A Method to Evaluate the Waste Heat Recovery Potential Across the Industrial Sectors

摘要

The energy value of waste heat emissions across all temperature levels in the French industry amounts roughly to 25％of the total industrial energy consumption.Although the theoretical potential of waste heat recovery is widely agreed to be significant,few studies quantify its accessible potential of technically and economically available heat.In addressing this issue,we face both a lack of available data,but also of evaluation methods.This paper proposes a method to evaluate the potential of waste heat recovery on a national level(France)for individual industrial sectors and under consideration of technological and economic constraints.The key idea is to segment waste heat recovery potential into three types.The first type is “avoidable waste heat” through the increase of efficiencies in the production system.The second type is “on-site reusable waste heat” to substitute local heat demand with waste heat.The third type is “off-site reusable waste heat” to supply heating and cooling grids,or to produce electricity.Each type sees its potential field deduced by the previous one.In order to evaluate the potential for “off-site reusable waste heat”,it is crucial to deduce first the “avoidable waste heat”,then the potential of “on-site reusable waste heat”.Industry experts and databases of the French electricity company EDF were used to gather information on energy consumption and waste heat characteristics.The EDF databases contain statistical survey results based on a large sample of industrial sites in France.For waste heat,these databases reveal detailed information on the availability,effluent type and temperature range.To illustrate the method,a case study in the cement industry is presented.By applying the procedure for further industrial sectors,the potential of waste heat recovery will be estimated on a national level.