In this steam process, a working fluid (e.g. Ethanol) gets evaporated under high pressure in an evaporator. The expansion takes place in an expansion machine. After the condensation of the working fluid in a coolant cooled condenser, the pump increases the pressure and provides the required mass flow, depending on the heat source that is available. This steam process is well known from stationary applications and was transferred to mobile on-road applications, says Mahle.
The energy out of the WHR system can be used whether coupled mechanically to the crankshaft or electrically stored in a battery. Mahle is offering product solutions for both kinds of energy coupling. By using the exhaust energy, the fuel consumption of heavy duty commercial vehicles can be reduced by 3 – 5% for longhaul applications, it claims.
