Exergetic analysis of an integrated power production solar system

The issue of energy resources and environmental pollution has been in the forefront of concerns for governments and various environmental organizations in the past few years. The continuous use of conventional energy sources, mainly hydrocarbons, and the uncertainty of their availability with the high environmental cost that is inflicted has led to efforts for the use of renewable energy sources. Also, the energy crisis of the 1970's made clear the need for gradual introduction of new clean energy sources with increase in the time span for their availability. Renewable energy sources satisfy all the environmental criteria but with one negative aspect, the low exergy efficiency. Solar energy among the renewable energy sources could play a vital role in providing enough energy to alleviate the heavy use of hydrocarbon. Solar energy is a clean And free source of energy that can provide power through solar-chemical, solar-thermal and solar-electric processes. Greece is a country with high solar radiation throughout the year and the use of solar energy becomes even more attractive. The production of electricity with the use of solar collectors requires an analysis of its exergy efficiency. The objective of this work is to show the design and analysis a small solar power system with production of 2 MW electricity. The main components of this system are made up of solar collectors, a typical Rankine power cycle and a heat exchanger network (H.E.N.) that absorbs the heat of the solar collector system and heats the flows that will be used in the Rankine cycle. The system is connected to the grid and is designed in such a way that during the months of the biggest solar radiation, it could generate and required power with the minimal input from fossil fuels. The H.E.N. is able to combine the streams on the basis of their temperature and their enthalpy, which will lead in the minimization of entropy generation. The system will operate at steady state conditions for each month, such as constant flow rates, constant pressures and temperatures for the Rankine cycle, etc.