Performance evaluation of a renewable source integrated power generation system coupled with heat storage

In this study, a novel integrated power generation system is developed and investigated which uses a combination of the Rankine cycle as the topping cycle and the Kalina cycle as the bottoming cycle. The plant is designed to operate under two modes of operation, which are charging mode and discharging mode, and hence the plant also integrates a storage facility. The synthetic organic oil Therminol, VP1 is employed as heat transfer and heat storage media. Both modes of operations are simulated in the industrial software Aspen Plus, and a thermodynamic analysis, including the energy and exergy assessments of both modes, is performed in the Engineering Equation Solver (EES). Several sensitivity analyses of various key variables are also presented. At 60 % concentrated ammonia -water mixture, the power production gets to its first peak and produces around 3263.30 kW of power. The net energetic performance of charging and discharging modes is found to be 51.08 and 49.30 % respectively, while the exergetic performance of charging and discharging is found to be around 88.1 and 85 % respectively. When the charging temperature is decreased to 200 degrees C, the overall energy-to-exergy efficiency ratio is decreased by 29.50 %. It is found that during the charging cyclic mode, the topping and bottoming cycle are responsible for around 73.12 % and 26.9 % of the total exergy destruction, while during the discharging mode of operation, high -temperature recuperator accounts for 21.71 % of exergy destruction. The results of the environmental impact and sustainability assessment studies demonstrate a net specific water footprint of around 1.93 L/kWh.