A METHOD AND SYSTEM FOR CONTROLLING THE ROTATIONAL SPEED OF AN EXPANDER IN A WASTE HEAT RECOVERY SYSTEM

• Main Authors: JOHANSSON, Björn, HÖCKERDAL, Erik, TIMREN, Thomas
• Format: Patent
• Language: English; French; German
• Published: 13.12.2023
• Subjects: ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS INVEHICLES; ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OFTRANSMISSIONS IN VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GASEXHAUST OR FUEL SUPPLY OF PROPULSION UNITS, IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; BLASTING; COMBUSTION ENGINES; ENGINE PLANTS IN GENERAL; ENGINE PLANTS NOT OTHERWISE PROVIDED FOR; ENGINES USING SPECIAL WORKING FLUIDS OR CYCLES; 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; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; LIGHTING; MACHINES OR ENGINES IN GENERAL; MECHANICAL ENGINEERING; NOT OTHERWISE PROVIDED FOR; PERFORMING OPERATIONS; STEAM ACCUMULATORS; STEAM ENGINE PLANTS; STEAM ENGINES; TRANSPORTING; USE OF WASTE HEAT OF COMBUSTION ENGINES; VEHICLES IN GENERAL; WEAPONS

The invention relates to a method, system, and computer program product for controlling a waste heat recovery system associated with a vehicle powertrain, the powertrain comprising a combustion engine and a gearbox connected to the combustion engine, the waste heat recovery system comprising a working fluid circuit; an evaporator; an expander; a condenser; a reservoir for a working fluid and a pump arranged to pump the working fluid through the circuit, wherein the evaporator is arranged for heat exchange between the working fluid and at least one heat source, wherein the waste heat recovery system further comprises a cooling circuit arranged in connection to the condenser, and wherein the expander is mechanically coupled to the powertrain. The method comprises the steps of determining the pressure and temperature of the working fluid upstream of the expander; and controlling the rotational speed of the expander based on the determined pressure and temperature.