JPS61134501A - Integral once-through type steam generator - 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 an integrated once-through heat exchange system that performs heat exchange between a secondary heat medium and water, which is a heat medium of a turbine drive system, in a fast breeder reactor power plant. Concerning vessels.

[Technical background of the invention]

Figure 2 shows the schematic configuration of a fast breeder reactor power plant. The primary heat medium, that is, the hot leg (liquid sodium) sent from the reactor vessel 1 is transferred to the intermediate heat exchanger via the secondary cooling system main circulation bomb 2. 3, is cooled by heat exchange with a secondary heat medium (liquid sodium), and is returned to the reactor vessel 1 through the cold leg piping. Further, the secondary heat medium is circulated between the intermediate heat exchanger 3 and the steam generator 5 by the secondary cooling system main circulation pump 4 . The steam generator 5 may be a recirculation type in which the evaporator and heater are separate, or
Although there are various types of steam generators, such as an integrated once-through steam generator that combines the functions of an evaporator and a heater, the present invention is directed to an economically viable integrated once-through steam generator.

On the other hand, the heat medium cycle of the turbine drive system is as follows. In other words, the superheated steam sent out from the steam generator 5 is
It is supplied through the main steam stop valve 6 to a steam turbine 7 for driving a generator, and drives this turbine 7. After driving the steam turbine 7, the steam is condensed and liquefied in a condenser 8, and sent by a condensate pump 9 to a deaerator 11 via a low-pressure feed water heater 10, where it is degassed. After that, the flow rate is adjusted by the feed water pump 12, and the high pressure feed water heater 13 and the feed water control valve 14
The water is then supplied to the steam generator 5, where it exchanges heat with the secondary heat medium and becomes superheated steam.

Note that a turbine bypass pass valve 15 is provided in a bypass path that bypasses the main steam stop valve 613 and the steam turbine 7.

FIG. 3 shows the other side of the steam generator. 18, and a steam outlet water chamber 19 are provided on the steam outlet side.The water supply inlet water chamber 18 and the steam outlet water chamber 19 are provided with
~6 pieces are provided at equal intervals in the circumferential direction of the main container 16.

The heat transfer tubes 17 are equally divided into a water supply inlet water chamber 1B and a steam outlet water chamber 19, and are connected to each water chamber 18.

As shown in FIGS. 4(a) and 4(t), the water supply inlet water chamber 18 is partitioned from the main body container 16 by a perforated tube plate 20, and is allocated to each water supply inlet water chamber 18. The heat exchanger tubes 17 are connected to each hole of the tube sheet 20 by welding. Note that reference numeral 21 denotes a water supply nozzle provided for each water supply inlet water chamber 18 , and a blind lid 22 is attached to the open end of the water supply inlet water chamber 18 with bolts 23 . Therefore, the water supply inlet water W18 from the water supply nozzle 21
The water flowing into the tube plate 20 is supplied into the heat transfer tube 17 through the holes in the tube plate 20, and is heated by the secondary heat medium in the feed water inlet water chamber 18 to become superheated steam, which then passes through the steam outlet water chamber 19 to the steam turbine 7 supplied to

In a fast breeder reactor power plant with the above configuration,
When a nuclear reactor is shut down, a large amount of decay heat is generated from the reactor core, so this decay heat must be removed.

The decay heat removal operation is performed with the main steam stop valve 6 closed and the bypass valve 15 open.

Therefore, the energy of decay heat generated from the core is transmitted to the intermediate heat exchanger 3 by the pump 2, and further transmitted to the steam generator 5 by the pump 4. On the other hand, the superheated steam sent out from the steam generator 5 flows into the condenser 8 via the bypass valve 15, where it is condensed and liquefied, and passed through the low pressure feed water heater 10 and the deaerator 11 by the condensate pump 9. After the flow rate is adjusted by the water supply pump 12, the water is supplied to the steam generator 5 via the high-pressure water supply superheater 13 and the water supply control valve 14.

[Problems with background technology]

The required amount of heat removal during decay heat removal operation is approximately 10% of the amount required for nuclear reactor operation immediately after the reactor is shut down, but decreases to approximately 1% after approximately one day has passed. For this reason, it is desirable to control the flow rate on the water supply side of the steam generator 5 so that it changes in accordance with the required amount of heat removal, which changes from moment to moment.

However, in the integrated once-through steam generator 5, if the feed water flow rate is extremely reduced during the decay heat removal operation, the flow state becomes unstable. For this reason, it is necessary to ensure a water supply flow rate above a certain level.

However, if the water supply is continued for too long in the winter, the heat removal effect will be too much and the temperature of the core will drop more than necessary, causing a problem in which the rise in output at the start of operation will be slow.

Therefore, the flow rate of the feed water must be controlled to maintain a stable fluid state and prevent the temperature of the reactor core from dropping too much, and such control of the flow rate of the feed water has been extremely difficult.

(Purpose of the Invention) The present invention has been made to solve such problems, and is intended to provide sufficient water supply to the heat exchanger tubes during decay heat removal operation in an integrated once-through steam generator of a fast stratified reactor power plant. The purpose is to ensure a flow rate to keep the flow state stable, and to be able to adjust the amount of heat removed as appropriate.

[Summary of the invention]

In order to achieve the above object, the integrated once-through steam generator according to the present invention houses a cylinder in the water supply inlet water chamber, and connects the cylinder to the water supply nozzle and a plurality of heat transfer tubes assigned to each water supply inlet water chamber. At the same time, by providing a valve body in this cylinder and moving this valve body within the cylinder using a driving source, the number of heat transfer tubes that can communicate with the water supply nozzle can be adjusted according to the amount of movement of the piston. It is configured to change gradually.

Therefore, by changing the flow rate of the water supply according to the required heat removal and at the same time moving the valve body to select the number of heat transfer tubes through which water flows, a constant flow rate is always ensured in the selected heat transfer tubes. It becomes possible to maintain the fluid state stably. 1 [Embodiment of the invention] 1st @ (a) and (b) are the feed water inlet water chamber of the integrated once-through steam generator 105 in an embodiment of the invention 118, this water supply inlet water chamber 118 is partitioned from the main body container 116 of the steam generator 105 by a perforated tube plate 120, and heat transfer tubes 117 are assigned to each water supply inlet water chamber 118. are connected to the matching holes in the tube sheet 120 by welding.

In addition, the code|symbol 121 is a water supply nozzle provided for each water supply inlet water v118, and the blind cover 122 is attached to the open end of the water supply inlet water chamber 118 by the bolt 123.

A cylinder 124 is housed inside the water supply inlet water chamber 118 . This cylinder 124 is connected to the blind lid 12.
2, so that it can be taken out of the water supply inlet water chamber 118 together with the blind M122.

The water supply nozzle 121 is connected to one end of the peripheral wall of the cylinder 124. Roughly, inside the water supply inlet water chamber 118, a plurality of connecting pipes 125 are accommodated which connect the matching holes of the tube plate 120 to the inside of the cylinder 124. Here, since a plurality of heat exchanger tubes 117 assigned to each water supply inlet water chamber 118 are connected to the matching holes of the tube plate 120, all of these heat exchanger tubes 117 are connected via the cylinder 124 and the connecting tube 125. This means that it communicates with the water supply nozzle 121. The connecting positions of the connecting pipe 125 and the cylinder 124 are uniformly and orderly arranged on the end wall of the cylinder 124 and in the circumferential direction and axial direction of the peripheral wall.

Further, a piston 126 as a valve body is housed inside the cylinder 124 so as to be capable of linear reciprocating movement in the axial direction of the cylinder 124. When the piston 126 is positioned at the outermost position (toward the blind lid 122 side), the connecting pipe 126
5 and the cylinder 124 are all connected to the water supply nozzle 12
1 side, and when positioned inwardly, only a small number of connection positions between the connecting pipe 125 and the cylinder 124 are on the water supply nozzle 121 side. The number of heat transfer tubes 117 communicating with the water supply nozzle 121 is configured to gradually change depending on the amount of movement of the piston 126.

A hydraulic cylinder 127 as a drive source for driving the piston 126 is provided outside the water supply inlet water chamber 118, and this hydraulic cylinder 127 is controlled by a control unit 128.

During the decay heat removal operation, the control unit 128 drives the piston 126 according to the required amount of heat removal, and maintains a transmission that communicates with the water supply nozzle 121 despite changes in the flow rate of water supplied to the steam generator 105 due to changes in the required amount of heat removed. The hydraulic cylinder 127 is controlled so that the flow rate inside the heat pipe 117 is always constant.

Therefore, according to the fast breeder reactor power plant using the above-described integrated once-through steam generator 105, during the decay heat removal operation associated with reactor shutdown, a sufficient water supply flow rate is maintained in the heat transfer tubes 117, and the overall The amount of heat removed can be adjusted according to changes in the decay heat level. That is, by gradually moving the piston 126 inward of the cylinder 124 as the water supply flow rate decreases, the number of heat exchanger tubes 117 communicating with the water supply nozzle 121 is reduced, and at this time, the number of heat exchanger tubes 117 communicating with the water supply nozzle 121 is reduced. In this case, the amount of water supply 8i above a certain amount is ensured.

Therefore, during the decay heat removal operation, the heat exchanger tubes 11 are
7, it is possible to ensure a sufficient water supply flow rate and maintain a stable flow state.

Further, the cylinder 124 is attached to the inner surface of a blind lid 122 that closes the open end of the water supply inlet water chamber 118, and can be taken out to the outside of the water supply inlet water v118 together with the blind lid 122, so that maintenance of the cylinder 124 is possible. Easy to inspect.

Note that the present invention is not limited to the above embodiments.

For example, the valve body may be rotatable within the cylinder by a certain angle, and the number of heat transfer tubes that can communicate with the water supply nozzle may be changed depending on the rotational position of the valve body.

In addition, the valve body can be moved back and forth linearly in the axial direction of the cylinder and can be rotated at a certain angle, and the number of heat transfer tubes that can be connected to the water supply nozzle can be changed depending on the axial position and rotational position of the cylinder. In this way, the number of heat exchanger tubes that can be communicated with the water supply nozzle can be adjusted even more minutely.

〔Effect of the invention〕

As described above, according to the present invention, in an integrated once-through steam generator of a fast breeder reactor power plant, during decay heat removal operation, sufficient water supply flow rate is ensured in the heat transfer tubes to maintain a stable flow state, Moreover, the heat removal m can be appropriately adjusted to prevent the reactor core from being cooled too much, and the rise in output at reactor startup can be made faster.

[Brief explanation of drawings]

FIG. 1(a) is a cross-sectional view of an integrated once-through steam generator showing an embodiment of the present invention, FIG. 1(b) is a half-sectional view taken along line 1-I in FIG. 1(a), and FIG. 3 is a system diagram of the fast breeder reactor power plant, FIG. 3 is a system diagram of the area around the steam generator in the same plant, and FIG. 1)) is a half cross-sectional view taken along the line IV-IV in FIG. 1... Nuclear reactor vessel, 7... Steam turbine, 8...
Condenser, 105...Integrated once-through steam generator, 116...
...Main container, 117...Heat transfer tube, 118...Water supply inlet water! , 121... tube plate, 122... blind lid,
124... Cylinder, 126... Piston (drive source), 127... Hydraulic cylinder, 128... Restraint part. A Procedural amendment layer March 6, 1985 1, Indication of the case Patent application No. 1987-257943 2, Name of the invention Integrated once-through steam generator 3, Person making the amendment Relationship with the case Patent applicant (307) Toshiba Corporation (1 idiot) 4. Agent No. 17 Mori Building, 1-26-5 Toranomon, Minato-ku, Tokyo 10
5 Telephone 03 (502>3181 (Main) 7゜Contents of amendment (1>"Figure2" in Mei 1B, page 3, line 8 is corrected to "Figure 3." (2) Specification Correct “Figure 3” on page 4, line 16 to “Figure 4.” (3) Correct “Figure 4” on page 5, line 6 of Book 1 to “Figure 5.” (4) Delete "1 fixed angle" on page 12, line 13 of the specification. (5) Delete "1 fixed angle" on page 12, line 17 of the book, as shown below. Corrected to ``This can be done for each piece.
As shown in the figure. As shown in the figure, the piston 126 reciprocates within the cylinder 24 while rotating. This allows for more precise meteor control. (6) On page 13, line 9 of the Memorandum, after ``~half-sectional view,'' ``Figure 2 (a> is a cross-sectional view of an integrated once-through steam generator showing another embodiment; (b> is a half-sectional view taken along the line I-I of the same figure (a>), and the same figure (C) is a perspective view showing the piston and cylinder.''(7> Specification, page 13, line 9) (8) Correct “Fig. 3” on page 13, line 10 of the specification to “Fig. 4.”
Correct figure J. (9>"Figure4" on page 13, line 11 of the specification [Figure 5]
Correct figure J. (10) Figure number display on drawings “M2 figure”, “Figure 3”
and ``Figure 4'' is corrected as ``Figure 3,'' ``Figure 4,'' and ``Figure 5,'' which are not included in the attached drawings. (11) Add Figure 2 of the drawing as attached. First signal cow first signal first! (a) ■ (b)

Claims (6)

[Claims] (1) In a fast breeder reactor power plant, the secondary heat medium is passed through the main vessel, and the water discharged from the condenser is passed through the water supply inlet water chamber provided at one end of the main vessel from the water supply nozzle. In an integrated once-through steam generator in which superheated steam generated by heat exchange with a secondary heat medium flows into a large number of heat transfer tubes arranged in a main body container and is sent toward a steam turbine, a A cylinder that is housed and communicates with the water supply nozzle and also communicates with a plurality of heat exchanger tubes, and a cylinder that is provided within this cylinder and gradually changes the number of heat exchanger tubes that can communicate with the water supply nozzle according to the amount of movement within the cylinder. What is claimed is: 1. An integrated once-through steam generator, comprising: a valve body that causes the valve body to rotate; and a drive source that drives the valve body outside a water supply inlet water chamber. (2) The integral once-through steam generator according to claim 1, wherein the valve body is a piston that is capable of linearly reciprocating in the axial direction of the cylinder. (3) The integrated once-through steam generator according to claim 1, wherein the drive source is a hydraulic cylinder. (4) The integrated unit according to claim 1, characterized in that the valve body is rotatable by a certain angle, and the number of heat transfer tubes that can communicate with the water supply nozzle is changed depending on the rotational position. Once-through steam generator. (5) The valve body is capable of reciprocating linearly in the axial direction of the cylinder and can be rotated by a certain angle, and the number of heat transfer tubes that can be communicated with the water supply nozzle is changed depending on the axial position and rotational position of the cylinder. An integrated once-through steam generator according to claim 1, characterized in that: (6) The cylinder is attached to the inner surface of a blind lid that closes the open end of the water supply inlet water chamber, and can be taken out to the outside of the water supply inlet water chamber together with the blind lid. An integrated once-through steam generator according to scope 1.