An arrangement for converting thermal energy from lost heat of an internal combustion engine into mechanical energy includes a working circuit for a working medium. An expansion engine is disposed in the working circuit. A heat exchanger is mounted upstream of the expansion engine in a flow direction of the working medium where the working circuit extends through the heat exchange. The heat exchanger includes an exhaust gas recirculation heat exchanger having a cold part and a warm part, an exhaust gas heat exchanger, and a phase transition cooling in the internal combustion engine. The heat exchanger is formed by serial connection in a sequence of the cold part of the exhaust gas recirculation heat exchanger, the exhaust gas heat exchanger, the phase transition cooling in the internal combustion engine, and the warm part of the exhaust gas recirculation heat exchanger.

An arrangement for converting thermal energy from lost heat of an internal combustion engine into mechanical energy includes a working circuit for a working medium. An expansion engine is disposed in the working circuit. A heat exchanger is mounted upstream of the expansion engine in a flow direction of the working medium where the working circuit extends through the heat exchange. The heat exchanger includes an exhaust gas recirculation heat exchanger having a cold part and a warm part, an exhaust gas heat exchanger, and a phase transition cooling in the internal combustion engine. The heat exchanger is formed by serial connection in a sequence of the cold part of the exhaust gas recirculation heat exchanger, the exhaust gas heat exchanger, the phase transition cooling in the internal combustion engine, and the warm part of the exhaust gas recirculation heat exchanger.

A method for cooling an engine includes increasing the pressure of a liquid coolant from a first pressure to a second pressure. Thereafter, components of the engine to be cooled are contacted with the liquid coolant so that the liquid coolant at least partially evaporates and forms a vapor with a particular state. Thereafter, the vapor is fed to a throttle to reduce the pressure of the liquid coolant to a third pressure. The particular state of the vapor is determined based on the temperature and the third pressure of the liquid coolant downstream of the throttle, and based on the second pressure of the liquid coolant under an assumption that the throttle is an adiabatic throttle such that enthalpy of the liquid coolant remains constant as the liquid coolant passes the throttle. A desired vapor state adjustment is made based on the determined particular state of the vapor.

A method for cooling an engine includes increasing the pressure of a liquid coolant from a first pressure to a second pressure. Thereafter, components of the engine to be cooled are contacted with the liquid coolant so that the liquid coolant at least partially evaporates and forms a vapor with a particular state. Thereafter, the vapor is fed to a throttle to reduce the pressure of the liquid coolant to a third pressure. The particular state of the vapor is determined based on the temperature and the third pressure of the liquid coolant downstream of the throttle, and based on the second pressure of the liquid coolant under an assumption that the throttle is an adiabatic throttle such that enthalpy of the liquid coolant remains constant as the liquid coolant passes the throttle. A desired vapor state adjustment is made based on the determined particular state of the vapor.