KR20070095052A - Fuel cell system - Google Patents

Abstract

A fuel cell system is provided to improve the operation efficiency and confidence of total system and to reduce the consumption of power for operating a pump by controlling the operation of a pump according to the level of condensed water. A fuel cell system(100) comprises a fuel cell main body(10); a reformer(20) which generates the reformed gas containing hydrogen mainly by the reformation reaction of fuel and water; a fuel supply source(30) which supplies the fuel to the reformer; a water supply source(40) which supplies the water to the reformer; a heat exchanger(60) which condenses the vapor discharged from the fuel cell main body into water; a separator(70) which is connected to the reformer to separate and store the reformed gas sand water discharged from the reformer, supplies the reformed gas to the fuel cell main body, and supplies the water to the water supply source; and a condensed water tank(80) which is connected to the heat exchanger and the separator, stores the water condensed at the heat exchanger, and selectively provides the water to the separator.

Description

Fuel Cell System {FUEL CELL SYSTEM}

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

2 is a cross-sectional view showing the structure of the condensate tank shown in FIG.

The present invention relates to a fuel cell system, and more particularly, to a fuel cell system capable of reusing moisture discharged from a fuel cell body.

As is known, a fuel cell system is configured as a power generation system that generates electric energy by oxidation reaction of hydrogen contained in hydrocarbon-based fuel and reduction reaction of oxygen.

Such a fuel cell system can be broadly classified into a polymer electrolyte fuel cell method and a direct oxidation fuel cell method.

Among them, the polymer electrolyte fuel cell has a structure in which electrical energy is generated by receiving hydrogen gas generated by reforming fuel and oxidizing the hydrogen gas and reducing the oxidant gas supplied separately.

The polymer electrolyte fuel cell system includes a reformer for generating hydrogen gas by a steam reforming reaction between fuel and water, a fuel tank for supplying fuel to the reformer, a water tank for supplying water to the reformer, and an oxidant gas. It is configured to include an oxidant gas supply device for supplying the fuel cell.

However, such a conventional fuel cell system discharges relatively high temperature water vapor generated by a reduction reaction of an oxidant gas into the atmosphere when the fuel cell operates, and thus, an energy source for generating electricity of the fuel cell is released as it is. Therefore, there was a problem in that the operating efficiency and reliability of the entire system is deteriorated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object thereof is to provide a fuel cell system capable of condensing water vapor discharged from a fuel cell into water and finally supplying this water to a water tank.

In order to achieve the above object, a fuel cell system according to an exemplary embodiment of the present invention includes a fuel cell body, a reformer for generating a reformed gas mainly composed of hydrogen by a reforming reaction between fuel and water, and the fuel. A fuel supply source for supplying the reformer, a water supply source for supplying the water to the reformer, a heat exchanger for condensing water vapor discharged from the fuel cell body with water, and connected to the reformer and discharged from the reformer A separator for separating and storing the reformed gas and water, and supplying the reformed gas to the fuel cell body and supplying the water to the water supply source, the heat exchanger, and the separator to be connected to the separator. To store the water condensed in the And a condensed water tank to provide a.

The fuel cell system may include a pump installed at a connection line connecting the condensate tank and the separator to suck water stored in the condensate tank, and pump the water to the separator through the connection line. .

In addition, the fuel cell system may include a control unit installed in the condensate tank to selectively drive the pump according to the level of water stored in the condensate tank.

In the fuel cell system, the control unit may include a sensor rod installed in an inner direction of the condensate tank, and an ohmmeter installed to be electrically connected to the sensor rod, the condensate tank, and the pump. In this case, the sensor rod and the condensate tank may be made of a conductive metal material.

In the fuel cell system, the water supply includes a water tank for storing the water, and the water tank may be installed to be connected to the reformer and the separator by a pipe-type connection line.

In the fuel cell system, the separator is a reformed gas storage unit that is installed to be connected to the fuel cell body while storing the reformed gas, and the water storage is connected to the water supply source and the condensate tank while storing the water It may include wealth.

In the fuel cell system, the water storage unit may be installed to be connected to the water tank and the condensate tank by a pipe-type connection line.

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 illustrating a configuration of a fuel cell system according to an exemplary embodiment of the present invention.

Referring to the fuel cell system 100 according to an embodiment of the present invention with reference to the drawings, the fuel cell system 100 reforms the fuel with water to generate a reformed gas mainly composed of hydrogen, It is configured as a polymer electrolyte fuel cell system that generates electrical energy by oxidation reaction of reforming gas and reduction reaction of oxidant gas.

Here, the fuel used in the system 100 may include a hydrocarbon-based liquid or gaseous fuel such as methanol, ethanol, LPG, LNG, gasoline, and the like.

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.

The fuel cell system 100 includes a polymer electrolyte fuel cell body 10 that generates electric energy by a reaction of a reforming gas and an oxidant gas, and a reformer that generates a reforming gas containing hydrogen by a reforming reaction between fuel and water. 20, a fuel supply source 30 for supplying fuel to the reformer 20, a water supply source 40 for supplying water to the reformer 20, and supplying air to the fuel cell body 10 Separator 70 for separately storing the air supply source 50, the heat exchanger 60 for condensing the water vapor discharged from the fuel cell body 10 with water, and the reformed gas and water discharged from the reformer 20, respectively. ), And a condensate tank 80 for collecting and storing the water condensed in the heat exchanger (60).

The fuel cell system 100 configured as described above supplies the water discharged from the fuel cell body 10 and the water discharged from the reformer 20 to the water supply 40 to supply the water required for the reforming reaction of the reformer 20. As a recycling system (recycling system) that can be reused.

In the above, the fuel cell body 10 is installed to be connected to the separator 70 and the air source 50, the reformed gas is supplied from the separator 70 and the air is supplied from the air source 50, hydrogen and oxygen And an electric generator 11 in a cell unit for generating electrical energy by an electrochemical reaction of the same.

Therefore, the fuel cell main body 10 according to the present embodiment includes a plurality of such electricity generating units 11, and is arranged as a stack having an aggregate structure of the electricity generating units 11 by arranging them continuously. Can be.

The fuel cell body 10 includes a first injection unit 15 for injecting reformed gas into the electricity generation units 11, a second injection unit 16 for injecting air into the electricity generation units 11, and In addition, the first discharge unit 17 for discharging the remaining unreacted reformed gas remaining in the electricity generating units 11 and the agent for discharging water vapor generated through the reduction reaction of oxygen by the electricity generating units 11 2 discharge part 18 is formed.

In the present embodiment, the reformer 20 is installed to be connected to the fuel supply source 30 and the water supply source 40, and receives fuel and water from the fuel supply source 30 and the water supply source 40 and vapor of the fuel and water. It is made as a structure which produces | generates the reformed gas which has hydrogen as a main component through a steam reforming (SR) reaction. Since the reformer 20 is configured as a conventional reformer employed in a polymer electrolyte fuel cell system, a detailed description thereof will be omitted.

The fuel supply source 30 for supplying the fuel to the reformer 20 includes a fuel tank 31 for storing fuel, which stores liquid fuel such as methanol or ethanol or butane. It is provided as a storage container which can store liquefied gas fuel containing as a main component. In this case, the fuel tank 31 may be installed to be connected to the reformer 20 by a first connection line L1 in the form of a pipe.

Here, when the fuel is a liquid fuel, the fuel supply source 30 is a pump installed in the first connection line (L1) for pumping the fuel stored in the fuel tank 31 to the reformer 20 (not shown in the figure) ) May be provided. In addition, when the fuel is a gaseous fuel, the fuel supply source 30 may compress the gaseous fuel to a predetermined pressure and store it in a liquefied state, and supply the gaseous fuel to the reformer 20 by the pressure of the gaseous fuel itself. It only has the fuel tank 31 which is present, and does not require a pump as described above.

The water source 40 for supplying water to the reformer 20 includes a water tank 41 for storing water. The water tank 41 may be installed to be connected to the reformer 20 by a second connecting line L2 in the form of a pipe. At this time, the water source 40 may be provided with a pump (not shown) installed in the second connection line (L2) for pumping the water stored in the water tank 41 to the reformer 20.

In this embodiment, an air supply source 50 for supplying air to the fuel cell body 10 is provided as an air pump 51 that sucks air in the atmosphere and pumps the air into the fuel cell body 10. . At this time, the air pump 51 and the second injection portion 16 of the fuel cell body 10 may be connected by a third connection line L3 in the form of a pipe. As an alternative, the air source 50 according to the present embodiment is not limited to having an air pump 51 as above, but may also include a blower which is generally well known in the art.

In the present embodiment, the heat exchanger 60 is for condensing the relatively high temperature water vapor discharged through the second discharge unit 18 of the fuel cell body 10 with water, and the water vapor inside the predetermined case 61. A flow path 62 in the form of a coil for flowing and a blowing fan 63 for blowing cooling air to the flow path 62 are provided. The heat exchanger 60 is provided as a condenser having a conventional structure in which cooling air is blown into the flow path 62 by the operation of the blower fan 63 to condense water vapor flowing along the flow path 62 with water.

In this embodiment, the separator 70 is installed to be connected to the reformed gas outlet (not shown in the figure) of the reformer 20. The separator 70 separates and stores the reformed gas and moisture discharged from the reformer 20 through heat exchange, supplies the reformed gas to the fuel cell body 10, and supplies water to the water tank 41. To function.

In detail, the separator 70 includes a reformed gas storage unit 71 storing a reformed gas discharged from the reformer 20 and a water storage unit 72 storing moisture discharged from the reformer 20. do. In this case, the reformed gas storage unit 71 has a predetermined storage space for storing the reformed gas and is connected to the first injection unit 15 of the fuel cell body 10 by the fourth connection line L4 in the form of a pipe. It is installed to connect with. The water storage unit 72 is installed to be connected to the water tank 41 by the fifth connection line L5 having a pipe shape while having a predetermined storage space for storing water. In addition, a pump (not shown) for pumping water stored in the water storage unit 72 into the water tank 41 may be installed in the fifth connection line L5.

In the present embodiment, the condensate tank 80 is configured as a structure capable of collecting and storing the water condensed in the heat exchanger 60, and selectively providing the water to the water storage unit 72 of the separator 70. .

The condensate tank 80 is provided as a storage container having a predetermined storage space, is installed to be connected to the heat exchanger 60, and the water storage part of the separator 70 by a sixth connecting line L6 in the form of a pipe. It is installed in connection with 72. At this time, the sixth connection line (L6) is provided with a pump (P) for pumping the water stored in the condensate tank 80 to the water storage unit 72 of the separator (70). The condensate tank 80 will be described in more detail later with reference to FIG. 2.

2 is a cross-sectional view showing the structure of the condensate tank shown in FIG.

1 and 2, the condensate tank 80 according to the present embodiment is provided as a body 81 in the form of a tube having a predetermined internal space, the body 81 is a conductive metal material, for example , Made of stainless steel.

In the above, the main body 81 is connected to the heat exchanger 60, the inlet (81a) for injecting the water condensed in the heat exchanger 60 into the internal space, and the separator (6) by the sixth connection line (L6) It is connected to the water storage unit 72 of 70 to form a discharge port (81b) for discharging the water stored in the internal space.

The fuel cell system 100 configured as described above is provided with a control unit 90 installed in the condensate tank 80, the control unit 90 is a sixth in accordance with the water level stored in the condensate tank 80 It functions as a so-called control device for selectively driving the pump (P) installed in the connection line (L6).

The control unit 90 is a sensor rod 91 installed in the inner direction of the main body 81, the ohmmeter 93 is installed to be electrically connected to the sensor rod 91, the main body 81 and the pump (P). It is configured to include.

The sensor rod 91 is made of a conductive metal material, for example, stainless steel, and is installed such that one end thereof penetrates through the upper end portion of the main body 81 and is inserted into the inner space of the main body 81. At this time, the sensor rod 91 is installed to be inserted into the insulating tube 92 which is supported by the upper end of the main body 81 and disposed in the inner space of the main body 81. One end of the sensor rod 91 is in contact with water in the inner space of the main body 81, and the other end of the sensor rod 91 is drawn out to the outside through the upper end portion of the main body 81.

In the above, the ohmmeter 93 is installed to be electrically connected to the sensor rod 91 and the main body 81 by a conventional conductive wire, and is electrically connected to the pump P through the controller (C) not shown in the figure. It is installed to be connected.

The ohmmeter 93 applies power to the sensor rod 91 and the main body 81 through a wire, so that when the sensor rod 91 is in contact with water stored in the inner space of the main body 81, the sensor rod ( 91 and a predetermined resistance value are taken out while forming a closed circuit with the main body 81. On the contrary, when the sensor rod 91 is not in contact with the water stored in the inner space of the main body 81, the ohmmeter 93 forms an open circuit with the sensor rod 91 and the main body 81 and draws out an infinite resistance value. Done.

Therefore, when the sensor rod 91 is in contact with water stored in the inner space of the main body 81, the controller C recognizes a predetermined resistance value measured by the ohmmeter 93 and drives the pump P. FIG. On the contrary, when the sensor rod 91 is not in contact with the water stored in the inner space of the main body 81, the resistance of the infinite resistance measured by the ohmmeter 93 is recognized to stop the driving of the pump P. do.

Hereinafter, the operation of the fuel cell system according to an exemplary embodiment of the present invention configured as described above will be described in detail.

First, the fuel stored in the fuel tank 31 is supplied to the reformer 20 through the first connection line L1, and at the same time, the water stored in the water tank 41 is supplied to the reformer (2) through the second connection line L2. 20). Then, the reformer 20 discharges the reformed gas mainly containing hydrogen, and water as the steam reforming reaction of the fuel and water proceeds.

The reformed gas is then stored in the reformed gas reservoir 71 of the separator 70 and the moisture is stored in the water reservoir 72 of the separator 70.

In this state, the reformed gas stored in the reformed gas storage unit 71 is supplied to the electricity generating units 11 of the fuel cell body 10 through the fourth connection line L4. Water stored in the water storage unit 72 is supplied to the water tank 41 through the fifth connection line (L5).

At the same time, the air pump 51 sucks air and supplies this air to the electricity generating units 11 of the fuel cell body 10. Then, the fuel cell body 10 generates electric energy of a predetermined capacity through the oxidation reaction of the reformed gas and the reduction reaction of oxygen by the electricity generating units 11.

During this process, the fuel cell body 10 generates high-temperature steam through a reduction reaction of oxygen by the electricity generating units 11, and discharges the steam through the second discharge unit 18. This water is condensed into water while passing through the heat exchanger 60, the water is injected into the interior space of the condensate tank (80).

In this case, when the water reaches the predetermined level while being continuously accommodated in the inner space of the condensate tank 80, the sensor rod 91 comes into contact with the water, and the ohmmeter 93 senses power through the wire. Since it is applied to the rod 91 and the condensate tank 80, a predetermined resistance value is taken out while forming a closed circuit with the sensor rod 91 and the condensate tank 80. Therefore, the controller C recognizes the predetermined resistance value measured by the ohmmeter 93 and drives the pump P. FIG. Thus, the water stored in the condensate tank 80 is supplied to the water storage unit 72 of the separator 70 through the sixth connection line (L6) by the pumping pressure of the pump (P). At this time, the water stored in the water storage unit 72 is supplied to the water tank 41 through the fifth connection line (L5) as mentioned above.

On the other hand, when the water stored in the inner space of the condensate tank 80 is supplied to the water tank 41 and the water level is lowered so that the sensor rod 91 is not in contact with the water, the ohmmeter 93 is the sensor rod 91 And while making an open circuit with the condensate tank 80, the infinite resistance value is withdrawn. Then, the controller C recognizes the infinite resistance value measured by the ohmmeter 93 and stops the driving of the pump P. FIG. As a result, the water stored in the condensate tank 80 is no longer supplied to the water tank 41.

Therefore, the fuel cell system 100 according to the present embodiment condenses water vapor discharged from the fuel cell main body 10 through water through such a series of processes and stores the water in the condensate tank 80. The water stored in the water storage unit 72 can be supplied to the water tank 41 while supplying the water stored in the water storage unit 72 to the water storage unit 72 of the separator 70 by the operation of the pump P. Will be.

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, since the water vapor discharged from the fuel cell body can be condensed with water and finally provided to the water tank, the operation efficiency and reliability of the entire system are further improved.

In addition, according to the present invention, since the driving of the pump is controlled according to the level of the condensate in the process of supplying the condensate stored in the condensate tank to the separator, it is possible to reduce the power consumption for driving the pump.

Claims (8)

A fuel cell body; A reformer for generating a reformed gas containing hydrogen as a main component by reforming the fuel and water; A fuel supply source for supplying the fuel to the reformer; A water source for supplying the water to the reformer; A heat exchanger for condensing water vapor discharged from the fuel cell body with water; A separator installed to be connected to the reformer to separately separate and store the reformed gas and water discharged from the reformer, supply the reformed gas to the fuel cell body, and supply the water to the water supply source; And A condensate tank installed to be connected to the heat exchanger and the separator to store water condensed in the heat exchanger, and selectively supplying the water to the separator Fuel cell system comprising a. According to claim 1, And a pump installed at a connection line connecting the condensate tank and the separator to suck water stored in the condensate tank, and pump the water to the separator through the connection line. The method of claim 2, And a control unit installed in the condensate tank to selectively drive the pump according to the level of water stored in the condensate tank. The method of claim 3, wherein The control unit, A sensor rod installed in an inner direction of the condensate tank; Ohmmeter is installed to be electrically connected to the sensor rod, the condensate tank and the pump Fuel cell system comprising a. The method of claim 4, wherein A fuel cell system in which the sensor rod and the condensate tank are made of a conductive metal material. According to claim 1, The water source includes a water tank for storing the water, The water tank is installed in the fuel cell system is connected to the reformer and the separator by a pipe-type connection line. According to claim 1, The separator, A reformed gas storage unit installed to be connected to the fuel cell body while storing the reformed gas; And a water storage unit installed to be connected to the water supply source and the condensate tank while storing the water. The method of claim 7, wherein The water storage unit is installed to be connected to the water tank and the condensate tank by a pipe-type connection line.

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