A free-piston engine power plant incorporating a first combustion cylinder, having a first combustion piston, a fluid expander having an expansion cylinder with an expander piston therein, the expander piston reciprocating in unison with the first combustion piston, a bottoming cycle having a working fluid and a 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.

An exhaust gas heat recovery system for an internal combustion engine has a pump for conveying an operating fluid, an evaporator for converting the operating fluid from the liquid state to the gaseous state, and a condenser for liquefaction of the operating fluid, and having an expansion engine through which the gaseous operating fluid can flow. A sensor is arranged on the expansion engine with which a function of the expansion engine can be monitored. An exhaust system may have such an exhaust gas heat recovery system, and a method for the diagnosis of such an exhaust heat recovery system.

An internal combustion engine having at least one combustion chamber, the internal combustion engine being connected via the exhaust thereof with an exhaust system. Disposed in the exhaust system is a heat exchanger of an exhaust heat recovery system, which can be used to transfer the waste heat of the exhaust gas to an operating fluid of the exhaust heat recovery system. Furthermore, the internal combustion engine is couplable to an air-conditioning compressor of an air-conditioning circuit. The exhaust heat recovery system has a further heat exchanger, in which the waste heat of a compressed refrigerant of the air-conditioning circuit is transferred to the operating fluid of the exhaust heat recovery system. A method for recovering the exhaust heat from such an internal combustion engine, an operating fluid of the exhaust heat recovery system being heated in a first method step by the waste heat of a compressed refrigerant of the air-conditioning circuit and, in a second method step, by the waste heat of the exhaust gas from the internal combustion engine.

The invention relates to a method for controlling a waste-heat utilization system (20) for an internal combustion engine (10) of a vehicle, wherein the waste-heat utilization system (20) has at least one expander (22), which can transmit torque to the internal combustion engine (10) and which can be bypassed by means of a bypass flow path (25), at least one evaporator (21), and at least one pump (24) for an operating medium, and wherein at least the evaporator (21) is arranged in the region of the exhaust gas system (11) of the internal combustion engine (10). The expander (22), which can be operated in several operating modes, has a driving connection to a secondary drive shaft (19) of the internal combustion engine in at least one operating mode. An operating mode of the waste-heat utilization system (20) is selected by a control device (30) on the basis of at least one input variable and the waste-heat utilization system (20) is operated in said operating mode. The input variable is selected by the control device (30) from the group consisting of expander rotational speed (n), gear information (GI), coasting information (CI), and pressure (p.sub.1, p.sub.2) and temperature (T.sub.1, T.sub.2) of the operating medium upstream or downstream of the expander (22). A first operating mode (1) is associated with a warm-up phase of the expander (22) and a second operating mode (2) is associated with a normal operating phase of the expander (22). In the first operating mode, the bypass flow path (25) is opened and the expander (22) is not connected to a secondary drive shaft (19) of the internal combustion engine (10). In the second operating mode, the bypass flow path (25) is closed and the expander (22) is connected to the internal combustion engine (10). The second operating mode (2) is selected if the pressure (p.sub.2) and/or the temperature (T.sub.2) of the operating medium downstream of the expander (22) exceeds a defined value.

A method and device for detecting and extracting a gaseous fluid contained in a closed loop operating on a Rankine cycle are provided. The loop includes a multiplicity of constituents with, successively, a circulation and compression pump for a working fluid, a heat exchanger associated with a hot source, an expansion machine, a cooling exchanger, a working fluid tank and circulation pipes connecting these constituents. The method and device measure the temperature (Trelle) and the pressure (Prelle) of the working fluid at a point of the loop when this loop is at rest, and, as soon as the measured pressure (Prelle) exceeds a threshold value (Pliquide satur) for a given ambient temperature (T), activate equipment for extracting the gaseous fluid in order to discharge it from the loop.

An exhaust heat recovery system with a working fluid circuit. The exhaust heat recovery system has a heat exchanger connected in an exhaust line of an internal combustion engine. The heat exchanger is a part of the working fluid circuit together with at least one expansion machine, a condenser, and a fluid pump. The exhaust heat recovery system has a protective device. The protective device protects the exhaust heat recovery system against a leakage amount of the working fluid escaping from the working fluid circuit and igniting. The protective device has a reservoir which stores a medium. The reservoir is a gas reservoir and the medium is a gas.

A cooling system for a combustion engine and a WHR-system in a vehicle (1) includes a first line (23) directing coolant at a first temperature (T.sub.1) to a condenser (18) of the WHR system, a second line (24) directing coolant at a second temperature (T.sub.2) to the condenser (18), a valve arrangement (25, 26, 29) by which the flow rate of the coolant in at least one of the lines (23, 24) is adjustable and a control unit (20) configured to control the valve arrangement (25, 26, 29) such that the coolant directed to the condenser (18) from the lines (23, 24) has a temperature and a flow rate which results in a cooling of the working medium in the condenser (18) to a predetermined condensation temperature/pressure at the actual operating condition.

A method and apparatus for utilizing the waste heat of combustion gases of an internal combustion engine, wherein the combustion gases are directed to a first turbine, a subsequent second turbine, and a precooling heat exchanger with water separation. Whereby the combustion gases formed as a result of combustion of air and fuel in a cylinder of the internal combustion engine according to an Electric Turbo Compounding (ETC) system are expanded after the first turbine to a pressure of less than 0.45 bar in the second turbine, and wherein said first turbine is connected by a shaft to a combustion gas compressor that pressurizes the combustion gases from the precooling heat exchanger to atmospheric pressure.

Integration of an oxyfuel combustion boiler at elevated pressures and a heat exchanger is achieved to produce carbon dioxide by feeding flue gas comprising carbon dioxide and water from the oxyfuel combustion boiler to a direct contact cooler column wherein water is condensed at a temperature of 0 to 10 C. lower than its dew point; feeding a portion of the condensed water from the direct contact cooler column to the oxyfuel combustion boiler; feeding a portion of the carbon dioxide from the direct contact cooler column to the oxyfuel combustion boiler; and recovering a portion of the carbon dioxide from the direct contact cooler column.