Device to measure turbulent pulsations of liquid flow speed

FIELD: measurement equipment.

SUBSTANCE: device comprises a dielectric body of streamlined shape with installed metering electrodes, a metering unit comprising amplifiers, to inputs of which electrodes are connected, a summator, inputs of which are connected with outputs of amplifiers, and also an additional electrode, at the same time metering electrodes are made in the form of wires with insulated side surface, assembled into a cord or bundle with a polished end, the minimum distance between which and the additional electrode exceeds the size of the turbulence zone, the number of amplifiers is equal to the number of metering electrodes, every of which is connected to the input of the appropriate amplifier, and the additional electrode is connected with the common bus of the metering unit. The additional electrode is made in the form of a hollow metal cylinder installed on the dielectric body, the surface area of which is ten times and more exceeds the total area of the end surface of metering electrodes, at the same time the cord of wires, in the form of which metering electrodes are arranged, is installed inside the second electrode so that its end protrudes beyond the edge of the additional electrode.

EFFECT: increased resolving capacity and increased accuracy of measurement of small-scale fluctuations of flow speed.

2 cl, 2 dwg

 

The device refers to the electro and can be used to study turbulence in the flow of a weakly conductive fluid, such as seawater or fresh water.

A device for measurement of turbulent pulsations of the velocity of the fluid - thermo-anemometer [1, p.69], which contains a sensor in the form of two dielectric columns and stretched between them a thin metal wire, a current source and measuring unit. The sensor is placed in the measurement area, the metal wire is passed the current, which it heats. The resistance of the wire varies in accordance with changes in the fluid velocity, because with the increase in the fluid velocity increases the heat transfer from the wire, the temperature and the resistance of the wire decreases. The measuring unit converts the resistance change of the sensor into an electrical voltage proportional to the change in velocity of the fluid. The disadvantages of similar following. First, the sensor has a low reliability, because having a small diameter (less than 10 µm) wire often breaks, so it is used only at low flow rates. Secondly, it is not applicable in the study of turbulent fluid flow in the presence of heat transfer. In particular, in the study of near-wall turbulence, if the wall temperature is different from the medium to the temperature of the liquid, and when mixing the flow of heated fluid with the same fluid the other temperature. Third, this lack of accuracy when conducting small-scale measurements, because the design speed sensor (anemometer) does not allow to make it a size smaller than a few millimeters. In this case, the sensor is the cause turbulent eddies, i.e. the accuracy of the measurements obtained is low. In addition, the wire has a thermal inertia, so the operating frequency range of the analog does not exceed hundred Hertz.

The closest analogue of the claimed device is the device [2], containing a dielectric housing with installed electrodes and the measuring unit, which includes amplifiers connected to the electrodes, and an adder. The building also housed a magnetic system with four magnets in the gaps between which are mounted the electrodes. The magnets in the measurement area, create a magnetic field. In accordance with the law of electromagnetic induction when moving in a magnetic field of a conducting liquid therein, an electric field, the intensity of which is proportional to the fluid velocity. The tension between the two liquid electrodes is also proportional to the velocity of the flowing between them fluid. The disadvantages of the prototype is a low area in the state resolution, and, as a consequence, the lack of accuracy in small-scale measurements. Resolution of the prototype is determined by the distance between the measuring electrodes, which must be much smaller than the size of the investigated turbulent eddies. Because the sensor comprising electrodes with a magnetic system that is of order 1 cm or more, the spatial resolution does not exceed 5...10 cm, while the sensor itself is a source of additional turbulence, which creates additional errors in the measurements. Often to research real-world problems resort to modeling them in laboratory conditions at small sizes simulators. In this case, the main requirement for the device is high spatial resolution and accuracy in the conditions of small-scale turbulence. In addition, at small sizes of turbulent eddies, the device must provide a wide frequency range of the measured pulsation speed, up to 1000 Hz or more.

The technical problem to be solved by the claimed device is to increase the resolution and accuracy in the conditions of small-scale turbulence. For this device to measure the turbulent fluctuations of the flow rate of a fluid containing dielectric body streamlined to establish the cult on it measuring electrode and the measuring unit, includes amplifiers, the inputs of which are connected to the electrodes, and the adder, the inputs of which are connected to the outputs of amplifiers, an additional electrode, the measuring electrode made in the form of wires with insulated lateral surface collected in the harness or a beam with a polished end face, the number of amplifiers equal to the number of measuring electrodes, each of which is connected to the input of the corresponding amplifier, with an additional electrode is connected to the common bus of the measuring unit, and the minimum distance between the additional electrode and the end face of the bundle exceeds the size of the zone of turbulence. In addition, the auxiliary electrode is made in the form mounted on the dielectric housing of a hollow metal cylinder, the surface area which is much more greater than the total area of the end surface of the measuring electrode, with a plait of wires, in the form which made measuring electrodes installed inside the second electrode so that its end extends over the edge of the additional electrode.

Figure 1 shows the proposed device, figure 2 shows schematically the contact with the liquid end surface of one of the measuring electrode (in the drawing shown by shading), which runs turbosound the liquid stream.

Device is on contains a dielectric housing 1, tightly gathered into a bun or plait the measuring electrodes 2, the additional electrode 3 and the measuring unit 4, which includes amplifiers 5 and the adder 6. The housing 1 is made in the form of a cylinder along an axis which is installed harness 2 from the measuring electrodes. They are made in the form of wires, the side surface of which is covered by the insulation layer, and polished end faces are in the same plane and have electrical contact with the liquid. To achieve the high mechanical strength of the wire is glued together. The additional electrode 3 is made in the form of a hollow metal cylinder mounted on the side surface of the housing 1. Harness 2 measuring electrodes installed inside additional electrode so that its end extends over the edge of the additional electrode 3 at a distance greater than the size of the zone of turbulence. The size of the zone of turbulence is determined by the specific task of measurement and a priori known with the precision necessary to select the length of the protruding part of the first electrode. Each of the measuring electrodes (wire harness 2) is connected to the input of the corresponding amplifier 5, a part of the measuring unit 4, the outputs of the amplifiers are connected to the inputs of the adder 6, and the additional electrode 3 is connected to the common bus of the measuring unit. To protect against interference change is sustained fashion electrodes connected to the amplifiers 5 shielded wire. To achieve high precision, it is necessary that the area of the additional electrode 3 and more than exceeded the total area of the end surface of the measuring electrode. In addition, it should be located outside the zone of turbulence, where the pulsations of fluid is minimal, and to have a streamlined shape, which does not create turbulence in the flow of his fluid. The whole working surface of the additional electrode must be located inside the liquid, because the interface of the liquid-air is the source of strong interference electrochemical nature. The auxiliary electrode does not have to be rigidly mechanically connected to the measuring electrodes. It can be installed separately from the measuring electrodes within the liquid in such a place, where the velocity of a fluid is minimal, and the shape it should have minimal impact on fluid flow in the measurement area. Preferred streamlined shape in the form of a cylinder, sphere or plate, the surface of which is parallel to the velocity vector of the fluid flow.

The device operates as follows. The sensor, consisting of mounted on the dielectric housing 1 of the measuring electrodes, made in the form of tightly gathered into a bun or plait 2 insulated wires, and the additional electrode 3, is placed in the fluid flow that is, the velocity vector is perpendicular to the axis of the bundle 2. The end of the harness 2 is placed in the zone of turbulence, where you want to measure. As shown below, the variable component of potential difference between the polished end surface of each of the wires and the fluid is determined by the variable component of the fluid velocity. Moreover, this potential difference depends on the electrode area in contact with the liquid. In particular, it is greater, the smaller the area of the electrode. In this case, the smaller the area of the polished end face of the wire, i.e. the smaller the wire diameter, the greater the potential difference. The potential difference between the surface of the additional electrode and the liquid is determined by the material properties of the electrode and the liquid and is almost constant, because, first, the auxiliary electrode is located outside the zone of turbulence and pulsation of the flow velocity in the area of its location small. Secondly, the area of the electrode is much larger than the total area of the end surface of the measuring electrodes, therefore, fluctuations in the potential caused by the pulsation speed, negligible. Thirdly, the cylindrical form of the additional electrode provides good flow and the absence of turbulence caused by the electrode. Thus, re the military component of the voltage between each measuring electrode and the additional electrode is proportional to the variable component, that is, the ripple, the fluid velocity. Due to the fact that the measuring electrodes are designed in the form of thin wires, tightly gathered into a bun or plait, the size of the end faces of the latter are small (1 mm or less) in comparison with the size of the turbulent eddies. Voltage applied to the measuring electrodes to the inputs of the amplifiers 5, fully correlated, so their output voltages are summed by the adder 6. The output voltage of the measuring unit 4 because of this increased N times, where N is the number of measurement electrodes, which increases the measurement accuracy by reducing the influence of external electric fields. This is essential because, as shown by our experiments, the voltage signal generated at the end surface of each wire is share microvolt. In addition, since the uncorrelated thermal and electrochemical noise end surface of each of the wires is summed up in power, the ratio of the voltage signal to the own noise of the sensor is increased inN

time. The location of the harness 2 inside additional electrode 3 provides shielding of the measuring electrodes from the external electric is Olya, which also increases the accuracy of the measurement. The output voltage of the measuring unit 4 proportion of the variable component of the flow velocity V

Uo=kV,

where the proportionality constant k is determined by calibration at a known measuring device, for example, by thermo-anemometer.

As the material for the electrodes should be selected metals with the lowest own electrochemical noise, such as titanium and stainless steel, because the noise of the measuring electrodes limits the lower limit of measurement of speed fluctuations.

The basis of the principle of operation of the device is discovered by the author of the communication between the instantaneous value of the potential of non-corroding cast metal electrode relative to the conductive fluid and the speed flowing to the electrode of the liquid. By placing the electrode in the electrolyte on the surface, as is well known [3], is formed of a double electrical layer (DPP). The reason for its formation in aqueous electrolytes on the surface of insoluble electrodes, as a rule, is a specific adsorption existing in the electrolyte ions of oxygen, which creates a negative surface charge. Thus, there is a first facing death, which structure is similar to a capacitor. The second (liquid) lining double layer is formed by positively charged IO is s hydrogen and metals, salt solution which is an electrolyte. In the liquid lining ECT emit dense and diffuse parts. The dense part of the ECT is a layer of counterions strongly associated electrostatic forces with the charged surface. Diffuse part is that part of the ECT, where the interaction energy of the counterions to the surface is comparable to thermal energy or less as a result of the shielding of the surface charge of the dense part of a liquid mantle. Around the electrode by the electrolyte stream portion of the liquid lining ECT fond of flow conditional on the sliding surfaces, separated by some distance from the electrode surface. The slip plane is located inside the ECT, i.e. in the region where the potential different from the potential in the bulk electrolyte by a certain amount, called electrokinetic potential, the magnitude of which depends on the electrode material.

Let flat rectangular electrode (figure 2) length and width L, the surface of which coincides with the plane coordinates XOY, and the front boundary with the OX axis, is placed in the water flow of the electrolyte so that the velocity vector V is directed along the axis Y. On the entire surface of the electrode, there is formed ECT, inner lining which is formed by adsorbed oxygen ions. Also in the oncoming stream is already formed region of the viscous sublayer, characterized by a linear law of increase of velocity perpendicular to the surface [1].

Along the axis g of a surface current, formed by moving with the flow of liquid coating ECT. On the anterior border of the electrode (Y=0) is replaced shaped diffuse part of the liquid lining ECT electrically neutral electrolyte, and therefore the surface has not compensated the charge densest part of the ECT. On the rear edge of the electrode (Y=B) there is not offset by a charge of the opposite sign. Thus, near the surface of the electrode, an electric field caused by outside force, tending to cause electric charges in equilibrium. The excess charge is removed from the electrode on the back of the border, under the influence of this electric field is given in the thickness of the electrolyte.

Near the anterior border of the electrode is the restoration of the structure of the ECT, in which excess charges are also discharged into the thickness of the electrolyte, closing the surface current. Thus, the surface of the electrode near its anterior border, there is an electric field having components directed along the axes Z and y Component of Ezparticipates in the restoration of the structure of the ECT, as component Eyaffects the speed of the charges, or condition is area, or slowing them in relation to the flow velocity. The length l in the Y axis direction is not restored part of the ECT depends on the speed V, which is different at different distances Z from the surface. However, at relatively high flow speed can be achieved inequality l>>d (d is the thickness of the ECT). This allows to consider the charged border electrode as charged a flat strip with varying charge density and, without claiming to be precise quantitative calculation, to obtain the qualitative dependence of the electrode potential on the velocity of the stream.

As is known [4], static free charge in the electrolyte is compensated by counterions such that the outside radius of the Debye (D) the electric field can be neglected. The duration of the relaxation process charge is ≅τ, D≅d. The time t for which the stream passes this distance, t ≅d/V. Above, it was assumed that l>>d, or Vτ>>d, i.e. d/V<<τ. This means that the relaxation process in the oncoming flow does not occur, and the speed of movement of ions in an electric field EYno significant effect.

At the surface of the electrode between its front and rear edges exist as a component of the field E2and EYthe latter creates the counterions in the diffuse part of the double electrical braking force, and therefore the charge density p is motivaional in the diffuse part of the ECT increases. The magnitude of the surface current does not change, because the increase of the charge density is compensated by a decrease in the speed of its orderly movement.

In the sequel we assume that the relative change of the charge density of the counterions in the diffuse part of the ECT is very small, therefore, the structure of the ECT, virtually the entire area of the electrode is close to the one that exists in the absence of movement of the electrolyte. Now, let the electrolyte flow is directed along a flat surface electrode, and the transverse velocity profile corresponds to the expression

(1) VY={0ppand0zz1and(z-z1)ppandz>z1,

where a is a coefficient depending on the flow velocity.

As part of the DPP, for which z>z1involved in the movement, there is a surface current density jY=qnV, where q is the charge of the counterion, and n is the excess concentration of the counterions, V is the velocity. Since both V and n, ablauts the functions z, the surface current is determined by the formula

(2)iY=z10LjYdzdx.

The concentration of excess charge p(z)=qn(z) in the ECT [4]

(3)p(z)=ε0εD2φ0e-z/D

where φ0- potential electrode surface, ε0- the dielectric constant, ε is the relative permittivity of the fluid (for water ε=81). Substituting (3) into the formula (2), we obtain taking into account expressions (1)

(4)iY=z10LjYdzdx=Lz1V (z)p(z)dz=Laε0εφ0e-z1/D.

The value of φ0e-z/Dthere electrokinetic potential ζ [4]. So,

(5)iY=Laε0εζ.

In equilibrium to maintain electroneutrality of the electrode must be satisfied with equality iY=iz. Denote by dQ overcharging elementary platform ds. Then

(6)iz=sσEds=sσdQ2ε0εdsds=σ2ε0εQ

Hence the excess of the edge, the charge of the metal plates ECT equal to

(7)iz=2ε0εσiY=2ε0εσLaε0εζ

That is,

(8)Q=ε0εtLaζ,

where τ=2εε0/σ - constant of relaxation time ECT. Because in General, the electrode is electrically neutral, it is missing in the liquid part of the ECT on the leading edge of the electrode charge Q is distributed throughout the rest of its area. ECT on the surface of the electrode can be likened to a flat capacitor plates are shifted relative to each other, with the difference that the strength of the electric interaction can not draw charges from the open edges of the plates in the region of their overlap. This is prevented by force specific adsorption on the front boundary of the electrode and the forces of internal friction in the fluid on the rear edge of the electrode. Shear plates of the capacitor charge QPLeach of them saved and the container is reduced by some the th value as, moreover, the relative change in capacitance of the capacitor is approximately equal to the relative change of the area of overlapping of the plates. Therefore, the potential difference between the plates, defined as the ratio of the total charge QPLthe vessel is increased by a certain amount Δφ, considering the surface charge density constant throughout the area S of the plates,

(9) ΔφQnlΔWith aWith a2=QC,

where Q is the charge of non-overlapping parts of the plates. For a capacitor formed by the DPP on the surface of the electrode, in accordance with (8) we obtain the change in the difference of potentials on the plates of the metal-electrolyte

(10)Δφ=tζε0εLaC,

where C is the capacitance of the death of the electrode. Given that C=CBEATSS, where CBEATS- specific capacity, i.e. the capacity of the unit electrode area,

(11)Δφ=a tζε0εBCYD

As you can see, its dependence on the velocity of the fluid is determined by the coefficient a, which, as shown by the author experiments, linearly dependent on speed. The increase in the linear dimension of the electrode leads to a decrease in the potential difference Δφ. In practice, the electrodes are covered with a layer of oxide which is an insulator, so DESU is formed at the boundary of the oxide-electrolyte interface. The role of the "metal" plates in this case performs the layer adsorbed from a solution of oxygen ions. In this case, the actual electrodes can be considered a continuation of the connecting wires which are connected to the load, and the oxide film - dividing capacitors with capacitance C, which are connected through the true electrode - adsorbed layers of oxygen ions.

To measure the fluctuations of the potential of the electrode relative to the liquid, the electrolyte must place an additional electrode, which must be located outside measurements. In the inventive device is the electrode 3. The change of potential decreases with increasing electrode area, therefore, the electrode must be small, and Vice versa, large. Still the way the auxiliary electrode has a large area, and the liquid velocity near him is minimal, therefore, fluctuations in the potential difference between the electrodes is determined by the fluctuations of the velocity of the fluid at the location of the measuring electrode. Both electrodes are connected to some load resistance (for example, to the input impedance of the amplifier). Since a constant current through the oxide film to leak cannot, then the voltage at the load can only exist when the unsteady nature of the flow. If the fluctuations of the flow velocity have a duration of t<<τE=(R+r)/2, where R is the load resistance, r is the resistance of the internal circuit of the electrode cell (spreading resistance between the electrodes), the load current is determined by the expression

(12)i(t)=atζε0εBCYD(R+r).

Therefore, the voltage across the load resistance is proportional to the fluctuations of the flow velocity.

Experimental research of the author [5] confirmed the justice of] the sky's conclusions about the link between fluctuations in electrode potential with fluctuations of the velocity of the fluid. Namely, confirmed proportional to the potential difference between the measuring and the additional electrodes and the fluctuations of the velocity of the fluid relative to the measuring electrode. In the experiment the electrode was performing harmonic oscillations in an aqueous solution of sodium chloride. An additional electrode is significantly larger area was stationary in the same vessel with the measuring electrode. The voltage between the electrodes also had the appearance of harmonic oscillations with a frequency equal to the frequency of mechanical oscillations of the electrode. The its amplitude proportional to the amplitude and frequency of mechanical vibrations. Therefore, the coefficient a in the formula (1) is proportional to the flow rate. The author also experimentally found that the increased area of contact with the liquid surface of the electrode, reduces the fluctuations of its potential around the electrode fluid flow [6].

Thus, the claimed technical solution uses two set of author fact: the variable component of the voltage between the reference and measuring electrodes is proportional to the fluctuations (ripple) velocity of the fluid and inversely proportional to the linear size of the electrode (or the square root of the electrode area). These facts obtained by the author theoretical is key and verified experimentally. If the surface area of one of the measuring electrode by two orders of magnitude smaller than the area of the additional electrode, according to (11) and (12) already provides a measurement error due to the influence of the latter is not more than 10%. If this additional electrode is located outside the zone of turbulence in the region where the liquid velocity has a small ripple, the measurement error due to its impact does not exceed fractions of a percent and can be neglected. The proposed device uses N>>1 of the measuring electrodes in the form of wires with a square end surface S, each, total area of which is equal to NS, so for practice enough to the surface area of the additional electrode was at least an order of magnitude greater than the area of the entire end surface of the measuring electrode.

Technical result achieved when using the proposed device is to increase the resolution and improve the measurement accuracy of small-scale fluctuations of the flow velocity. He provided the minimum diameter of the harness, the dimensions of the polished end faces which define the resolution of the device, while increasing the voltage of the useful signal, which reduces the effect of noise and interference on the measurement result. Resolution Ave is Loginova device reaches units of millimeters, which is ten times better than the prototype. Performing the measuring electrode is not continuous, but in the form of a bundle of N isolated wires and use the summation of correlated voltages taken with each of them, allows dozens of times to increase the output voltage of the device. Achieved increase inNtime relations voltage signal to the own noise of the sensor together with the shielding of the measuring electrodes from external electric fields also improves measurement accuracy. The device has no inertia. Even a very fast flow rate (duration in fractions of milliseconds) will result in corresponding changes in the potential difference between the electrodes, the frequency range of the measured fluctuations reaches of units of kilohertz or more. The lack of sensitivity to temperature changes allow it to be used in the study of turbulence near the wall, the temperature of which differs from the temperature of the liquid. Harness of wires glued has high strength.

Fluctuations of the surface potential of the electrodes is transmitted to the measuring unit through the layer of oxide, which plays the role of a coupling capacitor, so the lower bound is often the tion of the range of fluctuation of speed, which can be measured, is defined as ƒn≈1/2πRIS, where RI- input impedance of the amplifier 5 of the measuring unit, With the capacity of the electrode relative to the electrolyte. The electrodes are made of titanium and stainless steel have a specific capacity relative to the electrolyte of about 0,03 UF/mm2. When the square end surface of the wire of 0.05 mm2and the input impedance of the amplifier RI=100 Mω lower limit of the frequency range is about one Hertz.

Literature

1. Reynolds, A. J. Turbulent flows in engineering applications. TRANS. from English./M: Energy, 1979. - 408 S.

2. Auth. St. No. 1239604, IPC5G01P 5/08, publ. 23.06.1986, bull. No. 23.

I. povh, Alaranta, Vasukevich, I. Dunaevsky. Device for measuring the parameters of a turbulent fluid stream.

3. Frumkin, A.N., Bagotsky B.C., GPI Z.A., B. N. Kabanov. Kinetics of electrode processes. M.: Izd-vo MGU, 1952, 319 S.

4. S. Dukhin, derjaguin BV Electrophoresis. M.: Nauka, 1976, 328 S.

5. Akindinov CENTURIES, Maksimenko V.G. Experimental studies of the polarization of the metal electrode when driving in the electrolyte // radio engineering and electronics. - 1996. - V.41, №8. - S-989.

6. Maksimenko V.G. Problems reduce self-noise electrode sensors of the electric field moving in the electrolyte // radio engineering and electronics. - 2002. - C, No. 7. - S-813.

1. The device for measurement of turbulent fluctuations of the flow rate of a fluid containing dielectric body streamlined shape with installed measuring electrode and the measuring unit, which includes amplifiers, the inputs of which are connected to the electrodes, and the adder, the inputs of which are connected to the outputs of amplifiers, characterized in that it introduced an additional electrode, the measuring electrode made in the form of wires with insulated lateral surface collected in the harness or a beam with a polished end face, the number of amplifiers equal to the number of measuring electrodes, each of which is connected to the input of the corresponding amplifier, with an additional electrode is connected to the common bus of the measuring block, and the minimum distance between the additional electrode and the end face of the bundle exceeds the size of the zone of turbulence.

2. The device according to claim 1, characterized in that the auxiliary electrode is made in the form mounted on the dielectric housing of a hollow metal cylinder, the surface area which is much more greater than the total area of the end surface of the measuring electrode, with a plait of wires, in the form which made measuring electrodes installed inside additional electrode so that its end extends over the edge additionally what about the electrode.



 

Same patents:

FIELD: physics.

SUBSTANCE: disclosed is a system for monitoring local surface earthquake precursors on a secure territory, having two supply earth terminals connected to a probe current pulse generator, and a system of receiving earth terminals connected to a receiver which is connected to a signal processing unit. The system of receiving earth terminals is formed by N buried electrodes, N-1 of which are arranged uniformly on a circle of diameter D=0.5-0.6 km, and one central electrode placed at the centre of said circle. Radial conductors are connected each of the N-1 electrodes of the system of receiving earth terminals. Electrodes of the supply earth terminals are spaced apart by a distance L=(15-20)D. The system of receiving earth terminals is directed in the plan randomly relative electrodes of the supply earth terminals and lies from the latter at a distance X=(1.5-1.6)L. The probe current pulse generator generates current pulse bursts with frequency of 0.02-0.2 Hz, burst duration of 10-30 s and current in the pulse of 1-10 KA at least twice a day at the same time of the day.

EFFECT: high reliability of information on the hypocentre of an imminent surface earthquake and its parameters, particularly the event time and amplitude estimate.

5 cl, 3 dwg

FIELD: oil and gas industry.

SUBSTANCE: complex instrument includes loaded drilling pipe that consists of the first and the second part separated by isolated gap, and distant-measuring cartridge containing distant measuring scheme that includes power source generating voltage drop at isolated gap, and axle current at drilling column that is returned through geologic bed, it also includes isolated measuring electrode connected to the first part and scheme for specific resistance measuring connected in the course of operation to measuring electrode and distant-measuring scheme.

EFFECT: integration of possibilities to measure specific resistance into electro-magnetic distant-measuring instrument and obtaining the data of specific resistance as well as distant measuring.

58 cl, 11 dwg

FIELD: physics.

SUBSTANCE: at an observation line, two three-electrode electrical soundings are performed using an apparatus comprising four earthing contacts lying on one line symmetrically about the observation point. The fifth earthing contact relates to virtual "infinity" and is connected to one terminal of an electric current source. Central earthing contacts are connected to a voltage measuring device. When taking measurements, outermost power earthing contacts are successively connected to the other terminal of the electric current source. Potential drop Δ UAMN and ΔUA'MN between receiving earthing contacts is measured. The operations are repeated for all given positions of power earthing contacts. Potential drop for vertical electrical sounding and potential drop for unipolar sounding is calculated from the measured potential drop at each observation point for given differences. The distribution of apparent electrical resistance in sections for two three-electrode and vertical sounding and distribution in section of potential drop for unipolar sounding is determined from the measured and calculated potential drops. The results determine the presence and location in the section of geological irregularities.

EFFECT: high efficiency of detecting geological irregularities in the geological environment.

1 tbl, 1 dwg

FIELD: physics.

SUBSTANCE: potentially dangerous area is selected on territory to be analysed. At least three measuring modules are arranged on said area. Every said module consists of radiating electrode, main electrode pair with its one electrode making zero electrode, and at least one additional electrode pair. Said electrode pairs of measuring electrode are arranged at 180°/n to each other where n stands for number of electrode pair. All electrodes are located on one equipotentional line of radiating electrode. Electrodes of one pair are arranged on one line with radiating electrode. Directional diagrams of electrode pairs are plotted. Potential difference is measured between zero electrode and main electrode pair, and other electrodes of appropriate measuring module. Abnormal potential difference and direction diagram are used to determine direction for each measuring module to zone of rocks irregularities. Zone location is defined at intersection of said directions.

EFFECT: higher accuracy and validity.

3 dwg

FIELD: mining.

SUBSTANCE: at the profile points the current is supplied through a pair of feeding electrodes to the earth. Current value and potential difference between pair of receiving electrodes is measured. Feeding electrodes are moved with pitch equal to 1 m symmetrically relative to the centre to limit distance between feeding electrodes, which is determined by the specified investigation depth. As per measurement results the apparent specific resistance is calculated. As per data of apparent specific resistance the graph of its behaviour is built depending on half-spacings of feeding electrodes. Specific resistances of frozen beds are calculated as per apparent specific resistance graph. Percentage of clay in unit volume of rock is calculated as per data of specific resistances of frozen beds by the following formula: where ρclay - specific clay resistance, which in permafrost zone section is characterised as constant value which on average is equal to 100 ohm m, ρfb -specific resistance of frozen bed. Lithologic composition of sand-clay complex of frozen rocks is determined as per clay content.

EFFECT: reducing the cost of operations and improving informativity owing to determining lithologic composition of frozen rocks without any drilling data and using common data on geologic structure of investigation region.

1 tbl, 2 dwg

FIELD: physics.

SUBSTANCE: current is cutoff to soil through two point sources. The first source is placed close by vertical interface, and the second is taken to infinity. Position of one equipotential line of electric field is detected. Measuring electrodes is mounted by tangent to equipotential line symmetrically to tangency point of ray lined from auxiliary point presenting mirror reflection of point source relative to interface with specified equipotential. Besides, measuring electrodes can be placed by line, perpendicular to interface symmetrically to power supply provided close by interface. Near to interface there is compensatory point source with current value fixed by parity where I0, Ik are currents from the first and compensatory sources, ΔΨ1MN is differential of the space function that determinates position of measuring electrodes relative to the first source, ΔΨ2MN is differential of space function that determinates position of measuring electrodes relative to compensatory source. Measuring electrodes voltage indicates time variations of resistivity.

EFFECT: simplified positioning of electrical survey unit and improved measurement accuracy.

1 dwg

FIELD: geoelectrical prospecting.

SUBSTANCE: invention relates to geoelectrical prospecting by the electrical resistance method. The method uses two fixed supplying grounding circuits, the first of them being located in practical infinity, the other one along with two fixed reception grounding circuits being arranged nearby the observation profile, two additional movable grounding circuits located at equal distance from the second supplying grounding circuit. In measurements, in every position of the movable grounding circuits, the latter are connected in turns to a power source or an instrument. On connecting them to the power source, a voltage drop between the fixed reception grounding circuits is measured. On connecting them to instrument and measuring the voltage drop between them, the fixed supplying grounding circuits are connected to electric power source. The aforesaid operations are effected for all preset positions of the movable grounding circuits. Proceeding the measurement results, sections of apparent electrical resistance and voltage drop are plotted to estimate the availability of geoelectrical irregularities in the section.

EFFECT: higher efficiency of revealing geoelectrical irregularities and lower ambiguity in experimental data interpretation.

1 dwg

FIELD: physics; geophysics.

SUBSTANCE: current pulse is excited in the medium under investigation, and parameters of its induced polarisation are defined. Geoelectric section is generated to make a conclusion about the presence of hydrocarbon fields on the basis of abnormal manifestations of induced polarisation parameters. At that, electromagnetic and seismic waves are excited simultaneously or with a time shift. To excite the said waves unipolar rectangular impulses of direct current are generated, their absolute and relative duration depending on parameters of medium under investigation. In the beginning of timing pulse electric field is measured simultaneously at measuring probe groups of two detector lines towed at different depth. Besides, detector line depth and hydroacoustic pressure of seismic source are measured. Also a device is offered, which includes pulse generator, capacitor charging unit, power generator, bank of capacitors, switchboard, seismic emitter, transmitter/receiver line, receiver line, multi-channel gauge, echo-sounder, GPS satellite navigation receiver, signal processor.

EFFECT: higher reliability of research results.

18 cl, 6 dwg

FIELD: geophysical prospecting by electric means by the method of induced polarization.

SUBSTANCE: the device has an exciting field forming unit and a signal measurement unit. The exciting field forming unit has a ship generator, switch forming bipolar DC square pulses, generating plant and a ballast device. The signal measurement unit has a receiving multi-electrode line, resistivimeter, multi-channel measuring device, ship echo sounder, Global Position System receiving indicator and a signal processor. According to the claimed method, the research of the geological medium along the observation outline is carried out by excitation of periodic alternating current pulses and determination of geoelectric medium parameters, geoelectric sections are constructed, a conclusion is made on the presence of a deposit of hydrocarbons according to the exposed anomalies of conduction and the parameters of induced polarization.

EFFECT: enhanced reliability of the research results.

8 cl, 5 dwg

The invention relates to the engineering-geological surveys to obtain data on the structure of the upper part of the section (high frequency resolution) of rocks to issue recommendations for the construction of engineering structures, primarily in the areas of crossings over water obstacles

FIELD: geophysical prospecting by electric means by the method of induced polarization.

SUBSTANCE: the device has an exciting field forming unit and a signal measurement unit. The exciting field forming unit has a ship generator, switch forming bipolar DC square pulses, generating plant and a ballast device. The signal measurement unit has a receiving multi-electrode line, resistivimeter, multi-channel measuring device, ship echo sounder, Global Position System receiving indicator and a signal processor. According to the claimed method, the research of the geological medium along the observation outline is carried out by excitation of periodic alternating current pulses and determination of geoelectric medium parameters, geoelectric sections are constructed, a conclusion is made on the presence of a deposit of hydrocarbons according to the exposed anomalies of conduction and the parameters of induced polarization.

EFFECT: enhanced reliability of the research results.

8 cl, 5 dwg

FIELD: physics; geophysics.

SUBSTANCE: current pulse is excited in the medium under investigation, and parameters of its induced polarisation are defined. Geoelectric section is generated to make a conclusion about the presence of hydrocarbon fields on the basis of abnormal manifestations of induced polarisation parameters. At that, electromagnetic and seismic waves are excited simultaneously or with a time shift. To excite the said waves unipolar rectangular impulses of direct current are generated, their absolute and relative duration depending on parameters of medium under investigation. In the beginning of timing pulse electric field is measured simultaneously at measuring probe groups of two detector lines towed at different depth. Besides, detector line depth and hydroacoustic pressure of seismic source are measured. Also a device is offered, which includes pulse generator, capacitor charging unit, power generator, bank of capacitors, switchboard, seismic emitter, transmitter/receiver line, receiver line, multi-channel gauge, echo-sounder, GPS satellite navigation receiver, signal processor.

EFFECT: higher reliability of research results.

18 cl, 6 dwg

FIELD: geoelectrical prospecting.

SUBSTANCE: invention relates to geoelectrical prospecting by the electrical resistance method. The method uses two fixed supplying grounding circuits, the first of them being located in practical infinity, the other one along with two fixed reception grounding circuits being arranged nearby the observation profile, two additional movable grounding circuits located at equal distance from the second supplying grounding circuit. In measurements, in every position of the movable grounding circuits, the latter are connected in turns to a power source or an instrument. On connecting them to the power source, a voltage drop between the fixed reception grounding circuits is measured. On connecting them to instrument and measuring the voltage drop between them, the fixed supplying grounding circuits are connected to electric power source. The aforesaid operations are effected for all preset positions of the movable grounding circuits. Proceeding the measurement results, sections of apparent electrical resistance and voltage drop are plotted to estimate the availability of geoelectrical irregularities in the section.

EFFECT: higher efficiency of revealing geoelectrical irregularities and lower ambiguity in experimental data interpretation.

1 dwg

FIELD: physics.

SUBSTANCE: current is cutoff to soil through two point sources. The first source is placed close by vertical interface, and the second is taken to infinity. Position of one equipotential line of electric field is detected. Measuring electrodes is mounted by tangent to equipotential line symmetrically to tangency point of ray lined from auxiliary point presenting mirror reflection of point source relative to interface with specified equipotential. Besides, measuring electrodes can be placed by line, perpendicular to interface symmetrically to power supply provided close by interface. Near to interface there is compensatory point source with current value fixed by parity where I0, Ik are currents from the first and compensatory sources, ΔΨ1MN is differential of the space function that determinates position of measuring electrodes relative to the first source, ΔΨ2MN is differential of space function that determinates position of measuring electrodes relative to compensatory source. Measuring electrodes voltage indicates time variations of resistivity.

EFFECT: simplified positioning of electrical survey unit and improved measurement accuracy.

1 dwg

FIELD: mining.

SUBSTANCE: at the profile points the current is supplied through a pair of feeding electrodes to the earth. Current value and potential difference between pair of receiving electrodes is measured. Feeding electrodes are moved with pitch equal to 1 m symmetrically relative to the centre to limit distance between feeding electrodes, which is determined by the specified investigation depth. As per measurement results the apparent specific resistance is calculated. As per data of apparent specific resistance the graph of its behaviour is built depending on half-spacings of feeding electrodes. Specific resistances of frozen beds are calculated as per apparent specific resistance graph. Percentage of clay in unit volume of rock is calculated as per data of specific resistances of frozen beds by the following formula: where ρclay - specific clay resistance, which in permafrost zone section is characterised as constant value which on average is equal to 100 ohm m, ρfb -specific resistance of frozen bed. Lithologic composition of sand-clay complex of frozen rocks is determined as per clay content.

EFFECT: reducing the cost of operations and improving informativity owing to determining lithologic composition of frozen rocks without any drilling data and using common data on geologic structure of investigation region.

1 tbl, 2 dwg

FIELD: physics.

SUBSTANCE: potentially dangerous area is selected on territory to be analysed. At least three measuring modules are arranged on said area. Every said module consists of radiating electrode, main electrode pair with its one electrode making zero electrode, and at least one additional electrode pair. Said electrode pairs of measuring electrode are arranged at 180°/n to each other where n stands for number of electrode pair. All electrodes are located on one equipotentional line of radiating electrode. Electrodes of one pair are arranged on one line with radiating electrode. Directional diagrams of electrode pairs are plotted. Potential difference is measured between zero electrode and main electrode pair, and other electrodes of appropriate measuring module. Abnormal potential difference and direction diagram are used to determine direction for each measuring module to zone of rocks irregularities. Zone location is defined at intersection of said directions.

EFFECT: higher accuracy and validity.

3 dwg

FIELD: physics.

SUBSTANCE: at an observation line, two three-electrode electrical soundings are performed using an apparatus comprising four earthing contacts lying on one line symmetrically about the observation point. The fifth earthing contact relates to virtual "infinity" and is connected to one terminal of an electric current source. Central earthing contacts are connected to a voltage measuring device. When taking measurements, outermost power earthing contacts are successively connected to the other terminal of the electric current source. Potential drop Δ UAMN and ΔUA'MN between receiving earthing contacts is measured. The operations are repeated for all given positions of power earthing contacts. Potential drop for vertical electrical sounding and potential drop for unipolar sounding is calculated from the measured potential drop at each observation point for given differences. The distribution of apparent electrical resistance in sections for two three-electrode and vertical sounding and distribution in section of potential drop for unipolar sounding is determined from the measured and calculated potential drops. The results determine the presence and location in the section of geological irregularities.

EFFECT: high efficiency of detecting geological irregularities in the geological environment.

1 tbl, 1 dwg

FIELD: oil and gas industry.

SUBSTANCE: complex instrument includes loaded drilling pipe that consists of the first and the second part separated by isolated gap, and distant-measuring cartridge containing distant measuring scheme that includes power source generating voltage drop at isolated gap, and axle current at drilling column that is returned through geologic bed, it also includes isolated measuring electrode connected to the first part and scheme for specific resistance measuring connected in the course of operation to measuring electrode and distant-measuring scheme.

EFFECT: integration of possibilities to measure specific resistance into electro-magnetic distant-measuring instrument and obtaining the data of specific resistance as well as distant measuring.

58 cl, 11 dwg

FIELD: physics.

SUBSTANCE: disclosed is a system for monitoring local surface earthquake precursors on a secure territory, having two supply earth terminals connected to a probe current pulse generator, and a system of receiving earth terminals connected to a receiver which is connected to a signal processing unit. The system of receiving earth terminals is formed by N buried electrodes, N-1 of which are arranged uniformly on a circle of diameter D=0.5-0.6 km, and one central electrode placed at the centre of said circle. Radial conductors are connected each of the N-1 electrodes of the system of receiving earth terminals. Electrodes of the supply earth terminals are spaced apart by a distance L=(15-20)D. The system of receiving earth terminals is directed in the plan randomly relative electrodes of the supply earth terminals and lies from the latter at a distance X=(1.5-1.6)L. The probe current pulse generator generates current pulse bursts with frequency of 0.02-0.2 Hz, burst duration of 10-30 s and current in the pulse of 1-10 KA at least twice a day at the same time of the day.

EFFECT: high reliability of information on the hypocentre of an imminent surface earthquake and its parameters, particularly the event time and amplitude estimate.

5 cl, 3 dwg

FIELD: measurement equipment.

SUBSTANCE: device comprises a dielectric body of streamlined shape with installed metering electrodes, a metering unit comprising amplifiers, to inputs of which electrodes are connected, a summator, inputs of which are connected with outputs of amplifiers, and also an additional electrode, at the same time metering electrodes are made in the form of wires with insulated side surface, assembled into a cord or bundle with a polished end, the minimum distance between which and the additional electrode exceeds the size of the turbulence zone, the number of amplifiers is equal to the number of metering electrodes, every of which is connected to the input of the appropriate amplifier, and the additional electrode is connected with the common bus of the metering unit. The additional electrode is made in the form of a hollow metal cylinder installed on the dielectric body, the surface area of which is ten times and more exceeds the total area of the end surface of metering electrodes, at the same time the cord of wires, in the form of which metering electrodes are arranged, is installed inside the second electrode so that its end protrudes beyond the edge of the additional electrode.

EFFECT: increased resolving capacity and increased accuracy of measurement of small-scale fluctuations of flow speed.

2 cl, 2 dwg

Up!