Energy and Exergy Analysis of Solar Thermal Driven Multiple Output Thermodynamic Cycle

Abstract

Among various sources of energy, solar, geothermal, and waste heat exists extensively. Most of these energies can not utilized by conventional machines for power generation. The most traditional machine applied to utilize these forms of energy is the Rankine cycle which possesses some disadvantages due to the thermodynamic behavior of steam at low pressure. A solution of this problem is the use of organic Rankine cycle which can comfortably generate power by utilizing low temperature energy sources and an organic fluid. For this reason, there has been a massive resurgence of interest in adopting organic Rankine cycle to enable relatively low temperature exhaust energy recovery. Unique possibilities in simultaneous production of multi effect cooling, power and heating applications by using solar heat along with various advantages are the main motivating factors behind the present research work. In this context, the current study has been carried out to evaluate the thermodynamic performance of a solar operated combined organic Rankine cycle and ejector refrigeration cycle for simultaneous production of cooling and power by using different refrigerants such as R141b, R600, R601 and R601a. An exergy analysis and parametric analysis are conducted for the thermodynamic improvement of the cycle. The results show that the largest exergy destruction due to irreversibility occurs in a central receiver (52.5%) and the next largest exergy destruction occurs in Heliostat field (25%). A considerable amount of exergy is also destroyed in the ejector, heat recovery vapour generator and condenser. It is observed that the turbine inlet pressure, turbine back pressure, condenser temperature and the evaporator temperature have significant effect on the turbine power output, refrigeration output, energy efficiency, exergy efficiency and exergy destruction rate in various components of the combined ejector cooling and power cycle. newlineIn order to produce double effect cooling and power simultaneously, a solar powered combined organic Ran