DOI: 10.36347/sjet.2018.v06i12.010

Pages: 432-443

Comparative exergo-environmental analysis of simple and regenerative cycle gas turbine plants was carried out in this work using PG 6581 B gas turbine engine operated by a company in the Niger Delta area of Nigeria as a case study. A gas turbine engine model was created for the analysis using in-house software and the first and second law analyses were applied to both plants. The environmental sustainability indicators of both plants (depletion factor for each component, environmental sustainability index, waste exergy ratio, and environmental effect factor) were investigated. The regenerative cycle plant was analyzed exploiting regenerative effectiveness values of the regenerator between 80% and 100%, but, all the results for the regenerative cycle presented here were obtained at 80% regenerator effectiveness, the lowest value used. The thermal efficiency of the simple cycle plant is 35.19% but that of the regenerative cycle plant is 43.65% at 80% regenerative effectiveness. The second law efficiency of the regenerative cycle plant is 40.85% as against that of the simple cycle plant which is 32.93%. The exergy destruction in the combustion chamber is the highest in both cycles but the value is lower in the regenerative cycle and it decreases with increase in the regenerative effectiveness. The environmental sustainability index which indicates how sustainable the environment is with respect to engine operation for the simple cycle is 1.32 while that of the regenerative cycle is 1.43. Smaller values of the waste exergy ratio and the environmental effect factor indicate safer environment from engine operation but both of these values are greater in the simple cycle plant. The regenerative cycle plant is thus more favourable to operate in both engineering performance terms and in terms of environmental sustainability.