Fuel gas representation value error laser in-situ calibration device applied to hydrogen-doped natural gas
The mixer design with an annular cavity and gap structure solves the problem of uneven distribution of tracer particles, achieves uniform mixing of tracer particles and fuel gas, improves the accuracy and reliability of laser calibration, and meets the calibration requirements of international standards.
Patent Information
- Application Number
- CN202510953465.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-11
- Publication Date
- 2025-09-30
AI Technical Summary
In laser calibration devices, uneven distribution of tracer particles leads to flow rate measurement errors, especially affecting the accuracy and reliability of calibration results in complex flow fields. Existing technologies make it difficult to ensure uniform mixing of tracer particles and fluid.
A mixer with an annular cavity and gap structure is used to evenly mix the tracer particles with the hydrogen-doped natural gas in the gas pipeline. The annular cavity and gap design ensure that the tracer particles are evenly distributed in the gas pipeline, and the contact piece and tapered hole structure are used to accelerate the mixing, forming a gas film to improve the mixing uniformity.
The mixing uniformity of tracer particles and fuel gas is improved, ensuring the accuracy and reliability of laser calibration, meeting the calibration requirements of international standards, and reducing systematic errors.
Smart Images
Figure CN120721189A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of laser calibration, and in particular to a laser in-situ calibration device for gas indication value error applied to hydrogen-blended natural gas. Background Art
[0002] In critical scenarios such as natural gas trade settlement and industrial process control, minute errors in flow meters can lead to significant economic losses or safety risks, necessitating the measurement accuracy, reliability, and compliance of flow meters. Traditional flow meters (such as turbines and orifice plates) are prone to deviations after long-term use due to mechanical wear, fouling, or flow field disturbances. Laser calibration technologies (such as LDV / PIV) directly obtain the true flow velocity distribution of the fluid through non-contact measurement, with an accuracy of over ±0.1%. Furthermore, laser calibration can verify the performance of flow meters under different operating conditions (such as high pressure and variable temperature), meeting the mandatory verification requirements of international standards (such as ISO 5167 and OIMLR137). Laser technology can also identify installation defects (such as flow field distortion caused by insufficient straight pipe sections), providing data support for optimizing metering systems.
[0003] In laser calibration devices, the uniformity of tracer particle mixing directly determines the accuracy and reliability of flow velocity measurements. Evenly distributed tracer particles can truly reflect the fluid's motion state, ensuring that the signals captured by Laser Doppler Velocimetry (LDV) or Particle Image Velocimetry (PIV) are representative. Uneven particle distribution can lead to local concentrations that are too high or too low, causing signal distortion in the measurement area and introducing systematic errors. Particularly in complex flow fields (such as turbulent or eddy currents), uneven particle distribution can obscure the true flow velocity distribution characteristics, affecting the accuracy of calibration results. Furthermore, particle agglomeration or sedimentation can cause fluctuations in the laser scattering signal intensity and reduce the signal-to-noise ratio. Therefore, ensuring sufficient and uniform mixing of tracer particles and the fluid is a key prerequisite for achieving high-precision measurements with laser calibration devices and a core link in ensuring the credibility of flowmeter calibration data. Summary of the Invention
[0004] In response to the shortcomings of the existing technology, the present invention provides a laser in-situ calibration device for the gas indication error of hydrogen-blended natural gas. Through the annular cavity and gaps in the mixer, the tracer particles are evenly mixed with the hydrogen-blended natural gas in the gas pipeline, ensuring the accuracy of the laser calibration device.
[0005] To achieve the above object, the present invention provides the following technical solutions: A laser in-situ calibration device for gas indication error of hydrogen-blended natural gas comprises a tracer particle generator for injecting tracer particles into a gas pipeline, a laser generator, a high-speed camera, and a gas flow meter. The tracer particle generator is connected to the gas pipeline via a mixer; the mixer uniformly mixes the tracer particles with the fluid in the gas pipeline; the gas pipeline downstream of the mixer comprises a steady flow section, the end of which is connected to a transparent tube; a laser generator and a high-speed camera are provided on one side of the transparent tube; the laser generator is arranged in a first direction toward the center of the transparent tube, and the high-speed camera is arranged in a second direction toward the center of the transparent tube; the first direction is perpendicular to the second direction; and the end of the transparent tube is connected to the gas flow meter.
[0006] Furthermore, the mixer includes a sleeve arranged on the outside of the gas pipeline; an annular cavity is formed between the sleeve and the outer surface of the gas pipeline; the outlet pipe of the tracer particle generator is connected to the cavity; a contact piece is provided in the gas pipeline covered by the sleeve; the tracer particles generated by the tracer particle generator enter the contact piece through the cavity, and the tracer particles contact the fluid in the gas pipeline flowing through the contact piece; the contact piece accelerates the mixing of the tracer particles and the fluid in the gas pipeline.
[0007] Furthermore, a plurality of tapered holes are evenly arranged on the body of the contact piece; an annular groove is provided on the circumferential outer surface of the body, and a plurality of connecting parts are provided in the annular groove; a gap is provided in the middle of the body, and the gap extends radially along the body; the gap is connected to the plurality of tapered holes in the body; and the connecting part connects the bodies on both sides.
[0008] Furthermore, the cross-sectional area of the first end face of the tapered hole located upstream is larger than the cross-sectional area of the second end face located downstream; a conical surface is formed between the first end face and the second end face; the tapered surface causes the fluid in the gas pipeline to form a cross-sectional contraction along the flow direction, so that the fluid in the gas pipeline is deflected to flow along the tapered surface and be accelerated; the gap is located in the middle of the tapered surface; the tracer particles injected into the gap enter the tapered surface and form an air film along the tapered surface.
[0009] Furthermore, the gap is formed on and covers the circumference of the conical surface, so that the tracer particles injected into the gap enter the conical surface evenly from all four sides of the middle of the conical surface to form an air film of equal length on the circumference of the conical surface.
[0010] Furthermore, the tracer particles are guided by the gap and enter the conical surface from the edge of the ring to be preliminarily mixed with the fluid in the gas pipeline; the fluid forms turbulence near the second end surface, so that the fluid and the tracer particles are fully mixed.
[0011] Furthermore, a first flange and a second flange are respectively provided at both ends of the sleeve of the sleeve; the first flange and the second flange are sealedly connected to the side wall of the gas pipeline; an outlet cavity is provided at the connection position between the sleeve and the outlet pipe; the first flange, the second flange, the sleeve and the side wall of the gas pipeline form a cavity; the cavity is connected to the outlet cavity.
[0012] Furthermore, one side of the cylinder of the tracer particle generator is connected to an outlet pipe, and the other side is provided with an inlet; an end cover is provided at the end of the cylinder; an impeller assembly extending into the cylinder is provided on the end cover; a first motor transmission-connected to the impeller assembly is provided on the end cover; and the end cover is also provided with a material injection device.
[0013] Furthermore, a first impeller and a second impeller are arranged side by side on the rotating shaft of the impeller assembly; the rotating shaft is supported on the base of the end cover through a bearing; and the rotating shaft is connected to the output end of the first motor.
[0014] Furthermore, the storage barrel of the injection device is fixedly connected to the end cover; a screw is rotatably provided in the storage barrel; a push plate is connected to the screw through a threaded fit, and the push plate is arranged in the storage barrel through a guide mechanism; the output end of the second motor is connected to the screw; the push plate injects the tracer particles in the storage barrel into the cylinder body through the injection hole on the end cover.
[0015] Compared with the prior art, the present invention provides a laser in-situ calibration device for the error of gas indication value applied to hydrogen-blended natural gas, which has the following beneficial effects: the mixer of the tracer particles is formed with an annular cavity, which can make the tracer particles evenly distributed in the circumference of the gas pipeline, and then mix with the fluid in the gas pipeline when entering the contact piece, thereby improving the uniformity of the mixing of the tracer particles and the fluid in the gas pipeline; in addition, a planar structure gap is formed in the contact piece, and the gap and the conical surface of the conical hole form an annular contact area, so that the tracer particles are evenly injected into the conical hole from the circumference of the conical hole and form an equal-length air film on the circumference of the conical surface, thereby improving the uniformity of the mixing of the tracer particles and the fluid. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 This is a schematic diagram of the overall structure of the laser in-situ calibration device for the fuel gas indication value error of hydrogen-blended natural gas of the present invention; Figure 2 Schematic diagram of the internal structure of the mixer of the present invention; Figure 3 is a schematic structural diagram of a contact member of the present invention; Figure 4 A front view of a contact member of the present invention; Figure 5is a cross-sectional view of a contact member of the present invention; Figure 6 is a side cross-sectional view of a contact member of the present invention; Figure 7 It is a structural schematic diagram of the sleeve of the present invention; Figure 8 Schematic diagram of the structure of the tracer particle generator of the present invention; Figure 9 It is a structural schematic diagram of the injection device and impeller assembly of the present invention; In the picture: Tracer particle generator 1, cylinder 11, outlet pipe 12, outlet chamber 120, inlet 13, first motor 14, injection device 15, storage barrel 151, second motor 152, screw 153, push plate 154, end cover 16, injection hole 161, base 162, impeller assembly 17, rotating shaft 17a, first impeller 17b, second impeller 17c; Mixer 2, sleeve 21, sleeve 21a, first flange 21b, second flange 21c, cavity 20, contact member 22, tapered hole 220, first end surface 220a, second end surface 220b, tapered surface 220c, body 221, annular groove 222, gap 223, connecting portion 224; Flow stabilization section 3; transparent tube 4; laser generator 5; high-speed camera 6; gas flow meter 7; DETAILED DESCRIPTION
[0017] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.
[0018] The present invention is described in detail below with reference to the accompanying drawings. The laser in-situ calibration device for the gas indication value error of hydrogen-blended natural gas of the present invention includes a tracer particle generator 1 for injecting tracer particles into the gas pipeline, as well as a laser generator 5, a high-speed camera 6 and a gas flow meter 7. The tracer particle generator 1 is connected to the gas pipeline through a mixer 2; the mixer 2 uniformly mixes the tracer particles with the fluid in the gas pipeline; the gas pipeline downstream of the mixer 2 includes a steady flow section 3, and the end of the steady flow section 3 of the gas pipeline is connected to a transparent tube 4; a laser generator 5 and a high-speed camera 6 are provided on one side of the transparent tube 4; the laser generator 5 is arranged in a first direction toward the center of the transparent tube 4, and the high-speed camera 6 is arranged in a second direction toward the center of the transparent tube 4; the first direction is perpendicular to the second direction; the end of the transparent tube 4 is connected to the gas flow meter 7.
[0019] Specifically, after the tracer particle generator 1 generates the tracer particles, the tracer particles are uniformly mixed with the hydrogen-doped natural gas in the gas pipeline through the mixer 2 to prevent the tracer particles from being unevenly distributed in the gas pipeline and affecting the laser measurement accuracy; the flow fluctuations generated by the mixer 2 are then eliminated through the steady flow section 3, so that the tracer particles flow together with the hydrogen-doped natural gas in the transparent tube 4; the laser generator 5 is used as the Figure 1 The laser pulses are emitted in the horizontal direction and illuminate the tracer particles, and the high-speed camera 6 is used to Figure 1 The displacement of the tracer particles is photographed in the vertical direction, and the velocity field distribution is calculated by combining image processing. Then, the standard flow rate is calculated in combination with the cross-sectional area of the transparent tube 4, and compared and calibrated with the reading of the gas flow meter 7 to ensure high accuracy, reliability and consistency of the flow measurement.
[0020] The mixer 2 includes a sleeve 21 arranged on the outside of the gas pipeline; an annular cavity 20 is formed between the sleeve 21 and the outer surface of the gas pipeline; the outlet pipe 12 of the tracer particle generator 1 is connected to the cavity 20; a contact piece 22 is provided in the gas pipeline covered by the sleeve 21; the tracer particles generated by the tracer particle generator 1 enter the contact piece 22 through the cavity 20, and the tracer particles contact the fluid flowing through the contact piece 22 in the gas pipeline; the contact piece 22 accelerates the mixing of the tracer particles and the fluid in the gas pipeline.
[0021] Specifically, the tracer particles generated by the tracer particle generator 1 of the present invention first enter the annular cavity 20, where they are evenly distributed around the contact member 22. They then enter the contact member 22, allowing the tracer particles to be evenly distributed across the cross-section of the gas pipeline and evenly mixed with the hydrogen-blended natural gas in the pipeline. In another embodiment of the present invention, multiple outlet pipes 12 are evenly spaced around the sleeve 21, each of which is connected to the tracer particle generator 1.
[0022] A plurality of tapered holes 220 are evenly arranged on the body 221 of the contact piece 22; an annular groove 222 is provided on the circumferential outer surface of the body 221, and a plurality of connecting parts 224 are provided in the annular groove 222; a gap 223 is provided in the middle of the body 221, and the gap 223 extends radially along the body 211; the gap 223 is connected to the plurality of tapered holes 220 in the body 221; the connecting part 224 connects the body 221 on both sides.
[0023] Specifically, the body 221 of the contact member 22 is a disc structure, see Figure 3An annular groove 222 is provided on the outer side of the circumference of the disc structure body 221. A gap 223 extends from the end surface of the annular groove 222 toward the center of the body 221. The gap 223 connects each tapered hole 220 on the body 221. The gap 223 divides the body 221 into two parts. The connecting portion 224 connects the two parts of the body 221. Figure 5 Specifically, the connecting portions 224 are arranged at equal intervals in the annular groove 222 and are located circumferentially of the body 221. The multiple tapered holes 220 are connected via the gaps 223. Compared to connecting multiple tapered holes 220 via holes or pipes, the tracer particles can evenly fill the gaps 223 and enter each tapered hole 220. The flow field of the tracer particles in the gaps 223 can also be automatically changed according to the flow rate at different cross-sectional positions, allowing the tracer particles to evenly mix with the hydrogen-blended natural gas flowing through each tapered hole 220.
[0024] The cross-sectional area of the first end face 220a located upstream of the conical hole 220 is larger than the cross-sectional area of the second end face 220b located downstream; a conical surface 220c is formed between the first end face 220a and the second end face 220b; the conical surface 220c causes the fluid in the gas pipeline to form a cross-sectional contraction along the flow direction, so that the fluid in the gas pipeline is deflected to flow along the conical surface 220c and be accelerated; the gap 223 is located in the middle of the conical surface 220c; the tracer particles injected into the gap 223 enter the conical surface 220c and form an air film along the conical surface 220c.
[0025] The gap 223 is formed on and covers the circumference of the conical surface 220c, so that the tracer particles injected into the gap 223 enter the conical surface 220c evenly from all four sides of the middle of the conical surface 220c to form an air film of equal length on the circumference of the conical surface 220c.
[0026] For details, see Figure 6 Slit 223 is an extended planar structure, forming an annular inlet at its intersection with conical surface 220c. This annular inlet allows tracer particles injected into slit 223 to enter conical surface 220c evenly from all sides, thereby forming an air film of approximately equal length around conical surface 220c, allowing for uniform mixing of the tracer particles with the hydrogen-enriched natural gas in the gas pipeline. Conical surface 220c deflects the hydrogen-enriched natural gas in the gas pipeline along conical surface 220c, increasing its flow rate. This allows for more thorough mixing of the tracer particles and the hydrogen-enriched natural gas when the hydrogen-enriched natural gas contacts the tracer particle film formed on conical surface 220c.
[0027] The tracer particles are guided by the gap 223 and enter the conical surface 220c from the annular edge to be preliminarily mixed with the fluid in the gas pipeline; the fluid forms turbulence near the second end surface 220b, so that the fluid and the tracer particles are fully mixed.
[0028] For details, see Figure 6 After the hydrogen-blended natural gas in the gas pipeline is accelerated by the conical surface 220c, turbulence will be generated at the end position of the conical surface 220c, that is, the downstream position near the second end surface 220b. The turbulence tears and rolls up the gas film of the tracer particles formed on the conical surface 220c and is fully mixed with the hydrogen-blended natural gas.
[0029] A first flange 21b and a second flange 21c are respectively provided at both ends of the sleeve 21a of the sleeve 21; the first flange 21b and the second flange 21c are sealedly connected to the side wall of the gas pipeline; an outlet cavity 120 is provided at the connection position between the sleeve 21a and the outlet pipe 12; the first flange 21b, the second flange 21c, the sleeve 21a and the side wall of the gas pipeline form a cavity 20; the cavity 20 is connected to the outlet cavity 120.
[0030] For details, see Figure 7 An annular cavity 20 is formed between the annular sleeve 21a and the gas pipeline. When tracer particles are injected into the cavity 20 through the outlet pipe 12, the tracer particles can be evenly distributed in the annular cavity 20 at the position where the mixer 2 is installed in the gas pipeline. Then the tracer particles enter the conical surface 220c of the tapered hole 220 through the gap 223 in the mixer 2, thereby achieving contact and mixing with the fluid in the gas pipeline. The structure of the annular cavity 20 and the gap 223 in the present invention enables the tracer particles to be evenly injected into the tapered hole 220 from all directions of the cross-section of the gas pipeline and evenly mixed with the fluid in the gas pipeline.
[0031] One side of the cylinder 11 of the tracer particle generator 1 is connected to the outlet pipe 12, and the other side is provided with an inlet 13; the end of the cylinder 11 is provided with an end cover 16; the end cover 16 is provided with an impeller assembly 17 extending into the cylinder 11; the end cover 16 is provided with a first motor 14 that is transmission-connected to the impeller assembly 17; the end cover 16 is also provided with a material injection device 15.
[0032] For details, see Figure 8 The injection device 15 injects the tracer particles into the cavity of the cylinder 11, the inlet 13 is connected to the external air source, and the impeller assembly 17 rotates to break up the tracer particles, and then enters the mixer 2 through the outlet pipe 12.
[0033] The first impeller 17b and the second impeller 17c are arranged side by side on the rotating shaft 17a of the impeller assembly 17; the rotating shaft 17a is supported on the base 162 of the end cover 16 through a bearing; and the rotating shaft 17a is connected to the output end of the first motor 14.
[0034] The storage barrel 151 of the injection device 15 is fixedly connected to the end cover 16; a screw 153 is rotatably provided in the storage barrel 151; a push plate 154 is connected to the screw 153 through a threaded fit, and the push plate 154 is arranged in the storage barrel 151 through a guide mechanism; the output end of the second motor 152 is connected to the screw 153; the push plate 154 injects the tracer particles in the storage barrel 151 into the cylinder body 11 through the injection hole 161 on the end cover 16.
[0035] For details, see Figure 8-9 The cylinder 11 and the end cover 16 form a sealed cavity, and the injection device 15 injects tracer particles into the injection hole 161 of the end cover 16. The tracer particles are fully mixed with the gas source carrier entering from the inlet 13 through the first impeller 17b and the second impeller 17c of the impeller assembly 17, and then directly pass through the outlet pipe 12 into the mixer 2.
[0036] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.
Claims
1. A laser in-situ calibration device for gas indication error of hydrogen-doped natural gas, comprising a tracer particle generator (1) for injecting tracer particles into a gas pipeline, a laser generator (5), a high-speed camera (6) and a gas flow meter (7), characterized in that: The tracer particle generator (1) is connected to the gas pipeline via a mixer (2); The mixer (2) uniformly mixes the tracer particles with the fluid in the gas pipeline; The gas pipeline downstream of the mixer (2) includes a steady flow section (3), and the end of the steady flow section (3) of the gas pipeline is connected to a transparent tube (4); A laser generator (5) and a high-speed camera (6) are provided on one side of the transparent tube (4); The laser generator (5) is arranged in a first direction toward the center of the transparent tube (4), and the high-speed camera (6) is arranged in a second direction toward the center of the transparent tube (4); The first direction is perpendicular to the second direction; The end of the transparent tube (4) is connected to a gas flow meter (7).
2. The laser in-situ calibration device according to claim 1, characterized in that: The mixer (2) comprises a sleeve (21) arranged outside the gas pipeline; An annular cavity (20) is formed between the sleeve (21) and the outer surface of the gas pipeline; The outlet pipe (12) of the tracer particle generator (1) is in communication with the cavity (20); A contact piece (22) is provided in the gas pipeline covered by the sleeve (21); The tracer particles generated by the tracer particle generator (1) enter the contact piece (22) through the cavity (20), and the tracer particles come into contact with the fluid in the gas pipeline flowing through the contact piece (22); The contact member (22) accelerates the mixing of the tracer particles with the fluid in the gas pipeline.
3. The laser in-situ calibration device according to claim 2, characterized in that: A plurality of tapered holes (220) are evenly arranged on the body (221) of the contact member (22); An annular groove (222) is provided on the circumferential outer surface of the body (221), and a plurality of connecting portions (224) are provided in the annular groove (222); A gap (223) is provided in the middle of the body (221), and the gap (223) extends radially along the body (211); The gap (223) is in communication with the plurality of tapered holes (220) in the body (221); The connecting portion (224) connects the bodies (221) on both sides.
4. The laser in-situ calibration device according to claim 3, characterized in that: The cross-sectional area of the first end surface (220a) of the tapered hole (220) located upstream is larger than the cross-sectional area of the second end surface (220b) located downstream; A conical surface (220 c) is formed between the first end surface (220 a) and the second end surface (220 b); The conical surface (220c) causes the fluid in the gas pipeline to form a cross-sectional contraction along the flow direction, causing the fluid in the gas pipeline to be deflected to flow along the conical surface (220c) and be accelerated; The gap (223) is located in the middle of the conical surface (220c); The tracer particles injected into the gap (223) enter the conical surface (220c) and form an air film along the conical surface (220c).
5. The laser in-situ calibration device according to claim 4, characterized in that: The gap (223) is formed on and covers the circumference of the conical surface (220c), so that the tracer particles injected into the gap (223) enter the conical surface (220c) evenly from all four sides of the middle of the conical surface (220c), thereby forming an air film of equal length on the circumference of the conical surface (220c).
6. The laser in-situ calibration device according to claim 5, characterized in that: The tracer particles are guided by the gap (223) and enter the conical surface (220c) from the edge of the ring to be preliminarily mixed with the fluid in the gas pipeline; The fluid forms turbulence at a position near the second end surface (220b), so that the fluid and the tracer particles are fully mixed.
7. The laser in-situ calibration device according to claim 6, characterized in that: The sleeve (21a) of the sleeve (21) is provided with a first flange (21b) and a second flange (21c) at both ends thereof; The first flange (21 b) and the second flange (21 c) are sealed and connected to the side wall of the gas pipeline; An outlet cavity (120) is provided at the connection position between the sleeve (21a) and the outlet pipe (12); The first flange (21 b), the second flange (21 c), the sleeve (21 a) and the side wall of the gas pipeline form a cavity (20); The cavity (20) is in communication with the outlet cavity (120).
8. The laser in-situ calibration device according to claim 7, characterized in that: One side of the cylinder (11) of the tracer particle generator (1) is connected to an outlet pipe (12), and the other side is provided with an inlet (13); An end cap (16) is provided at the end of the cylinder (11); The end cover (16) is provided with an impeller assembly (17) extending into the cylinder (11); The end cover (16) is provided with a first motor (14) which is transmission-connected to the impeller assembly (17); The end cover (16) is also provided with a material injection device (15).
9. The laser in-situ calibration device according to claim 8, characterized in that: A first impeller (17b) and a second impeller (17c) are arranged side by side on the rotating shaft (17a) of the impeller assembly (17); The rotating shaft (17a) is supported by a bearing and arranged on the base (162) of the end cover (16); The rotating shaft (17a) is connected to the output end of the first motor (14).
10. The laser in-situ calibration device according to claim 9, characterized in that: The material storage barrel (151) of the injection device (15) is fixedly connected to the end cover (16); A lead screw (153) is rotatably provided in the storage barrel (151); The lead screw (153) is connected to a push plate (154) through threaded engagement, and the push plate (154) is arranged in the storage barrel (151) through a guide mechanism; The output end of the second motor (152) is connected to the lead screw (153); The push plate (154) injects the tracer particles in the storage barrel (151) into the barrel (11) through the injection hole (161) on the end cover (16).