To accurately predict the thermal hydraulic status of a PWR core and improve the economy and safety of the reactor operation, a study was conducted to reflect the strong coupling relationship between the heat release process of a fuel lattice cell and the flowing heat transfer process of a coolant and to improve the efficiency of the engineering application.Based on equivalence principle and geometry,mass and energy balance,and heat transfer in the liquid-solid area in the fuel lattice cell,a calculation scheme on liquid-solid conjugate heat transfer with e-quivalent gas gap was designed.A variable property calculation software was developed to realize an extensive cal-culation of the steady-state and transient conjugate heat transfer.The variable properties include fuel pellet, gas gap,cladding,and equivalent domain.By comparing various schemes, it was verified that the calculation on the purely liquid area may result in a wrong estimate of the circumferential heat transfer of the lattice cell.Comparing the calculation of liquid-solid conjugate heat transfer with equivalent gas gap and the calculation of non-simplified liquid-solid conjugate heat transfer, the maximum error is 0.1%, the minimum optimization on storage resources was 24.7%,and the minimum optimization on computing efficiency was 14.3%.%为准确预测压水堆堆芯的热工水力状态,提高反应堆运行的经济性与安全性,针对典型堆芯内数万燃料栅元中的燃料释热过程与冷却剂流动传热过程的强相互作用关系,以及工程化仿真预测的效率需求开展研究.依据几何、质能守恒、传热问题的等效原理,针对燃料栅元中的流固区域,设计气隙等效的流固共轭传热计算方案,开发芯块、气隙、包壳、等效域的变物性计算程序,实现了稳态与瞬态流固共轭传热的精细化计算.通过对比不同方案表明:纯流体域计算会导致栅元的周向传热计算失真;气隙等效的流固共轭传热计算与无简化流固共轭传热计算相比,精度的最大误差为0.1%,存储资源的最小优化量为24.7%,效率的最小优化量为14.3%.
展开▼
