不同条件下陶瓷金属化瞬态温度场的计算

Simulation of Transient Temperature Field in Metallization Hydrogen Furnace

目前工业生产中,陶瓷金属化工艺条件的选择大多是经验性设定,对其如何影响金属化过程缺乏认识。针对于此,本文在前期所建立的陶瓷金属化氢炉的瞬态温度场计算模型基础上,考虑辐射和对流作用,计算陶瓷金属化过程中炉内的流动与传热问题,着重讨论了陶瓷件数量、氢气流量等条件对陶瓷金属化氢炉温度场的影响关系。结果表明,陶瓷件数量对同一位置金属化层最高温度影响较小(<2℃),但对炉温均匀性影响很大,不同位置陶瓷金属化层温度相差达到几十摄氏度。炉内加热一段时间后出现温度统一区(z<0.45 m),这一区域内的陶瓷金属化层最高温度几乎不受氢气流量的影响,金属化质量具有更好的一致性。

The transient temperature field inthemetallization hydrogen furnace was mathematically modeled, theoretically analyzed and numerically simulated. The impact of the realistic situation, including the heat flow con- vection and radiation, H2 flow rate, number and locations of ceramic workpieces, on the temperature field was inves- tigated, As expected ,the heat convection of H2-flow strongly improves the uniformity of temperature field ,especially in the initial heat-up stage. In the holding time （ or the steady stage） of the metallization temperature, some areas with uniform temperature distribution emerge （z 〈 0. 45 m）, where depending weakly on the H2-flow, the highest temperature meets the requirement of metallization. The simulated results show that while strongly worsening the uni- formity of the temperature field,with AT, of the different loading-boards up to 27℃ ,the workpiece number on the same loading board little affects the highest temperature （ △T 〈 2℃ ） there.