基于CFD数值模拟的蒸汽喷射器结构研究

Research on structure of steam injector based on CFD numerical simulation

比较分析了管式换热器、板式换热器和刮板式换热器的应用及区别,对用于高黏稠物料蒸煮杀菌的蒸汽喷射装置的原理及应用进行了探讨。基于计算流体动力学(computational fluid dynamics,CFD)的数值模拟方法对不同结构蒸汽喷射装置的速度场、温度场和压力场分布情况进行研究。结果表明,螺旋导柱结构对蒸汽喷射器内部速度、温度场分布有较大影响,螺旋导柱位于混合区中间时喷射器内部温度、速度分布情况优于其位于混合区内部和外部时,蒸汽喷射孔的位置分布对消除原有蒸汽喷射器内部"死区"有明显作用,解决"死区"问题会导致物料流泵送功率有少量增加,但喷射器效率提升相比泵送功率增加更具有实用意义。研究结果为进一步改进蒸汽喷射器结构和提升喷射器的工作效率可提供必要的理论依据。

This paper discussed the applications of paper tube heat exchanger,plate heat exchanger and scraping plate heat exchanger,in order to explore the principles and applications of steam jet device in thermal sterilization for high viscous materials. The velocity field,temperature field and stress field in different steam jet devices were analyzed using Computational Fluid Dynamics （CFD） numerical simulation method. The results showed that the helical guide pillar had a big confluence on the distribution of the velocity field and temperature field in the steam injector. The velocity field and temperature field would have a better distribution when the helical guide pillar was in the center of the dilution zone. Changing the location of the spray-hole was visible to eliminate the“dead zone”in the customary steam injector. The resolving of dead zone will lead to a little increase in transporting power of pump,but the improvement of jet efficiency was more significant than the increase in transporting power of pump. The results could provide necessary theoretical steam injector structure and ejector efficiency improvement .