Fuel cell engine cooling system and vehicle

Abstract

The utility model relates to the technical field of fuel cells, and discloses a fuel cell engine cooling system and a vehicle. The first cooling system is connected with one end of the heat exchanger; the second cooling system is connected with the other end of the heat exchanger; both the first pipeline and the second pipeline contain cooling liquid, and the cooling liquid in the first pipeline is less than the cooling liquid in the second pipeline. On one hand, the first cooling system and the second cooling system are integrated through the heat exchanger, the space in the fuel cell is effectively saved, the dosage of cooling liquid in the first cooling system is greatly reduced by reducing the number of parts in the first cooling system, so that the cold start time of an electric pile is shortened, and the start efficiency is improved; and auxiliary devices such as an intercooler and a PTC heater do not need to be additionally mounted in the first cooling system, so that the ion content of the cooling liquid in the first cooling system can be kept in a relatively low range, and the insulativity of the electric pile can be kept in a relatively high level for a long time.

Description

Technical Field

[0001] The utility model relates to the technical field of fuel cells, in particular to a fuel cell engine cooling system and a vehicle. Background Art

[0002] As the economy continues to develop, humanity's demand for energy is increasing. Traditional energy sources generate significant pollution during use, necessitating the development of clean energy. Fuel cells are power generation devices that convert chemical energy directly into electrical energy. They offer advantages such as high efficiency, zero pollution, fast startup, smooth operation, and low noise, making them an ideal alternative to traditional energy sources.

[0003] The main function of the fuel cell engine cooling system is to ensure that the fuel cell stack operates within a reasonable temperature range. The traditional fuel cell engine cooling system includes a main cooling system and an auxiliary cooling system (such as Figure 2-3 As shown), both cooling systems need to be equipped with independent radiators, pipes and joints, which take up a lot of space, resulting in the existing cooling system being bloated and complicated. The existing main cooling system contains components such as PTC heaters and intercoolers, which requires a large amount of coolant to maintain the temperature of the main cooling system. Moreover, due to the large amount of coolant, the temperature change process of the coolant is longer, and the time required for the cold start of the fuel cell stack is longer. On the other hand, welded components such as PTC heaters and intercoolers will release a large amount of ions, resulting in an increase in the conductivity of the coolant, which affects the insulation performance of the fuel cell stack in the main cooling system. Utility Model Content

[0004] The present utility model aims to solve the above problems and provide a fuel cell engine cooling system and a vehicle, so as to solve the problems that the existing fuel cell engine cooling system has low integration, occupies a large space, has high cost, and has a long cold start time for the existing fuel cell stack, the ion content in the coolant is easily increased, and the insulation of the fuel cell stack is poor.

[0005] To achieve this purpose, the present invention adopts the following technical solutions:

[0006] A fuel cell engine cooling system comprising:

[0007] Heat exchangers, used for heat exchange between different systems;

[0008] a first cooling system connected to one end of the heat exchanger, the first cooling system comprising a fuel cell stack and a first water pump connected in sequence via a first pipe;

[0009] a second cooling system connected to the other end of the heat exchanger, the second cooling system comprising a second water pump, an intercooler, and a radiator connected in parallel to the second pipe;

[0010] The first pipe and the second pipe both contain coolant, and the coolant in the first pipe is less than the coolant in the second pipe.

[0011] Preferably, the flow direction of the coolant in the first pipe is opposite to the flow direction of the coolant in the second pipe.

[0012] Preferably, it also includes: at least one deionizer for reducing the ion concentration of the coolant in the first pipe; the deionizer is installed at the liquid inlet and / or liquid outlet of the fuel cell stack to improve the insulation of the fuel cell stack.

[0013] Preferably, it also includes: a first expansion water tank and a second expansion water tank; the first expansion water tank is installed on the first pipe, the second expansion water tank is installed on the second pipe, and the second expansion water tank is connected to the radiator; an air pump is connected to the second expansion water tank, and is used to extract air from the coolant in the second pipe.

[0014] Preferably, the second cooling system further includes: a DC / DC converter, an air compressor and a controller connected in parallel to the second pipeline.

[0015] Preferably, the second cooling system also includes: a PTC heater connected to the liquid inlet of the second water pump, for providing heat for the coolant in the second cooling system; a thermostat installed in the second pipe, for controlling the flow direction of the coolant in the second cooling system; the thermostat includes an a end, a b end and a c end, wherein the a end is connected to the heat exchanger, the b end is connected to the radiator, and the c end is connected to the PTC heater.

[0016] Preferably, the second cooling system further comprises: flow limiting holes, which are respectively provided at the liquid inlets of the intercooler, the DC / DC converter and the air compressor, and the flow limiting holes are used to limit the flow of the coolant.

[0017] Preferably, it further comprises: two filters, which are respectively installed on the first pipe and the second pipe, and the filters are used to remove particulate impurities contained in the coolant.

[0018] Preferably, the coolant is ethylene glycol or water.

[0019] A vehicle comprises the above cooling system.

[0020] The contribution of the present invention is that the present invention integrates the first cooling system and the second cooling system into one through a heat exchanger, thereby effectively saving space in the fuel cell. Due to the high degree of integration of the first cooling system and the second cooling system, a large number of pipes, joints and cooling components are also saved, thereby indirectly saving costs. By reducing the number of components in the first cooling system, the dosage of coolant in the first cooling system is greatly reduced, so that the cold start time of the fuel cell stack is shortened and the start-up efficiency is improved. On the other hand, since there is no need to install additional auxiliary devices such as intercoolers and PTC heaters in the first cooling system, the ion content of the coolant in the first cooling system can be maintained in a low range, and the insulation of the fuel cell stack can be maintained at a high level for a long time. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the fuel cell engine cooling system of the utility model;

[0022] Figure 2 It is a structural diagram of the main cooling system in the prior art;

[0023] Figure 3 It is a structural diagram of an auxiliary cooling system in the prior art;

[0024] Wherein: heat exchanger 10, first cooling system 20, second cooling system 30, deionizer 40, first expansion water tank 50, second expansion water tank 60, filter 70, vacuum pump 1a;

[0025] First pipeline 21 , fuel cell stack 22 , first water pump 23 , second pipeline 31 , second water pump 32 , intercooler 33 , radiator 34 , DC / DC converter 35 , air compressor 36 , controller 37 , PTC heater 38 , thermostat 39 , and flow limiting hole 310 . DETAILED DESCRIPTION

[0026] The following examples are provided to further explain and supplement the present invention and do not constitute any limitation to the present invention.

[0027] like Figure 1 As shown, a fuel cell engine cooling system includes: a heat exchanger 10 for exchanging heat between different systems; a first cooling system 20, connected to one end of the heat exchanger 10, the first cooling system 20 includes a fuel cell stack 22 and a first water pump 23 connected in sequence through a first pipe 21; a second cooling system 30, connected to the other end of the heat exchanger 10, the second cooling system 30 includes a second water pump 32, an intercooler 33 and a radiator 34 connected in parallel to the second pipe 31; the first pipe 21 and the second pipe 31 both contain coolant, and the coolant in the first pipe 21 is less than the coolant in the second pipe 31.

[0028] The traditional fuel cell engine cooling system includes the main cooling system and the auxiliary cooling system ( Figure 2 Schematic diagram of the main cooling system. Figure 3 (Schematic diagram of the auxiliary cooling system) Both cooling systems require independent radiators, pipes, and connectors, which take up a lot of space and make the existing cooling system bloated and complicated. In addition, the existing main cooling system contains components such as PTC heaters and intercoolers, which require more coolant to maintain the temperature. Welded components such as PTC heaters and intercoolers release a large amount of ions. When the ions enter the coolant, they increase the conductivity of the coolant and affect the insulation performance of the main cooling system.

[0029] In this embodiment, a heat exchanger 10 capable of heat exchange is set between the first cooling system 20 (equivalent to the traditional main cooling system) and the second cooling system 30 (equivalent to the traditional auxiliary cooling system). One end of the heat exchanger 10 transfers heat to the fuel cell stack 22 in the first cooling system 20, and the other end transfers heat to auxiliary components such as the intercooler 33 and the PTC heater 38 in the second cooling system 30, so that the pipeline of the first cooling system 20 is simplified (unlike the traditional main cooling system that requires the installation of intercooler 33, PTC heater 38 and other components). The first cooling system 20 and the second cooling system 30 are highly integrated together, which greatly reduces the space occupied by the fuel cell stack 22 cooling system and saves costs (equivalent to the traditional main cooling system and auxiliary cooling system being fully integrated at both ends of the heat exchanger 10).

[0030] On the other hand, due to the reduction of major components in the first cooling system 20 (i.e., there is no need to install additional components such as the intercooler 33 and the PTC heater 38), the coolant required to maintain the temperature of the fuel cell stack 22 in the first cooling system 20 is also greatly reduced. The substantial reduction in coolant reduces the time required to heat the coolant, and the heating rate of the fuel cell stack 22 is accelerated, thereby reducing the time required for the cold start of the fuel cell stack 22. On the other hand, since there is no need to install equipment such as the intercooler 33 and the PTC heater 38 in the first cooling system 20, the ion concentration contained in the coolant in the first pipeline is greatly reduced, which greatly improves the insulation performance of the fuel cell stack 22.

[0031] Since the first cooling system 20 and the second cooling system 30 are respectively connected to the two ends of the heat exchanger 10, the first cooling system 20 and the second cooling system 30 can operate independently. Therefore, if any component other than the heat exchanger 10 is damaged or the coolant is replaced, it is only necessary to disassemble and replace the corresponding cooling system (the first cooling system 20 or the second cooling system 30), which greatly improves maintenance efficiency.

[0032] The present invention integrates the first cooling system 20 and the second cooling system 30 into one through the heat exchanger 10, which effectively saves space in the fuel cell. Due to the high integration of the first cooling system 20 and the second cooling system 30, a large number of pipes, joints and cooling components are also saved (components such as the intercooler 33 and the PTC heater 38 are reduced in the first cooling system), thereby indirectly saving costs. By reducing the number of components in the first cooling system 20, the amount of coolant used in the first cooling system 20 is also greatly reduced, which shortens the cold start time of the fuel cell stack 22 and improves the start-up efficiency. On the other hand, since there is no need to install additional auxiliary devices such as the intercooler 33 and the PTC heater 38 in the first cooling system 20, the ion content of the coolant in the first cooling system 20 can be maintained in a low range, and the insulation of the fuel cell stack 22 can be maintained at a high level for a long time.

[0033] To further explain, the flow direction of the coolant in the first pipe 21 is opposite to the flow direction of the coolant in the second pipe 31 .

[0034] In this embodiment, the flow directions of the coolant on both sides of the heat exchanger 10 are opposite, that is, relative flow, which increases the heat transfer efficiency between the first cooling system 20 and the second cooling system 30, so that the temperature between the first cooling system 20 and the second cooling system 30 can be adjusted and controlled in time.

[0035] Further description also includes: at least one deionizer 40 for reducing the ion concentration of the coolant in the first pipe 21; the deionizer 40 is installed at the liquid inlet and / or liquid outlet of the fuel cell stack 22 to improve the insulation of the fuel cell stack 22.

[0036] In this embodiment, in order to ensure that the insulation of the battery stack 22 is maintained at a high level as much as possible, a deionizer 40 can be installed at the liquid inlet or outlet of the battery stack 22, or at both the liquid inlet and the liquid outlet. The deionizer 40 can remove ions in the coolant, thereby reducing the conductivity of the coolant and improving the insulation performance of the battery stack 22.

[0037] To further explain, since the second cooling system 30 includes welding equipment such as the intercooler 33 and the PTC heater 38, the rate of increase of the ion concentration in the coolant in the second cooling system 30 will be much higher than the rate of increase of the ion concentration in the coolant in the first cooling system 20. The current practice is usually to regularly empty the coolant in the second cooling system 30 and re-inject new coolant (the cost of replacing the coolant is much lower than the cost of replacing the deionizer 40) to ensure that the insulation performance of each auxiliary cooling equipment in the second cooling system 30 is within the allowable range.

[0038] Further, the first expansion tank 50 and the second expansion tank 60 are provided, the first expansion tank 50 is installed on the first pipeline 21, the second expansion tank 60 is installed on the second pipeline 31, and the second expansion tank 60 is connected with the radiator 34; and the air pump 1a is connected with the second expansion tank 60 and used for extracting air in the cooling liquid in the second pipeline 31. The first expansion tank 50 and the second expansion tank 60 are respectively used for providing cooling liquid for the first cooling system 20 and the second cooling system 30, the cooling liquid in the first pipeline 21 has a small amount, and the air mixed in the cooling liquid during the replacement process is small (generally within the allowable range) and does not affect the operation of the first water pump 23, but the cooling liquid in the second pipeline 31 has a much larger amount than that in the first pipeline 21 (the length of the second pipeline 31 is also larger than that of the first pipeline 21, and a large amount of air will be injected during the replacement process), in order to reduce the gas content in the cooling liquid in the second pipeline 31 and improve the working efficiency of the second water pump 32, the air pump 1a is provided in the embodiment, the air pump 1a is connected with the second expansion tank 60, and the second expansion tank 60 is connected with the air outlet of the radiator 34.

[0039] Since air is inevitably mixed in during the process of supplementing or replacing the cooling liquid in the second pipeline 31, the gas content in the cooling liquid in the second pipeline 31 is increased, which affects the working efficiency of the second water pump 32, and the air pump 1a is connected with the top of the second expansion tank 60 in the embodiment, the air pump 1a can extract the air in the second expansion tank 60, so that the air pressure in the second expansion tank 60 is reduced, at this time, the air pressure in the second pipeline 31 is greater than that in the second expansion tank 60, the gas in the second pipeline 31 flows into the second expansion tank 60 through the air outlet of the radiator 34, and is finally extracted to the external environment by the air pump 1a, so that the gas content in the cooling liquid in the second pipeline 31 is reduced, and the normal operation of the second water pump 32 is ensured.

[0040] Further, after a long time of work, the air contained in the cooling liquid in the first pipeline 21 may also exceed the standard, at this time, the method for removing air from the cooling liquid in the second pipeline 31 can be referred to for removing air from the cooling liquid in the first pipeline 21 (the radiator 34 and the air pump 1a can be shared).

[0041] Further, the second cooling system 30 further comprises the DC / DC converter 35, the air compressor 36 and the controller 37 connected in parallel with the second pipeline 31.

[0042] To further illustrate, the second cooling system 30 also includes a PTC heater 38 connected to the liquid inlet of the second water pump 32 to provide heat to the coolant in the second cooling system 30; and a thermostat 39 installed in the second pipeline to control the flow direction of the coolant in the second cooling system 30. The thermostat 39 includes ends a, b, and c, with end a connected to the heat exchanger 10, end b connected to the radiator 34, and end c connected to the PTC heater 38. The PTC heater 38 is often used to provide a large amount of heat to the coolant during a cold start of the stack 22, further shortening the stack 22's warm-up time and ensuring normal operation of the stack 22. The thermostat 39 is a three-way valve that divides the second cooling system 30 into a large circulation loop and a small circulation loop. When the temperature of the stack 22 does not reach the optimal temperature range, the coolant flows in the small circulation channel. When the temperature of the stack 22 reaches the optimal temperature range, the coolant flows in the large circulation channel.

[0043] To further explain, the small circulation loop is composed of a second water pump 32, a thermostat 39, a PTC heater 38 and a heat exchanger 10. When the coolant flows in the small circulation loop, the a and c ends of the thermostat 39 are opened, and the b end is closed. At this time, the coolant flows in the second pipe under the extraction of the second water pump 32. When the battery stack 22 is just started, the temperature of the battery stack 22 has not reached the optimal temperature range. At this time, the battery stack 22 needs to be heated up, so the coolant does not need to be cooled significantly, ensuring that the battery stack 22 can reach a suitable operating temperature in a relatively short time.

[0044] To further explain, the large circulation loop is composed of a second water pump 32, a radiator 34 and a thermostat 39. Compared with the small circulation loop, the coolant in the large circulation channel does not pass through the PTC heater 38 but flows through the radiator 34 instead. In this embodiment, the radiator 34 adopts an air-cooled heat dissipation method. The radiator 34 can take away the heat of the coolant in the second cooling system 30, so that the coolant in the second pipeline drops to a lower temperature. When the temperature of the battery stack 22 reaches the optimal temperature range, due to the electrochemical reaction of hydrogen and oxygen, heat will still be generated, causing the temperature of the coolant in the first cooling system 20 to rise. The coolant in the first cooling system 20 and the second cooling system 30 are heat-exchanged through the heat exchanger 10 to ensure that the battery stack 22 is always maintained in the optimal temperature range.

[0045] To further illustrate, the second cooling system 30 further includes: flow limiting holes 310, which are respectively provided at the liquid inlets of the intercooler 33, the DC / DC converter 35 and the air compressor 36. The flow limiting holes 310 are used to limit the flow of the coolant.

[0046] The aperture of the flow limiting hole 310 is set according to the heat dissipation requirements of the intercooler 33, the DC / DC converter 35 and the air compressor 36, so as to control the flow of coolant flowing through each component, thereby achieving the different heat dissipation requirements of the intercooler 33, the DC / DC converter 35 and the air compressor 36.

[0047] Further description also includes: two filters 70, which are installed in the first pipe 21 and the second pipe 31 respectively, and the filters 70 are used to remove particulate impurities contained in the coolant.

[0048] Further description, the coolant is ethylene glycol or water.

[0049] Another embodiment of the present invention relates to a vehicle including the above-mentioned fuel cell engine cooling system.

[0050] Another embodiment of the present invention relates to a control method, which is applied to the above-mentioned fuel cell engine cooling system and includes the following control steps:

[0051] Detecting the external ambient temperature and selecting a startup mode suitable for the fuel cell stack 22 according to the external ambient temperature, wherein the startup mode includes a normal temperature startup mode and a low temperature startup mode;

[0052] If the external ambient temperature is greater than 0°C, select the normal temperature start mode to start the battery stack 22;

[0053] If the external ambient temperature is less than 0° C., the impedance value of the proton exchange membrane in the fuel cell stack 22 is detected, and the low-temperature startup mode is performed according to the detected impedance value.

[0054] It should be noted here that the impedance value of the proton exchange membrane is inversely proportional to its wettability. The larger the impedance value, the drier the proton exchange membrane, and the smaller the impedance value, the higher the water content of the proton exchange membrane. Therefore, it is necessary to detect the impedance value of the proton exchange membrane to ensure the humidity state of the proton exchange membrane so as to facilitate the subsequent adoption of different startup methods.

[0055] To further illustrate this embodiment, performing a low-temperature start-up mode based on the detected impedance value includes the following steps: obtaining an impedance threshold (a range value, determined according to the condition of the proton exchange membrane in the fuel cell stack 22); comparing the detected impedance value with the impedance threshold to determine the humidity state of the proton exchange membrane in the fuel cell stack 22; wherein the humidity state of the proton exchange membrane includes a wetting state and a non-wetting state; when the proton exchange membrane is in a wetting state, the fuel cell stack 22 enters the low-temperature start-up mode.

[0056] To further explain, the normal temperature start-up mode includes the following steps: starting the fuel cell stack 22, starting the first water pump 23 and the second water pump 32, and opening the a and c ends of the thermostat 39 (small circulation loop, at this time the temperature of the fuel cell stack 22 is low and needs to be heated up as soon as possible), and closing the b end; when the outlet temperature of the fuel cell stack 22 reaches 40°C, gradually reduce the opening of the c end, and gradually increase the opening of the b end; when the outlet temperature of the fuel cell stack 22 reaches 65°C, the c end is closed and the b end is in a fully open state (at this time it is in a large circulation loop, the temperature of the fuel cell stack 22 is almost approaching the optimal temperature, and it is necessary to prepare to slow down the heating rate of the fuel cell stack 22); when the outlet temperature of the fuel cell stack 22 reaches 70°C, turn on the radiator 34, and adjust the speed of the radiator 34 according to the outlet temperature of the fuel cell stack 22 and the temperature difference between the inlet and outlet of the fuel cell stack 22, so that the outlet temperature of the fuel cell stack 22 is maintained at 75°C-80°C, and the temperature difference between the inlet and outlet of the fuel cell stack 22 is maintained at 2°C-4°C.

[0057] The low-temperature start-up mode includes the following steps: starting the fuel cell stack 22, starting the first water pump 23 and the second water pump 32, and opening the a and c ends of the thermostat 39, and closing the b end; turning on the PTC heater 38, and adjusting the PTC heater 38 to the maximum power; adjusting the PTC heater 38 to the maximum power to increase the temperature of the coolant in the second cooling system 30 as quickly as possible, and transferring the heat of the high-temperature coolant in the second coolant 30 to the first cooling system 20 through the heat exchanger 10, thereby assisting the fuel cell stack 22 in heating up.

[0058] When the outlet temperature of the fuel cell stack 22 reaches 5°C (to ensure that no ice will form on the proton exchange membrane in the fuel cell stack 22. To further explain, the low temperature environment may cause a layer of ice to adhere to the catalyst of the proton exchange membrane, affecting the reaction rate of the proton exchange membrane. When the impedance value of the proton exchange membrane is detected to be greater than the impedance threshold, in order to ensure that the fuel cell stack 22 can subsequently be stably switched to the normal temperature start-up mode, the temperature of the outlet of the fuel cell stack 22 will be appropriately increased to 5°C, and then the start-up mode will be switched), the cold start mode is completed and the fuel cell stack 22 switches to the normal temperature start-up mode.

[0059] To further illustrate this embodiment, when the humidity state of the proton exchange membrane is in a non-wetting state, the following control steps are included: obtaining the initial parameters of the fuel cell stack 22 when it is started, the initial parameters including the fuel cell stack 22 current I1, the hydrogen flow H1 and the air flow K1; when the impedance value obtained by detection is greater than the impedance threshold (the proton exchange membrane is in a dry state); adjusting the fuel cell stack 22 current I1 to the fuel cell stack 22 current I2, adjusting the hydrogen flow H1 to the hydrogen flow H2; adjusting the air flow K1 to the air flow K2 or the air flow K3, and the air flow K2 and the air flow K3 are alternately transformed within a preset period (3s-5s); when the impedance value obtained by detection is within the impedance threshold range , the proton exchange membrane changes from a non-wetting state to a wetting state, and the initial current parameters of the stack 22 are restored to operate; wherein, I1<I2, H1

[0060] Specifically, if the humidity of the proton exchange membrane is in a non-wetted state (including a dry state and a flooded state), it means that the proton exchange membrane is too dry or too wet, and the proton exchange membrane needs to be adjusted.

[0061] ​Further explanation, when the proton exchange membrane is too dry, the impedance value of the proton exchange membrane is greater than the impedance threshold. At this time, the stack 22 current I1 is adjusted to the stack 22 current I2. Increasing the stack 22 current can promote the reaction in the stack 22, and the amount of water generated by the stack 22 increases, thereby having a certain humidification effect on the proton exchange membrane. The hydrogen flow rate H1 is adjusted to the hydrogen flow rate H2 (preferably, H2 is 1.2-1.3 times that of H1). The hydrogen flow rate H2 has a larger air volume than the hydrogen flow rate H1. When hydrogen flows out from the anode outlet of the stack 22, it can take away a certain amount of moisture, thereby avoiding excessive flooding of the anode of the stack 22. Adjust the air flow K1 to air flow K2 or air flow K3, and the air flow K2 and air flow K3 are alternately changed within a preset period. Preferably, the air flow K2 is 0.85 times the air flow K1, and the air flow K3 is 1.3-1.35 times the air flow K1. Further explanation: since the moisture in the stack 22 is mainly generated at the cathode, the water content at the cathode will continue to increase, and the proton exchange membrane is easier to wet. When the air flow is H2, the air flowing out of the cathode outlet of the stack 22 will carry less moisture, ensuring that the proton exchange membrane at the cathode can be better wetted. When the air flow is H3, the single cell can be quickly purged to remove the excessive water generated at the cathode, which can also avoid flooding at the cathode. Through the above-mentioned adjustment method, the impedance value of the proton exchange membrane can be returned to the range of the impedance threshold, so that the proton exchange membrane is converted from a non-wetting state to a wetting state.

[0062] To further explain, when the proton exchange membrane is too wet, the impedance value of the proton exchange membrane is less than the impedance threshold. At this time, the current I1 of the stack 22 is maintained unchanged, and the air flow rate K1 is adjusted to the air flow rate K3. Specifically, maintaining the current of the stack 22 unchanged can ensure that the moisture on the proton exchange membrane will not increase further. By increasing the air flow rate, the cathode side of the stack 22 can be fully purged, thereby bringing out more moisture, thereby reducing the wetting degree of the proton exchange membrane. In addition to adjusting the current and air flow of the stack 22, it is also necessary to adjust the hydrogen flow rate, specifically to adjust the hydrogen flow rate H1 to the hydrogen flow rate H2 or the hydrogen flow rate H3 (H3 is 0.9 times of H1), and the hydrogen flow rate H2 and the hydrogen flow rate H3 are at the same level as the preset value. Assuming that alternating changes are performed within a cycle, it is further explained that by adjusting the hydrogen flow rate H1 to the hydrogen flow rate H3, the amount of hydrogen required for the reaction is reduced, which can reduce the generation of water to a certain extent, thereby reducing the humidity of the proton exchange membrane. By adjusting the hydrogen flow rate H1 to the hydrogen flow rate H2, when the air flow rate remains unchanged, the generation of water will not increase. At the same time, the gas flow rate on the anode side of the stack 22 can be increased, so that the gas flowing out of the outlet of the anode side of the stack 22 can carry more water, further reducing the wetting degree of the proton exchange membrane in the stack 22. Through the above-mentioned adjustment method, the impedance value of the proton exchange membrane can be returned to the range of the impedance threshold, so that the proton exchange membrane is changed from a non-wetting state to a wetting state.

[0063] To further explain, when the proton exchange membrane changes from a non-wetting state to a wetting state, since the fuel cell stack 22 has been adjusted during the process of the proton exchange membrane changing from a non-wetting state to a wetting state, the fuel cell stack 22 already has a certain temperature; if the outlet temperature of the fuel cell stack 22 is lower than 5°C at this time, the fuel cell stack 22 enters a low-temperature start-up mode; if the outlet temperature of the fuel cell stack 22 is higher than 5°C at this time, the fuel cell stack 22 enters a normal temperature start-up mode.

[0064] Although the present invention is disclosed through the above embodiments, the protection scope of the present invention is not limited thereto. Without departing from the concept of the present invention, any deformation or replacement of the above components shall fall within the scope of the claims of the present invention.

Claims

1. A fuel cell engine cooling system, characterized in that: include: A heat exchanger is used to exchange heat between different systems; a first cooling system is connected to one end of the heat exchanger, and the first cooling system includes a fuel cell stack and a first water pump connected in sequence through a first pipe; a second cooling system is connected to the other end of the heat exchanger, and the second cooling system includes a second water pump, an intercooler and a radiator connected in parallel on the second pipe; both the first pipe and the second pipe contain coolant, and the coolant in the first pipe is less than the coolant in the second pipe.

2. A fuel cell engine cooling system according to claim 1, characterized in that: The flow direction of the coolant in the first pipe is opposite to the flow direction of the coolant in the second pipe.

3. A fuel cell engine cooling system according to claim 1, characterized in that: Also includes: At least one deionizer is used to reduce the ion concentration of the coolant in the first pipeline; the deionizer is installed at the liquid inlet and / or liquid outlet of the fuel cell stack to improve the insulation of the fuel cell stack.

4. A fuel cell engine cooling system according to claim 1, characterized in that: Also includes: A first expansion water tank and a second expansion water tank; the first expansion water tank is installed in the first pipeline, the second expansion water tank is installed in the second pipeline, and the second expansion water tank is connected to the radiator; an air extraction pump is connected to the second expansion water tank and is used to extract air from the coolant in the second pipeline.

5. A fuel cell engine cooling system according to claim 1, characterized in that: The second cooling system further includes: a DC / DC converter, an air compressor and a controller connected in parallel to the second pipeline.

6. A fuel cell engine cooling system according to claim 1, characterized in that: The second cooling system also includes: a PTC heater connected to the liquid inlet of the second water pump, used to provide heat for the coolant in the second cooling system; a thermostat installed in the second pipe, used to control the flow direction of the coolant in the second cooling system; the thermostat includes an a end, a b end and a c end, wherein the a end is connected to the heat exchanger, the b end is connected to the radiator, and the c end is connected to the PTC heater.

7. A fuel cell engine cooling system according to claim 5, characterized in that: The second cooling system further includes: flow limiting holes, which are respectively provided at the liquid inlets of the intercooler, the DC / DC converter and the air compressor, and the flow limiting holes are used to limit the flow of the coolant.

8. The fuel cell engine cooling system according to claim 1, characterized in that: Also includes: Two filters are installed on the first pipe and the second pipe respectively, and the filters are used to remove particulate impurities contained in the coolant.

9. The fuel cell engine cooling system according to claim 1, characterized in that: The coolant is ethylene glycol or water.

10. A vehicle comprising the cooling system according to any one of claims 1 to 9.

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