Effect of ambient temperature on the performance of micro gas turbine with cogeneration system in cold region

Abstract

Abstract A small-scale prime mover especially micro gas turbine is a key factor in order to widespread the utilization of biogas. It is well known that a performance of large-scale gas turbine is greatly affected by its inlet air temperature. However, the effect of the inlet air temperature on the performance of small-scale gas turbine (micro gas turbine) is not widely reported. The purpose of the present study is to investigate the effect of the inlet air temperature on the performance of a micro gas turbine (MGT) with cogeneration system (CGS) arrangement. An analysis model of the MGT–CGS was set up on the basis of experimental results obtained in a previous study and a manufacturer standard data, and it was analysed under a various ambient temperature condition in a cold region. The results show that when ambient temperature increased, electrical efficiency ηele of the MGT decreased but exhaust heat recovery ηehr increased. It was also found that when ambient temperature increased, exhaust heat to mass flow rate Qexe/me and exhaust heat recovery to mass flow rate Qehr/me increased, with maximum ratios of 259 kJ/kg and 200 kJ/kg, respectively were found in summer peak. Furthermore, it was also found that the exhaust heat to power ratio Qexe/Pe had a similar characteristic with exhaust heat recovery to power ratio Qehr/Pe. Qexe/Pe and Qehr/Pe increased with the increase of ambient temperature. Moreover, although different values of total energy efficiency, fuel energy saving and CO2 reduction for every temperature condition were found comparing with a two conventional system that were considered, the MGT–CGS could annually reduce 30,000–80,000 m3/y of fuel consumption and 35–94 t-CO2/y of CO2 emissions.