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As global climate change continues to affect everyday life, energy efficiency is becoming more crucial. Automotive emissions contribute a sizeable portion of man-made pollution, so a shift to "greener" automobiles has become paramount. Since automotive air conditioning systems are one of the biggest energy needs within a vehicle, increasing air conditioning efficiency can reduce the carbon footprint and increase the range of vehicles on the road today.
This paper works towards this goal by focusing on control of an automotive evaporator in tandem with an expansion valve and a compressor. The partial differential equations describing the evaporator thermal dynamics are developed using first principles and are then converted into ordinary differential equations using finite volume discretization. Parameter identification is performed by comparing simulations of the evaporator with physical measurements and minimizing the discrepancies. After the model is validated, a sliding mode controller is developed to regulate the outlet air temperature, and its performance is compared to that of a proportional integral derivative controller similar to what may be currently utilized in production vehicles. The results from simulation indicate that the sliding mode controller operates with better temperature tracking and uses less energy, and both controllers are ready for testing on a physical system.