Design and operation of a heat recovery steam generator with minimum irreversibility

Thermodynamic analysis based on the minimisation of entropy generation is applied to the optimal design and operation of a heat recovery steam generator (HRSG) generating saturated steam for a combined gas and steam power cycle. The results show that: (i) an optimal saturation temperature exists for least irreversible operation of an existing HRSG with specified exhaust gas from the gas turbine of the 'topping' cycle; (ii) operating the HRSG at the maximum load reduces entropy generation; (iii) increase in the number of transfer units of the evaporator or the economiser of the HRSG beyond certain 'cut-off' values will have marginal benefit with respect to entropy generation. Copyright (C) 1997 Elsevier Science Ltd.