Condensation device and condensation method

Abstract

To provide the influence of vibration on the load on a sparger pipe.SOLUTION: A condensation device 13 includes: a storage tank 13A for storing condensed water 13H in the bottom part; a header pipe 13B arranged in a gas phase part located above the level of the condensed water 13H in the storage tank 13A, the header pipe being supplied with gas including vapor from the outside of the storage tank 13A; a plurality of sparger pipes 13D with a top end extending below from the header pipe 13B arranged in a liquid phase part of the condensed water 13H; and a connection unit 13K for connecting the plurality of sparger pipes 13D to each other.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to a condensation device and a condensation method. [Background technology]

[0002] For example, Patent Document 1 discloses a containment vessel maintenance equipment for ensuring the safety of a containment vessel that contains a reactor pressure vessel. This containment vessel maintenance equipment includes an exhaust pipe that is drawn out to the outside of the containment vessel, a rare gas storage tank (condenser) that is connected to the exhaust pipe outside the containment vessel, a water spraying unit that is disposed inside and above the rare gas storage tank and sprays water inside the rare gas storage tank to condense the steam in the gas, and a gas introduction unit that is disposed in the liquid phase of the condensed water stored inside the rare gas storage tank and introduces the gas by dispersing it into the condensed water. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6748012 Summary of the Invention [Problem to be solved by the invention]

[0004] The containment vessel maintenance equipment is installed as a measure against the assumption of a severe accident in a nuclear facility (nuclear plant). In the containment vessel maintenance equipment, cooling water is sprayed to remove decay heat in the containment vessel in the event of a severe accident, but the pressure inside the containment vessel rises due to gas evaporated from the cooling water, and to suppress this pressure rise, gas is sent from the containment vessel through an exhaust pipe to a condenser. In the condenser, the gas introduced from the gas introduction part is dispersed in the condensed water, suppressing the uneven flow of gas in the condenser, and the steam contained in the gas can be cooled and condensed by the condensed water.

[0005] Incidentally, with regard to the gas introduction section, a configuration is envisaged in which a header pipe is arranged in the gas phase portion above the water surface of the condensed water, and multiple sparger pipes extending downward from the header pipe are arranged in the liquid phase of the condensed water, thereby dispersing gas into the condensed water from the tips of the sparger pipes.

[0006] However, in such a configuration, the sparger pipe needs to have a sufficient vertical length to accommodate fluctuations in the condensate level, and vibrations occur along that length, which can cause the sparger pipe to be damaged by the load caused by the vibrations.

[0007] In addition, the sparger pipe undergoes a chugging phenomenon in which the steam contained in the gas supplied into the condensed water suddenly condenses, causing the sparger pipe to contract and reduce pressure, sucking up the condensed water, and then gas is supplied again, and this cycle is repeated. For this reason, the sparger pipe is subject to loads caused by the vibrations associated with the chugging phenomenon, which can cause it to break.

[0008] The present disclosure is intended to solve the above-mentioned problems, and has an object to provide a condensation device and a condensation method that can prevent the load effect due to vibration on the sparger pipe. [Means for solving the problem]

[0009] In order to achieve the above-mentioned object, a condensation device according to one embodiment of the present disclosure includes a storage tank in which condensed water is stored at the bottom, a header pipe disposed in a gas phase portion above the water level of the condensed water inside the storage tank and to which a gas containing steam is supplied from outside the storage tank, a plurality of sparger pipes whose ends extend downward from the header pipe and are disposed in a liquid phase portion of the condensed water, and a connection portion that connects the plurality of sparger pipes.

[0010] In order to achieve the above-mentioned object, a condensation device according to one embodiment of the present disclosure comprises a storage tank at the bottom of which condensed water is stored, a header pipe disposed in a gas phase portion above the water level of the condensed water inside the storage tank and to which a gas containing steam is supplied from outside the storage tank, and a plurality of sparger pipes whose tips extending downward from the header pipe are disposed in a liquid phase portion of the condensed water, the sparger pipes including an opening / closing portion provided at the tip and an elastic member that elastically supports the opening / closing portion so as to close the opening / closing portion, and the opening / closing portion opens and closes against the elastic force of the elastic member due to the pressure of the gas.

[0011] In order to achieve the above-mentioned object, a condensation method according to one embodiment of the present disclosure is a condensation method using a condensation device including: a storage tank at the bottom of which condensed water is stored; a header pipe disposed in a gas phase portion above the water level of the condensed water inside the storage tank, and into which a gas containing steam is supplied from outside the storage tank, the header pipe being branched into multiple parts via an on-off valve between the gas supply side and the gas supply side; a plurality of sparger pipes whose ends extending downward from the header pipe are disposed in a liquid phase portion of the condensed water; a pressure detection unit that detects the pressure of the gas sent to the header pipe; and a control unit that controls the opening and closing of each of the on-off valves in accordance with the pressure detected by the pressure detection unit, wherein the control unit controls each of the on-off valves to be open when the pressure detected by the pressure detection unit is on an upward trend, and controls to close a portion of the on-off valves when the pressure detected by the pressure detection unit is on a downward trend. Effect of the Invention

[0012] The present disclosure can prevent vibration load effects on the sparger pipes. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a configuration diagram of a containment vessel maintenance facility to which a condensation device according to an embodiment is applied. [Diagram 2] FIG. 2 is a block diagram of a control system of the containment vessel integrity system according to the embodiment. [Diagram 3] FIG. 3 is a cross-sectional view of a condensation device according to an embodiment. [Figure 4] FIG. 4 is a vertical cross-sectional view of a condensation device according to an embodiment. [Diagram 5] FIG. 5 is a partially enlarged cross-sectional view of a condensation device according to an embodiment. [Figure 6] FIG. 6 is a flowchart of a condensation method according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Note that the present invention is not limited to these embodiments. In addition, the components in the following embodiments include those that are easily replaceable by those skilled in the art, or those that are substantially the same. In addition, the components in the following embodiments can be appropriately combined.

[0015] FIG. 1 is a configuration diagram of a containment vessel maintenance facility to which a condensation device according to an embodiment is applied. In FIG. 1, a containment vessel 100 contains a reactor pressure vessel 101 that contains a plurality of fuel assemblies, which are a reactor core, in a sealed state in a nuclear power facility. In the nuclear power facility, water vapor (hereinafter, simply referred to as steam) is generated by utilizing the heat of high-temperature and high-pressure water heated in the reactor pressure vessel 101, and this steam drives a steam turbine provided outside the containment vessel 100 to generate power. The containment vessel 100 is erected on a solid foundation such as a bedrock and is robustly formed of reinforced concrete or the like, and is configured to be capable of containing a predetermined volume of condensable gas, steam, and gas including non-condensable gas such as air and radioactive rare gas within a predetermined pressure range.

[0016] The containment vessel maintenance equipment 50 ensures the safety of the containment vessel 100 during a severe accident, which is a severe event in which the core is damaged and the molten core flows out of the reactor pressure vessel 101. The containment vessel maintenance equipment 50 has a pressure detection unit 10, a filter unit 11, an exhaust pipe 12, a condenser 13, a cooling unit 14, a condensed water delivery unit 15, a dehumidifier 16, a first adsorption unit 17, a second adsorption unit 18, and a storage unit 19.

[0017] The pressure detection unit 10 detects the pressure inside the containment vessel 100 .

[0018] In the embodiment, the filter unit 11 is provided inside the containment vessel 100. The filter unit 11 has a filter provided inside the casing that captures radioactive iodine and particulate radioactive materials contained in the gas. The filter unit 11 removes radioactive iodine and particulate radioactive materials in the gas by passing the gas inside the containment vessel 100 through the inside of the casing. However, radioactive rare gases such as xenon (Xe) and krypton (Kr), steam, and air cannot be captured by the filter and pass through the casing. Therefore, the filter unit 11 captures and removes radioactive iodine and particulate radioactive materials, while allowing steam, which is a condensable gas, and gas containing non-condensable gases such as air and radioactive rare gases to pass through.

[0019] The exhaust pipe 12 has one end connected to the filter unit 11 and the other end drawn out to the outside of the containment vessel 100. A check valve 12A is provided midway along the exhaust pipe 12. The check valve 12A allows gas to pass from the one end connected to the filter unit 11 to the other end drawn out to the outside of the containment vessel 100, and prevents the gas from flowing in the opposite direction.

[0020] The condensation device 13 includes a storage tank 13A, a header pipe 13B, an on-off valve 13C, a sparger pipe 13D, a water spray section 13E, a drain section 13F, and an exhaust section 13G. The storage tank 13A is a sealed container with a hemispherical bottom and a hemispherical top connected by a cylindrical body. Condensed water 13H is stored in the bottom of the storage tank 13A. The header pipe 13B is disposed in a gas phase portion above the water level of the condensed water 13H inside the storage tank 13A. The header pipe 13B is connected to the exhaust pipe 12. The on-off valve 13C is disposed between the header pipe 13B and the exhaust pipe 12, and opens and closes the exhaust pipe 12 and the header pipe 13B. The sparger pipe 13D is provided extending downward from the header pipe 13B, and the tip extending downward is disposed in the liquid phase portion inside the condensed water 13H. The sprinkler unit 13E is disposed inside and above the storage tank 13A, and sprinkles water inside the storage tank 13A. The sprinkled water is stored at the bottom of the storage tank 13A as condensed water 13H. The drainage unit 13F is provided at the bottom of the storage tank 13A, and is a part that drains the condensed water 13H to the outside of the storage tank 13A. The exhaust unit 13G is provided at the top of the storage tank 13A, and is a part that exhausts the gas in the gas phase to the outside of the storage tank 13A. Therefore, the condenser 13 supplies the gas that has passed through the filter unit 11 to the storage tank 13A by opening the opening / closing valve 13C. The condenser 13 supplies gas to the inside of the condensed water 13H from the sparger pipe 13D via the header pipe 13B, and condenses the steam in the gas with the condensed water 13H. The condenser 13 also separates the steam from the non-condensable gas by condensing the steam in the gas.

[0021] The cooling unit 14 includes a circulation pipe 14A, a heat exchanger 14B, and a cooling pump 14C. One end of the circulation pipe 14A is connected to a drainage section 13F of the storage tank 13A, and the other end is connected to a water spray section 13E inside the storage tank 13A at the top of the storage tank 13A. Therefore, the circulation pipe 14A is provided in a loop shape including the storage tank 13A. The heat exchanger 14B is provided in the middle of the circulation pipe 14A. The heat exchanger 14B is provided with a heat transfer tube interposed in the middle of the circulation pipe 14A inside a casing to which the cooling water is supplied. The cooling water passes through the inside of the heat exchanger 14B casing. The cooling water is, for example, seawater or lake water, and is supplied by a cooling water supply pump (not shown) and returned to the sea or lake through the inside of the casing. Cooling pump 14C is provided midway through circulation piping 14A, and circulates condensed water 13H stored in storage tank 13A through circulation piping 14A. Therefore, condensed water 13H stored in storage tank 13A is cooled via heat exchanger 14B and sprayed from spray unit 13E of storage tank 13A.

[0022] The condensed water discharge section 15 includes a discharge pipe 15A, a discharge pump 15B, a discharge on-off valve 15C, and a check valve 15D. One end of the discharge pipe 15A is connected to the drainage section 13F of the storage tank 13A, and the other end is provided to reach the inside of the containment vessel 100. One end of the discharge pipe 15A is shared with one end of the circulation pipe 14A of the cooling section 14. The discharge pump 15B is provided in the middle of the discharge pipe 15A, and discharges the condensed water 13H stored in the storage tank 13A into the inside of the containment vessel 100 through the discharge pipe 15A. The discharge on-off valve 15C is provided on the discharge pipe 15A at one end side (storage tank 13A side) of the discharge pump 15B. The discharge on-off valve 15C opens and closes the discharge pipe 15A. The check valve 15D is connected to the other end of the delivery pipe 15A. The check valve 15D is provided on the other end side (the storage vessel 100 side) of the delivery pump 15B in the delivery pipe 15A. The check valve 15D allows the condensed water 13H to pass from one end connected to the storage tank 13A to the other end provided inside the storage vessel 100, and prevents the condensed water 13H from flowing in the opposite direction.

[0023] The dehumidification device 16 includes a dehumidification pipe 16A and a dehumidifier 16B. The dehumidification pipe 16A is connected to the exhaust portion 13G of the storage tank 13A, and sends the non-condensable gas inside the storage tank 13A to the outside of the storage tank 13A. The dehumidification pipe 16A is opened and closed by an opening and closing valve (not shown). The dehumidifier 16B is provided midway along the dehumidification pipe 16A, and removes moisture from the non-condensable gas passing through the dehumidification pipe 16A.

[0024] The first adsorption section 17 includes an adsorption tower 17A, a first exhaust pipe 17B, a second exhaust pipe 17C, and a vacuum pump 17D. The adsorption tower 17A is connected to the dehumidification pipe 16A. Thus, the non-condensable gas dehumidified by the dehumidifier 16B is sent to the adsorption tower 17A. The adsorption tower 17A accommodates a rare gas adsorbent inside a sealed container. Thus, the adsorption tower 17A adsorbs the radioactive rare gas contained in the non-condensable gas. The first exhaust pipe 17B is connected to the adsorption tower 17A and is opened and closed by an on-off valve (not shown). When the first exhaust pipe 17B is opened, air that is not adsorbed by the rare gas adsorbent is released to the atmosphere. The second exhaust pipe 17C is connected to the adsorption tower 17A and is opened and closed by an on-off valve (not shown). The vacuum pump 17D is provided in the second exhaust pipe 17C. When the second exhaust pipe 17C is opened, the radioactive rare gas adsorbed in the rare gas adsorbent is pumped out by driving the vacuum pump 17D.

[0025] The second adsorption section 18 includes an adsorption tower 18A, a first exhaust pipe 18B, a second exhaust pipe 18C, and a vacuum pump 18D. The adsorption tower 18A is connected to the second exhaust pipe 17C of the first adsorption section 17. Thus, the adsorption tower 18A is sent the radioactive rare gas sent from the adsorption tower 17A of the first adsorption section 17. The adsorption tower 18A accommodates a rare gas adsorbent inside a sealed container. Thus, the adsorption tower 18A adsorbs the sent radioactive rare gas. The first exhaust pipe 18B is connected to the adsorption tower 18A and is opened and closed by an opening and closing valve (not shown). When the first exhaust pipe 18B is opened, air that is not adsorbed by the rare gas adsorbent is released to the atmosphere. The second exhaust pipe 18C is connected to the adsorption tower 18A and is opened and closed by an opening and closing valve (not shown). The vacuum pump 18D is provided in the second exhaust pipe 18C. When the second exhaust pipe 18C is opened, the radioactive rare gas adsorbed in the rare gas adsorbent is pumped out by driving the vacuum pump 17D. Therefore, the second adsorption section 18 cooperates with the first adsorption section 17 to concentrate the radioactive rare gas, thereby reducing the volume.

[0026] The storage section 19 is composed of a sealed container, and is connected to the second exhaust pipe 18C of the second adsorption section 18. Therefore, the radioactive rare gas discharged from the adsorption tower 18A of the second adsorption section 18 is sent to the storage section 19. The storage section 19 stores the sent radioactive rare gas.

[0027] FIG. 2 is a block diagram of a control system of the containment vessel integrity system according to the embodiment.

[0028] The containment vessel maintenance equipment 50 described above is controlled by a control unit 20 shown in Fig. 2. The control unit 20 is, for example, a computer, and is realized by an arithmetic processing device including a microprocessor such as a CPU (Central Processing Unit), although not shown in the figure. The pressure detection unit 10 is connected to the control unit 20. The on-off valve 13C of the condenser 13 is connected to the control unit 20. The cooling pump 14C of the cooling unit 14 is connected to the control unit 20. The delivery pump 15B and the delivery on-off valve 15C of the condensed water delivery unit 15 are connected to the control unit 20. The vacuum pump 17D of the first adsorption unit 17 is connected to the control unit 20. The vacuum pump 18D of the second adsorption unit 18 is connected to the control unit 20. In addition, although not shown in the figure, the control unit 20 is also connected to an on-off valve that opens and closes the dehumidification piping 16A of the dehumidifier 16, an on-off valve that opens and closes the first exhaust pipe 17B of the first adsorption unit 17, an on-off valve that opens and closes the second exhaust pipe 17C of the first adsorption unit 17, an on-off valve that opens and closes the first exhaust pipe 18B of the second adsorption unit 18, and an on-off valve that opens and closes the second exhaust pipe 18C of the second adsorption unit 18.

[0029] In the containment vessel maintenance equipment 50, the control unit 20 controls the opening of the on-off valve 13C when the pressure inside the containment vessel 100 detected by the pressure detection unit 10 exceeds a predetermined value. In the containment vessel maintenance equipment 50, by opening the on-off valve 13C, steam, which is a condensable gas that has passed through the filter unit 11 from inside the containment vessel 100, and non-condensable gases such as air and radioactive rare gases are sent from the exhaust pipe 12 through the header pipe 13B and the sparger pipe 13D to the storage tank 13A. In the condenser 13, the steam is condensed by the condensed water 13H, which is a liquid phase part inside the storage tank 13A. Meanwhile, in the condenser 13, the non-condensable gas is stored in the gas phase part inside the storage tank 13A. In addition, in the containment vessel maintenance equipment 50, the control unit 20 drives and controls the cooling pump 14C of the cooling unit 14. In the containment vessel maintenance equipment 50, the cooling pump 14C is driven to circulate the condensed water 13H in the storage tank 13A through the circulation pipe 14A and to spray the water from the spray unit 13E. In the containment vessel maintenance equipment 50, the control unit 20 controls the opening of the delivery on-off valve 15C and drives the delivery pump 15B. In the containment vessel maintenance equipment 50, the condensed water 13H in the storage tank 13A is sent to the inside of the containment vessel 100 by opening the delivery on-off valve 15C and driving the delivery pump 15B, and is used for cooling the containment vessel 100, etc. In the condenser 13, the water level of the condensed water 13H in the storage tank 13A is adjusted to within a set range by sending the condensed water 13H to the containment vessel 100, and the tip side of the sparger pipe 13D is always positioned inside the condensed water 13H. In addition, in the containment vessel maintenance equipment 50, under the control of the control unit 20, the non-condensable gas inside the storage tank 13A is dehumidified by the dehumidifier 16, and the radioactive rare gas from which air has been removed in the first adsorption unit 17 and the second adsorption unit 18 is stored in the storage unit 19.

[0030] Fig. 3 is a transverse cross-sectional view of a condensing device according to an embodiment, Fig. 4 is a longitudinal cross-sectional view of a condensing device according to an embodiment, and Fig. 5 is a partially enlarged cross-sectional view of a condensing device according to an embodiment.

[0031] As shown in FIG. 3 to FIG. 5, the condensation device 13 of the embodiment includes a connection portion 13K that connects a plurality of sparger pipes 13D. The connection portion 13K connects a plurality of sparger pipes 13D. The connection portion 13K is disposed at the tip of the sparger pipe 13D. The connection portion 13K includes a main body member 13Ka made of a rigid member such as a water-resistant metal such as stainless steel, and a joint member 13Kb made of a flexible member such as a water-resistant synthetic resin material or rubber material. The joint member 13Kb is provided at a mounting portion to the sparger pipe 13D. The joint member 13Kb is formed, for example, in a ring shape so as to be mounted around the sparger pipe 13D. The main body member 13Ka is provided so as to connect each joint member 13Kb provided on each sparger pipe 13D. The main body member 13Ka is formed, for example, in a plate shape or a rod shape. The connection portion 13K may be entirely made of a flexible member such as a water-resistant synthetic resin material or rubber material.

[0032] In addition, as shown in FIG. 5, the condensation device 13 of the embodiment includes a stopper 13L that can be opened and closed in response to the pressure of the gas sent to the inside of the storage tank 13A through the sparger pipe 13D in the sparger pipe 13D. The stopper 13L includes an opening / closing part 13La that is provided at the tip of the sparger pipe 13D and is movable in the vertical direction inside the sparger pipe 13D, and an elastic member 13Lb that generates an elastic force to close the opening / closing part 13La. The opening / closing part 13La is a plate member having a diameter smaller than the inner diameter of the sparger pipe 13D, and closes the sparger pipe 13D by moving upward so as to abut against a ring-shaped valve seat 13Lc arranged on the inner wall of the sparger pipe 13D. The opening / closing part 13La opens the sparger pipe 13D by moving downward so as to move away from the valve seat 13Lc. The elastic member 13Lb is, for example, a compression coil spring, and is disposed between the locking portion 13Ld provided inside the tip of the sparger pipe 13D and the opening / closing portion 13La, and biases the opening / closing portion 13La to abut against the valve seat 13Lc by its elastic force. Therefore, when the pressure of the gas sent to the inside of the storage tank 13A through the sparger pipe 13D exceeds the elastic force of the elastic member 13Lb, the opening / closing portion 13La moves away from the valve seat 13Lc to open the sparger pipe 13D. On the other hand, when the pressure of the gas is smaller than the elastic force of the elastic member 13Lb, the opening / closing portion 13La abuts against the valve seat 13Lc to close the sparger pipe 13D.

[0033] Moreover, the condensation device 13 of the embodiment includes a perforated plate 13M inside the storage tank 13A, as shown in Fig. 4. The perforated plate 13M is provided inside the storage tank 13A below the sparger pipe 13D so as to divide the storage tank into upper and lower parts. The perforated plate 13M has a plurality of holes 13Ma formed therethrough in the vertical direction. The perforated plate 13M may be made of a net or may be made of a punched metal.

[0034] In addition, as shown in FIG. 4, the condensation device 13 of the embodiment includes a drainage section 13F at the bottom of the storage tank 13A. As described above, the drainage section 13F is a section that drains the condensed water 13H to the outside of the storage tank 13A, and is connected to the circulation pipe 14A of the cooling section 14 and the delivery pipe 15A of the condensed water delivery section 15. The drainage section 13F is disposed at the center of the hemispherical bottom inside the storage tank 13A, and includes a drainage pipe 13Fa, a blocking section 13Fb, and a through hole 13Fc. The drainage pipe 13Fa is formed in a cylindrical shape extending upward from the bottom inside the storage tank 13A. The lower end of the drainage pipe 13Fa is connected to the circulation pipe 14A and the delivery pipe 15A. The blocking section 13Fb is a section that blocks the upper end of the drainage pipe 13Fa. A plurality of through holes 13Fc are provided penetrating the peripheral wall of the drainage pipe 13Fa. The through hole 13Fc is disposed above the drain pipe 13Fa. Therefore, in the condensation device 13, the condensed water 13H in the storage tank 13A flows from the through hole 13Fc into the drain pipe 13Fa and is drained from the lower end of the drain pipe 13Fa to the circulation pipe 14A and the delivery pipe 15A.

[0035] 3 and 4, in the condenser 13 of the embodiment, a header pipe 13B is provided so as to branch off, and each of the header pipes is connected to the exhaust piping 12 via an on-off valve 13C. In the embodiment, the header pipe 13B is provided so as to branch off into two header pipes, a first header pipe 13B1 and a second header pipe 13B2.

[0036] The first header pipe 13B1 includes a connection part 13B1a connected to the on-off valve 13C and penetrating the inside and outside of the storage tank 13A, and a header part 13B1b connected to the connection part 13B1a inside the storage tank 13A. The connection part 13B1a is a pipe that connects the on-off valve 13C to the header part 13B1b. The header part 13B1b is a pipe in which the sparger pipe 13D is provided, and is formed in an arc shape (C-shape) along the cylindrical body part of the storage tank 13A. The header parts 13B1b of the embodiment are disposed on both sides of the connection part 13B1a in the horizontal direction inside the storage tank 13A, and are provided extending in the circumferential direction along the cylindrical body part of the storage tank 13A.

[0037] The second header pipe 13B2 includes a connection part 13B2a that is connected to another on-off valve 13C and penetrates the inside and outside of the storage tank 13A, and a header part 13B2b that is connected to the connection part 13B2a inside the storage tank 13A. The connection part 13B2a is a pipe that connects the on-off valve 13C to the header part 13B2b. The header part 13B2b is a pipe in which the sparger pipe 13D is provided, and is formed in an arc shape (C-shape) along the cylindrical body part of the storage tank 13A. The header part 13B2b of the embodiment is disposed on both sides of the connection part 13B2a in the horizontal direction inside the storage tank 13A, and is provided to extend in the circumferential direction along the cylindrical body part of the storage tank 13A. As shown in FIG. 4, the header part 13B2b of the second header pipe 13B2 is disposed along the horizontal direction inside the header part 13B1b of the first header pipe 13B1.

[0038] 3, sparger pipes 13D are arranged in an arc shape in a plan view along each of header portions 13B1b and 13B2b. Also, connection portions 13K that connect sparger pipes 13D are formed in an arc shape so as to connect sparger pipes 13D to each of header portions 13B1b and 13B2b.

[0039] Therefore, in the condensation device 13 of the embodiment, the header pipe 13B is provided between the exhaust pipe 12, which is the gas supply side, and is branched into a plurality of parts via the on-off valve 13C. In the condensation device 13 of the embodiment, the header pipe 13B is branched into two parts, a first header pipe 13B1 and a second header pipe 13B2. This configuration is not limited to the above, and the condensation device 13 may be branched into a total of four parts, with each header section 13B1b of the first header pipe 13B1 branched via an on-off valve 13C, and each header section 13B2b of the second header pipe 13B2 branched via an on-off valve 13C. Note that each on-off valve 13C is controlled to open and close by the control unit 20.

[0040] 3 and 4, the condensation device 13 of the embodiment includes a support portion 13J on which the header pipe 13B is placed. The support portion 13J is fixed inside the storage tank 13A and supports each of the header portions 13B1b, 13B2b. As shown in FIG. 4, the support portion 13J includes a plurality of support members 13Ja provided to extend horizontally inward from the inner wall of the storage tank 13A, reinforcing members 13Jb that reinforce the support members 13Ja, and a placement member 13Jc that is disposed above the support members 13Ja and places the header pipe 13B (each of the header portions 13B1b, 13B2b) on the header pipe 13B while allowing the header pipe 13B to move horizontally.

[0041] Thus, the condensation device 13 of the embodiment comprises a storage tank 13A in which condensed water 13H is stored at the bottom, a header pipe 13B that is positioned in the gas phase portion above the water level of the condensed water 13H inside the storage tank 13A and to which gas containing steam is supplied from outside the storage tank 13A, a plurality of sparger pipes 13D whose tips extend downward from the header pipe 13B and are positioned in the liquid phase portion of the condensed water 13H, and a connection portion 13K that connects the multiple sparger pipes 13D.

[0042] According to this condensation device 13, by connecting multiple sparger pipes 13D with connecting parts 13K, it is possible to prevent the vibration modes of the sparger pipes 13D from matching with each other and to prevent each sparger pipe 13D from becoming free. As a result, the condensation device 13 of the embodiment can prevent the load effect due to vibration on the sparger pipes 13D.

[0043] Moreover, in the condensation device 13 of the embodiment, the connection portion 13K includes a flexible joint member 13Kb provided at the attachment portion to the sparger pipe 13D. Therefore, according to this condensation device 13, the flexible joint member 13Kb can prevent the transmission of vibrations of each sparger pipe 13D, so that the effect of preventing the load influence due to vibrations on the sparger pipe 13D can be significantly obtained. Furthermore, in the condensation device 13 of the embodiment, even if the connection portion 13K itself has a flexible configuration, the same effect can be obtained because the transmission of vibrations of each sparger pipe 13D can be prevented.

[0044] In addition, in the condensation device 13 of the embodiment, the sparger pipe 13D is provided with a plug portion 13L that can be opened and closed according to the gas pressure. Therefore, according to this condensation device 13, when the gas pressure is high, the plug portion 13L is opened and the gas can be discharged from the sparger pipe 13D to the condensed water 13H. On the other hand, according to this condensation device 13, under conditions of low upstream pressure where the chugging phenomenon occurs, the plug portion 13L is closed to prevent the gas from flowing, thereby preventing the occurrence of the chugging phenomenon. As a result, the condensation device 13 of the embodiment can prevent the load effect on the sparger pipe 13D due to the vibration associated with the chugging phenomenon.

[0045] The condensation device 13 of the embodiment includes a drainage section 13F provided at the bottom of the storage tank 13A to discharge the condensed water 13H to the outside, and a perforated plate 13M disposed between the sparger pipe 13D and the drainage section 13F inside the storage tank 13A to separate the storage tank 13A into upper and lower sections. Generally, when gas is jetted into water and discharged from the drainage section 13F together with the condensed water 13H, the gas may be caught in the pump for draining the condensed water 13H, causing problems such as breakage of the pump shaft. In this regard, according to the condensation device 13 of the embodiment, the perforated plate 13M provided between the sparger pipe 13D and the drainage section 13F acts as a resistance to the gas, making it difficult for air bubbles to invade below the perforated plate 13M. Moreover, according to the condenser 13, gas bubbles coalesce at the porous plate 13M, which increases the buoyancy of the gas and makes it easier for the gas to rise, and it is difficult for the gas bubbles to penetrate below the porous plate 13M. As a result, the condenser 13 of the embodiment can prevent the gas from being discharged together with the condensed water 13H from the drainage section 13F, and can prevent problems such as breakage of the pump shaft.

[0046] In addition, the condensation device 13 of the embodiment includes a drainage section 13F that drains the condensed water 13H to the outside at the bottom of the storage tank 13A, and the drainage section 13F includes a drain pipe 13Fa that extends upward at the bottom of the storage tank 13A and whose lower end leads to the outside of the storage tank 13A, a blocking section 13Fb that blocks the upper end of the drain pipe 13Fa, and a through hole 13Fc formed in the peripheral wall of the drain pipe 13Fa. Generally, when a drain hole is provided at the bottom of the storage tank 13A, a vortex is generated by suction into the drain hole, making it easier for gas to be discharged together with the condensed water 13H. In this regard, according to the condensation device 13 of the embodiment, the upper end of the drain pipe 13Fa is blocked by the blocking section 13Fb, and a through hole 13Fc is formed in the peripheral wall of the drain pipe 13Fa, so that the generation of a vortex due to suction can be suppressed. As a result, the condensation device 13 of the embodiment can prevent the gas from being discharged together with the condensed water 13H from the drainage part 13F, and can prevent problems such as breakage of the pump shaft. In addition, the cross-sectional area of ​​the storage tank 13A decreases toward the bottom of the bowl-shaped hemispherical bottom, and the vertical water flow increases, so the degree of gas suction is large. In this regard, according to the condensation device 13 of the embodiment, the through hole 13Fc is disposed above the drainage pipe 13Fa, making it difficult for gas to be suctioned.

[0047] The condensation device 13 of the embodiment is also provided with a support portion 13J that is fixed inside the storage tank 13A and on which the header pipe 13B is placed while allowing it to move in the horizontal direction. Generally, in a configuration in which high-temperature gas is ejected from the sparger pipe 13D via the header pipe 13B, the header pipe 13B undergoes thermal expansion. In this regard, according to the condensation device 13 of the embodiment, the header pipe 13B is placed by the support portion 13J while allowing it to move in the horizontal direction, so that the header pipe 13B is not restricted by thermal expansion, and it is possible to prevent effects such as a load being generated on the support structure.

[0048] In addition, in the condensation device 13 of the embodiment, the header pipe 13B is branched into multiple parts via on-off valves 13C between the header pipe 13B and the exhaust piping 12, which is the gas supply side, and is equipped with a pressure detection unit 10 that detects the pressure of the gas sent to the header pipe 13B, and a control unit 20 that controls the opening and closing of each on-off valve 13C in accordance with the pressure detected by the pressure detection unit 10.

[0049] In the condensation method of the embodiment, the control unit 20 controls each on-off valve 13C to be open when the pressure detected by the pressure detection unit 10 is on an upward trend, and controls some of the on-off valves 13C to be closed when the pressure detected by the pressure detection unit 10 is on a downward trend.

[0050] Specifically, the condensation method according to the embodiment is shown in a flow chart of the condensation method according to the embodiment of FIG.

[0051] As shown in FIG. 6, the control unit 20 inputs the pressure detected by the pressure detection unit 10, and if the pressure is on the rise (step S1: Yes), controls all the on-off valves 13C to be open (step S2). If the pressure is not on the rise (step S1: No), the control unit 20 continues to input the pressure detected by the pressure detection unit 10. After that, the control unit 20 continues to input the pressure detected by the pressure detection unit 10, and if the pressure is on the fall (step S3: Yes), controls some of the on-off valves 13C to be closed (step S4). In step S4, specifically, for the above-mentioned first header pipe 13B1 and second header pipe 13B2, for example, the control unit 20 controls the on-off valve 13C connected to the first header pipe 13B1 to be closed, and controls the on-off valve 13C connected to the second header pipe 13B2 to be open. If the pressure is not on the fall (step S3: No), the control unit 20 continues to input the pressure detected by the pressure detection unit 10. Thereafter, the control unit 20 continues to input the pressure detected by the pressure detection unit 10, and when the pressure becomes less than the predetermined pressure X (step S5: Yes), controls to close all the on-off valves 13C (step S6). Note that when the pressure is equal to or greater than the predetermined pressure X (step S5: No), the control unit 20 continues to input the pressure detected by the pressure detection unit 10.

[0052] That is, in the containment vessel maintenance equipment 50, cooling water is sprayed to remove the decay heat in the containment vessel 100 in the event of a severe accident, and the pressure inside the containment vessel 100 rises due to the gas generated by the evaporation of the cooling water (step S1: Yes). Then, in the condensation device 13, gas is sent from the containment vessel 100 to the storage tank 13A to suppress this pressure rise (step S2). After that, under the condition that the degree of rise in the pressure inside the containment vessel 100 decreases and the steam flow rate flowing from the upstream side decreases (step S3: Yes), the condensation device 13 closes a part of the branched header pipes (first header pipe 13B1) (step S4) to reduce the steam mass flux per sparger pipe 13D. As a result, the condensation device 13 and the condensation method can make the chugging phenomenon less likely to occur. As a result, the condensation device 13 and the condensation method can prevent the load effect on the sparger pipe 13D due to the vibration associated with the chugging phenomenon. In addition, when the pressure inside the storage vessel 100 becomes less than a preset pressure X that can ensure the integrity of the storage vessel 100 (step S5: Yes), the condenser 13 stops sending gas to the storage tank 13A (step S6).

[0053] Although the condensation device 13 and the condensation method of the above-mentioned embodiment have been described as being applied to the containment vessel maintenance equipment 50, the present invention is not limited thereto. The condensation device 13 and the condensation method of the embodiment are applied to a configuration including a storage tank 13A having condensed water 13H stored at the bottom, a header pipe 13B disposed in a gas phase portion above the water surface of the condensed water 13H inside the storage tank 13A and to which a gas containing steam is supplied from outside the storage tank 13A, and a plurality of sparger pipes 13D whose tips extending downward from the header pipe 13B are disposed in a liquid phase portion of the condensed water 13H. [Explanation of symbols]

[0054] 10 Pressure detection section 13 Condenser 13A Storage tank 13B Header pipe 13C On-off valve 13D Sparger Pipe 13F Drainage section 13Fa drain pipe 13Fb Occlusion 13Fc through hole 13H Condensed water 13J Support part 13K Connection 13Kb Joint material 13La Closure 13Lb Elastic material 13M perforated plate 20 Control section

Claims

1. a storage tank at the bottom of which condensed water is stored; a header pipe disposed in a gas phase portion above the water level of the condensed water inside the storage tank and receiving a gas containing steam from outside the storage tank; A plurality of sparger pipes, each having a tip extending downward from the header pipe and disposed in a liquid phase portion of the condensed water; A connection portion that connects a plurality of the sparger pipes; Equipped with The condensation device, wherein the connection portion includes a flexible joint member provided at an attachment portion to each of the sparger pipes, and a main body member composed of a rigid member provided to connect only the joint members provided on the sparger pipes.

2. a storage tank at the bottom of which condensed water is stored; a header pipe disposed in a gas phase portion above the water level of the condensed water inside the storage tank and receiving a gas containing steam from outside the storage tank; A plurality of sparger pipes, each having a tip extending downward from the header pipe and disposed in a liquid phase portion of the condensed water; A connection portion that connects a plurality of the sparger pipes; Equipped with A condensation device, wherein the connection portion is entirely flexible.

3. a storage tank at the bottom of which condensed water is stored; a header pipe disposed in a gas phase portion above the water level of the condensed water inside the storage tank and receiving a gas containing steam from outside the storage tank; A plurality of sparger pipes, each having a tip extending downward from the header pipe and disposed in a liquid phase portion of the condensed water; A connection portion that connects a plurality of the sparger pipes; a drainage section provided at the bottom of the storage tank for discharging the condensed water to the outside; A perforated plate disposed between the sparger pipe and the drainage portion inside the storage tank so as to divide the storage tank into upper and lower parts; A condensation device comprising:

4. a storage tank at the bottom of which condensed water is stored; a header pipe disposed in a gas phase portion above the water level of the condensed water inside the storage tank and receiving a gas containing steam from outside the storage tank; A plurality of sparger pipes, each having a tip extending downward from the header pipe and disposed in a liquid phase portion of the condensed water; A connection portion that connects a plurality of the sparger pipes; a drainage section at the bottom of the storage tank for draining the condensed water to the outside, The drainage section of the condensation device includes a drainage pipe extending upward from the bottom of the storage tank and having a lower end leading to the outside of the storage tank, a blocking section that blocks the upper end of the drainage pipe, and a through hole formed in the peripheral wall of the drainage pipe.

5. a storage tank at the bottom of which condensed water is stored; a header pipe disposed in a gas phase portion above the water level of the condensed water inside the storage tank and receiving a gas containing steam from outside the storage tank; A plurality of sparger pipes, each having a tip extending downward from the header pipe and disposed in a liquid phase portion of the condensed water; A connection portion that connects a plurality of the sparger pipes; a support portion that is fixed inside the storage tank and supports the header pipe while allowing the header pipe to move in a horizontal direction.

6. a storage tank at the bottom of which condensed water is stored; a header pipe disposed in a gas phase portion above the water level of the condensed water inside the storage tank and receiving a gas containing steam from outside the storage tank; A plurality of sparger pipes, each having a tip extending downward from the header pipe and disposed in a liquid phase portion of the condensed water; A connection portion that connects a plurality of the sparger pipes; Equipped with The header pipe is branched into a plurality of parts via an on-off valve between the header pipe and the gas supply side, a pressure detection unit that detects the pressure of the gas sent to the header pipe; a control unit that controls opening and closing of each of the on-off valves in response to the pressure detected by the pressure detection unit; A condensation device comprising:

7. a storage tank at the bottom of which condensed water is stored; a header pipe disposed in a gas phase portion above the water level of the condensed water inside the storage tank and receiving a gas containing steam from outside the storage tank; A plurality of sparger pipes, each having a tip extending downward from the header pipe and disposed in a liquid phase portion of the condensed water; Equipped with The sparger pipe includes an opening / closing portion provided at a tip portion and an elastic member that elastically supports the opening / closing portion so as to close the opening / closing portion, and the opening / closing portion opens and closes against the elastic force of the elastic member due to the pressure of the gas.

8. a storage tank at the bottom of which condensed water is stored; a header pipe arranged in a gas phase portion above the water level of the condensed water inside the storage tank, to which a gas containing steam is supplied from outside the storage tank, and which is branched into a plurality of header pipes via an on-off valve between the gas supply side and the header pipe; A plurality of sparger pipes, each having a tip extending downward from the header pipe and disposed in a liquid phase portion of the condensed water; a pressure detection unit that detects the pressure of the gas sent to the header pipe; a control unit that controls opening and closing of each of the on-off valves in response to the pressure detected by the pressure detection unit; A condensation method using a condensation device comprising: The control unit controls each of the on-off valves to be open when the pressure detected by the pressure detection unit is on an upward trend, and controls some of the on-off valves to be closed when the pressure detected by the pressure detection unit is on a downward trend.

Images