This criterion is based on the occurrence of an extremum of hot spot parameters with respect to any of the input parameters of the reactor. The critical operation trajectory, the critical isoconcentration curve and th...This criterion is based on the occurrence of an extremum of hot spot parameters with respect to any of the input parameters of the reactor. The critical operation trajectory, the critical isoconcentration curve and the supercritical operation trajectory are defined. Applying the relationship between the hot spot of the critical operation trajectory and the inflection point of the supercritical, an approximate expression of the critical inlet conditions is derived. The computed results show that the influence of the cooling medium on the parametric sensitivity region is related to the heat capacity ratio α. And the greater α is, the more sensitive the reaction systems would be.展开更多
The discrepancy between pseudo-homogeneous one-dimensional model and pseudo-homogeneous two-dimensional model is studied. It is found that there are great differences between two models. This paper compares the maximu...The discrepancy between pseudo-homogeneous one-dimensional model and pseudo-homogeneous two-dimensional model is studied. It is found that there are great differences between two models. This paper compares the maximum and minimum values of the radial temperature in the hot spot in case that a single exothermic reaction is carried out, a correlation is obtained with pseudo-homogeneous one-dimensional model to describe the entire reactor behavior. A new runaway criterion, based on the occurrence of inflection in the hot spot locus, is developed for the case of pseudo-homogeneous two-dimensional model. This criterion predicts the maximum allowable temperature for safe operation and the regions of runaway, respectively. The calculated results show that, compared with the results based on pseudo-homogeneous one-dimensional model, runaway will easily occur when the radial temperature gradient has to be considered.展开更多
文摘This criterion is based on the occurrence of an extremum of hot spot parameters with respect to any of the input parameters of the reactor. The critical operation trajectory, the critical isoconcentration curve and the supercritical operation trajectory are defined. Applying the relationship between the hot spot of the critical operation trajectory and the inflection point of the supercritical, an approximate expression of the critical inlet conditions is derived. The computed results show that the influence of the cooling medium on the parametric sensitivity region is related to the heat capacity ratio α. And the greater α is, the more sensitive the reaction systems would be.
基金Supported by the Tianjin Natural Science Foundation.
文摘The discrepancy between pseudo-homogeneous one-dimensional model and pseudo-homogeneous two-dimensional model is studied. It is found that there are great differences between two models. This paper compares the maximum and minimum values of the radial temperature in the hot spot in case that a single exothermic reaction is carried out, a correlation is obtained with pseudo-homogeneous one-dimensional model to describe the entire reactor behavior. A new runaway criterion, based on the occurrence of inflection in the hot spot locus, is developed for the case of pseudo-homogeneous two-dimensional model. This criterion predicts the maximum allowable temperature for safe operation and the regions of runaway, respectively. The calculated results show that, compared with the results based on pseudo-homogeneous one-dimensional model, runaway will easily occur when the radial temperature gradient has to be considered.
