Thermodynamic Analysis of Cascaded Organic Rankine Cycle for Optimizing Thermal Efficiency

Abstract

Abstract

Power cycles converting medium temperature heat (~300°C) into electricity using working fluids like toluene, benzene etc. result in vacuum on condenser side operating near ambient temperatures. To overcome this, two stage cascaded power cycle is proposed with toluene in the top cycle and R- 245fa as a bottom cycle working fluid. In this scheme, condensation heat of toluene is used as a heat source for R- 245fa. A realistic analysis is performed considering inevitable irreversibilities in turbo-machinery and heat exchangers for various condenser temperatures of toluene. The proposed dual stage cascading cycle requires manageable expansion ratios in top and bottom cycle but at the cost of extra hardware, albeit both the schemes are found to offer identical efficiencies at their optimum operating conditions.

Keywords: Thermodynamic, power cycle, turbo-machinery, toluene, Rankine cycle.

Cite this Article

Sangewar Ravi Kumar. Thermodynamic Analysis of Cascaded Organic Rankine Cycle for Optimizing Thermal Efficiency. Journal of Thermal Engineering and Applications. 2018; 5(3): 30–35p.