Combustion Experiments of a Hydrogen Internal Combustion Stirling Engine

Performance and combustion characteristics of a hydrogen internal combustion Stirling engine were examined with increasing the injection rates of H_2 and O_2 up to 30% of total thermal input. The hydrogen internal combustion Stiring engine was prototyped by mainly modifying the cooler and the heater in Ecoby-SCM81 Stoichiometric combustion of H_2 and O_2 at a catalytic combustor functions as a heater in the conventional Stirling engine and a finned cooler with a water trap plays both roles of cooling the working gas and removing the water produced by the internal combustion. The P-V diagram of the internal combustion engine showed similar cycles to the external heating. Also, slight pressure rises, which were due to the water vapor and the unburned mixture remaining in the working fluid, appeared during the internal combustion operation. Such pressure rises lowered with the increase of the engine speed, showing that high-speed operation is effective to avoid the explosive combustion in the engine.