Heating device for nuclear fuel rod cladding axial non-uniform thermal destructive test

Abstract

The utility model discloses a heating device for an axial non-uniform thermal destructive test of a nuclear fuel rod cladding, which is characterized by comprising an inner sleeve and an outer sleeve which are matched with the cladding in length and are coaxially arranged, the inner diameter of the inner sleeve is larger than that of the cladding, and the inner sleeve is inserted and connected during the test; a spiral electric heating wire is arranged at the middle position in a cavity between the inner sleeve and the outer sleeve and wound around the inner sleeve, the spiral electric heating wire is at least composed of two sections with different heating power specifications in the axial direction, and the two ends of the spiral electric heating wire are each connected with an armored cable. The outer ends of the two armored cables penetrate out of the circumferential surfaces, close to the two ends, of the outer sleeve and are connected with positive and negative electrode leads, and a cavity between the inner sleeve and the outer sleeve is further filled with an insulating material in a sealed mode. According to the utility model, the thermal instability of nuclear reaction during the working of the cladding can be better simulated to detect the thermal destruction performance of the cladding, and the quality safety of products can be better ensured.

Description

TECHNICAL FIELD

[0001] The utility model relates to nuclear fuel rod cladding detection technical field, concretely relates to a nuclear fuel rod cladding axial non-uniform heat destructive test heating device. BACKGROUND

[0002] In the face of traditional resources gradually exhausted today, nuclear power generation with nuclear fuel becomes more and more potential. Nuclear fuel cladding is the sealed shell of nuclear fuel, because its overall is long strip pipe, so it is also called cladding tube or nuclear fuel rod cladding. Its function is to prevent the escape of fission products and avoid corrosion of the fuel by the coolant and effectively guide out the heat, and it is the second safety barrier of nuclear power plant, so the destructive performance quality detection of cladding is particularly important in the production process.

[0003] The existing cladding destructive performance detection method is usually to input high-temperature and high-pressure detection medium into the cladding to test its burst strength performance, such as CN202311606401.7 once disclosed a zirconium alloy cladding tube burst test energy storage measuring device and method, CN202122268106.8 once disclosed a rapid pressure rise burst system of nuclear fuel cladding tube, and CN202011052604.2 once disclosed a burst test device and test method of nuclear fuel cladding tube, and the like patents are similar technologies. But because the nuclear fuel reaction has great instability, so the cladding in the actual working process, each part is not subjected to uniform thermal pressure impact, and each part is subjected to different temperature. In addition, in the prior art, some use electric heating wire to heat the cladding, and at the same time, high-pressure gas is introduced into the cladding to detect the pressure. In this way, the electric heating wire is usually heated from the inside of the cladding and uniformly heated. The test cost is relatively lower. But still without considering the influence of nuclear fuel reaction instability, and the electric heating element is located in the cladding, which can affect the internal air pressure process.

[0004] Therefore, how to consider the non-uniformity of the cladding in the working environment to detect its thermal damage performance and better ensure its quality has become a problem to be considered and solved by those skilled in the art. UTILITY MODEL CONTENT

[0005] In view of the above technical problems of the prior art, the technical problem to be solved by the utility model is how to provide a nuclear fuel rod cladding axial non-uniform heat destructive test heating device that can better simulate the thermal instability of nuclear reaction during the working of the cladding to detect its thermal damage performance, so as to better ensure the product quality and safety.

[0006] In order to solve the above technical problems, the utility model adopts the following technical scheme:

[0007] The application discloses a heating device for axial non-uniform thermal damage test of a nuclear fuel rod cladding, characterized by comprising an inner sleeve and an outer sleeve which are coaxially arranged and have matched lengths and the inner diameter of the inner sleeve is larger than the cladding and the cladding is inserted into the inner sleeve during the test, a spiral electric heating wire is wound on the inner sleeve in the middle part of a cavity between the inner sleeve and the outer sleeve, the spiral electric heating wire is composed of at least two sections with different heating power specifications in the axial direction, each end of the spiral electric heating wire is connected with a one armored cable, the outer ends of the two armored cables are respectively led out from the circumferential surface of the outer sleeve near the end part of the outer sleeve and connected with positive and negative lead wires, and the cavity between the inner sleeve and the outer sleeve is filled with an insulating material.

[0008] Therefore, when the device is used, the cladding to be tested is inserted into the inner sleeve, nitrogen is introduced into the two ends of the cladding to form gas pressure, and then direct current is connected to the two positive and negative lead wires, so that the spiral electric heating wires with different power specifications in the middle part of the inner sleeve generate different heat; the cladding bears different heat and temperature at different positions in the axial direction; after the test time ends, the cladding is qualified if no rupture or deformation occurs. Therefore, the actual working condition of the cladding can be better simulated, and the thermal damage performance of the cladding when bearing non-uniform heat impact in the axial direction can be detected. Therefore, compared with the uniform heating mode, the detection effect can be better improved, and the safety of the cladding can be improved. Since the device is heated from the outside of the cladding, the pressure effect of the nitrogen in the cladding is not affected, and the heating power of the electric heating wire can be improved, and the simulation effect of heating can be improved.

[0009] In specific implementation, the spiral electric heating wire is composed of three sections with different heating power specifications in the axial direction, and the specifications are 0.8kW, 2kW and 0.8kW respectively.

[0010] Further, the insulating material is magnesium oxide powder, which has the advantages of good insulation effect and good heat conduction performance.

[0011] Further, the inner sleeve is a metal pipe, and the spiral electric heating wire is an armored electric heating wire.

[0012] Therefore, heat can be better transferred to the inside, and the spiral electric heating wire and the metal pipe are prevented from being in contact and conducting electricity.

[0013] Further, the end part of the spiral electric heating wire extends outward along the axial direction by a straight section, and the inner core of the spiral electric heating wire is connected with the inner core of the armored cable end head at the outer end of the straight section, and the connection position of the inner core of the spiral electric heating wire and the inner core of the armored cable is outwardly bent and welded.

[0014] Therefore, the electric leakage between the inner core of the spiral electric heating wire and the inner pipe at the welding position of the spiral electric heating wire and the armored cable can be better avoided.

[0015] Furthermore, a sealing head is provided at each end of the cavity between the inner and outer sleeves. The outer end of the armored cable passes through the sealing head and then exits the outer sleeve from the side. A sealing ring is provided on the outside of the sealing head. The inner ring of the sealing ring is fitted onto the outer surface of the inner sleeve and welded to seal and fix it. The inner side of the sealing ring abuts against the end face of the outer sleeve and is welded to seal and fix it.

[0016] This allows for better sealing and fixation.

[0017] Furthermore, the sealing head is made of silicone rubber, which provides good insulation and sealing performance.

[0018] Furthermore, a connecting handle sleeve is fitted at the junction of the outer end of the armored cable and the positive and negative leads, and the inside of the connecting handle sleeve is filled with sealing material.

[0019] This can better prevent the positive and negative leads from breaking due to pulling force.

[0020] Furthermore, the sealing material is silicone rubber.

[0021] In summary, this invention can better simulate the thermal instability of nuclear reactions during shell operation and detect its thermal destructive properties, thus better ensuring product quality and safety. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the heating device for axial thermal destructive testing of nuclear fuel rod cladding used in this utility model.

[0023] Figure 2 for Figure 1 Enlarged structural diagram at point A in the middle. Detailed Implementation

[0024] The present invention will now be described in further detail with reference to the accompanying drawings.

[0025] In specific implementation: a heating device for axial non-uniform thermal destructive testing of nuclear fuel rod cladding, see [reference needed]. Figures 1-2 The device includes an inner sleeve 11 and an outer sleeve 12, which are coaxially arranged and have matching lengths to the outer casing. The inner diameter of the inner sleeve 11 is larger than that of the outer casing and is inserted for connection during testing. A spiral heating wire 13 is wound around the inner sleeve at the middle position in the cavity between the inner sleeve 11 and the outer sleeve 12. The spiral heating wire 13 is composed of at least two sections with different heating power specifications in the axial direction. Each end of the spiral heating wire 13 is connected to an armored cable 14. The outer ends of the two armored cables 14 pass through the circumferential surface of the outer sleeve near the ends and are connected to positive and negative leads 15. The cavity between the inner sleeve 11 and the outer sleeve 12 is also filled with a sealed insulating material.

[0026] In this way, when the device is used, the cladding to be tested is inserted into the inner sleeve, nitrogen is introduced into the two ends of the cladding to be tested to form gas pressure, and then direct current is connected to the two positive and negative lead wires, so that the helical electric heating wires of different power specifications at the middle position of the inner sleeve emit different heat; so that the cladding at different positions in the axial direction bears different heat and temperature, and after the test time is over, if the cladding does not appear to be cracked or deformed, it is qualified. Therefore, this can better simulate the actual working condition of the cladding, and detect the thermal damage performance of the cladding when it bears uneven heat impact in the axial direction. Therefore, compared with the uniform heating mode, the detection effect can be better improved, and the safety of the cladding can be improved. At the same time, since the device is heated from the outside of the cladding, the pressure effect of the nitrogen in the inside will not be affected, and the heating power of the electric heating wire can be improved, and the heating simulation effect can be improved.

[0027] In specific implementation, the helical electric heating wire is composed of three sections with different heating power specifications in the axial direction, and the specifications are 0.8kW, 2kW and 0.8kW respectively.

[0028] The insulating material is magnesium oxide powder, which has the advantages of good insulation effect and good heat conduction performance.

[0029] The inner sleeve 11 is a metal pipe, and the helical electric heating wire 13 is an armored electric heating wire.

[0030] In this way, heat can be better transmitted inward, and contact and conduction between the helical electric heating wire and the metal pipe can be avoided.

[0031] The two end portions of the helical electric heating wire 13 extend along the axial direction by a straight section, and the inner core of the helical electric heating wire 13 is connected to the inner core of the end head of the armored cable 14 at the outer end of the straight section, and the inner core of the helical electric heating wire 13 and the inner core of the armored cable 14 are connected and welded after being bent outward as a whole.

[0032] In this way, the leakage between the inner core of the welding position of the helical electric heating wire and the inner tube can be better avoided.

[0033] The cavity between the inner sleeve 11 and the outer sleeve 12 is provided with a plugging head 16 at each end, the outer end of the armored cable 14 penetrates the plugging head 16 and then penetrates out of the outer sleeve 12 from the side, the outer side of the plugging head 16 is provided with a sealing ring 17, the inner ring of the sealing ring 17 is sleeved on the outer surface of the inner sleeve and is welded and sealed and fixed, and the inner side of the sealing ring 17 abuts against the end face of the outer sleeve and is welded and sealed and fixed.

[0034] In this way, the sealing and fixing can be better achieved.

[0035] The plugging head 16 is made of silicone rubber material, which has good insulation and sealing effect.

[0036] The connection handle sleeve 18 is sleeved at the joint of the outer end of the armored cable 14 and the positive and negative lead wires 15, and the inside of the connection handle sleeve is filled with a sealing material.

[0037] In this way, the positive and negative lead wires can be better prevented from being broken due to pulling stress.

[0038] The sealing material is a silicone rubber material.

Claims

1. A heating device for axial non-uniform thermal destructive testing of nuclear fuel rod cladding, characterized in that, It includes an inner sleeve and an outer sleeve with matching lengths and coaxial arrangement. The inner diameter of the inner sleeve is larger than that of the outer sleeve and is inserted for connection during testing. A spiral heating wire is wound around the inner sleeve in the middle of the cavity between the inner sleeve and the outer sleeve. The spiral heating wire is composed of at least two sections with different heating power specifications in the axial direction. Each end of the spiral heating wire is connected to an armored cable. The outer ends of the two armored cables pass through the circumferential surface of the outer sleeve near the ends and are connected to positive and negative leads. The cavity between the inner sleeve and the outer sleeve is also filled with a sealed insulating material.

2. The heating device for axial non-uniform thermal destructive testing of nuclear fuel rod cladding according to claim 1, characterized in that: The insulating material is magnesium oxide powder.

3. The heating device for axial non-uniform thermal destructive testing of nuclear fuel rod cladding according to claim 1, characterized in that: The inner sleeve is a metal tube, and the spiral heating wire is an armored heating wire.

4. The heating device for axial non-uniform thermal destructive testing of nuclear fuel rod cladding according to claim 3, characterized in that: The spiral heating wire has a straight section extending from both ends along the axial direction, and an inner core extending from the outer end of the straight section is connected to the inner core extending from the end of the armored cable. The inner core of the spiral heating wire and the inner core of the armored cable are bent outward and then welded together.

5. The heating device for axial non-uniform thermal destructive testing of nuclear fuel rod cladding according to claim 3, characterized in that: Each end of the cavity between the inner and outer sheaths is provided with a sealing head. The outer end of the armored cable passes through the sealing head and then exits the outer sheath from the side. A sealing ring is provided on the outside of the sealing head. The inner ring of the sealing ring is fitted onto the outer surface of the inner sheath and welded to seal and fix it. The inner side of the sealing ring abuts against the end face of the outer sheath and is welded to seal and fix it.

6. The heating device for axial non-uniform thermal destructive testing of nuclear fuel rod cladding according to claim 5, characterized in that: The sealing head is made of silicone rubber.

7. The heating device for axial non-uniform thermal destructive testing of nuclear fuel rod cladding according to claim 3, characterized in that: A connecting handle sleeve is fitted at the junction of the outer end of the armored cable and the positive and negative leads, and the inside of the connecting handle sleeve is filled with sealing material.

8. The heating device for axial non-uniform thermal destructive testing of nuclear fuel rod cladding according to claim 7, characterized in that: The sealing material is silicone rubber.

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