CN101331386A - Gas metering - Google Patents
Gas metering Download PDFInfo
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- CN101331386A CN101331386A CNA2006800468053A CN200680046805A CN101331386A CN 101331386 A CN101331386 A CN 101331386A CN A2006800468053 A CNA2006800468053 A CN A2006800468053A CN 200680046805 A CN200680046805 A CN 200680046805A CN 101331386 A CN101331386 A CN 101331386A
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Abstract
A gas meter comprises a conduit (1) for passage of a gas flow A and an ioniser (2) arranged to ionise the gas flow in the conduit (1). A modulating electrode structure (4) downstream of the ioniser modulates the ion distribution in the ionised gas flow. A first detecting electrode structure (8) and a second electrode structure (9) downstream of the modulating electrode structure (4) detect the modulated ion distribution in the ionised gas flow. The modulating electrode structure (4) and the detecting electrode structures (8, 9) can be configured to generate an electrical field having at least a substantial component parallel to the direction of the gas flow. The modulating electrode structure (4) and the detecting electrode structures (8, 9) can comprise a pair of electrodes (5, 6, 10, 11), each having a plurality of apertures defined therein for passage of the gas flow. The modulating electrode structure (4) can be arranged to capture ions of one polarity, to generate an ionised gas flow comprising a majority of ions of the opposite polarity, in which case the detecting electrode structure can comprise at least one electrode (11) connected to a source of charge. Movement of the ionised gas flow relative to the electrode causes a redistribution of charge in the electrode, which generates a current indicative of the ion distribution between the electrode (11) and the charge source. The various arrangements provide a gas meter that can operate with a modulating voltage of less than (10) volts and is therefore suitable as a domestic gas meter.
Description
Technical field
The present invention relates to volumetric gas meter field.Gas meter technology described herein is specially adapted to the gas meter that dwelling house is used.
Background technology
Volumetric dwelling house is a diaphragm gas meter with the most common form of gas meter.
This is a kind of mechanical hook-up with the work of positive displacement principle, and it allows the gas of fixed volume to pass through in each cycle completely.The influence that mechanical meters can be worn in normal operation, this will cause precision to reduce in time and the possibility of last complete failure.(Automatic Meter Reading, AMR) Zhuan Zhi increased popularity means and must form interface through the scrambler and the mechanical reader of forms more commonly used the automatic gauge reading, so that can automatically read consumption information.
Wishing to provide the gas meter that does not comprise moving component, i.e. static gas meter, and wherein, the measurement of the volume of the gas of consumption is directly to obtain with electronic form.From this realization, can also obtain other benefit, comprise the ability that complicated more price list is set based on service time, peak requirements or local gas price movement, perhaps share the ability of information with other family expenses energy such as electricity, oil or regenerative resource.Developed the gas meter of the static volumetric measurement of three types.The first kind is the travel-time formula ultrasonic flowmeter that niche is used that is used for that can commercially obtain, and niche is used the sky high cost that can support this flowmeter.The second type known technology is a thermal mass flow sensors, and this is the newer technology in this field, has adopted by-pass method and micro-machined sensor.The 3rd type is a fluidic oscillator meter, and this type developed in the 1950's.All these dosage technology all have the shortcoming more expensive than mechanical flow meter, and require a considerable amount of energy contents of battery, and this has also increased cost.
US 3,688, and 106 (Brain) have described a kind of flowmeter that is used for the gas velocity of measuring guide.This flowmeter has an ion gun and two ion collectors, so that at first being ionized in the conduit passed through collector then.Potential pulse is applied to first collector, measure this pulse and the effect that in the amount of ions that the second collector place collects, produces between the interval, provide gas velocity.By determining to come measurement gas density, from the product of speed and density, obtain mass rate in the quantity that second collector position is in the ion of gathering between the pulse.In this system, the potential pulse that is applied to first collector is the 100Hz square wave, and 120 volts voltage is applied in by second collector.High voltage and high modulation frequency make this design be not suitable for the needed low voltage power supply work of family expenses gas meter.At US 3,842,670 and US 2,632,326 in other structures of ionization rate gas meter have been described.
Be desirable to provide at US 3,688, the gas meter of the universal class of describing among 106 (Brain), it can be with the operating voltage work of several volts, so that can power economically to this flowmeter with standard cell.Yet for the geometry of the described flowmeter of Brain, the electrode that requires collector in essence is a sufficient distance, makes collector reveal very little impedance or not show impedance airmeter.Thereby, need an operating voltage that surpasses 100 volts to provide enough big electric field so that the electrode of flowmeter plays a role.Owing to will produce identical electric field with the operating voltage of having only several volts, the conduit diameter that is installed in the Brain flowmeter need be little 100 times, and this can stop the air-flow of domestic gas supply significantly.
At least in its preferred embodiment, the present invention seeks to provide a kind of gas meter of improved cubing, this flowmeter is with electrical operation principle and the testing of ionization air-flow, principle below adopting: the velocity field of gas and ionization distribute and interact, and change detected signal.In certain embodiments, this gas meter is specially adapted to measure the gas usage from the air feed network of country.
Summary of the invention
Therefore, consider from an aspect, the invention provides gas meter, this gas meter comprises an ionization device that is used as the conduit of current path and in use is used for making the air-flow ionization of conduit.Modulating electrode structure in the ionization device downstream is used for being modulated at the ion distribution of ionized air-flow.At least one first detector electrode structure in the modulating electrode structure downstream is used for detecting the modulated ion distribution of ionizing air.In configuration modulating electrode structure and the detector electrode structure at least one has the essence component part of electric field that at least one is parallel to airflow direction with generation.
Thereby according to the present invention, electrode structure produces electric field, and this electric field has at least one essence component that is parallel to airflow direction.By make electric field parallel rather than as situation of the prior art perpendicular to airflow direction, by the spacing between the electrode that changes electrode structure, can modulated electric fields intensity, this change of spacing does not need to influence the air-flow by conduit, by this way, can make the hydrodynamic of gas meter need be independent of the electricity needs, this feasible can manufacturing can be with the gas meter as the domestic gas flowmeter of enough low voltage power supply.
Can dispose modulating electrode structure produces and has at least one essence component part of electric field (for example) that is parallel to airflow direction and select particular polarity as the ion of ionized air-flow.In addition or replacedly, can the configuration detection electrode structure produce and have the particular polarity that the essence component part of electric field (for example) that is parallel to airflow direction at least optionally detects ion.
In a particular embodiment, the electric field of generation is arranged essentially parallel to the direction of air-flow.Yet this is dispensable.For example, high electric field can comprise component that is arranged essentially parallel to airflow direction and the component that is substantially perpendicular to airflow direction.
Modulating electrode structure and/or detector electrode structure can adopt any suitable shape and structure.For example, this electrode structure can be arch, semi-cylindrical, hemispheric or the like.Yet in common embodiment, modulating electrode structure comprises that relative substantially plate electrode is right, and it is positioned to the direction that is basically perpendicular to air-flow.In addition or replacedly, detector electrode structure can comprise that relative substantially plate electrode is right, it is positioned to the direction that is basically perpendicular to air-flow.Electrode " to " do not represent that these electrodes are identical, even they can be identical.
In a word, electrode is spaced on airflow direction.The interval of electrode can be less than 1mm, preferably less than 0.25mm.Usually, in use, between electrode, produce electric field.
In a preferred embodiment, electrode all has a plurality of holes that are limited to wherein, crosses the path of electrode as air communication.
This is considered to a kind of new structure in itself.Thereby, consider that from another aspect the invention provides a kind of gas meter, it comprises in use the conduit as current path, and the ionization device that is used for making the air-flow ionization of conduit.Modulating electrode structure in the ionization device downstream is used for modulating the ion distribution of ionized air-flow.At least one first detector electrode structure in the modulating electrode structure downstream is used for detecting the modulated ion distribution of ionizing air.In modulating electrode structure and the detector electrode structure at least one comprises at least one electrode, and it is disposed on the direction of cross-section airflow direction, and has a plurality of holes that are limited to wherein, crosses the path of this electrode as air communication.The quantity in hole can be above ten.
Thereby, according to this aspect of the invention, dispose this electrode, allow air communication to cross this electrode.By this way, can locate this electrode, there not to be electrical effect or the galvanomagnetic effect that acquisition is wanted under the situation that the air-flow by flowmeter is had a negative impact.
This electrode is disposed on the direction of cross-section airflow direction.This means that electrode is not parallel to airflow direction.Thereby air-flow impacts this electrode to a certain extent.Usually, electrode is positioned to the direction perpendicular to air-flow.By this way, the electrical modulation of ionizing air or electro-detection occur in along in the shortest potential range of conduit, so that can make the spatial resolution maximum of gas meter, and the accuracy of detection of gas meter are maximized.And vertical electrode can not make air-flow deflection catheter wall.
This electrode can comprise a plurality of conductors, wherein, provides these holes with the interval between the adjacent electrode conductor.Need in single unit, not form these conductors, but can provide with discrete conductor.Yet these conductors of an electrode in use all are connected to same electromotive force.Thereby, this electrode can adopt line (for example, parallel line) arrange form.Replacedly, this electrode can adopt the form (being generally sheet metal) of monolithic, and it has the hole that is formed on wherein.These holes can be with molding, cut, etching, pressure is stabbed or other modes are limited in the metal.These holes can be hole, groove, pin hole or other any suitable holes.
In preferred arrangement, this electrode can be the form of mesh or grid.Usually, grid is the hole that is limited to the regular array between the adjacent conductor.This array can extend in one direction, and for example, the grid of parallel groove perhaps can extend on both direction, for example, and the grid of level and vertical conductor.
Select the spacing of mesh that the electricity validity of electrode is maximized.In an embodiment of the present invention, the spacing of mesh is less than 5mm, preferably less than 3mm.Ideally, the activity coefficient of mesh is as much as possible little, to guarantee maximum air-flow.In an embodiment of the present invention, the activity coefficient of mesh is less than 30%, preferably less than 20%.In a word, select the structure of the electrode of modulating electrode structure and detector electrode structure, make the maximization of modulation or detection efficiency.Yet,, for example, can select identical electrode for the ease of the reason of producing.
In an embodiment of the present invention, gas meter comprises electrode pair, and this electrode pair is arranged on the direction of cross-section air-flow, and has a plurality of holes that are limited to the path of crossing as air communication wherein.Usually, these electrodes are the same, but must be the same.
Hole in the electrode of this electrode pair is offset with respect to the hole on other electrodes of electrode pair.This layout advantageous particularly is because the electric field between the electrode can comprise perpendicular to the component on the direction of electrode plane.This is advantageous particularly under the situation of modulator electrode at electrode, and this is because help the ion guide electrode is caught realizing at the component perpendicular to the electric field on the direction of electrode plane, thereby and increases the modulation efficiency of electrode structure.
Electrode pair can be spaced apart on airflow direction.Replacedly, electrode can be coplanar basically.For example, the conductor of an electrode can be in the interval between the conductor of other electrodes (hole).In other words, this electrode can be an interdigitated.With this layout, the electric field that electrode structure produces can be fully perpendicular to the direction of air-flow.
In a preferred embodiment, the skew between the hole of each electrode of this electrode pair is substantially equal to half of interval between the adjacent holes of an electrode in these electrodes.By this way, can make in any component maximization perpendicular to the electric field on the direction of electrode plane.
Modulating electrode structure can comprise the electrode of upstream and the electrode in downstream.In use, each modulated potentials can be applied to each electrode, to modulate the ion distribution in the ionizing air.The modulated potentials that is applied to downstream electrode can be opposite with the polarity of modulated potentials on being applied to upstream electrode, and has an amplitude of selection, so that in the downstream of this modulator electrode, the electric field neutralisation that the electric field that produces owing to upstream electrode is produced by the electrode owing to the downstream.
This is considered to a kind of new structure in itself.Thereby, from another aspect, the invention provides a gas meter, it comprises a conduit that in use is used as current path, and comprises an ionization device, it in use is used for making the air-flow ionization of conduit.Be arranged in the downstream modulator electrode structure of ionization device, be used for being modulated at the ion distribution in the ionized air-flow.At least one first detector electrode structure is arranged in the downstream of this modulator electrode, in order to detect the modulated ion distribution in ionizing air.This modulating electrode structure comprises a upstream electrode and a downstream electrode, in use, each modulated potentials is applied to each electrode, to be modulated at the ion distribution in the ionizing air.The modulated potentials that is applied to downstream electrode is opposite with the polarity of the modulated potentials that is applied to upstream electrode, and has the amplitude of selection, so that in the downstream of this modulator electrode, and the electric field neutralisation that the electric field that is produced by upstream electrode is produced by the electrode owing to the downstream.
With this layout, can adopt this modulated potentials, to guarantee can directly not influence the work of this detector electrode structure in the relevant electric field of this modulating electrode structure.
This modulating electrode structure can be used to preferentially catch a kind of ion of polarity, produces the ionizing air of the ion that comprises most of opposite polarity with this.Can apply an interchangeable modulated potentials to this modulating electrode structure, so that this modulating electrode structure is sequentially caught a kind of ion of polarity, and sequentially catch the ion of opposite polarity, comprise sequence area with this ionizing air that produces, the alternating polarity of the most of ion in this zone changes.By this way, with alternating signal this air-flow is encoded.Signal that receives at this detector electrode structure place and the retardation ratio between this modulated potentials provide the indication by the gas velocity of conduit.
This detector electrode structure can comprise that at least one is connected to the electrode of Charge Source, with this, the ionizing air that most of ion has a kind of polarity causes the redistribution of electric charge in electrode with respect to the motion of electrode, and this can produce the electric current indication of the ion distribution between electrode and the Charge Source.
This is considered to a kind of new structure in itself.Thereby, from another aspect, the invention provides a kind of gas meter, it comprises a conduit that in use is used as current path, and an ionization device, this ionization device is used for making the air-flow ionization of conduit.Modulating electrode structure in the downstream of ionization device is arranged the ion distribution that is modulated in the ionized air-flow.Be arranged the modulated ion distribution that detects in ionizing air at least one first detector electrode structure in the downstream of this modulating electrode structure.Modulating electrode structure is used to catch a kind of ion of polarity, produces with this to comprise that most of ion is the ionized air-flow of opposite polarity.This detector electrode structure comprises that at least one is connected to the electrode of Charge Source, with this, in use, most of ion have a kind of polarity ionizing air cause the redistribution of electric charge in electrode with respect to the motion of electrode, this can be created in electric current indication of the ion distribution between electrode and the Charge Source.Usually, Charge Source is an earthing potential.
According to this aspect of the invention, by because the advantage of the electric current that redistribution produced of electric charge in electrode structure, it can be the ionizing air of polarity alternation that this detector electrode structure detects what pass through.This has significant advantage, does not promptly need electric field between the electrode of detector electrode structure.In addition, under the situation of not catching ion, realize detecting, so that can arrange a series of this detector electrode structure along conduit.
Deposit at this cloth, detector electrode structure can include only a single electrode, and it is in response to the Ionized air-flow that passes through.Yet in certain embodiments, this detector electrode structure comprises the electrode of a upstream and the electrode in a downstream, and each electrode all is connected to Charge Source.The influence of the Ionized air-flow that this upstream electrode protection downstream electrode is not arrived, and provide from the better detection signal of the qualification of downstream electrode.
Gas meter can comprise second detector electrode structure that is positioned at the first detector electrode structure downstream, and each detector electrode structure all is arranged the modulated ion distribution that detects in ionizing air.
This is considered to a kind of new structure in itself.Thereby, from another aspect, the invention provides a kind of gas meter, it comprises the conduit that in use is used as current path, and comprises an ionization device, this ionization device in use is used for making the air-flow ionization of conduit.Be arranged the ion distribution that is modulated in the ionizing air in the modulating electrode structure in the downstream of this ionization device.Be arranged the modulated ion distribution that detects in ionizing air in first detector electrode structure in the downstream of this modulating electrode structure.Be arranged in second detector electrode structure in this modulating electrode structure downstream and detect in this modulated ion distribution in ionizing air.
Second detector electrode structure the dynamic range that can be used to increase gas meter is provided.Thereby first detector electrode structure can be arranged the ion distribution that detects low relatively flow velocity, and second detector electrode structure can be arranged the ion distribution that detects high flow velocities, and this moment, ion cloud moved fartherly in the identical time cycle.In certain embodiments, the distance from first modulating electrode structure to first detector electrode structure can be less than 10mm.In certain embodiments, the distance from first modulating electrode structure to second detector electrode structure can be greater than 50mm.Usually, the distance from first modulating electrode structure to second detector electrode structure is less than 100mm.
First detector electrode structure can be arranged the ion of preferentially catching a kind of polarity, and second detector electrode structure can be arranged the ion of preferentially catching opposite polarity.In this layout, first detector electrode structure is optionally caught a kind of polarity of ion, and second detector electrode structure is optionally caught another kind of polarity.By this way, what each detector electrode structure received it independently is used to the ion flow that detects, is not cut down by the operation of first detector electrode structure at the signal at the second detector electrode structure place.By this way, two detector electrode structure can be operated on the same ion flow.
First detector electrode structure can comprise that a spaced electrode is right.In use can between electrode, apply the ion that an electric field is caught ionized air-flow, and produce the electric current indication of ion distribution.In addition or replacedly, second detector electrode structure can comprise the electrode pair at an interval, in use can between electrode, apply an electric field and catch the ion of ionizing air and the electric current indication that produces ion distribution.
If necessary, gas meter can comprise the detector electrode structure more than two.
In common embodiment of the present invention, the modulation voltage that is applied to modulating electrode structure is the frequency less than 10Hz.Similarly, be applied to modulation voltage on this modulating electrode structure usually less than exchanging 10V.And the voltage (if any) that is applied to detector electrode structure is usually less than direct current 10V.With these running parameters, gas meter is suitable for battery-powered operation.
Gas meter according to the present invention is suitable for use as the domestic gas flowmeter.This means a kind ofly can be connected to country, zone or international air feed network in the user estate and rating surveyor's department, and the enough accurately information of user's gas usage being provided to the gas meter of network operator with the usefulness of making bill.Yet this gas meter according to the present invention can be used for the environment of other measurement gas volume, flow velocity and/or speed.
In an embodiment of the present invention, this ionization device is a kind of radioactive source.Yet, can adopt other ionization device, for example, by the ionization device of discharge operation.
Conduit is normally managed, and it can have circular cross section.In an embodiment of the present invention, the width of pipe (diameter) is less than 30mm.
Though the present invention is limited in the term gas meter, the present invention can also extend to the method for gas dosing and be used for the device of gas dosing as described herein.
Description of drawings
Only pass through example, and, embodiments of the invention are described with reference to accompanying drawing, wherein,
Fig. 1 is the synoptic diagram according to the gas meter of first embodiment of the invention;
Fig. 2 shows the mesh electrodes that is used for according to gas meter of the present invention;
Fig. 3 is the synoptic diagram according to the gas meter of second embodiment of the invention;
Fig. 4 is the schematically illustrating of modulation voltage of modulating electrode structure that is applied to the gas meter of Fig. 3;
The corresponding reference label is used for the corresponding components at each embodiment of the present invention.
Embodiment
Fig. 1 schematically shows the gas meter according to first embodiment of the invention.This gas meter comprises the conduit 1 as current path, and air-flow is represented with arrow A.In this embodiment, this conduit is that internal diameter is the cylindrical tube of 23mm.Ionization device 2 is disposed in the conduit side of the air-flow in the ionization conduit.In this embodiment, ionization device 2 is 1 μ Ci Americium, 241 radioactive sources that are limited in silver foil or the goldleaf (adopting in the family expenses smog monitor type).Source 2 has the radiation speed of 37000 α particles p.s. usually, has the scope of 3cm in air.Ionizing efficiency is that each α particle produces 200,000 ion pairs, wherein 50% in 100ms recombination.Radioactive source 2 makes near the directly gas ionization it, forms ionisation cloud 3, and it is carried by managing 1 by air-flow.
Modulating electrode structure 4 is provided in the pipe 1 in downstream of radioactive source 2.This modulating electrode structure 4 is modulated the ion distribution in the ionizing air, so that be discernible in this ionisation cloud of the downstream of this modulating electrode structure 4.In this embodiment, this modulating electrode structure 4 comprises a upstream electrode 5 and a downstream electrode 6.As shown in Figure 2, each electrode the 5, the 6th occurs with the form of mesh (or grid), and this mesh cuts out from sheet metal with appropriate method.The diameter of electrode 5,6 is corresponding to pipe 1 interior diameter, and these electrodes are positioned to the axle perpendicular to pipe 1, thereby and perpendicular to the direction of air-flow.Electrode 5,6 has thickness and 1mm or the littler spacing of 0.2mm.The activity coefficient of these electrodes (area percentage of mesh material) is 20% or littler.
In this embodiment, the spacing between upstream modulator electrode 5 and the downstream modulator electrode 6 is 0.125mm.As shown in Figure 1, variable modulation voltage is applied between the modulator electrode 5,6.This modulation voltage is the square wave with amplitude and 1-4Hz frequency of maximum 10V.This modulation voltage that applies produces the electric field between the modulator electrode 5,6.As shown in Figure 1, the mesh of upstream modulator electrode 5 and downstream modulator electrode 6 by relativity shift equal half distance of mesh spacing so that be arranged in the conductor 7 between the interval of an electrode with the spacing of other electrode, vice versa.By this way, on perpendicular to airflow direction (axle of pipe 1), has maximum component at the electric field between the modulator electrode 5,6.Ideally, the conductor 7 of each electrode 5,6 is intersected between perpendicular to the conductor of other electrodes on the same level of airflow direction, so that the electric field between two electrodes 5,6 is fully perpendicular to airflow direction.Yet such layout causes very complicated modulating electrode structure 4, thereby and be difficult to make, manufacturing cost is high.By spaced electrode on airflow direction 5,6 and be offset mesh, be convenient to have got compromise between manufacturing and the operating efficiency.
When the modulation voltage non-zero that is applied between the modulator electrode 5,6, under the positive ion and negative ion situation about being caught in of the electric field of generation in ion cloud 3, with they each modulator electrodes 5,6 that leads.Electric field makes the depart from maximum of ion to each modulator electrode 5,6 perpendicular to the high component on the airflow direction.This effect of periodic modulation voltage is to produce high and low ion concns continuum in the air-flow in the downstream of modulating electrode structure 4.As described below, can detect the flow velocity that these zones are determined these regional journey times and therefore determined gas.
The gas meter of Fig. 1 is included in the pipe 1 and detects electric machine structure 9 in first detector electrode structure 8 in modulating electrode structure 4 downstreams and second, detects the modulated ion distribution in ionizing air.Second electrode structure 9 is positioned at the downstream of first detecting electrode 8.In this embodiment, first and second detecting electrodes 8,9 each include a upstream electrode 10 and a downstream electrode 11.Each electrode 10,11 all has the form of common mesh (or grid), and it is to cut out from sheet metal with suitable method, as shown in Figure 2.The diameter of electrode 10,11 is corresponding to pipe 1 internal diameter, and electrode 10,11 is disposed on the direction perpendicular to the axle of pipe 1, and therefore perpendicular to the direction of air-flow.Electrode 10,11 has the spacing of thickness and the 2mm of 0.2mm.The activity coefficient of electrode (area percentage of mesh material) is 10% or littler.
In this embodiment, be 0.25mm at interval between upstream detector electrode 10 and the downstream detector electrode 11.As shown in Figure 1, the mesh of upstream detector electrode 10 and downstream detector electrode 11 is aligned.By this way, the electric field between the detecting electrode 10,11 is being parallel to the component that has maximum on the direction of air-flow (axle of pipe 1).By this way, not influencing under the situation that fluid flows through conduit 1,, can change the electric field intensity between the detecting electrode 10,11 by changing the spacing between the electrode 10,11.
As shown in Figure 1, between detecting electrode 10,11, apply detection voltage.In this embodiment, detect voltage and be+constant voltage of 3V D.C., it produces the electric field between detecting electrode 10,11.For first detector electrode structure 8, upstream detector electrode 10 is connected to earth potential, and downstream detector electrode 11 is connected to+3V D.C..For second detector electrode structure 9, downstream detector electrode 11 is connected to earth potential, and upstream detector electrode 10 is connected to+and 3V D.C..Thereby the direction of an electric field between the detecting electrode 10,11 of second detector electrode structure 9 is opposite with direction of an electric field between the electrical measurement electrode of first detector electrode structure 8.
Can see that the downstream electrode 11 of first detector electrode structure 8 and the upstream electrode 10 of second detector electrode structure 9 are positioned at same electromotive force.As a result, between these two electrodes, do not have electric field, thereby just owing to air-flow rather than owing to electrical effects, this helps the accurate measurement of air-flow to the ion transfer between these electrodes.That the upstream electrode 10 of adjusting the downstream electrode 6 of electrode structure 4 and first detector electrode structure 9 can also be in is same () electromotive force, so that between these two electrodes, do not have electric field.
First detector electrode structure, the 8 preferential positive ions of catching, positive ion is slowed down by the electric field between the upstream electrode 10 of positive downstream electrode 11 and ground connection.Identical electric field can make the negative ion by first detector electrode structure 8 quicken.The positive ion of the deceleration of the upstream electrode 10 of arrival ground connection is used as electric current and connects the electronics neutralization of drawing from ground.Can measure this electric current with amp gauge 12 or other current measuring devices.
Distance between the downstream electrode 6 of modulating electrode structure 4 and the upstream electrode 10 of first detector electrode structure 8 is 8mm.Distance between the downstream electrode 6 of modulating electrode structure 4 and the upstream electrode 10 of second detector electrode structure 9 is 70mm.The detector electrode structure 8,9 at two intervals is provided, has increased the dynamic range of this gas meter.For home applications, the common measurement range of gas meter that need to limit the rank precision is at per hour 40 liters and per hour between 6000 liters, 150: 1 dynamic range of this expression.According to embodiments of the invention, first detector electrode structure 8 is used for determining low flow velocity, wherein, at too many ion since once more in conjunction with and must detect this modulated ion cloud before from the modulated ion cloud, disappearing, and second detector electrode structure 9 is used for determining high flow rate, wherein, must before the modulated ion cloud is by whole flowmeter, detect this modulated ion cloud.Detected signal can be used for making the precision maximum of the flowmeter in whole measurement range from two detector electrode structure 8,9.
Fig. 3 schematically shows the gas meter according to second embodiment of the invention.This flowmeter comprise as current path conduit 1, air-flow is indicated by arrow A.In this embodiment, conduit is the cylindrical conduit with 23mm internal diameter.Ionization device 2 of side arrangement at pipe 1 makes the air-flow ionization in the conduit.In this embodiment, ionization device 2 is 1 μ Ci Americium, 241 radioactive sources that are limited in silver foil or the goldleaf (adopting in the family expenses smog monitor type).Source 2 has the radiation speed of 37000 α particles p.s. usually, has the scope of 3cm in air.Ionizing efficiency is that each α ion produces 200,000 ion pairs, wherein 50% in 100ms recombination.Radioactive source 2 makes near the directly gas ionization it, forms ionisation cloud 3, and it is carried by managing 1 by air-flow.
In pipe 1, provide the modulating electrode structure 4 that is positioned at radioactive source 2 downstreams.This modulating electrode structure 4 is modulated at the ion distribution in the ionizing air, so that ionisation cloud is discernible in the downstream of modulating electrode structure 4.In this embodiment, this modulating electrode structure 4 comprises upstream electrode 5 and downstream electrode 6.As shown in Figure 2, each electrode 5,6 all is to occur with the form of mesh (or grid), and mesh (or grid) is to cut out from sheet metal with suitable method.The diameter of electrode 5,6 is corresponding to pipe 1 internal diameter, and these electrodes are positioned to the axle perpendicular to pipe 1, and therefore perpendicular to the direction of air- flow.Electrode 5,6 has thickness and 1mm or the littler spacing p of 0.2mm.The activity coefficient of these electrodes (area percentage of mesh material) is 20% or littler.
In this embodiment, be 0.125mm at interval between upstream modulator electrode 5 and the downstream modulator electrode 6.As shown in Figure 3, the mesh of upstream modulator electrode 5 is aimed at the mesh of downstream modulator electrode 6.By this way, the electric field between the modulator electrode 5,6 has maximum component on the direction that is parallel to air-flow (axle of pipe 1).By this way, under the situation that does not influence the fluid stream by conduit 1,, can change the electric field intensity between modulator electrode 5,6 by changing the interval between the electrode 5,6.
As shown in Figure 3, between modulator electrode 5,6, apply the alternation modulation voltage.This modulation voltage is the square wave with amplitude and 1-4Hz frequency of maximum 10V.The modulation voltage that applies produces electric field between modulator electrode 5,6.When upstream modulator electrode 5 when being positive with respect to the modulator electrode 6 in downstream, upstream modulator electrode 5 is caught negative ions from ion cloud 3, and positive ion is quickened by this modulating electrode structure 4.By this way, the ion cloud in these modulating electrode structure 4 downstreams mainly comprises positive ion.When upstream modulator electrode 5 with respect to the modulator electrode 6 in downstream be bear the time, upstream modulator electrode 5 is caught positive ions from ion cloud 3, and positive ion is quickened by this modulating electrode structure 4.By this way, the ion cloud in these modulating electrode structure 4 downstreams mainly comprises negative ion.The effect of alternation modulation voltage is the continuum that produces positive ion density and negative ion density in the air-flow in the downstream of this modulating electrode structure 4.As described below, can detect the flow velocity that these zones are determined these regional journey times and therefore determined gas.
The gas meter of Fig. 3 is included in first detector electrode structure 8 and second electrode structure 9 that is positioned at these modulating electrode structure 4 downstreams in the pipe 1, detects the modulated ion distribution in ionized air-flow.Second electrode structure 9 is positioned at the downstream of first detector electrode structure 8.In this embodiment, each first and second detecting electrode 8,9 includes a upstream electrode 10 and a downstream electrode 11.Each electrode 10,11 has common mesh (or grid) form, and these mesh (or grid) are to cut out from sheet metal with suitable method, as shown in Figure 2.The diameter of electrode 10,11 is corresponding to pipe 1 internal diameter, and electrode 10,11 is positioned to the axle perpendicular to pipe 1, and therefore perpendicular to the direction of air- flow.Electrode 10,11 has the spacing of thickness and the 2mm of 0.2mm.The activity coefficient of electrode (area percentage of mesh material) is 10% or littler.
In this embodiment, be 0.125mm at interval between upstream detector electrode 10 and the downstream detector electrode 11.As shown in Figure 3, upstream detector electrode 10 mesh are in alignment with the mesh of downstream detector electrode 11.By this way,, change the interval of electrode 10,11, can change the relative electrical characteristics of detecting electrode 10,11 not influencing fluid by under the situation of conduit 1.
As shown in Figure 3, each detecting electrode 10,11 all is connected to earth potential.Along with the continuum of positive and negative ion concentration near and by detector electrode structure 8,9, the electric charge redistribution in upstream detector electrode 10 is to keep the zero potential in the electrode 10.This redistribution of electric charge causes electric current to flow through between electrode 10 and earth potential.Similarly, the electric charge redistribution in downstream detector electrode 11 is to keep the zero potential in the electrode 11.This redistribution of electric charge causes electric current to flow through between electrode 11 and earth potential.This electric current can be measured by amp gauge 12 or other current measuring devices, and can adopt the form of alternating signal, by comparing with modulation voltage, can determine the journey time of this ion cloud from this alternating signal.Select downstream detector electrode 11; be used to redistribute the measurement of electric current; this is because upstream detector electrode 10 electro permanent magnetic ground protection downstream detector electrode 11 is not subjected to the influence of approaching ion distribution; thereby the conversion between the negative ions at downstream detector electrode 11 places distributes is more remarkable than upstream detector electrode 10 places.
Distance between the downstream electrode 6 of modulating electrode structure 4 and the upstream electrode 10 of first detector electrode structure 8 is 8mm.Distance between the downstream electrode 6 of modulating electrode structure 4 and the upstream electrode 10 of second detector electrode structure 9 is 70mm.Provide the detector electrode structure 8,9 at two intervals to increase the dynamic range of this gas meter.For home applications, the common measurement range that the needs of air-flow limit the rank precision is per hour 40 per hour to be raised between 6000 liters, and this expression dynamic range is 150: 1.According to this embodiment of the invention, first detector electrode structure 8 is used for determining low flow velocity, wherein, at too many ion since once more in conjunction with and must detect this modulated ion cloud before from the modulated ion cloud, disappearing, and second detector electrode structure 9 is used for determining high flow rate, wherein, must before the modulated ion cloud is by whole flowmeter, detect this modulated ion cloud.Detected signal can be used for making the precision maximum of the flowmeter in whole measurement range from two detector electrode structure 8,9.
In the improvement of the foregoing description, upstream modulated potentials U and downstream modulated potentials D can be applied on the upstream and downstream modulator electrode 5,6 of correspondence of modulating electrode structure, and the modulation voltage between the electrode 5,6 is provided.As shown in Figure 4, downstream modulated potentials D can be selected as with upstream modulated potentials U anti-phase, and has the amplitude of selection, compensates the field effect far away of the electric field relevant with upstream modulator electrode 5.In other words, the galvanomagnetic effect in the combination of the upstream and downstream modulator electrode 5,6 in modulating electrode structure 4 downstreams is balanced out by downstream modulated potentials D.By this way, because opposite with the ion distribution that produces, modulating electrode structure 4 itself does not influence the signal that is produced by first and second detector electrode structure 8,9.
For this gas meter, by at the opposite side of this ionization device to the modulation and the detector electrode structure that provide outside above-mentioned modulating electrode structure and the detector electrode structure, can measure the air-flow of the opposite course in conduit.The mirror image that modulation outside being somebody's turn to do and detector electrode structure can be arranged to above-mentioned modulating electrode structure and detector electrode structure.Yet, in the family expenses flow meter applications, only need to detect rather than measure opposite stream.Therefore, the electrode structure of the appearance (because reverse direction flow) of the ionized gas that can detect present ionization device upstream only need be provided.For example, can arrange that this electrode structure measures the impedance of air-flow.
In a word, gas meter comprises the conduit 1 and the ionization device 2 that is used for making the air-flow ionization in the conduit 1 as the path of air current A.Modulating electrode structure 4 in this ionization device downstream is modulated at the ion distribution in the ionized air-flow.Being arranged in first detector electrode structure 8 in these modulating electrode structure 4 downstreams and second electrode structure 9 detects in the modulated ion distribution of ionizing air.Can dispose this modulating electrode structure 4 and this detector electrode structure 8,9 produces and has the essence component part of electric field that is parallel to airflow direction at least.This modulating electrode structure 4 and this detector electrode structure 8,9 can comprise electrode pair 5,6,10,11, and each electrode pair includes a plurality of holes that are limited in wherein, as the path of air-flow.This modulating electrode structure 4 can be used to catch the ion of a polarity, produces the ionizing air that comprises a plurality of opposite polarity ions, and in this case, detector electrode structure can comprise at least one electrode 11, and it is connected to Charge Source.Ionizing air causes the redistribution of electric charge in electrode with respect to the motion of electrode, and this will produce the electric current indication of the ion distribution between electrode 11 and the Charge Source.
Each layout provides a kind of gas meter, and this gas meter can be with the modulation voltage work less than 10V, and therefore is suitable for as the domestic gas flowmeter.Aspect the cost, power consumption or the performance need that satisfy the gas meter that is used for the self-tolerant cubing, this has significant advantage with respect to the existing metering method that can not directly be utilized.The usual reason of this situation is:
(a) they need high voltage to come bias electrode, this meeting consumed energy, and potential security threat is arranged;
(b) they do not have enough dynamic ranges or the linearity and satisfy the measuring requirement that the national standard system is provided with;
(c) activity accepted in family expenses are used is big usually for the specific activity of the radioactive source of Cai Yonging;
(d) they are not optimized to be used for cubing gas meter required common measurement bandwidth and signal to noise ratio (S/N ratio).
Specific embodiment of the present invention has overcome or has alleviated these problems at least.
Though the embodiment about specific distinct has described the present invention, this is not to limit the scope of the present disclosure.Therefore, those skilled in the art will recognize that the characteristic of an embodiment can be used in conjunction with the characteristic of another embodiment, even without clearly being mentioned.
Claims (28)
1. gas meter, it comprises: in use as the conduit of current path; Ionization device in use is used for the air-flow in the conduit is carried out ionization; Modulating electrode structure is positioned at the ionization device downstream, is arranged the ion distribution that is modulated in the ionizing air; And at least one is positioned at first detector electrode structure in described modulating electrode structure downstream, it is arranged the modulated ion distribution that detects in ionizing air, wherein, dispose at least one in described modulating electrode structure and the described detector electrode structure, produce and have the essence component part of electric field that is parallel to airflow direction at least.
2. according to the gas meter under the claim 1, wherein, dispose described modulating electrode structure and produce and have the essence component part of electric field that is parallel to airflow direction at least.
3. according to the described gas meter of any one claim before, wherein, dispose described detector electrode structure and produce and have the essence component part of electric field that is parallel to airflow direction at least.
4. according to the described gas meter of any one claim before, wherein, the electric field of described generation is basically parallel to the direction of air-flow.
5. according to the described gas meter of any one claim before, wherein, described modulating electrode structure comprises that relative substantially plane electrode is right, and it is positioned to the direction that is basically perpendicular to air-flow.
6. according to the described gas meter of any one claim before, wherein, described detector electrode structure comprises that relative substantially plane electrode is right, and it is positioned to the direction that is basically perpendicular to air-flow.
7. according to claim 5 or 6 described gas meters, wherein, described electrode at interval on described airflow direction.
8. according to claim 5,6 or 7 described gas meters, wherein, in use, described electric field is created between the electrode.
9. according to the described gas meter of claim 5-8, wherein, each all has a plurality of holes that are limited to wherein described electrode, is used as the path that air communication is crossed.
10. gas meter, it comprises: conduit, it is in use as the path of air-flow; Ionization device, it is used to the air-flow in the conduit is carried out ionization; Modulating electrode structure is positioned at the downstream of ionization device, is positioned to the ion distribution that is used for being modulated in the described ionizing air; And at least one first detecting electrode, be positioned at the downstream of described modulating electrode structure, be positioned to the modulated ion distribution that is used for detecting in described ionizing air, wherein, in described modulating electrode structure and the described detector electrode structure at least one comprises at least one electrode that cross-section airflow direction is arranged, and have a plurality of holes that are limited to wherein, with the path of crossing as air communication.
11. according to claim 9 or 10 described gas meters, wherein, described electrode is to occur with the form of mesh.
12. according to each described gas meter among the claim 9-11, it comprises the electrode pair that cross-section airflow direction is arranged, and have a plurality of holes that are limited to wherein, be used as the path that air communication is crossed, wherein, the hole in the electrode in the described electrode pair has been offset with respect to the hole at another electrode of described electrode pair on the direction of cross-section airflow direction.
13. gas meter according to claim 12 wherein, equals half of interval between one the adjacent holes of described electrode substantially in the skew between the hole of each electrode of described electrode pair.
14. according to the described gas meter of any one claim before, wherein, described modulating electrode structure comprises upstream electrode and downstream electrode, and in use, each modulated potentials is applied to each electrode, to be modulated at the ion distribution in the ionizing air, wherein, the described modulated potentials that is applied to downstream electrode is opposite with the polarity of the described modulated potentials that is applied to upstream electrode, and has a selected amplitude, so that in the downstream of this modulating electrode structure, the electric field neutralisation that the electric field that produces owing to upstream electrode is produced by the electrode owing to the downstream.
15. a gas meter, it comprises: conduit, and it in use is used as the path of air-flow; Ionization device, it is used to the air-flow in the conduit is carried out ionization; Modulating electrode structure is positioned at the downstream of ionization device, is positioned to the ion distribution that is used for being modulated in the described ionizing air; And at least one first detector electrode structure, be positioned at the downstream of described modulating electrode structure, be positioned to the modulated ion distribution that is used for detecting in described ionizing air, wherein, described modulating electrode structure comprises upstream electrode and downstream electrode, in use apply each modulated potentials to each electrode, to be modulated at the ion distribution in the ionizing air, wherein, the described modulated potentials that is applied to downstream electrode is opposite with the polarity of the described modulated potentials that is applied to upstream electrode, and have selected amplitude, and so that in the downstream of this modulator electrode, the electric field neutralisation that the electric field that produces owing to upstream electrode is produced by the electrode owing to the downstream.
16. according to the described gas meter of any one claim before, wherein, described modulating electrode structure is used to catch a kind of ion of polarity, produces ionized air-flow with this, the polarity of most of ion that it comprises is opposite polarity.
17. gas meter according to claim 16, wherein, described detector electrode structure comprises that at least one is connected to the electrode of Charge Source, therefore, most of ion be a kind of polarity ionizing air redistribute in electrode with respect to the mobile electric charge that causes of electrode, this can produce electric current indication of ion distribution between described electrode and described Charge Source.
18. a gas meter, it comprises: conduit, and it in use is used as the path of air-flow; Ionization device, it is used in use the air-flow in the conduit be carried out ionization; Modulating electrode structure is positioned at the downstream of ionization device, is positioned to the ion distribution that is used for being modulated in the described ionizing air; And at least one first detecting electrode, be positioned at the downstream of described modulating electrode structure, be positioned to the modulated ion distribution that is used for detecting in described ionizing air, wherein, described modulating electrode structure is used for preferentially catching a kind of ion of polarity, with this produce comprise most of ion be opposite polarity ionizing air, and, described detector electrode structure comprises that at least one is connected to the electrode of Charge Source, with this, in use, the ionizing air that most of ion has a kind of polarity redistributes in described electrode with respect to the mobile electric charge that causes of described electrode, and this has produced the electric current indication of the ion distribution between described electrode and described Charge Source.
19. according to claim 17 or 18 described gas meters, wherein, described Charge Source is an earth potential.
20. according to the described gas meter of any one claim before, it also comprises second detector electrode structure, it is positioned at the first detector electrode structure downstream, and each detector electrode structure is positioned to the modulated ion distribution that is used for detecting in ionizing air.
21. a gas meter, it comprises: the conduit that in use is used as current path; Ionization device, it is positioned in use the air-flow in the conduit is carried out ionization; Modulating electrode structure, the downstream that it is positioned at described ionization device is positioned to the ion distribution that is used for being modulated in the ionizing air; First detector electrode structure, the downstream that it is positioned at described modulating electrode structure is positioned to the modulated ion distribution that is used for detecting in ionizing air; And second detector electrode structure, the downstream that it is positioned at described modulating electrode structure is positioned to the modulated ion distribution that is used for detecting in ionizing air.
22. according to the described gas meter of any one claim before, wherein, first detector electrode structure is used for preferentially catching a kind of ion of polarity, second detector electrode structure is used for preferentially catching the ion of opposite polarity.
23. gas meter according to claim 22, wherein, described first detector electrode structure comprises that spaced electrode is right, in use, between described electrode, apply electric field, come from ionized air-flow, to catch ion, and produce the electric current indication of described ion distribution.
24. according to claim 22 or 23 described gas meters, wherein, second detector electrode structure comprises electrode pair at interval, in use, between described electrode, apply electric field, come the electric current indication of from ionized air-flow, catching ion and producing described ion distribution.
25. according to the described gas meter of any one claim before, wherein, the modulation voltage that is applied to described modulating electrode structure is what to be in less than the frequency of 10Hz.
26. according to the described gas meter of any one claim before, wherein, the modulation voltage that is applied to described modulating electrode structure is less than 10V A.C..
27. according to the described gas meter of any one claim before, wherein, described ionization device comprises a radioactive source.
28. according to the described gas meter of any one claim before, wherein, described flowmeter is battery powered.
Applications Claiming Priority (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB0525305A GB0525305D0 (en) | 2005-12-13 | 2005-12-13 | Gas meter with selective ion modulation |
| GB0525307.5 | 2005-12-13 | ||
| GB0525305.9 | 2005-12-13 | ||
| GB0525307A GB0525307D0 (en) | 2005-12-13 | 2005-12-13 | Time of flight ionisation gas meter |
| PCT/GB2006/003710 WO2007068869A1 (en) | 2005-12-13 | 2006-10-05 | Gas metering |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2010102058140A Division CN101871802B (en) | 2005-12-13 | 2006-10-05 | Gas metering |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101331386A true CN101331386A (en) | 2008-12-24 |
| CN101331386B CN101331386B (en) | 2010-08-25 |
Family
ID=35735998
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2006800468053A Expired - Fee Related CN101331386B (en) | 2005-12-13 | 2006-10-05 | Gas metering |
Country Status (3)
| Country | Link |
|---|---|
| CN (1) | CN101331386B (en) |
| GB (1) | GB0525305D0 (en) |
| UA (1) | UA92923C2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110715696A (en) * | 2018-07-11 | 2020-01-21 | 浙江大学 | Superconductive magnetic fluid flowmeter with built-in grating |
| CN112204358A (en) * | 2018-05-31 | 2021-01-08 | 森泰克有限公司 | Ultrasonic wave metering device |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1300555A (en) * | 1969-03-28 | 1972-12-20 | Nat Res Dev | Improvements in measuring the density, velocity and mass flow of gases |
| US4019383A (en) * | 1976-07-21 | 1977-04-26 | United Technologies Corporation | Four-collector flux sensor |
| US4186601A (en) * | 1977-11-17 | 1980-02-05 | Nissan Motor Company, Limited | Mass flow measuring apparatus |
| US4248086A (en) * | 1978-02-24 | 1981-02-03 | S.C.I. Le Brin | Device for measuring the mass flow or flow rate of an insulating liquid |
| US4393719A (en) * | 1981-07-20 | 1983-07-19 | United Technologies Corporation | Ionization flowmeter |
| CN2097395U (en) * | 1991-02-07 | 1992-02-26 | 中国矿业大学 | Ion type gas flowmeter |
| CN1087715A (en) * | 1992-12-03 | 1994-06-08 | 曲义坤 | Radioactive ionization capacitor and electromagnetic gas flowmeter |
-
2005
- 2005-12-13 GB GB0525305A patent/GB0525305D0/en not_active Ceased
-
2006
- 2006-10-05 CN CN2006800468053A patent/CN101331386B/en not_active Expired - Fee Related
- 2006-10-05 UA UAA200807929A patent/UA92923C2/en unknown
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112204358A (en) * | 2018-05-31 | 2021-01-08 | 森泰克有限公司 | Ultrasonic wave metering device |
| CN110715696A (en) * | 2018-07-11 | 2020-01-21 | 浙江大学 | Superconductive magnetic fluid flowmeter with built-in grating |
Also Published As
| Publication number | Publication date |
|---|---|
| GB0525305D0 (en) | 2006-01-18 |
| CN101331386B (en) | 2010-08-25 |
| UA92923C2 (en) | 2010-12-27 |
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