Development of evaporative intercooler heat exchanger for vehicle using CFD simulation

Improving engine performance with reduced fuel consumption and exhaust emissions levels nowadays is the concern of most vehicle manufacturers. The pollutions of harmful gases are released into the atmosphere, leading to global warming: the effects which include an increase in weather temperature in most countries. The used of cooled air charge temperature during operation of the engine will improve the engine performance and emissions levels. Thus, the new add-ons technique (intercooler heat exchanger) is introduced for enhancement of air mass density to the engine. The goal of this study is to develop an engine’s intercooler heat exchanger located in the intake manifold, using Computational Fluid Dynamics (CFD). The design presenting a pre-design simulation concept of evaporative intercooler which can be integrated in the air intake system of an engine. The simulation study will investigate the capability of the intercooler concept on design cooling capacity, which operate on R134a of the vehicle air-conditioning system refrigerant. The simulation results are dependent on air thermal property of temperature, pressure and velocity. The adopted design is shell-and-tube type with multi tube straight pass, counter flow, and evaporator coolant medium. The simulation shows significant ability of air temperature reduction of 30 – 40% of initial inlet hot air. Air pressure drop is not desired, which affects the thermal performance of the engine. The pressure drop effect can be reduced when air mass flow become higher due to less contact factor in evaporative pipes surface, because of reduce in heat transfer contacts between cooling pipe surface and inlet air, depending on engine speed. In this study, the pressure drop is vary with air inlet mass flow which is proportional to engine size capacity, engine RPM and Intercooler coolant feed, for this design about 5-20% drop. The simulation shows an enhancement on air charge property which is desirable in improving the engine performance.