Engine Waste Heat Recovery and Re-Use
Strategic objectives addressed
The reduction of CO2 emission is a strategic goal of the EU where heavy duty vehicles can contribute in a relevant way.
A very promising solution is the re-use of the waste heat, that is about the 60% of the combustion energy, transforming it in mechanical or electrical energy so to increase in overall vehicle energy efficiency and consequently its CO2 emissions and fuel consumption of about the 10% - 15% depending of the usage conditions. This benefit can be increased in case of a hybrid or hybrid-like powertrain where it is possible to store and then use the generated energy when is more convenient.
The heat re-use can be performed by means of a thermodynamic cycle (e.g. organic or non-organic Rankine cycles) using the waste heat as energy source as is being adopted for large stationary applications. The adoption of such technology in the automotive domain requires a specific R&D activity to develop the components, identify the most appropriate system architecture and integration level so to achieve sustainable cost and the reliability requirements.
The NoWaste Project aims to develop this system and demonstrate its feasibility with a test ring and a vehicle demonstrator.
The Project key points are:
definition of a reference mission
selection of the most appropriate architecture after a deep technology screening
innovative heat rejection system minimizing the cooling drag and the impact on the front end
development of specific heat exchangers to maximize the heat recuperation efficiency
Integration with the exhaust system
validation of the developed system at first on a test rig and then on vehicle demonstrator based on a hybrid powertrain
evaluation of the system on the applicability on various power trains for heavy duty trucks by mean of a model approach
Fuel Economy: >12% fuel consumption reduction at vehicle level on a reference mission
Cost (for the OEM): < 4500 Euro/system
Weight: < 150 kg
Concept and objectives
Despite recent improvements of diesel engine efficiency, a considerable amount of energy is still rejected as heat both in the exhaust gases and from the cooling system. The amount of waste energy is in the order of 50–60% of the combustion energy.
This energy, even if it is in form of high, medium and low temperature heat can be re-use and transformed in more useful forms as, for example, electricity.