Fuel assembly damping testing device

Abstract

The invention provides a fuel assembly damping testing device. The fuel assembly damping testing device comprises a sealed flow channel used for placing a fuel assembly, the flow channel is connected with a water pump, the water pump is used for forming a water environment in the flow channel, the temperature of the water environment is 21-190 DEG C, the fuel assembly damping testing device further comprises a displacement sensor used for measuring displacement of the fuel assembly, and the displacement sensor is installed on the first side of the flow channel; and an ejector rod of the servo electric cylinder extends into the flow channel through a through hole of a dynamic sealing device formed in the second side of the flow channel to provide pre-pressing initial displacement for the fuel assembly, the through hole is located opposite to the displacement sensor, and a bottom plate of the dynamic sealing device is attached and fixed to the outer wall of the second side. According to the fuel assembly damping testing device provided by the invention, the measurement of the damping ratio of the fuel assembly in a thermal state environment can be more accurately realized, the initial displacement is accurately controlled, and the device has a quick reset function and strict sealing performance.

Description

Technical Field

[0001] The invention relates to the technical field of nuclear energy, and in particular to a fuel assembly damping test device. Background Art

[0002] Fuel assemblies are the core components of the reactor, and the seismic resistance of fuel assemblies directly affects the safety of nuclear power plants. Therefore, seismic design is an important part of fuel assembly design. The dynamic response characteristics of fuel assemblies under earthquakes are evaluated to guide the seismic design of assemblies.

[0003] Damping ratio can reflect the energy dissipation of the system during vibration and plays a vital role in structural dynamics analysis. High damping means that the system dissipates energy faster and the vibration decays faster; low damping means that the energy dissipates slower and the vibration lasts longer. The damping ratio of the fuel assembly directly affects the dynamic response characteristics of the fuel assembly. Therefore, the measurement of the damping ratio of the fuel assembly is important for seismic analysis.

[0004] The test principle of the damping ratio of the fuel assembly is to apply an initial displacement to the fuel assembly in advance, and then suddenly release it to allow the fuel assembly to enter a free vibration state. The displacement changes of the fuel assembly are monitored in real time during the process of the fuel assembly entering the free vibration state. By analyzing the measured displacement curve, the attenuation coefficient of the amplitude of the fuel assembly can be calculated. We put the attenuation coefficient of the amplitude, that is, the reduction coefficient, into the following formula to accurately solve the damping ratio of the fuel assembly.

[0005]

[0006] Among them, Λ is the attenuation coefficient, which is obtained by measurement; ζ is the damping ratio, which is obtained by solving the formula.

[0007] Research has found that temperature has a significant impact on the damping ratio of fuel assemblies. However, existing fuel assembly damping ratio measurement devices all measure the damping ratio of fuel assemblies in water at room temperature. Based on the test results at room temperature, the damping ratio of fuel assemblies in high temperature environments is conservatively estimated. There is a lack of test equipment for measuring the water damping of fuel assemblies under high temperature hot conditions.

[0008] In order to overcome the above-mentioned defects of the prior art, the art urgently needs a fuel assembly damping test device for use in a high-temperature water environment, which can more accurately measure the damping ratio of the fuel assembly in a hot environment, accurately control the initial displacement, and have a fast reset function and strict sealing performance. Summary of the invention

[0009] A brief summary of one or more aspects is given below to provide a basic understanding of these aspects. This summary is not an exhaustive overview of all conceived aspects, and is neither intended to identify the key or critical elements of all aspects nor to define the scope of any or all aspects. Its only purpose is to give some concepts of one or more aspects in a simplified form as a prelude to a more detailed description that will be given later.

[0010] In order to overcome the above-mentioned defects of the prior art, the present invention provides a fuel assembly damping test device for use in a high-temperature water environment, which can more accurately measure the damping ratio of the fuel assembly in a hot environment, accurately control the initial displacement, and has a fast reset function and strict sealing performance.

[0011] Specifically, the above-mentioned fuel assembly damping test device provided according to the present invention includes a sealed flow channel for placing a fuel assembly, the flow channel is connected to a water pump, the water pump is used to form a water environment inside the flow channel, and the temperature of the water environment is 21-190°C. The fuel assembly damping test device also includes: a displacement sensor for measuring the displacement of the fuel assembly, the displacement sensor is installed on the first side of the flow channel; and a servo electric cylinder, the top rod of the servo electric cylinder extends into the flow channel through a through hole of a dynamic sealing device opened on the second side of the flow channel to provide a pre-stressed initial displacement for the fuel assembly, the through hole is located opposite to the displacement sensor, and the bottom plate of the dynamic sealing device is fixed to the outer wall of the second side.

[0012] Preferably, in an embodiment of the present invention, the pressure of the water environment is 0.1-1.2 MPa.

[0013] Preferably, in an embodiment of the present invention, the bottom plate of the dynamic sealing device and the outer wall of the second side are sealed by an O-ring.

[0014] Preferably, in an embodiment of the present invention, the push rod and the through hole of the dynamic sealing device are sealed by at least one O-ring inside the through hole of the dynamic sealing device.

[0015] Preferably, in an embodiment of the present invention, a regulating valve is provided between the water pump and the flow channel.

[0016] Preferably, in an embodiment of the present invention, the outlet of the water pump is connected to the bottom of the flow channel, and the top of the flow channel is connected to the return pipe of the test loop.

[0017] Preferably, in an embodiment of the present invention, the displacement sensor is installed at a middle position of the first side of the flow channel through a threaded hole.

[0018] Preferably, in an embodiment of the present invention, the servo electric cylinder further comprises a servo driver and a servo motor, and the servo driver drives the servo motor to control the extension and retraction of the push rod.

[0019] Preferably, in an embodiment of the present invention, the servo electric cylinder and the displacement sensor are connected to a host computer via a signal line.

[0020] Preferably, in an embodiment of the present invention, the displacement sensor is an LVDT displacement sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The above features and advantages of the present invention can be better understood after reading the detailed description of the embodiments of the present disclosure in conjunction with the following drawings. In the drawings, the components are not necessarily drawn to scale, and components with similar related properties or features may have the same or similar reference numerals.

[0022] Figure 1 A schematic diagram of a fuel assembly damping test device provided according to some embodiments of the present invention is shown;

[0023] Figure 2 A schematic diagram of a threaded hole provided according to some embodiments of the present invention is shown;

[0024] Figure 3 A schematic diagram of a displacement sensor provided according to some embodiments of the present invention is shown;

[0025] Figure 4 A schematic diagram of a servo electric cylinder provided according to some embodiments of the present invention is shown;

[0026] Figure 5 A schematic diagram of a dynamic sealing device provided according to some embodiments of the present invention is shown;

[0027] Figure 6 A schematic diagram of a bottom plate of a dynamic sealing device provided according to some embodiments of the present invention is shown;

[0028] Figure 7 A schematic diagram of cooperation between a dynamic sealing device and a flow channel provided according to some embodiments of the present invention is shown.

[0029] Reference numerals:

[0030] 100: Fuel assembly damping test device;

[0031] 101: fuel assembly;

[0032] 110: flow channel;

[0033] 120: Water pump;

[0034] 130: displacement sensor;

[0035] 140: Servo cylinder;

[0036] 141: ejector rod;

[0037] 150: return pipe;

[0038] 160: Host computer;

[0039] 200: threaded hole;

[0040] 300: displacement sensor;

[0041] 400: Servo cylinder;

[0042] 410: Servo drive;

[0043] 420: Servo motor;

[0044] 421: Ejector;

[0045] 501: O-ring;

[0046] 502: O-ring;

[0047] 610: threaded hole;

[0048] 710: Runner;

[0049] 720: dynamic sealing device;

[0050] 721: Base plate. DETAILED DESCRIPTION

[0051] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. Note that the aspects described below in conjunction with the accompanying drawings and specific embodiments are only exemplary and should not be construed as limiting the scope of protection of the present invention in any way.

[0052] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0053] In addition, the terms "upper", "lower", "left", "right", "top", "bottom", "horizontal" and "vertical" used in the following description should be understood as the directions shown in the paragraph and the related drawings. Such relative terms are only used for the convenience of description and do not mean that the device described therein must be manufactured or operated in a specific direction, and therefore should not be understood as limiting the present invention.

[0054] It is understood that although the terms "first", "second", "third", etc. may be used herein to describe various components, regions, layers and / or parts, these components, regions, layers and / or parts should not be limited by these terms, and these terms are only used to distinguish different components, regions, layers and / or parts. Therefore, the first component, region, layer and / or part discussed below may be referred to as a second component, region, layer and / or part without departing from some embodiments of the present invention.

[0055] As mentioned above, existing fuel assembly damping ratio measurement devices all measure the damping ratio of fuel assemblies in water at room temperature. Based on the test results at room temperature, a conservative estimate of the damping ratio of fuel assemblies in high temperature environments is made. There is a lack of test equipment for measuring the water damping of fuel assemblies under high temperature hot conditions.

[0056] In order to overcome the above-mentioned defects of the prior art, the present invention provides a fuel assembly damping test device for use in a high-temperature water environment, which can more accurately measure the damping ratio of the fuel assembly in a hot environment, and has precise control of the initial displacement, rapid reset function and strict sealing performance.

[0057] Please refer to Figure 1 , Figure 1 A schematic diagram of a fuel assembly damping test device provided according to some embodiments of the present invention is shown.

[0058] like Figure 1 As shown, the fuel assembly damping test device 100 may include a sealed flow channel 110 for placing the fuel assembly 101. The fuel assembly 101 may be installed inside the flow channel 110. In some non-limiting embodiments, the flow channel 110 may be cylindrical.

[0059] The flow channel 110 of the fuel assembly damping testing device 100 may be connected to a water pump 120 . The fuel assembly damping testing device 100 may further include a displacement sensor 130 located on a first side of the flow channel 110 and a servo electric cylinder 140 located on a second side of the flow channel 110 .

[0060] The flow channel 110 is connected to the water pump 120, and a regulating valve may be provided between the water pump 120 and the flow channel 110. The water pump 120 may be used to form a high-temperature water environment inside the flow channel 110 of the fuel assembly damping test device 100, and the temperature of the high-temperature water environment may be 21 to 190° C. In some embodiments, the water pump 120 may be a centrifugal pump. In a preferred embodiment, the pressure of the water environment inside the flow channel 110 may be 0.1 to 1.2 MPa.

[0061] In this way, the fuel assembly damping testing device 100 can measure the damping ratio of the fuel assembly in a high-temperature and high-pressure water environment.

[0062] exist Figure 1 In the illustrated embodiment, the outlet of the water pump 120 is connected to the bottom of the flow channel 110 , and the top of the flow channel 110 is connected to the return pipe 150 of the test loop.

[0063] The fuel assembly damping test device 100 may include a displacement sensor 130, which may be used to measure the displacement of the fuel assembly 101. The displacement sensor 130 may be installed on the first side of the flow channel 110. Preferably, the displacement sensor 130 may be installed at the middle position of the first side of the flow channel 110 through a threaded hole, so that the measurement result of the fuel assembly damping test device 100 is more accurate.

[0064] Please refer to Figure 2 and Figure 3 , Figure 2 shows a schematic diagram of a threaded hole provided according to some embodiments of the present invention, Figure 3 A schematic diagram of a displacement sensor provided according to some embodiments of the present invention is shown.

[0065] like Figure 2 As shown, a threaded hole with a specification of M18×1.5 (ordinary thread, nominal diameter 18 mm, pitch 1.5 mm) can be provided in the middle of the first side of the flow channel for installing the displacement sensor. Figure 3 As shown, the displacement sensor 300 is installed on the first side of the flow channel through the threaded hole 200 on the middle portion of the first side of the flow channel.

[0066] In some embodiments, the displacement sensor 300 may be a LVDT (Linear Variable Differential Transformer) displacement sensor, and the main performance indicators of the selected LVDT displacement sensor are a range of 50 mm and a full-scale linearity of 0.3%. The LVDT displacement sensor is a sensor based on the transformer principle and is mainly used to measure linear displacement.

[0067] In other embodiments, the displacement sensor 300 may also be other displacement sensors that can be used in a high temperature and high pressure environment and can measure the displacement of a component.

[0068] Please continue to refer to Figure 1 The fuel assembly damping test device 100 may further include a servo electric cylinder 140. A push rod 141 of the servo electric cylinder 140 may extend into the flow channel 110 through a through hole of a dynamic sealing device opened on the second side of the flow channel 110, and the push rod 141 may be used to provide a pre-compression initial displacement for the fuel assembly 101 installed inside the flow channel 110.

[0069] Please refer to Figure 4 , Figure 4 A schematic diagram of a servo electric cylinder provided according to some embodiments of the present invention is shown.

[0070] like Figure 4 As shown, the servo electric cylinder 400 may be composed of a servo driver 410, a servo motor 420 and a push rod 421 on the servo motor 420. The servo driver 410 drives the servo motor 420 to control the extension and retraction of the push rod 421, thereby realizing the functions of pre-pressing the fuel assembly to a target displacement and quickly releasing the push rod.

[0071] In some embodiments, the servo driver 410 may be a pulse-charged type, and the rated power of the servo motor 420 may be 750 W and the maximum speed may be 3000 rpm.

[0072] In this way, the fuel assembly damping test device can remotely and accurately control the initial displacement of preloading. As an important input condition for calculating the damping ratio, the accuracy of the initial displacement of preloading is directly related to the credibility of the test data. By utilizing the high-precision characteristics of the servo motor, the fuel assembly damping test device can achieve precise control of the initial displacement value of preloading and accurately preload the fuel assembly to the target displacement.

[0073] In addition, the fuel assembly damping test device can realize the rapid reset function through the servo electric cylinder. After releasing the push rod of the preloading device, the fuel assembly damping test device can quickly release the push rod by utilizing the fast response characteristics of the servo motor, and the reset speed of the push rod is significantly greater than the rebound speed of the fuel assembly, thereby avoiding the secondary contact between the fuel assembly and the preloading device during the rebound process, thereby ensuring that the fuel assembly always maintains a free vibration state after releasing the push rod without external interference.

[0074] Furthermore, the rapid release process of the servo electric cylinder's push rod pre-pressing the fuel assembly has very good repeatability. The operator can remotely control the servo motor of the fuel assembly damping test device, and use the high precision and fast response characteristics of the servo motor to accurately pre-press the fuel assembly to the target displacement and quickly release it to reset it. Compared with the test bench that relies on manual operation, the fuel assembly damping test device can greatly improve the success rate and efficiency of the test while having good repeatability. In addition, remote control of the servo motor can ensure the safety of the operator during high-temperature testing.

[0075] like Figure 1 As shown, the through hole of the dynamic sealing device opened on the second side of the flow channel 110 can be located opposite to the displacement sensor 130, and the top rod 141 of the servo electric cylinder 140 extends from the through hole to provide a pre-compression initial displacement for the fuel assembly 101. The bottom plate of the dynamic sealing device can be fixedly attached to the outer wall of the second side. In some embodiments, the material of the dynamic sealing device can be 304 stainless steel.

[0076] Please refer to Figure 5 and Figure 6 , Figure 5 shows a schematic diagram of a dynamic sealing device provided according to some embodiments of the present invention, Figure 6 A schematic diagram of a bottom plate of a dynamic sealing device provided according to some embodiments of the present invention is shown.

[0077] like Figure 5 As shown, the thickness of the bottom plate of the dynamic sealing device may be 13 mm, and the bottom plate of the dynamic sealing device may be sealed with the outer wall of the second side by an O-ring 501. The diameter of the O-ring 501 may be 46 mm, and the material may be FFKM. Figure 6 As shown, the bottom plate of the dynamic sealing device may be 78 mm in length and 78 mm in width, and is fixed to the outer wall of the flow channel through four threaded holes 610 with a specification of Φ10.

[0078] Please refer to Figure 7 , Figure 7 A schematic diagram of cooperation between a dynamic sealing device and a flow channel provided according to some embodiments of the present invention is shown.

[0079] like Figure 7 As shown, the bottom plate 721 of the dynamic sealing device 720 is fitted and fixed to the outer wall of the second side of the flow channel 710 .

[0080] Please continue to refer to Figure 5The diameter of the through hole of the dynamic sealing device opened on the second side of the flow channel can be 30 mm. The through hole of the dynamic sealing device is 73 mm long, the inner diameter of the front end portion with a length of 32 mm can be 30 mm, and the inner diameter of the rear end portion can be 31 mm.

[0081] The push rod of the servo electric cylinder can pass through the through hole of the dynamic sealing device to enter the interior of the flow channel, and the push rod and the through hole of the dynamic sealing device can be sealed by at least one O-ring inside the through hole of the dynamic sealing device. Figure 5 As shown, the push rod and the through hole of the dynamic sealing device can be sealed by two O-rings 502 inside the through hole. The O-ring 502 can be set at the front end of the through hole, with a diameter of 30 mm, the same as the inner diameter of the front end, and the material of the O-ring 502 can be full-rubber. Through the dynamic sealing device, dynamic sealing between the servo electric cylinder and the flow channel in a high-temperature water environment can be achieved, and the fuel assembly damping test device can have strict sealing performance.

[0082] In this way, the pre-stressing device, i.e., the ejector rod, can penetrate the pressure boundary of the flow channel and contact the fuel assembly inside the flow channel. At the same time, by utilizing the fast response characteristics of the servo motor, the fuel assembly damping test device can also ensure that the ejector rod can be quickly withdrawn. More importantly, through the dynamic sealing device, the sealing performance at the pressure boundary can be strictly guaranteed to prevent leakage problems in high-pressure water environments.

[0083] like Figure 1 As shown, the servo electric cylinder 140 and the displacement sensor 130 can also be connected to the host computer 160 through a signal line. The host computer 160 can be an industrial PC. Through the signal line, the servo electric cylinder 140 and the displacement sensor 130 can transmit data to the host computer 160 for analysis.

[0084] Please continue to refer to Figure 1 In the process of performing a damping test on the fuel assembly 101, the fuel assembly damping test device 100 can first start the water pump 120 to inject high-temperature deionized water into the test loop and the flow channel 110. After the water is filled and the water pump 120 is turned off, the fuel assembly damping test device 100 can measure the damping ratio of the fuel assembly 101 in a high-temperature static water environment.

[0085] In other embodiments, when the water pump 120 is running, the fuel assembly damping test device 100 can measure the damping ratio of the fuel assembly 101 under different flow conditions by adjusting the regulating valve in the test loop.

[0086] In summary, the fuel assembly damping test device provided by the present invention can pre-press the fuel assembly placed in the flow channel under the high-temperature water environment to the initial target displacement by the servo electric cylinder, and then measure the displacement by the displacement sensor to realize the damping test of the fuel assembly under the high-temperature water environment. By utilizing the high precision and fast response characteristics of the servo electric cylinder, the fuel assembly damping test device can accurately control the initial displacement and realize rapid reset, and through the dynamic sealing device, the fuel assembly damping test device can achieve strict sealing. Therefore, the fuel assembly damping test device provided by the present invention can more accurately realize the measurement of the damping ratio of the fuel assembly under the hot environment.

[0087] The previous description of the disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be apparent to those skilled in the art, and the general principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. Thus, the disclosure is not intended to be limited to the examples and designs described herein, but should be granted the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A fuel assembly damping test device, comprising a sealed flow channel for placing a fuel assembly, characterized in that: The flow channel is connected to a water pump, and the water pump is used to form a water environment inside the flow channel, and the temperature of the water environment is 21-190° C. The fuel assembly damping test device also includes: a displacement sensor, used to measure the displacement of the fuel assembly, the displacement sensor being installed on the first side of the flow channel; and A servo electric cylinder, the push rod of which extends into the flow channel through a through hole of a dynamic sealing device opened on the second side of the flow channel to provide a pre-stressed initial displacement for the fuel assembly, the through hole is located opposite to the displacement sensor, and the bottom plate of the dynamic sealing device is fixedly attached to the outer wall of the second side.

2. The fuel assembly damping test device according to claim 1, characterized in that: The pressure of the water environment is 0.1-1.2 MPa.

3. The fuel assembly damping test device according to claim 1, characterized in that: The bottom plate of the dynamic sealing device and the outer wall of the second side are sealed by an O-ring.

4. The fuel assembly damping test device according to claim 1, characterized in that: The push rod and the through hole of the dynamic sealing device are sealed by at least one O-ring inside the through hole of the dynamic sealing device.

5. The fuel assembly damping test device according to claim 1, characterized in that: A regulating valve is provided between the water pump and the flow channel.

6. The fuel assembly damping test device according to claim 1, characterized in that: The outlet of the water pump is connected to the bottom of the flow channel, and the top of the flow channel is connected to the return water pipeline of the test loop.

7. The fuel assembly damping test device according to claim 1, characterized in that: The displacement sensor is installed at a middle position of the first side of the flow channel through a threaded hole.

8. The fuel assembly damping test device according to claim 1, characterized in that: The servo electric cylinder also includes a servo driver and a servo motor, and the servo driver drives the servo motor to control the extension and retraction of the push rod.

9. The fuel assembly damping test device according to claim 1, characterized in that: The servo electric cylinder and the displacement sensor are connected to a host computer via a signal line.

10. The fuel assembly damping test device according to claim 1, characterized in that: The displacement sensor is an LVDT displacement sensor.

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