function is further improved.

[Brief description of the drawings]

FIG. 1 shows an intermediate body and a condenser of a steam turbine according to a first embodiment of the present invention, wherein (a) is a front view and (b) is a side view.

FIG. 2 is a partial perspective view of a condenser tube group support plate in an intermediate body and a condenser of a steam turbine according to a second embodiment of the present invention.

FIG. 3 shows an intermediate body and a condenser of a steam turbine according to a second embodiment of the present invention, wherein (a) is a front view of the condenser,
(B) is a side view.

FIG. 4 is a partial perspective view of a condenser tube group support plate in an intermediate body and a condenser of a steam turbine according to a third embodiment of the present invention.

FIG. 5 is a partial perspective view of a condenser tube group support plate in an intermediate body and a condenser of a steam turbine according to a fourth embodiment of the present invention.

6A and 6B show an intermediate body and a condenser of a conventional steam turbine, wherein FIG. 6A is a front view and FIG. 6B is a side view.

FIG. 7 is a partial perspective view of a tube support plate of a conventional condenser.

8A and 8B show an intermediate body and a condenser of a conventional steam turbine. FIG. 8A is a front view of a condenser tube group support plate, and FIG. 8B is a side view.

[Explanation of symbols]

 1,11,21 Partition plate 12,13 Opening / closing door 50 Exhaust chamber 51 Intermediate body 52 Condenser 54 Heater 61 Support plate 62-67 Gap

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazuyuki Matsumoto 2-1-1 Shinhama, Arai-machi, Takasago City, Hyogo Prefecture Inside the Takasago Research Laboratory, Mitsubishi Heavy Industries, Ltd. No. 1 Inside Mitsubishi Heavy Industries, Ltd. Takasago Works (72) Inventor Koichi Inoue 2-1-1, Shinhama, Arai-machi, Takasago-shi, Hyogo F-term in Mitsubishi Heavy Industries, Ltd. Takasago Works 3L065 DA20

Claims (5)

[Claims] 1. A low-pressure steam which is connected to an exhaust chamber for introducing low-pressure steam, and is provided with a bleeding pipe and two heater pipes connected to the bleeding pipe at the center of the inlet in parallel in the front-rear direction. And a condenser connected to a lower portion of the intermediate body and a condenser for cooling and condensing steam from the intermediate body.
Heater tube of the present is a transfer cylinder inlet transverse dimension that connects to the exhaust chamber X, the distance from the transfer cylinder inlet lateral center to the respective heaters Tube center as _{X 1, X 1 / X>} 0. An intermediate shell and a condenser of a steam turbine, wherein the intermediate shell and the condenser are arranged so as to be two. 2. An intermediate body connected to an exhaust chamber for introducing low-pressure steam and expanding downward in a laterally tapered shape to guide the low-pressure steam downward, and a condenser connected to a lower portion of the intermediate body. The condenser comprises a horizontally arranged tube group supported by a large number of support plates, and the support plates are vertically erected and arranged at predetermined intervals in the horizontal direction to penetrate the tube group. In the intermediate body and the condenser of the steam turbine configured to support the condenser, a specific one of the support plates arranged in the lateral direction of the condenser is formed of a partition plate on the left and right sides, respectively. An intermediate body of a steam turbine, which is supported by penetrating a pipe group and is in close contact with front and rear side walls and a bottom wall of the condenser inner wall, and partitions between a lateral side end and a center side; Condenser. 3. The lateral position of the partition plate is approximately 1/3 to 1 of the distance from the lateral end surface to the center of the lateral end surface.
3. The steam turbine intermediate body and condenser according to claim 2, wherein the steam turbine is disposed so as to have a distance of / 4. 4. The condenser according to claim 2, wherein the partition plate is in close contact with a bottom wall surface in the condenser, and has a predetermined gap between front and rear side wall surfaces of the condenser. Intermediate shell and condenser of steam turbine. 5. The steam turbine intermediate body and condenser according to claim 2, wherein an opening / closing door is provided at lower corners in both front and rear directions of the partition plate.