芯块-包壳间隙对燃料棒温度场影响的数值模拟

Numerical Simulation of Pellet-Clad Gap's Effect on Fuel Rod's Temperature Field

本文采用Simulation软件进行了芯块-包壳间隙对燃料棒温度场影响的数值模拟研究。结果表明:芯块-包壳间隙和燃料棒线功率对燃料棒温度场产生重要影响。与名义间隙状态相比,最大和最小间隙状态下的芯块温度场变化明显,但包壳温度场受影响较小;不同芯块-包壳间隙状态下的芯块中心温度差异随燃料棒线功率的提高先增大后逐渐减小;在芯块和包壳的不同尺寸状态下,芯块中心温度随芯块-包壳间隙变化近似成线性,与小包壳和小芯块相比,大包壳和大芯块状态下的芯块中心温度略高。

The temperature Field of fuel rod in different states of pellet-clad gaps were studied using the FEA software named Simulation. Results show that pellet-clad gap and linear power of fuel rod play important roles in the temperature field of fuel rod. In the maximum and minimum gap states, temperature field varies obviously in pellet but little in clad, comparing with nominal gap state. Between distinct pellet-clad gap states, temperature differernces of pellet in central of fuel rod increase with linear power early and then decrease gradually. Under different dimesions of pellet and clad, temperature of pellet in central of fuel rod changes about linearly with pellet-clad gaps, and states of maximum clad, maximum pellet share a slight higher temperature in centre of pellet comparing with states of minimum clad, minimum pellet.