Cathode closed type air-cooled fuel cell stack and heating method

Abstract

The invention belongs to the technical field of fuel cells, and particularly relates to a cathode closed type air-cooled fuel cell stack and a heating method, the cathode closed type air-cooled fuel cell stack comprises a stack, an upper computer, and a temperature detector, a heating device, a stack air inlet pipe, a stack exhaust pipeline and an air pump which are connected with the upper computer; the heating device is arranged on the electric pile and is used for heating the electric pile; the temperature detectors are arranged at a cathode air inlet and a cathode air outlet of the galvanic pile and are used for monitoring air temperatures at the two positions; the air pump is connected with a cathode exhaust port of the galvanic pile through a galvanic pile exhaust pipeline, and is connected with a cathode air inlet of the galvanic pile through a galvanic pile air inlet pipe; the galvanic pile, the galvanic pile exhaust pipeline, the air pump and the galvanic pile air inlet pipe form a circulation loop; the upper computer is used for adjusting the opening degree and / or the direction of an electric pile exhaust pipeline according to the received temperature data sent by the temperature detector, so that the air pump can intake tail gas or external air from an electric pile cathode; and the electric pile is started according to the set starting temperature of the electric pile and the detected temperature.

Description

Technical Field

[0001] The present invention belongs to the technical field of fuel cells, and particularly relates to a cathode-closed air-cooled fuel cell stack and a heating method thereof. Background Art

[0002] At present, air-cooled fuel cell stacks can be divided into cathode-open type and cathode-closed type. For cathode-open air-cooled fuel cells, since the cathode flow field needs to simultaneously have the functions of cathode air intake and heat dissipation, a gas intake metering ratio dozens of times is often required. In the case of a large air volume, the membrane electrode is relatively dry, the battery internal resistance is large, and the performance is poor. For cathode-closed air-cooled fuel cells, the cathode air intake and heat dissipation are carried out through independent channels. Therefore, the membrane electrode can ensure a certain humidity, and the battery performance is higher than that of the open-type air-cooled fuel cell. The main application scenarios of closed-type air-cooled fuel cells are small aircraft, portable power supplies, etc. There are relatively high requirements for the volume of the fuel cell stack and the compactness of the system layout. Therefore, the number of components, volume, and mass of the fuel cell stack will be reduced as much as possible. The common heating method for the cathode-closed type is to use internal fins and external heating wires to blow air for heating. Due to space and volume limitations, it is impossible to carry out a complex uniform air duct design for the heating and blowing device. Due to the limitations of distance and heat dissipation conditions, different single cells cannot achieve uniform heating, thus affecting the performance and service life of the fuel cell stack. Summary of the Invention

[0003] The purpose of the present invention is to provide a cathode-closed air-cooled fuel cell stack and a heating method thereof that use an air pump and a three-way solenoid valve to achieve self-circulation to promote uniform temperature distribution and improve the performance consistency and service life of the fuel cell stack, so as to solve the problem in the current cathode-closed air-cooled fuel cell stack that uniform heating cannot be achieved, thus affecting the performance and service life of the fuel cell stack.

[0004] The technical solution adopted by the present invention to achieve the above purpose is: a cathode-closed air-cooled fuel cell stack, including: a fuel cell stack, a host computer, and a temperature detector, a heating device, a fuel cell stack intake pipe, a fuel cell stack exhaust pipe, and an air pump connected to the host computer.

[0005] The heating device is arranged on the fuel cell stack and is used to heat the fuel cell stack according to the instruction issued by the host computer.

[0006] The temperature detector is arranged at the cathode air intake and cathode air exhaust of the fuel cell stack and is used to monitor the air temperature at the cathode air intake and cathode air exhaust and send it to the host computer.

[0007] The air pump is connected to the cathode air exhaust of the fuel cell stack through the fuel cell stack exhaust pipe, and the air outlet joint of the air pump is connected to the cathode air intake of the fuel cell stack through the fuel cell stack intake pipe and is used to supply air to the fuel cell stack.

[0008] The stack, the stack exhaust pipeline, the air pump, and the stack intake pipeline form a circulation loop.

[0009] The host computer is used to control the start and stop of the heating device. At the same time, according to the temperature data received from the temperature detector, it adjusts the opening degree and / or direction of the stack exhaust pipeline to enable the air pump to intake air from the cathode exhaust gas of the stack or the outside air; and according to the set start temperature of the stack and the detected temperature, it realizes the start of the stack.

[0010] The stack is composed of multiple single-cell units connected in series, and a set of fins is installed between every three single-cell units.

[0011] The heating device includes a fan, a wind hood, and a heating wire.

[0012] The edges of the wind hood are respectively fixed above the first end of the first single-cell unit and the first end of the last single-cell unit to form a sealed space; the first ends of the multiple single-cells and the second ends of the multiple single-cells are opposite to each other.

[0013] A through hole is opened at the center of the wind hood, and a fan is fixed at the through hole.

[0014] The heating wire is arranged below the stack to heat the stack.

[0015] The power of the heating wire is 50 - 200W.

[0016] The temperature detector includes a first temperature detector and a second temperature detector.

[0017] The first temperature detector is arranged at the cathode air inlet of the stack to monitor the air temperature at the cathode air inlet.

[0018] The second temperature detector is arranged at the cathode air outlet of the stack to monitor the air temperature at the cathode air outlet.

[0019] The stack exhaust pipeline includes an exhaust pipeline, an intake pipeline A, an intake pipeline B, a three-way solenoid valve A, and a three-way solenoid valve B.

[0020] A three-way solenoid valve B and a three-way solenoid valve A are sequentially arranged on the exhaust pipeline between the cathode exhaust port of the stack and the air inlet of the air pump.

[0021] The three-way solenoid valve A is respectively connected to the intake pipeline A, the outlet end of the three-way solenoid valve B, and the air inlet joint of the air pump.

[0022] The three-way solenoid valve B is respectively connected to the intake pipeline B, the intake end of the three-way solenoid valve A, and the cathode exhaust port of the stack.

[0023] The three-way solenoid valve A and the three-way solenoid valve B are respectively connected to the host computer, and the opening degree and / or direction of the three-way solenoid valve A and the three-way solenoid valve B are adjusted through the host computer to realize the intake of the air pump from the cathode exhaust gas of the stack or the outside air.

[0024] A heating method for a cathode-closed air-cooled fuel cell stack includes the following steps: 1) The host computer turns on the heating wire to heat the stack, and at the same time turns on the fan to make the hot air flow through the fins between each single cell unit to heat the stack.

[0025] 2) The host computer adjusts the three-way solenoid valve A and the three-way solenoid valve B to connect the air inlet of the air pump with the cathode outlet of the stack.

[0026] 3) Start the air pump to realize the gas circulation at the inlet and outlet of the cathode of the stack.

[0027] 4) The temperature detector monitors the air temperature at the cathode air inlet and the cathode exhaust outlet in real time and sends it to the host computer.

[0028] 5) The host computer judges the state of the stack according to the air temperature at the cathode air inlet and the cathode exhaust outlet monitored in real time and the set start temperature of the stack, adjusts the three-way solenoid valve A and the three-way solenoid valve B, and then performs the stack start operation.

[0029] The specific content of step 5) is as follows: The real-time temperature measured by the first temperature detector is T 1 , the real-time temperature measured by the second temperature detector is T 2 , and the set start temperature of the stack is T; where, T 2 > T 1 , heat T 1 to T - 1 ≤ T 1 ≤ T + 1, and then adjust the three-way solenoid valve A and the three-way solenoid valve B.

[0030] The adjustment of the three-way solenoid valve A and the three-way solenoid valve B includes two situations, specifically: When T ≥ T 2 - 2, the host computer judges that the temperature inside the stack is uniform at this time, stops heating the heating wire, adjusts the three-way solenoid valve A to communicate with the intake pipe A, and adjusts the three-way solenoid valve B to communicate with the intake pipe B, and then starts the stack.

[0031] When T < T 2 - 2, the host computer judges that the outlet gas temperature of the stack is too high at this time, stops heating the heating wire, continues to circulate the cathode air until T 2 - 2 < T < T 1 + 2, adjust the three-way solenoid valve A to communicate with the intake pipe A, and adjust the three-way solenoid valve B to communicate with the intake pipe B, and then start the stack.

[0032] The present invention has the following beneficial effects and advantages: 1. The method of the present invention for judging whether the stack is heated evenly by the temperature difference between the inlet and outlet does not require temperature monitoring of multiple battery cells, simplifies the system design, improves the temperature uniformity of different numbers of battery cells and different positions of a single battery cell during the stack temperature rise, thereby improving the performance consistency and stability during stack startup;

[0033] 2. Through the coordinated control of the air pump and the three-way solenoid valve, the present invention realizes the closed-loop circulation of the cathode exhaust gas and the intelligent switching with the outside air, significantly improving the stack heating uniformity. Compared with the comparative example, the voltage fluctuations of the present invention are reduced to 6.19 mV and 5.34 mV respectively, and the consistency is improved by more than 70%;

[0034] 3. The present invention not only simplifies the temperature monitoring system (only the inlet and outlet temperatures need to be monitored), but also avoids local overheating by dynamically adjusting the air flow path, extending the stack life;

[0035] 4. The compact circulation loop design of the present invention is suitable for miniaturized application scenarios (such as UAV power supplies), taking into account efficient heating and system lightweight in a limited space, and solving the long-existing problem of unstable startup performance of closed-air-cooled fuel cells. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 System framework diagram of Embodiment 1 of the present invention.

[0037] Figure 2 Performance effect diagram of each single cell of the stack during startup in Embodiment 1 of the present invention.

[0038] Figure 3 System framework diagram of Embodiment 2 of the present invention.

[0039] Figure 4 Performance effect diagram of each single cell of the stack during startup in Embodiment 2 of the present invention.

[0040] Figure 5 System framework diagram of the comparative example of the prior art.

[0041] Figure 6 Performance effect diagram of each single cell of the stack during startup in the comparative example of the prior art.

[0042] Among them, 1 is the fuel cell stack, 2 is the fan, 3 is the air shroud, 4 is the heating wire, 5 is the fuel cell stack intake pipe, 6 is the fuel cell stack exhaust pipe, 7 is the air pump, 11 is the single cell unit, 12 is the fin, 13 is the cathode air inlet, 14 is the cathode air outlet, 15 is the first temperature detector, 16 is the second temperature detector, 61 is the intake pipe A, 62 is the intake pipe B, 63 is the three-way solenoid valve A, 64 is the three-way solenoid valve B, 71 is the air outlet joint, and 72 is the air inlet joint. Detailed implementation mode

[0043] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0044] The present invention proposes a heating method for a closed air-cooled fuel cell stack. By means of the air path circulation, the uniformity of the fuel cell stack temperature can be improved. And by monitoring the inlet and outlet temperatures and comparing their differences, it can be simply judged whether the fuel cell stack is heated evenly, without complex battery temperature monitoring, which can reduce the temperature difference between different single cells of the fuel cell stack and improve the performance consistency of the fuel cell stack.

[0045] The heating device of the closed air-cooled fuel cell stack usually consists of the fins, air shroud, fan and heating wire built in the fuel cell stack. After the heating wire is heated, a hot air flow is formed by the fan inlet air, so as to heat the fuel cell stack by the fins. However, due to the application scenarios of the closed air-cooled fuel cell (small portable power supply, UAV power supply) limitations, it is impossible to design a complex air shroud and heating temperature change system to heat the fuel cell stack evenly, resulting in poor performance and consistency of the fuel cell stack during the startup stage.

[0046] Based on the above heating method, the present invention realizes the circulation of the hot air flow in the fuel cell stack through the channel switching of two three-way solenoid valves, so as to evenly heat the fuel cell stack. Specifically, as Figure 1 and 3 shown, it is the system structure schematic diagram of two embodiments of the present invention; a cathode closed air-cooled fuel cell stack of the present invention includes: a fuel cell stack 1, a host computer, and a temperature detector, a heating device, a fuel cell stack intake pipe 5, a fuel cell stack exhaust pipe 6, and an air pump 7 connected to the host computer.

[0047] The heating device is arranged on the fuel cell stack 1 and is used to heat the fuel cell stack according to the instruction issued by the host computer.

[0048] The temperature detector is arranged at the cathode air inlet 13 and the cathode air outlet 14 of the fuel cell stack 1, and is used to monitor the air temperatures at the cathode air inlet 13 and the cathode air outlet 14 and send them to the host computer.

[0049] The air pump is connected to the cathode air outlet 14 of the fuel cell stack 1 through the fuel cell stack exhaust pipe 6, and the air outlet joint 71 of the air pump 7 is connected to the cathode air inlet 13 of the fuel cell stack 1 through the fuel cell stack intake pipe 5, and is used to supply air to the fuel cell stack 1.

[0050] The stack 1, the stack exhaust gas pipeline 6, the air pump 7, and the stack intake air pipeline 5 form a circulation loop.

[0051] The host computer is used to control the start and stop of the heating device. At the same time, according to the temperature data received from the temperature detector, it adjusts the opening degree and / or direction of the stack exhaust gas pipeline 6 to enable the air pump to intake air from the cathode exhaust gas of the stack or the outside air; and according to the set start temperature of the stack and the detected temperature, it realizes the start of the stack.

[0052] Among them, the stack in the present invention is: multiple single cell units 11 connected in series, and a group of fins 12 is installed between every three single cell units 11. In Embodiment 1 and Embodiment 2, 4 groups of 12 single cell units and 3 groups of 9 single cell units are respectively selected for effect testing.

[0053] In the present invention, the heating device includes: a fan 2, a wind hood 3, and a heating wire 4.

[0054] The edges of the wind hood 3 are respectively fixed above the first end of the first single cell unit and the first end of the last single cell unit to form a sealed space; the first ends of the multiple single cells and the second ends of the multiple single cells are opposite to each other.

[0055] A through hole is opened at the center of the wind hood 3, and a fan 2 is fixed at the through hole.

[0056] The heating wire is arranged below the stack to heat the stack.

[0057] The power of the heating wire is 50 - 200W.

[0058] The temperature detector includes: a first temperature detector 15 and a second temperature detector 16.

[0059] The first temperature detector 15 is arranged at the cathode air inlet 13 of the stack 1 to monitor the air temperature at the cathode air inlet 13.

[0060] The second temperature detector 16 is arranged at the cathode air outlet of the stack 1 to monitor the air temperature at the cathode air outlet.

[0061] The stack exhaust gas pipeline 6 includes: an exhaust gas pipeline, an intake air pipeline A61, an intake air pipeline B62, a three-way solenoid valve A63, and a three-way solenoid valve B64.

[0062] A three-way solenoid valve B64 and a three-way solenoid valve A63 are sequentially arranged on the exhaust gas pipeline between the cathode exhaust port 14 of the stack 1 and the air inlet of the air pump.

[0063] The three-way solenoid valve A63 is respectively connected to the intake air pipeline A61, the outlet end of the three-way solenoid valve B64, and the air intake joint 72 of the air pump 7.

[0064] The three-way solenoid valve B64 is respectively connected to the intake pipeline B62, the intake end of the three-way solenoid valve A63, and the cathode exhaust port 14 of the fuel cell stack 1.

[0065] The three-way solenoid valve A63 and the three-way solenoid valve B64 are respectively connected to the host computer. By adjusting the opening degree and / or direction of the three-way solenoid valve A63 and the three-way solenoid valve B64 through the host computer, the air pump can intake air from the cathode tail gas of the fuel cell stack or the outside air.

[0066] Further, after arranging the battery fuel cell stack system as shown in the present invention Figure 1 and 3 After that, the fuel cell stack is heated. The present invention proposes a heating method for a cathode-closed air-cooled fuel cell stack, including the following steps: 1) The host computer turns on the heating wire 4 to heat the fuel cell stack 1. At the same time, the fan 2 is turned on to make the hot air flow through the fins 12 between each single cell unit 11 to heat the fuel cell stack.

[0067] 2) The host computer adjusts the three-way solenoid valve A63 and the three-way solenoid valve B64 to make the intake port of the air pump 7 communicate with the cathode outlet of the fuel cell stack 1.

[0068] 3) Start the air pump 7 to realize the circulation of the inlet and outlet gases at the cathode of the fuel cell stack 1.

[0069] 4) The temperature detector monitors the air temperature at the cathode intake port 13 and the cathode exhaust port 14 in real time and sends it to the host computer.

[0070] 5) The host computer judges the state of the fuel cell stack 1 according to the air temperature at the cathode intake port 13 and the cathode exhaust port 14 monitored in real time and the set start temperature of the fuel cell stack. After adjusting the three-way solenoid valve A63 and the three-way solenoid valve B64, the fuel cell stack start operation is carried out.

[0071] Among them, the real-time temperature measured by the first temperature detector is T 1 , the real-time temperature measured by the second temperature detector is T 2 , and the set start temperature of the fuel cell stack is T; among them, T 2 > T 1 , heat T 1 to T - 1 ≤ T 1 ≤ T + 1, and then adjust the three-way solenoid valve A63 and the three-way solenoid valve B64.

[0072] Adjusting the three-way solenoid valve A63 and the three-way solenoid valve B64 includes two situations, specifically: When T ≥ T 2-2, the host computer determines that the temperature inside the fuel cell stack 1 is uniform at this time, then stops the heating wire from heating, adjusts the three-way solenoid valve A63 to communicate with the intake pipe A61, and adjusts the three-way solenoid valve B64 to communicate with the intake pipe B62, and then starts the fuel cell stack; When T < T 2 -2, the host computer determines that the outlet gas temperature of the fuel cell stack 1 is too high at this time, then stops the heating wire from heating, continues to circulate the cathode air, until T 2 -2 < T < T 1 +2, adjusts the three-way solenoid valve A63 to communicate with the intake pipe A61, and adjusts the three-way solenoid valve B64 to communicate with the intake pipe B62, and then starts the fuel cell stack.

[0073] To verify the technical effects and practical application value of the present invention, the following conducts systematic tests and analyzes through specific examples and comparative examples. The example constructs a cathode closed-loop circulation system based on the foregoing technical solution, dynamically optimizes the gas circulation path inside the fuel cell stack through the coordinated action of regulating the three-way solenoid valve and the air pump; at the same time, combines the heating device and the temperature feedback mechanism to quantitatively evaluate the temperature uniformity and voltage consistency during the start-up stage of the fuel cell stack. During the test process, the example comprehensively verifies the adaptability of the present invention through different configurations of the number of single cells (12 and 9), heating power (50W and 100W), and start-up temperature threshold (35°C and 40°C), and forms a sharp contrast with the comparative example of the traditional heating method, intuitively demonstrating its significant advantages in temperature control accuracy, performance stability, and miniaturized integration.

[0074] Example 1:

[0075] As Figure 1 shown, the number of cells of the test fuel cell stack 1 is 12, the electrode area is 30 cm 2 , one fin is installed every 3 cells, and the fin and the cell are fixed by the pressure formed by the fuel cell stack screw or strap. A wind hood 3 is installed above the fuel cell stack, and the wind hood is fixed on the end plate by screws. A through hole is opened at the top of the wind hood 2 to install a fan, which is fixed on the wind hood 2 by screws. The power of the heating wire 4 is 50W, and both ends are connected through insulating devices (the appropriate shape can be 3D printed) and fixed by screws at a position 2 cm from the bottom end of the fuel cell stack. Set the start-up temperature T to 35°C, adjust the three-way solenoid valve A63 and the three-way solenoid valve B64, so that the intake port of the air pump 7 is the cathode outlet of the fuel cell stack. At the same time, start the heating wire 4, the fan 2, and the air pump 7. After 25 s, the real-time temperature measured by the first temperature detector 15 is T 1 is 34°C, and the real-time temperature T 2is 36°C, and at this time, it is considered that the inside of the stack is heated evenly. Adjust the three-way solenoid valve A63 and the three-way solenoid valve B64, adjust the three-way solenoid valve A63 to communicate with the intake pipe A61, and adjust the three-way solenoid valve B64 to communicate with the intake pipe B62. Hydrogen is introduced into the stack 1, and the set load current is 30 A for discharging. The performance of a single cell of the stack during startup is as Figure 2 .

[0076] Example 2:

[0077] As Figure 3 shown, the number of cells of the tested stack 1 is 9, the electrode area is 30 cm 2 , the power of the heating wire 4 is 100 W, and the rest of the structure and installation method are the same as those in Example 1. Set the startup temperature T to 40°C, start the fan 2 to heat the stack. After 18 s, the real-time temperature T 1 measured by the first temperature detector 15 is 38°C, and the real-time temperature T 2 measured by the second temperature detector 16 is 45°C. At this time, stop heating with the heating wire, continue to circulate the cathode air for 2.5 s, and then T 1 is 40°C, and T 2 is 42°C. At this time, it is considered that the inside of the stack is heated evenly. Adjust the three-way solenoid valve A63 and the three-way solenoid valve B64, adjust the three-way solenoid valve A63 to communicate with the intake pipe A61, and adjust the three-way solenoid valve B64 to communicate with the intake pipe B62. The stack 1 is normally ventilated, and the set load current is 30 A for discharging. The performance of a single cell of the stack during startup is as Figure 4 .

[0078] Comparative example: As Figure 5 shown, the number of cells of the tested stack 1 is 12, the electrode area is 30 cm 2 , the power of the heating wire 4 is 50 W, the set startup temperature T is 35°C, start the heating wire 4 and the fan 2 at the same time. After 25 s, the real-time temperature measured by the first temperature detector 15 is T 1 is 25°C, and the real-time temperature T 2 measured by the second temperature detector 16 is 46°C. The stack 1 is normally ventilated, and the set load current is 30 A for discharging. The performance of a single cell of the stack during startup is as Figure 6 shown.

[0079] The consistency of the stack voltage startup performance of 2 examples and 1 comparative example is as follows in the table: Table 1 Comparison of battery performance consistency Stack Example 1 Example 2 Comparative Example Stack voltage consistency / mV 6.19 5.34 23.64 It can be seen from the comparison in the above table that the voltage consistency of Example 1 and Example 2 is higher than that of the comparative example, indicating that the stack heating method proposed in the present invention can effectively promote the uniformity of temperature distribution, thereby improving the consistency of stack voltage and the stability of operation.

[0080] According to the above embodiments and comparative examples, Embodiment 1 and Embodiment 2 respectively adopt 12 - cell and 9 - cell single - cell unit configurations, verifying the universality and efficiency of the present invention. By adjusting the three - way solenoid valve to achieve cathode exhaust gas circulation, combined with the synergistic effect of heating wires (50W / 100W) and fans, the fuel cell stack reaches the set startup temperature (35°C / 40°C) within 25 seconds (Embodiment 1) and 18 seconds (Embodiment 2), and the temperature difference between the inlet and outlet is controlled within 2°C and 5°C respectively, indicating that the temperature distribution inside the fuel cell stack is highly uniform. The comparative example adopts the traditional heating method, with the temperature difference between the inlet and outlet as high as 21°C and the voltage consistency only being 23.64mV, far inferior to 6.19mV and 5.34mV of the present invention. The data comparison fully proves that through the closed - loop circulation and dynamic temperature control strategy, the present invention significantly reduces the temperature gradient inside the fuel cell stack, improves the startup stability and long - term service life, providing an efficient and compact solution for miniaturized fuel cell systems.

[0081] In summary, through the innovative loop design and intelligent temperature control strategy, the present invention significantly improves the heating uniformity and startup performance of the fuel cell stack. The core lies in the synergistic control of the air pump and the three - way solenoid valve to construct a cathode exhaust gas closed - loop circulation system, combined with the real - time analysis of temperature data by the upper computer to dynamically adjust the air flow path (fuel cell stack exhaust gas or external air), thereby optimizing the temperature distribution inside the fuel cell stack. In addition, by only monitoring the temperature difference between the cathode inlet and outlet, the overall heating uniformity can be judged, simplifying the system complexity. The heating device integrates a fan, a wind cover and heating wires, and with the fin design, efficient heat conduction is achieved in a limited space. The technical solution of the present invention effectively solves the problem of performance fluctuations caused by local overheating in closed - type air - cooled fuel cells, significantly improves the voltage consistency of the fuel cell stack (the fluctuation is reduced to 5 - 6mV in the embodiments, better than 23.64mV of the comparative example), and at the same time is suitable for miniaturized application scenarios such as UAV power supplies, with both lightweight and high reliability.

[0082] Those skilled in the art can understand that the above - mentioned are only the preferred embodiments of the present invention. The features described in each embodiment and / or claim of the present disclosure can be combined or combined in various ways, even if such combinations or combinations are not explicitly recorded in the present disclosure. It is not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

[0083] Although the preferred embodiments of the present invention have been described, additional changes and modifications can be made to these embodiments by those skilled in the art once they learn of the basic inventive concept. Therefore, the appended claims are intended to be construed to include the preferred embodiments as well as all changes and modifications that fall within the scope of the present invention. Obviously, those skilled in the art can make various changes and variations to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims

1. A cathode-enclosed air-cooled fuel cell stack, characterized in that: include: A fuel cell stack (1), a host computer and a temperature detector connected to the host computer, a heating device, a fuel cell stack air intake pipe (5), a fuel cell stack exhaust pipe (6), and an air pump (7); The heating device is arranged on the battery stack (1) and is used to heat the battery stack according to instructions issued by the host computer; The temperature detector is arranged at the cathode air inlet (13) and the cathode exhaust port (14) of the fuel cell stack (1), and is used to monitor the air temperature at the cathode air inlet (13) and the cathode exhaust port (14), and transmit the temperature to the host computer; The air pump is connected to the cathode exhaust port (14) of the fuel cell stack (1) via the fuel cell stack exhaust pipeline (6), and the air outlet connector (71) of the air pump (7) is connected to the cathode air inlet port (13) of the fuel cell stack (1) via the fuel cell stack air inlet pipe (5), so as to supply air to the fuel cell stack (1); The fuel cell stack (1), the fuel cell stack exhaust pipeline (6), the air pump (7), and the fuel cell stack air intake pipe (5) form a circulation loop; The host computer is used to control the start and stop of the heating device, and at the same time, according to the temperature data sent by the temperature detector, adjust the opening and / or direction of the stack exhaust pipeline (6) to achieve the intake of the air pump from the cathode exhaust gas of the stack or the outside air; and according to the set start-up temperature of the stack and the detected temperature, the stack is started.

2. A cathode-enclosed air-cooled fuel cell stack according to claim 1, characterized in that: The battery stack comprises: a plurality of single battery units (11) connected in series with each other, and a group of fins (12) is installed between every three single battery units (11).

3. The cathode-enclosed air-cooled fuel cell stack according to claim 1, characterized in that: The heating device comprises: a fan (2), a wind shield (3) and a heating wire (4); The edges of the wind shield (3) are respectively fixed above the first end of the head-end single battery unit and the first end of the tail-end single battery unit to form a closed space; the first end of the multiple single batteries and the second end of the multiple single batteries are opposite to each other; A through hole is provided at the center of the wind cover (3), and a fan (2) is fixedly installed at the through hole; The heating wire is arranged under the battery stack to heat the battery stack.

4. The cathode-enclosed air-cooled fuel cell stack according to claim 3, characterized in that: The power of the heating wire is 50-200W.

5. The cathode-enclosed air-cooled fuel cell stack according to claim 1, characterized in that: The temperature detector comprises: a first temperature detector (15) and a second temperature detector (16); The first temperature detector (15) is arranged at the cathode air inlet (13) of the fuel cell stack (1) and is used to monitor the air temperature of the cathode air inlet (13); The second temperature detector (16) is arranged at the cathode gas outlet of the fuel cell stack (1) and is used to monitor the air temperature at the cathode gas outlet.

6. The cathode-enclosed air-cooled fuel cell stack according to claim 1, characterized in that: The stack exhaust pipeline (6) comprises: an exhaust pipeline, an intake pipeline A (61), an intake pipeline B (62), a three-way solenoid valve A (63) and a three-way solenoid valve B (64); A three-way solenoid valve B (64) and a three-way solenoid valve A (63) are sequentially provided on an exhaust pipeline between a cathode exhaust port (14) of the fuel cell stack (1) and an air inlet of an air pump; The three-way solenoid valve A (63) is respectively connected to the air inlet pipeline A (61), the air outlet end of the three-way solenoid valve B (64) and the air inlet connector (72) of the air pump (7); The three-way solenoid valve B (64) is respectively connected to the air intake pipeline B (62), the air intake end of the three-way solenoid valve A (63) and the cathode exhaust port (14) of the fuel cell stack (1); The three-way solenoid valve A (63) and the three-way solenoid valve B (64) are respectively connected to a host computer, and the opening and / or direction of the three-way solenoid valve A (63) and the three-way solenoid valve B (64) are adjusted by the host computer to achieve air intake from the cathode tail gas of the fuel cell stack or external air for the air pump.

7. The method for heating a cathode closed air-cooled fuel cell stack according to claim 1, characterized in that: The following steps are involved: 1) The host computer turns on the heating wire (4) to heat the battery stack (1), and at the same time turns on the fan (2) to allow the hot air flow to pass through the fins (12) between each single battery unit (11) to heat the battery stack; 2) The host computer adjusts the three-way solenoid valve A (63) and the three-way solenoid valve B (64) so ​​that the air inlet of the air pump (7) is connected to the cathode outlet of the fuel cell stack (1); 3) starting the gas pump (7) to achieve inlet and outlet gas circulation at the cathode of the fuel cell stack (1); 4) The temperature detector monitors the air temperature at the cathode air inlet (13) and the cathode exhaust port (14) in real time and sends the temperature to the host computer; 5) The host computer determines the state of the fuel cell stack (1) based on the real-time monitoring of the air temperature at the cathode air inlet (13) and the cathode exhaust port (14) and the fuel cell stack set start temperature, adjusts the three-way solenoid valve A (63) and the three-way solenoid valve B (64), and then performs the fuel cell stack start operation.

8. The method for heating a cathode closed air-cooled fuel cell stack according to claim 7, characterized in that: The step 5) is specifically: The real-time temperature measured by the first temperature detector is T1, the real-time temperature measured by the second temperature detector is T2, and the starting temperature of the fuel cell stack is set to T; wherein, T2>T1, after T1 is heated to T-1≤T1≤T+1, the three-way solenoid valve A (63) and the three-way solenoid valve B (64) are adjusted.

9. A method for heating a cathode closed air-cooled fuel cell stack according to claim 8, characterized in that: The regulating three-way solenoid valve A (63) and the three-way solenoid valve B (64) include two situations, specifically: When T≥T2-2, the upper computer determines that the temperature in the fuel cell stack (1) is uniform, and stops heating the heating wire. The three-way solenoid valve A (63) is adjusted to be connected to the intake pipe A (61), and the three-way solenoid valve B (64) is adjusted to be connected to the intake pipe B (62), and then the fuel cell stack is started; When T<T2-2, the upper computer determines that the outlet gas temperature of the fuel cell stack (1) is too high, and stops heating the heating wire. The cathode air continues to circulate until T2-2<T<T1+2. The three-way solenoid valve A (63) is adjusted to be connected to the intake pipe A (61), and the three-way solenoid valve B (64) is adjusted to be connected to the intake pipe B (62), and then the fuel cell stack is started.

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