JP3207064B2 - Cooling water piping for electrical equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling water pipe for high-voltage electric equipment, and more particularly to a method for suppressing electrolytic corrosion of a pipe joint.

[0002]

2. Description of the Related Art Cooling of electrical equipment for processing large currents, such as coils for induction heaters for steel, or various industrial power supplies such as large welding machines, motor drive power supplies for vehicles, and thyristors used for power equipment. Employs a water-cooling system that has the best cooling effect.

FIG. 15 shows an example of a configuration diagram of an induction heating coil which is a main component of an induction heater for steel. As shown in FIGS. 16 and 17, the induction coil 1 is a coil unit in which a hollow conductor 2 is spirally wound, and a pipe joint 4 for connecting an electrical insulating pipe such as an insulating rubber hose for supplying and discharging cooling water to both ends thereof. After arranging a plurality of 1a in the axial direction and connecting them and taping them with glass tape 5 or the like,
The varnish is impregnated and integrated. Connection terminals 6 are provided at both ends of the induction coil 1, and a power cable is connected to energize the hollow conductor 2. In addition, cooling water is supplied to the inside of the hollow conductor 2 by connecting the water supply sources between the pipe joints 4 or the water supply sources with an electric insulating pipe.

FIG. 18 shows a configuration example of a thyristor stack 7 which is a main component of an inverter power supply for supplying a high-frequency current to the heater. 19, the thyristors 8 are alternately stacked in a plurality of stages together with the cooler 9 as shown in FIG. 19, and the thyristors 8 are pressed through the pressing plate 10b by the pressing action of the pressing bolts 10a and the like constituting the clamper 10. Blocked by. As shown in FIGS. 19 and 20, the cooler 9 is configured by attaching a pipe joint 4 for connecting an electrically insulating pipe such as an insulating rubber hose to a cooling body 9a, and supplies cooling water to a water passage 11 formed therein. It sinks and absorbs heat from the heating element thermally connected to the heat absorbing surface 9b. A connection terminal 6 is further attached to the cooling body 9a so that the thyristor 8 can be connected to a wiring.

FIG. 4 shows an example of the configuration of a cooling system for cooling the electric equipment shown in FIGS.
In the figure, the cooling system is a circulation pump 12, a heat exchanger 1
3. It is composed of an ion exchanger 14, a pure water tank 15, and the like. The cooling water sent from the circulation pump 12 is sent to the heat exchanger 13, and the secondary cooling water 17 on the secondary side is
The cooling water is sent to the water supply header 20 of the inverter power supply 18 along the arrow as primary cooling water 19. The thyristor stack 7 and other electric parts 21 constituting the inverter power supply 18 are supplied with water by the electric insulating tube 3, and the remaining part is sent to the ion exchanger 14 to remove ions dissolved in the cooling water. The purity of the water is maintained. The pure water from which the ions have been removed by the ion exchanger 14 is sent to the pure water tank 15 and returned to the water suction side of the circulation pump 12 via the drain header 22 together with the water returned from the thyristor stack 7 and other electric components 21. I am trying to do it. The secondary cooling water 17 flowing on the secondary side of the heat exchanger 13 is drained after cooling the pure water flowing on the primary side. A part of the secondary cooling water 17 is diverted and supplied as cooling water to the induction heating coil 1 or other electric equipment (not shown).

[0006] High voltages of different levels are applied to the thyristor stack 7 and the induction heating coil 1 in FIG. It is necessary to electrically insulate these voltage applying parts and the cooling water circulating equipment such as the circulating pump 12 and the heat exchanger 13 which are in a ground state. Therefore, the thyristor stack 7, which is a power-generating portion, and other electric components 21 are electrically insulated from the water supply header 20 and the drain header 22 by the electric insulating pipe 3.

FIG. 5 shows an example of supply of cooling water when a plurality of thyristor modules 23a to 23d each having a thyristor as a main component, such as a thyristor valve, are stacked in a plurality of stages in a potential series. is there. Since different levels of high voltage are applied to the thyristor modules 23a to 23d in FIG. 5, the thyristor modules 23a to 23d and the cooling water systems are electrically insulated in the same manner as in FIG. There is a need to. Therefore, from the water supply header 20 to each thyristor module 23a
To the water supply headers 20a to 20d of the thyristor modules 23 to 23d.
The drainage headers 22a to 22d and the drainage headers 22a to 23d are similarly connected by the electric insulating pipe 3 to drain water, and electrically insulate between the thyristor modules 23a to 23d and between the cooling water systems.

[0008]

Since the conventional construction of the cooling water pipe connection to the current-carrying section is constructed as described above, when the applied voltage is low, the leakage current from the voltage applying member to the cooling water is reduced. Although the amount was small, galvanic corrosion did not become apparent, but this became apparent as the equipment became higher in pressure and higher in power.

In general, water-cooled electric equipment is shown in FIGS.
As shown in FIG. 8, a structure in which an electric insulating pipe is connected to a metal joint such as the pipe joint 4 is used. Where a potential difference is generated between a pair of metal joints via cooling water, the following equation is used. In addition, at the contact surface between the high-potential side joint corresponding to the anode and the cooling water, a part of the metal is oxidized and eluted as shown by the equation (1), and an oxidation reaction such as generation of oxygen gas shown by the equation (2) is performed. At the low potential side joint corresponding to the cathode, reduction reactions such as metal deposition by the reaction represented by the equation (3) and generation of hydrogen gas represented by the equation (4) occur. High potential ^{side: Fe → Fe ++ + 2e -} .......................................... (1) H 2 O → 2H + + 2e - +1/20 2 ↑ .................. (2) Low potential side: Fe ⁺⁺ + 2e ⁻ → Fe... (3) 2H ⁺ + 2e ⁻ → H ₂ ↑ ………………… ( 4) When the potential of the power-generating portion increases with the increase in the power and the power of the device and the potential difference generated between the metal joints increases, the oxidation-reduction reaction represented by the above equation is accelerated. This causes water leakage due to galvanic corrosion of the metal joints, resulting in problems such as a decrease in dielectric strength, insulation breakdown, deterioration of cooling characteristics due to mixing of generated gas, and unstable operation of cooling water circulation. There was a problem.

If the problem is only corrosion of the pipe joint, a ceramic joint may be used in place of the metal joint. However, since the power-generating parts such as the induction heating coil and the cooler are made of metal, the space between the metal and the cooling water can be reduced. Since the potential difference is inevitably generated in the part, and the above problem occurs in that part, simply changing the material of the pipe joint does not provide a solution to the problem occurring at the boundary between the conductive part and the insulating part,
A conductive joint that does not cause the above-mentioned problems was required.

As a part of solving this problem, the relationship between the leakage current density and the corrosion rate when stainless steel was used as the metal joint was examined. FIG. 1 shows an example of the experimental results, in which the corrosion rate, that is, the amount of metal corrosion per amount of energized electricity has an exponential relationship with the current density per area of the surface where the current of the joint flows. Was found. FIG. 2 shows the relationship between the amount of electrolytic corrosion and the pH near the joint surface, and FIG. 3 shows the relationship between the pH and the current density obtained by using the flow velocity as a parameter. From the results of FIG. 3, the inventors concluded that the higher the flow rate of the cooling water, the higher the pH value near the surface of the joint, which was closer to the condition for suppressing metal corrosion, and found a quantitative relationship therebetween.

The present invention has been made based on the results of these studies, and provides a condition for increasing the flow velocity in the vicinity of a connection between a metal joint of a pipe joint and an electric insulating tube, and a component shape for realizing the condition. This is intended to solve the conventional problem. As another method, the problem is solved by disposing a sacrificial electrode at a different position from the water seal portion of the pipe joint. Furthermore, although ceramics is a good material from the viewpoint of corrosion, it has not been a solution to the problem because it is an electrically insulating material. This is another means for solving the above-mentioned problem by coating the liquid contact portion.

[0013]

According to the present invention, there is provided a cooling water piping apparatus for electric equipment, wherein a piping joint is connected to a current-carrying part.
Having an electrical insulation pipe connected to the metal joint and the cooling water pipe,
Cooling near the joint between the metal joint of the pipe joint and the electrically insulated pipe
Is accelerated and adjusted with respect to the flow velocity of the pipe portion . Further, a flow path constricted body composed of a columnar body having a reduced fluid resistance is arranged at the center of the flow path cross section of the pipe joint. Further, a fixing plate for arranging and fixing the flow path narrowing body at the center of the flow path cross section of the pipe joint is inclined with respect to the flow direction of the cooling water so as to form a swirling flow in the cooling water flow. .

Further, the inside diameter of the metal joint is reduced to increase the flow rate of cooling water in the metal joint. Further, a sacrificial electrode is provided on the water seal portion of the metal joint along the inner wall surface of the electric insulating tube. In addition, the material of the sacrificial electrode is the same material as the metal joint, a noble metal having a low degree of ionization, or solid carbon in which the electrode reactant is a gaseous substance.

Further, the liquid-contact part of the metal joint is coated with a conductive ceramic. Further, as the conductive ceramic, an oxide of a metal such as Al, Fe, Cr, Ti or an alloy thereof is used. In addition
And the flow velocity at the metal joint is 1.5 to 2.0 m / S, p
H was set to 3.4 to 3.65.

[0016]

In the cooling water piping device for electric equipment configured as described above, the pipe joint is connected to the metal joint connected to the current-carrying part.
And an electrically insulating tube which is connected to the hand to the cooling water piping, accelerating adjusted <br/> flow rate of the cooling water of the connecting portion near the metal fittings and electrically insulating tube of the pipe joint against flow rate of the pipe section As a result, corrosion is suppressed and the flow velocity in parts other than the pipe joints is suppressed to a low value, so that pressure loss can be suppressed low, pressure acting on the electrically insulating pipe can be reduced, and mechanical Reliability can be improved.

Further, ceramics having a conductivity sufficiently higher than the conductivity of the cooling water are specified at the liquid contact portion of the metal joint, and the ceramics are coated to suppress galvanic corrosion of the metal and to maintain the electrical environment. ing. Therefore, the reliability of the system is improved by configuring a cooling water piping system that is mechanically robust and does not cause galvanic corrosion even in a high-voltage environment.

[0018]

[Embodiment 1] The amount of galvanic corrosion caused by galvanic corrosion of a metal joint largely depends on the amount of leakage current and the physicochemical environment of the liquid contact surface. FIG. 1 shows an example of actual measurement results obtained by experimentally determining the amount of electrolytic corrosion with respect to current density when stainless steel (SUS304) is immersed in a flow of pure water and energized. In the pipe joint for connecting the electric insulating pipe 3 in the cooling pipe shown in FIGS.
It has been found that there is no practical problem if the weight loss rate due to electrolytic corrosion is 1.3 g / 30 years or less, preferably 0.9 g / 30 years or less. If the above-mentioned weight loss rate due to electrolytic corrosion and the time when 5 mA is allowed as the leakage current value are set as the criteria for the electrolytic corrosion countermeasure, the amount of electrolytic corrosion with respect to the leakage current is: electrolytic corrosion = weight reduction rate / (leakage current value × If the above criteria are applied, the amount of electrolytic corrosion is 1 m
g / A · hr or less, desirably 0.7 mg / A · hr or less. Since it is not economically feasible to limit the amount of electrolytic corrosion to an extremely small value, if the allowable range of the amount of electrolytic corrosion is set to 1 mg / A · hr, preferably 0.7 mg / A · hr, the corresponding leakage is set. The current densities were obtained from the measured data shown in FIG.
4m A / cm ² given by, a 3.5mA / cm ² as a desired value.

Electrolytic corrosion is related to the acidity of water on the wetted surface. FIG. 2 illustrates the result of obtaining the pH value of the liquid contact surface from the following calculation formula based on the experimental result of the amount of electrolytic corrosion with respect to the current density. i = 2FDΔC / δ / t ₊ ………………………… (5) C = C ₀ + ΔC ………………………………………… (6) pH = -Log (C × 1000) (7) where i: current density at the anode (A / cm ² ) F: Electrochemical equivalent (Coulomb / g equivalent) D: Ion diffusion coefficient (cm ² / sec) C ₀ : Bulk ion concentration (Equivalent / cm ² ) ΔC: Ion concentration difference (Equivalent / cm ² ) δ: Ion concentration boundary Film thickness (= d / Nu) d: inner diameter of tube (cm) Nu: Nusselt number t ₊ : ion transport number (= C ₀ L / κ) L: ion mobility (mho · cm ² / equivalent) ) Κ: Specific conductivity (mho / cm) In FIG. 2, line A is drawn along the measurement point, and line B is drawn along the boundary of the maximum value of the measurement point. . 3.4 to electrolytic corrosion amount from the figure below 1 mg / A · hr is the value of the point Q1 on the horizontal axis corresponding to the intersection of the dashed lines D ₁ and A line or electrolytic corrosion amount 0.7 mg / A, When the strictest conditions are applied within the range of hr or less, the broken line D in FIG.
The value of the point Q2 on the horizontal axis corresponding to the intersection of _0.7 and the B line is 3.65. Therefore, in order to make the amount of electrolytic corrosion 1 mg / A · hr or less, the pH of the joint surface is 3.4 or more, and when the amount of electrolytic corrosion is 0.7 mg / A · hr or less, the pH is set to 3. It is necessary to keep it at 65 or more.

The pH value at the joint liquid contact surface is a function of the ion concentration boundary film thickness δ, and is related to the flow rate of the cooling water flowing in the pipe. FIG. 3 shows the results obtained by calculating the current density and the pH value of the anode surface when the flow velocity in the tube is changed, using the above-described formula. As a result, the leakage current densities are shown at points P1 and P1 shown in FIG.
In order to maintain the pH value in the range of 3.5 to 4 mA / cm ² corresponding to the pH value of 3.4 or more, desirably in the range of 3.65 or more, as shown by the hatched area in FIG. , The flow velocity must be 1.5 m / sec or more, preferably 3 m / sec or more. In the case of power equipment requiring long-term durability, it is desirable to apply strict conditions. At this time, the flow velocity is 3 m / sec or more, which is a value corresponding to the point S1 in FIG. It is desirable to set it to 2 m / sec or more, which is a value corresponding to the above point S2. However, when water is passed through the pipeline, it is general to keep the flow velocity in the range of 1.5 to 2 m / sec from the viewpoint of pressure loss, and the above flow velocity value is too large from the viewpoint of pressure loss. Therefore, the flow velocity is accelerated only in the vicinity of the metal joint, and the pH value is maintained at about 3.4 to 3.6 to suppress electrolytic corrosion, and the pressure in other piping systems is reduced by reducing the flow velocity. Required.

Embodiment 2 FIG. FIG. 6 shows a configuration example of the pipe joint 4 according to the present invention. In the figure, reference numeral 24 denotes a mounting seat, and reference numeral 25 denotes a fastening fitting which connects the electric insulating tube 3 to an end of the mounting seat 24, and is connected by a fastening fitting 25 in a water-tight structure to form a pipe joint 4. , Cooling water is flowing in the direction of arrow A. Generally, a high voltage is applied to the pipe joint 4, so that a leakage current flows into the cooling water from the end.
As a result, the metal end forming the pipe joint 4 causes electrolytic corrosion and causes an accident such as water leakage, and therefore, it is necessary to suppress this phenomenon.

As described above, if the flow rate of the cooling water on the surface of the liquid-contacting portion 24a of the pipe joint 4 is increased, the electrolytic corrosion can be suppressed. Flow path constricted body 2 composed of a columnar body with reduced fluid resistance as shown
7 is disposed at the center of the cross section of the flow path as shown in FIG. 7, and the flow path cross section of the conduit is reduced to accelerate the flow velocity at the metal end portion shown by the area Z2 in FIG. The flow path narrowing member 26 is formed of an insulating material so as not to affect the potential distribution, and is similarly fixed inside the mounting seat 24 by a fixing plate 27 of the insulating material. The area of the metal pipeline region Z1 excluding the metal end and the area of the electrically insulating pipeline Z3 excluding the connection portion have a large flow path cross section and a low flow velocity, so that the pressure loss is low, thereby increasing the pressure of the entire system. Can be kept low.

Embodiment 3 FIG. In the second embodiment, the water flow is accelerated by arranging the flow path narrowing body 26 at the center of the inner flow path of the pipe joint 4 and reducing the cross section of the flow path. The flow velocity may be accelerated by forming a swirling flow. FIG. 9 shows a fixing plate 27 for fixing the flow path constricted body 26 to the pipe joint 4 in order to form a swirling flow.
a is inclined at an inclination angle θ with respect to the flow direction, and FIG. 10 shows a state in which this is fixed to a pipeline.

As a result, the cooling water flowing linearly in the axial direction in the area Z1 generates a swirling flow by the action of the fixed plate 27a that is inclined in the area Z2. At this time, the flow velocity of the swirling flow is represented by θ, the inclination angle of the fixed plate 27a with respect to the flow direction.
If the axial velocity is V, the turning velocity V _s is about V /
is accelerated to cos θ. By changing the inclination angle θ, it is possible to arbitrarily adjust the flow velocity to suppress galvanic corrosion. The swirling flow gradually enters the region Z3 and disappears, and flows again linearly in the axial direction. Thereby, the flow velocity is accelerated along the inner wall surface of the pipe joint 4 to suppress the electric erosion, and in the other parts, the flow velocity is suppressed low to reduce the pressure loss, thereby lowering the pressure of the entire system. .

Embodiment 4 FIG. In the above-described embodiment, an example has been described in which a member that narrows the cross-section of the flow channel or a member that hydrodynamically accelerates the flow velocity is disposed in the flow channel. However, as shown in FIG. Alternatively, the flow rate may be accelerated. In this case, it is necessary to increase the inner diameter downstream of the joint to match the inner diameter of the insulating tube 3. In this expansion area, the inner diameter is gradually expanded as shown in FIG. 11 so that streamlines are not disturbed and stagnation points do not occur. Also,
Because the flow velocity in the downstream part becomes low and it becomes a condition that causes electrolytic corrosion,
The insulating member 28 covers the inner wall of the mounting seat 24 so that no leakage current is generated.

Embodiment 5 FIG. In the above-described embodiment, the electric current is caused by the leakage current from the water seal portion of the mounting seat 24, thereby causing the problem of water leakage. However, the sacrifice electrode is disposed at a place other than the water seal portion, and the leakage current occurs. The problem may be solved by arranging the place in a part unrelated to the water seal. FIG. 12 shows an example in which a part of the mounting seat 24 is extended from the water seal portion of the mounting seat 24 in the axial direction along the inner wall surface of the electric insulating tube 3 to form a sacrificial electrode 29. Sacrificial electrode 29
By selecting the length in the flow direction, the potential gradient can be eliminated in the water seal portion. FIG. 13 shows the potential distribution in the left half with respect to the center line CL of the pipe joint.
As shown in this potential distribution diagram, no potential gradient is formed at the joint surface between the mounting seat 24 and the electric insulating tube 3. Therefore, no leakage current is generated, the leakage current location can be limited to the tip of the sacrificial electrode 29 where the potential gradient is concentrated, and electrolytic corrosion of the water seal mechanism can be prevented.

Embodiment 6 FIG. The sacrificial electrode 29 shown in FIG. 12 may be made of the same material by extending a part of the mounting seat 24 as it is, or by plating a noble metal, such as gold or platinum, which has a low degree of ionization and does not easily cause electrolytic corrosion. Alternatively, solid carbon, which is a gas component instead of metal ions in the electrolytic corrosion product, may be attached to the lower portion of the attachment seat 24.

Embodiment 7 FIG. The above description has been given of the case where the metal is in direct contact with the cooling water in the wetted part of the pipe joint, but when the metal in the wetted part of the pipe joint is an iron alloy and this is in direct contact with the cooling water, Then, on the low potential side, the reactions represented by the above-mentioned equations (1) to (4) are caused. That is,
On the high potential side, as shown in the equations (1) and (2), the metal of the mounting seat 24 is eluted as ions, and oxygen gas is generated. On the low potential side, the equations (3) and (4) are used. As shown, the metal ions lose charge and precipitate, and generate hydrogen gas. Further, in the process of flowing in water, metal ions generated on the high potential side may react with oxygen to form oxides, solidify and precipitate, and cause a problem.

A coating material having good water resistance, being chemically inert, being usable in a pure water system, and having better conductivity than cooling water is selected, and as shown in FIG. By coating with the coating material 30,
The above problem can be solved. Materials satisfying this requirement are electronic conductive semiconductor ceramics, ionic conductive ceramics, and the like. Since ceramics are electrochemically inert, the metal elution reaction on the high potential side shown by the equation (1) and the metal deposition reaction on the low potential side shown by the equation (3) are eliminated. There are only the two reactions shown. High potential ^{_{side: H 2 O → 2H + +}} 2e + 1 / 2O 2 ↑ ..................... (2) low potential ^{side: 2H + + 2e - → H} 2 ↑ ....................................... (4) That is, on the high potential side, only oxygen gas is generated and no electrolytic corrosion occurs, and since there is no metal ion, it reacts with oxygen in the process of flowing in water as described above to become an oxide and solidify to precipitate. Can be solved.

Embodiment 8 FIG. The electronic conductive semiconductor ceramics are oxides of metals such as Al, Fe, Cr, Ti or alloys thereof, which are sufficient for the conductivity of pure water of 10 ⁻⁷ Ω ⁻¹ cm ⁻¹ . Has great conductivity.

[0031]

As described above, according to the present invention, in the cooling water pipe of the electric equipment, the pipe joint is connected to the current-carrying part.
Metal fittings and electrical insulation pipes connected to the cooling water pipes.
And the inner wall surface along a flow velocity of the cooling water to suppress <br/> acceleration to galvanic corrosion against the flow rate of the pipe section, the other pipe part of the metal joint portion connecting the electrically insulating tube metallic fittings In order to prevent accidents such as water leakage due to electrolytic corrosion, it is possible to prevent accidents such as water leakage due to electrolytic corrosion, and to operate the system at a low system pressure. Is reduced, and the reliability of the system can be improved. Furthermore, by coating the liquid contact surface of the metal joint with a conductive coating material, the effect of suppressing electrolytic corrosion is enhanced, and the electrolytic corrosion reactant becomes a gas product, thereby facilitating the clean control of pure water. There is an effect that can be.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating the amount of electrolytic corrosion with respect to the current density of stainless steel for explaining Example 1 of the present invention.

FIG. 2 is a diagram illustrating the relationship between the amount of electrolytic corrosion of stainless steel and the pH value of the liquid contact surface for explaining Example 1 of the present invention.

FIG. 3 is a diagram illustrating a relationship between a current density and a pH value of an anode surface with respect to a flow velocity in a tube for explaining the first embodiment of the present invention.

FIG. 4 is a block diagram for explaining Embodiment 1 of the present invention;

FIG. 5 is a block diagram for explaining Embodiment 1 of the present invention.

FIG. 6 is a cross-sectional view for explaining Embodiment 2 of the present invention.

FIG. 7 is a cross-sectional view for explaining Embodiment 2 of the present invention.

FIG. 8 is a perspective view for explaining Embodiment 2 of the present invention.

FIG. 9 is a front view for explaining Embodiment 3 of the present invention.

FIG. 10 is a sectional view for explaining a third embodiment of the present invention.

FIG. 11 is a cross-sectional view for explaining a fourth embodiment of the present invention.

FIG. 12 is a cross-sectional view for explaining Embodiment 5 of the present invention.

FIG. 13 is a potential distribution diagram for explaining Embodiment 5 of the present invention.

FIG. 14 is a cross-sectional view for explaining Embodiment 7 of the present invention.

FIG. 15 is a plan view showing a conventional coil cooling unit.

FIG. 16 is a plan view showing a conventional coil cooling unit.

FIG. 17 is a side view showing a conventional coil cooling unit.

FIG. 18 is a plan view showing a conventional thyristor stack.

FIG. 19 is a side view showing a cooling block of a conventional thyristor.

FIG. 20 is a plan view showing a cooling block of a conventional thyristor.

[Explanation of symbols]

REFERENCE SIGNS LIST 3 electrical insulating pipe 4 pipe joint 7 thyristor stack 23 a to 23 d thyristor module 24 a liquid contact part 26 flow path constriction body 27 a fixing plate 29 sacrificial electrode 30 coating material

Continued on the front page (51) Int.Cl. ⁷ Identification code FI H05B 6/02 H05B 6/02 Z (72) Inventor Katsunori Asano 3-2-2 Nakanoshima, Kita-ku, Osaka-shi, Osaka Kansai Electric Power Company ( 72) Inventor Masahiro Hirose 2-5 Marunouchi, Takamatsu City, Kagawa Prefecture Inside Shikoku Electric Power Co., Inc. (72) Inventor Hiroyuki Irokawa 6-15-1, Ginza, Chuo-ku, Tokyo Inside Power Supply Development Co., Ltd. (72) Inventor Shiro Yamauchi 8-1-1, Tsukaguchi-Honmachi, Amagasaki-shi, Hyogo Mitsubishi Electric Corporation Itami Works (72) Inventor Nobuyoshi Takahashi 8-1-1, Tsukaguchi-Honmachi, Amagasaki City, Hyogo Prefecture Mitsubishi Electric Corporation Itami Works (72) Inventor Shungo Tsuboi 8-1-1, Tsukaguchi-Honcho, Amagasaki-shi, Hyogo Mitsubishi Electric Corporation Itami Works (72) Inventor Seiichi Mitsumoto 8-1-1, Tsukaguchi-Honmachi, Amagasaki-shi, Hyogo Mitsubishi Electric Corporation Materials and Devices Laboratory (56) References JP-A-5-109956 (JP, A) JP-A-6-94186 JP, A) JitsuHiraku flat 2-29594 (JP, U) (58 ) investigated the field (Int.Cl. ^7, DB name) F16L 17/00 C23F 13/00 C23F 15/00 F01D 11/06 F01P 11 / 04 H05B 6/02

Claims (9)

(57) [Claims] A cooling water is circulated to cool a current-carrying part of an electric device.
Cooling water pipingAnd the current-carrying partProvided at the connection
In pipe fittings,The pipe joint is connected to the metal joint connected to the current-carrying part.
An electrical insulating pipe connected to the cooling water pipe, Said In the vicinity of the connection between the metal joint of the pipe joint and the electrical insulation pipe
Cooling waterofFlow rateFor the flow velocity in the piping sectionAcceleration adjusted
Cooling water piping for electrical equipment characterized by having
apparatus. Wherein the flow velocity of the cooling water of the connecting portion near the metal fittings and electrically insulating tube of the pipe joint in order to <br/> accelerated adjusted relative velocity of the tubing portion, the columnar body of reduced fluid resistance 2. The cooling water piping device for electric equipment according to claim 1, wherein a flow path constricted body made of a pipe is disposed at the center of the flow path cross section of the pipe joint and is connected to an inner wall surface of the pipe joint. Wherein the flow velocity of the cooling water of the connecting portion near the metal fittings and electrically insulating tube of the pipe joint in order to <br/> accelerated adjusted relative velocity of the tubing portion, the columnar body of reduced fluid resistance A fixed plate for arranging and fixing the flow path constriction body composed of the pipe joint at the center of the flow path cross section of the pipe joint is inclined with respect to the flow direction of the cooling water so as to form a swirling flow in the cooling water flow. The cooling water piping device for electric equipment according to claim 1 or 2, wherein: 4. The flow rate of the cooling water of the connecting portion near the metal fittings and electrically insulating tube of the pipe joint in order to <br/> accelerated adjusted for flow rate of the pipe section, it has a small inner diameter of the metal fitting The cooling water piping device for electrical equipment according to claim 1, wherein: 5. A sacrificial electrode is provided along the inner wall surface of the electric insulating tube at a connection between the metal joint, which is a water seal portion of the pipe joint, and the electric insulating tube. The cooling water piping device for an electric device according to claim 1. 6. The material of the sacrificial electrode is the same as that of the metal joint.
6. The cooling water piping system for an electric device according to claim 5, wherein the noble metal having a low degree of ionization or the electrode reactant is solid carbon which is a gaseous substance. 7. The cooling water piping device for an electric device according to claim 1, wherein a connecting portion of the metal joint is coated with a conductive ceramic. 8. The conductive ceramic is made of Al, Fe, C.
The cooling water pipe of an electric device according to claim 7, wherein the cooling water pipe is an electronic conductive semiconductor ceramic having a conductivity of 10 ^-7 Ω ^-1 cm ^-1 or more, which is an oxide of a metal such as r or Ti or an alloy thereof. apparatus. 9. The method according to claim 8, wherein the flow velocity at said metal joint is 1.5 to 1.5.
The pH is 3.4 to 3.65 at 2.0 m / S.
The electrical device according to any one of claims 1 to 7, wherein
Cooling water piping system.