JPS6284207A - Moisture separating reheater - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to 1 a moisture separation reheater for reheating steam into superheated steam after removing moisture from highly humid steam in, for example, a nuclear power plant; Regarding.

[Technical background of the invention]

Generally, in a nuclear power plant, approximately 10% of the moisture contained in the high-pressure turbine exhaust steam is removed between the high-pressure turbine and the low-pressure turbine, and then reheated using the oil vapor of the high-pressure turbine and the steam generated in the nuclear reactor. A moisture separation heating device is installed to create superheated steam.

In FIG. 5, which shows a cylindrical housing cut at right angles to the longitudinal direction, a conventional moisture separation heating device has a cycle steam introduction pipe 3 in the lower part of the housing 1, and a cycle steam inlet pipe 3 in the upper part of the housing 1. Steam exhaust pipes 6 are provided at intervals in the axial direction of the housing 1, respectively.

In the bottom of the housing 1, a horizontally extending steam dividing plate 9 and a bottom plate 7 are provided above the steam dividing plate 9. Further, an upper bottom plate 8 is provided above the bottom plate 7 and is arranged parallel to the bottom plate 7. ing. An inlet perforated plate 1 extending in the axial direction of the housing 1 is provided at both ends in the width direction of the bottom plate 7 and the upper bottom plate 8.
2. A moisture separator 13 and an outlet perforated plate 15 are provided, above which an inlet steam partition plate 14 extends in the axial direction of the housing 1.

Further, a cycle steam flow passage 27 sandwiched between the shrouding plates 16 is formed in the upper part of the inlet steam partition plate 14.
Although not shown, a first-stage heated steam header is provided on the lower side and a second-stage heated steam header is provided on the upper side between the lid plate partition plate and the lid plate.
Shape heat transfer tubes 21a, 21b are disposed within the cycle steam flow passage 27.

In FIG. 5, a large number of U-shaped heat exchanger tubes 21a, 21b are shown.
passes through the cycle steam flow passage 27 at right angles to the plane of the paper.

Next, the heating side and the flow of cycle steam will be explained. First, the first-stage heated steam, which is oil vapor from the high-pressure turbine, flows through the first-stage heat exchanger tube 21a, and the second-stage heated steam, which is reactor generated steam, flows through the second-stage heat exchanger tube 21b. . During this time, the heat exchanger tube 21a.

The heated steam flowing through the heat exchanger tubes 21a and 21b gradually condenses as it exchanges heat with the cycle steam flowing outside the heat exchanger tubes 21a and 21b, and forms an annular flow, a wavy flow, an N-shaped flow, etc. while flowing inside the heat exchanger tubes 21a and 21b. It flows as a gas-liquid two-phase flow, and the flow pattern also varies. Therefore, near the inlets of the heat exchanger tubes 21a and 21b, the gas weight ratio, ie quality, is approximately 1 and is in the gas phase, whereas near the exits of the heat exchanger tubes 21a and 21b, it is approximately 0 and is almost a liquid phase drain.

This drain is collected in a drain tank (not shown).

On the other hand, cycle steam flows in from the cycle steam introduction pipe 3 and is divided into two parts by the steam dividing plate 9.The cycle steam flows through the inlet porous plate 12. Moisture is removed while passing through the perforated outlet plate 15 and the steam flows together again in the cycle steam flow passage 27. The moisture (drain) removed here flows down in the moisture separator 13 by gravity, is collected in a portion surrounded by the bottom plate 7 and the upper bottom plate 8, and is later collected in a drain tank (not shown).

The steam sent to the cycle steam passage 27 exchanges heat with the heated steam flowing inside the heat exchanger tubes 21a, 21b as described above while flowing outside the U-shaped heat exchanger tubes 21a, 21b of the first and second stages. The superheated steam becomes superheated steam, and finally flows out from the cycle steam exhaust pipe 6 and is sent to the low pressure turbine.

Therefore, the cycle steam outside the heat exchanger tubes 21a and 21b is
Since the temperature increases from the cycle steam flow passage 27 at the bottom of the tube bundle to the top of the tube bundle, the temperature of the shroud 16 having an inner surface through which cycle steam flows increases as it goes upward, similar to the cycle steam.

[Problems with background technology]

In the conventional moisture separator configured in this way,
Since the cycle steam is heated by the first stage heating device and the second stage heating device, the temperature difference between the upper and lower sides of the shroud 16 reaches a maximum of 90''C.

This causes a difference in thermal expansion due to the temperature difference between the upper and lower parts of the shrouding plate 16, and the U
The difference in elongation over the entire length of the letter-shaped heat exchanger tubes 21a and 21b is 30+m or more. These temperature differences also occur at the upper and lower parts of the housing 1, causing a similar difference in thermal expansion between the upper and lower portions of the housing 1, with the housing 1 having a higher central portion and lower portions of the two plates 2a and 2b. It becomes shaped like a hunched back.

Therefore, the complicated deformation of the shroud plate 16 fixed to the housing 1, the complicated deformation of the support plate fixed to the shroud plate 16,
Furthermore, heat exchanger tubes 21a, 21 supported by support plates
In some cases, the internal structure supporting the shroud plate 16°, the heat exchanger tubes 21a and 21b, or the shroud plate 16 may have extremely large structural stress, resulting in significant buckling or other problems. There is a risk of defects.

[Purpose of the invention]

An object of the present invention is to provide a moisture separation and reheating device that can prevent damage to these internal structures by suppressing the temperature difference between the upper and lower sides of the shroud and the housing, thereby suppressing the difference in thermal expansion. It is in.

[Summary of the invention]

The moisture separation and reheating device according to the present invention forms a cycle steam flow path in a cylindrical housing container from the bottom to the top in the axial direction, and the cycle steam flow path flows from the upstream to the downstream of the cycle steam flow path. In a moisture separation heating device in which a moisture separation device configured with a plurality of corrugated plates with drain pockets and a heating device configured with a large number of U-shaped heat transfer tube groups arranged in the axial direction are arranged in tandem, The axial side surface and the end side surface perpendicular to this of the U-shaped heat exchanger tube group of the heating device are surrounded by a shroud plate to form a part of the cycle steam flow passage leading from the lower part to the upper part, and the shroud plate on the axial side surface of the U-shaped heat transfer tube group is A portion of the cycle steam before flowing into the moisture separator outside the housing container flows along a part of the inner wall of the housing container and then flows along the outer wall of the axial side shroud. This device is characterized by providing a cooling steam passage for merging with cycle steam at the entrance of the heating device.

[Embodiments of the invention]

The present invention will be described below with reference to embodiments shown in FIGS. 1 and 2. On both sides, the vicinity of both ends of the cylindrical housing 1 extending in the horizontal direction is sealed by cover plates 2a and 2b, respectively, and the inside thereof is closed to the central plane A of the housing 1.
-The structure is almost symmetrical with respect to A. At the bottom of this housing 1 is a cycle steam introduction pipe 3. A drain discharge pipe 4, a shell drain discharge pipe 5, and a cycle steam discharge pipe 6 are provided in the upper part of the housing 1 at rvJ intervals in the axial direction of the housing 1, respectively. Further, the inside of the housing 1 is partitioned in the axial direction by a cover plate partition plate 10 in the vicinity of the cover plates 2a and 2b, and further, the center part of the housing 1 is partitioned in the axial direction by central partition plates 11a and Ilb except for the upper part. It's partitioned off.

At the bottom of the housing 1, as shown in FIG.
, llb, and a bottom plate 7 is provided above the vapor dividing plate 9, and furthermore, an upper bottom plate 8 is provided above the bottom plate 7 and is arranged parallel to the bottom plate 7. An inlet perforated plate 12, a moisture separator 13, and an outlet perforated plate I5 extending in the axial direction of the housing 1 are provided at both ends in the width direction of the bottom plate 7 and the upper bottom plate 8. An inlet steam partition plate 1.1 extends in the axial direction of the housing 1 and is connected to the lid partition plate 10 and the central partition plate 11a, llb.

Furthermore, the 21i! A cycle steam flow passage 27 is formed between the shroud plates 16 as shown in detail in FIG. Further, in FIG. 1, between the cover plate partition plate 10 and the cover plates 2a and 2b, a first stage reheating steam header 17a is provided on the lower side and a ladder 17b to the second stage heating steam is provided on the upper side. A large number of U-shaped heat exchanger tubes 21a from each heating steam header 17a, 17b.
, 21b are arranged in the cycle steam flow passage 27 in the axial direction of the housing 1. In FIG. 2, a large number of heat transfer tubes 21a, 21b are arranged in a cycle steam flow path 27 formed by a shroud 16 at right angles to the plane of the paper.

Oil steam from the high-pressure turbine flows into the heated steam introduction pipe 18a of the first stage reheat steam header 17a, passes through the heat transfer pipe 21a, and is then discharged from the steam exhaust pipe 20a.

Also, the heating steam introduction pipe 18 of the second stage reheat steam header 17b
Reactor-generated steam flows into the tube b, passes through the heat transfer tube 21b, and is then discharged from the steam exhaust tube 20b.

Therefore, in the moisture separation heating device according to the present invention, as shown in FIG. The outer guide plate 28 is installed along the inner surface, and the surrounding plate 1 is installed near the surrounding plate 16.
An inner guide plate 29 is installed along the outer guide plate 28 and its upper part is joined to the outer guide plate 28, and an outer cooling steam passage 30. An inner steam passage 31 for cooling is formed along the H-shaped plate 16, and the upper parts of the single-car passages 30 and 31 are communicated with each other.

Further, in the portion of the inlet steam partition plate 14 corresponding to the lower part of the outer cooling steam passage 30, an adjustment plate 3 having a small diameter hole is provided.
2 is installed, and a steam distribution chamber 35 and an outer steam passage 11 for cooling are installed.
3G is connected. On the other hand, the lower part of the cooling inner steam passage 31 communicates with the cycle steam flow passage 27 .

The outer guide plate 28 and the inner guide plate 29 are provided between the lid partition plate 10 and the center partition plate 11b in the longitudinal direction of the housing 1.

The cycle steam flowing in from the cycle steam main pipe 3 is distributed in the longitudinal direction of the housing 1 in the steam distribution chamber 35. 13, but a part of it flows into the adjustment plate 3.
It flows into the cooling outer steam passage 30 through the hole drilled in 2. Here, since the cooling outer steam passage 30 communicates with the cycle steam flow passage 27 via the cooling inner steam passage 31, the incoming cycle steam is The cycle steam flowing along the inner surface of the housing 1 and then along the outer surface of the shroud plate 16, at a relatively low temperature and containing moisture, cools the upper part of the bagging 1 and the upper part of the shroud plate 16, which are hot due to the above-mentioned reasons. The temperature difference between the upper and lower sides of these members is reduced, and the steam flows out into the cycle steam flow path 27.

By cooling the upper portions of the housing 1 and the shroud plate 16 in this manner, it is possible to reduce the difference in thermal expansion between the upper and lower portions of these members, thereby preventing damage such as buckling.

In another embodiment of the invention shown in FIG.

The cycle steam that has passed through the adjustment plate 32 provided on the inlet steam partition plate 14 and entered the outer steam passage 30 flows through the housing 1
and a cycle steam flow passage 27 for cooling the upper part of the shroud plate 16.
leaks to. On the other hand, a superheated steam partition plate 36 is installed at the upper part of the U-shaped heat transfer tube 21b so as to be connected to the shroud plate 16, and thermal expansion is performed so that only the lower part of the cycle steam discharge pipe 6 communicates with the superheated steam passage 37. An absorption tube 33 is arranged. This heats the cycle steam to a high temperature.
Contact with the upper part of the housing 1 is prevented, the temperature of the entire housing 1 is kept constant, and deformation of the housing 1 into a hunched back shape can be prevented. Furthermore, housing 1 and shroud 1
Since the difference in thermal expansion due to the temperature difference with 6 can be absorbed by the thermal expansion absorption tube 33, damage to the internal structure can be prevented.

Next, in another embodiment of the present invention shown in FIG. Outer steam passage 3 provided at the top
Flows into 0. In this case, the flow rate of the cycle steam for cooling is adjusted by changing the diameter and number of steam introduction pipes 34, or by attaching a throttle nozzle to the lower end or upper end of the steam introduction pipe 34.

(Effects of the Invention) As described above, according to the present invention, cycle steam containing moisture at a relatively low temperature before passing through the moisture separator is configured to flow along the inner surface of the housing, the upper part thereof, and the outer surface of the shroud. As a result, these members are cooled to reduce the temperature difference between the upper and lower parts due to the temperature rise of cycle steam, thereby suppressing the difference in thermal expansion between the upper and lower parts of these members, and preventing damage such as buckling. I can do it.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway front view showing an embodiment of the moisture separation and reheating device according to the present invention, Fig. 2 is a cutaway side view taken along the line ■-■ in Fig. 1, Figs. The figures are cut side views showing different embodiments of the present invention, and FIG. 5 is a cut side view showing main parts of a conventional moisture separation and reheating device. 1... Housing 3... Cycle 6...
・Cycle steam exhaust pipe 12...Inlet perforated plate 13・
...Moisture separator 14...Inlet steam partition plate 15...Outlet perforated plate 16...Shrouding plate 1
7a, 17b... Heating steam header 18a, 18b.
...Heating steam introduction pipes 20a, 20b...Bent steam discharge pipes 21a, 21b...U-shaped heat exchanger tube 27...
Cycle steam flow passage 28...outer guide plate 29...
-Inner guide plate 30...Outer steam passage for cooling 31...Inner steam passage for cooling 32...Adjustment plate 33...Thermal expansion absorption tube 34...Steam introduction pipe 35...Steam distribution chamber 36...Superheated steam partition plate 37...Superheated steam passage (8733) Agent: Patent attorney Yoshiaki Inomata (and 1 others)
Figure 2 Figure 3 Figure 4 Figure 5 Procedural Compensation 11 Official Book (Volunteer) February 2, 1986

Claims (4)

[Claims] (1) A cycle steam flow passage is formed in the cylindrical housing container from the bottom to the top in the axial direction, and a plurality of corrugated plates with drain pockets are formed from the upstream to the downstream of this cycle steam flow passage. In a moisture separation and heating device in which the configured moisture separator and a heating device configured by axially arranging a large number of U-shaped heat exchanger tubes are arranged in tandem, the U-shaped heat exchanger tubes of the heating device are arranged in tandem. The axial side surface of the group and the end side surface perpendicular thereto are surrounded by a shroud plate to form a part of the cycle steam flow passage leading from the lower part to the upper part, and the shroud plate on the axial side surface of the group is surrounded by a shroud plate. Before entering the moisture separator, a portion of the cycle steam flows along a portion of the inner wall of the housing vessel, and then flows along the outer wall of the axial side shroud to collect the cycle steam at the inlet of the heating device. A moisture separation and reheating device characterized by providing a cooling steam passage for merging with steam. (2) The cooling steam passage is provided with a steam partition plate that extends in the axial direction at the boundary between the moisture separator and the heating device in the housing, and a passage adjustment plate at one end on the upper surface of the steam partition plate. an outer steam passage for cooling, the other end of which communicates with the cycle steam before entering the moisture separator through the cooling device, and the other end of which extends along the inner wall of the housing vessel; Claim 1, characterized in that the cooling inner steam passage is configured such that the other communicating end thereof extends outside the axial side shroud plate of the heating device and communicates with the cooling outer steam passage. Moisture separation reheating equipment. (3) A cooling outer steam passage is formed between a part of the inner wall of the housing, and this part of the cooling outer steam passage and the moisture separator inlet steam at the lower part of the steam partition plate are connected to each other through a plurality of steam introduction pipes. The second claim characterized in that
Moisture separation and reheating equipment as described in Section. (4) A patent claim characterized in that a bellows-shaped thermal expansion absorption tube is provided between the upper part of the shroud of the heating device and the housing container, and the outside of this thermal expansion absorption tube is communicated with a cooling steam passage. The moisture separation reheating device according to item 1.