Reactor core heat exchange test device

Abstract

The invention discloses a reactor core heat exchange test device, which comprises a test body, the test body comprises an internal component and an external component, the internal component comprises a flow channel and a reactor core rod bundle, the reactor core rod bundle is arranged in the flow channel and extends along the extension direction of the flow channel, the reactor core rod bundle is a heating rod, and the external component is arranged in the flow channel and extends along the extension direction of the flow channel. The external component comprises an upper shell, a reactor core shell and a lower shell which are connected in sequence, the upper shell is provided with an upper cavity, the lower shell is provided with a lower cavity, an inner cavity of the reactor core shell is communicated with the upper cavity and the lower cavity, the reactor core shell is arranged on the flow channel in a sleeving manner, and the inner cavity of the reactor core shell is communicated with the upper cavity and the lower cavity. And the upper end of the reactor core rod bundle extends out of the upper chamber so as to be connected with a power supply. The reactor core heat exchange test device provided by the embodiment of the invention is high in structural strength and high in test precision, and can reproduce the geometric structure of the pressurized water reactor core to the greatest extent, and the obtained test data is closer to the real condition of the reactor core under the condition of a prototype power station accident.

Description

Technical Field

[0001] The invention relates to the technical field of nuclear power plants, and in particular to a reactor core heat exchange test device. Background Art

[0002] With the development of nuclear power, higher requirements are put forward for the thermal hydraulic and structural optimization design of nuclear reactor core. Fuel assembly is the main component of reactor core. Fuel assembly includes fuel rods and spacer grids. Fuel rods are usually arranged in a square rod bundle structure. Spacer grids are arranged at different positions in the axial direction of the rod bundle structure to position the fuel rods. Coolant flows through the rod bundle area to cool the fuel rods and take away the decay heat.

[0003] The flow channel of the rod cluster channel is geometrically complex, and heat and mass transfer can occur between the rod cluster sub-channels through the rod gaps. Therefore, the flow and heat transfer characteristics of the coolant in the rod cluster channel are more complex than those in a simple channel. In addition, due to the presence of the grid, the flow field downstream of the grid of the rod cluster channel is prone to strong mixing, thereby enhancing the heat transfer downstream of the grid, resulting in more complex flow and heat transfer characteristics of the rod cluster channel.

[0004] The thermal hydraulic performance of the rod bundle channel directly affects the safety, reliability and economy of the nuclear power plant. Although the pressurized water reactor is a single-phase flow under normal operating conditions, a certain degree of boiling is usually allowed when the heat output power is increased. In addition, boiling may also occur in other accidents such as loss of coolant in the pressurized water reactor. How to ensure that the temperature of the fuel cladding is still below the safety limit even in the event of a rupture loss of coolant in the main coolant system is one of the main tasks of the thermal hydraulic safety design of the reactor. Therefore, it is necessary to study the core heat transfer performance under accidents, so as to support design improvements and verification of safety analysis software. However, such research is difficult to carry out on prototype reactors, which makes it difficult to conduct experiments on the core heat transfer performance under accidents. Summary of the invention

[0005] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0006] To this end, an embodiment of the present invention provides a reactor core heat exchange test device.

[0007] The reactor core heat exchange test device according to the embodiment of the present invention comprises a test body, wherein the test body comprises:

[0008] An internal component, the internal component comprising a flow channel and a core rod bundle, the core rod bundle is arranged in the flow channel and extends along an extension direction of the flow channel, and the core rod bundle is a heating rod;

[0009] An external component, the external component includes an upper shell, a core shell and a lower shell connected in sequence, the upper shell has an upper chamber, the lower shell has a lower chamber, the inner cavity of the core shell is connected to the upper chamber and the lower chamber, the core shell is sleeved on the flow channel, and the upper end of the core rod bundle extends out of the upper chamber for connection to a power source.

[0010] The reactor core heat exchange test device of the embodiment of the present invention improves the compressive strength of the test body by arranging a core shell outside the flow channel to form a double-layer structure. The core rod bundle is an electric heating rod. The upper end of the core rod bundle is connected to a power supply to heat the core rod bundle, thereby ensuring that the test data is close to the actual test data of the prototype nuclear power plant and improving the accuracy of the test. Moreover, the electric heating rod is easy to obtain and easy to operate. In addition, the structure of the test body is simple, which reduces the test cost.

[0011] In some embodiments, the test body further includes a pressure balance tube, one end of which is disposed on the core shell and communicated with the upper chamber, and the other end of which extends in a direction away from the core shell.

[0012] In some embodiments, the test body also includes a sleeve, a pressure-supply tube and a ferrule, wherein the sleeve is disposed on the core shell and is connected to the inner cavity of the core shell, one end of the pressure-supply tube is connected to the flow channel, and the other end of the pressure-supply tube extends from the sleeve, and the ferrule is disposed on the sleeve, and the ferrule seals and connects the sleeve and the pressure-supply tube.

[0013] In some embodiments, the test body further includes a clamp, and the clamp is sleeved on the flow channel.

[0014] In some embodiments, there are a plurality of clamps, and the plurality of clamps are arranged at intervals along the axial direction of the flow channel.

[0015] In some embodiments, the test body further includes a support member, the support member is disposed between two adjacent clamps and connected to the clamps, and the support member is in an arc shape convex away from the flow channel.

[0016] In some embodiments, the upper shell further has a gas-liquid mixture inlet, a supercooled water inlet and a gas-liquid mixture outlet communicated with the upper chamber, and the gas-liquid mixture inlet is arranged opposite to the gas-liquid mixture outlet.

[0017] In some embodiments, the test body further includes a water distributor and a support plate, wherein the water distributor is disposed in the upper chamber, and the support plate is disposed at the lower end of the flow channel and supports the lower end of the core rod bundle.

[0018] In some embodiments, the lower shell also has a lower pipe opening and a thermocouple penetration piece connected to the lower chamber, the lower pipe opening is used to discharge the gas-liquid mixture or inject cooling water, and the thermocouple penetration piece is used to penetrate a thermocouple wire bundle for measuring the wall temperature of the flow channel.

[0019] In some embodiments, the reactor core heat exchange test device also includes a test bench, an upper tower hoop and a lower tower hoop, the upper tower hoop is arranged at the upper end of the test body to connect the upper end of the test body with the test bench, and the lower tower hoop is detachably arranged at the lower end of the test body to connect the lower end of the test body with the test bench. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is an overall schematic diagram of a reactor core heat exchange test device according to an embodiment of the present invention.

[0021] Figure 2 It is a schematic diagram of a partial structure of a reactor core heat exchange test device according to an embodiment of the present invention.

[0022] Figure 3 yes Figure 2 Enlarged schematic diagram of part A.

[0023] Figure 4 It is a cross-sectional view of the upper structure of the reactor core heat exchange test device according to an embodiment of the present invention.

[0024] Figure 5 It is a cross-sectional view of the lower structure of the reactor core heat exchange test device according to an embodiment of the present invention.

[0025] Figure numerals: 100, test body; 200, upper tower hoop; 300, lower tower hoop; 1, internal component; 11, flow channel; 12, core rod bundle; 2, external component; 21, upper shell; 211, upper chamber; 212, gas-liquid mixture inlet; 213, subcooled water inlet; 214, gas-liquid mixture outlet; 215, upper flange cover; 22, core shell; 23, lower shell; 231, lower chamber; 232, lower pipe mouth; 233, thermocouple penetration; 234, lower flange cover; 3, pressure balance pipe; 41, casing; 42, pressure lead pipe; 5, ferrule; 6, clamp; 7, support; 8, water distributor; 9, support plate. DETAILED DESCRIPTION

[0026] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0027] like Figure 1-5As shown, the reactor core heat exchange test device of the embodiment of the present invention includes a test body 100, and the test body 100 includes an internal component 1 and an external component 2. The internal component 1 includes a flow channel 11 and a core rod bundle 12. The core rod bundle 12 is arranged in the flow channel 11 and extends along the extension direction of the flow channel 11. The upper end of the core rod bundle 12 extends from the upper end of the flow channel 11. The core rod bundle 12 is a heating rod, preferably an electric heating rod, to simulate the reactor core, and the length of the heating section of the electric heating rod is consistent with the length of the real core heating section. A large number of thermocouple rods are arranged on the wall surface of the core rod bundle 12 to monitor the wall temperature and provide data for the core heat exchange research. Specifically, the cross-sectional area of ​​the flow channel 11 is square.

[0028] The external component 2 includes an upper shell 21, a core shell 22, and a lower shell 23 connected in sequence. The upper shell 21 has an upper chamber 211, the lower shell 23 has a lower chamber 231, the inner cavity of the core shell 22 is connected to the upper chamber 211 and the lower chamber 231, the core shell 22 is sleeved on the flow channel 11, and the upper end of the core rod bundle 12 extends out of the upper chamber 211 so as to be connected to the power supply externally. Specifically, the upper end of the core rod bundle 12 is connected to a DC power supply.

[0029] The reactor core heat exchange test device of the embodiment of the present invention improves the pressure resistance of the test body 100 by arranging the core shell 22 outside the flow channel 11 to form a double-layer structure. The core rod bundle 12 is an electric heating rod, and the upper end of the core rod bundle 12 is connected to a power supply to heat the core rod bundle 12, so as to ensure that the test data is close to the actual test data of the prototype nuclear power plant, improve the accuracy of the test, and the electric heating rod is easy to obtain and easy to operate. In addition, the structure of the test body 100 is simple, which reduces the test cost.

[0030] Specifically, the flow channel 11 is formed by splicing four stainless steel plates, three of which are welded first, and the last stainless steel plate is connected by screws. A sealing gasket (not shown) is arranged on the inner wall surface of the flow channel 11. Preferably, the sealing gasket is a high-temperature resistant sealing gasket made of SF300 material to improve the sealing performance and prevent the liquid in the flow channel 11 from leaking into the annular cavity between the flow channel 11 and the core shell 22.

[0031] Specifically, the test body 100 further includes a grid (not shown), and the grid uses a positioning grid consistent with a typical grid element of the prototype grid to position the core rod bundle 12. The grid is sleeved on the core rod bundle 12 to limit the core rod bundle 12 and ensure the stability of the structure of the core rod bundle 12. There is at least one grid, and at least one grid is arranged at intervals along the extension direction of the core rod bundle 12.

[0032] In some embodiments, the test body 100 further includes a pressure balance tube 3 , one end of which is disposed on the core shell 22 and communicates with the upper chamber 211 , and the other end of the pressure balance tube 3 extends in a direction away from the core shell 22 .

[0033] Specifically, the pressure balance pipe 3 is located at the upper end of the core shell 22 and is connected to the upper chamber 211 through an external pipeline to eliminate the pressure difference between the flow channel 11 and the core shell 22, thereby preventing the flow channel 11, which is designed to be non-pressurized, from being damaged by excessive pressure difference.

[0034] In some embodiments, the test body 100 further includes a sleeve 41, a pressure tube 42 and a ferrule 5. The sleeve 41 is disposed on the core shell 22 and communicates with the inner cavity of the core shell 22. One end of the pressure tube 42 is connected to the flow channel 11, and the other end of the pressure tube 42 extends from the sleeve 41. The pressure tube 42 is used to measure the pressure and pressure difference in the flow channel 11. The ferrule 5 is disposed on the sleeve 41, and the ferrule 5 seals and connects the sleeve 41 and the pressure tube 42.

[0035] Specifically, there are multiple sleeves 41, which are arranged at intervals along the axial direction of the core shell 22. There are multiple pressure-inducing pipes 42, which are arranged at intervals along the axial direction of the flow channel 11, and the multiple pressure-inducing pipes 42 correspond to the multiple sleeves 41 one by one, and the sleeves 41 are used to lead out the pressure-inducing pipes 42 provided on the flow channel 11. There are also multiple ferrules 5, which correspond to the multiple sleeves 41 one by one to ensure the sealing between the pressure-inducing pipes 42 and the sleeves 41.

[0036] In some embodiments, the test body 100 further includes a clamp 6, which is sleeved on the flow channel 11. Specifically, the flow channel 11 is designed to be long and thin, and the clamp 6 is sleeved on the flow channel 11 to increase the structural strength of the flow channel 11 and prevent the flow channel 11 from deforming during the hoisting process.

[0037] In some embodiments, there are multiple clamps 6, and the multiple clamps 6 are arranged at intervals along the axial direction of the flow channel 11, which further increases the structural strength of the flow channel 11 and ensures the structural stability of the flow channel 11 during movement.

[0038] In some embodiments, the test body 100 further includes a support member 7 , which is disposed between two adjacent clamps 6 and connected to the clamps 6 , and the support member 7 is in an arc shape convex away from the flow channel 11 .

[0039] Specifically, there are multiple support members 7, and the multiple support members 7 are divided into multiple groups. The multiple groups of support members 7 are arranged at intervals along the axial direction of the flow channel 11. Each group includes multiple support members 7, and the multiple support members 7 in each group are arranged at intervals along the circumferential direction of the flow channel 11. One end of the support member 7 is connected to one of the clamps 6, and the other end of the support member 7 is connected to another adjacent clamp 6. The convex arc surface of the support member 7 contacts the inner wall surface of the core shell 22 to prevent the flow channel 11 from horizontal displacement in the inner cavity of the core shell 22, ensure the stability of the installation of the flow channel 11, and also avoid the flow channel 11 from colliding with the inner wall surface of the core shell 22, ensuring the stability of the structure of the flow channel 11.

[0040] In some embodiments, the upper shell 21 also has a gas-liquid mixture inlet 212, a supercooled water inlet 213 and a gas-liquid mixture outlet 214 connected to the upper chamber 211, which are used for the inflow and outflow of the working medium in different test stages, wherein the gas-liquid mixture inlet 212 and the gas-liquid mixture outlet 214 are arranged opposite to each other.

[0041] Specifically, an upper flange cover 215 is connected to the top of the upper shell 21 for sealing. The upper end of the core rod bundle 12 extends through the upper flange cover 215, and the core rod bundle 12 and the upper flange cover 215 are sealed by graphite compression. In order to increase the sealing space and ensure the strength of the upper flange cover 215, the core rod bundle 12 has a larger rod spacing in the upper chamber 211.

[0042] In some embodiments, the test body 100 further includes a water distributor 8 and a support plate 9. The water distributor 8 is disposed in the upper chamber 211 so that the fluid entering the upper chamber 211 can be evenly distributed in the upper chamber 211. The support plate 9 is disposed at the lower end of the flow channel 11 and supports the lower end of the core rod bundle 12.

[0043] In some embodiments, the lower shell 23 also has a lower nozzle 232 and a thermocouple penetration 233 that are connected to the lower chamber 231. The lower nozzle 232 is used to discharge the gas-liquid mixture or inject cooling water. The thermocouple penetration 233 is arranged on the bottom surface of the lower shell 23 and is connected to the lower chamber 231. The thermocouple penetration 233 is used to penetrate a thermocouple wire bundle for measuring the wall temperature of the flow channel 11.

[0044] Specifically, the lower shell 23 and the lower end of the flow channel 11 are sealed and connected through the lower flange cover 234. The support plate 9 is arranged between the top of the lower shell 23 and the lower end of the flow channel 11 to support the lower end of the core rod bundle 12 in the flow channel 11. The lower nozzle 232 is arranged on the bottom surface of the lower shell 23, which can be used as an outlet for the gas-liquid mixture in the blowdown or refilling test or as an injection port for cooling water in the reflooding test.

[0045] It can be understood that the reactor core heat exchange test device of the embodiment of the present invention is provided with a variety of injection nozzles and measuring instruments, so that the test device can study the core heat exchange phenomenon in various stages of large break accidents such as high, medium and low pressure blowdown, refilling, reflooding and long-term cooling, and has complete functions.

[0046] In some embodiments, the reactor core heat exchange test device further includes a test bench (not shown), an upper tower hoop 200 and a lower tower hoop 300. The upper tower hoop 200 is welded to the upper end of the test body 100 to connect the upper end of the test body 100 with the test bench. The lower tower hoop 300 is detachably connected to the lower end of the test body 100 to connect the lower end of the test body 100 with the test bench. The lower tower hoop 300 can limit the displacement of the test body 100 in the horizontal direction without limiting its displacement in the vertical direction, which can effectively prevent the test body 100 from being subjected to excessive stress due to thermal expansion and contraction during the heating and cooling process, thereby improving the safety of the test device.

[0047] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0048] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0049] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0050] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0051] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0052] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A reactor core heat exchange test device, characterized in that: The invention comprises a test body (100), wherein the test body (100) comprises: An internal component (1), the internal component (1) comprising a flow channel (11) and a core rod bundle (12), the core rod bundle (12) being arranged in the flow channel (11) and extending along an extension direction of the flow channel (11), the core rod bundle (12) being a heating rod; An external component (2), the external component (2) comprising an upper shell (21), a core shell (22) and a lower shell (23) connected in sequence, the upper shell (21) having an upper chamber (211), the lower shell (23) having a lower chamber (231), the inner cavity of the core shell (22) being connected to the upper chamber (211) and the lower chamber (231), the core shell (22) being sleeved on the flow channel (11), and the upper end of the core rod bundle (12) extending out of the upper chamber (211) for connection to a power source.

2. The reactor core heat exchange test device according to claim 1, characterized in that: The test body (100) further comprises a pressure balance tube (3), one end of which is arranged on the core shell (22) and communicates with the upper chamber (211), and the other end of which extends in a direction away from the core shell (22).

3. The reactor core heat exchange test device according to claim 1, characterized in that: The test body (100) also includes a sleeve (41), a pressure-supply tube (42) and a ferrule (5); the sleeve (41) is arranged on the core shell (22) and is connected to the inner cavity of the core shell (22); one end of the pressure-supply tube (42) is connected to the flow channel (11); the other end of the pressure-supply tube (42) extends from the sleeve (41); the ferrule (5) is arranged on the sleeve (41); and the ferrule (5) seals and connects the sleeve (41) and the pressure-supply tube (42).

4. The reactor core heat exchange test device according to claim 3, characterized in that: The test body (100) further comprises a clamp (6), wherein the clamp (6) is sleeved on the flow channel (11).

5. The reactor core heat exchange test device according to claim 4, characterized in that: There are a plurality of clamps (6), and the plurality of clamps (6) are arranged at intervals along the axial direction of the flow channel (11).

6. The reactor core heat exchange test device according to claim 5, characterized in that: The test body (100) further comprises a support member (7), wherein the support member (7) is disposed between two adjacent clamps (6) and connected to the clamps (6), and the support member (7) is in an arc shape that bulges away from the flow channel (11).

7. The reactor core heat exchange test device according to claim 1, characterized in that: The upper shell (21) further comprises a gas-liquid mixture inlet (212), a supercooled water inlet (213) and a gas-liquid mixture outlet (214) which are connected to the upper chamber (211), and the gas-liquid mixture inlet (212) and the gas-liquid mixture outlet (214) are arranged opposite to each other.

8. The reactor core heat exchange test device according to claim 7, characterized in that: The test body (100) further comprises a water distributor (8) and a support plate (9), wherein the water distributor (8) is arranged in the upper chamber (211), and the support plate (9) is arranged at the lower end of the flow channel (11) and supports the lower end of the core rod bundle (12).

9. The reactor core heat exchange test device according to claim 1, characterized in that: The lower shell (23) also has a lower pipe opening (232) and a thermocouple penetration piece (233) that are in communication with the lower chamber (231); the lower pipe opening (232) is used to discharge a gas-liquid mixture or inject cooling water; the thermocouple penetration piece (233) is used to penetrate a thermocouple wire bundle (234) for measuring the wall temperature of the flow channel (11).

10. The reactor core heat exchange test device according to claim 1, characterized in that: The test bench also includes an upper tower hoop (200) and a lower tower hoop (300), wherein the upper tower hoop (200) is arranged at the upper end of the test body (100) to connect the upper end of the test body (100) with the test bench, and the lower tower hoop (300) is detachably arranged at the lower end of the test body (100) to connect the lower end of the test body (100) with the test bench.

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