Hydrogen fuel cell vehicle thermal management system and control method thereof

Abstract

The invention discloses a hydrogen fuel cell whole vehicle thermal management system and a control method thereof, and relates to the technical field of new energy vehicle thermal management. A fuel cell system is used for enabling cooling liquid output by an electric pile to flow to a radiator or a first heat exchanger; the low-temperature cooling loop drives the cooling liquid to flow; the passenger compartment heating loop is used for accessing heat of the electric pile through the first heat exchanger and transmitting cooling liquid heated by the heater to the electric pile through the first heat exchanger; the air-conditioning cooling loop is used for conveying refrigerating capacity of an air-conditioning system; the power battery heat management loop heats the battery system through the electric pile heat conveyed by the second heat exchanger or the heat of the passenger compartment heating loop through switching of the four-way valve, and cools the battery system through the refrigerating capacity conveyed by the third heat exchanger. The functions of electric pile heat management, passenger compartment heating, power battery heat management and cold start are integrated.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of new energy vehicle thermal management, in particular to a hydrogen fuel cell vehicle thermal management system and a control method thereof. BACKGROUND

[0002] The statements in this section merely provide background information related to the present application and do not necessarily constitute prior art.

[0003] The high hydrogen consumption of fuel cell vehicles has always been a problem in the industry, and the design of vehicle thermal management is an important way to reduce hydrogen consumption, especially in low temperature environments. However, hydrogen fuel cell vehicles still face the following problems when operating in low temperature environments.

[0004] Cold start difficulty of the stack: when the ambient temperature is lower than 0℃, the residual water in the stack will freeze, blocking the reaction gas channel, resulting in the system unable to start normally. The existing technology usually relies on a high-power PTC heater to preheat the stack, which significantly increases the energy consumption of the system during the start-up phase, and significantly increases the hydrogen consumption of the system during the start-up phase.

[0005] High energy consumption for passenger cabin heating: traditional fuel vehicles can use engine waste heat for heating, while pure electric vehicles usually use high-power PTC heaters or heat pump systems. Although hydrogen fuel cell vehicles can generate waste heat during operation, in the low temperature cold start phase or low load working condition, the available waste heat of the stack is small and of low quality, and often still needs to rely on additional PTC heating devices to meet the heating needs of the passenger cabin, further increasing energy consumption.

[0006] System complexity and energy consumption: the existing thermal management system usually sets up independently for stack thermal management, passenger cabin heating and power battery thermal management loop, there are a large number of valves, pump bodies, heat exchangers and connecting pipelines, resulting in complex system structure, large flow resistance and heat loss. High-power electronic water pumps, cooling fans and PTC heaters and other accessories consume a large amount of electric energy when working, and all energy consumption ultimately comes from the fuel cell itself or the power battery, resulting in increased hydrogen consumption of the vehicle and reduced economy. SUMMARY

[0007] In order to solve the above problems, the present application provides a hydrogen fuel cell vehicle thermal management system and a control method thereof, which integrates stack thermal management, passenger cabin heating, power battery thermal management and cold start functions, solves the problems of high energy consumption of stack cold start, passenger cabin heating and battery thermal management relying on external heat source, and complexity and low efficiency caused by independent operation of multiple systems.

[0008] In order to achieve the above purpose, the present application adopts the following technical solutions: In a first aspect, the present application provides a hydrogen fuel cell vehicle thermal management system, comprising: The fuel cell system comprises a stack, a radiator and a first heat exchanger connected with the stack, and a cooling liquid output by the stack flows to the radiator or the first heat exchanger; A low-temperature cooling loop is used to drive the flow of the cooling liquid; The passenger cabin heating loop comprises a heater, a second heat exchanger and a four-way valve connected in sequence, and the four-way valve is further connected with the first heat exchanger, so as to access the heat of the stack through the first heat exchanger, and transmit the cooling liquid heated by the heater to the stack through the first heat exchanger. The air conditioning cooling loop comprises an air conditioning system and a third heat exchanger used to transport the refrigeration capacity of the air conditioning system. The power battery thermal management loop comprises the second heat exchanger, the battery system and the third heat exchanger connected in sequence, and the battery system is heated by the heat of the stack transported through the second heat exchanger or the heat of the passenger cabin heating loop through the switching of the four-way valve, and the battery system is cooled by the refrigeration capacity transported through the third heat exchanger.

[0009] As an optional embodiment, the fuel cell system comprises an air supply loop, a hydrogen supply loop, a water thermal management loop and a control loop; the air supply loop comprises an air filter, an air flow meter, an air compressor and an intercooler connected in sequence; the intercooler is connected with the stack and is provided with a bypass valve; an air inlet cutoff valve is arranged on an air inlet pipeline of the stack, an air outlet cutoff valve is arranged on an air outlet pipeline of the stack, and the air outlet cutoff valve is further connected with a back pressure valve, a mixed exhaust valve and a secondary silencer in sequence, for exhausting the exhaust gas generated by the stack.

[0010] As an optional embodiment, the hydrogen supply loop comprises a high-pressure hydrogen storage bottle, a cutoff valve, a proportional valve and an ejector connected in sequence, the ejector is connected with the stack, for transporting hydrogen to the stack; the stack is connected with a steam-water separator, for separating and exhausting liquid water; the steam-water separator is connected with a circulating pump, and the circulating pump is connected with the ejector, for hydrogen circulation; the steam-water separator is connected with a first hydrogen exhaust valve and a second hydrogen exhaust valve respectively, the first hydrogen exhaust valve and the second hydrogen exhaust valve are both connected with the mixed exhaust valve, and the mixed exhaust valve is connected with the secondary silencer, for exhausting the exhaust gas generated by the stack.

[0011] As an optional embodiment, the water thermal management loop comprises a first water tank, a first water pump, a radiator, a filter, a three-way valve, a first heat exchanger and a deionizer; the heat generated by the stack reaction is taken out by the cooling liquid, the cooling liquid flows through the first water pump, the radiator and the filter, and the flow direction of the cooling liquid is controlled by the three-way valve to flow to the radiator or the first heat exchanger; the deionizer is used to maintain the electrical conductivity of the cooling liquid within a reasonable set range.

[0012] As an alternative implementation, the control loop includes an air compressor controller, a boost DC / DC converter, an EIS sensor, and an FCU; the air compressor controller is used to control the operation of the air compressor; the boost DC / DC converter is used to boost the voltage output; the EIS sensor is used for stack status monitoring; and the FCU, as the main controller of the fuel cell system, coordinates the operation of each component.

[0013] As an alternative implementation, the cryogenic cooling circuit includes a cryogenic radiator, a second water pump, a vehicle DC / DC converter, a vehicle CDU, and a motor controller connected in sequence. The motor controller is connected to the cryogenic radiator to form a circuit. The second water pump is used to drive the flow of coolant.

[0014] As an optional implementation, the power battery thermal management circuit includes a second heat exchanger, a battery system, a third water tank, a fourth water pump, and a third heat exchanger connected in sequence. The third heat exchanger is connected to the second heat exchanger to form a circuit. The second heat exchanger is used to extract heat from the passenger compartment heating circuit or the waste heat of the fuel cell stack, and the third heat exchanger is used to extract coolness from the air conditioning system. The second heat exchanger is connected to a four-way valve, which is used to switch the heating or cooling mode of the battery system.

[0015] As an alternative implementation, the air conditioning cooling circuit includes an air conditioning radiator, a third heat exchanger and an air conditioning compressor connected in sequence, with the air conditioning compressor connected to the air conditioning radiator to form a circuit. It also includes an air conditioner radiator, a condenser, and an air conditioner compressor connected in sequence, with the air conditioner compressor connected to the air conditioner radiator to form a circuit.

[0016] As an alternative implementation, the crew cabin heating circuit includes a high-pressure PTC heater, a second heat exchanger, a four-way valve and a fifth water pump connected in sequence, with the fifth water pump connected to the high-pressure PTC heater to form a circuit. It also includes a first heat exchanger, a third water pump, a heating air conditioner and a blower connected in sequence, with the heating air conditioner connected to a four-way valve; The high-pressure PTC heater serves as an auxiliary heat source to enable startup under low-temperature conditions; the first heat exchanger recovers waste heat from the fuel cell stack to provide heating for the crew cabin heating circuit; and the blower drives airflow through the heating air conditioning system to provide heating for the crew cabin.

[0017] Secondly, the present invention provides a control method for a thermal management system of a hydrogen fuel cell vehicle, comprising: When the fuel cell stack is operating normally and the crew compartment needs heating, the three-way valve is controlled to allow the coolant to flow through the first heat exchanger. The heat generated by the fuel cell stack is transferred to the crew compartment heating circuit through the first heat exchanger, heating the air flowing through the heating and air conditioning system to achieve crew compartment heating. When the fuel cell stack is cold-started, the high-voltage PTC heater is activated to heat the coolant in the crew cabin heating circuit. The heated coolant flows through the first heat exchanger and transfers heat to the fuel cell system to preheat the fuel cell stack. When the battery system is heated or cooled, the battery system is heated by the heat from the fuel cell stack or the crew cabin heating circuit delivered via the second heat exchanger, and cooled by the cooling capacity delivered via the third heat exchanger. When the fuel cell stack needs to dissipate heat but the crew compartment does not need to be heated, the coolant is controlled to flow through the radiator via a three-way valve, and the heat is dissipated through a low-temperature radiator and an electric fan.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention proposes a thermal management system and control method for a hydrogen fuel cell vehicle. By sharing components such as the first heat exchanger, high-pressure PTC heater, and four-way valve, and by eliminating the dedicated PTC heater for the fuel cell system, and coupling the stack thermal management circuit, the passenger compartment heating circuit, and the power battery thermal management circuit, the number of components and pipeline connections is significantly reduced, the system complexity and manufacturing cost are reduced, and the integration of the fuel cell system is improved.

[0019] This invention makes full use of the waste heat generated during the operation of the fuel cell stack to heat the passenger compartment and the battery system, reducing the start-up time and power consumption of the high-voltage PTC heater and the air conditioning compressor. During the cold start phase, the high-voltage PTC heater in the passenger compartment heating circuit is reused to heat the fuel cell stack, avoiding the high start-up energy consumption caused by setting up an independent high-power PTC, thereby effectively reducing the hydrogen consumption of the whole vehicle.

[0020] This invention achieves efficient coordination of multiple thermal management loops through intelligent control of components such as four-way valves and three-way valves, reducing flow resistance and heat loss, and improving the overall operating efficiency and reliability of the system.

[0021] Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0023] Fig. 1 This is a schematic diagram of a hydrogen fuel cell system provided in Embodiment 1 of the present invention; Fig. 2This is a schematic diagram of the thermal management principle of a hydrogen fuel cell vehicle provided in Embodiment 1 of the present invention; The components include: 1. Air filter; 2. Air flow meter; 3. Air compressor; 4. Intercooler; 5. Inlet shut-off valve; 6. Bypass valve; 7. Outlet shut-off valve; 8. Fuel cell stack; 9. First water tank; 10. First water pump; 11. Radiator; 12. Filter; 13. Three-way valve; 14. First heat exchanger; 15. Heating and ventilation system; 16. High-pressure PTC heater; 17. Deionizer; 18. Air compressor controller; 19. Boost DC / DC converter; 20. EIS detector; 21. FCU; 22. High-pressure hydrogen storage tank; 23. Shut-off valve; 24. Proportional valve; 25. Ejector; 26. Circulation pump; 27. Gas-liquid separator; 28. First hydrogen discharge valve; 29. ​​Second hydrogen discharge valve; 30. 31. Mixing valve; 32. Back pressure valve; 33. Secondary muffler; 34. Low-temperature radiator; 35. Air conditioning radiator; 36. Electric fan; 37. Water temperature sensor; 38. Second water pump; 39. Vehicle DC / DC converter; 40. Vehicle CDU; 41. Motor controller; 42. Air conditioning compressor; 43. Second water tank; 44. Third water pump; 45. Four-way valve; 46. Second heat exchanger; 47. First temperature sensor; 48. Battery system; 49. Second temperature sensor; 50. Third water tank; 51. Fourth water pump; 52. Third heat exchanger; 53. First environmental sensor; 54. Switch valve; 55. Fifth water pump; 56. Blower; 57. Condenser; 58. Second environmental sensor. Detailed Implementation

[0024] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0025] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0026] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments of the invention. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form as well. Furthermore, it should be understood that the terms “comprising” and “including”, and any variations thereof, are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0027] Where there is no conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0028] Example 1 As described in the background section, hydrogen fuel cell vehicles face difficulties in cold starting of the fuel cell stack in low-temperature environments, requiring a high-power PTC heater to preheat the stack. To meet the heating needs of the passenger compartment, additional PTC heating devices are still needed, further exacerbating energy consumption. Existing thermal management systems typically have separate circuits for fuel cell stack thermal management, passenger compartment heating, and power battery thermal management, resulting in a complex system structure, significant heat loss, increased hydrogen consumption, reduced economy, and increased costs.

[0029] Therefore, this embodiment provides a highly integrated, low-cost, and low-energy-consumption thermal management system for hydrogen fuel cell vehicles, such as... Figs. 1-2 As shown, it includes a fuel cell system, a cryogenic cooling circuit, a power battery thermal management circuit, a passenger compartment heating circuit, an air conditioning cooling circuit, and heat exchange devices connecting each circuit; thermal coupling and intelligent control between each circuit are achieved through multiple valves, pumps, sensors, and controllers, and it has multiple working modes to adapt to different operating conditions.

[0030] Specifically, it includes: A fuel cell system includes a stack and a radiator and a first heat exchanger connected to the stack, wherein the coolant output from the stack flows to the radiator or the first heat exchanger. Low-temperature cooling circuit, used to drive the flow of coolant; The crew compartment heating circuit includes a heater, a second heat exchanger and a four-way valve connected in sequence. The four-way valve is also connected to the first heat exchanger and is used to access the fuel cell stack heat through the first heat exchanger and to transfer the coolant heated by the heater to the fuel cell stack through the first heat exchanger. An air conditioning cooling circuit includes an air conditioning system and a third heat exchanger for delivering the cooling capacity of the air conditioning system. The power battery thermal management circuit includes a second heat exchanger, a battery system, and a third heat exchanger connected in sequence. It is used to heat the battery system by means of heat from the fuel cell stack delivered through the second heat exchanger or heat from the passenger compartment heating circuit, and to cool the battery system by means of cooling capacity delivered through the third heat exchanger, via the switching of a four-way valve.

[0031] The above system will be described in detail below.

[0032] In this embodiment, the fuel cell system is the power source of the entire vehicle, including an air supply circuit, a hydrogen supply circuit, a water and heat management circuit, and a control circuit.

[0033] Specifically: (1) The air supply circuit includes an air filter 1, an air flow meter 2, an air compressor 3, an intercooler 4, an intake shut-off valve 5, a bypass valve 6, an exhaust shut-off valve 7, an electric stack 8, a mixing valve 30, a back pressure valve 31, and a secondary silencer 32, all connected by pipelines.

[0034] The air filter 1, air flow meter 2, air compressor 3, and intercooler 4 are connected in sequence. The air filter 1 is used to filter the air entering the circuit. The air flow meter 2 is used to detect the intake air flow. The air compressor 3 is used to compress the air. The intercooler 4 is used to cool the compressed high-temperature air.

[0035] Intercooler 4 is connected to fuel cell stack 8 and is equipped with bypass valve 6. The bypass valve 6 is used to allow some air to bypass intercooler 4 and directly enter fuel cell stack 8 under certain conditions.

[0036] The fuel cell stack 8 is equipped with an intake shut-off valve 5 on its intake pipe and an exhaust shut-off valve 7 on its exhaust pipe. The intake shut-off valve 5 and the exhaust shut-off valve 7 are used to control the intake and exhaust of the fuel cell stack 8.

[0037] Back pressure valve 31 is connected to exhaust shut-off valve 7. Back pressure valve 31, mixing valve 30 and secondary silencer 32 are connected in sequence. The exhaust gas after reaction discharged from fuel cell stack 8 is discharged through back pressure valve 31, mixing valve 30 and secondary silencer 32. The ventilation port of fuel cell stack 8 is also connected to mixing valve 30 and then discharged through secondary silencer 32.

[0038] (2) The hydrogen supply circuit includes a high-pressure hydrogen storage cylinder 22, a shut-off valve 23, a proportional valve 24, an ejector 25, an electric stack 8, a circulating pump 26, a gas-water separator 27, a first hydrogen discharge valve 28, a second hydrogen discharge valve 29, a mixing and discharge valve 30, and a secondary silencer 32, all connected by pipelines.

[0039] The high-pressure hydrogen storage cylinder 22, the shut-off valve 23, the proportional valve 24, and the ejector 25 are connected in sequence. The high-pressure hydrogen storage cylinder 22 is used to store high-pressure hydrogen. The shut-off valve 23 is used to control the on / off of the hydrogen supply. The proportional valve 24 is used to adjust the hydrogen supply pressure. The ejector 25 is used to use the hydrogen flow to eject unreacted hydrogen for circulation.

[0040] Ejector 25 is connected to fuel cell stack 8 and is used to deliver hydrogen to fuel cell stack 8, where the hydrogen participates in electrochemical reactions.

[0041] The fuel cell stack 8 is connected to the steam-water separator 27, which is used to separate and discharge liquid water.

[0042] The gas-water separator 27 is connected to the circulation pump 26, and the circulation pump 26 is connected to the ejector 25 for hydrogen circulation.

[0043] The gas-water separator 27 is connected to the first hydrogen discharge valve 28 and the second hydrogen discharge valve 29 respectively, for periodically discharging impurity gases.

[0044] The first hydrogen discharge valve 28 and the second hydrogen discharge valve 29 are both connected to the mixing valve 30, which is connected to the secondary silencer 32. The exhaust gas is finally discharged through the mixing valve 30 and the secondary silencer 32.

[0045] (3) The water and heat management loop includes a first water tank 9, a first water pump 10, a radiator 11, a filter 12, a three-way valve 13, a first heat exchanger 14 and a deionizer 17 connected by pipelines; The heat generated by the reaction in the fuel cell stack 8 is carried away by the coolant, which flows through the first water pump 10, the radiator 11, and the filter 12. The flow of the coolant to the radiator 11 or the first heat exchanger 14 is controlled by the three-way valve 13. The deionizer 17 is used to maintain the conductivity of the coolant within a reasonable range.

[0046] (4) The control loop includes an air compressor controller 18, a boost DC / DC converter 19, an EIS detector 20 and an FCU 21; the air compressor controller 18 is used to control the operation of the air compressor 3; the boost DC / DC converter 19 is used to boost the voltage output; the EIS detector 20 is used for monitoring the status of the fuel cell stack 8; the FCU 21 is the main controller of the fuel cell system and coordinates the operation of each component.

[0047] In this embodiment, the low-temperature cooling circuit is used to cool the high-voltage electronic control components of the vehicle. It includes a low-temperature radiator 33, a second water pump 37, a vehicle DC / DC converter 38, a vehicle CDU 39, and a motor controller 40 connected in sequence through pipelines. The motor controller 40 is then connected to the low-temperature radiator 33 to form a circuit.

[0048] A water temperature sensor 36 is provided on the pipeline connecting the low-temperature radiator 33 and the second water pump 37. The second water pump 37 is used to drive the flow of coolant, and the water temperature sensor 36 is used to monitor the temperature of coolant. The low-temperature radiator 33 is also connected to the second water tank 42, and the second water tank 42 is then fed back to the low-temperature radiator 33, forming a loop.

[0049] This also includes an electronic fan 35, which adjusts its speed according to heat dissipation requirements.

[0050] Among them, the energy management and system coordination control of the whole vehicle are realized through electronic control components such as the whole vehicle DC / DC38, the whole vehicle CDU39 and the motor controller 40.

[0051] In this embodiment, the power battery thermal management circuit includes a second heat exchanger 45, a battery system 47, a third water tank 49, a fourth water pump 50, and a third heat exchanger 51 connected in sequence by pipelines. The third heat exchanger 51 is connected to the second heat exchanger 45 to form a circuit.

[0052] The second heat exchanger 45 is used to extract heat from the crew compartment heating circuit or the waste heat of the fuel cell stack, and the third heat exchanger 51 is used to extract cold from the air conditioning system. The second heat exchanger 45 is connected to a four-way valve 44, which is used to switch the heating or cooling mode of the battery system 47.

[0053] The battery system 47 has a first temperature sensor 46 at the water inlet and a second temperature sensor 48 at the water outlet, which are used to detect the water temperature at the water inlet and the water outlet, respectively.

[0054] In this embodiment, the air conditioning cooling circuit is used for refrigeration of the passenger compartment and battery cooling, including an air conditioning radiator 34, a third heat exchanger 51 and an air conditioning compressor 41 connected in sequence by pipes. The air conditioning compressor 41 is connected to the air conditioning radiator 34 to form a circuit.

[0055] It also includes an air conditioning radiator 34, a condenser 56 and an air conditioning compressor 41 connected in sequence by pipes. The air conditioning compressor 41 is connected to the air conditioning radiator 34 to form a circuit.

[0056] A second environmental sensor 57 and a switching valve 53 are provided on the connecting pipe between the air conditioner radiator 34 and the third heat exchanger 51. The second environmental sensor 57 is used to detect the temperature output by the air conditioner radiator 34, and the switching valve 53 is used to control the on / off of the cooling capacity input to the third heat exchanger 51.

[0057] A first environmental sensor 52 is provided on the connecting pipe between the third heat exchanger 51 and the air conditioning compressor 41 to detect the temperature output by the third heat exchanger 51. The air conditioning compressor 41 is used to drive the circulation of refrigerant to achieve the cooling function.

[0058] In this embodiment, the crew cabin heating circuit includes a high-pressure PTC heater 16, a second heat exchanger 45, a four-way valve 44 and a fifth water pump 54 connected in sequence by pipelines. The fifth water pump 54 is connected to the high-pressure PTC heater 16 to form a circuit.

[0059] The crew cabin heating circuit also includes a first heat exchanger 14, a third water pump 43, a heater / air conditioner 15 and a blower 55 connected in sequence by pipes, with the heater / air conditioner 15 connected to a four-way valve 44.

[0060] Among them, the high-pressure PTC heater 16 serves as an auxiliary heat source to enable startup under low-temperature conditions; the first heat exchanger 14 is used to recover waste heat from the fuel cell stack water thermal management circuit to provide heat for the crew cabin heating circuit; the blower 55 drives air to flow through the heater air conditioner 15 to provide heating for the crew cabin.

[0061] In this embodiment, the water-thermal management circuit of the fuel cell system is connected to the passenger compartment heating circuit through the first heat exchanger 14, and thermal coupling with the power battery thermal management circuit (heating) is achieved through the four-way valve 44 and the second heat exchanger 45. Thermal coupling with the power battery thermal management circuit (cooling) is achieved through the four-way valve 44 and the third heat exchanger 51.

[0062] Furthermore, all the electronic water pumps used in the above system are variable flow pumps, which adjust the flow rate according to actual needs to further reduce the energy consumption of accessories; the shut-off valves, three-way valves and four-way valves used are all electronically controlled valves, which are uniformly controlled by FCU21 to achieve precise flow path switching and energy distribution; by transmitting the temperature signals detected by each sensor to FCU21 and the vehicle controller, temperature-based closed-loop control is achieved.

[0063] In this embodiment, the system is configured with multiple operating modes: (1) Mode 1: Normal operation and waste heat heating.

[0064] When the fuel cell stack 8 is operating normally and the crew compartment requires heating, the FCU21 controls the three-way valve 13 to allow coolant to flow through the first heat exchanger 14. The first heat exchanger 14 transfers the waste heat generated by the fuel cell stack to the crew compartment heating circuit, heating the air flowing through the heater / air conditioning 15 to achieve crew compartment heating. At this time, the high-pressure PTC heater 16 does not start, maximizing the utilization of waste heat and reducing energy consumption.

[0065] (2) Mode 2: PTC-assisted cold start.

[0066] When the ambient temperature is low and the fuel cell stack 8 needs to be cold-started, the FCU21 starts the high-pressure PTC heater 16 in the crew cabin heating circuit to heat the coolant in the circuit. The heated coolant flows through the first heat exchanger 14 and transfers the heat to the water thermal management circuit of the fuel cell system, thereby preheating the fuel cell stack 8.

[0067] This mode reuses the PTC heater in the crew cabin heating circuit, avoiding the need for a dedicated high-power PTC, thus reducing system costs and startup energy consumption.

[0068] (3) Mode 3: Heating and cooling of the power battery system.

[0069] By switching control of the four-way valve 44, the battery system 47 is temperature-managed using waste heat or the air conditioning system, thereby achieving heating or cooling of the battery system 47.

[0070] Heating mode: When the battery temperature is low, the four-way valve 44 guides the circuit through the second heat exchanger 45 to heat the battery system 47 using waste heat from the fuel cell stack or heat from the crew cabin heating circuit. Cooling mode: When the battery temperature is high, the four-way valve 44 switches to the third heat exchanger 51 to use the cooling capacity of the air conditioning system to cool the battery system 47.

[0071] (4) Mode 4: Independent heat dissipation.

[0072] When the fuel cell stack 8 needs to dissipate heat and the crew compartment does not need to be heated, the coolant is controlled to flow through the radiator 11 via the three-way valve 13, and then dissipated through the low-temperature radiator 33 and the electric fan 35 to prevent heat from entering the crew compartment circuit.

[0073] In this embodiment, the system eliminates the need for a dedicated PTC heater for fuel cells by sharing components such as the first heat exchanger, high-pressure PTC heater, and four-way valve. This reduces the number of parts and pipeline connections, lowers manufacturing costs and installation space requirements, and improves the integration of the fuel cell system.

[0074] In this embodiment, the system fully utilizes the waste heat from the fuel cell stack for crew compartment heating and battery heating, reducing the operating time of the high-voltage PTC heater and air conditioning compressor. During cold start, the crew compartment PTC heater is reused to preheat the fuel cell stack, avoiding additional energy consumption.

[0075] In this embodiment, the system described above reduces flow resistance and heat loss and improves the overall thermal efficiency of the system through multi-loop thermal coupling and intelligent valve control.

[0076] The simplified system structure described above in this embodiment reduces the number of fault points, and the intelligent control strategy based on multi-sensor feedback improves the system's adaptability and stability, especially in low-temperature environments.

[0077] Example 2 This embodiment provides a control method for the thermal management system of a hydrogen fuel cell vehicle as described in Embodiment 1, characterized in that it includes: When the fuel cell stack is operating normally and the crew compartment needs heating, the three-way valve is controlled to allow the coolant to flow through the first heat exchanger. The heat generated by the fuel cell stack is transferred to the crew compartment heating circuit through the first heat exchanger, heating the air flowing through the heating and air conditioning system to achieve crew compartment heating. When the fuel cell stack is cold-started, the high-voltage PTC heater is activated to heat the coolant in the crew cabin heating circuit. The heated coolant flows through the first heat exchanger and transfers heat to the fuel cell system to preheat the fuel cell stack. When the battery system is heated or cooled, the battery system is heated by the heat from the fuel cell stack or the crew cabin heating circuit delivered via the second heat exchanger, and cooled by the cooling capacity delivered via the third heat exchanger. When the fuel cell stack needs to dissipate heat but the crew compartment does not need to be heated, the coolant is controlled to flow through the radiator via a three-way valve, and the heat is dissipated through a low-temperature radiator and an electric fan.

[0078] Understandably, the specific structural composition of each loop of the above system and its control method is considered as a relatively superior implementation method. Below, some other alternative solutions are given.

[0079] 1. Replacement of heat exchanger types and layouts.

[0080] (1) Plate heat exchangers replace shell and tube heat exchangers.

[0081] In a preferred embodiment of the present invention, the first heat exchanger, the second heat exchanger, and the third heat exchanger may be high-efficiency plate heat exchangers.

[0082] As an alternative, these heat exchangers can also be shell-and-tube heat exchangers, microchannel heat exchangers, or other forms of indirect heat exchangers. For example, in space-constrained areas, more compact microchannel heat exchangers can be used, which have higher heat exchange efficiency and smaller volume, helping to further optimize system layout and reduce weight.

[0083] Different types of heat exchangers can be flexibly selected and replaced according to the space constraints, cost requirements and heat exchange efficiency requirements of the vehicle layout. All of them can achieve the core function of effective heat exchange between different loops, and maintain the high integration and high efficiency of thermal energy utilization of the system.

[0084] (2) Integrated heat exchange module.

[0085] The functions of the first and second heat exchangers are integrated into a multi-channel integrated heat exchange module. This module has independent flow channels for heat exchange between the fuel cell stack coolant, the crew compartment heating coolant, and the battery heating coolant.

[0086] This solution further reduces external piping and interfaces, significantly lowering leakage risk and quality, and improving system compactness and reliability. Reducing the number of components enables a higher degree of integration, aligning with the goals of cost reduction and improved assembly efficiency.

[0087] 2. Replacement of valve body structure and control method.

[0088] (1) Multiple two-way valves can be combined to replace three-way or four-way valves.

[0089] Three-way and four-way valves that control flow path switching can be equivalently implemented using a combination of multiple two-way solenoid valves (shut-off valves). For example, by configuring the on / off combinations of three two-way valves on a specific pipeline, the switching function of a four-way valve between battery heating and cooling modes can be simulated.

[0090] While this may increase the number of valve bodies, two-way valves are simple in structure, low in cost, and technologically mature. This approach offers greater flexibility, allowing for the selection of the optimal valve body configuration based on specific control logic and cost budget, while still achieving precise flow path control.

[0091] (2) The proportional control valve replaces the on / off valve.

[0092] Some on / off valves (such as on / off valves or three-way valves) can be replaced with proportional control valves or electrically controlled control valves. For example, using a proportional three-way valve to replace an on / off three-way valve can achieve stepless regulation of the flow of fuel cell coolant to the radiator and the first heat exchanger, rather than a simple "on / off" or "path A / path B" switching.

[0093] Achieve more precise temperature control. By continuously adjusting the flow ratio of different branches, the heat dissipation intensity of the fuel cell stack or the heat transferred to the crew compartment / battery can be controlled more accurately, optimizing heat distribution efficiency and further improving the system's energy efficiency.

[0094] 3. Replacement of heat source and actuator.

[0095] (1) Heat pump system to assist or replace high pressure PTC.

[0096] In the crew cabin heating circuit, a refrigerant-based heat pump system can be added (partially reusing components of the air conditioning system, such as the compressor and evaporator, either in parallel with the high-pressure PTC16 or as an alternative). In extremely low temperature environments, the heat pump system typically has a higher coefficient of performance (COP) than direct PTC heating. The system can intelligently select whether to activate the PTC or the heat pump, or both, based on ambient temperature and demand.

[0097] This solution is particularly suitable for extremely cold regions, further reducing energy consumption for cabin heating in winter and thus saving hydrogen. It expands the system's ability to operate efficiently in ultra-low temperature environments and is an advanced alternative for improving energy efficiency.

[0098] (2) Waste heat from the fuel cell stack is used preferentially for battery heating.

[0099] In terms of control strategy, a priority mode can be added. When the fuel cell stack has just started up and the waste heat temperature is not high enough to meet the heating needs of the crew compartment, but the battery system still needs to be heated, this part of the low-grade waste heat can be preferentially guided to the power battery thermal management circuit through the second heat exchanger by controlling the four-way valve to heat the battery.

[0100] It makes full use of low-grade heat energy, avoids the waste of this heat, reduces the dependence of battery heating on high-voltage PTC, and further optimizes the energy utilization process of the whole vehicle, especially in the short period of time after cold start.

[0101] 4. System architecture expansion and simplification.

[0102] (1) Replacement of cooling circuit medium.

[0103] In addition to the conventional ethylene glycol-water solution, the heat transfer medium in each cooling circuit can also be replaced with other coolants, such as pure water (with stricter anti-corrosion and sealing measures), phase change coolant, or other new high-efficiency heat exchange medium, depending on different operating temperature ranges and performance requirements.

[0104] Different cooling media have different specific heat capacity, thermal conductivity and viscosity. Selecting the right medium can improve heat exchange efficiency or reduce pumping power under specific operating conditions, providing another way to optimize the system.

[0105] (2) Replacement of controller integration.

[0106] In this invention, the FCU is responsible for controlling the fuel cell system, while the vehicle control unit (VCU) may coordinate overall thermal management. Alternatively, the thermal management control function can be fully integrated into the FCU, or a separate thermal management controller (TMCU) can be dedicated to the coordinated control of all thermally related loops, communicating with the FCU and VCU via a CAN bus.

[0107] Different controller architectures can adapt to the electronic control system design habits and supply chain systems of different OEMs. Centralized control can improve response speed, while distributed control may reduce system complexity; both can achieve the core control logic of this invention.

[0108] The aforementioned alternatives demonstrate the core concept of this invention: achieving heat sharing and intelligent allocation across the three thermal management loops of the fuel cell stack, crew compartment, and battery through key heat exchange devices and valves, thereby achieving integration, energy saving, and cost reduction. This can be realized through various specific technical means. These alternatives involve variations and extensions in component selection, control strategies, and system architecture, but they all remain true to the core inventive idea of ​​this invention and can produce the same or similar beneficial technical effects. This fully demonstrates the universality and scalability of the technical solution of this invention, which is conducive to obtaining a patent right with a more reasonable scope of protection.

[0109] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A thermal management system for a hydrogen fuel cell vehicle, characterized in that, include: A fuel cell system includes a stack and a radiator and a first heat exchanger connected to the stack, wherein the coolant output from the stack flows to the radiator or the first heat exchanger. Low-temperature cooling circuit, used to drive the flow of coolant; The crew compartment heating circuit includes a heater, a second heat exchanger and a four-way valve connected in sequence. The four-way valve is also connected to the first heat exchanger and is used to access the fuel cell stack heat through the first heat exchanger and to transfer the coolant heated by the heater to the fuel cell stack through the first heat exchanger. An air conditioning cooling circuit includes an air conditioning system and a third heat exchanger for delivering the cooling capacity of the air conditioning system. The power battery thermal management circuit includes a second heat exchanger, a battery system, and a third heat exchanger connected in sequence. It is used to heat the battery system by means of heat from the fuel cell stack delivered through the second heat exchanger or heat from the passenger compartment heating circuit, and to cool the battery system by means of cooling capacity delivered through the third heat exchanger, through the switching of a four-way valve.

2. The thermal management system for a hydrogen fuel cell vehicle as described in claim 1, characterized in that, The fuel cell system includes an air supply circuit, a hydrogen supply circuit, a water and heat management circuit, and a control circuit; The air supply circuit includes an air filter, an air flow meter, an air compressor, and an intercooler connected in sequence; the intercooler is connected to the fuel cell stack and is equipped with a bypass valve; the fuel cell stack's inlet pipe is equipped with an inlet shut-off valve, and the outlet pipe is equipped with an outlet shut-off valve. The outlet shut-off valve is also connected in sequence to a back pressure valve, a mixing valve, and a secondary silencer for discharging the exhaust gas generated by the fuel cell stack.

3. The thermal management system for a hydrogen fuel cell vehicle as described in claim 2, characterized in that, The hydrogen supply circuit includes a high-pressure hydrogen storage cylinder, a shut-off valve, a proportional valve, and an ejector connected in sequence. The ejector is connected to the fuel cell stack for supplying hydrogen to the stack. The fuel cell stack is connected to a vapor-water separator for separating and discharging liquid water. The vapor-water separator is connected to a circulation pump, which is connected to the ejector for hydrogen circulation. The vapor-water separator is connected to a first hydrogen discharge valve and a second hydrogen discharge valve, both of which are connected to a mixing valve. The mixing valve is connected to a secondary silencer for discharging the waste gas generated by the fuel cell stack.

4. The thermal management system for a hydrogen fuel cell vehicle as described in claim 2, characterized in that, The hydrothermal management loop includes a first water tank, a first water pump, a radiator, a filter, a three-way valve, a first heat exchanger, and a deionizer. The heat generated by the fuel cell reaction is carried away by the coolant, which flows through the first water pump, the radiator, and the filter. The three-way valve controls the flow of the coolant to the radiator or the first heat exchanger. The deionizer is used to maintain the conductivity of the coolant within a set reasonable range.

5. A hydrogen fuel cell vehicle thermal management system as described in claim 2, characterized in that, The control loop includes an air compressor controller, a boost DC / DC converter, an EIS sensor, and an FCU; the air compressor controller is used to control the operation of the air compressor; the boost DC / DC converter is used to boost the voltage output; and the EIS sensor is used for fuel cell stack status monitoring. The FCU acts as the main controller of the fuel cell system, coordinating the operation of all components.

6. The thermal management system for a hydrogen fuel cell vehicle as described in claim 1, characterized in that, The cryogenic cooling circuit includes a cryogenic radiator, a second water pump, a vehicle DC / DC converter, a vehicle CDU, and a motor controller connected in sequence. The motor controller is connected to the cryogenic radiator to form a circuit. The second water pump is used to drive the flow of coolant.

7. A hydrogen fuel cell vehicle thermal management system as described in claim 1, characterized in that, The power battery thermal management circuit includes a second heat exchanger, a battery system, a third water tank, a fourth water pump, and a third heat exchanger connected in sequence. The third heat exchanger is connected to the second heat exchanger to form a circuit. The second heat exchanger is used to extract heat from the crew compartment heating circuit or the waste heat from the fuel cell stack, and the third heat exchanger is used to extract coolness from the air conditioning system. The second heat exchanger is connected to a four-way valve, which is used to switch the heating or cooling mode of the battery system.

8. A hydrogen fuel cell vehicle thermal management system as described in claim 1, characterized in that, The air conditioning cooling circuit includes an air conditioning radiator, a third heat exchanger and an air conditioning compressor connected in sequence, with the air conditioning compressor connected to the air conditioning radiator to form a circuit. It also includes an air conditioner radiator, a condenser, and an air conditioner compressor connected in sequence, with the air conditioner compressor connected to the air conditioner radiator to form a circuit.

9. A hydrogen fuel cell vehicle thermal management system as described in claim 1, characterized in that, The crew cabin heating circuit includes a high-pressure PTC heater, a second heat exchanger, a four-way valve and a fifth water pump connected in sequence, with the fifth water pump connected to the high-pressure PTC heater to form a circuit; It also includes a first heat exchanger, a third water pump, a heating air conditioner and a blower connected in sequence, with the heating air conditioner connected to a four-way valve; The high-pressure PTC heater serves as an auxiliary heat source to enable startup under low-temperature conditions; the first heat exchanger recovers waste heat from the fuel cell stack to provide heating for the crew cabin heating circuit; and the blower drives airflow through the heating air conditioning system to provide heating for the crew cabin.

10. A control method for a hydrogen fuel cell vehicle thermal management system according to any one of claims 1-9, characterized in that, include: When the fuel cell stack is operating normally and the crew compartment needs heating, the three-way valve is controlled to allow the coolant to flow through the first heat exchanger. The heat generated by the fuel cell stack is transferred to the crew compartment heating circuit through the first heat exchanger, heating the air flowing through the heating and air conditioning system to achieve crew compartment heating. When the fuel cell stack is cold-started, the high-voltage PTC heater is activated to heat the coolant in the crew cabin heating circuit. The heated coolant flows through the first heat exchanger and transfers heat to the fuel cell system to preheat the fuel cell stack. When the battery system is heated or cooled, the battery system is heated by the heat from the fuel cell stack or the crew cabin heating circuit delivered via the second heat exchanger, and cooled by the cooling capacity delivered via the third heat exchanger. When the fuel cell stack needs to dissipate heat but the crew compartment does not need to be heated, the coolant is controlled to flow through the radiator via a three-way valve, and the heat is dissipated through a low-temperature radiator and an electric fan.

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