Bidirectional flow wide-range venturi flowmeter

Abstract

A contraction section of a venturi tube is a double-taper contraction section, a diffusion section of the venturi tube is a double-taper diffusion section, and an inlet section, the double-taper contraction section, the double-taper diffusion section and an outlet section are symmetrically arranged relative to a throat section; a plurality of throat section pressure measuring holes communicated with the fluid through holes of the throat section are formed in the outer circle of the throat section of the Venturi tube in the circumferential direction, and a plurality of inlet section pressure measuring holes communicated with the fluid through holes of the inlet section are formed in the outer circle of the inlet section of the Venturi tube in the circumferential direction. A plurality of outlet section pressure measuring holes communicated with the fluid through holes of the outlet section are formed in the outer circle of the outlet section of the Venturi tube in the circumferential direction; the inlet section pressure measuring hole is communicated with the inner ring groove of the first pressure measuring ring, the throat section pressure measuring hole is communicated with the inner ring groove of the second pressure measuring ring, and the outlet section pressure measuring hole is communicated with the inner ring groove of the third pressure measuring ring. The two-way flow wide-range high-precision measurement of the venturi flow meter is realized by the two-way flow wide-range high-precision measurement device.

Description

TECHNICAL FIELD

[0001] The utility model relates to venturi flowmeter technical field, concretely relates to a bidirectional flow wide range venturi flowmeter. BACKGROUND

[0002] A venturi flowmeter is a differential pressure flow measurement device based on the Venturi effect. It calculates the flow rate of a fluid by measuring the pressure difference generated when the fluid passes through a section of pipe that gradually narrows and then widens. Venturi flowmeters are widely used in industrial and laboratory environments for measuring the flow of liquids and gases due to their simple structure, high precision, and low pressure loss.

[0003] A conventional venturi flowmeter includes a venturi tube composed of an inlet section, a converging section, a throat section, a diverging section, and an outlet section. The inner holes of the converging section and the diverging section are both conical holes. A typical venturi flow tube structure is a large high-precision main water supply venturi tube assembly (publication number CN111750938A) developed and authorized by our company. It reduces the disturbance of the fluid under high temperature and high pressure by setting a flow straightener plate at the front end of the venturi tube section and an upstream straight pipe, and a downstream straight pipe at the rear end of the venturi tube section, so that the fluid forms a more stable flow pattern on both sides of the venturi tube section, thereby improving the measurement accuracy of the large venturi tube flowmeter. However, this large venturi tube flowmeter is designed specifically for the unidirectional flow of fluid and cannot measure the flow under bidirectional flow conditions (i.e., sometimes forward flow and sometimes reverse flow).

[0004] To achieve bidirectional measurement, the converging section conical hole and the diverging section conical hole of the venturi tube can be made into a symmetrical structure. However, tests have shown that this symmetrical structure venturi tube improved on the basis of the conventional venturi flowmeter has a narrow range of measurement and limited accuracy.

[0005] In addition, the large high-precision main water supply venturi tube assembly also optimizes the inside diameter size of the closing cylinder section (throat cylinder section) of the product venturi tube section by setting a debugging venturi tube section to improve the performance of the venturi tube flowmeter. However, this debugging venturi tube section technology still has the following shortcomings:

[0006] First, the new closing cylinder section (throat cylinder section) inner hole experimental size is obtained by using the film sticking method, but the film sticking method requires the debugging venturi tube section to be disassembled for testing, which is time-consuming and troublesome. In addition, there are significant differences in performance and roughness between the film wall and the actual product venturi tube metal pipe wall, and there may be defects such as misalignment and step difference at the two ends of the film hole after sticking the film, which will affect the accuracy of the test.

[0007] Second, the inner hole diameter of the closed cylinder section (throat cylinder section) is adjusted by using the liquid plastic expansion ring, and the adjustment amount is small, and if the adjustment amount is increased, a large nonlinear deformation error (drum-shaped error of the middle part bulging towards the inner hole) will occur, which is greatly different from the straight hole shape of the simulation design, and if the nonlinear shape is applied to the actual product Venturi tube, it may lead to difficult processing, and the inner hole of the throat section may also affect the stability of the fluid if a special nonlinear shape is used, which is not conducive to improving the performance of the actual product Venturi tube.

[0008] Third, the inner hole size of the debugged Venturi tube section after test optimization cannot be measured online, and the debugged Venturi tube section needs to be removed from the test table to be measured, but since the deformation shape and size of the liquid plastic expansion ring is the result of the balance of the internal liquid plastic pressure and the internal fluid pressure of the debugged Venturi tube section, when the debugged Venturi tube section is removed, the balance of the fluid pressure is lost, so the inner hole size of the debugged Venturi tube obtained is different from the size during the actual test, thereby greatly affecting the test accuracy. Practical new type content

[0009] In order to solve the above problems, the utility model provides a kind of bidirectional flow wide range Venturi flowmeter and optimization design method, to overcome the above-mentioned shortcomings of existing Venturi flowmeter, realize the high-precision measurement of bidirectional flow wide range Venturi flowmeter.The specific technical scheme is as follows:

[0010] A kind of bidirectional flow wide range Venturi flowmeter, including Venturi tube and the flange connection component being arranged at the left and right ends of the Venturi tube, the Venturi tube includes sequentially arranged and connected inlet section, contraction section, throat section, diffusion section and outlet section from left to right, wherein the contraction section is double taper contraction section, the diffusion section is double taper diffusion section, and the inlet section, double taper contraction section and the double taper diffusion section, outlet section are symmetrically arranged at the two ends of the throat section relative to the throat section;A plurality of throat section pressure holes are arranged on the outer circle of the throat section of the Venturi tube and are in communication with the fluid through holes of the throat section, a plurality of inlet section pressure holes are arranged on the outer circle of the inlet section of the Venturi tube and are in communication with the fluid through holes of the inlet section, and a plurality of outlet section pressure holes are arranged on the outer circle of the outlet section of the Venturi tube and are in communication with the fluid through holes of the outlet section;First pressure ring, second pressure ring and third pressure ring with inner ring groove are further arranged on the outer circle of the Venturi tube, the inlet section pressure hole is in communication with the inner ring groove of the first pressure ring, the throat section pressure hole is in communication with the inner ring groove of the second pressure ring, and the outlet section pressure hole is in communication with the inner ring groove of the third pressure ring;Pressure tapping pipe is led out from the inner ring groove of first pressure ring, second pressure ring and third pressure ring.

[0011] Preferably, the number of the inlet section piezometer hole, the throat section piezometer hole and the outlet section piezometer hole is four and they are uniformly distributed along the outer circumference of the Venturi tube.

[0012] Preferably, the first piezometer ring, the second piezometer ring and the third piezometer ring are all sleeved on the outer circle of the Venturi tube and are arranged by welding to realize the closure of the inner ring groove.

[0013] In the utility model, the fluid through hole of the inlet section and the throat section is a straight hole, the fluid through hole of the double taper contraction section includes a large taper taper hole and a small taper taper hole which are sequentially arranged from left to right and the taper of the large taper taper hole is relatively large and the taper of the small taper taper hole is relatively small; the fluid through hole of the double taper diffusion section includes a small taper taper hole and a large taper taper hole which are sequentially arranged from left to right and the taper of the small taper taper hole is relatively small and the taper of the large taper taper hole is relatively large.

[0014] Preferably, the conical angle of the large taper taper hole is 80 DEG ± 5 DEG and the conical angle of the small taper taper hole is 14 DEG ± 2 DEG.

[0015] Preferably, the ratio of the hole diameter of the inlet section straight hole to the hole diameter of the throat section straight hole is 1.75:1-2.15:1.

[0016] Preferably, the inlet section piezometer hole is located at the edge position of the abutting position of the inlet section and the contraction section on the outer circle of the inlet section, the throat section piezometer hole is located at the middle position of the outer circle of the throat section and the outlet section piezometer hole is located at the edge position of the abutting position of the outlet section and the diffusion section on the outer circle of the outlet section.

[0017] In the utility model, the flange connecting assembly includes a pair of connecting flanges which are respectively arranged at the left end and the right end of the Venturi tube and are clamped and connected by a connecting screw, and one of the connecting flanges is welded to the end of the Venturi tube.

[0018] Preferably, an end surface ring groove is arranged between the clamping surfaces of the pair of connecting flanges and an annular sealing ring is arranged in the end surface ring groove.

[0019] Preferably, the geometric dimensions of the inlet section, the contraction section, the throat section, the diffusion section and the outlet section of the Venturi tube are the geometric dimensions obtained by simulation optimization.

[0020] Preferably, the geometric dimensions of the inlet section, the contraction section, the throat section, the diffusion section and the outlet section of the Venturi tube are further verified by test after simulation optimization, and the geometric dimensions of the contraction section, the throat section and the diffusion section of the Venturi tube are further optimized through test verification.

[0021] An optimization design method of a bidirectional flow wide-range Venturi flowmeter, comprising the following steps:

[0022] (1) Preliminary design: design the basic structure of the Venturi tube, which includes an inlet section, a converging section, a throat section, a diverging section and an outlet section, wherein the converging section is a double-tapered converging section, the diverging section is a double-tapered diverging section, and the inlet section, the double-tapered converging section and the double-tapered diverging section, the outlet section are symmetrically arranged at both ends of the throat section relative to the throat section;

[0023] (2) Simulation optimization: a simulation model of the bidirectional flow wide-range Venturi flowmeter is established to improve the measurement accuracy, and the inner hole geometric dimensions of the inlet section, the converging section, the throat section, the diverging section and the outlet section of the Venturi tube are simulated and optimized to obtain the simulation optimization size data of the Venturi tube;

[0024] (3) Production of test Venturi tube: according to the simulation optimization size data of the Venturi tube, a test Venturi tube is designed and produced, the inner hole geometric dimensions of the inlet section, the converging section, the throat section, the diverging section and the outlet section of the Venturi tube obtained by simulation optimization are taken as the initial data of the inner hole geometric dimensions of the test Venturi tube, and a geometric dimension adjusting device is arranged on the test Venturi tube, so that the test Venturi tube becomes a size-adjustable test Venturi tube with the inner hole geometric dimensions of the converging section, the throat section and the diverging section being synchronously adjustable; a geometric dimension online measurement module is also arranged on the size-adjustable test Venturi tube for dynamically measuring the inner hole geometric dimensions of the converging section, the throat section and the diverging section of the Venturi tube during the test;

[0025] (4) Test verification: the size-adjustable test Venturi tube is installed on the Venturi tube test bench for performance test and verification to obtain the actual flow measurement accuracy data under wide range;

[0026] (5) Dynamic adjustment: the geometric dimensions of the converging section, the throat section and the diverging section of the test Venturi tube are adjusted synchronously online through the geometric dimension adjusting device on the test Venturi tube, and the actual flow measurement accuracy of the test Venturi tube under wide range is verified after size adjustment; through continuous adjustment for several times, the optimal geometric dimensions of the converging section, the throat section and the diverging section of the test Venturi tube with the optimal actual flow measurement accuracy under wide range are obtained; the optimal geometric dimensions are measured by the photoelectric distance measuring sensor of the geometric dimension online measurement module;

[0027] (6) Final design: the optimal geometric dimensions of the test Venturi tube obtained in step (5) dynamic adjustment are taken as the final design size of the Venturi tube of the bidirectional flow wide-range Venturi flowmeter.

[0028] The actual flow measurement accuracy of the bidirectional flow wide-range Venturi flowmeter is obtained by comparing with the standard flowmeter on the test bench.

[0029] Preferably, the experimental bench is provided with a plurality of high-precision narrow-range Venturi flow meters as standard flow meters of different ranges, and the series combination of the plurality of narrow-range Venturi flow meters covers the wide-range measurement range of the bidirectional flow wide-range Venturi flow meter.

[0030] In the utility model, the size-adjustable experimental Venturi tube includes a circular straight cylinder and a composite thin-walled pipe connected to the middle part of the inner hole wall of the circular straight cylinder, the composite thin-walled pipe includes a convergent section thin-walled pipe for forming a convergent section inner hole, a throat section thin-walled pipe for forming a throat section inner hole and a diffuser section thin-walled pipe for forming a diffuser section inner hole, which are sequentially arranged and connected from left to right, the convergent section thin-walled pipe is connected by a large taper thin-walled pipe with relatively large taper and a small taper thin-walled pipe with relatively small taper which are sequentially arranged from left to right, the diffuser section thin-walled pipe is connected by a small taper thin-walled pipe with relatively small taper and a large taper thin-walled pipe with relatively large taper which are sequentially arranged from left to right, a closed annular cavity is formed between the composite thin-walled pipe and the inner hole of the circular straight cylinder, the geometric size adjusting device of the size-adjustable experimental Venturi tube includes a vacuum suction port arranged on the circular straight cylinder and connected to the annular cavity, and a vacuum system connected to the vacuum suction port through a vacuum suction pipeline, and a vacuum degree adjusting device for adjusting the vacuum degree inside the annular cavity is arranged on the vacuum suction pipeline.

[0031] Preferably, the number of the vacuum suction ports is multiple and is uniformly distributed on the outer circle of the middle section of the experimental Venturi tube.

[0032] Preferably, the connection between the pipe wall of the two ends of the composite thin-walled pipe and the inner hole wall of the circular straight cylinder adopts welding connection.

[0033] In order to obtain a larger elastic tensile deformation amount when the composite thin-walled pipe is stretched outward under the action of vacuum, the composite thin-walled pipe can be made of an elastic metal material, so that different test conditions can be repeatedly verified. Of course, the composite thin-walled pipe can also be made of a non-elastic metal material with good extension performance, and the test can start from the smallest tensile deformation and continue until the larger tensile deformation. Such a test can only be tested once for each size (because the composite thin-walled pipe cannot be reset after plastic deformation after stretching), and the advantage is that a larger diameter range can be obtained, thereby obtaining more test data.

[0034] Preferably, the vacuum degree adjusting device comprises a first electric regulating valve connected in series on the vacuum suction pipeline for cutting off or connecting the vacuum suction pipeline, a vacuum pressure gauge connected transversely on the vacuum suction pipeline for measuring the vacuum degree inside the annular cavity, and a second electric regulating valve connected transversely on the vacuum suction pipeline for adjusting the vacuum degree inside the annular cavity.

[0035] In the utility model, the geometric size on-line measurement module comprises a plurality of photoelectric distance measuring sensors which are arranged at intervals along the axial direction on the circular straight cylinder.

[0036] Preferably, a plurality of photoelectric distance measuring sensors are arranged at intervals along the circumferential direction on the same circumference of the circular straight cylinder.

[0037] Preferably, the inner hole geometric sizes of the inlet section, the contraction section, the throat section, the diffusion section and the outlet section of the simulation-optimized Venturi tube are used as the basis for manufacturing the test Venturi tube, and the inner hole geometric size of the contraction section, the throat section and the diffusion section of the simulation-optimized Venturi tube is appropriately reduced by a predetermined value e based on the inner hole size D of the throat section; during the test, the test verification is started from the smallest throat inner hole geometric size (D-e), and the composite-shaped thin-walled tube is subjected to step-by-step meridional stretching by gradually increasing the vacuum degree inside the annular cavity, so that the inner hole geometric sizes of the contraction section, the throat section and the diffusion section of the test Venturi tube are gradually expanded until the largest throat inner hole geometric size (D+e).

[0038] As a further improvement, the optimization design method of the bidirectional flow wide-range Venturi flowmeter also comprises a pore diameter linear smoothing processing module for compensating the nonlinear deformation of the composite-shaped thin-walled tube of the test Venturi tube under the action of the vacuum inside the annular cavity; the pore diameter linear smoothing processing module comprises a gas-permeable elastic thermal expansion foamed porous material filled inside the annular cavity, and a plurality of power-adjustable annular low-temperature heat tracing strips are embedded in the gas-permeable elastic thermal expansion foamed porous material at intervals along the axial direction, and the power-adjustable annular low-temperature heat tracing strips are connected to a temperature control system.

[0039] Preferably, the gas-permeable elastic thermal expansion foamed porous material is a silicon rubber gas-permeable elastic thermal expansion foamed porous material containing 10-30% aluminum powder.

[0040] Preferably, the silicon rubber gas-permeable elastic thermal expansion foamed porous material is formed by mixing aluminum powder, a foaming agent, a vulcanizing agent and a silicon rubber matrix, filling them inside the annular cavity of the Venturi tube, and decomposing the foaming agent and triggering the vulcanization reaction under a certain temperature and pressure.

[0041] In order to realize the filling of the foamed material, a filling port can be formed on the circular straight cylinder, and a sealing plug is arranged on the filling port.

[0042] Preferably, in order to prevent the deformation of the composite thin-walled sleeve during foaming, a pair of anti-deformation mandrels matched with the inner holes of the composite thin-walled tube (including the tapered hole) can be installed in the inner holes of the composite thin-walled tube during foaming (the anti-deformation mandrels are respectively installed from both ends).

[0043] In the utility model, the air-permeable elastic thermal expansion foamed porous material is provided with a detection avoidance hole for the detection light of the photoelectric distance measuring sensor to pass through; and a metal corrugated expansion pipe for forming the throat section pressure measuring hole is connected between the circular straight cylinder and the throat section thin-walled tube.

[0044] Preferably, in the step (5) of dynamic adjustment, the non-linear deformation (drum shape or concave shape) of the thin-walled tube of the contraction section, the throat section and the diffusion section of the test Venturi tube under the vacuum effect inside the annular cavity is corrected by the aperture linear smoothing processing module as follows:

[0045] S1, measurement: the aperture size data of the axial positions of the thin-walled tube of the contraction section, the throat section and the diffusion section of the test Venturi tube measured on line by the photoelectric distance measuring sensor,

[0046] S2, calculation: the non-linear deformation error of the thin-walled tube of the contraction section (including the large taper thin-walled tube and the small taper thin-walled tube), the non-linear deformation error of the thin-walled tube of the throat section and the non-linear deformation error of the thin-walled tube of the diffusion section (including the large taper thin-walled tube and the small taper thin-walled tube) are calculated respectively;

[0047] S3, correction: according to the non-linear deformation error data of different positions of the composite thin-walled sleeve, the temperature control system of the aperture linear smoothing processing module is started, different heating powers are applied to different positions of the air-permeable elastic thermal expansion foamed porous material by the power-adjustable annular low-temperature heat tracing pieces embedded in different positions inside the air-permeable elastic thermal expansion foamed porous material, so that the air-permeable elastic thermal expansion foamed porous material forms a gradient temperature difference, different elastic deformation compensation amounts are obtained at different positions, and the elastic deformation compensation amounts act on the composite thin-walled sleeve, so that the non-linear deformation of the thin-walled tube of the contraction section, the throat section and the diffusion section of the test Venturi tube is corrected.

[0048] The utility model has the advantages of:

[0049] First, the present invention relates to a bidirectional wide-range Venturi flow meter and its optimized design method, wherein the inlet section, constriction section, throat section, diffuser section and outlet section of the Venturi tube are arranged sequentially and symmetrically on both sides with the throat section as the center, which can realize bidirectional flow measurement; and the constriction section and the diffuser section both adopt a double-tapered structure, which is beneficial to improving the stability of the fluid and realizing bidirectional wide-range flow measurement.

[0050] Secondly, the bidirectional wide-range Venturi flow meter and its optimization design method of this utility model adopt a variable diameter design by using the vacuum tensile deformation principle for the adjustment Venturi tube. Its deformation range is large, which is conducive to finding the optimization point within a wide size range and improving the performance of the Venturi flow meter.

[0051] Third, the bidirectional wide-range Venturi flow meter and its optimized design method of this utility model allow for online dynamic adjustment of the venturi tube diameter without disassembly. The inner hole size after diameter adjustment is dynamically measured by a photoelectric distance sensor (the measurement is of a composite shape thin-walled tube, which is calculated by converting the wall thickness). This overcomes the drawback of the existing technology (CN111750938A A large high-precision main water supply venturi tube assembly) which requires disassembly after experimentation, resulting in dimensional distortion.

[0052] Fourth, the present invention relates to a bidirectional wide-range Venturi flow meter and its optimized design method. The Venturi tube is equipped with a linear smoothing module for aperture. By controlling the heating power of the adjustable annular low-temperature heating element at different locations, a temperature gradient can be formed inside the Venturi tube. This allows the thermal expansion of the permeable elastic thermal expansion foamed porous material inside the annular cavity to vary at different locations. Furthermore, the thermal expansion of the permeable elastic thermal expansion foamed porous material counteracts or reduces the nonlinear deformation error of the composite thin-walled tube during vacuum stretching deformation, thus providing a smoothing correction effect for the conical and straight holes on the composite thin-walled tube. This achieves the optimal design of the bidirectional wide-range Venturi flow meter. Attached Figure Description

[0053] Fig. 1 This is a schematic diagram of the structure of a bidirectional wide-range Venturi flow meter according to this utility model;

[0054] Fig. 2 This is a schematic diagram of the structure of the experimental venturi tube in this utility model;

[0055] Fig. 3 yes Fig. 1 and Fig. 2 A schematic diagram of the pressure measuring ring in the diagram.

[0056] In the figure: 100, Venturi tube, 101, flange connection assembly, 102, inlet section, 103, converging section, 104, throat section, 105, diverging section, 106, outlet section, 107, throat section pressure tapping hole, 108, inlet section pressure tapping hole, 109, outlet section pressure tapping hole, 110, inner ring groove, 111, first pressure tapping ring, 112, second pressure tapping ring, 113, third pressure tapping ring, 114, pressure tapping pipe, 115, large taper taper hole, 116, small taper taper hole, 117, coupling screw, 118, coupling flange, 119, annular sealing ring;

[0057] 200, test Venturi tube, 201, circular straight cylinder, 202, composite thin-walled tube, 203, converging section thin-walled tube, 204, throat section thin-walled tube, 205, diverging section thin-walled tube, 206, large taper thin-walled tube, 207, small taper thin-walled tube, 208, annular cavity, 209, vacuum suction port, 210, vacuum suction pipeline, 211, vacuum system, 212, vacuum degree adjusting device, 213, first electric regulating valve, 214, vacuum pressure gauge, 215, second electric regulating valve, 216, photoelectric distance measuring sensor, 217, aperture linear smoothing processing module, 218, air-permeable elastic thermal expansion foaming porous material, 219, power adjustable annular low temperature heat tracing piece, 220, temperature control system, 221, detection avoidance hole, 222, metal corrugated expansion pipe. DETAILED DESCRIPTION

[0058] The specific embodiments of the present application will be further described below in conjunction with the drawings and examples. The following examples are only used to more clearly illustrate the technical scheme of the present application, and cannot be used to limit the protection scope of the present application.

[0059] Example 1:

[0060] As Figs. 1 to 3The utility model discloses a two -way flow wide range of venturi flowmeter's embodiment, including venturi 100 and the flange connection assembly 101 of setting in the left and right two ends of venturi 100, venturi 100 includes the inlet section 102, the contraction section 103, the throat section 104, the diffusion section 105 and the outlet section 106 that are sequentially arranged and are connected from left to right, wherein, the contraction section 103 is two taper contraction section, the diffusion section 105 is two taper diffusion section, and the inlet section 102, two taper contraction section 103 with two taper diffusion section 105, outlet section 106 are relative to the throat section 104 and are arranged symmetrically in the both ends of throat section 104, a plurality of throat section pressure tapping hole 107 that the fluid through -hole of throat section 104 is linked together is arranged on the outer circle of the throat section 104 of venturi 100 along the circumference, a plurality of inlet section pressure tapping hole 108 that the fluid through -hole of inlet section 102 is linked together is arranged on the outer circle of inlet section 102 of venturi 100 along the circumference, a plurality of outlet section pressure tapping hole 109 that the fluid through -hole of outlet section 106 is linked together is arranged on the outer circle of outlet section 106 of venturi 100 along the circumference, first pressure ring 111 with inner ring groove 110, second pressure ring 112 and third pressure ring 113 are also arranged on the outer circle of venturi 100 respectively, the inner ring groove 110 of first pressure ring 111 is linked together with inlet section pressure tapping hole 108, the inner ring groove 110 of second pressure ring 112 is linked together with throat section pressure tapping hole 107, the inner ring groove 110 of third pressure ring 113 is linked together with outlet section pressure tapping hole 109, and first pressure ring 111, second pressure ring 112 and third pressure ring 113 are led out with the pressure tapping pipe 114 that is linked together with the inner ring groove 110 respectively.

[0061] Preferably, the number of inlet section pressure tapping hole 108, throat section pressure tapping hole 107 and outlet section pressure tapping hole 109 is four, and they are evenly distributed along the circumference of the outer circle of venturi 1000.

[0062] Preferably, the first pressure ring 111, the second pressure ring 112 and the third pressure ring 113 are all sleeved on the outer circle of the venturi 100 and are closed by welding.

[0063] In the utility model, the fluid through -hole of the inlet section 102 and the throat section 104 is a straight hole, the fluid through -hole of the two taper contraction section 103 includes a large taper taper hole 115 and a small taper taper hole 116 arranged from left to right in sequence, and the fluid through -hole of the two taper diffusion section 105 includes a small taper taper hole 116 and a large taper taper hole 115 arranged from left to right in sequence.

[0064] Preferably, the large tapering hole 115 has a conical angle of 80°±5°, and the small tapering hole 116 has a conical angle of 14°±2°.

[0065] Preferably, the ratio of the hole diameter of the straight hole of the inlet section 102 to the hole diameter of the straight hole of the throat section 104 is 1.75:1 to 2.15:1.

[0066] Preferably, the pressure tapping hole 108 of the inlet section is located at the edge of the outer circle of the inlet section 102 at the position where the inlet section 102 is adjacent to the contraction section 103, the pressure tapping hole 107 of the throat section is located at the middle position of the outer circle of the throat section 104, and the pressure tapping hole 109 of the outlet section is located at the edge of the outer circle of the outlet section 106 at the position where the outlet section 106 is adjacent to the diffusion section 105.

[0067] In the utility model, the flange connecting assembly 101 includes a pair of connecting flanges 118 which are respectively arranged at the left and right ends of the Venturi tube 100 and are clamped and docked through the clamping of connecting screws 117, and one of the connecting flanges 118 in the pair of connecting flanges 118 is welded to the end of the Venturi tube 100.

[0068] Preferably, an end face ring groove is formed between the clamping surfaces of the pair of connecting flanges 118, and a ring-shaped sealing ring 119 is arranged in the end face ring groove.

[0069] Preferably, the geometric dimensions of the inlet section 102, the contraction section 103, the throat section 104, the diffusion section 105 and the outlet section 106 of the Venturi tube 100 are obtained through simulation optimization.

[0070] Preferably, the geometric dimensions of the inlet section 102, the contraction section 103, the throat section 104, the diffusion section 105 and the outlet section 106 of the Venturi tube 100 are obtained through simulation optimization.

[0071] Embodiment 2:

[0072] An optimization design method of a bidirectional flow wide-range Venturi flowmeter, comprising the following steps:

[0073] (1) Preliminary design: design the basic structure of the Venturi tube 100, which includes an inlet section 102, a converging section 103, a throat section 104, a diverging section 105, and an outlet section 106, wherein the converging section 103 is a double-tapered converging section, the diverging section 105 is a double-tapered diverging section, and the inlet section 102, the double-tapered converging section 103, the double-tapered diverging section 105, and the outlet section 106 are symmetrically arranged at both ends of the throat section 105;

[0074] (2) Simulation optimization: establish a simulation model of a bidirectional flow wide-range Venturi flowmeter aimed at improving measurement accuracy under a wide range, and perform simulation optimization on the inner hole geometric dimensions of the inlet section 102, the converging section 103, the throat section 104, the diverging section 105, and the outlet section 106 of the Venturi tube 100 to obtain simulation optimization size data of the Venturi tube 100;

[0075] (3) Production of a test Venturi tube: according to the simulation optimization size data of the Venturi tube 100, design and produce a test Venturi tube 200, take the inner hole geometric dimensions of the inlet section 102, the converging section 103, the throat section 104, the diverging section 105, and the outlet section 106 of the Venturi tube 100 obtained through simulation optimization as the initial data of the inner hole geometric dimensions of the test Venturi tube 200, and set a geometric dimension adjustment device on the test Venturi tube 200, so that the test Venturi tube 200 becomes a size-adjustable test Venturi tube with the inner hole geometric dimensions of the converging section 103, the throat section 104, and the diverging section 105 being synchronously adjustable; the size-adjustable test Venturi tube is also provided with a geometric dimension online measurement module for dynamically measuring the inner hole geometric dimensions of the converging section 103, the throat section 104, and the diverging section 105 of the Venturi tube during testing;

[0076] (4) Test verification: install the size-adjustable test Venturi tube 200 on a Venturi tube test bench for performance testing and verification to obtain actual flow measurement accuracy data under a wide range;

[0077] (5) Dynamic adjustment: adjust the geometric dimensions of the converging section 103, the throat section 104, and the diverging section 105 of the test Venturi tube 200 synchronously and online through the geometric dimension adjustment device on the test Venturi tube 200, and test and verify the actual flow measurement accuracy of the test Venturi tube 200 under a wide range after size adjustment; through continuous adjustment for several times, obtain the optimal geometric dimensions of the converging section 103, the throat section 104, and the diverging section 105 of the test Venturi tube 200 under a wide range, which have the optimal actual flow measurement accuracy; the optimal geometric dimensions are measured by the geometric dimension online measurement module through an optical distance measuring sensor 216;

[0078] (6) Final design: the optimal geometric size of the test Venturi tube 200 obtained in step (5) dynamic adjustment is taken as the final design size of the Venturi tube 100 of the bidirectional flow wide-range Venturi flowmeter.

[0079] The actual flow measurement accuracy of the bidirectional flow wide-range Venturi flowmeter is obtained by comparison with the standard flowmeter on the test bench.

[0080] Preferably, a plurality of high-precision narrow-range Venturi flowmeters are arranged on the test bench as standard flowmeters of different ranges, and the series combination of the plurality of narrow-range Venturi flowmeters covers the wide-range measurement range of the bidirectional flow wide-range Venturi flowmeter.

[0081] In the utility model, the size-adjustable test Venturi tube 200 includes a circular straight cylinder 201 and a composite thin-walled tube 202 connected to the middle part of the inner hole wall of the circular straight cylinder 201, the composite thin-walled tube 202 includes a convergent section thin-walled tube 203 for forming the inner hole of the convergent section 103, a throat section thin-walled tube 204 for forming the inner hole of the throat section 104 and a diffuser section thin-walled tube 205 for forming the inner hole of the diffuser section 105, which are sequentially arranged and connected from left to right, the convergent section thin-walled tube 203 is connected by a large taper thin-walled tube 206 with relatively large taper and a small taper thin-walled tube 207 with relatively small taper, which are sequentially arranged from left to right, the diffuser section thin-walled tube 205 is connected by the small taper thin-walled tube 207 with relatively small taper and the large taper thin-walled tube 206 with relatively large taper, which are sequentially arranged from left to right, the composite thin-walled tube 202 and the inner hole of the circular straight cylinder 201 form a closed annular cavity 208, the geometric size adjusting device of the size-adjustable test Venturi tube includes a vacuum suction port 209 arranged on the circular straight cylinder 201 and connected with the annular cavity 208, and a vacuum system 211 connected with the vacuum suction port 209 through a vacuum suction pipeline 210, and a vacuum degree adjusting device 212 is arranged on the vacuum suction pipeline 210 for adjusting the vacuum degree inside the annular cavity 208.

[0082] Preferably, the number of the vacuum suction ports 209 is multiple and is uniformly distributed on the outer circle of the middle section of the test Venturi tube 200.

[0083] Preferably, the connection between the tube walls of the two ends of the composite thin-walled tube 202 and the inner hole wall of the circular straight cylinder 201 adopts welding connection.

[0084] In order to make the composite shape thin-walled tube 202 obtain a larger elastic tensile deformation under the action of vacuum, the composite shape thin-walled tube 202 can be made of an elastic metal material, so that different test conditions can be repeatedly verified. Of course, the composite shape thin-walled tube 202 made of a non-elastic metal material with good extension performance can be used, and the test can start from the smallest tensile deformation to the larger tensile deformation. Such a test can only test one size each time (because the composite shape thin-walled tube 202 cannot be reset after plastic deformation after stretching), and the advantage is that a larger diameter range can be obtained, thereby obtaining more test data.

[0085] Preferably, the vacuum degree adjusting device 212 includes a first electric regulating valve 213 connected in series on the vacuum suction pipeline 210 for cutting off or connecting the vacuum suction pipeline 210, a vacuum pressure gauge 214 connected transversely on the vacuum suction pipeline 210 for measuring the vacuum degree inside the annular cavity 208, and a second electric regulating valve 215 connected transversely on the vacuum suction pipeline 210 for realizing the adjustment of the vacuum degree inside the annular cavity 208.

[0086] In the utility model, the geometric size on-line measurement module includes a plurality of photoelectric distance measuring sensors 216 which are arranged at intervals along the axial direction on the circular straight cylinder 201.

[0087] Preferably, a plurality of photoelectric distance measuring sensors 216 are arranged at intervals along the circumferential direction on the same circumference of the circular straight cylinder 201.

[0088] Preferably, the inner hole geometric sizes of the inlet section 102, the contraction section 103, the throat section 104, the diffusion section 105 and the outlet section 106 of the Venturi tube 100 obtained through simulation optimization are used as the basis for manufacturing the test Venturi tube 200, and the inner hole geometric sizes of the contraction section 103, the throat section 104 and the diffusion section 105 of the Venturi tube 100 obtained through simulation optimization are appropriately reduced by a predetermined value e based on the inner hole size D of the throat section; during the test, the test verification starts from the smallest throat inner hole geometric size (D-e), and the composite shape thin-walled tube 202 is gradually stretched in the radial direction by gradually increasing the vacuum degree inside the annular cavity 208, so that the inner hole geometric sizes of the contraction section 103, the throat section 104 and the diffusion section 105 of the test Venturi tube 200 are gradually expanded until the maximum throat inner hole geometric size (D+e).

[0089] As a further improvement, the optimization design method of the bidirectional flow wide-range Venturi flowmeter further comprises a pore diameter linear smoothing processing module 217 for compensating the nonlinear deformation of the composite shape thin-walled pipe 202 of the test Venturi pipe 200 under the vacuum effect inside the annular cavity 208.

[0090] Preferably, the air-permeable elastic thermal expansion foamed porous material 218 is a silicon rubber air-permeable elastic thermal expansion foamed porous material containing 10-30% aluminum powder.

[0091] Preferably, the silicon rubber air-permeable elastic thermal expansion foamed porous material is formed by mixing aluminum powder, a foaming agent, a vulcanizing agent and a silicon rubber matrix, filling them into the annular cavity of the Venturi pipe, and decomposing the foaming agent and triggering the vulcanization reaction under certain temperature and pressure.

[0092] In order to realize the filling of the foamed material, a filling port can be formed on the circular straight cylinder 201, and a sealing plug is arranged on the filling port. The sealing plug can be closed by welding after filling to enhance the sealing performance.

[0093] Preferably, in order to prevent the deformation of the composite shape thin-walled sleeve 202 during foaming, a pair of anti-deformation shafts (anti-deformation shafts are respectively installed from both ends) matched with the inner hole (including the tapered hole) of the composite shape thin-walled pipe 202 can be installed in the inner hole of the composite shape thin-walled pipe 202 of the test Venturi pipe 200 during the foaming process.

[0094] In the utility model, the air-permeable elastic thermal expansion foamed porous material 218 is provided with a detection avoidance hole 221 for the detection light of the photoelectric distance measuring sensor 216 to pass through; a metal corrugated expansion pipe 222 for forming the throat section pressure measuring hole 107 is connected between the circular straight cylinder 201 and the throat section thin-walled pipe 204.

[0095] Preferably, in the step (5) of dynamic adjustment, the nonlinear deformation (drum shape or concave shape) of the thin-walled pipe of the contraction section 103, the throat section 104 and the diffusion section 105 of the test Venturi pipe 200 under the vacuum effect inside the annular cavity 208 is corrected by the pore diameter linear smoothing processing module 217 as follows:

[0096] S1, measurement: the aperture size data of the thin-walled tube of the contraction section 103, the throat section 104 and the diffusion section 105 of the test Venturi tube 200 measured on line by the photoelectric distance measuring sensor 216,

[0097] S2, calculation: the nonlinear deformation error of the thin-walled tube of the contraction section 203 (including the large taper thin-walled tube 206 and the small taper thin-walled tube 207), the nonlinear deformation error of the thin-walled tube of the throat section 204 and the nonlinear deformation error of the thin-walled tube of the diffusion section 205 (including the large taper thin-walled tube 206 and the small taper thin-walled tube 207) are calculated respectively;

[0098] S3, correction: according to the nonlinear deformation error data of different parts of the composite shape thin-walled sleeve 202, the temperature control system 220 of the aperture linear smoothing processing module 217 is opened, different heating powers are applied to different positions of the air-permeable elastic thermal expansion foamed porous material 218 through the power-adjustable annular low-temperature heating sheet 219 embedded in different positions inside the air-permeable elastic thermal expansion foamed porous material 218, so that the air-permeable elastic thermal expansion foamed porous material 218 forms a gradient temperature difference, so that different elastic deformation compensation amounts are obtained at different positions, and the elastic deformation compensation amounts act on the composite shape thin-walled sleeve 202, so that the nonlinear deformation of the thin-walled tube of the contraction section 103, the throat section 104 and the diffusion section 105 of the test Venturi tube 200 is corrected.

[0099] The above is only the preferred embodiment of the present application, it should be pointed out that for ordinary skilled in the art, without departing from the technical principles of the present application, can make a number of improvements and refinements, these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A bidirectional flow wide-range Venturi flowmeter characterized by, The application relates to a Venturi tube and a flange connecting assembly arranged at the left and right ends of the Venturi tube, wherein the Venturi tube comprises an inlet section, a converging section, a throat section, a diverging section and an outlet section arranged in sequence from left to right and connected, the converging section is a double-tapered converging section, the diverging section is a double-tapered diverging section, and the inlet section, the double-tapered converging section, the double-tapered diverging section and the outlet section are symmetrically arranged at the two ends of the throat section; a plurality of throat section pressure holes are arranged on the outer circle of the throat section of the Venturi tube and connected with fluid through holes of the throat section; a plurality of inlet section pressure holes are arranged on the outer circle of the inlet section of the Venturi tube and connected with fluid through holes of the inlet section; a plurality of outlet section pressure holes are arranged on the outer circle of the outlet section of the Venturi tube and connected with fluid through holes of the outlet section; a first pressure ring, a second pressure ring and a third pressure ring with inner ring grooves are arranged on the outer circle of the Venturi tube, the inlet section pressure holes are connected with the inner ring grooves of the first pressure ring, the throat section pressure holes are connected with the inner ring grooves of the second pressure ring, and the outlet section pressure holes are connected with the inner ring grooves of the third pressure ring; pressure tapping pipes are arranged on the first pressure ring, the second pressure ring and the third pressure ring and connected with the inner ring grooves.

2. A bidirectional flow wide-range Venturi flow meter according to claim 1, wherein, The number of the inlet section pressure holes, the throat section pressure holes and the outlet section pressure holes is four, and the holes are arranged on the outer circle of the Venturi tube.

3. A bidirectional flow wide-range Venturi meter according to claim 1, wherein, The first pressure ring, the second pressure ring and the third pressure ring are arranged on the outer circle of the Venturi tube and are welded to realize the closed arrangement of the inner ring grooves.

4. A bidirectional flow wide-range Venturi meter according to claim 1, wherein, The fluid through holes of the inlet section and the throat section are straight holes, the fluid through holes of the double-tapered converging section comprise a large taper hole with relatively large taper and a small taper hole with relatively small taper arranged in sequence from left to right, and the fluid through holes of the double-tapered diverging section comprise a small taper hole with relatively small taper and a large taper hole with relatively large taper arranged in sequence from left to right.

5. A bidirectional flow wide-range Venturi meter according to claim 4, wherein, The conical angle of the large taper hole is 80 DEG + / - 5 DEG, and the conical angle of the small taper hole is 14 DEG + / - 2 DEG.

6. A bidirectional flow wide-range Venturi meter according to claim 4, wherein, The ratio of the hole diameter of the inlet section straight hole to the throat section straight hole is 1.75:1-2.15:

1.

7. A bidirectional flow wide-range Venturi meter according to claim 1, wherein, The inlet section pressure hole is located at the edge position of the adjacent joint of the inlet section and the converging section on the outer circle of the inlet section, the throat section pressure hole is located at the middle position of the outer circle of the throat section, and the outlet section pressure hole is located at the edge position of the adjacent joint of the outlet section and the diverging section on the outer circle of the outlet section.

8. A bidirectional flow wide-range Venturi meter according to claim 1, wherein, The flange connecting assembly comprises a pair of connecting flanges arranged at the left and right ends of the Venturi tube and clamped and connected through coupling screws, and one of the connecting flanges is welded to the end of the Venturi tube.

9. A bidirectional flow wide-range Venturi meter according to claim 8, wherein, An end surface ring groove is arranged between the clamping surfaces of the connecting flanges, and a ring-shaped sealing ring is arranged in the end surface ring groove.

10. A bidirectional flow wide-range Venturi meter according to claim 1, wherein, The geometric sizes of the inlet section, the converging section, the throat section, the diffuser section and the outlet section of the Venturi tube are the geometric sizes obtained through simulation optimization and test verification. The geometric sizes of the inlet section, the converging section, the throat section, the diffuser section and the outlet section of the Venturi tube are the geometric sizes obtained through simulation optimization and test verification.

Images