A heated plate and a heat transfer simulation experiment device with the same

Abstract

The application relates to the technical field of reactor thermal hydraulic and safety, in particular to a heated plate and a heat transfer simulation experiment device with the same. The heated plate comprises a bubbling plate, a heating plate and an insulation layer; the bubbling plate is formed with grooves through a cast-pressing process; the heating plate is arranged in parallel and at intervals with the bubbling plate; the insulation layer is located between the bubbling plate and the heating plate, the insulation layer is connected with the heating plate, and the insulation layer is connected with the bubbling plate through vacuum diffusion welding to enclose the grooves on the bubbling plate into vacuum bubble-shaped parts. The application can accurately simulate the thermal power boundary when the dispersion type fuel element bubbles, realize the simulation and measurement of the flow heat transfer characteristics near the vacuum bubble-shaped parts, and the measurement result has high reduction degree and good reliability.

Description

Technical Field

[0001] This application relates to the fields of reactor thermal hydraulics and safety technology, specifically to a heat-receiving plate and a heat transfer simulation experimental device having the plate. Background Technology

[0002] Dispersed fuel elements exhibit bubbling during the heating process under high burnup conditions. Bubbling refers to the phenomenon where the fission gases generated by irradiation concentrate locally, causing plastic deformation of the fuel and resulting in bubbly protrusions on the element surface. Bubbling in dispersed fuel elements distorts the heat flow distribution and coolant channel geometry. These adverse conditions lead to completely different thermo-hydraulic characteristics within the channels compared to normal conditions, representing a key issue that needs to be addressed in the safety analysis of dispersed fuel elements.

[0003] Current research on the flow and heat transfer characteristics within narrow slit channels under bubbling conditions is limited, and most studies employ three-dimensional numerical simulations. The few similar experiments conducted are primarily for channel blockage conditions. Therefore, it is necessary to design an experimental setup for simulating the heat transfer characteristics of dispersed fuel element surfaces under bubbling conditions. This setup would facilitate the acquisition of flow and heat transfer characteristics near bubbling, including boiling two-phase heat transfer characteristics, providing technical support for the precise formulation of thermal-hydraulic design and safety criteria for dispersed fuel elements. Summary of the Invention

[0004] This application addresses the problems in the background art by providing a heat-receiving plate and a heat transfer simulation experimental device having the same.

[0005] This application is achieved through the following technical solution:

[0006] In a first aspect, this application provides a heat-receiving plate, comprising:

[0007] A foaming plate, wherein the foaming plate is formed with grooves by a casting process;

[0008] A heating plate, wherein the heating plate and the bubbling plate are arranged in parallel and spaced apart;

[0009] An insulating layer is located between the foaming plate and the heating plate. The insulating layer is connected to the heating plate and is connected to the foaming plate by vacuum diffusion welding to form a vacuum bubble-like part with the groove on the foaming plate.

[0010] The heated plate provided by the application is used in an experimental device for simulating the heat transfer characteristics of a dispersion type fuel element under a bubble condition on the surface of the dispersion type fuel element. Since the heated plate relies on electric heating to simulate the heating of the dispersion type fuel element, through the arrangement of the insulating layer, the current only passes through the heated plate and does not pass through the bubble plate, that is, only the heated plate is self-heated, the distribution of the heat source in the prototype fuel element is truly simulated, the case that the bubble plate is self-heated and affects the temperature field of the vacuum bubble part is avoided, the influencing factors of the temperature field of the vacuum bubble part are reduced, the subsequent theoretical analysis is facilitated, and the accuracy and reliability of the experimental results are ensured; and the insulating layer is connected with the heated plate through vacuum diffusion welding, the connection part has the characteristics of high temperature resistance, and is suitable for the bubble temperature environment on the surface of the dispersion type fuel element.

[0011] In some optional embodiments, the insulating layer is configured as an aluminum nitride ceramic coating.

[0012] In some optional embodiments, the thickness of the insulating layer is configured to be not more than 1 / 10 of the thickness of the bubble plate.

[0013] In some optional embodiments, the bubble plate is configured as an Inconel 625 plate, and the thickness of the bubble plate is configured to be not more than 1 / 10 of the thickness of the heated plate.

[0014] In some optional embodiments, the heated plate is configured as an S32168 plate.

[0015] In the second aspect, the application provides a heat transfer simulation experimental device, comprising:

[0016] any one of the heated plates as described in the first aspect;

[0017] a heat insulation base, the heated plate is connected to the working surface of the heat insulation base through the heated plate, an elastic sealing cavity is arranged in the heat insulation base, the elastic sealing cavity is filled with heat insulation powder, and a temperature measuring hole corresponding to the position of the vacuum bubble part is formed in the heat insulation base, so that the thermocouple can pierce the elastic sealing cavity and contact the heated plate through the temperature measuring hole;

[0018] a cover body, the cover body has a flow channel, the cover body is connected with the heat insulation base to seal the flow channel to form a narrow gap channel, and the heated plate is located in the narrow gap channel;

[0019] a medium introduction part, the medium introduction part is in communication with one end of the narrow gap channel;

[0020] a medium outlet part, the medium outlet part is in communication with the other end of the narrow gap channel;

[0021] conductive parts, two conductive parts are respectively connected to two ends of the heated plate, and the vacuum bubble part is located between the two conductive parts.

[0022] The heat transfer simulation experiment device provided by the application can simulate the structural state of the dispersed fuel element under bubbling, and form a narrow channel through the connection of the cover body and the heat insulation base, realize the circulation of the medium in the narrow channel through the medium introduction part and the medium outlet part, realize the heating of the heating plate through the conductive part, realize the one-sided diffusion of heat from the heating plate to the narrow channel under the heat insulation of the heat insulation base, so that the temperature field of the fluid in the narrow channel is measured, and the temperature of the heating plate is directly measured through the setting of the temperature measuring hole.

[0023] In some optional embodiments, the cover body is sealingly connected to the heat insulation base through a static sealing ring, wherein the static sealing ring is arranged around the flow channel.

[0024] In some optional embodiments, a mounting depression is formed on the working surface of the heat insulation base, the heating plate is connected to the mounting depression, and one plate surface of the heating plate is flush with the working surface.

[0025] In some optional embodiments, the heating plate and the inner wall of the mounting depression are connected through filling of sealing glue.

[0026] In some optional embodiments, the light transmittance of the cover body is configured to be not less than 98%.

[0027] In some optional embodiments, the cover body is configured to be optical quartz glass.

[0028] In some optional embodiments, the heat insulation base is configured to be an insulator.

[0029] In some optional embodiments, the heat insulation base is configured to be a resin body.

[0030] In some optional embodiments, the conductive part is connected to the heating plate through silver brazing.

[0031] In some optional embodiments, the number of temperature measuring holes is configured to be multiple, and the spacing between the multiple temperature measuring holes and the vacuum bubble-shaped part is not greater than 10 mm in the normal visual angle of the plate surface of the heating plate.

[0032] In some optional embodiments, at least one temperature measuring hole corresponds to the center position of the vacuum bubble-shaped part.

[0033] In some optional embodiments, the heat insulation base has a detachable positioning plate, the positioning plate includes a lower baffle and an upper baffle embedded on the lower baffle, an installation cavity suitable for accommodating the elastic sealing cavity is formed between the upper baffle and the lower baffle, and the temperature measuring hole is located on the positioning plate; wherein the positioning plate corresponds to the position of the vacuum bubble-shaped part.

[0034] In some optional embodiments, a pressure measuring connector is further included, which is in communication with the narrow gap channel.

[0035] In some optional embodiments, the medium inlet and / or medium outlet are configured with a temperature measuring connector.

[0036] In some optional embodiments, first and second pressure bearing blocks are further included, which are arranged at intervals and connected, wherein the first pressure bearing block is in abutment with the base, and the second pressure bearing block is in abutment with the cover.

[0037] Compared with the prior art, the present application has the following advantages and beneficial effects:

[0038] 1. When the heated plate is used in the experimental device for simulating the heat transfer characteristics of the surface bubbling condition of the dispersed fuel element, the heated plate relies on the heating by the current to simulate the heating of the dispersed fuel element. Through the arrangement of the insulating layer, the current only passes through the heated plate and does not pass through the bubbling plate, thereby truly simulating the heat source distribution in the prototype fuel element, avoiding the situation that the temperature field of the vacuum bubble-shaped part is affected by the self-heating of the bubbling plate, reducing the influencing factors of the temperature field of the vacuum bubble-shaped part, facilitating subsequent theoretical analysis, and ensuring the accuracy and reliability of the experimental results. Moreover, the insulating layer is connected with the heated plate by vacuum diffusion welding, and the connection part has the characteristics of high temperature resistance, which is suitable for the temperature environment of the surface bubbling of the dispersed fuel element.

[0039] 2. The vacuum bubble-shaped part on the heated plate of the heat transfer simulation experimental device can simulate the structural state of the dispersed fuel element under bubbling, and a narrow gap channel is formed by connecting the cover and the heat-insulating base. The medium inlet and the medium outlet are used to realize the flow of the medium in the narrow gap channel, and the electrically conductive part is used to heat the heated plate. At the same time, the heated plate realizes the unilateral diffusion of heat to the narrow gap channel under the heat-insulating action of the heat-insulating base, which can obtain the same heating condition and heat transfer condition as when the dispersed fuel element is bubbling, and provide the same coolant thermal boundary as when the dispersed fuel element is bubbling, thereby realizing the accurate simulation of the heating boundary and the flow channel geometric boundary of the dispersed fuel element. Finally, the direct measurement of the temperature of the heated plate can be conveniently realized through the arrangement of the temperature measuring hole.

[0040] 3. The heat transfer simulation experimental device provided by the present application has the following advantages: the temperature measuring element is external, and the temperature measuring element does not have to be continuously in a high-temperature working condition environment, which is beneficial to improve the accuracy of temperature measurement; after the measurement is completed, the elastic sealing cavity presses the heat-insulating powder in it by its own elasticity to fill the hole formed by the puncture of the temperature measuring element, thereby avoiding the heat loss of the heated plate and ensuring that the coolant thermal boundary in the narrow gap channel is basically consistent with the actual working condition. BRIEF DESCRIPTION OF DRAWINGS

[0041] In order to more clearly illustrate the technical solutions of the example embodiments of the present application, the drawings required to be used in the embodiments will be briefly introduced as follows. It should be understood that the following drawings only show some of the embodiments of the present application, and therefore should not be considered as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor. In the drawings:

[0042] Figure 1 A schematic diagram of the cross-sectional structure of the heated plate provided in the embodiments of the present application is shown in FIG. 1.

[0043] Figure 2 A schematic diagram of the structure of the heat transfer simulation experimental device provided in the embodiments of the present application is shown in FIG. 2.

[0044] Figure 3 A schematic diagram of the cross-sectional structure of the heated plate provided in the embodiments of the present application is shown in FIG. 1. Figure 2 A schematic diagram of the cross-sectional structure of the heated plate provided in the embodiments of the present application is shown in FIG. 1.

[0045] Figure 4 A schematic diagram of the local structure of the connection between the positioning plate and the first pressure-bearing block provided in the embodiments of the present application is shown in FIG. 4.

[0046] Figure 5 A schematic diagram of the cross-sectional structure of the heated plate provided in the embodiments of the present application is shown in FIG. 1.

[0047] The marks in the drawings and the corresponding names of the parts are as follows:

[0048] 1 - medium introduction part, 2 - medium discharge part, 3 - second pressure-bearing block, 4 - cover body, 5 - heated plate, 51 - blister plate, 52 - heating plate, 53 - insulation layer, 6 - heat insulation base, 7 - narrow gap channel, 8 - conductive part, 9 - first pressure-bearing block, 10 - temperature measurement hole, 11 - positioning plate, 111 - upper baffle, 112 - lower baffle, 113 - elastic sealing cavity, 114 - heat insulation powder, 12 - temperature measurement connecting pipe, 13 - pressure measurement connecting pipe. DETAILED DESCRIPTION

[0049] In order to make the purpose, technical solutions and advantages of the present application more clear and understandable, the present application will be further described in detail below with reference to the embodiments and drawings. The illustrative embodiments of the present application and the description thereof are only used to explain the present application, and should not be considered as a limitation on the present application.

[0050] In the first aspect, as Figure 1As shown, the embodiment of the present application provides a heated plate, which comprises a blister plate 51, a heating plate 52 and an insulation layer 53; the blister plate 51 is formed with grooves by a cast pressing process; the heating plate 52 is arranged in parallel and spaced apart from the blister plate 51; the insulation layer 53 is located between the blister plate 51 and the heating plate 52, the insulation layer 53 is connected with the heating plate 52, and the insulation layer 53 is connected with the blister plate 51 by vacuum diffusion welding to enclose the grooves on the blister plate 51 into a vacuum bubble part.

[0051] When the heated plate provided by the present application is used in an experimental device for simulating heat transfer characteristics under the blistering condition of the surface of a dispersion type fuel element, the heating plate 52 relies on electric heating to simulate the heating of the dispersion type fuel element, and the current only passes through the heating plate 52 and does not pass through the blister plate 51 by the arrangement of the insulation layer 53, which truly simulates the heat source distribution in the prototype fuel element, can avoid the case that the blister plate 51 self-heats and affects the temperature field near the vacuum bubble part, that is, reduces the influencing factors of the temperature field near the vacuum bubble part, is beneficial to subsequent theoretical analysis, and ensures the accuracy and reliability of the experimental results; and the insulation layer 53 is connected with the blister plate 51 by vacuum diffusion welding, the connection part has the characteristics of high temperature resistance, and is suitable for the blistering temperature environment of the surface of the dispersion type fuel element.

[0052] In actual implementation, the blister plate 51 is configured as an Inconel 625 plate, so that the thermal conductivity of the blister plate 51 can be similar to the parameters of the zirconium alloy cladding in the dispersion type fuel element, and the thickness of the blister plate 51 is configured to be not more than 1 / 10 of the thickness of the heating plate 52; the part for conduction on the heating plate 52 is configured as an S32168 plate to ensure better resistance to grain boundary corrosion and high temperature strength, and the whole heating plate 52 can be configured as an S32168 plate; the insulation layer 53 can be formed by using a PVD process to make an aluminum nitride ceramic coating layer on the surface of the heating plate 52, and the thickness of the insulation layer 53 is 30-50 μm to satisfy that it is not more than 1 / 10 of the thickness of the blister plate 51, so as to realize effective insulation under the operating condition of a maximum 50V voltage in the experiment; the resistivity of the blister plate is much higher than that of the heating plate, and if a crack occurs in the insulation layer 53 during the diffusion welding process or the use process, the heat generated by the blister plate 51 will not exceed 5% of the total heat generated by the electrical conduction, the influence of the heat generated by the blister plate 51 on the temperature field of the vacuum bubble part is within an acceptable range, so that the experimental device has a certain resistance to abnormality, thereby ensuring the success rate of the experiment.

[0053] In the second aspect, the embodiment of the present application provides a heat transfer simulation experimental device, which can be jointly referred to Figure 2 and Figure 3 The heat transfer simulation experimental device comprises an adiabatic base 6, a cover body 4, a medium introduction piece 1, a medium outlet piece 2, a conductive piece 8 and the heated plate 5 of the first aspect.

[0054] The heating plate 52 in the heated plate 5, in the case of electrical conduction, achieves the heated plate 5 heating by current work to simulate the heat release of the dispersion type fuel element.

[0055] The heated plate 5 can be connected to the working surface of the heat-insulating base 6 through the heating plate 52. The specific shape of the heat-insulating base 6 can not be limited, which can be configured as a cuboid, a triangular prism, a quadrangular prism, a polygonal prism, a spherical shape or other special-shaped structures. The working surface of the heat-insulating base 6 can be a plane to facilitate the connection of other components. For example, in the embodiment of the present application, the plate surface of the heating plate 52 has a large heat diffusion area when it is heated. The plate surface of the heating plate 52 can be attached to the working surface of the heat-insulating base 6 to reduce heat dissipation and achieve one-sided diffusion of the overall heat of the heated plate 5, wherein the vacuum bubble-shaped part is located on the plate surface of the heated plate 5 away from the heat-insulating base 6. The working surface can be obtained by machining, or the heat-insulating base 6 itself can have a plane. For example, when the heat-insulating base 6 is configured as a spherical shape, the working surface can be obtained on the heat-insulating base 6 by turning, milling, planing and other machining methods. For example, when the heat-insulating base 6 is configured as a cuboid, one of the side surfaces of the heat-insulating base 6 can serve as the working surface. In actual experimental operations, the heat-insulating base 6 usually needs to be fixed or clamped by other components. Therefore, the heat-insulating base 6 can be configured as a cuboid to facilitate the necessary operations of the experimental personnel. At this time, the contour shape of the working surface is a rectangle. Of course, the specific shape of the working surface can not be limited. In other embodiments, even if the heat-insulating base 6 is configured as a cuboid, a working surface with a triangular, pentagonal, hexagonal, star-shaped or other special-shaped contour can also be machined on one of the side surfaces of the heat-insulating base 6. The heat-insulating base 6 is provided with an elastic sealing cavity 113, which can be made of rubber or silicone material. The elastic sealing cavity 113 is filled with heat-insulating powder 114. In actual implementation, the heat-insulating powder 114 can be configured as glass fiber powder. The heat-insulating base 6 is also provided with a temperature measuring hole 10 corresponding to the position of the vacuum bubble-shaped part. The thermocouple can penetrate the elastic sealing cavity 113 through the temperature measuring hole 10 and contact the heated plate 5. In actual implementation, a puncture hole with a diameter much smaller than the thermocouple can be formed on the elastic sealing cavity 113. Due to the material properties of the elastic sealing cavity 113, after the thermocouple penetrates the elastic sealing cavity 113, the hole wall of the puncture hole can tightly adhere to the thermocouple due to its elastic deformation. At the same time, the heat-insulating powder 114 in the elastic sealing cavity 113 is more compact under the compression of the thermocouple, which means that the heat-insulating powder 114 can also tightly adhere to the thermocouple. Of course, due to the compression of the heat-insulating powder 114, the cavity wall of the elastic sealing cavity 113 will also be compressed and elastically deformed to a certain extent.After the temperature measurement is completed, the thermocouple is removed, the puncture hole of the elastic sealing cavity 113 restores to the original state under the action of elastic deformation, and the internal heat insulation powder 114 is compressed under the elastic action of the cavity wall of the elastic sealing cavity 113, so as to flow into the hole formed by the thermocouple, that is, under the elastic action of the elastic sealing cavity 113, the heat insulation powder 114 can be self-filled, thereby providing better heat insulation effect for the heated plate 5, avoiding heat loss of the heated plate 5, ensuring that the thermal boundary of the coolant in the narrow gap channel 7 is basically consistent with the actual working condition, and the extension direction of the temperature measurement hole 10 can not be limited, such as a straight line, a broken line, a curve or a combination of any two / three of the foregoing, in order to reduce the length of the temperature measurement hole 10 in the extension direction, the extension direction of the temperature measurement hole 10 can be a straight line, wherein the extension direction of the temperature measurement hole 10 can be perpendicular to the plate surface of the heating plate 52 or form an angle, in actual implementation, the extension direction of the temperature measurement hole 10 is preferably set to be perpendicular to the plate surface of the heating plate 52, thereby ensuring that the length of the temperature measurement hole 10 in the extension direction is short enough to facilitate temperature measurement of the heating plate 52 from the temperature measurement hole 10, and the temperature measurement hole 10 can also be isolated when it is not working, the shorter temperature measurement hole 10 can ensure that there is less heat exchange medium, such as air, in the internal isolation state, thereby reducing the influence of the air on the local temperature of the heating plate 52 during the test; the cross-sectional shape profile of the temperature measurement hole 10 can not be limited, such as a triangle, a rectangle, a square, a circle, a heart shape, a star shape or other special shapes, in actual implementation, the temperature measurement hole 10 can be set to be a circular straight hole.

[0056] The cover 4 has a flow channel, and the cover 4 is connected with the heat insulation base 6 to seal the flow channel to form a narrow gap channel 7, and the heated plate 5 is located in the narrow gap channel 7, that is, for the cover 4 and the heated plate 5, the heated plate 5 can be placed in the flow channel; the specific form of the flow channel can not be limited, which can be a closed groove on the cover 4, that is, only one slot, or an open groove, that is, the flow channel can pass through the cover 4 to form two / three slots; in actual implementation, the flow channel can be set as a closed groove, so that after the cover 4 is connected with the heat insulation base 6, the heat insulation base 6 can easily seal the flow channel through the working surface to form the narrow gap channel 7, of course, in other embodiments, if the flow channel is set as an open groove, the other slots can be individually sealed or sealed and connected with other components after the cover 4 is connected with the heat insulation base 6; the specific shape of the flow channel can not be limited, such as triangle, rectangle, square, circle or other special shapes, etc.; since the flow channel and the heat insulation base 6 form a narrow gap channel 7 for medium flow, the flow channel is preferably set as a groove shape with a certain length, for example, a rectangular groove, a square groove or a prism groove, preferably, the flow channel is set as a rectangular groove or a square groove, that is, in the length direction of the flow channel, the profile shape of the flow channel is a square or a rectangle, wherein when the flow channel is set as a rectangular groove or a square groove, the extension direction thereof can be a straight line or a curve, in actual implementation, the extension direction of the flow channel can be set as a straight line to ensure that the medium has a stable flow state in the narrow gap channel 7, in other embodiments, according to needs, the extension direction of the flow channel can also be set as a curve or a combination of curve and straight line. When the flow channel is set as a rectangular groove or a square groove, the whole heated plate 5 can be set as a rectangular plate, that is, the whole shapes of the heating plate 52 and the foaming plate 51 are rectangular plates, that is, the thickness of the heated plate 5 is uniform except the position of the vacuum bubble, at this time, the whole shape of the narrow gap channel 7 formed by the flow channel and the heat insulation base 6 is a rectangular, which is beneficial to the centering of the heated plate 5 in the narrow gap channel 7, ensures that the heat can be uniformly diffused in the narrow gap channel 7, and ensures that the medium is uniformly heated in the flow direction.

[0057] The medium introduction part 1 communicates with one end of the narrow gap channel 7; when the flow channel is set as a closed groove, the medium introduction part 1 can pass through the heat insulation base 6 to communicate with the narrow gap channel 7, and the medium introduction part 1 is sealingly connected with the heat insulation base 6; when the flow channel is set as an open groove, the medium introduction part 1 can be directly sealingly connected with the unsealed slot of the flow channel. The medium introduction part 1 is usually used for injection of coolant.

[0058] The medium outlet 2 is in communication with the other end of the narrow gap channel 7; when the flow channel is provided as a closed groove, the medium outlet 2 can penetrate the heat insulation base 6 to be in communication with the narrow gap channel 7, and the medium outlet 2 is sealingly connected to the heat insulation base 6; when the flow channel is provided as an open groove, the medium outlet 2 can be sealingly connected to the unsealed groove opening in the flow channel.

[0059] The two conductive members 8 are respectively connected to the two ends of the heating plate 52, and the conductive members 8 can be configured as, for example, copper bars, aluminum bars, stainless steel bars, zinc alloy bars, copper alloy bars, plastic conductive bars, etc., and in actual implementation, the two conductive members 8 can be the same or different, and preferably, the two conductive members 8 can be configured as copper bars, which have excellent electrical conductivity, can reduce heat loss, and have good mechanical strength, corrosion resistance, high flexibility, and good welding performance; the vacuum bubble-shaped part is located between the two conductive members 8, that is, when the heating plate 5 is provided as a rectangular plate, the two conductive members 8 can be connected to the two ends in the length direction of the heating plate 5, and in the length direction of the heating plate 5, the vacuum bubble-shaped part can be located at the middle position of the two conductive members 8, and of course, in other embodiments, the vacuum bubble-shaped part can also be located at other positions between the two conductive members 8.

[0060] The heat transfer simulation experiment device provided by the embodiments of the present application can simulate the structural state of the dispersed fuel element under the bubbling condition through the vacuum bubble-shaped part on the heating plate 5. After the two conductive members 8 are connected to the power supply and the medium inlet 1 and the medium outlet 2 are connected to the medium circulation system, the heating plate 52 can be electrically conducted to generate heat, thereby achieving temperature rise. Due to the heat insulation effect of the heat insulation base 6, most of the heat of the heating plate 5 is unilaterally dissipated into the narrow gap channel 7 to heat the medium in the narrow gap channel 7, thereby simulating the working state of the medium in the dispersed fuel element. The experiment personnel can obtain the flow and heat transfer characteristics near the vacuum bubble-shaped part by measuring the temperature field of the medium near the vacuum bubble-shaped part, directly measuring the temperature of the heating plate 5 at the corresponding position of the vacuum bubble-shaped part through the temperature measuring hole 10, and combining the medium pressure, medium flow rate and other parameters in the medium circulation system. The flow and heat transfer characteristics can provide technical support for the accurate formulation of the thermal hydraulic design and safety criteria of the dispersed fuel element.

[0061] Compared with the existing three-dimensional numerical simulation method, the heat transfer simulation experiment device provided by the embodiments of the present application can be directly measured, has relatively less calculation amount, is relatively more convenient to implement, has more intuitive and easier-to-obtain data, and has relatively high reliability of the measurement results.

[0062] The sealing connection between the cover body 4 and the heat insulation base 6 can be in various modes, for example, can adopt modes such as adhesive sealing, welding sealing, magnetic sealing, threaded sealing, and considering the maintainability of the whole device, in some optional embodiments, the cover body 4 is sealingly connected with the heat insulation base 6 through a static sealing ring, which can be configured as a rubber sealing ring, a metal sealing ring, a polytetrafluoroethylene sealing ring, a graphite sealing ring, etc., and in actual implementation, a suitable static sealing ring can be selected according to the heat conduction performance of the cover body 4, for example, when the heat conduction performance of the cover body 4 is low, a static sealing ring with general heat resistance, such as a rubber sealing ring, can be selected, and when the heat conduction performance of the cover body 4 is high, a static sealing ring with high heat resistance, such as a graphite sealing ring, can be selected, and in actual implementation, it is generally expected that the heat conduction performance of the cover body 4 is low to avoid a large amount of heat loss in the narrow gap channel 7, that is, the temperature of the cover body 4 is not too high in the working state, and the static sealing ring can be configured as a static sealing ring such as a rubber sealing ring, which is a static sealing ring with low cost; wherein the static sealing ring is arranged around the flow-through groove, and the shape of the static sealing ring can not be limited, for example, the static sealing ring can be in shapes such as rectangle, circle, triangle, diamond, etc., and can be designed adaptively according to the slot of the flow-through groove to avoid a large gap space after the cover body 4 is connected with the heat insulation base 6; for example, when the flow-through groove is a rectangular groove, the slot thereof is rectangular, and at this time, the static sealing ring can be configured as a rectangle, and of course, in other embodiments, according to needs, for example, under different installation conditions and different machining accuracies, the shape of the static sealing ring can also be other special shapes.

[0063] After the heat receiving plate 5 is connected with the heat insulation base 6, it is more expected that the heat receiving plate 5 has a single heat dissipation area to facilitate the control of the heat dissipation direction of the heat receiving plate 5, for example, to make one of the plate surfaces of the heat receiving plate 5 be in the narrow gap channel 7, and other surfaces be relatively isolated from the narrow gap channel 7, so that the heat of the heat receiving plate 5 can be basically dissipated from one of the plate surfaces of the heat receiving plate 5 to the narrow gap channel 7, and thus in some optional embodiments, a mounting sink is constructed on the working surface of the heat insulation base 6, and the heating plate 52 is connected in the mounting sink and one of the plate surfaces is flush with the working surface. Thus, other surfaces of the heating plate 52 are in contact with the heat insulation base 6, and the heat dissipation area of the heat receiving plate 5 in the narrow gap channel 7 is reduced, that is, the plate surface where the vacuum bubble exists serves as a heat dissipation surface, so that the heat dissipation direction of the heat receiving plate 5 is certain, which is beneficial to the analysis of the heat dissipation characteristics of the heat receiving plate 5 and the prediction of the heat distribution in the narrow gap channel 7, and can provide a certain theoretical basis for the experimental results.

[0064] The connection between the heating plate 52 and the heat insulation base 6 can not be limited, as long as the heating plate 52 can be surface-to-surface attached to the heat insulation base 6, thereby playing a better heat insulation role. However, due to the influence of machining precision, there may be a certain gap between the surface-to-surface attachment of the heating plate 52 and the heat insulation base 6. If the gap is a slit connected with the narrow slit channel 7, it may have a certain influence on the temperature of the local medium in the narrow slit channel 7, which will not be conducive to the fine study of the heat transfer characteristics of the local medium in the narrow slit channel 7. Therefore, in some optional embodiments, the heating plate 52 and the inner wall of the mounting sink are connected by filling sealant. The sealant can be a relatively heat-resistant sealant to prevent deformation due to high temperature and affect the sealing effect between the heating plate 52 and the sealant. It can be configured as, for example, silicone sealant, polyurethane sealant, fluororubber sealant, polytetrafluoroethylene sealant, high-temperature silicide sealant, etc.

[0065] The cover body 4 can be configured as a transparent or opaque material, both of which can achieve the measurement of the temperature and other parameters of the medium in the narrow slit channel 7. Of course, if the cover body 4 has a certain transparency, it can achieve the visual measurement of the velocity field and two-phase flow pattern of the medium in the narrow slit channel 7. Therefore, in some optional embodiments, the light transmittance of the cover body 4 is configured to be not less than 98%. Preferably, the cover body 4 can be configured as optical quartz glass. Optical quartz glass has good light transmittance performance and low thermal conductivity, which can reduce the heat loss of the medium in the narrow slit channel 7.

[0066] During the process of electrically conducting the heated plate 5, we hope that the current has better effective power, that is, the current basically only works on the heated plate 5. Therefore, in some optional embodiments, the heat insulation base 6 is configured as an insulator, thereby greatly reducing power loss and ensuring electrical safety during the test process. Preferably, the heat insulation base 6 can be configured as a resin body. In other embodiments, the material of the heat insulation base 6 can also be configured as ceramic material, fiber-reinforced ceramic-based material, graphene material, etc. according to needs. When the heat insulation base 6 is configured as an insulator, a ceramic tube can also be inserted into the temperature measuring hole 10 on the heat insulation base 6 to achieve the insulation function.

[0067] The conductive part 8 is usually connected with other devices having conductive requirements by welding. The heated plate 5 in the embodiment of the present application has a relatively high temperature in the working state. Therefore, the welding between the conductive part 8 and the heated plate 5 should have certain heat resistance. In some optional embodiments, the conductive part 8 is connected with the heated plate 5 by silver brazing. The thermal expansion coefficient of silver is smaller than that of copper, which means that the thermal stress generated at the silver brazing connection point is relatively small when the temperature changes, which helps to reduce the risk of loose connection. In addition, silver has good corrosion resistance, especially in a high-temperature environment, which helps to prolong the service life of the welded part and ensure the conductive performance between the conductive part 8 and the heated plate 5.

[0068] In order to conveniently obtain the temperature field characteristics of the vacuum bubble and its surroundings, in some optional embodiments, the number of temperature measurement holes 10 is configured to be multiple, and the spacing between the multiple temperature measurement holes 10 and the vacuum bubble is not greater than 10 mm in the normal viewing angle of the plate surface of the heated plate 5. It includes the temperature measurement hole 10 corresponding to the edge of the vacuum bubble, and at least one temperature measurement hole 10 corresponding to the center position of the vacuum bubble 10 mm away from the vacuum bubble in the medium flow direction.

[0069] For different heated plates 5, the positions and sizes of the vacuum bubble-shaped parts thereon are different, and for this case, in some optional embodiments, the heat insulation base 6 has a detachable positioning plate 11, which can be configured as a polytetrafluoroethylene plate, and specifically can include a lower baffle 112 and an upper baffle 111, the upper baffle 111 being embedded in the lower baffle 112, the overall shape of the lower baffle 112 being approximately a multi-diameter shaft body, a fitting groove being formed in the small-diameter section of the lower baffle 112, the overall shape of the upper baffle 111 being similar to a circular cover body, the upper baffle 111 being adapted in shape to the fitting groove so that the upper baffle 111 can be embedded in the fitting groove, wherein the open end of the upper baffle 111 is located in the fitting groove, and the closed end is located outside the fitting groove, the space in the upper baffle 111 serving as a mounting cavity, which is adapted in shape to the elastic sealing cavity 113 so that the outer wall of the elastic sealing cavity 113 can be fitted with the cavity wall of the mounting cavity, the positioning plate 11 having temperature measurement holes 10, i.e., part of the temperature measurement holes 10 are distributed on the positioning plate 11, specifically, coaxial holes are formed on the upper baffle 111 and the lower baffle 112 respectively, and each two coaxial holes on the upper baffle 111 and the lower baffle 112 serve as a temperature measurement hole 10, the distribution forms of the temperature measurement holes 10 on different positioning plates 11 being different, and according to the differences in the positions and sizes of the vacuum bubble-shaped parts, the sizes and positions of the temperature measurement holes 10 on the positioning plate 11 are different, i.e., according to the positions and sizes of the vacuum bubble-shaped parts, different positioning plates 11 can be replaced to facilitate the measurement of the heated plate 5 by the thermocouple; wherein the positioning plate 11 corresponds to the position of the vacuum bubble-shaped part; in actual implementation, the specific shape of the positioning plate 11 can not be limited, and it can be configured as a cylindrical shape to adapt to the detection range around the vacuum bubble-shaped part, and in other embodiments, the positioning plate 11 can also be configured as a prism shape, a hemispherical shape or other special shapes, etc. The positioning plate 11 can also be removed, at which time the blister position on the heated plate 5 is exposed, facilitating the wall temperature field measurement by the infrared temperature measuring instrument.

[0070] For reference Figure 4 It can be understood that the projection area of the positioning plate 11 on the normal direction of the heated plate 5 can be much larger than the vacuum bubble-shaped part, at which time the temperature measurement holes 10 can also be arranged on the corresponding positions of the positioning plate 11 around the vacuum bubble-shaped part, and these temperature measurement holes 10 are arranged in one-to-one correspondence and coaxially with the temperature measurement holes 10 on the heat insulation base 6.

[0071] In some optional embodiments, the heat transfer simulation experiment device further comprises pressure measuring connecting pipes 13 in communication with the narrow gap channel 7. In actual implementation, the pressure measuring connecting pipes 13 are in communication with the narrow gap channel 7 after penetrating through the heat insulation base 6, and the number of the pressure measuring connecting pipes 13 can be configured as two, which are respectively located on the two sides of the vacuum bubble-shaped part in the flow direction of the medium. Preferably, the two pressure measuring connecting pipes 13 are arranged close to the medium inlet 1 and the medium outlet 2. Through the arrangement of the pressure measuring connecting pipes 13, the medium pressure in the narrow gap channel 7 can be measured, and the variation characteristics of the medium pressure on the two sides of the vacuum bubble-shaped part can be obtained, which is beneficial to the research on the influence of the heat production state of the vacuum bubble-shaped part on the medium pressure.

[0072] In some optional embodiments, the medium inlet 1 and / or the medium outlet 2 are configured with temperature measuring connecting pipes 12. In actual implementation, the temperature measuring connecting pipes 12 can be arranged on the medium inlet 1 and the medium outlet 2 at the same time. Through the arrangement of the temperature measuring connecting pipes 12, the temperature of the medium before entering the narrow gap channel 7 and after flowing out of the narrow gap channel 7 can be conveniently measured / monitored, which can bring convenience to the measurement process and facilitate the acquisition of the dynamic variation characteristics of the medium temperature under long-time work.

[0073] In some optional embodiments, the heat transfer simulation experiment device further comprises first pressure bearing blocks 9 and second pressure bearing blocks 3 arranged at intervals, and the first pressure bearing blocks 9 are connected with the second pressure bearing blocks 3. The first pressure bearing blocks 9 are in abutment with the base, and the second pressure bearing blocks 3 are in abutment with the cover 4.

[0074] In the embodiments of the present application, the arrangement of the first pressure bearing blocks 9 and the second pressure bearing blocks 3 can press the cover 4 and the heat insulation base 6, so as to ensure the stability of the sealing performance between the cover 4 and the heat insulation base 6. The first pressure bearing blocks 9 and the second pressure bearing blocks 3 can be cuboids, the first pressure bearing blocks 9 can cover the heat insulation base 6, the second pressure bearing blocks 3 can cover the cover 4, and the first pressure bearing blocks 9 and the second pressure bearing blocks 3 can be fastened and connected by bolts. The temperature measuring connecting pipes 12, the electrically conductive part 8, the pressure measuring connecting pipes 13, the medium inlet 1, the medium outlet 2 and the positioning plate 11 can penetrate through the first pressure bearing blocks 9 and the heat insulation base 6 in sequence to be in communication with the narrow gap channel 7 or connected with the heated plate 5. When the cover 4 has a light transmittance of not less than 98%, an observation window can be arranged on the second pressure bearing block 3, and the vacuum bubble-shaped part is located within the range covered by the observation window in the normal direction of the plate surface of the heated plate 5.

[0075] In some optional embodiments, the heat transfer simulation experiment device further comprises first pressure bearing blocks 9 and second pressure bearing blocks 3 arranged at intervals, and the first pressure bearing blocks 9 are connected with the second pressure bearing blocks 3. The first pressure bearing blocks 9 are in abutment with the base, and the second pressure bearing blocks 3 are in abutment with the cover 4. Figure 4As shown, when the first pressure block 9 and the second pressure block 3 are arranged, the positioning plate 11 can be connected with the first pressure block 9 through bolts, so that the connecting structure corresponding to the positioning plate 11 does not need to be arranged on the heat insulation base 6, and only the relative positioning of the temperature measuring hole 10 and the vacuum bubble-shaped part is needed when the positioning plate 11 is installed, and the heat insulation base 6 does not participate in the connection and positioning of the positioning plate, so that the risk of damage to the structure of the heat insulation base 6 is greatly reduced, thereby ensuring that the heat insulation performance and / or the insulation performance of the heat insulation base 6 is long-term stable.

[0076] In summary, the heat transfer simulation experiment device provided by the embodiment of the present application can realize the simulation of the gap thermal resistance between the bubble regions of the dispersion type fuel element, the shape of the cooling boundary of the narrow slit channel 7 and the heat transfer condition thereof; is conducive to the measurement of the experimental data such as the wall temperature near the vacuum bubble-shaped part, the fluid temperature field and velocity field in the narrow slit channel 7, and the visualization measurement of the boiling two-phase flow pattern in the narrow slit channel 7, so as to obtain the flow and heat transfer characteristics near the vacuum bubble-shaped part, and further provide a reference basis for the research on the heat transfer characteristics of the actual dispersion type fuel element in the bubble state.

[0077] The above describes the embodiments of the present application by specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in the description. Although the description of the present application is introduced in combination with some examples, this does not mean that the features of the present application are limited to the embodiments. On the contrary, the purpose of introducing the present application in combination with the embodiments is to cover other options or modifications that can be extended based on the claims of the present application. In order to provide a deep understanding of the present application, many specific details are included in the above description. The present application can also be implemented without using these details. In addition, in order to avoid confusion or obscure the focus of the present application, some specific details are omitted in the description. It should be noted that the examples and features in the examples in the present application can be combined with each other without conflict.

[0078] It should be noted that in the description of the application, similar reference numerals and letters in different drawings represent similar items, therefore, once an item is defined in one drawing, it is not necessary to further define and explain it in the subsequent drawings. In the description of the present application, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance. In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or electrical connection; it can be direct connection, or indirect connection through an intermediate medium, or internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0079] Obviously, those skilled in the art can make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application also intends to include these modifications and variations.

Claims

1. A heat transfer simulation experiment apparatus characterized by comprising: The application relates to a heat receiving plate (5) comprising a blister plate (51), a heating plate (52) and an insulation layer (53); the blister plate (51) is formed with grooves through a cast pressing process; the heating plate (52) is arranged in parallel with the blister plate (51) at intervals; the insulation layer (53) is configured as an aluminum nitride ceramic coating layer, the insulation layer (53) is located between the blister plate (51) and the heating plate (52), the insulation layer (53) is connected with the heating plate (52), and the insulation layer (53) is connected with the blister plate (51) through vacuum diffusion welding to enclose the grooves on the blister plate (51) into vacuum bubble-shaped parts; an insulating base (6) is connected with the working surface of the heating plate (52), an elastic sealing cavity (113) is arranged in the insulating base (6), the elastic sealing cavity (113) is filled with heat insulation powder (114), and a temperature measuring hole (10) corresponding to the position of the vacuum bubble-shaped part is arranged on the insulating base (6) so that a thermocouple can pierce the elastic sealing cavity (113) and contact the heat receiving plate (5) through the temperature measuring hole (10); a cover body (4) has a flow channel, the cover body (4) is connected with the insulating base (6) so that the insulating base (6) seals the flow channel to form a narrow gap channel (7), and the heat receiving plate (5) is located in the narrow gap channel (7); a medium introduction part (1) is in communication with one end of the narrow gap channel (7); a medium outlet part (2) is in communication with the other end of the narrow gap channel (7); two conductive parts (8) are respectively connected to the two ends of the heating plate (52), and the vacuum bubble-shaped part is located between the two conductive parts (8). The thickness of the insulation layer (53) is configured to be not more than 1 / 10 of the thickness of the blister plate (51). The blister plate (51) is configured as an Inconel625 plate, and the thickness of the blister plate (51) is configured to be not more than 1 / 10 of the thickness of the heating plate (52). The heating plate (52) is configured as an S32168 plate. The cover body (4) is sealingly connected with the insulating base (6) through a static sealing ring, wherein the static sealing ring is arranged around the flow channel. The working surface of the insulating base (6) is provided with a mounting sunken part, the heating plate (52) is connected in the mounting sunken part, and one plate surface of the heating plate (52) is flush with the working surface. The heating plate (52) and the inner wall of the mounting sunken part are connected through filling of sealing glue.

2. The heat transfer simulation experiment apparatus according to claim 1, wherein The light transmittance of the cover body (4) is configured to be not less than 98%.

3. The heat transfer simulation experiment apparatus according to claim 1, wherein The cover body (4) is configured as optical quartz glass.

4. The heat transfer simulation experiment apparatus according to claim 1, wherein The insulating base (6) is configured as an insulator.

5. The heat transfer simulation experiment apparatus according to claim 1, wherein The insulating base (6) is configured as a resin body.

6. The heat transfer simulation experiment apparatus according to claim 1 or 5, wherein The conductive part (8) is connected with the heating plate (52) through silver brazing.

7. The heat transfer simulation experiment apparatus according to claim 6, wherein ​ 8. The heat transfer simulation experiment apparatus according to claim 1, wherein ​ 9. The heat transfer simulation experiment apparatus according to claim 8, wherein ​ 10. The heat transfer simulation experimental apparatus according to claim 1, wherein ​ 11. The heat transfer simulation experimental apparatus according to claim 10, wherein ​ 12. The heat transfer analog experimental apparatus of claim 1, wherein ​ 13. The heat transfer analog experimental apparatus of claim 1, wherein The number of the temperature measuring holes (10) is configured to be multiple, and the spacing between the multiple temperature measuring holes (10) and the vacuum bubble-shaped part is not greater than 10 mm in the normal view angle of the plate surface of the heating plate (52).

14. The heat transfer simulation experimental apparatus according to claim 13, wherein At least one temperature measuring hole (10) corresponds to the center position of the vacuum bubble-shaped part.

15. The heat transfer simulation experimental apparatus according to claim 13, wherein The heat insulation base (6) has a detachable positioning plate (11), the positioning plate (11) comprises a lower baffle (112) and an upper baffle (111) embedded on the lower baffle (112), an installation cavity suitable for accommodating the elastic sealing cavity (113) is formed between the upper baffle (111) and the lower baffle (112), and the temperature measuring hole (10) is located on the positioning plate (11); wherein the positioning plate (11) corresponds to the position of the vacuum bubble-shaped part.

16. The heat transfer analog experimental apparatus of claim 1, wherein A pressure measuring connecting pipe (13) is further included, and the pressure measuring connecting pipe (13) communicates with the narrow slit passage (7).

17. The heat transfer analog experimental apparatus of claim 1, wherein The medium introduction part (1) and / or the medium discharge part (2) are configured with a temperature measuring connecting pipe (12).

18. The heat transfer analog experimental apparatus of claim 1, wherein First and second pressure bearing blocks (9) and (3) are further included, the first pressure bearing block (9) is connected with the second pressure bearing block (3), wherein the first pressure bearing block (9) abuts against the base, and the second pressure bearing block (3) abuts against the cover (4). The number of the temperature measuring holes (10) is configured to be multiple, and the spacing between the multiple temperature measuring holes (10) and the vacuum bubble-shaped part is not greater than 10 mm in the normal view angle of the plate surface of the heating plate (52). At least one temperature measuring hole (10) corresponds to the center position of the vacuum bubble-shaped part. The heat insulation base (6) has a detachable positioning plate (11), the positioning plate (11) comprises a lower baffle (112) and an upper baffle (111) embedded on the lower baffle (112), an installation cavity suitable for accommodating the elastic sealing cavity (113) is formed between the upper baffle (111) and the lower baffle (112), and the temperature measuring hole (10) is located on the positioning plate (11); wherein the positioning plate (11) corresponds to the position of the vacuum bubble-shaped part. A pressure measuring connecting pipe (13) is further included, and the pressure measuring connecting pipe (13) communicates with the narrow slit passage (7). The medium introduction part (1) and / or the medium discharge part (2) are configured with a temperature measuring connecting pipe (12). First and second pressure bearing blocks (9) and (3) are further included, the first pressure bearing block (9) is connected with the second pressure bearing block (3), wherein the first pressure bearing block (9) abuts against the base, and the second pressure bearing block (3) abuts against the cover (4).

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