A thermal management system and method for cold start of fuel cell vehicles

Abstract

The present invention belongs to the technical field of fuel cell vehicles, and discloses a thermal management system and method for cold start of fuel cell vehicles, comprising a fuel cell stack, a heat accumulator, a heater and a radiator, which are connected by a three-way valve to form a circulation loop, and the thermal management comprises: judging the state of the fuel cell stack, when it is shut down and the temperature is low, heating it by using the heat accumulator or the heater; when it is not shut down and the temperature is low, directly heating it; when the temperature of the stack is between the rated ambient temperature and the first set temperature, the coolant is circulated; the temperature continues to rise, and the heat accumulator participates in cooling; if the maximum working temperature is reached, according to the temperature of the heat accumulator and the radiator, the radiator is selected to cool alone or both are cooled together to ensure that the temperature of the stack is appropriate; the present invention effectively manages the temperature changes during cold start and operation of fuel cell vehicles, improves thermal efficiency, prolongs battery life, optimizes overall performance, and realizes efficient utilization and distribution of thermal energy through intelligent regulation to meet the needs of different working conditions.

Description

Technical Field

[0001] The present invention belongs to the technical field of fuel cell vehicles, and in particular relates to a thermal management system and method for cold starting of a fuel cell vehicle. Background Art

[0002] As one of the cutting-edge technologies of clean energy, proton exchange membrane fuel cell vehicles have great potential in promoting zero emissions and efficient energy utilization in application fields, and have been a hot research and development topic over the past few decades. With the large-scale commercial application of proton exchange membrane fuel cell vehicles, the problem of low-temperature start-up in cold environments is a key technical problem that needs to be solved urgently. During the cold start of the fuel cell stack, the water generated inside it will freeze at low temperatures, hindering gas transmission and reducing the electrochemical reaction area. This freezing phenomenon will not only cause the performance of the stack to deteriorate, but may also cause an emergency stop, seriously affecting the durability and safety of the vehicle. Therefore, how to effectively deal with the problem of insulation after low-temperature shutdown, and then achieve a smooth low-temperature start of the fuel cell, has become a key basis for promoting the reliable operation of fuel cell vehicles in extremely cold environments. Summary of the invention

[0003] The purpose of the present invention is to provide a thermal management system and method for cold starting of a fuel cell vehicle to solve the problems existing in the above-mentioned prior art.

[0004] On the one hand, to achieve the above-mentioned purpose, the present invention provides a thermal management system for cold start of a fuel cell vehicle, comprising:

[0005] A fuel cell stack, wherein a liquid inlet end of the fuel cell stack is connected to a first valve port of a first three-way valve, and a liquid outlet end of the fuel cell stack is connected to a first valve port of a second three-way valve;

[0006] a heat accumulator, wherein a liquid inlet end of the heat accumulator is connected to a liquid outlet end of the fuel cell stack, and a liquid outlet end of the heat accumulator is connected to a second valve port of the first three-way valve;

[0007] a heater, wherein a liquid inlet end of the heater is connected to the third valve port of the second three-way valve, a liquid outlet end of the heater is connected to the second valve port of the third three-way valve, and the second valve port of the second three-way valve and the first valve port of the third three-way valve are both connected to the third valve port of the first three-way valve;

[0008] A radiator, wherein a liquid inlet end of the radiator is communicated with the third valve port of the second three-way valve, and a liquid outlet end of the radiator is communicated with the third valve port of the third three-way valve.

[0009] Optionally, a water pump is connected to the liquid outlet of the fuel cell stack, and the output end of the water pump is respectively connected to the liquid inlet end of the heat accumulator and the first valve port of the second three-way valve.

[0010] Optionally, a first water temperature sensor is provided between the liquid outlet of the fuel cell stack and the water pump.

[0011] Optionally, a second water temperature sensor is provided between the liquid outlet of the heat accumulator and the first three-way valve.

[0012] Optionally, a third water temperature sensor is provided between the liquid outlet of the radiator and the third three-way valve, and a cooling fan is installed on one side of the radiator.

[0013] On the other hand, to achieve the above-mentioned purpose, the present invention provides a thermal management method for cold start of a fuel cell vehicle, which is applied to the thermal management system for cold start of a fuel cell vehicle, comprising:

[0014] Step S1: judging the operating status of the fuel cell stack, when the fuel cell stack is shut down, executing step S2; when the fuel cell stack is not shut down, executing step S3;

[0015] Step S2: when the real-time temperature data of the fuel cell stack is less than the preset self-starting temperature threshold, the real-time temperature data of the heat accumulator is compared with the preset self-starting temperature threshold; when the real-time temperature data of the heat accumulator is greater than or equal to the preset self-starting temperature threshold, the fuel cell stack is heated by the heat accumulator; when the real-time temperature data of the heat accumulator is less than the preset self-starting temperature threshold, the fuel cell stack is heated by the heater;

[0016] Step S3: When the real-time temperature data of the fuel cell stack is less than the preset rated ambient temperature, heating the fuel cell stack by the heater;

[0017] When the real-time temperature data of the fuel cell stack is greater than or equal to the preset rated ambient temperature and less than the first set temperature, the coolant at the liquid outlet of the fuel cell stack passes through the second three-way valve and the first three-way valve in sequence and enters the liquid inlet of the fuel cell stack;

[0018] When the real-time temperature data of the fuel cell stack is greater than or equal to the first set temperature and less than the preset rated maximum operating temperature, cooling the fuel cell stack through the heat accumulator;

[0019] When the real-time temperature data of the fuel cell stack is greater than or equal to the preset rated maximum operating temperature, comparing the real-time heat storage temperature data and the real-time radiator temperature data with the preset rated minimum operating temperature;

[0020] When the real-time heat storage device temperature data is less than the preset minimum rated working temperature and the real-time radiator temperature data is greater than or equal to the preset minimum rated working temperature, the fuel cell stack is cooled by the radiator and the fuel cell stack is cooled by the heat storage device;

[0021] When the real-time heat storage temperature data is greater than or equal to the preset rated minimum operating temperature and the real-time radiator temperature data is less than the preset rated minimum operating temperature, the fuel cell stack is cooled by the radiator.

[0022] Optionally, heating the fuel cell stack by the heat accumulator specifically includes:

[0023] The coolant at the outlet end of the fuel cell stack passes through the first water temperature sensor and the water pump in turn into the heat accumulator for heating, and the heated coolant passes through the second water temperature sensor and the first three-way valve in turn into the inlet end of the fuel cell stack.

[0024] Optionally, heating the fuel cell stack by the heater specifically includes:

[0025] The coolant at the liquid outlet of the fuel cell stack passes through the first water temperature sensor, the water pump and the second three-way valve in sequence to enter the heater for heating, and the heated coolant passes through the third three-way valve and the first three-way valve in sequence to enter the liquid inlet of the fuel cell stack.

[0026] Optionally, cooling the fuel cell stack by means of the heat accumulator specifically includes:

[0027] The coolant at the outlet end of the fuel cell stack passes through the first water temperature sensor and the water pump in turn into the heat accumulator for heat exchange cooling, and the coolant after heat exchange cooling passes through the second water temperature sensor and the first three-way valve in turn into the inlet end of the fuel cell stack.

[0028] Optionally, cooling the fuel cell stack by a radiator specifically includes:

[0029] The coolant at the liquid outlet of the fuel cell stack passes through the first water temperature sensor, the water pump and the second three-way valve in sequence to enter the radiator for cooling; the cooled coolant passes through the third water temperature sensor, the third three-way valve and the first three-way valve in sequence to enter the liquid inlet of the fuel cell stack.

[0030] The technical effects of the present invention are:

[0031] The present invention includes a fuel cell stack, a heat accumulator, a heater and a radiator, and each device is connected by a three-way valve to form a circulation loop. The present invention effectively improves the rapid start-up capability of fuel cell vehicles in low temperature environments by integrating a water cooling circuit, reduces the power consumption during the heating process of the stack, and overcomes the problem of slow start-up in extremely cold environments by traditional cold start methods. The present invention integrates the heat dissipation, heating, bypass and insulation functions of the fuel cell stack into a set of systems, and uses a three-way valve to achieve flexible switching to meet the thermal management requirements of the fuel cell stack under different working conditions, reduce the number of components in the system, and improve the overall compactness and layout efficiency. The present invention realizes the low-temperature insulation function of the fuel cell system, reduces the heat loss when starting under extremely cold conditions, and improves the cruising range of fuel cell vehicles and the operating efficiency in low temperature environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0033] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0034] Figure 1 It is a schematic structural diagram of a fuel cell vehicle heat preservation system in an embodiment of the present invention;

[0035] Figure 2 This is a flow chart of a method for controlling a thermal insulation system of a fuel cell vehicle in an embodiment of the present invention;

[0036] Figure 3 A schematic diagram of a fuel cell system heat preservation circuit heating stack mode circuit in an embodiment of the present invention;

[0037] Figure 4 A schematic diagram of a heating stack mode circuit of a fuel cell system heating circuit in an embodiment of the present invention;

[0038] Figure 5 A schematic diagram of a fuel cell system bypass circuit heating stack mode circuit in an embodiment of the present invention;

[0039] Figure 6 A schematic diagram of a fuel cell system heat preservation circuit cooling stack mode circuit in an embodiment of the present invention;

[0040] Figure 7A schematic diagram of a fuel cell system heat preservation circuit and a heat dissipation circuit cooling a stack mode circuit in an embodiment of the present invention;

[0041] Figure 8 Schematic diagram of a heat dissipation circuit of a fuel cell system cooling stack mode circuit in an embodiment of the present invention.

[0042] Explanation of reference numerals: 101, fuel cell stack; 102, first water temperature sensor; 103, water pump; 104, heat accumulator; 105, second water temperature sensor; 106, first three-way valve; 201, second three-way valve; 301, heater; 302, third three-way valve; 401, radiator; 402, radiator fan; 403, third water temperature sensor. DETAILED DESCRIPTION

[0043] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0044] It should be understood that the terms described in the present invention are only for describing special embodiments and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0045] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those of ordinary skill in the art generally understood by the present invention. Although the present invention describes only preferred methods, any method similar or equivalent to that described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods related to the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0046] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to those skilled in the art. The present application description and examples are exemplary only.

[0047] The words “include,” “including,” “have,” “contain,” etc. used in this article are open-ended terms, meaning including but not limited to.

[0048] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0049] Embodiment 1

[0050] like Figure 1 - Figure 8 As shown, this embodiment provides a thermal management system for cold start of a fuel cell vehicle, including:

[0051] A fuel cell stack 101, wherein a liquid inlet end of the fuel cell stack 101 is connected to a first valve port of a first three-way valve 106, and a liquid outlet end of the fuel cell stack 101 is connected to a first valve port of a second three-way valve 201;

[0052] A heat accumulator 104, wherein a liquid inlet end of the heat accumulator 104 is connected to a liquid outlet end of the fuel cell stack 101, and a liquid outlet end of the heat accumulator 104 is connected to a second valve port of the first three-way valve 106;

[0053] A heater 301, wherein the liquid inlet end of the heater 301 is connected to the third valve port of the second three-way valve 201, and the liquid outlet end of the heater 301 is connected to the second valve port of the third three-way valve 302, and the second valve port of the second three-way valve 201 and the first valve port of the third three-way valve 302 are both connected to the third valve port of the first three-way valve 106;

[0054] The radiator 401 has a liquid inlet end connected to the third valve port of the second three-way valve 201 , and a liquid outlet end connected to the third valve port of the third three-way valve 302 .

[0055] A thermal management method for cold start of a fuel cell vehicle, applied to a thermal management system for cold start of a fuel cell vehicle, comprising:

[0056] Step S1: Determine the operating status of the fuel cell stack 101. When the fuel cell stack 101 is shut down, execute step S2; when the fuel cell stack 101 is not shut down, execute step S3;

[0057] Step S2: when the real-time temperature data of the fuel cell stack 101 is less than the preset self-starting temperature threshold, the real-time temperature data of the heat accumulator 104 is compared with the preset self-starting temperature threshold; when the real-time temperature data of the heat accumulator 104 is greater than or equal to the preset self-starting temperature threshold, the fuel cell stack 101 is heated by the heat accumulator 104; when the real-time temperature data of the heat accumulator 104 is less than the preset self-starting temperature threshold, the fuel cell stack 101 is heated by the heater 301;

[0058] Step S3: When the real-time temperature data of the fuel cell stack 101 is less than the preset rated ambient temperature, the fuel cell stack 101 is heated by the heater 301;

[0059] When the real-time stack temperature data of the fuel cell stack 101 is greater than or equal to the preset rated ambient temperature and less than the first set temperature, the coolant at the liquid outlet of the fuel cell stack 101 passes through the second three-way valve 201 and the first three-way valve 106 in sequence and enters the liquid inlet of the fuel cell stack 101;

[0060] When the real-time temperature data of the fuel cell stack 101 is greater than or equal to the first set temperature and less than the preset rated maximum operating temperature, the fuel cell stack 101 is cooled by the heat accumulator 104;

[0061] When the real-time temperature data of the fuel cell stack 101 is greater than or equal to the preset rated maximum operating temperature, the real-time temperature data of the heat storage device 104 and the real-time temperature data of the radiator 401 are compared with the preset rated minimum operating temperature;

[0062] When the real-time temperature data of the heat accumulator 104 is less than the preset minimum rated operating temperature and the real-time temperature data of the radiator 401 is greater than or equal to the preset minimum rated operating temperature, the fuel cell stack 101 is cooled by the radiator 401, and the fuel cell stack 101 is cooled by the heat accumulator 104;

[0063] When the real-time temperature data of the heat accumulator 104 is greater than or equal to the preset rated minimum operating temperature and the real-time temperature data of the radiator 401 is less than the preset rated minimum operating temperature, the fuel cell stack 101 is cooled by the radiator 401 .

[0064] The present embodiment provides a thermal management system and method for cold start of a fuel cell vehicle. The system includes a fuel cell stack 101, a heat accumulator 104, a heater 301 and a radiator 401, which are connected by a three-way valve to form a circulation loop. The method includes: judging the state of the fuel cell stack 101, and when it is shut down and the temperature is low, heating it with the heat accumulator 104 or the heater 301; when it is not shut down and the temperature is low, directly heating it; when the stack temperature is between the rated ambient temperature and the first set temperature, the coolant is circulated; when the temperature continues to rise, the heat accumulator 104 participates in cooling; if the maximum working temperature is reached, according to the temperatures of the heat accumulator 104 and the radiator 401, the radiator 401 is selected to cool alone or both cool together to ensure that the stack temperature is appropriate; the system and method effectively manage the temperature changes during cold start and operation of the fuel cell vehicle, improve thermal efficiency, extend battery life, optimize overall performance, and achieve efficient utilization and distribution of thermal energy through intelligent regulation to meet the needs of different working conditions.

[0065] As attached Figure 1 As shown, this embodiment provides a thermal management system for cold start of fuel cell vehicles, which mainly includes a fuel cell system insulation circuit, a fuel cell system bypass circuit, a fuel cell system heating circuit and a fuel cell system heat dissipation circuit. Each circuit performs flow regulation and heat exchange through a water valve.

[0066] The fuel cell system insulation circuit includes a fuel cell stack 101, a first water temperature sensor 102, a water pump 103, a heat accumulator 104, a second water temperature sensor 105 and a first three-way valve 106 connected in sequence to form a circuit. The first water temperature sensor 102 measures the outlet water temperature of the fuel cell stack 101, and the water temperature therein can be regarded as the temperature of the fuel cell stack 101; the second water temperature sensor 105 measures the outlet water temperature of the heat accumulator 104, and the water temperature therein can be regarded as the temperature of the heat accumulator 104. The heat accumulator 104 is a thermal energy storage device composed of phase change material and insulation material, and is provided with a coolant flow channel inside, and the fuel cell stack 101 can be heated or cooled by heat exchange between the phase change material and the coolant. The flow direction of the first three-way valve 106 controls the circulation of the coolant through the fuel cell system insulation circuit or the fuel cell system heat dissipation circuit.

[0067] The fuel cell system bypass loop includes a fuel cell stack 101, a first water temperature sensor 102, a water pump 103, a second three-way valve 201 and a first three-way valve 106 connected in sequence to form a loop; the flow direction of the second three-way valve 201 controls the coolant circulation through the fuel cell system bypass loop or the fuel cell system heat dissipation loop.

[0068] The fuel cell system heating circuit includes a fuel cell stack 101, a first water temperature sensor 102, a water pump 103, a second three-way valve 201, a heater 301, a third three-way valve 302 and a first three-way valve 106 which are sequentially connected to form a circuit; the flow direction of the third three-way valve 302 controls the circulation of the coolant through the fuel cell system heating circuit or the fuel cell system heat dissipation circuit.

[0069] The fuel cell system heat dissipation circuit includes a fuel cell stack 101, a first water temperature sensor 102, a water pump 103, a second three-way valve 201, a radiator 401, a third water temperature sensor 403, a third three-way valve 302 and a first three-way valve 106 which are sequentially connected to form a circuit. A radiator fan 402 is installed on the surface of the radiator 401, and the third water temperature sensor 403 measures the outlet water temperature of the radiator 401, and the water temperature at this outlet can be regarded as the temperature of the radiator 401.

[0070] like Figure 2 As shown, as a specific implementation of a control method for a fuel cell vehicle heat preservation system, the heat preservation system is subjected to vehicle heat management control, including the following steps:

[0071] In step S1, according to the operation status of the fuel cell stack 101, it is determined whether the fuel cell stack 101 is shut down; according to the above operation status determination result, the working state of each circuit of the fuel cell system is selected; if the fuel cell stack 101 is shut down, step S2 is executed, otherwise step S3 is executed;

[0072] In step S2, according to the temperature of the fuel cell stack 101, it is determined whether the fuel cell stack 101 is cold started; according to the above determination result, the working state of the fuel cell system insulation circuit and the fuel cell system heating circuit is controlled, which specifically includes the following steps:

[0073] In step S2.1, if the temperature of the fuel cell stack 101 is greater than or equal to the self-start temperature threshold T1 (10°C), the fuel cell stack 101 is not cold-started, and the fuel cell stack 101 does not need thermal management.

[0074] In step S2.2, the fuel cell stack 101 is cold started. If the temperature of the heat accumulator 104 is greater than or equal to the self-starting temperature threshold T1, the fuel cell system insulation circuit is entered to heat the stack; if the temperature of the heat accumulator 104 is less than the self-starting temperature threshold T1, the fuel cell system heating circuit is entered to heat the stack.

[0075] In the fuel cell system heat preservation loop heating stack mode, the fuel cell stack 101 is in a shutdown state. At this time, in order to avoid the fuel cell vehicle starting up for a long time at low temperature, the first three-way valve 106 is used to heat the coolant through the phase change material in the heat accumulator 104, and the coolant at the outlet of the heat accumulator 104 is introduced into the fuel cell stack 101 to increase its temperature. Figure 3 As shown: fuel cell stack 101 → first water temperature sensor 102 → water pump 103 → heat accumulator 104 → second water temperature sensor 105 → first three-way valve 106 → fuel cell stack 101 .

[0076] In the fuel cell system heating circuit heating stack mode, the temperature of the fuel cell stack 101 is too low and the heat accumulator 104 cannot meet the rapid heating requirement of the fuel cell stack 101. At this time, the first three-way valve 106, the second three-way valve 201, and the third three-way valve 302 are used to heat the coolant through the heater 301, and the coolant at the outlet of the heater 301 is introduced into the fuel cell stack 101 to increase its temperature. Figure 4 As shown: fuel cell stack 101 → first water temperature sensor 102 → water pump 103 → second three-way valve 201 → heater 301 → third three-way valve 302 → first three-way valve 106 → fuel cell stack 101 .

[0077] In step S3, if the temperature of the fuel cell stack 101 is lower than the rated ambient temperature T2 (25°C), the fuel cell system heating circuit is entered to heat the stack; if the temperature of the fuel cell stack 101 is greater than or equal to the rated ambient temperature T2 and lower than the set temperature T3 (50°C), the fuel cell system bypass circuit is entered to heat the stack; if the temperature of the fuel cell stack 101 is greater than or equal to the set temperature T3 and lower than the rated maximum operating temperature T4 (75°C), the fuel cell system insulation circuit is entered to cool the stack; if the temperature of the fuel cell stack 101 is greater than or equal to the rated maximum operating temperature T4, the temperature of the heat accumulator 104 is lower than the rated minimum operating temperature T5 (70°C) and the temperature of the radiator 401 is greater than or equal to the rated minimum operating temperature T5, the fuel cell system insulation circuit and the heat dissipation circuit are entered to cool the stack, otherwise the fuel cell system heat dissipation circuit is entered to cool the stack.

[0078] In the fuel cell system bypass loop heating stack mode, the temperature of the fuel cell stack 101 can be raised by its own working heat generation. At this time, the first three-way valve 106 and the second three-way valve 201 are used to introduce the coolant at the outlet of the fuel cell stack 101 to the inlet of the fuel cell stack 101 through the bypass passage. Figure 5 As shown: fuel cell stack 101 → first water temperature sensor 102 → water pump 103 → second three-way valve 201 → first three-way valve 106 .

[0079] In the fuel cell system heat preservation loop cooling stack mode, the fuel cell stack 101 is within the rated operating temperature range, and the heat accumulator 104 can be heated by the coolant to cool the fuel cell stack 101. At this time, the first three-way valve 106 is used to pass the coolant through the phase change material in the heat accumulator 104 for heat exchange, and the coolant at the outlet of the heat accumulator 104 is introduced into the fuel cell stack 101 to reduce its temperature. Figure 6 As shown: fuel cell stack 101 → first water temperature sensor 102 → water pump 103 → heat accumulator 104 → second water temperature sensor 105 → first three-way valve 106 → fuel cell stack 101. Figure 3 The coolant flow direction of the fuel cell system insulation circuit heating stack mode is consistent, only the high-temperature heat source and the low-temperature heat source replace each other.

[0080] In the fuel cell system heat preservation loop and heat dissipation loop cooling stack mode, the fuel cell stack 101 exceeds the rated operating temperature range, and the cooling effect of the radiator 401 itself cannot meet the cooling demand of the fuel cell stack 101. At this time, the first three-way valve 106, the second three-way valve 201, and the third three-way valve 302 are used to transfer the coolant through the heat accumulator 104 to the radiator 401 for heat exchange, and the coolant is introduced into the fuel cell stack 101 to reduce its temperature. Figure 7 As shown: the heat preservation circuit is fuel cell stack 101 → first water temperature sensor 102 → water pump 103 → heat accumulator 104 → second water temperature sensor 105 → first three-way valve 106 → fuel cell stack 101; the heat dissipation circuit is fuel cell stack 101 → first water temperature sensor 102 → water pump 103 → second three-way valve 201 → radiator 401 → third water temperature sensor 403 → third three-way valve 302 → first three-way valve 106 → fuel cell stack 101. The two circuits share the branch where the fuel cell stack 101, the first water temperature sensor 102, and the water pump 103 are located.

[0081] In the heat dissipation loop cooling stack mode of the fuel cell system, the fuel cell stack 101 exceeds the rated operating temperature range, and the cooling effect of the radiator 401 itself can meet the cooling demand of the fuel cell stack 101. At this time, the first three-way valve 106, the second three-way valve 201, and the third three-way valve 302 are used to pass the coolant through the radiator 401 for heat exchange, and the coolant is introduced into the fuel cell stack 101 to reduce its temperature. Figure 8 As shown: fuel cell stack 101 → first water temperature sensor 102 → water pump 103 → second three-way valve 201 → radiator 401 → third water temperature sensor 403 → third three-way valve 302 → first three-way valve 106 → fuel cell stack 101 .

[0082] This embodiment effectively improves the rapid start capability of the fuel cell vehicle in a low-temperature environment by integrating a water cooling circuit, reduces the power consumption during the heating process of the fuel cell stack, and overcomes the problem of slow start-up in extremely cold environments caused by the traditional cold start method.

[0083] This embodiment integrates the heat dissipation, heating, bypass and insulation functions of the fuel cell stack into a system, and uses a three-way valve to achieve flexible switching to meet the thermal management requirements of the fuel cell stack under different working conditions, reducing the number of components in the system and improving the overall compactness and layout efficiency.

[0084] This embodiment realizes the low-temperature heat preservation function of the fuel cell system, reduces the heat loss when starting under extremely cold conditions, and improves the cruising range of the fuel cell vehicle and the operating efficiency in low-temperature environments.

[0085] The above is only a preferred specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A thermal management method for cold start of a fuel cell vehicle, applied to a thermal management system for cold start of a fuel cell vehicle, characterized in that: include: The thermal management system comprises: a fuel cell stack (101), wherein a liquid inlet end of the fuel cell stack (101) is connected to a first valve port of a first three-way valve (106), and a liquid outlet end of the fuel cell stack (101) is connected to a first valve port of a second three-way valve (201); A heat accumulator (104), wherein a liquid inlet end of the heat accumulator (104) is connected to a liquid outlet end of the fuel cell stack (101), and the liquid outlet end is connected to a second valve port of the first three-way valve (106); a heater (301), wherein a liquid inlet end of the heater (301) is connected to a third valve port of the second three-way valve (201), and a liquid outlet end of the heater (301) is connected to a second valve port of the third three-way valve (302), and the second valve port of the second three-way valve (201) and the first valve port of the third three-way valve (302) are both connected to the third valve port of the first three-way valve (106); A radiator (401), wherein a liquid inlet end of the radiator (401) is communicated with a third valve port of the second three-way valve (201), and a liquid outlet end of the radiator is communicated with a third valve port of the third three-way valve (302); The liquid outlet end of the fuel cell stack (101) is connected to a water pump (103), and the output end of the water pump (103) is respectively connected to the liquid inlet end of the heat accumulator (104) and the first valve port of the second three-way valve (201); a first water temperature sensor (102) is provided between the liquid outlet end of the fuel cell stack (101) and the water pump (103); A second water temperature sensor (105) is provided between the liquid outlet end of the heat accumulator (104) and the first three-way valve (106); A third water temperature sensor (403) is provided between the liquid outlet end of the radiator (401) and the third three-way valve (302), and a cooling fan is installed on one side of the radiator (401); The thermal management method comprises: Step S1: determining the operating status of the fuel cell stack (101); when the fuel cell stack (101) is shut down, executing step S2; when the fuel cell stack (101) is not shut down, executing step S3; Step S2: when the real-time temperature data of the fuel cell stack (101) is less than a preset self-starting temperature threshold, comparing the real-time temperature data of the heat accumulator (104) of the heat accumulator (104) with the preset self-starting temperature threshold; when the real-time temperature data of the heat accumulator (104) is greater than or equal to the preset self-starting temperature threshold, heating the fuel cell stack (101) by the heat accumulator (104); when the real-time temperature data of the heat accumulator (104) is less than the preset self-starting temperature threshold, heating the fuel cell stack (101) by the heater (301); Step S3: when the real-time stack temperature data of the fuel cell stack (101) is less than the preset rated ambient temperature, heating the fuel cell stack (101) by means of the heater (301); When the real-time stack temperature data of the fuel cell stack (101) is greater than or equal to the preset rated ambient temperature and less than the first set temperature, the coolant at the liquid outlet of the fuel cell stack (101) passes through the second three-way valve (201) and the first three-way valve (106) in sequence and enters the liquid inlet of the fuel cell stack (101); When the real-time stack temperature data of the fuel cell stack (101) is greater than or equal to the first set temperature and less than a preset rated maximum operating temperature, the fuel cell stack (101) is cooled by the heat accumulator (104); When the real-time temperature data of the fuel cell stack (101) is greater than or equal to the preset rated maximum operating temperature, comparing the real-time temperature data of the heat storage device (104), the real-time temperature data of the heat sink (401) and the preset rated minimum operating temperature; When the temperature data of the real-time heat accumulator (104) is less than a preset minimum rated operating temperature and the temperature data of the real-time radiator (401) is greater than or equal to the preset minimum rated operating temperature, the fuel cell stack (101) is cooled by the radiator (401), and the fuel cell stack (101) is cooled by the heat accumulator (104); When the real-time heat storage device (104) temperature data is greater than or equal to the preset rated minimum operating temperature and the real-time radiator (401) temperature data is less than the preset rated minimum operating temperature, the fuel cell stack (101) is cooled by the radiator (401).

2. A thermal management method for cold start of a fuel cell vehicle according to claim 1, characterized in that: The fuel cell stack (101) is heated by the heat accumulator (104), specifically comprising: The coolant at the liquid outlet of the fuel cell stack (101) passes through a first water temperature sensor (102) and a water pump (103) in sequence to enter the heat accumulator (104) for heating, and the heated coolant passes through a second water temperature sensor (105) and the first three-way valve (106) in sequence to enter the liquid inlet of the fuel cell stack (101).

3. A thermal management method for cold start of a fuel cell vehicle according to claim 1, characterized in that: The fuel cell stack (101) is heated by the heater (301), specifically comprising: The coolant at the liquid outlet of the fuel cell stack (101) passes through the first water temperature sensor (102), the water pump (103) and the second three-way valve (201) in sequence to enter the heater (301) for heating, and the heated coolant passes through the third three-way valve (302) and the first three-way valve (106) in sequence to enter the liquid inlet of the fuel cell stack (101).

4. A thermal management method for cold start of a fuel cell vehicle according to claim 1, characterized in that: Cooling the fuel cell stack (101) by means of the heat accumulator (104) specifically comprises: The coolant at the liquid outlet of the fuel cell stack (101) passes through the first water temperature sensor (102) and the water pump (103) in sequence to enter the heat accumulator (104) for heat exchange cooling, and the coolant after heat exchange cooling passes through the second water temperature sensor (105) and the first three-way valve (106) in sequence to enter the liquid inlet of the fuel cell stack (101).

5. A thermal management method for cold start of a fuel cell vehicle according to claim 1, characterized in that: Cooling the fuel cell stack (101) through a radiator (401) specifically includes: The coolant at the liquid outlet of the fuel cell stack (101) passes through the first water temperature sensor (102), the water pump (103) and the second three-way valve (201) in sequence and enters the radiator (401) for cooling; the cooled coolant passes through the third water temperature sensor (403), the third three-way valve (302) and the first three-way valve (106) in sequence and enters the liquid inlet of the fuel cell stack (101).

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