Fluid flow measuring system of ultrasonic flowmeter

Abstract

The utility model provides a fluid flow measuring system of an ultrasonic flow meter, which at least comprises an ultrasonic flow meter with four or more sound channels, an embedded rectifier embedded in a fluid inlet of the ultrasonic flow meter, front-end straight pipe sections which are arranged at the front ends of the ultrasonic flow meter and the embedded rectifier and are not less than 5D in length, and the inner diameters of the front-end straight pipe sections and the front-end straight pipe sections are the same and are D; the embedded rectifier sequentially comprises a spiral flow generator, a straight pipe mixing cavity and a flow straightener in the flow direction of fluid. The space intersection angle O of the upper and lower end faces of the blades of the spiral flow generator and the intersection angle P of the blades and the outer wall of the inner rectification cylinder and the inner wall of the outer rectification cylinder are changed; meanwhile, the side length U and the wall thickness K of a regular hexagon rectification hole of the flow straightener are changed, it is verified that the embedded rectifier measures fluid through combination of a large amount of analog simulation data and single actual measurement verification experiment data, and the four-channel ultrasonic flowmeter can meet the fluid measurement precision of 1% under different turbulent flow conditions.

Description

Technical Field

[0001] The utility model belongs to the technical field of fluid measurement, and relates to a fluid flow measurement system, in particular to a fluid flow measurement system of an ultrasonic flow meter. Background Art

[0002] Ultrasonic flowmeters have the characteristics of high measurement accuracy, wide range ratio, small starting flow rate, and low pressure loss. They are safe and reliable to use and simple to install and maintain. They are widely used in the measurement of process gases such as oil and gas, coalbed methane, and nitrogen. They can also be used for the measurement of urban gas and natural gas for users of various industrial and commercial enterprises.

[0003] The main principle of ultrasonic flowmeter is the time difference method. It only needs to measure the sound velocity of several or more sound channels to calculate the flow rate. Therefore, the measurement accuracy of ultrasonic flowmeter is easily affected by the flow state of the fluid in the pipeline. When the ultrasonic flowmeter is working, it is necessary to ensure that the flow state of the fluid on the measuring surface is fully developed.

[0004] When calibrating an ultrasonic flowmeter, the front end is usually required to have a longer straight pipe section, which has little effect on the flow state. However, under actual working conditions, the front end pipeline not only has flow obstructions such as elbows and valves, but also the straight pipe section is relatively short, which will affect the fluid flow state, resulting in turbulent flow states such as asymmetric flow, secondary flow, and vortex flow, affecting the measurement accuracy of the flowmeter.

[0005] In order to solve the above problems, the prior art installs a rectifier at the front end of the ultrasonic flowmeter to improve the flow state and improve the measurement accuracy of the ultrasonic flowmeter. The prior art rectifier includes a front rectifier plate and an embedded rectifier. The front rectifier plate is usually installed at the front end of the ultrasonic flowmeter. The straight pipe section length needs to be 10D or more. It is connected to the pipes at both ends through flanges, which can effectively improve asymmetric flow, but the pressure loss is large. Although the embedded rectifier can effectively improve vortex flow, it has a poor effect on improving flow states such as asymmetric flow and secondary flow. The straight pipe section length installed at the front end of the ultrasonic flowmeter needs to be 10D or more, otherwise it will affect its measurement accuracy. Utility Model Content

[0006] In order to solve the problem that the fluid flow measurement system of the ultrasonic flowmeter in the prior art has poor improvement effect on asymmetric flow, secondary flow and other flow states, a front end straight pipe section with a length of 10D or more is installed at the front end of the ultrasonic flowmeter. The purpose of the utility model is to provide a fluid flow measurement system of an ultrasonic flowmeter with a length of 5D installed at the front end of the ultrasonic flowmeter, which can meet the accuracy requirements of fluid flow measurement. The fluid flow measurement system of the ultrasonic flowmeter includes: at least one ultrasonic flowmeter with four channels or more and an embedded rectifier embedded in its fluid inlet, and a front end straight pipe section with a length of not less than 5D is set at the front end of them, and their inner diameters are the same, both D,

[0007] The embedded rectifier includes a swirler, a straight tube mixing chamber and a flow straightener in sequence along the fluid flow direction;

[0008] The vortexer has a length A of 0.25 to 0.3D and comprises two concentric inner and outer rectifying cylinders, with 8 to 12 rotating blades disposed between the inner and outer rectifying cylinders; wherein the blade thickness M is 1 to 1.5 mm, and the outer diameter S of the inner rectifying cylinder is 0.35 to 0.4D; the intersection line where the inner end face of each blade intersects with the outer wall of the inner rectifying cylinder intersects with the axis of the inner rectifying cylinder in space, and the intersection angle P is 15° to 25°; the lower end face line of each blade is translated along its inner end face line to the upper end face line, and the intersection angle O between the lower end face line and the upper end face line is 25° to 35°; the end face of the vortexer faces the direction of the flow of the measured fluid;

[0009] The straight tube mixing chamber is an empty pipe with a length B of 0.35D to 0.4D;

[0010] The length C of the flow straightener is 0.35D to 0.4D; the interior of the flow straightener is a plurality of evenly distributed regular hexagonal rectifying holes, the side length U of the regular hexagon is 0.05 to 0.08D, and the wall thickness K is 0.1 to 0.2 mm.

[0011] Preferably, the length A of the vortexer is 0.27D, the intersection angle O is 30°, the intersection angle P is 20°, the number of blades is 12, the blade thickness M is 1.2mm, the outer diameter S of the inner rectifying cylinder is 0.4D; the length B of the straight tube mixing chamber is 0.36D; the length C of the flow straightener is 0.38D, the side length U of the regular hexagon is 0.05D, and its wall thickness K is 0.1mm.

[0012] Preferably, the spinner is made of 316L material and produced by 3D printing technology, and its surface roughness is Ra3.2 to Ra6.3.

[0013] Preferably, the straight tube mixing chamber and the flow straightener are made of 304 or 316L stainless steel, and the surface roughness thereof is Ra3.2.

[0014] Preferably, the ultrasonic flowmeter is a four-channel ultrasonic flowmeter.

[0015] On the basis of the existing technology, the utility model changes the spatial intersection angle O of the upper and lower end faces of the vortexer blades, and the intersection angle P of the blades with the outer wall of the inner rectifying cylinder and the inner wall of the outer rectifying cylinder; at the same time, changes the side length U and wall thickness K of the regular hexagonal rectifying hole of the flow straightener. The embedded rectifier of the present invention is verified for fluid measurement through a combination of a large amount of simulation data and a single actual measurement verification experimental data, and the four-channel ultrasonic flowmeter can meet the fluid measurement accuracy of 1% under different turbulent flow conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the front-end three-dimensional structure of an embedded rectifier in a fluid flow measurement system of the present invention;

[0017] Figure 2 for Figure 1 A schematic diagram of the front structure of the embedded rectifier shown in FIG;

[0018] Figure 3 for Figure 1 A rear view structural diagram of the embedded rectifier shown in FIG;

[0019] Figure 4 for Figure 1 A schematic diagram of the axial cross-section of the embedded rectifier shown in FIG;

[0020] Figure 5 for Figure 1 Schematic diagram of the three-dimensional structure of the intersection angle O and the intersection angle P in a certain blade is shown in FIG.

[0021] Explanation of the accompanying symbols: 1. swirler, 2. straight tube mixing chamber, 3. flow straightener, 4. blade, 5. outer rectifying cylinder, 6. inner rectifying cylinder, 7. rectifying hole, 8. end face of swirler 1, 9. translation line. DETAILED DESCRIPTION

[0022] The following describes in detail a fluid flow measurement system of an ultrasonic flow meter provided by the present invention, taking a specific metering system as an example and combining the accompanying drawings and specific embodiments.

[0023] Example:

[0024] An ultrasonic flowmeter fluid flow measurement system includes at least one ultrasonic flowmeter with three or more channels and an embedded rectifier embedded in its fluid inlet, and a front end straight pipe section with a length of not less than 5D provided at the front end thereof, and the inner diameters of the two are the same, both being D;

[0025] like Figure 1 As shown, the embedded rectifier includes a swirler 1, a straight tube mixing chamber 2 and a flow straightener 3 in sequence along the fluid flow direction;

[0026] The embedded rectifier is embedded in the inlet of the ultrasonic flowmeter. The fluid entering the ultrasonic flowmeter flows through the swirler 1, the straight tube mixing chamber 2, the flow straightener 3 in sequence and enters the ultrasonic flowmeter pipeline.

[0027] like Figures 1 to 4 As shown, the rotator 1 is located at the front end of the embedded rectifier, including two concentric inner and outer rectifier cylinders 5 and 6, and 8-12 rotating blades 4 are provided between the two concentric inner and outer rectifier cylinders 5 and 6; the intersection line (actually an arc line) where the inner end surface of each blade intersects with the outer wall of the inner rectifier cylinder intersects with the axis of the inner rectifier cylinder in space, and the intersection angle P is 15° to 25°, as shown in FIG. Figure 5 The lower end face line of each blade is translated along its inner end face line to the translation line 9 on the upper end face line, and the intersection angle O between the upper end face line is 25°~35°, such as Figure 5 The end face 8 of the rotator 1 should be facing the flow direction of the fluid being measured.

[0028] like Figures 1 to 4 As shown, in actual use, in order to make the embedded rectifier adapt to the needs of pipes with different diameters, rectifiers with different inner diameters should be designed according to the different inner diameters of the pipes, so that the embedded rectifier can be tightly embedded in the ultrasonic flowmeter. The length A of the vortexer 1 is generally 0.25~0.3D, the length B of the straight tube mixing chamber 2 is generally 0.35D~0.4D, and the length C of the flow straightener 3 is generally 0.35D~0.4D. The straight tube mixing chamber 2 is located in the middle of the embedded rectifier and is an empty pipe with no filling inside. In this embodiment, the flow straightener 3 is located at the end of the embedded rectifier, and the interior is a regular hexagonal uniformly distributed rectifier hole 7. The side length U of the regular hexagon has different lengths under different pipe diameters, generally 0.05~0.08D.

[0029] When the embedded rectifier is rectifying, the uneven fluid at the front end of the ultrasonic flowmeter first flows through the swirler 1, and the fluid is divided into multiple areas by the rotating blades 4, so that the fluid entering the ultrasonic flowmeter is dispersed, and the asymmetric flow and secondary flow in the fluid are basically eliminated.

[0030] After that, the dispersed fluid completes preliminary mixing in the straight tube mixing chamber 2. At this time, the asymmetric flow and secondary flow are basically eliminated, but there are still large-scale vortex flows in the fluid, which will still affect the accuracy and repeatability of the ultrasonic flowmeter measurement; when the fluid flows through the flow straightener 3, the evenly distributed regular hexagonal rectifying holes 7 will divide the fluid into multiple uniform direct currents, and the large-scale vortex flows in the fluid will be greatly eliminated, completing the final rectification of the uneven fluid. At this time, there is basically no turbulence in the fluid, and no new turbulence will be formed, thereby improving the measurement accuracy and stability of the ultrasonic flowmeter.

[0031] Specifically, the vortexer 1 can be produced using 3D printing technology and is made of 316L stainless steel, which offers high strength and corrosion resistance. Its surface can be ground and polished to a roughness of Ra 3.2 to Ra 6.3. The straight tube mixing chamber 2 and flow straightener 3 are made of materials including, but not limited to, 304 and 316L stainless steel, with a surface roughness of Ra 3.2.

[0032] Simulation experiment:

[0033] Fluent software is used to perform a large number of simulations on the rectification effects of various parameters of the embedded rectifier of the present invention within their ranges. A DN100 four-channel ultrasonic flowmeter produced by Xi'an Anson Intelligent Company is taken as an example. The length of the front straight pipe section of the ultrasonic flowmeter is 5D, the turbulence model uses the SST k-ω model, the inlet of the front straight pipe section is the mass flow inlet, and the outlet is the pressure outlet, which is set to 1 atmosphere. The roughness of the inner wall of the front straight pipe section and the ultrasonic flowmeter is 0.05 mm, and the velocity-pressure coupling uses the Coupled coupling algorithm.

[0034] Since the purpose of the embedded rectifier of the present invention is to deal with the disturbances that may occur on site, that is, whether the measurement accuracy of the ultrasonic flowmeter can still meet the level 1 accuracy under different disturbance conditions, when the front end of the ultrasonic flowmeter is a long straight pipe section, it can be considered that the flow state measured by the ultrasonic flowmeter is an ideal flow state. Therefore, the measurement error when the front end is a straight pipe section is used as a benchmark, and the error deviation when the front end is under different disturbance conditions (that is, when the front end is different spoilers) is compared with the error deviation when the front end is a straight pipe section. When the error deviation is within 1%, it is considered that the embedded rectifier can deal with the disturbances that occur on site. (Measurement error benchmark system: 5D straight pipe section pipeline at the front end - DN100 three-channel or four-channel ultrasonic flowmeter equipped with this patented rectifier; simulation of different spoiler measurement system: different spoilers at the front end - 5D straight pipe section pipeline at the front end - DN100 three-channel or four-channel ultrasonic flowmeter equipped with this patented rectifier)

[0035] Under the following different parameter conditions of the embedded rectifier of the present invention, simulation calculations show that under different flow rates, the front end is subjected to different turbulence conditions (the front end has different turbulence components, which are: 1. The single elbow is a DN100, 90-degree elbow; 2. The eccentric double elbow is two single elbows connected together, but the two elbows are not on the same plane; 3. The vortex generator is a component composed of 9 rotating blades, the shape of which is similar to a small cylinder with the center removed from the vortex generator; 4. The half-open valve is a DN100 gate valve with a valve opening of 50%.) and the error deviation when the length of the front straight pipe section is 5D is as follows:

[0036] 1. Change the intersection angle O:

[0037] 1) Embedded rectifier simulation conditions: intersection angle O: 25°, intersection angle P: 20°, vortexer length A: 0.27D, number of blades: 12, blade thickness M: 1.2mm, inner rectifier outer diameter S: 0.37D, straight tube mixing chamber length B: 0.35D, regular hexagon side length U: 0.06D, wall thickness K: 0.1mm, flow straightener length C: 0.35D; the error deviation data of the simulation calculation data and the front straight pipe section with a length of 5D are shown in Table 1A (three-channel ultrasonic flowmeter) and Table 1B (four-channel ultrasonic flowmeter):

[0038] Table 1A

[0039]

[0040] Table 1B

[0041]

[0042] 2) Embedded rectifier simulation conditions: intersection angle O: 28°, intersection angle P: 20°, vortexer length A: 0.27D, number of blades: 12, blade thickness M: 1.2mm, inner rectifier outer diameter S: 0.37D, straight tube mixing chamber length B: 0.35D, regular hexagon side length U: 0.06D, wall thickness K: 0.1mm, flow straightener length C: 0.35D. The error deviation data of the simulation calculation data and the front straight pipe section with a length of 5D are shown in Table 2A (three-channel ultrasonic flowmeter) and Table 2B (four-channel ultrasonic flowmeter):

[0043] Table 2A

[0044]

[0045] Table 2B

[0046]

[0047] 3) Embedded rectifier simulation conditions: intersection angle O: 32°, intersection angle P: 20°, vortexer length A: 0.27D, number of blades: 12, blade thickness M: 1.2mm, inner rectifier outer diameter S: 0.37D, straight tube mixing chamber length B: 0.35D, regular hexagon side length U: 0.06D, wall thickness K: 0.1mm, flow straightener length C: 0.35D. The error deviation data of the simulation calculation data and the front straight pipe section with a length of 5D are shown in Table 3A (three-channel ultrasonic flowmeter) and Table 3B (four-channel ultrasonic flowmeter):

[0048] Table 3A

[0049]

[0050] Table 3B

[0051]

[0052] 4) Embedded rectifier simulation conditions: intersection angle O: 35°, intersection angle P: 20°, vortexer length A: 0.27D, number of blades: 12, blade thickness M: 1.2mm, inner rectifier outer diameter S: 0.37D, straight tube mixing chamber length B: 0.35D, regular hexagon side length U: 0.06D, wall thickness K: 0.1mm, flow straightener length C: 0.35D. The error deviation data of the simulation calculation data and the front straight pipe section with a length of 5D are shown in Table 4A (three-channel ultrasonic flowmeter) and Table 4B (four-channel ultrasonic flowmeter):

[0053] Table 4A

[0054]

[0055] Table 4B

[0056]

[0057] 2. Change the intersection angle P

[0058] 1) Embedded rectifier simulation conditions: intersection angle O: 30°, intersection angle P: 15°, vortexer length A: 0.27D, number of blades: 12, blade thickness M: 1.2mm, inner rectifier outer diameter S: 0.37D, straight tube mixing chamber length B: 0.35D, regular hexagon side length U: 0.06D, wall thickness K: 0.1mm, flow straightener length C: 0.35D. The error deviation data of the simulation calculation data and the front straight pipe section with a length of 5D are shown in Table 5A (three-channel ultrasonic flowmeter) and Table 5B (four-channel ultrasonic flowmeter):

[0059] Table 5A

[0060]

[0061] Table 5B

[0062]

[0063] 2) Embedded rectifier simulation conditions: intersection angle O: 30°, intersection angle P: 20°, vortexer length A: 0.27D, number of blades: 12, blade thickness M: 1.2mm, inner rectifier outer diameter S: 0.37D, straight tube mixing chamber length B: 0.35D, regular hexagon side length U: 0.06D, wall thickness K: 0.1mm, flow straightener length C: 0.35D. The error deviation data of the simulation calculation data and the front straight pipe section with a length of 5D are shown in Table 6A (three-channel ultrasonic flowmeter) and Table 6B (four-channel ultrasonic flowmeter):

[0064] Table 6A

[0065]

[0066] Table 6B

[0067]

[0068] 3) Embedded rectifier simulation conditions: intersection angle O: 30°, intersection angle P: 25°, vortexer length A: 0.27D, number of blades: 12, blade thickness M: 1.2mm, inner rectifier outer diameter S: 0.37D, straight tube mixing chamber length B: 0.35D, regular hexagon side length U: 0.06D, wall thickness K: 0.1mm, flow straightener length C: 0.35D. The error deviation data of the simulation calculation data and the front straight pipe section with a length of 5D are shown in Table 7A (three-channel ultrasonic flowmeter) and Table 7B (four-channel ultrasonic flowmeter):

[0069] Table 7A

[0070]

[0071] Table 7B

[0072]

[0073] 3. Change the length A of the spinner

[0074] 1) Embedded rectifier simulation conditions: intersection angle O: 30°, intersection angle P: 20°, vortexer length A: 0.25D, number of blades: 12, blade thickness M: 1.2mm, inner rectifier outer diameter S: 0.37D, straight tube mixing chamber length B: 0.35D, regular hexagon side length U: 0.06D, wall thickness K: 0.1mm, flow straightener length C: 0.35D. The error deviation data of the simulation calculation data and the front straight pipe section with a length of 5D are shown in Table 8A (three-channel ultrasonic flowmeter) and Table 8B (four-channel ultrasonic flowmeter):

[0075] Table 8A

[0076]

[0077] Table 8B

[0078]

[0079] 2) Embedded rectifier simulation conditions: intersection angle O: 30°, intersection angle P: 20°, vortexer length A: 0.27D, number of blades: 12, blade thickness M: 1.2mm, inner rectifier outer diameter S: 0.37D, straight tube mixing chamber length B: 0.35D, regular hexagon side length U: 0.06D, wall thickness K: 0.1mm, flow straightener length C: 0.35D. The error deviation data of the simulation calculation data and the front straight pipe section with a length of 5D are shown in Table 9A (three-channel ultrasonic flowmeter) and Table 9B (four-channel ultrasonic flowmeter):

[0080] Table 9A

[0081]

[0082] Table 9B

[0083]

[0084] 3) Embedded rectifier simulation conditions: intersection angle O: 30°, intersection angle P: 20°, vortexer length A: 0.3D, number of blades: 12, blade thickness M: 1.2mm, inner rectifier outer diameter S: 0.37D, straight tube mixing chamber length B: 0.35D, regular hexagon side length U: 0.06D, wall thickness K: 0.1mm, flow straightener length C: 0.35D. The error deviation data of the simulation calculation data and the front straight pipe section with a length of 5D are shown in Table 10A (three-channel ultrasonic flowmeter) and Table 10B (four-channel ultrasonic flowmeter):

[0085] Table 10A

[0086]

[0087] Table 10B

[0088]

[0089] 4. Change the number of leaves

[0090] 1) Embedded rectifier simulation conditions: intersection angle O: 30°, intersection angle P: 20°, vortexer length A: 0.27D, number of blades: 8, blade thickness M: 1.2mm, inner rectifier outer diameter S: 0.37D, straight tube mixing chamber length B: 0.35D, regular hexagon side length U: 0.06D, wall thickness K: 0.1mm, flow straightener length C: 0.35D. The error deviation data of the simulation calculation data and the front straight pipe section with a length of 5D are shown in Table 11A (three-channel ultrasonic flowmeter) and Table 11B (four-channel ultrasonic flowmeter):

[0091] Table 11A

[0092]

[0093] Table 11B

[0094]

[0095] 2) Embedded rectifier simulation conditions: intersection angle O: 30°, intersection angle P: 20°, vortexer length A: 0.27D, number of blades: 10, blade thickness M: 1.2mm, inner rectifier outer diameter S: 0.37D, straight tube mixing chamber length B: 0.35D, regular hexagon side length U: 0.06D, wall thickness K: 0.1mm, flow straightener length C: 0.35D. The error deviation data of the simulation calculation data and the front straight pipe section with a length of 5D are shown in Table 12A (three-channel ultrasonic flowmeter) and Table 12B (four-channel ultrasonic flowmeter):

[0096] Table 12A

[0097]

[0098] Table 12B

[0099]

[0100] 3) Embedded rectifier simulation conditions: intersection angle O: 30°, intersection angle P: 20°, vortexer length A: 0.27D, number of blades: 11, blade thickness M: 1.2mm, inner rectifier outer diameter S: 0.37D, straight tube mixing chamber length B: 0.35D, regular hexagon side length U: 0.06D, wall thickness K: 0.1mm, flow straightener length C: 0.35D. The error deviation data of the simulation calculation data and the front straight pipe section with a length of 5D are shown in Table 13A (three-channel ultrasonic flowmeter) and Table 13B (four-channel ultrasonic flowmeter):

[0101] Table 13A

[0102]

[0103] Table 13B

[0104]

[0105] 4) Embedded rectifier simulation conditions: intersection angle O: 30°, intersection angle P: 20°, vortexer length A: 0.27D, number of blades: 12, blade thickness M: 1.2mm, inner rectifier outer diameter S: 0.37D, straight tube mixing chamber length B: 0.35D, regular hexagon side length U: 0.06D, wall thickness K: 0.1mm, flow straightener length C: 0.35D. The error deviation data of the simulation calculation data and the front straight pipe section with a length of 5D are shown in Table 14A (three-channel ultrasonic flowmeter) and Table 14B (four-channel ultrasonic flowmeter):

[0106] Table 14A Table 14B

[0107]

[0108] 5. Change the blade thickness M

[0109] 1) Embedded rectifier simulation conditions: intersection angle O: 30°, intersection angle P: 20°, vortexer length A: 0.27D, number of blades: 12, blade thickness M: 1mm, inner rectifier outer diameter S: 0.37D, straight tube mixing chamber length B: 0.35D, regular hexagon side length U: 0.06D, wall thickness K: 0.1mm, flow straightener length C: 0.35D. The error deviation data of the simulation calculation data and the front straight pipe section with a length of 5D are shown in Table 15A (three-channel ultrasonic flowmeter) and Table 15B (four-channel ultrasonic flowmeter):

[0110] Table 15A

[0111]

[0112] Table 15B

[0113]

[0114] 2) Embedded rectifier simulation conditions: intersection angle O: 30°, intersection angle P: 20°, vortexer length A: 0.27D, number of blades: 12, blade thickness M: 1.2mm, inner rectifier outer diameter S: 0.37D, straight pipe mixing chamber length B: 0.35D, regular hexagon side length U: 0.06D, wall thickness K: 0.1mm, flow straightener length C: 0.35D. The error deviation data of the simulation calculation data and the front straight pipe section with a length of 5D are shown in Table 16A (three-channel ultrasonic flowmeter) and Table 16B (four-channel ultrasonic flowmeter):

[0115] Table 16A

[0116]

[0117] Table 16B

[0118]

[0119] 3) Embedded rectifier simulation conditions: intersection angle O: 30°, intersection angle P: 20°, vortexer length A: 0.27D, number of blades: 12, blade thickness M: 1.5mm, inner rectifier outer diameter S: 0.37D, straight tube mixing chamber length B: 0.35D, regular hexagon side length U: 0.06D, wall thickness K: 0.1mm, flow straightener length C: 0.35D. The error deviation data of the simulation calculation data and the front straight pipe section with a length of 5D are shown in Table 17A (three-channel ultrasonic flowmeter) and Table 17B (four-channel ultrasonic flowmeter):

[0120] Table 17A

[0121]

[0122] Table 17B

[0123]

[0124] 6. Change the outer diameter S of the inner rectifier

[0125] 1) Embedded rectifier simulation conditions: intersection angle O: 30°, intersection angle P: 20°, vortexer length A: 0.27D, number of blades: 12, blade thickness M: 1.2mm, inner rectifier outer diameter S: 0.35D, straight tube mixing chamber length B: 0.35D, regular hexagon side length U: 0.06D, wall thickness K: 0.1mm, flow straightener length C: 0.35D. The error deviation data of the simulation calculation data and the front straight pipe section with a length of 5D are shown in Table 18A (three-channel ultrasonic flowmeter) and Table 18B (four-channel ultrasonic flowmeter):

[0126] Table 18A

[0127]

[0128] Table 18B

[0129]

[0130] 2) Embedded rectifier simulation conditions: intersection angle O: 30°, intersection angle P: 20°, vortexer length A: 0.27D, number of blades: 12, blade thickness M: 1.2mm, inner rectifier outer diameter S: 0.37D, straight tube mixing chamber length B: 0.35D, regular hexagon side length U: 0.06D, wall thickness K: 0.1mm, flow straightener length C: 0.35D. The error deviation data of the simulation calculation data and the front straight pipe section with a length of 5D are shown in Table 19A (three-channel ultrasonic flowmeter) and Table 19B (four-channel ultrasonic flowmeter):

[0131] Table 19A

[0132]

[0133] Table 19B

[0134]

[0135] 3) Embedded rectifier simulation conditions: intersection angle O: 30°, intersection angle P: 20°, vortexer length A: 0.27D, number of blades: 12, blade thickness M: 1.2mm, inner rectifier outer diameter S: 0.4D, straight tube mixing chamber length B: 0.35D, regular hexagon side length U: 0.06D, wall thickness K: 0.1mm, flow straightener length C: 0.35D. The error deviation data of the simulation calculation data and the front straight pipe section with a length of 5D are shown in Table 20A (three-channel ultrasonic flowmeter) and Table 20B (four-channel ultrasonic flowmeter):

[0136] Table 20A

[0137]

[0138] Table 20B

[0139]

[0140] 7. Change the length B of the straight tube mixing chamber

[0141] 1) Embedded rectifier simulation conditions: intersection angle O: 30°, intersection angle P: 20°, vortexer length A: 0.27D, number of blades: 12, blade thickness M: 1.2mm, inner rectifier outer diameter S: 0.37D, straight tube mixing chamber length B: 0.35D, regular hexagon side length U: 0.06D, wall thickness K: 0.1mm, flow straightener length C: 0.35D. The error deviation data of the simulation calculation data and the front straight pipe section with a length of 5D are shown in Table 21A (three-channel ultrasonic flowmeter) and Table 21B (four-channel ultrasonic flowmeter):

[0142] Table 21A

[0143]

[0144] Table 21B

[0145]

[0146] 2) Embedded rectifier simulation conditions: intersection angle O: 30°, intersection angle P: 20°, vortexer length A: 0.27D, number of blades: 12, blade thickness M: 1.2mm, inner rectifier outer diameter S: 0.37D, straight tube mixing chamber length B: 0.365D, regular hexagon side length U: 0.06D, wall thickness K: 0.1mm, flow straightener length C: 0.35D. The error deviation data of the simulation calculation data and the front straight pipe section with a length of 5D are shown in Table 22A (three-channel ultrasonic flowmeter) and Table 22B (four-channel ultrasonic flowmeter):

[0147] Table 22A

[0148]

[0149] Table 22B

[0150]

[0151] 3) Embedded rectifier simulation conditions: intersection angle O: 30°, intersection angle P: 20°, vortexer length A: 0.27D, number of blades: 12, blade thickness M: 1.2mm, inner rectifier outer diameter S: 0.37D, straight tube mixing chamber length B: 0.38D, regular hexagon side length U: 0.06D, wall thickness K: 0.1mm, flow straightener length C: 0.35D. The error deviation data of the simulation calculation data and the front straight pipe section with a length of 5D are shown in Table 23A (three-channel ultrasonic flowmeter) and Table 23B (four-channel ultrasonic flowmeter):

[0152] Table 23A

[0153]

[0154] Table 23B

[0155]

[0156] 4) Embedded rectifier simulation conditions: intersection angle O: 30°, intersection angle P: 20°, vortexer length A: 0.27D, number of blades: 12, blade thickness M: 1.2mm, inner rectifier outer diameter S: 0.37D, straight tube mixing chamber length B: 0.4D, regular hexagon side length U: 0.06D, wall thickness K: 0.1mm, flow straightener length C: 0.35D. The error deviation data of the simulation calculation data and the front straight pipe section with a length of 5D are shown in Table 24A (three-channel ultrasonic flowmeter) and Table 24B (four-channel ultrasonic flowmeter):

[0157] Table 24A

[0158]

[0159] Table 24B

[0160]

[0161] 8. Change the side length U of the regular hexagon

[0162] 1) Embedded rectifier simulation conditions: intersection angle O: 30°, intersection angle P: 20°, vortexer length A: 0.27D, number of blades: 12, blade thickness M: 1.2mm, inner rectifier outer diameter S: 0.37D, straight tube mixing chamber length B: 0.35D, regular hexagon side length U: 0.05D, wall thickness K: 0.1mm, flow straightener length C: 0.35D. The error deviation data of the simulation calculation data and the front straight pipe section with a length of 5D are shown in Table 25A (three-channel ultrasonic flowmeter) and Table 25B (four-channel ultrasonic flowmeter):

[0163] Table 25A

[0164]

[0165] Table 25B

[0166]

[0167] 2) Embedded rectifier simulation conditions: intersection angle O: 30°, intersection angle P: 20°, vortexer length A: 0.27D, number of blades: 12, blade thickness M: 1.2mm, inner rectifier outer diameter S: 0.37D, straight tube mixing chamber length B: 0.35D, regular hexagon side length U: 0.06D, wall thickness K: 0.1mm, flow straightener length C: 0.35D. The error deviation data of the simulation calculation data and the front straight pipe section with a length of 5D are shown in Table 26A (three-channel ultrasonic flowmeter) and Table 26B (four-channel ultrasonic flowmeter):

[0168] Table 26A

[0169]

[0170] Table 26B

[0171]

[0172] 3) Embedded rectifier simulation conditions: intersection angle O: 30°, intersection angle P: 20°, vortexer length A: 0.27D, number of blades: 12, blade thickness M: 1.2mm, inner rectifier outer diameter S: 0.37D, straight tube mixing chamber length B: 0.35D, regular hexagon side length U: 0.07D, wall thickness K: 0.1mm, flow straightener length C: 0.35D. The error deviation data of the simulation calculation data and the front straight pipe section with a length of 5D are shown in Table 27A (three-channel ultrasonic flowmeter) and Table 27B (four-channel ultrasonic flowmeter):

[0173] Table 27A

[0174]

[0175] Table 27B

[0176]

[0177] 4) Embedded rectifier simulation conditions: intersection angle O: 30°, intersection angle P: 20°, vortexer length A: 0.27D, number of blades: 12, blade thickness M: 1.2mm, inner rectifier outer diameter S: 0.37D, straight tube mixing chamber length B: 0.35D, regular hexagon side length U: 0.08D, wall thickness K: 0.1mm, flow straightener length C: 0.35D. The error deviation data of the simulation calculation data and the front straight pipe section with a length of 5D are shown in Table 28A (three-channel ultrasonic flowmeter) and Table 28B (four-channel ultrasonic flowmeter):

[0178] Table 28A

[0179]

[0180] Table 28B

[0181]

[0182] 9. Change the wall thickness K

[0183] 1) Embedded rectifier simulation conditions: intersection angle O: 30°, intersection angle P: 20°, vortexer length A: 0.27D, number of blades: 12, blade thickness M: 1.2mm, inner rectifier outer diameter S: 0.37D, straight tube mixing chamber length B: 0.35D, regular hexagon side length U: 0.06D, wall thickness K: 0.1mm, flow straightener length C: 0.35D. The error deviation data of the simulation calculation data and the front straight pipe section with a length of 5D are shown in Table 29A (three-channel ultrasonic flowmeter) and Table 29B (four-channel ultrasonic flowmeter):

[0184] Table 29A

[0185]

[0186] Table 29B

[0187]

[0188] 2) Embedded rectifier simulation conditions: intersection angle O: 30°, intersection angle P: 20°, vortexer length A: 0.27D, number of blades: 12, blade thickness M: 1.2mm, inner rectifier outer diameter S: 0.37D, straight tube mixing chamber length B: 0.35D, regular hexagon side length U: 0.06D, wall thickness K: 0.13mm, flow straightener length C: 0.35D. The error deviation data of the simulation calculation data and the front straight pipe section with a length of 5D are shown in Table 30A (three-channel ultrasonic flowmeter) and Table 30B (four-channel ultrasonic flowmeter):

[0189] Table 30A

[0190]

[0191] Table 30B

[0192]

[0193] 3) Embedded rectifier simulation conditions: intersection angle O: 30°, intersection angle P: 20°, vortexer length A: 0.27D, number of blades: 12, blade thickness M: 1.2mm, inner rectifier outer diameter S: 0.37D, straight tube mixing chamber length B: 0.35D, regular hexagon side length U: 0.06D, wall thickness K: 0.16mm, flow straightener length C: 0.35D. The error deviation data of the simulation calculation data and the front straight pipe section with a length of 5D are shown in Table 31A (three-channel ultrasonic flowmeter) and Table 31B (four-channel ultrasonic flowmeter):

[0194] Table 31A

[0195]

[0196] Table 31B

[0197]

[0198] 4) Embedded rectifier simulation conditions: intersection angle O: 30°, intersection angle P: 20°, vortexer length A: 0.27D, number of blades: 12, blade thickness M: 1.2mm, inner rectifier outer diameter S: 0.37D, straight tube mixing chamber length B: 0.35D, regular hexagon side length U: 0.06D, wall thickness K: 0.2mm, flow straightener length C: 0.35D. The error deviation data of the simulation calculation data and the front straight pipe section with a length of 5D are shown in Table 32A (three-channel ultrasonic flowmeter) and Table 32B (four-channel ultrasonic flowmeter):

[0199] Table 32A

[0200]

[0201] Table 32B

[0202]

[0203] 10. Change the length C of the flow straightener

[0204] 1) Embedded rectifier simulation conditions: intersection angle O: 30°, intersection angle P: 20°, vortexer length A: 0.27D, number of blades: 12, blade thickness M: 1.2mm, inner rectifier outer diameter S: 0.37D, straight tube mixing chamber length B: 0.35D, regular hexagon side length U: 0.06D, wall thickness K: 0.1mm, flow straightener length C: 0.35D. The error deviation data of the simulation calculation data and the front straight pipe section with a length of 5D are shown in Table 33A (three-channel ultrasonic flowmeter) and Table 33B (four-channel ultrasonic flowmeter):

[0205] Table 33A

[0206]

[0207] Table 33B

[0208]

[0209] 2) Embedded rectifier simulation conditions: intersection angle O: 30°, intersection angle P: 20°, vortexer length A: 0.27D, number of blades: 12, blade thickness M: 1.2mm, inner rectifier outer diameter S: 0.37D, straight tube mixing chamber length B: 0.35D, regular hexagon side length U: 0.06D, wall thickness K: 0.1mm, flow straightener length C: 0.365D. The error deviation data of the simulation calculation data and the front straight pipe section with a length of 5D are shown in Table 34A (three-channel ultrasonic flowmeter) and Table 34B (four-channel ultrasonic flowmeter):

[0210] Table 34A

[0211]

[0212] Table 34B

[0213]

[0214] 3) Embedded rectifier simulation conditions: intersection angle O: 30°, intersection angle P: 20°, vortexer length A: 0.27D, number of blades: 12, blade thickness M: 1.2mm, inner rectifier outer diameter S: 0.37D, straight tube mixing chamber length B: 0.35D, regular hexagon side length U: 0.06D, wall thickness K: 0.1mm, flow straightener length C: 0.38D. The error deviation data of the simulation calculation data and the front straight pipe section with a length of 5D are shown in Table 35A (three-channel ultrasonic flowmeter) and Table 35B (four-channel ultrasonic flowmeter):

[0215] Table 35A

[0216]

[0217] Table 35B

[0218]

[0219] 4) Embedded rectifier simulation conditions: intersection angle O: 30°, intersection angle P: 20°, vortexer length A: 0.27D, number of blades: 12, blade thickness M: 1.2mm, inner rectifier outer diameter S: 0.37D, straight tube mixing chamber length B: 0.35D, regular hexagon side length U: 0.06D, wall thickness K: 0.1mm, flow straightener length C: 0.4D. The error deviation data of the simulation calculation data and the front straight pipe section with a length of 5D are shown in Table 36A (three-channel ultrasonic flowmeter) and Table 36B (four-channel ultrasonic flowmeter):

[0220] Table 36A

[0221]

[0222] Table 36B

[0223]

[0224] Actual measurement verification experiment:

[0225] A DN100 embedded rectifier of the present invention was manufactured, wherein the intersection angle O was 30°, the intersection angle P was 20°, the vortexer length A was 0.27D, the number of blades was 12, the blade thickness M was 1.2 mm, the outer diameter S of the inner rectifier tube was 0.4D, the straight tube mixing chamber length B was 0.36D, the regular hexagon side length U was 0.05D, the wall thickness K was 0.1 mm, and the flow straightener length C was 0.38D.

[0226] When the length of the front straight pipe section is DN100, the experimental verification is carried out by installing the above-mentioned DN100 embedded rectifier on a DN100 four-channel ultrasonic flowmeter (product of Xi'an Ansen Intelligent Company, specification is DN100, PN16, model is ACFC-D), and the critical flow Venturi nozzle method gas flow standard device is used for experimental measurement. The measuring medium is air, and the expanded uncertainty of the standard experimental device is: Urel = 0.3%, k = 2; the flow stability of the standard experimental device is: 0.1%; the standard experimental device implements the standard: JJF 1240-2010 "Calibration Specification for Critical Flow Venturi Nozzle Method Gas Flow Standard Device".

[0227] First, under the preliminarily determined length of the front straight pipe section, 800m 3 / h、560m 3 / h、320m 3 / h、160m 3 / h、180m 3 / h、56m 3 / h、38m 3 / h、24m 3 / h、8m 3 / h 9 flow points, and record the indication error of each test point; then test 800m under four disturbance conditions respectively 3 / h、560m 3 / h、320m 3 / h、160m 3 / h、80m 3 / h、56m 3 / h、38m 3 / h、24m 3 / h、8m 3 / h 9 flow points, and record the indication error at each point, and calculate the error deviation compared to the case when the front end is a straight pipe section, see Table 37. (The four types of spoilers are: single elbow, double elbow with different planes, half-open valve and vortex generator. Vertical, horizontal and 45° only represent the installation method of each spoiler. The inner diameter of the four spoilers is DN100.) Table 37

[0228]

[0229] The above simulation experiments show that: under different parameters of the embedded rectifier of the present invention, such as the intersection angle O, intersection angle P, vortexer length A, number of blades, blade thickness M, inner rectifier tube outer diameter S, straight tube mixing chamber length B, regular hexagon side length U, wall thickness K, and flow straightener length C, when a front-end straight pipe section with a length of 5D is installed at the front end of the flowmeter and its flow rate is a fixed value, the measurement error E of the front-end straight pipe section of the flowmeter is obtained by simulation. The above-mentioned different disturbance conditions were set at the front end of the flowmeter. When the spoiler was a single elbow, the simulation obtained a flowmeter measurement error E1; when the spoiler was a double elbow with different surfaces, the simulation obtained a flowmeter measurement error E2; when the spoiler was a vortex generator, the simulation obtained a flowmeter measurement error E3; and when the spoiler was a half-open valve, the simulation obtained a flowmeter measurement error E4. The deviations between the errors E1, E2, E3, and E4 and the error E were calculated to obtain error deviations S1, S2, S3, and S4 (see Tables 1-36). The simulation results showed that S1, S2, S3, and S4 were basically less than 1%. In particular, when a four-channel ultrasonic flowmeter was used, the error deviations S1, S2, S3, and S4 (see Tables 1B-36B) were obtained. The simulation results showed that S1, S2, S3, and S4 were all less than 1%. This shows that when the front end of the flowmeter is a straight pipe section with a length of 5D and the embedded rectifier of the present invention is used, the field flowmeter can meet 1% accuracy under different disturbance conditions.

[0230] At the same time, the actual measurement verification experiment shows that: under the intersection angle O: 30°, intersection angle P: 20°, rotator length A: 0.27D, number of blades: 12, blade thickness M: 1.2mm, inner rectifier tube outer diameter S: 0.4D, straight tube mixing chamber length B: 0.36D, regular hexagon side length U: 0.05D, wall thickness K: 0.1mm, flow straightener length C: 0.38D of the embedded rectifier of the present invention, when the front end of the flowmeter is a front end straight pipe section with a length of 5D and its flow rate is a fixed value, the actual measurement verification experiment obtains the measurement error E when the flowmeter length is a front end straight pipe section of 5D. Under the above-mentioned different disturbance conditions, the front end is set as follows: when the spoiler is a single elbow, the simulation obtains the flow meter measurement error E1; when the spoiler is a double elbow with different surfaces, the simulation obtains the flow meter measurement error E2; when the spoiler is a half-open valve, the simulation obtains the flow meter measurement error E3; when the spoiler is a vortex generator, the experiment obtains the flow meter measurement error E4, and the deviation between the errors E1, E2, E3, E4 and the error E is calculated to obtain error deviations S1, S2, S3, S4 (see Table 37). The experimental results show that S1, S2, S3, S4 are substantially less than 0.5%. This shows that when the flow meter front end is a 5D front end straight pipe section in length and the embedded rectifier of the present invention is used, the field flow meter can meet the accuracy of 1% under different disturbance conditions.

[0231] In summary, the measured verification experimental data verified the accuracy of the simulation data, and further proved the consistency between the simulation data and the measured verification experimental data obtained by the present invention.

[0232] Although a four-channel ultrasonic flowmeter is taken as an example in the embodiment, a large number of simulations and single actual verification experiments are combined to describe in detail the embedded rectifier of the present invention for fluid measurement, which can enable the field flowmeter to meet the accuracy of 1% under different turbulence conditions. Of course, the embedded rectifier of the present invention can also be applied to ultrasonic flowmeters with four channels or above, but they all belong to equivalent technical solutions, and the above detailed description cannot be used to limit the scope of protection of the present invention; the scope of protection of the present invention is based on the claims, and any variation scheme that includes the main points of the invention and does not deviate from the purpose of the invention falls within the scope of protection of the present invention.

Claims

1. An ultrasonic flowmeter fluid flow measurement system, comprising at least one ultrasonic flowmeter with four or more channels and an embedded rectifier embedded in its fluid inlet, and a front straight pipe section with a length of not less than 5D provided at the front end thereof, and the inner diameters of the two sections being the same, namely, D, characterized in that: The embedded rectifier includes a swirler, a straight tube mixing chamber and a flow straightener in sequence along the fluid flow direction; The vortexer has a length A of 0.25 to 0.3D and comprises two concentric inner and outer rectifying cylinders, with 8 to 12 rotating blades disposed between the inner and outer rectifying cylinders; wherein the blade thickness M is 1 to 1.5 mm, and the outer diameter S of the inner rectifying cylinder is 0.35 to 0.4D; the intersection line where the inner end face of each blade intersects with the outer wall of the inner rectifying cylinder intersects with the axis of the inner rectifying cylinder in space, and the intersection angle P is 15° to 25°; the lower end face line of each blade is translated along its inner end face line to the upper end face line, and the intersection angle O between the lower end face line and the upper end face line is 25° to 35°; the end face of the vortexer faces the direction of the flow of the measured fluid; The straight tube mixing chamber is an empty pipe with a length B of 0.35D to 0.4D; The length C of the flow straightener is 0.35D to 0.4D; the interior of the flow straightener is a plurality of evenly distributed regular hexagonal rectifying holes, the side length U of the regular hexagon is 0.05 to 0.08D, and the wall thickness K is 0.1 to 0.2 mm.

2. The fluid flow measurement system according to claim 1, characterized in that: The spinner length A: 0.27D, the intersection angle O: 30°, the intersection angle P: 20°, the number of blades: 12, the blade thickness M: 1.2mm, the outer diameter of the inner rectifying cylinder S: 0.4D; the length of the straight tube mixing chamber B: 0.36D; the length of the flow straightener C: 0.38D, the side length of the regular hexagon U: 0.05D, its wall thickness K: 0.1mm.

3. The fluid flow measurement system according to claim 1 or 2, characterized in that: The spinner is made of 316L material and produced by 3D printing technology, and its surface roughness is Ra3.2 to Ra6.

3.

4. The fluid flow measurement system according to claim 1 or 2, characterized in that: The straight tube mixing chamber and the flow straightener are made of 304 or 316L stainless steel, and the surface roughness thereof is Ra3.

2.

5. The fluid flow measurement system according to claim 3, characterized in that: The straight tube mixing chamber and the flow straightener are made of 304 or 316L stainless steel, and the surface roughness thereof is Ra3.

2.

6. The fluid flow measurement system according to claim 1, 2 or 5, characterized in that: The ultrasonic flowmeter is a four-channel ultrasonic flowmeter.

7. The fluid flow measurement system according to claim 3, characterized in that: The ultrasonic flowmeter is a four-channel ultrasonic flowmeter.

8. The fluid flow measurement system according to claim 4, characterized in that: The ultrasonic flowmeter is a four-channel ultrasonic flowmeter.

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