本文主要研究内容
作者苏厚德（2019）在《开架式气化器流动与传热特性及特征参数研究》一文中研究指出：环境和能源问题日益成为世界经济发展的焦点,而天然气作为目前世界一次能源的三大支柱之一,因其热值高,对环境污染少,被公认为是洁净能源,也越来越多的被人们开发和利用,液化天然气(LNG)己经成为一门迅猛发展的新兴工业。LNG气化器是一种专门用于液化天然气气化的热交换设备。开架式海水气化器(Open-Rack Vaporizer,简称ORV)是LNG接收终端内重要的大型气化设备,其气化性能和效率直接影响LNG终端的负荷能力,也是该设备国产化的瓶颈之一。由此,本文以开架式气化器为研究对象,在深化国内外文献调研并结合气化器实际应用的基础上,通过对开架式海水气化器结构与工作原理进行了分析、设计,采用理论分析、数值模拟及实验研究相结合的方法,研究开架式海水气化器管内流动与传热规律,利用实验测量了换热管外壁面液膜的分布特征,在此基础上,分析了换热管外壁面液膜内部温度场的分布规律及结冰机理,最后通过实验的方法测试了开架式气化器换热管在大温差传热及高内压耦合作用下的应力应变特征,旨在探讨更为合理的结构和操作参数,提高开架式海水气化器的气化率,为实际工程应用提供数据支持,以期提高开架式海水气化器的国产化工程应用。通过本论文的研究,得出如下结论:1.分别建立了有/无扰流杆传热管内部流动和传热的数值计算模型,研究了传热管内流体流动与换热过程,分析了影响气化率的因素,得到了气化器传热管内液化天然气(LNG)多相多组特性与气化映射关系。通过数值模拟可以看出,传热管底端进口处LNG温度、含气率、混合物流速最低,压力最大;随着气化过程的进行,温度、含气率、流速沿管程不断提高,压力逐渐降低。2.利用无扰流杆的传热管流动和传热数值计算模型,分析了流速、入口温度等工况参数及换热管粗糙度对换热管内介质气化规律的影响。研究结果显示,不同流速和入口温度工作下,换热管管内介质气化过程相似,但气化速度不同。入口速度和入口温度越低,管内LNG被加热时间越长,气化过程也越充分。在2m到3m之间有一段含气率陡升的区域,在3m~6m之间的各截面上,温度和含气率基本平稳过渡,气化过程已经基本稳定。不同工况下的含气率最终都趋于一个定值则说明该传热管的气化能力是一定的,改变入口LNG速度只能改变气化过程的反应程度。3.利用换热管内部流动和传热数值计算模型,获得了带扰流杆的换热管内部流动与传热过程中温度、流速、压降等特征参数与气化率之间关系,并用实验的方法对传热过程的结果进行了对比验证。在相同边界条件下,与无扰流杆传热管计算结果相比,扰流杆的存在使得换热管内部LNG气化效率提高,出口处含气率相近,速度、温度均较低。在蒸发段内,无扰流杆传热管的气化效果要好于实际带扰流杆传热管的气化效果;在加热段内,两段流体掺混,在扰流杆的导流作用下,内部介质的速度增大,使掺混程度高,湍动程度加强,由环形间隙带来的高温介质与内管内温度较低的介质充分混合并持续进行热量交换,内管内的LNG气化程度增强,相应的带扰流杆换热管内部的气化率就高于不带扰流杆换热管的气化率,使得总的含气率快速上升。扰流杆的增加使内管中流体由原来的沿着轴向直线运动,变为顺扰流杆的螺旋运行,增加了内部流体的湍动程度,内部流体速度提高,沿程损失加大。在其他条件相同的情况下,比较不同管内壁粗糙度情况下两种传热管模型中沿管程不同截面处的气化率分布,随着管内壁粗糙度的增加,蒸发段内气化效果向好;带扰流杆翅片管模型在加热段内略有优势,但管内壁粗糙度的变化对含气率影响较小。4.搭建了开架式气化器换热管外壁面水膜特征测试实验,研发了海水分布器水膜厚度测量工具,测试了换热管外壁面上液膜厚度的分布特征,研究结果发现不同换热翅片间液膜随分布器垂直距离和水平距离的变化趋势基本是一致的,且随着流量的增大,液膜厚度增大,分布器与换热管之间水平距离对液膜厚度的影响大于分布器与与换热管之间垂直距离的影响,且随着流道尺寸的增大,液膜厚度减小,随着流量及相对位置的变化,液膜厚度基本维持在5mm~10mm之间。5.研究了在实际环境条件下,普遍存在的热质湍流输运效应和局部结冰-气化等相变过程对气化器输运过程的机理问题。通过对不同进口温度条件下两种液膜厚度非稳态数值模拟可以看出,液膜内的温度场是由外向内呈梯度变化,当入口海水温度为273.15K时,液膜内部会开始出现结冰现象。5mm液膜在固液交界面处有结冰现象,也有融冰现象,结冰情况动态变化,固液交界面位置基本浮动变化不大。开始考虑结冰过程后,10mm液膜时固液之间存在最先可能出现结冰现象的明显分界面;整个区域内温度差异在1K左右。6.用液氮替代LNG对气化器在通入液氮和管外结冰两种工况下的应变开展了试验研究,分析了气化器的应变随液氮入口温度的变化关系,由实验结果可知:气化器换热管束在充入液氮后发生收缩,且沿液氮流动方向的应变大于垂直方向的应变,这主要是由管道长度决定;同时,相同条件下,离液氮入口越近,应变越大。随着液氮的气化,温度升高,应变减小,在液氮的沸点附近,应变趋于零。集管和汇管的应变值明显大于换热管的应变量,且维持较高的应变水平;管外结冰,将影响换热管内外热交换,增加应变量,结冰不仅影响气化器换热效果,同时影响气化器的结构安全。
Abstract
huan jing he neng yuan wen ti ri yi cheng wei shi jie jing ji fa zhan de jiao dian ,er tian ran qi zuo wei mu qian shi jie yi ci neng yuan de san da zhi zhu zhi yi ,yin ji re zhi gao ,dui huan jing wu ran shao ,bei gong ren wei shi jie jing neng yuan ,ye yue lai yue duo de bei ren men kai fa he li yong ,ye hua tian ran qi (LNG)ji jing cheng wei yi men xun meng fa zhan de xin xing gong ye 。LNGqi hua qi shi yi chong zhuan men yong yu ye hua tian ran qi qi hua de re jiao huan she bei 。kai jia shi hai shui qi hua qi (Open-Rack Vaporizer,jian chen ORV)shi LNGjie shou zhong duan nei chong yao de da xing qi hua she bei ,ji qi hua xing neng he xiao lv zhi jie ying xiang LNGzhong duan de fu he neng li ,ye shi gai she bei guo chan hua de ping geng zhi yi 。you ci ,ben wen yi kai jia shi qi hua qi wei yan jiu dui xiang ,zai shen hua guo nei wai wen suo diao yan bing jie ge qi hua qi shi ji ying yong de ji chu shang ,tong guo dui kai jia shi hai shui qi hua qi jie gou yu gong zuo yuan li jin hang le fen xi 、she ji ,cai yong li lun fen xi 、shu zhi mo ni ji shi yan yan jiu xiang jie ge de fang fa ,yan jiu kai jia shi hai shui qi hua qi guan nei liu dong yu chuan re gui lv ,li yong shi yan ce liang le huan re guan wai bi mian ye mo de fen bu te zheng ,zai ci ji chu shang ,fen xi le huan re guan wai bi mian ye mo nei bu wen du chang de fen bu gui lv ji jie bing ji li ,zui hou tong guo shi yan de fang fa ce shi le kai jia shi qi hua qi huan re guan zai da wen cha chuan re ji gao nei ya ou ge zuo yong xia de ying li ying bian te zheng ,zhi zai tan tao geng wei ge li de jie gou he cao zuo can shu ,di gao kai jia shi hai shui qi hua qi de qi hua lv ,wei shi ji gong cheng ying yong di gong shu ju zhi chi ,yi ji di gao kai jia shi hai shui qi hua qi de guo chan hua gong cheng ying yong 。tong guo ben lun wen de yan jiu ,de chu ru xia jie lun :1.fen bie jian li le you /mo rao liu gan chuan re guan nei bu liu dong he chuan re de shu zhi ji suan mo xing ,yan jiu le chuan re guan nei liu ti liu dong yu huan re guo cheng ,fen xi le ying xiang qi hua lv de yin su ,de dao le qi hua qi chuan re guan nei ye hua tian ran qi (LNG)duo xiang duo zu te xing yu qi hua ying she guan ji 。tong guo shu zhi mo ni ke yi kan chu ,chuan re guan de duan jin kou chu LNGwen du 、han qi lv 、hun ge wu liu su zui di ,ya li zui da ;sui zhao qi hua guo cheng de jin hang ,wen du 、han qi lv 、liu su yan guan cheng bu duan di gao ,ya li zhu jian jiang di 。2.li yong mo rao liu gan de chuan re guan liu dong he chuan re shu zhi ji suan mo xing ,fen xi le liu su 、ru kou wen du deng gong kuang can shu ji huan re guan cu cao du dui huan re guan nei jie zhi qi hua gui lv de ying xiang 。yan jiu jie guo xian shi ,bu tong liu su he ru kou wen du gong zuo xia ,huan re guan guan nei jie zhi qi hua guo cheng xiang shi ,dan qi hua su du bu tong 。ru kou su du he ru kou wen du yue di ,guan nei LNGbei jia re shi jian yue chang ,qi hua guo cheng ye yue chong fen 。zai 2mdao 3mzhi jian you yi duan han qi lv dou sheng de ou yu ,zai 3m~6mzhi jian de ge jie mian shang ,wen du he han qi lv ji ben ping wen guo du ,qi hua guo cheng yi jing ji ben wen ding 。bu tong gong kuang xia de han qi lv zui zhong dou qu yu yi ge ding zhi ze shui ming gai chuan re guan de qi hua neng li shi yi ding de ,gai bian ru kou LNGsu du zhi neng gai bian qi hua guo cheng de fan ying cheng du 。3.li yong huan re guan nei bu liu dong he chuan re shu zhi ji suan mo xing ,huo de le dai rao liu gan de huan re guan nei bu liu dong yu chuan re guo cheng zhong wen du 、liu su 、ya jiang deng te zheng can shu yu qi hua lv zhi jian guan ji ,bing yong shi yan de fang fa dui chuan re guo cheng de jie guo jin hang le dui bi yan zheng 。zai xiang tong bian jie tiao jian xia ,yu mo rao liu gan chuan re guan ji suan jie guo xiang bi ,rao liu gan de cun zai shi de huan re guan nei bu LNGqi hua xiao lv di gao ,chu kou chu han qi lv xiang jin ,su du 、wen du jun jiao di 。zai zheng fa duan nei ,mo rao liu gan chuan re guan de qi hua xiao guo yao hao yu shi ji dai rao liu gan chuan re guan de qi hua xiao guo ;zai jia re duan nei ,liang duan liu ti can hun ,zai rao liu gan de dao liu zuo yong xia ,nei bu jie zhi de su du zeng da ,shi can hun cheng du gao ,tuan dong cheng du jia jiang ,you huan xing jian xi dai lai de gao wen jie zhi yu nei guan nei wen du jiao di de jie zhi chong fen hun ge bing chi xu jin hang re liang jiao huan ,nei guan nei de LNGqi hua cheng du zeng jiang ,xiang ying de dai rao liu gan huan re guan nei bu de qi hua lv jiu gao yu bu dai rao liu gan huan re guan de qi hua lv ,shi de zong de han qi lv kuai su shang sheng 。rao liu gan de zeng jia shi nei guan zhong liu ti you yuan lai de yan zhao zhou xiang zhi xian yun dong ,bian wei shun rao liu gan de luo xuan yun hang ,zeng jia le nei bu liu ti de tuan dong cheng du ,nei bu liu ti su du di gao ,yan cheng sun shi jia da 。zai ji ta tiao jian xiang tong de qing kuang xia ,bi jiao bu tong guan nei bi cu cao du qing kuang xia liang chong chuan re guan mo xing zhong yan guan cheng bu tong jie mian chu de qi hua lv fen bu ,sui zhao guan nei bi cu cao du de zeng jia ,zheng fa duan nei qi hua xiao guo xiang hao ;dai rao liu gan chi pian guan mo xing zai jia re duan nei lve you you shi ,dan guan nei bi cu cao du de bian hua dui han qi lv ying xiang jiao xiao 。4.da jian le kai jia shi qi hua qi huan re guan wai bi mian shui mo te zheng ce shi shi yan ,yan fa le hai shui fen bu qi shui mo hou du ce liang gong ju ,ce shi le huan re guan wai bi mian shang ye mo hou du de fen bu te zheng ,yan jiu jie guo fa xian bu tong huan re chi pian jian ye mo sui fen bu qi chui zhi ju li he shui ping ju li de bian hua qu shi ji ben shi yi zhi de ,ju sui zhao liu liang de zeng da ,ye mo hou du zeng da ,fen bu qi yu huan re guan zhi jian shui ping ju li dui ye mo hou du de ying xiang da yu fen bu qi yu yu huan re guan zhi jian chui zhi ju li de ying xiang ,ju sui zhao liu dao che cun de zeng da ,ye mo hou du jian xiao ,sui zhao liu liang ji xiang dui wei zhi de bian hua ,ye mo hou du ji ben wei chi zai 5mm~10mmzhi jian 。5.yan jiu le zai shi ji huan jing tiao jian xia ,pu bian cun zai de re zhi tuan liu shu yun xiao ying he ju bu jie bing -qi hua deng xiang bian guo cheng dui qi hua qi shu yun guo cheng de ji li wen ti 。tong guo dui bu tong jin kou wen du tiao jian xia liang chong ye mo hou du fei wen tai shu zhi mo ni ke yi kan chu ,ye mo nei de wen du chang shi you wai xiang nei cheng ti du bian hua ,dang ru kou hai shui wen du wei 273.15Kshi ,ye mo nei bu hui kai shi chu xian jie bing xian xiang 。5mmye mo zai gu ye jiao jie mian chu you jie bing xian xiang ,ye you rong bing xian xiang ,jie bing qing kuang dong tai bian hua ,gu ye jiao jie mian wei zhi ji ben fu dong bian hua bu da 。kai shi kao lv jie bing guo cheng hou ,10mmye mo shi gu ye zhi jian cun zai zui xian ke neng chu xian jie bing xian xiang de ming xian fen jie mian ;zheng ge ou yu nei wen du cha yi zai 1Kzuo you 。6.yong ye dan ti dai LNGdui qi hua qi zai tong ru ye dan he guan wai jie bing liang chong gong kuang xia de ying bian kai zhan le shi yan yan jiu ,fen xi le qi hua qi de ying bian sui ye dan ru kou wen du de bian hua guan ji ,you shi yan jie guo ke zhi :qi hua qi huan re guan shu zai chong ru ye dan hou fa sheng shou su ,ju yan ye dan liu dong fang xiang de ying bian da yu chui zhi fang xiang de ying bian ,zhe zhu yao shi you guan dao chang du jue ding ;tong shi ,xiang tong tiao jian xia ,li ye dan ru kou yue jin ,ying bian yue da 。sui zhao ye dan de qi hua ,wen du sheng gao ,ying bian jian xiao ,zai ye dan de fei dian fu jin ,ying bian qu yu ling 。ji guan he hui guan de ying bian zhi ming xian da yu huan re guan de ying bian liang ,ju wei chi jiao gao de ying bian shui ping ;guan wai jie bing ,jiang ying xiang huan re guan nei wai re jiao huan ,zeng jia ying bian liang ,jie bing bu jin ying xiang qi hua qi huan re xiao guo ,tong shi ying xiang qi hua qi de jie gou an quan 。
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论文详细介绍
论文作者分别是来自兰州理工大学的苏厚德，发表于刊物兰州理工大学2019-07-18论文，是一篇关于开架式气化器论文,数值模拟论文,流动传热特性论文,实验研究论文,力学特性论文,兰州理工大学2019-07-18论文的文章。本文可供学术参考使用，各位学者可以免费参考阅读下载，文章观点不代表本站观点，资料来自兰州理工大学2019-07-18论文网站，若本站收录的文献无意侵犯了您的著作版权，请联系我们删除。
标签：开架式气化器论文; 数值模拟论文; 流动传热特性论文; 实验研究论文; 力学特性论文; 兰州理工大学2019-07-18论文;