A Start-Up Strategy of Molten Carbonate Fuel Cell and Internal Combustion Engine Hybrid System for Distributed Power Generation

Abstract

A start-up strategy for molten carbonate fuel cell (MCFC) and internal combustion (IC) engine hybrid system, previously developed by the authors, has been developed to validate its operability. Because only design point operation of hybrid system was studied in previous research, adequate start-up strategy for MCFC-IC engine hybrid system is needed. To analyze the start-up strategy, start-up process of this hybrid system has been was divided into 4 stages. The first two stages compose the heat-up process to preheat the MCFC from ambient to the operating temperature (∼570 °C). The required heat for fuel cell is provided from the IC engine exhaust heat because the IC engine generates heat as well as power during the heat-up process whereas the MCFC does not generate any power. During the first heat-up stage, nitrogen flows into the fuel cell to prevent corrosion after the long time operating. When the MCFC temperature reaches 500°C, the second heat-up stage begins, and fuel start to flows into the fuel cell to prepare for power-up process. The next two stages following heat-up process compose the power-up process. During the power-up process, power is generated from both the MCFC engine as well as the IC engine. According to the operable range of each component, the power-up process is composed of the MCFC-SI engine stage and the MCFC-HCCI engine stage. Thus, the hybrid system is independently operable from the start-up to the full load operation without a need for either an electric heater or a catalytic burner.