JP2020024077A - Condenser and power generation plant - Google Patents

Abstract

To provide a condenser which enables reduction of flow resistance in a turbine exhaust duct while properly securing load bearing of the turbine exhaust duct in which turbine exhaust air flows.SOLUTION: A condenser according to one embodiment includes: a turbine exhaust duct 10 into which turbine exhaust air from a turbine flows; and a body shell container 11 which is connected to the turbine exhaust duct 10 and receives the turbine exhaust air from the turbine exhaust duct 10 to condense the turbine exhaust air with a coolant. The turbine exhaust duct 10 has a truncated four-sided pyramid shape in which a passage area is expanded to the body shell container 11 side. A corner part 20 of the turbine exhaust duct 10 is formed into a shell shape forming a curved surface.SELECTED DRAWING: Figure 1

Description

  Embodiments of the present invention relate to a condenser and a power plant.

  A condenser used in a steam turbine power plant, a gas turbine combined cycle power plant, or the like is a device for maintaining the back pressure of the turbine in a vacuum by condensing steam in turbine exhaust discharged from the turbine. Some of such condensers include an upper body and a lower body, and allow turbine exhaust from the turbine to flow from the upper body to the lower body. In this type of condenser, the upper body functions as an exhaust duct, and steam in the turbine exhaust flowing from the upper body to the lower body is condensed by the cooling pipe housed in the lower body. The upper main body may house a bleed tube or a feed water heater, and in this case, it is possible to reduce the size of the plant occupation area.

  In the above-described condenser, a relatively large external pressure load acts on the upper main body and the lower main body because the inside of the condenser becomes significantly negative pressure with respect to vacuum or atmospheric pressure during operation. Here, in the lower main body, a structure such as a cooling pipe and a plate or a pipe supporting the cooling pipe can also function as a reinforcing material against external pressure. On the other hand, in the upper body, a reinforcing member called a reinforcing rib or a reinforcing truss may be provided inside as a measure against an external pressure load.

  However, since the turbine exhaust passes through the upper main body and flows into the lower main body, the reinforcing member, the bleed pipe and the feed water heater installed in the upper main body generate flow resistance (pressure loss) when the turbine exhaust passes. Let it. From the viewpoint of plant performance, it is naturally desirable that such pressure loss is suppressed to a minimum.In the field of condensers, techniques for reducing pressure loss inside the condenser have been developed. Various proposals have been made.

Patent No. 4230841 JP 2002-195786 A JP 2004-108686 A

  In recent years, the flow of turbine exhaust from a turbine to a condenser can be accurately and three-dimensionally evaluated by a fluid analysis technique. As a result of analyzing the flow resistance of the turbine exhaust passing through the upper body by such analysis and evaluation, the distribution of the flow velocity from the turbine exhaust port and the positional relationship of the reinforcing members greatly affected the flow resistance received by the turbine exhaust. It was found that the More specifically, the conventional condenser has a structure in which the reinforcing members are uniformly installed over the entire same plane of the upper body without considering the distribution of the flow velocity, so that the flow velocity distribution from the turbine exhaust port is It was found that the flow resistance was particularly large at the high flow velocity points in. Such flow resistance can be suppressed by appropriately removing the reinforcing member, but in this case, the load resistance of the upper body may be undesirably reduced.

  The present invention has been made to solve the above-described problem, and provides a condenser and a power generation plant that can reduce flow resistance in a turbine exhaust duct while appropriately securing load resistance of the turbine exhaust duct. The purpose is to:

A condenser according to one embodiment includes a turbine exhaust duct into which turbine exhaust from a turbine flows, a main body connected to the turbine exhaust duct, and receiving turbine exhaust from the turbine exhaust duct and condensing the turbine exhaust with cooling water. And a container. The turbine exhaust duct has a truncated quadrangular pyramid shape that enlarges a flow path area toward the main body vessel, and a corner of the turbine exhaust duct is formed into a curved shell shape.
Further, the condenser according to one embodiment is connected to a turbine exhaust duct into which turbine exhaust from a turbine flows, and the turbine exhaust duct, and receives the turbine exhaust from the turbine exhaust duct and condenses it with cooling water. And a main body container. The turbine exhaust duct has a truncated conical shape for increasing the flow area toward the main body vessel.
A power plant according to one embodiment includes the above condenser.

  ADVANTAGE OF THE INVENTION According to this invention, the flow resistance in a turbine exhaust duct can be reduced, ensuring the load resistance of the turbine exhaust duct through which turbine exhaust flows.

It is a perspective view of the condenser concerning a 1st embodiment. It is a top view schematic diagram of a turbine exhaust duct of a condenser concerning a 1st embodiment, and is a figure showing arrangement arrangement of a reinforcement member provided in a turbine exhaust duct. It is a figure showing distribution of flow velocity of turbine exhaust which flows into a turbine exhaust duct of a condenser concerning a 1st embodiment. FIG. 6 is a diagram illustrating a modification of the first embodiment, and is a diagram illustrating an arrangement configuration of a reinforcing member different from the arrangement configuration of the reinforcing members illustrated in FIG. 2. It is a figure which shows the modification of 1st Embodiment, and is a figure which shows the condenser in which the reinforcement rib is provided in the outer peripheral surface of a turbine exhaust duct. It is a figure which shows the modification of 1st Embodiment, and is a figure which shows the condenser in which the reinforcement rib different from the example of FIG. 5 is provided in the outer peripheral surface of a turbine exhaust duct. It is a figure which shows the modification of 1st Embodiment, and is a figure which shows the condenser in which the reinforcement rib is provided inside the turbine exhaust duct. It is a figure which shows the modification of 1st Embodiment, and is a figure which shows the condenser which the shape of the corner part of a turbine exhaust duct differs from 1st Embodiment. It is a perspective view of the condenser concerning a 2nd embodiment. It is a figure which shows the modification of 2nd Embodiment, and is a figure which shows the condenser in which the reinforcement rib is provided in the outer peripheral surface of a turbine exhaust duct.

  Hereinafter, each embodiment will be described in detail with reference to the accompanying drawings.

<First embodiment>
The condenser 1 according to the first embodiment will be described with reference to FIGS. 1 to 3. A condenser 1 shown in FIG. 1 includes a turbine exhaust duct 10 into which turbine exhaust from a turbine flows, and a main body connected to the turbine exhaust duct 10 for receiving the turbine exhaust from the turbine exhaust duct 10 and condensing the turbine exhaust with cooling water. A container 11 and a water chamber 12 provided on a side surface of the main body container 11 are provided. Inside the main body case 11, a bundle of cooling pipes for passing cooling water is accommodated, and a water chamber 12 is provided for supplying cooling water to each cooling pipe.

  The turbine exhaust duct 10 is arranged above the main body casing 11, and the main body casing 11 receives the turbine exhaust from the turbine exhaust duct 10 from above. In this type of condenser 1, the turbine exhaust duct 10 may be referred to as an upper body, and the body shell 11 may be referred to as a lower body. In the present embodiment, a straight line passing through the center of the cross section of the turbine exhaust duct 10 in a direction orthogonal to the direction in which the turbine exhaust in the turbine exhaust duct 10 flows toward the main body case 11 is referred to as “axis C1”. Is defined.

  The turbine exhaust duct 10 according to the present embodiment has a truncated quadrangular pyramid shape whose flow path area is increased toward the main body container 11 and rises vertically along an upstream end portion 10A located at the upper end thereof. A connection piece 13 is provided. The connection piece 13 is provided to connect to a casing of a turbine (not shown), so that the turbine exhaust duct 10 can pass the turbine exhaust.

  Further, the corner portion 20 of the turbine exhaust duct 10 in the present embodiment is formed in a shell shape having a curved surface. Specifically, referring also to FIG. 2, the turbine exhaust duct 10 includes a pair of first body plate portions 21 arranged to face each other and a pair of first body plate portions 21 in a direction orthogonal to the direction in which the first body plate portions 21 face each other. A pair of second body plate portions 22 disposed opposite to each other, and the corner portions 20 form four corners of the turbine exhaust duct 10, and the first body plate portion 21 and the second body plate portion 22 adjacent to each other are formed. Are connected to each other. The cross-sectional shape of the corner 20 in the direction orthogonal to the axis C1 is an arc, and the corner 20 and the first body plate 21 or the second body plate 22 are smoothly connected to each other. That is, the cross-sectional shape of the turbine exhaust duct 10 in a plane orthogonal to the axis C1 is a rectangular shape with four rounded corners.

  FIG. 1 schematically shows the reinforcing member 30 disposed inside the upstream end portion 10A of the turbine exhaust duct 10, and FIG. 2 shows the arrangement of the reinforcing member 30 in detail. I have. As shown in FIGS. 1 and 2, in the present embodiment, two straight lines L11 and L12 passing through both ends of the pair of first body plate portions 21 in the direction in which the pair of first body plate portions 21 face each other. And the ratio of the reinforcing member 30 in the central area AC surrounded by two straight lines L21 and L22 passing through both ends of the pair of second body plate portions 22 in the direction in which the pair of second body plate portions 22 face each other. However, the reinforcing members 30 are arranged so as to be higher than the ratio of the reinforcing members 30 in the area AE outside the central area AC. In FIG. 2, for convenience of description, the central area AC is surrounded by a two-dot chain line.

  More specifically, the reinforcing member 30 is a columnar member provided between the wall portions facing each other, and the reinforcing member 30 is provided between the pair of first body plate portions 21 and between the pair of second body members. It is erected only between the plate portions 22. More specifically, a plurality of reinforcing members 30 are provided so as to be arranged in a horizontal direction between a pair of first body plate portions 21, and a plurality of reinforcing members 30 are arranged in a horizontal direction between a pair of second body plate portions 22. By providing the reinforcing members 30, the plurality of reinforcing members 30 are arranged so as to form a lattice. On the other hand, the reinforcing member 30 is not connected to the corner 20. Thereby, the ratio of the reinforcing member 30 (the ratio of the occupied area) in the central region AC is higher than the ratio of the reinforcing member 30 (the ratio of the occupied area) in the outer region AE.

  In the present embodiment, in the cross section of the upstream end 10A of the turbine exhaust duct 10 in a direction orthogonal to the axis C1, the ratio of one corner 20 to the maximum length in the longitudinal direction of the turbine exhaust duct 10 is reduced. , 15% or more and 25% or less, specifically, 20%.

  The cross section of the upstream end 10A of the turbine exhaust duct 10 described above can be identified with the state shown in FIG. 2, but in the present embodiment, the direction in which the main surface of the first body plate portion 21 extends is different. The length L in FIG. 2 indicates the maximum length of the upstream end 10A of the turbine exhaust duct 10 in the longitudinal direction. In the present embodiment, the ratio of the corner 20 to the maximum length L is 20% (0.2 L), and the ratio of the two corners 20 located in the longitudinal direction to the maximum length L is 40%. I have. Note that the size of such a corner 20 is not limited to the mode of the embodiment.

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

  In the condenser 1 according to the present embodiment, the turbine exhaust duct 10 has a truncated quadrangular pyramid shape, and the corner portion 20 is formed in a shell shape having a curved surface. Accordingly, even if the reinforcing member 30 is not provided for the curved corner portion 20 or the number of the reinforcing member 30 is reduced, it is possible to secure the load resistance to the corner portion 20 that can withstand the external pressure load generated during the operation of the turbine. Become. Thus, in the present embodiment, while reducing the reinforcing member 30 on the side where the corner 20 is located in the turbine exhaust duct 10, that is, on the end side, the turbine exhaust duct of the conventional general condenser is reduced. The required load resistance.

  That is, in the conventional general condenser, the cross-sectional shape of the turbine exhaust duct is rectangular, and the reinforcing member is installed uniformly over the entire rectangular plane, and in particular, the corner of the turbine exhaust duct is a right angle. Stress concentration is likely to occur, and the reinforcing member is usually provided to a position adjacent to the corner. In the present embodiment, in contrast to such a conventional general condenser turbine exhaust duct, in the present embodiment, the turbine exhaust duct 10 having a truncated quadrangular pyramid shape is formed in a shell shape, so that the turbine exhaust duct is formed. The desired load resistance is ensured while reducing the number of the reinforcing members 30 on the side where the corners 20 are located in the duct 10.

  As described above, according to the present embodiment, it is possible to reduce the flow resistance in the turbine exhaust duct 10 while appropriately securing the load resistance of the turbine exhaust duct 10, and as a result, it is possible to improve the turbine performance. Become.

  In other words, in the condenser in which the turbine exhaust duct has a truncated quadrangular pyramid shape, in the flow velocity distribution of the turbine exhaust discharged from the turbine, the flow velocity at the center side of the turbine exhaust port becomes slow, and both ends and the corner side of the exhaust port are reduced. Is generally faster. Such a flow velocity bias phenomenon is caused by a structure peculiar to a turbine, specifically, a structure in which turbine exhaust is discharged from a pair of final-stage moving blades located apart from each other. Also occurs in the form of FIG. 3 is a graph illustrating the flow velocity distribution of the turbine exhaust flowing into the turbine exhaust duct 10. In FIG. 3, the horizontal axis indicates the position of the turbine exhaust duct 10 in the longitudinal direction as a relative numerical value, a value “0” indicates one end of the turbine exhaust duct 10 in the longitudinal direction, and a value “50” indicates the turbine. The center position in the longitudinal direction of the exhaust duct 10 is shown. The vertical axis indicates a speed ratio obtained by averaging the flow speed of the turbine exhaust. In the example of FIG. 3, it can be seen that the flow velocity is high in the longitudinal range from one end of the turbine exhaust duct 10 to 15 in the longitudinal direction. In the region where the flow velocity is high, the pressure loss is increased if the reinforcing member is provided. Therefore, it is desirable not to install the reinforcing member. However, in the conventional condenser, as a measure against the external pressure load, the angle Since the reinforcing member needs to be installed near the portion, the pressure loss due to the reinforcing member has increased.

  On the other hand, in the present embodiment, as described above, the turbine exhaust duct 10 has a truncated quadrangular pyramid shape, and the corner portion 20 is formed in a shell shape having a curved surface. The desired load resistance is ensured while reducing the number of the reinforcing members 30 on the side where the corner portion 20 is located, that is, on the end side. Thereby, the flow resistance generated by the reinforcing member 30 with respect to the flow in the region where the flow velocity of the turbine exhaust is high (a large amount of turbine exhaust flows) can be reduced. Nature is secured. Therefore, according to the present embodiment, it is possible to reduce the flow resistance in the turbine exhaust duct 10 while appropriately securing the load resistance of the turbine exhaust duct 10, and as a result, it is possible to improve the turbine performance. It becomes possible.

  Further, in the present embodiment, the ratio of the corner portion 20 to the maximum length L in the longitudinal direction of the upstream end portion 10A of the turbine exhaust duct 10 is 20% (0.2 L), and two corners located in the longitudinal direction are provided. The ratio of the portion 20 to the maximum length L is 40%.

  In the present embodiment, as a countermeasure against the external pressure load, it is desirable to provide a reinforcing member 30 for connecting mutually facing ones of a plurality of boundary portions between the body plate portions 21 and 22 and the corner portion 20 of the curved surface, As shown in FIG. 2, between the boundary portions facing each other in the direction in which the pair of first body plate portions 21 face each other, and between the boundary portions facing each other in the direction in which the pair of second body plate portions 22 face each other. Each is connected by a reinforcing member 30. In this case, in order to prevent the reinforcing member 30 from entering the high flow velocity region shown in FIG. 3 up to 15% from the longitudinal end of the turbine exhaust duct 10, an angle with respect to the maximum length L in the longitudinal direction is required. The ratio of the portion 20 is preferably about 15% or more and about 25% or less. For this reason, in the present embodiment, the corner portion 20 with respect to the maximum length L in the longitudinal direction of the upstream end 10A of the turbine exhaust duct 10 is set. Is 20% (0.2 L). In such a configuration, the pressure loss can be suppressed, and the corners 20 do not excessively restrict the installation area of the reinforcing member 30. Therefore, the reinforcing member 30 can be provided so as to ensure appropriate load resistance.

  Various changes can be made to the first embodiment. Hereinafter, a modified example of the first embodiment will be described with reference to FIGS.

  First, in the above-described first embodiment, the plurality of reinforcing members 30 are arranged so as to form a lattice. However, as shown in FIG. 4, a brace is provided at the center side of the plurality of reinforcing members 30 which form a lattice. An additional reinforcing member 31 may be further provided. In the example of FIG. 4, the load resistance of the pair of second body plate portions 22 is improved by the additional reinforcing member 31 on the center side, so that the end portion side (the second body plate portion 22 side) with respect to the example of FIG. ), The number of reinforcing members 30 is reduced.

  In FIG. 5, a reinforcing rib 32 is provided on the outer peripheral surface of the turbine exhaust duct 10. In the example of FIG. 5, the reinforcing rib 32 extends along the circumferential direction with respect to the axis C1. More specifically, the reinforcing ribs 32 extend along the circumferential direction with respect to the axis C1 on both ends (second body plate portions 22) in the longitudinal direction on the outer peripheral surface of the turbine exhaust duct 10, and extend along the first body plate portion. It is not provided on the 21 side. On the other hand, as shown in FIG. 6, the reinforcing ribs 32 may be provided so as to extend over the entire outer peripheral surface of the turbine exhaust duct 10. 5 and 6, the durability against an external pressure load can be improved. Note that the state in which the reinforcing ribs 32 extend along the circumferential direction with respect to the axis C1 does not only mean a mode in which the reinforcing ribs 32 extend in a state completely coinciding with a circle centered on the axis C1. As shown in FIG. 6, the concept includes a mode extending along the outer peripheral surface of the non-circular cylindrical body (turbine exhaust duct 10) when viewed in the direction of the axis C <b> 1.

  Although FIG. 7 is a cross section in the vertical direction of the condenser, a reinforcing rib 32 may be provided on the inner surface of the turbine exhaust duct 10 as shown in FIG. It is desirable to be provided so as to extend in the flowing direction. In this case, as shown in FIG. 7, the reinforcing ribs 32 may be provided on each of the inner surfaces of the body plate portions facing each other, and the reinforcing member 30 may be provided between the reinforcing ribs 32.

  In the modification shown in FIG. 8, the corner portion 20 of the turbine exhaust duct 10 is formed so that the curved surface portion thereof gradually becomes smaller as it approaches the main body case 11. The end of the corner 20 on the side of the main body container 11 has an acute angle, and is connected to the corner of the main body container 11. In such a configuration, no step is formed between the turbine exhaust duct 10 and the main body case 11, and the flow path area can be increased, so that the pressure loss can be further reduced. it can.

  Further, in the first embodiment, the turbine exhaust duct 10 is disposed above the main body container 11, but the turbine exhaust duct 10 may be disposed on the side of the main body container 11.

<Second embodiment>
Next, a condenser according to a second embodiment will be described with reference to FIG. Among the components of the condenser according to the present embodiment, the same components as those of the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

  The condenser according to the second embodiment shown in FIG. 8 has a turbine exhaust duct 10 into which turbine exhaust from a turbine flows, and is connected to the turbine exhaust duct 10 to receive turbine exhaust from the turbine exhaust duct 10. The apparatus includes a main body container 11 that is condensed by cooling water, and a water chamber 12 provided on a side surface of the main body container 11. The turbine exhaust duct 10 has a truncated conical shape for increasing the flow area toward the main body container 11, and is connected to a side wall of the main body container 11. The condenser according to the present embodiment is connected to an axial exhaust turbine, and is of a horizontal inflow type in which turbine exhaust flows in a horizontal direction.

  The reinforcing member as described in the first embodiment is not provided inside the turbine exhaust duct 10. As shown in FIG. 9, a ring-shaped reinforcing rib 32 may be provided on the outer peripheral surface of the turbine exhaust duct 10. In the example of FIG. 9, a plurality of reinforcing ribs 32 are provided, and each of the reinforcing ribs 32 extends around the entire outer peripheral surface of the turbine exhaust duct 10 in a circumferential direction with respect to the axis C1.

  In an axial exhaust turbine, turbine exhaust is discharged in a horizontal direction, and an exhaust port connected to a condenser generally has a circular shape. In the present embodiment, since the cross-sectional shape of the turbine exhaust duct 10 is formed in a circular shape that matches the circular exhaust port of the turbine, sufficient load resistance to an external pressure load can be achieved without installing a reinforcing member inside. It is possible to secure. Thus, the turbine exhaust can flow into the main body container 11 without receiving the flow resistance from the reinforcing member. Therefore, also in the present embodiment, it is possible to reduce the flow resistance in the turbine exhaust duct 10 while appropriately ensuring the load resistance of the turbine exhaust duct 10, and to improve the turbine performance.

  Although the embodiments have been described above, the above embodiments are presented as examples and are not intended to limit the scope of the invention. This new embodiment can be implemented in other various forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. This embodiment and its modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and equivalents thereof.

DESCRIPTION OF SYMBOLS 1 ... Condenser, 10 ... Turbine exhaust duct, 10A ... Upstream end part, 11 ... Main body container, 12 ... Water chamber, 13 ... Connection piece, 20 ... Corner part, 21 ... 1st body plate part, 22 ... Second body plate portion, 30: reinforcing member, 31: additional reinforcing member, 32: reinforcing rib, AC: central region, AE: outer region

Claims (10)

A turbine exhaust duct into which turbine exhaust from the turbine flows,
A main body container that is connected to the turbine exhaust duct and receives turbine exhaust from the turbine exhaust duct and condenses with cooling water;
The turbine exhaust duct has a truncated quadrangular pyramid shape that increases the flow path area toward the main body vessel,
A condenser, wherein a corner of the turbine exhaust duct is formed in a shell shape having a curved surface.   The turbine exhaust duct includes a pair of first body plates arranged to face each other and a pair of second body plates arranged to face each other in a direction orthogonal to a direction in which the first body plates face. The condenser according to claim 1, further comprising a body plate portion, wherein the corner portion connects the first body plate portion and the second body plate portion adjacent to each other.   The condenser according to claim 2, wherein a reinforcing member is provided only between the pair of first body plates and between the pair of second body plates. A reinforcing member is disposed inside the turbine exhaust duct,
Two straight lines passing through both end portions of the pair of first body plate portions in the direction in which the pair of first body plate portions face each other, and both end portions of the pair of second body plate portions are paired with the second second body plate portion. The ratio of the reinforcing member in a central region surrounded by two straight lines that pass in the direction in which the body plate portion faces is higher than the ratio of the reinforcing member in a region outside the central region. The condenser according to claim 2.   In the cross section of the upstream end of the turbine exhaust duct in a direction orthogonal to the direction in which the turbine exhaust in the turbine exhaust duct flows toward the main body vessel side, the maximum length in the longitudinal direction of the turbine exhaust duct The condenser according to any one of claims 1 to 4, wherein a ratio of one of the corners to the angle is 15% or more and 25% or less. Reinforcing ribs are provided on the outer peripheral surface of the turbine exhaust duct,
When a straight line passing through the center of the cross section of the turbine exhaust duct in a direction orthogonal to the direction in which the turbine exhaust in the turbine exhaust duct flows toward the main body vessel side is defined as an axis, the reinforcing ribs are The condenser according to any one of claims 1 to 5, wherein the condenser extends along a circumferential direction with respect to the axis.   The condenser according to any one of claims 1 to 6, wherein the corner portion is formed so that a curved portion thereof becomes smaller as approaching the main body container. A turbine exhaust duct into which turbine exhaust from the turbine flows,
A main body container that is connected to the turbine exhaust duct and receives turbine exhaust from the turbine exhaust duct and condenses with cooling water;
The condenser, wherein the turbine exhaust duct has a truncated conical shape to increase a flow path area toward the main body container side. Reinforcing ribs are provided on the outer peripheral surface of the turbine exhaust duct,
The condenser according to claim 8, wherein the reinforcing rib extends in a circumferential direction with respect to an axis of the turbine exhaust duct over an entire outer circumference of the turbine exhaust duct.   A power plant comprising the condenser according to claim 1.

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