Thermodynamic evaluation of a state-of-art poly-generation system fueled by natural gas and biomass for cooling, power, and hot water generation

Abstract

The principal objective of this study was to conduct a thorough examination of the thermodynamic aspects of an innovative combined poly-generation facility, encompassing cooling load, hot water, and power generation cycles, powered by a combination of natural gas and biomass. A distinctive feature was the incorporation of syngas into natural gas to enhance overall plant performance. The plant design comprised three key subsystems: a gasification and combustion chamber, a double-effect absorption chiller, and a supercritical carbon dioxide cycle. Energy and exergy analyses were employed to systematically evaluate the thermodynamic behavior of the plant. The outcomes revealed that the exergy and energy efficiencies, along with the net power output, were determined to be approximately 35 %, 78 %, and 7422 kW, respectively. Additionally, the produced hot water and the coefficient of performance (COP) of the absorption chiller were estimated at around 14.71 kg/s and 1.209. Notably, the gasifier and combustion chamber emerged as the least efficient components of the system, primarily due to their elevated rates of exergy destruction. Furthermore, comprehensive parametric investigations were conducted to elucidate the influence of key variables on plant performance. The analysis indicated that variations in gasification temperature positively impacted the thermodynamic performance of the plant. Moreover, an increase in combustion pressure led to a notable enhancement in the net power output of the facility.