CA2015391C - Fluid sampler for detection and monitoring of failure conditions in fluid insulated electrical equipment - Google Patents
Fluid sampler for detection and monitoring of failure conditions in fluid insulated electrical equipmentInfo
- Publication number
- CA2015391C CA2015391C CA 2015391 CA2015391A CA2015391C CA 2015391 C CA2015391 C CA 2015391C CA 2015391 CA2015391 CA 2015391 CA 2015391 A CA2015391 A CA 2015391A CA 2015391 C CA2015391 C CA 2015391C
- Authority
- CA
- Canada
- Prior art keywords
- end portion
- dielectric liquid
- electrical system
- fluid conduit
- conduit loop
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M3/00—Investigating fluid-tightness of structures
- G01M3/02—Investigating fluid-tightness of structures by using fluid or vacuum
- G01M3/04—Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point
- G01M3/20—Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point using special tracer materials, e.g. dye, fluorescent material, radioactive material
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N1/00—Sampling; Preparing specimens for investigation
- G01N1/02—Devices for withdrawing samples
- G01N1/22—Devices for withdrawing samples in the gaseous state
- G01N1/24—Suction devices
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Sampling And Sample Adjustment (AREA)
Abstract
FLUID SAMPLER FOR DETECTION AND MONITORING OF
FAILURE CONDITIONS IN FLUID INSULATED
ELECTRICAL EQUIPMENT
ABSTRACT
An apparatus for sampling and analyzing the fluid in an electrical system such as a transformer, a circuit breaker, a reactance or another electrical apparatus using a dielectric fluid as insulating substance, which comprises means for attaching said apparatus to the electrical system, such means comprising at the same time an inlet portion and an outlet portion; conduit means through which the fluid can flow through the apparatus connecting said inlet portion in series to said outlet portion: pumping means whereby said fluid can be drawn into said apparatus, flow through the apparatus and be expelled back into said electrical system and means for attaching means for detecting the presence in said fluid of breakdown products, moisture and other parameters indicative of any failure condition in said electrical apparatus.
FAILURE CONDITIONS IN FLUID INSULATED
ELECTRICAL EQUIPMENT
ABSTRACT
An apparatus for sampling and analyzing the fluid in an electrical system such as a transformer, a circuit breaker, a reactance or another electrical apparatus using a dielectric fluid as insulating substance, which comprises means for attaching said apparatus to the electrical system, such means comprising at the same time an inlet portion and an outlet portion; conduit means through which the fluid can flow through the apparatus connecting said inlet portion in series to said outlet portion: pumping means whereby said fluid can be drawn into said apparatus, flow through the apparatus and be expelled back into said electrical system and means for attaching means for detecting the presence in said fluid of breakdown products, moisture and other parameters indicative of any failure condition in said electrical apparatus.
Description
201~"S3.
FIELD OF IH~INVENTION
The present invention relates generally to an improved device for the detection and monitoring of failure conditions in fluid insulated electrical equipment and more particularly to an apparatus for sampling and analyzing such fluid.
BACKGROUND OF THE INVENTION
", Syctems for detecting fault gases, moisture and breakdown products dissolved in a fluid contained in an electrical system such as a transformer, a circuit breaker or any electric apparatus using a dielectric fluid as an insulating substance are well known in the 15 art and have been described in prior art. -Such systems are described in Canadian Patent no. 1,054,223 ~ -(Bélanger), U.S. Patent no. 4,293,399 (Bélanger et al~ and U.S.
Patent no. 4,271,474 (Bélanger et al~. For example, the 20 concentration of gaseous hydrogen dissolved in a fluid is ~;
determined by a measure of an electric current generated by electro-chemical oxidation of the gaseous hydrogen at an electrode of detection. The prior art detecting and measuring device comprises a polymeric membrane permeable to hydrogen gas in contact -with the fluid; an electrolyte capable of producing 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; a measuring device connected across the electrode for measuring the intensity of the electrical current g~nerated by the electro-chemical reaction of oxidation of the hydrogen gas, this intensity being proportional to the concentration of hydrogen in the fluid.
8uoh detection devices are eRsential to provide an accurate dlagnosis of the incorrect operation of transformers, circuit '~: .'' A
~r~. Lt~
.... :~ .
.~, 201~91 breakers, reactance or any electro-apparatuses using a dielectric fluid such as oil or SF6 gas as insulating substance. It is indeed well-known that, in the event of a disturbance or malfunction of one of the above mentioned apparatuses due to a too high working temperature or a high electrical discharge, there is production of gases in the insulating fluid. Failure conditions may also produce moisture or breakdown products in the insulating fluid.
Accordingly, it can be easily understood that the utilization of a device allowing for immediate detection of an increase of the concentration of gases, moisture or breakdown products dissolved in the insulating fluid, is advantageous since it allows immediate diagnosis of the incorrect operation of the electrical apparatus on which the device is mounted, and when this incorrect operation is timely located, to avoid irreparable ruin of the apparatus.
These prior art devices have the drawback that the sample received by the detector may not be uniform or representative of the fluid contained in the electrical system at a given moment in time. For example, in US patent no. 4,293,399, the detector is attached to the wall of the electrical apparatus and the fluid must passively diffuse to that area to reach the detector. Such a passive ~ -sampling system has two inherent problems. Firstly, the sample that does reach the detector may not be uniform, and secondly if gase~, moi6ture or breakdown products are introduced at some point in the system, which is remote from the detector, it may taks considerable time before they will be detected.
Therefore it i~ desirable to develop a system whereby the sample of the fluid tested i8 an accurate representation of the actual fluid and the time required to detect gases, moisture or breakdown products is kept to a minimum.
Becau~e such devices are ~ensitive to temperature fluctuations, it is desirable to provide a means whereby the temperature of the ~ystem can be regulated.
" . ' . . ' ~ . ' '::
: .
2015~1 It is also desirable that the sampling and detecting apparatus be easily installed onto existing electrical systems.
QBJECTS OF THE_INVENTION
It is an object of this invention to provide an apparatus for sampling and analyzing the liquid in an electrical system which allows for sample to be more representative of the actual liquid contained in the electrical system.
It is a further object of the invention to provide an apparatus which will improve the uniformity of the liquid within the electrical system.
It i8 a still further object of the invention to provide an apparatus which will decrease the time reguired to detect the presence of failure conditions in an electrical system.
It is yet another object of the invention to provide means to requlate the operatin~ temperature of the detector.
SUMMARY_OF THE INVENTION
The present invention generally concerns an apparatus used to sample and monitor fluid for the presence of parameters indicative of ~ailure conditions in fluid insulated electrical equipment.
This invention may be used to detect the presence of fault gases, moisture or breakdown products contained in the insulating fluid of tran~formers.
More parti¢ularly, this invention describes a more reliable device for ~amplinq the liquid whereby the sample of liquid tested is subotantially uniform and thus more representative of the actual " -.
~. l; , ~
FIELD OF IH~INVENTION
The present invention relates generally to an improved device for the detection and monitoring of failure conditions in fluid insulated electrical equipment and more particularly to an apparatus for sampling and analyzing such fluid.
BACKGROUND OF THE INVENTION
", Syctems for detecting fault gases, moisture and breakdown products dissolved in a fluid contained in an electrical system such as a transformer, a circuit breaker or any electric apparatus using a dielectric fluid as an insulating substance are well known in the 15 art and have been described in prior art. -Such systems are described in Canadian Patent no. 1,054,223 ~ -(Bélanger), U.S. Patent no. 4,293,399 (Bélanger et al~ and U.S.
Patent no. 4,271,474 (Bélanger et al~. For example, the 20 concentration of gaseous hydrogen dissolved in a fluid is ~;
determined by a measure of an electric current generated by electro-chemical oxidation of the gaseous hydrogen at an electrode of detection. The prior art detecting and measuring device comprises a polymeric membrane permeable to hydrogen gas in contact -with the fluid; an electrolyte capable of producing 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; a measuring device connected across the electrode for measuring the intensity of the electrical current g~nerated by the electro-chemical reaction of oxidation of the hydrogen gas, this intensity being proportional to the concentration of hydrogen in the fluid.
8uoh detection devices are eRsential to provide an accurate dlagnosis of the incorrect operation of transformers, circuit '~: .'' A
~r~. Lt~
.... :~ .
.~, 201~91 breakers, reactance or any electro-apparatuses using a dielectric fluid such as oil or SF6 gas as insulating substance. It is indeed well-known that, in the event of a disturbance or malfunction of one of the above mentioned apparatuses due to a too high working temperature or a high electrical discharge, there is production of gases in the insulating fluid. Failure conditions may also produce moisture or breakdown products in the insulating fluid.
Accordingly, it can be easily understood that the utilization of a device allowing for immediate detection of an increase of the concentration of gases, moisture or breakdown products dissolved in the insulating fluid, is advantageous since it allows immediate diagnosis of the incorrect operation of the electrical apparatus on which the device is mounted, and when this incorrect operation is timely located, to avoid irreparable ruin of the apparatus.
These prior art devices have the drawback that the sample received by the detector may not be uniform or representative of the fluid contained in the electrical system at a given moment in time. For example, in US patent no. 4,293,399, the detector is attached to the wall of the electrical apparatus and the fluid must passively diffuse to that area to reach the detector. Such a passive ~ -sampling system has two inherent problems. Firstly, the sample that does reach the detector may not be uniform, and secondly if gase~, moi6ture or breakdown products are introduced at some point in the system, which is remote from the detector, it may taks considerable time before they will be detected.
Therefore it i~ desirable to develop a system whereby the sample of the fluid tested i8 an accurate representation of the actual fluid and the time required to detect gases, moisture or breakdown products is kept to a minimum.
Becau~e such devices are ~ensitive to temperature fluctuations, it is desirable to provide a means whereby the temperature of the ~ystem can be regulated.
" . ' . . ' ~ . ' '::
: .
2015~1 It is also desirable that the sampling and detecting apparatus be easily installed onto existing electrical systems.
QBJECTS OF THE_INVENTION
It is an object of this invention to provide an apparatus for sampling and analyzing the liquid in an electrical system which allows for sample to be more representative of the actual liquid contained in the electrical system.
It is a further object of the invention to provide an apparatus which will improve the uniformity of the liquid within the electrical system.
It i8 a still further object of the invention to provide an apparatus which will decrease the time reguired to detect the presence of failure conditions in an electrical system.
It is yet another object of the invention to provide means to requlate the operatin~ temperature of the detector.
SUMMARY_OF THE INVENTION
The present invention generally concerns an apparatus used to sample and monitor fluid for the presence of parameters indicative of ~ailure conditions in fluid insulated electrical equipment.
This invention may be used to detect the presence of fault gases, moisture or breakdown products contained in the insulating fluid of tran~formers.
More parti¢ularly, this invention describes a more reliable device for ~amplinq the liquid whereby the sample of liquid tested is subotantially uniform and thus more representative of the actual " -.
~. l; , ~
2~1~39~
liquid contained in the electrical system.
The apparatus for sampling and analyzing the liguid in an electrical system for the presence of fault gases, moisture and/or breakdown products in accordance with this invention may generally comprise:
- means for attaching said apparatu~ to said electrical system;
said means comprising an inlet portion and an outlet portion;
- conduit means for connecting said inlet portion in series to said outlet portion;
- pumping means whereby said liquid can efficiently be drawn into said apparatus from said electrical system, flow through the apparatus and be expelled back into said electrical system;
- attaching means for any detector of fault gases, moisture and breakdown products in said liquid.
The present invention, in accordance with one aspect provides an apparatus for sampling and analyzing a dielectric liquid in an interior of an electrical system for the presence, in the dielectric liquid, of a fault gas, moisture or a brea~down product, the apparatus comprising~
a fluid conduit loop comprising a mechanical pump, a first end portion and a second end portion, the first and second end portiono each having a mouth for liquid communication with the interior of the electrical system, the pump being connected in the fluid conduit loop intermediate the end portions for withdrawing dielectric liquid from the interior of the electrical system through one of the mouths, circulating dielectric liquid through the fluid 2~153~3 conduit loop and discharging dielectric liquid back into the interior of the electrical system through the other of the mouths, and detection means for the detection of a fault gas, moisture or a breakdown product in dielectric liquid circulating in the fluid conduit loop, the apparatus being characterized in that the fluid conduit loop consists of a liquid phase conduit loop, the second end portion c~mprises a first member and a 6econd member, said second member comprising the mouth of said second end portion, the first member of the second end portion is disposed within the first end portion in radially spaced relation therewith, the end portions are configured for connecting the fluid conduit loop to a single dielectric liquid access opening of the electrical system such that, when the fluid conduit loop is connected to the liquid access opening, the mouths of the first and second end portions communicate with the interior of the electrical system, the second member of the second end portion projects beyond the mouth of the first end portion, --and the mouth of the second end portion is disposed in the dielectric liquid remote from the mouth of the first end :-portion 80 as to inhibit the same portion of dielectric liquid being discharged back into the electrical system, from being recirculated through the fluid conduit loop, ~ .
and the detection means comprises a member having a surface configured for isolating a fault gas, moisture or a breakdown -~.
product from the dielectric liquid, the surface being disposed so as to contact dielectric liquid circulating through the fluid conduit loop.
, ", ~. .. . .
7 2~15~
In accordance with a further aspect the present invention provides an apparatus for sampling and analyzing a dielectric liquid in an interior of an electrical system for the presence, in the dielectric liquid, of a fault gas, the apparatus comprising: .
a fluid conduit loop comprising a mechanical pump, a first end --portion and a second end portion, the first and second end portions each having a mouth for liquid communication with the interior of the electrical system, the pump being connected in the fluid conduit loop intermediate the end portions for withdrawing dielectric liguid from the interior of the electrical system through one of the mouths, circulating dielectric liquid through the fluid conduit loop and discharging dielectric liquid back into the interior of the electrical system through the other of the mouths, and ~
detection means for the detection of a fault gas in dielectric . : .
liquid circulating through the fluid conduit loop, the apparatus being characterized in that the fluid conduit loop consists of a liquid phase conduit loop, the second end portion comprises a first member and a 6econd member, said second member comprising the mouth of said second end portion, the fir6t member of the ~econd end portion is disposed within the - ~ .
first end portion in radially spaced relation therewith, the end portions are configured for connecting the fluid conduit loop to a single dielectric liguid access opening of the electrical 6ystem ~uch that, when the fluid conduit loop is connected to the liquid access opening, the mouths of the first and second end portions communicate with the interior of the electrical system, ::
the ~econd member of the 6econd end portion projects beyond the mouth of the first end portion, and ' .
, ~' " .'' , 2~15~
the mouth of the second end portion is disposed in the dielectric liquid remote from the mouth of the fir6t end portion so as to inhibit the same portion of dielectric liquid being discharged back into the electrical system, from being recirculated through the fluid conduit loop, and the detection means comprises a membrane, permeable to the fault gas and i~permeable to the dielectric liquid, for isolating the fault gas from the dielectric liquid, the membrane being disposed eo as to contact dielectric liquid circulating through the fluid conduit loop.
In accordance with the present invention, the first member of the second end portion may be disposed concentrically within the first end portion.
In accordance with the present invention, the pump may be configured to create enough pressure so as to promote circulation of the dielectric liguid in the electrical system.
In accordance with the present invention, the detection means may be contained within a hollow housing unit comprising means to maintain the temperature in6ide the housing unit at a predetermined temperature. The predetermined temperature may be higher than the highest temperature of the external environment. The pump may be al~o contained in the hou~ing unit.
In ~ccordance with a further aspect, the present invention provides, in combination an electrical system comprising a dielectric liquid in an interior thereof, the electrical sy~tem comprising a liquid access opening for communication with the interior of the electrical system, and an apparatus ~or ~ampling and analyzing the dielectric liquid ~, , , 2~15~
for the presence, in the dielectric liquid, of a fault gas, moisture or a breakdown product, the system being as defined herein.
S The surface of the detector which contacts the liquid is preferably disposed perpendicularly to the flow of the liquid in the apparatus. This surface is preferably located immediately after the pumping means.
The pump allows the continuous and uniform flow of the liquid through the sampling and detection apparatus. Furthermore, the --expulsion of the tested sample back into the electrical system will ~;
create flow and hence mixing of the liquid within the smaller --systems. This will ensure that the samples entering such systems 15 are more uniform. -~
The use of a pump will also allow a greater volume of liquid to be ~
tested per unit time and hence decrease the time required to detect -the presence of hydrogen gas in the electrical system.
~
The detector is preferably installed inside a housing unit whereby ~ - -the temperature inside the unit can be maintained constant.
The present invention is easier to adapt to an existing electrical system as it contains only one inlet/outlet port to be attached to the electrical system.
. ' ' .: ~'. ' DESCRIPTION OF THE DRAWINGS -Figure 1 is a schematic repre~entation of an example system in ~-accordance with the present invention.
.:'". :.
; ~-.''', ." "' "''''.. '~
.~ ., ",:,, ':
201~
DESCRIPTION OF A PREFERRED E~BODIMENT
Referring generally to Figure 1, the detector for mea6uring the concentration of hydrogen gas dissolved in a fluid substance is shown schematically at 60. Such a device is preferably a device manufactured by Syprotec Inc. and sold under its trade mark Hydran.
The improved apparatus for sampling and determining levels of hydrogen gas dissolved in a liquid contained in an electrical system also comprises a special tee 20 comprising combined inlet/outlet 21, an outlet 22 and an inlet 23.
Inlet/outlet 21 is adapted to be attached to a single opening in the electrical system, so that liguid may enter the apparatus in the outer area 10 and exit back into the elect~ical system through the central area 15. A tube 25 connects said outlet 15 to inlet 23.
Conduit-30 connects outlet 22 of special tee 20 to the inlet 41 of pump 40. The outlet 44 of pump 40 is connected to inlet 51 of special tee 50 which is of a configuration similar to that of special tee 20.
A tube 55 is connected to the inlet 53 of special tee 50, such that the flow of liguid exiting the pump at 44 will continue in a generally straight trajectory until it hits the surface 61 of the detection means 60 which is disposed generally perpendicularly to the flow of said liquid. Thus, the liquid exiting tube 55 at 75 hit~ the membrane 61 of the detection means 60 and continues in the outer portion 70 of the inlet/outlet 51 of special tee 50. The llquid then exits special tee 50 at outlet 52, which is connected to lnlet 23 of 6pecial tee 20 by conduit 80 and elbow 90.
The pump and the detection system may be contained in a hollow hou8ing 100. The inside temperature of said housing will be ~'fi .if;~.
2 ~
maintained at a predetermined temperature, for example 45C, to ensure that variation of the temperature of the outside environment will not effect the operation of the detector which can be calibrated at the factory. Tubes 30 and 80 may be secured to said housing by any known means.
The apparatus functions as follows: Liquid (F) from the electrical system enters at 10 into special tee 20 and travels down tube 30 into the pump 40. The pump directs the liquid through tube 55 to the detection system 60. The hydroqen gas in the sample will enter the detection system 60 through the polymeric membrane 61. This membrane is permeable to hydrogen gas and impermeable to the liquid thereby allowing only the hydrogen gas to enter the detection system 60. The detection system 60 functions in a manner similar to the detection systems described in United States patents nos.
4,271,474, 4,293,399 and Canadian Patent no. 1,~54,223. ;
The liquid F after deflecting off the membrane 61 will enter special tee 50 and subsequently flow through tube 80 to the outlet 20 tube 25. Outl t tube 25 will be of sufficient length so that it -extends far enough into the electrical system to avoid the immediate intake of a sample recently tested. ~
.'~':' . .
The pumping unit 40 will not only create current within the -25 sampling system to allow continuou6 and uniform flow of the sample --liquid but in the case of 6maller electrical devices, should preferably al60 create currents within the liquid in the electrical device. This will allow better mixing and hence a more efficient ~- -~ampling of the liquid contained in the electrical apparatus.
Although a particular embodiment of the invention has been illu~trated and described, modification and changes will become apparent to tho~e ~killed in the art, and it is intended to cover in the appendant claims such modification and changes has come within the true spirit and scope of the invention. For example, : .:
::
,, ..................................................................... :
';:, 12 2~1 5~
although the detecting device which is described in the preferred embodiment is an hydrogen gas detector, the apparatus of the present inventor may also be used with any other de~ice for detecting other fault gases, moisture and/or breakdown products.
,~, . . .
liquid contained in the electrical system.
The apparatus for sampling and analyzing the liguid in an electrical system for the presence of fault gases, moisture and/or breakdown products in accordance with this invention may generally comprise:
- means for attaching said apparatu~ to said electrical system;
said means comprising an inlet portion and an outlet portion;
- conduit means for connecting said inlet portion in series to said outlet portion;
- pumping means whereby said liquid can efficiently be drawn into said apparatus from said electrical system, flow through the apparatus and be expelled back into said electrical system;
- attaching means for any detector of fault gases, moisture and breakdown products in said liquid.
The present invention, in accordance with one aspect provides an apparatus for sampling and analyzing a dielectric liquid in an interior of an electrical system for the presence, in the dielectric liquid, of a fault gas, moisture or a brea~down product, the apparatus comprising~
a fluid conduit loop comprising a mechanical pump, a first end portion and a second end portion, the first and second end portiono each having a mouth for liquid communication with the interior of the electrical system, the pump being connected in the fluid conduit loop intermediate the end portions for withdrawing dielectric liquid from the interior of the electrical system through one of the mouths, circulating dielectric liquid through the fluid 2~153~3 conduit loop and discharging dielectric liquid back into the interior of the electrical system through the other of the mouths, and detection means for the detection of a fault gas, moisture or a breakdown product in dielectric liquid circulating in the fluid conduit loop, the apparatus being characterized in that the fluid conduit loop consists of a liquid phase conduit loop, the second end portion c~mprises a first member and a 6econd member, said second member comprising the mouth of said second end portion, the first member of the second end portion is disposed within the first end portion in radially spaced relation therewith, the end portions are configured for connecting the fluid conduit loop to a single dielectric liquid access opening of the electrical system such that, when the fluid conduit loop is connected to the liquid access opening, the mouths of the first and second end portions communicate with the interior of the electrical system, the second member of the second end portion projects beyond the mouth of the first end portion, --and the mouth of the second end portion is disposed in the dielectric liquid remote from the mouth of the first end :-portion 80 as to inhibit the same portion of dielectric liquid being discharged back into the electrical system, from being recirculated through the fluid conduit loop, ~ .
and the detection means comprises a member having a surface configured for isolating a fault gas, moisture or a breakdown -~.
product from the dielectric liquid, the surface being disposed so as to contact dielectric liquid circulating through the fluid conduit loop.
, ", ~. .. . .
7 2~15~
In accordance with a further aspect the present invention provides an apparatus for sampling and analyzing a dielectric liquid in an interior of an electrical system for the presence, in the dielectric liquid, of a fault gas, the apparatus comprising: .
a fluid conduit loop comprising a mechanical pump, a first end --portion and a second end portion, the first and second end portions each having a mouth for liquid communication with the interior of the electrical system, the pump being connected in the fluid conduit loop intermediate the end portions for withdrawing dielectric liguid from the interior of the electrical system through one of the mouths, circulating dielectric liquid through the fluid conduit loop and discharging dielectric liquid back into the interior of the electrical system through the other of the mouths, and ~
detection means for the detection of a fault gas in dielectric . : .
liquid circulating through the fluid conduit loop, the apparatus being characterized in that the fluid conduit loop consists of a liquid phase conduit loop, the second end portion comprises a first member and a 6econd member, said second member comprising the mouth of said second end portion, the fir6t member of the ~econd end portion is disposed within the - ~ .
first end portion in radially spaced relation therewith, the end portions are configured for connecting the fluid conduit loop to a single dielectric liguid access opening of the electrical 6ystem ~uch that, when the fluid conduit loop is connected to the liquid access opening, the mouths of the first and second end portions communicate with the interior of the electrical system, ::
the ~econd member of the 6econd end portion projects beyond the mouth of the first end portion, and ' .
, ~' " .'' , 2~15~
the mouth of the second end portion is disposed in the dielectric liquid remote from the mouth of the fir6t end portion so as to inhibit the same portion of dielectric liquid being discharged back into the electrical system, from being recirculated through the fluid conduit loop, and the detection means comprises a membrane, permeable to the fault gas and i~permeable to the dielectric liquid, for isolating the fault gas from the dielectric liquid, the membrane being disposed eo as to contact dielectric liquid circulating through the fluid conduit loop.
In accordance with the present invention, the first member of the second end portion may be disposed concentrically within the first end portion.
In accordance with the present invention, the pump may be configured to create enough pressure so as to promote circulation of the dielectric liguid in the electrical system.
In accordance with the present invention, the detection means may be contained within a hollow housing unit comprising means to maintain the temperature in6ide the housing unit at a predetermined temperature. The predetermined temperature may be higher than the highest temperature of the external environment. The pump may be al~o contained in the hou~ing unit.
In ~ccordance with a further aspect, the present invention provides, in combination an electrical system comprising a dielectric liquid in an interior thereof, the electrical sy~tem comprising a liquid access opening for communication with the interior of the electrical system, and an apparatus ~or ~ampling and analyzing the dielectric liquid ~, , , 2~15~
for the presence, in the dielectric liquid, of a fault gas, moisture or a breakdown product, the system being as defined herein.
S The surface of the detector which contacts the liquid is preferably disposed perpendicularly to the flow of the liquid in the apparatus. This surface is preferably located immediately after the pumping means.
The pump allows the continuous and uniform flow of the liquid through the sampling and detection apparatus. Furthermore, the --expulsion of the tested sample back into the electrical system will ~;
create flow and hence mixing of the liquid within the smaller --systems. This will ensure that the samples entering such systems 15 are more uniform. -~
The use of a pump will also allow a greater volume of liquid to be ~
tested per unit time and hence decrease the time required to detect -the presence of hydrogen gas in the electrical system.
~
The detector is preferably installed inside a housing unit whereby ~ - -the temperature inside the unit can be maintained constant.
The present invention is easier to adapt to an existing electrical system as it contains only one inlet/outlet port to be attached to the electrical system.
. ' ' .: ~'. ' DESCRIPTION OF THE DRAWINGS -Figure 1 is a schematic repre~entation of an example system in ~-accordance with the present invention.
.:'". :.
; ~-.''', ." "' "''''.. '~
.~ ., ",:,, ':
201~
DESCRIPTION OF A PREFERRED E~BODIMENT
Referring generally to Figure 1, the detector for mea6uring the concentration of hydrogen gas dissolved in a fluid substance is shown schematically at 60. Such a device is preferably a device manufactured by Syprotec Inc. and sold under its trade mark Hydran.
The improved apparatus for sampling and determining levels of hydrogen gas dissolved in a liquid contained in an electrical system also comprises a special tee 20 comprising combined inlet/outlet 21, an outlet 22 and an inlet 23.
Inlet/outlet 21 is adapted to be attached to a single opening in the electrical system, so that liguid may enter the apparatus in the outer area 10 and exit back into the elect~ical system through the central area 15. A tube 25 connects said outlet 15 to inlet 23.
Conduit-30 connects outlet 22 of special tee 20 to the inlet 41 of pump 40. The outlet 44 of pump 40 is connected to inlet 51 of special tee 50 which is of a configuration similar to that of special tee 20.
A tube 55 is connected to the inlet 53 of special tee 50, such that the flow of liguid exiting the pump at 44 will continue in a generally straight trajectory until it hits the surface 61 of the detection means 60 which is disposed generally perpendicularly to the flow of said liquid. Thus, the liquid exiting tube 55 at 75 hit~ the membrane 61 of the detection means 60 and continues in the outer portion 70 of the inlet/outlet 51 of special tee 50. The llquid then exits special tee 50 at outlet 52, which is connected to lnlet 23 of 6pecial tee 20 by conduit 80 and elbow 90.
The pump and the detection system may be contained in a hollow hou8ing 100. The inside temperature of said housing will be ~'fi .if;~.
2 ~
maintained at a predetermined temperature, for example 45C, to ensure that variation of the temperature of the outside environment will not effect the operation of the detector which can be calibrated at the factory. Tubes 30 and 80 may be secured to said housing by any known means.
The apparatus functions as follows: Liquid (F) from the electrical system enters at 10 into special tee 20 and travels down tube 30 into the pump 40. The pump directs the liquid through tube 55 to the detection system 60. The hydroqen gas in the sample will enter the detection system 60 through the polymeric membrane 61. This membrane is permeable to hydrogen gas and impermeable to the liquid thereby allowing only the hydrogen gas to enter the detection system 60. The detection system 60 functions in a manner similar to the detection systems described in United States patents nos.
4,271,474, 4,293,399 and Canadian Patent no. 1,~54,223. ;
The liquid F after deflecting off the membrane 61 will enter special tee 50 and subsequently flow through tube 80 to the outlet 20 tube 25. Outl t tube 25 will be of sufficient length so that it -extends far enough into the electrical system to avoid the immediate intake of a sample recently tested. ~
.'~':' . .
The pumping unit 40 will not only create current within the -25 sampling system to allow continuou6 and uniform flow of the sample --liquid but in the case of 6maller electrical devices, should preferably al60 create currents within the liquid in the electrical device. This will allow better mixing and hence a more efficient ~- -~ampling of the liquid contained in the electrical apparatus.
Although a particular embodiment of the invention has been illu~trated and described, modification and changes will become apparent to tho~e ~killed in the art, and it is intended to cover in the appendant claims such modification and changes has come within the true spirit and scope of the invention. For example, : .:
::
,, ..................................................................... :
';:, 12 2~1 5~
although the detecting device which is described in the preferred embodiment is an hydrogen gas detector, the apparatus of the present inventor may also be used with any other de~ice for detecting other fault gases, moisture and/or breakdown products.
,~, . . .
Claims (26)
1. An apparatus for sampling and analyzing a dielectric liquid in an interior of an electrical system for the presence, in the dielectric liquid, of a fault gas, moisture or a breakdown product, said apparatus comprising:
a fluid conduit loop comprising a mechanical pump, a first end portion and a second end portion, said first and second end portions each having a mouth for liquid communication with said interior of the electrical system, said pump being connected in said fluid conduit loop intermediate said end portions for withdrawing dielectric liquid from said interior of said electrical system through one of said mouths, circulating dielectric liquid through said fluid conduit loop and discharging dielectric liquid back into said interior of the electrical system through the other of said mouths, and detection means for the detection of a fault gas, moisture or a breakdown product in dielectric liquid circulating in said fluid conduit loop, said apparatus being characterized in that said fluid conduit loop consists of a liquid phase conduit loop, said second end portion comprises a first member and a second member, said second member comprising the mouth of said second end portion, the first member of said second end portion is disposed within said first end portion in radially spaced relation therewith, said end portions are configured for connecting said fluid conduit loop to a single dielectric liquid access opening of the electrical system such that, when the fluid conduit loop is connected to said liquid access opening, the mouths of said first and second end portions communicate with said interior of the electrical system, the second member of the second end portion projects beyond the mouth of the first end portion, and the mouth of the second end portion is disposed in said dielectric liquid remote from the mouth of the first end portion so as to inhibit the same portion of dielectric liquid being discharged back into the electrical system, from being recirculated through the fluid conduit loop, and said detection means comprises a member having a surface configured for isolating a fault gas, moisture or a breakdown product from the dielectric liquid, said surface being disposed so as to contact dielectric liquid circulating through said fluid conduit loop.
a fluid conduit loop comprising a mechanical pump, a first end portion and a second end portion, said first and second end portions each having a mouth for liquid communication with said interior of the electrical system, said pump being connected in said fluid conduit loop intermediate said end portions for withdrawing dielectric liquid from said interior of said electrical system through one of said mouths, circulating dielectric liquid through said fluid conduit loop and discharging dielectric liquid back into said interior of the electrical system through the other of said mouths, and detection means for the detection of a fault gas, moisture or a breakdown product in dielectric liquid circulating in said fluid conduit loop, said apparatus being characterized in that said fluid conduit loop consists of a liquid phase conduit loop, said second end portion comprises a first member and a second member, said second member comprising the mouth of said second end portion, the first member of said second end portion is disposed within said first end portion in radially spaced relation therewith, said end portions are configured for connecting said fluid conduit loop to a single dielectric liquid access opening of the electrical system such that, when the fluid conduit loop is connected to said liquid access opening, the mouths of said first and second end portions communicate with said interior of the electrical system, the second member of the second end portion projects beyond the mouth of the first end portion, and the mouth of the second end portion is disposed in said dielectric liquid remote from the mouth of the first end portion so as to inhibit the same portion of dielectric liquid being discharged back into the electrical system, from being recirculated through the fluid conduit loop, and said detection means comprises a member having a surface configured for isolating a fault gas, moisture or a breakdown product from the dielectric liquid, said surface being disposed so as to contact dielectric liquid circulating through said fluid conduit loop.
2. An apparatus as defined in claim 1 wherein the first member of said second end portion is disposed concentrically within said first end portion.
3. An apparatus as defined in claim 1 wherein said pump is configured to create enough pressure so as to promote circulation of the dielectric liquid in the electrical system.
4. An apparatus as defined in claim 1 wherein said detection means is contained within a hollow housing unit comprising means to maintain the temperature inside said housing unit at a predetermined temperature.
5. An apparatus for sampling and analyzing a dielectric liquid in an interior of an electrical system for the presence, in the dielectric liquid, of a fault gas, said apparatus comprising:
a fluid conduit loop comprising a mechanical pump, a first end portion and a second end portion, said first and second end portions each having a mouth for liquid communication with said interior of the electrical system, said pump being connected in said fluid conduit loop intermediate said end portions for withdrawing dielectric liquid from said interior of the electrical system through one of said mouths, circulating dielectric liquid through said fluid conduit loop and discharging dielectric liquid back into said interior of the electrical system through the other of said mouths, and detection means for the detection of a fault gas in dielectric liquid circulating through aid fluid conduit loop, said apparatus being characterized in that said fluid conduit loop consists of a liquid phase conduit loop, said second end portion comprises a first member and a second member, said second member comprising the mouth of said second end portion, the first member of said second end portion is disposed within said first end portion in radially spaced relation therewith, said end portions are configured for connecting said fluid conduit loop to a single dielectric liquid access opening of the electrical system such that, when the fluid conduit loop is connected to said liquid access opening, the mouths of said first and second end portions communicate with said interior of the electrical system, the second member of the second end portion projects beyond the mouth of the first end portion, and the mouth of the second end portion is disposed in said dielectric liquid remote from the mouth of the first end portion so as to inhibit the same portion of dielectric liquid being discharged back into the electrical system, from being recirculated through the fluid conduit loop, and said detection means comprises a membrane, permeable to said fault gas and impermeable to said dielectric liquid, for isolating the fault gas from the dielectric liquid, said membrane being disposed so as to contact dielectric liquid circulating through said fluid conduit loop.
a fluid conduit loop comprising a mechanical pump, a first end portion and a second end portion, said first and second end portions each having a mouth for liquid communication with said interior of the electrical system, said pump being connected in said fluid conduit loop intermediate said end portions for withdrawing dielectric liquid from said interior of the electrical system through one of said mouths, circulating dielectric liquid through said fluid conduit loop and discharging dielectric liquid back into said interior of the electrical system through the other of said mouths, and detection means for the detection of a fault gas in dielectric liquid circulating through aid fluid conduit loop, said apparatus being characterized in that said fluid conduit loop consists of a liquid phase conduit loop, said second end portion comprises a first member and a second member, said second member comprising the mouth of said second end portion, the first member of said second end portion is disposed within said first end portion in radially spaced relation therewith, said end portions are configured for connecting said fluid conduit loop to a single dielectric liquid access opening of the electrical system such that, when the fluid conduit loop is connected to said liquid access opening, the mouths of said first and second end portions communicate with said interior of the electrical system, the second member of the second end portion projects beyond the mouth of the first end portion, and the mouth of the second end portion is disposed in said dielectric liquid remote from the mouth of the first end portion so as to inhibit the same portion of dielectric liquid being discharged back into the electrical system, from being recirculated through the fluid conduit loop, and said detection means comprises a membrane, permeable to said fault gas and impermeable to said dielectric liquid, for isolating the fault gas from the dielectric liquid, said membrane being disposed so as to contact dielectric liquid circulating through said fluid conduit loop.
6. An apparatus as defined in claim 5, wherein said membrane is disposed perpendicularly to the flow of dielectric liquid.
7. An apparatus as defined in claim 5 wherein the first member of said second end portion is disposed concentrically within said first end portion.
8. An apparatus as defined in claim 7, wherein said membrane is disposed perpendicularly to the flow of dielectric liquid.
9. An apparatus as defined in claim 5 wherein said pump is configured to create enough pressure so as to promote circulation of the dielectric liquid in the electrical system.
10. An apparatus as defined in claim 5, wherein the first member of said second end portion is disposed concentrically within said first end portion, wherein said pump is configured to create enough pressure so as to promote circulation of the dielectric liquid in the electrical system and wherein said membrane is disposed perpendicularly to the flow of dielectric liquid.
11. An apparatus as defined in claim 5 wherein said detection means is contained within a hollow housing unit comprising means to maintain the temperature inside said housing unit at a predetermined temperature.
12. An apparatus as defined in claim 10 wherein said detection means is contained within a hollow housing unit comprising means to maintain the temperature inside said housing unit at a predetermined temperature.
13. In combination an electrical system comprising a dielectric liquid in an interior thereof, said electrical system comprising a liquid access opening for communication with said interior of the electrical system, and an apparatus for sampling and analyzing said dielectric liquid for the presence, in the dielectric liquid, of a fault gas, moisture or a breakdown product, said apparatus comprising:
a fluid conduit loop comprising a mechanical pump, a first end portion and a second end portion, said first and second end portions each having a mouth for liquid communication with said interior of the electrical system, said pump being connected in said fluid conduit loop intermediate said end portions for withdrawing dielectric liquid from said interior of said electrical system through one of said mouths, circulating dielectric liquid through said fluid conduit loop and discharging dielectric liquid back into said interior of the electrical system through the other of said mouths, and detection means for the detection of a fault gas, moisture or a breakdown product in dielectric liquid circulating in said fluid conduit loop, said apparatus being characterized in that said fluid conduit loop consists of a liquid phase conduit loop, said second end portion comprises a first member and a second member, said second member comprising the mouth of said second end portion, the first member of said second end portion is disposed within said first end portion in radially spaced relation therewith, said fluid conduit loop is connected to said liquid access opening such that the mouths of said first and second end portions communicate with said interior of the electrical system, the second member of the second end portion projects beyond the mouth of the first end portion, and the mouth of the second end portion is disposed in said dielectric liquid remote from the mouth of the first end portion so as to inhibit the same portion of dielectric liquid being discharged back into the electrical system, from being recirculated through the fluid conduit loop, and said detection means comprises a member having a surface configured for isolating a fault gas, moisture or a breakdown product from the dielectric liquid, said surface being disposed so as to contact dielectric liquid circulating through said fluid conduit loop.
a fluid conduit loop comprising a mechanical pump, a first end portion and a second end portion, said first and second end portions each having a mouth for liquid communication with said interior of the electrical system, said pump being connected in said fluid conduit loop intermediate said end portions for withdrawing dielectric liquid from said interior of said electrical system through one of said mouths, circulating dielectric liquid through said fluid conduit loop and discharging dielectric liquid back into said interior of the electrical system through the other of said mouths, and detection means for the detection of a fault gas, moisture or a breakdown product in dielectric liquid circulating in said fluid conduit loop, said apparatus being characterized in that said fluid conduit loop consists of a liquid phase conduit loop, said second end portion comprises a first member and a second member, said second member comprising the mouth of said second end portion, the first member of said second end portion is disposed within said first end portion in radially spaced relation therewith, said fluid conduit loop is connected to said liquid access opening such that the mouths of said first and second end portions communicate with said interior of the electrical system, the second member of the second end portion projects beyond the mouth of the first end portion, and the mouth of the second end portion is disposed in said dielectric liquid remote from the mouth of the first end portion so as to inhibit the same portion of dielectric liquid being discharged back into the electrical system, from being recirculated through the fluid conduit loop, and said detection means comprises a member having a surface configured for isolating a fault gas, moisture or a breakdown product from the dielectric liquid, said surface being disposed so as to contact dielectric liquid circulating through said fluid conduit loop.
14. A combination as defined in claim 13 wherein the first member of said second end portion is disposed concentrically within said first end portion.
15. A combination as defined in claim 13 wherein said pump is configured to create enough pressure so as to promote circulation of the dielectric liquid in the electrical system.
16. A combination as defined in claim 13, wherein said detection means is contained within a hollow housing unit comprising means to maintain the temperature inside said housing unit at a predetermined temperature.
17. In combination an electrical system comprising a dielectric liquid in an interior thereof, said electrical system comprising a liquid access opening for communication with said interior of the electrical system, and an apparatus for sampling and analyzing said dielectric liquid for the presence, in the dielectric liquid, of a fault gas, said apparatus comprising:
a fluid conduit loop comprising a mechanical pump, a first end portion and a second end portion, said first and second end portions each having a mouth for liquid communication with aid interior of the electrical system, said pump being connected in said fluid conduit loop intermediate said end portions for withdrawing dielectric liquid from said interior of the electrical system through one of said mouths, circulating dielectric liquid through said fluid conduit loop and discharging dielectric liquid back into said interior of the electrical system through the other of said mouths, and detection means for the detection of a fault gas in dielectric liquid circulating through said fluid conduit loop, said apparatus being characterized in that said fluid conduit loop consists of a liquid phase conduit loop, said second end portion comprises a first member and a second member, said second member comprising the mouth of said second end portion, the first member of said second end portion is disposed within said first end portion in radially spaced relation therewith, said fluid conduit loop is connected to said liquid access opening such that the mouths of said first and second end portions communicate with said interior of the electrical system, the second member of the second end portion projects beyond the mouth of the first end portion, and the mouth of the second end portion is disposed in said dielectric liquid remote from the mouth of the first end portion so as to inhibit the same portion of dielectric liquid being discharged back into the electrical system, from being recirculated through the fluid conduit loop, and said detection means comprises a membrane, permeable to said fault gas and impermeable to said dielectric liquid, for isolating the fault gas from the dielectric liquid, said membrane being disposed so as to contact dielectric liquid circulating through said fluid conduit loop.
a fluid conduit loop comprising a mechanical pump, a first end portion and a second end portion, said first and second end portions each having a mouth for liquid communication with aid interior of the electrical system, said pump being connected in said fluid conduit loop intermediate said end portions for withdrawing dielectric liquid from said interior of the electrical system through one of said mouths, circulating dielectric liquid through said fluid conduit loop and discharging dielectric liquid back into said interior of the electrical system through the other of said mouths, and detection means for the detection of a fault gas in dielectric liquid circulating through said fluid conduit loop, said apparatus being characterized in that said fluid conduit loop consists of a liquid phase conduit loop, said second end portion comprises a first member and a second member, said second member comprising the mouth of said second end portion, the first member of said second end portion is disposed within said first end portion in radially spaced relation therewith, said fluid conduit loop is connected to said liquid access opening such that the mouths of said first and second end portions communicate with said interior of the electrical system, the second member of the second end portion projects beyond the mouth of the first end portion, and the mouth of the second end portion is disposed in said dielectric liquid remote from the mouth of the first end portion so as to inhibit the same portion of dielectric liquid being discharged back into the electrical system, from being recirculated through the fluid conduit loop, and said detection means comprises a membrane, permeable to said fault gas and impermeable to said dielectric liquid, for isolating the fault gas from the dielectric liquid, said membrane being disposed so as to contact dielectric liquid circulating through said fluid conduit loop.
18. A combination as defined in claim 17, wherein said membrane is disposed perpendicularly to the flow of dielectric liquid.
19. A combination as defined in claim 17 wherein the first member of said second end portion is disposed concentrically within said first end portion.
20. A combination as defined in claim 19 wherein said membrane is disposed perpendicularly to the flow of dielectric liquid.
21. A combination as defined in claim 17 wherein said pump is configured to create enough pressure so as to promote circulation of the dielectric liquid in the electrical system.
22. A combination as defined in claim 17, wherein the first member of said second end portion is disposed concentrically within said first end portion, wherein said pump is configured to create enough pressure so as to promote circulation of the dielectric liquid in the electrical system and wherein said membrane is disposed perpendicularly to the flow of dielectric liquid.
23. A combination as defined in claim 17 wherein said detection means is contained within a hollow housing unit comprising means to maintain the temperature inside said housing unit at a predetermined temperature.
24. A combination as defined in claim 22 wherein said detection means is contained within a hollow housing unit comprising means to maintain the temperature inside said housing unit at a predetermined temperature.
25. A combination as defined in claim 4 wherein said pump is contained within said housing unit.
26. A combination as defined in claim 16 wherein said pump is contained within said housing unit.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2015391 CA2015391C (en) | 1990-04-25 | 1990-04-25 | Fluid sampler for detection and monitoring of failure conditions in fluid insulated electrical equipment |
| US07/982,360 US5271263A (en) | 1990-04-25 | 1992-11-27 | Fluid sampler for detection and monitoring of failure conditions in fluid insulated electrical equipment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2015391 CA2015391C (en) | 1990-04-25 | 1990-04-25 | Fluid sampler for detection and monitoring of failure conditions in fluid insulated electrical equipment |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2015391A1 CA2015391A1 (en) | 1991-10-25 |
| CA2015391C true CA2015391C (en) | 1993-04-27 |
Family
ID=4144829
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2015391 Expired - Lifetime CA2015391C (en) | 1990-04-25 | 1990-04-25 | Fluid sampler for detection and monitoring of failure conditions in fluid insulated electrical equipment |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2015391C (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5749942A (en) * | 1997-02-14 | 1998-05-12 | Raychem Corporation | Apparatus for extracting a gas from a liquid and delivering the gas to a collection station |
-
1990
- 1990-04-25 CA CA 2015391 patent/CA2015391C/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| CA2015391A1 (en) | 1991-10-25 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5271263A (en) | Fluid sampler for detection and monitoring of failure conditions in fluid insulated electrical equipment | |
| US20030010918A1 (en) | Method and apparatus for leak detecting, and apparatus for semiconductor manufacture | |
| KR101442064B1 (en) | In insulating oil gas analyzer apparatus and method | |
| EP0988543A1 (en) | Method and apparatus for monitoring gas(es) in a dielectric fluid | |
| EP1039294A2 (en) | A method and apparatus for the analysis of a liquid carrying a suspension of organic matter | |
| US4745795A (en) | Apparatus for measuring gases dissolved in water | |
| CN108254683A (en) | Transformer Buchholz relay failure detector | |
| EP0730153B1 (en) | Water impurity analyzer | |
| RU83481U1 (en) | ELECTROCHEMICAL SIGNALING LEVEL OF ACCESSIBLE SEAWATER SEA WATER | |
| WO2020075917A1 (en) | Gas sensor module for diagnosing gas-insulated device | |
| CA2015391C (en) | Fluid sampler for detection and monitoring of failure conditions in fluid insulated electrical equipment | |
| CA2164438A1 (en) | Gas detection, identification and elemental and quantitative analysis system | |
| CN112539888A (en) | Phase modulator rotor packing cooling water leakage monitoring and analyzing device and application method | |
| CN110927771A (en) | Air radioactivity real-time monitoring system | |
| US4235689A (en) | Apparatus for detecting traces of a gas | |
| CN106501475B (en) | A kind of water monitoring device of tap water pipe network | |
| CA1257185A (en) | Gas decomposition detector for gas-insulated electrical apparatus | |
| CN205882453U (en) | Switch cabinet | |
| CN103076380A (en) | Electrochemical monitoring instrument for monitoring furfural content in transformer oil by using interfacial electrochemical reaction | |
| KR20090018741A (en) | Generator Stator Cooling Water System Leakage Hydrogen Gas Monitoring Method and Device | |
| US5994146A (en) | Water impurity analysis method | |
| CN106290343A (en) | Total surplus line oxide real-time detection apparatus and detection method | |
| CN107064233A (en) | The online moisture measurement apparatus of polyurethane | |
| CN113964015A (en) | A device for external standard quantification of time-of-flight mass spectrometry | |
| KR20010086812A (en) | Device for monitoring fault of transformer |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKEX | Expiry |