LOW-GRADE HEAT CONVERSION TO COOLING AND POWER WITH EJECTOR BASED ADVANCED THERMAL SYSTEMS

Abstract

Low-grade heat is abundantly available from various sources such as industrial waste heat, solar thermal energy and geothermal energy. Low-grade heat driven cooling and power systems can enhance both the energy efficiency and the share of renewable energy. In this PhD research work, based on modelling and simulation, ejectors (thermal compressor) have been used in a number of innovative thermal systems, which utilize low-grade heat for tropical operation having higher temperature heat sinks. In this work, analytical and numerical models of ejectors have been developed which allow the design, analysis and optimization of the innovative low-grade heat driven systems. The systems studies in the present work are (1) ejector refrigeration system (ERS), (2) organic Rankine cycle (ORC), (3) a novel ejector based combined cooling and power system (CCPS) and (4) a novel ejector enhanced vapour compression cycle (EVCC). For simulations, EES, FLUENT and EBSILON have been used.