OPEN ACCESS
In the last two decades, big efforts have been addressed to investigate new technologies for emissions abatement and oil dependence reduction. Among these, technologies focused on heat recovery from thermal processes or using low grade heat as energy source (i.e. geothermal, solar), have been gained big attention by the scientific community.
In this paper, a small Organic Rankine Cycle (ORC) plant was tested under different operating conditions and by using refrigerants (R245fa) as working fluids. During these first operational tests the plant was operated only in regenerative layout (i.e. heat from hot fluid coming out of the expander, was partially recovered in the regenerator to preheat liquid fluid at the pumping outlet section). The performances of each of them (first law efficiency, exergy efficiency) were evaluated by imposing the expander inlet temperature and the electrical load at the generator. A simple mathematical model, was also used to predict the reference value of each of the parameter investigated.
ORC, low grade heat recovery, scroll expander, refrigerant
[1] Feng YQ, Hung TC, He YL, et al. (2017). Operation characteristic and performance comparison of organic Rankine cycle (ORC) for low-grade waste heat using R245fa, R123 and their mixtures. Energy Conversion and Management 144: 153–163. http://dx.doi.org/10.1016/j.enconman.2017.04.048
[2] Piero Colonna, Emiliano Casati, Carsten Trapp and et al. (2015). Organic rankine cycle power systems: from the concept to current technology, applications, and an outlook to the future. Journal of Engineering for Gas Turbines and Power 137: 100801-1-100801-19. https://doi.org/10.1115/1.4029884
[3] Campana F, Bianchi M, Branchini L, et al. (2013). ORC waste heat recovery in European energy intensive industries: Energy and GHG savings. Energy Conversion and Management 76: 244-252. https://doi.org/10.1016/j.enconman.2013.07.041
[4] Wang K, Seth R. Sanders, Swapnil Dubey, Fook Hoong Choo, Duan F. (2016). Stirling cycle engines for recovering low and moderate temperature heat: A review. Renewable and Sustainable Energy Reviews 62: 89-108. https://doi.org/10.1016/j.rser.2016.04.031
[5] Aranguren P, Araiz M, Astrain D, Martínez A. (2017). Thermoelectric generators for waste heat harvesting: A computational and experimental approach. Energy Conversion and Management 148: 680-691. https://doi.org/10.1016/j.enconman.2017.06.040
[6] Zoltán Varga, Balázs Palotai. (2017). Comparison of low temperature waste heat recovery methods. Energy 137: 1286-1292. https://doi.org/10.1016/j.energy.2017.07.003.
[7] Pradeep Varma GV, Srinivas T. (2017). Power generation from low temperature heat recovery. Renewable and Sustainable Energy Reviews 75: 402-414. https://doi.org/10.1016/j.rser.2016.11.005
[8] Macchi E. (2017). Theoretical basis of the organic Rankine Cycle, in Organic Rankine Cycle (ORC) power system. Technologies and Applications, WP Woodhead Publishing – Elsevier 3-22.
[9] Muhammad Imran, Fredrik Haglind, Muhammad Asim and Jahan Zeb Alvi. (2018). Recent research trends in organic Rankine cycle technology: A bibliometric approach. Renewable and Sustainable Energy Reviews 81: 552-562. https://doi.org/10.1016/j.rser.2017.08.028