DefinePK

Abstract

This study presents a detailed thermodynamic analysis of a solar-powered poly-generation system employing parabolic trough collectors. The system integrates an organic Rankine cycle (ORC) for power generation, a multiple-effect distillation (MED) unit for desalination, and a Vapor Absorption Refrigeration Cycle (VARC) for cooling. The analysis is performed by solving the mass, energy, and exergy balance equations for all system components, utilizing technical specifications of the subsystems and the thermodynamic properties of the working fluids. A computer model was developed and validated for this purpose. The performance of the poly-generation plant was evaluated under the climatic conditions of Lahore, Pakistan, across a range of operating parameters. System performance was assessed using multiple indicators: the Energy Utilization Factor (EUF), Artificial Thermal Efficiency (ATE), Fuel Energy Saving Ratio (FESR), and Exergy Efficiency.  The primary results indicate that the EUF, ATE, and FESR trends correlate strongly with solar irradiance, peaking at midday. In contrast, the exergy efficiency was lowest at midday due to increased irreversibility from high temperatures. The EUF consistently recorded the highest values among the metrics. All performance parameters demonstrated higher values during the summer compared to the winter. The maximum instantaneous outputs for the winter day were 506 kW, 1061 kW, and 1628 kW for power, cooling, and desalination heat, respectively, which were surpassed by the summer day outputs of 558 kW, 1350 kW, and 2063 kW. Furthermore, freshwater production reached peaks of 6 kg/s in winter and 7.6 kg/s in summer.