A method for controlling a waste heat recovery system and such a waste heat recovery system

• Main Authors: Björn Johansson, Thomas Timren, Erik Höckerdal
• Format: Patent
• Language: English; Swedish
• Published: 13.01.2018
• Subjects: BLASTING; COMBUSTION ENGINES; ENGINE PLANTS IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNALCOMBUSTION ENGINES; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES ORENGINES IN GENERAL; HEATING; HOT GAS OR COMBUSTION-PRODUCT POSITIVE-DISPLACEMENT ENGINEPLANTS; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS; LIGHTING; MACHINES OR ENGINES IN GENERAL; MECHANICAL ENGINEERING; NOT OTHERWISE PROVIDED FOR; STEAM ENGINES; USE OF WASTE HEAT OF COMBUSTION ENGINES; WEAPONS

The invention relates to a method for controlling a waste heat recovery system (10) associated with a powertrain (3) of a vehicle (1), the powertrain (3) comprising a combustion engine (2) and a gearbox (4) connected to the combustion engine (2), the waste heat recovery system (10) comprising a working fluid circuit (12); an evaporator (14); an expander (16); a condenser (18); a reservoir (20) for a working fluid (WF) and a pump (22) arranged to pump the working fluid (WF) through the circuit (12), wherein the evaporator (14) is arranged for heat exchange between the working fluid (WF) and at least one heat source (24), wherein the waste heat recovery system (10) further comprises a cooling circuit (26) arranged in connection to the condenser (18), and wherein the expander (16) is mechanically coupled to the powertrain (3). The method comprises the steps of determining (s101 ) the pressure (P) and temperature (T) of the working fluid (WF) upstream of the expander (16); and controlling (s102) the rotational speed of the expander (16) based on the determined pressure (P) and temperature (T).The invention also relates to a waste heat recovery system (10), a vehicle (1) comprising such a system (10), a computer program (Pr) and a computer program product.(Fig. 2)