Gas Turbine Bottoming Cycles: Triple-Pressure Steam Versus Kalina

The performance of a triple-pressure steam cycle has been compared with a single-stage Kalina cycle and an optimized three-stage Kalina cycle as the bottoming sections of a gas turbine combined cycle power plant. A Monte Carlo direct search was used to find the optimum separator temperature and ammonia mass fraction for the three-stage Kalina cycle for a specific plant configuration. Both Kalina cycles were more efficient than the triple pressure steam cycle. Optimization of the three-stage Kalina cycle resulted in almost a two percentage point improvement.