Experimental evaluation and modeling of waste heat recovery in VECTO 2020-01-1287
Waste heat recovery based on an Organic Rankine Cycle is a technology proposed for the reduction of the fuel consumption of heavy-duty vehicles. This technology is currently not simulated by VECTO, the tool used in Europe to certify the fuel consumption and CO2 emissions of new heavy-duty vehicles. In this work, a class 5 lorry equipped with a prototype Organic Rankine Cycle system is tested on the chassis dyno during steady state and multiple transient driving cycles, with waste heat recovery enabled and disabled. The waste heat recovery system enabled a brake specific fuel consumption reduction of up to 6.5% during steady-state conditions, up to 3.1% during the World Harmonized Vehicle Cycle and up to 2.1% during the regional delivery cycle.
A model of the vehicle was created in VECTO based on the experimental data. The waste heat recovery system was modelled by creating a fuel consumption map with the combined power output of the engine and the waste heat recovery system during the steady state experiments. The regional delivery cycle was simulated in VECTO and the predicted fuel consumption was compared to the measured one. This showed that VECTO was able to predict the fuel consumption with an error of 0.7% for the regional delivery cycle. Finally, the model was used to predict the fuel consumption reduction with waste heat recovery for all regulatory driving cycles in VECTO.