Heat engine adapted and designed to perform at least one conversion of thermal energy into mechanical energy comprising at least one thermodynamic fluid and adapted and designed to implement a thermodynamic cycle comprising at least one isochoric heating phase, optionally an isobaric heating phase, an expansion phase and an isobaric cooling phase, the heat engine comprising at least: - a first heat source at a first temperature T1 configured to contain and transmit thermal energy to at least one heat transfer fluid, - a second heat source at a second temperature T2 configured to contain and transmit thermal energy to at least one heat transfer fluid, the first and second temperatures T1 and T2 being different, - at least one module (3, 3') for moving the thermodynamic fluid alternately between a cold part connected to the first heat source and a hot part connected to the second heat source, said at least one module (3, 3') comprising at least the cold part, said at least one module (3, 3') comprising a first heat transfer fluid supply circuit (A, B) connected to the first heat source and to the cold part, said at least one module (3, 3') comprising at least the hot part, said at least one module (3, 3') comprising a second heat transfer fluid supply circuit (C, D) connected to the second heat source and to the hot part, said at least one module (3, 3') comprising at least one chamber suitable and designed to contain said at least one thermodynamic fluid and which is connected to at least one thermodynamic fluid supply outlet at a first pressure P1 or to a hydraulic fluid supply outlet at a second pressure P2, - at least one first conversion unit for converting a pressure difference of the thermodynamic fluid into mechanical energy comprising at least one circuit which comprises at least mechanical conversion means, preferably a motor, said first conversion unit being connected to the thermodynamic fluid supply outlet or to the hydraulic fluid supply outlet, at least a first control unit at least partly disposed in the first conversion unit arranged at least to control the phase in which the thermodynamic cycle is in said at least one module (3, 3'), said heat engine is characterized in that said at least one module (3, 3') further comprises at least one displacer movable in said chamber alternately between the cold part and the hot part, said chamber being suitable and intended to contain said at least one high-pressure thermodynamic fluid having pressures between 50 bar and 300 bar and in the supercritical state, and in that it comprises a second control unit of said at least one module (3, 3') arranged to control the displacement of said at least one displacer alternately between the hot part and the cold part. - a first heat source at a first temperature T1 configured to contain and transmit thermal energy to at least one heat transfer fluid, - a second heat source at a second temperature T2 configured to contain and transmit thermal energy to at least one heat transfer fluid, the first and second temperatures T1 and T2 being different, - at least one module (3, 3') for moving the thermodynamic fluid alternately between a cold part connected to the first heat source and a hot part connected to the second heat source, said at least one module (3, 3') comprising at least the cold part, said at least one module (3, 3') comprising a first heat transfer fluid supply circuit (A, B) connected to the first heat source and to the cold part, said at least one module (3, 3') comprising at least the hot part, said at least one module (3, 3') comprising a second heat transfer fluid supply circuit (C, D) connected to the second heat source and to the hot part, said at least one module (3, 3') comprising at least one chamber suitable and designed to contain said at least one thermodynamic fluid and which is connected to at least one thermodynamic fluid supply outlet at a first pressure P1 or to a hydraulic fluid supply outlet at a second pressure P2, - at least one first conversion unit for converting a pressure difference of the thermodynamic fluid into mechanical energy comprising at least one circuit which comprises at least mechanical conversion means, preferably a motor, said first conversion unit being connected to the thermodynamic fluid supply outlet or to the hydraulic fluid supply outlet, at least a first control unit at least partly disposed in the first conversion unit arranged at least to control the phase in which the thermodynamic cycle is in said at least one module (3, 3'), said heat engine is characterized in that said at least one module (3, 3') further comprises at least one displacer movable in said chamber alternately between the cold part and the hot part, said chamber being suitable and intended to contain said at least one high-pressure thermodynamic fluid having pressures between 50 bar and 300 bar and in the supercritical state, and in that it comprises a second control unit of said at least one module (3, 3') arranged to control the displacement of said at least one displacer alternately between the hot part and the cold part.