JPS61224839A - Coolant monitor of rotary electric machine - Google Patents

Abstract

PURPOSE:To effectively perform a defect countermeasure previously by providing a corrosive material having large corrosion sensitivity, made of a material which is similar to that of a brazing unit of a coolant conduit of a rotary electric machine in the conduit and observing the corrosive state. CONSTITUTION:Coolant is fed under pressure from a coolant tank 3 by a pump 4 to the stator coil 2 of a generator 1, and the coolant of suitable temperature and amount is circulated through a cooler 5, a temperature control valve 7, a pressure regulating valve 8, and a filter 9. Conductivity meters 15, 14 are provided at the outlet and the inlet of the water of a stator coil 1 to monitor the purity of the water. Additionally, corrosion detector 100 is provided between the valve 8 and the filter 9. The detector 100 projects a detection unit 120 into a conduit. The unit 120 has a test piece 121, the material is similar to that of a brazing unit used for the conduit, and formed of the material having high corrosion sensitivity. The variation of a resistance between terminals 123C and 123d is externally monitored. Thus, the corrosive state of the brazing unit in the conduit can be readily observed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a cooling water monitoring device for a rotating electric machine, and more particularly to prevention of failure of a cooling system due to deterioration in the quality of cooling water.

[Background of the invention]

Large rotating electric machines use cooling devices that use pure water as cooling water. FIG. 6 shows a cooling water piping system of a cooling device in a conventional rotating electrical machine. A fixed amount of pure water, which is cooling water for cooling the stator coil 2 of the generator 1, is stored in a tank 3. One end of the stator coil 2 is passed from the tank 3 through a water supply pump 4, a temperature control mechanism including a cooler 5, its bypass circuit 6, and a temperature control valve 7, a pressure control valve 8, and a filter 9 for removing foreign matter. and is discharged from the other end of the stator coil 2 to the tank 3.
Flows through the first circulation line returning to. In addition, the temperature adjustment valve 7
A pipe branched from between the pressure regulating valve 8 and the pressure regulating valve 8 flows through a second circulation pipe that returns to the tank 3 via a check valve lO and a water purifier IL filter 12 using ion exchange resin powder. A water supply pipe 1 is provided between the check valve 10 and the deionizer 11 in the second circulation pipe.
Make-up water is supplied from No. 3, and a constant amount of cooling water of a constant purity is secured in the cooling system. This type of cooling device was developed in the 5th century.
It is described in Japanese Patent No. 5-69866.

This cooling system also has a conductivity monitor 1 that measures the conductivity of the cooling water on the inlet side of the stator coil 2 as a cooling water monitoring device.
4.Measure the electrical conductivity of the cooling water on the outlet side1.
5. A conductivity indicator 16 is provided to measure the electrical conductivity of the cooling water returning to the tank 3 via the water purifier 11, and the electrical insulation performance of the cooling water is monitored. The conductivity of the cooling water is an important factor in a cooling system that uses pure water as a refrigerant, and by monitoring the conductivity of the cooling water in this way, it is possible to monitor the electrical components such as stator coils to which the cooling water is supplied. An insulated state is ensured.

However, it has been found that the deterioration in the quality of the cooling water not only deteriorates the electrical insulation performance but also corrodes and damages the components that make up the cooling system.

[Purpose of the invention]

An object of the present invention is to provide a cooling water monitoring device for a rotating electric machine that can estimate the state of corrosion of components in a cooling system that occurs due to deterioration in the quality of cooling water, and thereby take preventive measures against failures. It is about providing.

[Summary of the invention]

In order to achieve this objective, the present invention provides a corrosion detector equipped with a corrosive object having a corrosive property and a higher corrosion sensitivity than the brazed part existing in the cooling water pipe in the vicinity of the brazed part. The present invention is characterized in that by monitoring the exaggerated state of corrosion of the corroded object, it is possible to estimate the deterioration of the quality of the cooling water and the state of corrosion of the brazed parts in the cooling waterway.

Next, this will be explained using a specific example. When mounting a stator coil for a zero-rotation electric machine, there will be parts that are brazed on the machine. Since it is not possible to clean the flux from this part after brazing, it is common to braze without flux using phosphor copper brazing.When a stator coil configured in this way is water-cooled, If chloride or ammonium gradually gets mixed into the cooling water due to incorrect selection of the backing material used in the piping system or inadequate water quality control of the make-up water, these will corrode the brazed parts. damage the part. Such deterioration of cooling water quality and corrosion of brazed parts cannot be monitored using conventional cooling water conductivity meters.

According to an embodiment of the present invention, such deterioration of cooling water quality can be solved by having a brazed part using phosphor brazing similar to the stator coil, and in addition, the core part is larger than the brazing part in the stator coil. A test piece configured to increase corrosion sensitivity is placed in a cooling waterway and monitored by observing exaggerated corrosion conditions occurring at the brazed joints of the detector test piece. The corrosion state of the brazed parts is also estimated.

The magnitude of the corrosion sensitivity of the brazed part of the test piece is
It does not matter if it is per unit part or if the effect of corrosion can be detected more greatly when observed as a whole.

[Embodiments of the invention]

FIG. 1 shows a cooling water piping system of a cooling water monitoring device for a rotating electric machine according to the present invention. Components that are the same as those of the conventional device are given the same reference numerals, and detailed explanation thereof will be omitted.

A feature of this embodiment is that a corrosion detection device 100 is provided between the pressure regulating valve 8 and the filter 9. As schematically shown in FIGS. 2(a) and 2(b), this corrosion detector f100 includes a detection tube 110 inserted in a pipeline between a pressure regulating valve 8 and a filter 9, and a detection tube 110 inserted into a pipeline between a pressure regulating valve 8 and a filter 9. The detector 120 includes a test piece 121 that is exposed to cooling water flowing through the detector 110 and is corroded by chlorine and ammonium contained in the cooling water.

The configuration of the detector 120 will be described in detail with reference to FIGS. 3 to 5. The test piece 121 is a plurality of copper pieces 121a
The two ends are connected by a brazed part 121b using phosphor solder, and both ends of the fastener 12 are embedded in the end faces of the legs 122a and 122b inside the approximately H-shaped support base 122.
3a, 123b with set screws 123c, 123d. Legs 122a of this support stand 122, 1
A tension rod 124 is interposed between the test pieces 121 and 22b, and by extending the length of the rod by turning an intermediate threaded portion 124a, the leg portions 122a and 122b are pushed apart to apply tension to the test piece 121, thereby performing the test. piece 121
The corrosion sensitivity of the brazed portion 121b is increased. This support base 122 is made of a stable insulating material such as Teflon or ceramic, and has legs 122c, 122 on the other side.
Terminals 125a, 125b are provided on the end face of d, and lead wires 126a, 126b buried in the legs 122a, 122c and 122b, 122d connect to the stoppers 123a, 123b and the terminals 125a, 125.
electrically connect between b. Test piece 12 like this
1 is attached to the support base 122 is the leg portion 122c.

122d is a hole 110a formed in the detection tube 110, 1
The backing 127 is attached to the inside of the detection tube 110 so as to pass through the detection tube 10b, and is in contact with the outside of the detection tube 1.
10 with screws 128a, 128b, . . . and is tightened with a presser plate 129 to maintain watertightness.

If the cooling water contains chlorine or ammonium, the brazed portion 121b of the test piece 121 of the detector 120 installed in the cooling waterway will be corroded by these, and the electrical resistance will change. Therefore, the terminal 125a,
If an electrical resistance meter is connected to 125b and the electrical resistance of the test piece 121 is measured, it is possible to detect that corrosive foreign matter has entered the cooling water based on the amount of change in electrical resistance. Further, such corrosive foreign matter detection can be easily performed using a simple instrument while the generator 1 is in operation. Based on this detection result, it is possible to detect deterioration in the quality of the cooling water and replace it, or to safely operate the rotating electric machine while estimating the state of corrosion of the brazed parts present in the cooling water channel.

It is difficult to detect a small amount of foreign matter mixed in with a commonly used cooling water conductivity meter, and even if it can be detected, it is not possible to estimate the state of corrosion of the brazed joint due to this foreign matter. According to 120,
The brazed portion 121b of the test piece 121 is corroded by foreign matter, similar to the brazed portion existing in the cooling channel, but to an exaggerated extent, and the corrosion accumulates. , if the corrosion state of the brazed portion 121b of this test piece 121 is observed,
It is possible to detect slight deterioration in cooling water quality and estimate the corrosion state of brazed parts in cooling channels.

The detector 120 described above is for observing corrosion of the brazed portion 121b of the test piece 121, but the entire test piece is made of the same corrosive material as the brazed portion 121b. Of course, it is possible. In addition, the corrosion state of the test piece 121 can be checked by the detector 120 when the generator is stopped for periodic inspection, etc.
It can also be removed and visually observed using a microscope, etc.

〔Effect of the invention〕

As described above, the present invention provides a corrosion detector in the cooling water piping system, which is equipped with a corroding object that has corrosive properties similar to those of the brazed parts existing in the cooling waterway, and has a higher corrosion sensitivity than the brazed parts. By observing the exaggerated state of corrosion of this corroding object, it is possible to detect the deterioration of the cooling water quality and estimate the accompanying corrosion state of the brazed parts in the cooling channel. There is an effect that can be done.

[Brief explanation of drawings]

Fig. 1 is a cooling water piping diagram of a cooling water monitoring device for a rotating electrical machine according to the present invention, and Fig. 2 is a schematic diagram of a corrosion detection device, where (a) is a longitudinal side view and (b) is a cross section taken along line B-B. Figures, Figures 3 to 5
The figure shows a detailed view of the corrosion detector. Figure 3 is a top view, Figure 4 is a vertical side view, Figure 5 is a bottom view, and Figure 6 is a cooling water monitoring system for a conventional rotating electric machine. It is a piping diagram. DESCRIPTION OF SYMBOLS 1... Generator, 2... Stator coil, 3... Tank for storing cooling water, 4... Water supply pump, 5... Cooler, 100... Corrosion detection device, 120... - Corrosion detector, 121... test piece. Figure 1 Figure 2 (a) (b) Figure 3 Figure 5

Claims (1)

[Scope of Claims] 1. In a machine equipped with a cooling water piping system for cooling the heat generating part of a rotating electric machine, the cooling water piping system has corrosive properties similar to those of the brazed parts existing in the cooling water channel. 1. A cooling water monitoring device for a rotating electric machine, characterized in that a corrosion detector is provided with a corrosive object having a higher corrosion sensitivity than that of a rotary electric machine. 2. In claim 1, the corroding object is
A cooling water monitoring device for a rotating electric machine, characterized in that copper pieces are connected by brazing with the same brazing material as a brazing part existing in a cooling waterway. 3. In claim 1, the corroding object is
A cooling water monitoring device for a rotating electrical machine, characterized in that copper pieces are connected by brazing with the same brazing material as a brazing part existing in a cooling waterway, and tension is applied. 4. A cooling water monitoring device for a rotating electric machine according to any one of claims 1 to 3, characterized in that an electrical resistance measuring terminal is connected to the corroded object.