Fuel cell-battery system and method of controlling the same

Abstract

A fuel cell-battery system and a control method thereof are provided. The system includes a battery module including a battery storing electric power and a coolant line through which a coolant circulates to cool the battery; a fuel cell module including a hydrogen tank storing hydrogen, a fuel cell generating electric power using the hydrogen, and a hydrogen line connecting the hydrogen tank and the fuel cell to deliver the hydrogen from the hydrogen tank to the fuel cell; and a heat exchange module through which the coolant line and the hydrogen line pass, such that the coolant is cooled by heat exchange with the hydrogen and the hydrogen is heated by heat exchange with the coolant.

Description

[0001] Cross-reference to related applications

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2020-0169191, filed with the Korean Intellectual Property Office on December 7, 2020, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to fuel cell-battery systems and control methods thereof. Background Technology

[0004] Fuel cells use hydrogen-containing fuel and oxygen-containing gas to generate electricity. For the purpose of stabilizing the output, the electricity generated by the fuel cell can be stored in a battery, which is an energy storage device such as a secondary battery or capacitor.

[0005] Batteries and fuel cells can be cooled via a common coolant line. However, battery systems and fuel cell systems are typically configured separately. They have individual coolant lines and use separate cooling systems to cool the circulating coolant. With separate cooling systems, the number of components may increase, and the generated heat may not be utilized efficiently. Summary of the Invention

[0006] This disclosure is made to solve the aforementioned problems in the prior art, while fully retaining the advantages achieved by the prior art.

[0007] One aspect of this disclosure provides a fuel cell-battery system for efficiently performing heat exchange and supplying coolant and fuel at appropriate temperatures. Another aspect of this disclosure provides a method for controlling the fuel cell-battery system.

[0008] The technical problems to be solved by this invention are not limited to those described above. Those skilled in the art will clearly understand from the following description any other technical problems not mentioned herein.

[0009] According to one aspect of this disclosure, a fuel cell-battery system includes a battery module comprising a battery for storing electrical energy and a coolant line through which coolant circulates to cool the battery. The system also includes a fuel cell module comprising a hydrogen tank for storing hydrogen, a fuel cell for generating electricity using the hydrogen, and a hydrogen line connecting the hydrogen tank and the fuel cell to deliver hydrogen from the hydrogen tank to the fuel cell. The system further includes a heat exchange module through which the coolant line and the hydrogen line pass, such that the coolant is cooled by heat exchange with the hydrogen and the hydrogen is heated by heat exchange with the coolant.

[0010] According to another aspect of this disclosure, a method for controlling a fuel cell-battery system is provided, the fuel cell-battery system comprising: a battery module that uses a coolant to cool a battery storing electrical energy; a fuel cell module that heats hydrogen and supplies the heated hydrogen to a fuel cell that uses the hydrogen to generate electricity; and a heat exchange module through which the coolant and hydrogen exchange heat with each other. The method includes: obtaining the temperature of the coolant released from the battery; passing the coolant through the heat exchange module to cool the coolant when the coolant temperature is higher than a target coolant temperature; and passing the coolant through a heater when the coolant temperature is lower than or equal to the target coolant temperature. Passing the coolant through the heater includes activating the heater when the coolant temperature is lower than the target coolant temperature.

[0011] According to another aspect of this disclosure, a method for controlling a fuel cell-battery system is provided, the fuel cell-battery system comprising: a battery module that uses a coolant to cool a battery storing electrical energy; a fuel cell module that uses an external heat exchanger to heat hydrogen stored in a hydrogen tank and supplies the heated hydrogen to a fuel cell that uses the hydrogen to generate electricity; and a heat exchange module through which the coolant and hydrogen exchange heat with each other. The method includes: obtaining the temperature of the hydrogen passing through the external heat exchanger; returning the hydrogen to the hydrogen tank to cool the hydrogen when the temperature of the hydrogen is higher than or equal to the upper limit of a target hydrogen temperature range; and returning the hydrogen to the external heat exchanger to heat the hydrogen when the temperature of the hydrogen is lower than or equal to the lower limit of the target hydrogen temperature range. Attached Figure Description

[0012] The above and other objects, features, and advantages of this disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings:

[0013] Figure 1 This is a schematic diagram of a fuel cell-battery system according to the first embodiment of this disclosure;

[0014] Figure 2 An example of a heat exchange module of a fuel cell-battery system according to a first embodiment of the present disclosure is shown;

[0015] Figure 3 This is a flowchart illustrating a method for controlling a fuel cell-battery system according to a first embodiment of the present disclosure;

[0016] Figure 4 This is a schematic diagram of a fuel cell-battery system according to a second embodiment of the present disclosure;

[0017] Figure 5 This is a schematic diagram of a fuel cell-battery system according to a third embodiment of the present disclosure;

[0018] Figure 6 This is a schematic diagram of a fuel cell-battery system according to the fourth embodiment of this disclosure; and

[0019] Figure 7 This is a schematic diagram of a fuel cell-battery system according to the fifth embodiment of this disclosure. Detailed Implementation

[0020] In the following, some embodiments of the present disclosure are described in detail with reference to the accompanying drawings. When adding reference numerals to components in each figure, it should be noted that the same reference numerals are used to denote components that are shown as identical or equivalent components in other figures. Furthermore, detailed descriptions of well-known features or functions have been omitted in the description of embodiments of the present disclosure to avoid unnecessarily obscuring the spirit of the disclosure.

[0021] In describing components according to embodiments of the present disclosure, terms such as first, second, "A", "B", (a), (b), etc., may be used. These terms are merely for distinguishing one component from another, and do not limit the nature, order, or sequence of the components. When a component is described as being "connected", "coupled", or "linked" to another component, this may mean that the component is not only directly "connected", "coupled", or "linked", but also indirectly "connected", "coupled", or "linked" via a third component.

[0022] First Embodiment

[0023] Figure 1 This is a schematic diagram of a fuel cell-battery system 1 according to a first embodiment of the present disclosure.

[0024] Reference Figure 1 According to a first embodiment of the present disclosure, the fuel cell-battery system 1 includes a battery module 10, a fuel cell module 20, and a heat exchange module 30. Figure 1In this context, solid lines can represent the connection relationships of fluid flow, while dashed lines can represent the direction of information transmission.

[0025] Battery Module 10

[0026] The battery module 10 includes a battery 11 for storing electrical energy and components for cooling the battery 11 to maintain it within a stable temperature range. The stable temperature range of the battery 11 can be from 0°C to 40°C. The battery module 10 may include the battery 11 and coolant lines 12. The battery module 10 may also include a pump 13, a battery valve 14, a heater 15, a heating line 18, a coolant temperature acquisition device 16, and a battery controller 17. The components of the battery module 10 may be embedded in the housing of the battery module 10. The battery module 10 may also include a battery temperature acquisition device for acquiring the temperature of the battery 11. The battery temperature acquisition device may be electrically connected to the battery controller 17 and may transmit the acquired temperature to the battery controller 17 in the form of an electrical signal.

[0027] The battery 11 for storing electricity can be a rechargeable battery or capacitor. However, there are no particular restrictions on the type of battery 11, as long as it can be repeatedly charged and discharged.

[0028] Coolant line 12 is configured such that coolant for cooling battery 11 circulates within coolant line 12. Coolant line 12 can be implemented by a conduit through which fluid flows. However, the type of component used to implement coolant line 12 is not limited thereto. Components described as lines in this disclosure can be implemented using the same or similar components as coolant line 12.

[0029] The coolant line 12 can form a closed loop including the battery 11, such that coolant released from the battery 11 is cooled while circulating through the coolant line 12 and is then returned to the battery 11. Coolant cooled by the coolant line 12 can be supplied to the battery 11, and heated coolant can be released from the battery 11. Therefore, the battery 11 can operate smoothly. The coolant line 12 can pass through the heat exchange module 30, allowing the coolant flowing in the coolant line 12 to be cooled.

[0030] Coolant line 12 may be equipped with pump 13. Pump 13 forces coolant to move along coolant line 12 to circulate the coolant. Figure 1 In the diagram, pump 13 is shown downstream of battery 11 relative to the direction in which coolant is released from battery 11. However, the location of pump 13 is not limited to this.

[0031] The battery module 10 may also include a heater 15 and a heating line 18. The heater 15 may be arranged to heat the coolant. The heater 15 may include a heat source that generates heat by burning fuel or by using electricity. The heater 15 may transfer heat generated from the heat source to the coolant flowing along the heating line 18. Therefore, the heating line 18 may be formed to pass through the heater 15. The heating line 18 may be connected to one point and another point on the coolant line 12, and may transport coolant from one point to the other. Regarding the direction of coolant flow, the one point may be located upstream of the heat exchange module 30, and the other point may be located downstream of the heat exchange module 30. Coolant bypassing to the heating line 18 may be heated by the heater 15.

[0032] Battery valve 14 can be located at this point. Battery valve 14 allows coolant released from battery 11 to flow along coolant line 12 into heat exchange module 30 or along heating line 18 into heater 15. Battery valve 14, which determines the coolant path, can be a three-way valve.

[0033] The battery module 10 may include a coolant temperature acquisition device 16, which acquires the temperature of the coolant released from the battery 11. The coolant temperature acquisition device 16 may be, but is not limited to, a thermocouple or a thermistor for acquiring the coolant temperature. The coolant temperature acquisition device 16 may be electrically connected to the battery controller 17 and may transmit the acquired temperature to the battery controller 17 in the form of an electrical signal.

[0034] The battery controller 17 can be electrically connected to components of the battery module 10 and can be electrically connected to the fuel cell controller 29 described below to perform control. The battery controller 17 can be a battery management system (BMS). The battery controller 17 can be a component including elements capable of performing logical operations to execute control commands. The battery controller 17 can include a central processing unit (CPU). The battery controller 17 can be connected to various types of components and can transmit signals to the respective components according to control commands. The battery controller 17 can be connected to various sensors or acquisition devices and can receive information acquired in signal form. In a first embodiment of this disclosure, the battery controller 17 can be electrically connected to a coolant temperature acquisition device 16, a battery valve 14, a heater 15, and a pump 13 included in the battery module 10. Because the battery controller 17 is electrically connected to components, the battery controller 17 can be wired to the components, or it can also include a communication module capable of wireless communication to communicate with the components.

[0035] The battery module 10 may also include a storage medium, and control commands executed by the battery controller 17 may be stored in and used on the storage medium. The storage medium may be, but is not limited to, devices such as hard disk drives (HDDs), solid-state drives (SSDs), servers, volatile media, non-volatile media, etc. Furthermore, data required by the battery controller 17 to perform its tasks may be additionally stored on the storage medium.

[0036] When the coolant temperature obtained by the coolant temperature acquisition device 16 is higher than the target coolant temperature, the battery controller 17 can execute control to cause the coolant to flow along the coolant line 12 and the heater 15 to stop operating. Conversely, when the coolant temperature is lower than the target coolant temperature, the battery controller 17 can execute control to cause the coolant to flow along the heating line 18 and the heater 15 to operate. The battery controller 17 can control the battery valve 14 and the heater 15 to execute control. Through control, coolant with a temperature higher than the target coolant temperature can be delivered through the coolant line 12 to the heat exchange module 30 and can be supplied to the battery 11 after being cooled by the heat exchange module 30. Coolant with a temperature lower than the target coolant temperature can be delivered through the heating line 18 to the heater 15 and can be supplied to the battery 11 after being heated by the heater 15. Therefore, coolant with a small temperature difference from the target coolant temperature suitable for the operation of the battery 11 can be supplied to the battery 11.

[0037] When the obtained coolant temperature equals the target coolant temperature, the battery controller 17 can control the battery valve 14 to allow coolant to flow along the heating line 18, and can also control the heater 15 to stop operating. This is because it is not necessary to heat or cool the coolant at the same temperature as the target coolant temperature.

[0038] Simultaneously, when the obtained coolant temperature is within the target coolant temperature range, including the target coolant temperature, the battery controller 17 can determine that the obtained coolant temperature is equal to the target coolant temperature and can perform control. In this case, when the obtained coolant temperature is higher than or equal to the upper limit of the target coolant temperature range, the battery controller 17 can control the battery valve 14 to allow coolant to flow to the heat exchanger 30. When the obtained coolant temperature is lower than or equal to the lower limit of the target coolant temperature range, the battery controller 17 can control the battery valve 14 to allow coolant to flow through the heating line 18 to the heater 15.

[0039] The battery controller 17 can receive the obtained coolant temperature from the coolant temperature acquisition device 16 and can calculate the target coolant temperature based on the obtained coolant temperature.

[0040] Fuel cell module 20

[0041] The fuel cell module 20 includes a fuel cell unit 26 that uses hydrogen to generate electricity and components that heat the hydrogen to a suitable temperature and deliver the heated hydrogen to the fuel cell unit 26. The fuel cell module 20 may include the fuel cell unit 26, a hydrogen tank 21, and a hydrogen pipeline 22. The fuel cell module 20 may also include an external heat exchanger 23, a return pipeline 27, a hydrogen temperature acquisition device 24, a fuel cell controller 29, a tank valve 281, a return valve 282, a return branch valve 283, and a fuel cell valve 284. The components of the fuel cell module 20 can be embedded within the housing of the fuel cell module 20.

[0042] Hydrogen tank 21 stores hydrogen. Hydrogen tank 21 may include a hydrogen storage container. The hydrogen stored in hydrogen tank 21 may be cryogenically compressed hydrogen, and hydrogen tank 21 may be a cryogenically compressed hydrogen storage container. Hydrogen can be stored in hydrogen tank 21 at a cryogenic temperature of approximately 38 K.

[0043] The hydrogen tank 21 may include an internal heat exchanger for regulating the pressure within the hydrogen tank 21. The internal heat exchanger allows the hydrogen storage container and the introduced materials to exchange heat with each other.

[0044] Fuel cell unit 26 uses hydrogen to generate electricity. Fuel cell unit 26 can be a fuel cell stack consisting of multiple stacked fuel cells. Each fuel cell can have a gas diffusion layer, a catalyst layer, and a membrane electrode assembly including an electrolyte membrane. The membrane electrode assembly can be surrounded by separators on both sides. Hydrogen-containing fuel can be supplied to the anode of fuel cell unit 26, and oxygen-containing gas can be supplied to the cathode of fuel cell unit 26. Fuel cell unit 26 can use the supplied fuel and gas to generate electricity.

[0045] The fuel cell valve 284 can be positioned upstream of the fuel cell unit 26 relative to the direction of hydrogen flow. The fuel cell valve 284 can be opened or closed to determine whether hydrogen is supplied to the fuel cell unit 26.

[0046] Hydrogen line 22 connects hydrogen tank 21 and fuel cell unit 26 to deliver hydrogen from hydrogen tank 21 to fuel cell unit 26. Hydrogen can be heated to a final target hydrogen temperature by heat exchange module 30 while passing through hydrogen line 22, and can then be delivered to fuel cell unit 26.

[0047] The hydrogen pipeline 22 may be equipped with a hydrogen tank 21, an external heat exchanger 23, a regulator 25, a heat exchange module 30, and a fuel cell device 26. Various parts of the hydrogen pipeline 22 can connect to these components. Specifically, a first hydrogen pipeline 221 can connect the hydrogen tank 21 and the external heat exchanger 23. A second hydrogen pipeline 222 can connect the external heat exchanger 23 and the regulator 25. A third hydrogen pipeline 223 can connect the regulator 25 and the heat exchange module 30. A fourth hydrogen pipeline 224 can connect the heat exchange module 30 and the fuel cell device 26. Hydrogen pipelines 221, 222, 223, and 224 can be connected together to form an integrated hydrogen pipeline 22, or they can be connected as components to form the hydrogen pipeline 22.

[0048] The tank valve 281 can be positioned downstream of the hydrogen tank 21 relative to the direction of hydrogen flow. The tank valve 281 can be a solenoid valve. The tank valve 281 can be opened or closed to determine whether hydrogen is delivered from the hydrogen tank 21 to the fuel cell unit 26 via the hydrogen line 22.

[0049] External heat exchanger 23 first heats the hydrogen flowing along hydrogen line 22. External heat exchanger 23 can be installed on hydrogen line 22 between heat exchange module 30 and hydrogen tank 21. External heat exchanger 23 heats the hydrogen to a predetermined hydrogen supply temperature. To heat the hydrogen, external heat exchanger 23 can be electrically connected to and controlled by fuel cell controller 29, as described below. The hydrogen supply temperature can be in the range of 30K to 358K. External heat exchanger 23 can be, but is not limited to, an electric heater that uses electricity applied to an electric heater to generate heat, or a device for heat exchange with externally stored fluid.

[0050] Regulator 25 can reduce the pressure of hydrogen flowing in hydrogen line 22 through external heat exchanger 23 so that the pressure of hydrogen to be supplied to fuel cell unit 26 is within a predetermined pressure range. For this purpose, regulator 25 can be disposed in hydrogen line 22 and can be located between external heat exchanger 23 and heat exchange module 30. Regulator 25 can be, but is not limited to, a pressure reducing valve.

[0051] The fuel cell module 20 may include a hydrogen temperature acquisition device 24, which acquires the temperature of hydrogen released from the external heat exchanger 23. The hydrogen temperature acquisition device 24 may be, but is not limited to, a thermocouple or a thermistor for acquiring the hydrogen temperature. The hydrogen temperature acquisition device 24 may be electrically connected to the fuel cell controller 29 and may transmit the acquired temperature to the fuel cell controller 29 in the form of an electrical signal.

[0052] The fuel cell module 20 may include a return line 27. The return line 27 allows hydrogen flowing through the external heat exchanger 23 to return to the upstream side of the external heat exchanger 23 relative to the direction of hydrogen flow in the hydrogen line 22. The hydrogen can be post-treated using the return line 27 to bring its temperature up to the hydrogen supply temperature.

[0053] By opening or closing the reflux valve 282, it can be determined whether hydrogen is returned to the reflux line 27 or whether hydrogen is delivered along the hydrogen line 22 to the fuel cell unit 26. The reflux valve 282 can be located at the point where the reflux line 27 connects to the hydrogen line 22. The reflux valve 282 can be a three-way valve.

[0054] The return line 27 may include a basic return line 271 that receives hydrogen from the hydrogen line 22 and returns the hydrogen along a fourth flow path R4; a cooling return line 273 that returns the hydrogen to the internal heat exchanger; and a heating return line 272 that returns the hydrogen from the hydrogen line 22 to the point between the external heat exchanger 23 and the hydrogen tank 21. The cooling return line 273 and the heating return line 272 may branch off from the basic return line 271 as flow paths 4-2R42 and 4-1R41, respectively.

[0055] The reflux branch valve 283 can be located at the point where the cooling reflux line 273 and the heating reflux line 272 branch off from the main reflux line 271. Whether hydrogen is supplied to the cooling reflux line 273 or the heating reflux line 272 can be determined by opening or closing the reflux branch valve 283. The reflux branch valve 283 can be a three-way valve.

[0056] The fuel cell controller 29 can be electrically connected to components of the fuel cell module 20 and can be electrically connected to the battery controller 17 to perform control. The fuel cell controller 29 can be a hydrogen storage system management unit (HMU). The fuel cell controller 29 can be a component including elements capable of performing logical operations to execute control commands. The fuel cell controller 29 can include a central processing unit (CPU). The fuel cell controller 29 can be connected to various types of components and can transmit signals depending on the control commands to the respective components. The fuel cell controller 29 can be connected to various sensors or acquisition devices and can receive information acquired in signal form. In a first embodiment of this disclosure, the fuel cell controller 29 can be electrically connected to the hydrogen temperature acquisition device 24, tank valve 281, reflux valve 282, reflux branch valve 283, fuel cell valve 284, regulator 25, external heat exchanger 23, and hydrogen tank 21 included in the fuel cell module 20. Because the fuel cell controller 29 is electrically connected to components, the fuel cell controller 29 can be wired to the components, or it can also include a communication module capable of wireless communication to communicate with the components.

[0057] The fuel cell module 20 may also include a storage medium, and control commands executed by the fuel cell controller 29 can be stored in and used in the storage medium. The storage medium may be, but is not limited to, devices such as hard disk drives (HDDs), solid-state drives (SSDs), servers, volatile media, non-volatile media, etc. Furthermore, data required by the fuel cell controller 29 to perform its tasks may be stored separately in the storage medium.

[0058] When the temperature of the hydrogen obtained by the hydrogen temperature acquisition device 24 is higher than or equal to the upper limit of the predetermined target hydrogen temperature range, the fuel cell controller 29 can execute control to return the hydrogen to the internal heat exchanger for cooling via the cooling return line 273. Furthermore, when the temperature of the hydrogen is lower than or equal to the lower limit of the target hydrogen temperature range, the fuel cell controller 29 can execute control to return the hydrogen to the external heat exchanger 23 for heating via the heating return line 272. In other words, when it is determined that the hydrogen is insufficiently heated by the external heat exchanger 23, the hydrogen can return to the external heat exchanger 23 for reheating. When it is determined that the hydrogen is overheated by the external heat exchanger 23, the hydrogen can return to the internal heat exchanger for cooling. The returned hydrogen can be directly delivered to the first hydrogen line 221.

[0059] The fuel cell controller 29 can receive the acquired coolant temperature and target coolant temperature from the battery controller 17. Based on the received information and the final hydrogen temperature required by the fuel cell unit 26, the fuel cell controller 29 can calculate the hydrogen supply temperature. This is because, when the acquired coolant temperature and target coolant temperature are known, the amount of heat transferred from the coolant to the hydrogen in the heat exchange module 30 can be identified. Based on the hydrogen supply temperature, the fuel cell controller 29 can control the degree to which the external heat exchanger 23 heats the hydrogen. This is because the purpose of the external heat exchanger 23 is to heat the hydrogen to the hydrogen supply temperature.

[0060] The target hydrogen temperature range can be determined based on the calculated hydrogen supply temperature. The target hydrogen temperature range can have an upper limit obtained by adding the hydrogen supply temperature to a predetermined temperature and a lower limit obtained by subtracting the predetermined temperature from the hydrogen supply temperature.

[0061] Heat exchange module 30

[0062] Figure 2 An example 30a of a heat exchange module 30 of a fuel cell-battery system 1 according to a first embodiment of the present disclosure is shown.

[0063] The heat exchange module 30 is a component through which the coolant line 12 and the hydrogen line 22 pass, allowing the coolant to be cooled by heat exchange with the hydrogen, and the hydrogen to be heated by heat exchange with the coolant. The heat exchange module 30 can be various heat exchangers through which the hydrogen and coolant exchange heat indirectly with each other. For example, the heat exchange module 30 can be one of a coaxial tube heat exchanger, a finned tube heat exchanger, or a plate heat exchanger. Figure 2 Example 30a of the heat exchange module 30 is shown as being formed by a coaxial tube heat exchanger. One of the hydrogen and the coolant can flow through the inner tube 301a, and the other of the hydrogen and the coolant can flow through the outer tube 302a surrounding the inner tube 301a. Thus, the hydrogen and the coolant can exchange heat with each other indirectly.

[0064] Control methods

[0065] Figure 3 This is a flowchart illustrating a method for controlling a fuel cell-battery system 1 according to a first embodiment of the present disclosure.

[0066] Reference Figure 3 According to Figure 3 The flowchart is used to control the fuel cell-battery system 1 according to the first embodiment of this disclosure. Figure 3 In the diagram, the solid line represents the control flow in the fuel cell module 20, and the dashed line represents the control flow in the battery module 10.

[0067] Coolant can begin to flow along coolant line 12. Coolant temperature acquisition device 16 can acquire the temperature of the coolant (S101). Battery controller 17 can receive the acquired coolant temperature from coolant temperature acquisition device 16. Battery controller 17 can receive the temperature of battery 11 from battery temperature acquisition device. Battery controller 17 can monitor the temperature of battery 11 and can calculate the target coolant temperature based on the temperature of battery 11 (S102).

[0068] After calculating the target coolant temperature, the battery controller 17 can determine whether the obtained coolant temperature is higher than the target coolant temperature (S103). When the obtained coolant temperature is higher than the target coolant temperature, the battery controller 17 can send coolant along the second flow path R2 (S108) and can send the coolant to the heat exchange module 30 (S301).

[0069] When the obtained coolant temperature is lower than or equal to the target coolant temperature, the battery controller 17 can send coolant along the first flow path R1 (S104) because the coolant does not need cooling. The battery controller 17 can determine whether the obtained coolant temperature is equal to the target coolant temperature (S105). When the obtained coolant temperature is equal to the target coolant temperature, the battery controller 17 can turn off the heater 15 (S106) because the coolant does not need to be heated. When the obtained coolant temperature is not equal to the target coolant temperature, the coolant needs to be heated, so the battery controller 17 can turn on the heater 15 and allow coolant to pass through the heater 15 (S107).

[0070] Coolant that has been cooled, heated, or not heat-treated can be recycled back into battery 11 (S109).

[0071] After calculating the target coolant temperature, the battery controller 17 can transmit the target coolant temperature and the obtained coolant temperature to the fuel cell controller 29. The fuel cell controller 29 can calculate the hydrogen supply temperature based on the received information and the final hydrogen temperature (S201). The tank valve 281 can be opened (S202), and hydrogen can be released from the hydrogen tank 21. The hydrogen flowing along the hydrogen pipeline 22 can be heated by the external heat exchanger 23 (S203). The hydrogen temperature acquisition device 24 can acquire the temperature of the hydrogen heated by the external heat exchanger 23 (S204). The hydrogen temperature acquisition device 24 can transmit the acquired hydrogen temperature to the fuel cell controller 29, and the fuel cell controller 29 can determine whether the absolute value of the difference between the acquired hydrogen temperature and the hydrogen supply temperature is less than a predetermined temperature value x (S205). In other words, the fuel cell controller 29 can determine whether the acquired hydrogen temperature is within a target hydrogen temperature range that is twice the predetermined temperature value x, with the hydrogen supply temperature as the center of the target hydrogen temperature range.

[0072] The predetermined temperature value x is a value that determines the control precision of the temperature of the supplied hydrogen. The predetermined temperature value x needs to be set to a level that ensures the temperature of the hydrogen passing through the heat exchange module 30 does not affect the performance of the fuel cell unit 26. The predetermined temperature value x can vary depending on the specifications of the fuel cell unit 26. For example, the predetermined temperature value x could be 5°C.

[0073] When the absolute value is greater than or equal to a predetermined temperature value x, the fuel cell controller 29 can determine whether the obtained hydrogen temperature is higher than the hydrogen supply temperature (S206). When the obtained hydrogen temperature is higher than the hydrogen supply temperature, the hydrogen can be returned to the internal heat exchanger through the cooling return line 273 and cooled by the internal heat exchanger (S207). The returned hydrogen can also be resupplyed to the external heat exchanger 23 (S203).

[0074] When the temperature of the obtained hydrogen is lower than the hydrogen supply temperature, the hydrogen can be returned to the external heat exchanger 23 through the heated return line 272 (S208), and can be heated by the external heat exchanger 23 (S203).

[0075] When the absolute value is less than the predetermined temperature value x, hydrogen can be supplied to the heat exchange module 30 as usual (S301). The fuel cell valve 284 can be opened (S209), and heated hydrogen can be supplied to the fuel cell unit 26 (S210).

[0076] Second Embodiment

[0077] Figure 4 This is a schematic diagram of a fuel cell-battery system 1b according to a second embodiment of the present disclosure.

[0078] Reference Figure 4 The fuel cell-battery system 1b according to the second embodiment of this disclosure is almost identical to the fuel cell-battery system 1 according to the first embodiment. However, the fuel cell-battery system 1b differs from the fuel cell-battery system 1 in that the battery module 10b does not include a heater and heating lines. In this case, the fuel cell controller 29 can set the hydrogen supply temperature to a temperature higher than that in the first embodiment and can control the external heat exchanger 23. In the second embodiment, the hydrogen supply temperature can be higher than the final hydrogen temperature.

[0079] Third Embodiment

[0080] Figure 5 This is a schematic diagram of a fuel cell-battery system 1c according to a third embodiment of the present disclosure.

[0081] Reference Figure 5 The fuel cell-battery system 1c according to the third embodiment of this disclosure is almost identical to the fuel cell-battery system 1b according to the second embodiment. However, the fuel cell-battery system 1c differs from the fuel cell-battery system 1b in that the fuel cell module 20c further includes a bypass line 225c and a bypass valve 285c. The bypass line 225c can be configured to bypass hydrogen flowing in the third hydrogen line 223 to the fuel cell device 26 before entering the heat exchange module 30. When the obtained coolant temperature is higher than the target coolant temperature, the fuel cell controller 29 can control the bypass valve 285c to allow hydrogen to pass through the heat exchange module 30. When the obtained coolant temperature is lower than or equal to the target coolant temperature, the fuel cell controller 29 can control the bypass valve 285c to allow hydrogen to flow along the bypass line 225c. The bypass valve 285c can be a three-way valve.

[0082] When hydrogen is bypassed to bypass line 225c, the coolant may not need to be cooled in heat exchange module 30. In other words, in the third embodiment, the temperature of the coolant may not be determined by using heater 15 and heat exchange module 30 as in the first embodiment, but rather by controlling the supply of hydrogen to heat exchange module 30.

[0083] Fourth embodiment

[0084] Figure 6 This is a schematic diagram of a fuel cell-battery system 1d according to the fourth embodiment of the present disclosure.

[0085] Reference Figure 6The fuel cell-battery system 1d according to the fourth embodiment of this disclosure is almost identical to the fuel cell-battery system 1 according to the first embodiment. However, the fuel cell-battery system 1d differs from the fuel cell-battery system 1 in that the fuel cell module 20d further includes a circulation line 226d, and the circulation line 226d is connected to the hydrogen line 22 via a fuel cell valve 284d.

[0086] The circulation line 226d allows hydrogen to return to the hydrogen tank 21 after passing through the heat exchange module 30 and before entering the fuel cell unit 26. One end of the circulation line 226d can be connected to the fourth hydrogen line 224 via the fuel cell valve 284d, and the opposite end can be connected to the cooling return line 273. The fuel cell valve 284d can be a three-way valve, allowing hydrogen to be delivered to the fuel cell unit 26 via the fourth hydrogen line 224 or allowing hydrogen to return via the circulation line 226d. Therefore, when hydrogen is not used to heat the battery module 10 in high-temperature areas, it can be used only for cooling the coolant without generating electricity from the fuel cell unit 26.

[0087] Fifth embodiment

[0088] Figure 7 This is a schematic diagram of a fuel cell-battery system 1e according to the fifth embodiment of this disclosure.

[0089] Reference Figure 7 The fuel cell-battery system 1e according to the fifth embodiment of this disclosure is almost identical to the fuel cell-battery system 1d according to the fourth embodiment. However, the fuel cell-battery system 1e differs from the fuel cell-battery system 1d in that the heat exchange module 30e includes a main heat exchange module 31e and auxiliary heat exchange modules 32e and 33e.

[0090] The main heat exchange module 31e allows heat exchange between the coolant of the battery module 10e and the hydrogen of the fuel cell module 20d. Additional heat exchange modules 32e and 33e allow heat exchange between the coolant of at least one of the vehicle's air conditioning system 40e, fuel cell stack 50e, or engine, and the hydrogen of the fuel cell module 20d. Although in Figure 7 The diagram shows a first additional heat exchange module 32e and a second additional heat exchange module 33e that are respectively connected to the vehicle air conditioning system 40e and the fuel cell stack 50e, but the number of additional heat exchange modules is not limited to this.

[0091] As described above, the fuel cell-battery system according to embodiments of the present disclosure can effectively perform heat exchange, thereby enabling efficient utilization of heat and provision of coolant and fuel at appropriate temperatures.

[0092] In the foregoing description of the embodiments of this disclosure, even though all components are coupled into a single entity or operate in a combined state, this disclosure is not limited to these embodiments. In other words, all components may operate in one or more selective combinations within the scope of the purpose of this disclosure. It should also be understood that the terms "comprising," "including," or "having" in the specification are "open-ended" expressions, simply indicating the presence of the corresponding component, and, unless specifically described to the contrary, do not exclude but may include additional components. Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure relates. These terms as defined in generally used dictionaries should be interpreted as having a meaning equivalent to that in the context of the relevant field and should not be interpreted as having an ideal or overly formal meaning unless expressly defined in this application as having an ideal or overly formal meaning. When components, devices, elements, etc., of this disclosure are described as having a purpose or performing an operation, function, etc., it should be understood herein that the component, device, or element is "configured" to satisfy that purpose or perform that operation or function. Furthermore, the controllers described herein may include processors programmed to perform operations, functions, etc.

[0093] Although this disclosure has been described above with reference to specific embodiments and accompanying drawings, it is not limited thereto. Various modifications and alterations can be made by those skilled in the art to which this disclosure pertains without departing from the spirit and scope of the disclosure as claimed in the appended claims. Therefore, the specific embodiments of this disclosure are provided to explain its spirit and scope, but not to limit it, so that the spirit and scope of the disclosure are not limited by the embodiments. The scope of this disclosure should be interpreted based on the appended claims, and all technical ideas within the scope equivalent to the claims should be included within the scope of this disclosure.

Claims

1. A fuel cell-battery system, comprising: A battery module includes a battery configured to store electrical energy and coolant lines through which coolant circulates to cool the battery; A fuel cell module includes a hydrogen tank configured to store hydrogen, a fuel cell configured to use hydrogen to generate the electricity, and a hydrogen pipeline configured to connect the hydrogen tank and the fuel cell to deliver the hydrogen from the hydrogen tank to the fuel cell. as well as A heat exchange module through which the coolant line and the hydrogen line pass, such that the coolant is cooled by heat exchange with the hydrogen and the hydrogen is heated by heat exchange with the coolant; The fuel cell module further includes: An external heat exchanger, disposed on the hydrogen pipeline between the heat exchange module and the hydrogen tank and configured to heat the hydrogen flowing in the hydrogen pipeline, and A return line is configured to return the hydrogen gas passing through the external heat exchanger to the upstream side of the external heat exchanger, relative to the direction of hydrogen gas flow in the hydrogen line.

2. The fuel cell-battery system according to claim 1, wherein, The battery module also includes: A heater is configured to heat the coolant; and A heating line is configured to pass through the heater to heat the coolant.

3. The fuel cell-battery system according to claim 2, wherein, The battery module also includes: A coolant temperature acquisition device is configured to acquire the temperature of the coolant released from the battery; and The battery controller is electrically connected to the coolant temperature acquisition device and the heater, and Wherein, the battery controller: When the obtained coolant temperature is higher than the target coolant temperature, control is executed to cause the coolant to flow along the coolant line and the heater to stop operating; and When the obtained coolant temperature is lower than the target coolant temperature, control is executed to make the coolant flow along the heating line and the heater operate.

4. The fuel cell-battery system according to claim 3, wherein, When the obtained coolant temperature equals the target coolant temperature, the battery controller performs control to cause the coolant to flow along the heating line and the heater to stop working.

5. The fuel cell-battery system according to claim 1, wherein, The fuel cell module also includes: A hydrogen temperature acquisition device is configured to acquire the temperature of the hydrogen passing through the external heat exchanger; and The fuel cell controller is electrically connected to the hydrogen temperature acquisition device. The hydrogen tank includes a hydrogen storage container for storing the hydrogen and an internal heat exchanger. The hydrogen storage container and the introduced material exchange heat with each other through the internal heat exchanger. Wherein, the fuel cell controller: When the obtained hydrogen temperature is higher than or equal to the upper limit of the target hydrogen temperature range, the hydrogen is returned to the internal heat exchanger through the return line to cool it; and When the obtained hydrogen temperature is lower than or equal to the lower limit of the target hydrogen temperature range, the hydrogen is returned to the external heat exchanger through the return line to heat the hydrogen.

6. The fuel cell-battery system according to claim 1, wherein, The battery module further includes a coolant temperature acquisition device and a battery controller. The coolant temperature acquisition device is configured to obtain the temperature of the coolant released from the battery, and the battery controller is electrically connected to the coolant temperature acquisition device. The fuel cell module further includes a bypass line and a fuel cell controller. Through the bypass line, hydrogen from the hydrogen pipeline is bypassed to the fuel cell before entering the heat exchange module. The fuel cell controller is electrically connected to the coolant temperature acquisition device and the battery controller. Wherein, the fuel cell controller: When the obtained coolant temperature is higher than the target coolant temperature, the hydrogen gas is allowed to pass through the heat exchange module; and When the obtained coolant temperature is lower than or equal to the target coolant temperature, the hydrogen is allowed to flow along the bypass line.

7. The fuel cell-battery system according to claim 1, wherein, The fuel cell module also includes a circulation pipeline through which the hydrogen is returned to the hydrogen tank before entering the fuel cell after passing through the heat exchange module.

8. The fuel cell-battery system according to claim 1, wherein, The fuel cell module also includes a regulator disposed in the hydrogen line and configured to reduce the pressure of the hydrogen flowing in the hydrogen line so that the pressure of the hydrogen to be supplied to the fuel cell is within a predetermined pressure range.

9. The fuel cell-battery system according to claim 1, wherein, The heat exchange module is one of a coaxial tube heat exchanger, a finned tube heat exchanger, and a plate heat exchanger, configured to allow the hydrogen and the coolant to exchange heat indirectly with each other.

10. The fuel cell-battery system according to claim 1, wherein, The heat exchange module includes: The main heat exchange module is through which the coolant of the battery module and the hydrogen of the fuel cell module exchange heat with each other; and An additional heat exchange module is provided, through which the coolant of at least one of the vehicle's air conditioning system, fuel cell stack, and engine exchanges heat with the hydrogen of the fuel cell module.

11. The fuel cell-battery system according to claim 1, wherein, The hydrogen tank is a cryogenic compressed hydrogen storage device.

12. A method for controlling a fuel cell-battery system, wherein, The fuel cell-battery system includes: a battery module configured to cool a battery using a coolant, wherein the battery is configured to store electricity; a fuel cell module configured to heat hydrogen and supply the heated hydrogen to a fuel cell, the fuel cell being configured to generate electricity using the hydrogen; and a heat exchange module through which the coolant and the hydrogen exchange heat with each other, the method comprising: To obtain the temperature of the coolant released from the battery; When the temperature of the coolant is higher than the target coolant temperature, the coolant is passed through the heat exchange module to cool it; and When the temperature of the coolant is lower than or equal to the target coolant temperature, the coolant is passed through the heater. The process of allowing the coolant to pass through the heater includes activating the heater when the temperature of the coolant is lower than the target coolant temperature. The battery module further includes a coolant temperature acquisition device and a battery controller. The coolant temperature acquisition device is configured to obtain the temperature of the coolant released from the battery, and the battery controller is electrically connected to the coolant temperature acquisition device. The fuel cell module further includes a bypass line and a fuel cell controller. Through the bypass line, hydrogen supplied to the fuel cell module is bypassed to the fuel cell before entering the heat exchange module. The fuel cell controller is electrically connected to the coolant temperature acquisition device and the battery controller. Specifically, when the obtained coolant temperature is higher than the target coolant temperature, the hydrogen is allowed to pass through the heat exchange module; and when the obtained coolant temperature is lower than or equal to the target coolant temperature, the hydrogen is allowed to flow along the bypass line.

13. A method for controlling a fuel cell-battery system, wherein, The fuel cell-battery system includes: a battery module configured to cool a battery using a coolant, wherein the battery is configured to store electricity; a fuel cell module configured to heat hydrogen stored in a hydrogen tank using an external heat exchanger and supply the heated hydrogen to the fuel cell, the fuel cell being configured to generate the electricity using the hydrogen; and a heat exchange module through which the coolant and the hydrogen exchange heat with each other, the method comprising: To obtain the temperature of the hydrogen gas passing through the external heat exchanger; When the temperature of the hydrogen gas is higher than or equal to the upper limit of the target hydrogen gas temperature range, the hydrogen gas is returned to the hydrogen tank to cool it; and When the temperature of the hydrogen is lower than or equal to the lower limit of the target hydrogen temperature range, the hydrogen is returned to the external heat exchanger to be heated.

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