阅读说明：本技术 一种用于高温超导带材的温度冲击检测方法及检测装置 (Temperature impact detection method and detection device for high-temperature superconducting strip ) 是由 王玉山 周彬 陈天博 蒋晓红 田卡 蔡渊 熊旭明 迮建军 于 2019-12-04 设计创作，主要内容包括：本发明公开了一种用于高温超导带材的温度冲击检测方法及检测装置,包括样品固定机构、临界电流检测机构、储液机构和驱动机构；样品固定机构包括操作台、液体箱和样品固定架；液体箱设置在操作台上；至少一个样品固定架设置在液体箱内部的侧壁上；临界电流检测机构包括电流线和电压线；样品固定架两端分别与电流线连接；储液机构与液体箱连通；驱动机构驱动储液机构上下运动。检测方法是通过对超导带材的温度冲击试验检测其临界电流并计算电流保留系数。本案实现对高温超导带材进行温度冲击处理并直接进行临界电流检测；操作简单,设备简单,成本低,可重复性高,适用性强；减少操作人员的安全隐患；对超导带材的应用可靠性进行验证和包覆的密封性验证。(The invention discloses a temperature impact detection method and a detection device for a high-temperature superconducting strip, which comprise a sample fixing mechanism, a critical current detection mechanism, a liquid storage mechanism and a driving mechanism, wherein the sample fixing mechanism is used for fixing a sample; the sample fixing mechanism comprises an operation table, a liquid tank and a sample fixing frame; the liquid tank is arranged on the operating platform; at least one sample fixing frame is arranged on the side wall in the liquid tank; the critical current detection mechanism comprises a current line and a voltage line; two ends of the sample fixing frame are respectively connected with the current wires; the liquid storage mechanism is communicated with the liquid tank; the driving mechanism drives the liquid storage mechanism to move up and down. The detection method is to detect the critical current of the superconducting tape through a temperature impact test of the superconducting tape and calculate the current retention coefficient. The scheme realizes the temperature impact treatment on the high-temperature superconducting strip and directly detects the critical current; the method has the advantages of simple operation, simple equipment, low cost, high repeatability and strong applicability; the potential safety hazard of operators is reduced; the application reliability of the superconducting tape and the sealing performance of the coating are verified.)

1. A temperature impact detection device for a high-temperature superconducting strip is characterized in that: the critical current detection device comprises a sample fixing mechanism, a critical current detection mechanism, a liquid storage mechanism and a driving mechanism; the sample fixing mechanism comprises an operation table, a liquid tank and a sample fixing frame; the liquid tank is arranged on the operating platform; the upper end of the liquid tank is opened; at least one sample fixing frame is arranged on the side wall of the interior of the liquid tank; the critical current detection mechanism comprises a current line and a voltage line; two ends of the sample fixing frame are respectively connected with the current wires; pressurizing and flowing a sample belt of the superconducting tape through a voltage line and a current line; the liquid storage mechanism is communicated with the liquid tank; the driving mechanism drives the liquid storage mechanism to move up and down.

2. The apparatus according to claim 1, wherein: the liquid storage mechanism comprises a liquid storage tank, a flow guide pipe and a liquid inlet; the guide pipe is connected with the liquid storage tank and the liquid box; the upper part of the liquid storage tank is provided with a liquid inlet.

3. The apparatus according to claim 1, wherein: the driving mechanism comprises a cylinder rod, a cylinder and a cylinder table; the liquid storage mechanism is arranged on the cylinder table; the cylinder drives the cylinder rod to drive the cylinder table to move up and down, and the height of the liquid storage mechanism is adjusted.

4. The apparatus according to claim 1, wherein: and a valve is arranged on the liquid tank and used for controlling liquid to enter and exit the liquid tank.

5. The apparatus according to claim 4, wherein: the valve is a valve loose piece; the valve loose piece moves in the vertical direction to shield a liquid flow port of the liquid tank.

6. The apparatus according to claim 1, wherein: and a voltage clamp is arranged at the tail end of the voltage wire.

7. A temperature impact detection method for a high-temperature superconducting strip is characterized by comprising the following steps: the specific detection steps comprise:

step 1: cutting a plurality of superconducting tape samples on the same superconducting tape, wherein the length of each section of superconducting tape sample is kept consistent, and the length of each section of superconducting tape sample is ensured to be enough for detection;

step 2: welding current leading belts on two ends of the superconducting tape sample by using the soldering flux so as to reduce the contact resistance between the electrode and the superconducting tape sample;

and step 3: respectively clamping a voltage electrode and a current electrode on a superconducting strip sample welded with a current leading belt;

and 4, step 4: putting the superconducting tape sample into liquid nitrogen to enable the superconducting tape sample to be completely immersed and soaked;

and 5: method for detecting critical current Ic of superconducting strip sample in liquid nitrogen environment by using four-lead method_S；

Step 6: taking out the superconducting tape sample from the liquid nitrogen, and naturally recovering to room temperature;

and 7: repeating the step 4, putting the superconducting tape sample into liquid nitrogen to enable the superconducting tape sample to be completely immersed and soaked; repeating the step 6, taking out the superconducting tape sample from the liquid nitrogen, and naturally recovering to room temperature; forming a temperature shock; repeating the liquid nitrogen temperature impact process for n times;

and 8: repeating the step 5, and carrying out critical current detection on the superconducting tape sample subjected to the liquid nitrogen temperature impact in the step 7 and recording;

and step 9: repeating the steps 7 to 8 for m times, and obtaining a critical current Ic each time_iWherein i is less than or equal to m;

step 10: soaking the superconducting tape sample subjected to liquid nitrogen temperature impact in water at room temperature, observing whether bubbles emerge around the superconducting tape sample, and recording;

step 11: after soaking, taking out the superconducting tape sample from the room temperature water, wiping water stains on the surface of the superconducting tape sample, and immediately repeating the step 4 and the step 5 to detect the critical current Ic of the superconducting tape sample_E；

Step 12: according to the critical current Ic_SAnd Ic_ECalculating a current retention coefficient delta, and the formula is as follows: δ = (Ic/Ic)_S）*100%。

Technical Field

The invention belongs to the field of superconducting performance detection of superconducting tapes, and particularly relates to a temperature impact experimental method and an experimental device for a high-temperature superconducting tape.

Background

The superconducting material can be converted into a superconducting state from a normal state only in a certain temperature environment, and the conversion temperature of the high-temperature superconducting material is in a liquid nitrogen temperature region, so that the high-temperature superconducting tape needs to work in the environment of the liquid nitrogen temperature region in the using process. The critical current Ic of the superconducting tape is an important performance index in its application. If the superconducting layer of the superconducting tape is damaged, the resistance of the superconducting tape is greatly increased, and the superconducting tape is easy to burn after being impacted by relatively large current. Therefore, in general, we can determine the superconducting performance of the superconducting tape by testing the critical current Ic of the superconducting tape.

Most high temperature superconducting tapes need to undergo multiple transformations at liquid nitrogen and room temperature, posing a significant challenge to their temperature cycling fatigue. Because the superconducting tape may have some defects, after a plurality of through-flows, the superconducting performance of the superconducting tape is also attenuated to a certain degree. On the other hand, the superconducting strip is easy to generate defects in the soldering coating process, and the working performance of the superconducting strip can be affected to different degrees. Firstly, when the superconducting tape works, environmental liquid permeates into the false solder joint, and the phenomenon of expansion with heat and contraction with cold is generated due to different temperatures after the environmental liquid is vaporized, so that the coating layer is easy to crack and bulge. The surface of the superconducting layer of the superconducting strip is plated with an Ag protective layer, the binding force of the Ag layer with the coating layer and the superconducting layer is larger than that of the superconducting layer with the isolating layer, and when the coating layer cracks, the superconducting layer is easily damaged, so that the superconducting layer generates irreversible physical damage, and the superconducting strip loses the superconducting performance. Secondly, the coating layer of the superconducting tape cracks, so that the superconducting layer loses the outer protective layer and is exposed outside, and the superconducting layer is deliquesced in the environment with higher humidity, so that the superconducting performance of the superconducting tape is attenuated. With the continuous advance of the industrialization process of the high-temperature superconducting tape, the application performance requirements of the superconducting tape are continuously challenged.

However, no special experimental method is available in the prior art for testing the influence of the high-temperature superconducting tape on the critical current after the high-temperature superconducting tape repeatedly works in the liquid nitrogen temperature region. Therefore, experiments need to be designed according to the working environment of the high-temperature superconducting tape, the application reliability of the superconducting tape is verified, the repeated working performance of the superconducting tape in a liquid nitrogen temperature area is detected, and the method can be used for verifying the sealing performance of the coating of the high-temperature superconducting tape, and has important reference value for the industrialization of the high-temperature superconducting tape.

Disclosure of Invention

The invention aims to: the method can test the fatigue, the stability and the coating integrity of the superconducting tape through a designed temperature impact experiment.

The technical scheme of the invention is as follows: a temperature impact detection device for a high-temperature superconducting strip comprises a sample fixing mechanism, a critical current detection mechanism, a liquid storage mechanism and a driving mechanism; the sample fixing mechanism comprises an operation table, a liquid tank and a sample fixing frame; the liquid tank is arranged on the operating platform; the upper end of the liquid tank is opened; at least one sample fixing frame is arranged on the side wall of the interior of the liquid tank; the critical current detection mechanism comprises a current line and a voltage line; two ends of the sample fixing frame are respectively connected with the current wires; pressurizing and flowing a sample belt of the superconducting tape through a voltage line and a current line; the liquid storage mechanism is communicated with the liquid tank; the driving mechanism drives the liquid storage mechanism to move up and down.

Preferably, the liquid storage mechanism comprises a liquid storage tank, a flow guide pipe and a liquid inlet; the guide pipe is connected with the liquid storage tank and the liquid box; the upper part of the liquid storage tank is provided with a liquid inlet, and the liquid inlet can be used as a liquid inlet for filling environmental liquid from the outside and can also be used as an air outlet for balancing the air pressure in the liquid storage tank.

Preferably, the driving mechanism comprises a cylinder rod, a cylinder and a cylinder table; the liquid storage mechanism is arranged on the cylinder table; the cylinder drives the cylinder rod to drive the cylinder table to move up and down, the height of the liquid storage mechanism is adjusted, and then the liquid level in the liquid tank is changed.

Preferably, the liquid tank is provided with a valve for controlling liquid to enter and exit the liquid tank.

Preferably, the valve is a valve loose piece; the valve loose piece moves in the vertical direction to shield a liquid flow port of the liquid tank, and the valve is detachable.

Preferably, a voltage clamp is arranged at the tail end of the voltage line.

A temperature impact detection method for a high-temperature superconducting strip comprises the following specific detection steps:

step 1: cutting a plurality of superconducting tape samples on the same superconducting tape, wherein the length of each section of superconducting tape sample is kept consistent, and the length of each section of superconducting tape sample is ensured to be enough for detection;

step 2: welding current leading belts on two ends of a superconducting tape sample by using soldering flux so as to reduce the contact resistance between an electrode and the superconducting tape sample and avoid burning near the electrode due to overlarge contact resistance in a critical current experiment;

and step 3: respectively clamping a voltage electrode and a current electrode on a superconducting strip sample welded with a current leading belt;

and 4, step 4: putting the superconducting tape sample into liquid nitrogen to enable the superconducting tape sample to be completely immersed and soaked;

and 5: method for detecting critical current Ic of superconducting strip sample in liquid nitrogen environment by using four-lead method_S；

Step 6: taking out the superconducting tape sample from the liquid nitrogen, and naturally recovering to room temperature;

and 7: repeating the step 4, putting the superconducting tape sample into liquid nitrogen to enable the superconducting tape sample to be completely immersed and soaked; repeating the step 6, taking out the superconducting tape sample from the liquid nitrogen, and naturally recovering to room temperature; forming a temperature shock; repeating the liquid nitrogen temperature impact process for n times;

and 8: repeating the step 5, and carrying out critical current detection on the superconducting tape sample subjected to the liquid nitrogen temperature impact in the step 7 and recording;

and step 9: repeating the steps 7 to 8 for m times, and obtaining a critical current Ic each time_iWherein i is a positive integer no greater than m;

step 10: soaking the superconducting tape sample subjected to liquid nitrogen temperature impact in water at room temperature, observing whether bubbles emerge around the superconducting tape sample, and recording;

step 11: after soaking, taking out the superconducting tape sample from the room temperature water, wiping water stains on the surface of the superconducting tape sample, and immediately repeating the step 4 and the step 5 to detect the critical current Ic of the superconducting tape sample_E；

Step 12: according to the critical current Ic_SAnd Ic_ECalculating a current retention rate delta, drawing a critical current retention rate attenuation curve, wherein the abscissa is the impact times (n x i), the ordinate is the current retention rate delta, and the formula is as follows: δ = (Ic/Ic)_S）*100%；

Step 13: the experiment terminates when the following occurs:

firstly, completing an experiment;

secondly, the strip loses the superconducting property and is irreversible;

and thirdly, the current retention rate is lower than the current retention coefficient K value.

The invention has the advantages that:

1. the critical current detection is directly carried out on the high-temperature superconducting tape subjected to the temperature impact;

2. the operation is simple, the equipment is simple, the cost is low, and the repeatability is high;

3. the applicability is strong, and the device can be used for temperature impact experiments of various high-temperature superconducting tapes;

4. potential safety hazards of operators in the operation process are reduced;

5. temperature impact test experiments can be simultaneously carried out on a plurality of groups of superconducting tapes;

6. the application reliability of the superconducting tape is verified, the repeated working performance of the superconducting tape in a liquid nitrogen temperature region is detected, and the method can be used for verifying the sealing performance of the high-temperature superconducting tape coating.

Drawings

The invention is further described with reference to the following figures and examples:

FIG. 1 is a schematic structural view of a temperature impact detection apparatus for a high temperature superconducting tape according to the present disclosure;

FIG. 2 is a schematic structural diagram of a sample fixing mechanism and a critical current detecting mechanism of a temperature impact detecting apparatus for a high temperature superconducting tape according to the present disclosure;

FIG. 3 is a schematic view showing a structure of a sample assembly of a superconducting tape used in the apparatus for detecting temperature impact of a high temperature superconducting tape according to the present invention;

FIG. 4 is a flowchart illustrating a method for detecting temperature shock of a high temperature superconducting tape according to the present disclosure;

fig. 5 is a graph illustrating critical current retention measured by the temperature impact measurement method for a high temperature superconducting tape according to the present disclosure.

Detailed Description