Humidity-controllable fuel cell humidifying system and fuel cell system

Abstract

The utility model provides a humidity-controllable fuel cell humidifying system and a fuel cell system. The humidity-controllable fuel cell humidifying system is provided with an air compressor, an intercooler and a membrane humidifier which are arranged in sequence, a humidity adjusting mechanism is further arranged between the air compressor and the intercooler and at least provided with a water collecting and adding system and an injection mechanism, the two ends of the injection mechanism are communicated with the air compressor and the intercooler respectively, and the injection mechanism is communicated with the water collecting and adding system. According to the scheme, the problem of insufficient dry-out moisture content caused by insufficient moisture content of a membrane humidifier when water production of the galvanic pile is insufficient at low current density can be effectively solved, and auxiliary humidification is cut off or reduced at high current density, so that galvanic pile flooding caused by excessive humidification is avoided; the temperature adjusting mechanism is used in cooperation with the film humidifier, and adjustable humidity supply in the full-power interval is achieved. And under the same humidifying requirement of the galvanic pile, the requirement on the humidifying capability of the membrane humidifier can be reduced, and the expensive cost of the membrane humidifier can be reduced.

Description

Technical Field

[0001] This application relates to the technical field of fuel cells, specifically to a fuel cell humidification system with controllable humidity. Background Art

[0002] In existing fuel cells, when the water production of the fuel cell stack is insufficient during cold start or under low current density conditions, for example, the membrane humidifier of the fuel cell cannot obtain sufficient moisture source and cannot provide appropriate inlet humidity to the stack. Therefore, auxiliary humidity adjustment is required. Summary of the Utility Model

[0003] This application provides a fuel cell humidification system with controllable humidity, which can effectively adjust the humidity of the air entering the stack.

[0004] This application provides a fuel cell humidification system with controllable humidity, which has a compressor, an intercooler, and a membrane humidifier arranged in sequence. Air enters the compressor for compression to form high-temperature and high-pressure gas, and the high-temperature and high-pressure gas is introduced into the intercooler for cooling; the cooled gas enters the membrane humidifier for humidification, and after being humidified by the membrane humidifier, it is introduced into the stack;

[0005] A humidity adjustment mechanism is also arranged between the compressor and the intercooler. The humidity adjustment mechanism at least has a water collection and addition system and an ejector mechanism. The two ends of the ejector mechanism are respectively connected to the compressor and the intercooler, and the ejector mechanism is connected to the water collection and addition system.

[0006] Further explanation, the water collection and addition system at least has a water storage tank, a heater, and a solenoid valve. The heater is arranged inside the water storage tank to heat the liquid water in the water storage tank to avoid a large temperature difference between the water entering the ejector mechanism and the gas from the compressor; the water storage tank is connected to the ejector mechanism through a water pipe, and the solenoid valve is installed on the water pipe between the water storage tank and the ejector mechanism to control the amount of water flowing from the water storage tank into the ejector mechanism.

[0007] Even further explanation, the water storage tank is provided with a water inlet, a drain outlet, and a ventilation port for water inlet, drainage, and ventilation respectively.

[0008] Further explanation, the ejector mechanism is a two-way bell mouth structure with the openings on both sides larger than the middle part of the ejector mechanism. The openings on both sides of the ejector mechanism are respectively an inlet connected to the compressor and an outlet connected to the intercooler; a jet port is arranged in the middle part.

[0009] Even further explanation, the number of the jet ports is greater than or equal to two.

[0010] For further explanation, the middle part of the ejector mechanism is connected to the water inlet pipe. The high-temperature and high-pressure gas at the inlet sucks the liquid water in the water storage tank introduced by the water inlet pipe, forms high-humidity gas, and then enters the intercooler through the outlet.

[0011] For further explanation, an atomization structure is provided in the middle part of the ejector mechanism and is fully vaporized in the high-temperature ejector mechanism. The water inflow is controlled by a solenoid valve. The water in the water storage tank is atomized after entering the ejector mechanism, so that the humidity of the gas entering the intercooler is in an unsaturated state and there is no liquid water when entering the membrane humidifier.

[0012] For further explanation, a steam-water separation device is provided between the stack and the membrane humidifier. The steam-water separation device is communicated with the water inlet of the water storage tank. The tail gas in the stack undergoes steam-water separation through the steam-water separation device, and the liquid water flows into the water storage tank through the water inlet. After the water storage tank is full of water, it is discharged through the drain port.

[0013] For further explanation, the membrane humidifier has a wet gas outlet, and the wet gas outlet is communicated with the water inlet of the water storage tank. The tail drainage discharged from the wet gas outlet enters the water storage tank through the water inlet.

[0014] This technical solution also provides a fuel cell system, and the fuel cell system has the above-mentioned fuel cell humidification system with controllable humidity.

[0015] By implementing the above-mentioned fuel cell humidification system with controllable humidity and the fuel cell, the following technical effects are achieved:

[0016] In the solution of the present application, a controllable humidity adjustment mechanism is added in front of the intercooler to humidify with adjustable humidity as an auxiliary membrane humidification structure, and the deficiency of the membrane humidifier is compensated by using the limited cost increase of adding an ejector mechanism and a water storage tank, etc. To ensure that when the stack produces insufficient water during cold start or low current density conditions, resulting in the membrane humidifier being unable to obtain sufficient wet gas source and unable to provide appropriate inlet stack humidity, the auxiliary function of this solution provides additional humidification. At the same time, when the current density is high, the auxiliary humidification is cut off or reduced to realize water storage and avoid stack waterlogging caused by excessive humidification;

[0017] In the solution of the present application, the ejector mechanism is used for ejecting, draining and atomizing. The dry gas source with high temperature from the air compressor is fully evaporated and vaporized in the intercooler. The introduced water volume is controlled at a small and sufficient level. The air humidity is in an unsaturated state, and there is no liquid water at all when entering the membrane humidifier, and the humidity is further increased through the membrane humidifier to meet the appropriate inlet stack humidity requirements, without parasitic power consumption;

[0018] In the solution of the present application, under the same humidification requirements of the stack, the requirement for the humidification ability of the membrane humidifier can be reduced, and the cost of the expensive membrane humidifier can be reduced;

[0019] The water storage tank of the solution of this application is combined with the membrane humidifier to effectively achieve adjustable humidity supply in the full power range. Description of the Drawings

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model, the drawings required for the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present utility model. For those skilled in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0021] Figure 1 It is a schematic structural diagram of a fuel cell humidification system with controllable humidity provided in the embodiment of this application;

[0022] Figure 2 is Figure 1 A schematic structural diagram of the ejector mechanism;

[0023] Among them, the reference numerals are:

[0024] 1. Air compressor, 2. Intercooler, 3. Membrane humidifier, 30. Moisture outlet, 4. Fuel cell stack, 5. Water collection and filling system, 50. Water storage tank, 51. Solenoid valve, 52. Heater, 6. Ejector mechanism, 61. Inlet, 62. Intermediate part, 63. Outlet, 64. Jet port, 7. Steam-water separation device, 8. Water inlet pipe. Detailed Embodiments

[0025] The technical solutions of the present utility model will be clearly and completely described below with reference to the drawings. Obviously, the described embodiments are some, but not all, of the embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0026] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present utility model. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. Among them, the terms "first position" and "second position" are two different positions. Moreover, the first feature being "above", "over" and "on" the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the first feature has a higher horizontal height than the second feature. The first feature being "below", "under" and "beneath" the second feature includes the first feature being directly below and obliquely below the second feature, or merely indicating that the first feature has a lower horizontal height than the second feature.

[0027] In the description of the present utility model, it should be noted that unless otherwise clearly specified and defined, the terms "installed", "connected", "joined" and "arranged" shall be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0028] The embodiments of the present utility model will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions from beginning to end. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present utility model and should not be construed as a limitation to the present utility model.

[0029] This application provides a fuel cell humidification system with controllable humidity and a fuel cell system, which will be described in detail below respectively.

[0030] Please refer to Figure 1 - Figure 2 , a fuel cell humidification system with controllable humidity, which has a compressor 1, an intercooler 2, and a membrane humidifier 3 arranged in sequence. Air enters the compressor 1 for compression to form high-temperature and high-pressure gas, and the high-temperature and high-pressure gas is introduced into the intercooler 2 for cooling; the cooled gas enters the membrane humidifier 3 for humidification, and after being humidified by the membrane humidifier 3, it is introduced into the fuel cell stack 4; the compressor 1, the intercooler 2, and the membrane humidifier 3 in the above structure can all adopt existing technologies and will not be elaborated in detail here.

[0031] A humidity adjustment mechanism is also provided between the air compressor 1 and the intercooler 2. The humidity adjustment mechanism at least includes a water collection and addition system 5 and an ejector mechanism 6. The two ends of the ejector mechanism 6 are respectively connected to the air compressor 1 and the intercooler 2, and the ejector mechanism 6 is connected to the water collection and addition system 5. More specifically, the water collection and addition system 5 at least includes a water storage tank 50, a heater 52 and a solenoid valve 51. The heater 52 is arranged in the water storage tank 50 to heat the liquid water in the water storage tank 50, so as to avoid a large temperature difference between the water entering the ejector mechanism and the gas from the air compressor. The water storage tank 50 is connected to the ejector mechanism 6 through a water pipe 8. The solenoid valve 51 is installed on the water pipe 8 between the water storage tank 50 and the ejector mechanism 6 to control the water volume flowing from the water storage tank 50 into the ejector mechanism 6 and the water supply timing. By adding a controllable humidity adjustment mechanism in front of the intercooler 2 to humidify with adjustable humidity as an auxiliary membrane humidification structure, the deficiency of the membrane humidifier 3 is compensated by increasing the ejector mechanism 6 and the water storage tank 50 at a limited cost. When the water production of the fuel cell stack 4 is insufficient during cold start or low current density operation, resulting in the membrane humidifier 3 being unable to obtain enough moisture source to provide a suitable inlet humidity for the stack, the auxiliary function of this solution provides additional humidification. At the same time, when the current density is high, the auxiliary humidification is cut off or reduced to achieve water storage and avoid flooding of the stack caused by excessive humidification.

[0032] For further explanation, the ejector mechanism 6 is a two-way flared structure with the openings on both sides larger than the middle part 62 of the ejector mechanism 6. The openings on both sides of the ejector mechanism 6 are respectively an inlet 61 connected to the air compressor 1 and an outlet 63 connected to the intercooler 2. A jet orifice 64 is provided in the middle part 62. A low-pressure area is formed inside the jet orifice 64 due to the high-speed passage of high-pressure air, sucking in the liquid water introduced from the solenoid valve 51 and blowing away the high-humidity gas mixed in. The number of jet orifices 64 is greater than or equal to two. The middle part 62 of the ejector mechanism 6 is connected to the water pipe 8. The high-temperature and high-pressure gas at the inlet 61 sucks in the liquid water in the water storage tank 50 introduced by the water pipe, forms high-humidity gas and then enters the intercooler 2 through the outlet 63. An atomization structure is provided in the middle part 62 of the ejector mechanism 6 and is fully vaporized in the high-temperature ejector mechanism 6. The water volume is controlled by the solenoid valve 51. After the water in the water storage tank 50 enters the ejector mechanism 6, it is atomized and introduced into the intercooler 2 to be fully mixed with the air. The ejector mechanism 6 uses ejector drainage and atomization, and uses the high-temperature and dry gas source of the air compressor 1 to achieve full evaporation and gasification in the intercooler 2. The introduced water volume is controlled at a small and sufficient level, and the air humidity is in an unsaturated state. When entering the membrane humidifier 3, it is completely vaporized without liquid water, and is further humidified by the membrane humidifier 3 to meet the appropriate inlet humidity requirements for the stack, without parasitic power consumption, realizing adjustable humidity and auxiliary humidification.

[0033] The water storage tank 50 has a box structure, and an inlet, a drain outlet, and a ventilation port are provided on the box structure for water inlet, drainage, and ventilation respectively. A steam-water separation device 7 is arranged between the fuel cell stack 4 and the membrane humidifier 3. The steam-water separation device 7 is communicated with the inlet of the water storage tank 50. The tail gas in the fuel cell stack 4 passes through the steam-water separation device 7 for water-vapor separation, and the liquid water flows into the water storage tank 50 through the inlet. Similarly, the membrane humidifier 3 has a wet gas outlet 30, and the wet gas outlet 30 is communicated with the inlet of the water storage tank 50. The tail drainage discharged from the wet gas outlet 30 enters the water storage tank 50 through the inlet, and is discharged from the water storage tank 50 through the drain outlet after the water storage tank 50 is full. The cooperation between the water storage tank 50 and the membrane humidifier 3 effectively realizes adjustable humidification in the full power range.

[0034] The fuel cell system of this solution has the above-mentioned fuel cell humidification system with controllable humidity.

[0035] The basic concepts have been described above. Obviously, for those skilled in the art, the above detailed disclosure is only an example and does not constitute a limitation to this application. Although not explicitly stated here, those skilled in the art may make various modifications, improvements, and corrections to this application. Such modifications, improvements, and corrections are proposed in this application, so such modifications, improvements, and corrections still belong to the spirit and scope of the exemplary embodiments of this application.

[0036] Similarly, it should be noted that, in order to simplify the description of this application disclosure and thus help the understanding of one or more utility model embodiments, in the previous description of the embodiments of this application, sometimes multiple features are merged into one embodiment, drawing, or description thereof. However, this disclosure method does not mean that the features required by the object of this application are more than those mentioned in the claims. In fact, the features of the embodiment are less than all the features of the above-disclosed single embodiment.

[0037] The above has introduced in detail a fuel cell humidification system with controllable humidity provided by the embodiments of this application. Specific examples are used herein to elaborate on the principle and implementation manner of this utility model. The description of the above embodiments is only used to help understand the method and its core idea of this utility model; at the same time, for those skilled in the art, according to the idea of this utility model, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to this utility model.

Claims

1. A controllable humidity fuel cell humidification system, comprising an air compressor, an intercooler and a membrane humidifier arranged in sequence, wherein air enters the air compressor for compression to form high-temperature and high-pressure gas, and the high-temperature and high-pressure gas is introduced into the intercooler for cooling; the cooled gas enters the membrane humidifier for humidification, and is introduced into the fuel cell stack after being humidified by the membrane humidifier; characterized in that: A humidity regulating mechanism is also provided between the air compressor and the intercooler. The humidity regulating mechanism has at least a water collecting and water adding system and an ejection mechanism. Both ends of the ejection mechanism are respectively connected to the air compressor and the intercooler, and the ejection mechanism is connected to the water collecting and water adding system.

2. The humidity-controlled fuel cell humidification system according to claim 1, characterized in that: The water collection and water adding system comprises at least a water storage tank, a heater and a solenoid valve. The heater is arranged in the water storage tank. The water storage tank and the ejection mechanism are connected through a water diversion pipeline. The solenoid valve is installed on the water diversion pipeline of the water storage tank and the ejection mechanism to regulate the amount of water flowing from the water storage tank into the ejection mechanism.

3. The humidity-controlled fuel cell humidification system according to claim 2, characterized in that: The water storage tank is provided with a water inlet, a water outlet and a vent on the box body, for water intake, water discharge and ventilation respectively.

4. The humidity-controlled fuel cell humidification system according to claim 2, characterized in that: The ejection mechanism is a two-way bell-mouth structure with openings on both sides larger than the middle part of the ejection mechanism. The openings on both sides of the ejection mechanism are respectively an inlet connected to the air compressor and an outlet connected to the intercooler; the middle part is provided with a jet port.

5. The humidity-controlled fuel cell humidification system according to claim 4, characterized in that: The number of the jet openings is greater than or equal to two.

6. The humidity-controlled fuel cell humidification system according to claim 4, characterized in that: The middle part of the ejection mechanism is connected to the water diversion pipeline, and the high-temperature and high-pressure gas at the inlet is sucked into the liquid water of the water tank introduced into the water diversion pipeline through the low pressure formed by the ejection mechanism, and enters the intercooler through the outlet.

7. The humidity-controlled fuel cell humidification system according to claim 2, characterized in that: The middle part of the ejection mechanism is provided with an atomization structure, and the water in the water storage tank is atomized after entering the ejection mechanism, so that the humidity of the gas entering the intercooler is in an unsaturated state, and there is no liquid water when entering the membrane humidifier.

8. The humidity-controlled fuel cell humidification system according to claim 3, characterized in that: A steam-water separation device is arranged between the battery stack and the membrane humidifier, and the steam-water separation device is connected to the water inlet of the water storage tank. The exhaust gas in the battery stack passes through the steam-water separation device to separate water vapor, and liquid water flows into the water storage tank through the water inlet. After the water storage tank is full of water, it is discharged through the drain outlet.

9. The humidity-controlled fuel cell humidification system according to claim 3, characterized in that: The membrane humidifier has a moisture outlet, and the moisture outlet is provided with a steam-water separation device, which is connected to the water inlet of the water storage tank. The tail water discharged from the moisture outlet enters the water storage tank through the water inlet.

10. A fuel cell system, characterized in that: The fuel cell system comprises the fuel cell humidification system with controllable humidity as claimed in any one of claims 1 to 9.

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