Ultrasonic gas meter flow guide pipe and ultrasonic gas meter
By grading the internal channels of the flow pipe and automatically switching the circulation channels using the gas pressure difference, the problem of inaccurate metering during low-speed circulation of gas is solved, and the gas can flow stably at both low-flow and high-flow velocity gas is achieved, which improves the metering accuracy of the gas meter.
Patent Information
- Application Number
- CN202510182757.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-19
- Publication Date
- 2025-06-10
AI Technical Summary
When the existing ultrasonic gas meter is circulating at low speed, the metering data is inaccurate, mainly due to the increase in the thickness of the viscous bottom layer in the diversion pipe and the unstable flow state.
By grading the internal channels of the flow guide and automatically switching the circulation channels using the gas pressure difference, the gas can flow stably at both low and high flow rates. Specific measures include setting the left cavity, the right cavity, the low-pass cavity and the high-pass cavity in the flow tube, and controlling the switching of the channel through the flow regulation module.
It ensures that both low flow and high flow rate gas can enter the ultrasonic measurement range stably, improves the metering accuracy of the gas meter, and removes dirt on the diversion pipe through vibration, avoiding the interference of dirt on the metering results.
Smart Images
Figure CN120121118A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of flow metering devices, and particularly to a flow guide pipe and an ultrasonic gas meter for an ultrasonic gas meter. Background Art
[0002] A gas meter is a special metering device for gas. With the popularization of gas across the country, gas meters are constantly being improved. The internal structure of the initial diaphragm type mechanical gas meter is complex. During operation, it not only generates heat, but also the wear of its internal mechanical structure gradually increases over time. All the above reasons will affect the measurement accuracy, which also determines the development trend of gas meters to be structurally simplified and electronically intelligent. Therefore, ultrasonic gas meters have become the mainstream today.
[0003] The internal structure of an ultrasonic gas meter is simple. Except for the meter body and the integrated circuit board, there are only an inlet valve and a flow guide pipe. The inlet valve is connected to the inlet port. In case of user arrears or other situations, the inlet valve will automatically close. The flow guide pipe is connected to the outlet port and is the core component for measuring gas. Its measurement principle is the time difference method: gas flows inside the flow guide pipe, and a pair of ultrasonic transducers (one for transmitting and the other for receiving) are arranged on the inner wall of the flow guide pipe cavity. By the time of ultrasonic signal transmission, the flow velocity of the gas can be calculated, and then combined with the cross-sectional area of the flow guide pipe to calculate the gas flow rate; in the above process, when the gas flow velocity in the flow guide pipe is too high, a turbulent flow phenomenon will occur, making the measurement data inaccurate. Therefore, in the prior art, a separator (i.e., a flow stabilizing plate) is usually added to the flow guide pipe to reduce the space for the gas to move horizontally in the flow guide pipe, and then guide the gas to move in a specific direction, so that the gas can maintain a stable motion state before entering the ultrasonic measurement range to ensure the accuracy of the measurement result.
[0004] The addition of the flow stabilizing plate will make the flow state of the high-speed flowing gas more stable. However, when the gas flows at a low speed, the Reynolds number of the gas is small, resulting in an increase in the thickness of the viscous sublayer in the flow guide pipe, so that the gas flow velocity near the cavity wall is extremely low, causing a larger velocity difference between gas molecules on the same flow plane. After flowing through a section of the flow stabilizing plate before entering the ultrasonic measurement range, the velocity difference between gas molecules will be even larger, leading to an unstable flow state of the gas, and thus the metering data of the gas meter is inaccurate.
[0005] In order to solve the problem of inaccurate metering of the gas meter when the gas flows at a low speed, a flow guide pipe and an ultrasonic gas meter for an ultrasonic gas meter are proposed. Summary of the Invention
[0006] The object of the present invention is to provide a flow guide pipe for an ultrasonic gas meter and an ultrasonic gas meter, which solves the problem of inaccurate measurement of the gas meter when the gas flows at a low speed. By grading the internal channels of the flow guide pipe and automatically switching the gas flow channels by means of the gas pressure difference, it is realized that both low-flow and high-flow gases can stably flow through the flow guide pipe to ensure accurate measurement of the gas meter.
[0007] To achieve the above object, the present invention provides the following technical solutions:
[0008] An ultrasonic gas meter flow guide pipe includes a flow guide section, a left flow stabilizer, a middle flow stabilizer, a right flow stabilizer, a flow regulation section and a flow regulation module. The middle flow stabilizer is arranged in the middle of the flow guide section, and the middle flow stabilizer divides the inner cavity of the flow guide section into a left cavity and a right cavity. The left flow stabilizer and the right flow stabilizer are respectively arranged in the left cavity and the right cavity. The upper ends of the left flow stabilizer, the middle flow stabilizer and the right flow stabilizer are flush, and the lower end of the left flow stabilizer is higher than the lower ends of the middle flow stabilizer and the right flow stabilizer. The flow regulation section is installed above the flow guide section. The flow regulation section includes a low-pass cavity, a high-pass cavity and an upper cavity. The low-pass cavity and the high-pass cavity are respectively located above the left cavity and the right cavity and are respectively connected to the left cavity and the right cavity. The upper cavity is located above the low-pass cavity and the high-pass cavity. The flow regulation module is arranged inside the upper cavity;
[0009] The gas is guided by the left cavity and the right cavity and flows into the low-pass cavity and the high-pass cavity respectively. The flow regulation module is affected by the pressure difference between the inlet and outlet of the gas and controls the connection states between the low-pass cavity and the upper cavity and between the high-pass cavity and the upper cavity to be one open and one closed.
[0010] The function of the flow regulation module is to control the connection states between the low-pass cavity and the upper cavity and between the high-pass cavity and the upper cavity to be one open and one closed. It can be seen that there are many structures to achieve the above functions. For example, the low-pass cavity is set as a frustum of a cone with a smaller upper part and a larger lower part, and the high-pass cavity is set as a frustum of a cone with a larger upper part and a smaller lower part. The interiors of the two frustums of the cone are hollow, and a certain mass of spherical balls are placed inside the two frustums of the cone. When the gas flow rate is lower than the set value, the pressure difference between the upper and lower parts of the spherical ball is small, and the spherical ball falls below the frustum of the cone, thereby enabling the low-pass cavity connected to the left cavity to flow and closing the high-pass cavity connected to the right cavity; when the gas flow rate is higher than the set value, the pressure difference between the upper and lower parts of the spherical ball is large, and the spherical ball floats up and abuts against the upper part of the frustum of the cone, thereby closing the low-pass cavity connected to the left cavity and enabling the high-pass cavity connected to the right cavity to flow. Compared with this solution, in the above solution, the movement states of the spherical balls in the left cavity and the right cavity are independent of each other, and there is no effective connection to ensure that both are switched to the connected or closed state at the same time. Moreover, due to the working principle of the above solution, the shapes of the low-pass cavity and the high-pass cavity will not be the same, resulting in inconsistent flow paths of the gas flowing through the low-pass cavity and the high-pass cavity, thus affecting the measurement results;
[0011] Preferably, the flow regulation module includes a bottom support, a rotating rod, a low-pass plug, and a high-pass plug. The bottom support is installed on the lower wall of the upper cavity. The rotating rod is hinged to the bottom support. The low-pass plug and the high-pass plug are respectively hinged to the left end and the right end of the rotating rod, and the low-pass plug and the high-pass plug respectively penetrate through the communication channels between the upper cavity and the low-pass cavity and between the upper cavity and the high-pass cavity.
[0012] In the above solution, the on-off states between the low-pass cavity and the upper cavity and between the high-pass cavity and the upper cavity are respectively controlled by the low-pass plug and the high-pass plug, and the rotating rod effectively connects the low-pass plug and the high-pass plug, so as to ensure that one of the low-pass cavity and the upper cavity and the high-pass cavity and the upper cavity is open and the other is closed. Moreover, when the low-pass plug and the high-pass plug switch states, they will impact the cavity wall, thereby generating vibrations to remove the dirt accumulated on the diversion pipe. In addition, benefiting from the working principle of this solution, the shapes of the low-pass cavity and the high-pass cavity are not limited, and thus the consistency of the shapes of the low-pass cavity and the high-pass cavity can be ensured, so as to ensure that the flow paths of the gas flowing through the low-pass cavity and the high-pass cavity are the same, thereby ensuring the accuracy of the measurement results.
[0013] Preferably, the lower ends of the low-pass plug and the high-pass plug are both provided with a conical structure with the tip facing downwards, and the bottom diameters of the conical structures of the low-pass plug and the high-pass plug are respectively larger than the diameters of the connection channels between the low-pass cavity and the upper cavity and between the high-pass cavity and the upper cavity.
[0014] In the above solution, through the setting of the conical structures at the lower ends of the low-pass plug and the high-pass plug, not only the guiding of the gas inside the low-pass cavity and the high-pass cavity is realized, making it easier for the gas to be discharged from the low-pass cavity and the high-pass cavity to the upper cavity, but also the force on the low-pass plug and the high-pass plug is more uniform, so that the low-pass cavity and the high-pass cavity always remain in a vertical state, thereby ensuring that the low-pass plug and the high-pass plug accurately and stably close the channel.
[0015] Preferably, the distance from the hinge point between the rotating rod and the bottom support to the hinge point between the rotating rod and the low-pass plug is denoted as m, and the distance from the hinge point between the rotating rod and the bottom support to the hinge point between the rotating rod and the high-pass plug is denoted as n, then m > n.
[0016] Through the above solution, by means of the lever principle, when no gas is used or the gas consumption is small, the moment for the rotating rod to rotate counterclockwise is greater, and the low-pass plug moves downward, so that the high-pass plug completes the closing of the high-pass cavity and the upper cavity; when the gas consumption is large, the moment for the rotating rod to rotate clockwise is greater, and the high-pass plug moves downward, so that the low-pass plug completes the closing of the low-pass cavity and the upper cavity.
[0017] Preferably, a pair of mounting seats are arranged on the front wall and the rear wall of each of the left cavity and the right cavity. The heights of the mounting seats on the front wall and the rear wall are equal, and the contours of the mounting seats on the inner walls of the left cavity and the right cavity are located between the upper end and the lower end of the left flow stabilizer. Each pair of the mounting seats is coaxially arranged.
[0018] In the above solution, a pair of mounting seats are arranged in each of the left chamber and the right chamber, both of which are used to mount ultrasonic transducers to measure the gas outlet volume during low-speed flow and high-speed flow. Moreover, the arrangement heights and arrangement methods of the two pairs of mounting seats are the same, so as to ensure that the measurement environments of the two pairs of ultrasonic transducers are the same, and to ensure the accuracy of the measurement results.
[0019] Due to the complex internal structure of the existing ultrasonic gas meter flow guide pipe, it is usually manufactured by 3D printing technology. However, the accuracy of general 3D printing is not high. If there is a coaxiality problem in the production process of a pair of mounting seats, it will have a great impact on the measurement results.
[0020] Preferably, the left flow stabilizer, the middle flow stabilizer and the right flow stabilizer are all detachably connected to the flow guide section, and the adjacent distances between the three are equal.
[0021] In the above solution, through the detachable connection of the left flow stabilizer, the middle flow stabilizer and the right flow stabilizer, the left flow stabilizer, the middle flow stabilizer and the right flow stabilizer do not need to be integrally formed with the flow guide section. Furthermore, the internal structure of the flow guide section is simplified, so that the flow guide section can be produced by an injection molding process to improve production efficiency. And during production, a rod-shaped mold can be used to inject a pair of mounting seats coaxially, so as to ensure the coaxiality of the mounting seats.
[0022] The measurement of the gas consumption of an ultrasonic gas meter is carried out by means of the transmission of ultrasonic waves. To ensure the accuracy of the measurement results, external ultrasonic noise interference with the working ultrasonic waves should be avoided as much as possible. Ultrasonic interference often occurs in the gas inlet channel and the gas outlet channel of the gas meter. Because whether it is connected or disconnected, valves are usually set. When the valve is not fully opened, ultrasonic waves will be output outward due to the airflow effect.
[0023] Preferably, the lower ends of the left flow stabilizer, the middle flow stabilizer and the right flow stabilizer are all set to be pointed structures to guide the gas at the lower ends of the left chamber and the right chamber to flow into the left chamber and the right chamber. And the upper ends of the left flow stabilizer and the right flow stabilizer are set to be rack-shaped structures, so as to reflect the ultrasonic noise transmitted in the gas multiple times to weaken the influence of the noise on the working ultrasonic waves.
[0024] Preferably, the inner cavities of the flow guide section and the flow regulation section are straight in the up and down direction, and the left-right symmetry plane of the flow regulation section coincides with the left-right symmetry plane of the middle flow stabilizer.
[0025] Through the above solution, the gas in the flow guide section and the flow regulation section is prevented from turning during the flow process, so as to reduce the energy loss during the gas transmission process, and the flow paths of the gas flowing through the left chamber and the right chamber are the same. Furthermore, the consistency of the measurement environment for the gas consumption in the left chamber and the right chamber is ensured, so as to guarantee the accuracy of the measurement results.
[0026] In the prior art, the arrangement of the flow guide pipe in the gas meter is usually of two types: U-shaped and L-shaped. For the U-shaped type, the two ends of the flow guide pipe are respectively connected to the gas inlet and the gas outlet of the gas meter. For the L-shaped type, one end of the flow guide pipe is connected to the gas outlet of the gas meter, and the other end is exposed in the cavity of the gas meter. However, both arrangement methods have obvious problems. The cavity inside the gas meter has the function of buffering gas, which can make the gas discharge more stable. For the U-shaped arrangement method, the buffering effect of the cavity of the gas meter becomes invalid, and the ultrasonic noise generated by the upstream valve of the gas meter will pass through the U-shaped flow guide pipe and directly act on the working ultrasonic wave, affecting the accuracy of the measurement result. The L-shaped arrangement method disconnects the connection between the flow guide pipe and the gas inlet of the gas meter, thus weakening the above problems. However, the L-shaped arrangement method still makes the inlet of the flow guide section close to the gas inlet of the gas meter, and the bend of the L-shaped type will cause energy loss when the gas flows through.
[0027] An ultrasonic gas meter includes a meter body, an inlet valve, a transducer, and the above-mentioned ultrasonic gas meter flow guide pipe. An air inlet and an air outlet are arranged from left to right above the meter body. The inlet valve is located inside the meter body and is connected to the air inlet. The air outlet is straight in the up and down direction. The flow regulating section is connected below the air outlet. The transducer is installed in the mounting seat.
[0028] In the above solution, the inlet valve is located above the meter body, and the inlet of the flow guide section is located below the meter body, so as to give full play to the buffering effect of the cavity of the meter body on the gas, make the gas outlet stable, and eliminate the ultrasonic noise emitted upstream of the gas meter through the large cavity of the meter body, avoiding interference with the ultrasonic wave generated by the transducer to ensure the accuracy of the measurement data.
[0029] As the working time of the gas meter increases, dirt will inevitably accumulate on the internal parts of the gas meter, resulting in a gradual increase in the deviation between the measurement environment and the original environment.
[0030] Preferably, the two transducers in each pair of transducers respectively have the functions of ultrasonic wave emission and ultrasonic wave reception, and the transducers with the same function are installed on the mounting seats on the same side wall of the flow guide section.
[0031] In the above solution, the two pairs of transducers always work, and the measured data are used as references for each other, so as to ensure high accuracy even after long-term operation.
[0032] Compared with the prior art, the beneficial effects of the present invention are:
[0033] 1. In the present invention, the internal passage of the flow guide pipe is divided into a left chamber and a right chamber. A left flow stabilizer with a short length and a right flow stabilizer with a long length are respectively arranged in the left chamber and the right chamber. Low-flow-rate and high-flow-rate gases flow through the left chamber and the right chamber respectively, so that the low-flow-rate gas and the high-flow-rate gas can respectively experience shorter and longer flow stabilization intervals before metering, so that both the low-flow-rate gas and the high-flow-rate gas can stably enter the ultrasonic measurement interval, ensuring the accuracy of the ultrasonic gas meter metering.
[0034] 2. In the present invention, by moving up and down the low-pass plug and the high-pass plug in the flow regulation module, the gas flow passage is switched. When the gas flows at a low speed, the high-pass plug abuts against the chamber wall, and the gas flows through the left chamber. When the gas flows at a high speed, the low-pass plug abuts against the chamber wall, and the gas flows through the right chamber. During the switching process, the low-pass plug and the high-pass plug will impact the chamber wall, causing the flow guide pipe to vibrate. With the help of the straight design of the flow guide pipe, the dirt on the chamber wall of the flow guide pipe will fall, avoiding the interference of dirt on the metering result and ensuring the accuracy of the metering result.
[0035] 3. In the present invention, a pair of mounting seats are arranged on both the left chamber and the right chamber. Through the detachable design of the flow stabilizer, the coaxiality of each pair of mounting seats during the production of the flow guide pipe is ensured. While ensuring the accuracy of the metering result, the mounting methods of the two pairs of transducers on the mounting seats are the same, so that the metering environments of the two pairs of transducers are the same, and the two pairs of transducers always work, and the metering data are used as references for each other, ensuring that the gas meter can still maintain high accuracy after long-term operation. BRIEF DESCRIPTION OF THE DRAWINGS
[0036] Figure 1 Isometric structural schematic diagram of the flow guide pipe of the present invention;
[0037] Figure 2 Full-section structural schematic diagram of the flow guide pipe of the present invention;
[0038] Figure 3 Of the present invention Figure 2 Enlarged schematic diagram of part A;
[0039] Figure 4 Schematic diagram of the position of the mounting seat of the present invention;
[0040] Figure 5 Exploded schematic diagram of the parts of the present invention;
[0041] Figure 6 Schematic diagram of the structure of the gas meter of the present invention;
[0042] Figure 7 Schematic diagram of the low-flow state of the present invention;
[0043] Figure 8 Schematic diagram of the high-flow state of the present invention.
[0044] In the figure: 1. Flow guiding section; 11. Left cavity; 12. Right cavity; 13. Mounting seat; 2. Left flow stabilizing piece; 3. Middle flow stabilizing piece; 4. Right flow stabilizing piece; 5. Flow regulating section; 51. Low-pass cavity; 52. High-pass cavity; 53. Upper cavity; 6. Flow regulating module; 61. Bottom support; 62. Rotating rod; 63. Low-pass plug; 64. High-pass plug; 7. Meter body; 71. Air inlet; 72. Air outlet; 8. Inlet valve; 9. Transducer. Specific implementation mode
[0045] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.
[0046] Please refer to Figures 1 to 8 , the present invention provides a flow guiding pipe for an ultrasonic gas meter and an ultrasonic gas meter, and the technical solutions are as follows:
[0047] A flow guiding pipe for an ultrasonic gas meter includes a flow guiding section 1, a left flow stabilizing piece 2, a middle flow stabilizing piece 3, a right flow stabilizing piece 4, a flow regulating section 5 and a flow regulating module 6. The middle flow stabilizing piece 3 is arranged in the middle of the flow guiding section 1, and the middle flow stabilizing piece 3 divides the inner cavity of the flow guiding section 1 into a left cavity 11 and a right cavity 12. The left flow stabilizing piece 2 and the right flow stabilizing piece 4 are respectively arranged in the left cavity 11 and the right cavity 12. The upper ends of the left flow stabilizing piece 2, the middle flow stabilizing piece 3 and the right flow stabilizing piece 4 are flush, and the lower end of the left flow stabilizing piece 2 is higher than the lower ends of the middle flow stabilizing piece 3 and the right flow stabilizing piece 4. The flow regulating section 5 is installed above the flow guiding section 1, and the left-right symmetry plane of the flow regulating section 5 coincides with the left-right symmetry plane of the middle flow stabilizing piece 3. The inner cavities of the flow guiding section 1 and the flow regulating section 5 are straight along the up-down direction. The flow regulating section 5 includes a low-pass cavity 51, a high-pass cavity 52 and an upper cavity 53. The low-pass cavity 51 and the high-pass cavity 52 are respectively located above the left cavity 11 and the right cavity 12 and are respectively communicated with the left cavity 11 and the right cavity 12. The upper cavity 53 is located above the low-pass cavity 51 and the high-pass cavity 52, and the flow regulating module 6 is arranged inside the upper cavity 53;
[0048] The gas is guided by the left cavity 11 and the right cavity 12 and flows into the low-pass cavity 51 and the high-pass cavity 52 respectively. The flow regulating module 6 is controlled by the pressure difference of the gas inlet and outlet to control the communication states between the low-pass cavity 51 and the upper cavity 53 and between the high-pass cavity 52 and the upper cavity 53 to be one open and one closed.
[0049] In the prior art, in order to reduce the turbulent flow phenomenon in the flow guide pipe of an ultrasonic gas meter so that the measurement result of the gas meter is more accurate, a separator (i.e., a flow stabilizer) is usually added to the flow guide pipe to reduce the space for the gas to move laterally in the flow guide pipe, thereby guiding the gas to move in a specific direction. However, the turbulent flow phenomenon in the flow guide pipe does not occur all the time (the flow state of the fluid is affected by various factors, and it is generally distinguished by calculating the Reynolds number (Re). When Re > 4000, the fluid presents a turbulent flow state), but is associated with the Reynolds number. The calculation formula of the Reynolds number is:
[0050]
[0051] Applying the above calculation formula to the flow guide pipe of an ultrasonic gas meter, first, the pipe size remains unchanged. The kinematic viscosity is related to the pressure, temperature of the fluid, and the inherent properties of the fluid molecules. Unlike traditional diaphragm gas meters, ultrasonic gas meters use low-power electronic devices (usually powered by dry batteries) inside, replacing the original complex structure. Therefore, there is no obvious temperature change inside the flow guide pipe; the inherent properties of the fluid molecules (such as molecular mass, etc.) will not change either; when the gas flow velocity in the flow guide pipe increases, the sealing effect inside the gas meter weakens, which in turn increases the distance between gas molecules, thereby weakening the intermolecular force and resulting in a decrease in the kinematic viscosity of the gas. In summary, inside the flow guide pipe of an ultrasonic gas meter, the Reynolds number of the gas increases with the increase in the gas flow velocity. And as the Reynolds number increases, the thickness of the viscous sublayer on the inner wall of the flow guide pipe decreases (approximately a "smooth pipe"), which further weakens the disturbance of the inner wall of the flow guide pipe to the gas. Therefore, when the gas flows at a high speed (i.e., when the gas consumption is large), the gas meter can measure more accurately; when the gas flows at a low speed, the Reynolds number of the gas is small, and the gas flow is more inclined to the laminar flow state. At this time, accurate data can be measured without a large-sized flow stabilizer for flow stabilization. On the contrary, the presence of the flow stabilizer at this time will increase the thickness of the viscous sublayer on the pipe wall (which can be regarded as a "rough pipe"), which will not only cause a large frictional loss along the way during the gas flow, increasing the gas supply energy consumption, but also make the gas flow state unstable, thus affecting the measurement result;
[0052] Therefore, the present invention aims to improve the flow stabilizer so that when the gas passes through the flow guide pipe at low and high speeds, it can contact the flow stabilizer with a small area and a large area respectively. It can be known that there are many such methods. For example, the flow stabilizer is set as a nested structure. At low flow rates, the flow stabilizer is shortened, and at high flow rates, the flow stabilizer is lengthened. Compared with this solution, a relatively large power is required to move the flow stabilizer in the above solution. Even if the position of the flow stabilizer can be simply adjusted by the different pressure differences at different gas flow rates, the distance of the flow stabilizer movement adjusted in this way is relatively large, and correspondingly, the wear generated is also relatively large;
[0053] In the present invention, a left flow stabilizer 2 and a right flow stabilizer 4 are respectively arranged in the left chamber 11 and the right chamber 12. When the gas flow rate is low, it flows through the left chamber 11. By passing through the left flow stabilizer 2 with a shorter length, the interference of the flow stabilizer on the gas flow state can be reduced, thereby making the measurement more accurate. When the gas flow rate is high, it flows through the right chamber 12. By passing through the right flow stabilizer 4 with a longer length, the turbulent flow phenomenon can be weakened, thereby making the measurement more accurate.
[0054] As an implementation manner of the present invention, referring to Figures 1 to 3 , the flow regulation module 6 includes a bottom support 61, a rotating rod 62, a low-pass plug 63 and a high-pass plug 64. The bottom support 61 is installed on the lower wall of the upper chamber 53. The rotating rod 62 is hinged to the bottom support 61. The low-pass plug 63 and the high-pass plug 64 are respectively hinged to the left end and the right end of the rotating rod 62, and the low-pass plug 63 and the high-pass plug 64 respectively penetrate the communication channels between the upper chamber 53 and the low-pass chamber 51, and between the upper chamber 53 and the high-pass chamber 52. The bottom support 61 includes a pair of bearing seats and a support shaft. The support shaft is supported on the bearing seats, and the bearing seats are threadedly connected to the lower wall of the upper chamber 53. When the gas enters the upper chamber 53 from the low-pass chamber 51 or the high-pass chamber 52, since the diameters of the communication channels between the low-pass chamber 51, the high-pass chamber 52 and the upper chamber 53 are small, the length of the channels should be minimized, and the thickness of the lower wall of the upper chamber 53 should be reduced to minimize the influence on the gas flow. During installation, first pass the support rod of the bottom support 61 through the rotating rod 62, then fix the support rod on the bearing seats, then fix the bearing seats on the lower wall of the upper chamber 53, and finally insert the low-pass plug 63 and the high-pass plug 64 into the upper chamber 53 from the low-pass chamber 51 and the high-pass chamber 52 respectively to complete the hinge connection with the rotating rod 62.
[0055] As an implementation manner of the present invention, referring to Figure 3 , the lower ends of the low-pass plug 63 and the high-pass plug 64 are both provided with a conical structure with the tip facing downwards, and the bottom diameters of the conical structures of the low-pass plug 63 and the high-pass plug 64 are respectively larger than the diameters of the connection channels between the low-pass chamber 51 and the upper chamber 53, and between the high-pass chamber 52 and the upper chamber 53. During manufacturing, the centers of gravity of the low-pass plug 63 and the high-pass plug 64 are made to fall on their own central axes. If the low-pass plug 63 or the high-pass plug 64 tilts during operation, the upwardly tilted side will come into contact with the chamber wall first. On the one hand, the small-area contact will increase the contact pressure, which will accelerate the damage of the local area over time, thereby affecting the sealing performance and the measurement result. On the other hand, the gas flow area on the upwardly tilted side is reduced, resulting in a difference from other areas, which is not conducive to the stability of gas flow. In addition, elastic sealing rings are arranged on the upper bottom surfaces of the low-pass plug 63 and the high-pass plug 64 to ensure effective sealing when the low-pass plug 63 and the high-pass plug 64 contact the chamber wall.
[0056] As an implementation manner of the present invention, referring to Figure 7 and Figure 8, the distance from the hinge point of the rotating rod 62 and the bottom support 61 to the hinge point of the rotating rod 62 and the low-pass plug 63 is denoted as m, and the distance from the hinge point of the rotating rod 62 and the bottom support 61 to the hinge point of the rotating rod 62 and the high-pass plug 64 is denoted as n, then m > n; while the low-pass plug 63 and the high-pass plug 64 move in the up and down direction, they will also move in the left and right direction. The up and down movement distance is limited, and the left and right movement distance is also small, which is ignored in theoretical calculation. In addition, without considering the influence of the self-weight of the rotating rod 62, when the rotating rod 62 is in a balanced state, the following equation should be satisfied:
[0057] [(p 入 -p 出 )S 1 -m 1 g]L 1 =[(p 入 -p 出 )S 2 -m 2 g]L 2
[0058] The variant can be obtained as follows,
[0059]
[0060] (where: p 出 —gas outlet pressure, p 入 —gas inlet pressure, m 1 —mass of the low-pass plug 63, L 1 —arm of force between the low-pass plug 63 and the hinge point, m 2 —mass of the high-pass plug 64, L 2 —arm of force between the high-pass plug 64 and the hinge point, S 1 —bottom area of the low-pass plug 63, S 2 —bottom area of the high-pass plug 64)
[0061] When the "=" in the above formula becomes "<", the high-pass plug 64 moves downward, and the high-pass cavity 52 is connected to the upper cavity 53. In other cases, the low-pass plug 63 moves downward, and the low-pass cavity 51 is connected to the upper cavity 53. The gas inlet pressure is determined by the pressure reducing valve upstream of the gas meter and usually remains constant. The gas outlet pressure is determined by the actual gas consumption of the user. In actual production, correction parameters can be introduced into the above formula to ensure that the low-pass plug 63 and the high-pass plug 64 can be accurately switched.
[0062] As an implementation mode of the present invention, refer to Figure 4The left cavity 11 and the right cavity 12 are each provided with a pair of mounting seats 13 on their front and rear walls, the heights of the mounting seats 13 on the front and rear walls are equal, and the contours of the mounting seats 13 on the inner walls of the left cavity 11 and the right cavity 12 are located between the upper and lower ends of the left flow stabilizing sheet 2, and each pair of mounting seats 13 are coaxially arranged; the mounting seats 13 and the guide section 1 are integrally formed by injection molding. During the injection molding, a rod is used as an inner mold of a pair of mounting seats 13 to ensure the coaxiality of the pair of mounting seats 13. After the injection molding, the interior of the mounting seats 13 is processed (milling or drilling) to obtain a shape matching the outer shape of the transducer 9.
[0063] As an embodiment of the present invention, refer to Figure 5 The left stabilizing sheet 2, the middle stabilizing sheet 3 and the right stabilizing sheet 4 are all detachably connected to the guide section 1, and the adjacent sheet distances of the three are equal; the lower ends of the left stabilizing sheet 2, the middle stabilizing sheet 3 and the right stabilizing sheet 4 are all set to a pointed structure, and the upper ends of the left stabilizing sheet 2 and the right stabilizing sheet 4 are set to a rack structure; there are two ways to form the installation grooves of the left stabilizing sheet 2, the middle stabilizing sheet 3 and the right stabilizing sheet 4 on the inner wall of the guide section 1: one is to form them together when the guide section 1 is injection molded, and the other is to perform subsequent processing after the guide section 1 is injection molded. The former has higher production efficiency, but the initial mold design cost is higher; the latter requires multiple processing, low efficiency, but low mold investment cost. When producing the guide section 1, you can choose between the two methods according to actual conditions.
[0064] Reference Figure 6 An ultrasonic gas meter comprises a meter body 7, an air inlet valve 8, a transducer 9 and the above-mentioned ultrasonic gas meter guide tube. An air inlet 71 and an air outlet 72 are arranged on the top of the meter body 7 from left to right. The air inlet valve 8 is located inside the meter body 7, and the air inlet valve 8 is connected to the air inlet 71. The air outlet 72 is straight in the up and down direction. The flow regulating section 5 is connected below the air outlet 72. When connected, a sealing ring is sleeved on the upper end of the flow regulating section 5 to ensure the sealing between the flow regulating section 5 and the air outlet 72. The transducer 9 is installed in a mounting seat 13; the two transducers 9 in each pair of transducers 9 respectively have ultrasonic emission and ultrasonic receiving functions, and the transducers 9 with the same function are installed on the mounting seat 13 on the same side wall of the guide section 1.
[0065] Working principle: The present invention divides the channel inside the flow guide section 1 into a left chamber 11 and a right chamber 12 for the circulation of low-flow gas and high-flow gas. A short left flow stabilizing plate 2 is provided in the left chamber 11, and a long right flow stabilizing plate 4 is provided in the right chamber 12, so that both low-flow gas and high-flow gas can flow stably through the flow guide tube, thereby ensuring the accuracy of the ultrasonic gas meter measurement.
[0066] Specifically, in order to switch the gas flow passage in the diversion section 1 (allowing the gas to flow through the left chamber 11 when the gas flow rate is low and through the right chamber 12 when the gas flow rate is high), a flow regulation module 6 is arranged in the flow regulation section 5. The on-off states between the low-pass chamber 51 and the upper chamber 53, and between the high-pass chamber 52 and the upper chamber 53 are controlled by the low-pass plug 63 and the high-pass plug 64 respectively. An effective connection is formed between the low-pass plug 63 and the high-pass plug 64 through the rotating rod 62, so as to ensure that one of the low-pass chamber 51 and the upper chamber 53, and one of the high-pass chamber 52 and the upper chamber 53 is open and the other is closed. Moreover, when the low-pass plug 63 and the high-pass plug 64 switch states, they will impact the chamber wall, thereby generating vibrations to remove the dirt accumulated on the diversion pipe.
[0067] In order to ensure the coaxiality of each pair of mounting seats 13 to ensure the accuracy of measurement after the transducer 9 is installed, the flow stabilizer is designed to be detachably installed, so that the left flow stabilizer 2, the middle flow stabilizer 3, and the right flow stabilizer 4 do not need to be integrally formed with the diversion section 1. Furthermore, the internal structure of the diversion section 1 is simplified, so that the diversion section 1 can be produced by an injection molding process to improve production efficiency. During production, a rod-shaped mold can be used to coaxially inject a pair of mounting seats 13, thereby ensuring the coaxiality of the mounting seats 13.
[0068] In order to reduce the interference of ultrasonic noise upstream and downstream of the gas meter on the operation of the transducer 9, on the one hand, the upper ends of the left flow stabilizer 2 and the right flow stabilizer 4 are set as rack-shaped structures, so as to reflect the ultrasonic noise conducted in the gas multiple times to weaken the influence of downstream noise on the working ultrasonic waves. On the other hand, the diversion pipe is set straight, and there is a large cavity between it and the intake valve 8, so as to weaken the ultrasonic noise generated upstream by means of the large cavity of the meter body 7.
[0069] In order to ensure that the gas meter still has high accuracy after long-term use, first, the arrangement heights of the two pairs of mounting seats 13 on the left chamber 11 and the right chamber 12 are the same. Second, the transducers 9 with the same function are installed on the mounting seats 13 on the same side wall of the diversion section 1, so that the two pairs of transducers 9 always work, and the measured data are used as references for each other, thereby ensuring high accuracy after long-term operation.
[0070] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.
Claims
1. An ultrasonic gas meter flow guide tube, characterized in that: The invention comprises a flow guide section (1), a left flow stabilizing sheet (2), a middle flow stabilizing sheet (3), a right flow stabilizing sheet (4), a flow regulating section (5) and a flow regulating module (6), wherein the middle flow stabilizing sheet (3) is arranged in the middle of the flow guide section (1), and the middle flow stabilizing sheet (3) divides the inner cavity of the flow guide section (1) into a left cavity (11) and a right cavity (12), and the left flow stabilizing sheet (2) and the right flow stabilizing sheet (4) are arranged in the left cavity (11) and the right cavity (12) respectively, and the upper ends of the left flow stabilizing sheet (2), the middle flow stabilizing sheet (3) and the right flow stabilizing sheet (4) are flush with each other, and the lower end of the left flow stabilizing sheet (2) is parallel to the left cavity (11). The end of the flow regulating section (5) is higher than the lower ends of the middle flow stabilizing sheet (3) and the right flow stabilizing sheet (4), the flow regulating section (5) is installed above the flow guiding section (1), the flow regulating section (5) comprises a low-pass cavity (51), a high-pass cavity (52) and an upper cavity (53), the low-pass cavity (51) and the high-pass cavity (52) are respectively located above the left cavity (11) and the right cavity (12), and are respectively connected to the left cavity (11) and the right cavity (12), the upper cavity (53) is located above the low-pass cavity (51) and the high-pass cavity (52), and the flow regulating module (6) is arranged inside the upper cavity (53); The gas is guided by the left chamber (11) and the right chamber (12) to flow into the low-pass chamber (51) and the high-pass chamber (52) respectively, and the flow regulating module (6) is acted upon by the pressure difference between the inlet and outlet of the gas to control the connection state between the low-pass chamber (51) and the upper chamber (53), and between the high-pass chamber (52) and the upper chamber (53) to be one open and one disconnected.
2. The ultrasonic gas meter flow guide tube according to claim 1, characterized in that: The flow regulating module (6) comprises a bottom support (61), a rotating rod (62), a low-pass plug (63) and a high-pass plug (64); the bottom support (61) is mounted on the lower wall of the upper chamber (53); the rotating rod (62) is hinged to the bottom support (61); the low-pass plug (63) and the high-pass plug (64) are respectively hinged to the left end and the right end of the rotating rod (62); and the low-pass plug (63) and the high-pass plug (64) respectively penetrate the communication channels between the upper chamber (53) and the low-pass chamber (51), and between the upper chamber (53) and the high-pass chamber (52).
3. The ultrasonic gas meter flow guide tube according to claim 2, characterized in that: The lower ends of the low-pass plug (63) and the high-pass plug (64) are both configured as conical structures with the tips facing downward, and the bottom diameters of the conical structures of the low-pass plug (63) and the high-pass plug (64) are respectively larger than the calibers of the connecting channels between the low-pass cavity (51) and the upper cavity (53), and between the high-pass cavity (52) and the upper cavity (53).
4. The ultrasonic gas meter flow guide tube according to claim 2, characterized in that: The distance from the hinge point of the rotating rod (62) and the bottom support (61) to the hinge point of the rotating rod (62) and the low-pass plug (63) is recorded as m, and the distance from the hinge point of the rotating rod (62) and the bottom support (61) to the hinge point of the rotating rod (62) and the high-pass plug (64) is recorded as n, then m>n.
5. The ultrasonic gas meter flow guide tube according to claim 1, characterized in that: The left cavity (11) and the right cavity (12) are each provided with a pair of mounting seats (13) on their front and rear walls, the mounting seats (13) on the front and rear walls are of equal height, and the contours of the mounting seats (13) on the inner walls of the left cavity (11) and the right cavity (12) are located between the upper end and the lower end of the left flow stabilizing sheet (2), and each pair of the mounting seats (13) are coaxially arranged.
6. The ultrasonic gas meter flow guide tube according to claim 5, characterized in that: The left flow stabilizing plate (2), the middle flow stabilizing plate (3) and the right flow stabilizing plate (4) are all detachably connected to the flow guide section (1), and the distances between adjacent plates of the three are equal.
7. The ultrasonic gas meter flow guide tube according to claim 6, characterized in that: The lower ends of the left flow stabilizing plate (2), the middle flow stabilizing plate (3) and the right flow stabilizing plate (4) are all arranged as pointed structures, and the upper ends of the left flow stabilizing plate (2) and the right flow stabilizing plate (4) are arranged as rack-shaped structures.
8. The ultrasonic gas meter flow guide tube according to claim 1, characterized in that: The inner cavities of the flow guide section (1) and the flow regulating section (5) are straight in the up-down direction, and the left-right symmetric plane of the flow regulating section (5) coincides with the left-right symmetric plane of the intermediate stabilizing flow sheet (3).
9. An ultrasonic gas meter, comprising the ultrasonic gas meter flow guide tube according to any one of claims 1 to 8, characterized in that: It also comprises a meter body (7), an air inlet valve (8) and a transducer (9); an air inlet (71) and an air outlet (72) are arranged on the top of the meter body (7) from left to right; the air inlet valve (8) is located inside the meter body (7), and the air inlet valve (8) is connected to the air inlet (71); the air outlet (72) is straight in the up-down direction; the flow regulating section (5) is connected below the air outlet (72); and the transducer (9) is mounted in a mounting seat (13).
10. The ultrasonic gas meter flow guide tube according to claim 9, characterized in that: The two transducers (9) in each pair of transducers (9) respectively have ultrasonic emission and ultrasonic reception functions, and the transducers (9) with the same functions are mounted on a mounting seat (13) on the same side wall of the guide section (1).