阅读说明：本技术 一种超声波流量计 (Ultrasonic flowmeter ) 是由 沈西琳 张宇明 于 2019-09-06 设计创作，主要内容包括：本发明提供了一种超声波流量计,包括超声波传感器、一次性流体管路以及与超声波传感器电连接的超声波流量测量电路和软件系统,其中,一次性流体管路包括管路主体和两个流体接口,管路主体包括依次连接的管段一、管段二和管段三,管段一和管段三均与管段二垂直,管段一和管段三与管段二连接处的转角部位具有反射面管壁,管段一和管段三的自由端封闭,两个自由端端部的表面为两个耦合界面,超声波传感器在耦合界面上与一次性流体管路耦合连接,超声波传感内部设置的超声波换能器发射的超声波信号能够穿过耦合界面传播至一次性流体管路内。本发明的使用可以保证待测液体的清洁,能有效避免测量过程产生交叉污染,并提高测量精度和可重复性。(The invention provides an ultrasonic flowmeter which comprises an ultrasonic sensor, a disposable fluid pipeline, an ultrasonic flow measuring circuit and a software system, wherein the ultrasonic flow measuring circuit and the software system are electrically connected with the ultrasonic sensor, the disposable fluid pipeline comprises a pipeline main body and two fluid interfaces, the pipeline main body comprises a first pipeline section, a second pipeline section and a third pipeline section which are sequentially connected, the first pipeline section and the third pipeline section are perpendicular to the second pipeline section, a reflection surface pipe wall is arranged at a corner part of the joint of the first pipeline section and the third pipeline section and the second pipeline section, free ends of the first pipeline section and the third pipeline section are closed, the surfaces of the end parts of the two free ends are two coupling interfaces, the ultrasonic sensor is coupled and connected with the disposable fluid pipeline on the coupling interfaces, and ultrasonic signals transmitted by an ultrasonic transducer arranged in the ultrasonic sensor can be transmitted into the disposable fluid pipeline through. The use of the invention can ensure the cleanness of the liquid to be measured, effectively avoid the cross contamination in the measuring process and improve the measuring precision and repeatability.)

1. An ultrasonic flow meter, comprising:

the ultrasonic sensor is internally provided with an ultrasonic transducer and is used for transmitting and receiving ultrasonic signals;

the disposable fluid pipeline comprises a U-shaped pipeline main body and two fluid interfaces, wherein the pipeline main body comprises a first pipe section, a second pipe section and a third pipe section which are sequentially connected, the first pipe section and the third pipe section are both vertical to the second pipe section, the corner part of the joint of the first pipe section and the second pipe section and the corner part of the joint of the third pipe section and the second pipe section are both provided with a reflecting surface pipe wall for reflecting the ultrasonic signals, the free ends of the first pipe section and the third pipe section are closed, one fluid interface is arranged on the side wall close to the free end of the first pipe section and serves as a fluid inlet, and the other fluid interface is arranged on the side wall close to the free end of the third pipe section and serves as a fluid outlet;

the surfaces of the free end parts of the first pipe section and the third pipe section are two coupling interfaces, the ultrasonic sensor is coupled and connected with the disposable fluid pipeline on the coupling interfaces, and an ultrasonic signal emitted by the ultrasonic transducer can be transmitted into the disposable fluid pipeline through the coupling interfaces;

and the ultrasonic flow measuring circuit and the software system are electrically connected with the ultrasonic sensor and used for measuring the flow velocity of the fluid according to the ultrasonic signal received by the ultrasonic transducer.

2. An ultrasonic flow meter according to claim 1, wherein the number of ultrasonic transducers is 1, disposed within the ultrasonic sensor at a position opposite a first coupling interface, the first coupling interface being a surface of a free end of the first pipe section; alternatively, the first and second electrodes may be,

the number of the ultrasonic transducers is 2, and the ultrasonic transducers are adjacently arranged at positions opposite to the first coupling interface in the ultrasonic sensor; alternatively, the first and second electrodes may be,

the number of the ultrasonic transducers is 2, the ultrasonic transducers are respectively arranged in the ultrasonic sensor at positions opposite to the first coupling interface and the second coupling interface, and the second coupling interface is the surface of the end part of the free end of the third pipe section.

3. An ultrasonic flow meter according to claim 1, wherein the disposable fluid conduit and the ultrasonic sensor are further provided with an acoustic coupling material between the connection of the coupling interfaces.

4. An ultrasonic flow meter according to claim 3, wherein alignment structure is further provided on said ultrasonic transducer and/or said disposable fluid line to assist in aligning said ultrasonic transducer and said disposable fluid line if said acoustic coupling material is provided.

5. An ultrasonic flow meter according to claim 2, wherein ultrasonic waves emitted by a first ultrasonic transducer are reflected by the two reflecting surface tube walls one after the other and received by a second ultrasonic transducer, the first ultrasonic transducer being the ultrasonic transducer disposed opposite the first coupling interface and the second ultrasonic transducer being the ultrasonic transducer disposed opposite the second coupling interface.

6. An ultrasonic flow meter according to claim 1 wherein the angle between the walls of the two reflecting surfaces and the second pipe section is within the range 45 ± 5 °.

7. An ultrasonic flow meter according to claim 1, wherein the length of the first tube section and the third tube section is in the range 1 to 15 cm and the length of the second tube section is in the range 2 to 30 cm.

Technical Field

The invention relates to the technical field of ultrasonic flow detection, in particular to an ultrasonic flow meter.

Background

Ultrasonic flow meters typically utilize the piezoelectric effect of a piezoelectric material, with appropriate transmit circuitry applying electrical energy to the piezoelectric element of a transmitting transducer to cause it to generate ultrasonic vibrations. Ultrasonic waves are transmitted into a fluid at an angle, received by a receiving transducer, and converted into electrical energy by a piezoelectric element for detection. According to the principle of signal detection, the current ultrasonic flowmeter mainly adopts two types of time difference method and Doppler method. The Doppler method is used for determining the flow of fluid by measuring the ultrasonic Doppler frequency shift scattered by scatterers in inhomogeneous fluid by using the acoustic Doppler principle, and is suitable for measuring the flow velocity of the fluid containing suspended particles, bubbles and the like. The time difference method reflects the flow velocity of fluid by measuring the difference between the propagation time of ultrasonic pulse during forward flow and backward flow propagation, and the propagation direction of ultrasonic wave can have a certain angle with a pipeline and can also be completely coaxial.

With the development of the bio-pharmaceutical and medical device industries, more and more production fields have high requirements on the hygiene degree, such as the purification and separation of chemicals, the liquid inlet and drainage process of a biological reaction container, the acid-base balance control in the chromatographic separation process, the monitoring of the flow rate of blood liquid medicine in a hemodialysis instrument, and the like, and in these fields, the use of a traditional ultrasonic flowmeter may cause the risk of cross contamination and the operation is complex.

In addition, in the application of many biological, pharmaceutical and medical instruments, the types of liquids to be measured are many, and the variation ranges of the density and the sound velocity are large, so that the measurement error is increased due to the change of the refraction angle of the ultrasonic wave caused by the variation, and the measurement accuracy of the ultrasonic flowmeter is reduced.

Disclosure of Invention

The invention aims to provide an ultrasonic flowmeter, which aims to solve the problems that in the prior art, the ultrasonic flowmeter has large measurement error, is difficult to operate and has low repeatability, and cross contamination is easily caused in the measurement process.

In order to solve the above technical problem, the present invention provides an ultrasonic flow meter, including:

the ultrasonic sensor is internally provided with an ultrasonic transducer and is used for transmitting and receiving ultrasonic signals;

the disposable fluid pipeline comprises a U-shaped pipeline main body and two fluid interfaces, wherein the pipeline main body comprises a first pipe section, a second pipe section and a third pipe section which are sequentially connected, the first pipe section and the third pipe section are both vertical to the second pipe section, the corner part of the joint of the first pipe section and the second pipe section and the corner part of the joint of the third pipe section and the second pipe section are both provided with a reflecting surface pipe wall for reflecting the ultrasonic signals, the free ends of the first pipe section and the third pipe section are closed, one fluid interface is arranged on the side wall close to the free end of the first pipe section and serves as a fluid inlet, and the other fluid interface is arranged on the side wall close to the free end of the third pipe section and serves as a fluid outlet;

the surfaces of the free end parts of the first pipe section and the third pipe section are two coupling interfaces, the ultrasonic sensor is coupled and connected with the disposable fluid pipeline on the coupling interfaces, and an ultrasonic signal emitted by the ultrasonic transducer can be transmitted into the disposable fluid pipeline through the coupling interfaces;

and the ultrasonic flow measuring circuit and the software system are electrically connected with the ultrasonic sensor and used for measuring the flow velocity of the fluid according to the ultrasonic signal received by the ultrasonic transducer.

Optionally, the number of the ultrasonic transducers is 1, and the ultrasonic transducers are arranged in the ultrasonic sensor at positions opposite to a first coupling interface, where the first coupling interface is a surface of a free end of the first pipe section; alternatively, the first and second electrodes may be,

the number of the ultrasonic transducers is 2, and the ultrasonic transducers are adjacently arranged at positions opposite to the first coupling interface in the ultrasonic sensor; alternatively, the first and second electrodes may be,

the number of the ultrasonic transducers is 2, the ultrasonic transducers are respectively arranged in the ultrasonic sensor at positions opposite to the first coupling interface and the second coupling interface, and the second coupling interface is the surface of the end part of the free end of the third pipe section.

Optionally, an acoustic coupling material is further disposed between the disposable fluid pipeline and the ultrasonic sensor at the connection of the coupling interface.

Optionally, an alignment structure is further disposed on the ultrasonic sensor and/or the disposable fluid line for assisting alignment of the ultrasonic sensor and the disposable fluid line in the case where the acoustic coupling material is disposed.

Optionally, the ultrasonic waves emitted by the first ultrasonic transducer are reflected by the two reflecting surface tube walls successively and received by the second ultrasonic transducer, the first ultrasonic transducer is an ultrasonic transducer arranged opposite to the first coupling interface, and the second ultrasonic transducer is an ultrasonic transducer arranged opposite to the second coupling interface.

Optionally, the included angle between the two reflecting surface pipe walls and the second pipe section is within 45 ± 5 degrees.

Optionally, the length ranges of the first pipe section and the third pipe section are 1-15 cm, and the length range of the second pipe section is 2-30 cm.

The ultrasonic flowmeter provided by the invention has the following beneficial effects:

the ultrasonic flowmeter comprises an ultrasonic sensor, a disposable fluid pipeline coupled and connected with the ultrasonic sensor, an ultrasonic flow measurement circuit and a software system, wherein the ultrasonic flow measurement circuit and the software system are electrically connected with the ultrasonic sensor, the disposable fluid pipeline comprises a pipeline main body and two fluid interfaces, the pipeline main body comprises a first pipeline section, a second pipeline section and a third pipeline section which are sequentially connected, the first pipeline section and the third pipeline section are both vertical to the second pipeline section, a reflection surface pipe wall is arranged at a corner part of the joint of the first pipeline section and the third pipeline section with the second pipeline section, the free ends of the first pipeline section and the third pipeline section are closed, one fluid interface is arranged on the side wall close to the free end of the first pipeline section and is used as a fluid inlet, the other fluid interface is arranged on the side wall close to the free end of the third pipeline section and is used as a fluid outlet, the surfaces of the end parts of, ultrasonic signals emitted by an ultrasonic transducer arranged inside the ultrasonic sensor can be transmitted to the disposable fluid pipeline through the coupling interface. Because the liquid to be measured does not directly contact with the ultrasonic sensor in the measuring process, the cleanness of the liquid to be measured is ensured, the invention can effectively avoid the cross contamination in the measuring process, and the acoustic passage is lengthened by the U-shaped pipeline main body, thereby improving the measuring precision and the repeatability.

Drawings

Fig. 1 is a schematic structural diagram of an ultrasonic flow meter according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of the disposable fluid line of an ultrasonic flow meter according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of another disposable fluid line of an ultrasonic flow meter according to an embodiment of the present invention;

FIG. 4 is a schematic structural diagram of the ultrasonic sensor for ultrasonic flow according to an embodiment of the present invention;

fig. 5 is a schematic structural diagram of a usage state of an ultrasonic flow meter according to an embodiment of the present invention;

fig. 6 is a schematic structural diagram of a use state of an ultrasonic flow meter according to a second embodiment of the present invention;

fig. 7 is a schematic structural diagram of a use state of an ultrasonic flow meter according to a third embodiment of the present invention;

fig. 8 is a schematic structural diagram of the pipe body of an ultrasonic flow meter according to a fourth embodiment of the present invention;

fig. 9 is a schematic structural diagram of the pipeline body of the ultrasonic flow meter according to the fifth embodiment of the present invention;

wherein the reference numerals of figures 1 to 9 are as follows:

01-disposable fluid line; 011-coupled interface; 0121-fluid inlet; 0122-fluid outlet; 013-pipe section one; 014-segment two; 015-pipe section three; 016-reflecting surface tube wall; 02-ultrasonic sensors; 021-ultrasonic transducer; 03-acoustic coupling material; 041-transmitting sound waves; 042-reflected sound wave; 05-reflecting an object.

Detailed Description

An ultrasonic flowmeter according to the present invention will be described in further detail with reference to the accompanying drawings and specific embodiments. Advantages and features of the present invention will become apparent from the following description and from the claims. It is to be noted that the drawings are in a very simplified form and are not to precise scale, which is merely for the purpose of facilitating and distinctly claiming the embodiments of the present invention.

< example one >

Referring to fig. 1 and fig. 2, fig. 1 is a schematic structural diagram of an ultrasonic flowmeter provided in this embodiment; fig. 2 is a schematic structural diagram of the disposable fluid pipeline of the ultrasonic flow meter provided in this embodiment.

The ultrasonic flow meter includes: ultrasonic sensor 02, disposable fluid line 01, ultrasonic flow measurement circuitry and software systems (not shown). The disposable fluid pipeline 01 is coupled with the ultrasonic sensor 02, and the ultrasonic flow measurement circuit and the software system are electrically connected with the ultrasonic sensor 02.

Specifically, an ultrasonic transducer 021 is disposed inside the ultrasonic sensor 02 and is used for transmitting and receiving an ultrasonic signal;

the disposable fluid pipeline 01 comprises a U-shaped pipeline main body and two fluid connectors, wherein the pipeline main body comprises a first pipe section 013, a second pipe section 014 and a third pipe section 015 which are sequentially connected, the first pipe section 013 and the third pipe section 015 are perpendicular to the second pipe section 014, and a reflection surface pipe wall 016 used for reflecting ultrasonic signals is arranged at a corner part of the connection part of the first pipe section 013, the third pipe section 015 and the second pipe section 014. The free ends of the first pipe section 013 and the third pipe section 015 are closed, one fluid connector is arranged on the side wall close to the free end of the first pipe section 013 to serve as a fluid inlet 0121, and the other fluid connector is arranged on the side wall close to the free end of the third pipe section 015 to serve as a fluid outlet 0122;

the end surface of the free end of the first pipe segment 013 and the end surface of the free end of the third pipe segment 015 are two coupling interfaces 011, the ultrasonic sensor is coupled with the disposable fluid pipeline 01 at the coupling interfaces 011, the ultrasonic signal transmitted by the ultrasonic transducer 021 can propagate into the disposable fluid pipeline 01 through the coupling interfaces 011, and the ultrasonic signal can also be received by the ultrasonic transducer 021 through the coupling interfaces 011 after being reflected in 01, and then the ultrasonic flow measurement circuit and the software system measure the flow rate of the fluid according to the ultrasonic signal received by the ultrasonic transducer 021.

It should be noted that the reflective surface tube 016 has two surfaces, i.e., the inner tube wall contacting the inside and the outer tube wall exposed outside, and one or both of the two surfaces are smooth. If the acoustic impedance of the material of the reflective surface wall 016 is close to that of the liquid, the sound wave reflected by the inner wall of the tube is weaker, and the sound wave reflected by the outer wall of the tube is stronger. If the acoustic impedance of the material of the reflective surface basket 016 is significantly larger or smaller than the acoustic impedance of the liquid, the sound waves reflected by the inner wall of the tube will be enhanced, the sound waves reflected by the outer wall of the tube will be correspondingly attenuated, and the sound waves reflected by the two surfaces will be superimposed and transmitted.

The ultrasonic flow measurement circuit and the software system are integrated inside the ultrasonic sensor 02, or are externally arranged in a separate package and connected to the ultrasonic sensor 02 by a cable. The propagation path of the ultrasonic wave in the fluid is called as an acoustic path, and in the measurement process, the acoustic path needs to be long enough, so that the ultrasonic flow measurement circuit and a software system can conveniently analyze Doppler effect caused by liquid flow or ultrasonic propagation time difference of forward flow and backward flow, and further calculate the flow speed and flow of the liquid. In the embodiment, the main body of the disposable fluid pipeline 01 in the ultrasonic flowmeter is in a U shape, so that an acoustic passage is greatly lengthened, the accuracy and the stability of liquid flow measurement are improved, and low-flow-rate liquid in a micro pipeline can be measured more easily.

In practical applications, the ultrasonic sensor 02 and the disposable fluid line 01 can be coupled together by applying pressure mechanically or physically to connect them together to achieve acoustic coupling. The connection mode of the two is not limited, and a specially designed clamp, or a spring device, or a buckle, or through magnetic absorption, or through threaded bolt fastening, etc. can be adopted.

Further, as shown in fig. 1, an acoustic coupling material 03 is further disposed between the disposable fluid pipeline 01 and the ultrasonic sensor 02 at the connection of the coupling interface 011, because the surfaces of the ultrasonic sensor 02 and the disposable fluid pipeline 02 are relatively hard, so that air needs to be exhausted between the connection of the coupling interface 011 between the disposable fluid pipeline 01 and the ultrasonic sensor 02 by the acoustic coupling material 03, and the tightness of the connection between the disposable fluid pipeline 01 and the ultrasonic sensor 02 is increased, so as to ensure that an ultrasonic signal passes through the connection interface of the two as much as possible. The acoustic coupling material may be rubber, flexible plastic, silicone, or the like, or may be grease, a jelly-like material, or other liquid material.

Referring to fig. 3 and 4, fig. 3 is a schematic structural diagram of another disposable fluid pipeline of the ultrasonic flow meter provided in the present embodiment; fig. 4 is a schematic structural diagram of the ultrasonic sensor for ultrasonic flow rate according to this embodiment.

The disposable fluid pipeline 01 is additionally provided with an acoustic coupling material 03 in a secondary injection molding or bonding mode, and the ultrasonic sensor 02 is provided with an alignment structure for assisting the alignment of the ultrasonic sensor and the disposable fluid pipeline. For example, in the present embodiment, as shown in fig. 3 and 4, the acoustic coupling material 03 is a circular pad made of rubber or soft plastic, and the acoustic coupling material 03 is pre-installed on the disposable fluid pipeline 01, and a circular groove is provided as an alignment structure on the ultrasonic sensor 02. It should be noted that the depth of the circular groove should be smaller than the thickness of the circular pad, so that the ultrasonic sensor 02 and the disposable fluid line 01 can be precisely aligned and pressed against the circular pad at the coupling interface 011 to ensure the accuracy and repeatability of the measurement of the ultrasonic flow meter. In another embodiment, a circular gasket may be pre-installed on the ultrasonic sensor 02, and a circular groove is provided as an alignment structure on the disposable fluid line 01. In still another embodiment, a circular groove is provided on both the disposable fluid pipeline 01 and the ultrasonic transducer 02, the sum of the depths of the two circular grooves is less than the height of a circular gasket, and the circular gasket can be pre-installed in the circular groove on the disposable fluid pipeline 01 or the circular groove on the ultrasonic transducer 02.

Specifically, the inner cross section of the pipeline main body can be circular, or elliptical, or rectangular, or other shapes. For example, the inner cross section of the pipeline main body is circular, and the diameter of the circle can be within the range of 1-50 mm. Therefore, the suitable wavelength range of the ultrasonic wave can be expanded, so that the emission frequency range of the ultrasonic wave is expanded, and the measurement accuracy of the ultrasonic flowmeter is ensured.

Further, the length of the first pipe section 013 and the third pipe section 015 ranges from 1 cm to 15 cm, and preferably, the length of the first pipe section 013 and the length of the third pipe section 015 ranges from 2 cm to 5 cm; the length range of the second pipe section 014 is 2-30 cm, and preferably, the length of the second pipe section 014 is 3-10 cm.

Preferably, the material of the disposable fluid line 01 is a plastic polymer material, such as PEEK material, PP material, ABS material, Acrylic material, PC material, Nylon material, etc. However, the material may be other non-metal or metal material, or a combination of multiple materials, for example, most of the material of each pipe segment is plastic, but the material at the reflective surface pipe wall 016 is a material with high reflectivity such as metal, ceramic or glass. It is to be noted that these materials themselves need to comply with hygienic safety and chemical compatibility regulations for the relevant applications, so as to guarantee the cleanliness of the measured liquids.

In addition, the form of the fluid joints of the two fluid interfaces is not limited, and the fluid joints can be straight round pipes, luer joints, pagoda joints, threaded joints or other fluid joints.

The production method of the disposable fluid pipeline 01 can adopt an injection molding method or a machining method, specifically, the disposable fluid pipeline can be formed by one-time injection molding, and can also be assembled by a plurality of components in a heat welding mode, an ultrasonic welding mode, a glue bonding mode, a mechanical connection mode and the like.

In practical application, after the ultrasonic flowmeter completes one measurement, the disposable fluid pipeline 01 is removed, and a new disposable fluid pipeline 01 is connected according to the next measurement requirement. It should be noted that the inner and outer shapes of the plurality of disposable fluid pipelines 01 need to be kept consistent, the dimensional error of the inner cross section of the pipeline does not exceed 1%, and is controlled to be within 0.5% as much as possible, so that the measurement accuracy of the ultrasonic flowmeter can be ensured while the ultrasonic flowmeter is not required to be calibrated again when a new disposable fluid pipeline 01 is replaced each time. In addition, the disposable fluid pipeline 01 needs to be disinfected and sterilized before use, so that cross contamination is avoided. The sterilization method can adopt steam heating, gamma ray irradiation or other methods.

The ultrasonic flowmeter provided by the embodiment is particularly suitable for the flow measurement process in the fields of biological pharmacy, medical instruments, semiconductors, chemical industry and the like with strict requirements on fluid pipeline sanitation.

In practical application, when the liquid to be measured flows into the disposable fluid pipeline 01 from the fluid inlet 0121 and then flows out of the disposable fluid pipeline 01 from the fluid outlet 0122, the liquid to be measured does not directly contact the ultrasonic sensor 02, so that the cleanness of the liquid to be measured is ensured, and the risk of cross contamination is avoided.

Referring to fig. 5, fig. 5 is a schematic structural diagram of a usage state of the ultrasonic flowmeter according to this embodiment.

The number of the ultrasonic transducers 021 is one, one ultrasonic transducer 021 is arranged in the ultrasonic sensor at a position opposite to a first coupling interface (the first coupling interface is the surface of the free end part of the first pipe section), the ultrasonic transducer 021 can transmit a continuous or pulsed ultrasonic signal through the first coupling interface to the disposable fluid line 01, that is, the transmitted sound wave 041, when the disposable fluid tube 01 is filled with the liquid to be measured and the liquid to be measured contains the reflecting object 05 such as solid particles, small bubbles or blood cells which can reflect the sound wave, the transmitted sound wave 041 is reflected back by the reflecting object 05 to form a reflected sound wave 042 and is received by the ultrasonic transducer 021, the ultrasonic sensor 02 propagates the received ultrasonic signal to the ultrasonic flow measurement circuitry and software system, the ultrasonic flow measurement circuitry and software system then measure the fluid velocity using the doppler principle. Since the internal cross-sectional area of the main body of the disposable fluid line 01 is fixed and known, the instantaneous flow of the liquid to be measured can be deduced from the measured fluid velocity.

< example two >

The difference from the first embodiment is that: in the ultrasonic flow meter of the present embodiment, the number of the ultrasonic transducers 021 is two.

Referring to fig. 6, fig. 6 is a schematic structural diagram of a usage state of the ultrasonic flow meter according to this embodiment.

The two ultrasonic transducers 021 are adjacently arranged in the ultrasonic sensor 02 at positions opposite to the first coupling interface. One of the ultrasonic transducers 021 can transmit a continuous or pulse ultrasonic signal to the disposable fluid pipeline 01 through the first coupling interface, that is, a sound wave 041 is generated, when the disposable fluid pipeline 01 is filled with a liquid to be measured and the liquid to be measured contains a reflecting object 05 such as solid particles, small bubbles or blood cells, which can reflect the sound wave, the transmitted sound wave 041 is reflected by the reflecting object 05 to form a reflected sound wave 042, the other ultrasonic transducer 021 can receive the reflected sound wave 042, and then the ultrasonic flow measurement circuit and the software system measure the fluid velocity using the doppler principle. Because the internal cross-sectional area of the main body of the disposable fluid line 01 is fixed and known, the instantaneous flow of the liquid to be measured can be deduced from the measured fluid velocity.

< example three >

The difference from the second embodiment is that: in the ultrasonic flow meter of the present embodiment, the setting positions of the two ultrasonic transducers 021 are changed.

Referring to fig. 7, fig. 7 is a schematic structural diagram of a usage state of the ultrasonic flow meter according to this embodiment.

The two ultrasonic transducers 021 are respectively arranged in the ultrasonic sensor at positions opposite to the first coupling interface and the second coupling interface, the ultrasonic transducer 021 arranged opposite to the first coupling interface is used as a first ultrasonic transducer, and the ultrasonic transducer 021 arranged opposite to the second coupling interface is used as a second ultrasonic transducer. Under the condition that the disposable fluid pipeline 01 is filled with liquid to be detected and the liquid to be detected does not contain or contains a small amount of reflecting objects 05 such as solid particles, small bubbles or blood cells capable of reflecting sound waves, continuous or pulse ultrasonic signals emitted by the first ultrasonic transducer enter the disposable fluid pipeline 01 through the first coupling interface and are transmitted in the liquid to be detected along each pipeline section, and in the transmission process, the ultrasonic waves emitted by the first ultrasonic transducer are reflected by the two reflecting surface pipeline walls 016 in sequence and are finally received by the second ultrasonic transducer.

Under the condition that the above conditions are met, the included angles between the two reflective surface tube walls 016 and the second tube segment 014 may have a certain angle range deviation, and the included angles between the two reflective surface tube walls 016 and the second tube segment 014 may not be equal to each other, for example, the angle range between the two reflective surface tube walls 016 and the second tube segment 014 may be extended to 35 to 55 degrees or larger. Preferably, the included angle between the two reflecting surface tube walls 016 and the second tube segment 014 is equal to 45 °, and if there is a processing error, the included angle should be kept within 45 ± 5 °, so that the advancing direction of the reflected ultrasonic waves is parallel to the corresponding propagation tube segment as much as possible. And one or both of the inner and outer surfaces of the two radial walls 016 are smooth.

And taking the reflecting surface pipe wall at the corner part of the joint of the first pipe section and the second pipe section as a first reflecting surface pipe wall, and taking the reflecting surface pipe wall at the corner part of the joint of the third pipe section and the second pipe section as a second reflecting surface pipe wall. The ultrasonic signal propagates to the first reflecting surface pipe wall and is reflected at the smooth surface of the first reflecting surface pipe wall, the propagation direction of the ultrasonic signal is changed by 90 degrees, then the ultrasonic signal meets the second reflecting surface pipe wall and is reflected at the smooth surface of the second reflecting surface pipe wall for the second time, the propagation direction of the ultrasonic signal is changed by 90 degrees again, and therefore the propagation direction of the ultrasonic signal in a primary propagation path is changed by 180 degrees in total. The ultrasonic signal then enters the ultrasonic sensor 02 via the second coupling interface and is received by the second ultrasonic transducer and converted into an electrical signal. Subsequently, the second ultrasonic transducer emits a continuous or pulsed ultrasonic signal into the disposable fluid line 01 via the second coupling interface, the ultrasonic wave propagates in the opposite direction to the first propagation path and is likewise emitted twice, finally enters the ultrasonic sensor 02 via the first coupling interface and is received by the first ultrasonic transducer and converted into an electrical signal.

The flow velocity and the instantaneous flow of the liquid to be measured can be calculated by transmitting and receiving ultrasonic waves in two opposite directions and comparing the propagation time difference or the phase difference of the ultrasonic signals received by the two ultrasonic transducers 021.

< example four >

The difference from the third embodiment is that: in the ultrasonic flowmeter of this embodiment, the outer surfaces of the two reflecting surface tube walls 016 are made into rough or irregular surfaces, so that the ultrasonic signal can be effectively reflected only on the inner surface of the reflecting surface tube wall, and diffused on the outer surface, and therefore, reflected waves of the inner and outer surfaces cannot be superposed and interfered with each other to further affect the flow measurement accuracy.

Referring to fig. 8, fig. 8 is a schematic structural diagram of the pipeline main body of the ultrasonic flow meter provided in this embodiment.

The outer surfaces of the two reflecting surface tube walls 016 are made into a sawtooth shape so as to achieve the purpose of diffuse reflection. It should be noted that the outer surface of the reflective surface tube 016 can be made into other irregular shapes, such as random uneven shapes.

< example five >

The difference from the first embodiment or the second embodiment or the third embodiment is that: the material density of the two reflecting surface tube walls 016 is much higher than that of the liquid, for example, the reflecting surface tube walls are made of stainless steel, ceramic or glass, and the acoustic impedance of the materials is much higher than that of the liquid.

Referring to fig. 9, fig. 9 is a schematic structural diagram of the pipeline main body of the ultrasonic flow meter provided in this embodiment.

These materials may be directly embedded into the reflective surface tube wall 016 during the injection molding process of the disposable fluid pipeline 01, or may be bonded or otherwise mounted at corresponding positions after the disposable fluid pipeline 01 is formed as the reflective surface tube wall.

In summary, the ultrasonic flowmeter provided by the invention has the following advantages:

the ultrasonic flowmeter comprises an ultrasonic sensor, a disposable fluid pipeline coupled and connected with the ultrasonic sensor, an ultrasonic flow measurement circuit and a software system, wherein the ultrasonic flow measurement circuit and the software system are electrically connected with the ultrasonic sensor, the disposable fluid pipeline comprises a pipeline main body and two fluid interfaces, the pipeline main body comprises a first pipeline section, a second pipeline section and a third pipeline section which are sequentially connected, the first pipeline section and the third pipeline section are both vertical to the second pipeline section, a reflection surface pipe wall is arranged at a corner part of the joint of the first pipeline section and the third pipeline section with the second pipeline section, the free ends of the first pipeline section and the third pipeline section are closed, one fluid interface is arranged on the side wall close to the free end of the first pipeline section and is used as a fluid inlet, the other fluid interface is arranged on the side wall close to the free end of the third pipeline section and is used as a fluid outlet, the surfaces of the end parts of, ultrasonic signals emitted by an ultrasonic transducer arranged inside the ultrasonic sensor can be transmitted to the disposable fluid pipeline through the coupling interface. Because the liquid to be measured does not directly contact with the ultrasonic sensor in the measuring process, the cleanness of the liquid to be measured is ensured, the invention can effectively avoid the cross contamination in the measuring process, and the acoustic passage is lengthened by the U-shaped pipeline main body, thereby improving the measuring precision and the repeatability.

Finally, it should be noted that the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting, and although the present invention is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions may be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.