Impact of IHX Sizing on Automotive Climate Control Performance Optimization 2021-28-0129

Air Conditioning System is one of the key elements of vehicle to provide thermal comfort for passengers. The optimization of fuel economy of the vehicle while delivering best in class cabin comfort is one of the biggest challenges for any thermal engineer. However to reduce the risk of compromising vehicle energy consumption performance with respect to thermal comfort, optimization need to be done during the initial design stage. Internal Heat Exchanger (IHX) is one of the major components which can be used to balance both parameter.

In recent studies, different types of IHX like co-axial IHX, spiral type IHX has been evaluated by designers for energy and performance optimization. Beside this micro design IHX and other IHX design have been studied and experimented. One of the problems highlighted during all these studies is optimization of IHX length for a given system is very difficult to avoid any adverse effect in performance.

This current study gives insight into optimization of co-axial IHX performance of different lengths and its impact on other components. In the present study, 1D simulation of AC system with different length of IHX which replicate same environment as vehicle condition is shown. Also comparison of actual experimental data of AC system with change IHX length at vehicle level tested in wind Tunnel is presented. Further comparison of 1D simulation results and actual experimented results is studied which helps in optimizing the AC performance by optimizing the size of IHX used in AC circuit. By optimizing the length of IHX, vent temperature at vehicle can be tweaked by 2~3°C with improvement in COP of system, IHX size and cost optimization. Study will help the designers to develop simulation based methodology to study the Impact of IHX sizing on automotive climate control performance optimization.