Fuel cell thermal management device and method

Abstract

The invention relates to the technical field of new energy, and discloses a fuel cell thermal management device and method.The fuel cell thermal management device comprises a plurality of fuel cell electric piles arranged in parallel, any fuel cell electric pile is connected with a thermal control system, and every two adjacent thermal control systems are controllably connected; any thermal control system comprises an electronic three-way valve with an A end connected with a cooling inlet of the fuel cell stack, a B end connected with a radiator, an input end of the radiator connected with a water pump, an input end of the water pump connected with a cooling outlet of the fuel cell stack, and a C end connected with an output end of the water pump. A cooling inlet and a cooling outlet of the fuel cell stack are correspondingly provided with a water inlet temperature sensor and a water outlet temperature sensor respectively; while the cold start speed of the fuel cell of the whole vehicle is ensured, heating devices are saved, the production cost is effectively reduced, the hydrogen utilization rate is improved, the overall efficiency is improved, and the system is suitable for being applied to heavy vehicles such as mine trucks requiring high power and long endurance.

Description

Technical Field

[0001] The present application relates to the field of new energy technology, and specifically to a fuel cell thermal management device and method. Background Art

[0002] The hydrogen fuel cell system generates electricity through the electrochemical reaction between the air at the cathode and the hydrogen at the anode on the proton exchange membrane. During the reaction, only water is produced without greenhouse gases and pollutants such as carbon oxides, nitrogen oxides and sulfides. Therefore, the hydrogen fuel cell system is a very clean energy solution. At the same time, compared with heat engines, the hydrogen fuel cell system is not limited by the Carnot cycle, so its efficiency can reach more than 50%, which is a very efficient energy solution. Finally, because the volume energy density and mass energy density of the hydrogen fuel cell system are much higher than those of lithium batteries, hydrogen fuel cell vehicles have a longer range and there is no mileage anxiety.

[0003] However, the disadvantages of hydrogen fuel cell systems are equally obvious. First, the hydrogen that undergoes electrochemical reactions is a secondary energy source and needs to be prepared by other means. Therefore, the current cost of hydrogen is expensive and the cost of use is high. Secondly, the platinum catalyst used in hydrogen fuel cells is expensive, which causes the material cost of hydrogen fuel cell stacks to remain high. Thirdly, hydrogen fuel cells are limited by the aging of platinum catalysts and metal bipolar plate coatings, resulting in their overall lifespan of up to 8000 hours, which is still a certain distance compared to thermal engines. Finally, hydrogen is a flammable and explosive gas with an explosion limit of 4%-75.6%. If it is not stored properly, it will have very dangerous consequences.

[0004] The cold start problem of the fuel cell stack is an important issue that needs to be solved urgently during the actual use of hydrogen fuel cells. Current hydrogen fuel cell systems generally use technical solutions such as water heating PTC, heat pump air conditioning, and fuel cell stack electric heaters to meet the low-temperature cold start requirements of the fuel cell stack.

[0005] When a hydrogen fuel cell stack is started in an environment below 0°C without any heating measures, the water generated by the reaction of hydrogen and oxygen and the water provided by the humidifier will freeze during the startup process, resulting in a reduction in the catalyst active area and obstruction of the air transmission path, causing a sudden drop in the stack voltage, leading to stack startup failure; at the same time, water changes from liquid to solid and increases in volume, causing irreversible structural damage to the proton exchange membrane.

[0006] A fuel cell system and method of use are disclosed, providing a method for recovering electrical energy from cathode exhaust gas of an evaporatively cooled fuel cell system, providing a method for recovering excess electrical energy using a dedicated generator and connecting a turbine to a common motor of an air compressor to reduce the net input power of the motor.

[0007] Disclosed are a fuel cell thermal management system, a fuel cell system, and a vehicle having the system. The heating system in the invention comprises a coolant heating system, an exhaust gas heating system, and an electric heating system, wherein the exhaust gas heating system is used to control the exhaust gas heating system to start and provide heating together with the coolant heating system when the maximum heating temperature of the coolant heating system is lower than a preset heating temperature.

[0008] Mining trucks have high demands for system power and are generally composed of two or more systems in parallel. The cold start process of each system is independent and identical. Most existing fuel cell systems use PTC heating for individual heating. The heating efficiency of the battery stack coolant is low and the overall heating energy consumption is high. Existing fuel cell thermal management devices are not suitable for heavy vehicles such as mining trucks that have high power demands and long endurance requirements.

[0009] Application Contents

[0010] The purpose of this application is to provide a fuel cell thermal management device and method that saves heating devices, effectively reduces production costs, improves hydrogen utilization, and improves overall efficiency while ensuring the cold start speed of the entire vehicle fuel cell. The device and method are suitable for use in heavy-duty vehicles such as mining trucks that require high power and long endurance.

[0011] In order to achieve the above object, the present invention adopts the following technical solutions:

[0012] A fuel cell thermal management device of the present invention comprises a plurality of fuel cell stacks arranged in parallel, any of the fuel cell stacks is connected to a thermal control system, the input ends of two adjacent thermal control systems are connected, and the output ends of two adjacent thermal control systems are controllably connected;

[0013] Any of the thermal control systems comprises an electronic three-way valve whose A end is connected to the cooling inlet of the fuel cell stack, whose B end is connected to a radiator, whose input end is connected to a water pump, whose input end is connected to the cooling outlet of the fuel cell stack, whose C end is connected to an output end of the water pump, whose cooling inlet of the fuel cell stack is provided with a water inlet temperature sensor, whose cooling outlet of the fuel cell stack is provided with a water outlet temperature sensor;

[0014] Any one of the thermal control systems further includes a heating component, wherein an input end of the heating component is connected to an output end of the water pump, and an input end of the heating component is connected to a C end of the electronic three-way valve.

[0015] Furthermore, the heating component includes a PTC heater and a first switch valve, and the water pump is connected in parallel with the C end of the electronic tee through the PTC heater and the first switch valve.

[0016] Furthermore, the output end of the thermal control system is connected to the output end of an adjacent thermal control system through a second switch valve.

[0017] A fuel cell thermal management method, which obtains the temperature data of the cooling fluid in the corresponding thermal control system by monitoring the water temperature sensor of the thermal control system connected to the heating component. If the temperature is lower than T1°C, the system enters the cold start mode, otherwise it starts at normal temperature.

[0018] Close the electronic three-way valves of all thermal control systems, and simultaneously start the water pump of the thermal control system connected to the heating component, cut off the connection between multiple thermal control systems, and heat the cooling fluid in the corresponding thermal control system to a temperature higher than T1°C through the heating component;

[0019] The fuel cell stack connected to the thermal control system with a cooling fluid temperature higher than T1°C is started and operated at a certain power to heat the cooling fluid;

[0020] When the temperature of the cooling fluid of the thermal control system connected to the heating component is higher than T2°C, where T2 is greater than T1, the output end and the input end of the thermal control system adjacent to the thermal control system are controlled to be connected to the thermal control system, and the water pumps of the two thermal control systems are turned on at the same time. While the fuel cell stack connected to the heating component is running, the fuel cell stack adjacent to the fuel cell stack starts cold start, and so on, driving the fuel cell system of the entire vehicle to complete the cold start;

[0021] When the temperature of the cooling fluid in all thermal control systems is higher than T2°C, the connection between multiple thermal control systems is blocked, the heating function of the heating component is turned off, and the electronic three-way valve of each thermal control system is opened, and each operates normally through the corresponding radiator to dissipate heat.

[0022] Furthermore, when the heating component needs to be heated, the first switch valve is closed on the basis of closing the electronic three-way valve, so that the cooling fluid flows through the flow channel of the PTC heater to heat the cooling fluid;

[0023] When the temperature of the cooling fluid in all thermal control systems is higher than T°C, the first switch valve is opened on the basis of opening the electronic three-way valve, and the heating function of the PTC heater is turned off, so that the heating component stops heating the cooling fluid.

[0024] Furthermore, during the cold start of the fuel cell stacks one by one, when the temperature of the cooling fluid in the thermal control system is higher than T2°C, the second switch valve is opened so that the output end and the input end of the thermal control system adjacent to the thermal control system are both connected to the thermal control system;

[0025] When the temperature of the cooling fluid in all the thermal control systems is higher than T2°C, the second switch valve is closed, so that each thermal control system can operate independently of each other in terms of heat dissipation.

[0026] Compared with the prior art, the beneficial effects of this application are:

[0027] In practical applications, the flow of cooling fluid is regulated by a water pump to control the temperature difference of the cooling fluid between the cooling inlet and the cooling outlet of the fuel cell stack. The water inlet temperature sensor is used to monitor the cooling fluid temperature at the cooling inlet of the fuel cell stack. The water outlet temperature sensor is used to monitor the cooling fluid temperature at the cooling outlet of the fuel cell stack. The radiator is used to dissipate heat for the cooling fluid normally. The heating component is used to heat the cooling fluid during cold start. The electronic three-way valve is used to switch the flow direction of the cooling fluid, thereby controlling the switching of heating or heat dissipation of the cooling fluid. The opening and closing of the electronic three-way valve is controlled according to the temperature signals monitored by the water inlet temperature sensor and the water outlet temperature sensor of the thermal control system connected to the heating component, thereby realizing the conversion between heating and heat dissipation of the cooling fluid. When the heating component heats the cooling fluid to a certain temperature, the corresponding connected fuel cell stack starts to run and generates heat, and the cooling fluid is heated together. Only A heating component is connected to a thermal control system. Since the input ends of two adjacent thermal control systems are connected and the output ends of the two adjacent thermal control systems are controllably connected, when the cooling fluid in the thermal control system connected to the heating component reaches a certain temperature, the thermal control system connected to the heating component is connected to the thermal control system adjacent to the thermal control system, and then the cooling fluid in the adjacent thermal control system is driven to heat and increase the temperature through one thermal control system. Similarly, the heat generated by the start-up and operation of two fuel cell stacks connected to the two thermal control systems is superimposed to heat and increase the temperature of the cooling fluid in the next thermal control system, thereby achieving an accelerated cold start of the corresponding fuel cell stack. While ensuring the cold start speed of the fuel cell of the entire vehicle, the present application saves heating devices, effectively reduces production costs, improves hydrogen utilization, and improves overall efficiency. It is suitable for heavy-duty vehicles such as mining trucks that require high power and long endurance. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the implementation methods of the present application, the drawings required for use in the implementation methods will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 is a schematic diagram of the electrical structure of this application;

[0030] Figure 2 It is a flow chart of the method of this application.

[0031] Reference numerals: electronic three-way valve 1; water inlet temperature sensor 2; fuel cell stack 3; water outlet temperature sensor 4; water pump 5; first switch valve 6; PTC heater 7; radiator 8; second switch valve 9. DETAILED DESCRIPTION

[0032] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0033] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and thus the drawings only show the layers related to the present invention rather than being drawn according to the number, shape and size of the layers in actual implementation. In actual implementation, the type, quantity and proportion of each layer may be changed arbitrarily, and the layer layout may also be more complicated.

[0034] In the following description, numerous details are discussed to provide a more thorough explanation of embodiments of the present invention; however, it is apparent to one skilled in the art that embodiments of the present invention may be practiced without these specific details.

[0035] See also Figure 1 , a fuel cell thermal management device, comprising a plurality of fuel cell stacks 3 arranged in parallel, any of the fuel cell stacks 3 being connected to a thermal control system, the input ends of two adjacent thermal control systems being connected, and the output ends of two adjacent thermal control systems being controllably connected;

[0036] Any of the thermal control systems includes an electronic three-way valve 1 whose A end is connected to the cooling inlet of the fuel cell stack 3, a radiator 8 is connected to the B end of the electronic three-way valve 1, a water pump 5 is connected to the input end of the radiator 8, the input end of the water pump 5 is connected to the cooling outlet of the fuel cell stack 3, the C end of the electronic three-way valve 1 is connected to an output end of the water pump 5, a water inlet temperature sensor 2 is provided at the cooling inlet of the fuel cell stack 3, and a water outlet temperature sensor 4 is provided at the cooling outlet of the fuel cell stack 3;

[0037] Any one of the thermal control systems further includes a heating component, the input end of the heating component is connected to an output end of the water pump 5 , and the input end of the heating component is connected to the C end of the electronic three-way valve 1 .

[0038] The flow rate of the cooling fluid is regulated by the water pump 5 to control the temperature difference of the cooling fluid between the cooling inlet and the cooling outlet of the fuel cell stack 3. The water inlet temperature sensor 2 is used to monitor the cooling fluid temperature at the cooling inlet of the fuel cell stack 3. The water outlet temperature sensor 4 is used to monitor the cooling fluid temperature at the cooling outlet of the fuel cell stack 3. The radiator 8 is used to dissipate heat for the cooling fluid normally. The heating component is used to heat the cooling fluid during cold start. The electronic three-way valve 1 is used to switch the flow direction of the cooling fluid, thereby controlling the switching of heating or heat dissipation of the cooling fluid. The opening and closing of the electronic three-way valve 1 is controlled according to the temperature signals monitored by the water inlet temperature sensor 2 and the water outlet temperature sensor 4 of the thermal control system connected to the heating component, thereby realizing the conversion between heating and heat dissipation of the cooling fluid. When the heating component heats the cooling fluid to a certain temperature, the correspondingly connected fuel cell stack 3 starts to run and generates heat, and together heats the cooling fluid to increase the temperature. ; A heating component is only connected to one thermal control system. Since the input ends of two adjacent thermal control systems are connected and the output ends of two adjacent thermal control systems are controllably connected, when the cooling fluid in the thermal control system connected to the heating component reaches a certain temperature, the thermal control system connected to the heating component is connected to the thermal control system adjacent to the thermal control system, and then the cooling fluid in the adjacent thermal control system is driven to heat and increase the temperature through one thermal control system. Similarly, the heat generated by the start-up and operation of the two fuel cell stacks 3 connected to the two thermal control systems is superimposed to heat and increase the temperature of the cooling fluid in the next thermal control system, thereby accelerating the cold start of the corresponding fuel cell stack 3. While ensuring the cold start speed of the whole vehicle fuel cell, the present application saves heating devices, effectively reduces production costs, improves hydrogen utilization, and improves overall efficiency. It is suitable for heavy-duty vehicles such as mining trucks that require high power and long endurance.

[0039] See also Figure 1 The heating component includes a PTC heater 7 and a first switch valve 6, and the water pump 5 is connected in parallel with the C end of the electronic tee through the PTC heater 7 and the first switch valve 6.

[0040] In this embodiment, after the first switch valve 6 and the PTC heater 7 are connected in parallel, one output end of the water pump 5 is connected to the C end of the electronic three-way valve 1. The first switch valve 6 is used to switch the cooling fluid flow in the PTC heater 7 to coordinate the switching of cooling fluid heating and heat dissipation of the fuel cell system.

[0041] See also Figure 1 The output end of the thermal control system is connected to the output end of the adjacent thermal control system through the second switch valve 9.

[0042] In this embodiment, the second switch valve 9 is used to control the on-off between two adjacent thermal control systems to achieve a controllable connection between the two adjacent thermal control systems.

[0043] See also Figure 2 , a fuel cell thermal management method, which obtains the temperature data of the cooling fluid in the corresponding thermal control system by monitoring the water temperature sensor of the thermal control system connected to the heating component. If the temperature is lower than T1°C, it enters the cold start mode, otherwise it starts at normal temperature;

[0044] Close the electronic three-way valves 1 of all thermal control systems, and simultaneously open the water pump 5 of the thermal control system connected to the heating component, so as to block the communication between the multiple thermal control systems, and heat the cooling fluid in the corresponding thermal control system to a temperature higher than T1°C through the heating component;

[0045] The fuel cell stack 3 connected to the thermal control system with a cooling fluid temperature higher than T1°C is started and operated at a certain power to heat the cooling fluid;

[0046] When the temperature of the cooling fluid of the thermal control system connected to the heating component is higher than T2°C, where T2 is greater than T1, the output end and the input end of the thermal control system adjacent to the thermal control system are controlled to be connected to the thermal control system, and the water pumps 5 of the two thermal control systems are turned on at the same time. While the fuel cell stack 3 connected to the heating component is running, the fuel cell stack 3 adjacent to the fuel cell stack 3 starts cold start, and so on, driving the whole vehicle fuel cell system to complete the cold start;

[0047] When the temperature of the cooling fluid in all thermal control systems is higher than T2°C, the connection between the multiple thermal control systems is blocked, the heating function of the heating component is turned off, and the electronic three-way valve 1 of each thermal control system is opened, and each of them operates normally through the corresponding radiator 8 to dissipate heat.

[0048] The temperature of the cooling fluid is monitored by the water inlet temperature sensor 2 and the water outlet temperature sensor 4, and the temperature data monitored by the water inlet temperature sensor 2 and the water outlet temperature sensor 4 are taken as the smaller one. If the temperature data is less than T1°C, a cold start is performed. During the cold start process of the whole vehicle, the cooling fluid in a thermal control system is first heated to a temperature higher than T2°C by the heating component, and then the corresponding connected fuel cell stack 3 is operated, and the heat generated by the operation of the fuel cell stack 3 is superimposed on the cooling fluid to heat the cooling fluid in the next thermal control system, and so on, so that the fuel cell stacks 3 of the whole vehicle fuel cell system can be cold started quickly one by one, while ensuring the cold start speed of the whole vehicle fuel cell system, the heat energy generated by the fuel cell system is reasonably utilized, the hydrogen utilization rate is improved, the heating devices in the system are reduced, the production cost and power consumption are reduced, and the high power output of the power system is ensured. It is suitable for heavy-duty vehicles such as mining trucks that require high power and long endurance.

[0049] See also Figure 2When the heating component needs to be heated, the first switch valve 6 is closed on the basis of closing the electronic three-way valve 1, so that the cooling fluid flows through the flow channel of the PTC heater 7 to heat the cooling fluid;

[0050] When the temperature of the cooling fluid in all thermal control systems is higher than T2°C, on the basis of opening the electronic three-way valve 1, the first switch valve 6 is opened, and the heating function of the PTC heater 7 is turned off, so that the heating component stops heating the cooling fluid.

[0051] See also Figure 2 , during the cold start of the fuel cell stacks 3 one by one, when the temperature of the cooling fluid in the thermal control system is higher than T2°C, the second switch valve 9 is opened so that the output end and the input end of the thermal control system adjacent to the thermal control system are both connected to the thermal control system;

[0052] When the temperature of the cooling fluid in all the thermal control systems is higher than T2° C., the second switch valve 9 is closed, so that each thermal control system can operate independently of each other in terms of heat dissipation.

[0053] In this embodiment, the connection and blockage between multiple thermal control systems are controlled by the second switch valve 9. During the cold start process of the entire vehicle, the second switch valves 9 are opened one by one to realize the cold start of the fuel cell stacks 3 one by one, so that the heat generated by the fuel cell stacks 3 that are cold started first is added one by one to the cooling fluid of the next thermal control system to perform a cold start, thereby rationally utilizing the heat energy generated by the fuel cell system.

[0054] In the above-mentioned embodiments, although the present invention has been described in conjunction with the specific embodiments of the present invention, many replacements, modifications and variations of these embodiments will be apparent to those skilled in the art according to the foregoing description. The embodiments of the present invention are intended to cover all such replacements, modifications and variations falling within the broad scope of the appended claims.

[0055] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A fuel cell thermal management device, characterized in that: It comprises a plurality of fuel cell stacks (3) arranged in parallel, each of the fuel cell stacks (3) being connected to a thermal control system, the input ends of two adjacent thermal control systems being connected, and the output ends of two adjacent thermal control systems being controllably connected; Any of the thermal control systems comprises an electronic three-way valve (1) whose A end is connected to the cooling inlet of the fuel cell stack (3); the B end of the electronic three-way valve (1) is connected to a radiator (8); the input end of the radiator (8) is connected to a water pump (5); the input end of the water pump (5) is connected to the cooling outlet of the fuel cell stack (3); the C end of the electronic three-way valve (1) is connected to an output end of the water pump (5); the cooling inlet of the fuel cell stack (3) is provided with a water inlet temperature sensor (2); and the cooling outlet of the fuel cell stack (3) is provided with a water outlet temperature sensor (4); Any one of the thermal control systems further comprises a heating component, wherein the input end of the heating component is connected to an output end of the water pump (5), and the input end of the heating component is connected to the C end of the electronic three-way valve (1).

2. A fuel cell thermal management device according to claim 1, characterized in that: The heating component comprises a PTC heater (7) and a first switch valve (6), and the water pump (5) is connected in parallel with the C end of the electronic tee through the PTC heater (7) and the first switch valve (6).

3. A fuel cell thermal management device according to claim 1, characterized in that: The output end of the thermal control system is communicated with the output end of an adjacent thermal control system via a second switch valve (9).

4. A fuel cell thermal management method, characterized in that: The water temperature sensor of the thermal control system connected to the heating component is used to monitor and obtain the temperature data of the cooling fluid in the corresponding thermal control system. If the temperature is lower than T1°C, the system enters the cold start mode, otherwise it starts at normal temperature. The electronic three-way valves (1) of all thermal control systems are closed, and the water pump (5) of the thermal control system connected to the heating component is turned on at the same time, so as to block the communication between the multiple thermal control systems, and heat the cooling fluid in the correspondingly connected thermal control systems to a temperature higher than T1°C through the heating component; A fuel cell stack (3) connected to a thermal control system with a cooling fluid temperature higher than T1°C is started and operated at a certain power to heat the cooling fluid; When the temperature of the cooling fluid of the thermal control system connected to the heating component is higher than T2°C, wherein T2 is greater than T1, the output end and the input end of the thermal control system adjacent to the thermal control system are controlled to be connected to the thermal control system, and the water pumps (5) of the two thermal control systems are turned on at the same time, and while the fuel cell stack (3) connected to the heating component is running, the fuel cell stack (3) adjacent to the fuel cell stack (3) starts cold starting, and so on, driving the entire vehicle fuel cell system to complete cold starting; When the temperature of the cooling fluid in all thermal control systems is higher than T2°C, the connection between the multiple thermal control systems is blocked, the heating function of the heating component is turned off, and the electronic three-way valve (1) of each thermal control system is opened, so that each heatsink (8) dissipates heat and operates normally.

5. A fuel cell thermal management method according to claim 4, characterized in that: When the heating component needs to be heated, the first switch valve (6) is closed on the basis of closing the electronic three-way valve (1), so that the cooling fluid flows through the flow channel of the PTC heater (7) to heat the cooling fluid; When the temperature of the cooling fluid in all thermal control systems is higher than T2°C, on the basis of opening the electronic three-way valve (1), the first switch valve (6) is opened, and the heating function of the PTC heater (7) is turned off, so that the heating component stops heating the cooling fluid.

6. A fuel cell thermal management method according to claim 4, characterized in that: During the cold start of the fuel cell stacks (3) one by one, when the temperature of the cooling fluid in the thermal control system is higher than T2°C, the second switch valve (9) is opened so that the output end and the input end of the thermal control system adjacent to the thermal control system are both connected to the thermal control system; When the temperature of the cooling fluid in all the thermal control systems is higher than T2°C, the second switch valve (9) is closed, so that the thermal control systems can operate independently of each other in terms of heat dissipation.

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