Measuring and testing – Gas content of a liquid or a solid
Reexamination Certificate
1999-03-15
2001-12-04
Williams, Hezron (Department: 2856)
Measuring and testing
Gas content of a liquid or a solid
C073S019120, C073S023310, C073S863830
Reexamination Certificate
active
06324891
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates generally to a means and a method for monitoring the presence of one or more gases in a fluid such as, for example, a dielectric fluid. The present invention in particular relates to the monitoring of one or more gas components in a fluid wherein either
a) a sample gas obtained from the fluid is enriched in at least one target gas which is to be subjected to analysis;
b) at least one target gas which is to be subjected to analysis is separated from a sample gas obtained from the fluid; or
c) both.
The present invention may in particular, for example, be exploited as part of a means for the monitoring (e.g. detection of) one or more substances in fluid insulated electrical equipment, e.g. to monitor incipient failure conditions. The dielectric fluid may be a dielectric liquid (e.g. oil) or a dielectric gas. More particularly, the present invention relates to an apparatus and method far monitoring one or more gas components in a dielectric fluid disposed in an interior of an electrical system wherein a sample gas obtained from the dielectric fluid is enriched in at least one target gas which is to be subjected to analysis and/or at least one target gas which is to be subjected to analysis is separated from a sample gas obtained from the dielectric fluid.
BACKGROUND OF THE INVENTION
The following will deal, by way of example only, with the detection of a gas in a fluid which is a dielectric fluid.
Electrical systems are well known in the art which use a dielectric fluid as an insulating substance; these systems include for example transformers, circuit breakers and the like.
It is known that, in the event of a disturbance or malfunction of an above mentioned type of device or system, the result may be the production of one or more undesired gases in the insulating fluid; this may occur for example if a device is working at high temperature or high conditions of electrical stress therein. Such conditions may also produce undesired moisture and/or one or more breakdown products of the dielectric material of the insulating system (i.e. insulating fluid). If such abnormal conditions are allowed to continue uncorrected, this may lead to irreparable damage to the electrical system. A timely (e.g. more or less immediate) detection and/or diagnosis of any such abnormal operation of an electrical apparatus is thus advantageous in order to be able to avoid irreparable harm to such a system.
Accordingly, various monitoring devices and systems have been proposed for the detection of any incipient failure conditions such as for example any undesired increase of the concentration of a fault gas (e.g. a combustible gas such as for example, hydrogen gas, carbon monoxide gas, methane gas, ethane gas, ethylene gas, acetylene gas and the like or a non-combustible gas such as for example, carbon dioxide), moisture (e.g. water), a breakdown product, contaminant substance, and/or the like contained (e.g. dissolved) in the insulating fluid.
Some such detection and/or monitoring systems are, for example, described in Canadian Patent no. 1,054,223 (Bélanger), U.S. Pat. No. 4,112,737 (Morgan), U.S. Pat. No. 4,293,399 (Bélanger et al), U.S. Pat. No. 4,271,474 (Bélanger et al), U.S. Pat. No. 5,070,738 (Morgan) and U.S. Pat. No. 5,271,263 (Gibeault). The entire contents of these patent references as well as any other patent or other types of references which are mentioned therein are incorporated herein by reference.
For example, U.S. Pat. No. 4,293,399 describes how the concentration of gaseous hydrogen dissolved in a fluid may be determined by a measure of an electric current generated by electro-chemical oxidation of the gaseous hydrogen at an electrode of the detector. The prior art detecting and measuring means described in this U.S. patent comprises a polymeric membrane permeable to hydrogen gas for contact with a fluid containing dissolved hydrogen gas; an electrolyte capable of facilitating oxidation of the hydrogen gas diffused through the polymeric membrane at a first electrode and reduction of an oxygen-containing gas such as air at a second electrode; and a measuring device connected across the electrode for measuring the intensity of the electrical current generated by the electrochemical reaction of oxidation of the hydrogen gas, this intensity being proportional to the concentration of hydrogen in the fluid.
It is advantageous for such monitoring (e.g. detection) devices, as described above, to be able to provide an accurate as possible detection and/or diagnosis of the incorrect operation of systems such as, for example, transformers, circuit breakers, shunt reactors or any electro-apparatuses using a dielectric fluid as an insulating substance such as a dielectric liquid (e.g. a dielectric oil) or a dielectric gas (e.g. SF
6
gas).
A number of the above mentioned prior art monitoring devices or systems have the drawback that the sample gas received by the detector may have a relatively low concentration of a target gas which it is desired to detect or monitor; e.g. a low concentration of acetylene gas relative to hydrogen gas. In such case, the low concentration of a target gas relative to the other gases present in a sample gas may be such that one or more of the other gases may interfere with the measurement of a predetermined target gas(es). In other words, the precision of the results of the detecting or monitoring device may thus be less than is desired; i.e. due to that fact that one or more extraneous gases may interfere with the reading of the target gas.
Accordingly, it would be advantageous to be able to facilitate analysis (e.g. detection) of one or more predetermined individual gases (i.e. target gases) of a sample gas mixture. It would, in general, be advantageous to be able obtain a sample gas enriched in a target gas, the presence of which is to be the subject of an analysis and/or separate from a sample gas mixture at least one target gas which is to be subjected to analysis. It would, further be advantageous to be able to facilitate analysis of target gases of a sample gas by separating one or more such target gases from the sample gas, the so separated target gas then being subjected to detection.
SUMMARY OF THE INVENTION
It is to be understood herein that the expression “detection component” as well as the words “detst”, “detecting” and the like include, but are not limited to, activities which involve checking for a substance, detecting a substance, determining the presence of a substance, etc.
It is also to be understood herein that the expression “analysing means for monitoring” as well as the words “monitor”, “monitoring” and the like include, but are not limited to, one or more activities which involve checking for a substance, detecting a substance, keeping track of a substance, determining the presence of a substance, the continuous measurement of a substance, the intermittent measurement of a substance, etc.
Accordingly, the present invention provides in an apparatus for detecting a gas in a fluid, the apparatus comprising:
a gas extraction component for extracting a sample gas mixture from said fluid, said sample
gas mixture comprising a target gas, and
a detection component for detecting the presence of said target gas,
the improvement wherein said apparatus includes
a gas removal component for preferentially removing a predetermined gas component of said sample gas mixture, said gas removal component comprising a gas-permeable element through which said predetermined gas component is able to preferentially pass.
In accordance with another aspect of the present invention there is provided in an apparatus for detecting a gas in a fluid, the apparatus comprising:
a wall component defining a gas chamber,
a gas extraction component comprising a first gas-permeable element through which a gas mixture is able to pass from said fluid into said gas chamber, said wall component comprising said first gas-permeable element, said gas mixture comprising a target gas,
a detection component for detecting the presence of said
Gibeault Jean-Pierre
Noirhomme Bernard
Qin Renyan
General Electric Company
Nixon & Vandehye P.C.
Politzer Jay L.
Williams Hezron
LandOfFree
Method and apparatus for monitoring GAS(ES) in a dielectric... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for monitoring GAS(ES) in a dielectric..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for monitoring GAS(ES) in a dielectric... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2566092