Design and multi-aspect analysis of a geothermal and biomass dual-source power, cooling, heating, and hybrid freshwater production system
Zhenhai Dou, Yunhe Zou, Amir Mohebbi
Abstract
This paper introduces an innovative hybrid system integrating renewable biomass and geothermal energy sources to address contemporary technological and environmental challenges. The proposed system enhances geothermal power plant operations by utilizing biomass combustion products for superheating the steam turbine's inlet stream. Additionally, it incorporates a modified Kalina cycle , flash desalination , and a multi-effect desalination subsystem to efficiently utilize the geothermal plant's waste heat, enabling the simultaneous production of power, heating, cooling, and freshwater. The system's performance is assessed through a combination of thermodynamic and economic analyses. A parametric study investigates the influence of four critical decision parameters on system operations. Moreover, a multi-objective Particle Swarm Optimization algorithm, coupled with a LINMAP decision-making approach, is employed to identify the system's optimal operational state. Results indicate that the system can generate 776.3 kW of power, 237 kW of heating, 15.5 kW of cooling, and 20.35 kg/s of freshwater. This operation mode yields an exergy efficiency of 19.61 % and an economic benefit of 2.78 M$, highlighting the system's dual efficiency and profitability. The performance is significantly influenced by the effectiveness of Heat Exchanger 1. Optimal system performance, characterized by an exergy efficiency of 20.55 % and a payback period of 5.21 years, is also achieved. These findings underscore the system's potential in sustainable energy production and resource optimization.