JP2000209812A - Hydrogen gas replacement device for cooling of rotating electric machines - Google Patents

Abstract

(57) [Problem] To provide an apparatus capable of automatically replacing hydrogen gas used for cooling a rotating electric machine with a minimum risk of an explosion accident and the like. An automatic valve provided in a line for discharging gas in a rotating electric machine to the atmosphere, a detector provided in an atmosphere release line for detecting gas pressure and gas concentration, and a signal from the detector. A control panel for generating a control signal for controlling the automatic valve.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to maintenance of a rotating electric machine,
The present invention relates to a hydrogen gas replacement device for extracting hydrogen gas for cooling enclosed inside at the time of inspection and refilling the hydrogen gas into the rotating electric machine after maintenance and inspection work.

[0002]

2. Description of the Related Art Hydrogen gas is used as a cooling gas for a rotating electric machine. However, if air is mixed into the hydrogen gas, an explosion accident may occur. Need to be extracted.

[0003] When extracting hydrogen gas, it is not possible to directly replace the air with air. Therefore, first, the hydrogen gas is replaced with an inert gas such as carbon dioxide gas, and then the carbon dioxide gas is replaced with air. ing.

[0004] When the maintenance and inspection work is completed, the air in the rotating electric machine is replaced with hydrogen gas in a procedure reverse to the above procedure.

[0005] The replacement operation of hydrogen gas requires complicated valve operation. If the valve operation procedure is incorrect, a serious accident may occur, and the operation has been performed by skilled personnel. or,
Since the work is complicated and time-consuming, improvement has been desired.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an apparatus which can automatically replace a cooling gas of a rotating electrical machine with a minimum risk of an explosion accident and the like.

[0007]

The object of the present invention is to provide a line for supplying a cooling gas into a rotating electric machine, a line for supplying a carbon dioxide gas, a line for supplying air, and discharging the gas in the rotating electric machine to the atmosphere. A line, an automatic valve provided on each of the lines, and a detector provided on the atmospheric release line for detecting gas pressure and gas concentration, and controlling the automatic valve according to a signal from the detector. And a control panel for generating a control signal to perform the control.

[0008]

FIG. 1 shows a configuration of a gas replacement device embodying the present invention. A rotating electric machine 23 includes a hydrogen gas supply valve 1, a gas supply line 26, Via valves 3 and 4, emergency shut-off valve 10,
Hydrogen gas is supplied. During normal operation of the rotating electric machine 23, hydrogen gas of a predetermined pressure is sealed in the inside of the machine, and the hydrogen monitoring panel 20 connected by the monitoring lines 28 and 30 constantly keeps the predetermined pressure and purity.

In order to remove moisture in the hydrogen gas sealed in the rotating electric machine 23, a gas dryer 19
7 and 29.

The emergency shutoff valve 10 of the hydrogen gas supply line 26
A bypass valve 2 is provided in parallel with the bypass valve 2.
Is closed when the rotary electric machine 23 is in a steady operation, and is configured as an automatic valve which is opened by a control signal from a control panel 15 described later.

An air supply unit 14 is connected to the gas supply line 26 via the air filling valve 12. The air charging valve 12 is an automatic valve that is closed during a steady operation and is closed by a control signal from the control panel 15 during gas replacement. An atmospheric release line 18 is provided in the gas supply line 26 between the hydrogen gas supply valve 1 and the bypass valve 2 in a branched manner, and the replacement control valve 5 is provided in this line 18. The carbon dioxide gas supply line 25 communicating the carbon dioxide gas unit 22 and the rotary electric machine 23 is provided with a carbon dioxide gas supply valve 8, and another replacement control valve is provided in a pipe 24 connecting the carbon dioxide gas supply line 25 and the atmospheric discharge line 18. 6 are provided.

The air release line 18 is provided with an outdoor discharge valve 7 which is opened when the air is released to the atmosphere. This valve is configured as an automatic valve that operates according to a control signal from a control panel 15 described later.

A pressure detector 13 for detecting the gas pressure of the carbon dioxide gas supply line 25 is provided on the line 25 via the valve 9. The signal from the pressure detector 13 is taken into the control panel 15.

A gas concentration detector 16 is connected to a pipe 17 branched from a part of the atmospheric discharge line 18. The gas concentration detector 16 measures the concentration of the gas flowing through the atmospheric release line 18 when the sampling valve 11 provided in the pipe 17 is opened, and supplies the signal to the control panel 15.

The control panel 15 takes in signals from the pressure detector 13 and the gas concentration detector 16 and a start signal of a gas replacement operation by an operator, and generates a valve operation signal shown in (a) to (h). The valve operation signals (a) to (h) open and close the automatic valves 1, 2, 5, 6, 7, 8, 11, and 12, respectively.

[0016]

[Table 1]

Table 1 shows the operation state of each automatic valve when performing a series of operations for extracting hydrogen gas from the steady state. Table 2 shows the operation state of the valve when hydrogen gas is sealed. The state is shown.

The operation of extracting hydrogen gas will be described with reference to Table 1. First, in the steady state of the rotating electric machine, the hydrogen gas supply valve 1 is open, and all other automatic valves are closed. At this time, the hydrogen gas from the unit 21 is supplied to the shut-off valve 1
0, which is supplied to the rotating electric machine 23 through a hydrogen gas supply line 26.

For maintenance and inspection work of the rotating electric machine 23, the operation of the rotating electric machine 23 is stopped, and a gas replacement start signal is input to the control panel 15. Then, the hydrogen gas release operation shown in Table 1 is started, and the hydrogen gas supply valve 1 is closed by a signal from the control panel 15, and the bypass valve 2, the substitution control valve 5, and the atmosphere release valve 7 are opened. The hydrogen gas in the rotating electric machine is released to the atmosphere through the line 26, the bypass valve 2, the displacement control valve 5, the atmosphere release valve 7, and the atmosphere release line 18 by the pressure.

The gas pressure in the rotating electric machine is detected by the pressure detector 13 via the line 25, and when the pressure becomes equal to or less than a predetermined value, a carbon dioxide gas replacement operation is started. When the carbon dioxide gas replacement operation starts, the carbon dioxide gas supply valve 8 and the sampling valve 11 are opened. Then, the carbon dioxide gas enters the machine from below the rotary electric machine from the carbon dioxide gas unit 22 via the carbon dioxide gas supply valve 8 and the line 25, and pushes out the remaining hydrogen gas to the atmosphere through the atmosphere discharge line. The hydrogen concentration of the released gas is monitored by a gas concentration detector 16 through a pipe 17 branched from the atmospheric release line 18 and the sampling valve 11, and when the hydrogen gas concentration falls below a predetermined value, the hydrogen in the machine is reduced. Substitution of the gas with carbon dioxide is substantially completed.

Next, the operation proceeds to the air displacement operation, and the displacement control valve 5 is operated.
And the carbon dioxide supply valve 8 is closed, and the displacement control valve 6 and the air filling valve 12 are opened. High-pressure air from the air supply unit 14 is supplied into the machine through the sealing valve 12 and the line 26, and carbon dioxide in the machine is discharged to the atmosphere through the line 25, the displacement control valve 6, the atmosphere release valve 7, and the line 18. You.

The concentration of released carbon dioxide is monitored by a gas concentration detector 16, and when the concentration of carbon dioxide becomes sufficiently low, the bypass valve 2, the displacement control valve 6, the atmospheric release valve 7, the sampling valve 11, the air The sealing valves 12 are both closed, and the process ends.

[0023]

[Table 2]

Table 2 shows the operation when hydrogen gas is sealed in the machine after the maintenance and inspection work is completed. The state before the replacement is the same as that at the end of the hydrogen gas extraction, and the air in the apparatus is first replaced with carbon dioxide gas. At the time of carbon dioxide replacement, the bypass valve 2, the replacement control valve 5, the atmosphere release valve 7, the carbon dioxide supply valve 8, and the sampling valve 11 are opened.

The carbon dioxide gas from the unit 22 passes through the carbon dioxide gas supply valve 8 and the line 25, enters the machine, and passes air through the line 26, the bypass valve 2, the displacement control valve 5, the atmosphere release valve 7, and the line 18. Release to atmosphere.

The concentration of carbon dioxide in the gas flowing through the atmosphere release line is measured by the gas concentration detector 16, and when the gas concentration exceeds a predetermined value, the air inside the machine is replaced with carbon dioxide, and the hydrogen gas filling operation is performed. Move on to

When hydrogen gas is charged, the hydrogen gas supply valve 1
The displacement control valve 6 is opened, and the displacement control valve 5 and the carbon dioxide supply valve 8 are opened.
Closes. The hydrogen gas from the unit 21 enters the machine through the supply valve 1, the bypass valve 2, and the line 26, and the carbon dioxide gas is supplied to the line 25, the displacement control valve 6, the atmosphere release valve 7, and the line 1
Release to atmosphere through 8. The concentration of hydrogen gas in the gas flowing through the atmosphere release line is detected by the detector 16, and when the concentration of hydrogen gas in the machine reaches a predetermined concentration, the bypass valve 2, the displacement control valve 6, the atmosphere release valve 7, and the sampling valve 11 are activated. Close and the enclosing operation ends.

As is clear from the above description, detection signals of the pressure in the rotating electric machine and the concentration of gas in the machine are taken into the control panel, and an open / close signal is supplied from the control panel to the automatic valve according to each state. The operator can safely and automatically perform the extraction and sealing of the hydrogen gas simply by giving the start signal of the gas sampling and the gas sealing.

When the hydrogen gas is extracted, the completion of the hydrogen gas releasing operation is determined based on the concentration of the hydrogen gas flowing through the release line, but this may be controlled by time. In the case of time control, the time required for the hydrogen gas to be released into the atmosphere may be set experimentally, and no problem occurs even if the hydrogen gas remains during the carbon dioxide gas replacement operation. In this embodiment, a timer is built in the control panel, and a temperature sensor for measuring the atmospheric temperature is further added. If the atmospheric release time is corrected based on the atmospheric temperature, the release of the hydrogen gas becomes more reliable.

[0030]

As described above, according to the present invention, the complicated valve operation at the time of replacing the hydrogen gas in the rotating electric machine is eliminated, and the risk of erroneous valve operation procedure leading to a serious accident is reduced. It is possible to reduce the human burden of complicated and troublesome replacement work.

Further, according to the present invention, it is possible to save labor time such as manual valve operation and monitoring time, and to reduce the inspection cost of the rotating electric machine.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a cooling hydrogen gas replacement device for a rotating electric machine according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Hydrogen gas supply valve, 2 ... Bypass valve, 5, 6 ... Substitution control valve, 7 ... Atmospheric release valve, 8 ... Carbon dioxide gas supply valve, 11 ... Sampling valve, 12 ... Air filling valve, 13 ... Pressure detector,
14 ... air supply unit, 15 ... control panel, 16 ... gas concentration detector, 18 ... atmosphere release line, 21 ... hydrogen gas unit, 22 ... carbon dioxide gas unit, 25 ... carbon dioxide gas supply line, 26 ... hydrogen gas supply line.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yasuhito Kondo 3-2-2 Sachimachi, Hitachi City, Ibaraki Prefecture Within Hitachi Engineering Services Co., Ltd. (72) Inventor Hiroyuki Kido 3-2-2 Sachimachi, Hitachi City, Ibaraki Prefecture No. 2 F-term in Hitachi Engineering Services, Ltd. (reference) 5H609 PP02 QQ03 QQ10 RR69 SS14 SS15 SS23

Claims (2)

[Claims] 1. A hydrogen gas supply line for supplying hydrogen gas into a rotating electric machine, an inert gas supply line for supplying an inert gas and an air supply line for supplying air, and a gas in the machine is discharged to the atmosphere. A discharge line, an automatic valve inserted into each of the lines, a pressure detector for detecting gas pressure in the machine, a gas concentration detector for also detecting a gas concentration in the discharge line, the pressure detector and a gas concentration. A controller for receiving a signal from a detector and generating a control signal for controlling the opening and closing of an automatic valve provided in each of the lines. 2. A hydrogen gas supply line for supplying hydrogen gas into the rotating electric machine, an inert gas supply line for supplying inert gas and an air supply line for supplying air, and a gas in the machine is discharged to the atmosphere. A discharge line, an automatic valve inserted into each of the lines, a detector for detecting the atmospheric temperature, a timer for measuring the elapsed time of the replacement work, and an atmospheric temperature and the elapsed time of the replacement work were provided for each of the lines. A controller for generating a control signal for controlling the opening and closing of the automatic valve.