Performance and economic optimization of an organic rankine cycle for a gasoline hybrid pneumatic powertrain

• The hybrid pneumatic powertrain is efficient for urban usage.
• Organic rankine cycle suits for peri-urban and holiday drives and downsized engines.
• Both technologies combine efficiently on combined driving cycles.
• For C-Segment vehicle, it emits less than 80 g CO2/km and cost around 30,000 euros.

This article presents an innovative concept for alternative hybridization, without electrical devices. The concept is studied on a C-Segment vehicle with targeted prices between 27,000 and 34,000 euros. Short term hybrid pneumatic energy storage and a waste heat recovery system are introduced for the efficiency improvement of a small downsized gasoline engine. The modeling methodology for the hybrid pneumatic powertrain is presented. The waste heat recovery system is an organic rankine cycle. An innovative methodology using energy integration and multi-objective optimization is applied for the design of the organic rankine cycle loop. The selection of the organic rankine cycle design is based on techno-economic indicators and is done by using a qualification utility function for the population of solutions on the Pareto curve. The concept of hybrid pneumatic powertrain and organic rankine cycle is evaluated on different driving cycles and the economic analysis of the customer mobility is done, according to his drive profile.