Static mixing device for uniformly mixing natural gas and hydrogen and working method

Abstract

The invention discloses a static mixing device for uniformly mixing natural gas and hydrogen and a working method, and relates to the field of mixed hydrogen conveying of natural gas pipelines, and torsion and turbulent flow units are fixed at intervals in each runner hole in the device; the torsion unit comprises a plurality of torsion elements which are sequentially and parallelly overlapped and fixed front and back, each torsion element is formed by fixedly overlapping a first torsion sheet and a second torsion sheet in a vertically symmetrical manner along the central axis of the runner hole, and the turbulent flow unit comprises a plurality of turbulent flow elements which are sequentially and fixedly spliced front and back; each turbulent flow element comprises a transverse turbulent flow part and a vertical turbulent flow part, each transverse turbulent flow part comprises an elliptical central transverse turbulent flow layer and auxiliary transverse turbulent flow layers which are symmetrically distributed along the central transverse turbulent flow layer up and down, and each vertical turbulent flow part comprises an elliptical central vertical turbulent flow layer and auxiliary vertical turbulent flow layers which are symmetrically distributed along the central vertical turbulent flow layer up and down; and the mixing effect and the gas uniformity are obviously improved.

Description

Technical Field

[0001] The invention relates to the field of natural gas pipeline mixed hydrogen transportation, and in particular to a static mixing device and a working method for uniformly mixing natural gas and hydrogen. Technical Background With the continuous advancement of energy structure transformation, especially the increasing maturity of renewable energy and clean energy technologies, hydrogen energy, as a green and low-carbon alternative energy source, is gradually gaining wider application. In this context, the mixed transportation technology of natural gas and hydrogen has become one of the hot spots in the energy field. This technology can not only effectively reduce carbon dioxide emissions and promote greenhouse gas emission reduction, but also promote the development of hydrogen energy and the optimization of energy structure. The mixing of hydrogen and natural gas not only helps to reduce environmental pollution, but also improves the efficiency of energy utilization. Therefore, how to ensure the efficiency and safety of the gas transportation process while ensuring the mixing effect has become a key issue that needs to be solved urgently.

[0003] Mixing hydrogen into natural gas for mixed transportation not only achieves clean energy utilization, but also places more stringent requirements on equipment. In order to ensure the uniform mixing of natural gas and hydrogen and avoid the occurrence of air flow instability or stratification during pipeline transportation, it is particularly important to design a device that can efficiently mix under wide flow rate range and variable flow conditions. How to improve the efficiency of gas mixing, reduce the energy consumption of equipment, and ensure stability and reliability in long-term operation has become a core issue that needs to be solved in natural gas and hydrogen mixing technology.

[0004] At present, in the field of gas mixing, common equipment types include dynamic mixers and static mixers. Dynamic mixers use external mechanical devices or energy sources (such as turbines, agitators, etc.) to promote gas mixing. Although they can improve the mixing effect to a certain extent, their complex structure, high energy consumption, and high equipment maintenance costs are also very obvious. In addition, the operating efficiency of dynamic mixers is usually affected by changes in gas velocity and pressure. Especially in large-scale, high-flow applications, the operation of dynamic devices will lead to reduced efficiency or even failure.

[0005] Compared with dynamic mixers, static mixers have gradually become the mainstream choice in the field of gas mixing due to their simple structure, stable operation, high energy efficiency and low maintenance requirements. Static mixers change the flow path and turbulence of the gas flow through internal static elements such as spirals, grids or spoilers, thereby effectively promoting the mixing of different gas components. Its main advantages are that it does not require an external power source, has low energy consumption, strong economy, a wide range of applications, and uniform gas mixing. However, when faced with the mixing of gases such as natural gas and hydrogen, which have large differences in physical and chemical properties, in complex working conditions with various mixing ratios, flow rates and flow rate fluctuations, traditional static mixers are difficult to adapt. For example, the SV type static mixer, whose SV element is a cylinder composed of a series of corrugated plates, has limited mixing uniformity and large pressure loss after the natural gas and hydrogen flow in, so the mixing effect is low and the mixing uniformity is low. Summary of the invention

[0006] In view of the problems existing in the prior art, the present invention provides a static mixing device and a working method for uniformly mixing natural gas and hydrogen, so as to solve the problems of low uniformity and large pressure loss of SV type static mixer when mixing natural gas and hydrogen. By optimizing the structure and arrangement of the mixing unit and combining the flow channel holes, it is not only suitable for the efficient mixing requirements and stable operation of gases under complex working conditions with different flow rates, flow velocities and input pressures, but also significantly improves the mixing effect and gas uniformity.

[0007] A static mixing device for uniformly mixing natural gas and hydrogen, comprising an air inlet pipeline, a static mixing unit and an air outlet pipeline which are sequentially connected and fixedly connected: The air inlet pipe is provided with a natural gas inlet and a hydrogen inlet, and the static mixing unit is provided with a plurality of flow channel holes penetrating both sides of the static mixing unit along its length direction, and the inner wall of each flow channel hole is fixed with a twisting unit and a turbulent unit at intervals; The torsion unit includes a plurality of torsion elements which are overlapped and fixed in parallel in sequence front and back, each torsion element is formed by two semicircular first torsion plates and a second torsion plates of the same diameter which are symmetrically fixed and overlapped along the central axis of the flow channel hole. The spoiler unit includes a plurality of spoiler elements which are spliced ​​and fixed in sequence front and back, each spoiler element includes a transverse spoiler and a vertical spoiler. The transverse spoiler includes an elliptical central transverse spoiler layer and auxiliary transverse spoiler layers which are symmetrically distributed along the central transverse spoiler layer. The vertical spoiler includes an elliptical central vertical spoiler layer and auxiliary vertical spoiler layers which are symmetrically distributed along the central vertical spoiler layer. The central transverse spoiler layer, the auxiliary transverse spoiler layer, the central vertical spoiler layer and the auxiliary vertical spoiler layer are all spliced ​​by a plurality of spoiler strips at intervals, and the central transverse spoiler layer and the central vertical spoiler layer are vertically plugged and fixed to each other along the central axis of the flow channel hole.

[0008] Preferably, the air inlet pipe includes a first pipe and a second pipe, and the air outlet pipe includes a third pipe and a fourth pipe, the first pipe and the fourth pipe have the same inner and outer diameters, the second pipe and the third pipe have the same inner and outer diameters, the outer diameter of the first pipe is smaller than the second pipe, a first arc-shaped transition section is provided at the junction of the first pipe and the second pipe, and a second arc-shaped transition section is provided at the junction of the third pipe and the fourth pipe, forcing the airflow to flow along different paths, thereby promoting forced mixing of the two gases and further improving the mixing effect, and the bending angles of the first arc-shaped transition section and the second arc-shaped transition section are the same, both of which are 5 degrees to 25 degrees.

[0009] Preferably, the static mixing unit is a cylindrical, regular triangular prism, regular quadrangular prism or regular hexagonal prism pipe, and the two ends of the pipe are respectively connected to the air inlet pipe and the air outlet pipe through two pairs of mutually aligned flanges, and each pair of mutually aligned flange edges are evenly provided with a plurality of bolt holes along the circumferential direction, and a corresponding bolt is installed in each bolt hole.

[0010] Preferably, the inner wall of the flow channel hole is provided with an internal thread, and the first torsion plate, the second torsion plate, the central transverse spoiler layer, and the central vertical spoiler layer are engaged in the internal thread; The flow channel holes are evenly distributed in 3-17 numbers along the cross section of the static mixing unit, the hole diameter is 3%-13% of the cross section specification of the static mixing unit, the center distance between adjacent flow channel holes is 4%-20% of the cross section specification of the static mixing unit, when the cross section of the static mixing unit is a circle, the corresponding specification is the diameter, when the cross section of the static mixing unit is an equilateral triangle, a square and a regular hexagon respectively, the corresponding specification is the circumscribed circle diameter.

[0011] Preferably, the first torsion plate and the second torsion plate are both distributed vertically, the center of the straight side of the first torsion plate and the center of the straight side of the second torsion plate are fixed, the angle between the straight side of the first torsion plate and the straight side of the second torsion plate is 30°-45°, the first torsion plate is located at the bottom, and the angle between the straight side of the first torsion plate and the central axis of the flow channel hole is 45°-65°.

[0012] Preferably, the spacing between two adjacent first torsion plates or second torsion plates is 0.1%-0.8% of the length of the static mixing unit, the front end of the straight edge of the second torsion plate is fixed to the front end of the straight edge of the previous first torsion plate, and the rear end of the straight edge of the second torsion plate is fixed to the rear end of the straight edge of the next first torsion plate.

[0013] Preferably, both surfaces of the central transverse spoiler layer, the auxiliary transverse spoiler layer, the central vertical spoiler layer and the auxiliary vertical spoiler layer are uniformly distributed with dot-shaped protrusions.

[0014] Preferably, the major and minor axes of the central horizontal spoiler layer and the central vertical spoiler layer are respectively equal, the auxiliary horizontal spoiler layer and the auxiliary vertical spoiler layer are each one layer, one end of the auxiliary horizontal spoiler layer and the auxiliary vertical spoiler layer are both arc-shaped, and the other ends of the auxiliary horizontal spoiler layer and the auxiliary vertical spoiler layer are both straight lines, wherein the arc-shaped end of the auxiliary horizontal spoiler layer located on the upper layer corresponds to the straight end of the auxiliary horizontal spoiler layer located on the lower layer, the arc-shaped end of the auxiliary vertical spoiler layer located on the right side corresponds to the straight end of the auxiliary vertical spoiler layer located on the left side, the size of the auxiliary horizontal spoiler layer is smaller than that of the central horizontal spoiler layer, and the size of the auxiliary vertical spoiler layer is smaller than that of the central vertical spoiler layer.

[0015] Preferably, the frontmost spoiler strip of the central vertical spoiler layer of the rear spoiler element is fixed to the rearmost spoiler strip of the central transverse spoiler layer and the auxiliary transverse spoiler layer of the front spoiler element, and all the central transverse spoiler layers and central vertical spoiler layers in the spoiler unit are respectively and evenly distributed; The distance between two adjacent torsion units or between the torsion unit and the disturbance unit in each flow channel hole is 6%-13% of the length of the static mixing unit.

[0016] A working method of a static mixing device for uniformly mixing natural gas and hydrogen, wherein natural gas flows in from a natural gas inlet, hydrogen flows in from a hydrogen inlet, and then enters a corresponding torsion unit and a spoiler unit through various flow channel holes, a first torsion plate and a second torsion plate gradually guide the airflow to rotate, disperse and reorganize, a transverse spoiler disrupts the axial flow of the airflow to generate transverse turbulence, and a vertical spoiler further disrupts the radial distribution of the airflow by arranging the spoilers in a staggered manner, thereby enhancing the depth and uniformity of the mixing, so that the natural gas and hydrogen are fully contacted and uniformly mixed inside the static mixing unit, and the mixed gas flows out from an outlet, thereby achieving efficient and uniform mixing of the natural gas and hydrogen.

[0017] Compared with the prior art, the present invention has the following beneficial technical effects: The present invention discloses a static mixing device for uniformly mixing natural gas and hydrogen. Each flow channel hole is alternately arranged with a torsion unit and a turbulence unit in sequence along the airflow direction to form a multi-stage mixing unit. By strengthening the synergistic effect of axial rotation, radial disturbance and lateral turbulence, the stratification phenomenon of the fluid can be effectively reduced, and the efficient mixing state of the airflow can be maintained, so that a good mixing effect can be achieved under complex working conditions with different flow rates, flow velocities and input pressures. The mixed gas can maintain good uniformity, and efficient and uniform mixing of natural gas and hydrogen can be achieved. The arrangement of the flow channel holes is highly consistent with the flow path of the airflow, ensuring that the airflow can achieve a stable and uniform mixing effect when passing through the static mixing unit, thereby ensuring the optimal mixing efficiency of natural gas and hydrogen. The structural design of the torsion element forms a certain angle with the direction of the airflow along the direction of the flow channel hole, gradually guiding the airflow to rotate, disperse and reorganize each time the fluid passes through, thereby effectively enhancing the mixing efficiency of natural gas and hydrogen. The structural design of the horizontal spoiler is arranged obliquely along the flow channel diameter direction, which is used to disrupt the axial flow of the airflow and generate lateral turbulence, thereby increasing the contact surface of the two gases and enhancing the mixing effect; the structural design of the vertical spoiler further disrupts the radial distribution of the airflow through a staggered arrangement, enhancing the depth and uniformity of the mixing, and can achieve efficient and uniform mixing of natural gas and hydrogen without an external power source, ensuring the reliability and consistency of gas mixing, and can be flexibly adjusted according to different working conditions, convenient for installation and maintenance, and also enables it to adjust the number of flow channel holes, the arrangement of mixing units and the size of the overall device according to specific application requirements, so as to adapt to the stable operation requirements of different flow rates, flow rates, input pressures and gas mixing ratios, and can withstand various different input pressures, with strong pressure bearing capacity and no input pressure limit. The present invention minimizes fluid resistance and reduces energy loss while maintaining high mixing efficiency, has a significant low pressure loss characteristic, and ensures low pressure loss operation of the system. At the same time, the detachable design enhances the adaptability of the device, enabling it to flexibly respond to diverse industrial needs, which not only improves the use efficiency of the device, but also greatly reduces operation and maintenance costs. These advantages make the present invention have broad application prospects and significant technical advantages in natural gas hydrogen blending, industrial gas processing and related fields. The present invention has higher mixing efficiency, lower energy loss and greater flexibility, and is suitable for natural gas hydrogen blending, industrial gas processing and other fields.

[0018] Furthermore, both surfaces of the central transverse spoiler layer, the auxiliary transverse spoiler layer, the central vertical spoiler layer and the auxiliary vertical spoiler layer are distributed with uniform dot-shaped protrusions, which can enhance the turbulence intensity and expand the contact area between the two gases. However, when the flow rate and flow velocity are large, reducing the height of the protrusions and increasing the spacing between the protrusions can reduce the pressure drop and energy loss.

[0019] The present invention discloses a working method of a static mixing device for uniformly mixing natural gas and hydrogen. Natural gas and hydrogen enter the static mixing unit from two independent air inlets (natural gas inlet and hydrogen inlet) of an air inlet pipeline, respectively. The airflow passes through the torsion unit and the spoiler unit in sequence through the flow channel hole. In the torsion unit, the semicircular first torsion plate and the second torsion plate gradually guide the airflow to rotate, disperse and reorganize, thereby realizing the stratification and remixing of the gas; in the spoiler unit, the horizontal spoiler disrupts the axial flow of the airflow to generate lateral turbulence, and the vertical spoiler further disrupts the radial distribution of the airflow through a staggered arrangement, thereby enhancing the depth and uniformity of the mixing, further disrupting the axial and radial flow characteristics of the airflow, and significantly improving the mixing depth and uniformity, so that the natural gas and hydrogen are fully contacted and uniformly mixed inside the static mixing unit. The mixed gas is discharged from the air outlet, and a high uniformity and high efficiency mixing effect can be achieved. The present invention makes up for the deficiencies of the prior art under conditions of different flow rates, flow velocities, input pressures and gas mixing ratios, and is suitable for various gas flow rates and ratio requirements, has a wide range of industrial application value, and can be used for natural gas hydrogen blending, industrial gas mixing and other related fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0021] Figure 1 It is a model diagram of the static mixing device described in the present invention.

[0022] Figure 2 It is a structural diagram of the static mixing device described in the present invention.

[0023] Figure 3 yes Figure 2 A magnified view of the static mixing unit.

[0024] Figure 4a yes Figure 2 Structural diagram of the torsion unit.

[0025] Figure 4b yes Figure 2 Structural diagram of the middle spoiler unit.

[0026] Figure 5 This is a diagram of the mesh division results of the static mixing device provided by the present invention.

[0027] Figure 6a It is a velocity vector cloud diagram at the XY cross-sectional position of the first mixing unit on the static mixing device of the present invention.

[0028] Figure 6b It is a velocity vector cloud diagram at the XY cross-sectional position of the second mixing unit on the static mixing device of the present invention.

[0029] Figure 6c It is a velocity vector cloud diagram at the YZ cross-section position of the static mixing device described in the present invention.

[0030] Figure 7 It is a distribution cloud diagram of the molar volume fraction of hydrogen at different XY cross-sectional positions before and after flowing through the static mixing device provided by the present invention.

[0031] Figure 8a It is a structural schematic diagram of the flow channel hole distribution of the first static mixing unit provided by the present invention.

[0032] Figure 8b It is a structural schematic diagram of the flow channel hole distribution of the second static mixing unit provided by the present invention.

[0033] Figure 8c It is a structural schematic diagram of the flow channel hole distribution of the third static mixing unit provided by the present invention.

[0034] Figure 8d It is a structural schematic diagram of the flow channel hole distribution of the fourth static mixing unit provided by the present invention.

[0035] Figure 8e It is a structural schematic diagram of the flow channel hole distribution of the fifth static mixing unit provided by the present invention.

[0036] Figure 8f It is a structural schematic diagram of the flow channel hole distribution of the sixth static mixing unit provided by the present invention.

[0037] Figure 9a It is a structural schematic diagram of the distribution position of the first static mixing unit provided by the present invention.

[0038] Figure 9b It is a structural schematic diagram of the distribution position of the second static mixing unit provided by the present invention.

[0039] Fig.9c It is a structural schematic diagram of the distribution position of the third static mixing unit provided by the present invention.

[0040] Fig.10a yes Figure 4a Front view of the torsion element.

[0041] Fig.10b yes Figure 4a Left side view of the torsion element.

[0042] Fig.10c yes Figure 4aTop view of the torsion element.

[0043] Fig.11a yes Figure 4b Front view of a single structure of the spoiler element.

[0044] Fig.11b yes Figure 4b A perspective view of a single structure of the spoiler element.

[0045] Fig.11c yes Figure 4b Another perspective view of the single structure of the spoiler element.

[0046] Fig.11d yes Figure 4b Figure 3. The front and rear splicing and fixing model diagram of the three spoiler elements.

[0047] In the figure: 1-first pipeline, 11-natural gas inlet, 12-hydrogen inlet, 13-gas outlet, 21-second pipeline, 22-third pipeline, 3-fourth pipeline, 41-first arcuate transition section, 42-second arcuate transition section, 51-first flange, 52-second flange, 53-third flange, 54-fourth flange, 6-bolt hole, 7-flow channel hole, 8-static mixing unit, 91-torsion unit, 92-spoiler unit, 93-horizontal spoiler, 94-vertical spoiler, 911-torsion element, 912-spoiler element, 914-first torsion plate, 915-second torsion plate, 931-central horizontal spoiler layer, 932-auxiliary horizontal spoiler layer, 941-central vertical spoiler layer, 942-auxiliary vertical spoiler layer. DETAILED DESCRIPTION

[0048] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0049] It should be noted that the terms "upper", "lower", "left", "right" and similar expressions used in the present invention are only for illustrative purposes. Unless otherwise defined, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0050] The present invention provides a new type of static mixing device for uniformly mixing natural gas and hydrogen. Figure 1 and Figure 2The core components include an intake pipe, a static mixing unit 8 and an outlet pipe which are connected and fixedly connected in sequence, specifically involving a natural gas inlet 11, a hydrogen inlet 12, a first pipe 1, a second pipe 21, a static mixing unit 8, a third pipe 22, a fourth pipe 3 and an outlet 13. The intake pipe includes a first pipe 1 and a fourth pipe 3, both of which have the same inner and outer diameters, which can be 20mm-1200mm; the outlet pipe includes a third pipe 22 and a fourth pipe 3, the second pipe 21 and the third pipe 22 have the same inner and outer diameters, which can be between 22mm-1400mm, the outer diameter of the first pipe 1 is smaller than that of the second pipe 21, and there are specific standards for the flow rate and flow rate that can be allowed to run under each inner diameter. A first arc-shaped transition section 41 is provided at the junction of the first pipeline 1 and the second pipeline 21. The cross section of the first arc-shaped transition section 41 is a circular ring. Its inner and outer diameters decrease successively from the first pipeline 1 to the second pipeline 21 to form an arc. A second arc-shaped transition section 42 is provided at the junction of the third pipeline 22 and the fourth pipeline 3. The second arc-shaped transition section 42 decreases successively from the third pipeline 22 to the fourth pipeline 3 to form an arc. The arcs formed by the outer diameters of the two are bent at the same angle, which can be 5 degrees to 25 degrees. A natural gas inlet 11 and a hydrogen inlet 12 are provided on the first pipeline 1. The hydrogen inlet 12 is perpendicular to the length direction of the first pipeline 1, and the inner diameter can be between 15 mm and 800 mm.

[0051] The static mixing unit 8 is a cylindrical, regular triangular prism, regular quadrangular prism or regular hexagonal prism pipeline, and its two ends are connected to the air inlet pipeline and the air outlet pipeline through two pairs of mutually aligned flanges. One end of the second pipeline 21 is connected to the first flange 51, and the two ends of the static mixing unit 8 are respectively fixed with the second flange 52 and the third flange 53, and one end of the third pipeline 22 is connected to the fourth flange 54. The first flange 51 and the second flange 52 are a pair, and the third flange 53 and the fourth flange 54 are a pair. A plurality of bolt holes 6 are evenly opened along the circumferential direction on the edges of the two pairs of flanges. The number of bolt holes 6 is 6 to 12, and the diameter is 3 to 15 mm. A corresponding bolt is installed in each bolt hole 6 to ensure the stable sealing and tight connection between the static mixing unit 8 and the air inlet pipeline and the air outlet pipeline, and can adapt to the needs of various flow rates, gas ratios and working conditions.

[0052] The static mixing unit 8 is provided with a plurality of flow channel holes 7 penetrating both sides of the static mixing unit 8 along its length direction. At low flow rate, the aperture is 3%-6% of the pipe diameter, and the center distance between adjacent flow channel holes 7 is 5%-9% of the pipe diameter (circumscribed circle diameter in the case of regular triangular prism, regular quadrangular prism or regular hexagonal prism); at medium flow rate, the aperture is 6%-9% of the pipe diameter, and the center distance between adjacent flow channel holes 7 is 9%-14% of the pipe diameter; at high flow rate, the aperture is 9%-13% of the pipe diameter, and the center distance between adjacent flow channel holes 7 is 14%-20% of the pipe diameter. The flow channel holes 7 are evenly distributed along the cross section of the static mixing unit 8, and the distribution and quantity can present various changes, such as Figure 8a , Figure 8b , Figure 8c , Figure 8d , Figure 8e and Figure 8f As shown, the number can be 3-17, but if you want to maintain a high mixing uniformity, the number of flow channel holes is preferably 5-17, such as Figure 3 As shown, the inner wall of each flow channel hole 7 is fixed with multiple twisting units 91 and turbulent units 92 at intervals. These mixing units ensure that rotation and disturbance can be generated during the flow of natural gas and hydrogen under different flow conditions, thereby achieving efficient and sufficient mixing. The arrangement of the flow channel holes 7 is highly consistent with the flow path of the airflow, ensuring that the airflow can achieve a stable and uniform mixing effect when passing through the static mixing unit 8, thereby ensuring the optimal mixing efficiency of natural gas and hydrogen.

[0053] like Figure 4a As shown, the torsion unit 91 includes a plurality of torsion elements 911 which are overlapped and fixed in parallel in sequence. The torsion unit 91 is in a spiral shape and is similar to the blades of a propeller in structure. The torsion elements 911 are arranged in a staggered manner along the axial direction of the flow channel hole 7. Each torsion element 911 is composed of two semicircular first torsion pieces 914 and second torsion pieces 915 (both vertically distributed) with the same diameter, which are symmetrically overlapped and fixed along the central axis of the flow channel hole 7. Specifically, as Fig.10a , Fig.10b and Fig.10c As shown, the center of the straight edge of the first torsion plate 914 and the center of the straight edge of the second torsion plate 915 are fixed, the angle (twist angle) between the straight edge of the first torsion plate 914 and the straight edge of the second torsion plate 915 is 30°-45°, the first torsion plate 914 is located at the bottom, and the angle between the straight edge of the first torsion plate 914 and the central axis of the flow channel hole 7 is 45°-65°. The spacing between two adjacent first torsion plates 914 or second torsion plates 915 is 0.1%-0.8% of the length of the static mixing unit 8, the front end of the straight edge of the second torsion plate 915 is fixed to the front end of the straight edge of the previous first torsion plate 914, and the rear end of the straight edge of the second torsion plate 915 is fixed to the rear end of the straight edge of the next first torsion plate 914.

[0054] like Figure 4b As shown, the spoiler unit 92 includes a plurality of spoiler elements 912 which are spliced ​​and fixed in sequence front to back. Fig.11a As shown, each spoiler element 912 includes a transverse spoiler 93 and a vertical spoiler 94. The transverse spoiler 93 includes an elliptical central transverse spoiler layer 931 and auxiliary transverse spoiler layers 932 symmetrically distributed along the central transverse spoiler layer 931. The vertical spoiler 94 includes an elliptical central vertical spoiler layer 941 and auxiliary vertical spoiler layers 942 symmetrically distributed along the central vertical spoiler layer 941. Fig.11b and Fig.11c As shown, the major and minor axes corresponding to the central transverse spoiler layer 931 and the central vertical spoiler layer 941 are respectively equal, the auxiliary transverse spoiler layer 932 and the auxiliary vertical spoiler layer 942 are both one layer, one end of the auxiliary transverse spoiler layer 932 and the auxiliary vertical spoiler layer 942 are both arc-shaped, and the other ends of the auxiliary transverse spoiler layer 932 and the auxiliary vertical spoiler layer 942 are both straight lines, and the distances between the two sides and their respective central spoiler layers are different, which can reduce pressure loss, wherein the arc-shaped end of the auxiliary transverse spoiler layer 932 located in the upper layer corresponds to the straight end of the auxiliary transverse spoiler layer 932 located in the lower layer, and the arc-shaped end of the auxiliary vertical spoiler layer 942 located on the right side corresponds to the straight end of the auxiliary vertical spoiler layer 942 located on the left side. The purpose of the horizontal spoiler 93 is to break the axial flow of the airflow and form transverse turbulence, thereby increasing the contact surface of the two gases and enhancing the mixing effect. The vertical spoilers 94 form a high and low distribution, and their arrangement presents a layered structure, so that the airflow produces a more complex flow path when passing through, further improving the uniformity of gas mixing. The central transverse spoiler layer 931, the auxiliary transverse spoiler layer 932, the central vertical spoiler layer 941 and the auxiliary vertical spoiler layer 942 are all composed of a plurality of thin sheet spoiler strips (i.e. Fig.11b The central transverse spoiler layer 931 and the central vertical spoiler layer 941 are spliced ​​at intervals, and the central transverse spoiler layer 931 and the central vertical spoiler layer 941 are vertically plugged and fixed to each other along the central axis of the flow channel hole 7. The size of the auxiliary transverse spoiler layer 932 is smaller than that of the central transverse spoiler layer 931 (that is, the outer edge is inside the central transverse spoiler layer 931), and the size of the auxiliary vertical spoiler layer 942 is smaller than that of the central vertical spoiler layer 941.

[0055] like Fig.11d As shown, the frontmost spoiler strip of the central vertical spoiler layer 941 of the rear spoiler element 912 is fixed to the rearmost spoiler strips of the central transverse spoiler layer 931 and the auxiliary transverse spoiler layer 932 of the front spoiler element 912, so that all the central transverse spoiler layers 931 and the central vertical spoiler layers 941 in the spoiler unit 92 are respectively and evenly distributed.

[0056] In each flow channel hole 7, each mixing unit is designed to maintain a certain distance (i.e., the distance between the last element of the previous mixing unit and the first element of the next mixing unit) based on the flow channel hole diameter and the gas flow rate optimization design, which is 6%-13% of the length of the static mixing unit 8, which not only ensures the uniform distribution of the airflow, but also avoids excessive fluid resistance, ensures that the airflow produces a rotation effect when passing through, and enhances the mixing efficiency through the turbulence of the airflow, gradually breaks the laminar state of the airflow, and promotes the initial stratification and mixing of the gas. Under high flow conditions, this design can effectively break the laminar state of the airflow, making the initial mixing of natural gas and hydrogen more uniform. The torsion element 911 forms a certain angle with the airflow direction along the direction of the flow channel hole 7, and gradually guides the airflow to rotate, disperse and reorganize each time the fluid passes, thereby effectively enhancing the mixing efficiency of natural gas and hydrogen.

[0057] Tiny dot-shaped protrusions are evenly distributed on the two surfaces of each spoiler strip, and evenly distributed dot-shaped protrusions are formed on the two surfaces of the central horizontal spoiler layer 931, the auxiliary horizontal spoiler layer 932, the central vertical spoiler layer 941 and the auxiliary vertical spoiler layer 942. At low flow rates and low flow rates, the fluid turbulence is weak and the mixing effect is poor. At this time, the turbulence can be enhanced and the mixing efficiency can be improved by increasing the height of the protrusions and reducing the spacing. At high flow rates and high flow rates, the fluid turbulence is strong and the mixing effect is better. At this time, the height of the protrusions can be appropriately reduced and the spacing can be increased according to actual conditions to reduce pressure drop and energy loss. The design of the dot-shaped protrusions further breaks the stability of the airflow, increases the turbulent intensity and turbulent flow of the gas, promotes the uniformity of mixing the two gases, and can effectively reduce the uneven distribution of gas components in the cross section or length direction of the pipeline to ensure the mixing effect.

[0058] The type, order and number of the mixing units installed in the flow channel hole 7 can be in various forms, such as Figure 9a , Figure 9b and Fig.9c As shown, each type of mixing unit is arranged in a staggered manner, although the length of each mixing unit may be different.

[0059] The inner wall of the flow channel hole 7 is provided with an internal thread, and the first torsion plate 914, the second torsion plate 915, the central horizontal spoiler layer 931, and the central vertical spoiler layer 932 are engaged in the internal thread, which can not only fix the position of all mixing units, but also help the gas to obtain rotational kinetic energy at the same time, cooperate with the mixing unit, and enhance the mixing efficiency of the gas.

[0060] The arc-shaped transition section at the junction of the inlet and outlet pipes is used to enhance the tortuosity of the gas flow path, forcing the gas flow to flow along different paths, thereby promoting the forced mixing of the two gases and further improving the mixing effect. The uneven distribution of gas components in the cross section or length direction of the pipe is eliminated by multiple changes in the flow direction, thereby ensuring sufficient mixing of the two gases.

[0061] The static mixing unit 8 and its connected pipes are made of stainless steel or high-strength corrosion-resistant alloy steel, ensuring their high temperature resistance, corrosion resistance and stability in long-term operation to adapt to the high temperature and high pressure working environment. During long-term use, no material aging, corrosion or performance degradation will occur, ensuring their stability and reliability in long-term operation.

[0062] The present invention provides a static mixing device for uniformly mixing natural gas and hydrogen. The specific assembly process is as follows: Step 1: As required, install several twisting units 91 and spoiler units 92 into the flow channel hole 7 in sequence, ensuring that each unit is correctly arranged in sequence to ensure accurate control of the mixing effect and the airflow path.

[0063] Step 2: The static mixing unit 8 is connected to the air inlet pipe and the air outlet pipe through flanges, and the flanges are fixed through bolt holes 6. The bolt holes are used to fasten the flanges with bolts to ensure the stability and airtightness of the flange connection parts.

[0064] Step 3: Use bolts to connect the bolt holes 6 at both ends of the flange to ensure a firm connection between the flange and the pipeline so that the airflow can flow smoothly through the static mixing unit 8.

[0065] Step 4: Perform an overall inspection of the installed static mixer to confirm that all components have been installed correctly and ensure that the equipment can work smoothly in actual operation.

[0066] CFD simulation can analyze the flow state and flow characteristics of the fluid under high-pressure flow conditions, and the relevant performance of the present invention can be further obtained through fluid-solid coupling. ANSYS Workbench simulation software is used for simulation calculation, and FLUENT module is selected for flow field calculation. Transient solution is selected; k-ε Realizable turbulence model is selected; fluid materials are specified as methane and hydrogen. Boundary conditions: Both air inlets are set as velocity inlets, and the inlet velocity conditions are set to 6m / s and 12m / s respectively, the pressure outlet is set as the outlet boundary condition, the pressure value is set to the gauge pressure 0Pa, and the boundary type of the fluid-solid coupling interface and the symmetry surface is set to the wall; the algorithm adopts the SIMPLE algorithm; the time step is set to 1500 steps, the time step is 0.002s, and the calculation is performed after initialization according to the following process.

[0067] In order to explore the characteristics of fluid flow in the device of the present invention, the non-flow-through parts of the model of the device of the present invention and some features that do not affect the overall performance are simplified in the three-dimensional mechanical design software SolidWorks. In the numerical simulation, other parts that do not affect the fluid flow and sealing are simplified, and the pipe wall and connecting flange of the static mixer device are removed. The model is imported into the Geometry module of the finite element analysis software ANSYS to extract the flow channel, and the tetrahedral grid is used for meshing, and the number of grids is 2.36 million grids, such as Figure 5 shown.

[0068] When the air inlet velocities at the air inlet are 6 m / s and 12 m / s respectively, the velocity vector cloud diagrams on the XY sections of the first mixing unit and the second mixing unit of the static mixing device are obtained by simulation, as shown in Figure 6a , Figure 6b As shown; the velocity vector cloud diagram of the YZ interface of the static mixer device is obtained, as shown Figure 6c shown.

[0069] Figure 6a The velocity vector cloud diagram of the XY section position of the first mixing unit is shown. Combined with the information that the first mixing unit is composed of a semicircular torsion element, the velocity distribution and vortex structure in the figure can clearly reflect the effect of the torsion element on the airflow. In the figure, multiple vortex areas can be seen in each flow channel hole, indicating that the airflow undergoes obvious rotation and disturbance when passing through the semicircular torsion element. The design of these torsion elements causes the airflow to form a strong vortex flow in the flow channel hole, thereby effectively breaking the laminar state of the airflow and promoting the mixing of natural gas and hydrogen. The areas with higher velocity in the figure usually appear near the edge of the flow channel hole and the torsion element, while the velocity in the center area of ​​the flow channel is lower, which shows that the effect of the torsion element increases the rotational kinetic energy of the airflow while also causing an uneven distribution of the flow velocity. The difference in velocity and the vortex flow work together to enhance the mixing effect between the two gases, especially under high flow conditions, ensuring the high efficiency and uniformity of the mixing. In general, the vortex effect produced by the semicircular torsion element helps to break the laminar flow of the airflow by changing the flow direction and velocity of the airflow, significantly improving the mixing efficiency of the gas.

[0070] Figure 6bThe velocity vector cloud diagram at the XY section position of the second mixing unit is shown. It can be seen from the figure that the airflow forms obvious turbulence and flow velocity changes due to the influence of the spoiler. The color bar in the figure represents the velocity range, from red (highest speed 121 m / s) to blue (lowest speed 0 m / s), with a large difference in flow velocity. The airflow shows a complex flow pattern under the longitudinal and transverse arrangement of the spoiler. It can be clearly seen from the figure that the airflow velocity is high near the spoiler, especially in the area close to the spoiler, the flow velocity increases significantly, forming a local high-speed airflow area. Compared with the torsion element of the first mixing unit, the spoiler further enhances the turbulence intensity by changing the direction of the airflow and increasing the complexity of the flow, so that the axial flow and radial flow of the airflow disturb each other, thereby improving the mixing uniformity of natural gas and hydrogen. The enhancement of vortex flow and turbulence effectively promotes the mutual mixing of the two gases, especially under high flow conditions, which helps to break the laminar state of the airflow and achieve more efficient mixing. In general, the second mixing unit effectively enhances the turbulence intensity of the airflow and promotes uniform mixing of gases through its unique spoiler design.

[0071] Figure 6c The velocity vector cloud diagram of the YZ section position of the static mixer is shown. The velocity distribution of the fluid in the figure is represented by a color bar. The red area represents the highest flow velocity (121 m / s) and the blue area represents the lowest flow velocity (0 m / s). It can be seen that after the airflow passes through different mixing units and flow channel holes in the static mixer, the flow velocity shows obvious changes and distribution characteristics. At both ends of the device, the velocity of the fluid is higher, especially in the outlet area of ​​the flow channel hole, the flow velocity is more concentrated and larger, which indicates that the velocity of the fluid increases after passing through multiple mixing units. In the middle part, especially in the flow channel hole, the airflow distribution is relatively uniform, and vortex flow of varying degrees appears, indicating that the airflow is disturbed when passing through the mixing unit and a turbulent effect is generated. This turbulent effect helps the mixing of gases and improves the uniformity of the mixing of natural gas and hydrogen. Areas with large velocity changes are usually related to the shape of the flow channel, the layout of the mixing unit, and the interaction between the fluid and the solid surface. These areas promote the full mixing of the two gases by changing the flow direction and velocity of the fluid. In general, the velocity distribution in the figure reflects that the static mixing device effectively promotes the turbulence and uniform mixing of the gas through multiple mixing units and flow channel design, and can maintain efficient mixing effects especially under high flow conditions.

[0072] Figure 7The figure shows the change in the molar volume fraction of hydrogen before and after the natural gas and hydrogen are mixed. Before mixing (before entering the static mixing unit 8), the distribution of hydrogen in the figure is obviously uneven, with a higher molar fraction of hydrogen in the top area, shown as red or orange, and a lower molar fraction in other areas, shown as blue or green, indicating that there is obvious unevenness in the distribution of hydrogen in the gas. After mixing (just out of the static mixing unit 8), the color of the entire area becomes more uniform, and almost all areas appear blue, indicating that the molar fraction of hydrogen tends to be consistent throughout the space, showing that the natural gas and hydrogen have been fully mixed. Through this comparison, it can be intuitively seen that the mixing device is effective in promoting uniform mixing of hydrogen and natural gas, and successfully transforming the distribution of hydrogen from an uneven state to a uniform state.

[0073] The static mixing device for uniformly mixing natural gas and hydrogen of the present invention controls the gas flow rate through an external metering device during operation. Under the conditions of different flow rates, flow velocities, input pressures and gas mixing ratios, natural gas flows in from a natural gas inlet 11, and hydrogen flows in from an upper hydrogen inlet 12. The inlets (11, 12) work in coordination with the mixing units in the mixing device, so that the two gases are fully contacted and uniformly mixed inside the mixing device. After the action of multiple units, the mixed gas flows out from the outlet 13, which can effectively reduce the stratification of the fluid and maintain the efficient mixing state of the gas flow, thereby achieving a good mixing effect under different flow conditions. The mixed gas can maintain good uniformity, ensuring that the gas mixing uniformity reaches more than 99%.

[0074] The above embodiments are only for illustrating the technical idea of ​​the present invention, and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the present invention.

Claims

1. A static mixing device for uniformly mixing natural gas and hydrogen, characterized in that: It comprises an air inlet duct, a static mixing unit (8) and an air outlet duct which are connected in sequence, wherein the static mixing unit (8) is provided with a plurality of flow channel holes (7) along its length direction, and the inner wall of each flow channel hole (7) is fixed with a twisting unit (91) and a spoiler unit (92) at intervals; The torsion unit (91) comprises a plurality of torsion elements (911) which are overlapped and fixed in parallel in sequence front and back, each torsion element (911) being formed by a first torsion plate (914) and a second torsion plate (915) being overlapped and fixed symmetrically up and down along the central axis of the flow channel hole (7), and the spoiler unit (92) comprises a plurality of spoiler elements (912) which are spliced ​​and fixed in sequence front and back, each spoiler element (912) comprising a transverse spoiler (93) and a vertical spoiler (94), the transverse spoiler (93) comprising an elliptical central transverse spoiler layer (931) and auxiliary transverse spoiler layers (932) symmetrically distributed up and down along the central transverse spoiler layer (931), and the vertical spoiler (94) comprising an elliptical central vertical spoiler layer (941) and auxiliary vertical spoiler layers (942) symmetrically distributed up and down along the central vertical spoiler layer (941).

2. The static mixing device for uniformly mixing natural gas and hydrogen according to claim 1, characterized in that: The air inlet pipeline comprises a first pipeline (1) and a second pipeline (21), the first pipeline (1) is provided with a natural gas inlet (11) and a hydrogen inlet (12), the air outlet pipeline comprises a third pipeline (22) and a fourth pipeline (3), the first pipeline (1) and the fourth pipeline (3) have the same inner and outer diameters, the second pipeline (21) and the third pipeline (22) have the same inner and outer diameters, the outer diameter of the first pipeline (1) is smaller than that of the second pipeline (21), a first arc-shaped transition section (41) is provided at the junction of the first pipeline (1) and the second pipeline (21), and a second arc-shaped transition section (42) is provided at the junction of the third pipeline (22) and the fourth pipeline (3), and the bending angles of the first arc-shaped transition section (41) and the second arc-shaped transition section (42) are the same, both being 5 degrees to 25 degrees.

3. The static mixing device for uniformly mixing natural gas and hydrogen according to claim 1, characterized in that: The static mixing unit (8) is a cylindrical, regular triangular prism, regular quadrangular prism or regular hexagonal prism pipeline, and the two ends of the pipeline are respectively fixedly connected to the air inlet pipeline and the air outlet pipeline through two pairs of mutually aligned flanges, and the edges of each pair of mutually aligned flanges are uniformly provided with a plurality of bolt holes (6) along the circumference, and a corresponding bolt is installed in each bolt hole (6).

4. The static mixing device for uniformly mixing natural gas and hydrogen according to claim 3, characterized in that: The inner wall of the flow channel hole (7) is provided with an internal thread, the first torsion plate (914) and the second torsion plate (915) are two semicircular structures with the same diameter, and the first torsion plate (914), the second torsion plate (915), the central transverse spoiler layer (931), and the central vertical spoiler layer (932) are engaged in the internal thread; The flow channel holes (7) are evenly distributed in a number of 3 to 17 along the cross section of the static mixing unit (8), the hole diameter is 3% to 13% of the cross section specification of the static mixing unit (8), the center distance between adjacent flow channel holes (7) is 4% to 20% of the cross section specification of the static mixing unit (8), when the cross section of the static mixing unit (8) is circular, the corresponding specification is the diameter, and when the cross section of the static mixing unit (8) is an equilateral triangle, a square, and a regular hexagon, respectively, the corresponding specification is the circumscribed circle diameter.

5. The static mixing device for uniformly mixing natural gas and hydrogen according to claim 4, characterized in that: The first torsion plate (914) and the second torsion plate (915) are both vertically distributed, the center of the straight edge of the first torsion plate (914) and the center of the straight edge of the second torsion plate (915) are fixed, the straight edge of the first torsion plate (914) and the straight edge of the second torsion plate (915) are at an angle of 30°-45°, the first torsion plate (914) is located at the bottom, and the straight edge of the first torsion plate (914) and the central axis of the flow channel hole (7) are at an angle of 45°-65°.

6. The static mixing device for uniformly mixing natural gas and hydrogen according to claim 5, characterized in that: The spacing between two adjacent first torsion plates (914) or second torsion plates (915) is 0.1%-0.8% of the length of the static mixing unit (8); the front end of the straight edge of the second torsion plate (915) is fixed to the front end of the straight edge of the previous first torsion plate (914); and the rear end of the straight edge of the second torsion plate (915) is fixed to the rear end of the straight edge of the next first torsion plate (914).

7. The static mixing device for uniformly mixing natural gas and hydrogen according to claim 1, characterized in that: Both surfaces of the central transverse spoiler layer (931), the auxiliary transverse spoiler layer (932), the central vertical spoiler layer (941) and the auxiliary vertical spoiler layer (942) are uniformly distributed with dot-shaped protrusions.

8. The static mixing device for uniformly mixing natural gas and hydrogen according to claim 1, characterized in that: The central transverse spoiler layer (931), the auxiliary transverse spoiler layer (932), the central vertical spoiler layer (941) and the auxiliary vertical spoiler layer (942) are all formed by splicing a number of spoiler strips at intervals, and the central transverse spoiler layer (931) and the central vertical spoiler layer (941) are vertically plugged and fixed to each other along the central axis of the flow channel hole (7); The major and minor axes of the central transverse spoiler layer (931) and the central vertical spoiler layer (941) are respectively equal, the auxiliary transverse spoiler layer (932) and the auxiliary vertical spoiler layer (942) are both one layer, one end of the auxiliary transverse spoiler layer (932) and the auxiliary vertical spoiler layer (942) are both arc-shaped, and the other ends of the auxiliary transverse spoiler layer (932) and the auxiliary vertical spoiler layer (942) are both straight lines, wherein the arc-shaped end of the auxiliary transverse spoiler layer (932) located in the upper layer corresponds to the straight end of the auxiliary transverse spoiler layer (932) located in the lower layer, and the arc-shaped end of the auxiliary vertical spoiler layer (942) located on the right side corresponds to the straight end of the auxiliary vertical spoiler layer (942) located on the left side, the size of the auxiliary transverse spoiler layer (932) is smaller than that of the central transverse spoiler layer (931), and the size of the auxiliary vertical spoiler layer (942) is smaller than that of the central vertical spoiler layer (941).

9. The static mixing device for uniformly mixing natural gas and hydrogen according to claim 8, characterized in that: The frontmost spoiler strip of the central vertical spoiler layer (941) of the rear spoiler element (912) is fixed to the rearmost spoiler strip of the central transverse spoiler layer (931) and the auxiliary transverse spoiler layer (932) of the front spoiler element (912), and all the central transverse spoiler layers (931) and central vertical spoiler layers (941) in the spoiler unit (92) are respectively arranged in parallel; The distance between two adjacent twisting units (91) or between the twisting unit (91) and the flow disturbance unit (92) in each flow channel hole (7) is 6% to 13% of the length of the static mixing unit (8).

10. The working method of the static mixing device for uniformly mixing natural gas and hydrogen according to any one of claims 1 to 9, characterized in that: Natural gas and hydrogen flow in from an air inlet pipe and then enter the corresponding torsion unit (91) and spoiler unit (92) through each flow channel hole (7). The first torsion plate (914) and the second torsion plate (915) gradually guide the airflow to rotate, disperse and reorganize. The transverse spoiler (93) disrupts the axial flow of the airflow to generate transverse turbulence. The vertical spoiler (94) further disrupts the radial distribution of the airflow through a staggered arrangement, thereby enhancing the depth and uniformity of mixing, so that the natural gas and hydrogen are fully contacted and evenly mixed inside the static mixing unit (8). The mixed gas flows out from the air outlet pipe, thereby achieving efficient and uniform mixing of the natural gas and hydrogen.

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