A multi-stage pressure natural gas pipeline hydrogen blending experimental system for medium and low pressure hydrogen blending

Abstract

The present invention discloses a multi-stage pressure natural gas pipeline hydrogen blending experimental system for medium and low pressure hydrogen blending. The present invention can complete the hydrogen blending process under medium and low pressure conditions, thereby avoiding the processing and construction difficulties caused by hydrogen blending under high pressure conditions. Subsequently, through pressurization and pressure regulation, experiments under multi-stage pressure conditions can be realized to obtain hydrogen-blended natural gas under different pressure conditions, which is convenient for carrying out hydrogen blending experiments under different pressure conditions, thereby improving experimental efficiency.

Description

Technical Field

[0001] The present invention relates to the field of hydrogen blending experiments, and in particular to a multi-stage pressure natural gas pipeline hydrogen blending experimental system for medium and low pressure hydrogen blending. Background Art

[0002] Against the backdrop of the "dual carbon" goals, to meet my country's energy needs and ensure energy security, the energy structure is moving towards a low-carbon direction, and renewable clean energy such as photovoltaics and wind power has ushered in an opportunity for rapid development. Hydrogen has no carbon emissions when used and can also be used as an energy storage medium for unstable renewable energy such as photovoltaics and wind power, which can promote the large-scale application of renewable energy in my country. However, for hydrogen to be applied industrially, its storage and transportation issues must be resolved. Compared with technologies such as high-pressure gaseous hydrogen storage, liquid hydrogen storage, and solid-state hydrogen storage, pipeline hydrogen blending utilizes existing natural gas pipelines to partially blend hydrogen with natural gas. This not only solves the problem of large-scale, low-cost transportation of hydrogen, but also makes full use of existing gas infrastructure. At the same time, pipeline hydrogen blending also helps to unify the calorific value of gas and reduce carbon emissions from gas use.

[0003] Developed countries in Europe and the United States have launched a number of pipeline hydrogen blending demonstration projects. China has also begun to explore the application demonstration of pipeline hydrogen blending and has achieved certain results. However, pipeline hydrogen blending is aimed at the existing gas transmission and distribution system. On the one hand, the portability of existing results is limited. The actual conditions of the existing transmission and distribution systems in different countries and regions vary greatly, such as pipe materials, pipe age, operating conditions, soil environment, etc., which require targeted research and evaluation. On the other hand, the natural gas transmission and distribution system is relatively complex, and there are currently no systematic research results. On the other hand, urban gas is located at the downstream of the natural gas industry chain and is the first scenario to be solved for pipeline hydrogen blending. The urban gas transmission and distribution system contains multiple pressure levels, and its adaptability in the hydrogen blending environment needs to be studied. For example, the risk of conducting hydrogen blending experiments by drawing branches from high-pressure / sub-high-pressure gas pipelines is relatively high.

[0004] In the existing experimental design and implementation plan of hydrogen blending experiments, it is difficult to blend natural gas with hydrogen under high-pressure conditions, which affects the accuracy of the experiment. In addition, only experimental environments are designed for medium and low pressure conditions, and hydrogen blending experiments under multi-level pressure conditions cannot be carried out.

[0005] Therefore, the existing technology still needs to be improved and developed. Summary of the Invention

[0006] In view of the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide a multi-stage pressure natural gas pipeline hydrogen blending experimental system for medium and low pressure hydrogen blending, aiming to solve the technical problems of how to blend hydrogen under medium and low pressure conditions and how to realize hydrogen blending experiments under multi-stage pressure conditions.

[0007] The technical solutions of the present invention are as follows:

[0008] In a first aspect, the present invention provides a multi-stage pressure natural gas pipeline hydrogen blending experimental system for medium and low pressure hydrogen blending, which includes:

[0009] A hydrogen blender is used to mix the input natural gas and hydrogen and output the hydrogen-blended natural gas;

[0010] A first valve body is connected to the input end of the hydrogen blender and is used to deliver natural gas within a first pressure threshold to the hydrogen blender;

[0011] The second valve body is connected to the input end of the hydrogen blending machine and is used to deliver hydrogen to the hydrogen blending machine;

[0012] A first experimental pipe section is connected to the output end of the hydrogen blender and is used to perform experiments within a first pressure threshold range;

[0013] a compressor connected to the first experimental pipe section, and configured to pressurize the hydrogen-blended natural gas to a second pressure threshold range;

[0014] a second experimental pipe section, connected to the compressor, for conducting experiments within a second air pressure threshold range;

[0015] A third valve body is connected to the output end of the hydrogen blender, the first experimental pipe section, and the second experimental pipe section, respectively, for transporting hydrogen-blended natural gas;

[0016] a fourth valve body, connected to the first experimental pipe section and the third valve body respectively, and used for conveying hydrogen-blended natural gas within a first pressure threshold range;

[0017] The second air pressure threshold is greater than the first air pressure threshold.

[0018] In one embodiment, the system further comprises:

[0019] a third experimental pipe section, connected to the second experimental pipe section, for conducting experiments within a third air pressure threshold range;

[0020] The third air pressure threshold is greater than the first air pressure threshold, and the second air pressure threshold is greater than the third air pressure threshold.

[0021] In one embodiment, the first experimental section comprises:

[0022] a first gas collecting column, connected to the hydrogen blender, for storing hydrogen-blended natural gas within a first pressure threshold range;

[0023] a first pipe experimental tooling section connected to the first gas collecting column;

[0024] The second experimental section includes:

[0025] A second pipe test fixture section connected to the compressor;

[0026] The third experimental section includes:

[0027] a second gas collecting column, connected to the second experimental pipe section, for storing hydrogen-blended natural gas;

[0028] A third pipe test fixture section is connected to the second gas collecting column;

[0029] The hydrogen-blended natural gas may sequentially pass through the first gas collection column, the first pipe test tooling section, the compressor, the second pipe test tooling section, the second gas collection column, and the third pipe test tooling section.

[0030] In one embodiment, the first valve body includes a first ball valve, a first shut-off valve, and a first pressure regulating valve connected in sequence, and the second valve body includes a second ball valve, a second shut-off valve, a second pressure regulating valve, and a first check valve connected in sequence;

[0031] The first pressure regulating valve is connected to the input end of the hydrogen blending machine, and the first check valve is connected to the input end of the hydrogen blending machine.

[0032] In one embodiment, the third valve body includes:

[0033] a third ball valve, wherein both ends of the third ball valve are respectively connected to the output end of the hydrogen blender and the first gas collecting column;

[0034] a fourth ball valve, both ends of which are connected to the first pipe test fixture section and the compressor respectively;

[0035] a third pressure regulating valve connected to the second gas collecting column;

[0036] a fifth ball valve, both ends of which are connected to the compressor and the second pipe test fixture section respectively;

[0037] a sixth ball valve, two ends of which are respectively connected to the compressor and the third pressure regulating valve;

[0038] a fourth pressure regulating valve connected to the third pipe test fixture section;

[0039] a seventh ball valve, both ends of which are connected to the second gas collecting column and the third pipe test fixture section respectively;

[0040] an eighth ball valve, two ends of which are respectively connected to the second gas collecting column and the fourth pressure regulating valve;

[0041] Wherein, the fifth ball valve and the sixth ball valve are arranged in parallel, and the seventh ball valve and the eighth ball valve are arranged in parallel.

[0042] In one embodiment, the fourth valve body includes:

[0043] a ninth ball valve connected to the output end of the hydrogen blending machine;

[0044] a tenth ball valve connected to the first pipe test fixture section;

[0045] an eleventh ball valve connected to the ninth ball valve and the tenth ball valve;

[0046] The ninth ball valve is connected to the third ball valve, the ninth ball valve is arranged in parallel with the tenth ball valve, and the eleventh ball valve is connected to the fourth pressure regulating valve.

[0047] In one embodiment, the third valve body further includes:

[0048] a twelfth ball valve connected to the fourth pressure regulating valve;

[0049] a fifth pressure regulating valve connected to the twelfth ball valve;

[0050] a second check valve connected to the fifth pressure regulating valve;

[0051] The system further comprises:

[0052] The terminal gas appliance is connected to the second check valve.

[0053] In a second aspect, the present invention provides a control method for a multi-stage pressure natural gas pipeline hydrogen blending experimental system for medium and low pressure hydrogen blending according to any one of the above, wherein the method comprises:

[0054] Determine experimental pressure information and experimental flow information corresponding to the hydrogen doping experiment; the experimental pressure information is single-stage pressure or multi-stage pressure, and the experimental flow information is a first flow or a second flow;

[0055] Determining experimental scheme information corresponding to the hydrogen doping experiment according to the experimental pressure information and the experimental flow information;

[0056] Controlling the first valve body to deliver natural gas and the second valve body to deliver hydrogen, thereby obtaining hydrogen-blended natural gas output by the hydrogen blender; wherein the natural gas delivered by the first valve body and the hydrogen delivered by the second valve body are both within a first pressure threshold range, and the hydrogen-blended natural gas output by the hydrogen blender is within the first pressure threshold range;

[0057] According to the experimental scheme information, the third valve body is controlled to transport the hydrogen-blended natural gas output by the hydrogen blender to the first experimental pipe section for experiment, thereby obtaining the hydrogen-blended natural gas after the experiment; wherein the hydrogen-blended natural gas after the experiment is within the first gas pressure threshold range.

[0058] In one embodiment, the experimental scheme information includes one of a first single-stage pressure experimental scheme, a second single-stage pressure experimental scheme, and a multi-stage pressure experimental scheme;

[0059] Determining experimental scheme information corresponding to the hydrogen doping experiment based on the experimental pressure information and the experimental flow information includes:

[0060] If the experimental pressure information is a single-stage pressure and the experimental flow information is a first flow, determining that the experimental scheme information is the first single-stage pressure experimental scheme; or

[0061] If the experimental pressure information is a single-stage pressure and the experimental flow information is a second flow, determining that the experimental scheme information is the second single-stage pressure experimental scheme; or

[0062] If the experimental pressure information is multi-level pressure, and the experimental flow information is the first flow or the second flow, the experimental scheme information is determined to be the multi-level pressure experimental scheme.

[0063] In one embodiment, the step of delivering the hydrogen-blended natural gas outputted by the hydrogen blender to the first experimental pipe section according to the experimental plan information to obtain the hydrogen-blended natural gas after the experiment includes:

[0064] According to the multi-stage pressure test scheme, the third valve body is controlled to transport the hydrogen-blended natural gas output by the hydrogen blender to the first test pipe section for testing, thereby obtaining the first hydrogen-blended natural gas;

[0065] controlling a compressor to pressurize the first hydrogen-blended natural gas to a second pressure threshold range to obtain a second hydrogen-blended natural gas;

[0066] The third valve body is controlled to transport the second hydrogen-blended natural gas to the second experimental pipe section for experiment, and the third valve body is controlled to regulate the pressure of the second hydrogen-blended natural gas to obtain the hydrogen-blended natural gas after the experiment.

[0067] Beneficial effects: The present invention provides a multi-stage pressure natural gas pipeline hydrogen blending experimental system for medium and low pressure hydrogen blending. The present invention can complete the hydrogen blending process under medium and low pressure conditions, thereby avoiding the processing and construction difficulties brought about by hydrogen blending under high pressure conditions. Subsequently, experiments under multi-stage pressure conditions can be realized through pressurization and pressure regulation, and hydrogen-blended natural gas under different pressure conditions can be obtained, which is convenient for carrying out hydrogen blending experiments under different pressure conditions, thereby improving experimental efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] Figure 1 It is a schematic planar structural diagram of the multi-stage pressure natural gas pipeline hydrogen blending experimental system for medium and low pressure hydrogen blending of the present invention.

[0069] Figure 2 It is a schematic diagram of the three-dimensional structure of the multi-stage pressure natural gas pipeline hydrogen blending experimental system for medium and low pressure hydrogen blending of the present invention.

[0070] Figure 3 The present invention is a flow chart of a control method for a multi-stage pressure natural gas pipeline hydrogen blending experimental system for medium and low pressure hydrogen blending.

[0071] Description of reference numerals:

[0072] 2. First filter; 3. First ball valve; 4. First shut-off valve; 5. First pressure regulating valve;

[0073] 7. Second filter; 8. Second ball valve; 9. Second shut-off valve; 10. Second pressure regulating valve; 11. First check valve;

[0074] 12. Hydrogen blender; 14. Third ball valve; 15. First gas collection column; 16. First valve test fixture section; 17. First metering instrument test fixture section; 18. First pipe test fixture section; 21. Fourth ball valve; 22. Compressor; 24. Fifth ball valve; 25. Second pipe test fixture section; 23. Sixth ball valve; 26. Third pressure regulating valve; 27. Second gas collection column; 37. Seventh ball valve; 29. Third pipe test fixture section; 28. Eighth ball valve; 38. Thirteenth ball valve; 30. Third metering instrument test fixture section; 32. Fourth pressure regulating valve; 33. Twelfth ball valve; 34. Fifth pressure regulating valve; 35. Second check valve.

[0075] 13. The ninth ball valve; 20. The tenth ball valve; 31. The eleventh ball valve. DETAILED DESCRIPTION

[0076] The present invention provides a multi-stage pressure natural gas pipeline hydrogen blending experimental system for medium- and low-pressure hydrogen blending. To clarify and clarify the objectives, technical solutions, and effects of the present invention, the present invention is described in further detail below. It should be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention.

[0077] It should be noted that when a component is referred to as being “fixed to” or “disposed on” another component, it may be directly on the other component or indirectly on the other component. When a component is referred to as being “connected to” another component, it may be directly connected to the other component or indirectly connected to the other component.

[0078] It should also be noted that the same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar components; in the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "left", "right", etc. indicating directions or positional relationships, they are based on the directions or positional relationships shown in the drawings. This is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting this patent. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0079] First, the terms involved in the embodiments of the present invention are introduced:

[0080] Ball valve, the opening and closing part (ball) is driven by the valve stem and rotates around the axis of the ball valve;

[0081] The shut-off valve is a type of actuator in the automation system. It consists of a multi-spring pneumatic diaphragm actuator or a floating piston actuator and a pressure regulating valve. It receives signals from the regulating instrument to control the shut-off, connection or switching of the fluid in the process pipeline.

[0082] The pressure regulating valve is an intuitive and simple flow regulation control device;

[0083] A check valve is a valve whose opening and closing member is a circular disc and which relies on its own weight and medium pressure to produce a movement to block the backflow of the medium.

[0084] In the existing experimental design and implementation plan of hydrogen blending experiments, it is difficult to blend natural gas with hydrogen under high-pressure conditions, which affects the accuracy of the experiment. In addition, only experimental environments are designed for medium and low pressure conditions, and hydrogen blending experiments under multi-level pressure conditions cannot be carried out.

[0085] In order to solve the above problems, the present invention provides a multi-stage pressure natural gas pipeline hydrogen blending experimental system for medium and low pressure hydrogen blending, which can complete the hydrogen blending process under medium and low pressure conditions, and subsequently realize the experiment under multi-stage pressure conditions by pressurization and pressure regulation, such as Figure 1 As shown, the system includes:

[0086] A hydrogen blender 12 is used to mix the input natural gas and hydrogen and output the hydrogen-blended natural gas;

[0087] The first valve body is connected to the input end of the hydrogen blending machine 12 (such as Figure 1 The left end of the horizontal air flow arrow direction shown in FIG1 is connected to the hydrogen blender 12 for delivering natural gas within a first pressure threshold;

[0088] The second valve body is connected to the input end of the hydrogen blending machine 12 and is used to deliver hydrogen to the hydrogen blending machine 12;

[0089] The first experimental pipe section is connected to the output end of the hydrogen blending machine 12 (such as Figure 1 The right end of the horizontal airflow arrow direction shown in FIG1 is connected to conduct experiments within the first air pressure threshold range;

[0090] A compressor 22 connected to the first experimental pipe section, used to pressurize the hydrogen-blended natural gas to a second pressure threshold range;

[0091] A second experimental pipe section, connected to the compressor 22, for conducting experiments within a second pressure threshold range;

[0092] The third valve body is connected to the output end of the hydrogen blender 12, the first experimental pipe section, and the second experimental pipe section respectively, for transporting hydrogen-blended natural gas;

[0093] a fourth valve body, connected to the first experimental pipe section and the third valve body respectively, and used for conveying hydrogen-blended natural gas within a first pressure threshold range;

[0094] The second air pressure threshold is greater than the first air pressure threshold.

[0095] It should be noted that hydrogen (within the first pressure threshold range, i.e., the medium and low pressure range) can be prepared by electrolysis of water, and thus transported to the hydrogen blender 12 through the second valve body, and natural gas (within the first pressure threshold range, i.e., the medium and low pressure range) is transported to the hydrogen blender 12 through the first valve body, thereby enabling the platform to blend hydrogen under medium and low pressure conditions. On the one hand, this avoids the insecurity of high-pressure gas extraction, and on the other hand, for hydrogen production by electrolysis of water, the cost investment of the hydrogen compressor between the hydrogen source and the hydrogen blender can be reduced, and for the hydrogen source of the hydrogen cylinder group, the effective utilization rate of the hydrogen in the cylinder group can be increased.

[0096] On the one hand, the experimental system of the present invention can enable the experimental platform to open gas from the medium and low pressure gas pipeline network and mix it under low pressure conditions, reducing the difficulty of processing and construction; on the other hand, by setting up pressurization and pressure regulating equipment, hydrogen-blended natural gas under different pressure conditions can be obtained according to experimental needs, facilitating hydrogen blending experiments under different pressure conditions.

[0097] The experimental systems of the present invention are all connected through pipes and pipelines. Except for the experimental pipe section which uses pipes commonly used in town gas, the remaining pipe sections are all made of 316 / 316L stainless steel to ensure stable operation of the system.

[0098] In this embodiment, the system further includes:

[0099] a third experimental pipe section, connected to the second experimental pipe section, for conducting experiments within a third air pressure threshold range;

[0100] The third air pressure threshold is greater than the first air pressure threshold, and the second air pressure threshold is greater than the third air pressure threshold.

[0101] Specifically, the first pressure threshold range (i.e., medium-low pressure range) is 0.01MPa to 0.04MPa (including 0.01MPa and 0.04MPa); the second pressure threshold range (i.e., high pressure range) is 1.6MPa to 4MPa (including 4MPa); and the third pressure threshold range (i.e., sub-high pressure range) is 0.4MPa to 1.6MPa (including 1.6MPa). The medium-low pressure hydrogen doping experiment is carried out through the first experimental pipe section, the high pressure hydrogen doping experiment is carried out through the second experimental pipe section, and the sub-high pressure hydrogen doping experiment is carried out through the third experimental pipe section. In this way, a separate medium-low pressure hydrogen doping experiment can be carried out; or a medium-low pressure hydrogen doping experiment and a high pressure hydrogen doping experiment; or a medium-low pressure hydrogen doping experiment and a sub-high pressure hydrogen doping experiment; or a medium-low pressure hydrogen doping experiment, a high pressure hydrogen doping experiment, and a sub-high pressure hydrogen doping experiment. In this way, the above four types of hydrogen doping experiments (one single-stage pressure condition, three multi-stage pressure conditions) are realized, and the effect of conducting multi-stage pressure experiments at the same time is achieved, so as to improve the experimental efficiency.

[0102] It should be noted that the hydrogen-blended natural gas (within the first pressure threshold range, i.e., the medium-low pressure range) obtained by the hydrogen blender 12 of the present invention first passes through the first experimental section (i.e., the medium-low pressure experimental section), and then enters the second experimental section (i.e., the high-pressure experimental section) and the third experimental section (i.e., the sub-high-pressure experimental section) in sequence. This makes it easier to conduct medium-low pressure experiments on the platform by rationally setting switches. If the experimental results are good, high-pressure and sub-high-pressure experiments are then carried out. This better conforms to the experimental path of low-to-high experimental pressure in the hydrogen-blended natural gas adaptability experiment, increases the accuracy of the experimental results, and improves the efficiency of the experiment.

[0103] The experimental system of the present invention is easy to operate. Specifically, it includes a natural gas source, a hydrogen source, a hydrogen blender, an experimental pipe section system, a pressure regulating valve, a PLC control cabinet, a flow pressure regulating valve, a flow meter, a pressure detector, a ball valve, a check valve, an end-user system and other equipment. After the natural gas source is filtered, it is sequentially passed through the ball valve and the pressure regulating valve to the hydrogen blender. After the hydrogen source is filtered, it is sequentially passed through the ball valve and the pressure regulating valve to the hydrogen blender and mixed with the natural gas. The hydrogen blender 12 outlet hydrogen blended natural gas enters the medium-pressure experimental pipe section area after passing through the check valve; the medium-pressure experimental pipe section outlet hydrogen blended natural gas passes through the compressor 22, is pressurized to high pressure, and enters the high-pressure experimental pipe section area; the high-pressure experimental pipe section outlet hydrogen blended natural gas passes through the pressure regulating valve, is adjusted to sub-high pressure, and enters the sub-high pressure experimental pipe section area; the sub-high pressure experimental pipe section outlet hydrogen blended natural gas pressure regulating valve is adjusted to medium pressure, and a part of the hydrogen blended natural gas is circulated back to the medium-pressure experimental section by using the pressure difference, and the other part is passed to the terminal gas appliance 36 (i.e., the end-user system).

[0104] In this embodiment, the first experimental section includes:

[0105] A first gas collecting column 15 is connected to the hydrogen blender 12 and is used to store hydrogen-blended natural gas within a first pressure threshold range;

[0106] The first pipe test fixture section 18 is connected to the first gas collecting column 15;

[0107] The second experimental section includes:

[0108] The second pipe test fixture section 25 is connected to the compressor 22;

[0109] The third experimental section includes:

[0110] A second gas collecting column 27, connected to the second experimental pipe section, is used to store hydrogen-blended natural gas within the first pressure threshold or the third pressure threshold;

[0111] The third pipe test fixture section 29 is connected to the second gas collecting column 27;

[0112] The hydrogen-blended natural gas can pass through the first gas collection column 15, the first pipe test tooling section 18, the compressor 22, the second pipe test tooling section 25, the second gas collection column 27 and the third pipe test tooling section 29 in sequence (this experimental scheme is a multi-stage pressure experimental scheme, that is, conducting medium and low pressure hydrogen blending experiments, high pressure hydrogen blending experiments and sub-high pressure hydrogen blending experiments), thereby improving the experimental efficiency.

[0113] Specifically, the first experimental pipe section (medium and low pressure experimental pipe section), the second experimental pipe section (high pressure experimental pipe section) and the third experimental pipe section (i.e., sub-high pressure experimental pipe section) are all tooling sections, and valve experimental tooling sections, metering instrument experimental tooling sections and pipe experimental tooling sections can be installed according to experimental requirements. For example, the first experimental pipe section includes two first pipe experimental tooling sections 18, a first valve experimental tooling section 16 and a first metering instrument experimental tooling section 17, the second experimental pipe section includes a second pipe experimental tooling section 25, and the third experimental pipe section includes a third pipe experimental tooling section 29 and a third metering instrument experimental tooling section 30. However, the present invention is not limited to this, and the specific settings can be modified according to actual needs.

[0114] It should be noted that the functions of the gas collecting column include solving the uniformity of gas supply and storing hydrogen-blended natural gas sources.

[0115] In this embodiment, the first valve body includes a first ball valve 3, a first shut-off valve 4, and a first pressure regulating valve 5 connected in sequence through a pipe, and the second valve body includes a second ball valve 8, a second shut-off valve 9, a second pressure regulating valve 10, and a first check valve 11 connected in sequence through a pipe.

[0116] The first pressure regulating valve 5 is connected to the input end of the hydrogen blending machine 12 , and the first check valve 11 is connected to the input end of the hydrogen blending machine 12 .

[0117] Specifically, the system further includes a first filter 2 (for filtering impurities in natural gas) and a second filter 7 (for filtering impurities in hydrogen). The first filter 2 is connected to the first ball valve 3 , and the second filter 7 is connected to the second ball valve 8 .

[0118] In this embodiment, if Figure 1 Said third-way valve body comprises:

[0119] a third ball valve 14, both ends of which are connected to the output end of the hydrogen blender 12 and the first gas collecting column 15 respectively;

[0120] a fourth ball valve 21 , both ends of which are connected to the first pipe test fixture section 18 and the compressor 22 , respectively;

[0121] a third pressure regulating valve 26 connected to the second gas collecting column 27;

[0122] a fifth ball valve 24 , both ends of which are connected to the compressor 22 and the second pipe test fixture section 25 ;

[0123] a sixth ball valve 23 , both ends of which are connected to the compressor 22 and the third pressure regulating valve 26 , respectively;

[0124] A fourth pressure regulating valve 32 connected to the third pipe test fixture section 29;

[0125] a seventh ball valve 37 , both ends of which are connected to the second gas collecting column 27 and the third pipe test fixture section 29 ;

[0126] an eighth ball valve 28 , both ends of which are connected to the second gas collecting column 27 and the fourth pressure regulating valve 32 , respectively;

[0127] The fifth ball valve 24 and the sixth ball valve 23 are arranged in parallel, and the seventh ball valve 37 and the eighth ball valve 28 are arranged in parallel.

[0128] Specifically, each first pipe test fixture section 18, a first valve test fixture section 16, and a first metering instrument test fixture section 17 constitutes a branch. That is, the first test pipe section has four branches, each of which is provided with at least one ball valve (further provided with two ball valves, one at each end of each branch) for switching to control the delivery of hydrogen-blended natural gas.

[0129] The fifth ball valve 24 and the second pipe test fixture section 25 are connected in series to form a branch, while the sixth ball valve 23 forms a separate branch. The branch of the fifth ball valve 24 and the branch of the sixth ball valve 23 are connected in parallel, that is, only one of the two branches is connected to transport hydrogen-blended natural gas. Furthermore, another ball valve is provided on the branch of the fifth ball valve 24, so that the two ball valves are located at both ends of the second pipe test fixture section 25.

[0130] The seventh ball valve 37 is connected in series with the third pipe test tooling section 29 to form a branch, the thirteenth ball valve 38 is connected in series with the third metering instrument test tooling section 30 to form a branch, the eighth ball valve 28 is a separate branch, and the branch of the seventh ball valve 37 is connected in parallel with the branch of the eighth ball valve 28, that is, only one of the two branches is selected to be connected to transport hydrogen-blended natural gas; further, another ball valve is provided on the branch of the fifth ball valve 24, so that the two ball valves are located at both ends of the second pipe test tooling section 25, and another ball valve is provided on the thirteenth ball valve, so that the two ball valves are located at both ends of the third metering instrument test tooling section 30.

[0131] In this embodiment, if Figure 1 As shown, the fourth valve body includes:

[0132] A ninth ball valve 13 is connected to the output end of the hydrogen blending machine 12;

[0133] a tenth ball valve 20 connected to the first pipe test fixture section 18;

[0134] an eleventh ball valve 31 connected to the ninth ball valve 13 and the tenth ball valve 20;

[0135] The ninth ball valve 13 is connected to the input end of the third ball valve 14 , the ninth ball valve 13 is arranged in parallel with the tenth ball valve 20 , and the eleventh ball valve 31 is connected to the output end of the fourth pressure regulating valve 32 .

[0136] Specifically, the ninth ball valve 13 and the eleventh ball valve 31 can be regarded as a branch, and the tenth ball valve 20 and the eleventh ball valve 31 can be regarded as a branch, so that the hydrogen-blended natural gas can pass through the tenth ball valve 20 and be output from the eleventh ball valve 31, or the hydrogen-blended natural gas can pass through the eleventh ball valve 31 and be output from the ninth ball valve 13 (to merge with the hydrogen-blended natural gas at the output end of the hydrogen blender 12).

[0137] In this embodiment, the third valve body further includes:

[0138] a twelfth ball valve 33 connected to the fourth pressure regulating valve 32;

[0139] a fifth pressure regulating valve 34 connected to the twelfth ball valve 33;

[0140] A second check valve 35 connected to the fifth pressure regulating valve 34;

[0141] The system further comprises:

[0142] The terminal gas appliance 36 is connected to the second check valve 35 .

[0143] In one implementation, separate medium- and low-pressure hydrogen doping experiments are performed. Specifically, for scenarios where only a low-flow medium- and low-pressure hydrogen doping experiment is required:

[0144] Close the ninth ball valve 13, the fourth ball valve 21, and the fourth pressure regulating valve 32, open the tenth ball valve 20 and the eleventh ball valve 31, and open the ball valves before and after one of the four branches in the first experimental pipe section according to experimental requirements;

[0145] The medium- and low-pressure natural gas (0.01-0.4 MPa) is filtered through the first filter 2, passes through the first ball valve 3, and is pressure-regulated by the first shut-off valve 4 and the first pressure-regulating valve 5 before being introduced into the hydrogen blender 12. The hydrogen is filtered through the second filter 7, passes through the second ball valve 8, and then passes through the second shut-off valve 9, the second pressure-regulating valve 10, and the first check valve 11 before being introduced into the hydrogen blender 12. The hydrogen-blended natural gas at the outlet of the hydrogen blender 12 passes through the third ball valve 14 and enters the first gas collecting column 15 (for collecting the hydrogen-blended natural gas). The hydrogen-blended natural gas at the outlet of the first gas collecting column 15 passes through one of the open medium- and low-pressure experimental pipe sections, and then passes through the tenth ball valve 20, the eleventh ball valve 31, and the twelfth ball valve 33 in sequence, and is pressure-regulated by the fifth pressure-regulating valve 34 before passing through the second check valve 35 and entering the terminal gas appliance 36.

[0146] In the second implementation, separate medium and low pressure hydrogen doping experiments are implemented. Specifically, for scenarios where only high flow medium and low pressure hydrogen doping experiments are required:

[0147] Close the tenth ball valve 20, the fifth ball valve 24, the seventh ball valve 37, and the thirteenth ball valve 38, open the ninth ball valve 13, the third ball valve 14, the sixth ball valve 23, the eighth ball valve 28, and the eleventh ball valve 31, and open the ball valves before and after the first valve test fixture section 16, the first metering instrument test fixture section 17, and the two first pipe test fixture sections 18;

[0148] The medium-low pressure natural gas (0.01-0.4MPa) is filtered through the first filter 2, passes through the first ball valve 3, and then is pressure-regulated by the first shut-off valve 4 and the first pressure regulating valve 5 before being introduced into the hydrogen blender 12. The hydrogen is filtered through the second filter 7, passes through the second ball valve 8, and then passes through the second shut-off valve 9, the second pressure regulating valve 10, and the first check valve 11 before being introduced into the hydrogen blender 12. The hydrogen-blended natural gas at the outlet of the hydrogen blender 12 passes through the third ball valve 14 and is introduced into the first gas collecting column 15. The hydrogen-blended natural gas at the outlet of the first gas collecting column 15 passes through the four branches of the medium-pressure experimental pipe section in parallel and is introduced into the compressor 22 through the tenth ball valve 20. After being pressurized, it reaches 4 MPa, it enters the third pressure regulating valve 26 through the sixth ball valve 23 and is adjusted to a medium high pressure of 1.6 MPa, and then enters the second gas collecting column 27. The hydrogen-blended natural gas at the outlet of the second gas collecting column 27 passes through the eighth ball valve 28 and enters the fourth pressure regulating valve 32, and is adjusted to a pressure slightly higher than that of the hydrogen-blended natural gas at the outlet of the hydrogen blender 12, so that a part of the hydrogen-blended natural gas passes through the eleventh ball valve 31 and the ninth ball valve 13 and circulates back to the input end of the first gas collecting column 15 to ensure that the hydrogen-blended natural gas in the experimental pipe section flows within the specified flow rate range; the other part of the hydrogen-blended natural gas passes through the twelfth ball valve 33, is pressure-regulated by the fifth pressure regulating valve 34, and then passes through the second check valve 35 and enters the terminal gas appliance 36.

[0149] In the third implementation method, medium- and low-pressure hydrogen doping experiments, high-pressure hydrogen doping experiments, and sub-high-pressure hydrogen doping experiments are realized. Specifically, for scenarios where only multi-level pressure hydrogen doping experiments are required:

[0150] Close the tenth ball valve 20, the sixth ball valve 23, and the eighth ball valve 28. Open the ninth ball valve 13, the third ball valve 14, the fourth ball valve 21, the eleventh ball valve 31, and the fourth pressure regulating valve 32. Open the ball valves before and after the medium-pressure, high-pressure, and sub-high-pressure test pipe sections.

[0151] The medium-low pressure natural gas (0.01-0.4MPa) is filtered through the first filter 2, passed through the first ball valve 3, and then pressure-regulated through the first shut-off valve 4 and the first pressure regulating valve 5, and then introduced into the hydrogen blender 12. The hydrogen is filtered through the second filter 7, passed through the second ball valve 8, and then passed through the second shut-off valve 9, the second pressure regulating valve 10, and the first check valve 11, and then introduced into the hydrogen blender 12. The hydrogen-blended natural gas at the outlet of the hydrogen blender 12 passes through the third ball valve 14 and then into the first gas collecting column 15. The hydrogen-blended natural gas at the outlet of the first gas collecting column 15 passes through the four branches of the medium-pressure experimental pipe section in parallel, and then passes into the compressor 22 through the third ball valve 14. After being pressurized to reach 4MPa, it passes into the high-pressure experimental pipe section through the fifth ball valve 24. The high-pressure experimental pipe section The outlet hydrogen-blended natural gas is pressure-regulated to 1.6 MPa by the third pressure-regulating valve 26 and then introduced into the second gas-collecting column 27. The hydrogen-blended natural gas at the outlet of the second gas-collecting column 27 passes through the sub-high-pressure test pipe section (the third pipe test tooling section 29 and the third metering instrument test tooling section 30) in parallel, and then is pressure-regulated by the fourth pressure-regulating valve 32 to a pressure slightly higher than that of the hydrogen-blended natural gas at the outlet of the hydrogen blender 12. As a result, a portion of the hydrogen-blended natural gas passes through the eleventh ball valve 31 and the ninth ball valve 13 and circulates back to the input end of the first gas-collecting column 15 to ensure that the hydrogen-blended natural gas in the test pipe section flows within the specified flow rate range; the other portion of the hydrogen-blended natural gas passes through the twelfth ball valve 33, is pressure-regulated by the fifth pressure-regulating valve 34, and then passes through the second check valve 35 before entering the terminal gas appliance 36.

[0152] Based on the above embodiment, the present invention also provides a control method for a multi-stage pressure natural gas pipeline hydrogen blending experimental system with medium and low pressure hydrogen blending, and the method is applied to the above multi-stage pressure natural gas pipeline hydrogen blending experimental system with medium and low pressure hydrogen blending, such as Figure 3 As shown, the method includes the following steps:

[0153] Step S100: Determine experimental pressure information and experimental flow information corresponding to the hydrogen doping experiment; the experimental pressure information is single-stage pressure or multi-stage pressure, and the experimental flow information is a first flow or a second flow.

[0154] Specifically, the hydrogen doping experiment of the present invention can be conducted not only under single-stage pressure (i.e., medium-low pressure) conditions, but also under multi-stage pressure conditions. Furthermore, the multi-stage pressure can be one of three conditions: a first multi-stage pressure, i.e., subsequent medium-low pressure hydrogen doping experiments and high-pressure hydrogen doping experiments; a second multi-stage pressure, i.e., subsequent medium-low pressure hydrogen doping experiments and sub-high pressure hydrogen doping experiments; or a third intermediate pressure, i.e., subsequent medium-low pressure hydrogen doping experiments, high pressure hydrogen doping experiments, and sub-high pressure hydrogen doping experiments.

[0155] The first flow rate includes low-flow transmission of hydrogen-blended natural gas, and the second flow rate includes high-flow transmission of hydrogen-blended natural gas (all four branches are open) and medium-flow transmission (multiple branches are open, and at least one branch is closed).

[0156] Step S200: Determine experimental scheme information corresponding to the hydrogen doping experiment according to the experimental pressure information and the experimental flow information.

[0157] Specifically, the experimental scheme information includes one of a first single-stage pressure experimental scheme, a second single-stage pressure experimental scheme, and a multi-stage pressure experimental scheme.

[0158] The step S200 specifically includes:

[0159] Step S220: If the experimental pressure information is a single-stage pressure and the experimental flow information is a first flow, determine that the experimental scheme information is the first single-stage pressure experimental scheme.

[0160] Step S220: If the experimental pressure information is a single-stage pressure and the experimental flow information is a second flow, determine that the experimental scheme information is the second single-stage pressure experimental scheme.

[0161] Step S230: If the experimental pressure information is multi-level pressure and the experimental flow information is the first flow or the second flow, determine that the experimental scheme information is the multi-level pressure experimental scheme.

[0162] In one implementation, the multi-stage pressure test scheme includes a first multi-stage scheme, a second multi-stage scheme, and a third multi-stage scheme.

[0163] The step S230 specifically includes:

[0164] If the multi-stage pressure is the first multi-stage pressure and the experimental flow rate information is the first flow rate or the second flow rate, the multi-stage pressure experimental scheme is determined to be the first multi-stage scheme (performing a low-pressure hydrogen doping experiment and a high-pressure hydrogen doping experiment); or

[0165] If the multi-stage pressure is the second multi-stage pressure and the experimental flow rate information is the first flow rate or the second flow rate, the multi-stage pressure experimental scheme is determined to be the second multi-stage scheme (performing a medium-low pressure hydrogen doping experiment and a sub-high pressure hydrogen doping experiment); or

[0166] If the multi-stage pressure is the third multi-stage pressure and the experimental flow information is the first flow or the second flow, the multi-stage pressure experimental scheme is determined to be the third multi-stage scheme (conducting medium and low pressure hydrogen mixing experiments, high pressure hydrogen mixing experiments and sub-high pressure hydrogen mixing experiments).

[0167] Step S300: Control the first valve body to deliver natural gas and the second valve body to deliver hydrogen, to obtain hydrogen-blended natural gas output by the hydrogen blender; wherein the natural gas delivered by the first valve body and the hydrogen delivered by the second valve body are both within a first pressure threshold range, and the hydrogen-blended natural gas output by the hydrogen blender is within the first pressure threshold range.

[0168] Specifically, the control is performed by controlling the first valve body, the second valve body, the third valve body and the fourth valve body, and the ball valve, the pressure regulating valve, the compressor and the like are further started to perform adjustment.

[0169] Step S400: According to the experimental scheme information, control the third valve body to transport the hydrogen-blended natural gas output by the hydrogen blender to the first experimental pipe section for experiment, thereby obtaining the hydrogen-blended natural gas after the experiment; wherein the hydrogen-blended natural gas after the experiment is within the first gas pressure threshold range.

[0170] Specifically, the experimental scheme information is the third multi-stage scheme of the multi-stage pressure experimental scheme, and performs medium and low pressure hydrogen doping experiments, high pressure hydrogen doping experiments, and sub-high pressure hydrogen doping experiments.

[0171] The step S400 specifically includes:

[0172] Step S410: According to the multi-stage pressure test plan, control the third valve body to transport the hydrogen-blended natural gas output by the hydrogen blender to the first test pipe section for testing, thereby obtaining a first hydrogen-blended natural gas;

[0173] Step S420: Control the compressor to pressurize the first hydrogen-blended natural gas to within a second pressure threshold range to obtain a second hydrogen-blended natural gas;

[0174] Step S430: Control the third valve body to transport the second hydrogen-blended natural gas to the second experimental pipe section for testing, and control the third valve body to regulate the pressure of the second hydrogen-blended natural gas to obtain the hydrogen-blended natural gas after the test.

[0175] The control method of the multi-stage pressure natural gas pipeline hydrogen blending experimental system with medium and low pressure hydrogen blending provided by the present invention is applied to the above-mentioned multi-stage pressure natural gas pipeline hydrogen blending experimental system with medium and low pressure hydrogen blending, thereby having all the beneficial effects of the above-mentioned multi-stage pressure natural gas pipeline hydrogen blending experimental system with medium and low pressure hydrogen blending, which will not be repeated here.

[0176] In summary, the present invention provides a multi-stage pressure natural gas pipeline hydrogen blending experimental system for medium and low pressure hydrogen blending. The present invention can complete the hydrogen blending process under medium and low pressure conditions, thereby avoiding the processing and construction difficulties brought about by hydrogen blending under high pressure conditions. Subsequently, through pressurization and pressure regulation, experiments under multi-stage pressure conditions can be realized to obtain hydrogen-blended natural gas under different pressure conditions, which is convenient for carrying out hydrogen blending experiments under different pressure conditions, thereby improving experimental efficiency.

[0177] It should be understood that the application of the present invention is not limited to the above examples. For those skilled in the art, improvements or changes can be made based on the above description. All these improvements and changes should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A multi-stage pressure natural gas pipeline hydrogen blending experimental system for medium and low pressure hydrogen blending, characterized in that: include: A hydrogen blender, used to mix the input natural gas and hydrogen and output the hydrogen-blended natural gas; A first valve body is connected to the input end of the hydrogen blender and is used to deliver natural gas within a first pressure threshold to the hydrogen blender; The second valve body is connected to the input end of the hydrogen blending machine and is used to deliver hydrogen to the hydrogen blending machine; A first experimental pipe section is connected to the output end of the hydrogen blender and is used to perform experiments within a first pressure threshold range; a compressor connected to the first experimental pipe section, and configured to pressurize the hydrogen-blended natural gas to a second pressure threshold range; a second experimental pipe section, connected to the compressor, for conducting experiments within a second air pressure threshold range; A third valve body is connected to the output end of the hydrogen blender, the first experimental pipe section, and the second experimental pipe section, respectively, for transporting hydrogen-blended natural gas; a fourth valve body, connected to the first experimental pipe section and the third valve body, respectively, for conveying hydrogen-blended natural gas within a first pressure threshold range; The second air pressure threshold is greater than the first air pressure threshold.

2. The multi-stage pressure natural gas pipeline hydrogen blending experimental system for medium and low pressure hydrogen blending according to claim 1 is characterized in that: The system further comprises: a third experimental pipe section, connected to the second experimental pipe section, for conducting experiments within a third air pressure threshold range; The third air pressure threshold is greater than the first air pressure threshold, and the second air pressure threshold is greater than the third air pressure threshold.

3. The multi-stage pressure natural gas pipeline hydrogen blending experimental system for medium and low pressure hydrogen blending according to claim 2 is characterized in that: The first experimental section includes: a first gas collecting column, connected to the hydrogen blender, for storing hydrogen-blended natural gas within a first pressure threshold range; a first pipe experimental tooling section connected to the first gas collecting column; The second experimental section includes: A second pipe test fixture section connected to the compressor; The third experimental section includes: a second gas collecting column, connected to the second experimental pipe section, for storing hydrogen-blended natural gas; A third pipe test fixture section is connected to the second gas collecting column; The hydrogen-blended natural gas may sequentially pass through the first gas collection column, the first pipe test tooling section, the compressor, the second pipe test tooling section, the second gas collection column, and the third pipe test tooling section.

4. The multi-stage pressure natural gas pipeline hydrogen blending experimental system for medium and low pressure hydrogen blending according to claim 3 is characterized in that: The first valve body includes a first ball valve, a first shut-off valve and a first pressure regulating valve connected in sequence, and the second valve body includes a second ball valve, a second shut-off valve, a second pressure regulating valve and a first check valve connected in sequence; The first pressure regulating valve is connected to the input end of the hydrogen blending machine, and the first check valve is connected to the input end of the hydrogen blending machine.

5. The multi-stage pressure natural gas pipeline hydrogen blending experimental system for medium and low pressure hydrogen blending according to claim 3 is characterized in that: The third valve body comprises: a third ball valve, both ends of which are connected to the output end of the hydrogen blender and the first gas collecting column respectively; a fourth ball valve, both ends of which are connected to the first pipe test fixture section and the compressor respectively; a third pressure regulating valve connected to the second gas collecting column; a fifth ball valve, both ends of which are connected to the compressor and the second pipe test fixture section respectively; a sixth ball valve, two ends of which are respectively connected to the compressor and the third pressure regulating valve; a fourth pressure regulating valve connected to the third pipe test fixture section; a seventh ball valve, both ends of which are connected to the second gas collecting column and the third pipe test fixture section respectively; an eighth ball valve, two ends of which are respectively connected to the second gas collecting column and the fourth pressure regulating valve; Wherein, the fifth ball valve and the sixth ball valve are arranged in parallel, and the seventh ball valve and the eighth ball valve are arranged in parallel.

6. The multi-stage pressure natural gas pipeline hydrogen blending experimental system for medium and low pressure hydrogen blending according to claim 5 is characterized in that: The fourth valve body comprises: a ninth ball valve connected to the output end of the hydrogen blending machine; a tenth ball valve connected to the first pipe test fixture section; an eleventh ball valve connected to the ninth ball valve and the tenth ball valve; The ninth ball valve is connected to the third ball valve, the ninth ball valve is arranged in parallel with the tenth ball valve, and the eleventh ball valve is connected to the fourth pressure regulating valve.

7. The multi-stage pressure natural gas pipeline hydrogen blending experimental system for medium and low pressure hydrogen blending according to claim 5 is characterized in that: The third valve body further includes: a twelfth ball valve connected to the fourth pressure regulating valve; a fifth pressure regulating valve connected to the twelfth ball valve; a second check valve connected to the fifth pressure regulating valve; The system further comprises: The terminal gas appliance is connected to the second check valve.

8. A control method for a multi-stage pressure natural gas pipeline hydrogen blending experimental system with medium and low pressure hydrogen blending according to any one of claims 1 to 7, characterized in that: The method comprises: Determine experimental pressure information and experimental flow information corresponding to the hydrogen doping experiment; the experimental pressure information is single-stage pressure or multi-stage pressure, and the experimental flow information is a first flow or a second flow; Determining experimental scheme information corresponding to the hydrogen doping experiment according to the experimental pressure information and the experimental flow information; Controlling the first valve body to deliver natural gas and the second valve body to deliver hydrogen, thereby obtaining hydrogen-blended natural gas output by the hydrogen blender; wherein the natural gas delivered by the first valve body and the hydrogen delivered by the second valve body are both within a first pressure threshold range, and the hydrogen-blended natural gas output by the hydrogen blender is within the first pressure threshold range; According to the experimental scheme information, the third valve body is controlled to transport the hydrogen-blended natural gas output by the hydrogen blender to the first experimental pipe section for experiment, thereby obtaining the hydrogen-blended natural gas after the experiment; wherein the hydrogen-blended natural gas after the experiment is within the first gas pressure threshold range.

9. The control method of the multi-stage pressure natural gas pipeline hydrogen blending experimental system for medium and low pressure hydrogen blending according to claim 8 is characterized in that: The experimental scheme information includes one of a first single-stage pressure experimental scheme, a second single-stage pressure experimental scheme, and a multi-stage pressure experimental scheme; Determining experimental scheme information corresponding to the hydrogen doping experiment based on the experimental pressure information and the experimental flow information includes: If the experimental pressure information is a single-stage pressure and the experimental flow information is a first flow, determining that the experimental scheme information is the first single-stage pressure experimental scheme; or If the experimental pressure information is a single-stage pressure and the experimental flow information is a second flow, determining that the experimental scheme information is the second single-stage pressure experimental scheme; or If the experimental pressure information is multi-level pressure, and the experimental flow information is the first flow or the second flow, the experimental scheme information is determined to be the multi-level pressure experimental scheme.

10. The control method of the multi-stage pressure natural gas pipeline hydrogen blending experimental system for medium and low pressure hydrogen blending according to claim 9 is characterized in that: The method of transporting the hydrogen-blended natural gas outputted by the hydrogen blender to the first experimental pipe section according to the experimental plan information to obtain the hydrogen-blended natural gas after the experiment includes: According to the multi-stage pressure test scheme, the third valve body is controlled to transport the hydrogen-blended natural gas output by the hydrogen blender to the first test pipe section for testing, thereby obtaining the first hydrogen-blended natural gas; controlling a compressor to pressurize the first hydrogen-blended natural gas to a second pressure threshold range to obtain a second hydrogen-blended natural gas; The third valve body is controlled to transport the second hydrogen-blended natural gas to the second experimental pipe section for experiment, and the third valve body is controlled to regulate the pressure of the second hydrogen-blended natural gas to obtain the hydrogen-blended natural gas after the experiment.

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