WO2016141628A1

WO2016141628A1 - Mass flow sensor

Info

Publication number: WO2016141628A1
Application number: PCT/CN2015/078103
Authority: WO
Inventors: 孙晓君; 史继颖; 王帅; 尚保园; 丁伟
Original assignee: 孙晓君; 加拿大沃森实业有限公司
Priority date: 2015-03-12
Filing date: 2015-04-30
Publication date: 2016-09-15
Also published as: CN104776891A

Abstract

A mass flow sensor. The mass flow sensor comprises a first measurement tube (1) and a second measurement tube (2). The structures and sizes of the first measurement tube (1) and the second measurement tube (2) are the same, and the first measurement tube (1) and the second measurement tube (2) are disposed in parallel in a housing (22). Each of the measurement tubes (1, 2) comprises a bent tube section (23), a first sloped tube (24), and a second sloped tube (25). The first sloped tube (24) and the second sloped tube (25) are symmetrical to each other in a manner of being perpendicular to and equally dividing the plane of the bent tube section (23). The axes of the first sloped tube (24) and the second sloped tube (25) are separately tangent to the axis of the bent tube section (23). By using the mass flow sensor, when the mass flow and the density of a medium are measured, resistance to the medium can be reduced.

Description

Mass flow sensor

Technical field

The invention relates to the field of test meter technology, in particular to a mass flow sensor.

Background technique

Coriolis Mass Flowmeter (CMF) is a resonant sensor that measures the flow of fluid through a pipe by the effect of the Coriolis effect generated by the fluid flowing through its vibrating pipe on the phase or amplitude of vibration at both ends of the pipe. The mass flow rate is capable of directly sensing the mass flow of the fluid while measuring the density of the fluid. The advantages of high precision, high reliability and stability make CMF more and more concerned, widely used in petroleum, chemical, natural gas, environmental protection, medical and health, food, trade settlement and other fields.

Coriolis mass flowmeters are divided into elbow type and straight tube type according to the shape of the measuring tube. Many types of elbows are disclosed in the prior art, and are U-shaped, Ω-shaped, Δ-shaped, ring-shaped, C-shaped, B-shaped, T-shaped, and water-drop type. The pipe wall is thicker, the rigidity is small, the corrosion is less affected, the resonance frequency is lower; the phase difference reflecting the mass flow is millisecond, and the electronic signal is easier to handle; but the curved pipe type tends to accumulate gas and fluid residue, causing errors, And the production process is complicated. Because the volume, structure and performance of the traditional curved tube type CMF sensor are constrained by the installation environment and measurement requirements, it is seriously restricted, and it is required to develop in the direction of small volume, low pressure loss, high precision, high sensitivity and good stability.

The straight tube type CMF has a high resonance frequency and is quite different from the general mechanical vibration frequency in the industry, so it is not easily interfered by external vibrations; it is difficult to accumulate gas and residue, and the outer shape is small; in order to make the resonance frequency not too high, The wall of the tube is designed to be thin, so the wear resistance and corrosion resistance are poor. The phase difference of the reflected quality is in the order of microseconds, and the processing of the electrical signal is difficult, which severely limits the measurement range of the CMF, and the sensitivity of the conventional vibrating straight tube CMF is low and is affected by temperature fluctuations.

The CMF currently developed has some shortcomings: the comprehensive performance of the CMF measuring tube design is poor, the pipeline installation is unstable, the mechanical realization of the tubular type is difficult; the CMF is sensitive to external vibration interference; the CMF system cannot be used to measure low density. medium.

A common Coriolis mass sensor measures mass flow by using the principle of Coriolis force that is proportional to mass flow when a fluid flows through a vibrating tube. At present, a vibrating tube type Coriolis mass flow sensor (Fig. 1) is generally used, mainly composed of a sensitive unit and a secondary instrument, wherein the sensitive unit a includes measuring tubes a1, a2, an aerator a5 and vibrators a3, a4; The secondary meter b includes a closed loop control unit b1 and a flow rate solving unit b2, which are control and signal processing systems of the sensitive unit, respectively. The sensitive unit outputs a vibration signal related to the measured flow rate; the closed-loop control unit b1 supplies an excitation signal to the exciter a5, maintains the measuring tube in a resonant state, and tracks the vibration frequency of the measuring tubes a1 and a2 in real time; The unit b2 processes the output signals of the vibrators a3, a4 and outputs measurement information c from which the mass flow and density of the fluid to be measured are determined.

However, the above sensors are bulky and cannot be self-emptied, which will generate a large resistance to the flow of the medium, and it is difficult to ensure a high working frequency and mechanical quality factor, good stability, small pressure loss, and strong resistance. Shock and anti-jamming capabilities.

Summary of the invention

The technical problem to be solved by the invention is how to reduce the resistance caused by the medium when measuring the mass flow rate and density of the medium, and ensure that the sensor has a high working frequency and mechanical quality factor, good stability, and small pressure. Damage, strong shock resistance and anti-interference ability.

To this end, the present invention proposes a mass flow sensor comprising:

a first measuring tube and a second measuring tube, the first measuring tube and the second measuring tube are identical in structure, equal in size, and disposed in parallel in the outer casing, wherein each measuring tube comprises an elbow section;

An actuator disposed at a bottom of the curved pipe section for exciting the first measuring pipe and the second measuring pipe;

a first detector disposed at the first end of the curved pipe section for detecting the first end First vibration signal;

a second detector disposed at the second end of the curved pipe section for detecting a second vibration signal of the second end;

And a processor configured to calculate a mass flow rate of the fluid in the first measuring tube and the second measuring tube according to the first vibration signal and the second vibration signal.

Preferably, each measuring tube further comprises:

a first inclined pipe section and a second inclined pipe section, the curved pipe sections are respectively connected to the first inclined pipe section and the second inclined pipe section, and the first inclined pipe section and the second inclined pipe section are vertical and wait The plane of the elbow section is symmetrical, the axis of the first inclined pipe section is tangent to the axis of the elbow section, and the axis of the second inclined pipe section is tangent to the axis of the elbow section.

Preferably, the method further comprises:

a first connector disposed inside the outer casing and connected to the first inclined pipe section of the first measuring pipe and the second measuring pipe;

a second connector disposed inside the outer casing and connected to the first inclined pipe section of the first measuring pipe and the second measuring pipe;

a first shunt disposed outside the outer casing and connected to the first connector;

a second shunt disposed outside the casing and connected to the second connector;

a first flange disposed outside the outer casing and connected to the first diverter;

The second flange is disposed outside the outer casing and connected to the second diverter.

Preferably, the method further comprises:

a first distance plate disposed on the first inclined tube section of the first measuring tube and the second measuring tube, adjacent to a side of the first connector;

a second distance determining plate disposed on the first inclined pipe section of the first measuring pipe and the second measuring pipe;

a third distance plate disposed on the second inclined pipe section of the first measuring pipe and the second measuring pipe, adjacent to a side of the second connector;

a fourth distance plate, disposed at the second measuring tube and the second measuring tube On the pipe section.

Preferably, the first distance plate is 2 cm to 4 cm from the first connector,

And/or the third distance plate is 2 cm to 4 cm from the second connector,

And/or the second distance plate is 2 cm from the first distance plate,

And/or the fourth distance plate is 2 cm from the third distance plate,

And/or the thickness of the second distance plate and the four distance plates are equal, the thickness of the first distance plate and the third distance plate are equal, and the thickness of the second distance plate is 2 to 3 times the thickness of the first distance plate,

And/or the first detector is spaced from the first connecting portion by 2 cm to 4 cm,

And/or the second detector is spaced from the second connecting portion by 2 cm to 4 cm.

Preferably, the method further comprises:

a first reinforcing sleeve disposed at a connecting portion of the first inclined pipe section of the first measuring pipe and the first connector;

a second reinforcing sleeve disposed at a connecting portion of the second inclined pipe segment of the first measuring tube and the second connector;

a third reinforcing sleeve disposed at a connecting portion of the first inclined pipe section of the second measuring pipe and the first connector;

And a fourth reinforcing sleeve disposed at a connecting portion of the second inclined pipe segment of the second measuring tube and the second connector.

Preferably, the first connector is connected to the first reinforcing sleeve and the third reinforcing sleeve by argon arc welding, and the second connector passes through argon arc welding with the second reinforcing sleeve and the first Four reinforcing sleeves are connected, the first reinforcing sleeve and the second reinforcing sleeve are respectively welded to the first measuring tube by brazing, and the third reinforcing sleeve and the fourth reinforcing sleeve are respectively welded to the second by brazing a measuring tube, the first connector and the second connector are respectively welded to the first shunt and the second shunt by argon arc welding, and the first shunt and the second shunt are argon-arc welded Soldered to the outer casing separately.

Preferably, the method further comprises:

And a connecting flange for connecting the outer casing and the mating flange, the mating flange being sealed with a mating bolt by a rubber column.

Preferably, the axis of the curved pipe section is a bad arc, and the radius of the inferior arc is 35 cm to 55 cm.

Preferably, the first detector comprises a first coil and a first magnetic steel disposed coaxially;

The second detector includes a second coil and a second magnetic steel disposed coaxially;

The exciter includes a third coil and a third magnetic steel disposed coaxially.

Wherein the first coil and the second coil and the third magnetic steel are staggered in the first measuring tube, and the first magnetic steel and the second magnetic steel and the third coil are interlaced And disposed on the second measuring tube.

Through the above technical solution, when measuring the mass flow rate and density of the medium, the resistance caused by the medium can be reduced, and the sensor has a high working frequency and mechanical quality factor, good stability, small pressure loss, and strong resistance. Shock and anti-jamming capabilities.

DRAWINGS

The features and advantages of the present invention are more clearly understood from the following description of the drawings.

1 is a schematic structural view of a mass flow sensor in the prior art;

2 is a schematic structural view of a mass flow sensor according to an embodiment of the present invention;

3 is a schematic structural view of a mass flow sensor according to still another embodiment of the present invention;

Figure 4 shows a front view of a mass flow sensor in accordance with one embodiment of the present invention;

Figure 5 illustrates a top plan view of a mass flow sensor in accordance with one embodiment of the present invention;

6 is a schematic structural view of a measuring tube in a mass flow sensor according to an embodiment of the present invention;

Figure 7 shows a schematic diagram of a detector and an exciter in a mass flow sensor in accordance with one embodiment of the present invention;

Figure 8 shows a schematic view of a spacer in a mass flow sensor in accordance with one embodiment of the present invention;

FIG. 9 is a schematic view showing the relationship between the distance plate and the measuring tube in the mass flow sensor according to an embodiment of the present invention.

Description of the reference numerals:

1-first measuring tube; 2-second measuring tube; 3-activator; 4-first detector; 5-second detector; 6-first distance plate; 7-second distance plate; - a third fixed distance plate; 9 - a fourth fixed distance plate; 10 - a first connector; 11 - a second connector; 12 - a first flow divider; 13 - a second flow divider; 14 - a first reinforcement sleeve; 15-second reinforcement sleeve; 16-third reinforcement sleeve; 17-fourth reinforcement sleeve; 18-first flange; 19-second flange; 20-connection pipe; 21-matching flange; ; 23 - elbow section; 24 - first inclined section; 25 - second inclined section.

detailed description

The above described objects, features and advantages of the present invention will become more apparent from the detailed description of the appended claims. It should be noted that the embodiments in the present application and the features in the embodiments may be combined with each other without conflict.

In the following description, numerous specific details are set forth in order to provide a full understanding of the invention, but the invention may be practiced otherwise than as described herein. Limitations of the embodiments.

As shown in FIG. 2, a mass flow sensor according to an embodiment of the present invention includes:

The first measuring tube 1 and the second measuring tube 2, the first measuring tube 1 and the second measuring tube 2 are identical in structure, equal in size, arranged in parallel in the outer casing, wherein each measuring tube comprises an elbow section 23;

The exciter 3 is disposed at the bottom of the curved pipe section 23 for exciting the first measuring pipe 1 and the second measuring pipe 2;

a first detector 4 disposed at the first end of the elbow section 23 for detecting the first vibration signal of the first end;

a second detector 5 disposed at the first end of the curved section 23 for detecting the second end Two vibration signals;

a processor (not shown in the drawing, connectable to the first detector 4 and the second detector 5) for calculating the first measuring tube 1 and the second measuring tube 2 according to the first vibration signal and the second vibration signal The mass flow of the fluid.

Firstly, the principle of the mass flow sensor is briefly explained. When the fluid flows through the tube, the effect of the Coriolis effect causes the elbow to generate a first-order torsion "sub-vibration" about the central axis of symmetry, which is directly flowed through. The "mass flow (kg/s)" is proportional. The mass flow rate of the fluid can be calculated by detecting the time difference (or phase difference) of the vibration signal by the first detector 4 and the second detector 5. The correspondence is:

Q _m = K ₁ Δt ₁₂

In the formula:

Q _m is the mass flow rate of the measured fluid, and the unit is kg/s;

K ₁ is a coefficient related to the shape, size, material, etc. of the measuring tube, and is determined by actual calibration, and the unit is kg/s ² ;

Δt ₁₂ is the time difference between the first detector 4 and the second detector 5 detecting the vibration signal, the unit is s;

In addition, when the measuring tube is filled with the fluid to be measured, its equivalent mass changes, and the resonant frequency also shifts. This frequency shift can reflect the fluid density.

The correspondence is as follows:

In the formula:

ρ _m is the density of the measured fluid, and the unit is kg/m ³ ;

K ₂ is a coefficient related to the shape, size, material and additional mass of the measuring tube, and is determined by an actual calibration experiment, and the unit is kg/m ³ ;

f ₀ is the resonant frequency of the measuring tube empty tube, the unit is Hz;

f _m is the resonant frequency of the measuring tube when it is filled with the fluid to be measured, in Hz.

According to the Coriolis effect, the double measuring plate is used in the first measuring tube 1 and the second measuring Both sides of the tube 2 are fixedly welded, and the two measuring tubes are welded in parallel and firmly to the first connector 10 and the second connector 11 to form a tuning fork to eliminate the influence of external vibration.

The two measuring tubes vibrate at a natural frequency under the electromagnetic excitation generated by the exciter 3, and the vibration phases are opposite. Due to the vibration effect of the measuring tube, each fluid micelle flowing in the tube obtains a Coriolis acceleration, and the measuring tube is subjected to a Coriolis force which is opposite to the direction of the acceleration. Since the direction of the Coriolis force received on both sides of the measuring tube is opposite, the measuring tube is twisted, and the degree of twist is proportional to the instantaneous mass flow rate in the tube. The first detector 4 and the second detector 5 located on the inflow side and the outflow side of the measuring tube detect two vibration signals during the vibration of the tuning fork, and the phase difference between the two signals and the torsion of the detecting tube Degree, that is, the instantaneous flow rate is proportional. The mass flow rate can be calculated by the processor calculating the phase difference between the signals. At the same time, since the measuring tube is filled with fluid, the resonant frequency changes, and the change in the resonant frequency reflects the real-time density information of the fluid.

In the present embodiment, the medium in the measuring tube only needs to flow in the curved pipe section 23, that is, only one bent portion is required during the flow, and the curved pipe section 23 is smoothly rounded, so that the medium is subjected to the curved pipe section 23 The resistance is small, the flow field effect is reduced, and the impact and corrosion of the medium on the inner wall of the pipe are reduced, and the service life of the pipe is improved.

As shown in FIG. 3 to FIG. 5, each measuring tube further includes: a first inclined pipe section 24 and a second inclined pipe section 25, and the curved pipe section 23 is connected to the first inclined pipe section 24 and the second inclined pipe section 25, respectively. And the first inclined pipe section 24 and the second inclined pipe section 25 are symmetric with respect to the plane of the vertical and equally divided curved pipe section 23, the axis of the first inclined pipe section 24 is tangent to the axis of the curved pipe section 23, and the axis of the second inclined pipe section 25 is The axis of the curved section 23 is tangent.

As shown in FIG. 6 , each measuring tube in the embodiment comprises three parts: a first inclined tube section 24, a second inclined tube section 25 and an elbow section 23, and the specific pipe can be made of 316L stainless steel, titanium or Hastelloy, or Select pipes of other materials as needed. The measuring tube can be integrally formed by a bending process, or can be assembled from a bent pipe section and a inclined pipe section.

Since the axis of the first inclined pipe section 24 is tangent to the axis of the curved pipe section 23, and the axis of the second inclined pipe section 25 is tangent to the axis of the curved pipe section 23, the first inclined pipe section 24 and the second inclined pipe section 25 are obtained. The connection portion with the curved pipe section 23 transitions smoothly, so that the medium flowing into the measuring tube receives little resistance and reduces the resistance when flowing through the connection portion of the first inclined pipe section 24 and the second inclined pipe section 25 and the curved pipe section 23. Flow field impact.

By arranging the inclined pipe on both sides of the curved pipe section 23, the assembly of the measuring pipe is made easier. In the assembly, the engagement with the connector is arc in relation to the direct connection of the curved pipe section 23 to the connector, in this embodiment. The fitting between the measuring tube and the connector is a straight line, and it is easier to ensure the accuracy and consistency of the equipment during assembly.

Moreover, after the inclined pipe is arranged on both sides of the curved pipe section 23, the distance through which the medium flows in the measuring pipe is longer, and under the premise of not changing the diameter and the wall thickness of the measuring pipe, in the case of the length of the same flange end face, The effect is more pronounced, that is, the sensitivity and the turndown ratio can be improved after the inclined tube section is set.

When the fluid does not flow through the sensor, the exciter 3 excites the two measuring tubes to vibrate at their natural frequencies. At this time, the sinusoidal signals detected by the first detector 4 and the second detector 5 on the inlet side and the outlet side of the measuring tube are measured. The frequency and phase are exactly the same, no phase difference. The measuring tube is an empty tube at this time, and the resonant frequency of the measuring tube is the density reference frequency, that is, the frequency when there is no fluid, and the measured real-time density and fluid mass flow value are zero.

When the fluid flows through the sensor, first, the flow of the fluid in the measuring tube induces the Coriolis effect, and the two ends of the measuring tube are subjected to the equal and oppositely distributed Coriolis force, which is represented by the phase difference between the sinusoidal signals detected by the two detectors. The phase difference is proportional to the mass flow rate of the fluid, and the real-time mass flow rate of the fluid can be obtained by detecting the phase difference. At the same time, since the measuring tube is filled with fluid and the equivalent mass changes, the resonant frequency shifts, which indicates the real-time density of the fluid.

In general, it also includes:

a first connector 10 disposed inside the casing and connected to the first inclined pipe section 24 of the first measuring pipe 1 and the second measuring pipe 2;

a second connector 11 disposed inside the casing and connected to the second inclined pipe section 25 of the first measuring pipe 1 and the second measuring pipe 2;

The first shunt 12 is disposed outside the casing and connected to the first connector 10;

a second shunt 13 disposed outside the casing and connected to the second connector 11;

The first flange 18 is disposed outside the outer casing and connected to the first flow divider 11;

The second flange 19 is disposed outside the casing and connected to the second diverter 12.

The connector and the splitter may be separately cast and then welded together, or may be cast together to form a unitary body.

Connecting the measuring tube and the shunt through the first connector 10 and the second connector 11 respectively can improve the stability of the connection between the measuring tube and the shunt, and the connector has better isolation effect, so that the external can be better isolated. The effect of the disturbance on the measuring tube.

As shown in FIG. 8 and FIG. 9, generally, it also includes:

a first distance plate 6, disposed on the first inclined tube section 24 of the first measuring tube 1 and the second measuring tube 2, adjacent to a side of the first connector 10;

a second spacer plate 7 disposed on the first inclined tube section 24 of the first measuring tube 1 and the second measuring tube 2;

a third spacer 16 disposed on the second inclined tube section 25 of the first measuring tube 1 and the second measuring tube 2, adjacent to a side of the second connector 11;

The fourth spacer plate 9 is disposed on the second inclined tube section 25 of the first measuring tube 1 and the second measuring tube 2.

The two-position distance plate can realize the double-distance mode respectively, which makes the measuring tube have higher working frequency, better stability, stronger shock resistance and anti-interference ability.

The four distance plates can simultaneously fix the two measuring tubes by vacuum brazing, so that the measuring tubes are not easily deformed, and the characteristics of the two measuring tubes are as identical as possible, while providing limited distortion and bending required for flow measurement. Changing the position of the double-distance plate in the inclined pipe section can change the resonant frequency of the sensor, so the position of the double-distance plate in the inclined pipe section can be determined according to the designed frequency, so as to reduce the vibration coupling of the internal measuring pipe and strengthen the measuring pipe Shock resistance.

Generally, the first distance plate 6 is spaced apart from the first connector 10 by 2 cm to 4 cm.

And/or the third distance plate 8 is spaced from the second connector 11 by 2 cm to 4 cm.

And/or the second distance plate 7 is 2 cm away from the first distance plate 6,

And/or the fourth distance plate 8 is spaced apart from the third distance plate 8 by 2 cm.

And / or the thickness of the second distance plate 7 and the four distance plate 9 are equal, the thickness of the first distance plate 6 and the third distance plate 8 are equal, and the thickness of the second distance plate 7 is the first distance plate 2 to 3 times the thickness of 6, as the measurement tube becomes stronger as it is closer to the curved portion 23, and the second fixed distance plate 7 and the fourth fixed distance plate 9 are opposed to the first fixed distance plate 6 and the third fixed distance plate 8 is closer to the curved portion 23, and the second fixed distance plate 7 and the fourth fixed distance plate 9 are thicker, which can improve the overall stability of the fixed distance double distance.

And/or the first detector 4 is 2 cm to 4 cm apart from the first connecting portion,

And/or the second detector 5 is spaced from the second connection by 2 cm to 4 cm.

In general, it also includes:

a first reinforcing sleeve 14 disposed at a connecting portion of the first inclined tube section 24 of the first measuring tube 1 and the first connector 10;

a second reinforcing sleeve 15 disposed at a connecting portion of the second inclined pipe section 25 of the first measuring tube 1 and the second connector 11;

a third reinforcing sleeve 16, disposed at a connecting portion of the first inclined tube section 24 of the second measuring tube 1 and the first connector 10;

The fourth reinforcing sleeve 17 is disposed at a connecting portion of the second inclined pipe section 25 of the second measuring pipe 1 and the second connector 11.

Generally, the first connector 10 is connected to the first reinforcing sleeve 14 and the third reinforcing sleeve 16 by argon arc welding, and the second connector 11 is connected to the second reinforcing sleeve 15 and the fourth reinforcing sleeve 17 by argon arc welding. A reinforcing sleeve 14 and a second reinforcing sleeve 15 are respectively welded to the first measuring tube 1 by brazing, and the third reinforcing sleeve 16 and the fourth reinforcing sleeve 17 are respectively welded to the second measuring tube 2 by brazing, the first connector 10 And the second connector 11 is separately welded to the first splitter 12 and the second splitter 13 by argon arc welding, and the first splitter 12 and the second splitter 13 are respectively welded to the outer casing by argon arc welding.

In general, it also includes:

The connecting pipe 20 and the mating flange 21 are used for connecting the outer casing and the mating flange 21, and the mating flange 21 is sealed with the mating bolt by a rubber column.

By sealing the mating method with the rubber column and the mating bolt, the sealing effect can be improved and the ease of installation can be improved.

Generally, the axis of the curved section 23 is a poor arc, and the radius of the inferior arc is 35 cm to 55 cm. Since the axis of the curved pipe section 23 is a poor arc, the space occupied by the superior arc (and the semi-arc) is smaller, and the first inclined pipe section 24 and the second inclined pipe section 25 connected thereto can conveniently guide the medium into the space. Moreover, the arc corresponding to the inferior arc is smaller, so the degree of bending is also smaller, so that the resistance to which the medium flows is reduced.

As shown in FIG. 7, generally, the first detector 4 includes a first coil and a first magnetic steel disposed coaxially;

The second detector 5 includes a second coil and a second magnetic steel disposed coaxially;

The exciter 3 includes a third coil and a third magnetic steel disposed coaxially.

The first coil and the second coil and the third magnetic steel are alternately disposed on the first measuring tube 1 , and the first magnetic steel and the second magnetic steel and the third coil are alternately disposed on the second measuring tube 2 .

The exciter 3 and the first detector 4 and the second detector 5 are both used by a coil and a magnetic steel, and the exciter 3 can be disposed at a midpoint of a line connecting the bottom apexes of the two measuring tubes, and the first detector 4 is disposed at At a distance of 2 cm to 4 cm from the first connecting portion, and/or the second detector 5 is disposed at a distance of 2 cm to 4 cm from the second connecting portion, together with the exciter 3 to form a good closed loop system, so that the sensor The two measuring tubes have a stable working state and reduce the influence of external disturbances, thereby improving the self-adjusting ability.

Disposing the first coil, the second coil and the third magnetic steel in the first measuring tube 1 , and disposing the first magnetic steel, the second magnetic steel and the third coil in the second measuring tube 2, so that the first detecting can be performed The weight of the second detector 5, the second detector 5 and the exciter 3 are evenly distributed on the two measuring tubes, so that the additional masses of the two measuring tubes are similar, so that the overall quality of the two measuring tubes is similar, so that the medium flows through When two measuring tubes are used, the vibration states of the two measuring tubes are the same. The Coriolis forces distributed throughout the two measuring tubes are consistent and the deflection is consistent, resulting in accurate measurement and calculation results.

Further, the wires of the first coil, the second coil and the excitation coil may extend from the coil itself to both sides to the inside of the mating flange, respectively, to ensure uniform distribution of the quality of the wires.

The technical solution of the present invention is described in detail above with reference to the accompanying drawings. In consideration of the related art, the use of a U-shaped tube having a large degree of curvature causes a large resistance to the flow of the medium, and it is difficult to ensure a high working frequency and mechanical quality. Factor, better stability, lower pressure loss, stronger shock resistance and anti-interference ability. Through the technical solution of the present application, when measuring the mass flow rate and density of the medium, the resistance caused by the medium can be reduced, and the measuring tube has a high working frequency and mechanical quality factor, good stability, and small pressure loss. Strong anti-shock and anti-interference ability.

In the present invention, the terms "first", "second", "third", "fourth" are used for descriptive purposes only, and are not to be construed as indicating or implying relative importance. The term "plurality" refers to two or more, unless specifically defined otherwise.

The above description is only the preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes can be made to the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and scope of the present invention are intended to be included within the scope of the present invention.

Industrial applicability

According to the mass flow sensor provided by the invention, the medium in the measuring tube only needs to flow in the curved pipe section, that is, only one bending part is required in the flow process, and the curved pipe section transitions smoothly, so that the medium is received in the curved pipe section. The resistance is small, the flow field effect is reduced, and the impact and corrosion of the medium on the inner wall of the pipe are reduced, and the service life of the pipe is improved.

Claims

A mass flow sensor, comprising:

a first measuring tube and a second measuring tube, the first measuring tube and the second measuring tube are identical in structure, equal in size, and disposed in parallel in the outer casing, wherein each measuring tube comprises an elbow section;

An actuator disposed at a bottom of the curved pipe section for exciting the first measuring pipe and the second measuring pipe;

a first detector disposed at the first end of the elbow section for detecting a first vibration signal of the first end;

a second detector disposed at the second end of the curved pipe section for detecting a second vibration signal of the second end;

And a processor configured to calculate a mass flow rate of the fluid in the first measuring tube and the second measuring tube according to the first vibration signal and the second vibration signal.
The mass flow sensor of claim 1 wherein each measuring tube further comprises:

a first inclined pipe section and a second inclined pipe section, the curved pipe sections are respectively connected to the first inclined pipe section and the second inclined pipe section, and the first inclined pipe section and the second inclined pipe section are vertical and wait The plane of the elbow section is symmetrical, the axis of the first inclined pipe section is tangent to the axis of the elbow section, and the axis of the second inclined pipe section is tangent to the axis of the elbow section.
The mass flow sensor of claim 2, further comprising:

a first connector disposed inside the outer casing and connected to the first inclined pipe section of the first measuring pipe and the second measuring pipe;

a second connector disposed inside the outer casing and connected to the first inclined pipe section of the first measuring pipe and the second measuring pipe;

a first shunt disposed outside the outer casing and connected to the first connector;

a second shunt disposed outside the casing and connected to the second connector;

a first flange disposed outside the outer casing and connected to the first diverter;

The second flange is disposed outside the outer casing and connected to the second diverter.
The mass flow sensor of claim 3, further comprising:

a first distance plate disposed on the first inclined tube section of the first measuring tube and the second measuring tube, adjacent to a side of the first connector;

a second distance determining plate disposed on the first inclined pipe section of the first measuring pipe and the second measuring pipe;

a third distance plate disposed on the second inclined pipe section of the first measuring pipe and the second measuring pipe, adjacent to a side of the second connector;

a fourth distance plate is disposed on the second inclined pipe section of the first measuring pipe and the second measuring pipe.
The mass flow sensor according to claim 4, wherein the first distance plate is 2 cm to 4 cm from the first connector,

And/or the third distance plate is 2 cm to 4 cm from the second connector,

And/or the second distance plate is 2 cm from the first distance plate,

And/or the fourth distance plate is 2 cm from the third distance plate,

And/or the thickness of the second distance plate and the four distance plates are equal, the thickness of the first distance plate and the third distance plate are equal, and the thickness of the second distance plate is 2 to 3 times the thickness of the first distance plate,

And/or the first detector is spaced from the first connecting portion by 2 cm to 4 cm,

And/or the second detector is spaced from the second connecting portion by 2 cm to 4 cm.
The mass flow sensor of claim 3, further comprising:

a first reinforcing sleeve disposed at a connecting portion of the first inclined pipe section of the first measuring pipe and the first connector;

a second reinforcing sleeve disposed at a connecting portion of the second inclined pipe segment of the first measuring tube and the second connector;

a third reinforcing sleeve disposed at a connecting portion of the first inclined pipe section of the second measuring pipe and the first connector;

And a fourth reinforcing sleeve disposed at a connecting portion of the second inclined pipe segment of the second measuring tube and the second connector.
The mass flow sensor according to claim 6, wherein the first connector is connected to the first reinforcing sleeve and the third reinforcing sleeve by argon arc welding, and the second connector passes through a argon arc Welding is connected to the second reinforcing sleeve and the fourth reinforcing sleeve, and the first reinforcing sleeve and the second reinforcing sleeve are respectively welded to the first measuring tube by brazing, the third reinforcing sleeve and the fourth reinforcing sleeve The reinforcing sleeve is separately welded to the second measuring tube by brazing, and the first connector and the second connector are respectively welded to the first shunt and the second shunt by argon arc welding, the first A splitter and a second splitter are separately welded to the outer casing by argon arc welding.
The mass flow sensor according to any one of claims 1 to 7, further comprising:

And a connecting flange for connecting the outer casing and the mating flange, the mating flange being sealed with a mating bolt by a rubber column.
The mass flow sensor according to any one of claims 1 to 7, wherein the axis of the curved pipe section is a bad arc, and the radius of the inferior arc is 35 cm to 55 cm.
The mass flow sensor according to any one of claims 1 to 7, wherein

The first detector includes a first coil and a first magnetic steel disposed coaxially;

The second detector includes a second coil and a second magnetic steel disposed coaxially;

The exciter includes a third coil and a third magnetic steel disposed coaxially.

Wherein the first coil and the second coil and the third magnetic steel are staggered in the first measuring tube, and the first magnetic steel and the second magnetic steel and the third coil are interlaced And disposed on the second measuring tube.