CN203772890U - Hand-held hollow flow meter - Google Patents

Abstract

The utility model discloses a hand-held hollow flow meter which comprises eight pressure sensors, eight pressure sensor leads, an MCU micro control unit, eight A/D conversion modules, a display, an outer sleeve, a hollow tube, a power supply, a keyboard matrix and a casing body. The middle part of the inner wall of the hollow tube contracts inward to form a beam narrow section. Four pressure sensors are equally and symmetrically distributed on the inner wall of an inlet of the hollow tube. The other four pressure sensors are equally and symmetrically distributed on the inner wall of the beam narrow section of the hollow tube. Eight pressure sensors are respectively connected with eight A/D conversion modules through eight pressure sensor leads. The MCU micro control unit is respectively connected with eight A/D conversion modules, the display, the power supply and the keyboard matrix through wires. The hand-held hollow flow meter provided by the utility model has the advantages of stable performance, less maintenance, being portable and low cost, can adapt to a complex condition, and can meet precision requirements of different levels.

Description

A kind of hand-held hollow current meter

Technical field

The utility model belongs to data acquisition equipment field, relates to a kind of hand-held hollow current meter, relates in particular to a kind of hand-held hollow current meter of the water velocity of measuring the water bodys such as river, lake and channel.

Background technology

The measurement of fluid velocity is of great significance for the interaction mechanism tool between the characteristics of motion and the internal fluid particle of Study of Fluid.Current meter is the instrument of measuring the water velocity of the water bodys such as river, lake and channel.Mainly contain at present machinery, electrical measurement and ultrasonic three types.Be divided into propeller current meter, electromagnetic type current meter, ultrasonic flow-velocity instrument for measuring and calculating.

1, propeller current meter

Mainly form by revolving oar, stature and empennage three parts.Revolve in oar signal contact and bearing rotating shaft etc. are housed, in the rotating shaft system of China's " 25-1 type " propeller type current meter, have tortuous labyrinth structure, inside is full of light machine oil, has good waterproof sand prevention performance, can in high flow rate and heavily silt-carrying river, use.Propeller current meter, cup-type current meter and Spiralism type current meter all belong to rotating element current meter, and principle of work is basic identical, are to utilize the rotation of flow dynamic drive rotor, inquire into flow velocity according to velocity of rotation.

Propeller current meter is the conventional type of current research and production, and measurement data is accurate, and performance is comparatively stable, but in actual measurement process, because reading separates with measuring, often needs more manually, is inconvenient in addition carry.Because being revolves paddle structure, rotor is outside exposed, impacted by high speed silt, stone, and uses the factors such as lack of standardization, is easy to impairedly, often overhaul, and maintenance cost is high, uses inconvenient.

2, electromagnetic type current meter

Principle is using current as conductor, and cutting magnetic line in certain magnetic field produces electromotive force, and its voltage is directly proportional to flow velocity.Instrument does not have rotor, smooth-shaped, and volume is little, low in energy consumption, has field coil in body cavity, studs with pair of electrodes and communicate with water body in surperficial vertical with magnetic line of force direction.In the time that current flow on its surface, on electrode, produce micro-voltage signal, be sent on counter with wire, through amplifying and the processing of circuit such as analog to digital conversion, can directly show flow velocity.

This kind of current meter convenient test, does not have rotor, has effectively solved rotor and has been easy to the problem of damaging, but test fluid flow electric conductivity is had relatively high expectations, and the scope of application has significant limitation.

3, ultrasonic velocity meter

Transducer is laid in to depth of water place, both sides, riverbank, is oblique line directions, A point sends sound pulse and arrives B and order the period of experiencing and be, otherwise that is checked and accepted by a B point A is lasted for, due to the existence of flow velocity, the direction velocity of sound lowers against the current, increase downstream, mistiming and flow velocity have linear functional relation.With the timekeeping circuit of Microsecond grade, calculate through processing, can directly show the mean flow rate on AB line segment.

This kind of current meter is applicable to test the mean flow rate on a certain line segment, is not suitable for the flow velocity of measurement point, and less application in hydraulic research especially, under complicated measurement environment, is difficult to lay transducer, realizes the function of velocity measurement.

Utility model content

In order to solve above-mentioned technical matters, the utility model provides a kind of stable performance, little maintenance, the current meter that can adapt to complex working condition easy to carry, simultaneously cheap, can meet the hand-held hollow current meter of different levels accuracy requirement.

The technical scheme that the utility model adopts is: a kind of hand-held hollow current meter, is characterized in that: comprise eight pressure transducers, eight pressure transducer sensor leads, MCU micro-control unit, eight A/D modular converters, display, outer tube, hollow tube, power supply, keyboard matrix and housings; Described MCU micro-control unit, A/D modular converter is arranged on described enclosure interior, and described display, keyboard matrix is arranged on described housing upper surface; Described outer tube one end through described housing bottom surface be fixedly connected with described housing, the other end is fixedly connected with described hollow tube through described hollow tube middle part, for eight pressure transducer sensor leads described in receiving; Narrow section of bundle is inwardly shunk, forms at described hollow tube inwall middle part, and four pressure transducers are distributed on described hollow tube import inwall symmetrically, and other four pressure transducers are distributed on described narrow section of inwall of hollow tube bank symmetrically; Eight described pressure transducers are connected with eight described A/D modular converters respectively by eight described pressure transducer sensor leads respectively, described MCU micro-control unit is connected by wire with described eight A/D modular converters, display, power supply and keyboard matrixs respectively, for carrying out exchanges data with eight described pressure transducers, eight A/D modular converters, display and keyboard matrixs.

As preferably, described hand-held hollow current meter also comprises grounding contact, eight sensor mask cover lead-in wires, described grounding contact and described MCU micro-control unit by wire be connected, eight sensor mask covers lead-in wires are arranged in described outer tube, described grounding contact one end go between respectively by eight described sensor mask covers be connected with the radome of described eight pressure transducers, the other end is connected with extraneous ground.

As preferably, described hollow tube is the hollow tube that outer wall has cavity, for receiving described eight pressure transducer sensor leads and eight sensor mask covers lead-in wires.

As preferably, termination and end tail that described hollow tube bank is narrow section are fillet type.

As preferably, described MCU micro-control unit is integrated with MEMS obliquity sensor.

As preferably, the entrance point of described hollow tube is fillet type.

The utility model, with respect to prior art, has following beneficial effect:

1, based on the incompressible constant total stream energy equation of viscosity, flow rate of water flow index is converted into the water flow pressure and the instrument obliquity information that are easy to measurement, utilizes MCU microcontroller chip to realize automatic collection, processing, calculating and the flow velocity Presentation Function of coherent signal in conjunction with MEMS pressure transducer, obliquity sensor;

2, hollow type current meter does as a whole by water body in pipe, compare old-fashioned propeller type current meter little to the interference of current, the introducing of high-precision sensor impels flow rate result more accurate, and unnecessary mechanical fault and mechanical wear has been avoided in the design of hollow type, applicable surface is wider, and maintenance cost is lower;

3, by each component packages together, the transmission of internal data information is reliable and stable for hollow tube, and this design makes instrument have the features such as little, lightweight, the easy to carry and antijamming capability of volume is strong;

4, this apparatus structure is simple, easy to use, with low cost, easy to utilize.

Brief description of the drawings

Fig. 1: the structure cut-open view of the utility model embodiment.

Fig. 2: the A-A structure cut-open view of the utility model embodiment.

Fig. 3: the B-B structure cut-open view of the utility model embodiment.

Fig. 4: move schematic diagram when the utility model embodiment horizontal positioned.

Fig. 5: move schematic diagram when the utility model embodiment slant setting.

Embodiment

Understand and enforcement the utility model for the ease of those of ordinary skill in the art, below in conjunction with drawings and Examples, the utility model is described in further detail, should be appreciated that exemplifying embodiment described herein is only for description and interpretation the utility model, and be not used in restriction the utility model.

Ask for an interview Fig. 1, Fig. 2 and Fig. 3, the technical scheme that the utility model adopts is: a kind of hand-held hollow current meter, comprises eight pressure transducers 1,2,3,4,5,6,7,8, eight pressure transducer sensor leads 9, MCU micro-control unit 10, eight A/D modular converters 11, grounding contact 12, display 13, outer tube 14, hollow tube 15, eight sensor mask cover lead-in wires 16, power supply 17, keyboard matrix 18 and housings 19, MCU micro-control unit 10 is integrated with MEMS obliquity sensor, MCU micro-control unit 10, A/D modular converter 11 are arranged on housing 19 inside, and display 13, keyboard matrix 18 are arranged on housing 19 upper surfaces, outer tube 14 one end through housing 19 bottom surfaces be fixedly connected with housing 19, the other end is fixedly connected with hollow tube 15 through hollow tube 15 middle parts, for receiving eight pressure transducer sensor leads 9 and eight sensor mask covers go between 16, hollow tube 15 has the hollow tube of cavity for outer wall, for receiving eight pressure transducer sensor leads 9 and eight sensor mask covers lead-in wires 16, the entrance point of hollow tube 15 is fillet type, narrow section of bundle is inwardly shunk, forms at hollow tube 15 inwall middle parts, termination and the end tail of restrainting narrow section are fillet type, four pressure transducers 1,2,3,4 are distributed on hollow tube 15 import inwalls symmetrically, and other four pressure transducers 5,6,7,8 are distributed in symmetrically hollow tube 15 and restraint on narrow section of inwall, eight pressure transducers 1, 2, 3, 4, 5, 6, 7, 8 are connected with eight A/D modular converters 11 respectively by eight pressure transducer sensor leads 9 respectively, grounding contact 12 is connected by wire with MCU micro-control unit 10, eight sensor mask cover lead-in wires 16 are arranged in outer tube 14, grounding contact 12 one end by eight sensor mask covers lead-in wire 16 respectively with eight pressure transducers 1, 2, 3, 4, 5, 6, 7, 8 radome connects, the other end is connected with extraneous ground, MCU micro-control unit 10 respectively with eight A/D modular converters 11, display 13, power supply 17 is connected by wire with keyboard matrix 18, be used for and eight pressure transducers 1, 2, 3, 4, 5, 6, 7, 8, eight A/D modular converters 11, grounding contact 12, display 13 and keyboard matrix 18 carry out exchanges data.

To measure current as example, the operation logic of hollow current meter of the present utility model is further elaborated below.

The utility model presents rule according to the some pressure of Heng Tong water gaging stream with the variation of its place discharge section area to be changed, the velocity parameters of current is converted into the pressure signal that is easy to collection, in conjunction with the obliquity information of obliquity sensor acquisition, can draw the speed of current.When test, the utility model is put in to tested point along flow direction.Because the utility model is by current isolation inside and outside it, can ignore the interference to the utility model in-pipe flow of turbulent flow that the utility model periphery may exist; Because import fillet section is redirected the traction of current, the streamline of the utility model in-pipe flow can be regarded as and be parallel to tube wall; Because the size of hollow tube 15 of the present utility model is less, in pipe, water volume flow rate can finely represent the water volume flow rate of tested point.Can think that the fluid motion in hollow tube 15 is steady flow, suppose that this fluid is incompressible homogeneous fluid.

Ask for an interview Fig. 4, during for the utility model horizontal positioned, move schematic diagram, taking the central plane O-O of hollow tube 15 sections as reference field, choosing A-A section and B-B section is research object, fluid visibility between two sections is uniform-flow or gradually varied flow, point flow velocity with section center replaces cross-sectional flow, writes out the incompressible constant fluid energy equation of viscosity (acquiescence adopts relative pressure, lower same):

$\frac{p_A}{\mathrm{\ρg}}+\frac{{\mathrm{\α}}_A{v}_A^2}{2g}=\frac{p_B}{\mathrm{\ρg}}+\frac{{\mathrm{\α}}_B{v}_B^2}{2g}+h_w$ (formula one)

$h_w=h_f+{\mathrm{\Σh}}_j=\mathrm{\λ}\frac{l}{d}\frac{v^2}{2g}+\mathrm{\Σ\ζ}\frac{v^2}{2g}\≈\mathrm{\Σ\ζ}\frac{v^2}{2g}$ (formula two)

In formula:

α _a, α _b: kinetic energy correction factor, get 1 here;

L: two section spacings, hollow tube longitudinal size is extremely short, and l ≈ 0, ignores friction loss;

∑ ζ: the closing of local loss coefficient, comprising local head loss's coefficient has ζ ₁(fillet import), ζ ₂(narrow section of fillet bundle).Table look-up to such an extent that the coefficient of shock resistance of fillet import is about 0.1;

P _a, p _b: the pressure of corresponding section current to tube wall, due to symmetry and the small size feature of hollow tube, think the inner water body isotropy of hollow tube:

$p_A=\frac{\underset{i=1}{\overset{4}{\mathrm{\Σ}}}{p}_i}{4}$ (formula three)

$p_B=\frac{\underset{i=5}{\overset{8}{\mathrm{\Σ}}}{p}_i}{4}$ (formula wantonly)

P _i: the hydrodynamic pressure size of corresponding period, is collected by corresponding label MEMS pressure transducer.

A-A section and B-B section are had to total stream continuity equation:

$v_A\frac{\mathrm{\π}{D}_A^2}{4}=v_B\frac{{\mathrm{\πD}}_B^2}{4}=Q$ (formula 5)

In formula:

V _a, v _b: the mean flow rate of corresponding section;

D _a, D _b: the internal diameter of corresponding section is design given value;

Can be obtained by formula one-Shi three:

$v_A={\left(\frac{D_B}{D_A}\right)}^2\sqrt{\frac{(\underset{i=5}{\overset{8}{\mathrm{\Σ}}}{p}_i-\underset{i=1}{\overset{4}{\mathrm{\Σ}}}{p}_i)}{2\mathrm{\ρ}[1.1-0.9{\left(\frac{D_B}{D_A}\right)}^4]}}$ (formula land)

Can be calculated tested point flow velocity v by MCU micro-control unit 10 _a.

Ask for an interview Fig. 5, during for the utility model slant setting, move schematic diagram, taking the surface level O-O at hollow tube 15 central point places as reference field, choosing A-A section and B-B section is research object, fluid visibility between two sections is uniform-flow or gradually varied flow, can have energy equation:

$z_y+\frac{p_A}{\mathrm{\ρg}}+\frac{{\mathrm{\α}}_A{v}_A^2}{2g}=\frac{p_B}{\mathrm{\ρg}}+\frac{{\mathrm{\α}}_B{v}_B^2}{2g}+h_w$ (formula seven)

$h_w=h_f+{\mathrm{\Σh}}_j=\mathrm{\λ}\frac{l}{d}\frac{v^2}{2g}+\mathrm{\Σ\ζ}\frac{v^2}{2g}\≈\mathrm{\Σ\ζ}\frac{v^2}{2g}$ (formula eight)

Z _y=L _aBsin θ (formula nine)

$v_A\frac{{\mathrm{\πD}}_A^2}{4}=v_B\frac{{\mathrm{\πD}}_B^2}{4}=Q$ (formula is picked up)

In formula:

θ: the angle of hollow tube and surface level, is collected by MEMS obliquity sensor.

Pick up and can obtain by formula eight-Shi:

$v_A={\left(\frac{D_B}{D_A}\right)}^2\sqrt{\frac{2(\underset{i=5}{\overset{8}{\mathrm{\Σ}}}{p}_i+{4\mathrm{\ρgL}}_{\mathrm{AB}}\·\sin \mathrm{\θ}-\underset{i=1}{\overset{4}{\mathrm{\Σ}}}{p}_i)}{4\mathrm{\ρ}[1.1-0.9{\left(\frac{D_B}{D_A}\right)}^4]}}$ (formula picks up one)

Can be calculated tested point flow velocity v by MCU micro-control unit 10 _a.

The utility model application prospect is good, can widespread use with:

1: for containing the more water body (as sewage, silt water, muddy water etc.) of solid impurity, adopt old-fashioned propeller current meter very easily because screw propeller is impeded or stop up the correct collection that affects flow velocity by impurity, and hand-held hollow current meter still can obtain accurately tested point flow velocity under this environment;

2: for the measurement of high flow velocity water body, adopt propeller type current meter very easily to cause and revolve oar excessive wear and even damage, the introducing maximizing of hollow current meter is avoided this type of wearing and tearing, reduces greatly equipment later maintenance cost;

3: this hand-held hollow current meter can be widely used in the open channel fluid-velocity survey in the fields such as hydrometric station, factories and miness, environmental monitoring station, farmland discharging-irrigating and University Scientific Research.

Although more used the term such as pressure transducer 1,2,3,4,5,6,7,8, eight pressure transducer sensor leads 9, MCU micro-control unit 10, eight A/D modular converters 11, grounding contact 12, display 13, outer tube 14, hollow tube 15, eight sensor mask cover lead-in wires 16, power supply 17, keyboard matrix 18 and housings 19 herein, do not got rid of the possibility that uses other terms.Use these terms to be only used to describe more easily essence of the present utility model, they are construed to any additional restriction is all contrary with the utility model spirit.

Should be understood that; the above-mentioned description for preferred embodiment is comparatively detailed; can not therefore think the restriction to the utility model scope of patent protection; those of ordinary skill in the art is under enlightenment of the present utility model; do not departing from the scope situation that the utility model claim protects; can also make and replacing or distortion, within all falling into protection domain of the present utility model, request protection domain of the present utility model should be as the criterion with claims.

Claims (6)

1. a hand-held hollow current meter, is characterized in that: comprise eight pressure transducers (1,2,3,4,5,6,7,8), eight pressure transducer sensor leads (9), MCU micro-control unit (10), eight A/D modular converters (11), display (13), outer tube (14), hollow tube (15), power supply (17), keyboard matrix (18) and housing (19), described MCU micro-control unit (10), A/D modular converter (11) is arranged on described housing (19) inside, and described display (13), keyboard matrix (18) is arranged on described housing (19) upper surface, described outer tube (14) one end through described housing (19) bottom surface be fixedly connected with described housing (19), the other end is fixedly connected with described hollow tube (15) through described hollow tube (15) middle part, for the eight pressure transducer sensor leads (9) described in receiving, narrow section of bundle is inwardly shunk, forms at described hollow tube (15) inwall middle part, four pressure transducers (1,2,3,4) are distributed on described hollow tube (15) import inwall symmetrically, and other four pressure transducers (5,6,7,8) are distributed in symmetrically described hollow tube (15) and restraint on narrow section of inwall, eight described pressure transducers (1, 2, 3, 4, 5, 6, 7, 8) be connected with described eight A/D modular converters (11) respectively by described eight pressure transducer sensor leads (9) respectively, described MCU micro-control unit (10) respectively with described eight A/D modular converters (11), display (13), power supply (17) is connected by wire with keyboard matrix (18), be used for and eight described pressure transducers (1, 2, 3, 4, 5, 6, 7, 8), eight A/D modular converters (11), display (13) and keyboard matrix (18) carry out exchanges data.

2. hand-held hollow current meter according to claim 1, it is characterized in that: described hand-held hollow current meter also comprises grounding contact (12), eight sensor mask cover lead-in wires (16), described grounding contact (12) is connected by wire with described MCU micro-control unit (10), eight sensor mask cover lead-in wires (16) are arranged in described outer tube (14), described grounding contact (12) one end by described eight sensor mask covers lead-in wires (16) respectively with described eight pressure transducers (1, 2, 3, 4, 5, 6, 7, 8) radome connects, the other end is connected with extraneous ground.

3. hand-held hollow current meter according to claim 1 and 2, it is characterized in that: described hollow tube (15) has the hollow tube of cavity for outer wall, for receiving described eight pressure transducer sensor leads (9) and eight sensor mask covers go between (16).

4. hand-held hollow current meter according to claim 1 and 2, is characterized in that: described hollow tube (15) is restrainted the termination of narrow section and held tail to be fillet type.

5. hand-held hollow current meter according to claim 1, is characterized in that: described MCU micro-control unit (10) is integrated with MEMS obliquity sensor.

6. hand-held hollow current meter according to claim 4, is characterized in that: the entrance point of described hollow tube (15) is fillet type.