JPS6011736Y2 - Heat exchanger venting device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a venting device for a heat exchanger installed in a hydrogen-cooled rotating electric machine such as a turbine generator and exchanging heat from gas to liquid.

Large-capacity rotating electric machines such as turbine generators generally have hydrogen gas at a predetermined pressure sealed inside the machine and are equipped with a heat exchanger to radiate the heat generated in the windings to the outside via the hydrogen gas. There is.

Hydrogen gas is circulated outside the cooling pipe of the heat exchanger by a fan installed on the shaft of the rotating machine, and cooling water is passed from the outside into the cooling pipe to cool the rotating electric machine.

In such a cooling system, the hydrogen gas pressure inside the machine is usually maintained higher than the cooling water pressure inside the cooling pipe.

Therefore, if the cooling pipe attachment portion of the heat exchanger becomes loose, or if the cooling pipe becomes corroded or cracked, hydrogen gas will infiltrate into the cooling pipe.

Therefore, the cooling water mixed into the cooling water accumulates in the upper ice chamber of the heat exchanger, which pushes down the water level in the cooler and reduces the amount of water flowing, which not only impairs the performance of the heat exchanger, but also causes hydrogen gas to heat up. There is a risk of leakage from the exchanger to the outside of the rotating electrical machine, which is extremely dangerous.

Furthermore, as cooling pipe cracks progress, there is a risk of serious accidents such as damage to the rotating electric machine itself.

In view of the above points, the purpose of this invention is to maintain cooling performance by automatically discharging the gas accumulated in the heat exchanger, and to detect the accumulated gas at an early stage. is to provide.

An embodiment of the present invention will be described below based on the drawings.

As shown in the accompanying drawings, a heat exchanger 2 is installed in a turbine generator 1 in which hydrogen gas is sealed.

A water chamber 3 in which a cooling pipe group is opened is provided in the upper part of the heat exchanger 2.

The upper part of this water chamber 3 and the separately placed gas separation tank 4 are connected through a communication pipe 9
A shutoff valve 5 is provided in the middle of this communication pipe 9.

The gas separation tank 4 separates liquid and gas, and has a weir inside, and when a mixture of water and hydrogen gas flows in, it separates hydrogen gas while circulating inside.

The gas then flows through the atmosphere communication pipe 7 and is exhausted into the outdoor atmosphere, and the water overflows the weir and is drained through the drain pipe 6.

Note that this drain pipe 6 is provided with a U-shaped pipe portion filled with seal water to prevent hydrogen gas from flowing out.

Next, the control mechanism of the shutoff valve 5 will be explained.

The shutoff valve 5 is opened and closed by a diaphragm mechanism.

This diaphragm mechanism is communicated with a compressed air supply device (not shown), and a solenoid valve 11 is connected in the middle of the supply pipe.

On the other hand, a water level detector 12 is attached to the upper part of the water chamber 3 of the heat exchanger 2.

This water level detector 12 has an electrode rod, and this electrode rod is connected to the water chamber 3.
It is attached so that it protrudes from the

The electrode rod becomes energized when it comes into contact with ice, and its lower end is set at the limit water level at which the amount of water flowing in the ice chamber 3 maintains a predetermined cooling performance of the heat exchanger.

This water level detector 12 and the above-mentioned solenoid valve 11 are connected to the relay 1.
3 and a timer 14.

This timer 14 is set for a predetermined time by an electric signal sent from the relay 13, that is, the time until the hydrogen gas accumulated in the water chamber 3 completely flows out to the gas separation tank 4, and is shut off for only this time. Valve 5 is opened.

Next, the hydrogen gas detection mechanism will be explained.

A hydrogen gas concentration detector 8 is attached to the atmosphere communication pipe 7 of the gas separation tank 4 described above.

This operates only when the gas being exhausted is hydrogen gas, and at the output end of the detector there is an alarm setting relay 21 and an alarm 22 that issues an alarm based on the signal from this relay 21.
is connected.

Although the water level detector 12 has been described as having an electrode rod, it may also be a capacitive level detector or a level detector using ultrasonic waves.

It is also possible to eliminate the need for the timer 14 by using a delay relay as the relay 13 of the control mechanism.

The function of the air venting device configured as described above is such that when hydrogen gas enters the inside of the cooling pipe of the heat exchanger 2, the gas gradually accumulates in the upper water chamber 3.

Then, as shown in the drawing, the water level decreases and finally falls below the lower end of the water level detector 12.

At that time, the water level detector 12 is de-energized.

When the current is turned off, the relay 13 operates and gives an operation signal to the timer 14, thereby opening the solenoid valve 11.

When the solenoid valve 11 is opened, pressure is supplied to the shutoff valve 5, and the shutoff valve 5 is opened.

When the shutoff valve 5 opens, hydrogen gas is pushed out together with water by water pressure.

Since the timer 14 is set to a time until the accumulated hydrogen gas completely flows out to the gas separation tank 4, the electromagnetic valve 11 and the shutoff valve 5 are closed after a predetermined period of time has elapsed.

The mixed water flowing into the gas separation tank 4 is completely separated into water and hydrogen gas, and each is discharged.

Hydrogen gas is detected by a hydrogen concentration detector 8 connected to an atmosphere communication pipe 7.
is detected, and the alarm device 22 issues an alarm.

In this manner, according to the present device, hydrogen gas that has entered the heat exchanger 2 is automatically discharged when it accumulates in the heat exchanger 2, so that a predetermined amount of cooling water can be maintained at all times.

Therefore, not only is it unnecessary to stop the generator to vent gas, but also the highest cooling efficiency can be maintained at all times.

Furthermore, since it is possible to detect pure hydrogen gas that does not contain moisture, it is possible to know at an early stage that damage has occurred to the heat exchanger 2.

Next, a case will be described in which the device of the present invention is used in a turbine generator for geothermal power generation.

As is well known, cooling water is produced by condensing geothermal steam in a condenser, sending the recovered water to a cooling tower, cooling it, supplying it to a heat exchanger with a pump, and returning to the condenser.

Typically, the turbine generator heat exchanger is located at the highest level above the condenser pump location.

Therefore, because the amount of cooling water fluctuates the most and because the drain pipe of the heat exchanger is connected to a depressurized condenser, the inside of the heat exchanger tends to be at atmospheric pressure or negative pressure.

In such a state, the gas mixed in the cooling water is likely to be separated inside the heat exchanger, and the gas will accumulate in the upper part of the heat exchanger.

This device is extremely effective in terms of maintenance when used in heat exchangers where gas frequently accumulates, or in heat exchangers such as generators that operate unmanned.

As explained above, according to the present invention, not only can the cooling performance of the heat exchanger be maintained at all times, but also damage to the heat exchanger can be detected at an early stage to eliminate the risk of serious accidents in the main engine. .

[Brief explanation of the drawing]

The drawing shows an air venting device for a heat exchanger installed in a hydrogen-cooled turbine generator, showing an embodiment of the present invention. 1... Turbine generator, 2... Heat exchanger, 3... Upper ice chamber, 4... Gas separation tank, 5... Sharai, 7...Atmospheric communication pipe, 8...Hydrogen gas concentration detector, 11...
...Solenoid valve, 3.21...Relay, ...Alarm. 12... Water level detector, 1 14... Timer 22...

Claims (1)

[Scope of utility model registration request] An upper ice chamber of a heat exchanger attached to a hydrogen-cooled rotating electric machine, a separation tank that communicates with the upper ice chamber via a shutoff valve and separates gas from the inflowing cooling water, and an upper ice chamber provided in the upper ice chamber. A water level detector that detects a predetermined water level that has fallen due to accumulated gas, a control mechanism that controls the shut-off valve to open only for a predetermined time based on an electric signal from the water level detector, and separation by the separation tank. A heat exchanger venting device equipped with a detection mechanism that detects hydrogen gas and issues an alarm.