Thermodynamic analysis of an externally fired Gas turbine (EFGT) combined cycle with biomass gasification

A thermodynamic analysis of combined cycle Integrated with Biomass Gasification plant has been performed based on energy balances in a proposed configuration. In this work, we choose paper as a fuel, thermal performance and sizing of such plants have been analyzed at various cycle pressure ratio (rp= ۷-۱۲), gas turbine inlet temperature (TIT = ۱۲۰۰–۱۴۰۰ K) and the heat exchanger cold end temperature difference (CETD = ۲۴۵–۲۷۵ K). It is observed that the thermal efficiency of the plant increases with pressure ratio depending upon the TIT and heat exchanger CETD to a maximum value. For a particular pressure ratio, thermal efficiency increases with the increase in TIT and decreases with the increase in heat exchanger CETD. The specific air flow, which is attributed to the size of the plant components, decreases with the increase in pressure ratio. This decline is sharp at the lower pressure but slowing at higher pressure ratio values. An increment in the TIT reduces the specific air flow. The specific steam flow, which is attributed to the size of the steam cycle components, increases with the increase in pressure ratio.

Keywords:

biomass , gasification , externally fired gas turbine , HRSG , thermal efficiency , exergy