JP2006105432A - Condenser - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a condenser with a plurality of small tube nests manufactured, having improved working efficiency when assembling and storing the small tube nests in the body barrel of the condenser after carried into a power generation plant. <P>SOLUTION: The tube nest consists of: a plurality of small cooking tubes 4; and tube plates for fixing the small cooking tubes at both ends. The tube nest is divided into a first tube nest 15 and a second tube nest 16, when manufactured. The small tube nests are connected to the first tube plate 13 and the second tube plate 14 in the power generation plant. A backing flange 19 with screw holes is arranged on the barrel side of an connection portion between the tube plates, and a stopper 23 is provided so that the hole cores of the screw holes easily correspond to the hole cores of the tube plates. Stud bolts 20 and cap nuts 21 are fastened together at the water chamber side of the connection portion between the tube plates. A backing plate 22 is welded to the connection portion between the divided tube plates to prevent the flow of low-temperature fluid from the water chamber via the connection portion into the barrel side. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a condenser for condensing exhaust steam of a steam turbine.

  The condenser condenses exhaust steam, which has finished its work in the steam turbine, with a low-temperature fluid that passes through the inside of the cooling thin tube to form condensate, and returns it to the system as boiler feed water again. The condenser is configured to include a lower trunk that houses a plurality of cooling thin tubes, a connecting trunk that guides turbine exhaust steam to the lower trunk, and an upper trunk.

  As described in Patent Document 1, cooling is performed as a condenser assembling method that reduces the size and size of the transport parts of the condenser so that it is within the dimensional limits for transportation, and simplifies the assembly work in the power plant. There is a method in which a plurality of small tube nests are supported by a tube plate and a support plate as a group of thin tubes, and the small tube nests are assembled into the main body of the condenser after being loaded into the power plant. At this time, in order to join the small tube nests into one tube nest, it is necessary to join the small tube plates constituting the small tube nests. The small tube plates are joined together by butt welding between the small tube plates from the water chamber side and the body side of the tube plates.

JP 2002-257492 A

  In order to butt weld the small tube sheets during the small tube nest joining, it is necessary to weld from the tube plate surface on the body side where a plurality of cooling thin tubes are densely packed. For this reason, the workability | operativity at the time of a small tube board joining worsens. Furthermore, since the welding operation is performed from the fuselage side, it is necessary to secure a work space on the fuselage side, which increases the size of the tube sheet.

  The present invention provides a condenser having a structure capable of improving workability when a plurality of small pipe nests are produced and the small pipe nests are carried into a power plant and then assembled and accommodated in a main body of the condenser. The purpose is to provide.

  In order to achieve the above object, the condenser of the present invention fixes a plurality of cooling thin tubes and both ends of the cooling thin tubes, and supplies a low-temperature fluid to the fuselage side where the cooling thin tubes are located and to the cooling thin tubes. It has a tube nest consisting of a tube plate that separates the side of the water chamber that receives the low-temperature fluid that has passed through the cooling thin tube, and the tube plate is manufactured by dividing, and the cooling tube is fixed to each of the divided tube plates. A condenser in which the tube plates are connected to form a tube nest, one fastening member disposed on the body side of the tube plate connection portion, and the water chamber of the tube plate connection portion The other fastening member is disposed on the side and fastened to one fastening member, and the one fastening member and the other fastening member are fastened through a hole formed in the tube plate, and fastened to the other fastening member. The divided tube sheets are connected to each other.

  In addition, a reinforcing plate is provided in the vicinity of the connecting portion of the tube plate so as to connect the tube plate on the water chamber side that supplies the low temperature fluid to the cooling thin tube and the tube plate on the water chamber side that receives the low temperature fluid that has passed through the cooling thin tube. It is preferable to prevent deformation in the vicinity of the divided tube plate connection due to the operating pressure of the water chamber.

  Further, a backing flange having a screw hole is used as one fastening member, and a bolt is used as the other fastening member.

  Moreover, it is preferable to use a stat bolt and a cap nut as the other fastening member so that the low-temperature fluid does not flow from the water chamber to the body side via the screw portion.

  Further, it is preferable that a stopper for positioning the backing flange is provided on any one of the divided tube sheets so that the hole core of the backing flange does not go out of alignment with the hole core of the tube sheet.

  Moreover, it is preferable to weld the connection part of the divided tube sheets from the water chamber side so that the low-temperature fluid does not flow from the water chamber to the body side via the connection part.

  ADVANTAGE OF THE INVENTION According to this invention, when joining a small pipe nest in a power station, it can carry out by the work from the water chamber side, and can aim at the improvement of workability | operativity of a small pipe plate joining work.

  Embodiments of the present invention will be described below with reference to the drawings. In the present embodiment, a connection structure and an assembling method in the tube nest replacement work of the condenser of the existing power plant when the condenser tube plate is divided into upper and lower parts will be described.

  FIG. 1 shows a cross-sectional view of a condenser to which the present invention is applied. In FIG. 2, the front view of the tube sheet part of the condenser of this invention is shown. The steam 2 discharged from the steam turbine 1 driven by steam is cooled by a cooling thin tube 4 that is a heat transfer pipe installed in the lower body of the condenser 3 to become condensed water. The cooling thin tubes 4 are grouped as a group and integrated by an inlet tube plate 5a, an outlet tube plate 5b, and a support plate 8. The inlet tube plate 5a and the outlet tube plate 5b fix and support the end of the cooling thin tube 4. The support plate 8 supports the cooling thin tube 4 so that fluid elastic vibration does not occur in the cooling thin tube 4. A set of the cooling tubules 4 is generally referred to as a “tube nest”. As shown in FIG. 2, two tube nests in which the cooling thin tubes 4 are arranged are arranged in parallel. Seawater led from the seawater inlet 6 a to the inlet water chamber 7 a is passed through the cooling thin tube 4. Seawater that has passed through the cooling thin tube 4 is discharged from the seawater outlet 6b via the outlet water chamber 7b. Condensate is stored in the condensate reservoir 9. The stored condensate is discharged from the condenser outlet 10 to the outside of the condenser 3 and supplied to a steam generator or the like. The inlet tube plate 5a and the outlet tube plate 5b also serve as a seal between the body in which the steam 2 is condensed and the inlet water chamber 7a or the outlet water chamber 7b, so that seawater flows into the body. It is preventing.

  FIG. 3 is a conceptual diagram for explaining a connection structure when the inlet tube plate 5a and the outlet tube plate 5b of the condenser according to the embodiment of the present invention are divided into upper and lower parts. (A) is a side view, (b) is a front view seen from the QQ arrow direction of (a), and (c) is a sectional view seen from the RR direction of (a).

  When all the cooling thin tubes 4 are replaced, the inlet tube plate 5a and the outlet tube plate 5b are integrally formed by replacing the cooling thin tubes 4, the support plate 8, the inlet tube plate 5a and the outlet tube plate 5b as a unitary tube nest. For this reason, it is often impossible to carry in due to restrictions on the size of the carry-in opening in the power plant.

  In the present embodiment, as shown in FIG. 3, the inlet tube plate (outlet tube plate) is divided into upper and lower parts, and the first tube plate 13 and the second tube plate 14 are also used as the first tube plate 15 and the first tube tube 15. By making the tube nest itself small as the two tube nest 16, it is possible to carry in even if the carry-in opening size is small.

  The first reinforcing plate 17 and the second reinforcing plate 18 are attached in the vicinity of the connecting portion between the first tube plate 13 and the second tube plate 14 divided into two parts, and the central portion of the entire tube plate is deformed by the operating pressure of the water chamber. It is preventing. These reinforcing plates are provided between the inlet tube plate and the outlet tube plate.

  Further, a back flange 19 is attached so that there is no discrepancy between the first tube plate 13 and the second tube plate 14 at the connection portion of the tube plate, and the first tube plate 13 and the second tube flange 19 are attached to the upper and lower common back flange 19. The two-pipe plate 14 is structured to be fastened with a stat bolt 20.

  The stat bolt 20 is tightened with a cap nut 21 so that cooling water, which is a low-temperature fluid, does not flow into the body side from the thread portion of the stat bolt 20.

  The contact plate 22 is welded between the first tube plate 13 and the second tube plate 14 from the water chamber side so that the cooling water does not flow into the body side from the gap between the first tube plate 13 and the second tube plate 14. It has a structure.

  A structure in which a stopper 23 is attached to the second reinforcing plate 18 in order to prevent movement in the vertical and longitudinal directions so that the hole cores of the first tube plate 13 and the second tube plate 14 and the backing flange 19 do not go out of order. I have to. It should be noted that a gap a of 5 mm is provided between the backing flange 19 and the stopper 23 so that the longitudinal movement is possible during the assembly operation.

  The hole on the outer periphery (flange) of the tube sheet is a bolt hole for attaching the tube sheet to the condenser 3.

  FIG. 4 is a cross-sectional view for explaining a tube nest assembling method when the inlet tube plate 5a and the outlet tube plate 5b of the condenser according to the embodiment of the present invention are divided into upper and lower parts. (A) shows a state in which the second tube nest 16 is carried into a predetermined position, (b) shows a state in which the backing flange 19 is set on the stopper 23, and (c) shows the first tube nest 15 in the first position. (D) shows a state in which the backing flange 19, the first tube plate 13 and the second tube plate 14 are fastened with the stat bolt 20 and the cap nut 21; ) Shows a state in which the contact plate 22 is sealed and welded to the first tube plate 13 and the second tube plate 14.

First, the lower second tube nest 16 to which the second tube plate 14 is attached is carried into a predetermined position. The backing flange 19 is set 5 mm away from the second tube plate 14 and placed on the stopper 23. The first tube sheet 13 and the backing flange 19 are set so that the upper first tube nest 15 is vertically suspended on the lower second tube nest 16 with a distance of 5 mm. The stat bolt 20 is fastened to the backing flange 19 from the water chamber side, the cap nut 21 is fastened, and the backing flange 19 is moved 5 mm in the direction of the first tube plate 13 and the second tube plate 14 to be integrated. Thereafter, the contact plate 22 is sealed and welded to the first tube plate 13 and the second tube plate 14.

According to the above-described embodiment of the present invention, it is possible to join the divided tube nests, that is, to connect the divided first tube plate 13 and second tube plate 14 only from the water chamber side. It becomes. Therefore, the work on the body side where the cooling thin tubes are dense is not required, and the work period can be shortened by improving workability in the power plant. Further, since the work space on the body side is not required, it is not necessary to increase the size of the tube plate more than necessary, and the mass of the condenser is reduced due to the reduction in the size of the tube plate.

The cross-sectional view of the condenser to which the present invention is applied. The front view of the tube plate part of the condenser with which this invention is applied. The conceptual diagram explaining the connection structure at the time of dividing the tube sheet of the condenser of the Example of this invention into upper and lower parts. The conceptual diagram used in order to demonstrate the connection structure and assembly method at the time of dividing the tube sheet of the condenser of the Example of this invention into upper and lower parts.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Steam turbine, 2 ... Steam, 3 ... Condenser, 4 ... Cooling thin tube, 5a ... Inlet tube plate, 5b ... Outlet tube plate, 6a ... Seawater inlet, 6b ... Seawater outlet, 7a ... Inlet water chamber, 7b ... Outlet water chamber, 8 ... support plate, 9 ... condensate reservoir, 10 ... condensate outlet, 11 ... support plate, 13 ... first tube plate, 14 ... second tube plate,
DESCRIPTION OF SYMBOLS 15 ... 1st pipe nest, 16 ... 2nd pipe nest, 17 ... 1st reinforcement board, 18 ... 2nd reinforcement board, 19 ... Backing flange, 20 ... Stat bolt, 21 ... Cap nut, 22 ... Batting plate, 23 …stopper.

Claims (6)

A plurality of cooling capillaries are fixed to both ends of the cooling capillaries, and a body side where the cooling capillaries are located is separated from a water chamber side that supplies a cryogenic fluid to the cooling capillaries or receives a cryogenic fluid that has passed through the cooling capillaries. Having a tube nest made of tube sheet,
The condenser is made by dividing the tube plate, the cooling tube is fixed to each of the divided tube plates, and the divided tube plates are connected to form the tube nest. There,
One fastening member disposed on the body side of the connecting portion of the tube sheet, and the other fastening member disposed on the water chamber side of the connecting portion of the tube sheet and fastened to the one fastening member, The fastening member and the other fastening member are fastened through a hole formed in the tube plate, and the divided tube plates are connected to each other by performing a fastening operation on the other fastening member. Condenser.   In Claim 1, the reinforcing plate provided so as to connect between the tube plate on the water chamber side that supplies the low temperature fluid to the cooling thin tube and the tube plate on the water chamber side that receives the low temperature fluid that has passed through the cooling thin tube. Having a condenser.   The condenser according to claim 1 or 2, wherein the one fastening member is a backing flange having a screw hole, and the other fastening member is a bolt.   4. The condenser according to claim 3, wherein the other fastening member includes a stat bolt and a cap nut.   The condenser according to claim 3 or 4, wherein a stopper for positioning the backing flange is provided on any one of the divided tube sheets. The condenser according to any one of claims 1 to 5, wherein a connection portion between the divided tube sheets is welded from the water chamber side.

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