Klaus Strasser

Numerical investigation of energy-efficient heat-up strategies considering a comprehensive HVAC-system

A comprehensive vehicle thermal analysis needs to examine in detail the interaction between every single thermal system involved in the heating process. In order to accurately predict the thermophysical behaviour of the total system during vehicle warm-up the use of simulation methods is recommended. This paper deals with the contradictory requirement of improving the energy-efficient heat-up behaviour of the passenger compartment without disregarding comfort and safety aspects.

Vehicle Warm-Up Analysis with Experimental and Co-Simulation Methods

A high accuracy of full-vehicle thermal models are required to predict the vehicle heat-up behaviour at every conceivable combination of driving cycle and ambient air temperature down to −20 °C. Within this work a methodology for modelling the thermal behaviour of an IC-engine is presented. The focus lies on the heat-path beginning with the combustion process followed by heat conduction through the combustion chamber walls and convective heat transfer between engine structure and coolant. The thermal engine model is coupled with other models (HVAC-system, powertrain, etc.) by an independent co-simulation platform in order to describe the virtual vehicle as a whole. Finally, the model validation is performed with two different driving cycles at two different start temperatures. Using the described full-vehicle model the potential of a heat storage system is discussed for several heat-up strategies.