A hydrogen fuel cell thermal management system

Abstract

The present invention relates to the field of automobile thermal management technology, and is a hydrogen fuel cell automobile thermal management technology, specifically a hydrogen fuel cell thermal management system; comprising a refrigerant pump, a four-way valve, a first three-way valve, a fuel cell stack, a liquid hydrogen tank, an air compressor, a second three-way valve, an intake cooling heat exchanger, a coolant pump, a coolant tank, a third three-way valve, a two-way expansion valve, a cooling module, and a passenger compartment, which are composed of a selectable switchable refrigerant circulation first circuit, a refrigerant circulation second circuit, and a refrigerant circulation third circuit; the output end of the refrigerant pump is connected to the first interface of the four-way valve, the second interface of the four-way valve is connected to the cooling module, the third interface of the four-way valve is connected to the first three-way valve, and the fourth interface of the four-way valve is connected to the input end of the refrigerant pump; the fuel cell stack is connected to the first port of the third three-way valve, the passenger compartment is connected to the second port of the third three-way valve, and the two-way expansion valve is bidirectionally connected to the third three-way valve and the cooling module.

Description

Technical Field

[0001] The present invention relates to the field of automobile thermal management technology, in particular to a hydrogen fuel cell automobile thermal management technology, and in particular to a hydrogen fuel cell thermal management system. Background Art

[0002] Energy and the environment are major challenges facing human society today. Efficient clean energy utilization technologies are crucial for achieving sustainable development. Hydrogen fuel cells are particularly popular due to their high efficiency and environmental friendliness. Hydrogen fuel cells generate significant heat during power generation, and the balance between heat generation and heat dissipation determines the battery's temperature. Batteries have stringent temperature requirements, allowing only slight deviations from the design temperature. Therefore, maintaining a uniform temperature near the design temperature through thermal management is crucial.

[0003] Current fuel cell thermal management systems all use coolant as a medium, and control the fuel cell temperature by connecting a heating device (such as a PTC heater) and a cooling device in series in the system. The fuel cell thermal management system is independent of the passenger compartment's air conditioning system.

[0004] The operating temperature of fuel cells is generally 60-80℃, and the operating pressure of high-power stacks usually reaches 2-3 atmospheres. The air temperature after compression by the air compressor is usually above 150℃. In order to prevent damage to the membrane electrode, an intercooler is required to cool the air after the air compressor and in front of the stack.

[0005] Some related technologies provide hydrogen fuel cell vehicles with both fuel cell heating and passenger compartment heating functions at low temperatures. These functions are achieved through the use of two high-voltage PTC water heaters. Due to the large size, high cost, and high power consumption of these high-voltage PTC water heaters at low temperatures, this makes overall vehicle layout difficult, resulting in high cost and high power consumption. Furthermore, the waste heat from the hydrogen fuel cell is not used to heat the power battery or passenger compartment, resulting in energy waste.

[0006] Existing technologies have employed a coupling method between the fuel cell thermal management system and the passenger compartment air conditioning system to enhance the performance of the fuel cell thermal management system. However, this approach essentially allows the fuel cell thermal management system and the air conditioning system to operate independently. Furthermore, existing technologies often utilize the circulation of coolant to heat and dissipate heat for the fuel cell. When the fuel cell requires heating, a heater within the circuit activates, heating the coolant and thereby raising the fuel cell temperature. When the fuel cell temperature is too high and the thermal management system's heat dissipation performance is insufficient, the air conditioning system begins operating, exchanging heat between the fuel cell thermal management circuit and the air conditioning system circuit through a heat exchanger to lower the coolant temperature, thereby lowering the fuel cell temperature. This thermal management system is complex and consumes a lot of energy. Summary of the Invention

[0007] In order to solve the above technical problems, the present application provides a hydrogen fuel cell thermal management system, which aims to solve multiple problems in the above existing technologies.

[0008] The present invention is achieved in that:

[0009] In the first aspect, a hydrogen fuel cell thermal management system includes a refrigerant pump, a four-way valve, a first three-way valve, a fuel cell stack, a liquid hydrogen tank, an air compressor, a second three-way valve, an intake cooling heat exchanger, a coolant pump, a coolant tank, a third three-way valve, a two-way expansion valve, a cooling module, and a passenger compartment, which are composed of a first refrigerant circulation circuit, a second refrigerant circulation circuit, and a third refrigerant circulation circuit that can be switched; the output end of the refrigerant pump is connected to the first interface of the four-way valve, the second interface of the four-way valve is connected to the cooling module, the third interface of the four-way valve is connected to the first three-way valve, and the fourth interface of the four-way valve is connected to the input end of the refrigerant pump; the fuel cell stack is connected to the first port of the third three-way valve, the passenger compartment is connected to the second port of the third three-way valve, and the two-way expansion valve is bidirectionally connected to the third three-way valve and the cooling module.

[0010] Furthermore, it also includes a fuel heat exchanger, which is connected to the second three-way valve and the coolant tank respectively.

[0011] Furthermore, there are heat absorption flow paths inside the intake air cooling heat exchanger and the fuel heat exchanger.

[0012] Furthermore, the heat absorption flow path of the intake air cooling heat exchanger is connected to the connecting pipeline between the air compressor and the fuel cell stack.

[0013] Furthermore, the heat absorption flow path of the fuel heat exchanger is connected to the connecting pipeline between the fuel cell stack and the liquid hydrogen tank.

[0014] Furthermore, the coolant tank is connected to the coolant pump, the coolant pump is connected to the intake air cooling heat exchanger, the intake air cooling heat exchanger is connected to the passenger compartment, the passenger compartment is connected to the fuel heat exchanger through the second three-way valve, and the fuel heat exchanger is connected to the fuel stack through the coolant tank and the coolant pump.

[0015] Furthermore, the intake air cooling heat exchanger is connected to the fuel heat exchanger, the air compressor is connected to the fuel cell stack, and the liquid hydrogen tank is connected to the fuel cell stack.

[0016] Furthermore, the first refrigerant circulation loop is a loop formed by the refrigerant pump, the four-way valve, the cooling module, the two-way expansion valve, the third three-way valve and the fuel cell stack.

[0017] Furthermore, the second refrigerant circulation loop is a loop consisting of the refrigerant pump, the four-way valve, the cooling module, the two-way expansion valve, the third three-way valve and the passenger compartment.

[0018] Furthermore, the third coolant circulation loop is a loop composed of the coolant tank, the coolant pump, the intake air cooling heat exchanger and the fuel heat exchanger.

[0019] The technical solution provided in the embodiments of this application utilizes refrigerant cooling, which has lower flow resistance and faster response than coolant. When the fuel cell operating temperature is too high, reducing the intake air temperature can lower the fuel cell temperature. During winter driving, the passenger compartment needs to be heated, and the excess heat from the intake air can be fully utilized. Not using gaseous hydrogen can reduce the hydrogen production process while fully utilizing the excess heat on the oxygen side. During heat transfer, the excess heat from the intake air can be utilized, reducing the frequency of use of the refrigerant pump and increasing its service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0021] The methods, systems, and / or programs in the accompanying drawings will be further described according to exemplary embodiments. These exemplary embodiments will be described in detail with reference to the drawings. These exemplary embodiments are non-limiting exemplary embodiments, wherein example numerals represent similar structures in the various views of the drawings.

[0022] Figure 1 This is a structural framework diagram of a thermal management system provided by an embodiment of the present invention.

[0023] icon:

[0024] 1-Refrigerant pump; 2-Four-way valve; 3-First three-way valve; 4-Cellular stack; 5-Liquid hydrogen tank; 6-Air compressor; 7-Second three-way valve; 8-Intake air cooling heat exchanger; 9-Coolant pump; 10-Coolant tank; 11-Third three-way valve; 12-Two-way expansion valve; 13-Cooling module; 14-Crew compartment; 15-Fuel heat exchanger. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0026] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0027] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" and the like indicate positions or locations based on the positions shown in the accompanying drawings, or the positions or locations in which the inventive product is typically placed when in use. These terms are intended solely to facilitate the description of the present invention and to simplify the description, and are not intended to indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third," etc., are used solely to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0028] In the description of the present invention, it should also be noted that, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to mechanical connections or electrical connections; they may refer to direct connections or indirect connections through an intermediate medium; and they may refer to internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0029] In the following detailed description, numerous specific details are set forth by way of example in order to provide a thorough understanding of the relevant teachings. However, it will be apparent to one skilled in the art that the present application can be practiced without these details. In other instances, well-known methods, procedures, systems, compositions, and / or circuits have been described at a relatively high level, without detail, to avoid unnecessarily obscuring aspects of the present application.

[0030] See also Figure 1In this embodiment, a hydrogen fuel cell thermal management system is provided for managing and utilizing heat in a hydrogen fuel cell.

[0031] See Figure 1 The thermal management system provided in this embodiment is composed of multiple components, specifically including a refrigerant pump 1, a four-way valve 2, a first three-way valve 3, a fuel cell stack 4, a liquid hydrogen tank 5, an air compressor 6, a second three-way valve 7, an intake air cooling heat exchanger 8, a coolant pump 9, a coolant tank 10, a third three-way valve 11, a two-way expansion valve 12, a cooling module 13, and a passenger compartment 14. The output end of the refrigerant pump 1 is connected to the first interface of the four-way valve 2, the second interface of the four-way valve 2 is connected to the cooling module 13, the third interface of the four-way valve 2 is connected to the first three-way valve 3, and the fourth interface of the four-way valve 2 is connected to the input end of the refrigerant pump 1; the fuel cell stack 4 is connected to the first port of the third three-way valve 11, the passenger compartment 14 is connected to the second port of the third three-way valve 11, and the two-way expansion valve 12 is bidirectionally connected to the third three-way valve 11 and the cooling module 13. The coolant tank 10 is connected to the coolant pump 9, the coolant pump 9 is connected to the intake air cooling heat exchanger 8, the intake air cooling heat exchanger 8 is connected to the passenger compartment 14, the passenger compartment 14 is connected to the fuel heat exchanger 15 through the second three-way valve 7, and the fuel heat exchanger 15 is connected to the fuel stack 4 through the coolant tank 10 and the coolant pump 9.

[0032] It also includes a dye heat exchanger connected to the second three-way valve 7 and the coolant tank 10. Both the fuel heat exchanger 15 and the intake air cooling heat exchanger 8 are internally provided with heat absorption channels. The heat absorption channel of the intake air cooling heat exchanger 8 is connected to the air compressor 6 and the fuel cell stack 4. The heat absorption channel of the fuel heat exchanger 15 is connected to the connecting pipes of the fuel cell stack 4 and the liquid hydrogen tank 5.

[0033] Moreover, for the above components, multiple circuits can be formed by switching the valve bodies, namely the four-way valve 2, the first three-way valve 3, the second three-way valve 7, and the third three-way valve 11, specifically the first refrigerant circulation circuit, the second refrigerant circulation circuit, and the third refrigerant circulation circuit.

[0034] In this embodiment, the first refrigerant circulation loop is formed by the refrigerant pump 1, four-way valve 2, cooling module 13, two-way expansion valve 12, third three-way valve 11, and fuel cell stack 4. The second refrigerant circulation loop is formed by the refrigerant pump 1, four-way valve 2, cooling module 13, two-way expansion valve 12, third three-way valve 11, and passenger compartment 14. The third coolant circulation loop is formed by the coolant tank 10, coolant pump 9, intake air cooling heat exchanger 8, and fuel heat exchanger 15.

[0035] Regarding the working principle of the thermal management system provided in this embodiment, as shown in FIG. Figure 1As shown, during heating, the high-temperature and high-pressure refrigerant from the refrigerant pump 1 enters port A of the four-way valve 2. At this time, port A of the four-way valve 2 is connected to port C, and port B is connected to port D. After passing through the first three-way valve 3, it can flow to the battery stack 4 and the passenger compartment 14 respectively. After the high-temperature and high-pressure refrigerant releases heat in the battery stack 4 and the passenger compartment 14, it becomes a low-temperature and high-pressure refrigerant. Then, it passes through the throttling effect of the two-way expansion valve 12 and becomes a low-temperature and low-pressure refrigerant. The refrigerant then enters port B of the four-way valve 2, exits from port D, and returns to the refrigerant pump 1, forming a heating cycle. When the battery stack 4 or the passenger compartment 14 needs to dissipate heat separately, the first three-way valve 3 can be controlled to dissipate heat to the battery stack 4 or the passenger compartment 14 respectively. The layout structure is simple and easy to control. Because the air temperature from air compressor 6 is around 150°C, while the operating temperature of the fuel cell stack is generally between 60°C and 80°C, the air needs to be cooled before entering the fuel cell stack. At this time, water from coolant tank 10 enters coolant pump 9 and then passes through intake air cooling heat exchanger 8. Simultaneously, the high-temperature gas from air compressor 6 undergoes heat exchange with intake air cooling heat exchanger 8 before entering fuel cell stack 4. The heat from the compressed air is transferred to the coolant before entering fuel cell stack 4. After absorbing heat, the coolant becomes gaseous coolant and flows to three-way valve 7, where it can flow to passenger compartment 14 and fuel heat exchanger 15, respectively. Liquid hydrogen from liquid hydrogen tank 5 is converted into hydrogen gas after heat exchange with fuel heat exchanger 15 and enters fuel cell stack 4. Meanwhile, the high-temperature coolant vapor undergoes superheat exchange with the liquid hydrogen and becomes low-temperature coolant, which flows back to coolant pump 10, forming a circulation loop that cools the fuel cell stack and heats the passenger compartment or liquid hydrogen. When the passenger compartment does not need to be heated in the summer, the gas coolant can close the passage between the passenger compartment and the passenger compartment 14 when flowing through the second three-way valve 7. When the passenger compartment needs to be heated in the winter, the second three-way valve 7 can be fully opened to heat the passenger compartment 14 and the liquid hydrogen at the same time. The layout structure is simple and easy to control.

[0036] like Figure 1As shown, during cooling, high-temperature, high-pressure refrigerant from refrigerant pump 1 enters port A of four-way valve 2. Port A of four-way valve 2 is now connected to port B, and port C is connected to port D. The high-temperature, high-pressure refrigerant exits port B of the four-way valve and enters cooling module 13, releasing heat and becoming low-temperature, high-pressure refrigerant. It then undergoes the throttling action of bidirectional expansion valve 12, becoming low-temperature, low-pressure refrigerant. It then passes through third three-way valve 11 and flows to the fuel cell stack or passenger compartment 14, respectively, to achieve a cooling effect. After passing through the fuel cell stack and passenger compartment, the low-temperature, low-pressure refrigerant becomes high-temperature refrigerant. It then passes through first three-way valve 3 and enters port C of four-way valve 2. It then flows through port D and returns to refrigerant pump 1, completing a refrigeration cycle. In winter, when the passenger compartment does not need to dissipate heat, the passage between third three-way valve 11 and passenger compartment 14 can be closed. In summer, when the passenger compartment does need to dissipate heat, the third three-way valve 11 can be fully opened, resulting in a simple and easy-to-control arrangement. Because the heat brought from the intake air cooling heat exchanger 8 and the heat from the refrigerant pump 1 can be delivered to the passenger compartment, but after the fuel cell stack is started, the heat of the compressed air is endless, so the heat brought from the intake air cooling heat exchanger 8 is used first, and the heat from the refrigerant pump 1 is used secondarily. This can maximize the use of the excess heat of the intake air temperature, while also reducing the output power and usage frequency of the refrigerant pump, thereby extending the service life of the refrigerant pump.

[0037] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A hydrogen fuel cell thermal management system, characterized in that: The invention comprises a refrigerant circulation first circuit, a refrigerant circulation second circuit and a refrigerant circulation third circuit which can be switched selectively, consisting of a refrigerant pump, a four-way valve, a first three-way valve, a fuel cell, a liquid hydrogen tank, an air compressor, a second three-way valve, an intake cooling heat exchanger, a coolant pump, a coolant tank, a third three-way valve, a two-way expansion valve, a cooling module and a passenger compartment; the output end of the refrigerant pump is connected to the first interface of the four-way valve, the second interface of the four-way valve is connected to the cooling module, the third interface of the four-way valve is connected to the first three-way valve, and the fourth interface of the four-way valve is connected to the input end of the refrigerant pump; the fuel cell is connected to the first port of the third three-way valve, and the passenger compartment is connected The second port of the third three-way valve is connected, and the two-way expansion valve is bidirectionally connected to the third three-way valve and the cooling module; the first refrigerant circulation loop is a loop formed by the refrigerant pump, the four-way valve, the cooling module, the two-way expansion valve, the third three-way valve and the fuel cell stack; it also includes a fuel heat exchanger, and the fuel heat exchanger is respectively connected to the second three-way valve and the coolant tank; the coolant tank is connected to the coolant pump, the coolant pump is connected to the intake air cooling heat exchanger, the intake air cooling heat exchanger is connected to the passenger compartment, the passenger compartment is connected to the fuel heat exchanger through the second three-way valve, and the fuel heat exchanger is connected to the fuel cell stack through the coolant tank and the coolant pump.

2. The hydrogen fuel cell thermal management system according to claim 1, characterized in that: Heat absorption flow paths are provided inside the intake air cooling heat exchanger and the fuel heat exchanger.

3. The hydrogen fuel cell thermal management system according to claim 2, characterized in that: The heat absorption flow path of the intake air cooling heat exchanger is connected to the connecting pipeline of the air compressor and the fuel cell stack.

4. The hydrogen fuel cell thermal management system according to claim 2, characterized in that: The heat absorption flow path of the fuel heat exchanger is connected to the connecting pipeline of the fuel cell stack and the liquid hydrogen tank.

5. The hydrogen fuel cell thermal management system according to claim 1, characterized in that: The intake air cooling heat exchanger is connected to the fuel heat exchanger, the air compressor is connected to the fuel cell stack, and the liquid hydrogen tank is connected to the fuel cell stack.

6. A hydrogen fuel cell thermal management system according to claim 1, characterized in that: The second refrigerant circulation loop is a loop consisting of the refrigerant pump, the four-way valve, the cooling module, the two-way expansion valve, the third three-way valve and the passenger compartment.

7. A hydrogen fuel cell thermal management system according to claim 1, characterized in that: The third coolant circulation loop is a loop composed of the coolant tank, the coolant pump, the intake air cooling heat exchanger and the fuel heat exchanger.

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