Hydrogen doping system and hydrogen doping method for natural gas transmission station

Abstract

The invention discloses a hydrogen doping system and a hydrogen doping method for a natural gas transmission station, and relates to the technical field of new energy. The hydrogen doping system comprises a natural gas gathering and transportation module which is used for being connected with a natural gas source pipeline and outputting natural gas with set pressure and flow; the hydrogen gathering and transporting module is used for connecting a hydrogen source and outputting hydrogen with set pressure and flow; the follow-up hydrogen doping module is provided with at least two hydrogen doping storage tanks in parallel, a natural gas connector of each hydrogen doping storage tank is connected with the gas outlet end of the natural gas gathering and transporting module, and a hydrogen connector of each hydrogen doping storage tank is connected with the gas outlet end of the hydrogen gathering and transporting module; the gas inlet ends of the rectifiers are connected with the gas outlet ends of the hydrogen-doped storage tanks, and the rectifiers can rectify the gas output by the hydrogen-doped storage tanks, so that the conveying flow of the natural gas hydrogen-doped system can be increased, and the natural gas hydrogen-doped system can be uniformly mixed. The hydrogen doping method is based on the hydrogen doping system.

Description

Technical Field

[0001] The present invention relates to the field of new energy technology, and in particular to a hydrogen blending system and a hydrogen blending method for a natural gas transmission station. Background Art

[0002] Natural gas hydrogen blending technology is an energy technology that directly replaces natural gas by blending hydrogen into natural gas at a certain volume ratio and transporting it through existing natural gas pipelines. A large number of research results show that the combustion of natural gas hydrogen blended gas can improve the combustion performance of terminal equipment and reduce nitrogen oxide pollution and carbon dioxide emissions.

[0003] Natural gas hydrogen blending has always been an important research direction for hydrogen transportation and large-scale utilization at home and abroad. At present, domestic research is in an accelerated stage. As natural gas pipeline hydrogen blending transportation has gradually been recognized, starting from the end of 2021 and the beginning of 2022, the hot spots of domestic natural gas hydrogen blending projects have undergone two key changes: from the transportation link to the application link, and from the civil field to the industrial field. The shift from transportation to application is conducive to the faster formation of commercial projects and the promotion of carbon reduction in energy terminal applications; compared with the civil field, the safety management in the industrial field is more standardized and easier to implement.

[0004] As the research on hydrogen blending and transportation of domestic natural gas pipelines started late, the pressure of hydrogen blending experimental platforms that have been built / are under construction and the hydrogen blending equipment of hydrogen blending pipeline projects are all below 4.5MPa and the output is below 10×104Nm3 / d, which cannot meet the needs of industrial transportation. Summary of the invention

[0005] In view of the technical problems that the delivery pressure and delivery of the existing natural gas hydrogen blending system cannot meet the industrial delivery needs, the present invention provides a natural gas transmission station hydrogen blending system and a hydrogen blending method, which can improve the stable delivery flow of the natural gas hydrogen blending system while ensuring that hydrogen and natural gas are evenly mixed during the delivery process to meet the industrial delivery needs of natural gas hydrogen blending.

[0006] The present invention is achieved through the following technical solutions:

[0007] In a first aspect, the present invention provides a natural gas transmission station hydrogen blending system, comprising: a natural gas gathering module, the natural gas gathering module is used to connect a natural gas source pipeline and output natural gas of set pressure and flow; a hydrogen gathering module, the hydrogen gathering module is used to connect a hydrogen source and output hydrogen of set pressure and flow; a follow-up hydrogen blending module, the follow-up hydrogen blending module is provided with at least two hydrogen blending storage tanks in parallel, the natural gas interface of each of the hydrogen blending storage tanks is connected to the gas outlet end of the natural gas gathering module, and the hydrogen interface of each of the hydrogen blending storage tanks is connected to the gas outlet end of the hydrogen gathering module; a rectifier, the gas inlet end of the rectifier is connected to the gas outlet end of the hydrogen blending storage tank, and the rectifier can rectify the gas output by multiple hydrogen blending storage tanks.

[0008] In the existing hydrogen blending system of natural gas transmission stations, hydrogen is blended by using an ejector on the horizontal pipe section, which is not conducive to uniform mixing of hydrogen during transportation and easily leads to hydrogen enrichment at the undulating parts of the long-distance pipeline. The present invention uses multiple hydrogen blending storage tanks to preliminarily mix natural gas and hydrogen, and then rectifies them through the rectifier flow, which can avoid hydrogen enrichment.

[0009] The natural gas transmission station hydrogen blending system provided by the present invention is provided with a natural gas gathering module, a hydrogen gathering module, and a follow-up hydrogen blending module. The follow-up hydrogen blending module is provided with at least two hydrogen blending storage tanks in parallel. The natural gas interface of each hydrogen blending storage tank is connected to the gas outlet end of the natural gas gathering module, and the hydrogen interface of each hydrogen blending storage tank is connected to the gas outlet end of the hydrogen gathering module. The gas inlet end of the rectifier is connected to the gas outlet end of the hydrogen blending storage tank, and the rectifier can rectify the gas output from multiple hydrogen blending storage tanks, so as to output natural gas with a set pressure and flow through the natural gas gathering module, and output hydrogen with a set pressure and flow through the hydrogen gathering module, and then preliminarily mix the natural gas and hydrogen through multiple hydrogen blending storage tanks provided in parallel with the follow-up hydrogen blending module, and then rectify the gas output from the multiple hydrogen blending storage tanks through the rectifier, so as to rectify the hydrogen-blended natural gas again, which can ensure that the hydrogen and natural gas are evenly mixed during the transportation process.

[0010] Among them, the follow-up hydrogen blending module is provided with at least two hydrogen blending storage tanks in parallel, which can increase the gas blending amount of the hydrogen blending system and improve the stable transmission flow rate of the natural gas hydrogen blending system. Therefore, the natural gas transmission station hydrogen blending system provided by the present invention can improve the stable transmission flow rate of the natural gas hydrogen blending system while ensuring that hydrogen and natural gas are evenly mixed during the transmission process to meet the needs of industrial transmission of natural gas hydrogen blending.

[0011] In an optional embodiment, the natural gas gathering and transportation module includes a natural gas volume flow meter and a natural gas flow regulating valve connected in series in sequence, and the natural gas gathering and transportation module also includes a natural gas pressure gauge, so as to monitor the flow of the natural gas input into the hydrogen-blended storage tank through the natural gas volume flow meter, monitor the pressure of the natural gas input into the hydrogen-blended storage tank through the natural gas pressure gauge, and adjust the flow of the natural gas input into the hydrogen-blended storage tank through the natural gas flow regulating valve, thereby outputting natural gas with a set pressure (natural gas source pipeline regulation) and flow.

[0012] In an optional embodiment, the hydrogen gathering and transportation module includes: a hydrogen storage tank for storing hydrogen; a hydrogen volume flow meter, serially connected to the gas outlet of the hydrogen storage tank, for measuring the volume flow rate of hydrogen output from the hydrogen storage tank; a first hydrogen pressure gauge, for monitoring the pressure of the hydrogen output from the hydrogen storage tank; a first hydrogen flow regulating valve, serially connected to the gas outlet end of the hydrogen volume flow meter, for regulating the gas flow output from the hydrogen storage tank; a hydrogen compressor, serially connected to the gas outlet end of the hydrogen flow regulating valve, for pressurizing the hydrogen output from the hydrogen storage tank; and a hydrogen storage container, for storing the hydrogen output from the hydrogen compressor.

[0013] Thus, the produced hydrogen is stored in a hydrogen storage tank, the volume flow rate of hydrogen output from the hydrogen storage tank is measured by a hydrogen volume flowmeter, the pressure of the hydrogen output from the hydrogen storage tank is monitored by a first hydrogen pressure gauge, the gas flow rate output from the hydrogen storage tank is adjusted by a first hydrogen flow regulating valve, the hydrogen output from the hydrogen storage tank is pressurized by a hydrogen compressor, and finally the hydrogen output from the hydrogen compressor is stored in a hydrogen storage container, so that the hydrogen gathering and transportation module can output hydrogen with set pressure and flow.

[0014] In an optional embodiment, the follow-up hydrogen blending module further includes: a second hydrogen pressure gauge for monitoring the pressure of hydrogen output from the hydrogen storage container; a second hydrogen flow regulating valve connected in series to the gas outlet of the hydrogen storage container for regulating the gas flow output from the hydrogen storage container; and a hydrogen thermometer for monitoring the temperature of hydrogen output from the hydrogen storage container. The flow and pressure of hydrogen output from the hydrogen gathering and transportation module can be controlled by monitoring the pressure of hydrogen output from the hydrogen storage container through the second hydrogen pressure gauge, regulating the gas flow output from the hydrogen storage container through the second hydrogen flow regulating valve, and monitoring the temperature of hydrogen output from the hydrogen storage container through the hydrogen thermometer, and the temperature can be used to provide data support for whether hydrogen blending is performed.

[0015] In an optional embodiment, the follow-up hydrogen blending module also includes a flow distributor, which is serially connected to the outlet end of the second hydrogen flow regulating valve, and a flow distribution valve is serially connected between the flow distributor and the corresponding hydrogen blending storage tank. On the one hand, the distributor can provide buffering for the hydrogen output from the hydrogen gathering and transportation module to improve the stability of the hydrogen entering the hydrogen blending storage tank. On the other hand, the distributor can allow the hydrogen output from the hydrogen gathering and transportation module to enter the corresponding hydrogen blending storage tank at a set flow rate.

[0016] In an optional embodiment, the rectifier includes an impeller mechanism connected in series in the pipeline, the impeller mechanism includes a rotating shaft arranged along the axial direction of the pipeline; a plurality of mixing blades are evenly distributed circumferentially on the side wall of the rotating shaft, each of the mixing blades is spirally arranged along the axial direction of the rotating shaft, and a plurality of rectifying protrusions are arranged on the side wall of each mixing blade, and the volume of the plurality of rectifying protrusions gradually decreases along the direction of airflow flow.

[0017] In an optional embodiment, the rectifying protrusion is hemispherical to reduce the flow resistance of the rectifying protrusion.

[0018] In an optional embodiment, the rectifying protrusions are distributed on both sides of the mixing blade in the length direction to ensure the uniformity of the rectifying of the rectifier.

[0019] In an optional embodiment, a mixed gas flow meter is further included, which is serially connected to the gas outlet of the rectifier, and the gas outlet of the mixed gas flow meter is also provided with a methane concentration detector and a hydrogen concentration detector, so as to detect the flow of the hydrogen-blended natural gas output by the mixed gas flow meter, and detect whether the quality of the hydrogen-blended natural gas meets the standards through the methane concentration detector and the hydrogen concentration detector.

[0020] In a second aspect, the present invention provides a method for hydrogen blending at a natural gas transmission station, based on the above-mentioned hydrogen blending system at a natural gas transmission station, comprising the following steps:

[0021] S10, inputting natural gas of set pressure and flow into all hydrogen-blended storage tanks through the natural gas gathering and transportation module;

[0022] S20, inputting hydrogen with set pressure and flow into the corresponding hydrogen blending storage tank through the hydrogen gathering and transportation module;

[0023] S30, mixing the hydrogen in the hydrogen blending tank with the natural gas and inputting the mixture into a rectifier;

[0024] S40, detecting whether the mixed gas output by the rectifier is qualified, and delivering the mixed gas that meets the blending requirements to the hydrogen blending delivery pipe.

[0025] The method for hydrogen blending at a natural gas transmission station provided by the present invention outputs natural gas of set pressure and flow through a natural gas gathering module, outputs hydrogen of set pressure and flow through a hydrogen gathering module, and then preliminarily mixes natural gas and hydrogen through a plurality of hydrogen blending storage tanks arranged in parallel with a follow-up hydrogen blending module, and then rectifies the gas outputted by the plurality of hydrogen blending storage tanks through a rectifier, thereby rectifying the hydrogen-blended natural gas again, which can ensure that hydrogen and natural gas are evenly blended during the transportation process. The follow-up hydrogen blending module is provided with at least two hydrogen blending storage tanks in parallel, which can increase the gas blending amount of the hydrogen blending system and improve the stable transmission flow of the natural gas hydrogen blending system.

[0026] Therefore, the natural gas transmission station hydrogen blending method provided by the present invention can improve the stable transmission flow rate of the natural gas hydrogen blending system while ensuring that hydrogen and natural gas are evenly mixed during the transportation process to meet the industrial transportation needs of natural gas hydrogen blending.

[0027] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0028] 1. The hydrogen blending system for a natural gas transmission station provided by the present invention is provided with a natural gas gathering module, a hydrogen gathering module, and a follow-up hydrogen blending module. The follow-up hydrogen blending module is provided with at least two hydrogen blending storage tanks in parallel. The natural gas interface of each hydrogen blending storage tank is connected to the gas outlet end of the natural gas gathering module, and the hydrogen interface of each hydrogen blending storage tank is connected to the gas outlet end of the hydrogen gathering module. The gas inlet end of the rectifier is connected to the gas outlet end of the hydrogen blending storage tank, and the rectifier can rectify the gas output from multiple hydrogen blending storage tanks to output the set pressure and flow through the natural gas gathering module. The natural gas is collected and transported, and the hydrogen with set pressure and flow is output through the hydrogen gathering and transportation module. The natural gas and hydrogen are preliminarily mixed through multiple hydrogen blending storage tanks arranged in parallel with the follow-up hydrogen blending module. The gas output from the multiple hydrogen blending storage tanks is rectified by the rectifier, so as to rectify the hydrogen-blended natural gas again, which can ensure that the hydrogen and natural gas are evenly mixed during the transportation process. Therefore, it can improve the stable transportation flow of the natural gas hydrogen blending system and ensure that the hydrogen and natural gas are evenly mixed during the transportation process to meet the needs of industrial transportation of natural gas blended with hydrogen.

[0029] 2. The hydrogen blending method for natural gas transmission station provided by the present invention outputs natural gas of set pressure and flow through the natural gas gathering module, outputs hydrogen of set pressure and flow through the hydrogen gathering module, and then preliminarily mixes natural gas and hydrogen through multiple hydrogen blending storage tanks arranged in parallel with the follow-up hydrogen blending module, and then rectifies the gas output by the multiple hydrogen blending storage tanks through the rectifier, so as to rectify the hydrogen-blended natural gas again, which can ensure that hydrogen and natural gas are evenly blended during the transportation process. The follow-up hydrogen blending module is equipped with at least two hydrogen blending storage tanks in parallel, which can increase the gas blending amount of the hydrogen blending system and improve the stable transportation flow of the natural gas hydrogen blending system. Therefore, the hydrogen blending method for natural gas transmission station provided by the present invention can improve the stable transportation flow of the natural gas hydrogen blending system while ensuring that hydrogen and natural gas are evenly blended during the transportation process to meet the needs of industrial transportation of natural gas hydrogen blending. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0031] In the attached picture:

[0032] Figure 1 It is a structural schematic diagram of a hydrogen blending system for a natural gas transmission station according to an embodiment of the present invention.

[0033] Figure 2 It is a structural schematic diagram of the rectifier impeller mechanism according to an embodiment of the present invention.

[0034] Marks and corresponding parts names in the attached drawings:

[0035] 10-natural gas gathering and transportation module, 11-natural gas flow meter, 12-natural gas flow regulating valve, 13-natural gas pressure gauge;

[0036] 20-hydrogen gathering and transportation module, 21-hydrogen storage tank, 22-hydrogen volume flow meter, 23-first hydrogen pressure gauge, 24-first hydrogen flow regulating valve, 25-hydrogen compressor, 26-hydrogen storage container;

[0037] 30- follow-up hydrogen blending module, 31- hydrogen blending storage tank, 32- second hydrogen pressure gauge, 33- second hydrogen flow regulating valve, 34- hydrogen thermometer, 35- flow distributor, 36- flow distribution valve;

[0038] 40-rectifier, 41-rotating shaft, 42-mixing blade, 43-rectifying protrusion;

[0039] 50-Natural gas source pipeline;

[0040] 60-mixed gas flow meter, 61-methane concentration detector, 62-hydrogen concentration detector;

[0041] 70-Hydrogen blending delivery pipe. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0043] In the description of the embodiments of the present application, the indicated orientation or position relationship is based on the orientation or position relationship shown in the accompanying drawings, or is the orientation or position relationship in which the product of the application is conventionally placed when in use, or is the orientation or position relationship conventionally understood by those skilled in the art. It is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply 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 on the present application.

[0044] At the same time, the terms "disposed", "opened", "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 directly connected, or indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0045] Example 1

[0046] Combination Figure 1The present embodiment provides a natural gas transmission station hydrogen blending system, comprising: a natural gas gathering module 10, the natural gas gathering module 10 is used to connect the natural gas source pipeline 50 and output natural gas with a set pressure and flow rate; a hydrogen gathering module 20, the hydrogen gathering module 20 is used to connect the hydrogen source and output hydrogen with a set pressure and flow rate; a follow-up hydrogen blending module 30, the follow-up hydrogen blending module 30 is provided with at least two hydrogen blending storage tanks 31 in parallel, the natural gas interface of each hydrogen blending storage tank 31 is connected to the gas outlet end of the natural gas gathering module 10, and the hydrogen interface of each hydrogen blending storage tank 31 is connected to the gas outlet end of the hydrogen gathering module 20; a rectifier 40, the gas inlet end of the rectifier 40 is connected to the gas outlet end of the hydrogen blending storage tank 31, and the rectifier 40 can rectify the gas output by multiple hydrogen blending storage tanks 31.

[0047] It is understandable that the natural gas gathering and transportation module 10 includes a natural gas volume flow meter and a natural gas flow regulating valve 12 connected in series, and the natural gas gathering and transportation module 10 also includes a natural gas pressure gauge 13, so as to monitor the flow of the natural gas input into the hydrogen-blended storage tank 31 through the natural gas volume flow meter, monitor the pressure of the natural gas input into the hydrogen-blended storage tank 31 through the natural gas pressure gauge 13, and adjust the flow of the natural gas input into the hydrogen-blended storage tank 31 through the natural gas flow regulating valve 12, so as to output natural gas with set pressure (natural gas source pipeline regulation) and flow. It is understandable that the natural gas gathering and transportation module 10 is also provided with a natural gas control valve to control the passage of the natural gas pipeline. The adjustment and opening and closing of various valves are usually controlled by PLC. Similarly, data collection of the flow meter and pressure gauge is also carried out by PLC.

[0048] In this embodiment, the hydrogen gathering and transportation module 20 includes: a hydrogen storage tank 21, which is used to store hydrogen; a hydrogen volume flow meter 22, which is serially connected to the gas outlet of the hydrogen storage tank 21, and is used to measure the volume flow rate of hydrogen output from the hydrogen storage tank 21; a first hydrogen pressure gauge 23, which is used to monitor the pressure of the hydrogen output from the hydrogen storage tank 21; a first hydrogen flow regulating valve 24, which is serially connected to the gas outlet end of the hydrogen volume flow meter 22, and is used to adjust the gas flow output from the hydrogen storage tank 21; a hydrogen compressor 25, which is serially connected to the gas outlet end of the hydrogen flow regulating valve, and is used to pressurize the hydrogen output from the hydrogen storage tank 21; a hydrogen storage container 26, which is used to store the hydrogen output from the hydrogen compressor 25.

[0049] Thus, the produced hydrogen is stored by the hydrogen storage tank 21, the volume flow rate of the hydrogen output by the hydrogen storage tank 21 is measured by the hydrogen volume flowmeter 22, the pressure of the hydrogen output by the hydrogen storage tank 21 is monitored by the first hydrogen pressure gauge 23, the gas flow rate output by the hydrogen storage tank 21 is adjusted by the first hydrogen flow regulating valve 24, the hydrogen output by the hydrogen storage tank 21 is pressurized by the hydrogen compressor 25, and finally the hydrogen output by the hydrogen compressor 25 is stored by the hydrogen storage container 26, so that the hydrogen gathering and transportation module 20 can output hydrogen with set pressure and flow.

[0050] The hydrogen collection and transportation module 20 is also equipped with a hydrogen control valve during use to control the on and off of hydrogen output. A one-way valve is also provided at the outlet of the hydrogen storage tank 21 to prevent hydrogen reflux. Various valves and metering instruments of the hydrogen collection and transportation module 20 are also controlled by PLC.

[0051] Recombination Figure 1 Specifically, the follow-up hydrogen blending module 30 also includes: a second hydrogen pressure gauge 32 for monitoring the pressure of hydrogen output from the hydrogen storage container 26; a second hydrogen flow regulating valve 33, which is serially connected to the gas outlet of the hydrogen storage container 26, for regulating the gas flow output from the hydrogen storage container 26; and a hydrogen thermometer 34, which is used to monitor the temperature of hydrogen output from the hydrogen storage container 26. The second hydrogen pressure gauge 32 is used to monitor the pressure of hydrogen output from the hydrogen storage container 26, the second hydrogen flow regulating valve 33 is used to adjust the gas flow output from the hydrogen storage container 26, and the hydrogen thermometer 34 is used to monitor the temperature of hydrogen output from the hydrogen storage container 26, thereby controlling the flow and pressure of hydrogen output from the hydrogen gathering and transportation module 20, and providing data support for whether to blend hydrogen through its temperature.

[0052] In this embodiment, the follow-up hydrogen blending module 30 also includes a flow distributor 35, which is serially connected to the outlet end of the second hydrogen flow regulating valve 33, and a flow distribution valve 36 is serially connected between the flow distributor 35 and the corresponding hydrogen blending storage tank 31. On the one hand, the distributor can provide buffering for the hydrogen output from the hydrogen gathering and transportation module 20 to improve the stability of the hydrogen entering the hydrogen blending storage tank 31. On the other hand, the distributor can output the hydrogen from the hydrogen gathering and transportation module 20 into the corresponding hydrogen blending storage tank 31 at a set flow rate.

[0053] Generally speaking, the hydrogen output from the hydrogen gathering and transporting module 20 is sprayed into the corresponding hydrogen blending storage tank 31 through a nozzle, the nozzle diameter is DN20-DN80, and the blending ratios under different nozzles are shown in Table 1.

[0054]

[0055] Table 1

[0056] Combination Figure 2 It should be noted that the rectifier 40 includes an impeller mechanism connected in series in the pipeline, and the impeller mechanism includes a rotating shaft 41 arranged along the axial direction of the pipeline; a plurality of mixing blades 42 are evenly distributed on the side wall of the rotating shaft 41 in the circumferential direction, and each of the mixing blades 42 is spirally arranged along the axial direction of the rotating shaft 41, and a plurality of rectifying protrusions 43 are arranged on the side wall of each of the mixing blades 42, and the volume of the plurality of rectifying protrusions 43 gradually decreases along the direction of the airflow. Among them, along the airflow direction, the mixing protrusions at the front of the mixing blade 42 can create turbulence to make the gas evenly distributed, and the small mixing protrusions at the rear can transition the gas flow state, so that the turbulent gas enters the laminar state faster, thereby ensuring the uniformity of the hydrogen-blended natural gas.

[0057] Preferably, the rectifying protrusion 43 is hemispherical to reduce the flow resistance of the rectifying protrusion 43 .

[0058] Optionally, the rectifying protrusions 43 are distributed on both sides of the mixing blade 42 in the length direction to ensure the uniformity of rectification of the rectifier 40 .

[0059] It can be understood that the number of blades of the impeller mechanism is determined according to the required mixing concentration. In the present embodiment, the number of mixing blades 42 of the impeller mechanism is 9, 11, and 15, corresponding to mixing concentrations of 3% to 10%, 10% to 20%, and 20% to 90%, respectively. Along the airflow direction, the diameter of the front straightening protrusion 43 of the mixing blade 42 is 7 mm, and the diameter of the rear straightening protrusion 43 is 3 mm.

[0060] On this basis, the present embodiment further includes a mixed gas flow meter 60, which is connected in series to the gas outlet of the rectifier 40, and is also provided with a methane concentration detector 61 and a hydrogen concentration detector 62 at the gas outlet of the mixed gas flow meter 60, so as to detect the flow of the hydrogen-blended natural gas output by the system through the mixed gas flow meter 60, and detect whether the quality of the hydrogen-blended natural gas meets the standard through the methane concentration detector 61 and the hydrogen concentration detector 62.

[0061] It should be noted that in the existing natural gas transmission station hydrogen blending system, hydrogen is blended by using an ejector on the horizontal pipe section, which is not conducive to uniform mixing of hydrogen during transportation and easily leads to hydrogen enrichment at the undulating parts of the long-distance pipeline. The present invention uses multiple hydrogen blending storage tanks 31 to preliminarily mix natural gas and hydrogen, and then rectifies them through the rectifier flow, which can avoid hydrogen enrichment.

[0062] The natural gas transmission station hydrogen blending system provided in the present embodiment first outputs natural gas of set pressure and flow through the natural gas gathering module 10, and outputs hydrogen of set pressure and flow through the hydrogen gathering module 20, and then preliminarily mixes the natural gas and hydrogen through a plurality of hydrogen blending storage tanks 31 arranged in parallel with the follow-up hydrogen blending module 30, and then rectifies the gas output from the plurality of hydrogen blending storage tanks 31 through the rectifier 40, thereby rectifying the hydrogen-blended natural gas again, which can ensure that the hydrogen and natural gas are evenly mixed during the transportation process.

[0063] Among them, the follow-up hydrogen blending module 30 is provided with at least two hydrogen blending storage tanks 31 in parallel, which can increase the gas blending amount of the hydrogen blending system and improve the stable transmission flow of the natural gas hydrogen blending system (can reach 200,000 standard cubic meters / day).

[0064] Therefore, the natural gas transmission station hydrogen blending system provided in this embodiment can improve the stable transmission flow rate of the natural gas hydrogen blending system while ensuring that hydrogen and natural gas are evenly mixed during the transportation process to meet the needs of industrial transportation of natural gas hydrogen blending.

[0065] Example 2

[0066] This embodiment provides a method for hydrogen blending at a natural gas transmission station, based on the hydrogen blending system at a natural gas transmission station of Embodiment 1, comprising the following steps:

[0067] The hydrogen blending system for the natural gas transmission station mentioned above includes the following steps:

[0068] S10 , natural gas with set pressure and flow is input into all hydrogen-blended storage tanks 31 through the natural gas gathering and transportation module 10 .

[0069] Specifically, the gas in the natural gas pipeline is directly supplied by the compressor, so the gas in the natural gas pipeline is high-pressure gas. The flow of the high-pressure gas is controlled by the natural gas electromagnetic control valve, and then under the monitoring of the natural gas pressure meter 13, the natural gas volume flow meter, and the natural gas flow regulating valve 12, the required natural gas volume output can be controlled through the adjustment of the PLC control system.

[0070] In this embodiment, natural gas is input from the natural gas flow regulating valve 12 and enters each hydrogen blending storage tank 31 from the bottom of the hydrogen blending storage tank 31 to ensure that the natural gas can be fully mixed with the hydrogen.

[0071] S20 , inputting hydrogen with set pressure and flow into the corresponding hydrogen blending storage tank 31 through the hydrogen gathering and transportation module 20 .

[0072] Generally speaking, hydrogen is first unloaded from a tank truck into a hydrogen storage tank 21. When hydrogen blending begins, the hydrogen control valve is opened, and the return valve is in a normally open state. The hydrogen then enters the hydrogen delivery pipeline, and the flow and pressure parameters of hydrogen are obtained through the hydrogen volume flow meter 22 and the hydrogen pressure sensor, and the signal is transmitted to the hydrogen flow regulating valve, that is, the PLC control system is used for logical control to ensure that the volume of hydrogen blending is controllable. Finally, the hydrogen enters the hydrogen compressor 25 for pressure boosting, and the pressurized hydrogen enters the hydrogen storage container 26 (hydrogen storage bottle group) to store the high-pressure hydrogen.

[0073] Combination Figure 1 The hydrogen in the hydrogen storage container 26 is monitored by pressure and temperature, and after the flow is controlled and stabilized by the flow regulating valve, it enters the flow distributor 35, and is precisely controlled by the flow distribution valve 36, so that the hydrogen is input into the hydrogen blending tank 31 according to the set pressure and flow, and then preliminarily mixed with the hydrogen in the hydrogen blending tank 31.

[0074] S30, the hydrogen in the hydrogen blending tank and the natural gas are mixed and then input into the rectifier 40.

[0075] S40 , detecting whether the mixed gas output by the rectifier 40 is qualified, and delivering the mixed gas that meets the blending requirements to the hydrogen blending delivery pipe 70 .

[0076] It should be understood that the rectified gas flows through the mixed gas flow meter 60 and can pass through the methane concentration detector 61 and the hydrogen concentration detector 62 to determine the hydrogen blending ratio, and then enter the hydrogen blending delivery pipe 70 to complete the hydrogen blending process.

[0077] In summary, the method for hydrogen blending at a natural gas transmission station provided by this embodiment first outputs natural gas of set pressure and flow through the natural gas gathering and transportation module 10, and outputs hydrogen of set pressure and flow through the hydrogen gathering and transportation module 20, and then preliminarily mixes natural gas and hydrogen through multiple hydrogen blending storage tanks 31 arranged in parallel with the follow-up hydrogen blending module 30, and then rectifies the gas output by the multiple hydrogen blending storage tanks 31 through the rectifier 40, so as to rectify the hydrogen-blended natural gas again, which can ensure that hydrogen and natural gas are evenly blended during the transportation process. The follow-up hydrogen blending module 30 is provided with at least two hydrogen blending storage tanks 31 in parallel, which can increase the gas blending amount of the hydrogen blending system and improve the stable transmission flow of the natural gas hydrogen blending system.

[0078] Therefore, the natural gas transmission station hydrogen blending method provided in this embodiment can improve the stable transmission flow rate of the natural gas hydrogen blending system while ensuring that hydrogen and natural gas are evenly mixed during the transportation process to meet the industrial transportation needs of natural gas hydrogen blending.

[0079] 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 natural gas transmission station hydrogen blending system, characterized in that: include: A natural gas gathering and transportation module (10), the natural gas gathering and transportation module (10) being used to connect a natural gas source pipeline (50) and output natural gas of set pressure and flow; A hydrogen gathering and transportation module (20), the hydrogen gathering and transportation module (20) being used to connect to a hydrogen source and output hydrogen at a set pressure and flow rate; A follow-up hydrogen blending module (30), wherein the follow-up hydrogen blending module (30) is provided with at least two hydrogen blending storage tanks (31) in parallel, the natural gas interface of each of the hydrogen blending storage tanks (31) is connected to the gas outlet end of the natural gas gathering and transportation module (10), and the hydrogen interface of each of the hydrogen blending storage tanks (31) is connected to the gas outlet end of the hydrogen gathering and transportation module (20); A rectifier (40), wherein the gas inlet end of the rectifier (40) is connected to the gas outlet end of the hydrogen-doped storage tank (31), and the rectifier (40) is capable of rectifying the gas output from a plurality of the hydrogen-doped storage tanks (31).

2. The natural gas transmission station hydrogen blending system according to claim 1, characterized in that: The natural gas gathering and transportation module (10) comprises a natural gas volume flow meter and a natural gas flow regulating valve (12) which are connected in series in sequence, and the natural gas gathering and transportation module (10) further comprises a natural gas pressure meter (13).

3. The natural gas transmission station hydrogen blending system according to claim 1, characterized in that: The hydrogen gathering and transportation module (20) comprises: A hydrogen storage tank (21) for storing hydrogen; A hydrogen volume flow meter (22) is connected in series to the gas outlet of the hydrogen storage tank (21) and is used to measure the volume flow of hydrogen output from the hydrogen storage tank (21); a first hydrogen pressure gauge (23), used for monitoring the pressure of hydrogen outputted from the hydrogen storage tank (21); A first hydrogen flow regulating valve (24), connected in series to the gas outlet end of the hydrogen volume flow meter (22), for regulating the gas flow output from the hydrogen storage tank (21); A hydrogen compressor (25) is connected in series to the outlet end of the hydrogen flow regulating valve and is used to pressurize the hydrogen output from the hydrogen storage tank (21); The hydrogen storage container (26) is used to store the hydrogen output by the hydrogen compressor (25).

4. The natural gas transmission station hydrogen blending system according to claim 1, characterized in that: The follow-up hydrogen doping module (30) further includes: a second hydrogen pressure gauge (32), used for monitoring the pressure of hydrogen outputted from the hydrogen storage container (26); A second hydrogen flow regulating valve (33) is serially connected to the gas outlet end of the hydrogen storage container (26) and is used to regulate the gas flow outputted from the hydrogen storage container (26); A hydrogen thermometer (34) is used to monitor the temperature of hydrogen output from the hydrogen storage container (26).

5. The natural gas transmission station hydrogen blending system according to claim 4, characterized in that: The follow-up hydrogen blending module (30) further comprises a flow distributor (35), wherein the flow distributor (35) is connected in series to the gas outlet end of the second hydrogen flow regulating valve (33), and a flow distribution valve (36) is connected in series between the flow distributor (35) and the corresponding hydrogen blending storage tank (31).

6. The natural gas transmission station hydrogen blending system according to claim 1, characterized in that: The rectifier (40) comprises an impeller mechanism connected in series in the pipeline, and the impeller mechanism comprises a rotating shaft (41) arranged along the axial direction of the pipeline; A plurality of mixing blades (42) are evenly distributed in the circumferential direction of the side wall of the rotating shaft (41), each of the mixing blades (42) is spirally arranged along the axial direction of the rotating shaft (41), and a plurality of rectifying protrusions (43) are arranged on the side wall of each of the mixing blades (42), and the volume of the plurality of rectifying protrusions (43) gradually decreases along the direction of airflow flow.

7. The natural gas transmission station hydrogen blending system according to claim 6, characterized in that: The rectifying protrusion (43) is hemispherical.

8. The natural gas transmission station hydrogen blending system according to claim 6, characterized in that: The rectifying protrusions (43) are distributed on both sides of the mixing blade (42) in the length direction.

9. The natural gas transmission station hydrogen blending system according to claim 1, characterized in that: It also comprises a mixed gas flow meter (60), which is connected in series to the gas outlet end of the rectifier (40), and the gas outlet end of the mixed gas flow meter (60) is also provided with a methane concentration detector (61) and a hydrogen concentration detector (62).

10. A method for blending hydrogen at a natural gas transmission station, characterized in that: The natural gas transmission station hydrogen blending system according to any one of claims 1 to 9 comprises the following steps: S10, inputting natural gas of set pressure and flow into all hydrogen-blended storage tanks (31) through the natural gas gathering and transportation module (10); S20, inputting hydrogen with set pressure and flow into a corresponding hydrogen-blending storage tank (31) through a hydrogen gathering and transportation module (20); S30, mixing the hydrogen in the hydrogen blending tank with the natural gas and inputting the mixture into a rectifier (40); S40, detecting whether the mixed gas output by the rectifier (40) is qualified, and delivering the mixed gas that meets the blending requirements to the hydrogen blending delivery pipe (70).

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