WO2013151381A1

WO2013151381A1 - Apparatus and method for anodizing inner surface of tube

Info

Publication number: WO2013151381A1
Application number: PCT/KR2013/002871
Authority: WO
Inventors: 김준원; 김무환; 엄경보; 김강훈; 안호선; 이찬
Original assignee: 포항공과대학교 산학협력단; 한전원자력연료 주식회사
Priority date: 2012-04-05
Filing date: 2013-04-05
Publication date: 2013-10-10
Also published as: KR101352356B1; KR20130113256A; US20150068910A1

Abstract

An apparatus for anodizing the inner surface of a tube of the present invention comprises: an electrolyte container for storing an electrolyte solution; a first solution conduit connected to the electrolyte container to be supplied with the electrolyte solution; a first jig for fixing one end of a target tube to the downstream end of the first solution conduit; a second solution conduit of which the upstream end is connected to the other end of the target tube to discharge the electrolyte solution flowing inside the target tube; a second jig for fixing the other end of the target tube to the upstream end of the second solution conduit; and a cathode rod inserted from the second jig and penetrating inside the target tube so as to be extended to the first jig, wherein the cathode rod acts as a cathode and the target tube acts as an anode so as to carry out anodization while the electrolyte solution passes through the inside of the target tube.

Description

【Specification】

[Name of invention]

Apparatus and Method for Internal Surface Anodization of Ljub

Technical Field

The present invention relates to an apparatus and a method for anodizing a surface of a structure having a non-planar surface mainly composed of zirconium such as cladding of a nuclear fuel rod. [Background technology]

Zirconium has a melting point of 1,852 degrees Celsius and is chemically stable, so it has a very strong resistance to corrosion from the outside. For this reason, zirconium or its alloys and oxides are used in non-corrosive products such as fuel rod coatings of nuclear power plants, rust-resistant ceramic kitchen utensils and tools for handling chemicals.

On the other hand, nuclear fuel is encased in aluminum or magnesium film so that harmful substances generated during the nuclear fission process do not mix with the coolant and flow out. In the case of light water reactors, low-concentration uranium dioxide (U0 ₂ ) powders are formed by sintering with a 2 cm diameter and a 2 cm high cylinder to form dark brown pellets. Zircaloy) is placed in a thin metal tube of about 3mm and sealed at both ends.

Typically, a bundle of tens or hundreds is used to make a fuel assembly and use it as a unit. There are hundreds of these in the reactor.

The cladding tube is made less than 1mm thick to ensure good thermal conductivity.In nuclear fission, the fuel pellets have a center temperature of about 200 ^° C, a surface temperature of 600 ^° C, and inner and surface temperatures of the fuel rods at 400 ^° C and 300 ^° C, respectively. It is enough.

As such, the rods that are exposed to high temperatures may be severely exposed to fission products when they are ruptured, causing serious problems. Therefore, efforts to increase their stability are continuously needed.

One of the safety indicators applied to a device that heats this type of working fluid is the critical heat flux (CHF) value, which does not damage the heater during heating. Means the maximum heat flux possible. Conversely, if this heat flux value is exceeded, the heater will break. Critical heat flux is a very important indicator because it can lead to extra-large accidents such as core melting in facilities such as nuclear power plants.

All machines that heat the working fluid, as well as nuclear power plants, are managed with a certain safety factor to ensure that the critical heat flux values are not exceeded during operation. However, such safety management is also to regenerate the performance of the device, so research is being made to improve the performance while maintaining the safety coefficient by increasing the critical heat flux value of the heater itself. In the past research, it is known that the surface of the heater is more hydrophilic, the value of the critical heat flux increases. In recent years, further studies have been conducted to increase the hydrophilicity and the critical heat flux using nanoparticles or microstructures.

[Detailed Description of the Invention]

[Technical problem]

Based on the technical background as described above, the present invention is to provide an anodizing device and a method for forming a microstructure on the surface of the zirconium-based tube has a hydrophilic inner surface.

Technical Solution

An inner surface anodization apparatus of a tube according to an embodiment of the present invention comprises an electrolyte container for storing an electrolyte solution; A first solution conduit connected to the electrolyte container to receive the electrolyte solution; A first jig securing one end of the object tube to a downstream end of the first solution conduit; A second solution conduit connected with the other end of the object tube to an upstream end to discharge the electrolyte solution flowing through the object stream; A second jig fixing the other end of the object tube to an upstream end of the second solution conduit; And a cathode rod inserted from the second jig and extending through the interior of the object tube to the first jig, wherein the cathode is applied to the cathode rod while the electrolyte solution passes through the interior of the object tube. An anode may be applied to the object tube to perform an anodization process.

The anodizing device may further include a cleaning solution container for storing the cleaning solution, and the cleaning solution container may be connected to each other through the three-way valve with the electrolyte container and the first solution conduit. The anodizing device further comprises a first constant temperature water tank containing a shell material, and the electrolyte container and the cleaning solution container are installed to be immersed in the coolant of the first constant temperature water tank.

The first solution conduit may be provided with a flow meter and a flow control device to control the flow of the electrolyte solution or the cleaning solution passing through the first solution conduit.

The anodizing device may further include a crab tank for accommodating a coolant, and the target tube is installed to be immersed in the coolant of the second bath. A solution conduit connection hole into which the solution conduit is inserted and determined is formed, and a target rib connection hole into which one end of the object rib is inserted and connected to a second side.

The first jig further includes a cathode rod insertion hole into which the cathode rod is inserted, and the target tube connection hole and the cathode rod insertion hole of the first jig are formed on the concentric shaft.

The second jig may have a solution conduit connection hole through which the second solution conduit is inserted and connected to one side of the crab, and a target rib connection hole through which the other end of the object tube is inserted and connected to the second side.

The second jig further includes a cathode rod insertion hole into which the cathode rod is inserted, and the target tube connection hole and the cathode rod insertion hole of the second jig are formed on the concentric shaft.

The first solution conduit, the object tube and the second solution conduit may be connected to each other to form a U-shaped conduit, and the object tube may be located on a downstream branch of the U-shaped conduit.

The electrolyte solution may be applied to a carboxylic acid solution, the subject rib may be a zirconium tube or a tube made of zirconium alloy. And the cathode rod may be applied to a stainless steel rod.

An internal surface anodization method of a tube according to an embodiment of the present invention, an electrolyte container for storing an electrolytic solution, a first solution conduit connected to the electrolyte container and supplied with the electrolyte solution, and the first A first jig for fixing one end of the object rib to the downstream end of the solution conduit, and the other end of the object tube A positive electrode including a second solution conduit connected to an upstream end and discharging an electrolyte solution which has introduced the inside of the object tube, and a second jig fixing the other end of the object tube to an upstream end of the second solution conduit An electrolyte solution supplying step of supplying the electrolyte solution while flowing through the first solution conduit, the object rib, and the second solution conduit while using an oxidizing device; Inserting a cathode rod to penetrate the inside of the object tube from the second jig to the first jig; And a power supply step of applying a cathode to the cathode rod and applying an anode to the object tube, and may perform anodization while the electrolyte solution flows inside the object tube. ^■

The method may further include a cleaning solution supplying step of supplying the cleaning solution to flow through the first solution conduit, the target tube, and the second solution conduit after the power supply is stopped to terminate the anodization process.

Advantageous Effects

According to the internal surface anodization apparatus of a tube made of zirconium or its alloy as described above, it is possible to form a hydrophilic oxide film having a microstructure formed on the inner surface of the tube, which cannot be easily applied by a method such as MEMS. In addition, it is possible to easily produce a cylindrical inner surface such as a nuclear fuel rod made of zirconium or an alloy thereof as a hydrophilic surface through anodization. By forming the nuclear fuel rod inner surface into a hydrophilic surface, it is possible to increase the critical heat flux, thereby increasing the efficiency of the nuclear power plant.

[Brief Description of Drawings]

1 is a schematic diagram illustrating a nuclear fuel rod constituting a fuel assembly used in a nuclear power plant.

2 is a schematic diagram illustrating a fuel assembly used in a nuclear power plant. Figure 3 is a schematic diagram showing an internal surface anodization apparatus of a cylindrical tube according to an embodiment of the present invention.

Figure 4A is an exploded cross-sectional view showing a jig of the inner surface anodizing device of the cylindrical tube according to an embodiment of the present invention, Figure 4B is a combined cross-sectional view. 5 is a photograph showing a zirconium alloy (zircaloy) tube applied to the anodization apparatus according to an embodiment of the present invention. 6 is a SEM photograph of the microstructure formed on the inner surface of the zirconium alloy (zircaloy) tube made by the anodization method according to an embodiment of the present invention.

FIG. 7 is a photograph of a spreading phenomenon of water droplets on an inner surface of a zirconium alloy (zircaloy) tube made by an anodization method according to an embodiment of the present invention.

8 is a graph showing a critical heat flux improvement rate in a flow boiling situation when using a zirconium alloy (zircaloy) stream made by the anodization method according to an embodiment of the present invention.

[Form for implementation of invention]

Hereinafter, a detailed description to the accompanying drawings to make the self-easy of ordinary skill in the invention ^0, the art with respect to the embodiment of the present invention carried out by reference. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like elements throughout the specification.

According to a preceding study (Kandlikar, S, G., 2001, "A Theoretical Model to Predict Pool Boiling CHF Incorporating Effects of Contact Angle and Orientation," Journal of Heat Transfer, Vol. 123, pp. 1071-1079.) The critical heat flux (CHF) increases as the surface of the heater approaches hydrophilicity in a boiling heater.

Increasing the critical heat flux point through surface modification allows the heat engine to operate at higher temperatures, which increases energy efficiency according to the principle of the Tankin cycle. In addition, even if the actual operating temperature is not increased, the difference between the heat flux and the critical heat flux at the time of operation becomes large, so that there is an advantage of higher stability. By applying this principle to a nuclear power plant, the cladding surface of a nuclear fuel rod exposed to high temperature can be made into a hydrophilic surface to increase the critical heat flux point, and consequently to achieve higher stability.

1 is a schematic view showing a nuclear fuel rod constituting a fuel assembly used in a nuclear power plant by way of example, Figure 2 is used in a nuclear power plant

A schematic diagram illustrating an exemplary fuel assembly. Fuel rods (10) with a built-in uranium dioxide (U0 ₂₎ pellets (sintered body) is not arranged in a 16x16 fixed by a grid (spacergrid) (21,23) can reach the fuel assembly 20. The fuel rods eu _{( 10)} is made of a cylindrical, likewise a plurality of pellets (12) made of a cylinder is stacked therein, the compression spring 15 is inserted in the upper portion to prevent the movement of the pellets 12 in the nuclear fuel rod (10) Can be. The cladding 17 forming the shell of the nuclear fuel rod 10 may be made of a zirconium alloy which is an alloy containing zirconium as a main component, and is also called a zircaloy.

Meanwhile, in order to make the surface of the solid hydrophilic, there are a method of changing the chemical properties of the surface and a method of changing the surface shape at the micro scale or the nano scale. In the embodiment of the present invention, the surface shape at the micro scale or the nano scale is used. Adopt ways to change

That is, in this embodiment, by applying the anodization method to the cladding of the nuclear fuel rod electrochemically ^' can be formed on the surface of the structure of the micro / nano scale while promoting the oxidation of the cladding surface. Such anodization

Basically, a clean facility is required, which is expensive, and can be applied to large area or curved surface compared to MEMS (microelectromechanical system) process using photolithography method which is difficult to apply to large area or curved surface.

To apply anodization to the cladding surface of a tube-shaped nuclear fuel rod, plate specimens and other anodization devices are required. That is, for anodic oxidation, basically, an anode and a cathode facing each other and an electrolyte filling a space therebetween are required. When voltage is applied between the anode and the cathode, anodization proceeds, and smooth circulation of the electrolyte is required for continuous anodization.

Figure 3 is a schematic diagram showing an internal surface anodization apparatus of a cylindrical tube according to an embodiment of the present invention. Anodizing apparatus as shown in FIG. 3 may be configured to satisfy the above-mentioned conditions and to anodize the inner surface of the rib. Referring to FIG. 3, the anodization apparatus according to the present embodiment includes an electrolyte container 31, a first solution conduit 37 and a crab 2 solution conduit 39 connected thereto. Electrolyte The container 31 stores the electrolyte solution, and the first solution conduit 37 receives the electrolyte solution from the electrolyte container 31. The second solution conduit 39 is connected to the first solution conduit 37 with the object rib 50 to be anodized, and the electrolyte solution supplied through the solution 11 conduit 37 is the object tube. Flowing inside the 50 is discharged through the second solution conduit (39).

The electrolyte container 31 may be installed to supply the electrolyte solution to the object rib 50 to be anodized without additional power using position energy. The first solution conduit 37, the object tube 50, and the second solution conduit 39 are connected to each other to form a U-shaped conduit, and the object rib 50 is downstream of the U-shaped conduit (right side). ) Can be located on the branch. Therefore, the flow of electrolyte solution

Even if interrupted, the electrolyte solution in the object tube 50 can be allowed to settle, and anodization can be continued without interruption.

A first jig 41 is provided to fix one end of the object tube 50 at the downstream end of the first solution conduit 37, and the object is located at an upstream end of the second solution conduit 39. A second jig 42 is installed to fix the other end of the tube 50. The structure of the jig 41, 42 will be described in detail with reference to FIGS. 4A and 4B below.

On the other hand, the cathode rod 45, which serves as the cathode in the anodization process, is inserted from the second jig 42 and installed to extend through the interior of the object tube 50 to the first jig 41. . That is, the electrolyte solution is to open the interior of the target tube (50)

During the holing, a cathode is applied to the cathode rod 45 and an anode is applied to the target tube 50 to perform anodization. Equipped separately

The negative terminal of the power supply 47 may be electrically connected to the negative electrode rod 45, and the positive terminal may be electrically connected to the target tube 50 to apply a voltage. The cathode rod 45 may be a rod of a conductive material having corrosion resistance to the electrolyte solution, and if the inside of the target tube 50, there is a risk of a short circuit (bending circuit) is not easily bent material.

The power supply 47 may perform real-time monitoring through the computer 49, and may control the voltage and the current to input the fill current or to reverse the negative and positive poles. Previous studies (Chan Lee, Hyungmo Kim, Ho Seon Ahn, Moo Hwan Kim, and Joonwon Kim, "Micro / nanostructure Evolution of Zircaloy Surface Using Anodization Technique: Application to Nuclear Fuel Cladding Modification ", Applied Surface Science, Vol. 258, issue 22, pp. 8724-8731,

According to 2012.09.01), in anodic oxidation of zirconium alloys, the surface structure depends on the duration of the reaction, and the surface properties, including wettability, change in stages. By monitoring the current in real time, and based on the result, it is possible to easily and selectively manufacture the surface structure according to the desired purpose through the function of measuring the reaction step and cutting off the current supply. In addition, when the negative electrode and the positive electrode are applied in reverse, the anodic oxidation process is changed to the plating process, so that the inside of the tube may be plated using the apparatus of the present embodiment.

The anodizing device of this embodiment includes a cleaning solution container 32 for storing the cleaning solution. The cleaning solution container 32 is connected to each other via the electrolyte container 31, the first solution conduit 37 and the three-way valve 35. Depending on the operation of the three-way valve 35, the electrolyte solution may be supplied through the first solution conduit 37, or the cleaning solution may be supplied. The electrolyte solution is continuously supplied during the anodization process, and the cleaning solution is immediately supplied when the anodization process is completed. For example, deionized water may be used as the washing solution.

The anodizing device of this embodiment is a low U containing a shell material.

It is provided with a constant temperature water tank 51, and the electrolyte container 31 and the cleaning solution container 32 may be installed to be immersed in the shell of the crab 1 constant temperature water tank (51).

In addition, the first solution conduit 37 is provided with a flow meter and a flow control device 36, the electrolyte solution passing through the first solution conduit 37 or

The flow of the cleaning solution can be controlled. Through this, it is possible to control the reaction rate of the anodic oxidation and the uniformity of the formed structure affected by the flow rate.

The anodizing device of this embodiment includes a second accommodating coolant.

The port is equipped with a tank (61). The object tube 50 is installed so as to be immersed in the shell material accommodated in the second constant temperature water tank 61 to help maintain an appropriate temperature.

Such a shell shell can maintain the temperature while being circulated by the circulation device 63 connected to the second constant temperature water tank 61. As the coolant, for example, water may be used. The second constant temperature water tank 61 has a coolant completely surrounding the outer side of the object rib 50. Since the structure is not an open structure but an open structure with an open top, the subject tube 50 can be easily inserted or taken out before and after the experiment. Therefore, proper temperature control is required for optimum reaction conditions.

In this embodiment, the temperature control device is provided in the circulation device 63 to adjust the temperature of the coolant supplied to the first constant temperature water tank 51 and the second constant temperature water tank 61. Therefore, in addition to indirect cooling through heat transfer from the outer surface of the target tube 50 using the second thermostat 61, the temperature control of the electrolyte solution itself directly contacting the reaction surface using the crab 1 thermostat 51. You can maximize the effect of adjusting silver by giving the angle through.

The electrolyte solution discharged through the second solution conduit (39) is an electrolyte

Collected into a reservoir (65), which can be circulated back to the electrolyte container (31) and reused.

Figure 4A is an exploded cross-sectional view showing a jig of the inner surface anodizing device of the cylindrical tube according to an embodiment of the present invention, Figure 4B is a combined cross-sectional view. 4A and 4B show the second jig 42 shown in FIG. 3, the structure of the first jig 41 also has a similar structure except that only the forming direction of the openings is different, so that the second jig 42 will be described below. Just explain.

Referring to FIG. 4A, the second jig 42 has a solution conduit connecting hole 421a through which the second solution conduit 39 is inserted and connected to the first side, and the other end of the object tube 50 on the second side. The jig body 421 in which the inserted object tube connecting hole 421b is formed is provided. An upper cover 425 is coupled to the upper part of the jig body 421 by a blt 424, and a lower cover 423 is coupled to the lower part of the jig body 421 by a bolt 424. The upper end of the jig body 421 is formed with a cathode rod insertion hole (421c) is inserted into the cathode rod 45, the target tube connecting hole (42 lb) and the cathode rod

The insertion hole 421c is formed on the concentric axis. O-ring between the jig body 421 and the upper cover 425 and between the jig body 421 and the lower cover 423 at the portion where the cathode rod insertion hole 421c and the target tube connecting hole 421b are formed. 427 and 428 may be provided to prevent the electrolyte solution from leaking to the outside. On the outer surface of the end portion of the second solution conduit 39 and the inner surface of the solution conduit connecting hole 421a, a thread is engaged with each other. Is formed can be screwed.

4B, it can be seen that the second solution conduit 39, the object tube 50, and the cathode rod 45 are coupled to the coupled crab 2 jig 42. That is, the second solution conduit 39 is inserted into and connected to the solution conduit connecting hole 421a.

The target tube 50 is inserted and connected to the connection hole 421b, and the cathode rod

The negative electrode 45 is inserted in the connection hole 421c. The inserted cathode rod 45 has a concentric axis with the object tube 50 and is installed to penetrate the inside of the object tube 50. In the anodization apparatus according to the present embodiment, for example, the object tube 50 may be a zircaloy tube, and the electrolyte solution may be a hydrofluoric acid solution. The cathode rod 45 inserted into the object tube 50 may be a stainless steel rod, and the first solution conduit 37 and the second solution conduit 39 may be PFAs.

It may consist of a conduit of perfluoroalkoxy material. The jig body ⁴² 1, the upper cover 425, the lower cover 423, and the bolt 424 constituting the ^second jig ⁴ 2 may be made of PTFE (Polytetrafluoroethylene) material, and the O-rings 427 and 428. )silver

Viton® O-rings can be applied.

Anodization Method

An internal surface anodization method of a tube made of zirconium or an alloy thereof according to an embodiment of the present invention using the anodization device shown in FIG. 3 will be described below.

First, the electrolyte solution stored in the electrolyte container 31 is supplied through the first solution conduit 37, the object tube 50, and the second solution conduit 39. In this embodiment, the temperature of the electrolyte solution may be applied to a solution in the range of 0 degrees to 15 degrees Celsius, the concentration of the electrolyte solution may be applied to a solution in the range of 0.01 to lwt%, for example the electrolyte solution 0.5% hydrofluoric acid solution of less than 10 degrees Celsius can be applied. The object tube 50 may be applied to a length of 10cm or more, a tube of zirconium alloy having an outer diameter of 3/8 inch can be applied. And the flow rate of the electrolyte solution flowing through the target tube 50 is about 300 to 1,000 ml / min.

Next, the negative electrode 45 is inserted so as to extend from the second jig 42 to the first jig 41 through the inside of the object tube 50. This cathode rod insertion step It may be inserted before the electrolyte solution supply. In the present embodiment, the cathode rod 45 may be a stainless steel rod having an outer diameter of 3mm.

Next, the cathode may be applied to the cathode rod 45, and the anode may be applied to the object tube 50 to supply power. In this embodiment, a voltage in the range of 5 to 40V may be applied between the anode and the cathode, and for example, a voltage of 15V may be applied. The time for applying the voltage may be applied in the range of 10 minutes to 40 minutes. Through this process, an anodization process is performed while the electrolyte solution flows inside the object tube 50, and as a result, micro- and nano-scale uneven structures are formed on the inner surface of the object tube 50. The uneven structure thus formed makes the inner surface of the object tube 50 hydrophilic.

Next, after the power supply is stopped to terminate the anodization process, the cleaning solution is supplied to flow through the first solution conduit 37, the target tube 50, and the second solution conduit 39. After anodization has been terminated (after stopping power supply)

Contact with the solution (fluoric acid solution) adversely affects the structure and can quickly destroy the microstructures on the surface, so it is necessary to rinse the electrolyte solution quickly. For this purpose, the three-way valve 35 can be operated to inject the cleaning solution immediately after the reaction is finished.

Experimental Example

Anodization method was performed using the anodization apparatus of an embodiment of the present invention as described above. A hydrofluoric acid solution of 0.5 ^% was used as the electrolyte solution, and deionized water was used as the cleaning solution.

5 is a photograph showing a zirconium alloy (zircaloy) tube applied to the anodization apparatus according to an embodiment of the present invention. The zircaloy tube is made of a zirconium alloy having an outer diameter of 3/8 inch and a length of 53 cm, and is shown by cutting in the longitudinal direction to show the inside.

The negative electrode rod was applied to a stainless steel rod having an outer diameter of 3mm, the voltage applied between the positive electrode and the negative electrode was _15V , the reaction time was ₂₅ minutes. The temperature of the bath was maintained at 3 degrees Celsius.

6 is a SEM of the microstructure formed on the inner surface of the zirconium alloy (zircaloy) tube made by the anodization method according to an embodiment of the present invention It is a photograph. According to the anodization method using the above-described anodizing device, it is shown that the microstructure can be actually formed on the curved inner surface of a large area. FIG. 7 is a photograph of a water droplet spreading phenomenon on an inner surface of a zirconium alloy (zircaloy) tube made by an anodization method according to an embodiment of the present invention. In other words, it can be seen that the water droplets placed on the surface is spreading within a short time, the surface formed by the anodizing method according to the present embodiment has a very high hydrophilic property, thus improving the high critical heat flux as described above You can expect

According to this embodiment, an experiment was performed to determine the critical heat flux enhancement rate in a flow boiling situation using a Zircaloy tube having a microstructure formed on an inner surface thereof. In other words, when water is flowed inside the tube and heat is applied from the outside to increase the temperature, the flowing water reaches a critical heat flux near a specific point of the tube. (CHF) values were measured, and the degree of improvement of the critical heat flux is shown in FIG. 8.

In Figure 8, the mass flux means the flow rate of water flowing in the tube, the inlet temperature means the temperature of the water entering the tube. Referring to Figure 8, the mass flux l, 500kg / m ² s conditions showed an improvement of about 60%. These results demonstrate that the surface microstructures created under these conditions significantly increase the critical heat flux under actual flow boiling conditions.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications and changes can be made within the scope of the claims and the detailed description of the invention and the accompanying drawings. Naturally, it belongs to the range of.

Claims

[Range of request]

[Claim 1]

An electrolyte container storing an electrolyte solution;

A first solution conduit connected to the electrolyte container to receive the electrolyte solution;

A first jig securing one end of the object tube to a downstream end of the first solution conduit;

A second solution conduit connected with the other end of the object tube to an upstream end to discharge the electrolyte solution that has opened the inside of the object tube;

A second jig fixing the other end of the object tube to an upstream end of the second solution conduit; And

Cathode rod inserted from the second jig and extending through the inside of the object tube to the hanging U jig

Including,

An anode is applied to the cathode rod while the electrolyte solution is passed through the inside of the object tube and an anode is applied to the object tube to perform an anodization process.

[Claim 2]

The method of claim 1,

Further comprising a cleaning solution container for storing the cleaning solution,

Wherein the cleaning solution container is connected to the electrolyte container and the first solution conduit via a three-way valve.

[Claim 3]

The method of claim 2,

Further comprising a first constant temperature water tank containing a coolant,

And the electrolyte container and the cleaning solution container are installed to be immersed in the shell of the first constant temperature water tank.

[Claim 4]

The method of claim 2, The first solution conduit is provided with a flow meter and a flow control device, the internal surface anodization apparatus of the tube, characterized in that for controlling the flow of the electrolyte solution or cleaning solution passing through the first solution conduit.

[Claim 5]

The method of claim 1,

게 It contains 2 constant temperature water tanks,

The subject tube is anodization apparatus of the inner surface of the tube, it characterized in that it is installed so as to be submerged in the shell of the second constant temperature water tank.

[Claim 6]

The method of claim 1,

The first jig has a solution conduit connecting hole for inserting and connecting the crab 1 solution conduit to a first side, and a target tube connecting hole for inserting and connecting one end of the target tube to a second side of the tube. Internal surface anodization device.

[Claim 7]

The method of claim 6,

The first jig further includes a cathode rod insertion hole into which the cathode rod is inserted, and the target tube connecting hole of the crater 1 jig and the cathode rod insertion hole are formed on a concentric shaft. Device.

[Claim 8]

The method of claim 1,

The crab 2 jig has a solution conduit connection hole for inserting the second solution conduit is connected to the first side is formed, the second tube is characterized in that the target tube connection hole is formed is inserted into the other end of the target tube Internal surface anodization device.

[Claim 9]

The method of claim 8,

The crab 2 jig further includes a cathode rod insertion hole into which the cathode rod is inserted, and the target tube connection hole of the crab 2 jig and the cathode rod insertion hole are formed on a concentric shaft. Device.

[Claim 10]

The method of claim 1,

An inner surface anodization apparatus of the tube further comprising a temperature control device having an angler or a heater to adjust the temperature of the angled shell material, and contacting the target tube with the angled shell material to maintain a set temperature during anodization reaction. .

[Claim 11]

According to claim 1,

The crab first solution conduit, the object tube and the second solution conduit are connected to each other to form a U-shaped conduit, wherein the object tube is located on a branch downstream of the U-shaped conduit .

[Claim 12]

The method of claim 1,

And the electrolyte solution is a hydrofluoric acid solution.

[Claim 13]

The method of claim 1,

The subject tube is a zirconium tube or zirconium alloy tube inner surface anodizing device, characterized in that the tube.

[Claim 14]

According to claim 1,

And the cathode rod is a stainless steel rod.

[Claim 15]

An electrolyte container for storing an electrolyte solution, a first solution conduit connected to the electrolyte container to receive the electrolyte solution, and a first jig for fixing one end of the object tube to a downstream end of the first solution conduit ), And a second solution conduit through which the other end of the object tube is connected to an upstream end to discharge the electrolyte solution which has taken the inside of the object tube, and the other end of the object tube at an upstream end of the second solution conduit In the anodizing method using an anodizing device comprising a fixed system 2 jig, An electrolyte solution supplying step of supplying the electrolyte solution through the first solution conduit, the object tube, and the second solution conduit;

Inserting a cathode rod from the crab 2 jig to extend through the inside of the object tube to the first jig; And

A power supply step of applying a cathode to the cathode rod and an anode to the object tube;

Including, The internal surface anodization method of the ribs, characterized in that to perform an anodization process while the electrolyte solution is going through the inside of the object tube.

[Claim 16]

The method of claim 15,

And a cleaning solution supplying step of supplying the cleaning solution to flow through the first solution conduit, the target tube, and the second solution conduit after the power supply is stopped to terminate the anodization process. Internal surface anodization method.