Experiment and optimization of a new kind once-through heat recovery steam generator (HRSG) based on analysis of exergy and economy

Abstract

In this work, we proposed a novel once-through heat recovery steam generator (HRSG) which could be used for low temperature heat resource recovery. Experiments have been done in a cement plant under different conditions to study its thermal performance. Exergetic and economic analyses of the HRSG have been performed. We also built a mathematical model based on the energy and mass balance equations. Moreover, a flash tank is implemented in this study and optimized researches are carried out to find the best exergy efficiency of the HRSG. Multiple sets of optimized results are compared and experiments have been done to show the rationality of the model. Results show that the HRSG is highly efficient in recovering energy from low temperature heat source. Higher feed water flow rate is more suitable for the working conditions than the lower one. When the flow rate is around 16m3/h and the diversion water temperature is around 413K, the highest exergy efficiency of the generating system and the HRSG can be up to 44.43% and 54.61%, respectively. The economic analysis result shows that annual income can be 121,242€ and the construction cost can be recovered in 1.1years.