cmt排水过程中初始参数对流体温度分布及冷凝特性影响研究-工程热物理专业毕业论文.docx

重庆大学博士学位论文
通过对CMT内水的轴向温度分析,发现CMT内的流体具有热分层特性,即上部为热水层,下部为冷水层,热水层内温度变化剧烈,吸收了蒸汽在液面凝结放出的大部分热量。而冷水层的温度在实验过程中基本保持不变。PRZ初始压力越大, 蒸汽射流的速度越高,形成的汽穴的深度越深,液面波动的越剧烈,压力平衡需要的时间越长,其热水层厚度增加。遮流板对减小凝结起着积极的作用,在蒸汽完全凝结和部分蒸汽快速凝结阶段下CMT加遮流板其凝结换热系数较无遮流板时减小
了3—5倍。
采用热力比RT(RT:三星丛孕-二;i兰盟,Irr>l即意味着冷凝能力大于蒸汽转换
力J窖I,'Vg
的能量,即蒸汽完全冷凝模式,RT<I即蒸汽不完全冷凝)作为蒸汽在过冷液面直接
接触式冷凝模式的判断准则,获得了汽液直接接触冷凝模型。无遮流板排水蒸汽全部凝结阶段和部分蒸汽快速凝结阶段的平均换热系数实
验关系式为Nu=“”Pro”,实验点落在预测值±16%以内;有遮流板排水蒸汽全部凝结阶段和蒸汽快速部分凝结阶段的平均换热系数实验关系式为 Nu= 65 Pr“”,实验点落在预测值4-19%以内:无遮流板排水实验缓慢凝结阶段平均换热系数实验关系式为Nu=()o一,实验点落在预测值±20%以内; 有遮流板排水实验缓慢凝结阶段平均换热系数实验关系式为Nu=(Cr·Pr)04,实验点落在预测值±19%以内。
在RELAP5/MOD3程序中引入了实验获得的直接接触冷凝模型,模拟计算了 CMT有、无遮流板时的排水特性,计算结果与实验结果有很好的一致性。说明本文建立的模型是合理的。
关键词:堆芯补水箱,凝结特性,温度分布,压力影响,凝结换热系数,
直接接触冷凝,热分层特性,RELAP5/MOD3
Ⅱ
ABSTRACT
ABSTRACT
The experiment of CMT(Core Makeup Tank)drain has been conducted in this aims to find the initial condition effect on the characteristic of pressure response。 distribution and condensation experimental parameters were嬲follow:the imtiN pressure of pressurizer P=— and the initial water temperature of CMT T=20一80℃.There are three kinds of experiment have been finished:CMT no drain,CMT drain with sparger,CMT drain without
experimental results show that the fuid temperature distribution end the
condensation behavior in the CMT dependent on the initial pressure of pressurizer and
the initial temperature of ,the pressure response of CMT is mainly affected by the initial temperature of CⅣrI:parison of results between the CMT drain、Ⅳim sparger and the CMT drain without sparger indicates that the sparger has
great affection on the system pressure response,temperature distribution and heat transfer condensation process of saturated steam is divided into three phase: steam supply limit,part steam rapid condensation and steam slow condensation. The heat transfer coe伍cients between the steam and water have been