Study On The Intensification And Application Of The Convective Heat Transfer Process In The Stirred Tank

Energetic compounds are the basic materials in manufacturing the composite explosives, gun propellant and solid propellant,playing an important role in national defense construction. The synthetic processes of the energetic compounds always involve reactions with high reaction rate, strongly exothermic effect. If the reaction heat can’t be removed quickly, it will cause the reaction heat accumulations and trigger safety problems. In the dissertation, the intensification of the convective heat transfer process in the stirred tank was studied in order to solve the heat transfer problems in the synthetic processes of the energetic compounds. At first, the heat transfer experiments were conducted in the stirred tank reactor with helical coils. Convective heat transfer coefficient values of the outer coil surface were obtained. Then, the heat transfer process in the stirred tank reactor with helical coils was simulated. At last, six scale-up stirred tank reactors for the synthetic processes of the energetic compounds were designed, the nitration tank reactor was simulated and optimized. The main contents are as follows:1. The heat transfer experiment were conducted in the stirred tank reactor with helical coils. The effect of the agitator impeller combination was studied. Convective heat transfer coefficient values of the outer surface of the coil were obtained, which could be helpful for selecting the impellers.2. The unsteady heat transfer process in a stirred tank equipped with helical coils was investigated by using software FLUENT. The temperature field and the heat transfer coefficient were obtained. The convective heat transfer processes for the outer coil surface and the inner coil were simulated include the helical coil thermal conduction. The boundary layer mesh for the coil was generated by means of subsection. The experiment results confirmed the precision of the simulation, and the simulation method is feasible in engineering application.3. The nitration tank reactor used in the scale-up process for the synthetic processes of the energetic compounds was designed, simulated and optimized. The improved nitration tank was proved to work well and reduce the power consumption.4. The other tank reactors used in the scale-up process for the synthetic processes of the energetic compounds were also designed, including the hydrolysis tank, the condensation tank, the mixing tank, the neutralization tank and the pyrolytic tank.