A hydrogen blending system and method for a natural gas transmission station

Abstract

The application discloses a natural gas transmission station hydrogen mixing system and a hydrogen mixing method, and relates to the technical field of new energy sources.The hydrogen mixing system comprises a natural gas gathering and transmission module, a hydrogen gas gathering and transmission module and a follow-up hydrogen mixing module.The natural gas gathering and transmission module is used for connecting a natural gas source pipeline and outputting natural gas with a set pressure and flow rate.The hydrogen gas gathering and transmission module is used for connecting a hydrogen gas source and outputting hydrogen gas with a set pressure and flow rate.The follow-up hydrogen mixing module is provided with at least two hydrogen mixing storage tanks in parallel connection.The natural gas interfaces of the hydrogen mixing storage tanks are connected with the gas outlet end of the natural gas gathering and transmission module.The hydrogen gas interfaces of the hydrogen mixing storage tanks are connected with the gas outlet end of the hydrogen gas gathering and transmission module.The gas inlet end of a rectifier is connected with the gas outlet end of the hydrogen mixing storage tank.The rectifier can rectify the gas output by the hydrogen mixing storage tanks, and can improve the hydrogen mixing system conveying flow rate and uniform mixing.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of new energy technology, in particular to a natural gas transmission station hydrogen mixing system and a hydrogen mixing method. BACKGROUND

[0002] Natural gas hydrogen mixing technology is a kind of energy technology that hydrogen is mixed into natural gas in a certain volume ratio to form hydrogen mixed natural gas, which is transported through existing natural gas pipelines and can directly replace natural gas. A large number of research results show that the combustion of natural gas hydrogen mixed gas can improve the combustion performance of terminal equipment, reduce nitrogen oxide pollution and carbon dioxide emission.

[0003] Natural gas hydrogen mixing has been an important research direction for hydrogen transportation and large-scale utilization at home and abroad. At present, domestic research is in the acceleration stage. With the gradual recognition of natural gas pipeline hydrogen mixing transportation, two key changes have occurred in the focus of domestic natural gas hydrogen mixing projects: from the transportation link to the application link, and from the civil field to the industrial field. The change from transportation to application is conducive to the faster formation of commercial projects and the promotion of energy terminal application carbon reduction; compared with the civil field, the safety management of the industrial field is more standardized and easier to implement.

[0004] Due to the late start of domestic natural gas pipeline hydrogen mixing transportation research, it cannot meet the needs of industrial transportation. SUMMARY

[0005] In view of the technical problem that the existing natural gas hydrogen mixing system cannot meet the needs of industrial transportation in terms of transportation pressure and transportation, the present application provides a natural gas transmission station hydrogen mixing system and a hydrogen mixing method, which can improve the stable transportation flow of the natural gas hydrogen mixing system while ensuring uniform mixing of hydrogen and natural gas during transportation, to meet the needs of industrial transportation of natural gas hydrogen mixing.

[0006] The present application is realized by the following technical scheme:

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

[0008] In the existing hydrogen mixing system of natural gas transmission station, the hydrogen is mixed by using an ejector on the horizontal pipe section, which is not conducive to the uniform mixing of hydrogen in the transmission process, and is easy to cause the enrichment of hydrogen at the ups and downs of the long transmission pipeline. The hydrogen enrichment can be avoided by the present application through the preliminary mixing of natural gas and hydrogen by multiple hydrogen mixing storage tanks, and then the rectification by the rectifier.

[0009] The natural gas transmission station hydrogen mixing system provided by the present application is provided with a natural gas gathering and transmission module, a hydrogen gathering and transmission module, and a follow-up hydrogen mixing module. The follow-up hydrogen mixing module is provided with at least two hydrogen mixing storage tanks in parallel. The natural gas interfaces of the hydrogen mixing storage tanks are connected with the gas outlet end of the natural gas gathering and transmission module. The hydrogen interfaces of the hydrogen mixing storage tanks are connected with the gas outlet end of the hydrogen gathering and transmission module. The gas inlet end of the rectifier is connected with the gas outlet end of the hydrogen mixing storage tank. The rectifier can rectify the gas output by the multiple hydrogen mixing storage tanks, so as to output natural gas with a set pressure and flow rate through the natural gas gathering and transmission module, output hydrogen with a set pressure and flow rate through the hydrogen gathering and transmission module, preliminarily mix the natural gas and hydrogen through the multiple hydrogen mixing storage tanks provided in parallel in the follow-up hydrogen mixing module, and then rectify the gas output by the multiple hydrogen mixing storage tanks through the rectifier again, so as to rectify the hydrogen mixed natural gas again, thereby ensuring the uniform mixing of hydrogen and natural gas in the transmission process.

[0010] The follow-up hydrogen mixing module is provided with at least two hydrogen mixing storage tanks in parallel, which can increase the gas mixing amount of the hydrogen mixing system and improve the stable transmission flow rate of the natural gas hydrogen mixing system. Therefore, the natural gas transmission station hydrogen mixing system provided by the present application can improve the stable transmission flow rate of the natural gas hydrogen mixing system while ensuring the uniform mixing of hydrogen and natural gas in the transmission process, so as to meet the demand of industrial transmission of natural gas hydrogen mixing.

[0011] In an optional embodiment, the natural gas gathering and transmission module comprises a natural gas volume flow meter and a natural gas flow regulating valve which are sequentially connected in series. The natural gas gathering and transmission module further comprises a natural gas pressure gauge. The flow rate of natural gas input into the hydrogen mixing storage tank is monitored by the natural gas volume flow meter, the pressure of natural gas input into the hydrogen mixing storage tank is monitored by the natural gas pressure gauge, and the flow rate of natural gas input into the hydrogen mixing storage tank is regulated by the natural gas flow regulating valve, so as to output natural gas with a set pressure (natural gas source pipeline regulation) and flow rate.

[0012] In an optional embodiment, the hydrogen gas collecting module comprises: a hydrogen gas storage tank for storing hydrogen gas; a hydrogen gas volume flow meter connected in series at the gas outlet of the hydrogen gas storage tank for measuring the volume flow of hydrogen gas output by the hydrogen gas storage tank; a first hydrogen gas pressure gauge for monitoring the pressure of hydrogen gas output by the hydrogen gas storage tank; a first hydrogen gas flow regulating valve connected in series at the gas outlet of the hydrogen gas volume flow meter for regulating the gas flow output by the hydrogen gas storage tank; a hydrogen gas compressor connected in series at the gas outlet of the hydrogen gas flow regulating valve for pressurizing the hydrogen gas output by the hydrogen gas storage tank; and a hydrogen storage container for storing the hydrogen gas output by the hydrogen gas compressor.

[0013] Thus, the hydrogen gas collecting module can output hydrogen gas with a set pressure and flow by storing the produced hydrogen gas in the hydrogen gas storage tank, measuring the volume flow of hydrogen gas output by the hydrogen gas storage tank with the hydrogen gas volume flow meter, monitoring the pressure of hydrogen gas output by the hydrogen gas storage tank with the first hydrogen gas pressure gauge, regulating the gas flow output by the hydrogen gas storage tank with the first hydrogen gas flow regulating valve, pressurizing the hydrogen gas output by the hydrogen gas storage tank with the hydrogen gas compressor, and finally storing the hydrogen gas output by the hydrogen gas compressor with the hydrogen storage container.

[0014] In an optional embodiment, the follow-up hydrogen doping module further comprises: a second hydrogen gas pressure gauge for monitoring the pressure of hydrogen gas output by the hydrogen storage container; a second hydrogen gas flow regulating valve connected in series at the gas outlet of the hydrogen storage container for regulating the gas flow output by the hydrogen storage container; and a hydrogen gas temperature gauge for monitoring the temperature of hydrogen gas output by the hydrogen storage container. The second hydrogen gas pressure gauge is used to monitor the pressure of hydrogen gas output by the hydrogen storage container, the second hydrogen gas flow regulating valve is used to regulate the gas flow output by the hydrogen storage container, and the hydrogen gas temperature gauge is used to monitor the temperature of hydrogen gas output by the hydrogen storage container, so as to control the flow and pressure of hydrogen gas output by the hydrogen gas collecting module and provide data support for whether to dope hydrogen according to the temperature of hydrogen gas.

[0015] In an optional embodiment, the follow-up hydrogen doping module further comprises a flow distributor connected in series at the gas outlet of the second hydrogen gas flow regulating valve, and a flow distribution valve connected in series between the flow distributor and the corresponding hydrogen doping storage tank. On the one hand, the flow distributor can buffer the hydrogen gas output by the hydrogen gas collecting module, thereby improving the stability of hydrogen gas entering the hydrogen doping storage tank. On the other hand, the flow distributor can make the hydrogen gas output by the hydrogen gas collecting module enter the corresponding hydrogen doping storage tank according to a set flow.

[0016] In an optional embodiment, the rectifier comprises an impeller mechanism connected in series in the pipeline, and the impeller mechanism comprises a rotating shaft arranged axially along the pipeline. The rotating shaft is circumferentially uniformly provided with a plurality of mixing blades, each of which is arranged axially along the rotating shaft in a spiral manner, and the side wall of each of the mixing blades is provided with a plurality of rectifying protrusions, the volumes of the plurality of rectifying protrusions gradually decrease in the direction of gas flow.

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

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

[0019] In an optional embodiment, a mixed gas flow meter is further included, which is connected in series at the gas outlet end of the rectifier, and the gas outlet end of the mixed gas flow meter is further provided with a methane concentration detector and a hydrogen concentration detector to detect the flow of the hydrogen-doped natural gas output by the mixed gas flow meter system and detect whether the quality of the hydrogen-doped natural gas meets the standard.

[0020] In a second aspect, the application provides a hydrogen-doping method for a natural gas transmission station, which is based on the above-mentioned hydrogen-doping system for a natural gas transmission station and includes the following steps:

[0021] S10, inputting natural gas with a set pressure and flow rate into all the hydrogen-doping storage tanks through a natural gas gathering and transmission module;

[0022] S20, inputting hydrogen gas with a set pressure and flow rate into corresponding hydrogen-doping storage tanks through a hydrogen gas gathering and transmission module;

[0023] S30, mixing the hydrogen gas and the natural gas in the hydrogen-doping tanks and then inputting the mixture into a rectifier;

[0024] S40, detecting whether the mixed gas output by the rectifier is qualified and transporting the mixed gas meeting the mixing requirements to a hydrogen-doping transmission pipe.

[0025] The hydrogen-doping method for a natural gas transmission station provided by the application can ensure uniform mixing of hydrogen gas and natural gas during the transmission process by outputting natural gas with a set pressure and flow rate through a natural gas gathering and transmission module, outputting hydrogen gas with a set pressure and flow rate through a hydrogen gas gathering and transmission module, preliminarily mixing the natural gas and the hydrogen gas through multiple hydrogen-doping storage tanks connected in parallel through a follow-up hydrogen-doping module, and then rectifying the gas output by the multiple hydrogen-doping storage tanks through a rectifier to re-rectify the hydrogen-doped natural gas.

[0026] Therefore, the hydrogen-doping method for a natural gas transmission station provided by the application can improve the stable transmission flow rate of the natural gas hydrogen-doping system while ensuring uniform mixing of hydrogen gas and natural gas during the transmission process to meet the demand of industrial transmission of hydrogen-doped natural gas.

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

[0028] 1. The natural gas transmission station hydrogen mixing system provided by the present application is provided with a natural gas gathering and transmission module, a hydrogen gathering and transmission module and a follow-up hydrogen mixing module, the follow-up hydrogen mixing module is provided with at least two hydrogen mixing storage tanks in parallel, the natural gas interfaces of the hydrogen mixing storage tanks are connected with the gas outlet end of the natural gas gathering and transmission module, the hydrogen interfaces of the hydrogen mixing storage tanks are connected with the gas outlet end of the hydrogen gathering and transmission module, and the gas inlet end of the rectifier is connected with the gas outlet end of the hydrogen mixing storage tank, and the rectifier can rectify the gas output by the hydrogen mixing storage tanks, so as to output natural gas with a set pressure and flow rate through the natural gas gathering and transmission module, output hydrogen with a set pressure and flow rate through the hydrogen gathering and transmission module, preliminarily mix the natural gas and hydrogen through the multiple hydrogen mixing storage tanks provided in parallel in the follow-up hydrogen mixing module, and then rectify the gas output by the multiple hydrogen mixing storage tanks through the rectifier, so as to rectify the hydrogenated natural gas again, which can ensure that the hydrogen and the natural gas are uniformly mixed in the transmission process, and thus, the stable transmission flow rate of the hydrogenated natural gas system can be improved, and the hydrogen and the natural gas can be uniformly mixed in the transmission process, so as to meet the demand of industrial transmission of hydrogenated natural gas.

[0029] 2. The natural gas transmission station hydrogen mixing method provided by the present application, which outputs natural gas with a set pressure and flow rate through the natural gas gathering and transmission module, outputs hydrogen with a set pressure and flow rate through the hydrogen gathering and transmission module, preliminarily mixes the natural gas and hydrogen through the multiple hydrogen mixing storage tanks provided in parallel in the follow-up hydrogen mixing module, and then rectifies the gas output by the multiple hydrogen mixing storage tanks through the rectifier, so as to rectify the hydrogenated natural gas again, which can ensure that the hydrogen and the natural gas are uniformly mixed in the transmission process. The follow-up hydrogen mixing module is provided with at least two hydrogen mixing storage tanks in parallel, which can increase the gas mixing amount of the hydrogen mixing system and improve the stable transmission flow rate of the hydrogenated natural gas system, and thus, the stable transmission flow rate of the hydrogenated natural gas system can be improved, and the hydrogen and the natural gas can be uniformly mixed in the transmission process, so as to meet the demand of industrial transmission of hydrogenated natural gas. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiments will be briefly introduced as follows. It should be understood that the following drawings only show some embodiments of the present application, and thus should not be regarded as a limitation on the scope. Other related drawings can also be obtained by those skilled in the art without creative labor.

[0031] In the drawings:

[0032] Figure 1 It is a structural schematic diagram of the natural gas transmission station hydrogen mixing system of the present application.

[0033] Figure 2The structural schematic diagram of the rectifier impeller mechanism of the embodiment of the present application.

[0034] The marks in the drawings and the corresponding component names:

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

[0036] 20-hydrogen gathering 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-following hydrogen-doped module, 31-hydrogen-doped storage tank, 32-second hydrogen pressure gauge, 33-second hydrogen flow regulating valve, 34-hydrogen temperature gauge, 35-flow distributor, 36-flow distribution valve;

[0038] 40-rectifier, 41-rotating shaft, 42-mixed 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-doped delivery pipe. DETAILED DESCRIPTION

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

[0043] In the description of the embodiments of the present application, the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship commonly placed when the product of the application is used, or the orientation or positional relationship commonly understood by those skilled in the art, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0044] Meanwhile, the terms "set", "open", "mount", "connected", "connection" should be broadly understood, for example, can be fixed connection, can also be detachable connection, or integrally connected; can be directly connected, can also be indirectly connected through an intermediate medium, can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0045] Embodiment 1

[0046] In combination Figure 1 The embodiment provides a natural gas station hydrogen mixing system, which comprises a natural gas gathering and transportation module 10, a hydrogen gathering and transportation module 20 and a follow-up hydrogen mixing module 30. The natural gas gathering and transportation module 10 is used for connecting a natural gas source pipeline 50 and outputting natural gas with a set pressure and flow rate. The hydrogen gathering and transportation module 20 is used for connecting a hydrogen source and outputting hydrogen with a set pressure and flow rate. The follow-up hydrogen mixing module 30 is provided with at least two hydrogen mixing storage tanks 31 in parallel. The natural gas interface of each hydrogen mixing storage tank 31 is connected with the gas outlet end of the natural gas gathering and transportation module 10, and the hydrogen interface of each hydrogen mixing storage tank 31 is connected with the gas outlet end of the hydrogen gathering and transportation module 20. The gas inlet end of a rectifier 40 is connected with the gas outlet end of the hydrogen mixing storage tank 31, and the rectifier 40 can rectify the gas output by the hydrogen mixing storage tanks 31.

[0047] It can be understood that the natural gas gathering and transportation module 10 comprises a natural gas volume flow meter and a natural gas flow rate regulating valve 12 connected in sequence. The natural gas gathering and transportation module 10 further comprises a natural gas pressure gauge 13, so as to monitor the flow rate of the natural gas input into the hydrogen mixing storage tank 31 through the natural gas volume flow meter, monitor the pressure of the natural gas input into the hydrogen mixing storage tank 31 through the natural gas pressure gauge 13, and regulate the flow rate of the natural gas input into the hydrogen mixing storage tank 31 through the natural gas flow rate regulating valve 12, thereby outputting natural gas with a set pressure (natural gas source pipeline regulation) and flow rate. It can be understood that the natural gas gathering and transportation module 10 is further provided with a natural gas control valve to control the passage of the natural gas pipeline. The regulation, opening and closing of various valves are usually controlled through a PLC. Similarly, the data acquisition of the flow meter and the pressure gauge is also carried out through the PLC.

[0048] In the present embodiment, the hydrogen gas collecting and transporting module 20 comprises: a hydrogen gas storage tank 21 for storing hydrogen gas; a hydrogen gas volume flow meter 22 connected in series at the gas outlet of the hydrogen gas storage tank 21 for measuring the volume flow of hydrogen gas output by the hydrogen gas storage tank 21; a first hydrogen gas pressure gauge 23 for monitoring the pressure of hydrogen gas output by the hydrogen gas storage tank 21; a first hydrogen gas flow regulating valve 24 connected in series at the gas outlet of the hydrogen gas volume flow meter 22 for regulating the gas flow output by the hydrogen gas storage tank 21; a hydrogen gas compressor 25 connected in series at the gas outlet of the hydrogen gas flow regulating valve for pressurizing the hydrogen gas output by the hydrogen gas storage tank 21; and a hydrogen storage container 26 for storing the hydrogen gas output by the hydrogen gas compressor 25.

[0049] Thus, by storing the produced hydrogen gas in the hydrogen gas storage tank 21, measuring the volume flow of hydrogen gas output by the hydrogen gas storage tank 21 through the hydrogen gas volume flow meter 22, monitoring the pressure of hydrogen gas output by the hydrogen gas storage tank 21 through the first hydrogen gas pressure gauge 23, regulating the gas flow output by the hydrogen gas storage tank 21 through the first hydrogen gas flow regulating valve 24, pressurizing the hydrogen gas output by the hydrogen gas storage tank 21 through the hydrogen gas compressor 25, and finally storing the hydrogen gas output by the hydrogen gas compressor 25 through the hydrogen storage container 26, the hydrogen gas collecting and transporting module 20 can output hydrogen gas at a set pressure and flow rate.

[0050] In use, the hydrogen gas collecting and transporting module 20 is also fitted with a hydrogen gas control valve to control the on-off of hydrogen gas output. A one-way valve is also provided at the gas outlet of the hydrogen gas storage tank 21 to avoid backflow of hydrogen gas. The various valves and measuring instruments of the hydrogen gas collecting and transporting module 20 are also controlled by a PLC.

[0051] Again in combination Figure 1 Specifically, the follow-up hydrogen doping module 30 further comprises: a second hydrogen gas pressure gauge 32 for monitoring the pressure of hydrogen gas output by the hydrogen storage container 26; a second hydrogen gas flow regulating valve 33 connected in series at the gas outlet of the hydrogen storage container 26 for regulating the gas flow output by the hydrogen storage container 26; and a hydrogen gas thermometer 34 for monitoring the temperature of hydrogen gas output by the hydrogen storage container 26. By monitoring the pressure of hydrogen gas output by the hydrogen storage container 26 through the second hydrogen gas pressure gauge 32, regulating the gas flow output by the hydrogen storage container 26 through the second hydrogen gas flow regulating valve 33, and monitoring the temperature of hydrogen gas output by the hydrogen storage container 26 through the hydrogen gas thermometer 34, the flow rate and pressure of hydrogen gas output by the hydrogen gas collecting and transporting module 20 can be controlled, and the temperature of hydrogen gas can provide data support for whether to dope hydrogen.

[0052] In the embodiment, the follow-up hydrogen-doping module 30 further comprises a flow distributor 35 connected in series at the outlet of the second hydrogen flow regulating valve 33, and a flow distribution valve 36 connected in series between the flow distributor 35 and the corresponding hydrogen-doping storage tank 31. On one hand, the flow distributor 35 can buffer the hydrogen output by the hydrogen collection module 20, and improve the stability of the hydrogen entering the hydrogen-doping storage tank 31. On the other hand, the flow distributor 36 can control the hydrogen output by the hydrogen collection module 20 to enter the corresponding hydrogen-doping storage tank 31 according to the set flow rate.

[0053] Generally, the hydrogen output by the hydrogen collection module 20 is sprayed into the corresponding hydrogen-doping storage tank 31 through a nozzle with a nozzle diameter of DN20-DN80. The mixing ratio under different nozzles is shown in Table 1.

[0054]

[0055] Table 1

[0056] In combination Figure 2 It should be noted that the rectifier 40 comprises an impeller mechanism connected in series in the pipeline, and the impeller mechanism comprises a rotating shaft 41 arranged axially along the pipeline. The rotating shaft 41 is circumferentially uniformly provided with a plurality of mixing blades 42, each of which is arranged axially spirally along the rotating shaft 41, and each of the mixing blades 42 is provided with a plurality of rectifying protrusions 43 on the side wall, and the volumes of the plurality of rectifying protrusions 43 gradually decrease in the direction of the gas flow. In the direction of the gas flow, the rectifying protrusions in the front part of the mixing blade 42 can create turbulent flow to make the gas distribution uniform, and the small rectifying protrusions in the rear part can transition the gas flow state, so that the turbulent gas can enter the laminar flow state more quickly, thereby ensuring the uniformity of the hydrogen-doped natural gas.

[0057] Preferably, the rectifying protrusions 43 are semispherical to reduce the flow resistance of the rectifying protrusions 43.

[0058] Optionally, the rectifying protrusions 43 are distributed on both sides of the length direction of the mixing blade 42 to ensure the uniformity 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 embodiment, the number of mixing blades 42 of the impeller mechanism is 9, 11, or 15, which respectively corresponds to a mixing concentration of 3%-10%, 10%-20%, or 20%-90%. In the direction of the gas flow, the diameter of the rectifying protrusions 43 in the front part of the mixing blade 42 is 7 mm, and the diameter of the rectifying protrusions 43 in the rear part is 3 mm.

[0060] On this basis, the embodiment also comprises a mixed gas flow meter 60, which is connected in series at 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, so as to detect the flow of hydrogen-doped natural gas output by the system through the mixed gas flow meter 60, and detect whether the quality of the hydrogen-doped 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 hydrogen-doping system of a natural gas transmission station, the hydrogen is doped by using an ejector on a horizontal pipe section, which is not conducive to the uniform mixing of hydrogen in the transmission process and is likely to cause enrichment of hydrogen at the undulating part of the long pipeline. However, the present application can avoid the enrichment of hydrogen by preliminarily mixing natural gas and hydrogen through multiple hydrogen-doping storage tanks 31 and then rectifying the gas output by the multiple hydrogen-doping storage tanks 31 through a rectifier.

[0062] The hydrogen-doping system of the natural gas transmission station provided in the embodiment can preliminarily mix natural gas and hydrogen through the multiple hydrogen-doping storage tanks 31 connected in parallel in the follow-up hydrogen-doping module 30, and then rectify the gas output by the multiple hydrogen-doping storage tanks 31 through the rectifier 40, so as to re-rectify the hydrogen-doped natural gas, thereby ensuring the uniform mixing of hydrogen and natural gas in the transmission process.

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

[0064] Therefore, the hydrogen-doping system of the natural gas transmission station provided in the embodiment can improve the stable transmission flow of the natural gas hydrogen-doping system while ensuring the uniform mixing of hydrogen and natural gas in the transmission process, so as to meet the demand of industrial transmission of hydrogen-doped natural gas.

[0065] Embodiment 2

[0066] The embodiment provides a hydrogen-doping method for a natural gas transmission station, which is based on the hydrogen-doping system for the natural gas transmission station of embodiment 1 and comprises the following steps.

[0067] The hydrogen-doping system for the natural gas transmission station comprises the following steps.

[0068] S10, input natural gas with a set pressure and flow rate into all the hydrogen-doping storage tanks 31 through the natural gas gathering and transmission 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 gauge 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 the present embodiment, the natural gas is input from the natural gas flow regulating valve 12 and enters each hydrogen-doped storage tank 31 from the bottom of the hydrogen-doped storage tank 31 to ensure that the natural gas can be fully mixed with hydrogen.

[0071] S20, the hydrogen gas with the set pressure and flow is input into the corresponding hydrogen-doped storage tank 31 through the hydrogen gas gathering and transporting module 20.

[0072] Generally, the hydrogen gas is first unloaded from the tank truck into the hydrogen gas storage tank 21, the hydrogen gas control valve is opened when hydrogen doping starts, and the back valve is always open. The hydrogen gas enters the hydrogen gas delivery pipeline, the flow and pressure parameters of the hydrogen gas are obtained through the hydrogen gas volume flow meter 22 and the hydrogen gas pressure sensor, and the signals are transmitted to the hydrogen gas flow regulating valve. Through the logical control of the PLC control system, the volume of the hydrogen-doped gas is controllable. Finally, the hydrogen gas enters the hydrogen gas compressor 25 for pressure boosting, and the hydrogen gas after pressure boosting enters the hydrogen storage container 26 (hydrogen storage bottle group) for storing high-pressure hydrogen gas.

[0073] In combination Figure 1 , the hydrogen gas in the hydrogen storage container 26 is input into the flow distributor 35 after pressure monitoring, temperature monitoring, and stable flow control through the flow regulating valve. The hydrogen gas is input into the hydrogen-doped storage tank 31 through the accurate control of the flow distribution valve 36, and then the hydrogen gas is preliminarily mixed with the hydrogen gas in the hydrogen-doped storage tank 31.

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

[0075] S40, whether the mixed gas output by the rectifier 40 is qualified is detected, and the mixed gas meeting the mixing requirements is transported to the hydrogen-doped delivery pipeline 70.

[0076] It should be understood that the rectified gas flows through the mixed gas flow meter 60, and after the hydrogen-doped proportion is determined through the methane concentration detector 61 and the hydrogen concentration detector 62, the hydrogen-doped gas enters the hydrogen-doped delivery pipeline 70, and the hydrogen-doping process is completed.

[0077] In summary, the natural gas transmission station hydrogen blending method provided by the embodiment first outputs natural gas with a set pressure and flow rate through the natural gas gathering and transmission module 10, outputs hydrogen with a set pressure and flow rate through the hydrogen gathering and transmission module 20, then preliminarily mixes the natural gas and hydrogen through the multiple hydrogen blending storage tanks 31 of the follow-up hydrogen blending module 30 in parallel, and then rectifies the gas output by the multiple hydrogen blending storage tanks 31 through the rectifier 40, thereby re-rectifying the hydrogen-blended natural gas, which can ensure uniform blending of hydrogen and natural gas during the transmission 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 rate of the natural gas hydrogen blending system.

[0078] Therefore, the natural gas transmission station hydrogen blending method provided by the embodiment can improve the stable transmission flow rate of the natural gas hydrogen blending system while ensuring uniform blending of hydrogen and natural gas during the transmission process, thereby meeting the demand of industrial transmission of natural gas hydrogen blending.

[0079] The specific embodiments described above further illustrate the purposes, technical solutions, and beneficial effects of the present application. It should be understood that the above description is only a specific embodiment of the present application and is not used to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A hydrogen blending system for a natural gas transmission station, comprising: The application relates to a hydrogen-doped natural gas module. The hydrogen-doped natural gas module comprises a natural gas collecting module (10) for connecting a natural gas source pipeline (50) and outputting natural gas with a set pressure and flow rate; a hydrogen gas collecting module (20) for connecting a hydrogen gas source and outputting hydrogen gas with a set pressure and flow rate; and a follow-up hydrogen-doped module (30) provided with at least two hydrogen-doped storage tanks (31) in parallel, wherein the natural gas interface of each hydrogen-doped storage tank (31) is connected with the gas outlet end of the natural gas collecting module (10), and the hydrogen gas interface of each hydrogen-doped storage tank (31) is connected with the gas outlet end of the hydrogen gas collecting module (20). The follow-up hydrogen-doped module (30) further comprises a rectifier (40) connected with the gas outlet end of the hydrogen-doped storage tank (31), and the rectifier (40) can rectify the gas output by the hydrogen-doped storage tank (31). The rectifier (40) comprises an impeller mechanism connected in series in a pipeline, and the impeller mechanism comprises a rotating shaft (41) arranged axially along the pipeline. The rotating shaft (41) is circumferentially provided with a plurality of mixing blades (42) on the side wall, each mixing blade (42) is arranged axially along the rotating shaft (41) in a spiral manner, and the side wall of each mixing blade (42) is provided with a plurality of rectifying protrusions (43), and the volumes of the plurality of rectifying protrusions (43) gradually decrease along the direction of gas flow. The natural gas collecting module (10) comprises a natural gas volume flow meter, a natural gas flow regulating valve (12) connected in series, and a natural gas pressure gauge (13). The hydrogen gas collecting module (20) comprises:

2. The natural gas transmission station hydrogen blending system of claim 1, wherein, a hydrogen gas storage tank (21) for storing hydrogen gas; 3. The natural gas transmission station hydrogen blending system of claim 1, wherein, a hydrogen gas volume flow meter (22) connected in series at the gas outlet of the hydrogen gas storage tank (21) for measuring the volume flow rate of the hydrogen gas output by the hydrogen gas storage tank (21); a first hydrogen gas pressure gauge (23) for monitoring the pressure of the hydrogen gas output by the hydrogen gas storage tank (21); a first hydrogen gas flow regulating valve (24) connected in series at the gas outlet end of the hydrogen gas volume flow meter (22) for regulating the flow rate of the gas output by the hydrogen gas storage tank (21); a hydrogen gas compressor (25) connected in series at the gas outlet end of the hydrogen gas flow regulating valve for pressurizing the hydrogen gas output by the hydrogen gas storage tank (21); a hydrogen storage container (26) for storing the hydrogen gas output by the hydrogen gas compressor (25). The follow-up hydrogen-doped module (30) further comprises: a second hydrogen gas pressure gauge (32) for monitoring the pressure of the hydrogen gas output by the hydrogen storage container (26); 4. The natural gas transmission station hydrogen blending system of claim 3, wherein, a second hydrogen gas flow regulating valve (33) connected in series at the gas outlet end of the hydrogen storage container (26) for regulating the flow rate of the gas output by the hydrogen storage container (26); a hydrogen gas thermometer (34) for monitoring the temperature of the hydrogen gas output by the hydrogen storage container (26). ​ ​ 5. The natural gas transmission station hydrogen blending system of claim 4, wherein, The follow-up hydrogen-doping module (30) further comprises a flow distributor (35) connected in series at the gas outlet end of the second hydrogen flow regulating valve (33), and a flow distribution valve (36) connected in series between the flow distributor (35) and the corresponding hydrogen-doping storage tank (31).

6. The hydrogen blending system for a natural gas transmission station of claim 1, wherein, The rectifying protrusion (43) is semispherical.

7. The hydrogen blending system for a natural gas transmission station of claim 1, wherein, The rectifying protrusions (43) are distributed on both sides of the length direction of the mixing blade (42).

8. The hydrogen blending system for a natural gas transmission station of claim 1, wherein, Further comprising a mixed gas flow meter (60) connected in series at the gas outlet end of the rectifier (40), and a methane concentration detector (61) and a hydrogen concentration detector (62) further arranged at the gas outlet end of the mixed gas flow meter (60).

9. A method of hydrogen blending at a natural gas transmission station, the method comprising: The natural gas station hydrogen-doping system according to any one of claims 1-8, comprising the following steps: S10, inputting natural gas with a set pressure and flow rate into all hydrogen-doping storage tanks (31) through a natural gas gathering and transferring module (10); S20, inputting hydrogen with a set pressure and flow rate into the corresponding hydrogen-doping storage tank (31) through a hydrogen gas gathering and transferring module (20); S30, mixing the hydrogen and natural gas in the hydrogen-doping tank and inputting the mixture into a rectifier (40); S40, detecting whether the mixed gas output by the rectifier (40) is qualified, and transporting the mixed gas meeting the mixing requirements to a hydrogen-doping transport pipe (70).

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