發(fā)布時間：2018-02-10 11:02

  本文關鍵詞： 液氫 泄漏 數(shù)值模擬 參數(shù)分析　出處：《浙江大學》2017年碩士論文　論文類型：學位論文

【摘要】：氫作為一種重要的清潔能源,在化工、清潔能源以及航天推進等諸多領域得到了廣泛的應用。對于氫的大規(guī)模儲存、運輸和應用,以低溫液氫的形態(tài)比能量密度較低的常溫氣氫更為經(jīng)濟可行,有望得到快速發(fā)展。然而,一旦儲存的液氫發(fā)生泄漏,可能會在周圍地面形成低溫液池,而快速蒸發(fā)形成的氫氣會發(fā)生積聚而形成易爆混合氣體,這對周圍人群和環(huán)境構(gòu)成巨大的潛在威脅,特別像在作為航天推進劑使用時的大規(guī)模液氫儲罐,其后果尤為嚴重。就大規(guī)模液氫的泄漏擴散過程開展數(shù)值模擬研究,對于掌握大規(guī)模液氫的泄漏擴散機制、.制定應急預案、劃定緊急疏散區(qū)域、評估事故危害后果等都有非常重要的現(xiàn)實意義。本文在綜合分析國內(nèi)外相關研究成果的基礎上,建立了基于CFD軟件FLUENT的大規(guī)模液氫泄漏擴散過程的數(shù)值模型。由于風對于氫氣在大氣中的漂移和擴散有著重要影響,有必要對液氫泄漏源附近的風場先進行模擬與分析。因此,相關模擬研究分成兩個階段進行,第一階段是對大氣邊界層內(nèi)的風場進行穩(wěn)態(tài)的數(shù)值模擬,得到大空間范圍內(nèi)風場的模擬數(shù)據(jù),第二階段則利用第一階段的數(shù)值模擬結(jié)果作為初始條件,對大規(guī)模液氫的泄漏過程進行非穩(wěn)態(tài)的數(shù)值模擬。在風場模型的建立過程中,通過分析風的基本特性和脈動風的主要屬性,確定平均風剖面的數(shù)學表達形式以及風的湍流參數(shù),并利用用戶自定義程序?qū)︼L的參數(shù)進行定義。在確定模型的計算流域并對計算流域進行網(wǎng)格劃分之后,選擇Realizablek-ε模型作為風場的湍流模型,對大空間范圍內(nèi)的風場進行了模擬。以風場的模擬結(jié)果作為初始條件,繼而進行大規(guī)模液氫泄漏和擴散過程的數(shù)值模擬。采用Mixture模型作為多相流模型,結(jié)合實驗中的地面情況,按照砂石的物理性質(zhì)確定下表面為恒溫的地面條件,對液氫的泄漏和擴散過程進行非穩(wěn)態(tài)模擬。通過與NASA的實驗結(jié)果之間的對比,對模型的準確性進行驗證,模擬結(jié)果對氫氣擴散的動態(tài)變化過程進行形象的展示�；谝呀�(jīng)構(gòu)建的大規(guī)模液氫泄漏擴散模型,著重對風溫、風速、地面溫度、地面粗糙度、液氫泄漏速率、泄漏出口的空化率等六個因素的改變對于大規(guī)模液氫泄漏擴散行為的影響進行分析。本文的研究結(jié)果對于探究建立更精確的大規(guī)模液氫泛溢后續(xù)行為特征的計算模型,以及建立大規(guī)模液氫泄漏擴散的后續(xù)補救和防護措施具有指導意義。
[Abstract]:Hydrogen, as an important clean energy, has been widely used in many fields, such as chemical industry, clean energy and space propulsion. The form of cryogenic liquid hydrogen is more economical and feasible than that of atmospheric hydrogen with lower energy density, and it is expected to develop rapidly. However, once the stored liquid hydrogen leaks, a cryogenic liquid tank may be formed on the surrounding ground. Hydrogen, which is rapidly evaporating, accumulates and forms explosive mixtures, posing a huge potential threat to the population and the environment, especially in large-scale liquid hydrogen storage tanks used as space propellant. The consequences are especially serious. A numerical simulation study on the leakage and diffusion process of large-scale liquid hydrogen is carried out. In order to master the mechanism of leakage and diffusion of large-scale liquid hydrogen, to formulate emergency plans and delineate emergency evacuation areas, It is of great practical significance to evaluate the consequences of accidents. Based on the comprehensive analysis of relevant research results at home and abroad, A numerical model of large-scale liquid hydrogen leakage diffusion process based on CFD software FLUENT is established. Since wind has an important effect on the drift and diffusion of hydrogen in the atmosphere, it is necessary to simulate and analyze the wind field near the liquid hydrogen leakage source. The related simulation research is divided into two stages. The first stage is the steady numerical simulation of the wind field in the atmospheric boundary layer, and the simulation data of the wind field in a large space range are obtained. In the second stage, the numerical simulation results of the first stage are used as the initial conditions to simulate the large-scale liquid hydrogen leakage process. By analyzing the basic characteristics of the wind and the main properties of the pulsating wind, the mathematical expression of the mean wind profile and the turbulence parameters of the wind are determined. The parameters of wind are defined by user-defined program. After determining the calculated watershed of the model and meshing the calculated watershed, the realizablek- 蔚 model is chosen as the turbulence model of wind field. The wind field in large space is simulated. The simulation results of wind field are taken as the initial condition, and then the numerical simulation of large-scale liquid hydrogen leakage and diffusion process is carried out. The Mixture model is used as the multiphase flow model, and the ground condition in the experiment is combined. According to the physical properties of sand and gravel, the unsteady state simulation of liquid hydrogen leakage and diffusion is carried out under the condition that the lower surface is at constant temperature. The veracity of the model is verified by comparing with the experimental results of NASA. The simulation results show the dynamic process of hydrogen diffusion. Based on the large scale liquid hydrogen leakage diffusion model, we focus on wind temperature, wind speed, ground temperature, ground roughness, liquid hydrogen leakage rate. The influence of six factors, such as cavitation rate of leakage outlet, on the behavior of large-scale liquid hydrogen leakage and diffusion is analyzed. The results of this paper are helpful to establish a more accurate computational model for the characteristics of the subsequent behavior of large-scale liquid hydrogen spills. And the establishment of a large-scale liquid hydrogen leakage and diffusion of follow-up remedial and protective measures have guiding significance.
【學位授予單位】：浙江大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：TQ116.27

【參考文獻】

相關期刊論文 前10條

1 孫永康;;燃料電池汽車加氫站設計規(guī)范安全距離的分析研究[J];上海煤氣;2016年02期

2 王占林;葛紹嶺;;液氫輸送管路絕熱性能試驗技術[J];低溫工程;2014年04期

3 陳亮;梁國柱;鄧新宇;胡煒;;貯箱內(nèi)低溫推進劑汽化過程的CFD數(shù)值仿真[J];北京航空航天大學學報;2013年02期

4 高會旺;顧明;王仁磊;薛宇歡;;北黃海海域大氣湍流強度特征及風速標準差相似性分析[J];中國海洋大學學報(自然科學版);2009年04期

5 許蕾;羅會信;;基于ANSYS ICEM CFD和CFX數(shù)值仿真技術[J];機械工程師;2008年12期

6 王贊社;顧兆林;馮詩愚;邱劍;;低溫推進劑貯箱增壓過程的傳熱傳質(zhì)數(shù)學模擬[J];低溫工程;2007年06期

7 翟建華;計算流體力學(CFD)的通用軟件[J];河北科技大學學報;2005年02期

8 張曉潔,殷志祥;電視塔脈動風荷載模擬研究[J];工程建設與設計;2004年09期

9 汪叢軍,黃本才,張昕,徐曉明,林高;越南國家體育場屋蓋平均風壓及風環(huán)境影響數(shù)值模擬[J];空間結(jié)構(gòu);2004年02期

10 龐加斌,葛耀君,陸燁;大氣邊界層湍流積分尺度的分析方法[J];同濟大學學報(自然科學版);2002年05期

，

本文編號：1500365