Latest improvement in ORC WHR system for the energy intensive industry: the case of glass

摘要

Waste Heat Recovery (WHR) systems are nowadays common solution for the energy intensive industry to increase energy efficiency. Their demand is growing under the commitment of the companies and the constraints given by government directives to reduce energy consumption, CO2 emissions as well as operating costs. Organic Rankine Cycle technology is a common choice being utilized to produce electricity from waste heat generated by industrial processes, such as the glass melting furnace. This technology has proven to give higher efficiency above all for lower temperature applications as well as more flexibility and competitive capital costs. Latest R&D improvements involved the ORC technology through the introduction of the innovative Radial Outflow Turbine (ROT). This new turbine configuration, converting the energy of the organic fluid with higher efficiency than the axial or radial inflow turbine in an ORC system, has given a major opportunity to minimize economic investment for a WHR system whilst increasing efficiency and profitability of the industrial production. This paper presents and discusses this ORC innovative technology and how it has been successfully applied in a heat recovery system for a glass mill, providing an evaluation of the benefit as improved payback period, energy savings, depending on the number of operating hours per year, and of the consequential decrease in CO2 emission and electricity expenditure.