Optimization Of Solid Oxide Fuel Cell Combined Heat And Power System

Given the advantage including high efficiency and non-pollution, the combined heat and power (CHP) system with solid oxide fuel cell (SOFC) as key component can been widely applied in various occasions. Hence, the SOFC-CHP system have been a research highlight in the new energy field. In this paper, based on Aspen PlusTM, SOFC electrochemistry model and CHP system model are developed and used to analyze merits of different processes. Furthermore, the optimal system process of distinct SOFC stacks are studied by simulating diverse SOFC-CHP with different fuel utilization (Uf). In addition, a coupled reactor with a catalytic combustor and a steam reformer for SOFC-CHP system is designed, and an experimental study on the reaction characteristics of this coupled reactor are observed by varying parameters. The results indicate that the simple heat recovery system often has a lower efficiency due to the big consumption of balance of plants (BOP). Benefiting from the high electric efficiency of anode off gas recovery (AOGR) and high heat efficiency of off gas combustion (OGC), the CHP efficiency of the system combined with AOGR and OGC can reach a maximum of92%. That means the AOGR&OGC system is best in all the8processes. When the stack Uf is lower than0.6, AOGR increase the electric efficiency and OGC increase the heat efficiency; When the stack Uf is between0.6and0.8, higher electric and heat efficiency can be simultaneously obtained in the AOGR&OGC system; When the stack Uf is higher than0.8, the system can also reach a higher electric efficiency without AOGR. The experimental consequence on the coupled reactor show a potential applicability and design technologies for the fuel processing of SOFC-CHP using an external reformer. The parameters adjustment can improve the steam reformer performance, such as increasing the inlet temperature of the catalytic combustor, reducing the air-fuel ratio of the SOFC system, using a stack with a lower Uf, and reducing the steam-to-carbon ratio. Specially, the Uf of stack has the most influence on the H2concentration.