A novel high-performance low-NOx fuel-rich/fuel-lean two-stage combustion gas and steam turbine system for power and heat generation

Abstract

This paper proposes, describes, and analyses a novel high temperature and performance reheat gas turbine (GT) cogeneration system. This newly proposed system employing two-stage fuel-rich and fuel-lean combustion system is named as the ‘Fuel Rich-Lean Combustion Reheat GT Cogeneration System’ (RLCC). Energy and exergy analyses (the latter mainly to evaluate and demonstrate the reduction in exergy loss of this combustion process compared with conventional single-stage and fuel lean-lean combustion) of the proposed cogeneration system were performed and compared with a conventional cogeneration system. The proposed RLCC system is predicted to have an overall power generation efficiency of up to 53.0 per cent (low heating value (LHV) basis), exergy efficiency up to 61.9 per cent, and specific power up to 524.3 kJ/kg. Compared with a conventional cogeneration (CGC) system, its energy utilization efficiency was as high as 95.0 percent, 4.0 percentage points higher than that of the CGC system, the overall power generation efficiency was higher by 6.2 percentage points, and the exergy efficiency was higher by 7.8 percentage points, and the overall power-based NO x emissions was reduced by up to 34.0 per cent.