KR20070038648A - Fuel cell system - Google Patents

Abstract

A fuel cell system according to an exemplary embodiment of the present invention includes a fuel cell body that generates electrical energy by reaction of hydrogen and oxygen, and a reformed gas containing hydrogen by reforming a liquefied gas fuel mainly containing butane. A fuel supply source for supplying the fuel to the reformer having a reformer for generating a gas and supplying the reformed gas to the fuel cell body, a fuel tank for storing the fuel, and an air pump for supplying air to the fuel cell body. And a heat exchanger installed to be connected to the fuel cell main body to condense the water vapor discharged from the fuel cell main body, wherein the heat exchanger includes a flow path part enabling the flow of the steam, and between the flow path part and the fuel tank. Is installed in the air to heat the fuel tank and send the air to the flow path portion. Includes a blowing fan.

Fuel cell, main body, stack, reformer, fuel supply source, fuel tank, liquefied gas fuel, vaporization, water vapor, condensation, heat exchanger, case member, flow path part, blowing fan

Description

Fuel Cell System {FUEL CELL SYSTEM}

1 is a block diagram schematically showing the overall configuration of a fuel cell system according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view showing the configuration of the fuel cell body shown in FIG. 1.

3 is a perspective view showing the configuration of the heat exchanger shown in FIG.

4 is a schematic cross-sectional configuration diagram of FIG. 3.

The present invention relates to a fuel cell system, and more particularly to a fuel cell system using liquefied gas fuel such as butane.

As is known, a fuel cell is configured as a power generation system that generates the chemical reaction energy of hydrogen and oxygen contained in a hydrocarbon-based fuel directly into electrical energy.

Such fuel cells may be broadly classified into polymer electrolyte fuel cells and direct oxidation fuel cells.

Among these, the polymer electrolyte fuel cell has excellent output characteristics compared to other fuel cells, has a low operating temperature, and fast start-up and response characteristics, so that the mobile power source such as automobiles, as well as the distributed power source and electronics such as houses and public buildings Its application range is wide, such as small power supplies for appliances.

The fuel cell system employing such a polymer electrolyte fuel cell system generates a hydrogen from this fuel by supplying a fuel cell body called a stack and thermal energy to reform the fuel and supply the hydrogen to the fuel cell body. A reformer and an air pump or fan for supplying oxygen to the fuel cell body. Therefore, in the fuel cell body, electrical energy is generated by the electrochemical reaction of hydrogen supplied from the reformer and oxygen supplied by the operation of the air pump or the fan.

On the other hand, recently, a fuel cell system for generating hydrogen through a reforming reaction of a gas fuel by a reformer using gas fuel, which is readily available on the market such as butane, has been disclosed. Since such gaseous fuel has a low boiling point and is easily liquefied even at a relatively small pressure, it is usually contained in a fuel tank and supplied to a reformer in a liquefied state under a predetermined pressure.

However, in such a conventional fuel cell system, since the fuel tank is discharged while the liquefied gas fuel is taken away from the surrounding heat and vaporized into gas, the temperature inside the tank is lowered and the surface temperature of the fuel tank is lower than the boiling point of the gas fuel. If it is lowered, condensation will occur on the surface of the fuel tank, and as a result, the pressure inside the tank is lowered, thereby lowering the gas fuel's vaporization capacity. Thus, the fuel tank is not able to smoothly supply fuel to the reformer as the amount of liquefied gas fuel vaporized substantially decreases.

In addition, the conventional fuel cell system discharges relatively high temperature water vapor by the reduction reaction of oxygen when the fuel cell body operates, and when the water vapor is directly discharged into the atmosphere maintaining a relatively low temperature, the water vapor described above Condensation occurs as the air contacts the atmosphere. As a result, the condensed water flows out through the case forming the exterior of the system, causing inconvenience to the user.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and an object thereof is to provide a fuel cell system capable of condensing water vapor discharged from a fuel cell body using air in the atmosphere and vaporizing liquefied gas fuel stored in a fuel tank. .

In order to achieve the above object, a fuel cell system according to an exemplary embodiment of the present invention, a fuel cell body for generating electrical energy by the reaction of hydrogen and oxygen, and a liquefied gas fuel containing butane as a main component A fuel supply source for supplying the fuel to the reformer while generating a reformed gas containing hydrogen and supplying the reformed gas to the fuel cell body, a fuel tank for storing the fuel, and air. An air pump for supplying a fuel cell main body, and a heat exchanger installed to be connected to the fuel cell main body to condense water vapor discharged from the fuel cell main body, wherein the heat exchanger includes a flow path unit for allowing the flow of the steam; And installed between the flow path portion and the fuel tank to apply the fuel tank by air. And it includes a blower fan for blowing the air as part the flow path.

In the fuel cell system, the heat exchanger may include a case member having the flow path part therein. In this case, the fuel cell system may be configured such that the blowing fan is integrally mounted to the case member.

In the fuel cell system, the blower fan may be configured to blow the air to the flow path part while sucking the air such that the air passes through the fuel tank between the fuel tank and the flow path part.

In the fuel cell system, the flow path portion may be configured as a metal material pipeline through which the water vapor flows. In this case, the pipeline may be formed to be bent in a zigzag form.

In the fuel cell system, the fuel cell body may include at least one electricity generating unit configured by placing a separator on both sides of a membrane-electrode assembly (MEA). In this case, the fuel cell main body may include a water vapor discharge part installed to be connected to the flow path part to discharge the water vapor generated by the electricity generator to the flow path part.

In the fuel cell system, the fuel cell body may be configured as a polymer electrolyte fuel cell (Polymer Electrolyte Membrance Fuel Cel).

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

1 is a block diagram schematically showing the overall configuration of a fuel cell system according to an embodiment of the present invention.

Referring to the fuel cell system 100 according to the present invention with reference to the drawings, the fuel cell system 100 is a small electronic device such as a notebook PC, PDA, mobile communication terminal device using the fuel and oxidant gas It is configured as a power generation system for providing electrical energy.

Specifically, the system 100 reforms a fuel to generate a reformed gas containing hydrogen, and generates a polymer electrolyte fuel cell that generates electrical energy through an oxidation reaction of the reformed gas and a reduction reaction of an oxidant gas. It is configured as a Membrane Fuel Cell) method.

The fuel used in the fuel cell system 100 may include a hydrocarbon-based liquid or gaseous fuel containing hydrogen such as methanol, ethanol, LPG, LNG, gasoline, and the like. However, the fuel described below means a gaseous fuel such as LPG or LNG, preferably a liquefied gas fuel mainly composed of butane, and in the embodiment of the present invention, the reformed gas containing hydrogen by reforming the liquefied gas fuel is reformed. Explain the example of generating.

The system 100 may use oxygen gas stored in a separate storage means as an oxidant gas, and may use air containing oxygen as it is. However, hereinafter, the latter will be described as an example.

The fuel cell system 100 includes a fuel cell body 10 configured as a polymer electrolyte fuel cell and a reformed gas containing hydrogen by reforming the fuel, and converting the reformed gas into the fuel cell body 10. And a reformer 30 to supply, a fuel supply source 50 for supplying fuel to the reformer 30, and an air supply source 70 for supplying air to the fuel cell body 10.

The fuel cell body 10 is installed to be connected to the reformer 30 and the air source 70, and receives the reformed gas from the reformer 30 and receives air from the air source 70 to contain hydrogen contained in the reformed gas. And an electric generator 11 in a cell unit for generating electrical energy by an electrochemical reaction of oxygen contained in the air.

Therefore, the fuel cell main body 10 according to the present embodiment includes a plurality of such electric generators 11, and by arranging these electricity generators 11 successively, the fuel cell body 10 is arranged in the aggregate structure of the electricity generators 11. It can be configured as a stack (stack) by.

FIG. 2 is an exploded perspective view showing the configuration of the fuel cell body shown in FIG. 1.

Referring to the drawings, the fuel cell main body 10 according to the present embodiment is formed as an aggregate structure of the electricity generating units 11 as mentioned above, and the electricity generating unit 11 is a membrane-electrode assembly (Membrane-Electrode). Assembly (MEA) 12 can be configured to be in close contact with the separator (Separator) 13 on both sides thereof.

Here, the membrane-electrode assembly 12 forms an anode electrode on one surface, a cathode electrode on the other surface, and forms an electrolyte membrane between these two electrodes. The anode electrode oxidizes hydrogen contained in the reforming gas to separate the hydrogen into electrons and hydrogen ions, and the electrolyte membrane transfers hydrogen ions to the cathode electrode, and the cathode electrode provides electrons, hydrogen ions, and separately provided from the anode electrode. Reducing the oxygen in the air is a reaction to generate a relatively high temperature water vapor.

And the separator 13 forms a reformed gas and an air movement channel for supplying the reformed gas to the anode electrode of the membrane-electrode assembly 12, and for supplying air to the cathode electrode of the membrane-electrode assembly 12. It functions as a conductor connecting the anode electrode and the cathode electrode of the electrode assembly 12 in series.

The fuel cell body 10 includes a reformed gas injector 15 (hereinafter, referred to as a “first injector”) for injecting reformed gas into the electricity generators 11, and air into electricity generators ( 11, an air injection unit 16 (hereinafter referred to as a "second injection unit") for injection, and an unreacted reformed gas discharge unit for discharging the reformed gas remaining after reacting in the electricity generating units 11 ( 17) (hereinafter referred to as " first outlet ") and steam outlet 18 (hereinafter, " second outlet ") for discharging water vapor generated by the reduction reaction in the electricity generating units 11; (See Fig. 1).

In this embodiment, the reformer 30 has a structure that generates a reformed gas containing hydrogen through a catalytic reaction such as steam reforming, steam reforming, partial oxidation or autothermal reaction, as shown in FIG. 1. . In this case, the reformer 30 may be installed to be connected to the first injection unit 15 of the fuel cell body 10 by a conventional pipeline or the like. Since the reformer 30 is made of a conventional reformer that is employed in a polymer electrolyte fuel cell system, a detailed description thereof will be omitted.

The fuel supply source 50 for supplying fuel to the reformer 30 includes a fuel tank 51 for compressing and storing liquefied gas fuel, as shown in FIG. 1. At this time, the fuel tank 51 may be installed to be connected to the reformer 30 by a conventional pipeline or the like having a discharge portion (not shown) for discharging the fuel by the pressure of the gaseous fuel itself. have.

An air supply source 70 for supplying air to the fuel cell body 10 is provided as a conventional air pump 71 that sucks air as shown in FIG. 1. In this case, the air pump 71 may be installed to be connected to the second injection unit 16 of the fuel cell body 10 by a conventional pipeline or the like.

When the fuel cell system 10 is configured as described above, the fuel cell body 10 generates relatively high temperature water vapor through a reduction reaction of air by the electricity generating units 11. It is discharged through the discharge portion 18 (see Fig. 1).

In addition, when the fuel cell system 100 operates, the fuel tank 51 is discharged as the liquefied gas fuel stored in the fuel tank 51 is discharged as it takes away the surrounding heat and vaporizes into a gas (commonly referred to as "latent heat of vaporization"). When the temperature inside the tank is lowered, condensation occurs on the surface of the fuel tank 51 when the temperature of the surface of the fuel tank 51 falls below the boiling point of the gaseous fuel. As the pressure of the gas is lowered, the gaseous fuel vaporization capacity is lowered. This prevents the fuel tank 51 from smoothly supplying fuel to the reformer 30 as the amount of gaseous fuel vaporized substantially decreases (see FIG. 1).

Accordingly, in the embodiment of the present invention, as shown in FIG. 1, the high temperature water vapor discharged through the second discharge unit 18 of the fuel cell body 10 is condensed by air in a relatively low temperature atmosphere. At the same time, a heat exchanger 90 is provided to heat the fuel tank 51 through the air to vaporize the liquefied gas fuel stored in the fuel tank 51.

3 is a perspective view illustrating the configuration of the heat exchanger illustrated in FIG. 1, and FIG. 4 is a schematic cross-sectional configuration diagram of FIG. 3.

1, 3, and 4, the heat exchanger 90 according to the present embodiment heats the fuel tank 51 by allowing the air in the atmosphere having a relatively low temperature to pass through the fuel tank 51. It consists of a structure which vaporizes the liquefied gas fuel stored in the fuel tank 51. In addition, the heat exchanger 90 according to the present embodiment passes through the fuel tank 51 to the second discharge part 18 of the fuel cell body 10 through the air deprived of heat from the fuel tank 51. It is provided on the flow path of the water vapor discharged through the condensation structure to the water vapor flowing along the discharge path.

Specifically, the heat exchanger 90 is a fuel passage 91 for circulating water vapor discharged through the second discharge portion 18 of the fuel cell body 10 and fuel through the air while inhaling air in the atmosphere. It comprises a blower 93 for blowing the air to the flow path portion 91 while applying heat to the tank (51).

The flow path portion 91 includes a metal pipe line 92 which is installed to be substantially connected to the second discharge portion 18 of the fuel cell body 10. The pipe line 92 is in the form of a coil or It is made of a structure banded in a zigzag form, preferably a structure banded in a zigzag form as shown in the figure. The reason why the pipeline 92 is formed in a zigzag form is to further extend the flow path of the water vapor discharged through the second discharge portion 18 of the fuel cell body 10.

In this embodiment, the blower portion 93 is integrally formed with the case member 94 in which the flow path portion 91 is embedded, and the case member 94 so as to be disposed between the fuel tank 51 and the flow path portion 91. And a blowing fan 99 which blows the air to the flow path portion 91 while sucking the air in the atmosphere.

The case member 94 forms an accommodating space 95 in which the flow path portion 91 is incorporated, and a mounting portion 96 for mounting the blower fan 99. At this time, the case member 94 forms a discharge port 94a for discharging the air having passed through the flow path portion 91 to the outside in the accommodation space 95.

In this embodiment, the blower fan 99 is mounted to the mounting portion 96 of the case member 94, and is disposed between the fuel tank 51 and the flow path portion 91. That is, based on the blowing fan 99, the fuel tank 51 is disposed on the suction path of the air sucked by the blowing fan 99 and flows, and the flow path portion 91 is the blowing fan 99. It is disposed on the blowing path of the air flowing and flows by). The blower fan 99 is provided as a blower fan having a conventional structure in which air in the atmosphere is sucked by driving the fan by driving the motor, and the air is blown into the accommodation space 95 of the case member 94.

The reason why the blower fan 99 is disposed between the fuel tank 51 and the flow path part 91 is that the air in the air sucked by the blower fan 99 passes through the fuel tank 51 and causes condensation. This is to vaporize the liquefied gas fuel stored in the fuel tank 51 by applying heat in the air to the generated fuel tank 51. In addition, by passing the air having a relatively low temperature from which the heat is lost to the fuel tank 51 while passing through the fuel tank 51 to the flow path 91, condensation of water vapor flowing along the flow path 91 with moisture is achieved. For sake.

Referring to the operation of the fuel cell system 100 according to the present embodiment configured as described above in detail as follows.

First, the liquefied gas fuel stored in the fuel tank 51 is supplied to the reformer 30 while being discharged from the fuel tank 51 by its pressure. Then, the reformer 30 generates a reformed gas containing hydrogen as the reforming reaction of the fuel proceeds, and supplies the reformed gas to the first injection unit 15 of the fuel cell body 10.

At the same time, the air pump 71 sucks air and supplies this air to the second injection portion 16 of the fuel cell body 10.

Therefore, the fuel cell body 10 outputs electric energy of a predetermined capacity through oxidation reaction of reformed gas by the electricity generating units 11 and reduction reaction of air, and the air by the electricity generating units 11. The relatively high temperature water vapor generated by the reduction reaction of is discharged through the second discharge unit 18.

Through this process, the water vapor is supplied to the pipeline 92 of the flow path portion 91. At this time, the pipeline 92 is maintained heated to a predetermined temperature as the hot water vapor flows along its flow path. In addition, since the fuel tank 51 is discharged while the liquefied gas fuel stored in the fuel tank 51 is taken away by vaporizing gas into the gas, the temperature of the surface of the fuel tank 51 is lower than the boiling point of the gas fuel. If it falls, condensation occurs on the surface of the fuel tank 51, and as the pressure inside the tank decreases, the gaseous fuel vaporization capacity is lowered. At this time, the surface temperature of the fuel tank 51 maintains the temperature lower than air | atmosphere in air | atmosphere.

In this state, since the blower fan 99 sucks air in the atmosphere, since the fuel tank 51 is disposed on the air intake path, the air in the atmosphere follows the dotted arrow direction shown in FIG. The liquefied gas fuel is vaporized by applying heat to the fuel tank 51 while passing through the fuel tank 51 in which the condensation occurs. Therefore, the fuel tank 51 can smoothly supply this gas fuel to the reformer 30 as the internal pressure rises and the vaporization capability of the gas fuel improves.

Thereafter, the air deprived of heat while passing through the fuel tank 51 is blown by the blower fan 99 into the accommodation space 95 of the case member 94 along the direction of the solid arrow shown in FIG. 4. Since the flow path part 91 is arrange | positioned on the air blower path | route in the accommodating space 95 of the case member 94, by cooling the pipeline 92 heated to predetermined temperature, Water vapor flowing along the flow path is condensed with moisture. Then, the water condensed in the pipeline 92 is collected into a separate storage space (not shown).

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications and changes can be made within the scope of the claims and the detailed description of the invention and the accompanying drawings. Naturally, it belongs to the scope of the invention.

According to the present invention as described above, by providing a heat exchanger for vaporizing liquefied gas fuel stored in the fuel tank while condensing water vapor discharged from the fuel cell body using air in the atmosphere, the liquefied gas fuel is converted into a reformer. Reliably supplied, the system can be operated continuously and the system can be operated with high efficiency.

In addition, according to the present invention, since the moisture condensed by the heat exchanger can be separately managed, the performance efficiency of the entire system and the reliability of the system for the user can be further improved.

Claims (9)

A fuel cell body generating electrical energy by reaction of hydrogen and oxygen; A reformer for reforming a liquefied gas fuel mainly composed of butane to generate the reformed gas containing hydrogen, and supplying the reformed gas to the fuel cell body; A fuel supply source having a fuel tank for storing the fuel and supplying the fuel to the reformer; An air pump supplying air to the fuel cell body; And Heat exchanger is installed to be connected to the fuel cell body to condense the water vapor discharged from the fuel cell body Including; The heat exchanger, And a flow path unit configured to enable the flow of the water vapor, and a blowing fan installed between the flow path unit and the fuel tank to blow the air to the flow path unit while heating the fuel tank by air. According to claim 1, And the heat exchanger includes a case member having the flow path unit therein. The method of claim 2, And the blower fan is integrally mounted to the case member. The method of claim 3, wherein And the blower fan is configured to blow the air to the flow path part while sucking the air between the fuel tank and the flow path part so that the air passes through the fuel tank. According to claim 1, And the flow path portion is configured as a metal material pipeline through which the water vapor flows. The method of claim 5, And the pipeline is formed to be bent in a zigzag form. According to claim 1, The fuel cell body, A fuel cell system comprising at least one electricity generating unit configured by centering a membrane-electrode assembly (MEA) and disposing separators on both sides thereof. The method of claim 7, wherein The fuel cell body, And a water vapor discharge part installed to be connected to the flow path part to discharge the water vapor generated by the electricity generation part to the flow path part. According to claim 1, The fuel cell body is configured as a polymer electrolyte fuel cell (Polymer Electrolyte Membrance Fuel Cel).

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