Fuel cell mixer and fuel cell system comprising same

Abstract

A fuel cell mixer device is disclosed. The shape of the fuel cell mixer of the present invention is optimized for fluidic flow, and condensate water can be collected in a condensate water outlet by gravity so that fuel and steam can be smoothly mixed, and the condensate water can be easily discharged. In addition, the fuel cell mixer can minimize welding so as to reduce costs and simplify processing, and thus can reduce manufacture time.

Description

Mixer for fuel cell and fuel cell system including same

[0001] The present invention relates to a mixer for a fuel cell and a fuel cell system including the same.

[0002] Fuel cell mixers mix the fuel and steam supplied to the fuel cell stack. Located before the reformer, they require high mixing and temperature maintenance. After the fuel cell system shuts down, its temperature drops, causing steam to condense inside the mixer, creating condensate. This accumulation of condensate requires additional preheating time to remove the condensate when the fuel cell system is restarted, delaying startup time and potentially causing corrosion, shortening the mixer's lifespan.

[0003] Fuel cell mixers vary in manufacturability and corrosion resistance depending on their shape. Specifically, the more welded parts there are, the more likely fuel and water vapor to leak, significantly increasing manufacturing costs and time. Consequently, demand is growing for fuel cell mixers that facilitate condensate removal and offer superior manufacturability, resulting in cost savings.

[0004] One object of the present invention is to provide a fuel cell mixer that can easily remove condensate and has excellent manufacturability, thereby reducing cost.

[0005] Another object of the present invention is to provide a fuel cell system including the above fuel cell mixer.

[0006] In order to achieve the above object, the present invention provides a mixer device for a fuel cell, comprising: a first end plate to which a first pipe connected to a steam generating device is connected, a second end plate facing the first end plate, and a side wall connecting the first end plate and the second end plate, the mixer device comprising: a chamber having an internal space; a first perforated plate and a second perforated plate spaced apart from each other inside the chamber and dividing the internal space into a first space adjacent to the first end plate, a second space adjacent to the second end plate, and a third space disposed between the first space and the second space; a fuel diffusion tank disposed inside the third space and connected to the second perforated plate; and a second pipe penetrating the first end plate and the first perforated plate so as to pass through the first space, and disposed so as to have an outlet located at a position adjacent to the fuel diffusion tank inside the third space, through which the hydrocarbon fuel moves.

[0007] According to one embodiment of the present invention, the chamber may include a condensate discharge port for discharging condensate generated within the internal space to the outside.

[0008] According to one embodiment of the present invention, the second end plate may have a smaller cross-sectional area than the first end plate.

[0009] According to one embodiment of the present invention, the chamber may be arranged such that the bottom surface of the side wall adjacent to the second end plate is higher than the bottom surface of the side wall adjacent to the first end plate.

[0010] According to one embodiment of the present invention, condensate formed inside the chamber can move to the condensate discharge port by gravity.

[0011] According to one embodiment of the present invention, the first and second end plates may have circular shapes with different diameters, and the internal space of the chamber may have a cylindrical structure.

[0012] According to one embodiment of the present invention, the chamber includes an outlet for discharging a mixed gas of the hydrocarbon fuel gas and the steam to a reformer, and the steam discharged from the first pipe moves through the first perforated plate and the second perforated plate and can be mixed with the hydrocarbon fuel in the second space.

[0013] According to one embodiment of the present invention, the second perforated plate may have perforations formed in a portion excluding an area facing the outlet of the second pipe.

[0014] According to one embodiment of the present invention, the second perforated plate may be formed with a plurality of perforations of different sizes.

[0015] According to one embodiment of the present invention, the diameter of the first pipe may be larger than the diameter of the second pipe.

[0016] According to one embodiment of the present invention, the fuel diffusion tank may have a curved surface protruding from the second perforated plate toward the outlet of the second pipe.

[0017] In addition, the present invention provides a fuel cell system including a steam generator that converts water into steam; a fuel supply device that supplies hydrocarbon fuel gas; a mixer device that is connected to the steam generator and the fuel supply device and mixes the steam and the hydrocarbon fuel gas; a reformer that reforms a mixed gas supplied from the mixer device to produce hydrogen; and a fuel cell stack that generates electric energy using reformed fuel supplied from the reformer and air from an external air supply device.

[0018] According to one embodiment of the present invention, the fuel cell stack further includes a combustor for combusting off-gas discharged from the fuel cell stack, and the steam generation device can convert water into steam by using the thermal energy of the combustion gas generated by the combustor.

[0019] According to one embodiment of the present invention, the fuel supply device may further include a heat exchanger that heats the hydrocarbon fuel gas through heat exchange between the hydrocarbon fuel gas and the high-temperature combustion gas and then supplies the heated hydrocarbon fuel gas to the mixer device.

[0020] According to the present invention, the shape of the fuel cell mixer of the present invention is optimized for the flow of fluid, and condensate can be collected in the condensate discharge port by gravity, so that mixing of fuel and steam can be smoothly achieved, and condensate discharge can be made easy.

[0021] Additionally, mixers for fuel cells can minimize welding, which reduces costs and simplifies processing, shortening manufacturing time.

[0022] In addition, the location of the fuel supply pipe is optimized so that the conductive heat generated during fuel cell operation can be supplied, and the fuel whose temperature has increased due to the conductive heat can be smoothly mixed with water vapor.

[0023] FIG. 1 is a cross-sectional view of a mixer for a fuel cell according to one embodiment of the present invention.

[0024] Figure 2 is a plan view of the first and second perforated plates according to one embodiment of the present invention.

[0025] FIG. 3 is a side perspective view of a mixer for a fuel cell according to one embodiment of the present invention.

[0026] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. The present invention can be modified in various ways and can take various forms, and thus specific embodiments are illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to a specific disclosed form, but should be understood to include all modifications, equivalents, and substitutes included in the spirit and technical scope of the present invention. In describing each drawing, similar reference numerals are used to indicate similar components. In the attached drawings, the dimensions of structures are shown larger than actual size to ensure clarity of the present invention.

[0027] While terms like "first" and "second" may be used to describe various components, these components should not be limited by these terms. These terms are used solely to distinguish one component from another. For example, without departing from the scope of the present invention, a first component could be referred to as a "second component," and similarly, a second component could also be referred to as a "first component."

[0028] The terminology used in this application is only used to describe specific embodiments and is not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, it should be understood that the terms "comprise" or "have" indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but do not preclude the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0029] Meanwhile, unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and shall not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

[0030]

[0031] FIG. 1 is a cross-sectional view of a mixer for a fuel cell according to one embodiment of the present invention, FIG. 2 is a plan view of first and second perforated plates according to one embodiment of the present invention, and FIG. 3 is a side perspective view of a mixer for a fuel cell according to one embodiment of the present invention.

[0032] Referring to FIGS. 1 to 3, a fuel cell mixer according to an embodiment of the present invention is a mixer device for mixing hydrocarbon fuel gas and steam, comprising: a first end plate (120) to which a first pipe (110) connected to a steam generating device is connected, a second end plate (130) facing the first end plate (120), and a side wall (140) connecting the first end plate (120) and the second end plate (130), the mixer having an internal space; a first perforated plate (150) and a second perforated plate (160) spaced apart from each other inside the chamber and dividing the internal space into a first space (10) adjacent to the first end plate (120), a second space (20) adjacent to the second end plate (130), and a third space (30) disposed between the first space and the second space; It may include a fuel diffusion tank (170) disposed inside the third space (30) and coupled to the second perforated plate (160); a second pipe (180) penetrating the first end plate (120) and the first perforated plate (150) so as to pass through the first space (10), and positioned so that an outlet is located adjacent to the fuel diffusion tank (170) inside the third space (30), and through which the hydrocarbon fuel moves.

[0033] The chamber may be formed on a side wall of the first space (10) and may include a condensate discharge port (190) for discharging condensate generated within the internal space to the outside. The condensate may be generated by condensation of water vapor when the temperature drops after the fuel cell is operated, and the condensate may be discharged to the outside of the fuel cell mixer through the condensate discharge port (190).

[0034] The second end plate (130) may have a smaller cross-sectional area than the first end plate (120), and due to the difference in area between the first and second end plates (120, 130), the chamber may be arranged so that the bottom surface of the side wall adjacent to the second end plate (130) is higher than the bottom surface of the side wall adjacent to the first end plate (120). The bottom surface of the chamber may be designed to be closer to gravity as it approaches the first end plate (120). By the design, condensate formed inside the chamber can move to the condensate outlet (190) by gravity. The condensate can naturally move by gravity and be coagulated, so that the condensate present inside the chamber can be easily discharged.

[0035] The first and second end plates (120, 130) may have circular shapes with different diameters, and the internal space of the chamber may have a cylindrical structure. If the internal space of the chamber is cylindrical, condensate can move to the bottom surface and easily coagulate, and the welding area can be minimized, thereby reducing cost and manufacturing time.

[0036]

[0037] The fuel cell mixer may be positioned at the bottom of the fuel heat exchanger. In this case, the thermal energy of the off-gas of the fuel cell stack may be transferred to the fuel cell mixer, and thus the fluid flowing within the second pipe (180) may also be heated. For example, the second pipe (180) may receive the thermal energy while passing through the first space (10) and the third space (30), and thus the temperature of the hydrocarbon fuel may rise before mixing with the steam, thereby increasing the mixing efficiency with the steam.

[0038] The chamber includes an outlet (not shown) for discharging a mixed gas of the hydrocarbon fuel gas and the steam to a reformer, and the steam discharged from the first pipe (110) moves through the first perforated plate (150) and the second perforated plate (160) and can be mixed with the hydrocarbon fuel in the third space (30).

[0039] The second perforated plate (160) may have perforations formed in a portion excluding the area facing the outlet of the second pipe (180), and the second perforated plate (160) may have a plurality of perforations formed with different sizes. The perforations formed around the area facing the outlet of the second pipe (180) in the second perforated plate (160) may have a smaller diameter than the perforations formed in the area near the side wall (140). In addition, the diameter of the perforations formed in the area near the side wall (140) may be relatively large, so that the water vapor can easily pass through the second perforated plate (160) and move to the outlet (not shown) connected to the reformer.

[0040]

[0041] The fuel diffusion tank (170) may have a curved surface protruding from the second perforated plate (160) toward the outlet of the second pipe (180). In addition, the fuel diffusion tank (170) may be disposed spaced apart from the second perforated plate (160). In general, when hydrocarbon fuel and water vapor move relatively quickly in the same direction, they tend not to mix with each other. In order to solve this problem, the fuel diffusion tank (170) and the outlet of the second pipe (180) are disposed adjacently, and the fuel diffusion tank (170) has a curved shape, so that the hydrocarbon fuel discharged from the second pipe (180) can reduce the flow rate and pressure of the hydrocarbon fuel as it collides with the fuel diffusion tank (170), and the hydrocarbon fuel can mix with the water vapor in the third space (30) as it flows backward due to the collision with the fuel diffusion tank (170). The mixed gas can pass through the second perforated plate (160) and move along an outlet (not shown) connected to the reformer. The volume of the fuel diffusion tank (170) can be changed depending on the flow rate of the hydrocarbon fuel.

[0042] The diameter of the first pipe (110) may be larger than the diameter of the second pipe (180). Due to the difference in diameter between the first pipe (110) and the second pipe (180), the amount of steam supplied may be greater than the amount of hydrocarbon fuel supplied.

[0043]

[0044] A fuel cell system according to one embodiment of the present invention may include a steam generating device that converts water into steam; a fuel supply device that supplies hydrocarbon fuel gas; a mixer device according to a fuel cell mixer that is connected to the steam generating device and the fuel supply device and mixes the steam and the hydrocarbon fuel gas; a reformer that reforms a mixed gas supplied from the mixer device to produce hydrogen; and a fuel cell stack that generates electric energy using reformed fuel supplied from the reformer and air from an external air supply device.

[0045] The fuel cell stack further includes a combustor for combusting off-gas discharged from the fuel cell stack, and the steam generation device can convert the water into steam using the thermal energy of the combustion gas generated by the combustor. The steam can move to the first pipe (110) and be discharged to the fuel cell mixer.

[0046] The fuel supply device may further include a heat exchanger that heats the hydrocarbon fuel gas through heat exchange between the hydrocarbon fuel gas and the high-temperature combustion gas and then supplies the heated hydrocarbon fuel gas to the mixer device. The fuel cell mixer may be disposed below the heat exchanger, and heat energy generated in the heat exchanger may be transferred to the fuel cell mixer.

[0047]

[0048] Although the present invention has been described above with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various modifications and changes may be made to the present invention without departing from the spirit and scope of the present invention as set forth in the claims below.

Claims

1. In a mixer device for mixing hydrocarbon fuel gas and steam, A chamber comprising a first end plate to which a first pipe connected to a steam generating device is connected, a second end plate facing the first end plate, and a side wall connecting the first end plate and the second end plate, and having an internal space; A first perforated plate and a second perforated plate are arranged spaced apart from each other inside the chamber and divide the internal space into a first space adjacent to the first end plate, a second space adjacent to the second end plate, and a third space arranged between the first space and the second space; A fuel diffusion tank disposed inside the third space and connected to the second perforated plate; A fuel cell mixer device, comprising: a second pipe penetrating the first end plate and the first perforated plate so as to pass through the first space, and positioned so as to have an outlet located adjacent to the fuel diffusion tank within the third space, through which the hydrocarbon fuel moves; 2. In paragraph 1, A fuel cell mixer device comprising a condensate discharge port for discharging condensate generated within the internal space of the chamber to the outside.

3. In paragraph 1, A fuel cell mixer device, wherein the second end plate has a smaller cross-sectional area than the first end plate.

4. In paragraph 3, A fuel cell mixer device, wherein the chamber is arranged such that the bottom surface of the side wall adjacent to the second end plate is higher than the bottom surface of the side wall adjacent to the first end plate.

5. In paragraph 2, A fuel cell mixer device in which condensate formed inside the chamber moves to the condensate outlet by gravity.

6. In paragraph 3, A fuel cell mixer device, wherein the first and second end plates have circular shapes of different diameters, and the internal space of the chamber has a cylindrical structure.

7. In paragraph 1, The chamber includes an outlet for discharging a mixed gas of the hydrocarbon fuel gas and the water vapor to a reformer, A fuel cell mixer device in which water vapor discharged from the first pipe moves through the first perforated plate and the second perforated plate and is mixed with the hydrocarbon fuel in the second space.

8. In paragraph 1, A fuel cell mixer device, wherein the second perforated plate has perforations formed in a portion excluding an area facing the outlet of the second pipe.

9. In paragraph 1, A fuel cell mixer device in which the second perforated plate is formed with a plurality of perforations of different sizes.

10. In paragraph 1, A fuel cell mixer device, wherein the diameter of the first pipe is larger than the diameter of the second pipe.

11. In paragraph 1, A fuel cell mixer device, wherein the fuel diffusion tank has a curved surface protruding from the second perforated plate toward the outlet of the second pipe.

12. A steam generator that converts water into steam; A fuel supply device that supplies hydrocarbon fuel gas; A mixer device according to any one of claims 1 to 10, connected to the steam generating device and the fuel supply device to mix the steam and the hydrocarbon fuel gas; A reformer that generates hydrogen by reforming a mixed gas supplied from the above mixer device; A fuel cell system comprising a fuel cell stack that generates electrical energy using reformed fuel supplied from the reformer and air from an external air supply device.

13. In paragraph 12, Further comprising a combustor that combusts off-gas discharged from the fuel cell stack, The above steam generating device is a fuel cell system that converts the water into the steam by using the heat energy of the combustion gas generated by the combustor.

14. In paragraph 13, A fuel cell system, wherein the fuel supply device further includes a heat exchanger that heats the hydrocarbon fuel gas through heat exchange between the hydrocarbon fuel gas and high-temperature combustion gas and then supplies the heated hydrocarbon fuel gas to the mixer device.

Images