原子能科学技术
原子能科學技術
원자능과학기술
ATOMIC ENERGY SCIENCE AND TECHNOLOGY
2014年
9期
1565-1570
,共6页
层流%边界层%传热特性%中间换热器
層流%邊界層%傳熱特性%中間換熱器
층류%변계층%전열특성%중간환열기
laminar flow%boundary layer%heat transfer characteristic%intermediate heat exchanger
为提高高温气冷堆中间换热器的换热效率,对中间换热器单元流道的层流流动边界层及热边界层进行了理论计算和模拟分析。利用幂次多项式速度分布的方法,对流道内的层流流动边界层和热边界层进行计算,结果表明,三次式的速度分布更为接近Blasius精确解,也更为符合数值模拟的结果。同时,结合不同位置的温度分布,可发现上、下边界层的相遇会使流动进入泊肃叶的抛物线形式,边界层理论继而不再适用。通过模拟还发现,氦气的进口温度和出口压力对于层流边界层的换热基本无影响;恒定热流密度下,壁面温度的变化分为明显的边界层区和泊肃叶区,在这两个区域壁面温度呈线性变化。
為提高高溫氣冷堆中間換熱器的換熱效率,對中間換熱器單元流道的層流流動邊界層及熱邊界層進行瞭理論計算和模擬分析。利用冪次多項式速度分佈的方法,對流道內的層流流動邊界層和熱邊界層進行計算,結果錶明,三次式的速度分佈更為接近Blasius精確解,也更為符閤數值模擬的結果。同時,結閤不同位置的溫度分佈,可髮現上、下邊界層的相遇會使流動進入泊肅葉的拋物線形式,邊界層理論繼而不再適用。通過模擬還髮現,氦氣的進口溫度和齣口壓力對于層流邊界層的換熱基本無影響;恆定熱流密度下,壁麵溫度的變化分為明顯的邊界層區和泊肅葉區,在這兩箇區域壁麵溫度呈線性變化。
위제고고온기랭퇴중간환열기적환열효솔,대중간환열기단원류도적층류류동변계층급열변계층진행료이론계산화모의분석。이용멱차다항식속도분포적방법,대류도내적층류류동변계층화열변계층진행계산,결과표명,삼차식적속도분포경위접근Blasius정학해,야경위부합수치모의적결과。동시,결합불동위치적온도분포,가발현상、하변계층적상우회사류동진입박숙협적포물선형식,변계층이론계이불재괄용。통과모의환발현,양기적진구온도화출구압력대우층류변계층적환열기본무영향;항정열류밀도하,벽면온도적변화분위명현적변계층구화박숙협구,재저량개구역벽면온도정선성변화。
To improve the heat efficiency of the high-temperature gas-cooled reactor intermediate heat exchanger , the theoretical calculation and simulation analysis of laminar flow and thermal boundary layers for the IHX were carried out .Through the way of polynomial velocity distribution ,it is found that a third order polynomial velocity distribution is close to the Blasius exact solution and the results of the numerical simulation .At the same time ,combined with the temperature distribution in different locations ,it is found that upper and lower boundary layers will meet .And then ,the flow changes to the Poiseuille flow and the boundary layer theory no longer applies .At last ,the effects of He inlet temperature and outlet pressure were analyzed ,which makes no difference .Under constant heat flux ,the changes of wall temperature can be divided into obvious boundary layer zone and Poiseuille flow zone and in both areas are linear .