Patent attributes
An apparatus (2) includes an internal combustion engine (4) and an inverted Brayton cycle heat engine (6). Hot exhaust gas from the internal combustion engine (4) contains water. The hot exhaust gas drives the inverted Brayton cycle heat engine. A condenser (22) in a fluid path of the exhaust gas between an inverted-Brayton-cycle turbine and an inverted-Brayton-cycle compressor condenses at least some of the water from the exhaust gas to form condensed water. This condensed water follows a recirculation path (30) so as to be re-introduced as a working fluid into one or more of the heat engines described above, or further heat engines, e.g. the condensed water is heated by the exhaust gas using a steam-generating heat exchanger (20) to generate steam which drives a steam turbine (32).