Dual-track ultrasonic metering module

Abstract

The utility model relates to a dual-track ultrasonic metering module. Two pairs of ultrasonic transducer sets are arranged on a flow channel of the metering module, transducer mounting holes are formed in the upstream and the downstream of the flow channel of the metering module respectively, and sound channels of one pair of ultrasonic transducer sets become conventional sound path sound channels for single reflection of signals by controlling the positions and inclination angles of the transducer mounting holes. And the sound channel of the other pair of ultrasonic transducer group is a lengthened sound path distance sound channel of which the signal is reflected for multiple times. Due to the design of the double sound path distance and sound channels, gas metering under different working conditions can be met at the same time through one-time installation of a product, the situation that a meter needs to be replaced by a newly-designed meter due to the fact that the installation environment temperature changes or gas source components change is avoided, and enterprise investment and social resource waste are reduced; the sound path is lengthened by the sound path lengthening sound channel through multiple times of reflection, so that a large time difference can still be obtained in a gas medium with a higher sound velocity, and the stable and reliable metering precision is further ensured.

Description

Technical Field

[0001] The utility model belongs to the field of gas flow measurement and relates to a dual-channel ultrasonic measurement module. Background Art

[0002] The propagation speed of sound waves in pure hydrogen is as high as 1300 m / s, far higher than 340 m / s in air and 430 m / s in CH4. Therefore, the measurement accuracy of hydrogen-blended natural gas will be affected by whether the acquisition ability and method are upgraded after the change of the sound speed of sound waves. The increase in the gas sound speed will shorten the time difference Δt between the forward and reverse flow times of sound waves in the transmission of hydrogen-blended natural gas, resulting in a larger calculation deviation of the gas flow velocity and making it difficult for the measurement accuracy to meet the standard requirements.

[0003] When the working environment (hereinafter referred to as the working condition) in the ultrasonic measurement flow channel changes, the gas sound speed will change. Since the length of the flow channel remains unchanged, at a fixed sound path, the one-way transmission and reception measurement time of the ultrasonic transducer group changes. At this time, the channel that is convenient for ensuring the signal acquisition accuracy should be selected to collect the forward and reverse flow times of ultrasonic waves passing through the medium within the transmission and reception cycle to improve the measurement accuracy. According to the propagation characteristics of ultrasonic waves in the flow channel, the propagation times under forward and reverse flows are expressed as follows:

[0004] Where, t up is the forward flow flight time of the transducer group (for example, ultrasonic transducer A emits and ultrasonic transducer B receives), t down is the reverse flow flight time (for example, ultrasonic transducer B emits and ultrasonic transducer A receives), L is the distance between the ultrasonic transducer groups, C is the sound speed, v is the fluid velocity, is the installation angle of the transducer; the propagation time difference Δt is obtained from the forward and reverse flow times, specifically as follows:

[0005]

[0006] This angle and the distance L are known, and the goal is to measure the fluid velocity v; the sound speed C of the ultrasonic signal of the known fluid medium composition is a known constant, so only the difference between the propagation time t up and the propagation time t down is required; however, the sound speed C of ultrasonic waves passing through a fixed medium will change with temperature and is a function of temperature. At the same time, the sound speed C of ultrasonic waves passing through media with different compositions will also change. Therefore, the sound speed C has variability; usually, ultrasonic measurement requires measuring the flight times t up and t down of a group of ultrasonic transducers for transmitting and receiving signals to eliminate the variability of C; the flow velocity calculation formula is specifically as shown in formula (2):

[0007]

[0008] It can be seen that the accuracy of time - of - flight measurement is crucial for the measurement accuracy of flow velocity obtained. When the sound velocity C of ultrasonic waves passing through the medium changes, if the sound path L remains unchanged, the larger the sound velocity C, the up and down the smaller the value of t. This poses a test to the accuracy of the signal acquisition unit and the timing unit. Therefore, it is considered to lengthen the sound path to facilitate the accurate acquisition of the time of flight to obtain an accurate time difference Δt. When the sound velocity C becomes smaller, the up and down the value of t becomes larger. Considering that the signal of ultrasonic waves in the flow channel medium will decay with time, it is necessary to reduce the sound path at this time to facilitate the accurate acquisition of the time of flight to obtain an accurate time difference Δt. It can be seen that if the sound path is designed singly, it is difficult to meet the measurement accuracy after the working conditions change. Utility Model Content

[0009] Aiming at the problems existing in the prior art, the purpose of the present utility model is to provide a technical solution of a dual - channel ultrasonic measurement module.

[0010] In the described dual - channel ultrasonic measurement module, one end of the measurement module is an integrally - formed horn - shaped air inlet, and the other end of the measurement module is connected to an air outlet conduit. It is characterized in that: two pairs of ultrasonic transducer groups are arranged on the flow channel of the measurement module, and the two ultrasonic transducers of each pair of ultrasonic transducer groups act as a transceiver with each other to form independent channels; transducer mounting holes are respectively arranged at the upstream and downstream of the flow channel of the measurement module, and the reflection point positions of the channels of each pair of ultrasonic transducer groups are offset from the transducer mounting holes. By controlling the position and inclination angle of the transducer mounting holes, the channel of one pair of ultrasonic transducer groups becomes a conventional sound path channel with single - reflection of signals, and the channel of the other pair of ultrasonic transducer groups is a lengthened sound path channel with multiple reflections of signals. In the described dual - channel ultrasonic measurement module, it is characterized in that a plurality of parallel flow - dividing sheets are installed in the flow channel of the measurement module, the flow - dividing sheets are perpendicular to the flow channel plane where the ultrasonic transducers are installed, and the flow - dividing sheets divide the interior of the flow channel into a plurality of parallel and independent cavities.

[0011] In the described dual - channel ultrasonic measurement module, it is characterized in that the two groups of ultrasonic transducer groups are installed in the same cavity and share a measurement flow channel.

[0012] In the described dual - channel ultrasonic measurement module, it is characterized in that the two groups of ultrasonic transducer groups are respectively installed in two different cavities, and the two different cavities respectively serve as the measurement flow channels corresponding to the two pairs of ultrasonic transducer groups.

[0013] In the described dual - channel ultrasonic measurement module, it is characterized in that the conventional sound path channel is a V - type single - reflection channel, and the lengthened sound path channel is an N - type or W - type multiple - reflection channel.

[0014] The described dual-channel ultrasonic metering module is characterized in that the operating frequencies of the two pairs of ultrasonic transducers are the same or have high and low differences.

[0015] Compared with the prior art, the present utility model has the following advantages:

[0016] 1) The design of the double-path sound channel enables the product to meet the gas metering under different working conditions with one installation, without the need to replace the meter with a newly designed one due to changes in the installation environment temperature or gas source components, reducing the investment of enterprises and waste of social resources;

[0017] 2) The lengthened sound path channel makes the sound path longer through multiple reflections, so that in a gas medium with a higher sound speed, a larger time difference can still be obtained, thereby ensuring the stability and reliability of the metering accuracy;

[0018] 3) Through the design of expanding the number of layers of the flow channel cavity by the partition piece, the module can be applied to a larger flow range on the premise of ensuring the metering accuracy, thereby expanding the product series specifications. For example, the G4 type gas meter in this example can be expanded into G6, G10, G16 type gas meters, etc.;

[0019] 4) When the two groups of ultrasonic transducer groups work in two different cavities respectively, the sound path reflection points of one group of ultrasonic transducer groups and the installation holes of the other group of ultrasonic transducer groups are not in the same cavity, and no additional staggered position design is required. Therefore, the space in the flow channel extension direction can be saved, which is convenient for the compact design of the internal cavity of the ultrasonic gas meter. Description of the Drawings

[0020] Figure 1 It is the sound path working principle diagram of the WV type metering module of the present utility model;

[0021] Figure 2 It is the sound path working principle diagram of the NV type metering module of the present utility model;

[0022] Figure 3 It is the structure diagram of the intake port direction of the multi-cavity metering module of the present utility model;

[0023] Figure 4 It is the assembly schematic diagram of the WV type double-cavity metering module of the present utility model (assembling the outlet conduit);

[0024] Figure 5 It is the working principle diagram of the A cavity of the WV type double-cavity metering module of the present utility model;

[0025] Figure 6 It is the working principle diagram of the B cavity of the WV type double-cavity metering module of the present utility model;

[0026] Figure 7It is the front view structure diagram (equipped with an adapter) of the WV type double-chamber metering module of the present utility model;

[0027] Figure 8 It is the double-chamber assembly schematic diagram (assembling the gas outlet duct) of the NV type double-chamber metering module of the present utility model;

[0028] Figure 9 It is the working principle diagram of chamber C of the NV type double-chamber metering module of the present utility model;

[0029] Figure 10 It is the working principle diagram of chamber D of the NV type double-chamber metering module of the present utility model;

[0030] Figure 11 It is the front view structure diagram (equipped with an adapter) of the NV type double-chamber metering module of the present utility model;

[0031] In the figure, 1 is the A1 transducer, 2 is the WV type sound path flow channel, 3 is the B1 transducer, 4 is the A2 transducer, 5 is the B2 transducer group, 6 is the gas outlet duct, 7 is chamber B, 8 is the shunt plate, 9 is chamber A, 10 is the NV type sound path flow channel, 11 is chamber C, 12 is chamber D, 13 is the air inlet, 14 is the large-diameter flow channel, 15 is the multi-layer shunt plate, and 16 is the connecting flange. Specific embodiments

[0032] The present utility model will be further described below in conjunction with the accompanying drawings of the specification:

[0033] A double-channel ultrasonic metering module, one end of the metering module is integrally provided with a horn-shaped air inlet, the other end of the metering module is connected to the gas outlet duct, two pairs of ultrasonic transducer groups are arranged on the flow channel of the metering module, and the two ultrasonic transducers of each pair of ultrasonic transducer groups act as a transceiver to form independent channels; transducer mounting holes are respectively arranged at the upstream and downstream of the flow channel of the metering module. By controlling the position and inclination angle of the transducer mounting holes, the channel of one pair of ultrasonic transducer groups becomes a conventional sound path channel with single reflection of the signal, and the channel of the other pair of ultrasonic transducer groups is a lengthened sound path channel with multiple reflections of the signal; by the independent operation of each ultrasonic transducer group, different ultrasonic forward and reverse flight time differences are obtained. Each pair of ultrasonic transducers works independently. By the transmission time difference of ultrasonic waves in the gas medium in the forward and reverse directions, the flow rate of the gas is calculated, and then the real-time flow rate of the gas is obtained, so as to cope with the deviation of the metering accuracy caused by the influence of the sound speed under different gas media.

[0034] A number of parallel shunt plates can be installed in the flow channel of the metering module. The shunt plates are perpendicular to the flow channel plane where the ultrasonic transducers are installed. The shunt plates divide the inside of the flow channel into a number of parallel and independent cavities. Two groups of ultrasonic transducer groups are installed in the same cavity and share a measuring flow channel. Alternatively, two groups of ultrasonic transducer groups are installed in two different cavities respectively, and the two different cavities serve as measuring flow channels corresponding to the two pairs of ultrasonic transducer groups.

[0035] Specifically:

[0036] Preferably, the conventional sound path channel is a V-type single reflection channel, and the extended sound path channel is an N-type or W-type multiple reflection channel.

[0037] It is preferred to set a diverter in the flow channel to divide it into N parallel and independent cavities (N is a natural number greater than 1, and the upper limit is set according to actual engineering needs), and select one of the cavities as the measurement flow channel so that the sound channels of the two sets of ultrasonic transducers are in the flow channel. This makes it easier to reduce pressure loss when the module works in a large-flow gas metering device.

[0038] It is preferred to set a diverter in the flow channel to divide it into N parallel and independent cavities (N is a natural number greater than 1, and the upper limit is set according to actual engineering needs), and any two cavities are set as the sound channel working areas of two groups of ultrasonic transducers, one of which is a conventional sound path sound channel working area, and the other is an extended sound path sound channel working area.

[0039] It should be noted that when two sets of ultrasonic transducer groups are placed in a cavity for operation, the reflection point position of the sound channel of each pair of ultrasonic transducer groups in the cavity must be staggered with the transducer mounting hole to prevent the failure to form a reflection sound channel. Therefore, there are higher requirements on the length or height of the flow channel measurement cavity. When two sets of ultrasonic transducer groups are placed in two different cavities for operation, the sound channel reflection point of one set of ultrasonic transducer groups and the mounting hole of the other set of ultrasonic transducer groups are not in the same cavity, and no additional staggered position design is required. Therefore, space in the extension direction of the flow channel can be saved, which is convenient for the compact design of the internal cavity of the ultrasonic gas meter.

[0040] The operating frequencies of the two pairs of ultrasonic transducers can be the same or have different frequencies, and the selection is made based on the requirements of the product solution.

[0041] The present invention illustrates the working principle and structure of WV-type and NV-type dual-cavity dual-channel metering modules, but the practical application is not limited to these embodiments.

[0042] like Figure 1 and Figure 2As shown in the figure, transducer mounting holes are respectively arranged at the upstream and downstream of an ultrasonic metering channel. Two pairs of ultrasonic transducers are installed in the transducer mounting holes. The long sides of the acoustic impedance matching layers of each pair of ultrasonic transducers are parallel to each other, and the direction is parallel to the long side of the channel. Transducer 1 of A1 and transducer 4 of A2 are one pair, with transducer 1 of A1 at the upstream and transducer 4 of A2 at the downstream; transducer 3 of B1 and transducer 5 of B2 are the other pair, with transducer 3 of B1 at the upstream and transducer 5 of B2 at the downstream; by designing the inclination angles of the transducer mounting holes of the two groups of ultrasonic transducers in the channel, the signals of the pair of transducers, i.e., transducer 3 of B1 and transducer 5 of B2, are reflected once in the sound channel, and the sound channel is in a V shape, so it is set as a conventional sound path channel; the signals of transducer 1 of A1 and transducer 4 of A2 are reflected multiple times in the channel to form an extended sound path channel.

[0043] As Figure 1 As shown in the figure, transducer 1 of A1 and transducer 4 of A2 are installed on one side of the channel, and transducer 3 of B1 and transducer 5 of B2 are installed on the other side of the channel at the installation positions of this pair of transducers. The ultrasonic wave emitted by transducer 1 of A1 is received by transducer 4 of A2 after 3 reflections, and then transducer 4 of A2 emits, and is received by transducer 1 of A1 after 3 reflections. The signal propagation sound channel of this pair of transducers is in a W shape. The ultrasonic wave emitted by transducer 3 of B1 is received by transducer 5 of B2 after 1 reflection, and then transducer 5 of B2 emits ultrasonic waves and is received by transducer 3 of B1. The signal propagation sound channel of this pair of transducers is in a V shape.

[0044] As Figure 2 As shown in the figure, transducer 1 of A1, transducer 3 of B1 and transducer 5 of B2 are installed on one side of the channel, and transducer 4 of A2 is installed on the other side of the channel at the installation positions of the above transducers. The ultrasonic wave emitted by transducer 1 of A1 is received by transducer 4 of A2 after 2 reflections, and then transducer 4 of A2 emits, and is received by transducer 1 of A1 after 2 reflections. The signal propagation sound channel of this pair of transducers is in an N shape. The ultrasonic wave emitted by transducer 3 of B1 is received by transducer 5 of B2 after 1 reflection, and then transducer 5 of B2 emits ultrasonic waves and is received by transducer 3 of B1. The signal propagation sound channel of this pair of transducers is in a V shape.

[0045] It should be noted that the reflection point positions of each ultrasonic sound channel are staggered from those at the transducer mounting holes to avoid failure in collection after reflection and inability to measure.

[0046] Furthermore, as Figure 3As shown, a multi-layer flow splitter 15 is provided in the flow channel to divide the interior of the WV-type large-diameter flow channel 14 into N parallel and independent cavities (shown as 6 cavities in the figure). One or two of these cavities are selected as the measurement sound channel area, and then connected to the corresponding gas outlet pipeline through the connecting flange 16. Such a solution facilitates reducing the pressure loss when the module works in an industrial and commercial gas metering device. At the same time, the airflow is preliminarily rectified by the flow splitter when entering the air inlet 13, which is conducive to the stability of the flow field and ensures the stability and reliability of metering. This design is also applicable to the NV-type large-diameter flow channel.

[0047] Figures 4 - 11 The illustrated embodiment is the case where the flow channel is divided into two cavities by the flow splitter, and each pair of transducers is respectively installed in one of the cavities. Its working principle is as follows: During operation, the transmission time difference Δt generated by a pair of ultrasonic transducers in the forward and reverse flows is independently measured to calculate the gas flow velocity, and then the real-time flow rate Q is obtained through the ratio relationship of the cross-sectional areas of the two cavity profiles. For example, if the flow velocity obtained in cavity A is V A , the cross-sectional area of cavity A is S A , and the cross-sectional area of cavity B is S B , the total flow rate Q of the device can be obtained as Q = V A *S A / (S A +S B ). Similarly, the total flow rate Q of the device can be calculated through cavity B, or two Q values can be calculated respectively from the parameters of cavities A and B and then weighted averaged, or the real-time flow rate can be calculated by calibrating the correlation coefficient according to the laboratory empirical values to reduce the metering error.

[0048] As Figure 4 shown, a WV-type dual-channel ultrasonic metering module is divided into two independent spaces, cavity A 9 and cavity B 7, by the flow splitter 8. The tail of the WV-type sound path flow channel 2 is connected to the gas outlet conduit 6.

[0049] As Figure 5 shown, an A1 transducer 1 and an A2 transducer 4 are installed in cavity A 9. The signal propagation sound channel of this pair of transducers is a W-type extended sound path channel. The ultrasonic wave emitted by the A1 transducer 1 in cavity A 9 is received by the A2 transducer 4 after 3 reflections, and then the A2 transducer 4 emits, and is received by the A1 transducer 1 after 3 reflections. Through the forward and reverse transmission time difference Δt A , the flow velocity V of the gas in the flow channel is calculated A . Through multiple reflections, the flight time of the ultrasonic wave is lengthened, and Δt A is correspondingly increased compared with the flight time of the conventional sound path, improving the metering accuracy.

[0050] As Figure 6As shown in the figure, a B1 transducer 3 and a B2 transducer 5 are installed in the B chamber 7. The signal propagation sound path of this pair of transducers is a V-shaped conventional sound path. The ultrasonic wave emitted by the B1 transducer 3 in the B chamber 7 is received by the B2 transducer 5 after 1 reflection. Then, the B2 transducer 5 emits an ultrasonic wave, which is received by the B1 transducer 3. Through the time difference Δt of the forward and reverse flow transmissions B , the flow velocity V of the gas in the flow channel is calculated B . The sound path in the B chamber is shorter, which is more conducive to low-power and refined measurement.

[0051] As Figure 7 shown, preferably, the cross-sectional areas of the A chamber 9 and the B chamber 7 of the WV-type double-channel ultrasonic metering module are set to be equal, and the internal flow field environments are similar, so that when the two pairs of transducers need to switch the working sound path due to working condition changes, the metering results are consistent.

[0052] As Figure 8 shown, an NV-type double-channel ultrasonic metering module is divided into two independent spaces, a C chamber 11 and a D chamber 12, by a shunt plate 8. The tail of the NV-type sound path flow channel 10 is connected to the air outlet conduit 6.

[0053] As Figure 9 shown, an A1 transducer 1 and an A2 transducer 4 are installed in the C chamber 11. The signal propagation sound path of this pair of transducers is an N-type extended sound path. The ultrasonic wave emitted by the A1 transducer 1 in the A chamber 9 is received by the A2 transducer 4 after 2 reflections. Then, the A2 transducer 4 emits, and after 2 reflections, it is received by the A1 transducer 1. Through the time difference Δt of the forward and reverse flow transmissions A , the flow velocity V of the gas in the flow channel is calculated A . After multiple reflections, the flight time of the ultrasonic wave is extended, and Δt A is correspondingly increased compared to the flight time of the conventional sound path, improving the metering accuracy.

[0054] As Figure 10 shown, a B1 transducer 3 and a B2 transducer 5 are installed in the D chamber 12. The signal propagation sound path of this pair of transducers is a V-shaped conventional sound path. The ultrasonic wave emitted by the B1 transducer 3 in the B chamber 7 is received by the B2 transducer 5 after 1 reflection. Then, the B2 transducer 5 emits an ultrasonic wave, which is received by the B1 transducer 3. Through the time difference Δt of the forward and reverse flow transmissions B , the flow velocity V of the gas in the flow channel is calculated B . The sound path in the B chamber is shorter, which is more conducive to low-power and refined measurement.

[0055] As Figure 11As shown, preferably, the cross-sectional areas of the C chamber 11 and the D chamber 12 of the NV-type two-channel ultrasonic metering module are set to be equal, and the flow field environments formed inside are similar, so that when the two pairs of transducers need to switch the working channels due to changes in working conditions, the metering results are consistent.

[0056] The specific examples described herein are merely illustrative of the spirit of the present invention. Those skilled in the art to which the present utility model pertains can make various modifications or supplements to the described specific examples or use similar methods for substitution, but will not deviate from the spirit of the present utility model or exceed the scope defined by the appended claims.

[0057] Although terms such as hydrogen-doped natural gas, ultrasonic wave, transducer, and forward and reverse flow transmission time difference are used more frequently herein, the possibility of using other terms is not excluded. The use of these terms is only for more convenient description and explanation of the essence of the present utility model, and interpreting them as any additional limitation is contrary to the spirit of the present utility model.

Claims

1. A two-channel ultrasonic metering module, one end of the metering module is a horn-shaped air inlet integrally provided, and the other end of the metering module is connected to an air outlet conduit, characterized in that: Two pairs of ultrasonic transducer groups are arranged on the flow channel of the metering module. The two ultrasonic transducers of each pair of ultrasonic transducer groups act as transceiver pairs to form independent sound channels. Transducer mounting holes are respectively arranged at the upstream and downstream of the flow channel of the metering module. The reflection point positions of the sound channels of each pair of ultrasonic transducer groups are staggered from the transducer mounting holes. By controlling the positions and tilting angles of the transducer mounting holes, the sound channel of one pair of ultrasonic transducer groups becomes a conventional sound path channel with single reflection of signals, and the sound channel of the other pair of ultrasonic transducer groups is an extended sound path channel with multiple reflections of signals.

2. The dual-channel ultrasonic metering module according to claim 1, wherein A number of parallel flow dividing plates are installed in the flow channel of the metering module. The flow dividing plates are perpendicular to the flow channel plane where the ultrasonic transducers are installed, and the flow channel is divided into several parallel and independent cavities.

3. The dual-channel ultrasonic metering module according to claim 2, wherein The two groups of ultrasonic transducer groups are installed in the same cavity and share a measurement flow channel.

4. The dual-channel ultrasonic metering module according to claim 2, characterized in that The two groups of ultrasonic transducer groups are respectively installed in two different cavities, and the two different cavities respectively serve as the measurement flow channels corresponding to the two pairs of ultrasonic transducer groups.

5. The dual-channel ultrasonic metering module according to claim 1, characterized in that The conventional sound path channel is a V-shaped single reflection channel, and the extended sound path channel is an N-shaped or W-shaped multiple reflection channel.

6. The dual-channel ultrasonic metering module according to claim 1, wherein The operating frequencies of the two pairs of ultrasonic transducers are the same or have high and low differences.

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