JP2004100986A - Condenser with straghtening device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a condenser with a straightening device capable of improving performance by making flow of steam flowing out of an exhaust chamber of a turbine uniform in a steam flow-in part of the condenser and dispersing it and making it flow into each heat transfer pipe nest equally. <P>SOLUTION: This condenser with the straightening device is constituted in such a way that the condenser 30 provided with the steam flow-in part in which steam flows and having the heat transfer pipe nest 32 composed of many heat transfer pipes inside it is provided with the straightening device 50 arranged in such a manner that it is extended inward so as to cross the direction of flow of steam flowing in through the steam flow-in part on an inner wall face of the steam flow-in part. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a condenser for exchanging heat between high-temperature steam and a large number of heat transfer tubes to cool and condense and recover the condensate, and in particular, a swirl component contained in a steam flow flowing into the condenser. The present invention relates to a rectifying device for removing and making a uniform inflow.
[0002]
[Prior art]
For example, high-temperature steam that has performed work in a turbine casing of a steam turbine is discharged from an exhaust chamber and flows into a condenser. Then, inside the condenser, the steam exchanges heat with a number of heat transfer tubes, and is cooled to be condensed and collected.
[0003]
FIGS. 7A and 7B are schematic views showing the flow of steam flowing into a conventional steam turbine condenser, wherein FIG. 7A is a top view thereof and FIG. 7B is a front view thereof. With reference to this figure, an exhaust chamber 10 of a turbine casing (not shown) is connected to an intermediate body 20 in the axial direction of the turbine shaft 1 and downstream in the steam flow direction. , To the condenser 30.
[0004]
The condenser 30 includes a box-shaped body 31. Inside the body 31, a heat transfer tube nest 32 composed of a number of heat transfer tubes is supported by a plurality of heat transfer tube support plates 33. The heat transfer tube nests 32 are provided separately in two vertical stages in the vertical direction and two stages in front and rear in the steam flow direction. A condensate sump 34 is provided below the heat transfer tube nest 32.
[0005]
The flow of steam to the steam turbine condenser configured as described above will be described. The high-temperature steam flow S that has completed the work in the turbine casing flows into the condenser 30 from the exhaust port 11 of the exhaust chamber 10 through the interior of the intermediate body 20. The high-temperature steam S that has flowed into the condenser 30 is guided into the heat transfer tube nests 32 and exchanges heat with the individual heat transfer tubes, and is cooled and condensed. The condensate is collected in a condensate sump 34 below the heat transfer tube nest 32 and collected from a condensate outlet (not shown).
[0006]
Here, in order to improve the performance of the condenser, it is desirable that good heat transfer be performed between the high-temperature steam and the heat transfer tube nest in a given load operation of the turbine. For this reason, it is desired that the high-temperature steam that has passed through the intermediate drum 20 has a uniform flow in the steam inflow portion of the condenser 30. That is, if the steam flow becomes uniform at the steam inflow portion of the condenser 30, the steam is evenly distributed to the heat transfer tube nests 32 divided vertically and vertically, and as a result, the steam is evenly distributed to the individual heat transfer tubes. This is because good heat exchange is performed between the two.
[0007]
On the other hand, the condenser cooling pipe group is condensed in the condenser where a plurality of condensers are connected by the connecting cylinder provided on the body wall of the condenser body located above the condenser cooling pipe group. In order to prevent erosion due to the droplets, a flow straightening plate is provided at both openings of the communication cylinder, or weirs are provided at the ends of the bottom plate on the opening side, and the liquid generated by turbine exhaust steam colliding with the bottom plate of the communication cylinder is provided. There is one that prevents the droplet from scattering to the condenser cooling tube group (for example, see Patent Document 1).
[0008]
[Patent Document 1]
JP-A-5-66094 (Abstract, FIGS. 1 and 2)
[0009]
[Problems to be solved by the invention]
However, the steam flowing into the condenser includes a swirl component generated by rotation of the turbine, and when the volume flow of the inflow steam is small (during turbine partial load operation), the swirl component is reduced in the condenser. Causes unevenness of the steam flow. That is, as shown in FIG. 7, the flow S of the steam flowing out from the exhaust port 11 of the exhaust chamber 10 becomes a drift near the wall surface 21 of the intermediate body 20. Such a bias of the steam flow causes a distribution in the amount of steam supplied to the heat transfer tube, and a pressure distribution occurs in the condenser. When this pressure distribution occurs, the saturation temperature of the low pressure portion decreases, and the heat transfer area apparently decreases, and the heat transfer performance of the condenser decreases, resulting in a problem of poor efficiency. There was a point.
[0010]
In addition, a plurality of straightening plates disclosed in Patent Document 1 are installed in parallel with the bottom plate of the communication cylinder, and it is completely impossible to make the bias of the steam flow due to the swirling component uniform in the steam inflow portion of the condenser. It was impossible.
[0011]
The present invention has been made in order to solve such a problem, and makes the flow of steam flowing out of the exhaust chamber of the turbine uniform in the steam inflow portion of the condenser and uniformly in each heat transfer tube nest. It is an object of the present invention to provide a rectifier-equipped condenser with improved performance by allowing the flow to be dispersed and introduced into the condenser.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, a condenser with a rectifier according to the present invention includes a steam inflow portion into which steam flows in and a heat transfer tube nest having a plurality of heat transfer tubes therein. A rectifying device is provided on the inner wall surface of the section so as to extend inward so as to intersect the flow direction of the steam flowing through the steam inflow section.
[0013]
The rectifying device is preferably disposed annularly along the inner wall surface of the steam inflow portion, and is preferably, for example, an orifice-shaped member, a guide vane-shaped member, or an orifice-shaped porous member. Further, the rectifying device may be disposed across the entire steam inflow section so as to cross the flow direction of the steam, and may be, for example, a honeycomb, a perforated plate, or a wire mesh.
[0014]
As a device to which the present invention is applied, a condenser for a steam turbine is preferable. In particular, it is preferable to dispose the rectifying device on an intermediate body disposed between the steam turbine and the condenser. preferable.
[0015]
[Action]
By rectifying the flow components of the steam flowing into the condenser by the rectifier, the steam is directed toward the heat transfer tube nests by preventing the steam flow from biasing toward the heat transfer tube nests in the condenser. The heat is uniformly guided, and the local heat transfer isolation inhibition region can be eliminated. Therefore, even when the steam discharged from the exhaust chamber has a drift near the wall surface during the partial load operation of the turbine, the steam is uniformly guided toward the heat transfer tube nest. Thus, the performance of the condenser can be ensured.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals indicate similar components.
[0017]
[First embodiment]
Hereinafter, an embodiment of the present invention will be described in detail with reference to FIG. FIG. 1 is a schematic diagram showing a first embodiment of a rectifier according to the present invention. In FIG. 1, the basic configuration will be described again. An exhaust chamber 10 of a turbine casing (not shown) The intermediate body 20 is connected to the intermediate body 20 in the axial direction of the turbine shaft 1 and downstream in the steam flow direction, and further connected to the condenser 30.
[0018]
The condenser 30 includes a box-shaped body 31. Inside the body 31, a heat transfer tube nest 32 including a number of heat transfer tubes is supported by a plurality of heat transfer tube support plates (not shown). . The heat transfer tube nests 32 are provided separately in the vertical direction and in the flow direction of the steam in order to make it easy for high-temperature steam to flow in and to enhance heat transfer performance with the steam. A condensate sump 34 is provided below the heat transfer tube nest 32.
[0019]
The intermediate body 20 includes an upper wall surface 21a, a lower wall surface 21b, and a pair of left and right wall surfaces (not shown). These wall surfaces include a turbine exhaust chamber on the upstream side and a condenser on the downstream side. 30 and is connected to the body 31. Such an intermediate body 20 may be formed separately from the body 31 or may be formed integrally with the body 31.
[0020]
The steam inflow portion according to the present invention, which alleviates the swirling component of the inflowing steam and transmits the steam to the heat transfer tube nest 32, is provided in the steam inflow portion that allows the steam to flow toward the heat transfer tube nest 32 disposed inside the condenser 30. A rectifying device 50 for preventing the deviation of the rectification is provided. In detail, the rectifying device 50 is annularly attached along the upper wall surface 21a, the lower wall surface 21b, and the inner wall surface including the pair of left and right wall surfaces near the exit position of the intermediate body 20 on the upstream side of the heat transfer tube nest 32. . The rectifying device 50 in this embodiment is of an orifice type and includes an annular plate portion 51 and a central opening 52 as can be clearly seen from FIG. The shape of the rectifying device 50 may be adjusted to the shape of the inner wall surface of the intermediate body 20 or the condenser 30, and may be rectangular, circular, or any shape as in this embodiment.
[0021]
Next, the flow of steam to the condenser 30 equipped with such an orifice type rectifier 50 will be described. The high-velocity steam flow containing the swirling component and discharged from the exhaust port 11 of the exhaust chamber 10 of the turbine becomes a flow that is biased toward the inner wall surface side of the intermediate drum 20. However, the large flow on the wall surface side passes through the central opening 52 after colliding with the plate-shaped portion 51 of the rectifying device 50, so that the whirl component is reduced by the rectifying device 50, and the steam flow is not biased and the flow is uniform. Then, it flows into the condenser 30 toward the heat transfer tube nest 32. When the flow is uniform, the pressure distribution is reduced, and the local heat transfer inhibition region can be eliminated. The steam flow guided into the heat transfer tube nest 32 exchanges heat with the heat transfer tubes and is cooled to become condensed water. The condensate is disposed in a condensate sump 34 provided on the lower side and condensed. Collected from exit.
[0022]
By the operation of the rectifier 50, the steam flow deflected to the vicinity of the wall surface of the intermediate drum 20 is uniformly guided to the inside of the heat transfer tube nest 32, so that good heat exchange with the heat transfer tube can be performed. It is possible to improve the performance of the condenser. This improves the condenser performance particularly during turbine partial load operation, in which the steam flow S from the exhaust chamber 10 tends to drift toward the vicinity of the wall surface, but also improves the condenser performance during operation at the rated point. Can be improved. When a high-speed steam flow from the turbine collides with the plate portion 51 of the rectifier 50, a pressure loss occurs. However, since the pressure distribution becomes uniform as a whole, the performance of the condenser 30 must be ensured as a result. Can be.
[0023]
[Second embodiment]
Next, a second embodiment of the present invention will be described in detail with reference to FIG. The basic configuration of the condenser 30 and the like is the same as that of the first embodiment shown in FIG. In this figure, the rectifying device 60 has substantially the same shape as the rectifying device 50 of the first embodiment, but differs in that the plate portion is a perforated plate 61 having a large number of small holes. Further, since the perforated plate 61 having a large number of small holes is used, the pressure loss with respect to the impinging steam flow is smaller than that of a mere plate-shaped portion, so that the perforated plate 61 extends from the inner wall surface to the center longer. Therefore, the central opening 62 can be smaller than the central opening 52 of the first embodiment. Thus, the rectifying device 60 of the perforated plate orifice type has a higher rectifying capability than the rectifying device 50 of the simple orifice type of the first embodiment. That is, the condenser performance at the time of the turbine partial load operation and at the time of the fixed point operation can be further improved as compared with the first embodiment.
[0024]
[Third embodiment]
Next, a third embodiment of the present invention will be described in detail with reference to FIG. In this embodiment, the basic configuration of the condenser 30 and the like is the same as that of the first embodiment shown in FIG. In this figure, the rectifying device 70 has the shape of a guide blade, and more specifically, has a guide blade portion 71 that curves inward from the outer peripheral portion along the flow direction of steam, and has a center side. Is provided with a central opening 72. According to the third embodiment, since the impinging steam flow is guided to the central opening 72 by the curved guide blade portion 71, the pressure loss can be further reduced as compared with the previous embodiment.
[0025]
[Fourth embodiment]
In the above, a rectifying device that can be used for a high flow velocity such as a turbine has been described. Hereinafter, a rectifying device that can be generally used when the flow velocity is low will be described. For example, as shown in FIGS. 5 and 6, the rectifier 80 is disposed over the entire steam inflow section. In this embodiment, the rectifying device 80 is formed of a perforated plate 81 and, unlike the previous embodiment, has no central opening. As described above, the rectifying device 80 disposed over the entire steam inflow port cannot be used because the pressure loss is too large when the flow rate of the steam is high, but when the flow rate of the steam is low, As a result, the rectifying action is improved, so that stable performance of the condenser 30 can be secured. It should be noted that the rectifying device 80 provided over the entire steam inflow port may be, for example, a honeycomb built-in type or a wire mesh type.
[0026]
In all of the above embodiments, any known means such as bolting or welding can be used for attaching the rectifier to each wall surface. Further, the rectifier and each wall surface may be integrally formed. Further, the rectifier can be formed from any material, but preferably has heat resistance because it comes into contact with high-temperature steam.
[0027]
Although the first embodiment has been described, the shape of each rectifying device may be adjusted to the shape of the inner wall surface of the intermediate body or the condenser, and is not limited to a rectangular shape as in these embodiments. , A circle, a polygon, or any other shape.
[0028]
【The invention's effect】
A steam turbine condenser according to the present invention is provided with a rectifying device disposed on an inner wall surface of a steam inflow portion so as to extend inward so as to cross a flow direction of steam flowing through the steam inflow portion. Because of this, the swirling component of the flow of steam flowing into the condenser can be reduced, and the bias of the steam flow toward the heat transfer tube nest in the condenser can be prevented. When the steam discharged from the exhaust chamber is drifted near the wall during partial load operation of the turbine by eliminating the area where heat transfer is prevented from being conducted uniformly toward the nest However, this steam flow is evenly directed toward the heat transfer tube nests, thereby performing good heat exchange with the heat transfer tubes and improving the condenser performance.
[Brief description of the drawings]
FIG. 1 is a schematic view showing a condenser with a rectifier according to the present invention.
FIG. 2 is a schematic diagram showing one embodiment of the rectifier shown in FIG.
FIG. 3 is a schematic diagram showing another embodiment of the rectifier.
FIG. 4 is a schematic diagram showing still another embodiment of the rectifier.
FIG. 5 is a schematic view showing another embodiment of the condenser with a rectifier according to the present invention.
FIG. 6 is a schematic view showing one embodiment of the rectifier shown in FIG.
FIG. 7 is a schematic diagram showing a flow of steam flowing into a conventional steam turbine condenser, wherein (A) is a top view thereof and (B) is a front view thereof.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Turbine shaft, 10 ... Exhaust chamber, 11 ... Exhaust port, 20 ... Intermediate body, 21 ... Wall surface, 21a ... Upper wall surface, 21b ... Lower wall surface, 30 ... Condenser, 31 ... Body, 32 ... Heat transfer tube nest, 33 ... heat transfer tube support plate, 34 ... condensate sump, 50 ... rectifier, 51 ... plate-shaped part, 52 ... central opening, 60 ... rectifier, 61 ... perforated plate, 62 ... central opening, 63 ... small hole, 70 ... Rectifier, 71 ... Guiding blade, 72 ... Central opening, 80 ... Rectifier, 81 ... Perforated plate, S: Steam flow.

Claims (11)

In a condenser having a steam inflow portion into which steam flows in and having a heat transfer tube nest composed of a number of heat transfer tubes inside,
A condenser with a rectifying device, comprising: a rectifying device disposed on an inner wall surface of the steam inflow portion so as to extend inward so as to cross a flow direction of steam flowing through the steam inflow portion. The condenser with a rectifying device according to claim 1, wherein the rectifying device is annularly disposed along the inner wall surface of the steam inflow portion. The condenser with a rectifier according to claim 2, wherein the rectifier is an orifice-shaped member. The condenser with a rectifier according to claim 2, wherein the rectifier is a guide blade-shaped member. The condenser with a rectifier according to claim 2, wherein the rectifier is an orifice-shaped porous member. The condenser with a rectifier according to claim 1, wherein the rectifier is disposed across the entire steam inflow portion so as to cross the flow direction of the steam. The condenser with a rectifier according to claim 6, wherein the rectifier is a honeycomb. The condenser with a rectifier according to claim 6, wherein the rectifier is a perforated plate. The condenser with a rectifier according to claim 6, wherein the rectifier is a wire mesh. The condenser with a rectifier according to any one of claims 1 to 5, wherein a steam turbine is connected to the steam inflow portion, and the steam is discharged from the steam turbine. The condenser with a rectifying device according to claim 10, wherein an intermediate body is provided continuously with the steam turbine, and the rectifying device is disposed on the intermediate body.

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