The invention relates to a thermodynamic cycle device, in particular an ORC device, comprising a preheater for preheating a working medium; an evaporator for evaporating and superheating a first mass flow of the preheated working medium; an expansion machine for expanding the evaporated and superheated first mass flow of the working medium; a condenser for condensing the working medium exiting the expansion machine; a feed pump for pumping condensed working medium to the preheater; and a first supply apparatus for supplying a second mass flow of the preheated working medium to the partially expanded first mass flow of the working medium in the expansion machine. The invention further relates to a corresponding method.

The invention relates to a method for controlling a waste-heat utilization system (20) for a motor vehicle driven by an internal combustion engine (10) by means of a drive train (13), wherein the waste-heat utilization system (20) has at least one expander (22), at least one evaporator (21), and at least one pump (24) for an operating medium, in particular ethanol. 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, performs work in at least one operating mode. One operating mode of at least two operating modes (1, 2, 4, 5) of the expander (22) is selected by a control device (30) on the basis of at least one input variable from the group 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) and the expander (22) is operated in said operating mode. 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). The bypass valve (26) is opened in the first operating mode (1) and closed in the second operating mode. 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.

The invention relates to a method for controlling a waste-heat utilization system (20) for a motor vehicle driven by an internal combustion engine (10) by means of a drive train (13), wherein the waste-heat utilization system (20) has at least one expander (22), at least one evaporator (21), and at least one pump (24) for an operating medium, in particular ethanol. 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, performs work in at least one operating mode. One operating mode of at least two operating modes (1, 2, 4, 5) of the expander (22) is selected by a control device (30) on the basis of at least one input variable from the group 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) and the expander (22) is operated in said operating mode. 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). The bypass valve (26) is opened in the first operating mode (1) and closed in the second operating mode. 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.

Apparatus for utilizing heat wasted from an engine includes first pressure detecting means (73) and first temperature detecting means (81) for detecting a pressure and a temperature in a refrigerant passage extending from a condenser (38) to a refrigerant pump (32), second pressure detecting means (72) and second temperature detecting means (82) for detecting a pressure and a temperature in a refrigerant passage extending from a heat exchanger (36) to an expansion device (37), and control means (71) responsive to these four detecting means when operating a Rankine cycle (31). Means (71) is for diagnosing whether or not an electromagnetic clutch (35) is stuck responsive to either the first pressure detecting means (73) and the first temperature detecting means (81), or the second pressure detecting means (72) and the second temperature detecting means (82).

Apparatus for utilizing heat wasted from an engine includes first pressure detecting means (73) and first temperature detecting means (81) for detecting a pressure and a temperature in a refrigerant passage extending from a condenser (38) to a refrigerant pump (32), second pressure detecting means (72) and second temperature detecting means (82) for detecting a pressure and a temperature in a refrigerant passage extending from a heat exchanger (36) to an expansion device (37), and control means (71) responsive to these four detecting means when operating a Rankine cycle (31). Means (71) is for diagnosing whether or not an electromagnetic clutch (35) is stuck responsive to either the first pressure detecting means (73) and the first temperature detecting means (81), or the second pressure detecting means (72) and the second temperature detecting means (82).

To effectively reduce a situation in which an over-rotation of an expander occurs or the expander becomes a load on an engine at the time of a stop of a Rankine cycle in an exhaust heat recovery device provided with the Rankine cycle that recovers exhaust heat of an engine. A pressure difference P between a high-pressure side and a low-pressure side of the Rankine cycle is obtained when the Rankine cycle is stopped (S1), a waiting time Ta is set (calculated) based on the obtained pressure difference P (S2). Then, a bypass valve is opened to allow a refrigerant to circulate while bypassing the expander (S3), and then an electromagnetic clutch is disengaged when the waiting time Ta has elapsed to block transmission of power between the expander and the engine (S4, S5).

To effectively reduce a situation in which an over-rotation of an expander occurs or the expander becomes a load on an engine at the time of a stop of a Rankine cycle in an exhaust heat recovery device provided with the Rankine cycle that recovers exhaust heat of an engine. A pressure difference P between a high-pressure side and a low-pressure side of the Rankine cycle is obtained when the Rankine cycle is stopped (S1), a waiting time Ta is set (calculated) based on the obtained pressure difference P (S2). Then, a bypass valve is opened to allow a refrigerant to circulate while bypassing the expander (S3), and then an electromagnetic clutch is disengaged when the waiting time Ta has elapsed to block transmission of power between the expander and the engine (S4, S5).

A twin-shaft gas turbine can be used for 50 and 60 Hz power generation without using a reducer. A gas generator includes a compressor that generates compressed air, a burner that burns a fuel mixed with the compressed air received from the compressor so as to generate combustion gas, and a high-pressure turbine that is rotationally driven by the combustion gas received from the burner and generates driving force for the compressor. An output turbine includes a low-pressure turbine that is driven by exhaust gas received from the high-pressure turbine and a power generator that is driven by the low-pressure turbine. A control device reduces opening degree of IGV of the compressor and thereby reduces power of the compressor, and the rotational frequency of the gas generator is increased in a full-speed no-load operating state of the power generator.

A twin-shaft gas turbine can be used for 50 and 60 Hz power generation without using a reducer. A gas generator includes a compressor that generates compressed air, a burner that burns a fuel mixed with the compressed air received from the compressor so as to generate combustion gas, and a high-pressure turbine that is rotationally driven by the combustion gas received from the burner and generates driving force for the compressor. An output turbine includes a low-pressure turbine that is driven by exhaust gas received from the high-pressure turbine and a power generator that is driven by the low-pressure turbine. A control device reduces opening degree of IGV of the compressor and thereby reduces power of the compressor, and the rotational frequency of the gas generator is increased in a full-speed no-load operating state of the power generator.

A facility for generating mechanical energy by means of a combined power cycle is disclosed herein, which includes at least means for carrying out a closed or semi-closed, constituent regenerative Brayton cycle, which uses water as a heat-transfer fluid, means for carrying out at least one Rankine cycle, a constituent fundamental Rankine cycle, interconnected with the regenerative Brayton cycle, and a heat pump (UAX) including a closed circuit that regenerates the constituent regenerative Brayton cycle, as well as to the method for generating energy using the facility.