JPH10327559A - Draining and drying apparatus for generator stator winding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a draining and drying apparatus for generator stator windings, which is capable of automatically monitoring pressure and operating a vent valve and an exhaust valve and quantitatively controlling the degree of dryness, when the inside of generator stator windings is drained and dried. SOLUTION: When the inside of generator stator windings 1 is drained and dried, a vent valve 5 is opened through a controller 13 to allow a dry gas enter the generator stator windings 1. When the pressure inside the generator stator windings 1 reaches a specified value, an exhaust valve 12 is opened for exhausting the dry gas, and further the vent valve 5 is closed. After the dry gas has been exhausted, the exhaust valve 12 is closed as well. The controller 13 repeats this ventilating operation, until the draining and drying of the inside of the generator stator windings 1 is completed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for draining and drying a generator stator winding for draining and drying a generator stator winding.

[0002]

2. Description of the Related Art In general, in a large-capacity generator, in order to suppress a temperature rise due to Joule heat generated in a stator winding during operation, cooling water is passed through the stator winding of the generator. It employs a so-called stator winding water cooling system that increases the cooling efficiency inside the machine. For this reason, it is required that there is no leakage of cooling water into the generator from brazed joints and welds in the generator stator winding.

[0003] At the brazed joints and welds in the stator windings of the generator, a leakage test is performed to monitor the leakage of cooling water when the generator is manufactured, after the installation is completed, and at the time of periodic inspection. In this way, the cooling water during operation is monitored to check the soundness of the generator.

[0004]

However, at the time of periodic inspection, since cooling water remains in the generator stator winding, drainage and drying are performed before a leakage test is performed. In this draining and drying, the drying gas is supplied from the ventilation side in the generator stator winding through a ventilation valve, and when the pressure in the generator stator winding reaches a specified pressure, the exhaust valve on the exhaust side is suddenly opened. Open and release to the atmosphere. This operation is usually repeated 130 times, and draining and drying are performed.

[0005] At this time, the monitoring of the pressure inside the stator winding of the generator and the rapid opening and closing of the exhaust valve are all performed by a human system, so that the physical fatigue of the operator is incalculable and the drying degree is also immeasurable. It was not managed quantitatively.

An object of the present invention is to automate the operation of the pressure monitoring and the operation of the vent valve and the exhaust valve in draining and drying the generator stator winding and to quantitatively control the degree of drying of the generator stator winding. An object of the present invention is to provide a blanket drying device.

[0007]

According to the first aspect of the present invention, there is provided a vent valve for ventilating a dry gas into a stator winding of a generator, and a vent valve for discharging the dry gas ventilated in the stator winding. And a control device that repeats a ventilation operation by opening the ventilation valve and opening the exhaust valve and closing the ventilation valve when the pressure in the stator winding reaches a predetermined value.

According to the first aspect of the present invention, when draining and drying inside the generator stator winding, the controller first opens the ventilation valve to ventilate the dry gas into the generator stator winding. Then, when the pressure in the stator winding reaches a predetermined value, the exhaust valve is opened to discharge the dry gas and the vent valve is closed. After the drying gas is discharged, the exhaust valve is also closed. The control device repeatedly performs such a ventilation operation.

According to a second aspect of the present invention, in the first aspect of the present invention, the control device determines whether or not the difference between the humidity on the ventilation side and the humidity on the exhaust side of the dry gas exceeds a predetermined value, and determines the predetermined value. When it exceeds, the ventilation operation is repeated, and when it is less than the predetermined value, the ventilation operation is terminated.

[0010] In the second aspect of the invention, in addition to the operation of the first aspect, the control device determines whether or not to repeatedly perform the ventilation operation. The determination is performed by determining whether the humidity difference between the ventilation side humidity and the exhaust side humidity of the dry gas exceeds a predetermined value, and when the humidity difference exceeds the predetermined value, repeat the ventilation operation,
If the value is less than the predetermined value, the ventilation operation ends.

[0011] The invention of claim 3 is claim 1 or claim 2.
In the invention, a safety valve is provided for releasing the dry gas to the atmosphere when the pressure in the stator winding rises abnormally.

According to a third aspect of the present invention, in addition to the operation of the first or second aspect, when the pressure in the stator winding rises abnormally during the ventilation operation, the safety valve is opened to release the dry gas into the atmosphere. Let go.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory view of a drain drying device for a stator winding of a generator according to an embodiment of the present invention.

As shown in FIG. 1, the generator stator winding 1 is provided with a cooling water inlet header drain pipe 2 and a cooling water outlet header drain pipe 3 via a stator frame 4.

The cooling water inlet header drain pipe 2 includes:
A ventilation pipe 7 for supplying a dry gas is connected, and the ventilation pipe 7 is provided with a ventilation valve 5. Also, the ventilation pipe 7
Is provided with a humidity detector 6 for detecting the humidity of the dry gas on the ventilation side.

On the other hand, an exhaust pipe 8 for discharging dry gas is connected to the cooling water outlet to the drain drain pipe 3, and the exhaust pipe 8 is provided with an exhaust valve 12. The exhaust pipe 8 has a pressure detector 9 for detecting the pressure in the generator stator winding 1, a humidity detector 11 for detecting the humidity of the dry air on the exhaust side, and a generator stator winding. A safety valve 10 is provided for releasing the pressure to the atmosphere when the pressure rises abnormally. The detection values obtained by the humidity detectors 6 and 11 and the pressure detection device 9 are input to the control device 13 and used for opening and closing control of the ventilation valve 5 and the exhaust valve 12.

The control device 13 includes a vent valve 5 and an exhaust valve 12
And automatically controls the ventilation of the drying gas for draining and drying the generator stator winding 1.
That is, when draining and drying inside the generator stator winding 1, the control device 13 first opens the ventilation valve 5 to allow the dry gas to flow through the generator stator winding 1. Then, when the pressure in the generator stator winding 1 reaches a predetermined value, the exhaust valve 12 is opened to discharge the dry gas, and the vent valve 5 is closed. After the drying gas is discharged, the exhaust valve 12 is also closed. The control device 13 repeatedly performs such a ventilation operation.

FIG. 2 is a configuration diagram of the control device 13 according to the embodiment of the present invention. The humidity of the dry gas on the ventilation side detected by the humidity detector 6 and the humidity of the dry gas on the exhaust side detected by the humidity detector 11 are determined by the input unit 14 of the control device 13.
Is input to Further, the pressure in the generator stator winding 1 detected by the pressure detecting device 9 is also input to the input unit 14.

A predetermined target value of a humidity difference between the humidity of the dry gas on the ventilation side and the humidity of the dry gas on the exhaust side is stored in the storage unit 15 in advance. This is the optimum data for determining that the inside of the winding 1 is dry.

The determination unit 16 stores a difference between the humidity of the dry gas on the ventilation side and the humidity of the dry gas on the exhaust side,
And if the humidity difference exceeds, it is determined that the ventilation operation needs to be repeated.

When it is determined that the ventilation operation is necessary,
An open command is output to the ventilation valve 5 via the operation output unit 17 to open the ventilation valve 5, and the dry gas is ventilated into the generator stator winding 1. When the pressure in the generator stator winding 1 detected by the pressure detection device 9 reaches a predetermined value, the operation output unit 1
An open command is output to the exhaust valve 12 and a close command is output to the ventilation valve 5 via the switch 7. As a result, the exhaust valve 12 is opened to discharge the dry gas, and the vent valve 5 is closed. Then, after the drying gas is discharged, the exhaust valve 12 is also closed. Then, it is determined whether or not the ventilation operation is necessary again, and the ventilation operation is repeatedly performed until the humidity difference reaches a predetermined target value.

As described above, according to the embodiment of the present invention, the humidity difference between the dry gas on the ventilation side and the dry gas on the exhaust side is sequentially calculated, and the opening and closing operations of the ventilation valve 5 and the exhaust valve 12 are automatically performed based on the humidity difference. It is possible to automate the draining and drying of the generator stator winding 1 and quantitatively manage the degree of drying.

Further, when the pressure in the generator stator winding 1 rises abnormally, a safety valve 10 for releasing the pressure to the atmosphere is provided, so that the abnormal pressure is manually monitored during the operation of the drainage / drying device. Is also unnecessary and labor can be saved.

[0024]

According to the present invention, the generator stator coil drainage / drying device sequentially detects the humidity difference between the gas on the ventilation side and the gas on the exhaust side, and operates the ventilation valve 5 and the exhaust valve 12 based on the detected value. As a result, it is possible to obtain a generator stator winding drain drying device capable of automating pressure monitoring and valve operation and quantitatively controlling the degree of drying in drain drying of the stator winding. .

[Brief description of the drawings]

FIG. 1 is an explanatory view of a drain drying device for a generator stator winding according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a control device used in a drain drying device for a generator stator winding according to the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Generator stator winding 2 Cooling water inlet header drain pipe 3 Cooling water outlet header drain pipe 4 Stator frame 5 Vent valve 6 Humidity detector 7 Vent pipe 8 Exhaust pipe 9 Pressure detector 10 Safety valve 11 Humidity detector 12 Exhaust Valve 13 Control device 14 Input unit 15 Storage unit 16 Judgment unit 17 Operation output unit

Claims (3)

[Claims] 1. A water-cooled generator for cooling a stator winding by passing cooling water through a generator stator winding to discharge and dry cooling water in the stator winding. In the machine stator winding water draining device, a ventilation valve for venting the dry gas into the stator winding, and an exhaust valve for discharging the dry gas ventilated in the stator winding, A generator for opening the ventilation valve and repeatedly performing a ventilation operation to open the exhaust valve and close the ventilation valve when the pressure in the stator winding reaches a predetermined value. Drain dryer for stator winding. 2. The control device determines whether a humidity difference between a ventilation side humidity and an exhaust side humidity of the dry gas exceeds a predetermined value, and when the humidity difference exceeds a predetermined value, repeats the ventilation operation, The apparatus for draining and drying a generator stator winding according to claim 1, wherein the ventilation operation is terminated when the value is less than a predetermined value. 3. The generator fixing device according to claim 1, further comprising a safety valve for releasing the dry gas to the atmosphere when the pressure in the stator winding rises abnormally. Drain dryer for child winding.