A cathode-enclosed air-cooled fuel cell stack and heating method

Abstract

The present invention belongs to the field of fuel cell technology, specifically a cathode closed air-cooled fuel cell stack and heating method, comprising: a stack, a host computer and a temperature detector connected to the host computer, a heating device, a stack air inlet pipe, a stack exhaust pipe, and an air pump; the heating device is arranged on the stack for heating the stack; the temperature detector is arranged at the cathode air inlet and cathode exhaust port of the stack for monitoring the air temperature at the two locations; the air pump is connected to the cathode exhaust port of the stack through the stack exhaust pipe, and is connected to the cathode air inlet of the stack through the stack air inlet pipe; the stack, the stack exhaust pipe, the air pump, and the stack air inlet pipe form a circulation loop; the host computer is used to adjust the opening and / or direction of the stack exhaust pipe according to the temperature data sent by the temperature detector, so as to realize the air pump to intake air from the cathode exhaust gas of the stack or the outside air; and to start the stack according to the set starting temperature of the stack and the detected temperature.

Description

Technical Field

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

[0002] Currently, air-cooled fuel cell stacks can be divided into open-cathode and closed-cathode types. Open-cathode air-cooled fuel cells often require an air intake ratio of several dozen times higher because the cathode flow field must simultaneously provide cathode air intake and heat dissipation. Under high air volume conditions, the membrane electrode is relatively dry, resulting in a large internal resistance and poor performance. In closed-cathode air-cooled fuel cells, however, cathode air intake and heat dissipation are handled through independent channels, allowing the membrane electrode to maintain a certain humidity, resulting in higher battery performance than open-cathode air-cooled fuel cells. Closed-cathode air-cooled fuel cells are primarily used in small aircraft and portable power supplies. These applications place high demands on the stack size and compactness of the system layout, minimizing the number of components, volume, and mass within the stack. Closed-cathode stacks typically use internal fins and external heating wires for heating. However, space and volume limitations preclude the use of complex, uniform air duct designs for the heating and blowing devices. Distance and heat dissipation limits uniform heating of different cells, thus impacting the stack's performance and service life. Summary of the Invention

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

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

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

[0006] The temperature detectors are arranged at the cathode air inlet and cathode exhaust of the fuel cell stack, and are used to monitor the air temperature at the cathode air inlet and cathode exhaust, and send the temperature to the host computer.

[0007] The air pump is connected to the cathode exhaust port of the fuel cell stack through the fuel cell stack exhaust pipeline, and the air outlet connector of the air pump is connected to the cathode air inlet port of the fuel cell stack through the fuel cell stack air inlet pipe, so as to supply air to the fuel cell stack.

[0008] The fuel cell stack, fuel cell stack exhaust pipeline, air pump, and fuel cell stack air intake pipe 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 sent by the received temperature detector, it adjusts the opening and / or direction of the exhaust pipe of the fuel cell stack to enable the air pump to take in air from the cathode exhaust gas of the fuel cell stack or the outside air; and realizes the startup of the fuel cell stack according to the set startup temperature of the fuel cell stack and the detected temperature.

[0010] The battery stack comprises: a plurality of single battery units connected in series, and a group of fins is installed between every three single battery units.

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

[0012] The edges of the wind shield are respectively fixed above the first end of the head single battery unit and the first end of the tail single battery unit to form a closed space; the first ends of the multiple single batteries are opposite to the second ends of the multiple single batteries.

[0013] A through hole is provided at the center of the wind cover, and a fan is fixedly arranged at the through hole.

[0014] The heating wire is arranged under the battery stack to heat the battery 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 fuel cell stack and is used to monitor the air temperature at the cathode air inlet.

[0018] The second temperature detector is arranged at the cathode gas outlet of the fuel cell stack and is used to monitor the air temperature at the cathode gas 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 provided on the exhaust pipe between the cathode exhaust port of the fuel cell stack and the air inlet of the air pump.

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

[0022] The three-way solenoid valve B is respectively connected to the air intake line B, the air intake end of the three-way solenoid valve A and the cathode exhaust port of the fuel cell 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 and / or direction of the three-way solenoid valve A and the three-way solenoid valve B are adjusted by the host computer to realize the air pump to take in air from the cathode tail gas of the fuel cell stack or the outside air.

[0024] A method for heating a cathode-enclosed air-cooled fuel cell stack comprises the following steps:

[0025] 1) The host computer turns on the heating wire to heat the stack, and at the same time turns on the fan to allow the hot air flow to pass through the fins between each single battery unit to heat the stack.

[0026] 2) The host computer adjusts three-way solenoid valve A and three-way solenoid valve B to connect the air inlet of the air pump with the cathode outlet of the fuel cell stack.

[0027] 3) Start the air pump to achieve inlet and outlet gas circulation at the cathode of the fuel cell stack.

[0028] 4) The temperature detector monitors the air temperature at the cathode air inlet and cathode exhaust in real time and sends it to the host computer.

[0029] 5) The host computer determines the status of the stack based on the real-time monitoring of the air temperature at the cathode air inlet and cathode exhaust port and the stack start-up temperature, adjusts the three-way solenoid valve A and the three-way solenoid valve B, and then starts the stack.

[0030] The step 5) is specifically as follows:

[0031] The real-time temperature measured by the first temperature detector is T1, and the real-time temperature measured by the second temperature detector is T2. The starting temperature of the fuel cell stack is set to T; among them, T2>T1. After heating T1 to T-1≤T1≤T+1, adjust the three-way solenoid valve A and the three-way solenoid valve B.

[0032] The adjustment of the three-way solenoid valve A and the three-way solenoid valve B includes two situations, specifically:

[0033] When T≥T2-2, the host computer determines that the temperature inside the fuel cell stack is uniform. At this time, the heating wire is stopped, the three-way solenoid valve A is adjusted to be connected to the intake pipe A, and the three-way solenoid valve B is adjusted to be connected to the intake pipe B, and then the fuel cell stack is started.

[0034] When T<T2-2, the upper computer determines that the outlet gas temperature of the fuel cell stack is too high. At this time, the heating wire is stopped and the cathode air is continued to circulate until T2-2<T<T1+2. The three-way solenoid valve A is adjusted to connect with the intake pipe A, and the three-way solenoid valve B is adjusted to connect with the intake pipe B, and then the fuel cell stack is started.

[0035] The present invention has the following beneficial effects and advantages:

[0036] 1. This method, which uses the temperature difference between the inlet and outlet of the stack to determine whether the stack is heating uniformly, eliminates the need for temperature monitoring of multiple battery cells, simplifies system design, and improves temperature uniformity across different battery cells and at different locations within a single battery cell during stack heating, thereby enhancing stack performance consistency and stability during startup.

[0037] 2. This invention achieves closed-loop circulation of cathode exhaust gas and intelligent switching between external air through the coordinated control of the air pump and three-way solenoid valve, significantly improving the uniformity of stack heating. Compared with the comparative example, the voltage fluctuation of this invention is reduced to 6.19mV and 5.34mV, respectively, improving consistency by over 70%.

[0038] 3. This 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 airflow path, thereby extending the life of the fuel cell stack.

[0039] 4. The compact circulation loop design of this invention is suitable for miniaturized applications (such as drone power supply), balancing efficient heating and lightweight system within a limited space, solving the long-standing problem of unstable startup performance in closed air-cooled fuel cells. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 System framework diagram of embodiment 1 of the present invention.

[0041] Figure 2 Performance renderings of each single cell in the stack during startup of Example 1 of the present invention.

[0042] Figure 3 System framework diagram of embodiment 2 of the present invention.

[0043] Figure 4 Performance renderings of each single cell in the stack during startup of Example 2 of the present invention.

[0044] Figure 5 System framework diagram of the prior art comparative example.

[0045] Figure 6 The performance effect diagram of each single cell in the battery stack during startup of the prior art comparative example.

[0046] Among them, 1 is the fuel cell stack, 2 is the fan, 3 is the wind cover, 4 is the heating wire, 5 is the fuel cell stack air intake pipe, 6 is the fuel cell stack exhaust pipe, 7 is the air pump, 11 is the single battery unit, 12 is the fin, 13 is the cathode air inlet, 14 is the cathode exhaust, 15 is the first temperature detector, 16 is the second temperature detector, 61 is the air intake pipe A, 62 is the air intake pipe B, 63 is the three-way solenoid valve A, 64 is the three-way solenoid valve B, 71 is the air outlet connector, and 72 is the air intake connector. DETAILED DESCRIPTION

[0047] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0048] The present invention proposes a heating method for a closed air-cooled fuel cell stack. By circulating the air, the temperature uniformity of the stack can be improved. By monitoring the inlet and outlet temperatures and comparing their differences, it is possible to simply determine whether the stack is heated evenly. Without the need for complex battery temperature monitoring, the temperature differences between different single cells in the stack can be reduced, thereby improving the performance consistency of the stack.

[0049] The heating device of a closed air-cooled fuel cell stack usually consists of fins, a wind hood, a fan and a heating wire built into the stack. After the heating wire is heated, air is introduced through the fan to form a hot air flow, thereby heating the stack by the fins. However, due to the limitations of the application scenarios of closed air-cooled fuel cells (small portable power supplies, drone power supplies), it is impossible to design a complex wind hood and heating temperature change system to ensure uniform heating of the stack, resulting in poor stack performance and consistency during the startup phase.

[0050] On the basis of the above heating method, the present invention realizes the circulation of hot air flow in the stack by switching the channels of two three-way solenoid valves, so that the stack can be heated evenly. Figure 1 and 3 The figure shows a schematic diagram of the system structure of two embodiments of the present invention; the present invention is a cathode closed air-cooled fuel cell stack, including: a stack 1, a host computer and a temperature detector connected to the host computer, a heating device, a stack air intake pipe 5, a stack exhaust pipe 6, and an air pump 7.

[0051] The heating device is provided on the fuel cell stack 1 and is used to heat the fuel cell stack according to instructions issued by the host computer.

[0052] The temperature detectors are provided at the cathode air inlet 13 and the cathode exhaust port 14 of the fuel cell stack 1 to monitor the air temperature at the cathode air inlet 13 and the cathode exhaust port 14 and send the temperature to the host computer.

[0053] The air pump is connected to the cathode exhaust port 14 of the fuel cell stack 1 through 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 13 of the fuel cell stack 1 through the fuel cell stack air inlet pipe 5, so as to supply air to the fuel cell stack 1.

[0054] The fuel cell stack 1, the fuel cell stack exhaust pipe 6, the air pump 7, and the fuel cell stack air inlet pipe 5 form a circulation loop.

[0055] The upper computer is used to control the start and stop of the heating device. At the same time, according to the temperature data sent by the temperature detector, it adjusts the opening and / or direction of the stack exhaust pipe 6 to enable the air pump to take in air from the cathode exhaust gas of the stack or the outside air; and realizes the stack startup according to the set stack startup temperature and the detected temperature.

[0056] The battery stack of the present invention comprises multiple battery cells 11 connected in series, with a set of fins 12 installed between every three battery cells 11. In Examples 1 and 2, four groups of 12 and three groups of 9 battery cells were used for effect testing, respectively.

[0057] In the present invention, the heating device includes: a fan 2 , a fan cover 3 and a heating wire 4 .

[0058] The edges of the air hood 3 are respectively fixed above the first end of the head single battery unit and the first end of the tail single battery unit to form a closed space; the first end of the multiple single batteries is opposite to the second end of the multiple single batteries.

[0059] A through hole is provided at the center of the wind cover 3, and a fan 2 is fixedly provided at the through hole.

[0060] The heating wire is arranged under the battery stack to heat the battery stack.

[0061] The power of the heating wire is 50-200W.

[0062] The temperature detector includes a first temperature detector 15 and a second temperature detector 16 .

[0063] The first temperature detector 15 is provided at the cathode air inlet 13 of the fuel cell stack 1 , and is used to monitor the air temperature at the cathode air inlet 13 .

[0064] The second temperature detector 16 is provided at the cathode gas outlet of the fuel cell stack 1 and is used to monitor the air temperature at the cathode gas outlet.

[0065] The stack exhaust pipeline 6 includes: an exhaust pipeline, an intake pipeline A61, an intake pipeline B62, a three-way solenoid valve A63 and a three-way solenoid valve B64.

[0066] A three-way solenoid valve B64 and a three-way solenoid valve A63 are sequentially provided on the exhaust pipeline between the cathode exhaust port 14 of the fuel cell stack 1 and the air inlet of the air pump.

[0067] The three-way solenoid valve A63 is respectively connected to the air inlet pipeline A61, the air outlet end of the three-way solenoid valve B64 and the air inlet connector 72 of the air pump 7.

[0068] The three-way solenoid valve B64 is respectively connected to the intake pipe B62, the intake end of the three-way solenoid valve A63 and the cathode exhaust port 14 of the fuel cell stack 1.

[0069] The three-way solenoid valve A63 and the three-way solenoid valve B64 are respectively connected to the host computer, and the opening and / or direction of the three-way solenoid valve A63 and the three-way solenoid valve B64 are adjusted by the host computer to realize the air pump to take in air from the cathode tail gas of the fuel cell stack or the outside air.

[0070] Further, after the present invention is arranged Figure 1 and 3 After the battery stack system is shown, the battery stack is heated. The present invention proposes a heating method for a cathode-enclosed air-cooled fuel cell stack, comprising the following steps:

[0071] 1) The host computer turns on the heating wire 4 to heat the stack 1 and simultaneously turns on the fan 2 to allow the hot air flow to pass through the fins 12 between each battery unit 11 to heat the stack.

[0072] 2) The host computer adjusts the three-way solenoid valve A63 and the three-way solenoid valve B64 to connect the air inlet of the air pump 7 with the cathode outlet of the fuel cell stack 1.

[0073] 3) Start the air pump 7 to achieve inlet and outlet gas circulation at the cathode of the fuel cell stack 1.

[0074] 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.

[0075] 5) The host computer determines the status of the 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 stack start-up temperature, adjusts the three-way solenoid valve A63 and the three-way solenoid valve B64, and then performs the stack start-up operation.

[0076] Among them, 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; among them, T2>T1, after T1 is heated to T-1≤T1≤T+1, the three-way solenoid valve A63 and the three-way solenoid valve B64 are adjusted.

[0077] There are two situations for adjusting the three-way solenoid valve A63 and the three-way solenoid valve B64, specifically:

[0078] When T≥T2-2, the host computer determines that the temperature inside the stack 1 is uniform. At this time, the heating wire is stopped, the three-way solenoid valve A63 is adjusted to connect with the intake pipe A61, and the three-way solenoid valve B64 is adjusted to connect with the intake pipe B62, and then the stack is started;

[0079] When T<T2-2, the upper computer determines that the outlet gas temperature of the fuel cell stack 1 is too high. At this time, the heating wire is stopped and the cathode air is continued to circulate until T2-2<T<T1+2. The three-way solenoid valve A63 is adjusted to be connected to the intake pipe A61, and the three-way solenoid valve B64 is adjusted to be connected to the intake pipe B62, and then the fuel cell stack is started.

[0080] In order to verify the technical effects and practical application value of the present invention, the following systematic tests and analyses are carried out through specific embodiments and comparative examples. The embodiment constructs a cathode closed circulation system based on the above-mentioned technical solution, and dynamically optimizes the gas circulation path in the fuel cell stack by regulating the coordinated action of the three-way solenoid valve and the air pump; at the same time, the temperature uniformity and voltage consistency of the fuel cell stack during startup are quantitatively evaluated by combining the heating device and the temperature feedback mechanism. During the test, the embodiment fully verifies the adaptability of the present invention through differentiated configurations of different numbers of single cells (12 and 9), heating power (50W and 100W), and startup temperature thresholds (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.

[0081] Example 1:

[0082] like Figure 1 As shown, the test stack has 12 sections and an electrode area of ​​30 cm 2 A fin is installed for every three cells. The fins are secured to the cells using pressure created by stack screws or straps. A fan hood 3 is installed above the stack, screwed to the end plate. A through-hole is provided at the top of the fan hood 2, which is screwed to the fan hood 2. The heating wire 4 has a power of 50W, connected at both ends by an insulating device (which can be 3D printed into a suitable shape) and screwed in 2 cm from the bottom of the stack. The starting temperature T is set to 35°C. The three-way solenoid valves A63 and B64 are adjusted so that the air inlet of the air pump 7 is at the cathode outlet of the stack. The heating wire 4, fan 2, and air pump 7 are simultaneously activated. After 25 seconds, the first temperature detector 15 measures a real-time temperature T1 of 34°C, and the second temperature detector 16 measures a real-time temperature T2 of 36°C. At this point, the stack is considered uniformly heated. Adjust the three-way solenoid valve A63 and the three-way solenoid valve B64, adjust the three-way solenoid valve A63 to connect with the intake pipe A61, adjust the three-way solenoid valve B64 to connect with the intake pipe B62, introduce hydrogen into the stack 1, set the load current to 30A for discharge, and the performance of the single cell of the stack at startup is as follows: Figure 2 .

[0083] Example 2:

[0084] like Figure 3 As shown, the test stack has 9 sections and the electrode area is 30cm 2, the power of the heating wire 4 is 100W, and the rest of the structure and installation method are the same as those in Example 1. Set the starting temperature T to 40°C, start the fan 2 to heat the fuel cell stack, and after 18s, the real-time temperature T1 measured by the first temperature detector 15 is 38°C, and the real-time temperature T2 measured by the second temperature detector 16 is 45°C. At this time, stop heating with the heating wire, and continue to circulate the cathode air for 2.5s. T1 is 40°C, and T2 is 42°C. At this time, it is considered that the inside of the fuel cell stack has been heated evenly. Adjust the three-way solenoid valve A63 and the three-way solenoid valve B64, adjust the three-way solenoid valve A63 to connect with the intake pipe A61, and adjust the three-way solenoid valve B64 to connect with the intake pipe B62. The fuel cell stack 1 is ventilated normally, and the load current is set to 30A for discharge. The performance of the single cell of the fuel cell stack at startup is as follows: Figure 4 .

[0085] Comparative Example:

[0086] like Figure 5 As shown, the test stack has 12 sections and an electrode area of ​​30 cm 2 The power of the heating wire 4 is 50W, the starting temperature T is set to 35℃, and the heating wire 4 and fan 2 are started at the same time. After 25s, the first temperature detector 15 measures the real-time temperature T1 to be 25℃, and the second temperature detector 16 measures the real-time temperature T2 to be 46℃. The stack 1 is ventilated normally, and the load current is set to 30A for discharge. The performance of the single cell of the stack at startup is as follows: Figure 6 shown.

[0087] The consistency of the stack voltage starting performance of the two embodiments and one comparative example is shown in the following table:

[0088] Table 1 Comparison of battery performance consistency

[0089] battery stack Example 1 Example 2 Comparative Example Stack voltage consistency / mV 6.19 5.34 23.64

[0090] From the comparison in the above table, it can be seen that the voltage consistency of Example 1 and Example 2 is higher than that of the comparative example, which shows that the stack heating method proposed in the present invention can effectively promote the uniformity of temperature distribution, thereby improving the consistency of the stack voltage and the stability of operation.

[0091] According to the above-mentioned embodiments and comparative examples, Example 1 and Example 2 respectively adopt 12 and 9 single battery unit configurations, which verify the universality and high efficiency of the present invention. By adjusting the three-way solenoid valve to realize the cathode exhaust circulation, combined with the synergistic effect of the heating wire (50W / 100W) and the fan, the stack reaches the set starting temperature (35°C / 40°C) within 25 seconds (Example 1) and 18 seconds (Example 2), and the inlet and outlet temperature differences are controlled within 2°C and 5°C respectively, indicating that the temperature distribution inside the stack is highly uniform. The comparative example adopts the traditional heating method, with an inlet and outlet temperature difference of up to 21°C and a voltage consistency of only 23.64mV, which is far inferior to the 6.19mV and 5.34mV of the present invention. The data comparison fully proves that the present invention significantly reduces the temperature gradient in the stack through closed-loop circulation and dynamic temperature control strategy, improves the startup stability and long-term service life, and provides an efficient and compact solution for miniaturized fuel cell systems.

[0092] In summary, the present invention significantly improves the heating uniformity and startup performance of the fuel cell stack through an innovative circulation loop design and intelligent temperature control strategy. The core of the system lies in the coordinated control of the air pump and the three-way solenoid valve to construct a closed-loop circulation system for the cathode exhaust gas. Combined with the real-time analysis of temperature data by the host computer, the airflow path (fuel cell exhaust gas or external air) is dynamically adjusted to optimize the temperature distribution inside the fuel cell stack. In addition, the overall heating uniformity can be judged by simply monitoring the temperature difference between the cathode inlet and outlet, which simplifies the complexity of the system. The heating device integrates a fan, a wind hood and a heating wire, and cooperates with the fin design to achieve efficient heat conduction in a limited space. The technical solution of the present invention effectively solves the problem of performance fluctuation caused by local overheating of closed air-cooled fuel cells, significantly improves the voltage consistency of the fuel cell stack (the fluctuation in the embodiment is reduced to 5-6mV, which is better than the 23.64mV of the comparative example), and is suitable for miniaturized application scenarios, such as drone power supplies, and has both lightweight and high reliability.

[0093] Those skilled in the art will understand that the above description is only a preferred embodiment of the present invention, and the features described in the various embodiments and / or claims of the present disclosure may be combined or coupled in various ways, even if such a combination or coupling is not explicitly described in the present disclosure. It is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art may still modify the technical solutions described in the aforementioned embodiments or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of protection of the present invention.

[0094] Although preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they are aware of the basic inventive concepts. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention. Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, the present invention is intended to include such changes and modifications as fall within the scope of the claims and their equivalents.

Claims

1. A cathode-enclosed air-cooled fuel cell stack, characterized in that: include: A fuel cell stack (1), a host computer, a temperature detector connected to the host computer, a heating device, a fuel cell stack air inlet pipe (5), a fuel cell stack exhaust pipe (6), and an air pump (7); The heating device is provided 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 provided 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) through 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) through the fuel cell stack air inlet pipe (5), so as to supply air to the fuel cell stack (1); The fuel cell stack (1), fuel cell stack exhaust pipeline (6), air pump (7), and fuel cell stack air inlet 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 pipe (6) to achieve the air pump to take in air from the cathode exhaust gas of the stack or the outside air; The stack is started according to the set stack starting temperature and the detected temperature; 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 the exhaust pipe between the cathode exhaust port (14) of the fuel cell stack (1) and the air inlet of the 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 pipe 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 the 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 realize the air pump to take in air from the cathode tail gas of the fuel cell stack or the outside air.

2. The 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, 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 shield (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-sealed 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 provided at the cathode air inlet (13) of the fuel cell stack (1) and is used to monitor the air temperature at the cathode air inlet (13); The second temperature detector (16) is provided 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. A method for heating a cathode-enclosed air-cooled fuel cell stack according to any one of claims 1 to 5, 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 air pump (7) to achieve inlet and outlet gas circulation at the cathode of the 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 data to the host computer; 5) The host computer determines the state of the 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 stack start-up temperature, adjusts the three-way solenoid valve A (63) and the three-way solenoid valve B (64), and then performs the stack start-up operation.

7. The method for heating a cathode-enclosed air-cooled fuel cell stack according to claim 6, characterized in that: The step 5) is specifically as follows: The first temperature detector measures a real-time temperature of T1, the second temperature detector measures a real-time temperature of T2, and the stack is set to a starting temperature of T; wherein, T2>T1, after heating T1 to T-1≤T1≤T+1, the three-way solenoid valve A (63) and the three-way solenoid valve B (64) are adjusted.

8. The method for heating a cathode-enclosed air-cooled fuel cell stack according to claim 7, 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 host computer determines that the temperature in the stack (1) is uniform, stops heating the heating wire, adjusts the three-way solenoid valve A (63) to be connected to the intake pipe A (61), adjusts the three-way solenoid valve B (64) to be connected to the intake pipe B (62), and then starts the stack; When T<T2-2, the host 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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