In the modern era of automotive industry, occupant comfort inside the cabin is a basic need and no more a luxury feature. With increase in number of vehicles, the expectations from customers are also changing. One of the major expectations from real world customers is quick cabin cooling thru all seasons, particularly when the vehicle is hot soaked and being used in summer conditions.
Occupant thermal comfort inside the vehicle cabin is provisioned by a mobile air conditioning (MAC) system, which operates on a vapor compression-based cycle using a refrigerant. The main components of a direct expansion (DX) based MAC system are, a compressor, condenser, evaporator, and expansion valve. Conditioned air is circulated inside the cabin using a blower, duct system and air vents.
The AC condenser is the most critical component in AC circuit as it rejects heat, thereby providing for a cooling effect inside the cabin. Right sizing and packaging of condenser, optimizing the condenser core, delivering proper airflow over condenser fins are some of the constraints while designing a condenser for any automobile application. MAC engineers need to continuously improve the efficiency of condenser particularly if there are application specific restrictions on the condenser core size and fan capacity; more so as the physical obstruction and heat rejection from condenser negatively impacts power train cooling and fuel economy of the vehicle.
To overcome these challenges, enhancements need to be incorporated in condenser design.
This paper discusses the development of an optimally designed super-efficient condenser for enhanced heat rejection capacity and overall efficiency. Various parameters such as fin geometry, tube geometry, pass structure have been studied and optimized for enhancement in performance. Theoretical calculations, along with simulation and experimental results for the new condenser, are presented and discussed in comparison a with baseline design. The results demonstrate a 20% improvement in heat rejection, which in turn amount to a 1-2 °C reduction in vehicle cabin temperatures.