Applying different optimization approaches to achieve optimal configuration of a dual pressure heat recovery steam generator

Abstract

SUMMARY The optimal design for heat recovery steam generator (HRSG) should be chosen based on technical and economic considerations. Therefore, parameters that are related to thermodynamic and economic aspects should be considered in optimization approaches. It is worth mentioning that one of the significant issues in the HRSG design is the diversity of arrangements between various components (economizer, evaporator, and superheater), which absolutely affect the HRSG performance. According to these facts, in the present article, different arrangements of a dual pressure HRSG are analyzed, and the economizer at the high‐pressure level is divided into two parts; these arrangements are optimized by applying different optimization approaches to achieve the optimal configuration. These approaches include the reduction of gas pressure drop, the reduction of generated steam cost and the consideration of both approaches as the third approach. These three approaches are also considered to perform economic and thermodynamic optimization. With regard to the limitations of optimization such as the pinch and approach point, seven different configurations are considered. First, a comprehensive model is developed for calculating thermodynamic, heat transfer, and pressure loss. To perform a thorough optimization, both thermodynamic and geometric variables as well as diversity of various arrangements is considered using genetic algorithm. The results of the optimization study show that the best arrangement is not unique, and each arrangement has different characteristics. Hence, the best arrangement for the HRSG is chosen according to the importance of the objective functions. Copyright © 2012 John Wiley & Sons, Ltd.

Multiobjective optimization design of the solar field and reverse osmosis system with preheating feed water using Genetic algorithm

“…The optimization parameters along with their allowable bounds are expressed in Table . The selected lower and upper bounds are according to previous studies …”

Investigation on the off-design performances of flue gas pre-dried lignite-fired power system integrated with waste heat recovery at variable external working conditions

“…Moreover, the impact of various external working conditions, involving the power load, ambient temperature and raw lignite compositions, on the performance of the power system were examined. The obtained data in the present work would provide the necessary information for further research of the FPLPS, such as exergy based analyses [28,29] and system optimization studies [30].…”

Thermal simulation of superheaters taking into account the processes occurring on the side of the steam and flue gas

“…In and Lee presented a simple method to find the optimum evaporation temperature of single stage HRSG systems under steady -state operating conditions. In both papers [29,30] simple models of heat exchangers were used in the thermodynamic analysis of the boiler. The method proposed in the work [30] can be used in optimization to perform heat exchanger calculations with greater accuracy.…”

“…In both papers [29,30] simple models of heat exchangers were used in the thermodynamic analysis of the boiler. The method proposed in the work [30] can be used in optimization to perform heat exchanger calculations with greater accuracy. Higher accuracy of the steam and flue gas temperature calculations would allow more accurate identification of pinch and approach points that are the most important performance parameters of an HRSG [30].…”

“…In and Lee [29] and Esmaieli et al [30] optimized heat recovery steam generators (HRSG). Various optimum configurations of heat transfer surfaces were proposed by changing the positions of economizer, evaporator, and superheater [29].…”