Heat engine and internal combustion engine exhaust gas waste heat recovery system

The invention provides a heat engine and an internal combustion engine exhaust gas waste heat recovery system, and the heat engine comprises a rotating wheel, a first piston cylinder device, a second piston cylinder device, a rotating shaft, a cooling fan, a sucking pump, a heat accumulator, a heat exchanger and an exhaust gas connecting pipe. The heat engine absorbs heat of high-temperature waste gas exhausted by the internal combustion engine in an approximately constant-volume regenerative mode, and outputs work outwards through the first piston of the first air cylinder in an adiabatic expansion mode. And after the work is output, the working medium enters the second air cylinder after constant-volume regenerative cooling is carried out, heat is dissipated outwards in an isothermal compression mode, the working medium returns to the initial state, and a power cycle is completed. The power cycle is repeated, and work can be output all the time. One part of work output by the power cycle is used for driving