Study Of Thermal Coupling Model And Its Use In Oxygen Enriched Glass Furnace

This thesis systematically reviewed three glass furnace studying methods, especially the numerical simulation method in detail. A thermal coupling model was established according to float glass procedure, linking combustion space and glass tank by heat transfer at the interface, and simplified the simulation of solid batch for the sake of CPU time. Feasibility of thermal coupling model was studied on a 250t/d glass furnace. Results were compared between separated method and thermal coupling method, showing that:(1) thermal coupling method has credible convergence criteria to make its results highly repeatable; (2) thermal coupling method is better at capturing the heterogeneity of heat transfer on the glass surface and has more precise results with respect to separated simulations; (3) thermal coupling method shortens simulation cycle compared with integrated coupling method by simplifying the simulation of solid batch.Furthermore, studying of 5 sets of fuel ratio was carried out on a 250t/d glass furnace using thermal coupling method. (1)Fuel ratio on each port is different between these 5 schemes. The fuel distributions of the first, second, and fourth scheme were symmetry, while in the third and fifth scheme, fuel ratio is different between the north ports and the south ports. In the last two schemes, fuel ratio is higher than that in the first three schemes. (2)The temperature profiles are different between the diverse fuel distributing schemes. Due to the shifting forward in fuel distribution of the last two schemes, temperature of scheme 1,2, and 3 is higher than that of scheme 4 and 5. And as a result of the differences in temperature profile, heat flux of scheme 1,2, and 3 is larger than that of scheme4 and 5. (3) Flow pattern in glass tank is also enfluenced by the temperature profile. Dominant pattern of glass flow in glass tank is circulation. Circulation in the middle of glass tank spreads from solid batch to the end of melter. One two sides of glass tank, direct heating of flame causes sharper temperature gradient, which leads to local convection between glass fluid from the top and the bottom. Curling current is observed from the sides to the middle on two sides of glass tank. In the end of glass tank, existing a circulation near the glass surface, the circulating direction of which is different from the major circulation. Flow pattern in the cooling end is simple circulation. (4)Local convection on two sides of glass tank causes rising flow, studying of which shows that, intensity of rising flow is determined by glass surface temperature. Rising flow in scheme3 is the strongest both on south side and north side. In the second and fourth scheme, the rising flow on the north side is much stronger than that on the south side. As a result, in these two schemes, the comparison of the south side and the north side is different. On the south side:Vz1st>Vz2nd, Vz5th>Vz4th. One the north side:Vz2nd>Vz1st,Vz4th>Vz5th.