Patent ID: 7584613
Filing Date: 2009-09-08
Classification: F02G

Abstract:
1. A method for operating a thermal engine to convert thermal energy to mechanical energy, comprising the steps of: providing a unit mass of working fluid at an ambient temperature and an ambient pressure; isentropically compressing the unit mass of working fluid to a higher temperature and a higher pressure; isothermally expanding the unit mass to a first subsequent volume; uniformly adding heat energy to the unit mass of working fluid by moving the unit mass past a heat exchanger while maintaining a constant Reynolds number through the heat exchanger; isentropically expanding the unit mass of working fluid to a second subsequent volume; driving with the isothermally expanding working fluid a first piston and a second piston in respective cylinders, thereby turning a shaft through at least one angular rotation; timing the driving of the first piston and the second piston such that a substantially equal amount of working fluid expansion energy is used for each angular rotation of the shaft; and exhausting at least a portion of the unit mass of working fluid; wherein the positions of the pistons in the cylinders during isothermal expansion are a function of a shaft rotation angle.