In the field of steel processing, such as steel works or foundries, huge amounts of waste heat arise from steel processing in furnaces, casting installations or in rolling mill equipment. On base of these applications it is shown, how unused waste heat can be recuperated and which conventional strategies already exist for this purpose. However, the investment amount for such systems is substantial and the time for the return of investment is still too long for this industry branch.
The aim of this feasibility study was to investigate, if commercially available thermoelectric converter (TEC) modules are suitable to recuperate electricity from waste heat. On base of single TECs (<10W) up to small systems (<1kW), fundamental aspects, materials and resulting possibilities and applications are discussed and an integrated concept is presented. Furthermore, the necessary engineering of commercially available modules for modular 1kW system is elaborated, which can be scaled up to the aimed 50kW system.
The presented system solution comprises 19 single 1kW modules and represents a compromise between system size, module efficiency and controllable engineering. To reach the target aim of 50kW, three of such systems have to be combined.
The fundamentals for the selection of materials and modules, heat transfer, cooling, serial or parallel electrical connections, thermodynamic possibilities for the system dimensioning, planning, and assessment as well as safety precautions and thermomechanical considerations are described and evaluated. On base of this a commonly applicable simulation a tool is set up, from which the properties of TEC modules can be simulated.