Thermal management subsystem, fuel cell system and method for performing thermal management on fuel cell system

Abstract

The invention provides a thermal management subsystem. The thermal management subsystem comprises a heat exchanger, a coolant loop and a flow guide mechanism, wherein the coolant loop is connected between a galvanic pile and the heat exchanger so that coolant can circulate between the galvanic pile and the heat exchanger. The flow guide mechanism is used for being communicated with a turbine outlet of a turbine arranged on a cathode exhaust pipeline to be driven by cathode exhaust gas and can be switched between a first flow guide state and a second flow guide state. The flow guide mechanism guides the cathode waste gas flowing out of the outlet of the turbine to the heat exchanger when being in the first flow guide state so that the cathode waste gas exchanges heat with a coolant in the heat exchanger, and guides the cathode waste gas flowing out of the outlet of the turbine to a position far away from the heat exchanger when being in the second flow guide state. And heat exchange with the coolant in the heat exchanger is avoided. According to the thermal management subsystem, the power consumption of the thermal management subsystem can be reduced, and the working efficiency of the thermal management subsystem can be improved. The invention also provides a fuel cell system comprising the thermal management subsystem and a thermal management method.

Description

Technical Field

[0001] The present application generally relates to the field of fuel cell technology, and more particularly to a thermal management subsystem for a fuel cell system, a fuel cell system including such a thermal management subsystem, and a method for thermally managing a fuel cell system. Background Art

[0002] Fuel cell systems that generate electricity by electrochemical reactions between fuel and oxidant are increasingly widely used to provide electricity, especially in the field of electric vehicles. A proton exchange membrane fuel cell (PEMFC) system is a widely used fuel cell system that uses hydrogen as fuel and oxygen as oxidant. The PEMFC system includes a stack and a support system (BoP). The stack is used to convert the chemical energy in the fuel and oxidant into electrical energy, and the support system provides the stack with the operating conditions required for the reaction. Part of the power generated by the stack needs to be consumed by the auxiliary system, so the efficiency of the PEMFC system depends on the performance of the stack and the power consumption of the auxiliary system. The auxiliary system usually includes a thermal management subsystem, which is configured to consume part of the power generated by the stack to adjust the temperature of the stack. The working efficiency of the thermal management subsystem directly affects the efficiency of the PEMFC system. Therefore, it is always expected to reduce the power consumption of the thermal management subsystem and improve its working efficiency to improve the efficiency of the fuel cell system. Summary of the invention

[0003] The purpose of the present application is to provide a thermal management subsystem for a fuel cell system and a method for thermal management of a fuel cell system, so as to improve the efficiency of the fuel cell system.

[0004] In one aspect, the present application proposes a thermal management subsystem for a fuel cell system. The fuel cell system includes a stack, a cathode exhaust line configured to receive cathode exhaust gas from the stack, and a turbine arranged on the cathode exhaust line to be driven by the cathode exhaust gas. The thermal management subsystem includes: a heat exchanger; a coolant loop, the coolant loop is configured to be connected between the stack and the heat exchanger, and can circulate the coolant between the stack and the heat exchanger; and a guide mechanism, the guide mechanism is configured to be connected to the turbine outlet of the turbine, and can be switched between a first guide state and a second guide state, the guide mechanism when placed in the first guide state directs the cathode exhaust gas flowing out of the turbine outlet to the heat exchanger, so that the cathode exhaust gas exchanges heat with the coolant in the heat exchanger, and when placed in the second guide state, the cathode exhaust gas flowing out of the turbine outlet is directed to a position away from the heat exchanger without exchanging heat between the cathode exhaust gas and the coolant in the heat exchanger.

[0005] In some embodiments, the heat exchanger includes a heat exchanger body and a fan, the coolant circuit is configured to be connected between the fuel cell stack and the heat exchanger body, and is capable of circulating the coolant between the fuel cell stack and the heat exchanger body, the fan is configured to drive air in the atmospheric environment surrounding the fuel cell system to flow through the heat exchanger body when enabled so that the air exchanges heat with the coolant in the heat exchanger body, and stop driving the air when disabled, the flow diversion mechanism is configured to guide the cathode exhaust gas flowing out of the turbine outlet when placed in the first flow diversion state so that the cathode exhaust gas is mixed with the air driven by the fan and flows through the heat exchanger body, and the thermal management subsystem is configured to enable the flow diversion mechanism to switch between the first flow diversion state and the second flow diversion state based on a comparison of the outlet temperature of the cathode exhaust gas flowing out of the turbine outlet with the air temperature of the air in the atmospheric environment.

[0006] In some embodiments, the thermal management subsystem is configured to respond to a cooling request to cool the battery stack by: (i) controlling the coolant loop to circulate the coolant between the battery stack and the heat exchanger body; (ii) enabling the fan to drive air through the heat exchanger body; and (iii) placing the flow diversion mechanism in the first flow diversion state when the outlet temperature is lower than the air temperature, and placing the flow diversion mechanism in the second flow diversion state when the outlet temperature is higher than or equal to the air temperature.

[0007] In some embodiments, the coolant circuit includes a cooling branch and a heating branch, the heat exchanger body is disposed on the cooling branch, the thermal management subsystem also includes a heater, the heater is disposed on the heating branch, and is configured to heat the coolant when the coolant flows through it, the coolant circuit is configured to be switchable between a first circulation state and a second circulation state, when placed in the first circulation state, the cooling branch is turned on and the heating branch is turned off, and the coolant circulates between the battery stack and the heat exchanger body, when placed in the second circulation state, the heating branch is turned on and the cooling branch is turned off. The branch is closed and the coolant circulates between the battery stack and the heater, and the thermal management subsystem is configured to respond to a heating request for heating the battery stack by: (i) placing the coolant loop in the second circulation state so that the coolant circulates between the battery stack and the heater; (ii) controlling the heater to heat the coolant flowing through it; and (iii) placing the flow guide mechanism in the first flow guide state and enabling the fan when the outlet temperature is higher than the air temperature, and placing the flow guide mechanism in the second flow guide state and deactivating the fan when the outlet temperature is lower than or equal to the air temperature.

[0008] In some embodiments, the fan is configured to drive the air to flow through the heat exchanger body along a first direction, and the flow guiding mechanism is configured to discharge the cathode exhaust gas flowing out of the turbine outlet in a second direction transverse to the first direction at a position upstream of the heat exchanger body along the first direction when placed in the first flow guiding state.

[0009] In some embodiments, the flow guiding mechanism includes a first branch, a second branch and a branch switch, wherein the first branch is configured to communicate with the turbine outlet, and when being turned on, guides the cathode exhaust gas flowing out of the turbine outlet to the heat exchanger so that the cathode exhaust gas exchanges heat with the coolant in the heat exchanger, and when being turned off, blocks the cathode exhaust gas from passing through it, the second branch is configured to communicate with the turbine outlet, and when being turned on, guides the cathode exhaust gas flowing out of the turbine outlet to a position away from the heat exchanger without exchanging heat between the cathode exhaust gas and the coolant in the heat exchanger, and when being turned off, blocks the cathode exhaust gas from passing through it, and the branch switch is configured to be able to switch between a first state and a second state, when being placed in the first state, the first branch is connected and the second branch is closed, so that the flow guiding mechanism is placed in the first flow guiding state, and when being placed in the second state, the second branch is connected and the first branch is closed, so that the flow guiding mechanism is placed in the second flow guiding state. In one of these embodiments, the fan may be configured to drive the air to flow through the heat exchanger body along a first direction, the outlet of the first branch is disposed upstream of the heat exchanger body in the first direction, and is oriented toward a second direction transverse to the first direction. Exemplarily, the outlet may have an elongated shape, and the outlet is oriented in a manner such that the length of the outlet is perpendicular to the first direction.

[0010] In some embodiments, the thermal management subsystem is configured to calculate the outlet temperature by the following formula:

[0011]

[0012] Among them, T out is the outlet temperature, T in is the inlet temperature of the cathode exhaust gas entering the turbine inlet of the turbine, P out is the outlet pressure of the cathode exhaust gas flowing out of the turbine outlet, P in is the inlet pressure of the cathode exhaust gas entering the turbine inlet, η is the efficiency of the turbine, Among them, C p is the constant pressure specific heat capacity of the cathode exhaust gas entering the turbine inlet, Cv is the constant volume specific heat capacity of the cathode exhaust gas entering the turbine inlet.

[0013] On the other hand, the present application proposes a fuel cell system. The fuel cell system includes: a stack; a cathode exhaust line configured to receive cathode exhaust gas from the stack; a turbine provided on the cathode exhaust line to be driven by the cathode exhaust gas; and the aforementioned thermal management subsystem, wherein the coolant loop is connected between the stack and the heat exchanger, and the flow guide mechanism is connected to the turbine outlet of the turbine.

[0014] On the other hand, the present application proposes a method for thermal management of a fuel cell system. The fuel cell system includes a stack, a cathode exhaust line configured to receive cathode exhaust gas from the stack, a turbine arranged on the cathode exhaust line to be driven by the cathode exhaust gas, and a thermal management subsystem. The thermal management subsystem includes: a heat exchanger; a coolant loop, the coolant loop is connected between the stack and the heat exchanger, and can circulate the coolant between the stack and the heat exchanger; and a guide mechanism, the guide mechanism is connected to the turbine outlet of the turbine, and can be switched between a first guide state and a second guide state, the guide mechanism when placed in the first guide state directs the cathode exhaust gas flowing out of the turbine outlet to the heat exchanger, so that the cathode exhaust gas exchanges heat with the coolant in the heat exchanger, and when placed in the second guide state, the cathode exhaust gas flowing out of the turbine outlet is directed to a position away from the heat exchanger without exchanging heat between the cathode exhaust gas and the coolant in the heat exchanger. The method includes switching the flow guiding mechanism between the first flow guiding state and the second flow guiding state.

[0015] In some embodiments, the heat exchanger includes a heat exchanger body and a fan, the coolant circuit is connected between the fuel cell stack and the heat exchanger body, and is capable of circulating the coolant between the fuel cell stack and the heat exchanger body, the fan is configured to drive air in the atmospheric environment surrounding the fuel cell system to flow through the heat exchanger body when enabled so that the air exchanges heat with the coolant in the heat exchanger body, and stop driving the air when disabled, the flow guide mechanism is configured to guide the cathode exhaust gas flowing out of the turbine outlet when placed in the first flow guide state so that the cathode exhaust gas is mixed with the air driven by the fan and flows through the heat exchanger body, and switching the flow guide mechanism between the first flow guide state and the second flow guide state includes switching the flow guide mechanism between the first flow guide state and the second flow guide state based on a comparison of the outlet temperature of the cathode exhaust gas flowing out of the turbine outlet with the air temperature of the air in the atmospheric environment.

[0016] In some embodiments, the method includes, in response to a cooling request to cool the battery stack: (i) controlling the coolant circuit to circulate the coolant between the battery stack and the heat exchanger body; (ii) enabling the fan to drive air through the heat exchanger body; and (iii) placing the flow guide mechanism in the first flow guide state when the outlet temperature is lower than the air temperature, and placing the flow guide mechanism in the second flow guide state when the outlet temperature is higher than or equal to the air temperature.

[0017] In some embodiments, the coolant circuit includes a cooling branch and a heating branch, the heat exchanger body is disposed on the cooling branch, the thermal management subsystem also includes a heater, the heater is disposed on the heating branch, and is configured to heat the coolant when the coolant flows through it, the coolant circuit is configured to be switchable between a first circulation state and a second circulation state, when placed in the first circulation state, the cooling branch is connected and the heating branch is closed, and the coolant circulates between the battery stack and the heat exchanger body, when placed in the second circulation state, the heating branch is connected and the cooling branch is closed, and the coolant circulates between the battery stack and the heater. The method includes, in response to a heating request for heating the battery stack: (i) placing the coolant circuit in the second circulation state so that the coolant circulates between the battery stack and the heater; (ii) controlling the heater to heat the coolant flowing therethrough; and (iii) placing the flow guide mechanism in the first flow guide state and activating the fan when the outlet temperature is higher than the air temperature, and placing the flow guide mechanism in the second flow guide state and deactivating the fan when the outlet temperature is lower than or equal to the air temperature.

[0018] These techniques may be used alone or in any suitable combination.The foregoing summary is provided by way of illustration and is not meant to be limiting.

[0019] According to the present application, the cathode exhaust gas flowing out of the turbine outlet of the turbine can be selectively allowed to exchange heat with the coolant in the heat exchanger, so that the power consumption of the thermal management subsystem can be reduced and its working efficiency can be improved, thereby improving the efficiency of the fuel cell system. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The above and other aspects of the present application will be more thoroughly understood and appreciated in conjunction with the accompanying drawings. It should be noted that the drawings are schematic only and are not drawn to scale. In different drawings, the same components are represented by the same reference numerals. In addition, for the sake of brevity, not all components or parts of the fuel cell system and thermal management subsystem according to the present application are shown or marked in the drawings. It should be understood that the size, proportional relationship and number of components of each component or part in the drawings are not intended to limit the present application. In the drawings:

[0021] Figure 1 A block diagram of a fuel cell system including a thermal management subsystem according to some embodiments of the present application is schematically shown, and a method for thermal management of a fuel cell system according to some embodiments of the present application may be implemented in the fuel cell system;

[0022] Figure 2A and Figure 2B is with Figure 1 A similar block diagram, which shows Figure 1 The thermal management subsystem shown performs operations in response to a cooling request to cool the stack;

[0023] Figure 3A and Figure 3B is with Figure 1 A similar block diagram, which shows Figure 1 The thermal management subsystem is shown to perform operations in response to a heating request to heat the stack;

[0024] Figure 4A It is schematically shown Figure 1 A perspective view of an exemplary version of a portion of a fuel cell system is shown;

[0025] Figure 4B yes Figure 4A Another perspective view of the device shown; and

[0026] Figure 5 is a flow chart schematically illustrating a method for thermal management of a fuel cell system according to some embodiments of the present application. DETAILED DESCRIPTION

[0027] Some embodiments of the present application are described in detail below in conjunction with the accompanying drawings. In the following embodiments, in order to facilitate the description of the thermal management subsystem for a fuel cell system according to the present application, a thermal management subsystem for a PEMFC system is used as an example of a thermal management subsystem according to the present application. However, it should be understood that such an example does not mean any limitation to the present application, and the thermal management subsystem according to the present application can also be used for other types of fuel cell systems. In addition, the various features in the various embodiments of the present application can be combined with each other without conflict.

[0028] Figures 1 to 4B A fuel cell system 1 according to some embodiments of the present application is schematically shown. The fuel cell system 1 may be a proton exchange membrane fuel cell (PEMFC) system, which uses hydrogen as a fuel and oxygen as an oxidant, and generates electricity by an electrochemical reaction between the fuel and the oxidant. For example, the fuel cell system 1 may be used in a vehicle to provide electricity, thereby driving a vehicle motor to provide power or enabling an onboard system to perform various functions.

[0029] Figure 1 A fuel cell system 1 is schematically shown. Figure 1 As shown, the fuel cell system 1 includes a stack 3 and an auxiliary system (not shown). The stack 3 is used to convert the chemical energy in the fuel and the oxidant into electrical energy, and the auxiliary system provides the operating conditions required for the reaction of the stack 3. Figure 1 As schematically shown in FIG. 1 , the stack 3 may include an anode 31, a cathode 32, and a cooling chamber 33. The auxiliary system may include an air subsystem (not shown), a fuel subsystem (not shown), and a thermal management subsystem 100 (e.g., Figure 1 The fuel subsystem, the air subsystem and the thermal management subsystem 100 may be respectively configured to introduce fuel, air and coolant into the anode 31, the cathode 32 and the cooling chamber 33 of the fuel cell stack 3, so as to provide stable operation conditions for the fuel cell stack 3.

[0030] Although the fuel subsystem is not shown in the figure, it should be understood that the fuel subsystem can have any suitable configuration to supply hydrogen (i.e., the fuel in this embodiment) to the anode inlet (not shown) of the anode 31, and receive unconsumed hydrogen, invalid gas (invalid gas refers to gas that does not participate in the reaction, mainly nitrogen) and product water from the anode outlet (not shown) of the anode 31. The fuel subsystem can also mix the unconsumed hydrogen with fresh hydrogen from the hydrogen source to be supplied to the anode inlet again, thereby improving the utilization efficiency of the fuel.

[0031] Please continue to see Figure 1, the air subsystem includes a cathode gas supply line 41 configured to supply air (in this embodiment, oxygen in the air is an oxidant) to the stack 3, a compressor 5 disposed on the cathode gas supply line 41, a cathode exhaust line 42 configured to receive cathode exhaust gas from the stack 3, and a turbine 6 disposed on the cathode exhaust line 42. The cathode gas supply line 41 is connected between the cathode inlet 32a of the cathode 32 of the stack 3 and the atmosphere around the fuel cell system 1 to inhale air from the atmosphere. The compressor 5 can be enabled and disabled. When enabled, the compressor 5 inhales air from the atmosphere around the fuel cell system 1 and pressurizes it, and delivers the pressurized air to the cathode inlet 32a of the cathode 32 of the stack 3, and stops supplying air to the cathode inlet 32a when disabled. The cathode exhaust line 42 is connected to the cathode outlet 32b of the cathode 32 of the stack 3 to receive cathode exhaust gas from the cathode 32. The cathode exhaust gas may include unconsumed oxygen, ineffective gas, and product water. The turbine 6 is disposed on the cathode exhaust line 42 to be driven by the cathode exhaust gas, thereby recovering energy from the cathode exhaust gas. The cathode exhaust gas enters the turbine 6 from the turbine inlet 6a of the turbine 6 and flows out from the turbine outlet 6b. When the cathode exhaust gas flows through the turbine 6, the turbine 6 recovers energy from the cathode exhaust gas, and the temperature and pressure of the cathode exhaust gas decrease, while the velocity increases. In some embodiments, as Figure 1 As shown, the compressor 5 can be configured to be at least partially driven by the turbine 6. The drive shaft 7 can rotationally connect the turbine (not shown) of the turbine 6 to the compressor wheel (not shown) of the compressor 5. The turbine (not shown) of the turbine 6 is driven by the cathode exhaust gas, thereby driving the compressor wheel of the compressor 5 to rotate through the drive shaft 7, so that the compressor 5 pressurizes the air in the cathode supply line 41. The compressor 5 can also be additionally driven by a motor (not shown). In other partial embodiments, the energy recovered from the cathode exhaust gas by the turbine 6 can drive other devices or be stored by other suitable mechanisms. In this case, the compressor 5 can be driven only by a motor. It should be understood that the air subsystem is not limited to this and can also include devices such as intercoolers and humidifiers.

[0032] The thermal management subsystem 100 can use the coolant to adjust the temperature of the fuel cell stack 3. Figure 1As shown, the thermal management subsystem 100 includes a heat exchanger 110 and a coolant loop 120, which is connected between the stack 3 and the heat exchanger 110 and can circulate the coolant between the stack 3 and the heat exchanger 110. The thermal management subsystem 100 also includes a flow guide mechanism 130, which is configured to selectively allow the cathode exhaust gas flowing out of the turbine outlet 6b of the turbine 6 (i.e., the cathode exhaust gas flowing through the turbine 6) to exchange heat with the coolant in the heat exchanger 110, so as to reduce the power consumption of the thermal management subsystem 100 and improve its working efficiency. This means that the thermal management subsystem 100 can efficiently adjust the temperature of the stack 3, thereby improving the performance and efficiency of the fuel cell system 1.

[0033] Specifically, the flow guide mechanism 130 is configured to communicate with the turbine outlet 6b of the turbine 6, and can be switched between a first flow guide state and a second flow guide state. When the flow guide mechanism 130 is placed in the first flow guide state, the cathode exhaust gas flowing out of the turbine outlet 6b is directed to the heat exchanger 110 so that the cathode exhaust gas exchanges heat with the coolant in the heat exchanger 110. Depending on the specific form of the heat exchanger 110, the flow guide mechanism 130 can be configured to direct the cathode exhaust gas flowing out of the turbine outlet 6b to the heat exchanger 110 when placed in the first flow guide state, or to a position adjacent to the heat exchanger 110 so that the cathode exhaust gas exchanges heat with the coolant in the heat exchanger 110. For example, a channel structure for receiving the cathode exhaust gas and facilitating heat exchange between the cathode exhaust gas and the coolant may be provided in the heat exchanger 110. In this case, the flow guide mechanism 130 can be configured to direct the cathode exhaust gas to the heat exchanger 110 when placed in the first flow guide state. As another example, the flow guide mechanism 130 may be configured to guide the cathode exhaust gas to a position adjacent to the heat exchanger 110 when placed in the first flow guide state, so that it flows through the heat exchanger 110 from the outside to exchange heat with the coolant in the heat exchanger 110. As will be described in detail below, when the cathode exhaust gas is guided to the heat exchanger 110 by the flow guide mechanism 130 to exchange heat with the coolant in the heat exchanger 110, the coolant in the heat exchanger 110 may be in a flowing state or a stationary state. The flow guide mechanism 130 guides the cathode exhaust gas flowing out of the turbine outlet 6b to a position away from the heat exchanger 110 when placed in the second flow guide state, without causing the cathode exhaust gas to exchange heat with the coolant in the heat exchanger 110. For example, the flow guide mechanism 130 may be configured to guide the cathode exhaust gas flowing out of the turbine outlet 6b to the tailpipe (not shown) of the fuel cell system 1 or the vehicle when placed in the second flow guide state, so as to be discharged into the atmospheric environment.

[0034] When the flow guiding mechanism 130 is placed in the first flow guiding state, the cathode exhaust gas flowing out of the turbine outlet 6b is directed to the heat exchanger 110 to exchange heat with the coolant in the heat exchanger 110. This makes it possible to use the cathode exhaust gas flowing out of the turbine outlet 6b to adjust the temperature of the coolant in the heat exchanger 110, so that the power consumption of the thermal management subsystem 100 can be reduced and its working efficiency can be improved. When the flow guiding mechanism 130 is placed in the second flow guiding state, the cathode exhaust gas flowing out of the turbine outlet 6b is directed to a position away from the heat exchanger 110 without exchanging heat with the coolant in the heat exchanger 110. Through this configuration, the flow guiding mechanism 130 allows the cathode exhaust gas flowing out of the turbine outlet 6b of the turbine 6 to selectively exchange heat with the coolant in the heat exchanger 110, so that the power consumption of the thermal management subsystem 100 can be reduced and its working efficiency can be improved, thereby improving the performance and efficiency of the fuel cell system 1.

[0035] The thermal management subsystem 100 and the method for thermal management of the fuel cell system 1 will be described below in conjunction with an exemplary type of the flow guiding mechanism 130. It should be understood that the present application is not limited thereto.

[0036] like Figure 1 As shown, the exemplary type of flow guide mechanism 130 may include a first branch 131, a second branch 132 and a branch switch 133. The first branch 131 may be configured to communicate with the turbine outlet 6b of the turbine 6 and can be turned on and off. When the first branch 131 is turned on, the cathode exhaust gas flowing out of the turbine outlet 6b is directed to the heat exchanger 110 so that the cathode exhaust gas exchanges heat with the coolant in the heat exchanger 110. Depending on the specific form of the heat exchanger 110, the first branch 131 may be configured to direct the cathode exhaust gas flowing out of the turbine outlet 6b to the heat exchanger 110, or to a position adjacent to the heat exchanger 110 so that the cathode exhaust gas exchanges heat with the coolant in the heat exchanger 110. For example, a channel structure for receiving the cathode exhaust gas and facilitating heat exchange between the cathode exhaust gas and the coolant may be provided in the heat exchanger 110. In this case, the first branch 131 may be configured to direct the cathode exhaust gas to the heat exchanger 110. For example, the following text will combine Figure 1 and FIG. 4A to FIG. 4BDescribed, the first branch 131 can be configured to direct the cathode exhaust gas to a position adjacent to the heat exchanger 110 so that it flows through the heat exchanger 110 from the outside to exchange heat with the coolant in the heat exchanger 110. The first branch 131 blocks the cathode exhaust gas from passing through it when it is closed. The second branch 132 is also configured to communicate with the turbine outlet 6b and can be turned on and off. The second branch 132 directs the cathode exhaust gas flowing out of the turbine outlet 6b to a position away from the heat exchanger 110 when it is turned on, without exchanging heat between the cathode exhaust gas and the coolant in the heat exchanger 110. For example, the second branch 132 can be configured to direct the cathode exhaust gas flowing out of the turbine outlet 6b to the tailpipe (not shown) of the fuel cell system 1 or the vehicle to be discharged to the atmospheric environment. The second branch 132 blocks the cathode exhaust gas from passing through it when it is closed. In some embodiments, the second branch 132 can be shared by the guide mechanism 130 and the cathode exhaust line 42 of the air subsystem.

[0037] The branch switch 133 is configured to be switchable between a first state and a second state, so that the flow guide mechanism 130 switches between the first flow guide state and the second flow guide state. When the branch switch 133 is placed in the first state, the first branch 131 is connected and the second branch 132 is closed, so that the flow guide mechanism 130 is placed in the first flow guide state, so that the cathode exhaust gas flowing out of the turbine outlet 6b is directed to the heat exchanger 110 to exchange heat with the coolant in the heat exchanger 110. This makes it possible to use the cathode exhaust gas flowing out of the turbine outlet 6b to adjust the temperature of the coolant in the heat exchanger 110, thereby reducing the power consumption of the thermal management subsystem 100 and improving its working efficiency. When the branch switch 133 is placed in the second state, the second branch 132 is turned on and the first branch 131 is turned off, so that the flow guide mechanism 130 is placed in the second flow guide state, so that the cathode exhaust gas flowing out of the turbine outlet 6b is directed to a position away from the heat exchanger 110, and does not exchange heat with the coolant in the heat exchanger 110. Through this configuration, the flow guide mechanism 130 enables the cathode exhaust gas flowing out of the turbine outlet 6b of the turbine 6 to selectively exchange heat with the coolant in the heat exchanger 110, so that the power consumption of the thermal management subsystem 100 can be reduced and its working efficiency can be improved, thereby improving the performance and efficiency of the fuel cell system 1.

[0038] In some embodiments, Figure 1As shown, the main line 8 can be connected to the turbine outlet 6b of the turbine 6 and extend from the turbine outlet 6b of the turbine 6 to guide the cathode exhaust gas flowing out from the turbine outlet 6b. The branch switch 133 can be in the form of a three-way valve and have a first outlet 133a, a second outlet 133b and an inlet 133c. The three-way valve is configured to be able to switch between a first flow state and a second flow state. When placed in the first flow state, the three-way valve allows fluid flow from the inlet 133c to the first outlet 133a, while blocking the fluid flow from the inlet 133c to the second outlet 133b, and when placed in the second flow state, the three-way valve allows fluid flow from the inlet 133c to the second outlet 133b, while blocking the fluid flow from the inlet 133c to the first outlet 133a. The branch switch 133 can be switched between the aforementioned first state and the second state by switching the three-way valve between the first flow state and the second flow state. In one of these embodiments, the main line 8 and the second branch line 132 may be shared by the flow guide mechanism 130 and the air subsystem. For example, the main line 8 and the second branch line 132 may be part of the cathode exhaust line 42, and the first branch line 131 is connected to the cathode exhaust line 42 downstream of the turbine 6 through a three-way valve.

[0039] In other partial embodiments, the branch switch 133 may include on-off valves respectively arranged on the first branch 131 and the second branch 132 to control the connection and closing of the corresponding pipelines. In this case, the branch switch 133 can be switched between the aforementioned first state and the second state by controlling these on-off valves. It should be understood that the present application is not limited thereto, and the branch switch 133 can be in any other suitable form to achieve switching between the aforementioned first state and the second state.

[0040] In some embodiments, the flow guiding mechanism 130 can be manually switched between the first flow guiding state and the second flow guiding state. As an example, the branch switch 133 can be manually switched between the first state and the second state, so that the flow guiding mechanism 130 switches between the first flow guiding state and the second flow guiding state. Figure 1 In the case of the three-way valve form shown, the three-way valve can be manually controlled by the user to switch between the first flow state and the second flow state. For another example, in the case where the branch switcher 133 includes on-off valves respectively arranged on the first branch 131 and the second branch 132, these on-off valves can be manually controlled by the user.

[0041] In other partial embodiments, the flow guiding mechanism 130 can switch between the first flow guiding state and the second flow guiding state under the control of a controller. The controller can be a control module (which can be regarded as a part of the thermal management subsystem 100) in a fuel cell control unit (FCU) (not shown) of the fuel cell system 1 for controlling the thermal management subsystem 100 or a separate controller of the thermal management subsystem 100. As an example, the branch switch 133 can be controlled by a corresponding control module in the FCU or a separate controller of the thermal management subsystem 100 to switch between the aforementioned first state and second state, so that the flow guiding mechanism 130 switches between the first flow guiding state and the second flow guiding state. For example, when the branch switch 133 is as shown in Figure 1 In the case of the three-way valve form shown, the three-way valve can be an electric three-way valve controlled by a corresponding control module or a separate controller in the FCU. For another example, in the case where the branch switch 133 includes on-off valves respectively arranged on the first branch 131 and the second branch 132, these on-off valves can be electric on-off valves controlled by a corresponding control module or a separate controller in the FCU. It should be understood that such a control module or a separate controller can be implemented by software and / or hardware.

[0042] In some embodiments, Figure 1 As shown, the heat exchanger 110 may include a heat exchanger body 111 and a fan (or referred to as a "blower") 112. The coolant loop 120 is connected between the fuel cell stack 3 and the heat exchanger body 111, and is capable of circulating the coolant between the fuel cell stack 3 and the heat exchanger body 111. The fan 112 is configured to drive the air in the atmospheric environment around the fuel cell system 1 (such as Figure 1 The air flow mechanism 130 (schematically indicated by the curved arrow 20 in FIG. 1 ) flows through the heat exchanger body 111 to exchange heat with the coolant in the heat exchanger body 111, and stops driving the air when it is deactivated. For example, the fan 112 can be disposed on the heat exchanger body 111 or adjacent to the heat exchanger body 111. The flow guide mechanism 130 is configured to guide the cathode exhaust gas (such as the exhaust gas) flowing out of the turbine outlet 6b when it is placed in the first flow guide state. Figure 1 110) to mix with the air driven by the fan 112 and flow through the heat exchanger body 111. With this configuration, the flow guide mechanism 130 is capable of adjusting the temperature of the gas flowing through the heat exchanger body 111 to exchange heat with the coolant in the heat exchanger body 111 by selectively mixing the cathode exhaust gas flowing out of the turbine outlet 6b with the air driven by the fan 112, thereby enabling the working efficiency of the thermal management subsystem 100.

[0043] In one of these embodiments, the thermal management subsystem 100 is configured to switch the flow guide mechanism 130 between the first flow guide state and the second flow guide state based on the comparison of the outlet temperature of the cathode exhaust gas flowing out of the turbine outlet 6b and the air temperature of the air in the atmosphere surrounding the fuel cell system 1. As an example, the fuel cell system 1 or the thermal management subsystem 100 may include a temperature sensor (not shown) to directly detect the outlet temperature of the cathode exhaust gas flowing out of the turbine outlet 6b and the air temperature of the air in the atmosphere surrounding the fuel cell system 1. The corresponding control module in the FCU or a separate controller may communicate with these temperature sensors to obtain the outlet temperature and the air temperature and compare them, and switch the flow guide mechanism 130 between the first flow guide state and the second flow guide state based on the comparison result. In this way, the cathode exhaust gas flowing out of the turbine outlet 6b can be more efficiently utilized to reduce the power consumption of the thermal management subsystem 100. Although the outlet temperature of the cathode exhaust gas flowing out of the turbine outlet 6b is described as being directly detected by the temperature sensor, as will be described below, the outlet temperature of the cathode exhaust gas can also be indirectly calculated.

[0044] In some embodiments, Figure 1 As shown, the coolant circuit 120 may include a cooling branch 120a and a heating branch 120b. The cooling branch 120a and the heating branch 120b are respectively configured to be connected between the coolant inlet 33a and the coolant outlet 33b of the cooling chamber 33 of the stack 3. The coolant circuit 120 may include a first main circuit 121 and a second main circuit 122. The first end of the first main circuit 121 may be connected to the coolant inlet 33a of the cooling chamber 33 of the stack 3, and the second end of the first main circuit 121 opposite to the first end may be connected to the first end of the cooling branch 120a and the first end of the heating branch 120b. The first end of the second main circuit 122 may be connected to the coolant outlet 33b of the cooling chamber 33 of the stack 3, and the second end of the second main circuit 122 opposite to the first end may be connected to the second end of the cooling branch 120a opposite to the first end and the second end of the heating branch 120b opposite to the first end through the three-way valve 150. In this way, the cooling branch 120a and the heating branch 120b can be respectively configured to be connected between the coolant inlet 33a and the coolant outlet 33b of the cooling chamber 33 of the stack 3. It should be understood that the present application is not limited to this. Alternatively or additionally, the second end of the first main circuit 121 can also be connected to the first end of the cooling branch 120a and the first end of the heating branch 120b through a three-way valve. Optionally, the cooling branch 120a and the heating branch 120b can be respectively provided with an on-off valve to control the connection and closing of the corresponding branch.

[0045] The heat exchanger 110 is disposed on the cooling branch 120a, and the coolant can pass through the heat exchanger 110. Figure 1 , the heat exchanger body 111 of the heat exchanger 110 is arranged on the cooling branch 120a, and the coolant can pass through the heat exchanger body 111. The thermal management subsystem 100 may also include a heater 140, which is arranged on the heating branch 120b and is configured to heat the coolant when the coolant flows therethrough. The coolant circuit 120 may also include a coolant pump 160 arranged on the first main path 121 to drive the coolant flow. It should be understood that the present application is not limited to this. Optionally, a coolant pump that drives the coolant flow may be provided on the second main path 122. Optionally, coolant pumps that drive the coolant flow may be provided on the cooling branch 120a and the heating branch 120b, respectively.

[0046] The coolant loop 120 is configured to be switchable between a first circulation state and a second circulation state. When the coolant loop 120 is placed in the first circulation state, the cooling branch 120a is turned on and the heating branch 120b is closed (for example, by adjusting the three-way valve 150) so that the coolant circulates between the stack 3 and the heat exchanger body 111 of the heat exchanger 110. In this way, for example, during normal operation of the stack 3, the thermal management subsystem 100 can transfer the heat generated by the stack 3 to the heat exchanger 110 through the coolant and dissipate it to the atmosphere through the heat exchanger 110, thereby cooling the stack 3. When the coolant loop 120 is placed in the second circulation state, the heating branch 120b is turned on and the cooling branch 120a is closed (for example, by adjusting the three-way valve 150) so that the coolant circulates between the stack 3 and the heater 140. In this way, for example, during a cold start of the fuel cell stack 3 , the thermal management subsystem 100 can heat the coolant through the heater 140 and circulate the heated coolant through the fuel cell stack 3 , thereby heating the fuel cell stack 3 .

[0047] As will be described in detail below, the thermal management subsystem 100 can be configured to adjust the temperature of the stack 3 in response to a request to adjust the temperature of the stack 3 by controlling one or more of the heat exchanger 110, the coolant loop 120, the flow guide mechanism 130, and the heater 140 based on a comparison of the outlet temperature of the cathode exhaust gas flowing out of the turbine outlet 6b with the air temperature of the air in the atmospheric environment surrounding the fuel cell system 1. The request to adjust the temperature of the stack 3 may include a cooling request to cool the stack 3 and a heating request to heat the stack 3. The request to adjust the temperature of the stack 3 may be automatically triggered by the FCU based on the state of the stack 3, the environment in which the stack 3 is located, etc., or may be manually triggered by an operator (for example, by inputting a command or a mechanical key).

[0048] During normal operation of the fuel cell stack 3, for example, a cooling request may be issued to the thermal management subsystem 100 so that the thermal management subsystem 100 cools the fuel cell stack 3. The thermal management subsystem 100 may be configured to, in response to the cooling request to cool the fuel cell stack 3: (1) control the coolant loop 120 to circulate the coolant between the fuel cell stack 3 and the heat exchanger body 111 of the heat exchanger 110, i.e., place the coolant loop 120 in a first circulation state; (2) enable the fan 112 to drive air in the atmospheric environment to flow through the heat exchanger body 111; and (3) based on a comparison of the outlet temperature of the cathode exhaust gas flowing out of the turbine outlet 6b with the air temperature of the air in the atmospheric environment surrounding the fuel cell system 1, when the outlet temperature of the cathode exhaust gas is lower than the air temperature of the air, place the flow guide mechanism 130 in a first flow guide state, and when the outlet temperature of the cathode exhaust gas is higher than or equal to the air temperature of the air, place the flow guide mechanism 130 in a second flow guide state.

[0049] Figure 2A and Figure 2B is with Figure 1 A similar block diagram, which shows Figure 1 The thermal management subsystem shown performs operations in response to a cooling request to cool the stack 3 of the fuel cell system 1. Figure 2A and Figure 2B In the figure, the connected pipelines, main lines and branches in the fuel cell system 1 are indicated by solid lines, the flow direction of the fluid is indicated by arrows on the solid lines, and the closed branches are indicated by dotted lines.

[0050] Figure 2A FIG. 2 shows the operation of the thermal management subsystem in response to a cooling request for cooling the fuel cell stack 3 when the outlet temperature of the cathode exhaust gas flowing out of the turbine outlet 6 b is lower than the air temperature of the air in the atmosphere surrounding the fuel cell system 1 . Figure 2A As shown, the thermal management subsystem 100 can respond to a cooling request for cooling the fuel cell stack 3 by: (1) controlling the coolant loop 120 to circulate the coolant between the fuel cell stack 3 and the heat exchanger body 111 of the heat exchanger 110, that is, placing the coolant loop 120 in a first circulation state; (2) enabling the fan 112 to drive air in the atmospheric environment to flow through the heat exchanger body 111; and (3) placing the flow guide mechanism 130 in a first flow guide state. This operating mode may also be referred to as the first operating mode of the thermal management subsystem 100. In the first operating mode, the coolant circulates between the fuel cell stack 3 and the heat exchanger body 111 of the heat exchanger 110, the coolant transfers the heat generated by the fuel cell stack 3 to the heat exchanger body 111, and the fan 112 drives the air in the atmospheric environment to flow through the heat exchanger body 111 ( Figure 2AThe cathode exhaust gas (shown schematically by the curved arrow 20 in FIG. 1 ) is discharged from the turbine outlet 6b to remove the heat from the heat exchanger body 111 and dissipate it into the atmosphere, thereby cooling the stack 3. Figure 2A The cathode exhaust gas (schematically indicated by the straight arrow 30 in FIG. 1 ) is guided by the flow guide mechanism 130 to mix with the air driven by the fan 112 and flow through the heat exchanger body 111. Since the outlet temperature of the cathode exhaust gas is lower than the air temperature of the air, the cathode exhaust gas can reduce the temperature of the gas driven through the heat exchanger body 111 to exchange heat with the coolant. This makes it possible to reduce the power consumption of the thermal management subsystem 100 and improve its working efficiency, thereby improving the performance and efficiency of the fuel cell system 1.

[0051] Figure 2B FIG. 2 shows the operation of the thermal management subsystem in response to a cooling request for cooling the fuel cell stack 3 when the outlet temperature of the cathode exhaust gas flowing out of the turbine outlet 6 b is higher than or equal to the air temperature of the air in the atmosphere surrounding the fuel cell system 1 . Figure 2B As shown, the thermal management subsystem 100 can respond to a cooling request for cooling the fuel cell stack 3 by: (1) controlling the coolant loop 120 to circulate the coolant between the fuel cell stack 3 and the heat exchanger body 111 of the heat exchanger 110, that is, placing the coolant loop 120 in a first circulation state; (2) enabling the fan 112 to drive air in the atmospheric environment to flow through the heat exchanger body 111; and (3) placing the flow guide mechanism 130 in a second flow guide state. This operating mode may also be referred to as the second operating mode of the thermal management subsystem 100. In the second operating mode, the coolant circulates between the fuel cell stack 3 and the heat exchanger body 111 of the heat exchanger 110, the coolant transfers the heat generated by the fuel cell stack 3 to the heat exchanger body 111, and the fan 112 drives the air in the atmospheric environment to flow through the heat exchanger body 111 ( Figure 2A The heat exchanger body 111 is schematically represented by the curved arrow 20 in the figure to remove the heat from the heat exchanger body 111 and dissipate it into the atmosphere, thereby cooling the fuel cell stack 3. The cathode exhaust gas flowing out of the turbine outlet 6b is guided by the guide mechanism 130 to a position away from the heat exchanger 110 without exchanging heat with the coolant in the heat exchanger 110, so as to prevent the power consumption of the thermal management subsystem 100 from being adversely increased.

[0052] During, for example, a cold start of the fuel cell stack 3, a heating request may be issued to the thermal management subsystem 100 so that the thermal management subsystem 100 heats the fuel cell stack 3. The thermal management subsystem 100 may be configured to, in response to the heating request to heat the fuel cell stack 3: (1) control the coolant loop 120 to circulate the coolant between the fuel cell stack 3 and the heater 140, i.e., place the coolant loop in the second circulation state; (2) control the heater 140 to heat the coolant flowing therethrough; and (3) based on a comparison of the outlet temperature of the cathode exhaust gas flowing out of the turbine outlet 6b with the air temperature of the air in the atmospheric environment surrounding the fuel cell system 1, when the outlet temperature of the cathode exhaust gas is higher than the air temperature of the air, place the flow guide mechanism 130 in the first flow guide state and enable the fan 112, and when the outlet temperature of the cathode exhaust gas is lower than or equal to the air temperature of the air, place the flow guide mechanism 130 in the second flow guide state and disable the fan 112.

[0053] Figure 3A and Figure 3B is with Figure 1 A similar block diagram, which shows Figure 1 The thermal management subsystem shown performs operations in response to a heating request to heat the fuel cell stack 3. Figure 3A and Figure 3B In the figure, the connected pipelines, main lines and branches in the fuel cell system 1 are indicated by solid lines, the flow direction of the fluid is indicated by arrows on the solid lines, and the closed branches are indicated by dotted lines.

[0054] Figure 3A FIG. 2 shows the operation of the thermal management subsystem in response to a heating request for heating the fuel cell stack 3 when the outlet temperature of the cathode exhaust gas flowing out of the turbine outlet 6 b is higher than the air temperature of the air in the atmosphere surrounding the fuel cell system 1 . Figure 3A As shown, the thermal management subsystem 100 can respond to a heating request to heat the fuel cell stack 3 by: (1) controlling the coolant loop 120 to circulate the coolant between the fuel cell stack 3 and the heater 140, that is, placing the coolant loop in a second circulation state; (2) controlling the heater 140 to heat the coolant flowing therethrough; and (3) placing the flow guide mechanism 130 in a first flow guide state, and enabling the fan 112. This operating mode may also be referred to as the third operating mode of the thermal management subsystem 100. In the third operating mode, the coolant circulates between the fuel cell stack 3 and the heater 140, and the coolant transfers the heat generated by the heater 140 to the fuel cell stack 3, thereby heating the fuel cell stack 3. At this time, the coolant in the heat exchanger body 111 and the cooling branch 120a does not flow. The cathode exhaust gas ( Figure 3AThe cathode exhaust gas (schematically indicated by the straight arrow 30 in FIG. 1 ) is guided by the flow guide mechanism 130 to mix with the air driven by the fan 112 and flow through the heat exchanger body 111. Since the outlet temperature of the cathode exhaust gas is higher than the air temperature of the air, the mixed gas driven through the heat exchanger body 111 can heat the coolant in the heat exchanger body 111. This can be advantageous during, for example, a cold start of the fuel cell stack 3. Because the temperature of the mixed gas is higher than the air temperature of the air in the atmospheric environment, the coolant in the heat exchanger body 111 and the cooling branch 120a can be heated. This can increase the temperature of the coolant in the heat exchanger body 111 and the cooling branch 120a, and reduce the viscosity of the coolant in the heat exchanger body 111 and the cooling branch 120a. For example, when the stack 3 switches from cold start to normal operation and the coolant circuit 120 switches from the heating branch 120b to the cooling branch 120a, the energy required for the coolant pump 160 to drive the coolant flow in the heat exchanger body 111 and the cooling branch 120a can be reduced, thereby reducing the power consumption of the thermal management subsystem 100 and improving its working efficiency. The speed of the fan 112 in the third operating mode can be much smaller than the speed of the fan 112 in the first operating mode and the second operating mode.

[0055] Figure 3B FIG. 2 shows the operation of the thermal management subsystem in response to a heating request for heating the fuel cell stack 3 when the outlet temperature of the cathode exhaust gas flowing out of the turbine outlet 6 b is lower than or equal to the air temperature of the air in the atmosphere surrounding the fuel cell system 1 . Figure 3B As shown, the thermal management subsystem 100 can respond to a cooling request for cooling the stack 3 by: (1) controlling the coolant loop 120 to circulate the coolant between the stack 3 and the heater 140, that is, placing the coolant loop in the second circulation state; (2) controlling the heater 140 to heat the coolant flowing therethrough; and (3) placing the flow guide mechanism 130 in the second flow guide state, and deactivating the fan 112. This operating mode may also be referred to as the fourth operating mode of the thermal management subsystem 100. In the fourth operating mode, the coolant circulates between the stack 3 and the heater 140, and the coolant transfers the heat generated by the heater 140 to the stack 3, thereby heating the stack 3. At this time, the coolant in the heat exchanger body 111 and the cooling branch 120a does not flow. The cathode exhaust gas flowing out of the turbine outlet 6b is directed by the flow guide mechanism 130 to a position away from the heat exchanger 110, without exchanging heat with the coolant in the heat exchanger 110, thereby preventing the temperature of the coolant in the heat exchanger 110 from being adversely reduced. The fan 112 is also deactivated and no air is driven through the heat exchanger body 111 .

[0056] In some embodiments, as described above, the fuel cell system 1 or the thermal management subsystem 100 may include a temperature sensor to directly detect the outlet temperature of the cathode exhaust gas flowing out of the turbine outlet 6b. For some fuel cell systems, this approach requires the addition of an additional temperature sensor, resulting in increased costs.

[0057] In some other embodiments, the thermal management subsystem is configured to calculate the outlet temperature of the cathode exhaust gas flowing out of the turbine outlet 6b by the following formula:

[0058]

[0059] Where: T out is the outlet temperature of the cathode exhaust gas flowing out of the turbine outlet 6b, in K; T in is the inlet temperature of the cathode exhaust gas entering the turbine inlet 6a, in K; P out is the outlet pressure of the cathode exhaust gas flowing out of the turbine outlet 6b, in bar; P in is the inlet pressure of the cathode exhaust gas entering the turbine inlet 6a, in bar; η is the efficiency of the turbine, in %; Among them, C p is the constant pressure specific heat capacity of the cathode exhaust gas entering the turbine inlet 6a, in J / (kg·K); C v is the constant-pressure specific heat capacity of the cathode exhaust gas entering the turbine inlet 6a, with the unit of J / (kg·K).

[0060] Specifically, the fuel cell system 1 or the thermal management subsystem 100 may include a temperature sensor to detect the inlet temperature T of the cathode exhaust gas entering the turbine inlet 6a. in , and includes a pressure sensor to detect the outlet pressure P of the cathode exhaust gas flowing out of the turbine outlet 6b out and the inlet pressure P of the cathode exhaust gas entering the turbine inlet 6a in The efficiency η of the turbine and the constant pressure specific heat capacity C of the cathode exhaust gas entering the turbine inlet 6a are p and the constant pressure specific heat capacity C of the cathode exhaust gas entering the turbine inlet 6a v The fuel cell system 1 can be configured to meet different device models and different operating conditions (for example, different inlet temperatures T in , inlet pressure P in , the power generation state of the stack 3) is pre-calibrated and stored in the aforementioned control module or a separate controller in the form of a lookup table, etc. Optionally, the outlet pressure P of the cathode exhaust gas outIt can be regarded as equal to the pressure in the atmosphere, for example, 1 bar. For a fuel cell system 1 that already includes these temperature sensors and pressure sensors, the outlet temperature T of the cathode exhaust gas can be indirectly calculated using the temperature and pressure values ​​measured by these sensors. out , there is no need to add an additional temperature sensor to the fuel cell system 1, thus saving costs.

[0061] Figure 4A and Figure 4B The schematic diagram shows an exemplary type of a part of the devices of the fuel cell system 1. These devices include a compressor 5, a turbine 6, a main line 8, a first branch line 131 and a second branch line 132, and a heat exchanger 110 including a heat exchanger body 111 and a fan 112. Figure 4A and Figure 4B Other devices, pipelines, main routes and branch routes have been omitted to avoid unnecessarily obscuring the present application.

[0062] In some embodiments, Figure 4A and Figure 4B As shown, the fan 112 is configured to drive air in the atmospheric environment along a first direction 40 (eg, Figure 4A ) flows through the heat exchanger body 111, and the flow guide mechanism 130, when placed in the first flow guide state, discharges the cathode exhaust gas flowing out of the turbine outlet 6b at a position upstream of the heat exchanger body 111 along the first direction 40 toward a second direction 50 transverse to the first direction 40. In this way, the cathode exhaust gas can flow transversely to the air driven by the fan 112, thereby promoting the mixing of the cathode exhaust gas and the air driven by the fan 112. This makes it possible to further improve the working efficiency of the thermal management subsystem 100.

[0063] As an example, Figure 4A and Figure 4B As shown, the outlet 134a of the first branch 131 of the flow guide mechanism 130 is arranged upstream of the heat exchanger body 111 in the first direction 40, and is oriented toward a second direction 50 transverse to the first direction 40. The outlet 134a may have an elongated shape and be oriented in such a way that the length of the outlet 134a is perpendicular to the first direction 40. With this configuration, the mixing of the cathode exhaust gas and the air driven by the fan 112 can be further promoted. For example, the main body section of the first branch 131 may be tubular, and the first end of the main body section may be connected to the main line 8 (for example, through a three-way valve, not in Figure 4A and Figure 4B), a diffuser 134 may be provided at the second end of the main body section opposite to the first end. The diffuser 134 may be formed with the aforementioned outlet 134a. The diffuser 134 may make the cross section of the channel for circulating cathode exhaust gas transition from a circular shape to the shape of the outlet 134a. It should be understood that the present application is not limited thereto, and the flow guide mechanism 130 may have any other suitable structure to be configured with such an outlet.

[0064] Although the above description is made in conjunction with a specific embodiment in which the coolant loop 120 of the thermal management subsystem 100 includes a cooling branch 120a and a heating branch 120b, it should be understood that in other embodiments, the coolant loop 120 may not include the heating branch 120b. For example, the coolant loop 120 may only include the cooling branch 120a, which is connected between the stack 3 and the heat exchanger 110. The thermal management subsystem 100 may be configured to respond to a cooling request for cooling the stack 3 by: (1) controlling the coolant loop 120 to circulate the coolant between the stack 3 and the heat exchanger body 111; (2) enabling the fan 112 to drive air to flow through the heat exchanger body 111; and (3) placing the flow guide mechanism 130 in a first flow guide state when the outlet temperature of the cathode exhaust gas is lower than the air temperature of the air, and placing the flow guide mechanism 130 in a second flow guide state when the outlet temperature of the cathode exhaust gas is higher than or equal to the air temperature of the air.

[0065] Although the above description is made in conjunction with a specific embodiment in which the heat exchanger 110 includes a heat exchanger body 111 and a fan 112, it should be understood that the specific type of the heat exchanger 110 is not limited thereto and can be any suitable type of heat exchanger. In addition, in addition to the heat exchanger 110, the coolant circuit 120 can be provided with other heat exchangers.

[0066] Although the above description is made in conjunction with a specific embodiment in which the flow guiding mechanism 130 includes a first branch 131, a second branch 132, and a branch switch 133, it should be understood that the specific type of the flow guiding mechanism 130 is not limited thereto. For example, the flow guiding mechanism 130 may also be a pipeline connected to the cathode exhaust pipeline 42 downstream of the turbine 6 through a three-way valve, or may be a swung air nozzle to guide the cathode exhaust gas to a position adjacent to the heat exchanger 110 and a position away from the heat exchanger 110.

[0067] The inventors also recognize and appreciate a method for thermal management of a fuel cell system. The method may include thermal management of the fuel cell system using the aforementioned thermal management subsystem 100 to adjust the temperature of the stack 3. The method includes switching the flow guide mechanism 130 of the thermal management subsystem 100 between a first flow guide state and a second flow guide state. As described above, when the flow guide mechanism 130 is placed in the first flow guide state, the cathode exhaust gas flowing out of the turbine outlet 6b is directed to the heat exchanger 110 so that the cathode exhaust gas is heat exchanged with the coolant in the heat exchanger 110, and when the flow guide mechanism 130 is placed in the second flow guide state, the cathode exhaust gas flowing out of the turbine outlet 6b is directed to a position away from the heat exchanger 110 without causing the cathode exhaust gas to heat exchange with the coolant in the heat exchanger 110. In this way, the cathode exhaust gas flowing out of the turbine outlet 6 b of the turbine 6 can be selectively heat exchanged with the coolant in the heat exchanger 110 , so that the power consumption of the thermal management subsystem 100 can be reduced and its operating efficiency can be improved, thereby improving the performance and efficiency of the fuel cell system 1 .

[0068] In some embodiments, the method may further include switching the guide mechanism 130 between the first guide state and the second guide state based on a comparison of the outlet temperature of the cathode exhaust gas flowing out of the turbine outlet 6 b and the air temperature of the air in the atmospheric environment surrounding the fuel cell system 1 .

[0069] In one of these embodiments, the method may include, in response to a request to adjust the temperature of the fuel cell stack 3, adjusting the temperature of the fuel cell stack 3 by controlling one or more of the heat exchanger 110, the coolant loop 120, the flow guide mechanism 130 and the heater 140 based on a comparison of the outlet temperature of the cathode exhaust gas flowing out of the turbine outlet 6b with the air temperature of the air in the atmospheric environment surrounding the fuel cell system 1.

[0070] Exemplarily, the method may include, in response to a cooling request to cool the fuel cell stack 3: (1) controlling the coolant loop 120 to circulate the coolant between the fuel cell stack 3 and the heat exchanger body 111 of the heat exchanger 110, i.e., placing the coolant loop 120 in a first circulation state; (2) enabling the fan 112 to drive air in the atmospheric environment to flow through the heat exchanger body 111; and (3) based on a comparison of the outlet temperature of the cathode exhaust gas flowing out of the turbine outlet 6b with the air temperature of the air in the atmospheric environment surrounding the fuel cell system 1, when the outlet temperature of the cathode exhaust gas is lower than the air temperature of the air, placing the flow diversion mechanism 130 in a first flow diversion state, and when the outlet temperature of the cathode exhaust gas is higher than or equal to the air temperature of the air, placing the flow diversion mechanism 130 in a second flow diversion state.

[0071] Exemplarily, the method may include, in response to a heating request to heat the fuel cell stack 3: (1) controlling the coolant loop 120 to circulate the coolant between the fuel cell stack 3 and the heater 140, i.e., placing the coolant loop in a second circulation state; (2) controlling the heater 140 to heat the coolant flowing therethrough; and (3) based on a comparison of the outlet temperature of the cathode exhaust gas flowing out of the turbine outlet 6b with the air temperature of the air in the atmospheric environment surrounding the fuel cell system 1, when the outlet temperature of the cathode exhaust gas is higher than the air temperature of the air, placing the flow diversion mechanism 130 in a first flow diversion state and enabling the fan 112, and when the outlet temperature of the cathode exhaust gas is lower than or equal to the air temperature of the air, placing the flow diversion mechanism 130 in a second flow diversion state and deactivating the fan 112.

[0072] Figure 5 FIG. 1 is a flow chart schematically showing a method for thermal management of a fuel cell system 1. Figure 5 As shown, in step S101 , the thermal management subsystem 100 may receive a request for regulating the temperature of the fuel cell stack 3 .

[0073] Next, in step S102, the thermal management subsystem 100 may determine whether the request is a cooling request to cool the battery stack 3 or a heating request to heat the battery stack 3. In response to the request being a cooling request to cool the battery stack 3, the process proceeds to step S103. In response to the request being a heating request to heat the battery stack 3, the process proceeds to step S104.

[0074] In step S103, the thermal management subsystem 100 selects a temperature control unit based on a comparison between the outlet temperature of the cathode exhaust gas flowing out of the turbine outlet 6b and the air temperature of the air in the atmosphere surrounding the fuel cell system 1. Figure 2A The first operating mode shown or Figure 2B The second operation mode shown. When the outlet temperature of the cathode exhaust gas is lower than the air temperature of the air, go to step S105. In step S105, the thermal management subsystem 100 operates in the first operation mode. When the outlet temperature of the cathode exhaust gas is higher than or equal to the air temperature of the air, go to step S106. In step S106, the thermal management subsystem 100 operates in the second operation mode.

[0075] In step S104, the thermal management subsystem 100 selects a temperature control unit based on a comparison between the outlet temperature of the cathode exhaust gas flowing out of the turbine outlet 6b and the air temperature of the air in the atmosphere surrounding the fuel cell system 1. Figure 3A The third operating mode shown or Figure 3BThe fourth operation mode shown. When the outlet temperature of the cathode exhaust gas is higher than the air temperature of the air, go to step S107. In step S107, the thermal management subsystem 100 operates in the third operation mode. When the outlet temperature of the cathode exhaust gas is lower than or equal to the air temperature of the air, go to step S108. In step S108, the thermal management subsystem 100 operates in the fourth operation mode.

[0076] It should be understood that the method described above can be an executable program instruction, and the executable program instruction is stored on a machine-readable non-volatile storage medium. The various steps and technical details of the method described above can be stored in the control unit in the form of software, or implemented in the form of a combination of software and hardware. The present application also relates to a machine-readable storage medium, which stores executable instructions, which, when executed, cause the processor to perform the above method.

[0077] In addition, the terms “first,” “second,” “third,” and “fourth” are only used to distinguish one element, device or state from another element, device or state, but these elements, devices and states should not be limited by such terms.

[0078] The present application has been described in detail above in conjunction with specific embodiments. Obviously, the above description and the embodiments shown in the accompanying drawings should be understood as exemplary and do not constitute a limitation to the present application. For those skilled in the art, various modifications or changes can be made to the present application without departing from the spirit of the present application, and these modifications or changes do not depart from the scope of the present application.

Claims

1. A thermal management subsystem (100) for a fuel cell system, characterized in that: The fuel cell system comprises a fuel cell stack (3), a cathode exhaust pipeline (42) arranged to receive cathode exhaust gas from the fuel cell stack, and a turbine (6) arranged on the cathode exhaust pipeline to be driven by the cathode exhaust gas, wherein the thermal management subsystem comprises: Heat exchanger (110); a coolant circuit (120) configured to be connected between the fuel cell stack and the heat exchanger and capable of circulating a coolant between the fuel cell stack and the heat exchanger; and A flow guiding mechanism (130), the flow guiding mechanism being configured to be connected to a turbine outlet (6b) of the turbine and being switchable between a first flow guiding state and a second flow guiding state, wherein the flow guiding mechanism guides the cathode exhaust gas flowing out of the turbine outlet to the heat exchanger when placed in the first flow guiding state so that the cathode exhaust gas exchanges heat with the coolant in the heat exchanger, and guides the cathode exhaust gas flowing out of the turbine outlet to a position away from the heat exchanger without exchanging heat between the cathode exhaust gas and the coolant in the heat exchanger when placed in the second flow guiding state.

2. The thermal management subsystem according to claim 1, characterized in that: The heat exchanger comprises a heat exchanger body (111) and a fan (112), the coolant circuit is configured to be connected between the fuel cell stack and the heat exchanger body, and can circulate the coolant between the fuel cell stack and the heat exchanger body, the fan is configured to drive air in the atmospheric environment surrounding the fuel cell system to flow through the heat exchanger body when enabled so that the air exchanges heat with the coolant in the heat exchanger body, and stop driving the air when disabled; The flow guide mechanism is configured to guide the cathode exhaust gas flowing out of the turbine outlet when placed in the first flow guide state so that the cathode exhaust gas is mixed with the air driven by the fan and flows through the heat exchanger body; as well as The thermal management subsystem is configured to switch the flow guiding mechanism between the first flow guiding state and the second flow guiding state based on a comparison of an outlet temperature of cathode exhaust gas flowing out of the turbine outlet and an air temperature of air in the atmospheric environment.

3. The thermal management subsystem according to claim 2, characterized in that: The thermal management subsystem is configured to respond to a cooling request to cool the stack: (i) controlling the coolant circuit to allow the coolant to circulate between the fuel cell stack and the heat exchanger body; (ii) activating the fan to drive air through the heat exchanger body; and (iii) when the outlet temperature is lower than the air temperature, the flow guiding mechanism is placed in the first flow guiding state, and when the outlet temperature is higher than or equal to the air temperature, the flow guiding mechanism is placed in the second flow guiding state.

4. The thermal management subsystem according to claim 2, characterized in that: The coolant circuit comprises a cooling branch (120a) and a heating branch (120b), the heat exchanger body is arranged on the cooling branch, the thermal management subsystem further comprises a heater (140), the heater is arranged on the heating branch and is configured to heat the coolant when the coolant flows through the heater, the coolant circuit is configured to switch between a first circulation state and a second circulation state, when placed in the first circulation state, the cooling branch is connected and the heating branch is closed, and the coolant circulates between the battery stack and the heat exchanger body, when placed in the second circulation state, the heating branch is connected and the cooling branch is closed, and the coolant circulates between the battery stack and the heater; and The thermal management subsystem is configured to respond to a heating request to heat the stack: (i) placing the coolant circuit in the second circulation state so that the coolant circulates between the fuel cell stack and the heater; (ii) controlling the heater to heat the coolant flowing therethrough; and (iii) when the outlet temperature is higher than the air temperature, placing the air guide mechanism in the first air guide state and activating the fan; and when the outlet temperature is lower than or equal to the air temperature, placing the air guide mechanism in the second air guide state and deactivating the fan.

5. The thermal management subsystem according to any one of claims 2 to 4, characterized in that: The fan is configured to drive the air to flow through the heat exchanger body along a first direction (40), and the guide mechanism is configured to discharge the cathode exhaust gas flowing out of the turbine outlet in a second direction (50) transverse to the first direction at a position upstream of the heat exchanger body along the first direction when placed in the first guide state.

6. The thermal management subsystem according to any one of claims 2 to 4, characterized in that: The flow guiding mechanism comprises a first branch (131), a second branch (132) and a branch switch (133), wherein the first branch is configured to communicate with the turbine outlet and, when turned on, guides the cathode exhaust gas flowing out of the turbine outlet to the heat exchanger so that the cathode exhaust gas exchanges heat with the coolant in the heat exchanger, and when turned off, blocks the cathode exhaust gas from passing through the branch, and the second branch is configured to communicate with the turbine outlet and, when turned on, guides the cathode exhaust gas flowing out of the turbine outlet to the heat exchanger. The branch switch is located away from the heat exchanger so that the cathode exhaust gas does not exchange heat with the coolant in the heat exchanger, and when closed, the cathode exhaust gas is blocked from passing through it. The branch switch is configured to be able to switch between a first state and a second state. When placed in the first state, the first branch is connected and the second branch is closed, so that the diversion mechanism is placed in the first diversion state. When placed in the second state, the second branch is connected and the first branch is closed, so that the diversion mechanism is placed in the second diversion state.

7. The thermal management subsystem according to claim 6, characterized in that: The fan is configured to drive the air to flow through the heat exchanger body along a first direction (40), and the outlet (134a) of the first branch is arranged upstream of the heat exchanger body in the first direction and is oriented in a second direction (50) transverse to the first direction.

8. The thermal management subsystem according to claim 7, characterized in that: The outlet has an elongated shape, and the outlet is oriented in such a way that the length of the outlet is perpendicular to the first direction.

9. The thermal management subsystem according to any one of claims 2 to 4, characterized in that: The thermal management subsystem is configured to calculate the outlet temperature by the following formula: Among them, T out is the outlet temperature, T in is the inlet temperature of the cathode exhaust gas entering the turbine inlet of the turbine, P out is the outlet pressure of the cathode exhaust gas flowing out of the turbine outlet, P in is the inlet pressure of the cathode exhaust gas entering the turbine inlet, η is the efficiency of the turbine, Among them, C p is the constant pressure specific heat capacity of the cathode exhaust gas entering the turbine inlet, C v is the constant volume specific heat capacity of the cathode exhaust gas entering the turbine inlet.

10. A fuel cell system, characterized in that: The fuel cell system comprises: Battery stack (3); a cathode exhaust line (42) configured to receive cathode exhaust gas from the stack; a turbine (6) disposed on the cathode exhaust line to be driven by the cathode exhaust gas; and According to the thermal management subsystem (100) according to any one of claims 1 to 9, the coolant circuit (120) is connected between the fuel cell stack and the heat exchanger (110), and the flow guide mechanism (130) is connected to the turbine outlet (6b) of the turbine.

11. A method for thermal management of a fuel cell system, characterized in that: The fuel cell system comprises a fuel cell stack (3), a cathode exhaust pipeline (42) arranged to receive cathode exhaust gas from the fuel cell stack, a turbine (6) arranged on the cathode exhaust pipeline to be driven by the cathode exhaust gas, and a thermal management subsystem (100), wherein the thermal management subsystem comprises: Heat exchanger (110); a coolant circuit (120) connected between the fuel cell stack and the heat exchanger and capable of circulating a coolant between the fuel cell stack and the heat exchanger; and a flow guiding mechanism (130), the flow guiding mechanism being connected to a turbine outlet (6b) of the turbine and being switchable between a first flow guiding state and a second flow guiding state, wherein the flow guiding mechanism guides cathode exhaust gas flowing out of the turbine outlet to the heat exchanger when placed in the first flow guiding state so that the cathode exhaust gas exchanges heat with a coolant in the heat exchanger, and guides cathode exhaust gas flowing out of the turbine outlet to a position away from the heat exchanger without exchanging heat between the cathode exhaust gas and the coolant in the heat exchanger when placed in the second flow guiding state; and The method includes switching the flow guiding mechanism between the first flow guiding state and the second flow guiding state.

12. The method according to claim 11, characterized in that: The heat exchanger comprises a heat exchanger body (111) and a fan (112), the coolant circuit is connected between the fuel cell stack and the heat exchanger body, and can circulate the coolant between the fuel cell stack and the heat exchanger body, the fan is configured to drive air in the atmospheric environment surrounding the fuel cell system to flow through the heat exchanger body when enabled so as to exchange heat between the air and the coolant in the heat exchanger body, and stop driving the air when disabled; The flow guide mechanism is configured to guide the cathode exhaust gas flowing out of the turbine outlet so that the cathode exhaust gas is mixed with the air driven by the fan and flows through the heat exchanger body when placed in the first flow guide state; and Switching the flow guide mechanism between the first flow guide state and the second flow guide state includes switching the flow guide mechanism between the first flow guide state and the second flow guide state based on a comparison of an outlet temperature of cathode exhaust gas flowing out of the turbine outlet and an air temperature of air in the atmospheric environment.

13. The method according to claim 12, characterized in that The method includes, in response to a cooling request to cool the stack: (i) controlling the coolant circuit to allow the coolant to circulate between the fuel cell stack and the heat exchanger body; (ii) activating the fan to drive air through the heat exchanger body; and (iii) when the outlet temperature is lower than the air temperature, the flow guiding mechanism is placed in the first flow guiding state, and when the outlet temperature is higher than or equal to the air temperature, the flow guiding mechanism is placed in the second flow guiding state.

14. The method according to claim 12, characterized in that: The coolant circuit comprises a cooling branch (120a) and a heating branch (120b), the heat exchanger body is arranged on the cooling branch, the thermal management subsystem further comprises a heater (140), the heater is arranged on the heating branch and is configured to heat the coolant when the coolant flows through the heater, the coolant circuit is configured to switch between a first circulation state and a second circulation state, when placed in the first circulation state, the cooling branch is connected and the heating branch is closed, and the coolant circulates between the battery stack and the heat exchanger body, when placed in the second circulation state, the heating branch is connected and the cooling branch is closed, and the coolant circulates between the battery stack and the heater; and The method includes, in response to a heating request to heat the stack: (i) placing the coolant circuit in the second circulation state so that the coolant circulates between the fuel cell stack and the heater; (ii) controlling the heater to heat the coolant flowing therethrough; and (iii) when the outlet temperature is higher than the air temperature, placing the air guide mechanism in the first air guide state and activating the fan; and when the outlet temperature is lower than or equal to the air temperature, placing the air guide mechanism in the second air guide state and deactivating the fan.

Images