A method and device for controlling temperature and humidity of an air-cooled hydrogen fuel cell

Abstract

The present invention discloses a method and device for controlling temperature and humidity of an air-cooled hydrogen fuel cell, comprising an air-cooled hydrogen fuel cell, a reflux hot gas humidity control device, a hydrogen storage system, a three-way valve 1, a three-way valve 2, a cold and hot air mixing chamber, an air filter, an air inlet fan, a temperature and humidity sensor 1, a temperature and humidity sensor 2, a temperature and humidity sensor 3 and an electronic control unit (ECU). Through the hot gas reflux of the scheme, the environmental adaptability of the cathode open air-cooled hydrogen fuel cell is improved without significantly increasing parasitic power consumption and additional weight. The temperature and humidity required for the normal and efficient operation of the air-cooled fuel cell are controlled separately, which is more variable-specific and more beneficial to creating a scene suitable for the fuel cell reaction. The monitoring and control of the system are integrated in the electronic control unit, which has autonomous control capability. The control form has a simple flow, high execution efficiency, and is safe and reliable.

Description

Technical Field

[0001] The present invention relates to a temperature and humidity control device and method for a hydrogen fuel cell, and in particular to a temperature and humidity control method and device for an air-cooled hydrogen fuel cell. Background Art

[0002] With the strong support of the national fuel cell-related policies, proton exchange membrane hydrogen fuel cell technology has developed rapidly. At present, water-cooled hydrogen fuel cells and air-cooled hydrogen fuel cells are used in the aviation field internationally. Air-cooled hydrogen fuel cells are widely used in China. Compared with water-cooled hydrogen fuel cells, they have the advantages of higher system unit mass power, low parasitic weight and low parasitic power consumption, but they are inferior in environmental adaptability. Air-cooled proton exchange membrane fuel cells generally have difficulties in cold start at low temperatures and difficulty in maintaining core temperature in low temperature environments. Since the cathode side of the air-cooled proton exchange membrane fuel cell will generate water from oxygen in the air and hydrogen protons migrating through the membrane during the reaction, the proton exchange membrane, as a key component of the fuel cell, also needs to maintain a certain amount of liquid water, that is, a soaked state, in order to maintain normal operation. In a low temperature (below 0°C) environment, this water is very easy to freeze, block the gas flow channel, affect the characteristic size of the membrane electrode, and even cause the membrane to rupture and reverse polarity, which is extremely unfavorable to the normal and safe use of hydrogen fuel cells. At present, there are mainly the following methods to improve the adaptability of air-cooled hydrogen fuel cells to low-temperature environments: 1. Heating the inlet air, 2. Using the waste heat generated by the air-cooled fuel cell to exchange heat with the inlet air, 3. Introducing an appropriate amount of hydrogen on the cathode side in advance to completely convert its chemical energy into thermal energy to increase the core temperature. These methods can solve the problem of low-temperature use of air-cooled fuel cells to a certain extent, but there are problems such as large parasitic power consumption, low heat exchange efficiency and a certain degree of danger, and the core temperature cannot be maintained for a long time.

[0003] The present invention provides a hydrogen fuel cell temperature and humidity control device and method, which greatly improves the low-temperature environment adaptability of air-cooled fuel cells at the lowest possible weight and power consumption cost. While the proton exchange membrane hydrogen fuel cell generates electrical power, it basically also generates an equal amount of thermal power. Fully and effectively utilizing this part of heat is of great significance for broadening the application scenarios of air-cooled fuel cells. Summary of the invention

[0004] The object of the present invention is to provide a method and device for controlling temperature and humidity of an air-cooled hydrogen fuel cell to solve the problems raised in the above-mentioned background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A method for controlling temperature and humidity of an air-cooled hydrogen fuel cell, the specific steps are as follows:

[0007] 1) First, turn on the power of the electronic control unit (ECU), which will collect signals from various sensors to determine whether to start the fuel cell;

[0008] 2) If the gas pressure in the hydrogen storage system is lower than the set minimum starting pressure, the instruction to open the solenoid valve will not be executed;

[0009] 3) If it is higher than the set minimum starting air pressure, the working environment of the fuel cell at this time is determined by combining the collected air temperature and humidity and core temperature data;

[0010] 4) Open the solenoid valve to control the air inlet fan to start. At the beginning of the startup, if the fuel cell inlet air temperature is low and the humidity is appropriate, the hot air discharge of the three-way valve 2 is reduced, the hot air circulation volume is increased, and the speed of the air inlet fan and the fuel cell fan is reduced at the same time, so as to increase the air temperature output to the fuel cell inlet end after mixing in the cold and hot air mixing chamber, and reduce the heat of the fuel cell stack carried away by the airflow. After the core temperature rises to a level suitable for the normal operation of the fuel cell (generally not less than 50°C), the core temperature of the fuel cell is maintained by jointly controlling the hot air reflux ratio of the three-way valve 2, the air inlet fan speed and the fuel cell fan speed;

[0011] 5) If the air temperature at the fuel cell inlet is high, the internal circulation will not be started, and the hot and humid air generated by the fuel cell will be discharged through the hot and humid air discharge valve;

[0012] 6) If it is detected that the humidity of the gas at the inlet of the mixed gas is high, it is necessary to partially separate and dehydrate the exhausted hot and humid air through a humidity-controlled dehumidification device, increase the air flow rate entering the gas drying chamber, and reduce the air flow rate entering the humidity holding chamber;

[0013] 7) If it is detected that the humidity of the gas at the inlet of the mixed gas is low, the opposite is true.

[0014] A device for controlling temperature and humidity of an air-cooled hydrogen fuel cell, comprising an air-cooled hydrogen fuel cell, a reflux hot air humidity control device, a hydrogen storage system, a three-way valve 1, a three-way valve 2, a cold and hot air mixing chamber, an air filter, an air inlet fan, a temperature and humidity sensor 1, a temperature and humidity sensor 2, a temperature and humidity sensor 3 and an electronic control unit (ECU), wherein the anode side of the air-cooled hydrogen fuel cell is connected to the hydrogen storage system through a solenoid valve and a pressure reducing valve, the cathode air inlet side end face interface is connected to the output end interface of the cold and hot air mixing chamber, and the air outlet interface of the air-cooled hydrogen fuel cell is connected to the outlet interface of the hot and humid air with a flow The input port of the three-way valve 1 with a flow control function is connected, the three-way valve 1 is provided with two air flow outputs, the upper air flow output passes through the gas drying chamber, and water vapor adsorption material or high molecular water-absorbing resin or molecular sieve can be used to achieve complete separation of water vapor and hot air, the lower air flow output passes through the flow control valve and enters the humidity holding chamber, the two hot air flows are gathered in the hot air mixing chamber, the mixed hot air passes through the three-way valve 2 with flow control function, and then is output to the hot and cold air mixing chamber, the other end of the hot and cold air mixing chamber inputs external cold air through the air filter and the air inlet fan.

[0015] As a further solution of the present invention: the structural design of the three-way valve 2 is the same as that of the three-way valve 1, and the three-way valve 2 is used to control the flow rate of the reflux hot gas.

[0016] As a further solution of the present invention: the electronic control unit collects the temperature and humidity of the air flow output from the cold and hot air mixing chamber to the air intake end face of the fuel cell through the temperature and humidity sensor 1.

[0017] As a further solution of the present invention: a core temperature sensor is provided inside the air-cooled fuel cell to collect the core temperature of the fuel cell.

[0018] As a further solution of the present invention: a temperature and humidity sensor 2 arranged at the fan outlet of the air-cooled hydrogen fuel cell collects the temperature and humidity of the hot and humid air at the fan outlet.

[0019] As a further solution of the present invention: a temperature and humidity sensor 3 arranged at the outside air inlet collects the temperature and humidity of the outside air.

[0020] As a further solution of the present invention: a pressure sensor arranged at the bottle mouth of the hydrogen storage system collects the hydrogen pressure in the gas cylinder to determine the remaining gas volume in the hydrogen storage system.

[0021] As a further solution of the present invention: the output signal includes an air inlet fan speed control signal, a fuel cell hydrogen inlet solenoid valve opening and closing signal, a fuel cell fan speed control signal, an upstream and downstream flow ratio control signal of the three-way valve 1 with flow control function, a hot gas release ratio control signal of the three-way valve 2 with flow control function, and a humid hot air release valve opening and closing signal.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. Through the hot gas reflow of this solution, the environmental adaptability of the cathode open air-cooled hydrogen fuel cell is improved without significantly increasing parasitic power consumption and additional weight.

[0024] 2. The temperature and humidity required for the normal and efficient operation of air-cooled fuel cells are controlled separately, which is more variable-specific and more conducive to creating a scene suitable for fuel cell reactions.

[0025] 3. The system's monitoring and control are integrated in the electronic control unit, which has autonomous control capabilities. Its control form is simple in process, highly efficient in execution, safe and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The present invention is a structural schematic diagram of a method and device for controlling temperature and humidity of an air-cooled hydrogen fuel cell. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] See also Figure 1In an embodiment of the present invention, a device for controlling temperature and humidity of an air-cooled hydrogen fuel cell is provided. Before use, the cathode open air-cooled hydrogen fuel cell should keep its core temperature above 0°C to prevent water from freezing in the membrane. The anode side is connected to the hydrogen storage system through a solenoid valve and a pressure reducing valve. The cathode air inlet side end face interface is connected to the output end interface of the hot and cold air mixing chamber. The hot and humid air outlet interface of the fuel cell is connected to the input port of a three-way valve 1 with a flow control function. The three-way valve 1 has two air flow outputs. The flow ratio of the two air flow outputs can be controlled by the flow control valve inside it. The upper path completely passes through the gas drying chamber, and water vapor adsorption materials or polymer water-absorbing resins or separation can be used. Sub-sieves, etc. are used to achieve complete separation of water vapor and hot air. The lower path passes through the flow control valve and enters the humidity holding chamber. Then the two hot air flows converge in the hot air mixing chamber. The mixed hot air passes through the three-way valve 2 with flow control function and is output to the cold and hot air mixing chamber. It is also one input and two outputs. The three-way valve 2 is mainly used to control the flow of the reflux hot air to achieve the purpose of controlling the temperature after the cold and hot air are mixed. The other end of the cold and hot air mixing chamber is input with external cold air through the air filter and the air inlet fan. The air filter is used to filter dust, carbon monoxide, sulfur oxides, etc. in the inhaled air to prevent impurity gases from having adverse effects on the performance of the membrane electrode;

[0029] The electronic control unit collects the temperature and humidity of the airflow output from the cold and hot air mixing chamber to the intake end face of the fuel cell through the temperature and humidity sensor 1, collects the fuel cell core temperature through the core temperature sensor set inside the fuel cell, collects the temperature and humidity of the hot and humid air at the fan outlet through the temperature and humidity sensor 2 set at the fuel cell fan outlet, collects the temperature and humidity of the outside air through the temperature and humidity sensor 3 set at the outside air inlet, and collects the hydrogen pressure in the gas cylinder through the pressure sensor set at the bottle mouth of the hydrogen storage system, so as to judge the remaining gas volume in the hydrogen storage system. The output signal includes the air inlet fan speed control signal, the fuel cell hydrogen inlet solenoid valve opening and closing signal, the fuel cell fan speed control signal, the up and down flow ratio control signal of the three-way valve 1 with flow control function, the hot gas discharge ratio control signal of the three-way valve 2 with flow control function, and the hot and humid air discharge valve opening and closing signal.

[0030] A method for controlling temperature and humidity of an air-cooled hydrogen fuel cell, the specific steps are as follows:

[0031] 1) First, turn on the power of the electronic control unit (ECU), which will collect signals from various sensors to determine whether to start the fuel cell;

[0032] 2) If the gas pressure in the hydrogen storage system is lower than the set minimum starting pressure, the instruction to open the solenoid valve will not be executed;

[0033] 3) If it is higher than the set minimum starting air pressure, the working environment of the fuel cell at this time is determined by combining the collected air temperature and humidity and core temperature data;

[0034] 4) Open the solenoid valve to control the air inlet fan to start. At the beginning of the startup, if the fuel cell inlet air temperature is low and the humidity is appropriate, the hot air discharge of the three-way valve 2 is reduced, the hot air circulation volume is increased, and the speed of the air inlet fan and the fuel cell fan is reduced at the same time, so as to increase the air temperature output to the fuel cell inlet end after mixing in the cold and hot air mixing chamber, and reduce the heat of the fuel cell stack carried away by the airflow. After the core temperature rises to a level suitable for the normal operation of the fuel cell (generally not less than 50°C), the core temperature of the fuel cell is maintained by jointly controlling the hot air reflux ratio of the three-way valve 2, the air inlet fan speed and the fuel cell fan speed;

[0035] 5) If the air temperature at the fuel cell inlet is high, the internal circulation will not be started, and the hot and humid air generated by the fuel cell will be discharged through the hot and humid air discharge valve;

[0036] 6) If it is detected that the humidity of the gas at the inlet of the mixed gas is high, it is necessary to partially separate and dehydrate the exhausted hot and humid air through a humidity-controlled dehumidification device, increase the air flow rate entering the gas drying chamber, and reduce the air flow rate entering the humidity holding chamber;

[0037] 7) If it is detected that the humidity of the gas at the inlet of the mixed gas is low, the opposite is true.

[0038] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for controlling temperature and humidity of an air-cooled hydrogen fuel cell, characterized in that: The anode side of the air-cooled hydrogen fuel cell is connected to the hydrogen storage system through a solenoid valve and a pressure reducing valve, and the cathode air inlet side end face interface is connected to the output end interface of the cold and hot air mixing chamber, and the humid hot air outlet interface of the air-cooled hydrogen fuel cell is connected to the input port of the three-way valve 1 with a flow control function. The three-way valve 1 is provided with two airflow outputs. The upper airflow output passes through the gas drying chamber, and a polymer water-absorbing resin or a molecular sieve is used to achieve complete separation of water vapor and hot air. The lower airflow output passes through the flow control valve and enters the humidity holding chamber. The two hot air flows are collected in the hot air mixing chamber. The mixed hot air passes through the three-way valve 2 with a flow control function, and then output to the cold and hot air mixing chamber. The other end of the cold and hot air mixing chamber inputs external cold air through an air filter and an air inlet fan. The specific steps are as follows: 1) First, turn on the power of the electronic control unit (ECU), which will collect signals from various sensors to determine whether to start the fuel cell; 2) If the gas pressure in the hydrogen storage system is lower than the set minimum starting pressure, the instruction to open the solenoid valve will not be executed; 3) If it is higher than the set minimum starting air pressure, the working environment of the fuel cell at this time is determined by combining the collected air temperature and humidity and core temperature data; 4) Open the solenoid valve to control the air inlet fan to start. At the beginning of the startup, if the fuel cell inlet air temperature is low and the humidity is appropriate, the hot air discharge of the three-way valve 2 is reduced, the hot air circulation volume is increased, and the speed of the air inlet fan and the fuel cell fan is reduced at the same time, so as to increase the air temperature output to the fuel cell inlet end after the cold and hot air mixing chamber is mixed, and reduce the heat of the fuel cell stack carried away by the airflow. After the core temperature rises to not less than 50°C, the core temperature of the fuel cell is maintained by jointly controlling the hot air reflux ratio of the three-way valve 2, the air inlet fan speed and the fuel cell fan speed; 5) If the air temperature at the fuel cell inlet is high, the internal circulation will not be started, and the hot and humid air generated by the fuel cell will be discharged through the hot and humid air discharge valve; 6) If it is detected that the humidity of the gas at the inlet of the mixed gas is high, it is necessary to partially separate and dehydrate the exhausted hot and humid air through a humidity-controlled dehumidification device, increase the air flow rate entering the gas drying chamber, and reduce the air flow rate entering the humidity holding chamber; 7) If it is detected that the humidity of the gas at the inlet of the mixed gas is low, the opposite is true.

2. A device for controlling temperature and humidity of an air-cooled hydrogen fuel cell using the control method of claim 1, comprising an air-cooled hydrogen fuel cell, a humidity-controllable water removal device, a hydrogen storage system, a three-way valve 1, a three-way valve 2, a cold and hot air mixing chamber, an air filter, an air inlet fan, a temperature and humidity sensor 1, a temperature and humidity sensor 2, a temperature and humidity sensor 3 and an electronic control unit (ECU), characterized in that: The anode side of the air-cooled hydrogen fuel cell is connected to the hydrogen storage system through a solenoid valve and a pressure reducing valve, and the cathode air inlet side end face interface is connected to the output end interface of the cold and hot air mixing chamber, and the humid hot air outlet interface of the air-cooled hydrogen fuel cell is connected to the input port of the three-way valve 1 with a flow control function. The three-way valve 1 is provided with two air flow outputs. The upper air flow output passes through the gas drying chamber, and a polymer water-absorbing resin or a molecular sieve is used to achieve complete separation of water vapor and hot air. The lower air flow output passes through the flow control valve and enters the humidity holding chamber. The two hot air flows converge in the hot air mixing chamber, and the mixed hot air passes through the three-way valve 2 with a flow control function, and then is output to the cold and hot air mixing chamber. The other end of the cold and hot air mixing chamber inputs external cold air through an air filter and an air inlet fan.

3. The device for controlling temperature and humidity of an air-cooled hydrogen fuel cell according to claim 2, characterized in that: The structural design of the three-way valve 2 is the same as that of the three-way valve 1, and the three-way valve 2 is used to control the flow rate of the reflux hot gas.

4. The device for controlling temperature and humidity of an air-cooled hydrogen fuel cell according to claim 2, characterized in that: The electronic control unit collects the temperature and humidity of the airflow output from the cold and hot air mixing chamber to the air intake end face of the fuel cell through the temperature and humidity sensor 1.

5. The device for controlling temperature and humidity of an air-cooled hydrogen fuel cell according to claim 2, characterized in that: A core temperature sensor is provided inside the air-cooled fuel cell to collect the fuel cell core temperature.

6. The device for controlling temperature and humidity of an air-cooled hydrogen fuel cell according to claim 2, characterized in that: The temperature and humidity sensor 2 arranged at the fan outlet of the air-cooled hydrogen fuel cell collects the temperature and humidity of the hot and humid air at the fan outlet.

7. The device for controlling temperature and humidity of an air-cooled hydrogen fuel cell according to claim 2, characterized in that: The temperature and humidity sensor 3 arranged on the air inlet fan collects the temperature and humidity of the external air.

8. The device for controlling temperature and humidity of an air-cooled hydrogen fuel cell according to claim 2, characterized in that: The pressure sensor arranged at the bottle mouth of the hydrogen storage system collects the hydrogen pressure in the gas cylinder and determines the remaining gas volume in the hydrogen storage system.

9. The device for controlling temperature and humidity of an air-cooled hydrogen fuel cell according to claim 2, characterized in that: The signals collected by the electronic control unit (ECU) include an air inlet fan speed control signal, a fuel cell hydrogen inlet solenoid valve opening and closing signal, a fuel cell fan speed control signal, an upstream and downstream flow ratio control signal of a three-way valve 1 with a flow control function, a hot gas release ratio control signal of a three-way valve 2 with a flow control function, and a humid hot air release valve opening and closing signal.

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