A method and system of high-stability hydrogen storage and transportation technology

Abstract

This disclosure relates to a method and system for high-stability hydrogen storage and transportation technology. The system includes a hydrogen storage main line, a hydrogen storage unit, a hydrogen export compressor, and the hydrogen export main line connected sequentially. The hydrogen buffer branch line has a first operating state and a second operating state that can be switched between each other. In the first operating state, the hydrogen buffer branch line is not connected to the hydrogen storage main line, and the outlet of the hydrogen storage unit is connected to the hydrogen inlet of the hydrogen export compressor via the hydrogen storage main line, allowing hydrogen to directly enter the hydrogen export compressor from the hydrogen storage main line. In the second operating state, the outlet of the hydrogen storage unit is connected to the hydrogen inlet of the hydrogen export compressor via the hydrogen buffer branch line. Using the system of this disclosure, the unstable characteristics of the hydrogen production process can be balanced, system energy consumption can be reduced, equipment utilization can be improved, and equipment safety can be enhanced.

Description

Technical Field

[0001] This disclosure relates to the field of hydrogen energy storage and transportation technology, specifically to a method and system for a highly stable hydrogen storage and transportation technology. Background Technology

[0002] Hydrogen energy, as an ideal ultimate clean energy source, has significant advantages as a green energy source with abundant reserves, wide availability, and high energy density, and has therefore attracted widespread attention. Currently, the process of producing hydrogen through water electrolysis using wind and solar power, and using hydrogen to "store" wind and solar energy, is an important way to utilize new energy. Hydrogen can not only serve as a carrier for energy storage, but is also an important raw material in the petrochemical and steel metallurgical fields. This method can replace part of the production capacity of hydrogen from fossil fuels (especially coal chemical industry), and also reduce the direct emission of pollutants such as CO2 by reacting carbon elements of carbon monoxide in coal chemical production, which is of great significance for protecting the natural and ecological environment.

[0003] Currently, hydrogen production from new energy sources mainly refers to using wind and solar power to generate electricity, which is then used to electrolyze water to produce hydrogen. Due to the unstable nature of wind and solar energy resources, hydrogen production fluctuates significantly at different times during the power generation process. Typically, downstream hydrogen users have relatively stable demand, which places high technical demands on hydrogen storage and transportation. Achieving a balance between upstream and downstream processes is crucial. For hydrogen storage and transportation systems, the impact of fluctuations in hydrogen production at different times increases as the scale of hydrogen production facilities expands. Currently, it remains necessary to address the instability of hydrogen produced from new energy hydrogen production facilities during storage, transportation, and external transmission, as well as the difficulties in long-distance transportation. Summary of the Invention

[0004] The purpose of this disclosure is to provide a system and method for hydrogen storage and transportation technology, with the aim of addressing the challenges of balancing the instability of produced hydrogen with the difficulties of long-distance hydrogen transportation.

[0005] To achieve the above objectives, the first aspect of this disclosure provides a system for high-stability hydrogen storage and transportation technology. This system includes a hydrogen storage main line, a hydrogen storage unit, a hydrogen export compressor, and a hydrogen export main line connected sequentially. The hydrogen inlet of the hydrogen storage main line is connected to the hydrogen outlet of a hydrogen production device. The high-pressure hydrogen outlet of the hydrogen export main line is connected to a terminal hydrogen-using device. A hydrogen buffer branch line is also connected in parallel on the hydrogen storage main line between the outlet of the hydrogen storage unit and the hydrogen inlet of the hydrogen export compressor. A buffer pressurization tank is provided on the hydrogen buffer branch line. The hydrogen buffer branch line has a first operating state and a second operating state that can be switched between each other. In the first operating state, the hydrogen buffer branch line is not connected to the hydrogen storage main line, and the outlet of the hydrogen storage unit and the hydrogen inlet of the hydrogen export compressor are connected through the hydrogen storage main line. In the second operating state, the outlet of the hydrogen storage unit and the hydrogen inlet of the hydrogen export compressor are connected through the hydrogen buffer branch line.

[0006] Optionally, the hydrogen storage unit includes a first pressure control device and one or more hydrogen storage tanks.

[0007] Optionally, the system further includes an intermediate booster station located on the main hydrogen export line; the intermediate booster station includes a first pressure control device and a hydrogen compressor; the first pressure control device is located at the outlet of the hydrogen compressor; the number of hydrogen compressors is one or more, and the multiple hydrogen compressors are connected in parallel.

[0008] Optionally, the system further includes a terminal pressurization unit disposed on the main hydrogen export line; the terminal pressurization unit includes a second pressure control device, a terminal pressurization branch line, and a hydrogen compressor; the hydrogen compressor is disposed on the terminal pressurization branch line; the terminal pressurization branch line has an in-line state and an out-of-line state that can be switched between each other by the second pressure control device; in the out-of-line state, the terminal pressurization branch line is not connected to the main hydrogen export line, and the hydrogen outlet of the hydrogen export compressor is connected to the terminal hydrogen-using device through the main hydrogen export line; in the in-line state, the terminal pressurization branch line is connected to the main hydrogen export line, and the hydrogen outlet of the hydrogen export compressor is connected to the terminal hydrogen-using device through the terminal pressurization branch line.

[0009] The second aspect of this disclosure employs a method for hydrogen storage and transportation using the system described in the first aspect of this disclosure. The method includes: feeding hydrogen produced by a hydrogen production unit into the system via the hydrogen inlet, sequentially passing through the hydrogen storage unit, the hydrogen export compressor, and the hydrogen export main line, and then entering the terminal hydrogen device via the high-pressure hydrogen outlet; wherein, when the pressure of the hydrogen from the hydrogen production unit is greater than an upper pressure threshold, the system is in a first operating state; when the pressure of the hydrogen from the hydrogen production unit is less than a lower pressure threshold, the system is in a second operating state; the upper pressure threshold is 1.2 MPa to 1.4 MPa, and the lower pressure threshold is 1.2 MPa to 1.4 MPa.

[0010] Optionally, the method further includes: when the length of the hydrogen export main line is above a second threshold, the system is in a long-distance transmission state; when the length of the hydrogen export main line is below the second threshold, the system is in a short-distance transmission state; the second threshold is 100-200 km.

[0011] Optionally, in the long-distance transportation state, the inlet hydrogen pressure of the hydrogen export compressor is 1.2 to 1.4 MPa, and the outlet hydrogen pressure is 2.5 to 10 MPa; in the short-distance transportation state, the inlet hydrogen pressure of the hydrogen export compressor is 1.2 to 1.4 MPa, and the outlet hydrogen pressure is 2.5 to 10 MPa.

[0012] Optionally, in the long-distance transportation mode, an intermediate booster station is set on the main hydrogen export line; the outlet hydrogen pressure of the intermediate booster station is 2.5 to 10 MPa; preferably, on the main hydrogen export line, one intermediate booster station is set at a distance of the second threshold.

[0013] Optionally, in the long-distance transportation state, a terminal pressurization unit is provided on the main hydrogen export line, and the outlet hydrogen pressure of the terminal pressurization unit is 2.5 to 10 MPa; when the hydrogen pressure entering the terminal pressurization unit is greater than a third threshold, the terminal pressurization branch of the terminal pressurization unit is in a cut-out state; when the hydrogen pressure entering the terminal pressurization unit is less than the third threshold, the terminal pressurization branch of the terminal pressurization unit is in a cut-in state; the ratio of the third threshold to the outlet hydrogen pressure of the terminal hydrogen device is (1 to 1.1):1.

[0014] Optionally, the hydrogen storage unit includes multiple hydrogen storage tanks; when the pressure of the hydrogen from the hydrogen production device is greater than the upper pressure threshold, the hydrogen storage unit is in a storage state; when the pressure of the hydrogen from the hydrogen production device is less than the lower pressure threshold, the hydrogen storage unit is in a release state; in the storage state, hydrogen storage is performed sequentially according to the hydrogen storage tank pressure from high to low; when the pressure of the hydrogen storage tank undergoing the hydrogen storage process reaches a fourth threshold, the process switches to another hydrogen storage tank, the fourth threshold being 1.35–1.4 MPa; in the release state, hydrogen is released sequentially according to the hydrogen storage tank pressure from low to high; when the pressure of the hydrogen release tank undergoing the hydrogen release process reaches a fourth threshold, the process switches to another hydrogen storage tank, the fifth threshold being 0.2–0.3 MPa.

[0015] Through the above technical solution, this disclosure adopts a storage system that is highly matched with the hydrogen production device, and by flexibly controlling the working status of the main hydrogen storage line and the hydrogen buffer branch line, it is possible to balance the unstable characteristics of the hydrogen production process before hydrogen transportation; at the same time, the setting of the hydrogen buffer branch line on the main hydrogen storage line can reduce the system's energy consumption, improve equipment utilization and equipment safety.

[0016] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0017] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings:

[0018] Figure 1 This is a process flow diagram of a long-distance, highly stable hydrogen storage and transportation technology.

[0019] Figure 2 This is a process flow diagram of a short-distance, high-stability hydrogen storage and transportation technology.

[0020] Explanation of reference numerals in the attached figures

[0021] 1. Hydrogen production unit; 2. Hydrogen storage unit; 3. First pressure control device; 4. Second instrument control valve; 5. Hydrogen compressor; 6. First instrument control valve; 7. Buffer pressurization tank; 8. Hydrogen export compressor; 9. Intermediate pressurization station; 10. Hydrogen compressor; 11. Hydrogen compressor; 12. First pressure control device; 13. Pressure control valve; 14. Second pressure control device; 15. Third instrument control valve; 16. Fourth instrument control valve; 17. Hydrogen compressor; 18. Hydrogen compressor; 19. Second pressure control device; 20. Pressure regulating valve; 21. Terminal pressurization unit; 22. Terminal hydrogen supply unit. Detailed Implementation

[0022] The specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.

[0023] In this disclosure, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in its normal operating state. "Inner" and "outer" refer to the outline of the device itself; furthermore, the terms "first," "second," "third," "fourth," and "fifth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first," "second," "third," "fourth," or "fifth" may explicitly or implicitly include one or more of that feature. In the description of this disclosure, "a plurality of" means two or more, unless otherwise explicitly specified.

[0024] This disclosure provides a system for high-stability hydrogen storage and transportation technology. The system includes a hydrogen storage main line, a hydrogen storage unit 2, a hydrogen export compressor 8, and a hydrogen export main line connected sequentially. The hydrogen inlet of the hydrogen storage main line is connected to the hydrogen outlet of a hydrogen production unit 1, allowing hydrogen produced by the hydrogen production unit 1 to enter the hydrogen storage main line. The high-pressure hydrogen outlet of the hydrogen export main line is connected to a terminal hydrogen consumption unit 22, allowing hydrogen transported using this system to enter the terminal hydrogen consumption unit 22. The hydrogen storage main line is connected between the outlet of the hydrogen storage unit 2 and the hydrogen inlet of the hydrogen export compressor 8. A hydrogen buffer branch line is also connected in parallel; a buffer pressurization tank 7 is provided on the hydrogen buffer branch line; the hydrogen buffer branch line has a first working state and a second working state that can be switched between each other; in the first working state, the hydrogen buffer branch line is not connected to the hydrogen storage main line, and the outlet of the hydrogen storage unit 2 is connected to the hydrogen inlet of the hydrogen export compressor 8 through the hydrogen storage main line, so that hydrogen can directly enter the hydrogen export compressor 8 from the hydrogen storage main line; in the second working state, the outlet of the hydrogen storage unit 2 is connected to the hydrogen inlet of the hydrogen export compressor 8 through the hydrogen buffer branch line.

[0025] Through the above technical solution, this disclosure adopts a storage system that is highly matched with the hydrogen production device 1, and by flexibly controlling the working status of the main hydrogen storage line and the hydrogen buffer branch line, it is possible to balance the unstable characteristics of the hydrogen production process before hydrogen transportation; at the same time, the setting of the hydrogen buffer branch line on the main hydrogen storage line can reduce the system's energy consumption, improve equipment utilization and equipment safety.

[0026] In one embodiment, the hydrogen storage unit 2 includes a first pressure control device 3, and one or more hydrogen storage tanks.

[0027] When the hydrogen storage unit 2 of this disclosure includes multiple hydrogen storage tanks, the multiple hydrogen storage tanks are connected in parallel and / or in series. In a specific embodiment of this disclosure, the multiple hydrogen storage tanks are connected in a combination of series and parallel connections.

[0028] In the above embodiments, the first pressure control device 3 in the hydrogen storage unit 2 is a conventional choice in the art and is not specifically required in this application. For example, in one embodiment of this disclosure, the first pressure control device 3 is a pressure transmitter. In addition, the first pressure control device 3 is installed at a suitable location in each hydrogen storage tank. The type of hydrogen storage tank in the hydrogen storage unit 2 is a conventional choice in the art and is not specifically required in this application. For example, the type of hydrogen storage tank is an underground gas well, a pressure storage tank, etc.

[0029] In one embodiment, a first instrument control valve 6 is also provided on the main hydrogen storage line between the outlet of the hydrogen storage unit 2 and the hydrogen inlet of the hydrogen export compressor 8; a second instrument control valve 4, a hydrogen compressor 5, and a buffer pressurization tank 7 are sequentially provided on the hydrogen buffer branch line along the hydrogen flow direction. When the hydrogen buffer branch line is in the first working state, the second instrument control valve 4 is closed and the first instrument control valve 6 is open, so that the hydrogen generated from the outlet of the hydrogen storage unit 2 enters the inlet of the hydrogen export compressor 8 through the main hydrogen storage line; when the hydrogen buffer branch line is in the second working state, the second instrument control valve 4 is open and the first instrument control valve 6 is closed, so that the hydrogen generated from the outlet of the hydrogen storage unit 2 is pressurized by the hydrogen compressor 5 on the hydrogen buffer branch line and then enters the inlet of the hydrogen export compressor 8.

[0030] In one embodiment, when the distance for transporting hydrogen is long, one or more intermediate booster stations 9 and terminal booster units 21 are provided on the main hydrogen export line; when the distance for transporting hydrogen is short, intermediate booster stations 9 and terminal booster units 21 are not provided on the main hydrogen export line.

[0031] In one embodiment, the intermediate booster station 9 includes a first pressure control device 12 and a hydrogen compressor; the first pressure control device 12 is located at the outlet of the hydrogen compressor; the number of hydrogen compressors is one or more, and the multiple hydrogen compressors are connected in parallel. For example, in a specific embodiment of this disclosure, the intermediate booster station 9 has two booster units, namely a hydrogen compressor 10 and a hydrogen compressor 11.

[0032] In one embodiment, the terminal pressurization unit 21 includes a second pressure control device 14, a terminal pressurization branch line, and two hydrogen compressors; wherein the two hydrogen compressors are hydrogen compressor 17 and hydrogen compressor 18; the hydrogen compressors are disposed on the terminal pressurization branch line; the terminal pressurization branch line has an in-line state and an out-of-line state that can be switched between each other by the second pressure control device 14; in the out-of-line state, the terminal pressurization branch line is not connected to the main hydrogen export line, and the hydrogen outlet of the hydrogen export compressor 8 is connected to the terminal hydrogen device 22 through the main hydrogen export line, so that hydrogen can directly enter the terminal hydrogen device 22 through the main hydrogen export line; in the in-line state, the terminal pressurization branch line is connected to the main hydrogen export line, and the hydrogen outlet of the hydrogen export compressor 8 is connected to the terminal hydrogen device 22 through the terminal pressurization branch line, so that hydrogen can be pressurized by the terminal pressurization branch line and then enter the terminal hydrogen device 22.

[0033] In this embodiment, the second pressure control device further includes a second pressure control device 19; a third instrument control switch valve 15 and a fourth instrument control switch valve 16; when the terminal booster branch line is in the disconnected state, the fourth instrument control switch valve 16 and the pressure regulating valve 20 are closed, and the third instrument control switch valve 15 is open, so that hydrogen can directly enter the terminal hydrogen unit 22 through the hydrogen export main line; when the terminal booster branch line is in the connected state, the third instrument control switch valve 15 is closed, and the fourth instrument control valve 16 and the pressure regulating valve 20 are open, so that hydrogen can be boosted through the terminal booster branch line and then enter the terminal hydrogen unit 22.

[0034] The second aspect of this disclosure employs a method for hydrogen storage and transportation using the system described in the first aspect of this disclosure. The method includes: feeding hydrogen produced by a hydrogen production unit 1 into the system via the hydrogen inlet, sequentially passing through the hydrogen storage unit 2, the hydrogen export compressor 8, and the hydrogen export main line, and then entering the terminal hydrogen device 22 via the high-pressure hydrogen outlet; wherein, when the pressure of the hydrogen from the hydrogen production unit 1 is greater than an upper pressure threshold, the system is in a first operating state; when the pressure of the hydrogen from the hydrogen production unit 1 is less than a lower pressure threshold, the system is in a second operating state; the upper pressure threshold is 1.2–1.4 MPa, preferably 1.35–1.4 MPa, and the lower pressure threshold is 1.2–1.4 MPa, preferably 1.30 MPa–1.35 MPa. The upper and lower pressure thresholds may be the same or different, and the lower pressure threshold is lower than the upper pressure threshold. When the upper pressure threshold and the lower pressure threshold are the same, the upper pressure threshold and the lower pressure threshold are used as the first threshold.

[0035] In one embodiment, the hydrogen storage unit 2 includes one or more hydrogen storage tanks.

[0036] In one embodiment, when the pressure of hydrogen from the hydrogen production device 1 is greater than the upper pressure threshold, the hydrogen storage unit 2 is in a gas storage state; when the pressure of hydrogen from the hydrogen production device 1 is less than the lower pressure threshold, the hydrogen storage unit 2 is in a release state.

[0037] In one embodiment, during the storage state, hydrogen storage is performed sequentially according to the hydrogen storage tank pressure from high to low. When the pressure of the hydrogen storage tank undergoing the storage process reaches a fourth threshold, the process switches to another hydrogen storage tank. The fourth threshold is 1.35–1.4 MPa. During the release state, hydrogen release is performed sequentially according to the hydrogen storage tank pressure from low to high. When the pressure of the hydrogen release tank undergoing the release process reaches a fifth threshold, the process switches to another hydrogen storage tank. The fifth threshold is 0.2–0.3 MPa.

[0038] In one specific embodiment, under the gas storage state, excess hydrogen gas preferentially enters the storage tank with a pressure higher than 1.05 MPa through the pressure control system. When the operating pressure of the storage tank reaches 1.4 MPa, the inlet valve of that storage tank is closed. If the hydrogen production capacity is still excessive at this time, the inlet valve of the storage tank with a pressure lower than 1.05 MPa but higher than other storage tanks is opened. When the pressure of that storage tank reaches 1.4 MPa, the inlet valve of that storage tank is closed, and so on, always selecting the storage tank with the higher pressure to complete the hydrogen filling.

[0039] In the release state, the hydrogen outlet valve of the storage tank with a pressure lower than 0.4 MPa is opened through the pressure control system. When the operating pressure of the storage tank reaches 0.2 MPa, the outlet valve of that storage tank is closed. If the hydrogen production capacity is still insufficient at this time, the outlet valve of the storage tank with a pressure higher than 0.4 MPa but lower than other storage tanks is opened. When the pressure of that storage tank reaches 0.2 MPa, the outlet valve of that storage tank is closed. This process is repeated, and the storage tank with the lowest pressure is always selected to complete the hydrogen release.

[0040] By controlling the connection status of the hydrogen buffer branch through the above method, it is possible to select whether to increase the pressure based on the hydrogen pressure at the outlet of the hydrogen storage unit 2. This ensures that all adjustments (flow rate and pressure) are completed downstream of the hydrogen storage unit 2 and upstream of the hydrogen export compressor 8. It also ensures the relative stability of the inlet operating pressure of the hydrogen export compressor 8, thereby further balancing the instability of the hydrogen produced by the hydrogen production unit 1. Furthermore, it is applicable to both long-distance and short-distance hydrogen transportation. Long-distance transportation refers to a hydrogen transportation distance above the second threshold, while short-distance transportation refers to a hydrogen transportation distance below the second threshold.

[0041] In one embodiment, the method further includes: when the length of the hydrogen export main line is above a second threshold, the system is in a long-distance transmission state; when the length of the hydrogen export main line is below the second threshold, the system is in a short-distance transmission state; the second threshold is 100-200km, preferably 120-170km.

[0042] In one embodiment, in the long-distance transportation state, the inlet hydrogen pressure of the hydrogen export compressor 8 is 1.2–1.4 MPa, preferably 1.3–1.4 MPa; the outlet hydrogen pressure is 2.5–10 MPa, preferably 3–6 MPa. When the pressure of the hydrogen from the hydrogen production device 1 is less than the pressure threshold, in the short-distance transportation state, the inlet hydrogen pressure of the hydrogen export compressor 8 is 1.2–1.4 MPa, preferably 1.3–1.4 MPa; the outlet hydrogen pressure is 2.5–10 MPa, preferably 3–6 MPa.

[0043] For long-distance hydrogen transportation, the hydrogen pressure gradually decreases during long-distance transportation after being compressed by the external compressor, with a pressure decrease rate of 0.001 to 0.01 MPa per kilometer. To ensure the hydrogen transportation capacity, an intermediate booster station 9 needs to be set up on the main hydrogen transportation line. In one embodiment of this disclosure, when the length of the main hydrogen transportation line is above a second threshold, an intermediate booster station 9 is set up on the main hydrogen transportation line. The outlet hydrogen pressure of the intermediate booster station 9 is 2.5 to 10 MPa, preferably 3 to 6 MPa.

[0044] In a preferred embodiment, an intermediate booster station 9 is set at intervals of the second threshold along the main hydrogen export line. In this embodiment, by setting an intermediate booster station 9 at certain intervals, it can be ensured that the hydrogen pressure exiting from the last intermediate booster station 9 is always within a high pressure range.

[0045] During long-distance hydrogen transportation, the hydrogen pressurized by the intermediate booster station 9 is transported to downstream users via the main hydrogen export line. During this process, the hydrogen pressure may decrease. To further ensure the stability of the hydrogen pressure received by downstream users, a terminal booster unit 21 needs to be installed on the main hydrogen export line before the downstream users. Specifically, the terminal booster unit 21 is located between the intermediate booster station 9 and the downstream users. In one embodiment of this disclosure, when the length of the main hydrogen export line is greater than or equal to the second threshold, a terminal booster unit 21 is installed on the main hydrogen export line. The terminal booster unit 21 is located between the intermediate booster station 9 and the terminal hydrogen device 22. The outlet hydrogen pressure of the terminal booster unit 21 is 2.5–10 MPa, preferably 3–6 MPa.

[0046] In one embodiment, when the hydrogen pressure entering the terminal pressurization unit 21 is greater than a third threshold, the terminal pressurization branch of the terminal pressurization unit is in a cut-out state; when the hydrogen pressure entering the terminal pressurization unit 21 is less than the third threshold, the terminal pressurization branch of the terminal pressurization unit is in a cut-in state; the ratio of the third threshold to the hydrogen demand pressure of the terminal hydrogen device 22 is (1~1.1):1.

[0047] In this embodiment, based on the downstream hydrogen users' standards for hydrogen pressure, a reasonable range of the third threshold is set. If the hydrogen pressure entering the terminal pressurization unit 21 is above the third threshold, no pressurization is required. If the hydrogen pressure entering the terminal pressurization unit 21 is below the third threshold, the hydrogen needs to be introduced into the terminal pressurization branch line for pressurization before being transported downstream. This method further reduces the difficulty of long-distance hydrogen transportation.

[0048] In one implementation, such as Figure 1 As shown, the methods for long-distance, highly stable hydrogen storage and transportation technology include:

[0049] Hydrogen produced by hydrogen production unit 1 is fed into hydrogen storage unit 2 through hydrogen inlet and stored in storage tank. When the pressure of hydrogen from hydrogen production unit 1 is greater than 1.2 MPa, the second instrument control switch valve 4 is closed and the first instrument control switch valve 6 is opened. Hydrogen directly enters the inlet of hydrogen export compressor 8 through pipeline at a pressure of 1.2-1.4 MPa. After being pressurized to 2.5-10 MPa by hydrogen export compressor 8, it is sent to the main hydrogen export line. After being transported for 100-200 km through the main hydrogen export line, hydrogen enters intermediate booster station 9, where a pressure control valve 13 is installed at the outlet to control the compressor outlet pressure at 2.5-10 MPa. Hydrogen continues to be transported under pressure through pipeline for 100-200 km to reach terminal booster unit 21. At this time, hydrogen is directly sent to downstream terminal hydrogen use unit 22 at a pressure of 1.25-5 MPa through terminal booster unit 21. When the pressure of hydrogen from the hydrogen production unit 1 is less than 1.2 MPa, the second instrument control switch valve 4 opens and the first instrument control switch valve 6 closes. Hydrogen enters the inlet of the hydrogen compressor 5 at a pressure of 0.2 MPa to 1.35 MPa. After being compressed and cooled by the compressor, it is pressurized to 1.2 to 1.4 MPa and then enters the hydrogen buffer tank 7. It is then sent to the hydrogen export compressor 8 for export pressurization and then sent to the main hydrogen export line. After being transported for 100 to 200 km on the main hydrogen export line, the hydrogen enters the intermediate booster station 9. The pressure control valve 13 controls the compressor outlet pressure to be 2.5 to 10 MPa. The hydrogen continues to be transported under pressure for 100 to 200 km through the pipeline and reaches the terminal booster unit 21. At this time, the hydrogen is directly sent to the downstream terminal hydrogen use unit 22 at a pressure of 1.25 to 5 MPa through the terminal booster unit 21.

[0050] For short-distance hydrogen transportation solutions, the transportation distance is short and the transportation rate is fast, eliminating the need for a pressurization device on the main hydrogen export line. Therefore, to ensure the stability of the downstream terminal hydrogen unit 22, the hydrogen storage capacity of the hydrogen storage unit 2 needs to be increased to complete the hydrogen pressure balancing operation before the hydrogen export compressor 8. In one embodiment of this disclosure, the hydrogen storage unit 2 is equipped with multiple hydrogen storage tanks.

[0051] In one embodiment, during the short-distance transport mode, the inlet hydrogen pressure of the hydrogen export compressor 8 is 1.2–1.4 MPa, and the outlet hydrogen pressure is 2.5–10 MPa, preferably 2.5–6 MPa. In this embodiment, when the hydrogen pressure from the outlet of the hydrogen production unit 1 is less than the lower pressure threshold, the hydrogen export compressor 8 pressurizes the hydrogen to 2.5–4 MPa and sends it into the main hydrogen export line; when the hydrogen pressure from the outlet of the hydrogen production unit 1 is greater than the upper pressure threshold, the hydrogen export compressor 8 pressurizes the hydrogen to 4–6 MPa and sends it into the main hydrogen export line.

[0052] In one implementation, such as Figure 2 As shown, the methods for short-distance, high-stability hydrogen storage and transportation technology include:

[0053] Hydrogen produced by hydrogen production unit 1 is fed into hydrogen storage unit 2 through hydrogen inlet and stored in storage tank. When the pressure of hydrogen from hydrogen production unit 1 is greater than 1.2-1.4 MPa, the second instrument control switch valve 4 is closed and the first instrument control switch valve 6 is opened. Hydrogen is directly fed into the inlet of hydrogen export compressor 8 through pipeline at a pressure of 1.2-1.4 MPa. After being pressurized to 2.5-6 MPa by hydrogen export compressor 8, it is sent to the main hydrogen export line. After being transported for a distance of less than 100 km by the main hydrogen export line, the hydrogen enters the terminal hydrogen use unit 22. When the pressure of hydrogen from the hydrogen production unit 1 is less than 1.2-1.4 MPa, the second instrument control switch valve 4 opens and the first instrument control switch valve 6 closes. Hydrogen enters the inlet of the hydrogen compressor 5 at a pressure of 0.2-1.4 MPa. After being compressed and cooled by the compressor, it is pressurized to 4-6 MPa and then enters the hydrogen buffer tank 7. It is then sent to the hydrogen export compressor 8 for export pressurization and then sent to the main hydrogen export line. After the hydrogen is transported for a distance of less than 100 km through the main hydrogen export line, it enters the downstream terminal hydrogen unit 22.

[0054] The present disclosure will be further illustrated by the following examples, but the present disclosure is not limited thereto.

[0055] The hydrogen self-production device used in the following examples is powered by new energy power generation. The hydrogen produced by the water electrolysis hydrogen production device has a purity of 99.99 vol%, with an oxygen content of <1 ppm, a nitrogen content of <5 ppm, a dew point below -70°C, an operating temperature of 40°C, and an operating pressure of 1.4 MPa. According to the fluctuation curve of the new energy power generation, the hydrogen pressure of the hydrogen production device is 1.35 ± 0.5 MPa.

[0056] Example 1

[0057] The downstream hydrogen users are hydrogen-consuming units of refining and chemical enterprises, located approximately 300 kilometers from hydrogen production unit 1 and the hydrogen storage system. These units consume a large volume of hydrogen, and the hydrogen transmission pipeline has a diameter of DN500. The upper and lower pressure thresholds are both 1.35 MPa.

[0058] Hydrogen produced by hydrogen production unit 1 is fed into hydrogen storage unit 2 through the hydrogen inlet and stored in a storage tank. When the pressure of the hydrogen from hydrogen production unit 1 is greater than 1.35 MPa, the second instrument control valve 4 closes and the first instrument control valve 6 opens. The hydrogen, at a pressure of 1.35 MPa, enters the inlet of hydrogen export compressor 8 through the pipeline. After being pressurized to 3.0 MPa by hydrogen export compressor 8, it is sent to the main hydrogen export line. After being transported 150 km by the main hydrogen export line, the hydrogen enters intermediate booster station 9. After being pressurized by hydrogen compressors 10 and 11, the outlet hydrogen pressure is controlled to 2.8 MPa by pressure control valve 13 located at the outlet of intermediate booster station 9. a. Hydrogen continues to be transported under pressure for 150km through the pipeline before reaching the terminal pressurization unit 21. When the hydrogen pressure entering the terminal pressurization unit 21 is above 2.5MPa, the fourth pressure control switch valve 16 closes and the third instrument control switch valve 15 opens, allowing the hydrogen to be directly delivered to the downstream terminal hydrogen unit 22 at a pressure of 3MPa via the main hydrogen export line. When the hydrogen pressure entering the terminal pressurization unit 21 is below 2.5MPa, the fourth and third instrument control switch valves 15 close and the pressure control switch valve 16 opens, enabling the hydrogen to be pressurized by the hydrogen compressors 17 and 18 on the terminal pressurization branch line and delivered to the downstream terminal hydrogen unit 22 at a pressure of 3±0.1MPa.

[0059] When the pressure of hydrogen from the hydrogen production unit 1 is less than 1.35 MPa, the second instrument control switch valve 4 opens and the first instrument control switch valve 6 closes. Hydrogen enters the inlet of the hydrogen compressor 5 at a pressure less than 1.35 MPa. After compression and cooling by the compressor, it is pressurized to 1.35 MPa and then enters the hydrogen buffer tank 7. It is then sent to the hydrogen export compressor 8 for external pressurization to 3.0 MPa before being sent to the main hydrogen export line. After being transported 150 km along the main hydrogen export line, the hydrogen enters the intermediate booster station 9. After being pressurized by hydrogen compressors 10 and 11, the outlet hydrogen pressure is controlled to 2.8 MPa by the pressure control valve 13 located at the outlet of the intermediate booster station 9. After being transported under pressure for 150km through the pipeline, the hydrogen reaches the terminal pressurization unit 21. When the hydrogen pressure entering the terminal pressurization unit 21 is above 2.5MPa, the fourth pressure control switch valve 16 closes and the third instrument control switch valve 15 opens, allowing the hydrogen to be directly delivered to the downstream terminal hydrogen unit 22 at a pressure of 2.5MPa via the main hydrogen export line. When the hydrogen pressure entering the terminal pressurization unit 21 is below 2.5MPa, the fourth and third instrument control switch valves 15 close and the pressure control switch valve 16 opens, allowing the hydrogen to be pressurized by the hydrogen compressors 17 and 18 on the terminal pressurization branch line and delivered to the downstream terminal hydrogen unit 22 at a pressure of 2.5±0.1MPa.

[0060] Example 2

[0061] Downstream hydrogen users are hydrogen-consuming units in refining and chemical enterprises, located approximately 3 kilometers from hydrogen production unit 1 and the hydrogen storage system. Their usage is relatively small, with a hydrogen transmission pipeline diameter of DN150 and six hydrogen storage tanks. The upper pressure threshold is 1.4 MPa, and the lower pressure threshold is 1.35 MPa.

[0062] When the pressure of hydrogen from the hydrogen production unit 1 is greater than 1.4 MPa, the hydrogen produced by the hydrogen production unit 1 is sent through the hydrogen inlet to the hydrogen storage unit 2 to a hydrogen storage tank with a pressure higher than 1.0 MPa. When the operating pressure of the hydrogen storage tank reaches 1.4 MPa, the inlet valve of the hydrogen storage tank is closed, and the inlet valve of another hydrogen storage tank with a pressure lower than 1.0 MPa but higher than the other hydrogen storage tanks is opened. When the pressure of the hydrogen storage tank reaches 1.4 MPa, the inlet valve of the hydrogen storage tank is closed, and so on, always using a hydrogen storage tank with a higher pressure to complete the filling and storage of hydrogen. The second instrument control switch valve 4 is closed, and the first instrument control switch valve 6 is opened. The hydrogen directly enters the inlet of the hydrogen export compressor 8 through the pipeline at a pressure of 1.4 MPa. After being pressurized to 5 ± 0.1 MPa by the hydrogen export compressor 8, it is sent to the main hydrogen export line. The hydrogen is transported for 3 km through the main hydrogen export line and then enters the terminal hydrogen use unit 22.

[0063] When the pressure of hydrogen from the hydrogen production unit 1 is less than 1.35 MPa, the outlet valve of the hydrogen storage tank in hydrogen storage unit 2 with a pressure below 0.4 MPa is opened. When the operating pressure of the hydrogen storage tank reaches 0.2 MPa, the outlet valve of that hydrogen storage tank is closed. Then, the outlet valve of another hydrogen storage tank with a pressure higher than 0.4 MPa but lower than the others is opened. When the pressure of that hydrogen storage tank reaches 0.2 MPa, the outlet valve of that hydrogen storage tank is closed, and so on, always selecting... Hydrogen is released using a low-pressure hydrogen storage tank; the second instrument control valve 4 is opened and the first instrument control valve 6 is closed, allowing hydrogen to enter the inlet of the hydrogen compressor 5 at a pressure of less than 1.35 MPa. After being compressed and cooled by the compressor, the hydrogen is pressurized to 1.4 MPa and then enters the hydrogen buffer tank 7. It is then sent to the hydrogen export compressor 8 for export pressurization to 3 ± 0.1 MPa, and then sent to the main hydrogen export line. The hydrogen is transported for 3 km via the main hydrogen export line and then enters the terminal hydrogen use unit 22.

[0064] As can be seen from the data in Examples 1 and 2, the system and method used in this disclosure are applicable to both long-distance and short-distance hydrogen transportation. Furthermore, regardless of the application, they can effectively balance the instability of hydrogen in the hydrogen production process. In addition, using the system disclosed in this disclosure can improve system safety, increase the utilization rate of equipment within the system, and reduce system energy consumption.

[0065] The preferred embodiments of the present disclosure have been described in detail above with reference to the accompanying drawings. However, the present disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present disclosure, various simple modifications can be made to the technical solutions of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0066] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0067] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A system for high-stability hydrogen storage and transportation technology, characterized in that, The system includes a hydrogen storage main line, a hydrogen storage unit (2), a hydrogen export compressor (8), and a hydrogen export main line connected in sequence; The hydrogen inlet of the hydrogen storage main line is used to connect with the hydrogen outlet of the hydrogen production unit (1); the high-pressure hydrogen outlet of the hydrogen export main line is used to connect with the terminal hydrogen use unit (22). A hydrogen buffer branch line is also connected in parallel on the main hydrogen storage line between the outlet of the hydrogen storage unit (2) and the hydrogen inlet of the hydrogen export compressor (8); a buffer booster tank (7) is provided on the hydrogen buffer branch line. The hydrogen buffer branch line has a first working state and a second working state that can be switched between each other. In the first working state, the hydrogen buffer branch is not connected to the hydrogen storage main line, and the outlet of the hydrogen storage unit (2) and the hydrogen inlet of the hydrogen export compressor (8) are connected through the hydrogen storage main line. In the second working state, the outlet of the hydrogen storage unit (2) and the hydrogen inlet of the hydrogen export compressor (8) are connected through the hydrogen buffer branch line; The hydrogen storage unit (2) includes multiple hydrogen storage tanks; When the pressure of hydrogen from the hydrogen production device (1) is greater than the upper pressure threshold, the hydrogen storage unit (2) is in a gas storage state. When the pressure of hydrogen from the hydrogen production device (1) is less than the lower pressure threshold, the hydrogen storage unit (2) is in a release state; In the gas storage state, hydrogen storage is carried out sequentially according to the hydrogen storage tank pressure from high to low. When the pressure of the hydrogen storage tank undergoing the hydrogen storage process reaches the fourth threshold, the process is switched to another hydrogen storage tank. The fourth threshold is 1.35~1.4MPa. In the release state, hydrogen is released sequentially according to the hydrogen storage tank pressure from low to high. When the pressure of the hydrogen storage tank undergoing the hydrogen release process reaches a fifth threshold, the process is switched to another hydrogen storage tank. The fifth threshold is 0.2~0.3 MPa.

2. The system according to claim 1, characterized in that, The hydrogen storage unit (2) includes a first pressure control device (3).

3. The system according to claim 1, characterized in that, The system also includes an intermediate booster station (9) located on the main hydrogen export line; The intermediate booster station (9) includes a first intermediate pressure control device (12) and a hydrogen compressor; the first intermediate pressure control device (12) is located at the outlet of the hydrogen compressor; the number of hydrogen compressors is one or more, and the multiple hydrogen compressors are connected in parallel.

4. The system according to claim 1, characterized in that, The system also includes a terminal pressurization unit (21) located on the main hydrogen export line; the terminal pressurization unit (21) includes a second pressure control device (14), a terminal pressurization branch line and a hydrogen compressor; the hydrogen compressor is located on the terminal pressurization branch line; The end-pressurization branch line has an in-cut and out states that can be switched between each other by the second pressure control device (14); In the cut-out state, the terminal pressurization branch is not connected to the main hydrogen export line, and the hydrogen outlet of the hydrogen export compressor (8) is connected to the terminal hydrogen device (22) through the main hydrogen export line; In the cut-in state, the terminal booster branch line is connected to the hydrogen export main line, and the hydrogen outlet of the hydrogen export compressor (8) is connected to the terminal hydrogen device (22) through the terminal booster branch line.

5. A method for hydrogen storage and transportation using the system described in any one of claims 1 to 4, characterized in that, The method includes: The hydrogen produced by the hydrogen production unit (1) is fed into the system through the hydrogen inlet, passes through the hydrogen storage unit (2), the hydrogen export compressor (8) and the hydrogen export main line in sequence, and then enters the terminal hydrogen device (22) through the high-pressure hydrogen outlet. When the pressure of hydrogen from the hydrogen production device (1) is greater than the upper pressure threshold, the hydrogen buffer branch of the system is put into the first working state. When the pressure of hydrogen from the hydrogen production device (1) is less than the lower pressure threshold, the hydrogen buffer branch of the system is put into the second working state. The upper pressure threshold is 1.2MPa~1.4MPa, the lower pressure threshold is 1.2MPa~1.4MPa, and the upper pressure threshold is greater than or equal to the lower pressure threshold.

6. The method according to claim 5, characterized in that, The method also includes: When the length of the hydrogen export main line is above the second threshold, the system is in a long-distance transmission state; When the length of the hydrogen export main line is below the second threshold, the system is in a short-distance transmission state; The second threshold is 100~200km.

7. The method according to claim 6, characterized in that, In the long-distance transportation state, the inlet hydrogen pressure of the hydrogen export compressor (8) is 1.2~1.4 MPa, and the outlet hydrogen pressure is 2.5~10 MPa; In the short-distance transport state, the inlet hydrogen pressure of the hydrogen export compressor (8) is 1.2~1.4MPa and the outlet hydrogen pressure is 2.5~10MPa.

8. The method according to claim 6, characterized in that, In the long-distance transportation mode, an intermediate booster station (9) is set on the main hydrogen export line; the outlet hydrogen pressure of the intermediate booster station (9) is 2.5~10MPa.

9. The method according to claim 8, characterized in that, On the main hydrogen export line, one intermediate booster station (9) is set up every second threshold distance.

10. The method according to claim 6, characterized in that, In the long-distance transportation mode, a terminal pressurization unit (21) is installed on the main hydrogen export line, and the outlet hydrogen pressure of the terminal pressurization unit (21) is 2.5~10MPa; When the hydrogen pressure entering the terminal pressurization unit (21) is greater than the third threshold, the terminal pressurization branch of the terminal pressurization unit (21) is cut off. When the hydrogen pressure entering the terminal pressurization unit (21) is less than the third threshold, the terminal pressurization branch of the terminal pressurization unit (21) is put into the cut-in state. The ratio of the third threshold to the hydrogen demand pressure of the terminal hydrogen device (22) is (1~1.1):1.

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