A device and method for on-line measurement of nuclear fuel rod diameter

Abstract

The application discloses a device and method for online measurement of the diameter of a nuclear fuel rod, and the device comprises a first support (1), a second support (2), a winding skeleton (3), a primary winding (4), a secondary winding (5), an armature (6), a voltage measurement module and a calculation module. The method comprises the following steps: the calculation module calculates the distance between the A end and the B end of the armature (6) and the winding skeleton (3) according to the relationship between the input voltage of the primary winding (4) and the output voltage of the secondary winding (5); and the aforementioned steps are repeated to calculate the distance change between the A end and the B end of the armature (6) and the winding skeleton (3) at different time, namely the rotating degree of the armature. The application only needs to measure the differential change of the induced electromotive force to obtain the rotating angle of the armature, and then the surface deformation size and type (protrusion or depression) of the fuel rod can be obtained. The device is simple and reliable, and has strong adaptability.

Description

Technical Field

[0001] This invention relates to the field of nuclear power plants, specifically to a device and method for online measurement of the diameter of nuclear fuel rods. Background Technology

[0002] Nuclear energy is one of my country's important energy types. As a clean energy source, it plays a crucial role in power generation, hydrogen production, and isotope production. A nuclear test reactor is a reactor used for comprehensive experimental and engineering application research. Conducting more measurement experiments on relevant components within the test reactor ensures the stable operation of the devices and promotes the development of nuclear safety.

[0003] Test reactor measurement technology mainly includes in-core measurements, out-of-core measurements, and online measurements conducted within the engineering test reactor. Among these, online measurement technology is the most difficult and challenging to implement. Online measurement technology must ensure a high signal-to-noise ratio in the output signal while achieving real-time monitoring.

[0004] The main online measurements for the experimental reactor include environmental parameters, nuclear parameters, and irradiation deformation parameters. As a crucial fuel element in the reactor, the deformation measurement of fuel rods is a critical aspect of the online measurements. During operation, fuel rods are exposed to environments with strong radiation, significant pressure differentials, and large temperature gradients. Irradiation causes phenomena such as irradiation growth, irradiation swelling, and irradiation creep. Pressure and temperature differences result in varying stresses on different parts of the fuel rod, all of which lead to deformation. These deformations can be clearly observed through changes in the fuel rod's diameter.

[0005] However, there is currently no system available for measuring and assessing the deformation of nuclear fuel rods. Summary of the Invention

[0006] The purpose of this invention is to provide a device for online measurement of the diameter of nuclear fuel rods, comprising a first support, a second support, a winding frame, a primary winding, a secondary winding, an armature, a voltage measurement module, and a calculation module.

[0007] The first bracket is used to fix the D end of the fuel rod to be measured.

[0008] The second bracket is used to fix the E end of the fuel rod to be measured.

[0009] One end of the winding frame is fixed to the first bracket, and the other end is fixed to the second bracket.

[0010] Both the primary winding and the secondary winding are wound on the winding frame.

[0011] The rotation center of the armature is fixed to the winding frame, allowing the armature to rotate.

[0012] The voltage measurement module acquires the input voltage of the primary winding and the output voltage of the secondary winding, and transmits them to the calculation module.

[0013] The calculation module processes the input voltage of the primary winding and the output voltage of the secondary winding to calculate the degree of armature rotation used to characterize the surface deformation of the fuel rod.

[0014] Furthermore, the steps for processing the input voltage of the primary winding and the output voltage of the secondary winding include:

[0015] Based on the relationship between the input voltage of the primary winding and the output voltage of the secondary winding, calculate the change in distance between the armature ends A and B and the winding frame within time t. This change in distance between the armature ends A and B and the winding frame represents the degree of armature rotation.

[0016] Furthermore, the relationship between the input voltage of the primary winding and the output voltage of the secondary winding is as follows:

[0017]

[0018] In the formula, U1 and U2 are the input voltage of the primary winding and the output voltage of the secondary winding, respectively. W1 and W2 are the number of turns in the primary and secondary windings, respectively. δ A and δ B These are the distances between the armature's A and B ends and the winding frame, respectively.

[0019] Furthermore, the first bracket has mounting holes.

[0020] The mounting hole is used to allow the D end of the fuel rod to be measured and the A end of the armature to extend into it.

[0021] The D end of the fuel rod to be measured and the A end of the armature are shaped to match.

[0022] Furthermore, the primary winding includes at least two primary coil windings.

[0023] The primary coil windings are connected in series with the same name at the same time.

[0024] Furthermore, the number of turns in the primary coil winding is equal.

[0025] Furthermore, the secondary winding includes at least two secondary coil windings.

[0026] The terminals of the secondary coil windings are connected in reverse series.

[0027] Furthermore, the number of turns in the secondary coil winding is equal.

[0028] Furthermore, the voltage measurement module includes a voltage sensor.

[0029] A method using a device for online measurement of the diameter of nuclear fuel rods includes the following steps:

[0030] 1) Insert the D end of the fuel rod to be measured into the mounting hole of the first bracket to fix the fuel rod to be measured to the first bracket.

[0031] Fix end E of the fuel rod to be measured to the second support.

[0032] Insert the A end of the armature into the mounting hole of the first bracket.

[0033] 2) The voltage measurement module is used to obtain the input voltage of the primary winding and the output voltage of the secondary winding in real time, and then transmits them to the calculation module.

[0034] 3) The calculation module calculates the distance between the armature A end, B end and the winding frame based on the relationship between the input voltage of the primary winding and the output voltage of the secondary winding.

[0035] 4) Repeat steps 2)-3) to calculate the changes in distance between the armature A end, B end and the winding frame at different times, that is, the degree of armature rotation.

[0036] If the distance between end A of the armature and the winding frame changes to a positive value, the fuel rod to be measured on the same side as end A of the armature will be dented, or the fuel rod to be measured on the same side as end B of the armature will be bulging.

[0037] If the distance between end A of the armature and the winding frame changes to a negative value, the fuel rod to be measured on the same side as end A of the armature will bulge, or the fuel rod to be measured on the same side as end B of the armature will dent.

[0038] The technical effects of this invention are undeniable. This invention provides a nuclear fuel rod diameter measurement system that can measure and evaluate the deformation of nuclear fuel rods, thereby providing a necessary means for the safe operation of reactors.

[0039] This invention only requires measuring the differential change of the induced electromotive force to obtain the angle of armature rotation, and then to obtain the size and type (protrusion or depression) of the fuel rod surface deformation. The device is simple, reliable and highly adaptable. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the device structure;

[0041] Figure 2 This is a schematic diagram of the equivalent magnetic circuit of the device;

[0042] Figure 3 The induced electromotive force of a coil in an alternating magnetic circuit;

[0043] In the figure, there are 1 first support, 2 second support, 3 winding frame, 4 primary winding, 5 secondary winding, 6 armature, and 7 fuel rod to be measured. Detailed Implementation

[0044] The present invention will be further described below with reference to embodiments, but it should not be construed that the scope of the present invention is limited to the following embodiments. Various substitutions and modifications made based on ordinary technical knowledge and common practices in the art without departing from the above-described technical concept of the present invention should be included within the scope of protection of the present invention.

[0045] Example 1:

[0046] See Figures 1 to 3 A device for online measurement of the diameter of nuclear fuel rods includes a first support 1, a second support 2, a winding frame 3, a primary winding 4, a secondary winding 5, an armature 6, a voltage measurement module, and a calculation module.

[0047] The first bracket 1 is used to fix the D end of the fuel rod 7 to be measured.

[0048] The second bracket 2 is used to fix the E end of the fuel rod 7 to be measured.

[0049] One end of the winding frame 3 is fixed to the first bracket 1, and the other end is fixed to the second bracket 2.

[0050] The primary winding 4 and the secondary winding 5 are both wound on the winding frame 3.

[0051] The rotation center of the armature 6 is fixed to the winding frame 3, so that the armature 6 can rotate.

[0052] The voltage measurement module acquires the input voltage of the primary winding 4 and the output voltage of the secondary winding 5, and transmits them to the calculation module.

[0053] The calculation module processes the input voltage of the primary winding 4 and the output voltage of the secondary winding 5 to calculate the degree of armature rotation used to characterize the surface deformation of the fuel rod.

[0054] Example 2:

[0055] A device for online measurement of nuclear fuel rod diameter, with the same technical content as Embodiment 1, further comprising the following steps for processing the input voltage of the primary winding 4 and the output voltage of the secondary winding 5:

[0056] Based on the relationship between the input voltage of the primary winding 4 and the output voltage of the secondary winding 5, the change in distance between the A and B ends of the armature 6 and the winding frame 3 within time t is calculated. The change in distance between the A and B ends of the armature 6 and the winding frame 3 represents the degree of armature rotation.

[0057] Example 3:

[0058] A device for online measurement of nuclear fuel rod diameter, with technical content the same as any one of Embodiments 1-2, further wherein the relationship between the input voltage of the primary winding 4 and the output voltage of the secondary winding 5 is as follows:

[0059]

[0060] In the formula, U1 and U2 are the input voltage of the primary winding 4 and the output voltage of the secondary winding 5, respectively. W1 and W2 are the number of turns of the primary winding 4 and the secondary winding 5, respectively. δ A and δ B These are the distances between the armature 6A end, the armature 6B end, and the winding frame 3, respectively.

[0061] Example 4:

[0062] A device for online measurement of the diameter of nuclear fuel rods, with the same technical content as any one of embodiments 1-3, further wherein the first bracket 1 is provided with mounting holes.

[0063] The mounting hole is used to allow the D end of the fuel rod 7 to be measured and the A end of the armature 6 to extend into it.

[0064] The D end of the fuel rod 7 to be measured and the A end of the armature 6 have matching shapes.

[0065] Example 5:

[0066] An apparatus for online measurement of the diameter of nuclear fuel rods, with the same technical content as any one of embodiments 1-4, further wherein the primary winding 4 includes at least two primary coil windings.

[0067] Example 6:

[0068] A device for online measurement of nuclear fuel rod diameter, with the same technical content as any one of embodiments 1-4, further wherein the primary winding 4 includes two primary coil windings.

[0069] Example 7:

[0070] A device for online measurement of the diameter of nuclear fuel rods, with the same technical content as any one of embodiments 1-6, further wherein the corresponding ends of the primary coil winding are connected in series in the same direction.

[0071] Example 8:

[0072] An apparatus for online measurement of the diameter of nuclear fuel rods, with the same technical content as any one of embodiments 1-7, further wherein the number of turns of the primary coil winding is equal.

[0073] Example 9:

[0074] A device for online measurement of nuclear fuel rod diameter, with the same technical content as any one of embodiments 1-8, further wherein the secondary winding 5 includes at least two secondary coil windings.

[0075] Example 10:

[0076] A device for online measurement of nuclear fuel rod diameter, with the same technical content as any one of embodiments 1-9, further wherein the secondary winding 5 includes two secondary coil windings.

[0077] Example 11:

[0078] A device for online measurement of nuclear fuel rod diameter, with the same technical content as any one of embodiments 1-10, further wherein the corresponding ends of the secondary coil winding are connected in reverse series.

[0079] Example 12:

[0080] An apparatus for online measurement of the diameter of nuclear fuel rods, with the same technical content as any one of embodiments 1-11, further wherein the number of turns of the secondary coil winding is equal.

[0081] Example 13:

[0082] An apparatus for online measurement of the diameter of nuclear fuel rods, with the same technical content as any one of Embodiments 1-12, further comprising a voltage measurement module including a voltage sensor.

[0083] Example 14:

[0084] A device for online measurement of the diameter of nuclear fuel rods, with the same technical content as any one of embodiments 1-13, further comprising the device for detecting the type and magnitude of deformation that occurs in the nuclear fuel rods during use. The deformation types include protrusions and indentations. The magnitude of the deformation (protrusion height, indentation depth) is characterized by the degree of armature rotation.

[0085] Example 15:

[0086] A device for online measurement of the diameter of nuclear fuel rods, with the same technical content as any one of embodiments 1-14, further comprising the step of establishing the relationship between the input voltage of the primary winding 4 and the output voltage of the secondary winding 5, including:

[0087] The coil has W turns wound on the coil frame. 1A =W 2A The two primary coil windings and W 1B =W 2BThe two primary windings have two secondary coil windings. The corresponding segments of the two primary windings are connected in series in the same direction, while the corresponding segments of the two secondary windings are connected in series in opposite directions. The circuit flowing through the primary coil is i1, and the circuit flowing through the secondary coil is i2. Based on this structure, the magnetic field can be analyzed as two magnetic circuits Φ1 and Φ2, with the total magnetic reluctance of the two magnetic circuits on the coil frame being R1 and R2, respectively. m1 and R m2 Therefore, according to the formula for calculating the magnetic reluctance of a magnetic circuit, R... m1 and R m2 They can be represented as:

[0088]

[0089]

[0090] Where l1 and l2 are the magnetic circuit lengths of the coil frame and armature, respectively; μ1 and μ2 are the permeabilities of the coil frame and armature, respectively; and S1 and S2 are the cross-sectional areas of the magnetic circuit of the core and armature, respectively. -0 S0 represents the permeability and cross-sectional area of ​​the air gap, and δ A and δ B These represent the distances between the two ends of the armature and the coil frame, respectively.

[0091] Because the permeability of air is much smaller than that of the coil frame and armature, that is:

[0092]

[0093]

[0094] Therefore, the magnetic reluctance of the two magnetic circuits can be rewritten as:

[0095]

[0096]

[0097] According to Ohm's law for magnetic circuits, the magnetic reluctance in a single magnetic circuit is equal to the magnetomotive force divided by the magnetic flux. Therefore, the magnetic flux Φ in a magnetic circuit is equal to the magnetomotive force F acting on that magnetic circuit divided by the magnetic reluctance R of the magnetic circuit. m We can obtain:

[0098]

[0099] In the above formula, I is the excitation current, Φ is the magnetic flux, W is the number of coil turns, F is the magnetomotive force, and R is the magnetic flux density. m Let be the magnetic reluctance of the magnetic circuit. Therefore, based on the Ohm's law for the magnetic circuit, the following two equations can be derived for the structure shown in the figure:

[0100]

[0101]

[0102] Substituting into the expression for the magnetic reluctance of the magnetic circuit, we get:

[0103]

[0104]

[0105] For alternating magnetic circuits, such as Figure 3 As shown.

[0106] Satisfies the circuit equations:

[0107]

[0108] In the formula: (-e L ) and (-e σ ) are the main magnetic flux and leakage magnetic flux Φ, respectively. σ The induced electromotive force generated, W, is the number of turns in the coil. Generally, u R If it is very small, then we can obtain:

[0109]

[0110] Therefore, we can obtain the following two equations:

[0111]

[0112]

[0113]

[0114] According to the transformer turns ratio formula, the voltage on the secondary winding can be obtained as follows:

[0115]

[0116]

[0117] Therefore, by combining the formula for the ratio of different variables, we can obtain:

[0118]

[0119] Therefore, the output voltage on the secondary coil is:

[0120]

[0121] Therefore, the relationship between the secondary coil output voltage and the primary coil input voltage can be obtained as follows:

[0122]

[0123] The magnetic circuit analysis of the diameter gauge above shows that there is a linear relationship between the output voltage and the input voltage. The linearity coefficient is related to the number of turns in the primary coil, the number of turns in the secondary coil, and the distance between the two ends of the armature and the coil frame. Keeping the number of coil turns constant, within a certain range, the linearity coefficient is only related to δ. A δ B related.

[0124] Example 16:

[0125] A device for online measurement of the diameter of nuclear fuel rods, with the same technical content as any one of Embodiments 1-15, further comprising δ A and δ B The sum of these values ​​is a fixed value, which is the range.

[0126] Example 17:

[0127] A device for online measurement of the diameter of nuclear fuel rods, with the same technical content as any one of Embodiments 1-16, further wherein the measuring range is ±2mm, δ A and δ B The sum of the values ​​is 4mm.

[0128] Example 18:

[0129] A method for using the apparatus for online measurement of nuclear fuel rod diameter as described in any one of Examples 1-17 includes the following steps:

[0130] 1) Insert the D end of the fuel rod 7 to be measured into the mounting hole of the first bracket 1 to fix the fuel rod 7 to be measured to the first bracket 1.

[0131] Fix end E of the fuel rod 7 to be measured to the second bracket 2.

[0132] Insert end A of armature 6 into the mounting hole of first bracket 1.

[0133] 2) The voltage measurement module is used to obtain the input voltage of the primary winding 4 and the output voltage of the secondary winding 5 in real time, and then transmits them to the calculation module.

[0134] 3) The calculation module calculates the distance between the A and B ends of the armature 6 and the winding frame 3 based on the relationship between the input voltage of the primary winding 4 and the output voltage of the secondary winding 5.

[0135] 4) Repeat steps 2-3 to calculate the changes in distance between the armature 6A end, B end and the winding frame 3 at different times, that is, the degree of armature rotation.

[0136] Example 19:

[0137] The method of using the apparatus for online measurement of nuclear fuel rod diameter described in any one of Examples 1-17 is the same as that in Example 18. Furthermore, the output amplitude signals of the two secondary coils have different phases, and the deformation type and magnitude at different positions of the nuclear fuel rod can be determined according to the phase difference method.

[0138] Example 20:

[0139] The method of using the apparatus for online measurement of nuclear fuel rod diameter described in any one of Examples 1-17 is the same as that in Example 18. Furthermore, the output amplitude signals of the two secondary coils are in different phases. The deformation type and magnitude of the side where the nuclear fuel rod is located (D end and E end) can be determined according to the phase difference method.

[0140] Example 21:

[0141] The method of using the apparatus for online measurement of nuclear fuel rod diameter described in any one of Examples 1-17 is the same as that in Example 18. Furthermore, if the change in distance between the armatures (6) is positive, the fuel rod (7) to be measured will be concave; if the change in distance is negative, the fuel rod (7) to be measured will be convex.

[0142] When both bulges and depressions exist, the phase difference method (the phase difference between the output amplitude signals of the two secondary coils) is used to determine the positions of the bulges and depressions.

[0143] Example 22:

[0144] A device for online measurement of nuclear fuel rod diameter mainly consists of left / right side supports, a coil frame, an armature, and primary / secondary coils. The core components are the coil frame and the rotatable armature connected to it. The overall structural dimensions of the device are 52mm*19mm*17mm.

[0145] When the diameter of the fuel rod changes, the armature rotates. During the rotation of the armature, the gap between the two ends of the armature and the coil frame changes. This change in gap alters the magnetic reluctance, which in turn causes a change in magnetic flux. The change in magnetic flux is reflected in the induced electromotive force generated by the secondary coil. Therefore, by measuring the differential change in the induced electromotive force, the angle of armature rotation can be obtained, and thus the magnitude and type (protrusion or depression) of the surface deformation of the fuel rod can be determined.

[0146] The deformation of the fuel rod causes the armature in contact with it to rotate, which in turn changes the magnetic flux in the device and causes a change in the electromotive force of the coil. By measuring the electromotive force, the magnitude and type of deformation on the surface of the fuel rod can be obtained. The fuel rod is fixed and clamped by a rotatable armature and a support. The rotation center of the armature is fixedly connected to the coil frame with a certain size.

Claims

1. A device for online measurement of the diameter of nuclear fuel rods, characterized in that: It includes a first support (1), a second support (2), a winding frame (3), a primary winding (4), a secondary winding (5), an armature (6), a voltage measurement module, and a calculation module; The first bracket (1) is used to fix the D end of the fuel rod (7) to be measured; The second bracket (2) is used to fix the E end of the fuel rod (7) to be measured; One end of the winding frame (3) is fixed on the first bracket (1), and the other end is fixed on the second bracket (2); The primary winding (4) and the secondary winding (5) are both wound on the winding frame (3); The rotation center of the armature (6) is fixed to the winding frame (3), so that the armature (6) can rotate; The voltage measurement module acquires the input voltage of the primary winding (4) and the output voltage of the secondary winding (5), and transmits them to the calculation module; The calculation module processes the input voltage of the primary winding (4) and the output voltage of the secondary winding (5) to calculate the degree of armature rotation used to characterize the surface deformation of the fuel rod.

2. The device for online measurement of nuclear fuel rod diameter according to claim 1, characterized in that, The steps for processing the input voltage of the primary winding (4) and the output voltage of the secondary winding (5) include: Based on the relationship between the input voltage of the primary winding (4) and the output voltage of the secondary winding (5), the distance change between the A and B ends of the armature (6) and the winding frame (3) within time t is calculated; the distance change between the A and B ends of the armature (6) and the winding frame (3) is the degree of armature rotation.

3. The device for online measurement of nuclear fuel rod diameter according to claim 2, characterized in that, The relationship between the input voltage of the primary winding (4) and the output voltage of the secondary winding (5) is as follows: In the formula, U1 and U2 are the input voltage of the primary winding (4) and the output voltage of the secondary winding (5); W1 and W2 are the number of turns of the primary winding (4) and the secondary winding (5); δ A and δ B These are the distances between the A and B ends of the armature (6) and the winding frame (3), respectively.

4. The device for online measurement of nuclear fuel rod diameter according to claim 1, characterized in that: The first bracket (1) has mounting holes; The mounting hole is used for the D end of the fuel rod (7) to be measured and the A end of the armature (6) to be inserted; The D end of the fuel rod (7) to be measured and the A end of the armature (6) have matching shapes.

5. The device for online measurement of nuclear fuel rod diameter according to claim 1, characterized in that: The primary winding (4) includes at least two primary coil windings; The primary coil windings are connected in series with the same name at the same time.

6. The device for online measurement of nuclear fuel rod diameter according to claim 3, characterized in that: The primary coil windings have the same number of turns.

7. The device for online measurement of nuclear fuel rod diameter according to claim 1, characterized in that: The secondary winding (5) includes at least two secondary coil windings; The terminals of the secondary coil windings are connected in reverse series.

8. The apparatus for online measurement of nuclear fuel rod diameter according to claim 7, characterized in that: The number of turns in the secondary coil windings is equal.

9. The apparatus for online measurement of nuclear fuel rod diameter according to claim 1, characterized in that, The voltage measurement module includes a voltage sensor.

10. A method using the apparatus for online measurement of the diameter of nuclear fuel rods according to any one of claims 1-9, characterized in that, Includes the following steps: 1) Insert the D end of the fuel rod (7) to be measured into the mounting hole of the first bracket (1) to fix the fuel rod (7) to be measured to the first bracket (1); Fix the E end of the fuel rod (7) to be measured to the second bracket (2); Insert the A end of the armature (6) into the mounting hole of the first bracket (1); 2) The input voltage of the primary winding (4) and the output voltage of the secondary winding (5) are obtained in real time using the voltage measurement module and transmitted to the calculation module; 3) The calculation module calculates the distance between the A and B ends of the armature (6) and the winding frame (3) based on the relationship between the input voltage of the primary winding (4) and the output voltage of the secondary winding (5); 4) Repeat steps 2)-3) to calculate the distance changes between the A and B ends of the armature (6) and the winding frame (3) at different times, that is, the degree of armature rotation.

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