JPH0311955A - Cooling device - Google Patents

Abstract

PURPOSE:To detect abnormality of cooling water system in a container containing pressurized gas quickly by providing an optical bubble detecting means for detecting bubble in cooling water flow path and an abnormality diagnosis unit for judging existence of abnormality in a cooling water circulation system based on an output signal from the bubble detecting means. CONSTITUTION:Upon breakdown of cooling water system 14 piping in a machine, several ten times of hydrogen gas leaks to cooling water circulation systems 3, 14 when compared with normal level because of high hydrogen gas pressure in the machine and high permeability of hydrogen gas thus producing bubbles in the cooling water flow paths 3, 14. Since only liquid phase exists normally in the cooling water flow path, light passed through a rod lens 4 is not scattered but goes toward another rod lens 4. When bubbles exist, the light is scattered at the gas-liquid interface. Light led through an optical fiber 6 is detected by means of a measuring system 7 and an alarm is produced when variation of the amount of light exceeds over a reference level.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Field of Application) The present invention is directed to the use of pressurized gas with good cooling performance, such as hydrogen gas, as a heat medium, and to a rotating electric machine or the like having a cooling water circulation system. Regarding a cooling device.

(Prior art) For example, rotating electric machines, especially the rotor side, are cooled using a cooling gas such as hydrogen gas that has relatively good cooling performance, that is, a gas with high thermal conductivity that is pressurized to a pressure higher than atmospheric pressure and fixed. In rotating electric machines where the child side is cooled by circulating cooling water, a small amount of hydrogen gas enters the cooling water circulation system through electrical insulation tubes made of fluororesin, etc., and enters the atmospheric pressure tank such as the cooling water tank. Precipitate. Utilizing this characteristic, an abnormality diagnosis system can be considered that detects damage in the cooling water circulation system inside the machine based on the amount of precipitated cooling gas.

Conventionally, a cooling gas concentration measuring device is installed in the middle of the atmospheric discharge pipe that discharges the cooling gas deposited in the cooling water tank into the atmosphere, and when a predetermined concentration is detected, an alarm is issued to notify you of an abnormality. system has been adopted.

(Problems to be Solved by the Invention) In such a conventional system, cooling gas precipitates in the cooling water tank during normal normal operation and then flows out into the atmosphere through the atmosphere discharge pipe. Since the amount is minute, it flows out due to the diffusion effect with the atmosphere inside the discharge pipe.

For this reason, a concentration distribution of the cooling gas occurs depending on the location within the atmosphere discharge pipe.

Further, the pressure inside the cooling water tank is approximately atmospheric pressure, and water vapor, cooling gas (for example, hydrogen gas), and the atmosphere exist within the tank according to their respective partial pressures.

For example, when adjusting the generator load due to fluctuations in power consumption even with large generators, as is the case these days, the temperature in the cooling water tank (water temperature) changes significantly depending on the load. Since the water vapor pressure in the tank changes accordingly, the atmosphere enters and exits through the atmosphere discharge pipe, and the gas concentration of the cooling gas in the atmosphere discharge pipe changes each time.

For this reason.

Detection of an abnormality in the in-flight cooling water system, which requires an emergency, will be delayed, and an extremely dangerous situation for safety is expected.

SUMMARY OF THE INVENTION An object of the present invention is to overcome such conventional drawbacks and provide a cooling device that can quickly detect abnormalities in a cooling water system in a container containing pressurized gas under any operating conditions.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above object, the cooling device of the present invention includes a cooling pipe provided inside a container containing pressurized gas, and a cooling water circulation device provided outside the container. In a cooling device that connects piping to form a cooling water circulation system and cools the inside of the container,
bubble detection means consisting of a pair of optical fibers for detecting bubbles in a cooling water flow path provided in a piping section of a cooling water circulation system;
and an abnormality diagnosis device Vi for determining the presence or absence of an abnormality in the cooling water circulation system from the output signal of the bubble detection means.

(Function) The present invention is configured as described above, and if the pressure of the cooling gas inside the container is higher than the pressure inside the piping of the cooling water circulation system, if there is a defect such as a crack in the piping in the cooling water system inside the container, Cooling gas flows into the cooling water circulation system from that point. As the amount of cooling gas flowing in due to a defect in the cooling water circulation system increases, a two-phase flow occurs in which air bubbles are mixed in the cooling water flow path. Since this two-phase flow causes light scattering at the bubble interface, the presence of bubbles can be detected optically by a bubble detection means consisting of a pair of optical fibers installed in the cooling water flow path. By installing a sensor, it becomes possible to identify the defective location.

(Example) An example of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a configuration diagram showing an example of a cooling water circulation system of a generator equipped with a cooling device according to the present invention.

The inside of the generator (1) is filled with cooling hydrogen gas pressurized above atmospheric pressure, and the cooling water circulates along the arrow in the figure and passes through the fixed pre-cooling channel ■ inside the machine. The stator section is cooled. A pair of rod lenses (A) are provided in a part of the cooling water m ring system piping, one of which is connected to the light emitting device I (15).
The other side is connected to the measurement system ■ by optical fiber 〇.

The cooling water that cooled the inside of the aircraft then flows into the water storage tank (■) via an air vent connected to the top water level of the cooling water circulation system. The tank upper space (10) is filled with precipitated hydrogen gas and water vapor. The gas phase is discharged through the atmosphere discharge pipe (
11) and communicates with the atmosphere.

The cooling water is supplied to the cooling water circulation pump (1) after releasing the hydrogen gas.
2) and the heat radiator (13), it flows into the machine again and cools the stator section inside the machine.

During operation, a small amount of hydrogen gas permeates into the cooling water circulation system through the insulating water pipe (14) and the like.

In the cooling water circulation system configured in this way.

Under normal conditions, the amount of permeated hydrogen gas from the water pipe (14) is at most several cc/min, and does not reach the point where bubbles are formed.

On the other hand, if damage occurs to the piping of the cooling water system in one aircraft, the amount of hydrogen gas leaking into the cooling water circulation system will be small due to the high hydrogen gas pressure inside the aircraft and the extremely high permeability of hydrogen gas. The temperature reaches several tens of times the normal value, which causes bubbles to form in the cooling water flow path.

FIG. 2 shows the relationship between the rod lens (A) attached to the piping of the cooling water circulation system and the precipitated hydrogen gas bubbles (15).

In normal times, the light emitted from the rod lens 0) is only in the liquid phase in the cooling water flow path, so it is not scattered and goes toward the other rod lens (a). However, bubbles (15)
If this exists, light scattering will occur at the gas-liquid interface.

The light guided by the optical fiber 〇 is detected by the measurement system ■, and an alarm is generated if the change in the light amount exceeds the standard value.

In this way, in this embodiment, it is possible to reliably detect leaked hydrogen gas that has flowed into the cooling water of the cooling water circulation system.

Furthermore, it is also possible to semi-quantitatively detect the amount of leaking gas from temporal changes such as the pulse interval and frequency of light intensity changes, and it is also possible to determine the extent of the problem. This makes it possible to identify the location of the leak.

〔Effect of the invention〕

As explained above, according to the present invention, the presence of gas entering the cooling water due to a malfunction in the cooling water circulation system is detected by the bubble detection means installed in the cooling water piping, and abnormalities such as leakage of the cooling water are detected with certainty. It is possible to provide a cooling device that can detect

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing an embodiment of a cooling device according to the present invention, and FIG. 2 is an enlarged sectional view of a main part for explaining the principle of abnormality detection in FIG. 1. 1...@Electric machine 2...Hydrogen gas 4...Rod lens 5...Light emitting device 6...Optical fiber 7...Measuring device 8...Air vent part 9...Water storage tank 11 ...Atmospheric discharge pipe 14...Water pipe 15...Bubble Figure 2

Claims (1)

[Claims] In a cooling device that cools the inside of a container by connecting a cooling piping provided inside a container containing pressurized gas and a cooling water circulation device provided outside the container to form a cooling water circulation system, cooling water circulation is performed. a bubble detection means consisting of a pair of optical fibers for detecting bubbles in a cooling water flow path provided in a piping section of the system; and an abnormality diagnosis device for determining the presence or absence of an abnormality in the cooling water circulation system from an output signal of the bubble detection means. A cooling device characterized by comprising: