The present invention relates to an arrangement comprising a waste heat recovery system (WHR-system) and a method for controlling the arrangement. The arrangement comprises an expansion tank having a constant inner volume, first cooling means configured to cool the working fluid in the condenser and a control unit configured to control the first cooling means such that the working fluid is cooled to a desired condensation temperature in the condenser during operation of the WHR system. The arrangement comprises further a sub-cooler arranged in a position downstream of the condenser and second cooling means configured to cool the working fluid in the sub-cooler, and that the control unit is configured to control the second cooling means such that the working fluid receives a determined subcooling in the sub-cooler during operation of the WHR system.

The present invention relates to an arrangement comprising a waste heat recovery system (WHR-system) and a method for controlling the arrangement. The arrangement comprises an expansion tank having a constant inner volume, first cooling means configured to cool the working fluid in the condenser and a control unit configured to control the first cooling means such that the working fluid is cooled to a desired condensation temperature in the condenser during operation of the WHR system. The arrangement comprises further a sub-cooler arranged in a position downstream of the condenser and second cooling means configured to cool the working fluid in the sub-cooler, and that the control unit is configured to control the second cooling means such that the working fluid receives a determined subcooling in the sub-cooler during operation of the WHR system.

This single-shaft combined cycle plant comprises: a power generator; a gas turbine; a steam turbine that is driven by using waste heat from the gas turbine, and is connected to the power generator by a clutch when the rotational speed syncs with the rotational speed of the gas turbine; a steam turbine over-rotation prevention device; a gas turbine over-rotation prevention device; and a control device. The control device sets the power generator to an unloaded state and, whilst maintaining the rotational speed Ng of the gas turbine so as to be higher than the rotational speed Ns of the steam turbine and lower than the maximum rotational speed Nglim of the gas turbine, increases the rotational speed Ns of the steam turbine to the maximum rotational speed Nslim of the steam turbine (time t2-t4) and tests whether or not the steam turbine over-rotation prevention device operates normally.

An arrangement and a method for controlling a shutdown phase of a WHR-system. The WHR system includes a main circuit (4) which includes a pump (3), an evaporator (5), an expander (7) and a condenser (10), and a compensation tank (12) which is configured to compensate for volume changes of a working fluid in the main circuit (4) during operation of the WHR system. The arrangement includes a control unit (26) configured to receive information when the shutdown phase of the WHR system is to be initiated and a flow device able to supply working fluid from the compensation tank (12) to the main circuit (4). The control unit (26) is configured to activate the flow device such that working fluid is supplied from the compensation tank (12) to the main circuit (4) when it receives information indication that the shutdown phase of the WHR system is to be initiated.

A control device includes a reception unit configured to receive a load schedule indicating a load in the future of a combined cycle plant, a steam temperature control unit configured to control a temperature of steam flowing into a steam turbine, and a fuel control unit configured to control a flow rate of fuel supplied to a gas turbine. The steam temperature control unit is configured to output a command indicating an amount of operation for decreasing the temperature of the steam to a steam temperature regulator prior to a load decrease time at which the load is to be decreased in the load schedule.

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.

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 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 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 transmission system selectively coupled to an engine crankshaft of an internal combustion engine arranged on a vehicle includes a waste heat recovery (WHR) system, a brake assembly and a phase-change thermal heat storage system. The WHR system selectively circulates a WHR fluid in the transmission system. The brake assembly selectively couples a transmission output shaft to a drive axle. The brake assembly is configured to operate in a braking mode that retards relative rotation between the transmission output shaft and the drive axle while generating heat. The heat storage system includes a housing defining at least one cavity and a fluid transfer manifold. A phase-change material is disposed in the cavity that is configured to change phase during the braking mode. The WHR system circulates the WHR fluid through the fluid transfer manifold collecting braking heat to be used at a later time in the form of driveline power.