Hydrogen supply system and method for hydrogen sub-station

Abstract

This invention belongs to the field of hydrogen refueling station gas supply technology, specifically a hydrogen supply system and method for hydrogen refueling substations. The system includes a hydrogen purification device, multiple compressors connected in parallel, first and second filling main pipes, a hydrogen supply main pipe, and a DCS system. Each compressor outlet is connected to the two filling main pipes and the hydrogen supply main pipe via three branches, each branch equipped with a controlled shut-off valve. The method includes: setting an operating mode for the compressors and establishing valve interlocking relationships; real-time monitoring of pressure on each line, and automatically opening the corresponding shut-off valve when the pressure difference between the compressor outlet and the target pipeline is ≤0.1MPa, to synchronously or alternately complete the filling of long-tube trucks and the hydrogen supply to the substations. This invention, through flexible scheduling of multiple compressors and intelligent valve control, ensures stable hydrogen supply pressure at the substations while meeting rapid filling requirements, effectively avoiding frequent compressor start-stop cycles, and improving overall energy efficiency and operational safety.

Description

Technical Field

[0001] This invention belongs to the field of hydrogen energy refueling station gas supply technology, and in particular, a method for a hydrogen supply guarantee system for hydrogen refueling mother and daughter stations. Background Technology

[0002] Hydrogen refueling stations are core infrastructure of the hydrogen energy industry chain, playing a crucial role in replenishing hydrogen fuel cell vehicles, coordinating the industry chain, and transforming the energy structure. Their core function is to pressurize hydrogen to 35MPa or 70MPa using compressors, enabling rapid refueling of vehicles and ensuring the driving range of fuel cell vehicles. As a hub connecting upstream hydrogen production and downstream applications, hydrogen refueling stations promote the extension of hydrogen energy from an industrial byproduct to multiple scenarios in transportation and industry.

[0003] Traditional hydrogen refueling stations have the following problems:

[0004] Traditional hydrogen refueling stations rely on long-tube trucks to transport hydrogen. When the residual pressure of these trucks drops below 8 MPa, the trucks need to be replaced, leading to frequent compressor start-stop cycles and a significant decrease in hydrogen flow rate (refueling time exceeds 30 minutes when the pressure is below 10 MPa). This results in increased energy consumption and a poor user experience. Furthermore, skid-mounted stations lack gas storage cylinders, leading to poor pressure stability and further impacting filling efficiency.

[0005] Replacing a long-tube vehicle requires inverted operation, which poses risks of hydrogen leakage and wasted purging. Skid-mounted stations require connecting the unloading column and compressor via hoses, and the pipeline needs to be replaced every time a vehicle is changed, resulting in a hydrogen venting loss of 30-100 standard cubic meters per instance.

[0006] In summary, to overcome the aforementioned shortcomings, many regions across the country are actively developing and applying mother-daughter refueling stations. As the primary hydrogen source for refueling stations, the mother station delivers hydrogen via pipeline, resolving the reliance on long-haul trucks to transport hydrogen to surrounding areas. This addresses the pain points of high hydrogen storage and transportation costs and insufficient infrastructure, ensuring stable refueling at nearby stations and thus guaranteeing the stable transportation of hydrogen fuel cell vehicles in the surrounding region.

[0007] A hydrogen refueling mother station can serve the purposes of filling long-tube vehicles and replenishing hydrogen refueling daughter stations. A mother station can be equipped with multiple hydrogen compressors; for example, four compressors. To improve filling efficiency, the main filling pipeline often has two or more lines; for example, two main filling pipelines. Figure 1 As shown: The outlet of the hydrogen purification unit P101 is connected to the product gas main pipe 1. The product gas main pipe 1 is divided into four streams. One stream is connected to the inlet of the first compressor C101 through the first compressor inlet pipe 2. The second stream is connected to the inlet of the second compressor C102 through the second compressor inlet pipe 3. The third stream is connected to the inlet of the third compressor C103 through the third compressor inlet pipe 4. The fourth stream is connected to the inlet of the fourth compressor C104 through the fourth compressor inlet pipe 5.

[0008] The outlet of the first compressor C101 is connected to the first compressor outlet pipeline 10. The first compressor outlet pressure gauge PIC1 and the first check valve ZV1 are installed sequentially on the first compressor outlet pipeline 10. The first compressor outlet pipeline 10 is divided into two branches. One branch is connected to the first filling main pipeline 14 through the first pressure removal main pipeline 1-1, and the second branch is connected to the second filling main pipeline 15 through the first pressure removal second main pipeline 1-2. The compressor outlet branch manual valve V5 is installed on the first pressure removal main pipeline 1-1 and the first pressure removal second main pipeline 1-2 respectively. Similarly, the outlet of the second compressor C102 is connected to the outlet pipeline 11 of the second compressor. The outlet pressure gauge PIC2 and the second check valve ZV2 of the second compressor are installed sequentially on the outlet pipeline 11. The outlet pipeline 11 of the second compressor splits into two branches: one branch connects to the first filling main pipeline 14 via the second-to-first main pipeline 2-1, and the other branch connects to the second filling main pipeline 15 via the second-to-second main pipeline 2-2. Compressor outlet branch hand valves V are installed on the second-to-first main pipeline 2-1 and the second-to-second main pipeline 2-2, respectively. 5; The outlet of the third compressor C103 is connected to the outlet pipeline 12 of the third compressor. The outlet pressure gauge PIC3 and the third check valve ZV3 of the third compressor are installed sequentially on the outlet pipeline 12. The outlet pipeline 12 of the third compressor splits into two branches: one branch connects to the first filling main pipeline 14 via the three-pressure-to-first main pipeline 3-1, and the second branch connects to the second filling main pipeline 15 via the three-pressure-to-second main pipeline 3-2. Compressor outlet branch hand valves V5 are installed on the three-pressure-to-first main pipeline 3-1 and the three-pressure-to-second main pipeline 3-2, respectively. The outlet of the fourth compressor C104 is connected to the outlet pipeline 13 of the fourth compressor. The outlet pressure gauge PIC4 and the fourth check valve ZV4 of the fourth compressor are installed sequentially on the outlet pipeline 13 of the fourth compressor. The outlet pipeline 13 of the fourth compressor is divided into two branches. One branch is connected to the first filling main pipeline 14 through the fourth compressor to the first main pipeline 4-1, and the second branch is connected to the second filling main pipeline 15 through the fourth compressor to the second main pipeline 4-2. The compressor outlet branch manual valve V5 is installed on the fourth compressor to the first main pipeline 4-1 and the fourth compressor to the second main pipeline 4-2 respectively.

[0009] A first filling manifold manual valve V2 and a first filling manifold pressure gauge PIC5 are sequentially installed on the first filling manifold 14. The first filling manifold 14 is divided into two branches. One branch is connected to one end of the filling manifold manual valve V1 via a pipeline, and the other end of the filling manifold manual valve V1 is connected to one end of the filling hose 17. The other end of the filling hose 17 is connected to the long tube vehicle T1. The other branch is connected to the hydrogen refueling substation via the hydrogen supply manifold 16. A hydrogen supply manual valve V4 and a hydrogen storage cylinder group T2 are sequentially installed on the hydrogen supply manifold 16. Similarly, a second filling manifold manual valve V3 and a second filling manifold pressure gauge PIC6 are sequentially installed on the second filling manifold 15. The second filling manifold 15 is connected to one end of the filling manifold manual valve V1 via a pipeline, and the other end of the filling manifold manual valve V1 is connected to one end of the filling hose 17. The other end of the filling hose 17 is connected to the long tube vehicle T1.

[0010] Since the hydrogen refueling mother station both fills long-tube vehicles and supplies hydrogen refueling daughter stations, the following problems arise:

[0011] 1. Since the demand for hydrogen at hydrogen refueling stations is not fixed, hydrogen from the hydrogen storage tank group is generally used first. If the hydrogen storage tank group is made large, it will increase the investment cost. If the hydrogen storage tank group is made small, the supply hydrogen pressure will drop rapidly, which will greatly affect the hydrogen refueling efficiency.

[0012] 2. If a hydrogen refueling mother station has a dedicated compressor to replenish hydrogen for hydrogen refueling daughter stations, the compressor will frequently start and stop when the usage of hydrogen refueling daughter stations is low. This will not only affect the filling efficiency of long-tube trucks, but also seriously affect the service life of the compressor due to the frequent start and stop of the compressor. Summary of the Invention

[0013] The purpose of this invention is to improve filling efficiency while ensuring a stable hydrogen supply to hydrogen refueling stations, and at the same time reduce the workload of operators and improve the level of automation.

[0014] The first aspect of the present invention is to provide a hydrogen supply system for a hydrogen refueling station, including a hydrogen purification device, multiple hydrogen compressors connected in parallel, a first filling main pipe, a second filling main pipe, a hydrogen supply main pipe, and a distributed control system (DCS).

[0015] The inlet of each compressor is connected to the outlet of the hydrogen purification unit via its own compressor inlet pipeline;

[0016] Each compressor outlet is connected to three parallel branches via its own compressor outlet pipeline: the first branch is connected to the first filling main pipe via a first type of shut-off valve, the second branch is connected to the second filling main pipe via a second type of shut-off valve, and the third branch is connected to the hydrogen supply main pipe via a third type of shut-off valve.

[0017] The first and second filling main pipes are used to connect to the long-tube vehicle; the hydrogen supply main pipe is used to connect to the hydrogen refueling substation, on which a hydrogen storage cylinder group is installed;

[0018] The DCS is connected to the outlet pressure gauge of each compressor, the first filling main pipe pressure gauge, the second filling main pipe pressure gauge, the hydrogen supply main pipe pressure gauge, and all the shut-off valves, and is used to control the opening and closing of the shut-off valves based on pressure data.

[0019] Furthermore, for any given compressor, there is a first interlocking relationship between its corresponding first-type shut-off valve and second-type shut-off valve, preventing them from opening simultaneously.

[0020] Furthermore, there is a second interlock relationship between all the first type of shut-off valves connected to the first filling manifold, such that the number of valves opened simultaneously does not exceed a first set threshold; there is a second interlock relationship between all the second type of shut-off valves connected to the second filling manifold.

[0021] Furthermore, all of the aforementioned third-type shut-off valves have a third interlocking relationship, ensuring that the number of valves opened simultaneously does not exceed a second set threshold.

[0022] Furthermore, the DCS is configured such that the controlled target shut-off valve can only be opened when the absolute value of the pressure difference between the two ends of the branch where the target shut-off valve is located is less than or equal to 0.1 MPa.

[0023] Furthermore, the multiple parallel hydrogen compressors include a first compressor, a second compressor, a third compressor, and a fourth compressor. The first compressor has a first reflux regulating valve on its outlet pipeline, the second compressor has a second reflux regulating valve on its outlet pipeline, the third compressor has a third reflux regulating valve on its outlet pipeline, and the fourth compressor has a fourth reflux regulating valve on its outlet pipeline. Each of the reflux regulating valves is connected to the DCS signal.

[0024] The DCS is configured to: control the reflux regulating valve of the compressor to open when the compressor outlet pressure reaches a first set pressure value; and control the reflux regulating valve to gradually close after any target shut-off valve corresponding to the compressor is opened.

[0025] Furthermore, the DCS is configured to provide multiple selectable operating modes for each compressor, the operating modes including at least: a first separate filling mode for limiting the compressor to supply gas only to the first filling manifold, a second separate filling mode for limiting the compressor to supply gas only to the second filling manifold, a first mixed filling mode for limiting the compressor to supply gas to both the first filling manifold and the hydrogen supply manifold, a second mixed filling mode for limiting the compressor to supply gas to both the second filling manifold and the hydrogen supply manifold, and a separate hydrogen supply mode for limiting the compressor to supply gas only to the hydrogen supply manifold.

[0026] A second aspect of the present invention provides a method for ensuring hydrogen supply to the above-described system, comprising:

[0027] Mode setting steps: Select an operating mode for at least one compressor in the system, and establish the opening and closing interlocking relationship of the first type of shut-off valve, the second type of shut-off valve and the third type of shut-off valve of the corresponding compressor according to the selected mode;

[0028] Pressure balancing steps: Monitor the compressor outlet pressure, filling main pipe pressure and hydrogen supply main pipe pressure in real time, and adjust the compressor outlet pressure so that the absolute value of the pressure difference between it and the target pipeline reaches the preset threshold range.

[0029] Valve linkage steps: When the pressure difference meets the preset threshold range and conforms to the interlocking relationship, the corresponding shut-off valve connecting the compressor and the target pipeline is automatically opened to perform the filling of the long-tube vehicle and / or the hydrogen supply operation to the hydrogen refueling substation.

[0030] Furthermore, in the valve linkage step, the redundant delivery capacity of the compressor that is performing the long tube truck filling operation is preferentially utilized. By opening its corresponding third type of shut-off valve, hydrogen is replenished to the hydrogen supply main and the hydrogen storage cylinder group to maintain the pressure of the hydrogen supply main above the preset hydrogen supply pressure lower limit.

[0031] Furthermore, the method also includes a pressure protection step: when the compressor outlet pressure reaches a first set pressure value and no target shut-off valve is opened, the compressor's reflux regulating valve is controlled to open to release pressure and self-circulate; when a target shut-off valve is opened, the reflux regulating valve is controlled to gradually close.

[0032] The advantages and positive effects of this invention are:

[0033] 1. This invention can ensure that the hydrogen pressure at the hydrogen refueling station is always maintained above 16MPa, which improves the refueling efficiency of hydrogen-powered vehicles and ensures a stable hydrogen supply to the hydrogen refueling station.

[0034] 2. This invention uses a DCS system to control multiple compressors to automatically pressurize the hydrogen refueling substation, and makes full and reasonable use of the effective time of the operating compressors, avoiding frequent start-stop of the compressors, improving the service life of the compressors, reducing the workload of operators, and improving work efficiency.

[0035] 3. By making reasonable use of the selection buttons, this invention ensures both the stability of hydrogen supply at the hydrogen refueling substation and the filling needs of the hydrogen refueling mother station. It is highly flexible and can fully meet the needs of sudden increases or decreases in load.

[0036] 4. This invention effectively prevents cross-pressure during the filling process by setting the number of shut-off valves on the compressor to the filling main pipe, thereby improving the stability of the device and reducing safety risks. Attached Figure Description

[0037] Figure 1 Background technical solution: Original process flow diagram;

[0038] Figure 2 : Process flow diagram of the present invention;

[0039] Among them: P101 - Hydrogen purification unit, C101 - First compressor, C102 - Second compressor, C103 - Third compressor, C104 - Fourth compressor, T1 - Long tube vehicle, T2 - Hydrogen storage cylinder group, 1 - Product gas main pipe, 2 - First compressor inlet pipeline, 3 - Second compressor inlet pipeline, 4 - Third compressor inlet pipeline, 5 - Fourth compressor inlet pipeline, 6 - First reflux pipeline, 7 - Second reflux pipeline, 8 - Third reflux pipeline, 9 - Fourth reflux pipeline, 10 - First compressor outlet pipeline, 11 - Second compressor outlet pipeline, 12 - Third compressor outlet pipeline, 13 - Fourth compressor outlet pipeline, 14 - 15-Second filling main pipe, 16-Hydrogen supply main pipe, 17-Filling hose, 1-1-Pressure-removed main pipe, 1-2-Pressure-removed secondary main pipe, 1-3-Pressure-removed substation pipe, 2-1-Second pressure-removed main pipe, 2-2-Second pressure-removed secondary main pipe, 2-3-Second pressure-removed substation pipe, 3-1-Third pressure-removed main pipe, 3-2-Third pressure-removed secondary main pipe, 3-3-Third pressure-removed substation pipe, 4-1-Fourth pressure-removed main pipe, 4-2-Fourth pressure-removed secondary main pipe, 4-3-Fourth pressure-removed substation pipe, XV1-1-Pressure-removed main shut-off valve, XV1-2-Pressure-removed secondary main shut-off valve, XV1-3-Pressure-removed substation shut-off valve XV2-1 - Two-pressure-to-one main shut-off valve, XV2-2 - Two-pressure-to-two-main shut-off valve, XV2-3 - Two-pressure-to-substation shut-off valve, XV3-1 - Three-pressure-to-one main shut-off valve, XV3-2 - Three-pressure-to-two-main shut-off valve, XV3-3 - Three-pressure-to-substation shut-off valve, XV4-1 - Four-pressure-to-one main shut-off valve, XV4-2 - Four-pressure-to-two-main shut-off valve, XV4-3 - Four-pressure-to-substation shut-off valve, V1 - Filling manual valve, V2 - First filling main pipe manual valve, V3 - Second filling main pipe manual valve, V4 - Hydrogen supply manual valve, V5 - Compressor outlet branch manual valve, ZV1 - First check valve, ZV2 - Second check valve, ZV3 - Third check valve, ZV 4-Fourth check valve, ZV5-First hydrogen supply check valve, ZV6-Second hydrogen supply check valve, ZV7-Third hydrogen supply check valve, ZV8-Fourth hydrogen supply check valve, PIC1-First compressor outlet pressure gauge, PIC2-Second compressor outlet pressure gauge, PIC3-Third compressor outlet pressure gauge, PIC4-Fourth compressor outlet pressure gauge, PIC5-First filling main pipe pressure gauge, PIC6-Second filling main pipe pressure gauge, PIC7-Hydrogen supply main pipe pressure gauge, FIC1-Hydrogen supply flow meter, PV1-First reflux regulating valve, PV2-Second reflux regulating valve, PV3-Third reflux regulating valve, PV4-Fourth reflux regulating valve. Detailed Implementation

[0040] The present invention will be further described in detail below through specific embodiments. The following embodiments are merely descriptive and not limiting, and should not be used to limit the scope of protection of the present invention.

[0041] A hydrogen supply system for a hydrogen refueling station includes the following process flow: multiple hydrogen compressors can be installed; taking four hydrogen compressors and two filling main pipes as an example... Figure 2 As shown: The outlet of the hydrogen purification unit P101 is connected to the product gas main pipe 1. The product gas main pipe 1 is divided into four streams. One stream is connected to the inlet of the first compressor C101 through the first compressor inlet pipe 2. The second stream is connected to the inlet of the second compressor C102 through the second compressor inlet pipe 3. The third stream is connected to the inlet of the third compressor C103 through the third compressor inlet pipe 4. The fourth stream is connected to the inlet of the fourth compressor C104 through the fourth compressor inlet pipe 5.

[0042] The outlet of the first compressor C101 is connected to the first compressor outlet pipeline 10. A first compressor outlet pressure gauge PIC1 and a first check valve ZV1 are sequentially installed on the first compressor outlet pipeline 10. The first compressor outlet pipeline 10 branches into three streams: one stream connects to the first filling main pipeline 14 via a first depressurization main pipeline 1-1, and a first depressurization main shut-off valve XV1-1 is installed on the first depressurization main pipeline 1-1; the second stream connects to the second filling main pipeline 15 via a first depressurization secondary main pipeline 1-2, and a second depressurization secondary shut-off valve XV1-2 is installed on the first depressurization secondary main pipeline 1-2; the third stream... The first substation is connected to the main hydrogen supply line 16 via a substation line 1-3. A first hydrogen supply check valve ZV5 and a substation shut-off valve XV1-3 are installed sequentially on the substation line 1-3. Similarly, the outlet of the second compressor C102 is connected to the outlet line 11 of the second compressor. A second compressor outlet pressure gauge PIC2 and a second check valve ZV2 are installed sequentially on the outlet line 11. The outlet line 11 of the second compressor is divided into three branches. One branch is connected to the first filling main line 14 via a substation line 2-1. A substation line 2-1 is installed on the substation line 2-1. The second branch of the shut-off valve XV2-1 is connected to the second filling main pipe 15 via the second pressure to second main pipe 2-2. A second pressure to second main shut-off valve XV2-2 is installed on the second pressure to second main pipe 2-2. The third branch is connected to the hydrogen supply main pipe 16 via the second pressure to substation pipe 2-3. A second hydrogen supply check valve ZV6 and a second pressure to substation shut-off valve XV2-3 are installed sequentially on the second pressure to substation pipe 2-3. The outlet of the third compressor C103 is connected to the third compressor outlet pipe 12. A third compressor outlet pressure gauge PIC3 and a third check valve are installed sequentially on the third compressor outlet pipe 12. ZV3, the third compressor outlet pipeline 12 is divided into three branches. One branch is connected to the first filling main pipeline 14 via the three-pressure-to-first main pipeline 3-1. A three-pressure-to-first main shut-off valve XV3-1 is installed on the three-pressure-to-first main pipeline 3-1. The second branch is connected to the second filling main pipeline 15 via the three-pressure-to-second main pipeline 3-2. A three-pressure-to-second main shut-off valve XV3-2 is installed on the three-pressure-to-second main pipeline 3-2. The third branch is connected to the hydrogen supply main pipeline 16 via the three-pressure-to-substation pipeline 3-3. A third hydrogen supply check valve ZV7 and a three-pressure-to-substation shut-off valve XV3-3 are installed sequentially on the three-pressure-to-substation pipeline 3-3.The outlet of the fourth compressor C104 is connected to the fourth compressor outlet pipeline 13. A fourth compressor outlet pressure gauge PIC4 and a fourth check valve ZV4 are installed sequentially on the fourth compressor outlet pipeline 13. The fourth compressor outlet pipeline 13 branches into three streams: one stream connects to the first filling main pipeline 14 via the fourth compressor to the first main pipeline 4-1, and a fourth compressor to the first main shut-off valve XV4-1 is installed on the fourth compressor to the first main pipeline 4-1; the second stream connects to the second filling main pipeline 15 via the fourth compressor to the second main pipeline 4-2, and a fourth compressor to the second main shut-off valve XV4-2 is installed on the fourth compressor to the second main pipeline 4-2; the third stream connects to the hydrogen supply main pipeline 16 via the fourth compressor to the substation pipeline 4-3, and a fourth hydrogen supply check valve ZV8 and a fourth compressor to the substation shut-off valve XV4-3 are installed sequentially on the fourth compressor to the substation pipeline 4-3.

[0043] A first filling manifold manual valve V2 and a first filling manifold pressure gauge PIC5 are sequentially installed on the first filling manifold 14. The first filling manifold 14 is connected to one end of the filling manifold manual valve V1 via a pipeline, and the other end of the filling manifold manual valve V1 is connected to one end of the filling hose 17. The other end of the filling hose 17 is connected to the long tube vehicle T1. Similarly, a second filling manifold manual valve V3 and a second filling manifold pressure gauge PIC6 are sequentially installed on the second filling manifold 15. The second filling manifold 15 is connected to one end of the filling manifold manual valve V1 via a pipeline, and the other end of the filling manifold manual valve V1 is connected to one end of the filling hose 17. The other end of the filling hose 17 is connected to the long tube vehicle T1. The hydrogen supply manifold 16 is connected to the hydrogen refueling substation. A hydrogen supply manual valve V4, a hydrogen supply manifold pressure gauge and PIC7, a hydrogen storage cylinder group T2, and a hydrogen supply flow meter FIC1 are sequentially installed on the hydrogen supply manifold 16.

[0044] The compressor outlet pressure gauge is connected to the compressor reflux regulating valve and the signal is transmitted to the DCS system to ensure the compressor's pressure increase and decrease rates.

[0045] The signals of the following valves are connected to the DCS system: one main shut-off valve XV1-1, one secondary main shut-off valve XV1-2, one substation shut-off valve XV1-3, two main shut-off valves XV2-1, two secondary main shut-off valves XV2-2, two substation shut-off valves XV2-3, three main shut-off valves XV3-1, three secondary main shut-off valves XV3-2, three substation shut-off valves XV3-3, four main shut-off valves XV4-1, four secondary main shut-off valves XV4-2, and four substation shut-off valves XV4-3.

[0046] The number of valve closing signals of the first main shut-off valve XV1-1 and the second main shut-off valve XV1-2 is ≥1, that is, when one shut-off valve is open, the other shut-off valve cannot be opened, thus preventing cross-pressure.

[0047] The number of valve closing signals for the two pressure-removing main shut-off valves XV2-1 and XV2-2 is ≥1, meaning that when one shut-off valve is open, the other shut-off valve cannot be opened, thus preventing cross-pressure.

[0048] The number of valve closing signals for the three-pressure-to-one main shut-off valve XV3-1 and the three-pressure-to-two main shut-off valve XV3-2 is ≥1, meaning that when one shut-off valve is open, the other shut-off valve cannot be opened, thus preventing cross-pressure.

[0049] The number of valve closing signals for the four-pressure-to-one main shut-off valve XV4-1 and the four-pressure-to-two main shut-off valve XV4-2 is ≥1, meaning that when one shut-off valve is open, the other shut-off valve cannot be opened, thus preventing cross-pressure.

[0050] The number of valve closing signals for the first pressure-removing main shut-off valve XV1-1, the second pressure-removing main shut-off valve XV2-1, the third pressure-removing main shut-off valve XV3-1, and the fourth pressure-removing main shut-off valve XV4-1 is ≥2. That is, when two of the shut-off valves are open, the other shut-off valves cannot be opened to prevent excessive flow velocity from flushing the pipeline.

[0051] The number of valve closing signals for the first pressure-removing second main shut-off valve XV1-2, the second pressure-removing second main shut-off valve XV2-2, the third pressure-removing second main shut-off valve XV3-2, and the fourth pressure-removing second main shut-off valve XV4-2 is ≥2. That is, when two of the shut-off valves are open, the other shut-off valves cannot be opened to prevent excessive flow velocity from flushing the pipeline.

[0052] The number of closing signals for the first pressure-removing substation shut-off valve XV1-3, the second pressure-removing substation shut-off valve XV2-3, the third pressure-removing substation shut-off valve XV3-3, and the fourth pressure-removing substation shut-off valve XV4-3 is ≥2. That is, when two of the shut-off valves are open, the other shut-off valves cannot be opened to prevent excessive flow velocity from flushing the pipeline.

[0053] The opening condition of the pressure relief valve XV1-1 is that the absolute value of the pressure difference between the first filling main pipe pressure gauge PIC5 and the first compressor outlet pressure gauge PIC1 is ≤0.1MPa. That is, when the absolute value of the pressure difference is >0.1MPa, the pressure relief valve XV1-1 is closed.

[0054] The opening condition of the first pressure relief valve XV1-2 is that the absolute value of the pressure difference between the second filling main pipe pressure gauge PIC6 and the first compressor outlet pressure gauge PIC1 is ≤0.1MPa. That is, when the absolute value of the pressure difference is >0.1MPa, the first pressure relief valve XV1-2 is closed.

[0055] The opening condition of the first pressure reduction substation shut-off valve XV1-3 is that the absolute value of the pressure difference between the hydrogen supply main pipe pressure gauge PIC7 and the first compressor outlet pressure gauge PIC1 is ≤0.1MPa. That is, when the absolute value of the pressure difference between the two is >0.1MPa, the first pressure reduction substation shut-off valve XV1-3 is closed.

[0056] The opening condition of the two-pressure-removal-one-main-shutdown valve XV2-1 is that the absolute value of the pressure difference between the first filling main pipe pressure gauge PIC5 and the second compressor outlet pressure gauge PIC2 is ≤0.1MPa. That is, when the absolute value of the pressure difference between the two is >0.1MPa, the two-pressure-removal-one-main-shutdown valve XV2-1 is closed.

[0057] The opening condition of the two-pressure-removal-two-main-shutdown valve XV2-2 is that the absolute value of the pressure difference between the second filling main pipe pressure gauge PIC6 and the second compressor outlet pressure gauge PIC2 is ≤0.1MPa. That is, when the absolute value of the pressure difference between the two is >0.1MPa, the two-pressure-removal-two-main-shutdown valve XV2-2 is closed.

[0058] The opening condition for the secondary pressure depletion substation shut-off valve XV2-3 is that the absolute value of the pressure difference between the hydrogen supply main pipe pressure gauge PIC7 and the second compressor outlet pressure gauge PIC2 is ≤0.1MPa. That is, when the absolute value of the pressure difference between the two is >0.1MPa, the secondary pressure depletion substation shut-off valve XV2-3 is closed.

[0059] The opening condition of the three-pressure-removal-one-main-shutdown valve XV3-1 is that the absolute value of the pressure difference between the first filling main pipe pressure gauge PIC5 and the third compressor outlet pressure gauge PIC3 is ≤0.1MPa. That is, when the absolute value of the pressure difference between the two is >0.1MPa, the three-pressure-removal-one-main-shutdown valve XV3-1 is closed.

[0060] The opening condition of the three-pressure-to-two-main-shutdown valve XV3-2 is that the absolute value of the pressure difference between the second filling main pipe pressure gauge PIC6 and the third compressor outlet pressure gauge PIC3 is ≤0.1MPa. That is, when the absolute value of the pressure difference between the two is >0.1MPa, the three-pressure-to-two-main-shutdown valve XV3-2 is closed.

[0061] The opening condition for the three-pressure depletion substation shut-off valve XV3-3 is that the absolute value of the pressure difference between the hydrogen supply main pipe pressure gauge PIC7 and the third compressor outlet pressure gauge PIC3 is ≤0.1MPa. That is, when the absolute value of the pressure difference between the two is >0.1MPa, the three-pressure depletion substation shut-off valve XV3-3 is closed.

[0062] The opening condition of the four-pressure-removal-one-main-shutdown valve XV4-1 is that the absolute value of the pressure difference between the first filling main pipe pressure gauge PIC5 and the fourth compressor outlet pressure gauge PIC4 is ≤0.1MPa. That is, when the absolute value of the pressure difference between the two is >0.1MPa, the four-pressure-removal-one-main-shutdown valve XV4-1 is closed.

[0063] The opening condition of the four-pressure-to-two-main-shutdown valve XV4-2 is that the absolute value of the pressure difference between the second filling main pipe pressure gauge PIC6 and the fourth compressor outlet pressure gauge PIC4 is ≤0.1MPa. That is, when the absolute value of the pressure difference between the two is >0.1MPa, the four-pressure-to-two-main-shutdown valve XV4-2 is closed.

[0064] The opening condition for the four-pressure depletion substation shut-off valve XV4-3 is that the absolute value of the pressure difference between the hydrogen supply main pipe pressure gauge PIC7 and the fourth compressor outlet pressure gauge PIC4 is ≤0.1MPa. That is, when the absolute value of the pressure difference between the two is >0.1MPa, the four-pressure depletion substation shut-off valve XV4-3 is closed.

[0065] The water volume of the hydrogen storage cylinder group T2 is greater than 20 cubic meters.

[0066] Each compressor in the DCS system is equipped with a selection screen for "Separate filling of #1", "Separate filling of #2", "Mixed filling of #1", "Mixed filling of #2" and "Separate hydrogen supply", which are used to select the hydrogen supply status and filling status.

[0067] When the first compressor outlet pressure gauge PIC1 reaches 20MPa, the first reflux regulating valve PV1 will automatically and slowly open. When the opening and closing signal of one of the following valves is received, namely the first main shut-off valve XV1-1, the second main shut-off valve XV1-2, and the substation shut-off valve XV1-3, the first reflux regulating valve PV1 will automatically and slowly close until it is fully closed.

[0068] When the outlet pressure gauge PIC2 of the second compressor reaches 20MPa, the second reflux regulating valve PV2 will automatically and slowly open. When the opening and closing signal of one of the valves XV2-1 (second compressor to main shut-off valve), XV2-2 (second compressor to secondary main shut-off valve), and XV2-3 (second compressor to substation shut-off valve) is fed back, the second reflux regulating valve PV2 will automatically and slowly close until it is fully closed.

[0069] When the outlet pressure gauge PIC3 of the third compressor reaches 20MPa, the third reflux regulating valve PV3 will automatically and slowly open. When the opening and closing signal of one of the three pressure-to-one main shut-off valves XV3-1, XV3-2, and XV3-3 is fed back, the third reflux regulating valve PV3 will automatically and slowly close until it is fully closed.

[0070] When the outlet pressure gauge PIC4 of the fourth compressor reaches 20MPa, the fourth reflux regulating valve PV4 will automatically and slowly open. When the opening and closing signal of one of the four main shut-off valves XV4-1, XV4-2, and XV4-3 of the four substation shut-off valves is fed back, the fourth reflux regulating valve PV4 will automatically and slowly close until it is fully closed.

[0071] With a compressor air volume of 1000 Nm 3 / h, the maximum hydrogen refueling capacity of the hydrogen refueling substation is 2000 Nm³. 3 Taking / h as an example, its working principle and operation steps are as follows:

[0072] The "Individual Filling 1#" selection button for the compressor indicates that this compressor can only fill long-tube trucks and cannot be used for hydrogen refueling. It is suitable for situations where the hydrogen refueling mother station has a high business volume or where users have an urgent need for hydrogen. In other words, the compressor's shut-off valve to the second main station and the shut-off valve to the substation are in an interlocked closed state, and the compressor's shut-off valve to the first main station opens and closes based on the pressure difference between the front and rear.

[0073] The "Separate Filling #2" selection button for the compressor indicates that this compressor can only fill long-tube trucks and cannot be used for hydrogen refueling. It is suitable for situations where the hydrogen refueling mother station has a high business volume or where users have an urgent need for hydrogen. In other words, the compressor's main shut-off valve and the shut-off valve to the substation are in an interlocked closed state, and the compressor's shut-off valve to the second main shut-off valve opens and closes based on the pressure difference between the front and rear valves.

[0074] The compressor's "1# Mixed Filling" selection button indicates that the compressor can both fill the long-tube truck T1 via the first filling main pipe 14 and be used for hydrogen refueling. This is suitable for situations where the hydrogen refueling mother station has low business volume and few hydrogen refueling users. Specifically, the compressor's shut-off valve to the second main pipe is in an interlocked closed state, while the compressor's shut-off valves to the first main pipe and the shut-off valve to the substation operate based on the pressure difference between the front and rear.

[0075] The compressor's "2# Mixed Filling" selection button indicates that the compressor can both fill the long-tube truck T1 of the second filling main pipe 15 and be used for hydrogen refueling. This is suitable for situations where the hydrogen refueling mother station has low business volume and few hydrogen refueling users. Specifically, the compressor's main shut-off valve is in an interlocked closed state, while the compressor's main shut-off valves for the second main pipe and the shut-off valves for the substation open and close based on the pressure difference.

[0076] The "Separate Hydrogen Supply" selection button for the compressor indicates that the compressor can only be used for hydrogen refueling and cannot fill long-tube trucks. This is suitable for situations where the hydrogen refueling mother station has low business volume but users urgently need hydrogen refueling. Specifically, the compressor's main shut-off valve (both the primary and secondary shut-off valves) is interlocked closed, and its opening and closing action is based on the pressure difference across the shut-off valves at the substation.

[0077] Example 1: Hydrogen refueling station refueling volume less than 1000 Nm 3 In the case of / h, taking the first filling manifold 14 filled by two compressors with a long tube car T1 as an example.

[0078] When the average usage of the hydrogen refueling substation, i.e., the average flow rate displayed by the hydrogen supply flow meter FIC1, is below 1000 Nm 3When the first filling manifold 14 has a long-tube car T1 that needs filling, the operator can select "1# Mixed Filling" for the running compressor according to the actual situation. For example, if the first compressor C101 is selected as "1# Mixed Filling" and the second compressor C102 is selected as "Separate Filling 1#", after connecting the filling hose 17, the operator opens the filling hand valve V1 and the first filling manifold hand valve V2, and selects the "1# Mixed Filling" button for the first compressor C101. The DCS system then controls the first reflux regulating valve PV1 through the first compressor outlet pressure gauge PIC1. When the pressure of the first compressor outlet pressure gauge PIC1 is adjusted to be less than 0.1 MPa different from the pressure displayed on the first filling manifold pressure gauge PIC5, the first pressure cut-off valve XV1-1 opens, the first reflux regulating valve PV1 gradually closes, and the system begins to pressurize; similarly... When the second compressor C102 selects the "Individual Filling 1#" button, the DCS system controls the second reflux regulating valve PV2 through the second compressor outlet pressure gauge PIC2. When the pressure of the second compressor outlet pressure gauge PIC2 is adjusted to be less than 0.1MPa from the pressure displayed by the first filling main pipe pressure gauge PIC5, the second pressure to the first main shut-off valve XV2-1 opens, the second reflux regulating valve PV2 gradually closes, and the system begins to pressurize. Both the first compressor C101 and the second compressor C102 fill the first filling main pipe 14 with the long pipe car T1. When the pressure difference between the second compressor outlet pressure gauge PIC2 and the hydrogen supply main pressure gauge PIC7 is less than 0.1 MPa, open the second pressure decompression substation shut-off valve XV2-3 and connect it to the hydrogen storage cylinder group T2 to jointly replenish the pressure of the long-tube vehicle T1 and the hydrogen storage cylinder group T2 until the pressure of the first compressor outlet pressure gauge PIC1 and the second compressor outlet pressure gauge PIC2 rises to 20 MPa. The DCS system controls the first reflux regulating valve PV1 to be fully open through the first compressor outlet pressure gauge PIC1 and controls the second reflux regulating valve PV2 to be fully open through the second compressor outlet pressure gauge PIC2. The pressure of both compressors is reduced to the minimum and put into standby. After replacing the long-tube vehicle T1, continue filling according to the above operation.

[0079] During the process of the second compressor C102 filling the long-tube vehicle T1 of the first filling main pipe 14, the pressure difference between the second compressor outlet pressure gauge PIC2 and the hydrogen supply main pipe pressure gauge PIC7 is large, and the second compressor outlet substation shut-off valve XV2-3 has not yet opened. Due to the continuous refueling of hydrogen vehicles, the pressure of the hydrogen supply main pipe pressure gauge PIC7 is lower than 16MPa. Then, the DCS system controls the second reflux regulating valve PV2 through the second compressor outlet pressure gauge PIC2 to adjust the pressure of the second compressor outlet pressure gauge PIC2 to be the same as the pressure of the hydrogen supply main pipe pressure gauge PIC7. When the pressure of the second compressor outlet pressure gauge PIC2 is adjusted to be less than 0.1MPa from the pressure displayed by the hydrogen supply main pipe pressure gauge PIC7, the second compressor outlet substation shut-off valve XV2-3 is opened and the second compressor outlet main shut-off valve XV2-1 is closed, and the second compressor supplies hydrogen to the hydrogen refueling substation alone. When the pressure gauge PIC7 of the hydrogen supply main pipe rises to 20MPa, the DCS system controls the second reflux regulating valve PV2 through the second compressor outlet pressure gauge PIC2 to reduce the pressure of the second compressor outlet pressure gauge PIC2 to less than 0.1MPa from the pressure displayed by the first filling main pipe pressure gauge PIC5. Then, the second pressure to the first main shut-off valve XV2-1 is opened, and the first filling main pipe 14 continues to be filled by the long pipe cart T1 until the pressure gauge PIC5 of the first filling main pipe rises to 20MPa. The second compressor outlet pressure gauge PIC2 controls the second reflux regulating valve PV2 to be fully opened, reducing the pressure to the minimum and setting it aside. After replacing the long pipe cart T1, the filling continues according to the above operation.

[0080] Example 2: Hydrogen refueling station refueling volume exceeds 1000 Nm 3 / h situation

[0081] When the average usage of the hydrogen refueling substation, i.e., the average flow rate displayed by the hydrogen supply flow meter FIC1, exceeds 1000 Nm... 3 If the pressure is / h, select the "Separate Hydrogen Supply" button for one of the compressors. This compressor's outlet pressure is controlled by the DCS. When the pressure difference between the compressor outlet pressure gauge and the hydrogen supply main pressure gauge PIC7 is less than 0.1MPa, the shut-off valve to the substation will open, while the shut-off valves to the first and second main stations will be interlocked and closed. This compressor will only supply hydrogen to the hydrogen refueling substation. Simultaneously, select the mixed filling button for the other compressor supplying the long-tube truck. For example, if the first compressor C101 is currently filling the long-tube truck T1 at the first filling main 14, then the first compressor C101 will select the "1# Mixed Filling" button. One of the remaining compressors will select the "Separate Hydrogen Supply" button. When the compressor supplying hydrogen alone cannot fully meet the pressure of the hydrogen supply main pressure gauge PIC7 (which is higher than 16MPa), the first compressor C101 can replenish the pressure in time to ensure that the pressure of the hydrogen supply main pressure gauge PIC7 remains above 16MPa.

[0082] Example 3: A long-tube vehicle T1 user urgently needs to charge their vehicle.

[0083] When the user of the long-tube truck T1 urgently needs to charge, the operator can select the "Individual Charging" button for both compressors simultaneously. For example, if the long-tube truck T1 with the first charging manifold 14 urgently needs to be charged, both compressors can be selected, and the "Individual Charging 1#" button can be selected simultaneously. The shut-off valves to the second main station and the shut-off valves to the substation of these two compressors will be interlocked and closed, charging only the long-tube truck T1 with the first charging manifold 14 until the pressure gauge PIC5 of the first charging manifold rises to 20MPa, and the compressors are depressurized to the minimum and put on standby. After the long-tube truck is replaced, the pressurization and charging will be carried out again.

[0084] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several modifications and improvements can be made without departing from the inventive concept, and these all fall within the protection scope of the present invention.

Claims

1. A hydrogen supply system for hydrogen refueling mother and daughter stations, characterized in that, It includes a hydrogen purification unit (P101), multiple parallel hydrogen compressors, a first filling main pipe (14), a second filling main pipe (15), a hydrogen supply main pipe (16), and a distributed control system (DCS); The inlet of each compressor is connected to the outlet of the hydrogen purification unit (P101) via its own compressor inlet pipeline; Each compressor outlet is connected to three parallel branches via its own compressor outlet pipeline: the first branch is connected to the first filling main pipe (14) via a first type of shut-off valve, the second branch is connected to the second filling main pipe (15) via a second type of shut-off valve, and the third branch is connected to the hydrogen supply main pipe (16) via a third type of shut-off valve. The first filling main pipe (14) and the second filling main pipe (15) are used to connect to the long pipe vehicle (T1); the hydrogen supply main pipe (16) is used to connect to the hydrogen refueling substation, on which a hydrogen storage cylinder group (T2) is installed. The DCS is connected to the outlet pressure gauge of each compressor, the first filling main pressure gauge (PIC5), the second filling main pressure gauge (PIC6), the hydrogen supply main pressure gauge (PIC7), and all the shut-off valves, for controlling the opening and closing of the shut-off valves based on pressure data. The multiple parallel hydrogen compressors include a first compressor (C101), a second compressor (C102), a third compressor (C103), and a fourth compressor (C104). The first compressor (C101) is equipped with a first reflux regulating valve (PV1) on its outlet pipeline, the second compressor (C102) is equipped with a second reflux regulating valve (PV2) on its outlet pipeline, the third compressor (C103) is equipped with a third reflux regulating valve (PV3) on its outlet pipeline, and the fourth compressor (C104) is equipped with a fourth reflux regulating valve (PV4) on its outlet pipeline. Each of the reflux regulating valves is connected to the DCS signal. The DCS is configured to: control the compressor's reflux regulating valve to open when the compressor outlet pressure reaches a first set pressure value; When any target shut-off valve corresponding to the compressor is opened, the reflux regulating valve is controlled to gradually close. The DCS is configured to provide multiple selectable operating modes for each compressor, including at least: a first separate filling mode for limiting the compressor to supply gas only to the first filling manifold (14), a second separate filling mode for limiting the compressor to supply gas only to the second filling manifold (15), a first mixed filling mode for limiting the compressor to supply gas to both the first filling manifold (14) and the hydrogen supply manifold (16), a second mixed filling mode for limiting the compressor to supply gas to both the second filling manifold (15) and the hydrogen supply manifold (16), and a separate hydrogen supply mode for limiting the compressor to supply gas only to the hydrogen supply manifold (16).

2. The system according to claim 1, characterized in that, For any given compressor, there is a first interlocking relationship between its corresponding first-type shut-off valve and second-type shut-off valve, which prevents the two from opening simultaneously.

3. The system according to claim 1, characterized in that, There is a second interlock relationship between all the first type of shut-off valves connected to the first filling manifold (14) such that the number of valves opened simultaneously does not exceed a first set threshold; there is a second interlock relationship between all the second type of shut-off valves connected to the second filling manifold (15).

4. The system according to claim 1, characterized in that, There is a third interlocking relationship among all the third type of shut-off valves, so that the number of valves opened at the same time does not exceed a second set threshold.

5. The system according to claim 1, characterized in that, The DCS is configured such that the controlled target shut-off valve can only be opened when the absolute value of the pressure difference between the two ends of the branch where the target shut-off valve is located is less than or equal to 0.1 MPa.

6. A method for ensuring hydrogen supply based on the system according to any one of claims 1 to 5, characterized in that, include: Mode setting steps: Select an operating mode for at least one compressor in the system, and establish the opening and closing interlocking relationship of the first type of shut-off valve, the second type of shut-off valve and the third type of shut-off valve of the corresponding compressor according to the selected mode; Pressure balancing steps: Monitor the compressor outlet pressure, filling main pipe pressure and hydrogen supply main pipe pressure in real time, and adjust the compressor outlet pressure so that the absolute value of the pressure difference between it and the target pipeline reaches the preset threshold range. Valve linkage steps: When the pressure difference meets the preset threshold range and conforms to the interlocking relationship, the corresponding shut-off valve connecting the compressor and the target pipeline is automatically opened to perform the filling of the long tube vehicle (T1) and / or the hydrogen supply operation to the hydrogen refueling substation.

7. The method according to claim 6, characterized in that, In the valve linkage step, the redundant delivery capacity of the compressor that is performing the long tube truck filling operation is given priority. By opening the corresponding third type of shut-off valve, hydrogen is replenished to the hydrogen supply main pipe (16) and the hydrogen storage cylinder group (T2) to maintain the pressure of the hydrogen supply main pipe (16) above the preset hydrogen supply pressure lower limit.

8. The method according to claim 6, characterized in that, The method further includes a pressure protection step: when the compressor outlet pressure reaches a first set pressure value and no target shut-off valve is opened, the compressor's reflux regulating valve is controlled to open to release pressure and self-circulate; when a target shut-off valve is opened, the reflux regulating valve is controlled to gradually close.

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