FIELD: energy conversion facilities. SUBSTANCE: proposed method and device for conversion of heat energy into mechanical energy are designed for generating the energy by imparting heat energy to working liquid in reservoir sufficient to convert working liquid from liquid into vapor state. Gas is added into working liquid placed in reservoir. Molecular mass of gas does not exceeds practically the molecular mass of working liquid. Heat energy is imparted to liquid from heating device until liquid changes into vapor. Then liquid in vapor state is fed into energy converter where vapor expands and temperature decreases. Gas is isolated from expanded and cooled working medium and the latter, in liquid state, and separated gas are returned into reservoir. Water is used as working medium in proposed method of increasing enthalpy and compressibility factor of water vapor. Water is heated in reservoir until steam is formed and hydrogen or helium, 0.1-9% (by mass) is added into water to form gas and steam mixture featuring increased enthalpy and compressibility factor. EFFECT: reduced enthalpy of system, increased efficiency of conversion of heat energy into mechanical energy. 14 cl, 10 dwg
