Study on Flow Blockage Accident of HFETR Multi-layer Annular Fuel Assembly
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摘要: 高通量工程试验堆(HFETR)的燃料组件采用了多层环形窄缝流道的设计来提高换热能力。然而,需要注意的是窄缝流道发生堵流的可能性较高。本文基于RELAP5程序建立了HFETR燃料组件模型,经过计算值与试验值的对比验证,结果表明该模型合理准确。基于该模型研究了堵流事故工况下热盒燃料组件的瞬态特性及其影响因素。结果表明:①当堵流比大于0.5时,随着堵流比的增加,燃料包壳与芯体峰值温度显著上升;②即使单个流道发生全部堵流,由于周围流道的冷却,燃料包壳峰值温度最大值只有218.6℃,能够保证燃料包壳的完整性;③单个流道全部堵流事故工况初期流量等参数波动较大,而在事故发生15 s后燃料组件主要参数基本稳定。
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关键词:
- RELAP5 /
- 多层环形窄缝流道 /
- 堵流事故 /
- 高通量工程试验堆(HFETR)
Abstract: The fuel assembly of High Flux Engineering Test Reactor (HFETR) adopts multi-layer annular narrow slot flow channel design to improve the heat transfer capacity. However, it should be noted that the narrow slot flow channel is more likely to be blocked. In this paper, the HFETR fuel assembly model is established based on the RELAP5 program. The comparison between the calculated value and the experimental value shows that the model is reasonable and accurate. Based on the model, the transient characteristics and influencing factors of hot box fuel assembly under flow blockage accident are studied. The results show that: ① When the flow blockage ratio is greater than 0.5, the peak temperature of fuel cladding and core increases significantly with the increase of flow blockage ratio; ② Even if a single flow channel is blocked completely, due to the cooling of the surrounding flow channels, the maximum peak temperature of the fuel cladding is only 218.6 ℃, which can ensure the integrity of the fuel cladding; ③ The flow rate and other parameters fluctuate greatly at the initial stage of a single flow channel full blockage accident, but the main parameters of the fuel assembly are basically stable 15 s after the accident. -
表 1 计算值与试验值对比
Table 1. Comparison of Calculated Value and Experimental Value
参数 计算值 试验值 偏差/% 出口水温/℃ 55.1 55.0 0.07 压降/kPa 480.3 470.0 2.19 测点包壳温度/℃ 89.3 87.5 2.06 -
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