Stirred tank reactor is one of the three typical chemical machinery equipments and widely used in petroleum, chemical, pharmaceutical and other industrial fields .It is the basis of understanding the flow of fluid in stirred tank for optimizing design of reactor. This paper aims at the process of suspension polymerization of polyvinyl chloride (PVC) which is an important raw material of chemical production, and uses conventional design method to design the PVC stirred tank of 50m3 from the structure design. According to the fluid dynamics theory, standard K-E turbulent calculation model is established under the function of impeller, the corresponding boundary conditions are listed, and the grid is carried out successfully. And finally the FLOTRAN CFD software is used to simulate the complex flow field and flow pattern according to the multiple reference frame method.

The research of the flow simulation in the inner stirring tank with the single pipe and dual pipe was studied by CFD, which has demonstrated the fluid simulation effect of the single pipe and dual pipe. It has found that the effect is better in the single pipe stirring tank than the dual pipe one. Basing on this result, the flow simulation effect of dual pipe is better than the single one, and the result has a certain practical significance effect on industry.

The peak of power consumption will be brought by the rapid development of the industry. Thermal power is still the main component of electric energy at present. More and more attention has been paid on the atmospheric pollution caused by the thermal power plant in our country. The sulfur dioxide (SO2), one of the thermal power plant flue gases, is dangerous to the environment and human. Effective SO2 control technology can not only reduce the environmental pollution but also the sulfur can be recovered in order to conserve resources.

In view of the importance in the national industry of PVC,the subject of the PVC polymerization stirred tank uses finite element analysis software (ANSYS) of the thermodynamic analysis,mainly for the temperature field analysis.By observing the displacement vector image and temperature,the heat transfer capacity is enough, and the heat transfer component selection is reasonable.