Biomass energy conversion in EFGT (Externally Fired Gas Turbine): an experimental-numerical analysis

摘要

Biomass is one of the most significant options to generate electric power from distributed renewable sources. This may be of particular interest in countries like Italy, due to the relatively large abundance of wood, coming directly from both the agricultural sector or from wood-based industrial sectors, and for the strict dependence on foreign fossil sources. In such a context, the availability of economically sustainable technologies is the key issue, as the optimal size of a single power plant mayresult to be in the low power range (100-500 kW) mainly reflecting the impact of the fuel logistic chain on system economics. In this range the possibility of combining heat deployment to power production is instrumental as it allows for having maximumexploitation of the fuel potential. Furthermore, flexibility to fuel type may also represent a powerful feature as it allows the use of available local fuel quantities which may even derive from residues of other processes. In this paper a technology based on an externally fired gas turbine fed by woody biomass is presented in the 100 kW power range. The multifuel prototype power plant which has been realized and experimentally demonstrated at the University of Rome Tor Vergata is described. A model isalso presented to better understand the impact of fuel properties on performance by analyzing every single component of the power plant (i.e. furnace, heat exchangers, turbomachinery, etc). Moreover possible economic and management model are described and used to better assess the economic sustainability of the solution depending on the characteristics of the fuel (fuel-end), matched with the utilization pattern (user-end) especially in terms of thermal/heat power values over the year.