Volume 10: Sustainable Energy Solutions for Changing the World: Part II

Application of pinch analysis in waste heat recovery system of slag dry centrifugal granulation Ningwen Xu

Abstract

The liquid slag of 1450oC has a massive output in the iron and steel industry, and its efficient recovery is an important measure to achieve energy saving and consumption reduction. At present, centrifugal granulation has become an essential means to recover high-temperature waste heat in the iron and steel industry. The recovery rate of waste heat and the reduction of energy consumption are the indexes to judge the system’s advantages and disadvantages. The pinch analysis can optimize the heat recovery system and reduce energy consumption by calculating thermodynamically feasible energy targets (or minimum energy consumption). Aiming at the problem of waste heat recovery in the slag centrifugal granulation system design, the problem table method in pinch analysis method was used to analyze the design system’s data to optimize the heat recovery system. This paper presented the corresponding material balance and energy balance and used the heat cascade table to extract and analyze the cold and hot material flows. Finally, the pinch temperature was 145oC. The utility system can be designed to provide the minimum heating and cooling heat of 20895.74kJ/s and 1108.75kJ/s respectively to achieve the function of energy saving and consumption reduction

Keywords slag, process system, pinch analysis