Study On Heat Transfer And Safety Design Of The Stirred Tank For Strongly Exothermic Reaction Process

Energetic compounds are key materials for the development of advanced weaponry, playing an important role in national defense construction. They can act as not only rocket and missile propellants, but also power energy for damaging. The production process of energetic compounds always involves reactions which are large and rapid exothermic. During the strongly exothermic reactions process, it is easy to run away and be out of control. Therefore, the reactors for these reactions should be designed with higher standards. In this dissertation, the heat transfer process in the stirred tank was researched by both experiment method and CFD simulation method. Then a reactor for the strongly exothermic reaction was designed based on the conclusions from experiments and simulations. The main contents are generalized as follows:1. Coils are the key part of heat transfer process. Experiments in stirred tank with coils of five different screw pitches were conducted. The temperature was measured in six different rotation speed to calculate the convective heat transfer coefficient values. These data can be the reference of design and the basis for the subsequent simulations.2. The experiment processes were simulated by a CFD software named FLUENT. In order to get more close to reality with less computation space, a staging strategy was applied. The main idea of this method was to do the simulation in key temperature and average the results. During the meshing, coils were split into several sections to avoid skew. The simulation results were compared with experiment results in two aspects-outlet temperature of coils and heat transfer coefficient values of the outer surface of coils. The method was demonstrated to be reliable.3. In order to investigate the effects of structural parameters on heat transfer coefficient values, several simulations were conducted through the method. Conclusions in diameter of impellers, coiled diameter, double coils and double impellers were obtained to serve as the reference for design and the direction of future experiment research.4. A reactor for diazotization reaction was designed based on both the conclusions and the standards in design handbooks. Recently, the reactor was put on production and operated well.