Anti-freezing device and anti-freezing method for fuel cell system and fuel cell system

Abstract

The invention relates to the field of fuel cells, in particular to an anti-freezing device for a fuel cell system, and the fuel cell system comprises an electric pile with an anode and a cathode; an anode gas supply branch for supplying anode gas to the anode and an anode exhaust branch for exhausting the anode gas from the anode; a cathode gas supply branch for supplying cathode gas to the cathode and a cathode exhaust branch for exhausting the cathode gas from the cathode; the liquid discharge part is positioned on the anode exhaust branch; and the air compressor is positioned on the cathode air supply branch, and the anti-freezing device is configured to guide air compressed by the air compressor to the liquid discharge part. The invention also relates to a fuel cell system, an anti-freezing method for a fuel cell system and a computer program product. According to the fuel cell system, the gas which is compressed by the air compressor and has heat energy is guided to the liquid discharge part of the anode exhaust branch to preheat the liquid discharge part, so that the liquid discharge part is effectively prevented from being frozen in a low-temperature environment, system faults caused by pipeline blockage are avoided, and the low-temperature environment adaptability of the fuel cell system is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cells, and in particular to an antifreeze device for a fuel cell system, a fuel cell system, an antifreeze method for a fuel cell system, and a computer program product. Background Art

[0002] With the development of society, the demand for clean and renewable energy is increasing. Fuel cells, as a highly efficient electrochemical device, can directly convert chemical energy into electrical energy and are widely used in transportation, portable and fixed power generation and other fields.

[0003] However, there are still some technical problems to be solved in the use of traditional fuel cell systems, among which the antifreeze problem in low temperature environment is particularly prominent. Since a certain amount of liquid (especially liquid water formed by water vapor) is produced when the fuel cell is working, this part of the liquid needs to be discharged from the fuel cell system. However, under low temperature conditions, this part of the liquid can easily freeze in pipes or valves leading to the external environment, causing blockage, which especially affects the normal flow of liquid and gas, and thus seriously affects the overall operation of the fuel cell system.

[0004] Therefore, there is still a real need for further improvement in the antifreeze of fuel cell systems. Summary of the invention

[0005] In view of this, an object of the present invention is to provide an improved antifreeze device for a fuel cell system, an improved fuel cell system, an improved antifreeze method for a fuel cell system and an improved computer program product to at least solve part of the problems in the prior art and / or overcome other possible shortcomings not mentioned herein.

[0006] According to a first aspect of the present invention, there is provided an antifreeze device for a fuel cell system, wherein the fuel cell system comprises: a fuel cell stack having an anode and a cathode; an anode gas supply branch adapted to supply anode gas to the anode and an anode exhaust branch adapted to discharge anode gas from the anode; a cathode gas supply branch adapted to supply cathode gas to the cathode and a cathode exhaust branch adapted to discharge cathode gas from the cathode; a drain located on the anode exhaust branch; and an air compressor located on the cathode gas supply branch, wherein the antifreeze device is configured to guide gas compressed by the air compressor to the drain.

[0007] According to an optional embodiment of the present invention, the fuel cell system also includes a bypass path branching from the cathode gas supply branch, the bypass path is connected to the cathode exhaust branch, and a bypass valve located on the bypass path, wherein the antifreeze device includes a gas supply pipeline leading from the bypass path and / or the bypass valve to the drain part.

[0008] According to an optional embodiment of the present invention, the fuel cell system further comprises at least one switch valve located upstream of the drain portion in the anode exhaust branch, wherein the antifreeze device is connected downstream of the at least one switch valve.

[0009] According to an optional embodiment of the present invention, the antifreeze device includes a regulator suitable for adjusting the opening degree of the bypass valve.

[0010] According to an optional embodiment of the present invention, the antifreeze device includes a flow diverter joint connected to the downstream of the bypass valve, a first joint of the flow diverter joint is connected to the cathode exhaust branch and a second joint is connected to the gas supply pipeline.

[0011] According to an optional embodiment of the present invention, the antifreeze device comprises a first temperature sensor adapted to detect the ambient temperature of the fuel cell system.

[0012] According to an optional embodiment of the present invention, the antifreeze device includes a second temperature sensor suitable for detecting the gas temperature of the gas compressed by the air compressor.

[0013] According to an optional embodiment of the present invention, the antifreeze device comprises a first pressure sensor adapted to detect the outlet pressure of the anode.

[0014] According to an optional embodiment of the present invention, the antifreeze device includes a second pressure sensor adapted to detect the outlet pressure of the bypass valve.

[0015] According to an optional embodiment of the present invention, the antifreeze device includes a flow sensor suitable for detecting the gas flow in the gas supply pipeline.

[0016] According to an optional embodiment of the present invention, the antifreeze device includes a controller, which is suitable for comparing the ambient temperature of the fuel cell system and / or the gas temperature of the gas compressed by the air compressor with a preset temperature threshold and controlling the flow cross-section of the bypass valve and / or the diverter joint based on the comparison result.

[0017] According to an optional embodiment of the present invention, the at least one switch valve includes a drain valve located on the anode exhaust branch, and the liquid drain portion is constructed as a drain steel pipe extending from the drain valve.

[0018] According to a second aspect of the present invention, there is provided a fuel cell system, comprising the antifreeze device provided by any optional embodiment of the first aspect above.

[0019] According to a third aspect of the present invention, there is provided an antifreeze method for a fuel cell system provided in any optional embodiment of the second aspect, wherein the antifreeze method comprises the following steps:

[0020] S100: monitoring the ambient temperature of the fuel cell system;

[0021] S200: Activate the antifreeze device based on the ambient temperature.

[0022] According to an optional embodiment of the present invention, the antifreeze method further comprises the following steps:

[0023] S101: Acquire a pressure difference between an outlet pressure of a bypass valve located on a bypass path of the fuel cell system and an outlet pressure of an anode of the fuel cell stack;

[0024] S201: Compare the pressure difference with a preset pressure value;

[0025] S202: Based on the comparison result, close at least one switch valve on the anode exhaust branch of the fuel cell system.

[0026] According to a fourth aspect of the present invention, there is provided a computer program product, comprising computer program instructions, wherein when the computer program instructions are executed by a processor, the steps of the antifreeze method provided in any optional embodiment of the third aspect are implemented.

[0027] According to certain exemplary embodiments of the present invention, the gas compressed by the air compressor is guided to the drain portion of the anode exhaust branch. Since the compressed gas has thermal energy, the drain portion can be preheated, thereby effectively preventing the drain portion of the anode exhaust branch from freezing in a low-temperature environment, avoiding system failures caused by pipeline blockage, and improving the low-temperature environment adaptability of the fuel cell system. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present invention will be described in more detail below with reference to the accompanying drawings, so that the principles, features and advantages of the present invention can be better understood. The accompanying drawings include:

[0029] Figure 1 A schematic diagram showing an antifreeze device for a fuel cell system according to an exemplary embodiment of the present invention is shown;

[0030] Figure 2 A schematic diagram of a fuel cell system according to an exemplary embodiment of the present invention is shown;

[0031] Figure 3A flow chart showing a method for antifreezing a fuel cell system according to an exemplary embodiment of the present invention is shown;

[0032] Figure 4 A flow chart showing a method for antifreezing a fuel cell system according to another exemplary embodiment of the present invention is shown;

[0033] Figure 5 A flow chart showing a method for antifreezing a fuel cell system according to another exemplary embodiment of the present invention; and

[0034] Figure 6 A structural framework diagram of a computer system according to an embodiment of the present invention is shown.

[0035] Reference numerals:

[0036] 1000: fuel cell system; 900: antifreeze device; 901: gas supply pipeline; 1100: fuel cell stack; 10: anode; 20: cathode; 110: anode gas supply branch; 120: anode exhaust branch; 121: drainage section; 210: cathode gas supply branch; 211: air compressor; 220: cathode exhaust branch; 230: bypass path; 231: bypass valve; 30: gas-liquid separator; 40: intercooler; 50: ejector; 60: ejector; 70: circulating fan; V1: drain valve; V2: exhaust valve; 2000: antifreeze method. DETAILED DESCRIPTION

[0037] In order to make the technical problems, technical solutions and beneficial technical effects to be solved by the present invention more clearly understood, the present invention will be further described in detail below in conjunction with the accompanying drawings and multiple exemplary embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the scope of protection of the present invention, and that various embodiments may share the same view or multiple views for description, but all features appearing in the same view cannot be interpreted as features that must be possessed by an embodiment.

[0038] First, for ease of understanding, the description in the background technology section of the present invention may be traced back or recalled. One of the purposes of the present invention is to provide an antifreeze device for a fuel cell system, wherein the fuel cell system comprises: a stack having an anode and a cathode; an anode gas supply branch suitable for supplying anode gas to the anode and an anode exhaust branch suitable for discharging anode gas from the anode; a cathode gas supply branch suitable for supplying cathode gas to the cathode and a cathode exhaust branch suitable for discharging cathode gas from the cathode; a drain located on the anode exhaust branch; and an air compressor located on the cathode gas supply branch, wherein the antifreeze device is configured to guide the gas compressed by the air compressor to the drain. Thus, by guiding the gas compressed by the air compressor to the drain of the anode exhaust branch, the drain can be preheated because the compressed gas has thermal energy, thereby effectively preventing the drain of the anode exhaust branch from freezing in a low temperature environment, avoiding system failures caused by pipeline blockage, and improving the low temperature environment adaptability of the fuel cell system.

[0039] Exemplary embodiments of the present invention will be described below with reference to the accompanying drawings.

[0040] Figure 1 A schematic diagram of an antifreeze device 900 for a fuel cell system 1000 according to an exemplary embodiment of the present invention is shown. Here, the fuel cell system 1000 includes a stack 1100, and the stack 1100 has an anode 10 and a cathode 20. The fuel cell system 1000 also includes an anode gas supply branch 110 and an anode exhaust branch 120, wherein the anode gas supply branch 110 supplies anode gas (e.g., hydrogen) to the anode 10 of the stack 1100, and the anode exhaust branch 120 guides the exhaust anode gas from the anode 10 of the stack 1100, and a drain portion 121 leading to the external environment and an exhaust portion not shown here are generally provided at the end of the anode exhaust branch 120. The fuel cell system 1000 further includes a cathode gas supply branch 210 and a cathode exhaust branch 220, wherein the cathode gas supply branch 210 supplies cathode gas (e.g., air) to the cathode 20 of the stack 1100, and the cathode exhaust branch 220 guides the cathode gas to be discharged from the cathode 20 of the stack 1100, and an air compressor 211 is usually provided on the cathode gas supply branch 210 for pressurizing the cathode gas in the cathode gas supply branch 210. In order to prevent the freezing problem at the initial start-up of the fuel cell system 1000 at low temperatures, the antifreeze device 900 is configured to guide the gas compressed by the air compressor 211 to the drain 121. Since the temperature of the air compressed by the air compressor 211 is relatively high, the air is used to supply heat to the drain 121, thereby avoiding the freezing problem under low temperature conditions.

[0041] Figure 2A schematic diagram of a fuel cell system 1000 according to an exemplary embodiment of the present invention is shown. Here, the fuel cell system 1000 also includes a bypass path 230 branching from the cathode gas supply branch 210, and the bypass path 230 is connected to the cathode exhaust branch 220. Since in the fuel cell system, the anode gas (such as hydrogen mixed gas) supplied by the anode gas supply branch and the mixed gas exhausted from the stack shell may still contain incompletely reacted oxygen, nitrogen, water vapor and other impurities after passing through the stack, the opening of the bypass path is conducive to the introduction of additional air from the cathode gas supply branch to mix and dilute these exhausted gases, which can especially improve the composition ratio of the exhaust gas to meet the emission requirements. A silencer is usually provided at the end of the cathode exhaust branch 220 to reduce the injection noise and monitor the gas composition when necessary. Figure 2 As shown, the fuel cell system 1000 further includes a bypass valve 231 located on the bypass path 230, which is used to control the opening and closing of the bypass path 230 leading to the cathode exhaust branch 220. Preferably, the antifreeze device 900 may include (such as Figure 2 The antifreeze device 900 is a device for controlling the amount of hot air flowing to the drain 121 (indicated by the dotted arrow) from the bypass valve 231 to the gas supply line 901 of the drain 121, thereby utilizing the bypass valve 231 originally provided by the fuel cell system 1000 without adding additional components. Further preferably, the antifreeze device 900 may include a regulator suitable for adjusting the opening of the bypass valve 231, thereby, by adjusting the opening of the bypass valve 231, the amount of hot air flowing to the drain 121 can be accurately controlled, the drain 121 can be heated as needed, and the antifreeze effect can be optimized. Optionally, the antifreeze device 900 may also include a gas supply line 901 leading from other parts of the bypass path 230 to the drain 121. For example, the antifreeze device 900 may include a bypass joint connected downstream of the bypass valve 231, the first joint of which is connected to the cathode exhaust branch 220 and the second joint is connected to the gas supply pipeline 901. Thus, the hot air can be guided to the cathode exhaust branch 220 for gas mixing and dilution on the one hand, and to the drain part 121 for preheating on the other hand. This realizes the dual utilization of hot air and simplifies the pipeline layout.

[0042] from Figure 2 It can also be seen that a gas-liquid separator 30 is provided on the anode exhaust branch 120, which is used to separate the fluid discharged from the anode 10 of the stack 1100, and then resupply the anode gas (such as hydrogen) that has not been completely consumed by the stack 1100 to the anode gas supply branch 110, and the remaining gas (such as nitrogen, water vapor, etc.) is purged and guided to the external environment through the exhaust valve V2, and the separated liquid (such as liquid water) is discharged to the external environment through the drain valve V1. Figure 2As schematically shown by the thick arrow, the drain portion 121 can be constructed as a drain steel pipe drawn from the drain valve V1. Although such a steel pipe is low in cost, it is particularly easy to freeze and cause blockage in a low temperature environment because it is always in contact with the liquid. Through the embodiments of the present invention, the use of such a steel pipe can be allowed without worrying about causing the above-mentioned problems. Optionally, the fuel cell system 1000 may also include Figure 2 The intercooler 40 schematically shown in the figure is connected to the downstream of the air compressor 211. Although the intercooler 40 may reduce the temperature of the air compressed by the air compressor 211, the temperature of the compressed air at this time is usually still higher than the low temperature ambient temperature (e.g., 5° C.), which is sufficient to preheat the drain 121. In addition, the fuel cell system 1000 may also include Figure 2 The essential components of a conventional fuel cell system, such as the ejector 40 and the ejector 50 on the anode gas supply branch 110 and the circulation fan 60 on the anode exhaust branch 120, are schematically shown in the figure, as well as other essential components not shown in the drawings.

[0043] In an embodiment not shown in the drawings, the antifreeze device 900 may further include a first temperature sensor for detecting the ambient temperature of the fuel cell system 1000, which can, for example, directly monitor the temperature conditions under which the antifreeze device 900 should be activated; the antifreeze device 900 may further include a second temperature sensor for detecting the gas temperature of the gas compressed by the air compressor 211, which can, for example, ensure that sufficient antifreeze heat is provided; the antifreeze device 900 may further include a first pressure sensor for detecting the outlet pressure of the anode 10, which can, for example, prevent the compressed air from unexpectedly entering the fuel cell stack 1100 due to the pressure difference; the antifreeze device 900 may further include a second pressure sensor for detecting the outlet pressure of the bypass valve 231. force, which can, for example, determine the start-up timing of the antifreeze device 900 in combination with the outlet pressure of the anode 10; the antifreeze device 900 may also include a flow sensor for detecting the gas flow in the gas supply pipeline 901, which can, for example, monitor the amount of air flowing to the drain portion 121 in real time; the antifreeze device 900 may also include a controller for comparing the ambient temperature of the fuel cell system 1000 with a preset temperature threshold or comparing the gas temperature of the gas compressed by the air compressor 211 with a preset temperature threshold, and controlling the flow cross-section of the bypass valve 231 (or the first and second connectors of the above-mentioned diverter connector) based on the comparison result, thereby achieving accurate and reliable temperature control and antifreeze without manual intervention.

[0044] Figure 3 FIG. 2 shows a flow chart of a method 2000 for preventing freezing of a fuel cell system 1000 according to an exemplary embodiment of the present invention. Figure 3As shown, the antifreeze method 2000 may include steps S100 and S200. In step S100, the ambient temperature of the fuel cell system 1000 is monitored. In step S200, the antifreeze device 900 is started based on the ambient temperature, and the gas compressed by the air compressor 211 is directed to the drain 121. Thus, the accurate timing of starting the antifreeze device 900 can be ensured by continuously monitoring the ambient temperature of the fuel cell system 1000. Optionally, steps S100 and S200 can be used to automatically obtain the ambient temperature of the fuel cell system 1000 before the cold start of the fuel cell system 1000 and start the antifreeze device 900 based on the ambient temperature to ensure that the possibility of freezing has been eliminated after the cold start of the fuel cell system 1000, or they can be continuously performed at the initial start of the fuel cell system 1000 to ensure that the possibility of freezing is avoided throughout the initial start stage.

[0045] Figure 4 FIG. 2 shows a flow chart of a method 2000 for preventing freezing of a fuel cell system 1000 according to another exemplary embodiment of the present invention. Figure 4 As shown, the antifreeze method 2000 may include steps S100, S10, S20 and S210. In step S10, the ambient temperature is compared with a preset temperature threshold (e.g., 5°C) to determine whether the ambient temperature is lower than the preset temperature threshold. If the ambient temperature is lower than the preset temperature threshold, step S20 is performed, otherwise the step S100 is returned to be executed. In step S20, the gas temperature of the gas in the antifreeze device 900, such as the gas supply pipeline 901, is compared with a preset temperature threshold (e.g., 5°C) to determine whether the gas temperature is higher than the preset temperature threshold. If the gas temperature is higher than the preset temperature threshold, step S210 is performed to start the antifreeze device 900, otherwise the step S10 is returned to be executed. Thus, for example, accurate antifreeze control can be continuously implemented for temperature conditions before or at the initial stage of cold start of the fuel cell system 1000.

[0046] Figure 5 FIG. 2 shows a flow chart of a method 2000 for preventing freezing of a fuel cell system 1000 according to another exemplary embodiment of the present invention. Figure 5As shown, the antifreeze method 2000 may include steps S100, S10, S20, S101, S201, S202 and S210. In step S101, the pressure difference between the outlet pressure of the bypass valve 231 located on the bypass path 230 of the fuel cell system 1000 and the outlet pressure of the anode 10 of the fuel cell stack 1100 is obtained. In step S201, the pressure difference is compared with a preset pressure value (for example, tens of millibars). When the pressure difference obtained by subtracting the outlet pressure of the anode 10 from the outlet pressure of the bypass valve 231 is greater than the preset pressure value, step S202 is executed, otherwise, step S101 is returned to be executed. In step S202, at least one switch valve on the anode exhaust branch 120 of the fuel cell system 1000 is closed, for example, Figure 2 The drain valve V1 and the exhaust valve V2 are shown. This double majority judgment can especially avoid unnecessary misoperation, especially prevent the compressed air from unexpectedly entering the fuel cell stack 1100 through the drain valve V1 or the exhaust valve V2.

[0047] Figure 6 FIG. 2 shows a structural framework diagram of a computer system according to an embodiment of the present invention, wherein the computer system is configured to execute the various steps of the antifreeze method 2000 provided according to the above-mentioned embodiments of the present invention. Figure 4 As shown, the computer system includes a memory 1, a processor 2, a communication interface 3 and a bus 4. Here, the memory 1, the processor 2, and the communication interface 3 are connected to each other through the bus 4. According to one aspect of the present invention, it also relates to a computer program product, including computer program instructions, wherein when the computer program instructions are executed by a processor, especially by the processor 2 of the above-mentioned computer system, the various steps of the antifreeze method 2000 provided according to the above-mentioned embodiments of the present invention are implemented.

[0048] Other advantages and alternative embodiments of the present invention are obvious to those skilled in the art. Therefore, the present invention is not limited to the specific details, representative structures and exemplary embodiments shown and described in its broader sense. Various modifications and substitutions can be made by those skilled in the art without departing from the basic spirit and scope of the present invention.

Claims

1. An antifreeze device (900) for a fuel cell system (1000), wherein: The fuel cell system (1000) comprises: A battery stack (1100), wherein the battery stack (1100) comprises an anode (10) and a cathode (20); an anode gas supply branch (110) adapted to supply anode gas to the anode (10) and an anode exhaust branch (120) adapted to exhaust anode gas from the anode (10); a cathode gas supply branch (210) adapted to supply cathode gas to the cathode (20) and a cathode exhaust branch (220) adapted to exhaust cathode gas from the cathode (20); a liquid drain portion (121) located on the anode exhaust branch (120); and an air compressor (211) located on the cathode gas supply branch (210), Wherein, the antifreeze device (900) is configured to guide the gas compressed by the air compressor (211) to the liquid discharge part (121).

2. The antifreeze device (900) according to claim 1, wherein: The fuel cell system (1000) further comprises: a bypass path (230) branching from the cathode gas supply branch (210), the bypass path (230) being connected to the cathode exhaust branch (220), and a bypass valve (231) located on the bypass path (230), The antifreeze device (900) comprises an air supply pipeline (901) leading from the bypass path (230) and / or the bypass valve (231) to the liquid discharge portion (121).

3. The antifreeze device (900) according to claim 1 or 2, wherein: The fuel cell system (1000) further comprises: at least one switch valve located upstream of the liquid discharge portion (121) in the anode exhaust branch (120), Wherein, the antifreeze device (900) is connected downstream of the at least one switch valve.

4. The antifreeze device (900) according to claim 2 or 3, wherein: The antifreeze device (900) comprises: a regulator adapted to adjust the opening of the bypass valve (231); and / or A flow diversion joint is connected to the downstream of the bypass valve (231), wherein a first joint of the flow diversion joint is connected to the cathode exhaust branch (220) and a second joint of the flow diversion joint is connected to the gas supply pipeline (901).

5. The antifreeze device (900) according to any one of claims 2 to 4, wherein: The antifreeze device (900) comprises: a first temperature sensor adapted to detect the ambient temperature of the fuel cell system (1000); and / or a second temperature sensor adapted to detect the gas temperature of the gas compressed by the air compressor (211); and / or a first pressure sensor adapted to detect the outlet pressure of the anode (10); and / or a second pressure sensor adapted to detect the outlet pressure of the bypass valve (231); and / or A flow sensor suitable for detecting the gas flow in the gas supply pipeline (901).

6. The antifreeze device (900) according to any one of claims 2 to 5, wherein: The antifreeze device (900) comprises a controller, wherein the controller is adapted to compare the ambient temperature of the fuel cell system (1000) and / or the gas temperature of the gas compressed by the air compressor (211) with a preset temperature threshold value and control the flow cross section of the bypass valve (231) and / or the diverter joint based on the comparison result; and / or The at least one switch valve comprises a drain valve (V1) located on the anode exhaust branch (120), and the drain portion (121) is configured as a drain steel pipe extending from the drain valve (V1).

7. A fuel cell system (1000), comprising the antifreeze device (900) according to any one of claims 1 to 6.

8. A method (2000) for preventing freezing of a fuel cell system (1000) according to claim 7, wherein: The antifreeze method (2000) comprises the following steps: S100: monitoring the ambient temperature of the fuel cell system (1000); S200: Activate the antifreeze device (900) based on the ambient temperature.

9. The antifreeze method (2000) according to claim 8, wherein: The antifreeze method (2000) further comprises the following steps: S101: Obtaining a pressure difference between an outlet pressure of a bypass valve (231) located on a bypass path (230) of the fuel cell system (1000) and an outlet pressure of an anode (10) of the fuel cell stack (1100); S201: Compare the pressure difference with a preset pressure value; S202: Based on the comparison result, close at least one switch valve on the anode exhaust branch (120) of the fuel cell system (1000).

10. A computer program product comprising computer program instructions, wherein: When the computer program instructions are executed by a processor, the steps of the antifreeze method (2000) according to claim 8 or 9 are implemented.

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