Study on Hydrogen Internal Combustion Stirling Engine. 1st Report, Combustion Experiment on Prototyped Engine.

This paper presents a new concept of hydrogen internal combustion Stirling engine and experimentally clarifies the effect of the internal combustion by comparing performances of a prototyped engine on internally heating and externally heating. The hydrogen combustion Stirling engine utilizes internal combustion of stoichiometric H2 and O2 mixture injected into the working fluid gas as thermal input, and the cyclic operation completes with the removal of the water from the engine after the condensation at the cooler. The prototyped engine substitutes a catalytic combustor for the conventional heater and H2-O2 mixture is injected at a constant flow rate between the regenerator and the cooler. The engine performance was evaluated measuring temporal change in pressure and temperature in the expansion and the compression space, thermal input and rejected heat. The internal heating performance showed almost the same characteristics as that of external heating except for the increase of expansion work due to the direct thermal input. The increase of expansion work improved the engine performance, particularly in high engine speed region. Furthermore, the steady premixed injection method showed a possibility to suppress easily the mixture strength in working gas.