An Environmental Impact Assessment of an Orc-Based Exhaust Heat Recovery System for Application in Vehicles

Abstract

The paper presents the study performed to assess the environmental consequences of a proposed organic Rankine cycle-based exhaust heat recovery system for application in vehicles. A life-cycle assessment of fifteen (15) midpoints and two (2) endpoint levels was performed using the SimaPro database to determine the potential environmental consequences of the main parts of the proposed system resulting from the various raw materials used in these parts. The performance results of the organic Rankine cycle-based exhaust heat recovery system show that it can generate up to 3.10 kW of net power output from the engine exhaust, which otherwise is released into the environment as waste heat, with a thermal efficiency of 6.36%. The life-cycle assessment results show that the presence of steel in these components is responsible for the majority of these environmental consequences. The evaporator showed the highest impact potential, with values ranging from 37% in marine eutrophication to 72% in ionizing radiation. From the two (2) endpoint impact assessments, it is clear that the pump has the maximum human health impact potential of 0.0138 DALY, with the condenser having the lowest contribution of 0.0005 DALY. The evaporator and condenser contribute 2297.25 PDF.m2.yr and 158.30 PDF.m2.yr ecosystem quality impact potentials, respectively, as the highest and lowest. Therefore, the organic Rankine cycle-based exhaust heat recovery system has relatively little impact potential on climate change threats, with a value of 1.37E-03 kgCO2.