Comparison of ORC and Kalina cycles for waste heat recovery in the steel industry

摘要

This paper presents the results of a comparative study of waste heat recovery systems based on the Organic Rankine Cycle (ORC) and Kalina Cycle (KC) that could be applied to the steel industry. The simulations were performed for an electric arc furnace (EAF) steel mill and waste heat recovery system with saturated steam as a heat carrier. Commercial software ASPEN-HYSYS? was used to calculate system performances under different loads for ORC with different working fluids (butylobenzene, n-hexane, n-pentane) and for KC. Each case was optimized for maximum system efficiency. In terms of net system electric efficiency and electric power output, under nominal operating conditions similar performances were obtained for ORC with n-pentane working fluid and KC based systems. The highest system efficiency was observed for ORC with butylobenzene as working fluid, whereas the KC becomes competitive versus ORC for heat carrier temperatures of 200°C and above.