Load calculation and system evaluation for electric vehicle climate control

摘要

This paper presents an analysis of the applicability of alternative systems for electric vehicle (EV) heating and air conditioning (HVAC). The paper consists of two parts. The first part is a cooling and heating load calculation for electric vehicles. The second part is an evaluation of several systems that can provide the desired cooling and heating in EVs. These systems are ranked according to their overall weight The overall weight is calculated by adding the system weight and the weight of the battery necessary to provide energy for system operation. The system with the minimum overall weight is considered to be the best, because minimum vehicle weight decreases the energy required for propulsion, and therefore increases the vehicle range. Three systems are considered as the best choices for EV HVAC. These are, vapor compression, ice storage and adsorption systems. These systems are evaluated, including calculations of system weight, system volume, and COP. The paper also includes a calculation on how the battery energy storage capacity affects the overall system weights and the selection of the optimum system. The results indicate that, at the conditions analyzed in this paper, an ice storage system has the minimum weight of all the systems considered. Vapor compression air conditioners become the system with the minimum weight for battery storage capacities above 230 kJ/kg.