阅读说明：本技术 一种高温高压电化学测试电极 (High-temperature high-pressure electrochemical test electrode ) 是由 胡静静 王翠 于 2020-04-15 设计创作，主要内容包括：本发明公开了一种高温高压电化学测试三电极,该三电极顶端分别设有银丝导线,通过银丝导线与电化学工作站连接从而进行电化学测试；该三电极伸出釜盖以外的冷端顶部距离釜盖的距离为加长距离,在三电极冷端顶部附近设有电极密封组件,该电极密封组件上还设有铜镀金材质的十字架过渡接头,该十字架过渡接头上方和下方分别设有采用聚四氟乙烯材质的用于绝缘和密封的上、下组合密封垫,其能够对目标物体提供横向和纵向的双向压力；在上组合密封垫和电极密封组件的密封壳体之间还设有金属蝶形垫片,该蝶形垫片用于满足上、下组合密封垫使用中对于压缩载荷的持续要求；本发明实现了对于高温高压电化学测试电极的持久有效绝缘和密封效果,实现了免维护。(The invention discloses a high-temperature high-pressure electrochemical test three-electrode, wherein silver wire leads are respectively arranged at the top ends of the three-electrode and are connected with an electrochemical workstation through the silver wire leads so as to carry out electrochemical test; the distance from the top of the cold end of the three-electrode extending out of the kettle cover to the kettle cover is a lengthening distance, an electrode sealing assembly is arranged near the top of the cold end of the three-electrode, a cross transition joint made of copper and gold-plated materials is further arranged on the electrode sealing assembly, and upper and lower combined sealing gaskets which are made of polytetrafluoroethylene and used for insulation and sealing are respectively arranged above and below the cross transition joint and can provide transverse and longitudinal bidirectional pressure for a target object; a metal butterfly gasket is arranged between the upper combined sealing gasket and the sealing shell of the electrode sealing assembly and used for meeting the continuous requirement of the upper and lower combined sealing gaskets on the compression load in use; the invention realizes the lasting and effective insulation and sealing effects of the high-temperature and high-pressure electrochemical test electrode and realizes maintenance-free.)

1. A high-temperature high-pressure electrochemical test electrode comprises a working electrode, a reference electrode and an auxiliary electrode; the working electrode is used for testing a sample, the reference electrode is used for determining the potential of the working electrode, and the auxiliary electrode is used for conducting current; the top ends of the three electrodes are respectively provided with a silver wire lead which is connected with an electrochemical workstation through the silver wire lead so as to carry out electrochemical test; the method is characterized in that: the distance from the top of the cold end of the three electrodes extending out of the kettle cover to the kettle cover is a lengthened distance, an electrode sealing assembly is arranged near the top of the cold end of the three electrodes, a cross transition joint made of copper and gold-plated materials is further arranged on the electrode sealing assembly, an upper combined sealing gasket and a lower combined sealing gasket which are made of polytetrafluoroethylene materials and used for insulation and sealing are respectively arranged above and below the cross transition joint, and the upper combined sealing gasket and the lower combined sealing gasket can provide transverse and longitudinal bidirectional pressure for a target object; a metal butterfly gasket is arranged between the upper combined sealing gasket and the sealing shell of the electrode sealing assembly and used for meeting the continuous requirement of the upper and lower combined sealing gaskets on the compression load in use; the middle lower parts of the three electrodes are respectively provided with a cutting sleeve joint, and the three electrodes penetrate through the respective cutting sleeve joints to be inserted into corrosive liquid of a high-temperature high-pressure kettle below the cutting sleeve joints.

2. A high temperature high pressure electrochemical test electrode according to claim 1, wherein: the electrode sealing assembly arranged on the three electrodes close to the top end comprises an upper part, a middle part and a lower part, wherein the middle part is a sealing main body, and a sealing shell is sleeved on the upper part of the outer surface of the sealing main body and locked with the external thread of the sealing main body; the lower part of the outer surface of the sealing main body is sleeved with a clamping sleeve nut and locked with the external thread of the sealing main body.

3. A high temperature high pressure electrochemical test electrode according to claim 1, wherein: the cross transition joint is arranged between the sealing main body and the sealing shell, is upwards connected with the silver wire and is downwards connected with the electrode core; the cross transition joint comprises an upper cylinder and a lower cylinder, wherein the parts of the upper cylinder and the lower cylinder, which are close to the ends, are hollow cylinders, and the rest parts are solid bodies which are used for preventing an electrode below the solid bodies from being blown out; the lower cylindrical hollow cylinder is radially arranged between the electrode core insulating sleeve and the electrode core, and the outer wall of the lower cylindrical hollow cylinder is inserted into the inner wall of the electrode core insulating sleeve below the lower cylindrical hollow cylinder; the hollow cylinder of the upper cylinder is radially arranged between the silver wire insulating sleeve and the silver wire, and the outer wall of the hollow cylinder is inserted into the inner wall of the silver wire insulating sleeve above the hollow cylinder; the outer diameter of the lower cylindrical hollow cylinder is slightly larger than the inner diameter of the electrode core insulating sleeve, so that the electrode core insulating sleeve can be firmly sleeved; the outer diameter of the upper cylindrical hollow cylinder is slightly larger than the inner diameter of the silver wire insulating sleeve, so that the silver wire insulating sleeve can be firmly sleeved.

4. A high temperature high pressure electrochemical test electrode according to claim 1, wherein: each electrode of the three electrodes comprises an upper part and a lower part which are connected through a transition joint, each electrode is positioned at the part above the central point of the transition joint, the outer layer is a silver wire insulating sleeve, and the inner layer is a silver wire lead; each electrode is positioned at the part below the central point of the transition joint, the outer layer is an electrode protection sleeve, and the inner layer is an electrode core; the electrode protection sleeves are respectively a reference electrode protection sleeve, a working electrode protection sleeve and an auxiliary electrode protection sleeve; the electrode core is respectively a reference electrode core, a working electrode core and an auxiliary electrode core.

5. A high temperature high pressure electrochemical test electrode according to claim 1, wherein: the upper combined sealing gasket is sleeved around the upper cylindrical hollow cylinder of the transition joint, the lower combined sealing gasket is sleeved around the lower cylindrical hollow cylinder of the transition joint, and the upper combined sealing gasket is used for insulation between the transition joint and the sealing shell and is used for holding the silver wire insulating sleeve so that the silver wire insulating sleeve cannot fall off; the lower combined sealing gasket is used for sealing and insulating the transition joint and the sealing main body, and simultaneously embraces and squeezes the reference electrode insulating sleeve to prevent leakage of salt bridge liquid; the upper combined sealing gasket and the lower combined sealing gasket are both composed of an outer arc sealing gasket and an inner arc sealing gasket, the angle of an outer arc is slightly larger than that of an inner arc, the angle of an arc of the outer arc sealing gasket is 60 degrees, the angle of the inner arc sealing gasket is 55 degrees, when the upper combined sealing gasket and the lower combined sealing gasket are pressed up and down, an inner hole of the outer arc sealing gasket is shrunk and tightly holds the electrode core insulating sleeve or the silver wire insulating sleeve, and therefore longitudinal pressure and transverse pressure on the electrode core insulating sleeve or the silver wire insulating sleeve are achieved.

6. A high temperature high pressure electrochemical test electrode according to claim 3, wherein: the inner wall of the reference electrode core insulating sleeve close to the bottom end is stuffed with a micropore ceramic column, and the outer diameter of the micropore ceramic column is slightly larger than the inner diameter of the reference electrode insulating sleeve, so that the micropore ceramic column is prevented from falling off.

7. The high temperature, high pressure electrochemical test electrode of claim 6, wherein: the reference electrode core insulating sleeve of the reference electrode is filled with salt bridge liquid, the salt bridge liquid is saturated potassium chloride solution, and the pores of the microporous ceramic column are nano-scale micropores for allowing gas and electric ions to freely penetrate through but blocking liquid from penetrating through.

8. A high temperature high pressure electrochemical test electrode according to claim 1, wherein: the three-electrode insertion kettle can resist 300 ℃ of high temperature, the distance between the three-electrode insertion kettle and the top of the cold end higher than the kettle cover is 30 cm, and the temperature around the sealed assembly is not more than 50 ℃.

Technical Field

The invention relates to the technical field of electrochemical test electrodes for nuclear power station materials, in particular to a high-temperature high-pressure electrochemical test electrode.

Background

The corrosion damage of the nuclear power station material in the high-temperature and high-pressure water environment is an electrochemical corrosion behavior, and with the deep research of the nuclear power station material in China, the requirement on the high-temperature and high-pressure electrochemical corrosion test is more and more urgent. The high-temperature high-pressure electrochemical corrosion test generally adopts a high-temperature high-pressure reaction kettle and an electrochemical electrode to simulate the high-temperature high-pressure water environment of a nuclear power station to perform the electrochemical corrosion test on the material.

At present, the technology of domestic high-temperature autoclaves is mature, but the research and invention of high-temperature high-pressure test electrodes have defects. The biggest difficulty of the high-temperature and high-pressure test electrode is that the electrode is sealed and insulated at high temperature and high pressure. The sealing and insulation of the high-temperature and high-pressure test electrode are roughly divided into two conditions at present, the first condition is that the sealing and insulation are directly carried out on a reaction kettle cover (a high-temperature end) in the method of 201910376671.0, in order to solve the problems of insulation and sealing, a transition electrode (a copper electrode) is arranged between the kettle cover and a three-electrode, and because a copper electrode boss is subjected to downward acting force of a compression screw and reaction force of electrode hole shoulders, the boss blocks the path of gas leakage from bottom to top, the danger that the copper electrode is upwards fleed due to the fact that the copper electrode is subjected to high pressure from bottom to top is also shielded, and the problems of effective sealing of the copper electrode under high temperature and high pressure and firm locking of the copper electrode are solved. Although this approach solves the insulation and sealing problems to some extent, three disadvantages remain, the first: three electrodes are arranged under the reaction kettle cover, the three electrodes are directly exposed in the high-temperature reaction kettle without protective sleeves, the three electrodes are generally made of polytetrafluoroethylene or PEEK materials, and the three electrodes are easy to deform in a high-temperature environment; the second disadvantage is that: this transition electrode (copper electrode) is direct to stretching to in the reation kettle, be corrosion solution in the cauldron, though not touching solution, but there is steam corrosion copper transition electrode under the high temperature, in case the corrosion solution in the cauldron can be influenced by the corruption of copper transition electrode, if corrosion solution pollutes easily, then test effect is just inaccurate. Although the gold plating can be plated outside the copper transition electrode for corrosion prevention, the gold plating layer can be worn off due to frequent friction at the external threads of the nut and the copper transition electrode, so that the copper transition electrode directly extending into the reaction kettle body has great possibility of being corroded; the third is not enough, this patent cross transition all is sealed the pad that the PEEK material was made about from top to bottom, thereby this 4 sealed nuts that rely on the top completely exert vertical pressure to them sealed the pad, the insulating pad of this kind of material also has the inflation under high temperature for a long time, be high temperature environment when doing the experiment at every turn, sealed pad can expand under the high temperature environment, the experiment cooling has been done, sealed pad then can contract after the cooling, sealed pad shrink, the nut just can not compress tightly sealed pad, therefore produce gas leakage, the solution is that to do the experiment and twist the jackscrew once, also be exactly screw up gland nut above the cross transition, just so relatively more troublesome, the maintenance volume has been increased. In the second situation, the sealing and insulation are led out of the reaction kettle, a cold water jacket is arranged for cooling the electrode, and the sealing and insulation are carried out at the cold end of the electrode, so that the sealing and insulation problems of the electrode are solved skillfully by the design, such as 201110282690.0. However, the electrochemical corrosion test is a long-term continuous work, one sample needs to be continuously tested for at least two weeks, water is not safely supplied when no one person is in conservation at night, and water resources are wasted. And secondly, the electrode core is a conducting wire with the same diameter and is fixed by the extrusion of the rubber sealing plug and the stopping plug, but the electrode core is possibly blown out under the condition of high pressure, so that the electrode core is dangerous.

In summary, in the prior art, sealing and insulation are performed at the high-temperature end, but the high-temperature end is used for sealing, and due to expansion caused by heat and contraction caused by cold, the sealing element at the high-temperature end cannot realize lasting effective sealing, and the nut needs to be screwed down again after an experiment is performed each time to be reused; or adopt and do sealed and insulating at the electrode cold junction, but the cold junction is sealed and insulating because can not solve the firm problem of electrode and make the electrode easily blow off, simultaneously because can not solve the cooling problem of cold extreme end sealing member, need set up cold water cover alone, extravagant manpower and water resource.

Disclosure of Invention

The invention provides a high-temperature high-pressure electrochemical test electrode for solving the problems of the prior art that the high-temperature end is sealed, the lasting and effective sealing cannot be realized, the cold end is sealed, the electrode firmness problem and the cooling problem cannot be solved, the electrode is easy to blow out, and a cold water jacket needs to be separately arranged, so that the water resource is wasted.

A high-temperature high-pressure electrochemical test electrode comprises a working electrode, a reference electrode and an auxiliary electrode; the working electrode is used for testing a sample, the reference electrode is used for determining the potential of the working electrode, and the auxiliary electrode is used for conducting current; the top ends of the three electrodes are respectively provided with a silver wire lead which is connected with an electrochemical workstation through the silver wire lead so as to carry out electrochemical test; the method is characterized in that: the distance from the top of the cold end of the three electrodes extending out of the kettle cover to the kettle cover is a lengthened distance, an electrode sealing assembly is arranged near the top of the cold end of the three electrodes, a cross transition joint made of copper and gold-plated materials is further arranged on the electrode sealing assembly, an upper combined sealing gasket and a lower combined sealing gasket which are made of polytetrafluoroethylene materials and used for insulation and sealing are respectively arranged above and below the cross transition joint, and the upper combined sealing gasket and the lower combined sealing gasket can provide transverse and longitudinal bidirectional pressure for a target object; a metal butterfly gasket is arranged between the upper combined sealing gasket and the sealing shell of the electrode sealing assembly and used for meeting the continuous requirement of the upper and lower combined sealing gaskets on the compression load in use; the middle lower parts of the three electrodes are respectively provided with a cutting sleeve joint, and the three electrodes penetrate through the respective cutting sleeve joints to be inserted into corrosive liquid of a high-temperature high-pressure kettle below the cutting sleeve joints.

The electrode sealing assembly arranged on the three electrodes close to the top end comprises an upper part, a middle part and a lower part, wherein the middle part is a sealing main body, and a sealing shell is sleeved on the upper part of the outer surface of the sealing main body and locked with the external thread of the sealing main body; the lower part of the outer surface of the sealing main body is sleeved with a clamping sleeve nut and locked with the external thread of the sealing main body.

The cross transition joint is arranged between the sealing main body and the sealing shell, is upwards connected with the silver wire and is downwards connected with the electrode core; the cross transition joint comprises an upper cylinder and a lower cylinder, wherein the parts of the upper cylinder and the lower cylinder, which are close to the ends, are hollow cylinders, and the rest parts are solid bodies which are used for preventing an electrode below the solid bodies from being blown out; the lower cylindrical hollow cylinder is radially arranged between the electrode core insulating sleeve and the electrode core, and the outer wall of the lower cylindrical hollow cylinder is inserted into the inner wall of the electrode core insulating sleeve below the lower cylindrical hollow cylinder; the hollow cylinder of the upper cylinder is radially arranged between the silver wire insulating sleeve and the silver wire, and the outer wall of the hollow cylinder is inserted into the inner wall of the silver wire insulating sleeve above the hollow cylinder; the outer diameter of the lower cylindrical hollow cylinder is slightly larger than the inner diameter of the electrode core insulating sleeve, so that the electrode core insulating sleeve can be firmly sleeved; the outer diameter of the upper cylindrical hollow cylinder is slightly larger than the inner diameter of the silver wire insulating sleeve, so that the silver wire insulating sleeve can be firmly sleeved.

Each electrode of the three electrodes comprises an upper part and a lower part which are connected through a transition joint, each electrode is positioned at the part above the central point of the transition joint, the outer layer is a silver wire insulating sleeve, and the inner layer is a silver wire lead; each electrode is positioned at the part below the central point of the transition joint, the outer layer is an electrode protection sleeve, and the inner layer is an electrode core; the electrode protection sleeves are respectively a reference electrode protection sleeve, a working electrode protection sleeve and an auxiliary electrode protection sleeve; the electrode core is respectively a reference electrode core, a working electrode core and an auxiliary electrode core.

The upper combined sealing gasket is sleeved around the upper cylindrical hollow cylinder of the transition joint, the lower combined sealing gasket is sleeved around the lower cylindrical hollow cylinder of the transition joint, and the upper combined sealing gasket is used for insulation between the transition joint and the sealing shell and is used for holding the silver wire insulating sleeve so that the silver wire insulating sleeve cannot fall off; the lower combined sealing gasket is used for sealing and insulating the transition joint and the sealing main body, and simultaneously embraces and squeezes the reference electrode insulating sleeve to prevent leakage of salt bridge liquid; the upper combined sealing gasket and the lower combined sealing gasket are both composed of an outer arc sealing gasket and an inner arc sealing gasket, the angle of an outer arc is slightly larger than that of an inner arc, the angle of an arc of the outer arc sealing gasket is 60 degrees, the angle of the inner arc sealing gasket is 55 degrees, when the upper combined sealing gasket and the lower combined sealing gasket are pressed up and down, an inner hole of the outer arc sealing gasket is shrunk and tightly holds the electrode core insulating sleeve or the silver wire insulating sleeve, and therefore longitudinal pressure and transverse pressure on the electrode core insulating sleeve or the silver wire insulating sleeve are achieved.

The inner wall of the reference electrode core insulating sleeve close to the bottom end is stuffed with a micropore ceramic column, and the outer diameter of the micropore ceramic column is slightly larger than the inner diameter of the reference electrode insulating sleeve, so that the micropore ceramic column is prevented from falling off.

The reference electrode core insulating sleeve of the reference electrode is filled with salt bridge liquid, the salt bridge liquid is saturated potassium chloride solution, and the pores of the microporous ceramic column are nano-scale micropores for allowing gas and electric ions to freely penetrate through but blocking liquid from penetrating through.

The three-electrode insertion kettle can resist 300 ℃ of high temperature, the distance between the three-electrode insertion kettle and the top of the cold end higher than the kettle cover is 30 cm, and the temperature around the sealed assembly is not more than 50 ℃.

Advantageous effects of the invention

1. The invention realizes the lasting effective insulation and sealing effect of the high-temperature high-pressure electrochemical test electrode by organically combining a disc-shaped gasket which can apply pressure to a target object under constant tension, a combined sealing gasket which has an outer arc and an inner arc and is applied in a bidirectional way, wherein the outer arc is slightly larger than the inner arc, and the disc-shaped gasket, the inner arc and the outer arc are organically combined, thereby really realizing the maintenance-free effect, solving the biggest problem that the sealing and insulation are carried out under the high-temperature high-pressure condition for a long time in the field, generating the leap from quantitative change to qualitative change, and having outstanding substantive characteristics and remarkable progress.

2. The electrode seal assembly is arranged in an environment far away from high temperature, the temperature of the electrode seal assembly at the cold end of the electrode is guaranteed not to exceed 50 ℃, and therefore components in the electrode seal assembly are guaranteed not to be influenced by high temperature.

3. According to the invention, the metal butterfly gasket is arranged in the electrode sealing assembly, and the characteristics that the metal butterfly gasket can store energy and release energy are utilized, so that the metal butterfly gasket can continuously meet the requirement of the combined sealing gasket on constant tension loading, and the problem that the pressure degree can be gradually weakened to influence the sealing effect due to fatigue damage in the long-term use process of the combined sealing gasket is solved.

4. According to the invention, the combined sealing gasket consisting of the outer arc sealing gasket and the inner arc sealing gasket is arranged in the combined sealing element, and the arc angle of the outer arc sealing gasket is slightly larger than that of the inner arc, so that the inner hole of the outer arc sealing gasket is shrunk to be small when the outer arc and the inner arc are compressed up and down, and the electrode core insulating sleeve or the silver wire insulating sleeve is held tightly.

5. According to the invention, through arranging the transition joint, the combined sealing gasket and the metal butterfly gasket, triple protection on the firmness of the electrode core is realized, and the danger that the electrode core is blown out of the kettle by high pressure in the kettle is effectively avoided.

6. The invention has simple structure, easy processing, low cost and easy disassembly and assembly of the three electrodes, and the whole electrode can be drawn out only by unscrewing the clamping sleeve on the clamping sleeve joint on the high-temperature high-pressure kettle cover, thereby being convenient for replacement and maintenance.

Drawings

FIG. 1 is a schematic view of a three-electrode installation;

FIGS. 2A, 2B and 2C are structural diagrams of reference electrodes;

FIG. 3 is a view showing the construction of an auxiliary electrode;

FIG. 4 is a view of the construction of the working electrode;

in the figure: 1: a reference electrode; 101: a reference electrode core; 102: a microporous ceramic post; 103: an electrode core insulating sleeve; 104: an electrode protection sleeve; 105: a salt bridge solution; 2: an auxiliary electrode; 201: an auxiliary electrode core; 3: a working electrode; 301: a working electrode core; 302: testing the sample; 305: an insulating pad; 4: high-temperature high-pressure autoclave; 401: corrosive liquid; 5: a ferrule fitting; 6: a three-electrode seal assembly; 605: double cutting sleeves; 606: a ferrule nut; 607: a sealing body; 608: sealing the housing; 609: a transition joint; 609-1: a transition joint upper cylinder; 609-2: a lower cylinder of the transition joint; 7: silver wire; 8: a silver wire insulating sleeve; 901: an outer circular arc sealing gasket; 902: an inner arc sealing gasket; 11: flattening the cushion; 12: a disc-shaped gasket.

Detailed Description

The invention will be further explained with reference to the drawings

Design principle of the invention

The comparison document 1 is the closest comparison document, and compared with the comparison document 1, the invention has the most prominent substantive characteristic and remarkable improvement in solving the problems of lasting effectiveness and maintenance-free of the electrode sealing assembly. The principle for realizing the lasting and effective sealing of the sealing component is as follows:

the first reason for achieving a durable and effective seal is: lay electrode seal assembly at the electrode cold junction to the distance that the design electrode cold junction reachd the high temperature reaction kettle lid is long enough, obtains through many times of experiments: when the temperature in the high-temperature high-pressure kettle is 300 ℃, when the distance between the cold end of the electrode and the cover of the high-temperature reaction kettle is 30 cm, the temperature of the electrode sealing assembly can be kept at 50 ℃, the temperature can ensure that a combined sealing gasket in the electrode sealing assembly and a disc-shaped gasket cannot expand with heat and contract with cold due to the influence of high temperature, compared with the comparison document 1, the comparison document 1 arranges the sealing assembly at the high-temperature end, so that the expansion with heat and the contraction with cold are generated, and the expansion with heat and the contraction with cold are the root causes of the repeated maintenance work required by the comparison document 1. Compared with the comparison document 2, although the comparison document 2 also sets the sealing assembly at the cold end, it does not find a suitable distance point which can not cool the sealing assembly, so that the risk of thermal expansion and cold contraction still exists, and in order to ensure the safety, the method of cooling the cold water jacket has to be adopted, but the labor cost and the water resource cost are increased.

The second reason for achieving a durable and effective seal is: the metal butterfly has the properties of storing and releasing energy, which are of particular importance for achieving a durable and effective seal: when the sealing main body and the sealing shell are screwed tightly, deformation is generated until the sealing main body and the sealing shell are flattened, and at the moment, the metal butterfly sheet stores live load in the form of stored energy. In long-term use of the three-electrode, although the temperature around the combined sealing gasket is ensured to be 50 ℃, slight expansion with heat and contraction with cold still exist, the three-electrode still generates creep after multiple times of slight expansion with heat and contraction with cold, and the disc-shaped gasket can automatically convert into additional compression load required by sealing, so that the continuous requirement of the combined sealing gasket on constant tension in use is reduced. Compared with the comparison document 1, the comparison document 1 applies the longitudinal pressure to the contracted sealing gasket again after the experiment is performed each time, that is, a device capable of automatically applying the longitudinal pressure to the contracted sealing gasket is not adopted, and the disc-shaped gasket plays a role in automatically applying the longitudinal pressure to the contracted sealing gasket.

A third reason for achieving a durable and effective seal is: the invention adopts the circular-arc combined sealing gasket with an upper layer and a lower layer, the circular arc of the sealing gasket of the layer which applies pressure downwards is larger than the circular arc of the sealing gasket of the layer which receives the pressure, so that the sealing gasket with the large circular arc on the upper layer is necessarily tightened in the process of applying the pressure downwards, the transverse pressure on the electrode insulating sleeve is generated in the tightening process, the electrode insulating sleeve also receives the longitudinal pressure which is generated by the external threads at the upper end and the lower end of the sealing main body and moves in opposite directions, compared with the comparison document 1, the comparison document 1 applies the pressure on the sealing gasket from one direction, namely the longitudinal direction, by screwing the nut, and the invention applies the pressure on the sealing gasket from the longitudinal direction and the transverse direction simultaneously. The sealing of the electrode core by the reference 2 is much simpler and cruder than the reference 2, and it is obviously very dangerous to directly use a method in which a sealing gasket surrounds the electrode core in an attempt to block the electrode core from being blown out by a frictional force therebetween.

Based on the principle, the invention designs the high-temperature high-pressure electrochemical test electrode.

A high-temperature high-pressure electrochemical test electrode is shown in figure 1, figure 2A, figure 2B and figure 2C, and comprises a working electrode 2, a reference electrode 1 and an auxiliary electrode 3; the working electrode 2 is used for testing a sample, the reference electrode 1 is used for determining the potential of the working electrode 2, and the auxiliary electrode 3 is used for conducting current; the top ends of the three electrodes are respectively provided with a silver wire lead 7, and the silver wires 7 are connected with an electrochemical workstation to perform electrochemical test; the method is characterized in that: the distance from the top of the cold end of the three-electrode extending out of the kettle cover to the kettle cover (the kettle cover is positioned between the mark 5 and the mark 4 in figure 1) is a lengthening distance, an electrode sealing assembly 6 is arranged near the top of the cold end of the three-electrode, a cross transition joint made of copper and gold-plated materials is further arranged on the electrode sealing assembly 6, an upper combined sealing gasket and a lower combined sealing gasket (the combined sealing gaskets are 901 and 902 in figure 2B) which are made of polytetrafluoroethylene materials and used for insulation and sealing are respectively arranged above and below the cross transition joint, and the upper combined sealing gasket and the lower combined sealing gasket can provide transverse and longitudinal bidirectional pressure for a target object; a metal butterfly gasket (12 in figures 2A and 2B) is arranged between the upper combined sealing gasket and the sealing shell of the electrode sealing assembly and is used for meeting the continuous requirement of the upper combined sealing gasket and the lower combined sealing gasket on the compression load in use; the middle lower parts of the three electrodes are respectively provided with a cutting sleeve joint 606, and the three electrodes penetrate through the respective cutting sleeve joints 606 and are inserted into the corrosive liquid 401 of the high-temperature autoclave below the cutting sleeve joints.

As shown in fig. 2A, the electrode sealing assembly disposed near the top end of the three electrodes includes an upper portion, a middle portion and a lower portion, the middle portion is a sealing main body 607, and a sealing housing 608 is further sleeved above the outer surface of the sealing main body and locked with the external thread of the sealing main body 607; a clamping sleeve nut 606 is sleeved below the outer surface of the sealing main body 607 to be locked with the external thread of the sealing main body.

As shown in fig. 2B and 2C, the cross transition joint 609 is disposed between the sealing body 607 and the sealing shell 608, and is connected with the silver wire 7 upwards and the electrode core 101 downwards; the cross transition joint 609 comprises an upper cylinder 609-1 and a lower cylinder 609-2, as shown in fig. 2C, the parts of the upper cylinder 609-1 and the lower cylinder 609-2 close to the ends are hollow cylinders, and the rest parts are solid bodies which are used for preventing the electrode core 101 below the solid bodies from being blown out; the lower cylindrical hollow cylinder 609-2 is radially arranged between the electrode core insulating sleeve 104 and the electrode core 101, and the outer wall of the lower cylindrical hollow cylinder is inserted into the inner wall of the electrode core insulating sleeve 104 below the lower cylindrical hollow cylinder; the hollow 609-1 column of the upper cylinder is radially arranged between the silver wire insulating sleeve 8 and the silver wire 7, and the outer wall of the upper cylinder is inserted into the inner wall of the silver wire insulating sleeve 8 above the upper cylinder; the outer diameter of the lower cylindrical hollow cylinder 609-2 is slightly larger than the inner diameter of the electrode core insulating sleeve 104, so that the electrode core insulating sleeve can be firmly sleeved; the outer diameter of the upper cylindrical hollow cylinder 609-1 is slightly larger than the inner diameter of the silver wire insulating sleeve 8, so that the silver wire insulating sleeve 8 can be firmly sleeved.

Each electrode of the three electrodes comprises an upper part and a lower part which are connected through a transition joint 609, each electrode is positioned at the part above the central point of the transition joint, the outer layer is a silver wire insulating sleeve 8, and the inner layer is a silver wire lead 7; each electrode is positioned at the part below the central point of the transition joint, the outer layer is an electrode protection sleeve, and the inner layer is an electrode core; the electrode protection sleeves are respectively a reference electrode protection sleeve 104, a working electrode protection sleeve 104 and an auxiliary electrode protection sleeve 104; the electrode cores are respectively a reference electrode core 101, an auxiliary electrode core 201 and a working electrode core 301.

As shown in fig. 2C, the upper combined sealing gaskets (901,902) are sleeved around the upper cylindrical hollow cylinder 609-1 of the transition joint 609, the lower combined sealing gaskets (901,902) are sleeved around the lower cylindrical hollow cylinder 609-2 of the transition joint, and the upper combined sealing gaskets (901,902) are used for insulation between the transition joint 609 and the sealing shell 608 and for holding the silver wire insulating sleeve 8 so that the silver wire insulating sleeve cannot fall off; the lower combined sealing gaskets (901,902) are used for sealing and insulating the transition joint 609 and the sealing main body 607, and meanwhile, the lower combined sealing gaskets embrace the reference electrode insulating sleeve 104 and are tightly squeezed, so that the salt bridge liquid 105 is prevented from leaking; the upper and lower combined sealing gaskets are composed of an outer arc sealing gasket 901 and an inner arc sealing gasket 902, the angle of the outer arc is slightly larger than that of the inner arc, the angle of the arc of the outer arc sealing gasket 901 is 60 degrees, the angle of the inner arc sealing gasket 902 is 55 degrees, when the upper and lower combined sealing gaskets are pressed up and down, the inner hole of the outer arc sealing gasket is shrunk to be tightly held on the electrode core insulating sleeve 104 or the silver wire insulating sleeve 8, and therefore longitudinal pressure and transverse pressure on the electrode core insulating sleeve 104 or the silver wire insulating sleeve 8 are achieved.

As shown in fig. 2C, the inner wall of the reference electrode core insulating sleeve 104 near the bottom end is plugged into the microporous ceramic column 102, and the outer diameter of the microporous ceramic column 102 is slightly larger than the inner diameter of the reference electrode core insulating sleeve 104, so as to ensure that the microporous ceramic column 102 does not fall off.

As shown in fig. 2C, the insulating sleeve 104 of the reference electrode core of the reference electrode 1 is filled with a salt bridge solution 105, the salt bridge solution 105 is a saturated potassium chloride solution, and the pores of the microporous ceramic column 102 are nano-scale micropores for allowing gas and electric ions to freely penetrate therethrough but blocking liquid from passing therethrough.

The three-electrode inserted into the kettle can resist 300 ℃ of high temperature, the distance between the three-electrode inserted into the kettle and the top of the cold end higher than the kettle cover is 30 cm, and the temperature around the sealing assembly 6 is not more than 50 ℃.

Supplementary explanation:

one and three electrode function

The object of investigation is a sample on a working electrode, a reference electrode determines the potential of the working electrode, and an auxiliary electrode is used to conduct current. The three-electrode system comprises two loops, wherein one loop consists of a working electrode and a reference electrode and is used for testing the electrochemical reaction process of the working electrode, and the other loop consists of the working electrode and an auxiliary electrode and plays a role in transmitting electrons to form a loop.

Second, further explanation of reference numerals in relation to FIGS. 1-4

1. With respect to the explanation of the reference numerals of fig. 1:

the corrosive liquid (401) simulates cooling water in a loop of a nuclear power plant.

2. With regard to the explanation of the reference numerals in fig. 2A, 2B, 2C:

the silver wire (7) has excellent conductivity; the silver wire insulating sleeve (8) is made of a polytetrafluoroethylene tube and used for insulation; the material of the reference electrode core (101) is silver/silver chloride wire, which is the conventional method of the reference electrode; the microporous ceramic column (102) is used for transferring ions and is also a conventional method of a reference electrode; the electrode core insulating sleeve (103) is made of a polytetrafluoroethylene tube and is used for insulation between the electrode core and the protective sleeve. The electrode protection sleeve (104) is made of nickel-based alloy, has excellent corrosion resistance and is used for protecting an electrode core and salt bridge liquid. The salt bridge solution (105) is used for supplementing charges, and is a saturated potassium chloride solution which is also a conventional method of a reference electrode; the double cutting sleeves (605) are used for connecting and sealing the electrode protection sleeve and the sealing main body; the ferrule nut (606) is used for compressing the double ferrules; the sealing body (607) is made of stainless steel; the sealing shell (608) is made of stainless steel and is in threaded connection with the sealing main body; the transition joint (609) is made of a copper gold-plated material and is used for connecting the silver wire and the electrode core; the outer arc sealing gasket (901) and the inner arc sealing gasket (902) are matched into an upper combined sealing gasket and a lower combined sealing gasket which are made of polytetrafluoroethylene materials and used for sealing and insulating the transition joint, the sealing main body and the sealing shell, and the inner arc sealing gasket embraces the electrode core insulating sleeve to prevent the electrode core insulating sleeve from falling off and seal the transition joint lower cylinder (613). The upper cylinder (615) of the transition joint is connected with the silver wire. The disc-shaped gasket (12) is in a conical disc shape, and deforms after the sealing main body and the sealing shell are screwed tightly until the sealing main body and the sealing shell are flattened to store energy as live load. When the three-electrode combined sealing gasket is used for a long time, creep deformation can be generated after the combined sealing gasket is subjected to multiple times of thermal expansion and cold contraction, and at the moment, the disc-shaped gasket can be automatically converted into additional compression load required by sealing, so that the continuous requirement on tightening in the use of the combined sealing gasket is reduced. The flat gasket (11) increases the area of the disc-shaped gasket that exerts pressure on the composite seal. The upper and lower combined sealing gaskets are also matched by the outer arc sealing gasket (901) and the inner arc sealing gasket (902) and are used for insulation between the transition joint and the sealing shell, and the silver wire insulating sleeve is embraced, so that the silver wire insulating sleeve does not fall off.

3. With regard to the explanation of the reference numerals in fig. 3:

the auxiliary electrode core (201) is made of platinum wire.

4. With regard to the explanation of the reference numerals in fig. 4:

the working electrode core (301) is made of nickel-based alloy, the test sample (302) is a research object, and the insulation pad (305) is made of polytetrafluoroethylene, so that the insulation between the test sample and the electrode protection sleeve is realized.

Operation relating to three-electrode replacement

If the three electrodes need to be replaced or maintained, the whole electrode can be drawn out only by unscrewing the clamping sleeve screw cap on the clamping sleeve joint on the high-temperature high-pressure kettle cover. During installation, the three electrodes are inserted into a high-temperature high-pressure kettle, and then the clamping sleeve nut on the clamping sleeve joint is screwed, so that precious time is saved for scientists. Meanwhile, the structure is simple, the processing is easy, and the cost is low.

Fourthly, the contrast electrode (auxiliary electrode 3) and the working electrode 2

Explanation regarding fig. 4: as shown in a comparison electrode figure 4, the electrode sealing assembly (6) of the comparison electrode and the working electrode are installed in the same way as the reference electrode, except that the electrode core (201) of the comparison electrode is also contacted with the corrosive liquid, and the material of the nickel-based alloy is also selected. A platinum wire (202) was placed on the tip of the comparative electrode core inserted into the autoclave. The purpose of the platinum wire is not to be electrolyzed when used as an anodic inert electrode. The working electrode core (301) can also contact with the corrosive liquid, and the nickel-based alloy material is also selected. The top end of a working electrode core inserted into a high-temperature high-pressure autoclave is provided with an external thread, a sample to be tested (302) is provided with an internal thread and screwed on the working electrode core, and an insulating pad (305) is arranged between the test sample and a protective sleeve of a working electrode.

The above description is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments, and all technical solutions belonging to the idea of the present invention belong to the protection scope of the present invention. It should be noted that modifications and embellishments within the scope of the invention may occur to those skilled in the art without departing from the principle of the invention, and are considered to be within the scope of the invention.