“华龙一号”核电厂烟囱气态流出物取样系统验证的试验与分析

Verification for the representative sampling system of “Hualong Ⅰ” NPP gaseous effluent: test and analysis

目的通过试验验证以确保中国自主研发的第三代压水堆核电站"华龙一号"堆型烟囱气态流出物取样系统(采用单嘴取样头设计)充分满足取样代表性要求。方法本文基于美国国家标准ANSI/HPS N13.1-1999要求,建造了"华龙一号"反应堆烟囱1:5的比例模型,在比例模型上完成了3个不同标高取样截面的平均气旋角、气体流速分布、示踪气体分布、示踪气溶胶分布验证试验,并在福清核电站1、2号机组的烟囱上开展了气旋角、气体流速、示踪气体浓度分布的验证试验。结果在"华龙一号"比例模型烟囱三个预选取样截面(Q1、Q2、Q3)中心2/3区域内,在两种设计通风工况下,气体流速分布变异系数(COV)≤1.1%,所有测点最大气旋角为11.38°,示踪气体分布浓度分布COV≤4.4%,示踪气溶胶浓度分布COV≤4.7%;在实际烟囱预选取样截面中心2/3面积内气体流速分布COV≤8.4%,所有测点气旋角平均绝对值为11.3°(且最大值<20°),并且由DVN碘排风、DVN正常排风系统注入示踪气体时,测量截面上示踪气体浓度分布COV分别为2.2%、1.3%。结论 "华龙一号"模型烟囱和实际烟囱的所有测试指标,全部符合ANSI/HPS N13.1-1999标准对于取样截面上污染物混合均匀性的要求,即可以采用单点取样方式来设计"华龙一号"烟囱气态流出物取样系统。

Objective Through experimental verification to ensure the sampling system(a single nozzle sampling head design） for the chimney gaseous effluent designed for the third-generation pressurized water reactor nuclear power plant＂Hualong Ⅰ＂independently developed in China fully meets the sampling representative requirements. Methods Based on the requirements of American National Standard ANSI/HPS N13. 1-1999,a 1： 5 scale model of the＂Hualong Ⅰ＂reactor stack was built to test the average cyclonic angle,gas flow velocity distribution,tracer gas distribution and tracer aerosol distribution in three different sampling cross sections. The verifications of the cyclonic angle,gas flow rate,and tracer gas concentration distribution were conducted in the Fuqing Nuclear Power Plant No. 1 and No. 2. Results In the central 2/3 area of the three pre-selected sampling sections(Q1,Q2,Q3） in the＂Hualong Ⅰ＂proportional model stack and under two designed ventilation conditions,the coefficient of variations(COVs） of the gas flow velocity distributions were ≤1. 1%,the maximum cyclone angle of all the measured point was 11. 38°,the COVs of the tracer gas concentrations distribution were ≤4. 4%,the COVs of the tracer aerosol concentrations distributions were ≤4. 7%. As well as in the central 2/3 area of the real stack pre-selected sampling section,COVs of the gas flow velocity distributions were ≤8. 4%,the mean absolute value of cyclone angles at all points was 11. 3°(the maximum value was 20°）. When the tracer gas injected from DVN iodine exhaust and the DVN normal exhaust,the distribution COVs of the tracer gas concentrations on the measured section were 2. 2% and 1. 3% respectively. Conclusion All test indicators of the＂Hualong Ⅰ＂model stack and the real stack agree well with the requirements of ANSI/HPS N13. 1-1999 standard for mixing uniformity of pollutants on the sampling section,the single point sampling method can be used to design the ＂Hualong Ⅰ＂stack gas flow sampling system.