A new static mixer

Abstract

The utility model discloses a novel static mixer is applied to natural gas hydrogen blending technical field, it includes the mixer main part, the mixer main part is equipped with air inlet pipeline, premixing section, turbulence section, mixing section and air outlet pipeline from left to right in proper order in oneself, be equipped with turbulence element in the turbulence section, the turbulence element includes three pieces corrugated board of parallel, interval distribution's top angle is 90 DEG, the corrugated board includes first corrugated board, second corrugated board and third corrugated board, the rotation angle between first corrugated board and second corrugated board, second corrugated board and third corrugated board are 150 DEG all, it effectively solved the evenness of mixing of existing static mixer poor, pressure loss is big, the complex structure and difficult to clean and so on, the utility model has the advantages such as the number of corrugated board is less, and the processing and manufacturing are convenient, and it is compact, zero energy consumption operation, low maintenance requirement, and the strong advantages such as flexible adaptability, and in the process of using, pressure loss is small, and the mixing efficiency is high, and the scope of application is wide.

Description

Technical Field

[0001] This utility model relates to the field of natural gas hydrogen blending technology, specifically a novel static mixer. Background Technology

[0002] With the gradual rise of the hydrogen energy industry chain, hydrogen transportation has become a key bottleneck restricting the development of hydrogen energy. Integrating hydrogen into existing natural gas pipelines for extraction and utilization at the terminal is an effective measure to expand the scale of hydrogen energy applications, reduce hydrogen storage and transportation costs, and achieve carbon emission reduction. While relying on the natural diffusion mixing of hydrogen and natural gas has advantages such as no need for power equipment, low operating costs, and high reliability, its mixing efficiency is low. Achieving the required mixing uniformity requires a long pipeline length, leading to excessively high local hydrogen concentrations. This increases the risk of hydrogen embrittlement in steel materials, reduces the performance of rubber seals, causes compressor surge, and affects the combustion stability of end users, among other problems, which are detrimental to the safe operation of the gas pipeline network. To achieve the required mixing uniformity within a shorter pipeline length after mixing, it is necessary to install flow-disrupting elements.

[0003] Static mixers, which achieve efficient mixing of different fluids solely through the disturbance of mixing units with varying structures without requiring additional power, are increasingly being applied in the field of hydrogen-blended natural gas technology. Patent application CN118625529A discloses a static mixer for hydrogen-blended natural gas, in which baffles are installed in the flow section to enhance airflow disturbance and improve the uniformity of gas mixing. However, the large number of baffles results in a complex overall structure that is difficult to clean, leading to an overall structure that does not meet requirements and needs improvement. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide a novel static mixer with a corrugated plate structure suitable for mixing hydrogen into natural gas. It has a simple structure, reasonable design, requires fewer corrugated plates, is easy to process, can achieve uniform mixing of hydrogen and natural gas in a short distance, and has low pressure loss, which is conducive to cleanliness.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:

[0006] This utility model includes a mixer body. From left to right, the mixer body is provided with an inlet pipe, a premixing section, a turbulence section, a mixing section, and an outlet pipe. The inlet pipe includes a natural gas inlet pipe connected to natural gas and a hydrogen inlet pipe connected to hydrogen. The natural gas exiting the natural gas inlet pipe and the hydrogen exiting the hydrogen inlet pipe mix in the premixing section and enter the turbulence section. The turbulence section is provided with turbulence elements, each comprising three corrugated plates with a 90° apex angle, arranged in parallel and spaced intervals. The corrugated plates include a first corrugated plate, a second corrugated plate, and a third corrugated plate. The rotation angle between the first and second corrugated plates, and between the second and third corrugated plates, is 150°.

[0007] A further improvement of this utility model is that the turbulence element is disposed between the premixing section and the mixing section, and the distance from the premixing section is not less than three times the diameter of the natural gas inlet pipe.

[0008] A further improvement of this invention is that the body rotation angle of the disturbance element is 60°.

[0009] A further improvement of this utility model is that the length of the turbulence-disrupting element is 1-1.5 times the diameter of the natural gas intake pipe.

[0010] A further improvement of this utility model is that the length of the turbulence-disrupting element is 1.5 times the diameter of the natural gas intake pipe.

[0011] A further improvement of this utility model is that the thickness of the corrugated plate is 2mm.

[0012] A further improvement of this utility model is that the turbulence element is a first turbulence element and a second turbulence element arranged in parallel, and the distance between the first turbulence element and the second turbulence element is 20mm.

[0013] A further improvement of this utility model is that the hydrogen inlet pipe is located at the bottom of the natural gas inlet pipe, and the outlet direction of the hydrogen inlet pipe is opposite to the outlet direction of the natural gas inlet pipe.

[0014] A further improvement of this utility model is that the hydrogen inlet pipe includes a vertical pipe, a horizontal pipe, and a bend connecting the vertical pipe and the horizontal pipe, wherein the horizontal pipe coincides with the central axis of the natural gas inlet pipe.

[0015] The beneficial effects achieved by this utility model due to the adoption of the above technical solution are as follows:

[0016] This utility model has a simple structure and novel design, and successfully achieves the requirement of uniform mixing of hydrogen and natural gas within a short distance after hydrogen is injected into the natural gas pipeline network, thus avoiding any impact on downstream equipment and user safety.

[0017] Hydrogen gas ejected from a horizontal pipe and natural gas transported from the natural gas intake pipe flow counter-currently in the premixing section, mixing through intermolecular forces. As they flow through the turbulence section, the two gases are separated, displaced, and merged by turbulence elements, altering the velocity and direction of the mixed gas and enhancing turbulence. This improves the mixing uniformity of hydrogen and natural gas, and the mixture finally flows out through the outlet pipe. The significantly improved mixing uniformity of natural gas and hydrogen effectively solves the problems of poor mixing uniformity, high pressure loss, complex structure, and difficulty in cleaning found in existing static mixers for hydrogen blending in natural gas.

[0018] This mixer boasts advantages such as fewer corrugated plates, ease of manufacturing, low pressure loss, high mixing efficiency, and wide applicability during operation. In summary, its compact structure, zero-energy operation, low maintenance requirements, and strong adaptability make it the preferred solution for current hydrogen-blended natural gas pipeline mixing technology. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0020] Figure 2 This is a schematic diagram of the connection structure of the two air intake pipes of this utility model;

[0021] Figure 3 This is a schematic diagram of the structure of the turbulence section of this utility model;

[0022] Figure 4 This is a schematic diagram of the structure of the turbulence-disrupting element of this utility model.

[0023] The components include: 1. Mixer body; 2. Natural gas inlet pipe; 3. Hydrogen inlet pipe; 31. Vertical pipe; 32. Bend pipe; 33. Horizontal pipe; 4. Premixing section; 5. Turbulence section; 51. First turbulence element; 52. Second turbulence element; 511. First corrugated plate; 512. Second corrugated plate; 513. Third corrugated plate; 6. Mixing section; 7. Gas outlet pipe. Detailed Implementation

[0024] The present invention will be further described in detail below with reference to embodiments:

[0025] A new type of static mixer, such as Figure 1-4As shown, the mixer body 1 includes an inlet pipe, a premixing section 4, a turbulence section 5, a mixing section 6, and an outlet pipe 7 arranged sequentially from left to right within the mixer body 1. The inlet pipe includes a natural gas inlet pipe 2 connected to natural gas and a hydrogen inlet pipe 3 connected to hydrogen. The wall thickness of the inlet pipes is 2 mm. Natural gas discharged from the outlet of the natural gas inlet pipe 2 and hydrogen discharged from the outlet of the hydrogen inlet pipe 3 are mixed in the premixing section 4 and enter the turbulence section 5. The mixed gas collides with the corrugated plates in the turbulence section 5, changing the flow direction and increasing the turbulence intensity, thereby achieving uniform mixing of the two gases. Finally, the uniformly mixed hydrogen-blended natural gas is directly transported to the end user for use as fuel through the natural gas pipeline network via the outlet pipe 7.

[0026] like Figure 1 and Figure 2 As shown, the hydrogen inlet pipe 3 is located at the bottom of the natural gas inlet pipe 2, and the outlet direction of the hydrogen inlet pipe 3 is opposite to the outlet direction of the natural gas inlet pipe 2, which is conducive to the full mixing of natural gas and hydrogen.

[0027] like Figure 2 As shown, the hydrogen inlet pipe 3 includes a vertical pipe 31, a horizontal pipe 33, and a bend 32 connecting the vertical pipe 31 and the horizontal pipe 33. The horizontal pipe 33 coincides with the central axis of the natural gas inlet pipe 2. The vertical pipe 31 is connected to the hydrogen inlet. After the vertical pipe 31 enters the natural gas inlet pipe 2 from the bottom in an orthogonal direction, the hydrogen enters the horizontal pipe 33 from the vertical pipe 31 via the bend 32 at a 90° angle in the opposite direction. It then flows in the opposite direction to the main flow of natural gas, creating a countercurrent flow that promotes the mixing of natural gas and hydrogen. The horizontal pipe 33 at the hydrogen outlet coincides with the central axis of the natural gas inlet pipe 2. In this way, the hydrogen at the outlet of the horizontal pipe 33 and the natural gas at the outlet of the natural gas inlet pipe 2 form a countercurrent injection, creating a countercurrent flow that promotes the premixing of hydrogen and natural gas. This provides a basis for the uniform mixing of natural gas and hydrogen in the turbulence section 5 to form a uniformly mixed hydrogen-blended natural gas.

[0028] like Figure 1 and Figure 3 As shown, the turbulence section 5 is equipped with turbulence elements, which include three corrugated plates with a 90° apex angle that are parallel and spaced apart. Considering the target mixing uniformity and pressure loss, it is more appropriate to select a 90° apex angle for the corrugated plates of the static mixer.

[0029] Increasing the thickness of the flow-dispersing element does not significantly change the fluid mixing uniformity, but it does increase pressure loss. Considering the improvement in mixing uniformity per unit pressure drop, δ=2mm is the optimal value. The thickness of the flow-dispersing element changes the cross-sectional area and velocity of the flow channel, thus affecting the mixing uniformity and pressure loss of hydrogen and natural gas. Comparative analysis of flow-dispersing elements with corrugated plate thicknesses of δ=2, 2.5, and 3mm shows that as the thickness of the flow-dispersing element increases, the velocity and pressure loss at the same location of the flow-dispersing element increase accordingly. Based on the improvement in mixing uniformity per unit pressure drop, a corrugated plate thickness of δ=2mm is the most suitable among the three corrugated plate thicknesses mentioned above.

[0030] like Figure 4 As shown, the corrugated plate includes a first corrugated plate 511, a second corrugated plate 512, and a third corrugated plate 513. The rotation angle between the first corrugated plate 511 and the second corrugated plate 512, and between the second corrugated plate 512 and the third corrugated plate 513, is 150°. When the apex angle of the corrugated plate is θ = 90°, rotating both the upper and lower corrugated plates clockwise around the Y-axis by an angle α can enhance the turbulence intensity of the fluid flowing through the corrugated plates of the turbulence element, which is beneficial to promoting fluid mixing. When analyzing the effect of the rotation angle between the corrugated plates on the mixing effect, when the rotation angles are 30° and 150°, and 60° and 120°, the high-speed region and the high-concentration region of hydrogen at the outlet of the turbulence element are basically the same in size but opposite in position, indicating that the two complementary angles have basically the same effect on the change in fluid velocity and concentration. The changes in fluid velocity are most pronounced at α=30° and 150°, with the maximum velocity value being significantly lower than the other three angles. At α=90°, the proportion of high-speed fluid within the pipe is highest, and the gaps between the rotated corrugated plates carry the high-concentration hydrogen region from the vertical flow channel area within the plates towards the pipe wall. Therefore, when α=30° and α=150°, the velocity distribution is more uniform, the proportion of high-speed hydrogen-mixed natural gas within the pipe is smaller, and the pressure loss is also lower among the five angles. Based on the calculated improvement in mixing uniformity per unit pressure drop using different corrugated plate rotation angles, the optimal rotation angle between the corrugated plates under the research conditions was selected as α=150°.

[0031] The volumetric rotation angle β of the disturbance element is 60°. Taking the length direction of the natural gas inlet pipe 2 as the Z direction, the entire disturbance element is rotated around the Z direction by a certain angle β. After rotation, the entire disturbance element forms a certain angle with the pipe axis, changing the flow direction of hydrogen and natural gas and strengthening the disturbance intensity. When β = 0°, 30°, 45°, 60°, and 90°, the pressure loss at the inlet and outlet of the mixer continuously decreases as the volumetric rotation angle increases. Based on the calculation of the unit pressure drop mixing uniformity improvement value based on different corrugated plate volumetric rotation angles, the optimal volumetric rotation angle β of the corrugated plate under the research conditions is selected as 60°.

[0032] The flow-disrupting element is positioned between the premixing section 4 and the mixing section 6, at a distance from the premixing section 4 that is no less than three times the diameter of the natural gas inlet pipe 2, i.e., at position 3D, where D is the diameter of the natural gas inlet pipe 2. Research results indicate that arranging the flow-disrupting element at intervals with the premixing section 4 can reduce pressure loss and improve mixing uniformity. Considering that the mixer body length should not be too long, based on the calculated improvement in mixing uniformity per unit pressure drop, the optimal mixing uniformity is achieved when the distance between the flow-disrupting element and the premixing section 4 is three times the diameter of the natural gas inlet pipe 2; that is, the optimal placement position mentioned above is 3D.

[0033] The length of the flow-dispersing element is 1-1.5 times the diameter of the natural gas inlet pipe 2, with the optimal length being 1.5 times the diameter of the natural gas inlet pipe 2. Under fixed parameters of a natural gas inlet pipe 2 diameter D=100mm, a corrugated plate apex angle θ=90°, and a corrugated plate rotation angle α=150°, the influence of the flow-dispersing element's length-to-diameter ratio L / D on mixing uniformity and pressure drop is analyzed. When L / D=1, the high-concentration hydrogen region at the outlet of the flow-dispersing element is concentrated in the central region of the pipe, and the proportion of the high-concentration hydrogen region is relatively large. As the length of the flow-dispersing element increases, the fluid mixing degree at the outlet of a single flow-dispersing element is enhanced. When L / D=1.5, the pressure loss also increases with the increase in the length of the flow-dispersing element. Therefore, based on the calculation results of the increase in mixing uniformity per unit pressure drop, the optimal length-to-diameter ratio for the flow-dispersing element is selected as 1.5, that is, when the natural gas diameter is D=100mm, the length of the flow-dispersing element is L=150mm.

[0034] The flow-dispersing elements are a first flow-dispersing element 51 and a second flow-dispersing element 52 arranged side by side, with a distance of 20 mm between them. The number of flow-dispersing elements inside the pipe can be increased by adjusting the structure, placement, and rotation angle of the flow-dispersing elements described above. To eliminate errors caused by excessively small gaps between flow-dispersing elements, the spacing between adjacent flow-dispersing elements is set to 10 times the thickness of the corrugated plate, d = 20 mm. Therefore, to obtain higher mixing uniformity, the optimal mixer structure is selected as two flow-dispersing elements with a spacing of 20 mm.

[0035] Based on the influence of the above structural parameters on the gas mixing effect, the optimal structural parameters of the turbulence element are as follows: apex angle θ = 90°, inter-plate rotation angle α = 150°, length-to-diameter ratio L / D = 1.5, thickness δ = 2mm, placement of the turbulence element at a distance S = 3D from the initial mixing position, body rotation angle β = 60°, number of turbulence elements N = 2 and distance between turbulence elements d = 20mm.

[0036] Under the optimal mixer structure described above, a higher hydrogen doping ratio, flow rate, and pressure result in a shorter distance to achieve the target mixing uniformity, but also cause a significant pressure loss along the flow path. A high mixing uniformity can be obtained by fixing the hydrogen doping ratio at 20% and using mixing conditions of V=10m / s and P=0.4MPa.

[0037] In summary, this mixer has advantages such as compact structure, zero-energy operation, low maintenance requirements, and strong flexibility and adaptability, and will become the preferred solution for future hydrogen-blended natural gas pipeline mixing technology.

[0038] Finally, it should be noted that the above embodiments are merely examples for clearly illustrating the present invention and are by no means intended to limit the implementation. Those skilled in the art can make other variations or modifications based on the above description; it is impossible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom still fall within the protection scope of this invention.

Claims

1. A novel static mixer, comprising a mixer body (1), characterized in that: The mixer body (1) is provided with an air inlet pipe, a premixing section (4), a turbulence section (5), a mixing section (6) and an air outlet pipe (7) from left to right. The air inlet pipe includes a natural gas inlet pipe (2) connected to natural gas and a hydrogen inlet pipe (3) connected to hydrogen. The natural gas at the outlet of the natural gas inlet pipe (2) and the hydrogen at the outlet of the hydrogen inlet pipe (3) are mixed in the premixing section (4) and enter the turbulence section (5). The turbulence section (5) is provided with turbulence elements, which include three corrugated plates with a 90° apex angle that are parallel and spaced apart. The corrugated plates include a first corrugated plate (511), a second corrugated plate (512), and a third corrugated plate (513). The rotation angle between the first corrugated plate (511) and the second corrugated plate (512), and between the second corrugated plate (512) and the third corrugated plate (513) is 150°.

2. The novel static mixer according to claim 1, characterized in that: The turbulence element is located between the premixing section (4) and the mixing section (6), and the distance from the premixing section (4) is not less than three times the diameter of the natural gas inlet pipe (2).

3. A novel static mixer according to claim 2, characterized in that: The volume rotation angle of the disturbance element is 60°.

4. A novel static mixer according to claim 3, characterized in that: The length of the turbulence element is 1-1.5 times the diameter of the natural gas intake pipe (2).

5. A novel static mixer according to claim 4, characterized in that: The length of the turbulence element is 1.5 times the diameter of the natural gas intake pipe (2).

6. The novel static mixer according to any one of claims 1-5, characterized in that: The thickness of the corrugated plate is 2mm.

7. A novel static mixer according to claim 6, characterized in that: The turbulence-disrupting elements are a first turbulence-disrupting element (51) and a second turbulence-disrupting element (52) arranged in parallel, with a distance of 20 mm between the first turbulence-disrupting element (51) and the second turbulence-disrupting element (52).

8. A novel static mixer according to claim 1, characterized in that: The hydrogen inlet pipe (3) is located at the bottom of the natural gas inlet pipe (2), and the outlet direction of the hydrogen inlet pipe (3) is opposite to the outlet direction of the natural gas inlet pipe (2).

9. A novel static mixer according to claim 8, characterized in that: The hydrogen intake pipe (3) includes a vertical pipe (31), a horizontal pipe (33) and a bend (32) connecting the vertical pipe (31) and the horizontal pipe (33), wherein the horizontal pipe (33) coincides with the central axis of the natural gas intake pipe (2).

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