JP2015040751A - Cooling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate start-up by preventing freezing of water in a circulation path.SOLUTION: A cooling device includes: circulation pipelines (inhalant canals 42, 92 and exhalent canals 44, 94) for circulating cooling water for exchanging heat by utilizing heat generated from a reactor of a nuclear facility; a heat exchanger 52 provided on the circulation pipelines, for acquiring heat of the cooling water in the circulation pipelines by heat exchange; and heating means 60 for transferring heat acquired from natural heat energy to the heat exchanger 52.

Description

  The present invention relates to a cooling device that acquires heat generated in a nuclear reactor by heat exchange.

  For example, in a nuclear power plant having a pressurized water reactor (PWR), primary cooling water is heated in the nuclear reactor to become high-temperature high-pressure water that does not boil, and is supplied to the steam generator through the primary cooling water pipe. In the steam generator, heat exchange between the primary cooling water and the secondary cooling water is performed, so that the secondary cooling water evaporates and becomes steam. The secondary cooling water converted into steam by heat exchange is supplied to the turbine. The turbine is driven by evaporation of secondary cooling water. Then, the power of the turbine is transmitted to the generator to generate power. The steam used to drive the turbine is condensed into water and supplied to the steam generator. On the other hand, the primary cooling water after heat exchange in the steam generator is supplied to the nuclear reactor through the primary cooling water pipe.

  In such a nuclear facility, in the unlikely event of an accident, it is possible to install a cooling device that obtains heat generated in the reactor by heat exchange by cooling the secondary cooling water as a safety measure. It is desired.

  In addition, although it is not a cooling device which cools secondary cooling water, there exists an air cooling type cooler shown in patent document 1 as a cooler which cools the heat exchanger tube which a medium distribute | circulates.

JP-A-9-239230

  Cooling devices installed in nuclear facilities are equipped with heat exchangers in circulation piping through which primary and secondary cooling water, which is cooling water, is circulated, and circulate with on-off valves during normal operation. When the piping is closed and the circulation piping is opened by the on-off valve in the event of an abnormality, the heat of the cooling water is acquired by the heat exchanger and cooling is performed. However, if water is added to the circulation path including the circulation pipe and the heat exchanger tube of the heat exchanger from the normal time in advance, water may freeze in winter and the circulation path (especially the heat exchanger tube of the heat exchanger) may be damaged. is there. On the other hand, if water is not applied to the circulation path during normal times but water is supplied during abnormal conditions, it takes time and effort to start up the cooling device.

  The present invention solves the above-described problems, and an object thereof is to provide a cooling device that can be easily started up by preventing freezing of water in a circulation path.

  In order to achieve the above-described object, the cooling device of the present invention is provided with a circulation pipe for circulating cooling water that performs heat exchange using heat generated in a nuclear reactor of a nuclear facility, and the circulation pipe. And a heat exchanger that acquires heat of the cooling water of the circulation pipe by heat exchange, and a heating unit that transmits heat acquired from natural heat energy to the heat exchanger.

  According to this cooling device, by providing a heating means that transmits heat obtained from natural heat energy to the heat exchanger, the cooling water of the circulation pipe is heated, and the cooling water of the heat exchanger is frozen in winter, It is possible to prevent snow from being accumulated around the heat exchanger. For this reason, since the cooling water is stretched in the circulation path including the circulation pipe and the heat exchanger and the cooling water is prevented from freezing, the apparatus can be easily started up. Moreover, since the cooling water is prevented from freezing, the maintenance of the apparatus can be simplified.

  In the cooling device of the present invention, the heating means includes a bypass circulation pipe for bypassing the circulation pipe and circulating the cooling water including the heat exchanger, and a part of the bypass circulation pipe is provided. It is characterized by being buried in the ground.

  According to this cooling device, it is possible to heat the cooling water and prevent the cooling water in the circulation path including the circulation pipe and the heat exchanger from freezing in winter.

  In the cooling device of the present invention, the heating means includes a bypass circulation pipe for bypassing the circulation pipe and circulating the cooling water including the heat exchanger, and a part of the bypass circulation pipe is provided. It is embedded in water.

  According to this cooling device, it is possible to heat the cooling water and prevent the cooling water in the circulation path including the circulation pipe and the heat exchanger from freezing in winter.

  In the cooling device of the present invention, a check valve that allows the cooling water to flow only in one direction is provided on at least one end side where the bypass circulation pipe is connected to the circulation pipe.

  According to this cooling device, since the circulation direction of the cooling water by the detour circulation pipe is set to a fixed direction by providing the check valve, the cooling water can be smoothly circulated, so that the cooling water can be frozen. The effect to prevent can be acquired notably.

  In the cooling device of the present invention, a heat insulating material is provided on an outer periphery on one end side where the bypass circulation pipe is connected to the circulation pipe.

  According to this cooling device, one end side of the bypass circulation pipe provided with the heat insulating material can suppress the temperature drop of the cooling water heated by natural heat energy. Since the circulating direction of the cooling water is determined to be a fixed direction, the cooling water can be smoothly circulated, so that the effect of preventing the cooling water from freezing can be obtained remarkably.

  Further, in the cooling device of the present invention, an opening / closing valve is provided for each of the circulation pipe and the bypass circulation pipe, and the opening / closing valve of the bypass circulation pipe is closed while the opening / closing valve of the circulation pipe is closed during normal operation of the nuclear power facility. A control unit is provided that opens the open / close valve of the circulation pipe and closes the open / close valve of the bypass circulation pipe when the nuclear power plant is abnormal.

  According to this cooling device, during normal operation of nuclear power facilities, the cooling water does not circulate in the circulation path, and the cooling water is circulated through the bypass circulation pipe including the heat exchanger, so that the cooling water is heated by natural heat energy. In this way, freezing can be prevented. On the other hand, when the nuclear facility is abnormal, the cooling water circulates in the circulation path, and the cooling water is cooled in the heat exchanger. At this time, since freezing of the cooling water is prevented by natural heat energy, the cooling water can be smoothly sent to the heat exchanger.

  Moreover, in the cooling device of the present invention, the heating means contacts a heat pipe in which a heat medium is sealed inside a hollow cylinder with the heat exchanger, and a part of the heat pipe is embedded in the ground. It is characterized by that.

  According to this cooling device, it is possible to heat the cooling water and prevent the cooling water in the circulation path including the circulation pipe and the heat exchanger from freezing in winter.

  Moreover, in the cooling device of the present invention, the heating means is configured such that a heat pipe in which a heat medium is sealed inside a hollow cylinder is brought into contact with the heat exchanger, and a part of the heat pipe is embedded in water. It is characterized by.

  According to this cooling device, it is possible to heat the cooling water and prevent the cooling water in the circulation path including the circulation pipe and the heat exchanger from freezing in winter.

  Moreover, in the cooling device of the present invention, the heating means includes a heat storage section disposed around the heat exchanger and a heat collection section that collects solar heat in the heat storage section.

  According to this cooling device, it is possible to heat the cooling water and prevent the cooling water in the circulation path including the circulation pipe and the heat exchanger from freezing in winter.

  According to the present invention, it is possible to easily start up by preventing freezing of water in the circulation path.

FIG. 1 is a schematic configuration diagram schematically showing a nuclear facility provided with a cooling device according to an embodiment of the present invention. FIG. 2 is a schematic configuration diagram schematically showing an air cooler in the cooling device according to the embodiment of the present invention. FIG. 3 is a configuration diagram of the cooling device according to the first embodiment of the present invention. FIG. 4 is a configuration diagram of the cooling device according to the first embodiment of the present invention. FIG. 5 is a configuration diagram of the cooling device according to the first embodiment of the present invention. FIG. 6 is a configuration diagram of a cooling device according to Embodiment 2 of the present invention. FIG. 7 is a configuration diagram of a cooling device according to Embodiment 3 of the present invention.

  Embodiments according to the present invention will be described below in detail with reference to the drawings. In addition, this invention is not limited by this embodiment. In addition, constituent elements in the following embodiments include those that can be easily replaced by those skilled in the art or those that are substantially the same.

  FIG. 1 is a schematic configuration diagram schematically showing a nuclear facility provided with a cooling device according to the present embodiment. In the nuclear power facility 1 shown in FIG. 1, for example, a pressurized water reactor (PWR) is used as the nuclear reactor 5. The nuclear power plant 1 using this pressurized water reactor 5 is composed of a primary cooling system 3 including the nuclear reactor 5 and a secondary cooling system 4 that exchanges heat with the primary cooling system 3. The primary cooling water as the cooling water flows through the secondary cooling system 4, and the secondary cooling water as the cooling water flows through the secondary cooling system 4.

  The primary cooling system 3 includes a nuclear reactor 5 and a steam generator 7 connected to the nuclear reactor 5 via a cooling water pipe 6a serving as a cold leg and a cooling water pipe 6b serving as a hot leg. The cooling water pipe 6 b is provided with a pressurizer 8. The cooling water pipe 6a is provided with a cooling water pump 9. These reactor 5, cooling water pipes 6 a and 6 b, steam generator 7, pressurizer 8 and cooling water pump 9 are accommodated in a robust reactor containment vessel 10.

  As described above, the nuclear reactor 5 is a pressurized water reactor, and the inside thereof is filled with primary cooling water. The nuclear reactor 5 contains a large number of fuel assemblies 15 therein, and a large number of control rods 16 that control the nuclear fission of the fuel assemblies 15 are provided in the fuel assemblies 15 so as to be inserted and removed. The control rod 16 is driven in the insertion / removal direction by the control rod driving device 17 with respect to the fuel assembly 15. When the control rod 16 is inserted into the fuel assembly 15 by the control rod driving device 17, the nuclear reaction in the fuel assembly 15 is reduced and stopped. On the other hand, when the control rod 16 is pulled out by the control rod driving device 17, the nuclear reaction in the fuel assembly 15 increases and becomes a critical state. Further, the control rod driving device 17 is configured to insert the control rod 16 into the fuel assembly 15 when the supply of electric power is cut off and the electric power is lost.

  When the fuel assembly 15 is fissioned while controlling the fission reaction by the control rod 16, thermal energy is generated by the fission. The generated thermal energy heats the primary cooling water, and the heated primary cooling water is sent to the steam generator 7 through the cooling water pipe 6b. On the other hand, the primary cooling water sent from the steam generator 7 through the cooling water pipe 6 a flows into the reactor 5 and cools the inside of the reactor 5.

  The pressurizer 8 provided in the cooling water pipe 6b suppresses boiling of the primary cooling water by pressurizing the primary cooling water that has become high temperature. In addition, the steam generator 7 heat-exchanges the primary cooling water having a high temperature and high pressure with the secondary cooling water, thereby evaporating the secondary cooling water to generate steam, and the primary cooling having a high temperature and high pressure. Cool the water. The cooling water pump 9 circulates the primary cooling water in the primary cooling system 3, sends the primary cooling water from the steam generator 7 to the reactor 5 through the cooling water pipe 6 a, and cools the primary cooling water from the reactor 5. It feeds into the steam generator 7 through the water pipe 6b. In addition, although the steam generator 7 is illustrated in a form in which one steam generator 7 is provided for one reactor 5, a plurality of steam generators 7 may be provided.

  Here, a series of operations in the primary cooling system 3 of the nuclear facility 1 will be described. When the primary cooling water is heated by the heat energy generated by the nuclear fission reaction in the nuclear reactor 5, the heated primary cooling water is supplied to the steam generator 7 via the cooling water pipe 6b which becomes a hot leg by the cooling water pump 9. Sent to. The high-temperature primary cooling water that passes through the cooling water pipe 6b serving as a hot leg is pressurized by the pressurizer 8 to suppress boiling, and flows into the steam generator 7 in a state of high temperature and pressure. The high-temperature and high-pressure primary cooling water that has flowed into the steam generator 7 is cooled by exchanging heat with the secondary cooling water, and the cooled primary cooling water passes through the cooling water pipe 6 a that becomes a cold leg by the cooling water pump 9. To the reactor 5. And the reactor 5 is cooled because the cooled primary cooling water flows into the reactor 5. That is, the primary cooling water circulates between the nuclear reactor 5 and the steam generator 7. The primary cooling water is light water used as a coolant and a neutron moderator.

  The secondary cooling system 4 connects the turbine 22 connected to the steam generator 7 via the steam pipe 21, the condenser 23 connected to the turbine 22, and the condenser 23 and the steam generator 7. And a water supply pump 24 interposed in the water supply pipe 26. A generator 25 is connected to the turbine 22.

  Here, a series of operations in the secondary cooling system 4 of the nuclear facility 1 will be described. When steam flows from the steam generator 7 into the turbine 22 through the steam pipe 21, the turbine 22 rotates. When the turbine 22 rotates, the generator 25 connected to the turbine 22 generates power. Thereafter, the steam flowing out from the turbine 22 flows into the condenser 23. The condenser 23 has a cooling pipe 27 disposed therein, and one of the cooling pipes 27 is connected to a water intake pipe 28 for supplying cooling water (for example, seawater). Is connected to a drain pipe 29 for draining the cooling water to the water discharge channel. The condenser 23 cools the steam flowing in from the turbine 22 by the cooling pipe 27, thereby returning the steam to a liquid. The secondary cooling water that has become liquid is sent to the steam generator 7 via the water supply pipe 26 by the water supply pump 24. The secondary cooling water sent to the steam generator 7 becomes steam again by exchanging heat with the primary cooling water in the steam generator 7.

  A cooling device 40 is connected to the secondary cooling system 4. The cooling device 40 is a cooling system of a different system from the above-described flow for rotating the above-described turbine 22 of the secondary cooling system 4. The cooling device 40 is a preliminary cooling system that cools the secondary cooling water of the secondary cooling system 4 when the cooling water cannot be cooled. The operation of the cooling device 40 is controlled by the control unit 41.

  The cooling device 40 includes an inflow pipe 42 and an outflow pipe 44 that form circulation piping for circulating cooling water (secondary cooling water) that performs heat exchange using heat generated in the nuclear reactor 5 of the nuclear power facility 1, and opens and closes It has valves 46 and 48, a pump 49, and an air cooler 50. The inflow pipe 42 is a pipe that guides the secondary cooling water in the liquid state (water) of the steam generator 7 to the air cooler 50. The outflow pipe 44 is a pipe that guides the secondary cooling water cooled by the air cooler 50 to the steam generator 7. The on-off valve 46 is disposed in the inflow pipe 42 and switches between opening and closing of the inflow pipe 42. The on-off valve 46 is closed to suppress the secondary cooling water of the steam generator 7 from flowing into the air cooler 50, and is opened to transfer the secondary cooling water of the steam generator 7 to the air cooler 50. Make it ready for inflow. The on-off valve 48 is disposed in the outflow pipe 44 and switches between opening and closing of the outflow pipe 44. The on-off valve 48 is closed to suppress the secondary cooling water of the air cooler 50 from flowing into the steam generator 7, and is opened to allow the secondary cooling water of the air cooler 50 to the steam generator 7. Make it ready for inflow. The pump 49 is installed in the outflow pipe 44. The pump 49 circulates the secondary cooling water flowing in the cooling device 40 with the steam generator 7 by sending the secondary cooling water in the outflow pipe 44 to the steam generator 7. The air cooler 50 is an air-cooled cooler that cools the secondary cooling water by blowing air to the secondary cooling water guided by the inflow pipe 42 and exchanging heat between the air and the secondary cooling water. It is. The structure of the air cooler 50 will be described later.

  The cooling device 40 opens the on-off valves 46 and 48 by the control unit 41 and drives the pump 49 to drive the steam generator 7, the inflow pipe 42, the air cooler 50, the outflow pipe 44, and the steam generator 7. The secondary cooling water is circulated in order. Thus, the inflow pipe 42, the outflow pipe 44, and the air cooler 50 form a circulation path for circulating the secondary cooling water of the steam generator 7. Further, the cooling device 40 cools the circulating secondary cooling water with the air cooler 50. Thereby, the secondary cooling water in the steam generator 7 can be cooled, and the primary cooling water can be continuously cooled by the secondary cooling water.

  A cooling device 90 is connected to the primary cooling system 3. The cooling device 90 is a cooling system of a different system from the above-described flow for heat exchange by the steam generator 7 of the primary cooling system 3 described above. The cooling device 90 is a preliminary cooling system that cools the primary cooling water of the primary cooling system 3 when the cooling water cannot be cooled. The operation of the cooling device 90 is controlled by the control unit 91.

  The cooling device 90 includes an inflow pipe 92 and an outflow pipe 94 that form circulation piping for circulating cooling water (primary cooling water) that performs heat exchange using heat generated in the nuclear reactor 5 of the nuclear power facility 1, and an on-off valve. 96, 98, a pump 99, and an air cooler 50. The inflow pipe 92 is a pipe that is connected to the cooling water pipe 6 a and guides the primary cooling water supplied from the steam generator 7 to the nuclear reactor 5 to the air cooler 50. The outflow pipe 94 is a pipe that is connected to the cooling water pipe 6 b and guides the primary cooling water cooled by the air cooler 50 to the steam generator 7. The on-off valve 96 is disposed in the inflow pipe 92 and switches between opening and closing of the inflow pipe 92. The on-off valve 96 is closed to prevent the primary cooling water from flowing into the air cooler 50, and is opened to allow the primary cooling water to flow into the air cooler 50. The on-off valve 98 is disposed in the outflow pipe 94 and switches between opening and closing of the outflow pipe 94. The on-off valve 98 suppresses the primary cooling water of the air cooler 50 from flowing into the steam generator 7 by being closed, and the primary cooling water of the air cooler 50 can flow into the steam generator 7 by being opened. State. The pump 99 is installed in the outflow pipe 94. The pump 99 circulates the primary cooling water flowing in the cooling device 90 with the steam generator 7 by sending the primary cooling water in the outflow pipe 94 to the steam generator 7. The air cooler 50 is an air-cooled cooler that cools the primary cooling water by blowing air to the primary cooling water guided by the inflow pipe 92 and exchanging heat between the air and the primary cooling water. The structure of the air cooler 50 will be described later.

  The cooling device 90 opens the on-off valves 96 and 98 by the control unit 91 and drives the pump 99 to drive the steam generator 7, the inflow pipe 92, the air cooler 50, the outflow pipe 94, and the steam generator 7. The secondary cooling water is circulated in order. Thus, the inflow pipe 92, the outflow pipe 94, and the air cooler 50 form a circulation path for circulating the primary cooling water of the steam generator 7. Further, the cooling device 90 cools the circulating primary cooling water with the air cooler 50. Thereby, the primary cooling water in the steam generator 7 can be cooled, and the primary cooling water and the secondary cooling water can be continuously cooled. In addition, the control part 91 may be independent from the control part 41 of the cooling device 40 mentioned above, or may be one thing.

  Next, the configuration of the air cooler 50 will be described. FIG. 2 is a schematic configuration diagram schematically showing an air cooler in the cooling device according to the present embodiment. As described above, the air cooler 50 is provided in the cooling device 40 and the cooling device 90. In the following description, the cooling device 40 will be described, and the reference numeral for the cooling device 90 is shown in parentheses.

  As shown in FIG. 2, the air cooler 50 includes a blower 51 and a heat exchanger 52. The blower 51 and the heat exchanger 52 are supported outdoors by a frame (not shown) installed on the ground or foundation concrete provided on the ground.

  The blower 51 is, for example, an axial fan or a suction fan that discharges an air flow in the axial direction. In the present embodiment, the heat exchangers 52 are arranged to face each other, and the blower 51 is provided between the heat exchangers 52. And the air blower 51 sends an airflow to each heat exchanger 52 which opposes by sending air from the bottom up.

  The heat exchanger 52 includes a supply unit 52A, a discharge unit 52B, a heat transfer tube 52C, and fins 52D. The supply unit 52A is a container that forms a water chamber for storing cooling water (primary cooling water or secondary cooling water), and is supplied with cooling water that is connected to the inflow pipe 42 (92) and flows through the inflow pipe 42 (92). Is done. The discharge part 52B is a container that forms a water chamber for storing cooling water, and is connected to the outflow pipe 44 (94) to discharge the stored cooling water to the outflow pipe 44 (94). The heat transfer tube 52C is provided to extend between the supply part 52A and the discharge part 52B, and each end is connected to the supply part 52A and the discharge part 52B. A plurality of the heat transfer tubes 52C are arranged in parallel. That is, in each heat transfer tube 52C, the cooling water supplied to the supply unit 52A is distributed and supplied from the supply unit 52A, and the cooling water is collected and sent to the discharge unit 52B. The fins 52D are formed in a thin plate shape, penetrate the heat transfer tubes 52C perpendicularly to the direction in which the heat transfer tubes 52C extend, and are arranged in a plurality along the direction in which the heat transfer tubes 52C extend. The heat exchanger 52 causes the heat exchange between the cooling water flowing in from the inflow pipe 42 and the air flow guided by the blower 51 to cool the cooling water.

[Embodiment 1]
3 to 5 are configuration diagrams of the cooling device according to the present embodiment. As shown in FIGS. 3 to 5, the cooling device 40 (90) of the present embodiment includes a heating unit 60.

  The heating means 60 transmits heat obtained from natural heat energy to the heat exchanger 52, and includes a heat exchanger 52 that bypasses the inflow pipe 42 (92) and the outflow pipe 44 (94) forming the circulation pipe. A bypass circulation pipe 61 for circulating the cooling water is provided. A part of the bypass circulation pipe 61 is buried in the ground or underwater (the sea, a lake, or the like). A portion of the bypass circulation pipe 61 embedded in the ground or in water is heated by natural heat energy. The cooling water supplied to the bypass circulation pipe 61 is heated by a part of the bypass circulation pipe 61 buried in the ground or in the water, and rises from the ground or the water to the heat exchanger 52 by the principle of the thermosyphon. In the heat exchanger 52, heat is exchanged with the outside air, the heat is taken away, and it is cooled and circulated without using electric power by returning to a part of the bypass circulation pipe 61 buried in the ground or underwater. The circulation direction of the cooling water by the bypass circulation pipe 61 is the same as the circulation direction in the inflow pipe 42 (92) and the outflow pipe 44 (94) forming the circulation pipe in the heat exchanger 52, but is reverse. Also good.

  As described above, the cooling device 40 (90) of the present embodiment includes the heating means 60 that transmits the heat acquired from the natural heat energy to the heat exchanger 52, thereby heating the cooling water and setting a circulation path in winter or the like. It is possible to prevent the cooling water in the heat transfer tube 52C of the formed heat exchanger 52 from freezing or snowing around the heat exchanger 52. For this reason, since cooling water is stretched over the circulation path including the inflow pipe 42 (92) and the outflow pipe 44 (94) and the heat exchanger 52 to prevent the cooling water from freezing, the cooling device 40 (90) Startup can be performed easily. Moreover, since the cooling water is prevented from freezing, the maintenance of the cooling device 40 (90) can be simplified.

  In the cooling device 40 (90) of the present embodiment, the heating means 60 bypasses the inflow pipe 42 (92) and the outflow pipe 44 (94) and includes a heat exchanger 52 to bypass the cooling water. A circulation pipe 61 is provided, and a part of the detour circulation pipe 61 is buried in the ground or underwater (the sea, a lake, or the like).

  According to the cooling device 40 (90), it is possible to prevent the cooling water in the heat transfer pipe 52C of the heat exchanger 52 that forms a circulation path by heating the cooling water and freezes in winter.

  Further, in the cooling device 40 (90) of the present embodiment, as shown in FIG. 4, the detour circulation pipe 61 is connected to at least one end connected to the inflow pipe 42 (92) and the outflow pipe 44 (94). It is preferable to provide a check valve 64 that allows cooling water to flow only in one direction. FIG. 4 shows a configuration in which check valves 64 are provided on both end sides where the bypass circulation pipe 61 is connected to the inflow pipe 42 (92) and the outflow pipe 44 (94).

  According to this cooling device 40 (90), by providing the check valve 64, the circulation direction of the cooling water by the bypass circulation pipe 61 is set to a constant direction, so that the cooling water can be circulated smoothly. The effect of preventing the cooling water in the heat transfer tube 52C from being frozen can be remarkably obtained. Also in this case, the circulation direction of the cooling water by the bypass circulation pipe 61 is reverse in the heat exchanger 52 even if it is the same as the circulation direction in the inflow pipe 42 (92) and the outflow pipe 44 (94) forming the circulation pipe. It may be.

  Further, in the cooling device 40 (90) of the present embodiment, as shown in FIG. 5, the bypass circulation pipe 61 is an inflow pipe 42 (92) and an outflow pipe 44 that are not buried in the ground or in water. It is preferable to provide a heat insulating material 65 on the outer periphery on one end side connected to (94).

  According to this cooling device 40 (90), since one end side provided with the heat insulating material 65 can suppress a decrease in the temperature of the cooling water heated by natural heat energy, the detour circulation piping is based on the principle of the thermosyphon. Since the circulating direction of the cooling water by 61 is determined to be a constant direction, the cooling water can be smoothly circulated, so that the effect of preventing the cooling water in the heat transfer pipe 52C from being frozen can be remarkably obtained. Also in this case, the circulation direction of the cooling water by the bypass circulation pipe 61 is reverse in the heat exchanger 52 even if it is the same as the circulation direction in the inflow pipe 42 (92) and the outflow pipe 44 (94) forming the circulation pipe. It may be.

  Further, in the cooling device 40 (90) of the present embodiment, as shown in FIG. 3, the bypass circulation pipe 61 is bypassed on each end side where it is connected to the inflow pipe 42 (92) and the outflow pipe 44 (94). On-off valves 62 and 63 for opening and closing the circulation pipe 61 are provided. The on / off valves 62 and 63 are controlled to be opened and closed by the control unit 41 (91). Further, as described above, the inflow pipe 42 (92) and the outflow pipe 44 (94) as the circulation pipe are provided with the on-off valves 46 and 48 (96 and 98) and the pumps 49 and 99, and the control unit 41 (91 ). The configuration provided with the on-off valves 62 and 63 and controlled by the control unit 41 (91) can be applied to the forms shown in FIGS.

  Then, the control unit 41 (91) closes the on-off valves 46 and 48 (96, 98) of the inflow pipe 42 (92) and the outflow pipe 44 (94) during normal operation (normal time) of the nuclear power facility 1. At the same time, the on-off valves 62 and 63 of the bypass circulation pipe 61 are opened. For this reason, the cooling water does not circulate in the inflow pipe 42 (92), the outflow pipe 44 (94), and the steam generator 7 as a circulation path, and the cooling water is circulated in the bypass circulation pipe 61 including the heat exchanger 52. Therefore, the cooling water can be heated by natural heat energy to prevent freezing. On the other hand, the control unit 41 is in the event of an abnormality in the nuclear power facility 1 (when steam cannot be used by the turbine 22 of the secondary cooling system 4 and cooling water is not cooled, or when the reactor 5 cannot be controlled). The on-off valves 46 and 48 (96, 98) of the inflow pipe 42 (92) and the outflow pipe 44 (94) are opened, and the on-off valves 62 and 63 of the bypass circulation pipe 61 are closed. For this reason, cooling water circulates in the inflow pipe 42 (92), the outflow pipe 44 (94), the heat exchanger 52, and the steam generator 7 as a circulation path, and the said cooling water is cooled. At this time, since freezing of the cooling water is prevented by natural heat energy, the cooling water can be smoothly sent to the heat transfer tube 52C of the heat exchanger 52.

[Embodiment 2]
FIG. 6 is a configuration diagram of the cooling device according to the present embodiment. As shown in FIG. 6, the cooling device 40 (90) of the present embodiment includes a heating unit 70. In addition, the air blower 51 is abbreviate | omitted in FIG.

  The heating means 70 transmits heat acquired from natural heat energy to the heat exchanger 52, and has a heat pipe 71 in which a heat medium is sealed inside a hollow cylinder. The heat pipe 71 is provided in contact with the heat exchanger 52, and a part thereof is buried in the ground or in water (such as the sea or a lake). The heat pipe 71 contacts at least one of the supply unit 52A, the discharge unit 52B, the heat transfer tube 52C, or the fin 52D in the heat exchanger 52.

  As described above, the cooling device 40 (90) of the present embodiment includes the heating means 70 that transmits the heat acquired from the natural heat energy to the heat exchanger 52, thereby heating the cooling water and setting a circulation path in winter. It is possible to prevent the cooling water in the heat transfer tube 52C of the formed heat exchanger 52 from freezing or snowing around the heat exchanger 52. For this reason, since cooling water is stretched over the circulation path including the inflow pipe 42 (92) and the outflow pipe 44 (94) and the heat exchanger 52 to prevent the cooling water from freezing, the cooling device 40 (90) Startup can be performed easily. Moreover, since the cooling water is prevented from freezing, the maintenance of the cooling device 40 (90) can be simplified.

  Further, in the cooling device 40 (90) of the present embodiment, the heating means 70 causes the heat pipe 71, in which the heat medium is sealed inside the hollow cylinder, to contact the heat exchanger 52, and a part of the heat pipe 71 is used. It is preferable to be buried in the ground or underwater (such as the sea or a lake).

  According to the cooling device 40 (90), it is possible to prevent the cooling water in the heat transfer pipe 52C of the heat exchanger 52 that forms a circulation path by heating the cooling water and freezes in winter.

[Embodiment 3]
FIG. 7 is a configuration diagram of the cooling device according to the present embodiment. As shown in FIG. 7, the cooling device 40 (90) of the present embodiment includes a heating unit 80. In addition, the air blower 51 is abbreviate | omitted in FIG.

  The heating unit 80 includes a heat storage unit 81 disposed around the heat exchanger 52 and a heat collection unit 82 that collects solar heat in the heat storage unit 81. A heat storage material such as paraffin, fatty acid, inorganic hydrated salt, molten salt, high-density polyethylene, metal, or the like can be applied to the heat storage unit 81. Although it is preferable that the lower part of the heat exchanger 52 heats the heat exchanger 52 around the heat exchanger 52 in which the heat storage unit 81 is disposed, the side part or the upper part of the heat exchanger 52 may be used. Moreover, what collects sunlight by a concave lens, a convex lens, a reflecting plate, etc. can be applied to the heat collecting part 82.

  As described above, the cooling device 40 (90) of the present embodiment includes the heating means 80 that transmits the heat acquired from the natural heat energy to the heat exchanger 52, thereby heating the cooling water and setting a circulation path in winter or the like. It is possible to prevent the cooling water in the heat transfer tube 52C of the formed heat exchanger 52 from freezing or snowing around the heat exchanger 52. For this reason, since cooling water is stretched over the circulation path including the inflow pipe 42 (92) and the outflow pipe 44 (94) and the heat exchanger 52 to prevent the cooling water from freezing, the cooling device 40 (90) Startup can be performed easily. Moreover, since the cooling water is prevented from freezing, the maintenance of the cooling device 40 (90) can be simplified.

  Moreover, in the cooling device 40 (90) of this embodiment, the heating means 80 has the heat storage part 81 arrange | positioned around the heat exchanger 52, and the heat collecting part 82 which collects solar heat in the heat storage part 81. It is preferable to become.

  According to the cooling device 40 (90), it is possible to prevent the cooling water in the heat transfer pipe 52C of the heat exchanger 52 that forms a circulation path by heating the cooling water and freezes in winter.

1 Nuclear equipment 40 Cooling device 41 Control unit 42 Inflow pipe (circulation piping)
44 Outflow pipe (circulation pipe)
46, 48 On-off valve 49 Pump 50 Air cooler 51 Blower 52 Heat exchanger 60 Heating means 61 Detour circulation piping 62, 63 On-off valve 64 Check valve 65 Heat insulating material 70 Heating means 71 Heat pipe 80 Heating means 81 Heat storage part 82 Collection Heating section 90 Cooling device 91 Control section 92 Inflow pipe (circulation piping)
94 Outflow pipe (circulation pipe)
96, 48 On-off valve 99 Pump

Claims (9)

A circulation pipe for circulating cooling water that performs heat exchange using heat generated in a nuclear reactor of a nuclear facility;
A heat exchanger provided in the circulation pipe to obtain heat of the cooling water of the circulation pipe by heat exchange;
Heating means for transferring heat obtained from natural heat energy to the heat exchanger;
A cooling device comprising:   The heating means includes a bypass circulation pipe for bypassing the circulation pipe and circulating the cooling water including the heat exchanger, and a part of the bypass circulation pipe is embedded in the ground. The cooling device according to claim 1, wherein   The heating means includes a bypass circulation pipe for bypassing the circulation pipe and circulating the cooling water including the heat exchanger, and a part of the bypass circulation pipe is embedded in water. The cooling device according to claim 1.   4. The cooling device according to claim 2, wherein a check valve that allows the cooling water to flow only in one direction is provided on at least one end of the bypass circulation pipe connected to the circulation pipe. 5. .   The cooling device according to claim 2 or 3, wherein a heat insulating material is provided on an outer periphery on one end side where the bypass circulation pipe is connected to the circulation pipe.   An opening / closing valve is provided for each of the circulation piping and the bypass circulation piping, and the opening / closing valve of the circulation piping is closed and the opening / closing valve of the bypass circulation piping is opened during normal operation of the nuclear power facility. 6. The cooling according to claim 2, further comprising a control unit that opens the open / close valve of the circulation pipe and closes the open / close valve of the bypass circulation pipe when the abnormality occurs. apparatus.   2. The heating means according to claim 1, wherein a heat pipe in which a heat medium is sealed inside a hollow cylinder is brought into contact with the heat exchanger, and a part of the heat pipe is embedded in the ground. The cooling device as described.   The said heating means makes the heat pipe with which the heat medium was enclosed inside the hollow cylinder contact the said heat exchanger, and a part of the said heat pipe is embed | buried underwater. Cooling system.   The cooling device according to claim 1, wherein the heating unit includes a heat storage unit arranged around the heat exchanger and a heat collection unit that collects solar heat in the heat storage unit.

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