Against the background of increasingly stricter national and international climate protection regulations, the energy-intensive container glass industry in Germany must reduce its energy consumption and CO2 emissions. In addition, energy prices are rising and the availability of natural gas as a fuel is partially limited.
The "ZeroCO2Glas" research project, funded by the German Federal Ministry for Economic Affairs and Climate Action, is addressing this issue: Within the scope of the project, a highly flexible pilot glass furnace for the CO2-neutral production of container glass is being developed and commissioned. The hybrid-heated furnace generates its melting capacity through the oxyfuel combustion of hydrogen and electrical heating with six pairs of electrodes. Conventional container glass furnaces operate at 12 to 20% of their melting capacity with electrical heating. The pilot furnace, however, allows the level of electrical heating to be flexibly varied between 20 and 80%. The increased electric power affects the flow of the glass melt in the area of the electrodes and therefore the residence time of the glass particles in the furnace. This can have a significant impact on the quality of the finished container glass product.
Due to the high temperatures and poor accessibility, the ability to analyse the melt flow in the pilot tank is very limited. For this reason, a simpler and more cost-effective method of investigation was used: In order to simulate the melt flow, a CFD model of the lower furnace of the pilot plant was developed to simulate the melt flow. The numerical model allows setting different electrical power/ burner power ratios in order to investigate their influence on the glass melt flow. In the presentation, the simulation results of the limit cases 20%/80% and 80%/20% will be presented and compared.