Static rectifying device for large-diameter hydrogen-doped natural gas pipeline

Abstract

The invention discloses a static rectifying device for a large-diameter hydrogen-doped natural gas pipeline, and relates to the technical field of hydrogen doping of natural gas. The left end of the natural gas pipe body is a natural gas inlet and the right end is a mixed gas outlet; the hydrogen injection pipe is a bent pipe, is of an inverted-L-shaped leftward-bent structure and extends into the natural gas pipe body, the part is coaxial with the natural gas pipe body, and three rows of hydrogen injection holes are distributed in the circumference of the tail end of the hydrogen injection pipe, so that hydrogen is injected into the natural gas pipe body more sufficiently and is pre-mixed with natural gas. Mixed gas is continuously divided, shunted, collided and overlapped through the mandrel, the turbulent flow blades and the turbulent flow rods in the turbulent flow pipe, and the mixing uniformity of natural gas and hydrogen is enhanced. Compared with the prior art, the problem that a traditional SK type mixer is poor in mixing uniformity can be effectively solved, and the vacancy of a large-diameter natural gas pipeline hydrogen-doped mixing device is filled up.

Description

Technical Field

[0001] The present invention belongs to the technical field of natural gas hydrogen blending, and particularly relates to a static rectifying device for large-diameter hydrogen-blended natural gas pipelines. Background Art

[0002] With the increasing maturity of the construction and expansion of the natural gas pipeline network, the transportation convenience and supply stability of natural gas have been greatly improved. Under the macro background of the global pursuit of lower carbon emissions and cleaner energy utilization, many countries are actively exploring innovative application paths for natural gas, thus giving rise to the emerging development trend of natural gas hydrogen blending. In order to reduce infrastructure costs, it has become a feasible solution to use existing natural gas pipelines to blend hydrogen into natural gas in a certain proportion for hydrogen transportation, and it is also one of the generally accepted hydrogen energy long-distance transportation solutions at home and abroad. Due to the characteristic differences between natural gas and hydrogen, after hydrogen enters the natural gas pipeline, stratification is likely to occur, and the local hydrogen concentration is too high. With the transportation of the pipeline, hydrogen embrittlement is likely to occur, and the uneven mixed gas entering the downstream terminal directly affects the gas use safety of users. Therefore, ensuring the mixing uniformity of natural gas and hydrogen is one of the key issues in the technical field of natural gas hydrogen blending.

[0003] Existing foreign static mixers include the Kenics type developed by Chemineer in the United States, the LPD type in New York, USA, and the SMX type, SMV type, and SMI type developed by Sulzer in Switzerland; domestic static mixers mainly include the SK type, SH type, SX type, SL type, and SV type. Different mixers have different mixing principles and different mixing effects. As the working conditions in actual projects become more complex, especially in the application of large-diameter natural gas hydrogen-blended natural gas pipelines, traditional mixers cannot take into account the mixing uniformity and pressure drop loss of the blended fluid in actual projects.

[0004] Patent No. 202411193099.1 discloses "A Natural Gas Hydrogen Blending Static Mixer", which includes a mixer body, a hydrogen inlet pipe, a natural gas inlet pipe, a diffuser section, a turbulence section, a mixing section, and a mixed gas outlet pipe. After hydrogen and natural gas are mixed, they enter the diffuser section. The diffuser section reduces the flow resistance of the mixed gas while converting part of the dynamic pressure into static pressure, strengthening the mixing of hydrogen and natural gas. Subsequently, the mixed gas enters the turbulence section and collides with the sidewall turbulence plates and the central turbulence plate in sequence, changing the flow field of the mixed gas and further improving the mixing uniformity of hydrogen and natural gas. Patent No. 201410057380.2 proposes "A Concentric Double Helix Static Mixer in Pipe", which includes an inner left-handed blade, an inner right-handed blade, an outer left-handed blade, an outer right-handed blade, a positioning round rod, and a pipe body with a length-to-diameter ratio of 1-3 times. The fluid forms two concentric spiral flows with opposite rotation directions inside and outside under the action of the inner and outer spiral elements. The fluid in each spiral flow is cut, rotated, and merged, further strengthening the radial mixing of the fluid. The structures of the above two patents are relatively complex, not suitable for large-diameter pipelines, and have large pressure drop losses, and there is room for improvement in the mixing uniformity. Therefore, it is necessary to propose a new type of natural gas hydrogen blending static rectification device to improve the traditional static mixer structure to improve the mixing uniformity and make it more suitable for large-diameter hydrogen-blended natural gas pipelines. Summary of the Invention

[0005] In view of the above problems, the object of the present invention is to provide a static rectification device for large-diameter hydrogen-blended natural gas pipelines, which solves the problems of uneven mixing, complex structural design, large pressure drop loss, and inapplicability to large-diameter natural gas pipelines of the existing static rectification devices for hydrogen-blended natural gas pipelines.

[0006] To achieve the object of the present invention, the present invention is realized through the following technical solutions:

[0007] A static rectification device for large-diameter hydrogen-blended natural gas pipelines is composed of a natural gas pipe body, a hydrogen injection pipe, and a turbulence pipe; both ends of the natural gas pipe body are open. The left end is provided with a natural gas inlet, and the hydrogen injection pipe and the turbulence pipe are connected in sequence inside. The right end of the natural gas pipe body is provided with a mixed gas outlet.

[0008] Furthermore, the hydrogen injection pipe is an inverted "L" - shaped left - bent pipe structure. One end is sealed and extends into the natural gas pipe body, and the other end is provided with a hydrogen inlet; in the part extending into the natural gas pipe body, its central axis coincides with the central axis of the natural gas pipe body, and three jet holes with the same diameter are respectively arranged on the upper, lower, left, and right directions along the circumference at the end. Hydrogen can be more fully injected into the natural gas pipe body through the jet holes, pre - blended with natural gas, and to a certain extent, alleviate the stratification phenomenon of natural gas and hydrogen.

[0009] Further, the spoiler tube includes a spoiler tube body, a mandrel, spoiler vanes and a plurality of spoiler rods; the central axis of the spoiler tube coincides with the central axis of the natural gas pipe body, and both ends are fixedly arranged in the natural gas pipe body in an open shape; the spoiler vanes are fixed on the inner wall of the spoiler tube body and have the same diameter as the spoiler tube body; the mandrel is fixed at the center of the spoiler vanes, and its central axis coincides with the central axis of the spoiler tube body.

[0010] Further, the spoiler vanes are composed of two gradually decreasing spiral vanes and two gradually increasing spiral vanes; the left end diameter of the gradually decreasing spiral vane is equal to the inner diameter of the spoiler tube body, and the right end diameter is smaller than the left end diameter; the right end diameter of the gradually increasing spiral vane is equal to the inner diameter of the spoiler tube body, and the left end diameter is smaller than the right end diameter; the left end diameter of the gradually increasing spiral vane is equal to the right end diameter of the gradually decreasing spiral vane; the spoiler vanes are successively connected end to end by the first gradually decreasing spiral vane, the first gradually increasing spiral vane, the second gradually decreasing spiral vane and the second gradually increasing spiral vane.

[0011] Further, the aspect ratios of the spoiler vanes are all 0.85, and the twists are all 180°, which can enhance the air flow disturbance and improve the mixing uniformity of large-diameter natural gas pipelines.

[0012] When hydrogen is introduced into the natural gas pipe body from the hydrogen inlet and natural gas is introduced into the natural gas inlet, hydrogen and natural gas start to mix at the hydrogen injection holes at the end of the hydrogen injection pipe. Subsequently, after a period of free mixing, the mixed gas enters the spoiler tube, the fluid forms a rotation, the mixed fluid is split into two rotating flows, and then collide and merge at the junction, generating intense turbulence, so that the mixed gas is fully mixed.

[0013] Compared with the prior art, the advantages of the present invention are as follows:

[0014] 1. The hydrogen injection pipe is provided with hydrogen injection holes, and hydrogen can be more fully injected into the natural gas pipe body through the hydrogen injection holes, improving the layering phenomenon of the mixing of hydrogen and natural gas and achieving the pre-mixing effect;

[0015] 2. The combination of the gradually decreasing spoiler vanes, the gradually increasing spoiler vanes and the spoiler rods changes the flow field of the mixed gas, greatly enhances the turbulence degree of the fluid, increases the number of times the mixed gas is divided, split, collided and recombined, and further improves the mixing uniformity;

[0016] 3. The spoiler tube structure of the present invention is simple, each unit is formed into a whole by welding, and the flow resistance is small. During mixing, blockage is not likely to occur;

[0017] 4. The present invention has a wide application range and is applicable to various industrial fields, working conditions such as high pressure and high-viscosity media, and is especially suitable for multi-flow mixing under large-diameter pipelines. Description of the Drawings

[0018] Figure 1Assembly structure diagram of the present invention;

[0019] Figure 2 Schematic diagram of the hydrogen injection pipe structure of the present invention;

[0020] Figure 3 Schematic diagram of the flow disturbance principle of the flow disturbance pipe of the present invention;

[0021] Figure 4 Schematic diagram of the internal structure of the flow disturbance pipe of the present invention.

[0022] Description of the markings in the figure:

[0023] 100 - Natural gas pipe body, 110 - Natural gas inlet, 120 - Mixed gas outlet, 200 - Hydrogen injection pipe, 210 - Natural gas inlet, 220 - Hydrogen injection hole, 300 - Flow disturbance pipe, 310 - Flow disturbance pipe body, 320 - Mandrel, 330 - Flow disturbance blade, 331 - Gradually decreasing spiral blade, 332 - Gradually increasing spiral blade, 340 - Flow disturbance rod. Detailed implementation manner

[0024] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention and are not used to limit the present invention.

[0025] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first", "second", etc. are used to distinguish similar objects, rather than to describe a specific order or sequence. It should be understood that the use of such data can be interchanged under appropriate circumstances so that the embodiments of the present invention can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are usually of the same type, and do not limit the number of objects. For example, the first object can be one or more. In addition, "and / or" in the specification and claims means at least one of the connected objects; the character " / ", generally represents an "or" relationship between the associated objects before and after.

[0026] The present invention provides a static rectifying device for a large-diameter hydrogen-doped natural gas pipeline, which includes a natural gas pipe body 100, a hydrogen injection pipe 200, and a flow disturbing pipe 300. Both ends of the natural gas pipe body 100 are open. The left end is a natural gas inlet 110, which is sequentially connected to the hydrogen injection pipe 200 and the flow disturbing pipe towards the right, and the right end is a mixed gas outlet 120.

[0027] In this embodiment, the hydrogen injection pipe 200 is an inverted "L" - shaped pipe bent to the left. One end is hermetically inserted into the natural gas pipe body 100, and the other end is provided with a hydrogen inlet 210. The diameter of the hydrogen injection pipe 200 is smaller than that of the natural gas pipe body 100, and the central axis of the part inserted into the natural gas pipe body 100 coincides with the central axis of the natural gas pipe body 100.

[0028] In this embodiment, on the end side wall of the part of the hydrogen injection pipe 200 inserted into the natural gas pipe body 100, three circles of hydrogen injection holes 220 are circumferentially distributed. Each circle of hydrogen injection holes 220 is respectively in four directions of "up", "down", "left", and "right". The diameter of the hydrogen injection holes 220 is smaller than that of the hydrogen injection pipe 200.

[0029] In this embodiment, the interior of the flow disturbing pipe 300 includes a flow disturbing pipe body 310, a central shaft 310, flow disturbing vanes 330, and a number of flow disturbing rods 340. The flow disturbing pipe 300 has the same central axis as the natural gas pipe body 100; the central shaft 310 passes through the center of the flow disturbing vanes 330 and is fixed, and the flow disturbing vanes 330 are welded and fixed to the inner wall of the flow disturbing pipe body 310.

[0030] In this embodiment, the flow disturbing vanes 330 are sequentially composed of a first gradually decreasing spiral vane 331, a first gradually increasing spiral vane 332, a second gradually decreasing spiral vane 331, and a second gradually increasing spiral vane 332 welded end to end. The twist of each gradually decreasing spiral vane 331 and gradually increasing spiral vane 332 is 180°, and the aspect ratio is 0.85. The smaller aspect ratio can enhance the airflow disturbance, and the irregular flow disturbing vanes 330 change the flow field, enhance the turbulence degree of the fluid, and improve the mixing efficiency of hydrogen and natural gas.

[0031] In this example, the flow disturbing rods 340 are circumferentially welded on the central shaft 320 at the connection position between the first gradually decreasing spiral vane 331 and the first gradually increasing spiral vane 332, and on the central shaft 320 at the connection position between the second gradually decreasing spiral vane 331 and the second gradually increasing spiral vane 332; the flow disturbing rods 340 increase the number of times of splitting, collision, and recombination of the fluid in the flow disturbing vanes 330, and further increase the mixing uniformity.

[0032] Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of the present invention. The present invention will also have various changes and improvements, and these changes and improvements shall fall within the scope of the claimed invention.

Claims

1. A static rectifying device for a large-diameter hydrogen-blended natural gas pipeline, comprising a natural gas pipe body (100), a hydrogen injection pipe (200), and a flow disturbance pipe (300), characterized in that: The natural gas pipe body (100) is open at both ends, a natural gas inlet (110) is provided at the left end of the natural gas pipe body (100), a hydrogen injection pipe (200) and a flow disturbance pipe (300) are connected in sequence inside the natural gas pipe body (100), and a mixed gas outlet (120) is provided at the right end of the natural gas pipe body (100).

2. The large-diameter hydrogen-blended natural gas pipeline static rectification device according to claim 1 is characterized in that: The hydrogen injection pipe (200) is a curved pipe with an inverted "L"-shaped left-bend structure, one end of which extends into the natural gas pipe body (100) in a sealed manner, and the other end of which is provided with a hydrogen inlet (210); the diameter of the hydrogen injection pipe (200) is smaller than the diameter of the natural gas pipe body (100).

3. The large-diameter hydrogen-blended natural gas pipeline static rectification device according to claim 2 is characterized in that: The central axis of the portion of the hydrogen injection pipe (200) extending into the natural gas pipe body (100) coincides with the central axis of the natural gas pipe body (100). The side wall of the portion of the hydrogen injection pipe (200) extending into the natural gas pipe body (100) is provided with a plurality of hydrogen perforations (220). The diameter of the hydrogen perforations (220) is smaller than the diameter of the hydrogen injection pipe (200). The hydrogen perforations (220) are distributed in three circles along the circumference of the hydrogen injection pipe (200) extending into the natural gas pipe body (100) and coaxial therewith, with four per circle.

4. The large-diameter hydrogen-blended natural gas pipeline static rectification device according to claim 1 is characterized in that: The spoiler tube (300) comprises a spoiler tube body (310), a spindle (320), spoiler blades (330) and a plurality of spoiler rods (340); The central axis of the flow-turbulating tube (300) coincides with the central axis of the natural gas pipe body (100), both ends of the flow-turbulating tube (300) are open, and the flow-turbulating tube (300) is fixed inside the natural gas pipe body (100).

5. The large-diameter hydrogen-blended natural gas pipeline static rectification device according to claim 4 is characterized in that: The spoiler blade (330) is fixed on the inner wall of the spoiler tube body (310), the outer diameter of the spoiler blade (330) is the same as the diameter of the spoiler tube body (310), the mandrel (320) is fixed at the center of the spoiler blade (330), and the central axis of the mandrel (320) coincides with the central axis of the spoiler tube body (310); The spoiler blade (330) comprises two gradually smaller spiral blades (331) and two gradually larger spiral blades (332), the left end diameter of the gradually smaller spiral blade (331) is equal to the inner diameter of the spoiler tube body (310), the right end diameter of the gradually smaller spiral blade (331) is smaller than the left end diameter, the right end diameter of the gradually larger spiral blade (332) is equal to the inner diameter of the spoiler tube body (310), the left end diameter of the gradually larger spiral blade (332) is smaller than the right end diameter, and the left end diameter of the gradually larger spiral blade (332) is equal to the right end diameter of the gradually smaller spiral blade (331).

6. The large-diameter hydrogen-blended natural gas pipeline static rectification device according to claim 5 is characterized in that: The spoiler blade (330) is sequentially composed of a first gradually decreasing spiral blade (331), a first gradually increasing spiral blade (332), a second gradually decreasing spiral blade (331), and a second gradually increasing spiral blade (332) connected end to end; the aspect ratio of the gradually decreasing spiral blade (331) and the gradually increasing spiral blade (332) is 0.85; and the torsion of the gradually decreasing spiral blade (331) and the gradually increasing spiral blade (332) is 180°.

7. The large-diameter hydrogen-blended natural gas pipeline static rectification device according to claim 4 is characterized in that: The spoiler rod (340) is respectively fixed along the circumferential direction on the mandrel (320) at the connection position between the first gradually smaller spiral blade (331) and the first gradually larger spiral blade (332), and on the mandrel (320) at the connection position between the second gradually smaller spiral blade (331) and the second gradually larger spiral blade (332).

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