Fuel cell thermal management system

Abstract

The application discloses a fuel cell thermal management system. The fuel cell thermal management system comprises a stack temperature control loop, a sensor module arranged on the stack temperature control loop, and a controller connected with the sensor module and the stack temperature control loop. The stack temperature control loop comprises a temperature control main loop connected with a fuel cell, an expansion water tank and a first water pump connected with the temperature control main loop, a low-temperature heat dissipation loop connected with the first water pump, and a second water pump connected with the low-temperature heat dissipation loop and the temperature control main loop. The expansion water tank is connected with the first water pump. The sensor module is arranged on the temperature control main loop. The first water pump and the second water pump are connected with the controller.

Description

Technical Field

[0001] This invention relates to the field of fuel cell auxiliary management technology, and in particular to a fuel cell thermal management system. Background Technology

[0002] Fuel cell vehicles are automobiles powered by fuel cells. Because fuel cells use fuel and oxygen as raw materials and have no mechanical transmission components, fuel cell vehicles have the advantages of less gas and noise pollution during operation. A fuel cell is a chemical device that directly converts the chemical energy of fuel into electrical energy through an electrochemical reaction.

[0003] In a fuel cell, multiple individual cells are stacked in series to form a fuel cell stack, which is the site of electrochemical reactions. Because the fuel cell stack generates significant heat during these reactions, a stack temperature control loop is required to prevent damage from excessive heat. This loop uses coolant flowing through it to dissipate the heat generated by the fuel cell. A water pump controls the coolant flow within the loop to achieve heat dissipation. However, high pump head can put excessive pressure on components connected to the pump outlet, posing a risk of leakage during long-term operation and affecting component lifespan. Especially when the water pump is located at the fuel cell stack inlet, the stack's pressure resistance is limited, necessitating restrictions on the pump speed, which in turn affects the heat dissipation effect of the fuel cell thermal management system. Summary of the Invention

[0004] This invention provides a fuel cell thermal management system to address the problem that current fuel cell thermal management systems suffer from excessive pressure on components connected to the water pump during heat dissipation, which affects service life and heat dissipation efficiency.

[0005] A fuel cell thermal management system includes a stack temperature control circuit, a sensor module disposed on the stack temperature control circuit, and a controller connected to the sensor module and the stack temperature control circuit. The stack temperature control circuit includes a main temperature control circuit connected to the fuel cell, an expansion tank and a first water pump connected to the main temperature control circuit, a low-temperature heat dissipation circuit connected to the first water pump, and a second water pump connected to the low-temperature heat dissipation circuit and the main temperature control circuit. The expansion tank is connected to the first water pump. The sensor module is disposed on the main temperature control circuit. The first water pump and the second water pump are connected to the controller.

[0006] Preferably, the temperature control main circuit includes a first temperature control branch and a second temperature control branch connected in parallel; the first temperature control branch includes a battery stack, the inlet of which is connected to the second water pump, and the outlet of which is connected to the expansion tank and the first water pump; the second temperature control branch includes an ion exchanger and a water-air cooler connected in series, one end of which is connected to the second water pump, and one end of which is connected to the expansion tank and the first water pump.

[0007] Preferably, the temperature control main circuit further includes a third temperature control branch connected in parallel with the first temperature control branch and the second temperature control branch; the third temperature control branch includes an electric two-way valve and an anode heat exchanger connected in series; the electric two-way valve is connected to the controller, and one end of the electric two-way valve is connected to the second water pump; one end of the anode heat exchanger is connected to the expansion tank and the first water pump.

[0008] Preferably, the first temperature control branch further includes a particulate filter connected in series with the battery stack, and the particulate filter is disposed at the water inlet of the battery stack.

[0009] Preferably, the sensor module includes a first temperature and pressure sensor disposed at the water inlet of the battery stack and a second temperature and pressure sensor disposed at the water outlet of the battery stack.

[0010] Preferably, the low-temperature heat dissipation circuit includes a heat dissipation branch, an energy storage branch, and a heat exchange branch arranged in parallel; the heat dissipation branch, the energy storage branch, and the heat exchange branch are connected to the second water pump through an electric four-way valve; the first water pump is connected to the heat dissipation branch, the energy storage branch, and the heat exchange branch, or the first water pump is installed on the heat dissipation branch.

[0011] Preferably, the heat dissipation branch includes a battery radiator, and the output end of the battery radiator is connected to the expansion tank.

[0012] Preferably, the energy storage branch includes a phase change energy storage device.

[0013] Preferably, the heat exchange branch includes a heat exchanger and a heat exchange control loop connected to the heat exchanger.

[0014] Preferably, the heat exchange control circuit is a warm air control circuit, which includes an electric heater, a warm air radiator, a warm air kettle, and a warm air water pump connected in series with the heat exchanger.

[0015] This invention provides a fuel cell thermal management system in which a temperature control main circuit, a first water pump, a low-temperature heat dissipation circuit, and a second water pump are connected in series. The first water pump is positioned between the temperature control main circuit and the low-temperature heat dissipation circuit, and the second water pump is positioned between the low-temperature heat dissipation circuit and the temperature control main circuit. Based on the sensor measurement data of the temperature control main circuit collected in real time by the sensor module, the rotation speeds of the first and second water pumps are adjusted respectively to control the inflow rate and inflow pressure of the coolant in the fuel cell stack temperature control circuit. This ensures pressure balance in the fuel cell stack temperature control circuit and avoids problems such as excessively high local pressure and uncontrollable inflow pressure. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of a fuel cell thermal management system according to one embodiment of the present invention;

[0018] Figure 2 This is another schematic diagram of a fuel cell thermal management system in one embodiment of the present invention;

[0019] Figure 3 This is a schematic diagram of an electric four-way valve in one embodiment of the present invention.

[0020] In the diagram: 10. Temperature control main circuit; 11. Battery stack; 12. Particulate filter; 13. Ion exchanger; 14. Water-air cooler; 15. Electric two-way valve; 16. Anode heat exchanger; 20. Expansion tank; 30. First water pump; 40. Low-temperature heat dissipation circuit; 41. Battery radiator; 42. Phase change energy storage device; 43. Heat exchanger; 44. Electric heater; 45. Warm air radiator; 46. Warm air kettle; 47. Warm air water pump; 50. Second water pump; 60. Electric four-way valve; 61. First circulation interface; 62. Second circulation interface; 63. Third circulation interface; 64. Fourth circulation interface; 71. First temperature and pressure sensor; 72. Second temperature and pressure sensor. Detailed Implementation

[0021] To make the technical problems solved, technical solutions, and beneficial effects of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0022] In the description of this invention, it should be understood that the terms "longitudinal," "radial," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0023] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0024] Figure 1 and Figure 2 This invention illustrates a fuel cell thermal management system according to an embodiment of the present invention. The fuel cell thermal management system includes a stack temperature control loop, a sensor module disposed on the stack temperature control loop, and a controller connected to the sensor module and the stack temperature control loop. The stack temperature control loop includes a main temperature control loop 10 connected to the fuel cell, an expansion tank 20 connected to the main temperature control loop 10, a first water pump 30, a low-temperature heat dissipation loop 40 connected to the first water pump 30, and a second water pump 50 connected to the low-temperature heat dissipation loop 40 and the main temperature control loop 10. The expansion tank 20 is connected to the first water pump 30. The sensor module is disposed on the main temperature control loop 10. The first water pump 30 and the second water pump 50 are connected to the controller.

[0025] The fuel cell stack temperature control loop is a circuit connected to the fuel cell to control its temperature, preventing excessive heat generation during the electrochemical reaction from damaging the fuel cell. In this example, the stack temperature control loop controls temperature through heat conduction via coolant pipes. The coolant pipes are used to transport coolant; understandably, temperature control in the stack temperature control loop is achieved through heat conduction via the coolant flowing within these pipes.

[0026] The sensor module is a functional module installed in the fuel cell stack temperature control loop to collect sensor measurement data such as temperature and pressure. The controller is a device in the fuel cell thermal management system used to achieve temperature control.

[0027] As an example, the sensor module collects sensor measurement data such as water temperature and water pressure values ​​in the fuel cell stack temperature control loop in real time and sends the sensor measurement data to the controller. The controller queries N preset control logics based on the received sensor measurement data, determines the preset control logic that matches the sensor measurement data as the target control logic, and controls the electrical components in the fuel cell stack temperature control loop according to the target control logic to achieve temperature control of the fuel cell, avoid the fuel cell temperature from being too high, which would affect the normal use of the fuel cell and reduce the service life of the fuel cell.

[0028] The temperature control main circuit 10 is the part of the fuel cell stack temperature control circuit that is connected to the fuel cell. That is, the temperature control main circuit 10 is in contact with the fuel cell so that heat can be transferred through the temperature control main circuit 10. Since the temperature control main circuit 10 is connected to the fuel cell, the coolant flowing through the temperature control main circuit 10 can carry away the heat generated during the operation of the fuel cell each time temperature regulation is performed, thereby achieving the purpose of temperature regulation.

[0029] The expansion tank 20 is a component in the fuel cell thermal management system used to store and supply coolant, which is a fuel cell-specific coolant. The expansion tank 20 can accommodate water expansion, reducing water pressure fluctuations in the fuel cell thermal management system caused by water expansion, thus improving the safety and reliability of system operation. It also replenishes water to the fuel cell thermal management system when leakage or cooling causes a drop in the water level in the expansion tank 20. Furthermore, it helps stabilize the system pressure of the fuel cell thermal management system and remove air released during the heating process.

[0030] like Figure 1 and Figure 2 As shown, the first water pump 30 and the expansion tank 20 are located at the outlet of the temperature control main circuit 10. Specifically, the temperature control main circuit 10 is connected to the first water pump 30 through a liquid delivery pipe, and the temperature control main circuit 10 is connected to the expansion tank 20 through an overflow pipe. The expansion tank 20 is connected to the first water pump 30 through a water supply pipe. During temperature regulation, the high-temperature coolant output from the outlet of the temperature control main circuit 10 can be transported to the first water pump 30 through the liquid delivery pipe, and then input into the low-temperature heat dissipation circuit 40 for heat dissipation and cooling. Furthermore, the gaseous coolant overflowing from the outlet of the temperature control main circuit 10 can be input into the expansion tank 20 through the overflow pipe, so that the coolant can be recycled using the expansion tank 20, ensuring the safety and reliability of the system operation.

[0031] The cryogenic heat dissipation circuit 40 is a circuit in the fuel cell stack temperature control circuit used to achieve the cooling and heat dissipation function. In this example, the temperature control main circuit 10 and the cryogenic heat dissipation circuit 40 are connected by a coolant pipe, so that the coolant in the coolant pipe flows between the temperature control main circuit 10 and the cryogenic heat dissipation circuit 40. The high-temperature coolant output from the temperature control main circuit 10 connected to the fuel cell is input into the cryogenic heat dissipation circuit 40, cooled by the cryogenic heat dissipation circuit 40, and then output as cryogenic coolant, which is then input back into the temperature control main circuit 10 to reduce the temperature of the fuel cell.

[0032] The first water pump 30 and the second water pump 50 are electronic water pumps used to control the flow rate of coolant in the fuel cell stack temperature control loop, thereby regulating the temperature of the fuel cell. As an example, the first water pump 30 is located between the outlet of the main temperature control loop 10 and the low-temperature heat dissipation loop 40, and the second water pump 50 is located between the low-temperature heat dissipation loop 40 and the inlet of the main temperature control loop 10. A controller is connected to the first water pump 30 and the second water pump 50. The controller can determine the target control logic based on the sensor measurement data collected in real time by the sensor module on the fuel cell stack temperature control loop, and control the rotation speed of the first water pump 30 and the second water pump 50 respectively, thereby controlling the inflow rate and inflow pressure of the coolant in the fuel cell stack temperature control loop, ensuring pressure balance in the fuel cell stack temperature control loop, and avoiding problems such as excessively high local pressure and uncontrollable inflow pressure. Understandably, the rotation speeds of the first water pump 30 and the second water pump 50 can be the same or different.

[0033] In the fuel cell thermal management system provided in this embodiment, the temperature control main circuit 10, the first water pump 30, the low-temperature heat dissipation circuit 40, and the second water pump 50 are connected in series. The first water pump 30 is located between the temperature control main circuit 10 and the low-temperature heat dissipation circuit 40, and the second water pump 50 is located between the low-temperature heat dissipation circuit 40 and the temperature control main circuit 10. Based on the sensor measurement data of the temperature control main circuit 10 collected in real time by the sensor module, the rotation speed of the first water pump 30 and the second water pump 50 can be adjusted respectively to control the inflow rate and inflow pressure of the coolant in the stack temperature control circuit, ensuring pressure balance in the stack temperature control circuit and avoiding problems such as excessive local pressure and uncontrollable inflow pressure.

[0034] In one embodiment, such as Figure 1 and Figure 2 As shown, the temperature control main circuit 10 includes a first temperature control branch and a second temperature control branch connected in parallel; the first temperature control branch includes a battery stack 11, the water inlet of the battery stack 11 is connected to the second water pump 50, and the water outlet of the battery stack 11 is connected to the expansion tank 20 and the first water pump 30; the second temperature control branch includes an ion exchanger 13 and a water-air cooler 14 connected in series, one end of the ion exchanger 13 is connected to the second water pump 50, and one end of the water-air cooler 14 is connected to the expansion tank 20 and the first water pump 30.

[0035] The first temperature control branch is a branch connected to the fuel cell for transmitting coolant. Specifically, the first temperature control branch includes the fuel cell stack 11, specifically referring to the branch used to connect to the fuel cell stack 11 for temperature regulation. When the fuel cell thermal management system is operating, low-temperature coolant flows into the fuel cell stack 11 from its inlet. As the coolant flows through the fuel cell stack 11, it undergoes heat conduction, causing the coolant temperature to rise and the fuel cell stack 11 temperature to drop. This allows high-temperature coolant to flow out from the fuel cell stack 11's outlet, thus achieving the purpose of regulating the temperature of the fuel cell stack 11.

[0036] The second temperature control branch is a branch connected to the fuel cell for transmitting coolant. Specifically, the second temperature control branch includes an ion exchanger 13 and a water-air intercooler 14 connected in series. One end of the ion exchanger 13 is connected to the second water pump 50, and the other end is connected to the water-air intercooler 14. One end of the water-air intercooler 14 is connected to the ion exchanger 13, and the other end is connected to the expansion tank 20 and the first water pump 30. When the fuel cell thermal management system is working, the low-temperature coolant in the coolant pipeline flows in from the inlet of the ion exchanger 13, and then flows from the ion exchanger 13 into the water-air intercooler 14. The ion exchanger 13 reduces the conductivity of the coolant, and the water-air intercooler 14 reduces the inlet temperature of the battery stack 11, thereby achieving temperature regulation of the second temperature control branch containing the ion exchanger 13 and the water-air intercooler 14 using coolant.

[0037] Specifically, the ion exchanger 13 can be a resin tank containing ion exchange resin particles. A filter screen can be installed inside the resin tank, and an exchanger inlet and an exchanger outlet are located on both sides of the resin tank. Understandably, the ion exchange resin particles inside the ion exchanger 13 are ion exchange agents, and the ion exchanger 13 can restore its ion exchange capacity through regeneration after the ion exchange agents become ineffective. The water-air cooler 14 uses water as the cooling medium to cool the pressurized air at the air compressor outlet, ensuring that the air temperature entering the battery stack 11 meets the operating requirements of the battery stack 11.

[0038] In the fuel cell thermal management system provided in this embodiment, the fuel cell stack 11 is the site of electrochemical reactions in the fuel cell, generating significant heat during operation. A first temperature control branch is formed based on the fuel cell stack 11, and it is not connected in series with other devices that generate energy during operation, thus helping to ensure the efficiency and effectiveness of temperature control for the fuel cell stack 11. Since the flow rate requirements of the ion exchanger 13 and the water-to-air intercooler 14 are close during temperature control, connecting the ion exchanger 13 and the water-to-air intercooler 14 in series effectively reduces coolant flow loss. Furthermore, the second temperature control branch formed by the series connection of the ion exchanger 13 and the water-to-air intercooler 14 is connected in parallel with the first temperature control branch, preventing interference from the first temperature control branch during temperature control, thus helping to ensure the efficiency and effectiveness of temperature control for the second temperature control branch. For example, if the ion exchanger 13 or the water-air cooler 14 is connected in series with the battery stack 11, the low-temperature coolant input to the inlet of the battery stack 11 will be the high-temperature coolant output from the outlet of the ion exchanger 13 and the water-air cooler 14. The temperature of the coolant is higher than that of the low-temperature coolant input to the inlet of the battery stack 11 by the second water pump 50. This will result in the battery stack 11 requiring more coolant flow and being less efficient in the heat dissipation and cooling process.

[0039] Furthermore, connecting the ion exchanger 13 and the water-to-air intercooler 14 in series in the second temperature control branch can avoid the problem of increased system flow demand and large flow resistance loss caused by the ion exchanger 13 and the water-to-air intercooler 14 occupying a single working branch. For example, if the total coolant flow demand received at the inlet of the temperature control main circuit 10 is S, the coolant flow demand in the first temperature control branch is I1, and the coolant flow demand in the second temperature control branch is I2, then the flow demand through both the ion exchanger 13 and the water-to-air intercooler 14 is I2. Therefore, the system flow demand required by the first and second temperature control branches is S = I1 + I2. Accordingly, if the ion exchanger 13 and the water-to-air intercooler 14 are connected in parallel with the battery stack 11 to form three temperature control branches, then if the total coolant flow rate received at the inlet of the temperature control main circuit 10 is S, the coolant flow rate requirement on the first temperature control branch is I1, and the coolant flow rate requirements flowing through the ion exchanger 13 and the water-to-air intercooler 14 are respectively I1, I2, and I3, I4, I5, I6, I7, I8, I9 ... 21 and I 22 Then the system traffic demand is S = I1 + I 21 +I 22 Since the flow rate requirement of ion exchanger 13 is close to that of water-air cooler 14 during temperature regulation, then I 21 ≈I 22≈I2, therefore it is determined that connecting the ion exchanger 13 and the water-air cooler 14 in parallel with the battery stack 11 will lead to an increase in system flow demand, that is, the ion exchanger 13 and the water-air cooler 14 occupying a working branch alone will result in a large waste.

[0040] In one embodiment, such as Figure 1 and Figure 2 As shown, the temperature control main circuit 10 also includes a third temperature control branch connected in parallel with the first and second temperature control branches; the third temperature control branch includes an electric two-way valve 15 and an anode heat exchanger 16 connected in series; the electric two-way valve 15 is connected to the controller, and one end of the electric two-way valve 15 is connected to the second water pump 50; one end of the anode heat exchanger 16 is connected to the expansion tank 20 and the first water pump 30.

[0041] The third temperature control branch is a branch connected to the fuel cell for transmitting coolant. This third temperature control branch is connected in parallel with the first and second temperature control branches to avoid mutual interference during temperature control and to ensure the efficiency and effectiveness of temperature regulation by each branch. The third temperature control branch includes an electrically operated two-way valve 15 and an anode heat exchanger 16 connected in series. One end of the electrically operated two-way valve 15 is connected to the second water pump 50, and the other end is connected to the anode heat exchanger 16. One end of the anode heat exchanger 16 is connected to the electrically operated two-way valve 15, and the other end is connected to the expansion tank 20 and the first water pump 30.

[0042] In this example, the electrically operated two-way valve 15 is a two-way valve used to control the valve body opening. This electrically operated two-way valve 15 is connected to the controller and is used to control the opening or closing of the electrically operated two-way valve 15 based on sensor measurement data collected by the sensor module, thereby determining whether to connect the anode heat exchanger 16 in parallel with the first and second temperature control branches for temperature regulation. The anode heat exchanger 16 is an exchanger used to realize heat exchange between the coolant and the anode hydrogen gas; specifically, the anode heat exchanger 16 can be a plate heat exchanger.

[0043] In this embodiment, the electric two-way valve 15 and the anode heat exchanger 16 are connected in series to form a third temperature control branch. This branch controls the opening or closing of the electric two-way valve 15 based on the sensor measurement data collected in real time by the sensor module. This ensures that the temperature during anode heating is controlled, allowing the anode heating process to better adapt to the working environment. For example, when the working environment temperature of the fuel cell is low, the anode heat exchanger 16 needs to operate. In this case, the opening degree of the electric two-way valve 15 can be controlled to regulate the flow rate of coolant through the anode heat exchanger 16, making the temperature of the hydrogen entering the stack close to the temperature of the coolant. This avoids the generation of condensate during the mixing of low-temperature and high-temperature gases, thereby ensuring the reliability of the anode operation. Conversely, when the working environment temperature of the fuel cell is high, the hydrogen entering the stack also has a high operating temperature, and the anode heat exchanger 16 does not need to operate. The electric two-way valve 15 can be closed, preventing the coolant from passing through the anode heat exchanger 16 and reducing unnecessary flow loss.

[0044] In one embodiment, such as Figure 1 and Figure 2 As shown, the first temperature control branch also includes a particulate filter 12 connected in series with the battery stack 11. The particulate filter 12 is located at the water inlet of the battery stack 11. This particulate filter 12 is a device used to perform filtration. In this example, the particulate filter 12 is connected in series with the battery stack 11 to form the first temperature control branch. Specifically, the particulate filter 12 is located at the water inlet of the battery stack 11 so that the coolant entering through the coolant pipe must flow through the particulate filter 12 before flowing into the battery stack 11, thereby filtering out fixed impurity particles in the coolant. It is understandable that integrating the particulate filter 12 into the first temperature control branch where the battery stack 11 is located, rather than between the second water pump 50 and the temperature control main circuit 10, avoids the significant flow resistance loss caused by placing it in the temperature control main circuit 10. Furthermore, integrating the particulate filter 12 into the first temperature control branch where the battery stack 11 is located helps save layout space and facilitates replacement. In this example, the particulate filter 12 is specifically a Y-type particulate filter 12, which can be connected to the stack manifold of the battery stack 11. It can replace the filter element without draining the coolant, making the filter element replacement process simple and convenient.

[0045] In one embodiment, such as Figure 1 and Figure 2 As shown, the sensor module includes a first temperature and pressure sensor 71 disposed at the water inlet of the battery stack 11 and a second temperature and pressure sensor 72 disposed at the water outlet of the battery stack 11.

[0046] The first temperature and pressure sensor 71 and the second temperature and pressure sensor 72 are integrated temperature and pressure sensors capable of collecting both temperature and pressure data. Since the fuel cell stack 11 generates the most heat during operation and has a greater impact on temperature control, the first temperature and pressure sensor 71 is placed at the water inlet of the fuel cell stack 11, and the second temperature and pressure sensor 72 is placed at the water outlet. This allows the first and second sensors 71 and 72 to collect real-time temperature and pressure data from both ends of the fuel cell stack 11. This makes the temperature control process based on sensor data more precise and effectively prevents the heat generated by the fuel cell stack 11 from damaging the fuel cell.

[0047] In one embodiment, such as Figure 1 and Figure 2 As shown, the low-temperature heat dissipation circuit 40 includes a heat dissipation branch, an energy storage branch, and a heat exchange branch arranged in parallel; the heat dissipation branch, the energy storage branch, and the heat exchange branch are connected to the second water pump 50 through an electric four-way valve 60; the first water pump 30 is connected to the heat dissipation branch, the energy storage branch, and the heat exchange branch, or the first water pump 30 is installed on the heat dissipation branch.

[0048] like Figure 1 As shown, the first water pump 30 is connected to the heat dissipation branch, the energy storage branch, and the heat exchange branch. Furthermore, the heat dissipation branch, the energy storage branch, and the heat exchange branch are connected to the second water pump 50 via an electric four-way valve 60. This allows the high-temperature coolant flowing from the first water pump 30 to pass through the heat dissipation branch, the energy storage branch, and the heat exchange branch, respectively. The low-temperature coolant, after being processed by the heat dissipation branch, the energy storage branch, and the heat exchange branch, then flows into the second water pump 50, thus achieving temperature control based on coolant heat conduction. Understandably, both the first water pump 30 and the second water pump 50 are connected in parallel with the heat dissipation branch, the energy storage branch, and the heat exchange branch. By adjusting the rotational speeds of the first water pump 30 and the second water pump 50, the pressure of the coolant flowing through the heat dissipation branch, the energy storage branch, and the heat exchange branch can be effectively controlled, preventing damage to these branches due to excessive local pressure.

[0049] like Figure 2As shown, the first water pump 30 is installed on the heat dissipation branch. The heat dissipation branch, energy storage branch, and heat exchange branch are connected to the second water pump 50 via an electric four-way valve 60, so that the coolant output from the expansion tank 20 flows through the first water pump 30 through the heat dissipation branch and directly into the energy storage branch and heat exchange branch. After being processed by the heat dissipation branch, energy storage branch, and heat exchange branch, the coolant flows back into the second water pump 50 to achieve temperature regulation based on the heat conduction of the coolant. Since the fuel cell generates a large amount of heat during operation, which can damage the fuel cell, heat dissipation is the primary purpose of the fuel cell thermal management system. It is the most important branch in the low-temperature heat dissipation circuit 40, making its usage frequency higher than other branches. Installing the second water pump 50 on the heat dissipation branch can effectively prevent damage to the heat dissipation branch due to excessive local pressure. Moreover, when it is necessary to control the operation of the energy storage branch and the heat exchange branch, only the operation of the second water pump 50 needs to be controlled, without controlling the operation of the first water pump 30. This helps to reduce the difficulty of water pump control, and the performance of the two water pumps can be matched to ensure that they operate at their optimal efficiency points.

[0050] The heat dissipation branch is the branch in the low-temperature heat dissipation circuit 40 used to achieve the heat dissipation function. As an example, the heat dissipation branch includes a battery radiator 41, the output of which is connected to the expansion tank 20. The battery radiator 41 is a device used to dissipate heat generated during the operation of the fuel cell; specifically, the battery radiator 41 can be a car radiator. Figure 1 and Figure 2 As shown, the input end of the battery radiator 41 is connected to the first water pump 30, the output end of the battery radiator 41 is connected to the second water pump 50, and the output end of the battery radiator 41 is connected to the expansion tank 20 through an overflow pipe, which is used to input the gas overflowing from the battery radiator 41 during operation into the expansion tank 20 so that the expansion tank 20 can replenish water according to the water expansion.

[0051] In this example, the temperature control main circuit 10, expansion tank 20, first water pump 30, heat dissipation branch, second water pump 50, and temperature control main circuit 10 form a closed loop through coolant pipes, thus forming the first working cycle. The heat dissipation branch cools the coolant flowing in the first working cycle to remove the heat generated during fuel cell operation, achieving the purpose of cooling the fuel cell during operation using the coolant in the first working cycle. Understandably, the controller can control the speed of the first water pump 30 and the second water pump 50 to ensure pressure balance during the first working cycle, preventing excessive local pressure that could cause excessive stress on local components and affect their service life.

[0052] The energy storage branch is a section of the cryogenic heat dissipation circuit 40 used to absorb and store the heat generated during the operation of the fuel cell. As an example, the energy storage branch includes a phase change energy storage device 42, which utilizes a phase change material undergoing a phase change at a phase change temperature to absorb and store energy. In this example, during the second working cycle of the energy storage branch, the high-temperature coolant output from the temperature control main circuit 10 is input into the phase change energy storage device 42, causing the phase change material in the device to absorb heat from the high-temperature coolant and undergo a phase change, effectively increasing the heat dissipation capacity of the fuel cell thermal management system.

[0053] like Figure 1 As shown, the temperature control main circuit 10, expansion tank 20, first water pump 30, energy storage branch, second water pump 50, and temperature control main circuit 10 form a closed loop through coolant pipes, thus forming the second working cycle; or, as shown... Figure 2 As shown, the temperature control main circuit 10, expansion tank 20, energy storage branch, second water pump 50, and temperature control main circuit 10 form a closed loop through coolant pipes, thus forming the second working cycle. Understandably, the energy storage branch absorbs and stores the heat generated by the coolant flowing in the second working cycle, thereby using the coolant in the second working cycle to cool the heat generated during fuel cell operation and improve heat dissipation.

[0054] Among them, the heat exchange branch is a branch in the low-temperature heat dissipation circuit 40 used to realize the heat exchange between the fuel cell and other components during the operation of the fuel cell. It can be understood that by setting up the heat exchange branch, the heat generated during the operation of the fuel cell can be fully utilized for heat exchange, so as to make full use of the heat and avoid waste.

[0055] As an example, such as Figure 1 and Figure 2 As shown, the heat exchange branch includes a heat exchanger 43 and a heat exchange control loop connected to the heat exchanger 43. The heat exchanger 43 is a device used to transfer heat from a hot fluid to a cold fluid to meet specified process requirements. In this example, the heat exchanger 43 is specifically a liquid-liquid heat exchanger to achieve heat exchange between coolants. The heat exchange control loop is a pre-set control loop that can exchange heat with the heat generated during fuel cell operation; specifically, it can be understood as a control loop that needs to utilize heat. Generally, since the fuel cell generates heat during operation, to achieve heat exchange, the heat exchanger 43 can be used to transfer the heat generated during fuel cell operation to other heat exchange control loops that require heat, thereby fully utilizing the heat generated during fuel cell operation and avoiding heat loss.

[0056] like Figure 1As shown, the temperature control main circuit 10, expansion tank 20, first water pump 30, heat exchange branch, second water pump 50, and temperature control main circuit 10 form a closed loop through coolant pipes, thus forming the third working cycle; or, as... Figure 2 As shown, the temperature control main circuit 10, expansion tank 20, heat exchange branch, second water pump 50, and temperature control main circuit 10 form a closed loop through coolant pipes, thus forming the third working cycle. Understandably, the heat exchange branch is used to exchange heat from the coolant flowing in the third working cycle to achieve waste heat heating, thereby cooling the heat generated during fuel cell operation using the coolant in the third working cycle. Specifically, during the operation of the third working cycle where the heat exchange branch is located, the high-temperature coolant output from the temperature control main circuit 10 flows through the heat exchanger 43, where it exchanges heat with the heat exchange control circuit to transfer heat to the circuit. This achieves waste heat utilization during fuel cell operation, both dissipating heat during fuel cell operation and utilizing waste heat to avoid energy waste.

[0057] In one embodiment, such as Figure 1 and Figure 2 As shown, the heat exchange control circuit is a warm air control circuit, which includes an electric heater 44, a warm air radiator 45, a warm air kettle 46, and a warm air water pump 47 connected in series with the heat exchanger 43.

[0058] In this example, the heat exchange control loop connected to the heat exchanger 43 includes, but is not limited to, the heating control loop. The heating control loop is a control loop used in fuel cell vehicles to achieve air conditioning and heating; it is a control loop that needs to receive energy for heating. For example... Figure 1 and Figure 2 The heating control circuit includes an electric heater 44, a heating radiator 45, a heating kettle 46, and a heating water pump 47 connected in series with the heat exchanger 43. The electric heater 44 is a PTC heater, which can quickly heat the fluid after being energized. The heating radiator 45 is a radiator installed in the heating control circuit. The heating kettle 46 is a kettle installed in the heating control circuit. The heating water pump 47 is a water pump installed in the heating control circuit to control the flow of coolant. The heating water pump 47 is connected to a controller to adjust its speed according to the controller's control. In this embodiment, the electric heater 44, heating radiator 45, heating kettle 46, and heating water pump 47 are connected in series to form a fourth working cycle.

[0059] Among them, the electric four-way valve 60 is a four-way valve used to control the opening degree of the valve body. The electric four-way valve 60 is connected to the heat dissipation branch, the energy storage branch, the heat exchange branch and the second water pump 50. It is used to switch at least one of the three branches, namely the heat dissipation branch, the energy storage branch and the heat exchange branch, to be connected to the second water pump 50 so that the fuel cell stack temperature control circuit works in the first working cycle, the second working cycle or the third working cycle, and realizes the corresponding functions by utilizing the heat dissipation branch, the energy storage branch and the heat exchange branch.

[0060] like Figure 3 As shown, the electric four-way valve 60 includes a first circulation port 61, a second circulation port 62, a third circulation port 63, and a fourth circulation port 64. The first circulation port 61 is connected to the heat dissipation branch, the second circulation port 62 is connected to the energy storage branch, the third circulation port 63 is connected to the heat exchange branch, and the fourth circulation branch is connected to the second water pump 50. Furthermore, the controller is connected to the electric four-way valve 60 and is used to switch at least one of the first circulation port 61, the second circulation port 62, and the third circulation port 63 to the fourth circulation port 64 based on the sensor measurement data collected by the sensor module, so as to achieve the purpose of switching at least one of the heat dissipation branch, the energy storage branch, and the heat exchange branch to be connected to the second water pump 50.

[0061] In the fuel cell thermal management system provided in the above embodiment, the outlet of the temperature control main circuit 10 is connected to the input of the low-temperature heat dissipation circuit 40 via a first water pump 30, and the output of the low-temperature heat dissipation circuit 40 is connected to the inlet of the temperature control main circuit 10 via a second water pump 50. This dual-pump setup allows for adjustment of the speeds of the first water pump 30 and the second water pump 50 based on sensor measurement data collected by the sensor module installed on the temperature control main circuit 10. This ensures pressure balance in the fuel cell stack temperature control circuit and prevents damage to components due to excessive local pressure. The low-temperature heat dissipation circuit 40 includes a heat dissipation branch, an energy storage branch, and a heat exchange branch connected in parallel. When connected to the second water pump 50, the temperature control main circuit 10, and the first water pump 30, it forms a first working cycle, a second working cycle, and a third working cycle, respectively. Furthermore, the heat exchange branch includes a warm air control circuit connected to the heat exchanger 43. The electric heater 44, warm air radiator 45, warm air kettle 46, and warm air pump 47 in the warm air control circuit form a fourth working cycle, connected in series. The following describes the working process of a fuel cell thermal management system using specific application scenarios:

[0062] (1) During the cold start of the fuel cell, i.e. when the fuel cell is powered on, the temperature is low because the fuel cell has not yet carried out an electrochemical reaction. At this time, the controller can control the third circulation port 63 and the fourth circulation port 64 in the electric four-way valve 60 to make the third working cycle in which the heat exchange branch is located work, and control the fourth working cycle in which the warm air control circuit is located work. At this time, the first working cycle and the second working cycle do not work. By controlling the electric heater 44 in the warm air control circuit to turn on the heating function, the heat generated by the electric heater 44 during the heating process is transferred to the third working cycle through the heat exchanger 43. The heat is transferred to the fuel cell through the coolant in the third working cycle to shorten the cold start time of the fuel cell and realize the cold start auxiliary heating function.

[0063] (2) After the fuel cell cold start is completed and it is working, when the output power of the battery stack 11 is high and the coolant temperature is high, but not close to the upper limit of the allowable operating temperature, the controller can control the first circulation port 61 and the fourth circulation port 64 in the electric four-way valve 60 to be turned on. At this time, the first working cycle is working, and the second, third and fourth working cycles are not working. The battery heat sink 41 in the first working cycle is used for heat dissipation to dissipate the excess heat generated during the operation of the fuel cell.

[0064] (3) When the output power of the battery stack 11 is high and the coolant temperature is high, approaching the upper limit of the allowable operating temperature, the controller keeps the first circulation port 61 and the fourth circulation port 64 in the electric four-way valve 60 open while controlling the second circulation port 62 and the fourth circulation port 64 in the electric four-way valve 60 to open, so that the first working cycle and the second working cycle work simultaneously, while the third working cycle and the fourth working cycle do not work. At this time, during the operation of the first working cycle, the battery heat sink 41 in the first working cycle is used for heat dissipation to dissipate the excess heat generated during the operation of the fuel cell; during the operation of the second working cycle, the phase change material in the phase change energy storage device 42 absorbs the heat in the high-temperature coolant and undergoes a phase change, which can effectively increase the heat dissipation capacity of the fuel cell thermal management system and extend the duration of peak power output of the battery stack 11 to realize the phase change energy storage function.

[0065] (4) When the coolant temperature output by the battery stack 11 is high and the air conditioning system has heating requirements, the controller can control the third circulation interface 63 and the fourth circulation interface 64 in the electric four-way valve 60 to be connected while keeping the first circulation interface 61 and the fourth circulation interface 64 in the electric four-way valve 60 connected, so that the first working cycle and the third working cycle work simultaneously, and control the fourth working cycle to dissipate heat in the battery radiator 41 in the first working cycle, so as to dissipate the excess heat generated during the operation of the fuel cell. At the same time, the excess heat generated by the fuel cell is transferred to the heating control circuit through the heat exchanger 43 to reduce the power of the electric heater 44, so as to realize the utilization of waste heat and achieve the purpose of energy saving.

[0066] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A fuel cell thermal management system, comprising a stack temperature control loop, a sensor module disposed on the stack temperature control loop, and a controller connected to the sensor module and the stack temperature control loop, characterized in that, The stack temperature control circuit includes a temperature control main circuit connected to the fuel cell, an expansion tank and a first water pump connected to the temperature control main circuit, a low-temperature heat dissipation circuit connected to the first water pump, a second water pump connected to the low-temperature heat dissipation circuit and the temperature control main circuit, the expansion tank being connected to the first water pump, the sensor module being mounted on the temperature control main circuit, and the first water pump and the second water pump being connected to the controller. The temperature control main circuit includes a first temperature control branch and a second temperature control branch connected in parallel; the first temperature control branch includes a battery stack, the inlet of which is connected to the second water pump, and the outlet of which is connected to the expansion tank and the first water pump; the second temperature control branch includes an ion exchanger and a water-air cooler connected in series, one end of which is connected to the second water pump, and one end of which is connected to the expansion tank and the first water pump. The temperature control main circuit also includes a third temperature control branch connected in parallel with the first temperature control branch and the second temperature control branch; the third temperature control branch includes an electric two-way valve and an anode heat exchanger connected in series; the electric two-way valve is connected to the controller, and one end of the electric two-way valve is connected to the second water pump; one end of the anode heat exchanger is connected to the expansion tank and the first water pump; The controller is used to control the electric two-way valve to open or close based on the sensor measurement data collected by the sensor module, and to connect the anode heat exchanger in parallel or not in parallel with the first temperature control branch and the second temperature control branch.

2. The fuel cell thermal management system as described in claim 1, characterized in that, The first temperature control branch also includes a particulate filter connected in series with the battery stack, and the particulate filter is located at the water inlet of the battery stack.

3. The fuel cell thermal management system as described in claim 1, characterized in that, The sensor module includes a first temperature and pressure sensor disposed at the water inlet of the battery stack and a second temperature and pressure sensor disposed at the water outlet of the battery stack.

4. The fuel cell thermal management system as described in claim 1, characterized in that, The low-temperature heat dissipation circuit includes a heat dissipation branch, an energy storage branch, and a heat exchange branch arranged in parallel; the heat dissipation branch, the energy storage branch, and the heat exchange branch are connected to the second water pump through an electric four-way valve; the first water pump is connected to the heat dissipation branch, the energy storage branch, and the heat exchange branch, or the first water pump is installed on the heat dissipation branch.

5. The fuel cell thermal management system as described in claim 4, characterized in that, The heat dissipation branch includes a battery radiator, the output end of which is connected to the expansion tank.

6. The fuel cell thermal management system as described in claim 4, characterized in that, The energy storage branch includes a phase change energy storage device.

7. The fuel cell thermal management system as described in claim 4, characterized in that, The heat exchange branch includes a heat exchanger and a heat exchange control loop connected to the heat exchanger.

8. The fuel cell thermal management system as described in claim 7, characterized in that, The heat exchange control circuit is a warm air control circuit, which includes an electric heater, a warm air radiator, a warm air kettle, and a warm air water pump connected in series with the heat exchanger.

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