Energy, exergy, sustainability, and economic analysis of a waste heat recovery for a heavy fuel oil-based power plant using Kalina cycle integrated with Rankine cycle

In this study, a comparative analysis of the thermodynamic, exergy, economic, and environmental aspects of high-temperature Kalina cycle and the Rankine cycle integrated with the Kalina cycle has been investigated. The Kalina cycle either stand-alone or in combination with the Rankine cycle is examined using the diesel engine waste heat from the Katakhali 50 MW HFO-based peaking powerplant, Bangladesh as the heat source. EBSILON Professional software is used for simulation and finding out various state conditions of the cycle, whereas the engineering equation solver (EES) is used for parametric analysis. Results from this analysis indicate that a combined cycle can provide 348 kW more power output at an electricity cost of only 0.0175 $/kWh than stand-alone Kalina cycle. The combined cycle produces around 4075 kW with 27% and 59% as energy and exergy efficiencies, respectively. Meanwhile, the stand-alone cycle offers 3725 kW with 25% and 54% energy and exergy efficiencies. Economic analysis results show that the combined cycle involves capital costs of approximately $370,000 lower than the stand-alone Kalina cycle, primarily due to its high energy conversion. The payback period for the combined cycle is 1.94 years whereas 2.41 years for the stand-alone cycle. In addition, the combined cycle is almost 60% more environmentally sustainable. The best operating condition for the suggested configurations is set by parametric analysis to determine the high output power with low electricity cost. Finally, it can be concluded that the proposed model can be an effective combined model to generate power by recovering waste heat for the power plants operating in Bangladesh.