【摘要】：小型反應堆所具有的安全設計理念、結構簡化等特點,以及在特殊領域的應用優(yōu)勢,推動了其快速發(fā)展。安全殼作為小型反應堆中防止放射性物質擴散的最后一道屏障,在LOCA\MSLB事故后必須保證其完整性以盡可能的降低核事故的危害。目前,部分小型反應堆采用鋼制結構的安全殼,例如Nuscale、ACP100。除了作為最后一道屏障外,鋼制安全殼在破口事故后還具有導出殼內熱量的作用,能有效降低事故后安全殼內的溫度和壓力。隨著小型堆的全面發(fā)展,研究小型堆的安全性,尤其是破口事故后安全殼的非能動冷卻能力,對小型堆的推廣有著尤為重要的意義。本文主要研究破口事故下小型堆安全殼內的溫度分布和安全殼的傳熱特性,希望對小型堆的結構設計和安全分析提供一定的參考。為研究小型安全殼破口事故后由強迫射流、浮力射流引起的熱分層現(xiàn)象及安全殼傳熱特性,本文進行了實驗和數(shù)值計算兩方面的工作。實驗以蒸汽為工質,通過測量安全殼內空間和壁面溫度以及內壁面凝結水量,研究破口噴射流量、破口直徑、破口高度和外部噴淋流量四個因素對安全殼內部熱分層現(xiàn)象和安全殼殼壁傳熱的影響。數(shù)值計算工作利用FLUENT軟件進行,采用歐拉多相流模型,引入軟件自帶的蒸發(fā)-冷凝模型,研究不同條件下安全殼內的溫度分布、氣體組分和氣體流動,以補充實驗測量的不足,并驗證計算模型的準確性,為以后的實驗和反應堆專有程序的開發(fā)提供一些參考。通過分析實驗數(shù)據(jù)發(fā)現(xiàn),破口事故后安全殼內普遍存在熱分層現(xiàn)象,安全殼上部的溫度攪混均勻,存在明顯的等溫區(qū),下部則是有一定溫度梯度的低溫區(qū)。噴射流量、破口直徑、破口高度對熱分層的影響主要表現(xiàn)為改變了等溫區(qū)厚度,噴淋流量則是整體性改變了安全殼的空間溫度,安全殼的熱流密度則受到了等溫區(qū)厚度和溫度的影響。在模擬計算結果中也出現(xiàn)了安全殼熱分層現(xiàn)象,結合殼內流場發(fā)現(xiàn)氣體速度對熱分層現(xiàn)象的影響較大,但是計算結果中安全殼空間溫度偏高,且下部溫度梯度不明顯。
[Abstract]:The small reactor has the characteristics of safety design, structural simplification and its application in special fields, which promote its rapid development. Containment, as the last barrier against the spread of radioactive material in small reactors, must be kept intact after the LOCA\ MSLB accident in order to minimize the damage caused by nuclear accidents. At present, some small reactors use steel containment, such as Nuscale,ACP100. In addition to being the last barrier, the steel containment has the function of deriving the heat in the shell after the break accident, which can effectively reduce the temperature and pressure in the containment after the accident. With the overall development of the small reactor, it is of great significance to study the safety of the small reactor, especially the passive cooling ability of the containment after the break accident. In this paper, the temperature distribution and heat transfer characteristics in the containment of small reactor are studied in order to provide some reference for the structural design and safety analysis of the small reactor. In order to study the thermal stratification phenomenon caused by forced jet and buoyant jet and the heat transfer characteristics of containment after a small containment break accident, two aspects of experiment and numerical calculation have been carried out in this paper. In this experiment, steam was used as working medium. By measuring the space and wall temperature of containment and the amount of condensate on the inner wall, the jet flow rate and the diameter of the break were studied. The influence of four factors such as break height and external spray flow rate on the thermal stratification phenomenon and heat transfer in the containment wall. The numerical calculation is carried out by FLUENT software. The Euler multiphase flow model is used to study the temperature distribution, gas composition and gas flow in containment under different conditions. The accuracy of the calculation model is verified and some references are provided for future experiments and the development of reactor proprietary procedures. By analyzing the experimental data, it is found that thermal stratification is common in the containment after the break accident, the temperature in the upper part of the containment is mixed uniformly, there is an obvious isothermal zone, and the lower part is the low temperature zone with a certain temperature gradient. The influence of jet flow rate, break diameter and break height on thermal delamination mainly shows that the thickness of isothermal zone is changed, while the spray flow rate changes the space temperature of containment as a whole. The heat flux of containment is influenced by the thickness and temperature of isothermal zone. The phenomenon of thermal stratification of containment was also found in the simulation results. Combined with the flow field in the shell, it was found that the gas velocity had a great influence on the thermal stratification, but the temperature of the containment space was higher and the temperature gradient of the lower part was not obvious.
【學位授予單位】：華北電力大學(北京)
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：TK124;TM623.2

【參考文獻】

相關期刊論文 前7條

1 劉曉壯;;國內外部分小型壓水堆安全特性比較分析[J];核安全;2015年01期

2 玉宇;張鶴;單祖華;胡迎秋;王升飛;牛風雷;劉鑫;剛直;;AP1000安全殼流動循環(huán)與熱分層一維模型分析[J];原子能科學技術;2014年10期

3 夏吉莊;;雙調和樣條內插方法在測井和地震資料整合中的應用[J];石油與天然氣地質;2010年02期

4 劉志銘;丁亮波;;世界小型核電反應堆現(xiàn)狀及發(fā)展概況[J];國際電力;2005年06期

5 鄔田華;混合對流條件下浮升力對環(huán)形通道中流動及傳熱的影響[J];熱科學與技術;2004年01期

6 譚曙時,冷貴君,程旭,倪永君;非能動安全殼冷卻系統(tǒng)熱工水力單項試驗[J];核動力工程;2002年S1期

7 俞冀陽,李坤,賈寶山;AC600非能動安全殼冷卻系統(tǒng)長期效應分析[J];核動力工程;2002年03期

相關碩士學位論文 前1條

1 蔡駿馳;大空間內混合與熱分層試驗研究[D];華北電力大學;2015年

，

本文編號：2268377