Comparative Analysis of Environmental Sustainability and Performance Indices of Different Gas Turbine Inlet Cooling Systems

Background:  A  thermodynamic  analysis  was  performed  on  the  inlet  air  cooling  system  of  a natural  gas-fueled  turbine  at  the  Afam  power  plant  in  Nigeria.  The  objective  was  to  identify optimal  conditions  for  environmental  sustainability,  performance  output,  fossil  fuel  economy, and cost-effectiveness. Methods:  Three  cooling  methods  were  evaluated:  spray  cooler  with  wetted  media,  fogging system,  and  mechanical  chiller.  Energy,  exergy,  and  exergy-economic  models  for  both  the existing  and  modeled  turbine  units  were  compared.  The  developed  program  source  code indicated  that  both  sustainability  and  performance  indices  improved  when  the  turbine  inlet cooling system adhered to design specifications. Results:   The   refrigeration   method   achieved   the   lowest   inlet   temperature   at   ۱۵   ℃  and   a sustainability index (SI) of ۲.۲۴۳. The SI decreased with increasing ambient temperatures due to higher  total  exergetic  destruction.  Regarding  performance  indices—net  turbine  output,  energy efficiency,  and  exergy  efficiency—the  spray  cooler  had  the  highest  values  at  ۹۸.۸۴۵  WM, ۲۹.۰۵%, and ۲۸.۴۹% respectively. This was followed by the mechanical chiller at ۱۰۰.۶۹۲ WM, ۲۹.۲۵%, and ۲۹.۰۳%, and the fogging system at ۹۸.۶۹۵ WM, ۲۹.۰۳%, and ۲۸.۴۵%. The base system recorded the lowest values at ۹۵.۷۰ WM, ۲۸.۶۹%, and ۲۷.۵۸%, attributed to increased compressor  work.  Both  the  environmental  effect  factor  (EEF)  and  waste  exergy  ratio  (WER) decreased with rising ambient temperature due to total exergetic destruction. conclusion: The refrigeration cooling method is recommended due to its lower inlet conditions, minimal exergy destruction, and high environmental sustainability, performance efficiency, and cost-effectiveness.  Inlet-air  cooling  remains  an  efficient  technique  for  improved  performance.

کلیدواژه ها:

Gas turbine ، Environmental Sustainability ، Performance output ، Cooling systems ، Techno-economy