US-20260128334-A1 - SOLID OXIDE FUEL CELL SYSTEM

Abstract

Proposed is a solid oxide fuel cell system including a fuel gas supply part configured to supply fuel gas, an air supply part configured to supply air, a reformer configured to receive the fuel gas and the air and generate reformed gas containing hydrogen, a fuel cell stack configured to produce electricity by reacting the reformed gas and the air, a burner configured to receive the fuel gas and the air for combustion, and raise temperature inside the reformer to a set temperature corresponding to operating conditions of the reformer by a heat generated during the combustion, and a controller configured to control an operation of the system, wherein the controller operates the reformer to generate the reformed gas when the temperature inside the reformer reaches the set temperature corresponding to the operating conditions of the reformer.

Inventors

• Hoon Yang Park

Assignees

• ENERTECH CO., LTD

Dates

Publication Date

20260507

Application Date

20251105

Priority Date

20241106

Claims (4)

1. 1 . A solid oxide fuel cell system, comprising: a fuel gas supply part configured to supply fuel gas; an air supply part configured to supply air; a reformer configured to receive the fuel gas and the air and generate reformed gas containing hydrogen; a fuel cell stack configured to produce electricity by reacting the reformed gas and the air; a burner configured to receive the fuel gas and the air for combustion, and raise temperature inside the reformer to a set temperature corresponding to operating conditions of the reformer by heat generated during the combustion; and a controller configured to control an operation of the system, wherein the controller operates the reformer to generate the reformed gas when the temperature inside the reformer reaches the set temperature corresponding to the operating conditions of the reformer.
2. 2 . The system of claim 1 , further comprising: a first supply line connecting the fuel gas supply part and the burner; a second supply line connecting the air supply part and the burner; a first branch line branched from the first supply line and connected to the reformer; a second branch line branched from the second supply line and connected to the reformer; a first directional valve provided at a branch point of the first supply line; and a second directional valve provided at a branch point of the second supply line.
3. 3 . The system of claim 2 , wherein the first directional valve and the second directional valve are three-way valves.
4. 4 . The system of claim 2 , wherein the controller controls a flow path of the fuel gas supplied from the fuel gas supply part and a flow path of the air supplied from the air supply part by means of the first directional valve and the second directional valve, controls the flow paths by means of the first directional valve and the second directional valve so that the fuel gas and the air are supplied to the burner through the first supply line and the second supply line, respectively, in order to increase the temperature inside the reformer, and when the temperature inside the reformer reaches the set temperature corresponding to the operating conditions of the reformer, controls the flow paths by means of the first directional valve and the second directional valve so that the fuel gas and the air are supplied to the reformer through the first branch line and the second branch line, respectively, in order to generate the reformed gas.

Description

ACKNOWLEDGEMENT National Research and Development Project Supporting the Present Disclosure Project Serial Number: 2420001796 Project Number: 00269831 Ministry Name: Ministry of SMEs and Startups Project Management (Specialized) Institution: Korea Technology and Information Promotion Agency for SMEs Research Business: Tech-bridge utilization commercialization technology development Research Topic: Development of a 5 kW solid oxide fuel cell system using flameless fuel reforming technology Project Performing Institution: Enertech Research Period: From Jan. 1, 2024 to Dec. 31, 2024 CROSS REFERENCE TO RELATED APPLICATION The present application claims priority to Korean Patent Application No. 10-2024-0156021, filed Nov. 6, 2024, the entire contents of which is incorporated herein for all purposes by this reference. BACKGROUND Technical Field The present disclosure relates to a solid oxide fuel cell system and, more particularly, to a solid oxide fuel cell system that generates electricity by reacting a fuel gas with air. Description of the Related Art Fuel cells are electrochemical devices that convert the chemical energy of hydrogen and oxygen into electrical energy. Depending on their operating temperature and primary fuel type, fuel cells can be classified into alkaline fuel cells (AFCs), phosphoric acid fuel cells (PAFCs), molten carbonate fuel cells (MCFCs), solid oxide fuel cells (SOFCs), and polymer electrolyte membrane fuel cells (PEMFCs). Alkaline fuel cells and polymer electrolyte fuel cells operate at temperatures from room temperature to below 100° C., while phosphoric acid fuel cells operate at around 150° C. to 200° C. Molten carbonate fuel cells and solid oxide fuel cells are classified as high-temperature fuel cells, operating at temperatures ranging from approximately 600° C. to 1,000° C. For these high-temperature fuel cells to be operated on ships, they need to be maintained at elevated temperatures. In this case, a solid oxide fuel cell (SOFC) is a type of fuel cell that uses a solid oxide material, which is permeable to oxygen ions, as its electrolyte. It converts a fuel (e.g., hydrogen, methane, natural gas, etc.) and an oxidant (e.g., air) into electricity and heat through an electrochemical reaction. An SOFC typically consists of an anode (fuel electrode), a cathode (air electrode), and a solid electrolyte positioned therebetween. At the anode, the fuel is oxidized, while at the cathode, oxygen from air is reduced. Because solid oxide fuel cells use solid-state electrolytes, there is relatively little electrolyte loss or corrosion, which can improve long-term stability and durability. Solid oxide fuel cells facilitate fuel utilization through internal reforming, and their high-temperature exhaust gases enable cogeneration by using waste heat. However, conventional solid oxide fuel cells utilize expensive catalysts, such as reforming and combustion catalysts, which increase costs. Moreover, a high catalyst thermal mass can delay the attainment of the operating temperature during initial startup. In this case, a reforming catalyst is a catalyst used in the fuel reforming process. Solid oxide fuel cells (SOFCs) can reform fossil fuels (e.g., natural gas, methanol) at high temperatures to produce hydrogen using such a catalyst. This process generates hydrogen as well as other gases, such as carbon monoxide and carbon dioxide. A combustion catalyst promotes combustion reactions and can be used to oxidize unburned fuel in solid oxide fuel cells when the fuel is not completely combusted. SUMMARY Accordingly, the present disclosure has been made keeping in mind the above problems occurring in the related art, and the present disclosure is intended to provide a solid oxide fuel cell system that improves efficiency and performance by combusting fuel gas and air by a burner, heating the inside of a reformer to a set temperature corresponding to the operating conditions of the reformer by the heat generated during combustion, and using the air heated by the reformer's internal heat to warm up the fuel cell stack to a set temperature corresponding to the operating conditions of the fuel cell stack. In order to achieve the above objective, according to an aspect of the present disclosure, there is provided a solid oxide fuel cell system including: a fuel gas supply part configured to supply fuel gas; an air supply part configured to supply air; a reformer configured to receive the fuel gas and the air and generate reformed gas containing hydrogen; a fuel cell stack configured to produce electricity by reacting the reformed gas and the air; a burner configured to receive the fuel gas and the air for combustion, and raise temperature inside the reformer to a set temperature corresponding to operating conditions of the reformer by heat generated during the combustion; and a controller configured to control an operation of the system, wherein the controller may operate the reformer to generate the reform