Apparatus for testing performance of containment vessel cooling system of small modular reactor, and testing method using same

Abstract

The present invention relates to an apparatus for testing the performance of a containment vessel cooling system of a small modular reactor, and a testing method using same. The apparatus for testing the performance of a containment vessel cooling system of a small modular reactor, according to the present invention, comprises: a simulated containment vessel, which is elongated in the vertical direction so as to form an inner space; a heat exchange part positioned in the inner space; a cooling water tank which is positioned outside the simulated containment vessel, and which supplies cooling water to the heat exchange part and collects same therein; and a steam supply part for supplying steam to the inner space, wherein the heat exchange part includes: a first heat exchanger in which heat exchange is performed in a single tube extending in the vertical direction; and a second heat exchanger which is positioned between an upper header and a lower header, and in which heat exchange is performed in a plurality of tubes extending in the vertical direction.

Description

Device for testing the performance of a containment cooling system of a small modular reactor and a method for testing using the same

[0001] The present invention relates to an apparatus for testing the performance of a containment vessel cooling system of a small modular reactor and an experimental method using the same.

[0002] Conducting thermohydraulic experiments is essential for evaluating the performance of safety systems and verifying the safety of Small Modular Reactors (SMRs).

[0003] Therefore, in the development of small modular reactors, it is necessary to construct a passive containment cooling system performance test facility and verify the performance and safety of the passive containment cooling system by securing various experimental data.

[0004] Therefore, the objective of the present invention is to provide an apparatus for testing the performance of a containment vessel cooling system of a small modular reactor and an experimental method using the same.

[0005] The objective of the present invention is achieved by an apparatus for testing the performance of a containment vessel cooling system of a small modular reactor, comprising: a simulated containment vessel that is vertically extended and forms an internal space; a heat exchanger located in the internal space; a cooling water tank located outside the simulated containment vessel and supplying and recovering cooling water to the heat exchanger; and a steam supply unit that supplies steam to the internal space; wherein the heat exchanger comprises: a first heat exchanger in which heat exchange is performed in a single tube extended in the vertical direction; and a second heat exchanger located between an upper header and a lower header in which heat exchange is performed in a plurality of tubes extended in the vertical direction.

[0006] It may further include a first pressure regulating unit located in the cooling space and positioned between the cooling water tank and the first heat exchanger, which lowers the pressure of the cooling water supplied to the first heat exchanger; and a second pressure regulating unit located between the cooling water tank and the second heat exchanger, which lowers the pressure of the cooling water supplied to the second heat exchanger.

[0007] The first pressure regulating unit and the second pressure regulating unit may each include an orifice flow meter.

[0008] The first heat exchanger and the second heat exchanger may be spaced apart in the vertical direction.

[0009] In the above-described simulated containment vessel, an inlet is formed through which steam from the steam supply unit is supplied into the internal space, and the inlet may include a first inlet located at the upper part of the heat exchange unit; and a second inlet located at the lower part of the heat exchanger.

[0010] The objective of the present invention is achieved by a method for testing the performance of a containment cooling system of a small modular reactor, comprising the steps of: providing a performance testing device, wherein the performance testing device comprises: a simulated containment vessel that is vertically extended and forms an internal space; a heat exchanger located in the internal space; a cooling water tank located outside the simulated containment vessel that supplies and recovers cooling water to the heat exchanger; and a steam supply unit that supplies steam to the internal space; wherein the heat exchanger comprises: a first heat exchanger in which heat exchange is performed in a single tube extended in the vertical direction; and a second heat exchanger in which heat exchange is performed in a plurality of tubes extended in the vertical direction; setting the pressure and temperature of the internal space; supplying cooling water to the heat exchanger; and measuring the internal and external temperatures of the tubes while cooling the internal space through the heat exchanger while supplying steam to the internal space.

[0011] In the step of supplying cooling water to the heat exchanger, if the cooling water is naturally circulated, the cooling water can be supplied to the first heat exchanger, and if the cooling water is forcibly circulated, the cooling water can be supplied to the second heat exchanger.

[0012] When supplying cooling water to the first heat exchanger, the water level of the cooling water tank may be lower than the water level of the cooling water tank when supplying cooling water to the second heat exchanger.

[0013] Steam may be supplied at a position lower than the first heat exchanger when supplying cooling water to the first heat exchanger, and at a position higher than the second heat exchanger when supplying cooling water to the second heat exchanger.

[0014] The cooling water supplied to the above heat exchanger can be supplied with a pressure drop through an orifice flow meter.

[0015] The above steam supply can be terminated when the change in the water level of the cooling water located at the bottom of the above-mentioned simulated containment vessel is below a certain level for a certain period of time.

[0016] According to the present invention, an apparatus for testing the performance of a containment vessel cooling system of a small modular reactor and an experimental method using the same are provided.

[0017] FIG. 1 is a schematic diagram of an experimental apparatus according to an embodiment of the present invention, and

[0018] FIG. 2 shows a first heat exchanger in an experimental apparatus according to an embodiment of the present invention, and

[0019] FIG. 3 shows a second heat exchanger in an experimental apparatus according to an embodiment of the present invention, and

[0020] FIG. 4 is an enlarged view of an important part of an experimental apparatus according to an embodiment of the present invention, and

[0021] FIG. 5 is a flowchart of an experimental method according to an embodiment of the present invention.

[0022] Hereinafter, various embodiments of the present invention will be described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. The present invention may be embodied in various different forms and is not limited to the embodiments described herein.

[0023] To clearly explain the present invention, parts unrelated to the explanation have been omitted, and the same reference numerals are used for identical or similar components throughout the specification.

[0024] In addition, the size and thickness of each component shown in the drawings are depicted arbitrarily for convenience of explanation, so the present invention is not necessarily limited to what is illustrated.

[0025] SMRs currently under development aim to ensure safety by applying passive safety systems. Therefore, to verify the design feasibility following the introduction of passive safety systems, it is necessary to understand the major physical phenomena that may occur in the system and to establish an experimental apparatus to demonstrate the natural circulation cooling performance of the SMR passive safety system. Through the experimental setup and experiments according to the present invention, the design feasibility and safety of the SMR passive safety system can be verified. Furthermore, objective technical capabilities regarding the heat removal performance and natural circulation cooling performance of the SMR passive containment cooling system can be demonstrated.

[0026] With reference to FIGS. 1 to 4, an experimental apparatus according to one embodiment of the present invention will be described.

[0027] FIG. 1 is a schematic diagram of an experimental apparatus according to an embodiment of the present invention, FIG. 2 shows a first heat exchanger in an experimental apparatus according to an embodiment of the present invention, FIG. 3 shows a second heat exchanger in an experimental apparatus according to an embodiment of the present invention, and FIG. 4 is an enlarged view of an important part in an experimental apparatus according to an embodiment of the present invention.

[0028] As shown in FIG. 1, the experimental apparatus (1) includes a simulated containment vessel (10), a heat exchanger (20), a cooling water tank (30), a steam generator (40), and a heating unit (50).

[0029] The simulated containment vessel (10) is a model of the containment vessel of an SMR, is provided in a reduced size, and is extended vertically. The simulated containment vessel (10) forms an internal space inside.

[0030] The heat exchanger (20) is modeled after a vertical tube heat exchanger module (PCCHX, Passive Containment Cooling Heat exchanger), is located in the internal space, and performs the function of cooling steam generated in the internal space.

[0031] The cooling water tank (30) accommodates cooling water and is located outside the simulated containment vessel (10). The cooling water tank (30) may be located above the heat exchanger (20).

[0032] The cooling water of the cooling water tank (30) is supplied to the heat exchanger (20) through the supply pipe (61, see FIG. 4), and the cooling water heated through heat exchange in the heat exchanger (20) is returned to the cooling water tank (30) through the return pipe (62, see FIG. 4).

[0033] The steam generator (40) is located outside the simulated containment vessel (10) and generates steam. The steam (saturated steam) generated from the steam generator (40) is supplied into the internal space through a first inlet (111) located at the top of the heat exchanger (20) or a second inlet (112) located at the bottom of the heat exchanger (20).

[0034] The steam generator (40) is intended to provide steam that is released from the reactor into the containment vessel in the event of an accident.

[0035] The heating unit (50) is located at the bottom of the reaction space and is used to raise the temperature of the internal space.

[0036] Although not shown, the experimental device (1) may further include support configurations for each piece of equipment, equipment for fluid flow such as pipes / pumps, and sensors (thermometers, pressure gauges, flow meters, water level gauges), etc.

[0037] The heat exchanger (20) is composed of a first heat exchanger (210) and a second heat exchanger (220).

[0038] As illustrated in FIG. 2, the first heat exchanger (210) includes a first tube (211, straight tube section) arranged in a vertical direction. The first tube (211) may be located at the center of the horizontal cross-section of the internal space. The first tube (211) is where heat exchange takes place in the first heat exchanger (210) and is provided as a single unit. Except for the first tube (211) in the first heat exchanger (210), the first heat exchanger (210) may be insulated.

[0039] As illustrated in FIG. 3, the second heat exchanger (220) includes a second tube (221), a lower header (222), and an upper header (223). The second tube (221) is a portion where heat exchange takes place in the second heat exchanger (220) and is provided in multiple (bundles), but is not limited thereto, and can be provided in a 4 by 4 configuration.

[0040] The lower end of each second tube (221) is connected to the lower header (222), and the upper end is connected to the upper header (223). The lower header (222) is connected to the supply pipe (61), and the upper header (223) is connected to the recovery pipe (62).

[0041] As shown in FIG. 4, the first heat exchanger (210) and the second heat exchanger (220) are arranged vertically along the longitudinal direction of the simulated containment vessel (10).

[0042] The cooling water supplied from the supply pipe (61) is supplied to the first heat exchanger (210) and the second heat exchanger (220) via an orifice flow meter (pressure regulating part, 63, 64).

[0043] The role of the orifice flow meter (63, 64) is explained as follows.

[0044] In actual SMRs, pressure drop occurs for the following reasons.

[0045] 1) When a fluid (e.g., water) flows through a pipe, energy is consumed, which causes a pressure drop. In other words, the fluid moves due to this pressure drop.

[0046] 2) The main factors causing pressure drop are diverse, including friction within the fluid itself, friction between the fluid and the pipe wall, pipe shape and length, fluid characteristics (viscosity, density, etc.), fluid velocity, etc.

[0047] 3) In the device of the present invention, the cooling water tank is installed at a relatively high position, so that when the experiment starts, a pressure drop occurs due to the influence of gravity, causing water to start flowing. The water heated by heat transfer in the heat exchanger creates a difference in temperature and density compared to the cold water in the cooling water tank, allowing it to flow with a natural circulation driving force.

[0048] In such a situation, an orifice flow meter is installed with the following considerations.

[0049] 1) Calculation of pressure drop occurring in the natural circulation piping of the experimental apparatus

[0050] 2) Verify by comparing with the pressure drop under flow rate conditions in the simulated SMR.

[0051] 3) Install an orifice flowmeter in the experimental apparatus to preserve the same pressure drop as the simulated SMR.

[0052] 4) Since the experimental apparatus is smaller in scale compared to the target SMR, the pressure drop is small. Therefore, an orifice flowmeter was installed to preserve the pressure drop to be the same as that of the target SMR.

[0053] The recovery pipe (62) can be supplied to a high position (A) and / or a low position (B) of the cooling water tank (30).

[0054] The valve, pump, and piping, etc., shown in FIG. 4 are omitted from the description. The piping, etc., may be insulated or have tracing heaters installed to minimize heat loss.

[0055] An experimental method according to an embodiment of the present invention will be described below with reference to FIG. 5.

[0056] First, the initial state is set (S10).

[0057] The initial state may include the temperature and pressure of the internal space. Among these, the pressure of the internal space may be a vacuum, but is not limited thereto. Additionally, the setting of the initial state may include filling the lower part of the internal space with a certain level of cooling water.

[0058] Next, it is determined whether to use a pump (S20). The pump is for cooling water circulation, and depending on whether the pump is used, a natural circulation experiment or a forced circulation experiment is selected.

[0059] If a forced circulation experiment is to be conducted using a pump, the water level of the cooling water tank (30) can be raised (e.g., 8 m, S31), and if a natural circulation experiment is to be conducted without using a pump, the water level of the cooling water tank (30) can be lowered (e.g., 4 m, or 30 to 70% of the water level of the forced circulation experiment, S32).

[0060] Forced circulation experiments are conducted to select boundary conditions for evaluating the heat removal performance of the passive containment cooling system heat exchanger (PCCHx) through natural circulation, and natural circulation experiments are conducted to verify cooling performance via natural circulation in the event of an accident.

[0061] Next, select the heat exchanger (210, 220) to be tested.

[0062] When a first heat exchanger (210) composed of a single tube is selected, steam is injected (S51) through a second inlet (112) lower than the first heat exchanger (210), and when a second heat exchanger (220) composed of bundle tubes is selected, steam is injected (S52) through a first inlet (111) higher than the second heat exchanger (220).

[0063] The experiment using the first heat exchanger (210) is intended to verify the cooling capacity of the heat exchanger inside the simulated containment vessel. The heating unit (50) is operated, and when the target temperature inside the containment vessel is reached, the heating unit (50) is turned off and steam is injected.

[0064] The experiment using the second heat exchanger (220) is intended to verify the natural circulation performance according to the arrangement of the tube assembly heat exchanger and does not use the heating unit (50).

[0065] When steam is injected, heat exchange takes place in the first heat exchanger (210) or the second heat exchanger (220), the steam condenses and collects at the bottom of the lower space, and the cooling water circulates.

[0066] In this process, the internal and external temperatures of the tubes (211, 221) can be measured, and the temperature of other parts of the internal space and changes in pressure within the internal space can also be measured. For example, measurement variables such as the lower coolant level inside the simulated containment vessel (10), the internal temperature / pressure of the simulated containment vessel (10), the internal and external wall temperatures of the heat exchanger (20), the internal coolant temperature, pressure and flow rate of the heat exchanger (20), and the internal coolant temperature of the coolant tank (30) can be monitored.

[0067] The experiment may be terminated if there is no change in the water level of the cooling water at the bottom of the receiving space. Here, no change in water level means that the change in water level is below a certain level (e.g., less than 5%, less than 1%, less than 10 cm, less than 5 cm, or less than 1 cm, etc.) for a certain period of time (e.g., minutes or tens of minutes).

[0068] Subsequently, the performance of the cooling system is verified by analyzing the measured temperature and / or pressure results.

[0069] The aforementioned embodiments are examples for explaining the present invention, and the present invention is not limited thereto. Since a person skilled in the art to which the present invention pertains can implement the present invention by making various modifications therefrom, the technical scope of protection of the present invention should be determined by the appended claims.

Claims

1. In a device for testing the performance of a containment vessel cooling system of a small modular reactor, A simulated containment vessel that is extended vertically and forms an internal space; A heat exchanger located in the above internal space; A cooling water tank located outside the above-mentioned simulated containment vessel and supplying and recovering cooling water to the heat exchanger; and It includes a steam supply unit that supplies steam to the internal space; and The above heat exchanger is, A first heat exchanger in which heat exchange is performed in a single tube extended in the vertical direction; and A device comprising a second heat exchanger located between an upper header and a lower header, wherein heat exchange takes place in a plurality of tubes extending in a vertical direction.

2. In Paragraph 1, Located in the above cooling space, A first pressure regulating unit located between the cooling water tank and the first heat exchanger, which lowers the pressure of the cooling water supplied to the first heat exchanger; and A device further comprising a second pressure regulating unit located between the cooling water tank and the second heat exchanger, which lowers the pressure of the cooling water supplied to the second heat exchanger.

3. In Paragraph 2, The first pressure regulating unit and the second pressure regulating unit each comprise an orifice flow meter.

4. In Paragraph 3, The above first heat exchanger and the above second exchanger are devices arranged spaced apart in the vertical direction.

5. In Paragraph 3, In the above-mentioned simulated containment vessel, an inlet is formed through which steam from the steam supply unit is supplied into the internal space, and The above injection port is, A first inlet located at the top of the heat exchanger; and A device including a second inlet located at the bottom of the heat exchanger.

6. A method for testing the performance of a containment vessel cooling system of a small modular reactor, Step of preparing a performance testing device, Here, the above performance test device is, A simulated containment vessel that is extended vertically and forms an internal space; A heat exchanger located in the above internal space; A cooling water tank located outside the above-mentioned simulated containment vessel and supplying and recovering cooling water to the heat exchanger; and It includes a steam supply unit that supplies steam to the internal space; and The above heat exchanger is, A first heat exchanger in which heat exchange is performed in a single tube extended in the vertical direction; and It includes a second heat exchanger in which heat exchange takes place in a plurality of tubes extended in the vertical direction; Step of setting the pressure and temperature of the internal space; A step of supplying cooling water to the heat exchanger; and A method comprising the step of measuring the internal and external temperatures of the tube while supplying steam to the internal space of the device and cooling the internal space through the heat exchanger.

7. In Paragraph 6, In the step of supplying cooling water to the heat exchanger, When the cooling water is naturally circulated, the cooling water is supplied to the first heat exchanger, and A method of airing the cooling water into the second heat exchanger by forcibly circulating the cooling water.

8. In Paragraph 7, A method in which the water level of the cooling water tank when supplying cooling water to the first heat exchanger is lower than the water level of the cooling water tank when supplying cooling water to the second heat exchanger.

9. In Paragraph 7, Steam is, When supplying cooling water to the first heat exchanger, it is supplied at a position lower than the first exchanger, and A method in which cooling water is supplied to the second heat exchanger at a position higher than the second heat exchanger.

10. In Paragraph 7, A method in which the cooling water supplied to the heat exchanger is supplied by pressure drop through an orifice flow meter.

11. In Paragraph 7, The above steam supply is, A method for terminating when the change in the water level of the cooling water located at the bottom of the above-mentioned simulated containment vessel is below a certain level for a certain period of time.

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