CN1549374A

CN1549374A - Fuel box of fuel cell with B compound as fuel

Info

Publication number: CN1549374A
Application number: CNA031298370A
Authority: CN
Inventors: 朴明T; 朴明碩; 曺泰熙; 李明浩; 崔鴻; 黄龍俊; 高承兌; 許成根
Original assignee: LG Electronics Tianjin Appliances Co Ltd
Current assignee: LG Electronics Tianjin Appliances Co Ltd
Priority date: 2003-05-20
Filing date: 2003-05-20
Publication date: 2004-11-24

Abstract

The present invention relates to a fuel tank of fuel cell using B compound as fuel, belonging to the field of fuel cell technology. Said fuel tank is mainly characterized by that it has a mixed liquid inlet tube mounted in the lower portion of one side of the fuel tank, and has a pure BH4- discharge tube mounted on another side of the fuel tank, and the interior of its tank body is divided into a mixed liquid storage chamber for storing mixed liquid formed from BH4-, BO2- and 2H2O, etc. which are flowed into the storage chamber from mixed liquid inlet tube and a pure fuel storage chamber for storing BH4- by means of fuel partion board with a certain height. Said fuel tank can only make the pure fuel BH4- be supplied into the interior of cell pile by means of discharge tube so as to raise its power generation performance.

Description

Fuel tank of fuel cell using B compound as fuel

Technical Field

The invention belongs to the field of fuel cells and manufacturing thereof, and relates to a fuel cell which supplies fuel and air from the outside to perform electrochemical reaction to generate electricity. More particularly, to BH that prevents supply to a cell stack₄ ^-The fuel tank of a fuel cell in which the concentration of (A) is abruptly changed.

Background

In general, a fuel cell is a device for directly converting energy of fuel into electric energy, and a porous anode and a porous cathode are closely attached to both sides of a polymer electrolyte membrane as a center. Electrochemical oxidation of hydrogen fuel occurs at the anode (oxidation electrode or fuel electrode), and electrochemical reduction of oxidant oxygen occurs at the cathode (reduction electrode or air electrode), and the generated electrons move to generate electric energy.

The hydrogen supplied to such a fuel cell is obtained by subjecting a hydrocarbon-based (CH-based) fuel such as LNG, LPG, CH3OH, gasoline, etc. to a de-yellowing process, reforming reaction, and hydrogen refining process in a reformer to convert hydrogen (H)₂) Refining the slurry to obtain a gaseous BHor a solid BH₄ ^-And (4) converting the solution into an aqueous solution state, and directly using the aqueous solution as a fuel in a BFC (boron fuel cell) mode.

The BFC fuel cell does not use a reformer because the aqueous solution state BH is directly supplied to the anode of the stack of the power generation device₄ ^-In the above aspect, since the reforming reaction is generated in the electrode, the reformer is not required, and the entire fuel cell system can be simplified.

However, BH has been used in the prior art₄ ^-Fuel cell for fuel, BH in aqueous solution stored in fuel tank₄ ^-Mixed with air in the stackBO to be later recovered₂ ^-BO thereof₂ ^-Bibh of₄ ^-So that a large amount of BO exists on the lower side of the fuel tank₂ ^-Therefore, when the fuel tanks are alternated, BO present on the bottom of the fuel tanks is present after a certain time has elapsed₂ ^-The fuel supply pipe connected to the lower side is supplied to the stack in a large amount, and therefore, there is a problem in that the power generation efficiency is lowered.

In addition, BO present at the bottom of the same tank as described above₂ ^-The concentration thereof also increases with time, and also causes a problem of clogging the supply pipe on the lower side as it is solidified.

Disclosure of Invention

The main object of the present invention is to provide a fuel tank for a fuel cell using a B compound as a fuel, which has no disadvantages as described above.

Another object of the present invention is to provide a fuel tank capable of preventing a certain time from passing due to BO in the fuel tank₂ ^-A fuel tank for a fuel cell using a B compound as a fuel, which is supplied to a stack to drastically reduce the power generation performance.

The third purpose of the invention is to prevent BO₂ ^-A fuel tank of a fuel cell using a B compound as a fuel, which is used for increasing the fuel supply of the fuel cell stack by blocking a supply pipe of the fuel tank.

In order to achieve the object of the present invention constituted as above, there is provided a fuel cell in which a compound B stored in a fuel tank is supplied to an anode of a cell stack, and air is supplied to a cathode of the cell stack, so that electric energy is obtained from a chemical reaction of the supplied compound B and air.

The fuel tank is provided with BH recovered from the cell stack from one side lower part₄ ^-、BO₂ ^-、2H₂O mixed liquid inflow pipe, and BH is discharged only by installing on the other side₄ ^-The discharge pipe of (1) has a box body with a certain space formed on the inner side and has fuel with a certain heightThe partition plate (120) divides the interior of the tank body into a plurality of parts for storing BH flowing in from the mixed liquid inflow pipe₄ ^-、BO₂ ^-、2H₂Storage chamber for O and other mixed liquids and BH₄ ^-The fuel tank of a fuel cell using the compound B as a fuel, characterized by the pure fuel storage chamber of (1).

The advantages and positive effects are as follows:

as described above, the inside of the fuel tank of the fuel cell of the present invention using the B compound as the fuel is divided by the fuel separation plate into: the mixed liquid storage chamber and thepure fuel storage chamber are formed by only storing pure BH in the pure fuel storage chamber₄ ^-The fuel is supplied to the stack to have an effect of preventing the power generation performance from being lowered due to a rapid change in the fuel concentration.

In addition, since only BHs are present₄ ^-The fuel is supplied from the fuel tank to the stack through the discharge pipe, so that there is also an effect of preventing clogging of the pipe.

Drawings

Fig. 1 is a structural diagram of a fuel cell using a B compound as a fuel, which utilizes the fuel tank of the present invention.

Fig. 2 is a cross-sectional view of a single cell structure utilizing the stack of the present invention.

Fig. 3 is a longitudinal sectional view of a fuel tank using the present invention.

Fig. 4 is a longitudinal sectional view of a modified example of the fuel tank using the present invention.

In each figure:

1: fuel cell, 10: a cell stack,

21: electrolyte membrane, 22: an anode,

23: cathode, 24: a membrane-electrode combination,

25: partition plate, 26: a collector plate,

27: collector plate, 30: a fuel supply pipe,

31: flow channel groove, 32: a flow channel groove,

40: fuel recovery pipe, 50: an air supply pipe,

60: air outlet duct, 70: an air pump,

100: fuel tank, 101: mixed liquid inflow pipe

102: discharge pipe, 103: space part

110: case body, 111: a mixed liquid storage chamber,

112: pure fuel storage chamber, 120: a fuel partition plate,

201: hose, 202: a weight cone,

300: a fuel pump;

BFC: boron fuel cell, B: boron,

LNG: liquefied natural gas, LPG: liquefied petroleum gas,

CH₃OH: methanol.

DETAILED DESCRIPTION OF EMBODIMENT (S) OF INVENTION

The fuel tank of the fuel cell using the compound B of the present invention configured as described above will be described in detail below with reference to the example drawings.

As shown in the figure, the whole fuel cell (1) is configured to have BH in a state of storing an aqueous solution on one side of a cell stack (10) for generating electric power₄ ^-The fuel tank (100). A fuel supply pipe (30) and a fuel recovery pipe (40) of a fuel tank (100) and an anode of a cell stack (10) are connected together, and a fuel pump (300) for pumping out fuel is installed on the fuel supply pipe (30).

An air supply pipe (50) and an air discharge pipe (60) are attached to the cathode of the stack (10). An air pump (70) for pumping out air is installed on the air supply pipe (50).

The cell stack (10) is manufactured by bolting unit cells that undergo chemical reactions or stacked unit cells. If a single cell structure is described with reference to fig. 2, it is formed by combining the anode (22) and the cathode (23) on both sides of the electrolyte MEMBRANE (21) to form a MEMBRANE-ELECTRODE ASSEMBLY (MEA) (24); SEPARATORs (SEPARATOR) (25) which are attached to both sides of the membrane-electrode assembly (24) in a manner to be in close contact with each other and which have fuel gas and oxygen gas flow channels (31) formed in the anode (22) and the cathode (23), and current collectors (26, 27) which are disposed on both sides of the SEPARATORs (25) and which collect the current from the anode (22) and the cathode (23).

The electrolyte membrane (21) of the membrane-electrode assembly (24) is an ion exchange membrane made of a polymer material, a representative commercial electrolyte membrane (21) is a NAFION membrane, which plays a role of a conductor of ions and also plays a role of preventing contact between oxygen and hydrogen, and the anode (22) and the cathode (23) are used as a support for supporting a platinum catalyst layer, and the structure is that porous CARBON PAPER (CARBON PAPER) or CARBON CLOTH (CARBON CLOTH) is closely bonded to both sides of the electrolyte membrane (21).

The separator (25) which is in close contact with both sides of the membrane-electrode assembly (24) is formed of a dense carbon plate, and has a plurality of flow channels (31, 32) formed on one side thereof, that is, a fuel gas flow channel (31) formed on the surface of the anode (22) and a gas flow channel (32) containing oxygen formed on the surface of the cathode (23).

The current collecting plates (26, 27) should have good electrical conductivity, high corrosion resistance, and no hydrogen odor, and may be any of aluminum, copper, and the like that can satisfy the above conditions.

As shown in FIG. 3, the fuel tank 100 is provided with BH recovered from the cell stack 10 from one side lower part₄ ^-、BO₂ ^-、2H₂O mixed liquid inflow pipe (101), discharge pipe (102) for discharging BH 4-only is mounted on the other side, tank body (110) with space (103) of certain size formed inside, fuel partition plate (120) with certain height divides the interior of tank body (110) to store the mixed liquid inflow pipe(101) Influent BH₄ ^-、BO₂ ^-、2H₂Storage chamber (111) for mixed liquid such as O and the like and BH₄ ^-Is formed by the pure fuel storage chamber (112).

Next, the operation and effect of the fuel cell using the fuel tank according to the present invention will be described.

If a user operates a switch of the fuel cell (1), the fuel pump is operated according to a control system in which an electronic control part (not shown) has been set(300) BH in an aqueous solution state stored in a fuel tank (100)₄ ^-The fuel is supplied to the anode of the stack (10) through the fuel supply pipe (30), and at the same time, the air pump (70) is operated to supply air to the cathode of the stack (10) through the air supply pipe (50).

BH in the form of an aqueous solution supplied to a cell stack (10)₄ ^-Flows along the fuel gas flow path groove (31), diffuses in front of the anode (22) of the membrane-electrode assembly (24), performs electrochemical oxidation of hydrogen, flows along the oxygen-containing gas flow path groove (32), diffuses in front of the cathode (23) of the membrane-electrode assembly (24), and generates electrochemical reduction of oxygen. At this time, electricity is generated by the movement of the generated electrons, and the generated electricity is collected on the collector plates (26, 27) and used as energy.

The reaction formula at this time is:

E0＝1.64V

and BH after reaction in the cell stack (10)₄ ^-、BO₂ ^-，2H₂The mixed liquor of O is recovered by a fuel recovery pipe (40), and the fuel mixed liquor thus recovered flows into a mixed liquor storage chamber (111) formed inside the tank body (110) through a mixed liquor inflow pipe (101) provided below the tank body (110).

Then, BH having a relatively low specific gravity is added to the mixed liquid flowing into the mixed liquid storage chamber (111)₄ ^-In BO of high specific gravity₂ ^-Are separated by layering, the so-separated BHs₄ ^-After passing through the upper end of the fuel partition plate (120) installed at a certain height, the pure fuel continues to enter the pure fuel storage chamber (112). Thus, only BH flowing into the pure fuel storage chamber (112)₄ ^-Is supplied to the cell stack (10) through the discharge pipe (102).

That is, the fuel supplied from the fuel tank (100) to the cell stack (10) is mainly BH having a high concentration₄ ^-Therefore, the problem of the power generation performance reduction caused by the rapid change of the fuel concentration when the fuel cell (1) is operated is prevented.

Fig. 4 is a longitudinal sectional view of a modified example of the fuel tank using the present invention. As shown, the basic structure is the same as the fuel tank structure of fig. 3. In addition, the pure fuel storage chamber (112) is provided with a hose (201) connected with the inner end of the discharge pipe (102) at the inner side, and a weight cone (202) is installed on the end part of the hose (201), so the BH stored in the pure fuel storage chamber (112)₄ ^-All can be supplied to the cell stack (10) through the discharge pipe (102).

Claims

1. A fuel tank of a fuel cell using a B compound as a fuel, which supplies a B chemical stored in the fuel tank to an anode of a cell stack and supplies air to a cathode of the cell stack, and which obtains electric energy from a chemical reaction between the supplied B chemical and the air, characterized in that: the fuel tank is provided with a fuel supply device for supplying BH to the cell stack from one side lower part₄ ^-、BO₂ ^-、2H₂A mixed liquid inflow pipe for O mixed liquid, and a lower part on the other side for discharging BH₄ ^-The discharge pipe of (1), a tank body having a space part with a certain size formed on the inner side thereof, wherein a fuel partition plate with a certain height is designed in the tank body to divide the tank body into a plurality of parts for storing BH flowing from the mixed liquid inflow pipe₄ ^-、BO₂ ^-、2H₂Storage chamber for O and other mixed liquids and BH₄Is formed by the pure fuel storage chamber.

2. The fuel tank of a fuel cell using a compound B as a fuel according to claim 1, wherein a hose is provided inside the pure fuel storage chamber to connect an inner end of the discharge pipe, and a weight cone is attached to an end of the hose.