Natural gas hydrogen mixing unit

Abstract

This invention discloses a natural gas-hydrogen mixing device, relating to the field of gas mixing equipment. It includes a main pipeline comprising a tapered section and a straight section sealed to the smaller end of the tapered section. The larger end of the tapered section is the natural gas inlet, and the other end of the straight section is the natural gas outlet. A hydrogen injection pipe is fixedly installed within the straight section, with its axis perpendicular to the axis of the straight section. The end of the hydrogen injection pipe extending beyond the straight section is the hydrogen inlet. A hydrogen distribution structure includes multiple homogenizing gases. The inner cavity of each homogenizing gas is connected to the hydrogen injection pipe via a connecting pipe. Each homogenizing gas is annular, and all homogenizing gases are coaxially arranged with the straight section. The end of each homogenizing gas furthest from the tapered section is the outlet, which has a hydrogen outlet hole. The outlets of all homogenizing gases are located on the same plane, with a gap between any two adjacent homogenizing gases. This invention improves the mixing uniformity of hydrogen and natural gas.

Description

Technical Field

[0001] This invention relates to the field of gas mixing equipment, and in particular to a natural gas-hydrogen mixing device. Background Technology

[0002] Hydrogen blending into natural gas is one of the main forms of hydrogen energy utilization. It involves injecting hydrogen produced by the electrolysis of renewable energy sources or excess hydrogen generated under full-load operation of hydrogen refueling stations into the natural gas pipeline network to form hydrogen-blended natural gas. This blended natural gas is then transported to end users through the pipeline network, thus realizing a hydrogen energy industry chain of "blending-transportation-utilization" and promoting the deep integration of "hydrogen energy and gas network". Natural gas blending technology not only improves the utilization rate of renewable energy but also contributes to reducing pollutants generated from the combustion of natural gas at the end-user level, solving air pollution problems, and achieving carbon emission reduction.

[0003] Due to the significant differences in properties between hydrogen and methane, especially in their combustion performance, low uniformity of mixing or stratification in the downstream pipeline can lead to disordered Wobbe numbers and combustion potential. Both gases are flammable and explosive media, which can easily compromise the safety of gas-using equipment. Therefore, the uniformity of mixing in the core mixing components must reach over 98%. Each improvement requires verification through mixing simulation and pressure loss simulation. Advanced blending processes place high demands on the internal structure of the equipment mixer. Only a reasonable and advanced structure and layout can guarantee the uniformity of gas mixing.

[0004] Existing natural gas and hydrogen mixing equipment often places the hydrogen inlet pipe in the center of the natural gas pipeline and then mixes the hydrogen with the natural gas. This method causes the hydrogen to concentrate in the middle of the natural gas pipeline, resulting in poor mixing uniformity. Summary of the Invention

[0005] The purpose of this invention is to provide a natural gas-hydrogen mixing device to solve the problems existing in the prior art and improve the mixing uniformity of hydrogen and natural gas.

[0006] To achieve the above objectives, the present invention provides the following solution:

[0007] This invention provides a natural gas-hydrogen mixing device, comprising:

[0008] The main pipeline includes a tapered section and a straight section that is sealed to the smaller end of the tapered section. The larger end of the tapered section is the natural gas inlet, and the other end of the straight section is the natural gas outlet.

[0009] A hydrogen injection pipe is fixedly installed in the straight pipe section. The axial direction of the hydrogen injection pipe is perpendicular to the axial direction of the straight pipe section. One end of the hydrogen injection pipe extending out of the straight pipe section is the hydrogen inlet, and the other end of the hydrogen injection pipe is closed.

[0010] A hydrogen uniform distribution structure is provided, comprising multiple uniform gases. The inner cavity of each uniform gas is connected to the hydrogen injection pipe via a connecting pipe. Each uniform gas is annular, and all uniform gases are coaxially arranged with the straight pipe section. The end of each uniform gas away from the conical pipe section is the outlet end, and the outlet end is provided with multiple circumferentially uniformly distributed hydrogen outlet holes. The outlet ends of all uniform gases are located on the same plane, and there is a gap between any two adjacent uniform gases.

[0011] Preferably, the end of the gas flow near the conical pipe section is a guide end, and the guide end is provided with a conical surface and an inverted conical surface. The conical surface is farther away from the center of the straight pipe section than the inverted conical surface, and the end of the conical surface near the conical pipe section is connected to the end of the inverted conical surface near the conical pipe section.

[0012] Preferably, the lengths of each gas along the axial direction of the straight pipe section are equal.

[0013] Preferably, the diameter and number of hydrogen outlet holes on different homogenizing gases are different; the closer to the center of the straight pipe section, the smaller the diameter and the fewer the number of hydrogen outlet holes on the homogenizing gas.

[0014] Preferably, the hydrogen distribution structure further includes an intermediate cone coaxial with the straight pipe section. The end of the intermediate cone away from the conical pipe section is provided with a plurality of hydrogen outlet holes, and the end of the intermediate cone away from the conical pipe section is located on the same plane as the outlet end. The gas distribution closest to the intermediate cone is spaced apart from the intermediate cone.

[0015] Preferably, the hydrogen outlet holes on the intermediate cone are smaller in diameter and fewer in number than the hydrogen outlet holes on the homogenizing gas.

[0016] Preferably, the inner wall of the straight pipe section is further provided with an annular inverted conical surface coaxial with the straight pipe section, and the end of the annular inverted conical surface away from the conical pipe section is located on the same plane as the gas outlet end; the gas closest to the annular inverted conical surface is spaced apart from the annular inverted conical surface.

[0017] Preferably, it further includes a swirl plate, the outer periphery of which is sealed to the inner wall of the straight pipe section; and the swirl plate is closer to the tapered pipe section than the hydrogen uniform distribution structure.

[0018] Preferably, the inner cavity of each of the gas chambers is connected to the hydrogen injection pipe via two of the connecting pipes.

[0019] Preferably, the tapered pipe section is coaxial with the straight pipe section.

[0020] The present invention achieves the following technical effects compared to the prior art:

[0021] The natural gas-hydrogen mixing device of the present invention can uniformly mix hydrogen and natural gas.

[0022] The natural gas-hydrogen mixing device of the present invention achieves uniform radial mixing of hydrogen into natural gas through multiple annular homogenizing gases.

[0023] Furthermore, the tapered pipe section in this invention can increase the flow rate of natural gas entering the straight pipe section; while the annular protrusion in the guide end of the gas equalization can create a Venturi effect, thereby further increasing the flow rate of natural gas. When natural gas flows through the outlet of the gas equalization, it can form turbulence and adsorb hydrogen flowing out from the hydrogen outlet, thereby fully mixing with hydrogen and achieving good mixing uniformity.

[0024] Furthermore, the middle cone shape can work with the innermost inverted cone surface of the homogenizing gas to create a Venturi effect in the natural gas flowing through the gap between them, and the annular inverted cone surface can work with the outermost cone surface of the homogenizing gas to create a Venturi effect in the natural gas flowing through the gap between them.

[0025] Furthermore, the smaller the diameter and fewer the number of hydrogen outlet holes on the gas homogenizing gas closer to the center of the straight pipe section, the more hydrogen needs to be mixed in as the radial dimension increases, thus improving the uniformity of hydrogen mixing into the natural gas.

[0026] Furthermore, the swirl plate allows the natural gas to rotate, which in turn allows the mixed hydrogen to rotate along with the natural gas, enabling the hydrogen to diffuse evenly in the natural gas as quickly as possible, thus achieving a uniform mixing effect. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the natural gas-hydrogen mixing device of the present invention;

[0029] Figure 2 This is a partial structural schematic diagram of the natural gas-hydrogen mixing device of the present invention.

[0030] Figure 3 This is a partial structural schematic diagram of the natural gas-hydrogen mixing device of the present invention.

[0031] Figure 4 This is a partial structural schematic diagram of the natural gas-hydrogen mixing device of the present invention.

[0032] Among them, 1. Main pipeline; 101. Conical pipe section; 102. Straight pipe section; 103. Natural gas inlet; 104. Natural gas outlet; 2. Swirl plate; 3. Hydrogen injection pipe; 4. Connecting pipe; 5. Gas equalization; 501. Conical surface; 502. Inverted conical surface; 503. Hydrogen outlet; 6. Annular inverted conical surface; 7. Intermediate cone. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] The purpose of this invention is to provide a natural gas-hydrogen mixing device to solve the problems existing in the prior art and improve the mixing uniformity of hydrogen and natural gas.

[0035] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] like Figures 1 to 4 As shown, this embodiment provides a natural gas-hydrogen mixing device, including a main pipeline 1, a hydrogen injection pipe 3, a hydrogen distribution structure, and a swirl plate 2.

[0037] The main pipeline 1 includes a tapered section 101 and a straight section 102, one end of which is sealed and connected to the smaller end of the tapered section 101. The tapered section 101 and the straight section 102 are coaxial. The larger end of the tapered section 101 is the natural gas inlet 103, and the other end of the straight section 102 is the natural gas outlet 104. In use, both the natural gas inlet 103 and the natural gas outlet 104 need to be connected to the natural gas network so that the natural gas in the natural gas network flows through the main pipeline 1 before flowing to the user end. The tapered section 101 in the main pipeline 1 can increase the flow velocity of the natural gas entering the straight section 102, thus accelerating the flow of natural gas.

[0038] The outer periphery of the swirl plate 2 is sealed to the inner wall of the straight pipe section 102; and the swirl plate 2 is closer to the tapered pipe section 101 than the hydrogen uniform distribution structure. The arrangement of the swirl plate 2 allows the natural gas to generate rotational motion, thereby allowing the mixed hydrogen to rotate along with the natural gas, enabling the hydrogen to diffuse evenly in the natural gas as quickly as possible, thus achieving a uniform mixing effect. The swirl plate 2 is a mature existing product, and its structure and principle will not be described in detail in this embodiment.

[0039] The hydrogen injection pipe 3 is fixedly installed in the straight pipe section 102, and is located between the swirl plate 2 and the hydrogen distribution structure. The axis of the hydrogen injection pipe 3 is perpendicular to the axis of the straight pipe section 102. The height of the hydrogen injection pipe 3 is preferably located in the middle of the straight pipe section 102. One end of the hydrogen injection pipe 3 that extends out of the straight pipe section 102 is the hydrogen inlet, which is connected to the hydrogen source. The other end of the hydrogen injection pipe 3 is closed. The hydrogen injection pipe 3 serves as a delivery pipe for hydrogen injection and is also fixedly connected to the straight pipe section 102 to serve as the frame for the subsequent hydrogen distribution structure.

[0040] The hydrogen distribution structure includes a central cone 7 and multiple uniform gases 5. Each uniform gas 5 is annular, and the inner cavity of each uniform gas 5 is connected to the hydrogen injection pipe 3 through two connecting pipes 4. The connecting pipes 4 are rigid, which fixes the uniform gas 5 to the hydrogen injection pipe 3. In practical applications, the uniform gas 5 can also be fixed to the inner wall of the straight pipe section 102 through a connecting rod. The central cone 7 and all the uniform gases 5 are coaxially arranged with the straight pipe section 102. The end of the uniform gas 5 away from the cone pipe section 101 is the gas outlet end. Multiple circumferentially uniform hydrogen outlet holes 503 are provided on the gas outlet end. The gas outlet ends of all the uniform gases 5 are located on the same plane. There is a gap between any two adjacent uniform gases 5. The gap between two adjacent uniform gases 5 is a natural gas channel. The middle cone 7 is provided with several hydrogen gas outlet holes 503 at the end away from the cone section 101, and the end of the middle cone 7 away from the cone section 101 is located on the same plane as the outlet end; there is a gap between the homogenizing gas 5 closest to the middle cone 7 and the middle cone 7, and this gap also serves as a channel for natural gas to flow through, i.e., a natural gas channel.

[0041] It should be noted that the diameter and number of hydrogen outlet holes 503 on different homogenizing gases 5 are different. In this embodiment, the hydrogen outlet holes 503 on the homogenizing gas 5 closer to the center of the straight pipe section 102 have smaller diameters and fewer numbers. The hydrogen outlet holes 503 on the intermediate cone 7 have smaller diameters and fewer numbers than those on any homogenizing gas 5. Since the contact area between the outlet end of a larger homogenizing gas 5 and natural gas is larger, more hydrogen needs to be mixed in as the radial dimension increases. Therefore, the smaller the diameter and fewer the number of hydrogen outlet holes 503 on the homogenizing gas 5 closer to the center of the straight pipe section 102, the better the uniformity of the initial hydrogen injection.

[0042] In this embodiment, each gas 5 has the same length along the axial direction of the straight pipe section 102.

[0043] The end of the gas homogenizer 5 near the conical section 101 is a guide end. The guide end is provided with a conical surface 501 and an inverted conical surface 502. The conical surface 501 is further away from the center of the straight pipe section 102 than the inverted conical surface 502. The end of the conical surface 501 near the conical section 101 is connected to the end of the inverted conical surface 502 near the conical section 101 (see reference). Figure 2 It should be noted that, for ease of observation, Figure 2 The dashed lines in the middle represent the intersection lines of the conical surface 501 and the inverted conical surface 502 on each guide end.

[0044] An annular inverted conical surface 6, coaxial with the straight pipe section 102, is also provided on the inner wall of the straight pipe section 102. The end of the annular inverted conical surface 6 away from the conical pipe section 101 is located on the same plane as the gas outlet end. The gas 5 closest to the annular inverted conical surface 6 is separated from the annular inverted conical surface 6. This gap also serves as a channel through which natural gas flows, i.e., a natural gas channel.

[0045] The conical surface 501 and the inverted conical surface 502 on the guide end form an annular protrusion facing the conical pipe section 101. The function of this annular protrusion is twofold: firstly, to guide natural gas into the interval (i.e., natural gas channel) next to the equalizing gas 5, so that the natural gas can flow smoothly and avoid gas blockage; secondly, the setting of this annular protrusion can increase the flow velocity of natural gas, and perform secondary acceleration of natural gas. After the secondary acceleration, the natural gas has a faster flow velocity and a rotational movement. After the natural gas flows through the interval between two adjacent equalizing gases 5, the interval between equalizing gas 5 and the middle conical body 7, and / or the interval between equalizing gas 5 and the annular inverted conical surface 6, it will form a strong negative pressure adsorption effect on the gas outlet of equalizing gas 5 and the gas outlet of the middle conical body 7, so that the hydrogen flowing out of each hydrogen outlet 503 is quickly absorbed into the nearby natural gas. With the natural gas moving axially towards the straight pipe section 102 and also rotating, under the action of rotation, the hydrogen and natural gas can be rapidly mixed, thereby improving the mixing uniformity of hydrogen and natural gas.

[0046] In this embodiment, the tapered pipe section 101, the straight pipe section 102, the hydrogen injection pipe 3, the connecting pipe 4, the gas equalization pipe 5, the intermediate cone 7, and the annular inverted cone surface 6 are all made of hydrogen-resistant stainless steel.

[0047] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A natural gas-hydrogen mixing device, characterized in that, include: The main pipeline includes a tapered section and a straight section that is sealed to the smaller end of the tapered section. The larger end of the tapered section is the natural gas inlet, and the other end of the straight section is the natural gas outlet. A hydrogen injection pipe is fixedly installed in the straight pipe section. The axial direction of the hydrogen injection pipe is perpendicular to the axial direction of the straight pipe section. One end of the hydrogen injection pipe extending out of the straight pipe section is the hydrogen inlet, and the other end of the hydrogen injection pipe is closed. A hydrogen uniform distribution structure is provided, comprising multiple uniform gases. The inner cavity of each uniform gas is connected to the hydrogen injection pipe via a connecting pipe. Each uniform gas is annular, and all uniform gases are coaxially arranged with the straight pipe section. The end of each uniform gas away from the conical pipe section is the outlet end, and the outlet end is provided with multiple circumferentially uniformly distributed hydrogen outlet holes. The outlet ends of all uniform gases are located on the same plane, and there is a gap between any two adjacent uniform gases. The end of the gas distribution structure closest to the conical tube section is a guide end, which has a conical surface and an inverted conical surface. The conical surface is further away from the center of the straight tube section than the inverted conical surface. The end of the conical surface closest to the conical tube section is connected to the end of the inverted conical surface closest to the conical tube section. The hydrogen distribution structure also includes an intermediate conical body coaxial with the straight tube section. The end of the intermediate conical body furthest from the conical tube section has several hydrogen outlet holes, and the end of the intermediate conical body furthest from the conical tube section is on the same plane as the outlet end. The gas distribution structure closest to the intermediate conical body is spaced apart from the intermediate conical body. The inner wall of the straight tube section is also provided with a structure similar to the one described above. The straight pipe section has an annular inverted conical surface coaxial with it, the end of the annular inverted conical surface away from the conical pipe section being on the same plane as the gas outlet end; the homogenizing gas closest to the annular inverted conical surface is spaced apart from the annular inverted conical surface; the diameter and number of hydrogen outlet holes on different homogenizing gases are different; the closer to the center of the straight pipe section, the smaller the diameter and the fewer the number of hydrogen outlet holes on the homogenizing gas; the hydrogen outlet holes on the intermediate cone are smaller in diameter and fewer in number than the hydrogen outlet holes on the homogenizing gas; it also includes a swirl plate, the outer periphery of which is sealed to the inner wall of the straight pipe section; and the swirl plate is closer to the conical pipe section than the hydrogen homogenization structure.

2. The natural gas-hydrogen mixing device according to claim 1, characterized in that: Each of the gas streams has an equal length along the axial direction of the straight pipe section.

3. The natural gas-hydrogen mixing device according to claim 1, characterized in that: The inner cavity of each of the gas homogenization chambers is connected to the hydrogen injection pipe via two of the connecting pipes.

4. The natural gas-hydrogen mixing device according to claim 1, characterized in that: The tapered pipe section is coaxial with the straight pipe section.

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