Experimental Analysis of a PCM Based I.C. Engine Exhaust Waste Heat Recovery System

Abstract

The exhaust gas in an internal combination engine carries away about 35% of the heat of combustion and it goes as a waste, it not utilised properly. Air pre heater using waste heat recovery system, cogeneration and concept of heat battery are successful techniques to improve the overall thermal efficiency of the system to a certain extent. However, there is still a large potential to store and utilise the exit stream energy by the efficient implementation of waste heat recovery system. The major technical constraint that prevents successful implementation of such a system in intermittent and time mismatched demand and availability of energy. In the present work, a heat recovery heat exhanger integrated with an I.C. engine and a combined sensible and latent heat storage system with spherical PCM (phase change material) capsules, as the latent heat material is designed, fabricated and tested. Performance characteristics of the system are also studied in detail. It is found that about 15% fuel power is stored in the combined storage system, which is available at higher temperature for suitable applications.