Optimization of Helical Coil Heat Exchanger as a Waste Recovery System for Efficient Fuel Consumption

Abstract

The study endeavors to harness waste heat from the exhaust gas of a diesel engine through the utilization of a helical coil heat exchanger (HCHE), with the overarching goal of enhancing engine efficiency. Employing SolidWorks CAD software and SolidWorks Flow Simulation, the HCHE was meticulously modeled and simulated to optimize its design parameters. The HCHE design incorporated a coil length of 30 millimeters, an inside diameter of 4mm, and an outside diameter of 5mm. Through systematic variation of coil pitch at operational speeds of 1500, 2000, and 2500 revolutions per minute, the optimization process aimed to identify the most efficient configuration. Remarkably, the simulation results indicated that a coil pitch of 20mm yielded optimal performance. Notably, the simulation revealed a significant increase in the temperature of diesel fuel, from 15.6°C to 32.5°C, resulting in a corresponding decrease in density from 832 kg/m³ to 820.491 kg/m³. This thermal enhancement led to an average reduction in volume consumption of 10%, consequently translating to a proportional decrease in fuel consumption. Furthermore, the simulation analysis indicated a resulting pressure drop of 5.3075 kPa, well within the acceptable threshold of 20.77 kPa. This underscores the safety and efficacy of the 20mm coil pitch configuration in mitigating pressure drop issues within the fuel line. These findings validated the effectiveness of the helical coil heat exchanger design, closely aligning with expectations. Moreover, the exchanger's performance was linked to diesel fuel temperature dynamics. Further exploration of parameters influencing heat recovery is recommended for future research and technological advancements.