Thermodynamic Analysis And Comparison Of Different Hybrid Configurations Of Organic Rankine Cycle Driven By Solar And Geothermal Energy

Electrical power consumption is considered as one of the key factors in a country’s economic and technological growth.The sources for power generation in the world are mainly fossil fuels which are subjected to deplete in upcoming decades.Due to climate change and depletion of fossil fuels,the researchers from all over the world have turned their attention towards the production of clean and renewable energy.So,there is a need of producing power through clean energy and there is no threat of its depletion with time.The world is full of renewable energy sources and they can serve the humanity for a lifetime.The most prominent renewable energy sources are solar,geothermal etc.Solar energy has emerged as one of the most rapidly growing renewable sources of power generation.There are several ways to use these resources for power production.One of the most promising technology for this purpose is organic Rankine cycle.It is an attractive option for coupling with low-medium temperature resources.The small-scale solar/geothermal ORC systems are promising technologies.However,there are few problems associated with the systems such as fluctuating and less efficient power generation.Recently,the researchers have started working on the combined configuration for solar and geothermal ORCs.This is a relatively new research area and it has produced better results for power production considering the economic and thermodynamic aspects together.This study aims to exploit this research gape further.Thus,a thermodynamic comparison of three different hybrid configurations of organic Rankine cycle driven by solar and geothermal energy have been presented and analysed.The thermodynamic models for each configuration were made using MATLAB and NIST/REFPOPM.The thermodynamic analysis mainly concerns with the net output work,the thermal efficiency,the exergy efficiency and the exergy losses in the ORC components.The three models presented in this thesis are:Solar superheat model,solar pre-heat model and geothermal pre-heat model.The models were optimized according to evaporation temperature.For R245fa,solar superheat model produces W_net of 921kW,_?of 7.3%,₀)of 48%,solar pre-heat produces W_net of 884kW,_?of 7.3%,₀)of 17,geothermal pre-heat model produces W_net of 1994kW,_?of 7.4%,₀)of 49%at the optimal evaporation temperature.