SOEC에 과열기의 고온 스팀을 공급하는 Interface의 열전달에 관한 전산해석

• Published in: 한국수소 및 신에너지학회 논문집 Vol. 31; no. 2; pp. 169 - 176
• Main Authors: 변현승(HYUN SEUNG BYUN), 한단비(DANBEE HAN), 박성룡(SEONGRYONG PARK), 조종표(CHONGPYO CHO), 백영순(YOUNGSOON BAEK)
• Format: Journal Article
• Language: Korean
• Published: 한국수소및신에너지학회 2020
• Subjects: 기계공학; Superheater(과열기); SRF(고형연료); CFD(전산유체해석); Hydrogen(수소); SOEC(고체산화물수전해전지)
• ISSN: 1738-7264; 2288-7407

There is a growing interest in hydrogen energy utilization since an alternative energy development has been demanded due to the depletion of fossil fuels. Hydrogen is produced by the reforming reaction of natural gas and biogas, and the electrolysis of water. An solid oxide electrolyte cell (SOEC) is reversible system that generates hydrogen by electrolyzing the superheated steam or producing the electricity from a fuel cell by hydrogen. If the water can be converted into steam by waste heat from other processes it is more efficient for high-temperature electrolysis to convert steam directly. The reasons are based upon the more favorable thermodynamic and electrochemical kinetic conditions for the reaction. In the present study, steam at over 180℃ and 3.4 bars generated from a boiler were converted into superheated steam at over 700℃ and 3 bars using a cylindrical steam superheater as well as the waste heat of the exhaust gas at 900℃ from a solid refuse fuel combustor. Superheated steam at over 700℃ was then supplied to a high-temperature SOEC to increase the hydrogen production efficiency of water electrolysis. Computational fluid dynamics (CFD) analysis was conducted on the effects of the number of 90° elbow connector for piping, insulation types and insulation layers of pipe on the exit temperature using a commercial Fluent simulator. For two pre-heater injection method of steam inlet and ceramic wool insulation of 100 mm thickness, the highest inlet temperature of SOEC was 744℃ at 5.9 bar.