Liquefied hydrogen charging system

Abstract

The present invention relates to a liquefied hydrogen charging system for vaporizing hydrogen in a storage tank in which liquefied hydrogen is stored and supplying same to a charger, the liquefied hydrogen charging system comprising: a storage tank in which liquefied hydrogen is stored; a vaporizer for vaporizing liquefied hydrogen supplied from the storage tank; a first heat exchanger for recovering cold heat from hydrogen gas introduced from the vaporizer through heat medium oil; a heater for heating hydrogen gas supplied from the first heat exchanger; a buffer for storing hydrogen gas supplied from the heater; a third heat exchanger for cooling hydrogen gas supplied from the buffer; a charger for receiving hydrogen gas supplied from the third heat exchanger; and a second heater directly connected from the vaporizer to the charger.

Description

Liquid hydrogen refueling system

[0001] The present invention relates to a liquid hydrogen refueling system, and more specifically, to a liquid hydrogen refueling system that overcomes the disadvantages of existing liquid hydrogen refueling stations, such as the waste of cold energy of liquid hydrogen and the generation and disposal of vaporized gas.

[0002] Generally, hydrogen fuel cell vehicles utilizing gaseous fuels such as hydrogen gas are attracting attention as low-emission vehicles to address recent environmental issues, and hydrogen refueling stations are required to stably and efficiently refuel the fuel tanks mounted on the vehicles in order to promote the widespread adoption of such hydrogen fuel cell vehicles.

[0003] Prior art related to such hydrogen refueling devices includes Application No. 10-2022-0120105 (hydrogen refueling device) and Application No. 10-2021-0064509 (hydrogen refueling device).

[0004] In these prior art technologies related to hydrogen refueling devices, energy loss occurs during the process in which liquid hydrogen vaporizes into gaseous hydrogen when cryogenic hydrogen gas is supplied from a pressure tank to a refueling device.

[0005] Application No. 10-2023-0019957 (liquid hydrogen filling system with cold heat recovery method) was proposed to minimize energy loss occurring during the process of supplying such cryogenic hydrogen gas to a charger.

[0006] Figure 1 is a conceptual diagram illustrating a conventional liquid hydrogen charging system.

[0007] The liquid hydrogen charging system illustrated in Fig. 1 proposes a system that increases energy efficiency generated during the process of supplying cryogenic hydrogen gas to a charger.

[0008] However, conventional hydrogen refueling systems have problems such as wasted cold energy from liquid hydrogen, a large amount of vaporized gas generated, and the waste of the generated vaporized gas.

[0009] In addition, there is a problem in that it is difficult to adjust the amount of hydrogen gas supplied to the charger according to the amount of hydrogen gas charged in the vehicle.

[0010] The liquid hydrogen charging system according to the present invention aims to provide a liquid hydrogen charging system that recovers cold energy wasted during the process of liquid hydrogen in a storage tank vaporizing, reduces the amount of vaporized gas generated, and solves the problem of wasting the generated vaporized gas.

[0011] In addition, the purpose is to provide a liquefied hydrogen charging system that uses energy more efficiently by directly supplying hydrogen, rather than storing it in a tank according to the charging amount.

[0012] A liquid hydrogen charging system according to the present invention is a liquid hydrogen charging system that vaporizes hydrogen from a storage tank in which liquid hydrogen is stored and supplies it to a charger, and is characterized by comprising: a storage tank in which liquid hydrogen is stored; a vaporizer that vaporizes liquid hydrogen supplied from the storage tank; a first heat exchanger that recovers cold heat from hydrogen gas flowing in from the vaporizer through a heat transfer fluid; a heater that heats hydrogen gas supplied from the first heat exchanger; a buffer in which hydrogen gas supplied from the heater is stored; a third heat exchanger that cools hydrogen gas supplied from the buffer; a charger that receives hydrogen gas supplied from the third heat exchanger; and a second heater that is directly connected from the vaporizer to the charger.

[0013] Here, the supply pipe connecting from the storage tank to the vaporizer is characterized by being installed to wrap around the outer wall of the storage tank.

[0014] In addition, the first heat exchanger is characterized by having a double structure of a front heat exchanger and a rear heat exchanger.

[0015] In addition, the first heat exchanger is characterized by including a low-temperature heat transfer fluid storage section and a high-temperature heat transfer fluid storage section.

[0016] In addition, the low-temperature heat transfer fluid storage unit is equipped with an auxiliary cooler, and the high-temperature heat transfer fluid storage unit is equipped with an auxiliary heater.

[0017] In addition, it is characterized by further including a vapor gas reuse line that supplies vapor gas generated in the storage tank to the buffer.

[0018] In addition, the above-mentioned vaporized gas reuse line is characterized by being installed to surround the outer wall of the above-mentioned storage tank.

[0019] In addition, another embodiment of the liquid hydrogen charging system according to the present invention is a liquid hydrogen charging system that vaporizes hydrogen from a storage tank in which liquid hydrogen is stored and supplies it to a charger, characterized in that it comprises: a storage tank in which liquid hydrogen is stored; a vaporizer that vaporizes liquid hydrogen supplied from the storage tank; a first heat exchanger including a front heat exchanger and a rear heat exchanger that recovers cold heat from hydrogen gas flowing in from the vaporizer through a heat transfer fluid; a heater that heats hydrogen gas supplied from the first heat exchanger; a buffer in which hydrogen gas supplied from the heater is stored; a third heat exchanger that cools hydrogen gas supplied from the buffer; and a charger that receives hydrogen gas supplied from the third heat exchanger.

[0020] Here, the first heat exchanger is characterized by including a low-temperature heat transfer fluid storage section in which the heat transfer fluid that has passed through the downstream heat exchanger is stored, and a high-temperature heat transfer fluid storage section in which an auxiliary heater is installed to heat the heat transfer fluid supplied from the low-temperature heat transfer fluid storage section.

[0021] In addition, the low-temperature heat transfer fluid storage unit is characterized by having an auxiliary cooler installed therein, and an auxiliary heat transfer fluid line is formed to supply heat transfer fluid from the low-temperature heat transfer fluid storage unit to a third heat exchanger and to connect the heat transfer fluid flowing in from the third heat exchanger to the low-temperature heat transfer fluid storage unit.

[0022] Finally, in a liquid hydrogen charging system that vaporizes hydrogen from a storage tank in which liquid hydrogen is stored and supplies it to a charger, the system comprises: a storage tank in which liquid hydrogen is stored; a vaporizer that vaporizes liquid hydrogen supplied from the storage tank; a first heat exchanger that recovers cold heat from hydrogen gas flowing in from the vaporizer through a heat transfer fluid; a heater that heats hydrogen gas supplied from the first heat exchanger; a buffer in which hydrogen gas supplied from the heater is stored; a third heat exchanger that cools hydrogen gas supplied from the buffer through the heat transfer fluid of the first heat exchanger; a charger that receives hydrogen gas supplied from the third heat exchanger; and a second heater line that is directly connected from the vaporizer to the charger.

[0023] The liquid hydrogen charging system according to the present invention includes a second heater directly connected from the vaporizer to the charger, and has the advantage of being able to efficiently use and supply energy according to the required amount of gaseous hydrogen charging.

[0024] In addition, the structure of the first heat exchanger, which recovers cold heat through hydrogen gas via a heat transfer fluid, is composed of upstream and downstream heat exchangers, and has the advantage of efficiently recovering cold heat through a separate auxiliary cooler, auxiliary heater, and auxiliary heat transfer fluid line.

[0025] In addition, by having the vaporized gas reuse line wrap around the outer wall of the storage tank, it has the advantage of recovering the cold energy wasted during the vaporization process of liquid hydrogen in the storage tank, and improving upon existing disadvantages by reducing the amount of vaporized gas generated while reusing the generated vaporized gas that would otherwise be wasted.

[0026] FIG. 1 is a conceptual diagram illustrating a conventional liquid hydrogen charging system.

[0027] FIG. 2 is a conceptual diagram illustrating a liquid hydrogen charging system according to a preferred embodiment of the present invention.

[0028] Figure 3 is a modified version of Figure 2 with an auxiliary heat transfer fluid line added.

[0029] FIG. 4 is a conceptual diagram illustrating a liquid hydrogen charging system according to another preferred embodiment of the present invention.

[0030] Figure 5 is a modified version of Figure 4 with a vaporized gas reuse line added.

[0031] FIG. 6 is a side view of the storage tank of FIG. 5.

[0032] Fig. 7 is a plan view of the storage tank of Fig. 5.

[0033] Fig. 8 is an enlarged view of section T of Fig. 5.

[0034] <Explanation of Symbols>

[0035] 1: Supply pipe

[0036] 10: Storage tank

[0037] 15: Pump

[0038] 20: Carburetor

[0039] 30: First heat exchanger

[0040] 30a: Shear heat exchanger

[0041] 30b: Rear heat exchanger

[0042] 40: Heater

[0043] 50: Buffer

[0044] 50a: Low pressure buffer

[0045] 50b: High-pressure buffer

[0046] 60: Third heat exchanger

[0047] 70: Charger

[0048] 80: Second heater

[0049] 90: Heat transfer oil storage unit

[0050] 90a: Cold heat transfer fluid storage section

[0051] 90b: High-temperature heat transfer fluid storage section

[0052] 93: Auxiliary cooler

[0053] 95: Auxiliary heater

[0054] 98: Cooling valve

[0055] 99: Anti-icing valve

[0056] 100: Vaporized gas reuse line

[0057] 110: Auxiliary heat transfer fluid line

[0058] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings.

[0059] FIG. 2 is a conceptual diagram illustrating a liquid hydrogen charging system according to a preferred embodiment of the present invention.

[0060] As illustrated in FIG. 2, the liquid hydrogen charging system according to the present invention basically consists of a storage tank (10) in which liquid hydrogen is stored, a vaporizer (20), a first heat exchanger (30), a heater (40), a buffer (50), a third heat exchanger (60), and a charger (70) that supplies hydrogen gas to a vehicle.

[0061] First, liquid hydrogen is supplied to a vaporizer (20) through a pump (15) connected to a storage tank (10), and in the vaporizer (20), the liquid hydrogen is vaporized into low-temperature gaseous hydrogen.

[0062] And the vaporizer (20) is a device that vaporizes liquid hydrogen through an electric heater, and in order to solve the cooling problem of the heater that occurs during the process of vaporizing liquid hydrogen into high-temperature hydrogen gas all at once through the vaporizer (20), it vaporizes the liquid hydrogen only to a temperature below a certain temperature and then supplies gaseous hydrogen to the first heat exchanger.

[0063] In the first heat exchanger (30), the gaseous hydrogen is heated to a certain temperature through a heat transfer fluid that transfers heat at a certain temperature, and then in the heater (40), after being heated (approximately 0 degrees Celsius), it is stored in a buffer (50).

[0064] The first heat exchanger (30) serves to recover cold heat from the hydrogen gas flowing in from the vaporizer (20) through a heat transfer fluid, and the hydrogen gas stored in the buffer (50) is supplied to the charger (70) in a state where it has been re-cooled to -40 degrees through the third heat exchanger (60).

[0065] This heat transfer fluid is stored in a heat transfer fluid storage unit (90) and supplied to the first heat exchanger (30) in the required amount. A detailed description of this heat transfer fluid storage unit (90) will be provided later.

[0066] In this process, unlike conventional hydrogen charging systems, the present invention includes a second heater that is directly connected from the vaporizer (20) to the charger (70).

[0067] In cases where a small amount of hydrogen is required, such as for passenger cars, hydrogen gas is supplied along the hydrogen gas supply line described above; however, in cases where a large amount of hydrogen gas is required (large hydrogen vehicles such as cargo trucks, large tanks, etc.), the hydrogen gas supplied from the vaporizer (20) is heated by the second heater (80) and supplied directly to the charger (70).

[0068] Of course, a control valve must be installed on each line connected to each line. (Omitted in Fig. 2)

[0069] Additionally, if necessary, each line can be operated simultaneously, and under normal conditions, hydrogen gas is supplied to the charger through the buffer via the line passing through the first heat exchanger.

[0070] Figure 3 is a modified version of Figure 2 with an auxiliary heat transfer fluid line added.

[0071] As shown in FIG. 3, this is an embodiment in which an auxiliary heat transfer fluid line (110) is formed to supply the heat transfer fluid that has passed through the first heat exchanger from the heat transfer fluid storage unit (90) to the third heat exchanger, and to connect the heat transfer fluid flowing in from the third heat exchanger back to the heat transfer fluid storage unit.

[0072] As shown in FIG. 3, the heat transfer fluid that has passed through the first heat exchanger (30) is cooled by hydrogen gas (approximately -50°C), and this cold heat is used as a cooling heat source to cool the hydrogen gas supplied from the buffer (50) to the charger (70) to -40°C.

[0073] Next, FIG. 4 is a conceptual diagram illustrating a liquid hydrogen charging system according to another preferred embodiment of the present invention.

[0074] As shown in FIG. 4, the supply pipe (1) connecting from the storage tank (10) to the vaporizer (20) is installed to surround the outer wall of the storage tank (10).

[0075] That is, the cold heat loss of the storage tank (10) is minimized through the supply pipe (1a) that surrounds the outer wall of the storage tank (10), thereby minimizing the generation of vaporized gas (BOG).

[0076] Next, the embodiment illustrated in FIG. 4 is an embodiment in which the first heat exchanger (30) is formed with a double structure of a front heat exchanger (30a) and a rear heat exchanger (30b).

[0077] As a specific example, hydrogen gas passing through the vaporizer is supplied to the front heat exchanger (30a) at -70 degrees Celsius, and is first cooled through the heat transfer fluid to -50 degrees Celsius, passing through the rear heat exchanger (30b) and rising to -50 degrees Celsius.

[0078] In other words, through the multi-stage heat exchanger, damage to the heat exchanger caused by hydrogen gas can be prevented, and sufficient cold energy can be transferred to the heat transfer fluid.

[0079] The heat transfer fluid that has passed through the front heat exchanger (30a) and the rear heat exchanger (30b) is stored in the low-temperature heat transfer fluid storage unit (90a) and is used as cold energy to re-cool the hydrogen gas supplied to the charger through the third heat exchanger (60).

[0080] The heat transfer fluid, from which sufficient cold heat has been recovered through this process, is stored in a high-temperature heat transfer fluid storage unit (90b).

[0081] In the circulation process of the heat transfer fluid, if the low-temperature heat transfer fluid storage unit (90a) is at a temperature where it is difficult to transfer sufficient cold heat, it is re-cooled in the low-temperature heat transfer fluid storage unit (90a) through the installed auxiliary cooler (93).

[0082] Likewise, if the temperature is insufficient to heat the hydrogen gas in the shear heat exchanger (30a), the temperature of the heat transfer fluid stored in the high-temperature heat transfer fluid storage unit (90b) is raised through the auxiliary heater (95).

[0083] Next, we will look at the buffer (50).

[0084] As shown in FIG. 4, the buffer (50) is a place for storing hydrogen gas heated to a constant temperature (approximately 0 degrees Celsius) through a heater (40), and is divided into a low-pressure buffer (50a) and a high-pressure buffer (50b) depending on the type and pressure of the storage tank of the vehicle being charged.

[0085] That is, considering the charging pressure and charging amount of the vehicle being charged, it is efficiently supplied to the charger through control valves installed in the low-pressure buffer (50a) and high-pressure buffer (50b), respectively (through the third heat exchanger).

[0086] The hydrogen gas stored in this buffer (50) is supplied to the charger (70) through the third heat exchanger and directly charged into the hydrogen vehicle.

[0087] Figure 5 is a modified version of Figure 4 with the addition of a vaporized gas reuse line.

[0088] The embodiment illustrated in FIG. 5 is an embodiment further comprising a vaporized gas reuse line (100) that supplies vaporized gas generated in a storage tank (10) to the buffer (50).

[0089] In addition, the above-mentioned vaporized gas reuse line (100) is installed to surround the outer wall of the storage tank (10) and minimizes cold heat loss by using the same principle as the supply pipe (1) connected to the vaporizer (20) through the pump described earlier, thereby minimizing the generation of vaporized gas (BOG).

[0090] The vaporized gas (BOG) discharged through the vaporized gas reuse line (100) is collected in the vaporized gas storage tank (101), and is supplied to the low-pressure buffer (50a) and reused in a state where it is compressed to a pressure that can be supplied to the low-pressure buffer (50a) through the compressor (102).

[0091] That is, when the vaporized gas (BOG) generated in the storage tank (10) is compressed to the pressure of the high-pressure buffer (50b), the efficiency of reuse is greatly reduced, so it is compressed to the pressure of the low-pressure buffer (50a) and reused.

[0092] To examine in more detail the installation of the vaporized gas reuse line (100) and supply pipe (1) surrounding the storage tank, FIG. 6 is a side view of the storage tank of FIG. 5, and FIG. 7 is a top view of the storage tank of FIG. 5.

[0093] As shown in FIG. 6, the vaporized gas reuse line (100) and the supply pipe (1) form a zigzag shape that wraps around the outer wall of the storage tank (10), and the vaporized gas reuse line (100) and the supply pipe (1) are arranged in an intersecting manner so that the waste of cold energy can be prevented through heat exchange between them.

[0094] In addition, the arrangement of the vaporized gas reuse line (100) and the supply pipe (1) must be installed considering the amount of vaporized gas generated and the characteristics of the area where the filling station is installed.

[0095] The amount of BOG generated is reduced by preventing external heat intrusion through the vaporized gas reuse line (100) and supply pipe (1) surrounding the storage tank (10) of this structure.

[0096] Figure 8 is an enlarged view of section T of Figure 5.

[0097] As shown in FIG. 8, a line is installed connecting the low-temperature heat transfer fluid storage unit (90a) to the high-temperature heat transfer fluid storage unit (90b), and a cooling valve (98) is installed in this line.

[0098] In addition, a line is installed connecting the high-temperature heat transfer fluid storage unit (90b) to the low-temperature heat transfer fluid storage unit (90a), and an anti-icing valve (99) is installed in this line.

[0099] Through these cooling valves (98) and anti-icing valves (99), heat transfer fluid is rapidly transferred between the high-temperature heat transfer fluid storage unit (90b) and the low-temperature heat transfer fluid storage unit (90a), thereby efficiently addressing the phenomenon of insufficient cooling through temperature control of the heat transfer fluid and enabling rapid temperature management of the heat transfer fluid.

[0100] As described above, the main technical concept of the present invention is to provide a liquid hydrogen charging system. Since the embodiment described above with reference to the drawings is merely one example, the true scope of the present invention should be determined by the claims.

Claims

1. In a liquid hydrogen charging system that vaporizes hydrogen from a storage tank in which liquid hydrogen is stored and supplies it to a charger, A storage tank in which liquid hydrogen is stored; A vaporizer for vaporizing liquid hydrogen supplied from the above storage tank; A first heat exchanger that recovers cold heat through a heat transfer fluid and hydrogen gas flowing in from the above vaporizer; A heater for heating hydrogen gas supplied from the first heat exchanger; A buffer in which hydrogen gas supplied from the above heater is stored; A third heat exchanger for cooling hydrogen gas supplied from the above buffer; A charger that receives hydrogen gas supplied from the third heat exchanger; A liquid hydrogen charging system characterized by including a second heater directly connected from the above vaporizer to the above charger.

2. In Paragraph 1, A liquid hydrogen filling system characterized in that the supply pipe connecting the storage tank to the vaporizer is installed to surround the outer wall of the storage tank.

3. In Paragraph 1, The above-mentioned first heat exchanger is, A liquid hydrogen charging system characterized by a double structure of a front heat exchanger and a rear heat exchanger.

4. In Paragraph 3, The above-mentioned first heat exchanger is, low-temperature heat transfer fluid storage and A liquid hydrogen filling system characterized by including a high-temperature heat transfer fluid storage unit.

5. In Paragraph 4, An auxiliary cooler is installed in the above-mentioned low-temperature heat transfer fluid storage unit, and A liquid hydrogen filling system characterized by having an auxiliary heater installed in the high-temperature heat transfer fluid storage section.

6. In Paragraph 1, A liquid hydrogen filling system characterized by further including a vapor gas reuse line that supplies vapor gas generated in the storage tank to the buffer.

7. In Paragraph 6, The above-mentioned vaporized gas reuse line is, A liquid hydrogen filling system characterized by being installed to surround the outer wall of the storage tank.

8. In a liquid hydrogen charging system that vaporizes hydrogen from a storage tank in which liquid hydrogen is stored and supplies it to a charger, A storage tank in which liquid hydrogen is stored; A vaporizer for vaporizing liquid hydrogen supplied from the above storage tank; A first heat exchanger comprising a front heat exchanger and a rear heat exchanger that recover cold heat through a heat transfer fluid for hydrogen gas introduced from the above vaporizer; A heater for heating hydrogen gas supplied from the first heat exchanger; A buffer in which hydrogen gas supplied from the above heater is stored; A third heat exchanger for cooling hydrogen gas supplied from the above buffer; A liquid hydrogen charging system characterized by including a charger that receives hydrogen gas supplied from the third heat exchanger.

9. In Paragraph 8, The above-mentioned first heat exchanger is, A liquid hydrogen charging system characterized by including a low-temperature heat transfer fluid storage unit in which heat transfer fluid that has passed through the aforementioned downstream heat exchanger is stored, and a high-temperature heat transfer fluid storage unit in which an auxiliary heater is installed to heat the heat transfer fluid supplied from the low-temperature heat transfer fluid storage unit.

10. In Paragraph 9, A liquid hydrogen filling system characterized by having an auxiliary cooler installed in the above-mentioned low-temperature heat transfer fluid storage unit.

11. In Paragraph 9, A liquid hydrogen charging system characterized by supplying heat transfer fluid from the above-mentioned low-temperature heat transfer fluid storage unit to a third heat exchanger, and forming an auxiliary heat transfer fluid line that connects the heat transfer fluid flowing in from the third heat exchanger to the above-mentioned low-temperature heat transfer fluid storage unit.

12. In a liquid hydrogen charging system that vaporizes hydrogen from a storage tank in which liquid hydrogen is stored and supplies it to a charger, A storage tank in which liquid hydrogen is stored; A vaporizer for vaporizing liquid hydrogen supplied from the above storage tank; A first heat exchanger that recovers cold heat through a heat transfer fluid and hydrogen gas flowing in from the above vaporizer; A heater for heating hydrogen gas supplied from the first heat exchanger; A buffer in which hydrogen gas supplied from the above heater is stored; A third heat exchanger that cools hydrogen gas supplied from the above buffer through the heat transfer fluid of the first heat exchanger; A charger that receives hydrogen gas supplied from the third heat exchanger; A liquid hydrogen charging system characterized by including a second heater line directly connected from the above vaporizer to the above charger.

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