A natural gas hydrogen blending device

Abstract

The utility model relates to the technical field of urban gas equipment, and specifically to a natural gas hydrogen blending device. The device includes a natural gas transmission pipeline, and a plurality of hydrogen transmission units are arranged on the radial circumferential surface of the natural gas transmission pipeline. The plurality of hydrogen transmission units are arranged in sequence along the axial direction of the natural gas transmission pipeline. Each hydrogen transmission unit includes a plurality of hydrogen transmission pipelines, and the plurality of hydrogen transmission pipelines are arranged in an array with the central axis of the natural gas transmission pipeline as the central circumference. Each hydrogen transmission pipeline extends to the inside of the natural gas transmission pipeline at a certain inclination angle with the radial circumferential surface of the natural gas transmission pipeline. The inner wall of the natural gas transmission pipeline is also connected to a rib plate, which is arranged at the front side of the hydrogen outlet of the hydrogen transmission pipeline located inside the natural gas transmission pipeline. The utility model has a simple structural design, uses a multi-layer multi-angle cut circle mixing method, and relies on the natural flow and rotation mixing of the gas to improve the hydrogen blending efficiency.

Description

Technical Field

[0001] The utility model relates to the technical field of town gas equipment, in particular to a natural gas hydrogen blending device. Background Art

[0002] Hydrogen blending in natural gas pipelines can reduce the carbon content of natural gas, reduce carbon emissions during combustion, increase the utilization ratio of renewable energy, and avoid the problem of disposing of wind power hydrogen and industrial by-product hydrogen.

[0003] However, due to the large difference in the physical properties of hydrogen and natural gas, the flow characteristics of the mixed flow of hydrogen and natural gas will change during the transportation process. Uneven mixing will lead to stratification between the two gases. Due to the flammable and explosive properties of hydrogen, hydrogen-blended natural gas with low mixing uniformity will affect the use of end users and pose certain safety risks.

[0004] Common gas mixing technologies include Venturi injection, high pressure ratio regulation and dynamic flow ratio regulation. Although Venturi injection and high pressure ratio regulation can achieve uniform blending of natural gas and hydrogen, hydrogen blending is more complicated than fixed or mixed flow regulation.

[0005] Therefore, a newly designed pipeline structure is needed to meet the new mixing mode of natural gas and hydrogen, relying on the natural flow and rotation of the gas to overcome the above defects. Utility Model Content

[0006] In order to solve the above problems, the utility model provides a natural gas hydrogen blending device, the pipeline structure design is simple and ingenious, and can meet the natural flow and rotation mixing requirements of hydrogen and natural gas when blending.

[0007] The utility model provides a natural gas hydrogen blending device, comprising a natural gas transmission pipeline, wherein a plurality of stages of hydrogen transmission units are arranged on the radial circumferential surface of the natural gas transmission pipeline, wherein the plurality of stages of hydrogen transmission units are sequentially spaced along the axial direction of the natural gas transmission pipeline, wherein each of the hydrogen transmission units comprises a plurality of hydrogen transmission pipelines, wherein the plurality of hydrogen transmission pipelines are arranged in an array with the central axis of the natural gas transmission pipeline as the central circumference, wherein each of the hydrogen transmission pipelines extends to the inside of the natural gas transmission pipeline at a certain inclination angle with the radial circumferential surface of the natural gas transmission pipeline, wherein the inner wall of the natural gas transmission pipeline is further connected with a rib plate, wherein the rib plate is arranged at the front side of the hydrogen outlet of the hydrogen transmission pipeline located inside the natural gas transmission pipeline.

[0008] Furthermore, the inclination angle between the radial circumferential surfaces of the hydrogen transmission pipeline and the natural gas transmission pipeline ranges from 30° to 65°.

[0009] Furthermore, the inclination angle between the rib plate and the inner wall of the natural gas transmission pipeline ranges from 15° to 45°.

[0010] Furthermore, each level of the hydrogen delivery unit includes 4 hydrogen delivery pipelines.

[0011] Furthermore, each of the hydrogen transmission pipelines includes a straight pipe section and an inclined pipe section, the straight pipe section is parallel to the natural gas transmission pipeline, and the inclined pipe section forms a certain inclination angle with the radial circumferential surface of the natural gas transmission pipeline and extends into the interior of the natural gas transmission pipeline.

[0012] Furthermore, the connection between the hydrogen delivery pipeline and the natural gas delivery pipeline is welded.

[0013] Furthermore, the rib plate is welded to the inner wall of the natural gas transmission pipeline.

[0014] Furthermore, the length of the rib plate is longer than the length of the hydrogen transmission pipeline extending into the interior of the natural gas transmission pipeline.

[0015] Furthermore, several levels of hydrogen delivery units are equidistantly arranged along the axial direction of the natural gas delivery pipeline.

[0016] Beneficial effects:

[0017] 1. The utility model realizes the regulation of hydrogen blending ratio by arranging multi-stage hydrogen delivery units along the axial direction on the radial circumference of the natural gas transmission pipeline. The more stages of hydrogen delivery units there are, the hydrogen content in the natural gas transmission pipeline increases step by step. After reaching the specified hydrogen blending ratio, the natural gas is output to the outside.

[0018] 2. The utility model realizes the radial input of hydrogen from the natural gas transmission pipeline by setting the radial circumferential surface of the hydrogen transmission pipeline and the natural gas transmission pipeline at a certain inclination angle and extending it to the inside of the natural gas transmission pipeline. In addition, since the hydrogen transmission pipelines included in the hydrogen transmission unit in each stage are arranged in a circular array with the central axis of the natural gas transmission pipeline as the central circumference, after the hydrogen enters the natural gas transmission pipeline, it can flow naturally and rotate and mix with the natural gas in the natural gas transmission pipeline to improve the mixing uniformity.

[0019] 3. The utility model arranges ribs in front of the hydrogen outlet of the hydrogen delivery pipeline, so that when hydrogen hits the ribs from the hydrogen outlet of the hydrogen delivery pipeline at a certain flow rate, it is blocked by the ribs and continues to move forward, resulting in backflow, thereby accelerating the mixing speed of hydrogen and natural gas in the area near the ribs and improving the mixing uniformity.

[0020] 4. The hydrogen delivery pipeline and the natural gas delivery pipeline of the utility model are welded, have good sealing, will not leak and are firmly installed.

[0021] It should be appreciated that all combinations of the foregoing concepts, as well as additional concepts described in greater detail below, may be considered part of the inventive subject matter of the present disclosure, provided such concepts are not mutually inconsistent.

[0022] The foregoing and other aspects, embodiments and features of the present invention can be more fully understood from the following description in conjunction with the accompanying drawings. Other additional aspects of the present invention, such as the features and / or beneficial effects of the exemplary embodiments, will be apparent from the following description or learned from the practice of the specific embodiments according to the teachings of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings are not drawn to scale according to actual reference objects. In the accompanying drawings, each identical or approximately identical component shown in each figure may be represented by the same reference numeral. For the sake of clarity, not every component is labeled in each figure. Now, embodiments of various aspects of the utility model will be described by way of example and with reference to the accompanying drawings, in which:

[0024] Figure 1 It is a schematic longitudinal section diagram of the natural gas hydrogen blending device of the utility model.

[0025] Figure 2 It is a cross-sectional schematic diagram of the natural gas hydrogen blending device of the utility model.

[0026] Explanation of the accompanying drawings: 1- natural gas transmission pipeline; 2- hydrogen transmission pipeline; 3- rib plate. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0028] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicating orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0029] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or mutual communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0030] The disclosure below provides many different embodiments or examples to realize the different structures of the present application. In order to simplify the disclosure of the present application, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present application. In addition, the present application can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplification and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the various specific processes and material examples provided by the present application, but those of ordinary skill in the art can appreciate the application of other processes and / or the use of other materials.

[0031] There is a growing interest in hydrogen-blended natural gas at home and abroad. However, the physical properties of hydrogen and natural gas are quite different, which leads to changes in their mixed flow characteristics and the impact on pipelines. Uneven mixing will lead to stratification between the two gases. Due to the flammable and explosive properties of hydrogen, hydrogen-blended natural gas with low mixing uniformity will affect the use of end users and pose a certain risk of combustion and explosion.

[0032] Common gas mixing technologies include Venturi injection method, high pressure ratio regulation method and follow-up flow ratio regulation method. Although Venturi injection method and high pressure ratio regulation method can achieve uniform mixing of natural gas and hydrogen, the fixed hydrogen mixing ratio or mixing flow rate regulation is relatively complicated. Based on this problem, the embodiment of the utility model provides a natural gas hydrogen mixing and transportation system, which uses a new multi-layer multi-angle cut-circle mixing method and relies on the natural flow of gas to rotate and mix.

[0033] Please refer to Figure 1 and Figure 2As shown, an embodiment of the utility model provides a natural gas hydrogen blending device, comprising a natural gas transmission pipeline 1, a plurality of stages of hydrogen transmission units are arranged on the radial circumferential surface of the natural gas transmission pipeline 1, and the plurality of stages of hydrogen transmission units are arranged in sequence along the axial direction of the natural gas transmission pipeline 1. Each of the hydrogen transmission units comprises a plurality of hydrogen transmission pipelines 2, and the plurality of hydrogen transmission pipelines 2 are arranged in an array with the central axis of the natural gas transmission pipeline 1 as the central circumference, and each of the hydrogen transmission pipelines 2 extends to the inside of the natural gas transmission pipeline 1 at a certain inclination angle with the radial circumferential surface of the natural gas transmission pipeline 1, and the inner wall of the natural gas transmission pipeline 1 is also connected to a rib plate 3, and the rib plate 3 is arranged at the front side of the hydrogen outlet of the hydrogen transmission pipeline 2 located inside the natural gas transmission pipeline 1.

[0034] The utility model realizes the regulation of hydrogen blending ratio by arranging multi-stage hydrogen delivery units along the axial direction on the radial circumferential surface of the natural gas delivery pipeline 1. The hydrogen content in the natural gas delivery pipeline 1 increases step by step as more stages of hydrogen delivery units are passed through. After reaching the specified hydrogen blending ratio, the natural gas is output to the outside.

[0035] The multi-stage hydrogen delivery units arranged on the radial circumferential surface of the natural gas delivery pipeline 1 are arranged within a certain interval length in the axial direction of the natural gas delivery pipeline 1, and the hydrogen delivery units are not arranged on the radial circumferential surface of the entire natural gas delivery pipeline 1. The number of stages of the hydrogen delivery units can be adjusted according to actual conditions. When the mixing ratio of hydrogen and natural gas meets the requirements, there is no need to arrange hydrogen delivery units in the delivery direction of natural gas.

[0036] The utility model realizes the radial input of hydrogen from the natural gas transmission pipeline 1 by setting the hydrogen transmission pipeline 2 and the radial circumferential surface of the natural gas transmission pipeline 1 at a certain inclination angle and extending the hydrogen transmission pipeline 2 to the inside of the natural gas transmission pipeline 1. Since the hydrogen transmission unit in each stage includes a plurality of hydrogen transmission pipelines 2 arranged in a circumferential array with the central axis of the natural gas transmission pipeline 1 as the central axis, hydrogen enters the natural gas transmission pipeline 1 from the radial periphery of the natural gas transmission pipeline 1 and is fully mixed with the natural gas from the radial periphery of the natural gas transmission direction. The mixing is performed by the natural rotation flow of the natural gas and hydrogen to improve the mixing uniformity.

[0037] The utility model arranges a rib plate 3 at the front side of the hydrogen outlet of the hydrogen delivery pipeline 2, so that when hydrogen hits the rib plate 3 from the hydrogen outlet of the hydrogen delivery pipeline 2 at a certain flow rate, it is blocked by the rib plate 3 and continues to move forward, resulting in reflux, thereby accelerating the mixing speed of hydrogen and natural gas in the area adjacent to the rib plate 3 and improving the mixing uniformity.

[0038] In some embodiments of the present invention, the inclination angle between the radial circumferential surfaces of the hydrogen delivery pipeline 2 and the natural gas delivery pipeline 1 is in the range of 30° to 65°.

[0039] In some embodiments of the present invention, the inclination angle between the rib plate 3 and the inner wall of the natural gas transmission pipeline 1 ranges from 15° to 45°.

[0040] By further optimizing the inclination angle between the hydrogen transmission pipeline 2 and the natural gas transmission pipeline 1, the hydrogen is easier to mix with the natural gas in the initial flow direction when entering the natural gas pipeline. By further optimizing the inclination angle between the rib plate 3 and the natural gas transmission pipeline 1, the mixing speed of hydrogen and natural gas is accelerated.

[0041] In some embodiments of the utility model, each level of the hydrogen delivery unit includes four hydrogen delivery pipelines 2, and the number is set reasonably to meet the requirements of rotating mixing of the natural gas and hydrogen gas during natural flow.

[0042] In some embodiments of the present invention, each of the hydrogen delivery pipelines 2 includes a straight pipe section and an inclined pipe section, wherein the straight pipe section is parallel to the natural gas delivery pipeline 1, and the inclined pipe section is inclined at a certain angle to the radial circumferential surface of the natural gas delivery pipeline 1 and extends to the inside of the natural gas delivery pipeline 1. On the one hand, the straight pipe section is parallel to the natural gas delivery pipeline 1, which is beneficial to the arrangement of the overall pipeline of the device, and on the other hand, the inclined pipe section extends to the inside of the natural gas delivery pipeline 1, which limits the flow direction of hydrogen into the natural gas. The hydrogen delivery pipeline 2 is reasonably designed and simple in structure, which expands the scope of application of the device.

[0043] In some embodiments of the present invention, the connection between the hydrogen delivery pipeline 2 and the natural gas delivery pipeline 1 is welded, has good sealing performance, does not leak, and is firmly installed.

[0044] In some embodiments of the present invention, the rib plate 3 is welded to the inner wall of the natural gas transmission pipeline 1, which is convenient for connection and has a firm installation effect.

[0045] In some embodiments of the present invention, the length of the rib plate 3 is longer than the length of the hydrogen delivery pipeline 2 extending into the interior of the natural gas delivery pipeline 1, ensuring that the hydrogen can fully impact the rib plate 3 and generate sufficient reflux, thereby accelerating the mixing speed with the natural gas and also improving the mixing uniformity.

[0046] In some embodiments of the present invention, several levels of hydrogen delivery units are equidistantly arranged along the axial direction of the natural gas delivery pipeline 1. The equidistant arrangement avoids the inconvenience caused by the varying distances between adjacent hydrogen delivery units in controlling the hydrogen blending ratio.

[0047] The hydrogen flow rate calculation process in the utility model is:

[0048] The hydrogen flow rate is calculated based on the methane flow rate and the hydrogen blending ratio. That is, the ratio of the hydrogen inlet flow rate to the mixed gas flow rate is the hydrogen blending ratio:

[0049]

[0050] V 1 - Hydrogen flow rate;

[0051] V 2 —Natural gas flow rate;

[0052] d 1 —Diameter of hydrogen delivery pipeline 2;

[0053] d 2 —Diameter of natural gas transmission pipeline1;

[0054] a—the number of hydrogen delivery pipelines 2 in each level of hydrogen delivery unit;

[0055] b—Number of hydrogen transport unit stages.

[0056] This paper uses the widely used coefficient of variation Cov of the gas concentration sample volume fraction to quantify this indicator. The size of Cov is equal to the ratio of the standard deviation of the sample volume fraction to the average volume fraction of the sample.

[0057] Where c i Indicates the hydrogen gas volume fraction at the sampling point; It represents the average value of hydrogen gas volume fraction at all sampling points; n represents the number of sampling points, and the larger the n value, the more accurate the calculation result. In this paper, the sampling points are all the grid nodes on the cross section.

[0058]

[0059] σ=100%-Cov

[0060] The larger the σ, the more uniform the gas mixture. When σ=100%, the gas is completely mixed, and when σ=0, the gas is completely separated. Generally, in industry, if σ≥95%, it can be considered that the gas in the system is completely mixed. According to calculations, the uniformity of hydrogen and methane mixing corresponding to this device can reach 98.8%.

[0061] In summary, natural gas and hydrogen can be output after reaching the specified hydrogen blending ratio after being mixed through this device. The structural design of this device enables hydrogen to be mixed with natural gas using a multi-stage multi-angle cutting circle mixing method, and the natural flow and rotation of the gas improves the mixing uniformity, which can effectively improve the hydrogen blending efficiency and reduce the stratification of natural gas and hydrogen.

[0062] Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. A person with ordinary knowledge in the technical field to which the present invention belongs may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be determined by the definition of the claims.

Claims

1. A natural gas hydrogen blending device, comprising a natural gas transmission pipeline, characterized in that: A plurality of stages of hydrogen delivery units are arranged on the radial circumferential surface of the natural gas delivery pipeline, and the plurality of stages of hydrogen delivery units are arranged in sequence and at intervals along the axial direction of the natural gas delivery pipeline. Each of the hydrogen delivery units includes a plurality of hydrogen delivery pipelines, and the plurality of hydrogen delivery pipelines are arranged in a circumferential array with the central axis of the natural gas delivery pipeline as the central axis. Each of the hydrogen delivery pipelines extends into the interior of the natural gas delivery pipeline at a certain inclination angle with the radial circumferential surface of the natural gas delivery pipeline. The inner wall of the natural gas delivery pipeline is also connected to a rib plate, and the rib plate is arranged in front of the hydrogen outlet of the hydrogen delivery pipeline located inside the natural gas delivery pipeline.

2. The natural gas hydrogen blending device according to claim 1, characterized in that: The inclination angle between the radial circumferential surfaces of the hydrogen delivery pipeline and the natural gas delivery pipeline is in the range of 30° to 65°.

3. The natural gas hydrogen blending device according to claim 1, characterized in that: The inclination angle between the rib plate and the inner wall of the natural gas transmission pipeline ranges from 15° to 45°.

4. The natural gas hydrogen blending device according to claim 1, characterized in that: Each level of the hydrogen delivery unit includes 4 hydrogen delivery pipelines.

5. The natural gas hydrogen blending device according to claim 1, characterized in that: Each hydrogen delivery pipeline comprises a straight pipe section and an inclined pipe section, wherein the straight pipe section is parallel to the natural gas delivery pipeline, and the inclined pipe section forms a certain inclination angle with the radial circumferential surface of the natural gas delivery pipeline and extends into the interior of the natural gas delivery pipeline.

6. The natural gas hydrogen blending device according to claim 1, characterized in that: The connection between the hydrogen delivery pipeline and the natural gas delivery pipeline is welded.

7. The natural gas hydrogen blending device according to claim 1, characterized in that: The rib plate is welded to the inner wall of the natural gas transmission pipeline.

8. The natural gas hydrogen blending device according to claim 1, characterized in that: The length of the rib plate is longer than the length of the hydrogen transmission pipeline extending into the interior of the natural gas transmission pipeline.

9. The natural gas hydrogen blending device according to claim 1, characterized in that: Several levels of hydrogen delivery units are equidistantly arranged along the axial direction of the natural gas delivery pipeline.

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