An Approach to Rating of Vehicle Climate Controls in Hybrid and Electric Driven Vehicles for Energy Efficiency

Abstract

As part of the auxiliary components, climate controls and heating devices do have a relatively high energy consumption maintaining the comfort in the passenger cabin, which is a problem in the development of hybrid and especially electric vehicles. Hence, these vehicles have high potentials in optimizing the climate control. Several concepts of optimizing energy consumption are well known, such as insulation, glasses with better transmission coefficients, pre-conditioning or heat exchanger of outlet air. The efforts, the complexity, the installation space and the weight of these implementations are increasing. The weight of these additional components has an impact on the energy consumption of the vehicle. In order to evaluate the interdependencies between the direct energy consumption of possible solutions and their additional effects in early stages of product development, this paper introduces one possible approach for rating. Using the example of a heat pump which will be used for heating and cooling the passenger’s cabin, the applicable modeling in Matlab/Simulink will be demonstrated. One part of this implementation is a comparison of the approach based on Frank [Gro10] and another approach based on Nitz and Hucho [Gro10] in aspects of a sensitivity study. Furthermore, the impact of different insulation methods (glass transmission, insulation of the carriage) at extreme and average environmental boundary conditions as well as the changed weight and installation space is investigated. Therefore an environmental model is introduced which takes day time, season as well as GPS data into account. Target of this investigation is defining the minimum necessary power of a heat pump in the passenger cabin of a commercial vehicle with the smallest possible installation space and increase in weight. By modeling and analyzing this example scenario, sustainable values are derived in order to enable a cost-utility analysis of different vehicles in their respective market segments and the chosen solution of climate control.