Numerical Heat Transfer Aanalysis Of The Fuel Rod In Reactor Core

The accident of Fukushinia Nuclear Power Plant proved again that the development of nuclear power must put safety the first, especially the inherent safety which was the most effective way of stopping serious accidents. All kinds of the design basis accidents must be taken into account in the thermal design of reactor. This study was in the unstructured grids, the unsteady heat conduction equation was discretized from the fully implicit finite volume method. The programs which were created by FORTRAN completed the temperature computation and heat transfer regularity of different cases. All conclusions provided useful references for the thermal design and judgment on reactor inherent safety.This paper first based on uniform medium neutron diffusion theory, and the cylindrical reactor distribution of heat release rate was derived through the analysis of critical theory. In consideration of the complex Bessel function and Cosine function in heat source, it’s difficult to derive the exact solution. To prove the numerical solution and defined the influence of all kinds of factors on the temperature distribution, the approximating expression for the fuel rod was derived through integral. Comparing the two results, there was a good agreement between them. The temperature distribution and variation were also analyzed.On that basis, the temperature distributions of bare cylindrical column in three operating conditions were computed using prototype model of AC-600. This reactor has asymmetrical heat source distribution which the Bessel function in radial direction and Cosine function at axis direction. One conceivable operating condition, trap heat loss and an actual operating condition were simulated separately; thermal environments and the heat transfer disciplinarian were obtained through analysis the results. The results judged inherent safety for PWR.Then, analyze the dynamic temperature field distribution of two different geometry reactor fuel elements which had variable time heat source that gave corresponding positive or negative reactivity according to a power function. The asymptotic solutions were obtained by the separation of variable method, at the same time, the temperature distributions were computed by the FVM. Comparing the asymptotic solution with the numerical results, derive and show the thermal environment and the heat transfer regularity.Last, the regions of flows were researched considering the facts. Analyze the laminar, transition and turbulent regions by engineering method respectively, and combine the calculator program, the temperature distribution which was more close to engineering practice was derived. All these provided a useful reference for the research of operation safety...