Effects of different simulation models on pyrolysis performance predictions for regenerative cooling applications

摘要

The one-dimensional plug flow reactor (PFR) model is commonly used in regenerative cooling simulations. However, the extreme operational conditions in regenerative cooling channels may affect the predictive accuracy of PFR, in which the effects of turbulent flow and heat transfer were not considered. In this study, we compared the chemical reaction predictions from PFR and Computational Fluid Dynamics (CFD) in regenerative cooling channels, and studied the effects of the main operating conditions on predictive accuracy, namely: pressure, flow rate, and heat flux. Experiments were performed to validate the CFD model and illustrate the predicative deviations in PFR under different operating conditions. Additional simulations with special operational conditions were also carried out to analyze the key factors. Results revealed that turbulence and radial temperature heterogeneity caused by turbulent flow and convective heat transfer influenced the pyrolysis predictions in different ways. The intensities of the two competitive effects changed with the operating conditions, which affect the accuracy of PFR model. Besides, the importance of heat transfer effects was emphasized in predicting the changing regularity of heat sink. This work is expected to provide novel understandings of reacting flow to engineering applications.