Evaluating and improving the efficiency of steam power plants using chillers

¹ Department of Mechanical Engineering, University of Guilan, Rasht, Iran
² School of Industrial Engineering and Centre of Excellence for Intelligent Based Experimental Mechanics, College of Engineering, University of Tehran, Tehran, Iran

^a Corresponding author: Hadizadeh.a@gmail.com

Received: 16 January 2016
Accepted: 3 June 2016

Abstract

One of the indispensable technologies to produce electricity with high efficiency is using absorption cooling system instead of mechanical vapor compression (MVC) cooling system. In this paper, firstly heating and cooling loads are calculated for experimental model development for combined cycle power plant of Parehsar, located in province Guilan. Then according to this model, thermal energy needed for heat supporting of absorption thermal generator is computed and the appropriate chiller is chosen in order to secure cooling of model spaces. In addition, for the actual case study, the portion of generated low and high pressure steam of heat recovery steam generator (HRSG) and Turbine is investigated for the absorption chillers used in residential space cooling of power plant. Results indicate that the steam extraction of HP-Turbine approach is more effective than the other approaches for improving the power planet energy efficiency. In addition, parametric study indicates the effects of different parameters, such as steam to gas mass flow rate ratio, fraction of steam extraction from the exhaust of LP line in HRSG for the generator of absorption chillers and inlet LP and HP steam turbine temperature on the performance of present power plant. Finally, the relative advantage of using absorption cooling over mechanical vapor compression (MVC) cooling in combined cycle power plant and its role in improvement of power plant efficiency is demonstrated.