Flow Pattern Construction-based Transport Process Intensification And Its Applications

The performance of a chemical process(system)is closely related with the internal structure of the chemical production equipment,thus structure optimization is an important and effective way for process intensification.The internal structure has a decisive impact on the transport phenomena which contribute to the chemical process performance,and,consequently,a crucial factor concerning with the structure optimization is the transport phenomena construction.In the present study,the construction of transport phenomena,including moment transfer(fluid flow),heat transfer(heat conduction and convective heat transfer)and mass transfer(mixing),has been investigated using a flow pattern construction-based approach,a general and novel concept for process intensification.Firstly,the mathematical model for the purpose of minimizing the viscous dissipation has been established and applied to the flow drag reduction.The solution of the model,namely,an optimal flow pattern with minimum viscous dissipation(mechanical energy loss),is obtained using variational calculus.After the flow pattern construction,the porous media model and Volume of Fluid model has been employed to generate a streamlined flow passage with a reduced pressure drop,according to the constructed flow pattern.Secondly,the mathematical model for the purpose of heat transfer entropy generation extremum has been established and applied to the “area to point” heat conduction intensification.The solution of the model,namely,an optimal distribution of thermal conductivity,is obtained using variational calculus.After the conductivity field construction,a temperature gradient-based design method has been employed to generate an efficient conductive path which contributes to an improved thermal performance.Thirdly,the mathematical model for the purpose of heat transfer entropy generation extremum has been established and applied to the tubular heat exchange intensification.The solution of the model,namely,an optimal flow pattern with improved heat transfer performance,is obtained using variational calculus.After the flow pattern construction,the porous media model and Volume of Fluid model has been employed to generate an enhanced heat transfer tube with a higher heat transfer coefficient,according to the constructed flow pattern.Finally,a quantity describing the synergy effect of a mass transfer system has been proposed via an analogy between the gas-liquid interfacial mass transfer and the heat-work conversion.After that,the mathematical model has been established in terms of mass transfer synergy,and applied to the mixing intensification.The solution of the model,namely,an optimal flow pattern with improved gas mixing performance,is obtained using variational calculus.After the flow pattern construction,a velocity-based design method has been employed to generate a mixing device with an improved mixing effect.In terms of chemical production process,the transport phenomena construction builds the bridge between the transport process intensification and internal structure optimization.By establishing and solving the mathematical model,the phenomena with best transfer performance have been constructed,after that the internal structure has been optimized to intensify the transfer process according to the constructed phenomena.