On The Thermodynamics of Dual Purpose Power Desalting Plants with Gas Turbine.(Dept.M)

Abstract

Recent advances in gas turbine cycles and combined gas/steam turbine cycles are presented. First and second law analysis of gas turbine cycles is presented and shows that substantial available energy (up to 30% of fuel availability) is carried out by gas turbine exhaust gases. This available energy can be utilized for further heat to work conversion or for direct process heating. Heat recoverd from gas turbine exhaust gases in heat recovery steam generator (HRSG) can generate relatively high pressure steam to be supplied to Rankine steam power cycle to form gas/steam power cycle of high efficiency (40-45%). Steam can be generated at low pressure in the HRSG for direct supply to the brine heater of a multistage flash (MSF) desalting system. Possible combination of simple gas turbine cycle or combined gas/steam cycle with reverse osmosis or MSF sea water desalting systems are presented and evaluated. The evaluation indicates that most of these combination are more superior than combination with steam power plants from energy view points.