Natural gas and hydrogen combined storage and conveying system and method based on LNG (Liquefied Natural Gas) filling station

Abstract

The invention discloses a natural gas and hydrogen combined storage and conveying system and method based on an LNG filling station, and belongs to the technical field of low-temperature adsorption gas storage and energy storage. The system comprises an LNG storage system, a zeolite molecular sieve low-temperature adsorption hydrogen storage system and a hydrogen-doped natural gas conveying system. The LNG storage system is based on an existing LNG filling station, and LNG cold energy is fully utilized on the basis that natural gas output is not affected. The zeolite molecular sieve low-temperature adsorption hydrogen storage system comprises a three-stage cooling step, so that the cold energy of the LNG filling station is fully utilized, and the hydrogen storage density of physical adsorption hydrogen storage is improved; according to the hydrogen-doped natural gas conveying system, on the basis that independent gas supply is reserved, two kinds of gas fuel are mixed to replace the urban natural gas supply rate. The system provided by the invention is safe, efficient and low in cost, and improves the storage and supply efficiency of urban clean energy.

Description

Technical Field

[0001] The present invention belongs to the fields of low-temperature adsorption gas storage technology and energy storage technology, and specifically relates to a natural gas and hydrogen combined storage and transportation system and method based on an LNG filling station. Background Art

[0002] The situation of global warming is becoming increasingly severe, and the development and utilization of clean energy is an important development direction in the energy field. Among them, hydrogen energy has become an ideal energy form for the future society due to its clean and efficient characteristics. The storage of hydrogen energy has always been one of the key factors limiting its utilization. Physical adsorption hydrogen storage has the advantage of high safety and is an important hydrogen storage method. Since physical adsorbents such as zeolite and activated carbon significantly increase the amount of hydrogen adsorption at low temperatures, low-temperature physical adsorption hydrogen storage can obtain a higher hydrogen storage density under appropriate pressure, while also having the advantage of high safety. However, there are fewer ways to dissipate the high-grade cold energy of liquid natural gas (LNG), which often results in energy waste. Studies have shown that the appropriate addition of hydrogen to natural gas can help improve the combustion performance of the fuel and increase the calorific value of the fuel. In addition, hydrogen-blended natural gas can be directly transported through urban natural gas pipelines without the need to build additional hydrogen transmission pipelines.

[0003] Therefore, there is an urgent need to provide a natural gas and hydrogen combined storage and transportation system. Summary of the invention

[0004] The purpose of the present invention is to solve the problem of energy waste in hydrogen storage in the prior art, and to provide a natural gas and hydrogen combined storage and transportation system and method based on an LNG filling station. The system uses the cold energy of LNG output to pre-cool hydrogen, and assists other cold sources to reduce the temperature of hydrogen and increase the amount of hydrogen storage. At the same time, the gasified natural gas can be directly output as a gas station product, or it can be mixed with the stored hydrogen to form hydrogen-blended natural gas.

[0005] The specific technical solutions adopted by the present invention are as follows:

[0006] In a first aspect, the present invention provides a natural gas and hydrogen combined storage and transportation system based on an LNG filling station, comprising a zeolite molecular sieve hydrogen storage tank, an LNG storage tank, a first-stage heat exchanger, a second-stage heat exchanger, a third-stage heat exchanger, a gas mixer, a hydrogen-blended natural gas storage tank, a normal temperature and high-pressure hydrogen storage tank, a normal temperature and high-pressure natural gas storage tank, and a cold hydrogen buffer tank;

[0007] The inlet of the LNG storage tank is connected to the external liquefied natural gas, and the low-temperature LNG outlet at the bottom of the LNG storage tank is connected to the cold side inlet of the second-stage heat exchanger through a pipeline to provide cooling for the second-stage heat exchanger; the cold side outlet of the second-stage heat exchanger is divided into two branches through a pipeline, one branch is connected to the natural gas inlet of the gas mixer, and the other branch is connected to the inlet of the normal temperature and high-pressure natural gas storage tank;

[0008] The hot side inlet of the first stage heat exchanger is connected to the external hydrogen to cool the hydrogen; the hot side outlet of the first stage heat exchanger is connected to the second stage heat exchanger and the third stage heat exchanger in sequence through a pipeline, and then connected to the inlet of the zeolite molecular sieve hydrogen storage tank;

[0009] The zeolite molecular sieve hydrogen storage tank is filled with zeolite molecular sieve as a hydrogen storage material, and the outlet of the zeolite molecular sieve hydrogen storage tank is connected to the cold side inlet of the first stage heat exchanger after passing through the cold hydrogen buffer tank, so as to provide cold capacity for the first stage heat exchanger; the cold side outlet of the first stage heat exchanger is divided into two branches through a pipeline, one branch is connected to the hydrogen inlet of the gas mixer, and the other branch is connected to the inlet of the normal temperature and high pressure hydrogen storage tank;

[0010] The gas mixer mixes part of the hydrogen from the zeolite molecular sieve hydrogen storage tank and part of the natural gas from the LNG storage tank; the outlet of the gas mixer is connected to the hydrogen-blended natural gas storage tank through a pipeline.

[0011] Preferably, the volume ratio of hydrogen in the gas mixer is 10-12%, and the volume ratio of natural gas is 88-90%.

[0012] Furthermore, the volume ratio of hydrogen in the gas mixer is 12%, and the volume ratio of natural gas is 88%.

[0013] Preferably, liquid nitrogen is introduced into the cold side inlet of the third stage heat exchanger to further cool the hydrogen so that the temperature of the hydrogen drops to the liquid nitrogen temperature range to increase the adsorption hydrogen storage capacity.

[0014] Preferably, the zeolite molecular sieve hydrogen storage tank is filled with SOD framework molecular sieve as a hydrogen storage material; a heater is also provided in the zeolite molecular sieve hydrogen storage tank to heat the hydrogen storage material to desorb hydrogen.

[0015] Preferably, the first-stage heat exchanger, the second-stage heat exchanger and the third-stage heat exchanger are all plate-fin heat exchangers.

[0016] Preferably, the first stage heat exchanger cools the hydrogen from the outside to 180-220K.

[0017] Preferably, the second stage heat exchanger further cools the hydrogen from the first stage heat exchanger to 120-160K.

[0018] Preferably, the third stage heat exchanger further cools the hydrogen from the second stage heat exchanger to 75-80K.

[0019] In a second aspect, the present invention provides an operation method of the natural gas and hydrogen combined storage and transportation system according to the first aspect, which is as follows:

[0020] S1: When there is no hydrogen filling system, the first-stage heat exchanger, the second-stage heat exchanger and the third-stage heat exchanger are all inoperative; the low-temperature LNG at the bottom of the LNG storage tank directly enters the cold side inlet of the second-stage heat exchanger, exchanges heat with the air to evaporate and gasify to form natural gas, a portion of the natural gas enters the gas mixer, and the remaining natural gas enters the normal temperature and high-pressure natural gas storage tank for storage; the heater in the zeolite molecular sieve hydrogen storage tank heats the hydrogen storage material to desorb hydrogen; the cold hydrogen from the bottom of the zeolite molecular sieve hydrogen storage tank first enters the cold hydrogen buffer tank, and then enters the cold side inlet of the first-stage heat exchanger, exchanges heat with the air to form normal temperature hydrogen, a portion of the hydrogen enters the gas mixer, and the remaining hydrogen enters the normal temperature and high-pressure hydrogen storage tank for storage; the gas mixer extracts natural gas and hydrogen from the LNG storage tank and the zeolite molecular sieve hydrogen storage tank respectively according to the proportion, forms hydrogen-blended natural gas, and then enters the hydrogen-blended natural gas storage tank for storage;

[0021] S2: When hydrogen is charged into the system, the first-stage heat exchanger, the second-stage heat exchanger and the third-stage heat exchanger all work to cool the hydrogen; the heater in the zeolite molecular sieve hydrogen storage tank heats the hydrogen storage material to desorb the hydrogen; the cold hydrogen from the bottom of the zeolite molecular sieve hydrogen storage tank first enters the cold hydrogen buffer tank, and then enters the cold side inlet of the first-stage heat exchanger, and is pre-cooled by heat exchange with normal temperature hydrogen in the first-stage heat exchanger; the hydrogen at the cold side outlet of the first-stage heat exchanger passes through the output pipeline, a part of which enters the gas mixer, and the rest enters the normal temperature high-pressure hydrogen storage tank for storage; The low-temperature LNG at the bottom of the LNG storage tank enters the cold side inlet of the second-stage heat exchanger to exchange heat with hydrogen; the LNG absorbs heat and vaporizes to form natural gas, part of which enters the gas mixer, and the remaining natural gas enters the normal temperature and high-pressure natural gas storage tank for storage; then, liquid nitrogen enters the cold side of the third-stage heat exchanger to fully exchange heat with the hydrogen, and then is filled into the zeolite molecular sieve hydrogen storage tank for low-temperature adsorption and storage; the gas mixer draws natural gas and hydrogen from the LNG storage tank and the zeolite molecular sieve hydrogen storage tank in proportion, respectively, to form hydrogen-blended natural gas, which is then input into the hydrogen-blended natural gas storage tank for storage.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] (1) The present invention makes full use of the excess cold energy of LNG filling stations and provides a combined storage method of LNG and hydrogen, which does not require a large amount of additional equipment and realizes efficient storage of hydrogen energy. At the same time, the hydrogen storage method has low energy consumption, high safety and stability, considerable hydrogen storage density, good economy and operability, and controllable safety risks.

[0024] (2) The present invention provides a low-cost and convenient method for generating and storing hydrogen-blended natural gas fuel by utilizing existing LNG filling station equipment. Compared with commonly used pure natural gas fuel, hydrogen-blended natural gas fuel has higher calorific value and cleanliness, and can be transported using existing urban natural gas pipelines. It is an ideal clean fuel and helps promote the development and utilization of clean energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The overall flow chart of the natural gas and hydrogen combined storage and transportation system provided for this embodiment;

[0026] In the figure: zeolite molecular sieve hydrogen storage tank 1, LNG storage tank 2, first stage heat exchanger 3, second stage heat exchanger 4, third stage heat exchanger 5, gas mixer 6, hydrogen-blended natural gas storage tank 7, normal temperature and high pressure hydrogen storage tank 8, normal temperature and high pressure natural gas storage tank 9, cold hydrogen buffer tank 10. DETAILED DESCRIPTION

[0027] The present invention is further described and illustrated below in conjunction with the accompanying drawings and specific embodiments. The technical features of each embodiment of the present invention can be combined accordingly without conflicting with each other.

[0028] like Figure 1 As shown, as a preferred embodiment of the present invention, this embodiment provides a natural gas and hydrogen combined storage and transportation system based on an LNG filling station. The system includes an LNG storage system, a zeolite molecular sieve low-temperature adsorption hydrogen storage system and a hydrogen-blended natural gas transportation system.

[0029] The LNG storage system includes an LNG storage tank 2, a second-stage heat exchanger 4, and a normal-temperature high-pressure natural gas storage tank 9. The zeolite molecular sieve low-temperature adsorption hydrogen storage system includes a zeolite molecular sieve hydrogen storage tank 1, a first-stage heat exchanger 3, a second-stage heat exchanger 4, a third-stage heat exchanger 5, a normal-temperature high-pressure hydrogen storage tank 8, and a cold hydrogen buffer tank 10. The hydrogen-blended natural gas delivery system includes a gas mixer 6 and a hydrogen-blended natural gas storage tank 7.

[0030] like Figure 1 As shown, in the system provided by the present invention, the inlet of the LNG storage tank 2 is connected to the external liquefied natural gas. The low-temperature LNG outlet at the bottom of the LNG storage tank 2 is connected to the cold side inlet of the second-stage heat exchanger 4 through a pipeline, and the cold energy when the LNG is output can provide cold energy for the hydrogen in the second-stage heat exchanger 4; the cold side outlet of the second-stage heat exchanger 4 is divided into two branches through a pipeline, one branch is connected to the natural gas inlet of the gas mixer 6, and the other branch is connected to the inlet of the normal temperature and high pressure natural gas storage tank 9. After the liquefied natural gas from the LNG storage tank 2 is gasified into natural gas through the second-stage heat exchanger 4, a part of it enters the gas mixer 6, and the other part enters the normal temperature and high pressure natural gas storage tank 9 for storage.

[0031] In the system provided by the present invention, the hot side inlet of the first stage heat exchanger 3 is connected to the hydrogen from the outside, and the first stage heat exchanger 3 cools the hydrogen; the hot side outlet of the first stage heat exchanger 3 is connected to the second stage heat exchanger 4 and the third stage heat exchanger 5 in sequence through a pipeline, and then connected to the inlet of the zeolite molecular sieve hydrogen storage tank 1. The hydrogen cooled by the first stage heat exchanger 3 is further cooled by the second stage heat exchanger 4 and the third stage heat exchanger 5 in sequence, and then enters the zeolite molecular sieve hydrogen storage tank 1 for storage.

[0032] The zeolite molecular sieve hydrogen storage tank 1 is filled with zeolite molecular sieve as a hydrogen storage material. In this embodiment, the hydrogen storage material in the zeolite molecular sieve hydrogen storage tank 1 adopts a SOD skeleton molecular sieve material with a high specific surface area. The hydrogen storage capacity of this material is 2.75% under the conditions of 77K and 1MPa. The hydrogen storage pressure in this working condition is low and the safety is high. Increasing the hydrogen storage pressure can still greatly increase the hydrogen storage capacity. Compared with the commonly used 70MPa compressed gaseous hydrogen storage, this method has significant safety advantages, and compared with liquid hydrogen storage, it has lower energy consumption and economic advantages. The zeolite molecular sieve hydrogen storage tank 1 is also provided with a heater. When hydrogen needs to be output, the heater heats the hydrogen storage material to desorb hydrogen.

[0033] In the system provided by the present invention, the outlet of the zeolite molecular sieve hydrogen storage tank 1 is connected to the cold side inlet of the first stage heat exchanger 3 after passing through the cold hydrogen buffer tank 10, providing cold capacity for the first stage heat exchanger 3; the cold side outlet of the first stage heat exchanger 3 is divided into two branches through a pipeline, one branch is connected to the hydrogen inlet of the gas mixer 6, and the other branch is connected to the inlet of the normal temperature and high pressure hydrogen storage tank 8. A part of the hydrogen from the zeolite molecular sieve hydrogen storage tank 1 enters the gas mixer 6, and the other part enters the normal temperature and high pressure hydrogen storage tank 8 for storage.

[0034] In the system provided by the present invention, part of the hydrogen from the zeolite molecular sieve hydrogen storage tank 1 and part of the natural gas from the LNG storage tank 2 are mixed in the gas mixer 6; the outlet of the gas mixer 6 is connected to the hydrogen-blended natural gas storage tank 7 through a pipeline. Properly doping hydrogen in natural gas helps to improve the combustion performance of the fuel and increase the calorific value of the fuel. The volume ratio of hydrogen in the gas mixer 6 is controlled at 10-12%, and the volume ratio of natural gas is controlled at 88-90%. In this embodiment, the volume ratio of hydrogen in the gas mixer 6 is 12%, and the volume ratio of natural gas is 88%.

[0035] In this embodiment, the first-stage heat exchanger 3, the second-stage heat exchanger 4 and the third-stage heat exchanger 5 are all plate-fin heat exchangers. The first-stage heat exchanger 3 cools the hydrogen from the outside to about 200K, and the second-stage heat exchanger 4 further cools the hydrogen from the first-stage heat exchanger 3 to about 150K. Liquid nitrogen is introduced into the cold side inlet of the third-stage heat exchanger 5 to further cool the hydrogen, so that the temperature of the hydrogen drops to the liquid nitrogen temperature zone to increase the adsorption hydrogen storage capacity. The third-stage heat exchanger 5 further cools the hydrogen from the second-stage heat exchanger 4 to 75-80K.

[0036] The specific operation mode of the system provided in this embodiment is as follows:

[0037] 1) When no hydrogen is charged into the system, the first stage heat exchanger 3, the second stage heat exchanger 4 and the third stage heat exchanger 5 do not work. The low-temperature LNG at the bottom of the LNG storage tank 2 directly enters the cold side inlet of the second stage heat exchanger 4, exchanges heat with the air to evaporate and gasify to form natural gas, a part of which enters the gas mixer 6, and the remaining natural gas enters the normal temperature and high pressure natural gas storage tank 9 for storage and output as needed.

[0038] The heater in the zeolite molecular sieve hydrogen storage tank 1 heats the hydrogen storage material to desorb hydrogen. The cold hydrogen from the bottom of the zeolite molecular sieve hydrogen storage tank 1 first enters the cold hydrogen buffer tank 10, and then enters the cold side inlet of the first-stage heat exchanger 3, exchanges heat with the air to form room-temperature hydrogen, a part of the hydrogen enters the gas mixer 6, and the remaining hydrogen enters the room-temperature high-pressure hydrogen storage tank 8 for storage and output as needed.

[0039] The gas mixer 6 extracts natural gas and hydrogen from the LNG storage tank 2 and the zeolite molecular sieve hydrogen storage tank 1 in a volume ratio of 88% natural gas and 12% hydrogen, respectively, to form hydrogen-blended natural gas, which is then input into the hydrogen-blended natural gas storage tank 7 for storage and connected to the city natural gas pipeline for output on demand.

[0040] 2) When hydrogen is filled into the system, the first-stage heat exchanger 3, the second-stage heat exchanger 4 and the third-stage heat exchanger 5 all work to cool the hydrogen. The heater in the zeolite molecular sieve hydrogen storage tank 1 heats the hydrogen storage material to desorb the hydrogen. The cold hydrogen (about 150K) from the bottom of the zeolite molecular sieve hydrogen storage tank 1 first enters the cold hydrogen buffer tank 10, and then enters the cold side inlet of the first-stage heat exchanger 3. It is pre-cooled by heat exchange with normal temperature hydrogen in the first-stage heat exchanger 3, and the hydrogen temperature drops to about 200K. The hydrogen at the cold side outlet of the first-stage heat exchanger 3 passes through the output pipeline, and a part of it enters the gas mixer 6, and the rest enters the normal temperature high-pressure hydrogen storage tank 8 for storage.

[0041] The low-temperature LNG (about 111K) from the bottom of the LNG storage tank 2 enters the cold side inlet of the second-stage heat exchanger 4 to exchange heat with hydrogen, reducing the temperature of the hydrogen to about 150K. LNG absorbs heat and vaporizes to form natural gas, a part of which enters the gas mixer 6, and the remaining natural gas enters the normal temperature and high pressure natural gas storage tank 9 for storage. Subsequently, liquid nitrogen enters the cold side of the third-stage heat exchanger 5, fully exchanges heat with hydrogen, reducing its temperature to about 77-80K, and then is filled into the zeolite molecular sieve hydrogen storage tank 1 for low temperature adsorption and storage.

[0042] The gas mixer 6 extracts natural gas and hydrogen from the LNG storage tank 2 and the zeolite molecular sieve hydrogen storage tank 1 in a volume ratio of 88% natural gas and 12% hydrogen, respectively, to form hydrogen-blended natural gas, which is then input into the hydrogen-blended natural gas storage tank 7 for storage and connected to the city natural gas pipeline for output on demand.

[0043] The above-described embodiment is only a preferred solution of the present invention, but it is not intended to limit the present invention. A person skilled in the relevant technical field may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, any technical solution obtained by equivalent replacement or equivalent transformation falls within the protection scope of the present invention.

Claims

1. A natural gas and hydrogen combined storage and transportation system based on an LNG filling station, characterized in that: It comprises a zeolite molecular sieve hydrogen storage tank (1), an LNG storage tank (2), a first-stage heat exchanger (3), a second-stage heat exchanger (4), a third-stage heat exchanger (5), a gas mixer (6), a hydrogen-blended natural gas storage tank (7), a normal temperature and high pressure hydrogen storage tank (8), a normal temperature and high pressure natural gas storage tank (9) and a cold hydrogen buffer tank (10); The inlet of the LNG storage tank (2) is connected to the external liquefied natural gas, and the low-temperature LNG outlet at the bottom of the LNG storage tank (2) is connected to the cold side inlet of the second-stage heat exchanger (4) through a pipeline, so as to provide cooling capacity for the second-stage heat exchanger (4); the cold side outlet of the second-stage heat exchanger (4) is divided into two branches through a pipeline, one branch is connected to the natural gas inlet of the gas mixer (6), and the other branch is connected to the inlet of the normal temperature and high pressure natural gas storage tank (9); The hot side inlet of the first-stage heat exchanger (3) is connected to external hydrogen to cool the hydrogen; the hot side outlet of the first-stage heat exchanger (3) is connected to the second-stage heat exchanger (4) and the third-stage heat exchanger (5) in sequence through pipelines, and then connected to the inlet of the zeolite molecular sieve hydrogen storage tank (1); The zeolite molecular sieve hydrogen storage tank (1) is filled with zeolite molecular sieve as a hydrogen storage material. The outlet of the zeolite molecular sieve hydrogen storage tank (1) is connected to the cold side inlet of the first stage heat exchanger (3) after passing through the cold hydrogen buffer tank (10), thereby providing cold energy for the first stage heat exchanger (3); the cold side outlet of the first stage heat exchanger (3) is divided into two branches through a pipeline, one branch is connected to the hydrogen inlet of the gas mixer (6), and the other branch is connected to the inlet of the normal temperature and high pressure hydrogen storage tank (8); The gas mixer (6) mixes part of the hydrogen from the zeolite molecular sieve hydrogen storage tank (1) and part of the natural gas from the LNG storage tank (2); the outlet of the gas mixer (6) is connected to the hydrogen-blended natural gas storage tank (7) through a pipeline.

2. The natural gas and hydrogen combined storage and transportation system based on the LNG filling station according to claim 1 is characterized in that: The volume ratio of hydrogen in the gas mixer (6) is 10-12%, and the volume ratio of natural gas is 88-90%.

3. The natural gas and hydrogen combined storage and transportation system based on the LNG filling station according to claim 2 is characterized in that: The volume ratio of hydrogen in the gas mixer (6) is 12%, and the volume ratio of natural gas is 88%.

4. The natural gas and hydrogen combined storage and transportation system based on the LNG filling station according to claim 1 is characterized in that: Liquid nitrogen is introduced into the cold side inlet of the third stage heat exchanger (5) to further cool the hydrogen, so that the temperature of the hydrogen drops to the liquid nitrogen temperature range to increase the adsorption hydrogen storage capacity.

5. The natural gas and hydrogen combined storage and transportation system based on the LNG filling station according to claim 1 is characterized in that: The zeolite molecular sieve hydrogen storage tank (1) is filled with SOD framework molecular sieve as a hydrogen storage material; a heater is also provided in the zeolite molecular sieve hydrogen storage tank (1) to heat the hydrogen storage material so as to desorb hydrogen.

6. The natural gas and hydrogen combined storage and transportation system based on the LNG filling station according to claim 1 is characterized in that: The first-stage heat exchanger (3), the second-stage heat exchanger (4) and the third-stage heat exchanger (5) are all plate-fin heat exchangers.

7. The natural gas and hydrogen combined storage and transportation system based on the LNG filling station according to claim 1 is characterized in that: The first stage heat exchanger (3) cools the hydrogen from the outside to a temperature of 180-220K.

8. The natural gas and hydrogen combined storage and transportation system based on the LNG filling station according to claim 1 is characterized in that: The second stage heat exchanger (4) further cools the hydrogen from the first stage heat exchanger (3) to 120-160K.

9. The natural gas and hydrogen combined storage and transportation system based on the LNG filling station according to claim 1 is characterized in that: The third stage heat exchanger (5) further cools the hydrogen from the second stage heat exchanger (4) to 75-80K.

10. An operating method using the natural gas and hydrogen combined storage and transportation system according to any one of claims 1 to 9, characterized in that: The details are as follows: S1: When no hydrogen is charged into the system, the first-stage heat exchanger (3), the second-stage heat exchanger (4) and the third-stage heat exchanger (5) are all inoperative; the low-temperature LNG at the bottom of the LNG storage tank (2) directly enters the cold side inlet of the second-stage heat exchanger (4), exchanges heat with air to evaporate and gasify to form natural gas, a portion of which enters the gas mixer (6), and the remaining natural gas enters the normal temperature and high-pressure natural gas storage tank (9) for storage; the heater in the zeolite molecular sieve hydrogen storage tank (1) heats the hydrogen storage material to desorb hydrogen; The cold hydrogen at the bottom of the zeolite molecular sieve hydrogen storage tank (1) first enters the cold hydrogen buffer tank (10), then enters the cold side inlet of the first stage heat exchanger (3), exchanges heat with air to form room temperature hydrogen, a portion of the hydrogen enters the gas mixer (6), and the remaining hydrogen enters the room temperature high pressure hydrogen storage tank (8) for storage; the gas mixer (6) extracts natural gas and hydrogen from the LNG storage tank (2) and the zeolite molecular sieve hydrogen storage tank (1) respectively according to proportion, forms hydrogen-blended natural gas, and then enters the hydrogen-blended natural gas storage tank (7) for storage; S2: When hydrogen is charged into the system, the first-stage heat exchanger (3), the second-stage heat exchanger (4) and the third-stage heat exchanger (5) all work to cool the hydrogen; the heater in the zeolite molecular sieve hydrogen storage tank (1) heats the hydrogen storage material to desorb the hydrogen; the cold hydrogen from the bottom of the zeolite molecular sieve hydrogen storage tank (1) first enters the cold hydrogen buffer tank (10), and then enters the cold side inlet of the first-stage heat exchanger (3), and is pre-cooled by heat exchange with normal temperature hydrogen in the first-stage heat exchanger (3); the hydrogen at the cold side outlet of the first-stage heat exchanger (3) passes through the output pipeline, a part of which enters the gas mixer (6), and the rest enters the normal temperature high-pressure hydrogen storage tank (8) for storage; Low-temperature LNG from the bottom of the LNG storage tank (2) enters the cold side inlet of the second-stage heat exchanger (4) to exchange heat with hydrogen; the LNG absorbs heat and gasifies to form natural gas, a portion of which enters the gas mixer (6), and the remaining natural gas enters the normal temperature and high-pressure natural gas storage tank (9) for storage; then, liquid nitrogen enters the cold side of the third-stage heat exchanger (5), fully exchanges heat with the hydrogen, and is then filled into the zeolite molecular sieve hydrogen storage tank (1) to be adsorbed and stored at low temperature; the gas mixer (6) extracts natural gas and hydrogen from the LNG storage tank (2) and the zeolite molecular sieve hydrogen storage tank (1) respectively in proportion to form hydrogen-blended natural gas, which is then input into the hydrogen-blended natural gas storage tank (7) for storage.

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