Gas filling and storing method of hydrogen refueling station for optimizing conveying path of hydrogen storage bottle group and improving gas taking efficiency

Abstract

The invention discloses a hydrogen refueling station gas filling and storing method for optimizing a hydrogen storage bottle set conveying path and improving gas taking efficiency. After hydrogen needs to be injected into the hydrogen injection machine and the pressure of the high-pressure storage tank is smaller than or equal to 35 MPa, the following steps are executed: 1, judging whether a vehicle is not injected for a long time or not; if no vehicle is filled for a long time, executing the step 2; if the vehicle is not filled for a long time, the high-pressure storage tank, the medium-pressure storage tank and the low-pressure storage tank inject hydrogen into the hydrogen filling machine, and the process is ended; 2, if the pressure of the low-pressure storage tank is larger than or equal to 15 MPa, hydrogen in the low-pressure storage tank is extracted through a hydrogen compressor, and the hydrogen is injected into the high-pressure storage tank after being pressurized; if the pressure of the low-pressure storage tank is smaller than 15 MPa, hydrogen in the medium-pressure storage tank is extracted through a hydrogen compressor, and the hydrogen is injected into the high-pressure storage tank after being pressurized; and 3, after the pressure of the high-pressure storage tank reaches 40MPa, injecting hydrogen into the hydrogenation machine through the high-pressure storage tank. The application of the invention can greatly improve the gas extraction rate of the hydrogen refueling station.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogen refueling station construction, and in particular to a hydrogen refueling station gas filling and storage method for optimizing the transportation path of hydrogen storage bottle groups and improving gas extraction efficiency. Background Art

[0002] The current mainstream 45MPa / 90MPa hydrogen refueling stations mainly use a three-stage compression method to refuel hydrogen fuel vehicles with an on-board storage tank pressure of 35MPa / 70MPa. The hydrogen refueling station is equipped with three pressure levels of hydrogen storage tanks with a maximum hydrogen storage pressure of 45MPa / 90MPa, namely high pressure, medium pressure and low pressure. Hydrogen refueling vehicles are refueled with hydrogen through hydrogen storage tanks.

[0003] During peak vehicle refueling periods at hydrogen refueling stations, a high level of hydrogen often remains in the tertiary tanks. However, due to a drop in pressure in the high-pressure tanks, the station is unable to continue refueling and needs to replenish hydrogen from an external source. This phenomenon results in low efficiency of the high-pressure hydrogen storage system, with a gas withdrawal rate of approximately 43%, affecting the economic efficiency of the hydrogen refueling station. The main reason for this is that the low- and medium-pressure hydrogen storage tanks used in the traditional refueling process cannot directly replenish the high-pressure tanks and can only be replenished from an external source. The non-circulation of hydrogen transport within the hydrogen storage system results in a low gas withdrawal rate, ultimately affecting the economic efficiency of the hydrogen refueling station.

[0004] Therefore, how to improve the gas extraction rate of hydrogen refueling stations has become a technical problem that needs to be urgently solved by those skilled in the art. Summary of the Invention

[0005] In view of the above-mentioned defects of the prior art, the present invention provides a hydrogen filling and storage method for a hydrogen refueling station that optimizes the transportation path of the hydrogen storage bottle group and improves the gas extraction efficiency, so as to achieve the purpose of improving the gas extraction rate of the hydrogen refueling station.

[0006] To achieve the above objectives, the present invention discloses a method for filling and storing gas at a hydrogen refueling station that optimizes the transportation path of a hydrogen storage bottle group and improves gas extraction efficiency. The hydrogen refueling station includes a hydrogen unloading column, a hydrogen compressor, a gas bottle group and a hydrogen refueling machine connected in sequence.

[0007] Wherein, the gas cylinder group includes a high-pressure storage tank, a medium-pressure storage tank and a low-pressure storage tank connected in parallel;

[0008] A third valve, a second valve and a first valve are respectively provided between the high-pressure storage tank, the medium-pressure storage tank and the low-pressure storage tank and the hydrogen compressor;

[0009] A medium-pressure hydrogen return pipeline is provided between the medium-pressure storage tank and the second valve via a tee;

[0010] The medium-pressure hydrogen return pipeline is provided with a fifth valve;

[0011] A low-pressure hydrogen return pipeline is provided between the low-pressure storage tank and the first valve via a tee;

[0012] The low-pressure hydrogen return pipeline is provided with a fourth valve;

[0013] When hydrogen needs to be injected into the hydrogenator and the pressure of the high-pressure storage tank is less than or equal to 35 MPa, perform the following steps:

[0014] Step 1: Determine whether the vehicle has not been refueled for a long time;

[0015] If the vehicle has not been refueled for a long time, proceed to step 2;

[0016] If there is no refueling of the vehicle for a long time, keep the first valve, the second valve and the third valve open, keep the fourth valve and the fifth valve closed, and allow the high-pressure storage tank, the medium-pressure storage tank and the low-pressure storage tank to inject hydrogen into the hydrogen refueling machine, and end the process;

[0017] Step 2: Determine whether the pressure of the low-pressure storage tank is greater than or equal to 15 MPa;

[0018] If the pressure of the low-pressure storage tank is greater than or equal to 15 MPa, keep the third valve and the fourth valve open, close the first valve, the second valve, and the fifth valve, extract the hydrogen in the low-pressure storage tank through the hydrogen compressor, and inject the pressurized hydrogen into the high-pressure storage tank, and skip step 3 and go to step 4;

[0019] If the pressure of the low-pressure storage tank is less than 15 MPa, proceed to step 3;

[0020] Step 3: Determine whether the pressure of the medium pressure storage tank is greater than or equal to 25 MPa;

[0021] If the pressure of the medium-pressure storage tank is greater than or equal to 25 MPa, keep the third valve and the fifth valve open, close the second valve, the first valve, and the fourth valve, extract the hydrogen in the medium-pressure storage tank through the hydrogen compressor, and inject the pressurized hydrogen into the high-pressure storage tank;

[0022] If the pressure of the medium-pressure storage tank is less than 25 MPa, the process ends and waits for external hydrogen source replenishment;

[0023] Step 4: After the pressure of the high-pressure storage tank reaches 40 MPa, keep the third valve open, close the first valve, the second valve, the fifth valve and the fourth valve, and inject hydrogen into the hydrogenator through the high-pressure storage tank.

[0024] Preferably, the fifth valve, the fourth valve, the third valve, the second valve and the first valve are all electric regulating valves with a response time of less than 0.5 seconds.

[0025] Preferably, after the tube trailer has filled the gas cylinder group with hydrogen, the third valve, the second valve and the first valve are opened, and the fifth valve and the fourth valve are closed during hydrogenation.

[0026] Beneficial effects of the present invention:

[0027] The application of the present invention can greatly improve the gas extraction rate of the hydrogenation station.

[0028] The concept, specific structure and technical effects of the present invention will be further described below in conjunction with the accompanying drawings to fully understand the purpose, characteristics and effects of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A structural diagram of an embodiment of the present invention is shown.

[0030] Figure 2 A flow chart showing an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0031] Example 1

[0032] like Figure 1 and Figure 2 As shown, a hydrogen filling and storage method for a hydrogen refueling station is provided for optimizing the transportation path of a hydrogen storage bottle group to improve gas extraction efficiency. The hydrogen refueling station includes a hydrogen unloading column 1, a hydrogen compressor 2, a gas bottle group 3 and a hydrogen refueling machine 4 connected in sequence.

[0033] The gas cylinder group 3 includes a high-pressure storage tank 33, a medium-pressure storage tank 32 and a low-pressure storage tank 31 connected in parallel;

[0034] A third valve V3, a second valve V2 and a first valve V1 are respectively provided between the high-pressure storage tank 33, the medium-pressure storage tank 32 and the low-pressure storage tank 31 and the hydrogen compressor 2;

[0035] Between the medium-pressure storage tank 32 and the second valve V2, a medium-pressure return hydrogen pipeline 5 is provided through a tee;

[0036] The medium-pressure hydrogen return line 5 is provided with a fifth valve V5;

[0037] A low-pressure hydrogen return pipeline 6 is provided between the low-pressure storage tank 31 and the first valve V1 through a tee;

[0038] The low-pressure hydrogen return pipeline 6 is provided with a fourth valve V4;

[0039] When hydrogen needs to be injected into the hydrogenator 4 and the pressure of the high-pressure storage tank 33 is less than or equal to 35 MPa, the following steps are performed:

[0040] Step 1: Determine whether the vehicle has not been refueled for a long time;

[0041] In practical applications, a vehicle without refueling for a long time means that no hydrogen refueling request is detected for more than 30 minutes. 30 minutes is the optimal balance point, and the gas extraction rate improvement effect is the best at this time.

[0042] If the vehicle has not been refueled for a long time, proceed to step 2;

[0043] If the vehicle is not refueled for a long time, keep the first valve V1, the second valve V2 and the third valve V3 open, keep the fourth valve V4 and the fifth valve V5 closed, and allow the high-pressure storage tank 33, the medium-pressure storage tank 32 and the low-pressure storage tank 31 to inject hydrogen into the hydrogen refueling machine 4, and end the process;

[0044] Step 2: Determine whether the pressure of the low-pressure storage tank 31 is greater than or equal to 15 MPa;

[0045] If the pressure of the low-pressure storage tank 31 is greater than or equal to 15 MPa, keep the third valve V3 and the fourth valve V4 open, close the first valve V1, the second valve V2, and the fifth valve V5, extract the hydrogen in the low-pressure storage tank 31 through the hydrogen compressor 2, and inject the pressurized hydrogen into the high-pressure storage tank 33, skipping step 3 and going to step 4;

[0046] If the pressure of the low-pressure storage tank 31 is less than 15 MPa, proceed to step 3;

[0047] Step 3: Determine whether the pressure of the medium pressure storage tank 32 is greater than or equal to 25 MPa;

[0048] If the pressure of the medium-pressure storage tank 32 is greater than or equal to 25 MPa, keep the third valve V3 and the fifth valve V5 open, close the second valve V2, the first valve V1, and the fourth valve V4, and extract the hydrogen in the medium-pressure storage tank 32 through the hydrogen compressor 2, and inject the pressurized hydrogen into the high-pressure storage tank 33;

[0049] If the pressure of the medium-pressure storage tank 32 is less than 25 MPa, the process ends and waits for external hydrogen source to be replenished;

[0050] Step 4: After the pressure of the high-pressure storage tank 33 reaches 40 MPa, keep the third valve V3 open, close the first valve V1, the second valve V2, the fifth valve V5 and the fourth valve V4, and inject hydrogen into the hydrogenator 4 through the high-pressure storage tank 33.

[0051] The present invention adds a low-pressure hydrogen return pipeline 6 and a medium-pressure hydrogen return pipeline 5 between the low-pressure storage tank 31 and the inlet of the hydrogen compressor 2, and between the medium-pressure storage tank 32 and the inlet of the hydrogen compressor 2. Since the hydrogen compressor 2 is a diaphragm compressor, its inlet pressure P is actually proportional to the actual external output Q of the compressor. Therefore, using a low-pressure or medium-pressure storage tank as the compressor inlet can increase the filling flow of the compressor.

[0052] When high-pressure hydrogen is insufficient and there is no vehicle refueling, open the third valve V3 and the fourth valve V4 (or the fifth valve V5), close the second valve V2, the first valve V1 and the fifth valve V5 (or the fourth valve V4), and "return" the pressurized hydrogen in the low-pressure storage tank 31 (or the medium-pressure storage tank 32) to the high-pressure storage tank 33 to fully utilize the hydrogen in the low-pressure storage tank 31 and the medium-pressure storage tank 32.

[0053] In certain embodiments, the fifth valve V5 , the fourth valve V4 , the third valve V3 , the second valve V2 , and the first valve V1 are all electrically operated regulating valves with a response time of less than 0.5 seconds.

[0054] In certain embodiments, after the tube trailer has filled the gas cylinder group 3 with hydrogen, the third valve V3 , the second valve V2 , and the first valve V1 are opened, and the fifth valve V5 and the fourth valve V4 are closed during hydrogenation.

[0055] Example 2

[0056] Take the 45MPa hydrogen refueling station as an example.

[0057] The hydrogen refueling station is equipped with nine hydrogen storage cylinders, each with a water capacity of 1000L and a gas storage pressure of 45MPa. The hydrogen refueling station is used to refuel hydrogen fuel cell heavy trucks, with a target filling pressure of 35MPa. Each refueling operation involves approximately 20kg of hydrogen. When the hydrogen refueling station tanks employ the technology of the present invention and do not accept external hydrogen replenishment, the technical effectiveness is tested using the last high-pressure hydrogen storage cylinder group nearing the 36MPa limit where refueling is stopped. The hydrogen refueling station can refuel seven hydrogen heavy trucks at a time with a gas extraction rate of 55.2%, a significant increase of 28% compared to conventional systems.

[0058] High-pressure tank gas extraction rate and comparison table

[0059] index Traditional systems The present invention Gas extraction rate 43％ 55.2％ Number of refueling vehicles 5 vehicles 7 vehicles Filling quality 99.4kg 130.3kg

[0060] This method adds a hydrogen return pipeline between the low / medium pressure hydrogen storage bottle group and the compressor inlet, controls the hydrogen return pipeline valve when there is no vehicle refueling at the hydrogen refueling station, and compresses the hydrogen from the low / medium pressure hydrogen storage bottle group into the high-pressure hydrogen storage bottle group. The gas extraction rate of the hydrogen storage tank can reach 55%, thereby improving the economic efficiency of the hydrogen refueling station.

[0061] The air extraction rate in the present invention is defined as φ = △m / M*100%

[0062] △m is the mass kg of hydrogen filled in the vehicle;

[0063] M is the mass of hydrogen stored in the hydrogen storage tank, kg.

[0064] The above describes in detail the preferred embodiments of the present invention. It should be understood that those skilled in the art can make numerous modifications and variations based on the concepts of the present invention without inventive effort. Therefore, any technical solutions that can be derived by those skilled in the art through logical analysis, reasoning, or limited experimentation based on the concepts of the present invention and the prior art should be within the scope of protection defined by the claims.

Claims

1. A hydrogen filling and storage method for a hydrogen refueling station that optimizes the transport path of hydrogen storage bottles and improves gas extraction efficiency; characterized in that: The hydrogen refueling station comprises a hydrogen unloading column (1), a hydrogen compressor (2), a gas cylinder group (3) and a hydrogen refueling machine (4) which are connected in sequence; The gas cylinder group (3) comprises a high-pressure storage tank (33), a medium-pressure storage tank (32) and a low-pressure storage tank (31) connected in parallel; A third valve (V3), a second valve (V2) and a first valve (V1) are respectively provided between the high-pressure storage tank (33), the medium-pressure storage tank (32) and the low-pressure storage tank (31) and the hydrogen compressor (2); A medium-pressure hydrogen return pipeline (5) is provided between the medium-pressure storage tank (32) and the second valve (V2) via a tee; The medium-pressure hydrogen return pipeline (5) is provided with a fifth valve (V5); A low-pressure hydrogen return pipeline (6) is provided between the low-pressure storage tank (31) and the first valve (V1) via a tee; The low-pressure hydrogen return pipeline (6) is provided with a fourth valve (V4); When hydrogen needs to be injected into the hydrogenator (4) and the pressure of the high-pressure storage tank (33) is less than or equal to 35 MPa, the following steps are performed: Step 1: Determine whether the vehicle has not been refueled for a long time; If the vehicle has not been refueled for a long time, proceed to step 2; If the vehicle is not refueled for a long time, the first valve (V1), the second valve (V2) and the third valve (V3) are kept open, and the fourth valve (V4) and the fifth valve (V5) are kept closed, so that the high-pressure storage tank (33), the medium-pressure storage tank (32) and the low-pressure storage tank (31) inject hydrogen into the hydrogen refueling machine (4), and the process ends; Step 2: determining whether the pressure of the low-pressure storage tank (31) is greater than or equal to 15 MPa; If the pressure of the low-pressure storage tank (31) is greater than or equal to 15 MPa, keep the third valve (V3) and the fourth valve (V4) open, close the first valve (V1), the second valve (V2) and the fifth valve (V5), extract the hydrogen in the low-pressure storage tank (31) through the hydrogen compressor (2), and inject the pressurized hydrogen into the high-pressure storage tank (33), and skip step 3 and execute step 4; If the pressure of the low-pressure storage tank (31) is less than 15 MPa, proceed to step 3; Step 3: Determine whether the pressure of the medium-pressure storage tank (32) is greater than or equal to 25 MPa; If the pressure of the medium-pressure storage tank (32) is greater than or equal to 25 MPa, the third valve (V3) and the fifth valve (V5) are kept open, the second valve (V2), the first valve (V1) and the fourth valve (V4) are closed, the hydrogen in the medium-pressure storage tank (32) is extracted by the hydrogen compressor (2), and the pressurized hydrogen is injected into the high-pressure storage tank (33); If the pressure of the medium-pressure storage tank (32) is less than 25 MPa, the process is terminated and the external hydrogen source is waited for replenishment; Step 4: After the pressure in the high-pressure storage tank (33) reaches 40 MPa, keep the third valve (V3) open, close the first valve (V1), the second valve (V2), the fifth valve (V5) and the fourth valve (V4), and inject hydrogen into the hydrogenator (4) through the high-pressure storage tank (33).

2. The hydrogen filling and storage method for optimizing the hydrogen storage bottle group transportation path to improve gas extraction efficiency according to claim 1 is characterized in that: The fifth valve (V5), the fourth valve (V4), the third valve (V3), the second valve (V2) and the first valve (V1) are all electric regulating valves with a response time of less than 0.5 seconds.

3. The hydrogen filling and storage method for optimizing the hydrogen storage bottle group transportation path and improving the gas extraction efficiency according to claim 1 is characterized in that: After the long tube trailer has filled the gas cylinder group (3) with hydrogen, the third valve (V3), the second valve (V2) and the first valve (V1) are opened, and the fifth valve (V5) and the fourth valve (V4) are closed during hydrogenation.

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