High temperature electric heating element for simulating loss of coolant accident conditions

Abstract

The present invention proposes a high-temperature electric heating element for simulating the working condition of a loss of coolant accident. The high-temperature electric heating element for simulating the working condition of a loss of coolant accident comprises: a cladding tube, a high-temperature resistant tube, an electric heating rod, an insulating heat-conducting layer, a first seal, a second seal, a pressure-charging conduit and a loading member. The high-temperature resistant tube is arranged in the cladding tube, and a pressure-charging chamber is defined between the inner circumference of the cladding tube and the outer circumference of the high-temperature resistant tube. At least part of the electric heating rod is arranged in the high-temperature resistant tube. The insulating heat-conducting layer is arranged in the high-temperature resistant tube and surrounds the electric heating rod. One end of the cladding tube is arranged in the first sealed chamber and is sealedly connected to the first seal. The other end of the cladding tube is arranged in the second sealed chamber and is sealedly connected to the second seal. The pressure-charging chamber communicates with the first sealed chamber and the second sealed chamber. The pressure-charging conduit is sealedly connected to the second seal and communicates with the second sealed chamber. The loading member is connected to the second seal. The high-temperature electric heating element for simulating the working condition of a loss of coolant accident of the present invention has the advantage of good test effect.

Description

Technical Field

[0001] The present invention relates to the technical field of simulation test, and in particular to a high-temperature electric heating element for simulating a loss of coolant accident condition. Background Art

[0002] In the case of a loss of coolant accident in a pressurized water reactor, the fuel cores in the cladding tube expand rapidly, and the fission gas generates a large internal pressure in the cladding tube. The cladding tube also generates a large axial stress under the action of bulging deformation, transient thermal stress, etc., which increases the failure risk of the cladding tube. The test device in the related technology performs a performance simulation test on the cladding tube. However, the test device in the related technology uses the method of gas heating and expansion to perform a pressure test on the cladding tube. The high-pressure gas cannot directly contact the cladding tube, and the test effect is poor. Summary of the invention

[0003] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0004] To this end, an embodiment of the present invention provides a high-temperature electric heating element for simulating a loss of coolant accident condition. The high-temperature electric heating element for simulating a loss of coolant accident condition has the advantage of good test effect.

[0005] The high temperature electric heating element for simulating the working condition of a loss of coolant accident according to the embodiment of the present invention comprises:

[0006] Cladding tube;

[0007] A high temperature resistant tube, wherein the high temperature resistant tube is arranged in the cladding tube, and a gap is provided between the inner circumference of the cladding tube and the outer circumference of the high temperature resistant tube, and a pressure charging cavity is defined;

[0008] An electric heating rod, at least a portion of which is disposed in the high temperature resistant tube;

[0009] An insulating heat-conducting layer, which is arranged in the high-temperature resistant tube and surrounds the electric heating rod;

[0010] A first sealing member and a second sealing member, wherein the first sealing member has a first sealing cavity, the second sealing member has a second sealing cavity, one end of the cladding tube is disposed in the first sealing cavity and is sealed and connected to the first sealing member, the other end of the cladding tube is disposed in the second sealing cavity and is sealed and connected to the second sealing member, and the pressure chamber communicates with the first sealing cavity and the second sealing cavity;

[0011] a pressure charging conduit, the pressure charging conduit being sealedly connected to the first sealing member and communicating with the first sealing cavity, or the pressure charging conduit being sealedly connected to the second sealing member and communicating with the second sealing cavity;

[0012] A loader is connected to one of the first sealing member and the second sealing member.

[0013] The high-temperature electric heating element for simulating the working condition of a loss of coolant accident in the embodiment of the present invention uses the gap between the cladding tube and the high-temperature resistant tube as the pressure chamber, and the pressure duct is connected to the first sealed cavity or the second sealed cavity, so that the first sealed cavity or the second sealed cavity can be used to communicate with the pressure chamber, thereby facilitating the entry of gas into the pressure chamber, and the gas in the pressure chamber can directly contact the cladding tube after heating, thereby improving the test effect. In addition, the gap between the cladding tube and the high-temperature resistant tube is smaller than the tube cavity volume of the cladding tube, and the gas can be quickly heated and expanded in the pressure chamber, which can increase the temperature rise rate of the gas in the pressure chamber, thereby reducing the heating time of the heating rod, and thus facilitating the protection of the heating rod.

[0014] In addition, the loading member is connected to one of the first sealing member and the second sealing member, and there is a gap between the cladding tube and the high temperature resistant tube. The loading member can directly load the cladding tube through the first sealing member or the second sealing member to avoid the high temperature resistant tube from affecting the cladding tube, thereby facilitating improving the test effect.

[0015] Therefore, the high-temperature electric heating element for simulating the loss of coolant accident condition in the embodiment of the present invention has the advantage of good test effect.

[0016] In some embodiments, the electric heating rod includes a central heating rod, a first connecting conductor and a second connecting conductor. The diameter of the central heating rod is smaller than the diameter of each of the first connecting conductor and the second connecting conductor. The central heating rod is connected between the first connecting conductor and the second connecting conductor. The central heating rod is located in the high temperature resistant tube. One end of the first connecting conductor is located in the high temperature resistant tube and connected to one end of the central heating rod. The other end of the first connecting conductor extends out of the high temperature resistant tube and is used to connect to a power source. One end of the second connecting conductor is located in the high temperature resistant tube and connected to the other end of the central heating rod. The other end of the second connecting conductor extends out of the high temperature resistant tube and is used to connect to a power source.

[0017] In some embodiments, the high-temperature electric heating element simulating the loss-of-coolant accident condition further includes a first cooling jacket and a second cooling jacket, wherein the first cooling jacket and the second cooling jacket are both mounted on the cladding tube, the first cooling jacket is disposed adjacent to the first seal, and the second cooling jacket is disposed adjacent to the second seal.

[0018] In some embodiments, the loader is connected to the second sealing member, the loader is provided with a through hole, the axial direction of the through hole is orthogonal to the length direction of the cladding tube, one end of the charging conduit passes through the through hole and is connected to the second sealing member, and the charging conduit is connected to the second sealing cavity.

[0019] In some embodiments, the second sealing member is provided with an annular groove, and the loader is fitted in the annular groove.

[0020] In some embodiments, the high-temperature electric heating element simulating the loss of coolant accident condition also includes a first pole and a second pole, the first pole is connected to the other end of the first connecting conductor, the second pole is connected to the other end of the second connecting conductor, the cladding tube is located between the first pole and the second pole, there is a gap between the cladding tube and the first pole, and there is a gap between the cladding tube and the second pole.

[0021] In some embodiments, one end of the first pole is located in the first sealed cavity and connected to the other end of the first connecting conductor, and the other end of the first pole extends out of the first sealed cavity. One end of the second pole is located in the second sealed cavity and connected to the other end of the second connecting conductor, and the other end of the second pole extends out of the second sealed cavity. The first pole is sealedly connected to the first seal, and the second pole is sealedly connected to the second seal.

[0022] In some embodiments, the high-temperature electric heating element simulating the loss of coolant accident condition also includes a first sealing ring and a second sealing ring, the first sealing ring is connected between the first pole and the first seal so that the first pole is sealed and connected to the first seal, and the second sealing ring is connected between the second pole and the second seal so that the second pole is sealed and connected to the second seal.

[0023] In some embodiments, a diameter of the first electrode is larger than a diameter of the first connecting conductor, and a diameter of the second electrode is larger than a diameter of the second connecting conductor.

[0024] In some embodiments, the central heating rod is a molybdenum rod, and the diameter of the central heating rod is greater than or equal to 1.8 mm and less than or equal to 2.2 mm. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic structural diagram of a high-temperature electric heating element for simulating a loss of coolant accident condition according to an embodiment of the present invention.

[0026] Figure 2 yes Figure 1 A local enlarged schematic diagram of point A in the middle.

[0027] Reference numerals:

[0028] Cladding tube 10; Pressurized chamber 101;

[0029] High temperature resistant pipe 20;

[0030] Central heating rod 31; first connecting conductor 32; second connecting conductor 33;

[0031] Insulating heat-conducting layer 40;

[0032] First sealing member 51; first sealing cavity 511; first sealing ring 512;

[0033] Second sealing member 52; second sealing cavity 521; annular groove 522; second sealing ring 523;

[0034] A pressure-filling conduit 60;

[0035] Loading element 70;

[0036] A first cooling jacket 81; a second cooling jacket 82;

[0037] A first pole 91; a second pole 92. DETAILED DESCRIPTION

[0038] 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.

[0039] The high temperature electric heating element for simulating a loss of coolant accident condition according to an embodiment of the present invention will be described below with reference to the accompanying drawings.

[0040] like Figure 1 and Figure 2 As shown, the high temperature electric heating element for simulating the working condition of the loss of coolant accident of the embodiment of the present invention comprises: a cladding tube 10, a high temperature resistant tube 20, an electric heating rod, an insulating heat conductive layer 40, a first seal 51, a second seal 52, a pressure charging conduit 60 and a loading member 70. Among them, the first seal 51 and the second seal 52 are arranged in the length direction of the cladding tube 10 (such as Figure 1 The two arms are arranged at intervals in the up and down directions.

[0041] The high temperature resistant tube 20 is arranged in the cladding tube 10, and there is a gap between the inner circumference of the cladding tube 10 and the outer circumference of the high temperature resistant tube 20 and defines a pressure chamber 101, and at least part of the electric heating rod is arranged in the high temperature resistant tube 20. That is, part of the electric heating rod is arranged in the high temperature resistant tube 20, and the other part extends out of the high temperature resistant tube 20, or the whole of the electric heating rod is arranged in the high temperature resistant tube 20. Specifically, the gap between the cladding tube 10 and the high temperature resistant tube 20 is 0.08 mm.

[0042] The insulating heat-conducting layer 40 is arranged in the high temperature resistant tube 20 and surrounds the electric heating rod. The first sealing member 51 has a first sealing cavity 511, and the second sealing member 52 has a second sealing cavity 521. One end of the cladding tube 10 (such as Figure 1The lower end of the cladding tube 10 is disposed in the first sealing cavity 511 and is sealed with the first sealing member 51. The other end of the cladding tube 10 (such as Figure 1 The upper end of the middle cladding tube 10 is arranged in the second sealed cavity 521 and is sealed and connected to the second seal 52, and the pressure chamber 101 is connected to the first sealed cavity 511 and the second sealed cavity 521. Among them, the insulating heat-conducting layer 40 is a ceramic powder filled in the high-temperature resistant tube 20. The ceramic powder is specifically magnesium oxide ceramic powder, so that the insulating heat-conducting layer 40 has an insulating and heat-conducting effect.

[0043] The charging conduit 60 is sealed and connected to the first seal 51 and communicates with the first sealed cavity 511 , or the charging conduit 60 is sealed and connected to the second seal 52 and communicates with the second sealed cavity 521 , and the loading member 70 is connected to one of the first seal 51 and the second seal 52 .

[0044] The high-temperature electric heating element for simulating the working condition of a loss of coolant accident in the embodiment of the present invention uses the gap between the cladding tube 10 and the high-temperature resistant tube 20 as the pressure chamber 101, and the pressure pipe 60 is connected with the first sealed cavity 511 or the second sealed cavity 521, so that the first sealed cavity 511 or the second sealed cavity 521 can be used to communicate with the pressure chamber 101, thereby facilitating the gas to enter the pressure chamber 101, and the gas in the pressure chamber 101 can directly contact the cladding tube 10 after being heated, thereby improving the test effect. In addition, the gap between the cladding tube 10 and the high-temperature resistant tube 20 is smaller than the tube cavity volume of the cladding tube 10, and the gas can be quickly heated and expanded in the pressure chamber 101, which can increase the temperature rise rate of the gas in the pressure chamber 101, thereby reducing the heating time of the heating rod, and thus facilitating the protection of the heating rod.

[0045] In addition, the loading member 70 is connected to one of the first sealing member 51 and the second sealing member 52, and there is a gap between the cladding tube 10 and the high temperature resistant tube 20. The loading member 70 can directly load the cladding tube 10 through the first sealing member 51 or the second sealing member 52, thereby avoiding the high temperature resistant tube 20 from affecting the cladding tube 10, thereby facilitating improving the test effect.

[0046] Therefore, the high-temperature electric heating element for simulating the loss of coolant accident condition in the embodiment of the present invention has the advantage of good test effect.

[0047] It is understandable that the charging conduit 60 and the loading member 70 may be connected to the first sealing member 51 or the second sealing member 52 at the same time, or the charging conduit 60 and the loading member 70 may be connected to the first sealing member 51 or the second sealing member 52 separately.

[0048] Preferably, the charging conduit 60 and the loading member 70 are simultaneously connected to the second sealing member 52, and the stamping conduit is communicated with the second sealing cavity 521. Specifically, the loading member 70 is provided with a through hole, the axial direction of the through hole is orthogonal to the length direction of the cladding tube 10, the end of the charging conduit 60 facing the second sealing member 52 passes through the through hole and is connected to the second sealing member 52, and the charging conduit 60 is communicated with the second sealing cavity 521. Furthermore, the second sealing member 52 is provided with an annular groove 522, and the loading member 70 fits in the annular groove 522, so that the loading member 70 can directly axially load the cladding tube 10 through the side wall of the annular groove 522 of the second sealing member 52, thereby avoiding the influence of the high temperature resistant tube 20 on the cladding tube 10, which is conducive to improving the test effect.

[0049] In some embodiments, Figure 1 As shown, the high-temperature electric heating element simulating the loss of coolant accident condition also includes a first cooling jacket 81 and a second cooling jacket 82. The first cooling jacket 81 and the second cooling jacket 82 are both mounted on the cladding tube 10. The first cooling jacket 81 is arranged adjacent to the first sealing member 51, and the second cooling jacket 82 is arranged adjacent to the second sealing member 52.

[0050] It is understandable that the first cooling jacket 81 can cool the first sealing member 51 to prevent the first sealing member 51 from being overheated, thereby protecting the first sealing member 51. The second cooling jacket 82 can cool the second sealing member 52 to prevent the second sealing member 52 from being overheated, thereby protecting the second sealing member 52.

[0051] The first cooling jacket 81 and the second cooling jacket 82 may be fed with circulating water or circulating gas, and of course, may also be fed with gas heat exchange medium.

[0052] In some embodiments, Figure 1 As shown, the electric heating rod includes a central heating rod 31, a first connecting conductor 32 and a second connecting conductor 33. The diameter of the central heating rod 31 is smaller than the diameter of each of the first connecting conductor 32 and the second connecting conductor 33. The central heating rod 31 is connected between the first connecting conductor 32 and the second connecting conductor 33. The central heating rod 31 is located in the high temperature resistant tube 20. One end of the first connecting conductor 32 (such as Figure 1 The upper end of the first connecting conductor 32 is located in the high temperature resistant tube 20 and is connected to one end of the central heating rod 31 (such as Figure 1 The lower end of the central heating rod 31 is connected to the other end of the first connecting conductor 32 (such as Figure 1 The lower end of the first connecting conductor 32 in the middle) extends out of the high temperature resistant tube 20 and is used to connect to the power supply, and one end of the second connecting conductor 33 (such as Figure 1 The lower end of the second connecting conductor 33 is located in the high temperature resistant tube 20 and is connected to the other end of the central heating rod 31 (such as Figure 1The other end of the second connecting conductor 33 (such as the upper end of the central heating rod 31) is connected. Figure 1 The upper end of the second connecting conductor 33 in the middle) extends out of the high temperature resistant tube 20 and is used to connect the power supply. That is, part of the electric heating rod is arranged in the high temperature resistant tube 20, and the other part extends out of the high temperature resistant tube 20.

[0053] Among them, the diameters of the first connecting conductor 32 and the second connecting conductor 33 are both larger than the diameter of the central heating rod 31. The central heating rod 31, the first connecting conductor 32 and the second connecting conductor 33 are made of the same material and are connected as one piece. The diameters of the first connecting conductor 32 and the second connecting conductor 33 are larger than the diameter of the central heating rod 31, that is, the cross-sectional area of ​​the first connecting conductor 32 and the second connecting conductor 33 is larger than the cross-sectional area of ​​the central heating rod 31, and the heating efficiency of the first connecting conductor 32 and the second connecting conductor 33 is lower than that of the central heating rod 31, thereby reducing the heat generation, thereby avoiding the first sealing member 51 and the second sealing member 52 from being too high in temperature, and protecting the first sealing member 51 and the second sealing member 52.

[0054] Preferably, the central heating rod 31 , the first connecting conductor 32 and the second connecting conductor 33 are made of molybdenum.

[0055] It is understandable that the lower end of the first connection conductor 32 can extend out of the first sealed cavity 511 or can be located in the first sealed cavity 511. When the lower end of the first connection conductor 32 extends out of the first sealed cavity 511, the lower end of the first connection conductor 32 is sealed and connected to the first sealing member 51, thereby ensuring that the first sealed cavity 511 is isolated from the outside, and the lower end of the first connection conductor 32 can be directly connected to the power supply. When the lower end of the first connection conductor 32 is located in the first sealed cavity 511, the lower end of the first connection conductor 32 can be connected to the power supply through other conductors extending into the first sealed cavity 511.

[0056] The upper end of the second connection conductor 33 can extend out of the second sealed cavity 521 or can be located in the second sealed cavity 521. When the upper end of the second connection conductor 33 extends out of the second sealed cavity 521, the upper end of the second connection conductor 33 is sealed and connected to the second sealing member 52, thereby ensuring that the second sealed cavity 521 is isolated from the outside, and the lower end of the first connection conductor 32 can be directly connected to the power supply. When the upper end of the second connection conductor 33 is located in the second sealed cavity 521, the upper end of the second connection conductor 33 can be connected to the power supply through other conductors extending into the second sealed cavity 521.

[0057] In some embodiments, Figure 1As shown, the high-temperature electric heating element for simulating the working condition of a loss of coolant accident in the embodiment of the present invention further includes a first pole 91 and a second pole 92, wherein the first pole 91 is connected to the other end of the first connecting conductor 32, and the second pole 92 is connected to the other end of the second connecting conductor 33. Specifically, the lower end of the first connecting conductor 32 is located in the first sealed cavity 511 and is connected to the first pole 91 extending into the first sealed cavity 511. The upper end of the second connecting conductor 33 is located in the second sealed cavity 521 and is connected to the second pole 92 extending into the second sealed cavity 521.

[0058] The cladding tube 10 is located between the first pole 91 and the second pole 92, and there is a gap between the cladding tube 10 and the first pole 91, and there is a gap between the cladding tube 10 and the second pole 92. Therefore, the cladding tube 10 is not in contact with the first pole 91 and the second pole 92, so that the cladding tube 10 is insulated from the first pole 91 and the second pole 92, so as to avoid affecting the accuracy of the test after the cladding tube 10 is charged.

[0059] In some embodiments, Figure 1 As shown, one end of the first pole 91 (as shown Figure 1 The upper end of the first pole rod 91 is located in the first sealed cavity 511 and is connected to the other end of the first connecting conductor 32. The other end of the first pole rod 91 (such as Figure 1 The lower end of the first pole 91 in the middle) extends out of the first sealed cavity 511, and one end of the second pole 92 (such as Figure 1 The lower end of the second pole rod 92 is located in the second sealed cavity 521 and is connected to the other end of the second connecting conductor 33. The other end of the second pole rod 92 (such as Figure 1 The upper end of the second pole 92 extends out of the second sealed cavity 521.

[0060] Specifically, the upper end of the first pole 91 is located in the first sealed cavity 511 and connected to the lower end of the first connecting conductor 32. The other end of the first pole 91 (eg Figure 1 The lower end of the first pole 91 extends out of the first sealed cavity 511, the lower end of the second pole 92 is located in the second sealed cavity 521 and connected to the upper end of the second connecting conductor 33, and the upper end of the second pole 92 extends out of the second sealed cavity 521.

[0061] Therefore, the electric heating rod is connected to the power source through the first pole 91 and the second pole 92.

[0062] In some optional embodiments, the diameter of the first pole 91 is greater than the diameter of the first connecting conductor 32, and the diameter of the second pole 92 is greater than the diameter of the second connecting conductor 33. That is, the cross-sectional area of ​​the first pole 91 is greater than the cross-sectional area of ​​the first connecting conductor 32, and the cross-sectional area of ​​the second pole 92 is greater than the cross-sectional area of ​​the second connecting conductor 33. Furthermore, the heating efficiency of the first pole 91 is less than the heating efficiency of the first connecting conductor 32, and the heating efficiency of the second pole 92 is less than the heating efficiency of the second connecting conductor 33. Therefore, the heat generation of the first pole 91 and the second pole 92 is small, which can prevent the power supply from overheating.

[0063] In addition, the first pole 91 is sealed and connected to the first sealing member 51 , thereby ensuring that the first sealed cavity 511 is isolated from the outside world, and the second pole 92 is sealed and connected to the second sealing member 52 , thereby ensuring that the second sealed cavity 521 is isolated from the outside world.

[0064] Specifically, Figure 1 As shown, the high-temperature electric heating element for simulating the working condition of a loss of coolant accident in an embodiment of the present invention also includes a first sealing ring 512 and a second sealing ring 523. The first sealing ring 512 is connected between the first pole rod 91 and the first sealing member 51 to seal the first pole rod 91 with the first sealing member 51. The second sealing ring 523 is connected between the second pole rod 92 and the second sealing member 52 to seal the second pole rod 92 with the second sealing member 52.

[0065] In some embodiments, the central heating rod 31 is a molybdenum rod, and the diameter of the central heating rod 31 is greater than or equal to 1.8 mm and less than or equal to 2.2 mm. Preferably, the diameter of the central heating rod 31 is 2 mm. Therefore, the cross-sectional area of ​​the central heating rod 31 is moderate, that is, the heating efficiency and reliability of the central heating rod 31 are moderate, which can ensure the heating efficiency and avoid burning. Specifically, the melting point of the molybdenum rod is 2620°C, therefore, the central heating rod 31 can withstand high temperatures above 1000°C for a long time, meeting the temperature requirements under the working conditions of a loss of coolant accident.

[0066] A specific example of a high temperature electric heating element for simulating a loss of coolant accident condition according to an embodiment of the present invention is described below.

[0067] The material of the electric heating rod is pure molybdenum, and the diameter of the electric heating rod is 2mm and the length is 500mm. The material of the high temperature resistant tube 20 is 800 nickel-based alloy, with an outer diameter of 8.2mm, an inner diameter of 6.5mm, a wall thickness of 0.85mm and a length of 1200mm. Ceramic powder is filled between the high temperature resistant tube 20 and the electric heating rod and compacted to form an insulating heat conductive layer 40 to ensure that there is no gap. The high temperature resistant tube 20 has good high temperature resistance and maintains good integrity at high temperature. The metal material has a certain ductility and can be subjected to tube shrinkage process and later heat treatment process. The ceramic powder in the tube can be tightly compacted. The high temperature resistant tube 20 also has good thermal conductivity, which can quickly conduct the heat generated by the electric heating rod to avoid overheating and burning of the internal central heating rod 31.

[0068] The insulating heat-conducting layer 40 is made of magnesium oxide, which has good high-temperature resistance, will not expand or deform at high temperatures, and has good stability. Therefore, the insulating heat-conducting layer 40 has high thermal conductivity and electrical insulation performance, can quickly conduct the heat of the electric heating rod, prevent the central heating rod 31 from overheating and burning, and can also provide good electrical isolation between the heating rod and the high-temperature resistant tube 20. In addition, since the powdered material wraps the electric heating rod well, it plays a mechanical protection role, preventing the electric heating rod from being broken due to deformation stress, etc.

[0069] The outer diameter of the cladding tube 10 is 9.5 mm, the inner diameter is 8.36 mm, and the wall thickness is 0.57 mm. The gap between the cladding tube 10 and the high-temperature resistant tube 20 is 0.08 mm. The high-temperature electric heating element simulating the dehydration accident working condition of the embodiment of the present invention uses the gap to pressurize the gas in the cladding tube 10. Due to the small gap and fast heat transfer, the electric heating rod will not be overheated and burned, thereby meeting the high temperature requirement of the cladding tube 10 in the dehydration state.

[0070] The first pole 91 is a copper rod with a diameter of 16 mm and a length of 60 mm. It is used as the positive electrode of the power input. To avoid welding damage, the first pole 91 is directly connected to the first connecting conductor 32 using a nesting technique. The copper rod has excellent electrical conductivity and strong heat dissipation capacity. Therefore, when a high-power power supply is input instantly, the first pole 91 can maintain a relatively low temperature and will not be damaged due to excessive temperature.

[0071] The second pole 92 is a copper rod, with a diameter of 7.5 mm and a length of 65 mm. The second pole 92 and the second connecting conductor 33 are directly connected by nesting technology to avoid damage caused by welding. The copper rod has excellent conductivity and fast heat dissipation. Therefore, when a high power source is input instantly, the second pole 92 can maintain a relatively low temperature and will not be damaged due to excessive temperature.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] Although the above embodiments have been shown and described, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. Changes, modifications, substitutions and variations of the above embodiments by those of ordinary skill in the art are all within the scope of protection of the present invention.

Claims

1. A high temperature electric heating element for simulating the working condition of a loss of coolant accident, characterized in that: include: Cladding tube; A high temperature resistant tube, wherein the high temperature resistant tube is arranged in the cladding tube, and a gap is provided between the inner circumference of the cladding tube and the outer circumference of the high temperature resistant tube, and a pressure charging cavity is defined; An electric heating rod, at least a portion of which is disposed in the high temperature resistant tube; An insulating heat-conducting layer, which is arranged in the high-temperature resistant tube and surrounds the electric heating rod; A first sealing member and a second sealing member, wherein the first sealing member has a first sealing cavity, the second sealing member has a second sealing cavity, one end of the cladding tube is disposed in the first sealing cavity and is sealed and connected to the first sealing member, the other end of the cladding tube is disposed in the second sealing cavity and is sealed and connected to the second sealing member, and the pressure chamber communicates with the first sealing cavity and the second sealing cavity; a pressure charging conduit, the pressure charging conduit being sealedly connected to the first sealing member and communicating with the first sealing cavity, or the pressure charging conduit being sealedly connected to the second sealing member and communicating with the second sealing cavity; a loading member connected to one of the first sealing member and the second sealing member; The electric heating rod includes a central heating rod, a first connecting conductor and a second connecting conductor. The diameter of the central heating rod is smaller than the diameter of each of the first connecting conductor and the second connecting conductor. The central heating rod is connected between the first connecting conductor and the second connecting conductor. The central heating rod is located in the high temperature resistant tube. One end of the first connecting conductor is located in the high temperature resistant tube and connected to one end of the central heating rod. The other end of the first connecting conductor extends out of the high temperature resistant tube and is used to connect to a power source. One end of the second connecting conductor is located in the high temperature resistant tube and connected to the other end of the central heating rod. The other end of the second connecting conductor extends out of the high temperature resistant tube and is used to connect to a power source.

2. The high temperature electric heating element for simulating the working condition of a loss of coolant accident according to claim 1, characterized in that: The invention also includes a first cooling jacket and a second cooling jacket. The first cooling jacket and the second cooling jacket are both sleeved on the cladding tube. The first cooling jacket is disposed adjacent to the first sealing member, and the second cooling jacket is disposed adjacent to the second sealing member.

3. The high temperature electric heating element for simulating the working condition of a loss of coolant accident according to claim 1, characterized in that: The loading member is connected to the second sealing member, and the loading member is provided with a through hole, the axial direction of the through hole is orthogonal to the length direction of the cladding tube, one end of the charging conduit passes through the through hole and is connected to the second sealing member, and the charging conduit is communicated with the second sealing cavity.

4. The high temperature electric heating element for simulating the working condition of a loss of coolant accident according to claim 3, characterized in that: The second sealing member is provided with an annular groove, and the loading member is fitted in the annular groove.

5. The high temperature electric heating element for simulating the working condition of a loss of coolant accident according to claim 1, characterized in that: It also includes a first pole and a second pole, the first pole is connected to the other end of the first connecting conductor, the second pole is connected to the other end of the second connecting conductor, the cladding tube is located between the first pole and the second pole, there is a gap between the cladding tube and the first pole, and there is a gap between the cladding tube and the second pole.

6. According to the high-temperature electric heating element for simulating the working condition of a loss of coolant accident as described in claim 5, one end of the first pole is located in the first sealed cavity and is connected to the other end of the first connecting conductor, and the other end of the first pole extends out of the first sealed cavity, one end of the second pole is located in the second sealed cavity and is connected to the other end of the second connecting conductor, and the other end of the second pole extends out of the second sealed cavity, the first pole is sealedly connected to the first seal, and the second pole is sealedly connected to the second seal.

7. The high temperature electric heating element for simulating the working condition of a loss of coolant accident according to claim 6, characterized in that: It also includes a first sealing ring and a second sealing ring, wherein the first sealing ring is connected between the first pole and the first sealing member to seal the first pole and the first sealing member, and the second sealing ring is connected between the second pole and the second sealing member to seal the second pole and the second sealing member.

8. The high temperature electric heating element for simulating the working condition of a loss of coolant accident according to claim 7, characterized in that: The diameter of the first pole is larger than the diameter of the first connection conductor, and the diameter of the second pole is larger than the diameter of the second connection conductor.

9. The high temperature electric heating element for simulating the working condition of a loss of coolant accident according to claim 8, characterized in that: The central heating rod is a molybdenum rod, and the diameter of the central heating rod is greater than or equal to 1.8 mm and less than or equal to 2.2 mm.

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