HTR-10超高温运行堆芯温度场分析

Core temperature distributions in HTR-10 operating at very high temperatures

10 MW高温气冷实验堆(HTR-10)在额定工况下满功率稳态运行时,燃料的温度裕度较大,存在将冷却剂出口温度在700℃的基础上进一步提升的潜力,对实现球床式高温气冷堆超高温运行具有重要意义。该文根据堆芯发热功率和冷却剂载出热量之间的平衡关系,为HTR-10设计了多个稳态超高温运行工况,运用改进的热工模型分析了初装堆芯下各工况的堆芯温度场,给出其分布特征,并讨论了燃料分布不均匀性对堆芯最高温度的影响。结果表明:当堆芯出口冷却剂温度达到1000℃,且假设最高温度区燃料球和石墨球分布的不均匀程度达到极限时,堆芯最高温度仍未达到燃料温度限值。

The 10 MW high temperature gas-cooled reactor test module(HTR-10)has a relatively large fuel temperature margin when operating at full power and steady state for the rated condition;thus,the coolant outlet temperature can be further increased above 700℃,which is useful for pebble-bed very high temperature gas-cooled reactors(HTGR)to operate with high coolant temperature at the core outlet.Several steady-state very high temperature operating conditions were designed for HTR-10 in this study based on a heat balance between the core heating power and the heat carried by the coolant.An improved thermal hydraulic model was used to analyze the core temperature distribution at each condition for the initial core to determine the temperature distribution characteristics,and the maximum core temperature for the nonuniform fuel distribution was discussed.For the coolant outlet temperature of 1000℃,the predicted maximum core temperature is still below the fuel temperature limit,even when the most serious nonuniform distribution of the fuel and graphite balls occurs.