Performance Evaluation of a Solar Powered Organic Rankine Cycle for Residential or Small Commercial Applications

Organic Rankine cycles (ORC) are used to convert energy from low temperature heat transfer into electrical energy. In this paper, a model for an hourly solar powered organic Rankine cycle is presented, and the effect of average hourly outdoor temperatures on the system performance is investigated. The solar ORC was modeled and evaluated in Jackson, MS, using five different dry organic working fluids. The purpose of this study is to investigate how hourly temperature change affects the electricity production rates of the solar ORC, as well as to determine the best working fluid for the proposed system. The effect of average hourly outdoor temperatures on the ORC performance is evaluated by modeling the ORC in two locations with the same latitude but different climate conditions. In addition, a parametric analysis to determine how temperature and pressure of the organic working fluid as well as the solar collector area affects the electricity production in the solar ORC is performed. Results show that the ORC produces the most electricity during the middle of the day when the temperatures are the highest and when the solar collectors have the highest efficiency. Furthermore, results also indicate that R-236ea is the working fluid that shows the best performance out of the five organic fluids evaluated.