The Application of ORC Systems for Waste Heat Recovery in Metal Smelting Industry

orc2019 Tracking Number 97

The metal smelting industry is characterized by significant emission of waste heat. This applies to both ironworks and non-ferrous smelters. In various technological processes related to the processing of metal ores, waste substances (in the form of liquids and gases) are released. These include cooling water and oils, slag disposal, throat gas, blast furnace gas, converter gas and other waste gases. Significant amounts of waste heat are also emitted from smelting products (castings, etc.). At different stages of metal production, different waste heat carriers are emitted at the different temperature and capacity levels. The assessment of the applicability of the heat source for the heat recovery requires a multi-aspect analysis of the heat source's characteristics as well as chemical aggressiveness and contamination of the carrier. In many cases, waste gases are containing components which are harmful and aggressive to construction materials. Moreover, the capacity of these gases is often floating. Due to the high power of waste heat sources generated in metal processing industries, ORC systems are promising for heat recovery application. The article presents an analysis of the applicability of ORC systems for waste heat recovery in this branch of industry. The output and thermal characteristics of generated waste heat sources are comprehensively discussed in first part of this paper. The thermal power of these sources is then determined and the calculation models of ORC systems dedicated to waste heat recovery from these sources are proposed. Model calculations were carried out and the results of modelling on the ORC systems operating parameters and their performance are presented in this article. Modelling was carried out for various working fluids with a vaporization temperature appropriate for the temperature range of the different heat sources. The results of the analyses indicate that the potential of waste heat sources generated in smelting industry is significant and ORC system is a promising technology for application in this branch of industry.