|Cutaway diagram of the heat2power system mounted on an engine. Click to enlarge.|
The Paris, France-based developer of a waste heat recovery (WHR) system, heat2power, won the Powertrain Innovation of the Year Award at the Professional Motorsport World Expo in Cologne (11-13 November) with its Thermal Energy Recovery System (TERS). heat2power says that its WHR system can provide fuel savings of 15-35% under all driving conditions at a cost of approximately 30% more than a comparable turbocharged gasoline engine.
The heat2power system uses one or more cylinders for the regeneration of waste heat. These cylinders can be in replacement of the combustion cylinders inside an existing engine or as an add-on module that is connected to the engine by means of a gear set or a belt drive. It is also possible to have no mechanical linkage between the combustion engine and the WHR unit in case the power from the regeneration unit is taken off electrically.
|System layout of a heat2power add-in configuration and power flows. Click to enlarge.|
The heat2power system, like other thermodynamic cycles, intakes and compresses a gas, heats it and allows it to it expand. The difference between an ICE and the heat2power system is that the heat input is not by a combustion inside the cylinder but by heat exchange external to the cylinder.
The regeneration device comprises:
One or more piston, cylinder and rod groups, with 4 valves per cylinder, driven by standard camshafts;
One gas-gas heat exchanger; and
One dedicated boosting turbocharger.
|Specific fuel consumption for conventional engine (left) and engine with heat2power (right). Click to enlarge.|
After the expansion stroke, the air is released at low temperatures (250-300° C instead of 600-950°C). The heat exchanger in the exhaust is placed after the catalyst (gasoline vehicles) or after the particle filter (diesel vehicles), allowing the exhaust aftertreatment system to be unaffected. heat2power recommends application of thermal insulation of the exhaust manifold and the first part of the exhaust and catalyst/DPF so that a maximum amount of heat is available for the regeneration process.
The system is compatible with all fuel types (e.g., diesel, gasoline, ethanol, CNG, LPG, etc.) and complementary with hybrid electric powertrain concepts.
heat2power is seeking partners for prototyping and testing of its devices.