Concentration field measuring device for hydrogen-doped natural gas

Abstract

The invention discloses a hydrogen-doped natural gas concentration field measuring device which comprises a mixing section, a measuring section and a stabilizing frame, the mixing section comprises a main pipeline and a plurality of mixing pipelines, the input end of the main pipeline is communicated with a natural gas source, the input ends of the mixing pipelines are communicated with a hydrogen source, and the output ends of the mixing pipelines are communicated with the main pipeline; the output ends of any two mixing pipelines are positioned on different buses of the main pipeline; both the main pipeline and the mixing pipeline are provided with stop valves and pressure sensors; the measuring section comprises a measuring pipeline and a plurality of concentration sensors, and the input end of the measuring pipeline is communicated with the output end of the main pipeline; the plurality of concentration sensors are arranged on the pipe wall of the measuring pipeline along the axial direction of the measuring pipeline; the mixing section and the measuring section are fixedly connected with an external environment through a stabilizing frame. The technical problem that an existing concentration measuring device cannot accurately measure the concentration field of hydrogen-doped natural gas in a pipeline can be solved.

Description

Technical Field

[0001] The invention relates to the technical field of hydrogen-doped natural gas concentration field measurement, and in particular to a concentration field measurement device for hydrogen-doped natural gas. Background Art

[0002] The combustion product of hydrogen is water, and no carbon emissions are produced, so hydrogen energy is defined as green energy. As a new energy and green fuel for future industrial energy, it will gradually replace traditional fossil energy such as oil and natural gas.

[0003] Hydrogen is generally transported by pipeline. Hydrogen produced upstream is injected into the natural gas pipeline in service. The transportation and utilization of hydrogen energy can be achieved by relying on the existing mature natural gas pipeline network. It has the characteristics of low cost and high efficiency, and is gradually becoming the main hydrogen energy transportation technology in the future.

[0004] When hydrogen is mixed into existing natural gas pipelines for co-transmission, there is a risk of hydrogen embrittlement of the pipe due to the presence of a large amount of hydrogen components inside the pipeline, which may in turn cause pipeline leakage or even explosion. Therefore, the hydrogen embrittlement problem is the core issue restricting the safe transportation of pipelines. The concentration distribution and value of hydrogen directly determine the location of pipeline hydrogen embrittlement and the possible degree of hydrogen embrittlement damage. Only by obtaining the concentration distribution and concentration value of the mixed gas inside the pipeline can the risk and degree of damage of pipeline hydrogen embrittlement be reasonably determined.

[0005] Existing concentration measurements are often conducted to measure the gas leakage and diffusion concentration under open space conditions. However, the requirements and test conditions for hydrogen-blended natural gas concentration field measurements are quite different, mainly reflected in the following points: (1) Hydrogen-blended natural gas pipelines are high-pressure closed containers. Traditional catalytic concentration detection devices under open space conditions are single-point detection devices and cannot effectively detect the pipeline concentration field; (2) Hydrogen-blended natural gas pipelines are flowing transmission pipelines. The interior of the pipeline is under high pressure. The method of directly sampling the interior and then measuring the gas concentration outside will destroy the original internal concentration field, making it impossible to determine where the sampled gas is inside the pipeline. (3) As for the gas concentration field, due to the low density of the gas itself, the tiny vibrations inside the pipeline caused by the compressor, high-pressure gas cylinder and other devices will transfer kinetic energy to the inside of the pipeline, causing drastic changes in the movement of gas molecules, which may cause the destruction of the original gas concentration field distribution, thereby affecting the accurate measurement of the concentration field, and even making it impossible to complete the identification of the concentration field using existing concentration measurement instruments; (4) After completing the velocity or pressure measurement and experiment, the gas needs to be vented. During venting, the hydrogen at the vent port is likely to reach the explosion limit and explode when in contact with air. Summary of the invention

[0006] The purpose of the present invention is to provide a concentration field measuring device for hydrogen-blended natural gas, so as to solve the technical problem that the existing concentration measuring device cannot accurately measure the concentration field of hydrogen-blended natural gas in a pipeline.

[0007] The present invention is achieved through the following technical solutions:

[0008] A concentration field measuring device for hydrogen-blended natural gas comprises: a blending section, the blending section comprises a main pipeline and a plurality of blending pipelines, the input end of the main pipeline is connected to a natural gas source, the input end of the blending pipeline is connected to a hydrogen source, the output end of the blending pipeline is connected to the main pipeline, and the output ends of any two blending pipelines are located at different busbars of the main pipeline; the main pipeline and the blending pipeline are both provided with a shut-off valve and a pressure sensor; a measuring section, the measuring section comprises a measuring pipeline and a plurality of concentration sensors, the input end of the measuring pipeline is connected to the output end of the main pipeline; the plurality of concentration sensors are arranged on the pipe wall of the measuring pipeline along the axial direction of the measuring pipeline; and a stabilizing frame, the blending section and the measuring section are fixedly connected to the external environment through the stabilizing frame.

[0009] Optionally, all the concentration sensors are divided into multiple groups; the multiple concentration sensors included in each group are arranged in a ring shape on the same cross-section of the measuring pipe; and the multiple groups of concentration sensors are arranged along the axial direction of the measuring pipe.

[0010] Optionally, one concentration sensor is selected from any two groups of concentration sensors, respectively, and the obtained two concentration sensors are located at different busbars of the measuring pipeline.

[0011] Optionally, the probes of all the concentration sensors in each group of the concentration sensors are arranged along the radial direction of the measuring pipe and at the same setting depth; and the probes of two adjacent groups of the concentration sensors are located at different setting depths.

[0012] Optionally, the arrangement depths of the probes of two adjacent groups of the concentration sensors are respectively a first depth and a second depth.

[0013] Optionally, the axis of the mixing pipeline is perpendicular to and intersects with the axis of the main pipeline.

[0014] Optionally, the main pipeline is arranged horizontally; all the mixing pipelines include a top mixing pipe, a bottom mixing pipe and a side mixing pipe; the top mixing pipe is arranged vertically and connected to the top of the main pipeline; the bottom mixing pipe is arranged vertically and connected to the bottom of the main pipeline; the top mixing pipe is arranged horizontally and connected to the side of the main pipeline.

[0015] Optionally, the output end of the measuring pipeline is connected to a vent pipeline, and a plurality of fan-blade agitators are arranged axially in the vent pipeline; a plurality of vent pressure sensors are arranged along the length direction of the vent pipeline; the vent pipeline is provided with a vent stop valve; the vent pipeline is fixedly connected to the external environment through the stabilizing frame.

[0016] Optionally, the venting pipe includes a deceleration pipe and an exhaust pipe connected in an L-shape, the end of the deceleration pipe away from the exhaust pipe is connected to the measuring pipe, and the exhaust pipe is arranged vertically upward; the fan agitator is axially arranged in the deceleration pipe; the venting stop valve is arranged at the top of the exhaust pipe.

[0017] Optionally, a sampling tube is connected to the exhaust pipe, the sampling tube is provided with a sampling valve and a sampling pressure sensor, and the sampling tube is fixedly connected to the external environment through the stabilizing frame.

[0018] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0019] The present invention provides a concentration field measuring device for hydrogen-blended natural gas. The device comprises a blending section, which comprises a main pipeline and a plurality of blending pipelines, and the blending pipeline is connected to the main pipeline. The main pipeline is used to transmit natural gas while the blending pipeline is used to mix hydrogen into the main pipeline. The output ends of the blending pipelines are further arranged at different busbars, so that the plurality of blending pipelines can mix hydrogen from different directions, so as to fully simulate the influence of different blending positions on the blending concentration, and preliminarily improve the measurement accuracy. The device further comprises a stop valve and a pressure sensor, and the opening and closing of each pipeline is independently controlled, and the air pressure in the pipeline is detected. On this basis, the device comprises a measuring section, which comprises a measuring pipeline and a plurality of concentration sensors, and the measuring pipeline is connected to the main pipeline, and the natural gas mixed with hydrogen is passed into the measuring pipeline, and then the concentration field of the hydrogen-blended natural gas flowing therein is measured at multiple points by using the plurality of concentration sensors, so as to further improve the measurement accuracy. On this basis, the device comprises a stabilizing frame, and the stabilizing frame is used to fully fix the blending section and the measuring section to the external environment, so as to improve the structural stability of the two, and avoid the interference and damage of the pipeline vibration caused by other equipment such as the compressor on the concentration field, so as to further improve the measurement accuracy. Through the mutual cooperation of the above components, the concentration field measuring device for hydrogen-blended natural gas can solve the technical problem that the existing concentration measuring device cannot accurately measure the concentration field of hydrogen-blended natural gas in the pipeline. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0021] Figure 1A schematic front view of a concentration field measuring device for hydrogen-doped natural gas provided in an embodiment of the present invention;

[0022] Figure 2 A front view schematic diagram of a mixing section of a concentration field measuring device for hydrogen-blended natural gas provided in an embodiment of the present invention;

[0023] Figure 3 A schematic side view of a mixing section of a concentration field measuring device for hydrogen-blended natural gas provided in an embodiment of the present invention;

[0024] Figure 4 A schematic front view of a measuring section of a concentration field measuring device for hydrogen-blended natural gas provided in an embodiment of the present invention;

[0025] Figure 5 A schematic side view of a measuring section of a concentration field measuring device for hydrogen-blended natural gas provided in an embodiment of the present invention;

[0026] Figure 6 A schematic front view of an empty discharge pipeline of a concentration field measuring device for hydrogen-blended natural gas provided in an embodiment of the present invention;

[0027] Figure 7 A schematic side view of an empty discharge pipeline of a concentration field measuring device for hydrogen-blended natural gas provided in an embodiment of the present invention.

[0028] Marks and corresponding parts names in the attached drawings:

[0029] 10-main pipeline; 11-mixing pipeline; 111-top mixing pipe; 112-bottom mixing pipe; 113-side mixing pipe; 12-stop valve; 13-pressure sensor; 20-measurement pipeline; 21-concentration sensor; 30-stabilizing frame; 40-empty pipeline; 401-empty pressure sensor; 402-empty stop valve; 41-fan agitator; 42-speed reduction pipe; 43-exhaust pipe; 44-sampling tube; 441-sampling valve; 442-sampling pressure sensor. DETAILED DESCRIPTION

[0030] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0031] Example 1

[0032] Please refer to Figures 1 to 5The embodiment of the present invention provides a concentration field measuring device for hydrogen-blended natural gas, comprising: a blending section, the blending section comprises a main pipeline 10 and a plurality of blending pipelines 11, the input end of the main pipeline 10 is connected to a natural gas source, the input end of the blending pipeline 11 is connected to a hydrogen source, the output end of the blending pipeline 11 is connected to the main pipeline 10, and the output ends of any two blending pipelines 11 are located at different busbars of the main pipeline 10; the main pipeline 10 and the blending pipeline 11 are both provided with a stop valve 12 and a pressure sensor 13; the second comprises a measuring section, the measuring section comprises a measuring pipeline 20 and a plurality of concentration sensors 21, the input end of the measuring pipeline 20 is connected to the output end of the main pipeline 10; the plurality of concentration sensors 21 are arranged on the pipe wall of the measuring pipeline 20 along the axial direction of the measuring pipeline 20; the third comprises a stabilizing frame 30, the blending section and the measuring section are fixedly connected to the external environment through the stabilizing frame 30.

[0033] The concentration field measuring device for hydrogen-blended natural gas provided in this embodiment is provided with a blending section, which includes a main pipeline 10 and a plurality of blending pipelines 11, and the blending pipeline 11 is provided to be connected with the main pipeline 10, and the main pipeline 10 is used to transmit natural gas while the blending pipeline 11 is used to mix hydrogen into the main pipeline 10, and the output end of the blending pipeline 11 is further provided at different busbars of the main pipeline 10, so that the plurality of blending pipelines 11 can mix hydrogen from different directions, so as to fully simulate the influence of different blending positions on the blending concentration, and preliminarily improve the measurement accuracy, and further, by providing a stop valve 12 and a pressure sensor 13, the opening and closing of each pipeline is independently controlled, and the pipeline is controlled. The gas pressure inside is detected; on this basis, by setting a measuring section, it is set to include a measuring pipe 20 and multiple concentration sensors 21, and the measuring pipe 20 is connected to the main pipe 10, and the natural gas mixed with hydrogen is passed into the measuring pipe 20, and then the concentration field of the mixed hydrogen natural gas flowing therein is measured at multiple points using multiple concentration sensors 21, so as to further improve the measurement accuracy; on this basis, by setting a stabilizing frame 30, the mixing section and the measuring section are fully fixed to the external environment, so as to improve the structural stability of the two, and avoid the interference and damage of the concentration field caused by pipeline vibration of other equipment such as compressors, so as to further improve the measurement accuracy. Through the mutual cooperation of the above-mentioned components, the concentration field measuring device for hydrogen-blended natural gas can solve the technical problem that the existing concentration measuring device cannot accurately measure the concentration field of hydrogen-blended natural gas in the pipeline.

[0034] It should be noted that the above-mentioned external environment includes large-volume, fixed-structure, and fixed-position structures such as the ground, walls, and domes.

[0035] It should be noted that the above-mentioned multiple concentration sensors 21 are arranged on the wall of the measuring pipe 20 along the axial direction of the measuring pipe 20, which means that: all the concentration sensors 21 are arranged along a straight line or a specific curve, along the axial direction of the measuring pipe 20, or, all the concentration sensors 21 are arranged in groups, each group is located in the same cross-section of the measuring pipe 20, and the groups are arranged along the axial direction of the measuring pipe 20; arranged on the side wall of the measuring pipe 20 means that: the concentration sensor 21 is set on the side wall of the measuring pipe 20, and its probe is located in the measuring pipe 20.

[0036] It should be noted that the stabilizing frame 30 is any steel structure support in the prior art, and can be of segmented detachable or integrated type.

[0037] Example 2

[0038] Please refer to Example 1 for further details. Figure 4 and Figure 5 The embodiment of the present invention provides a concentration field measuring device for hydrogen-doped natural gas, which is a further improvement of embodiment 1, and the difference is that:

[0039] In order to fully cover the surface of the measuring pipe 20 and fully measure the concentration field of the hydrogen-blended natural gas in the measuring pipe 20, all the concentration sensors 21 are divided into multiple groups; each group includes multiple concentration sensors 21 arranged in a ring shape on the same cross-section of the measuring pipe 20; multiple groups of concentration sensors 21 are arranged along the axial direction of the measuring pipe 20.

[0040] Through the above arrangement, the concentration sensor 21 covers the surface of the measuring pipe 20 from both the axial direction and the circumferential direction of the measuring pipe 20 , so as to fully measure the concentration field of the hydrogen-blended natural gas in the measuring pipe 20 .

[0041] In order to further improve the coverage of the concentration sensors 21 , one concentration sensor 21 is randomly selected from any two groups of the concentration sensors 21 , and the obtained two concentration sensors 21 are located on different busbars of the measuring pipe 20 .

[0042] Through the above arrangement, any two concentration sensors 21 at different positions in the axial direction are staggered, so as to further cover the surface of the measuring pipe 20 without setting a large number of concentration sensors 21, thereby avoiding redundant setting of concentration sensors 21.

[0043] In order to further increase the sample volume in the direction of measurement depth and to further improve the accuracy of concentration field measurement, the probes of all the concentration sensors 21 in each group of the concentration sensors 21 are arranged radially along the measurement pipe 20 and at the same setting depth; the probes of two adjacent groups of the concentration sensors 21 are located at different setting depths.

[0044] Preferably, the probes of two adjacent groups of the concentration sensors 21 are arranged at a first depth and a second depth, respectively.

[0045] Through the above settings, a uniform staggered setting is formed between the groups, wherein the measurement depths of the odd-numbered groups are the same and the measurement depths of the even-numbered groups are the same, which is conducive to comparative analysis and convenient for subsequent data processing.

[0046] Example 3

[0047] Please refer to Example 2 for further details. Figure 2 and Figure 3 The embodiment of the present invention provides a concentration field measuring device for hydrogen-doped natural gas, which is a further improvement of embodiment 2, and the difference is that:

[0048] In order to avoid unnecessary swirl during hydrogen blending and to affect the concentration field of hydrogen-blended natural gas, the axis of the blending pipeline 11 is perpendicular to and intersects with the axis of the main pipeline 10 .

[0049] In order to further optimize the setting position of the mixing pipe 11, the main pipe 10 is horizontally set; all the mixing pipes 11 include a top mixing pipe 111, a bottom mixing pipe 112 and a side mixing pipe 113; the top mixing pipe 111 is vertically set and connected to the top of the main pipe 10; the bottom mixing pipe 112 is vertically set and connected to the bottom of the main pipe 10; the top mixing pipe 113 is horizontally set and connected to the side of the main pipe 10.

[0050] Through the above-mentioned arrangement, hydrogen can be mixed from three directions, namely, upward, downward and sideways, to form a Cartesian coordinate system. By controlling any two or three mixing directions at the same time, any mixing vector in the coordinate system can be effectively simulated to avoid structural redundancy caused by setting up a large number of mixing pipes 11.

[0051] Example 4

[0052] Please refer to Example 3. Figure 6 and Figure 7 The embodiment of the present invention provides a concentration field measuring device for hydrogen-doped natural gas, which is a further improvement of embodiment 3, and the difference is that:

[0053] In order to deal with the explosion that may be caused by excessive hydrogen concentration during emptying, the output end of the measuring pipeline 20 is connected to an emptying pipeline 40, and a plurality of fan-blade agitators 41 are arranged axially in the emptying pipeline 40; a plurality of emptying pressure sensors 401 are arranged along the length direction of the emptying pipeline 40; the emptying pipeline 40 is provided with an emptying stop valve 402; the emptying pipeline 40 is fixedly connected to the external environment through the stabilizing frame 30.

[0054] Through the above arrangement, the hydrogen-doped natural gas flow is decelerated by utilizing a plurality of fan blade agitators 41 in the empty discharge pipeline 40, and the kinetic energy of the mixed gas flow is converted into the kinetic energy of the fan blade agitators 41, thereby reducing the flow rate and pressure of the hydrogen-doped natural gas flow while improving its mixing uniformity, thereby reducing the probability of explosion and ensuring the safe empty discharge of the hydrogen-doped natural gas.

[0055] In order to further explain the specific structure of the venting pipe 40, the venting pipe 40 includes a speed reduction pipe 42 and an exhaust pipe 43 connected in an L shape, the speed reduction pipe 42 is connected to the measuring pipe 20 at one end away from the exhaust pipe 43, and the exhaust pipe 43 is arranged vertically upward; the fan agitator 41 is axially arranged in the speed reduction pipe 42; the venting stop valve 402 is arranged at the top of the exhaust pipe 43.

[0056] Through the above arrangement, the hydrogen-enriched natural gas is decelerated and reduced in pressure by using the horizontally arranged deceleration pipe 42, and then discharged by using the vertically arranged exhaust pipe 43. The inflection point of the two can also further reduce the flow rate of the hydrogen-enriched natural gas flow.

[0057] Preferably, a sampling tube 44 is connected to the exhaust pipe 43 , and the sampling tube 44 is provided with a sampling valve 441 and a sampling pressure sensor 442 . The sampling tube 44 is fixedly connected to the external environment through the stabilizing frame 30 .

[0058] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A concentration field measuring device for hydrogen-blended natural gas, characterized in that: include: A blending section, the blending section comprising a main pipeline (10) and a plurality of blending pipelines (11), the input end of the main pipeline (10) being connected to a natural gas source, the input end of the blending pipeline (11) being connected to a hydrogen source, the output end of the blending pipeline (11) being connected to the main pipeline (10), and the output ends of any two blending pipelines (11) being located at different busbars of the main pipeline (10); the main pipeline (10) and the blending pipeline (11) are both provided with a stop valve (12) and a pressure sensor (13); A measuring section, the measuring section comprising a measuring pipe (20) and a plurality of concentration sensors (21), the input end of the measuring pipe (20) being connected to the output end of the main pipe (10); the plurality of concentration sensors (21) being arranged on the pipe wall of the measuring pipe (20) along the axial direction of the measuring pipe (20); A stabilizing frame (30), wherein the mixing section and the measuring section are fixedly connected to the external environment via the stabilizing frame (30).

2. The concentration field measuring device for hydrogen-blended natural gas according to claim 1, characterized in that: All of the concentration sensors (21) are divided into multiple groups; The plurality of concentration sensors (21) included in each group are arranged in a ring shape on the same cross section of the measuring pipe (20); A plurality of groups of concentration sensors (21) are arranged along the axial direction of the measuring pipe (20).

3. The concentration field measuring device for hydrogen-blended natural gas according to claim 2, characterized in that: One concentration sensor (21) is randomly selected from any two groups of concentration sensors (21), and the obtained two concentration sensors (21) are located on different busbars of the measuring pipe (20).

4. The concentration field measuring device for hydrogen-blended natural gas according to claim 3, characterized in that: The probes of all the concentration sensors (21) in each group of the concentration sensors (21) are arranged along the radial direction of the measuring pipe (20) and are arranged at the same depth; The probes of two adjacent groups of concentration sensors (21) are located at different setting depths.

5. The concentration field measuring device for hydrogen-blended natural gas according to claim 4, characterized in that: The probes of two adjacent groups of concentration sensors (21) are arranged at a first depth and a second depth respectively.

6. The concentration field measuring device for hydrogen-blended natural gas according to any one of claims 1 to 5, characterized in that: The axis of the mixing pipeline (11) is perpendicular to and intersects with the axis of the main pipeline (10).

7. The concentration field measuring device for hydrogen-blended natural gas according to claim 6, characterized in that: The main pipeline (10) is arranged horizontally; All of the mixing pipes (11) include a top mixing pipe (111), a bottom mixing pipe (112) and a side mixing pipe (113); The top mixing pipe (111) is vertically arranged and communicated with the top of the main pipeline (10); The bottom mixing pipe (112) is vertically arranged and communicated with the bottom of the main pipeline (10); The top mixing pipe (113) is arranged horizontally and is connected to the side of the main pipeline (10).

8. The concentration field measuring device for hydrogen-blended natural gas according to claim 7, characterized in that: The output end of the measuring pipe (20) is connected to an emptying pipe (40), and a plurality of fan blade stirrers (41) are arranged in the axial direction in the emptying pipe (40); The emptying pipe (40) is provided with a plurality of emptying pressure sensors (401) along the length direction; The venting pipeline (40) is provided with an venting stop valve (402); The emptying pipeline (40) is fixedly connected to the external environment via the stabilizing frame (30).

9. The concentration field measuring device for hydrogen-blended natural gas according to claim 8, characterized in that: The emptying pipe (40) comprises a speed reduction pipe (42) and an exhaust pipe (43) which are connected in an L shape, wherein one end of the speed reduction pipe (42) away from the exhaust pipe (43) is connected to the measuring pipe (20), and the exhaust pipe (43) is arranged vertically upward; The fan blade stirrer (41) is arranged in the speed reduction tube (42) along the axial direction; The air discharge stop valve (402) is arranged at the top end of the exhaust pipe (43).

10. The concentration field measuring device for hydrogen-blended natural gas according to claim 9, characterized in that: The exhaust pipe (43) is connected to a sampling pipe (44) on its side. The sampling pipe (44) is provided with a sampling valve (441) and a sampling pressure sensor (442). The sampling pipe (44) is fixedly connected to the external environment through the stabilizing frame (30).

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