A novel fuel cell-IC engine hybrid system for distributed power generation

Abstract

A novel molten carbonate fuel cell (MCFC) and homogenous charge compression ignition (HCCI) engine hybrid system is suggested that replaces the catalytic burner in standalone fuel cell system, with an HCCI engine to improve the overall system efficiency. HCCI engine is chosen over conventional spark-ignition or compression-ignition engines as it has been shown to operate with the extremely fuel-lean mixture, which is the case with MCFC anode off-gas. A non-isothermal numerical model that incorporates major fuel cell losses is developed to predict fuel cell performance. The fuel cell model assumes parallel anode and cathode flow configuration with LiNaCO3 as electrolyte. It is then integrated with an in-house HCCI engine model to investigate hybrid system performance. At the selected design point operation, the maximum hybrid system efficiency is almost 28% (relative) higher than that of standalone fuel cell system, which demonstrates the potential of the hybrid system as a highly-efficient distributed power generation source in the near-future.