板状燃料组件具有结构紧凑、换热效率高、深燃耗等特点,故被广泛应用在一体化反应堆和实验用研究堆中。在堆芯窄矩形流道中,冷却剂一般采用自上向下的强迫循环方式。在某些事故工况下,譬如由于燃料元件的辐照肿胀、堆内材料碎片或异物随冷却剂循环流入堆芯,可能引发堵流事故。该事故将造成燃料板失冷,板温升高,可能导致局部冷却剂蒸干,威胁燃料包壳的完整性,甚至造成放射性外泄,引发严重事故后果。本文采用CFD软件ANSYS FLUENT 12.1对板状燃料组件在入口95%部分堵塞和全部堵塞的工况进行了瞬态数值模拟。计算中考虑了冷却剂和燃料板的流固耦合传热问题,并对所得三维流场、温度场及影响因素进行了分析。 Plate-shaped fuel assemblies with compact structure, high heat transfer efficiency, deep burn and so on, it is widely used in integrated reactors and experimental research reactor. In the core narrow rectangular flow channel, the coolant generally adopts the forced circulation mode from top to bottom. Under certain accidental conditions, for example, due to the swelling of the fuel element, material debris or foreign material in the reactor may flow into the reactor core with the coolant, which may cause a blockage accident. The accident will cause the fuel plate to lose heat and increase the plate temperature, which may result in the local coolant evaporating to dryness, threatening the integrity of the fuel cladding and even causing radioactive leakage and causing serious accidental consequences. In this paper, the CFD software ANSYS FLUENT 12.1 was used to transiently simulate the plate-type fuel assembly partially blocked and completely blocked at the inlet of 95%. The fluid-solid coupling heat transfer between the coolant and the fuel plate is taken into account in the calculation, and the three-dimensional flow field, temperature field and influencing factors are analyzed.