發(fā)布時(shí)間：2018-09-01 20:17

【摘要】：隨著工業(yè)的飛速發(fā)展和人類(lèi)生活水平的提高,能源需求量一直處于上升趨勢(shì)。由于不合理的開(kāi)采和利用,能源短缺問(wèn)題已在全球范圍內(nèi)出現(xiàn),但能源浪費(fèi)現(xiàn)象依然十分嚴(yán)重,因此采用合理有效的方法提高能源利用率顯得尤為重要。儲(chǔ)能技術(shù)可以將太陽(yáng)能、工業(yè)余熱等以熱能的形式儲(chǔ)存起來(lái),緩解能源供給與使用之間存在的空間和時(shí)間差問(wèn)題,成為提高能源利用率的有效手段。儲(chǔ)能技術(shù)的研究主要包括對(duì)儲(chǔ)熱材料和儲(chǔ)熱裝置結(jié)構(gòu)的研究。由于大部分的儲(chǔ)熱材料熱導(dǎo)率不高,使得儲(chǔ)熱裝置整體傳熱效率較低,因此尋求合適的強(qiáng)化傳熱手段以提高系統(tǒng)充放熱效率很重要。本文選取中高溫儲(chǔ)熱材料中常見(jiàn)的NaNO3-46KNO3、LiNO3、己二酸作為相變儲(chǔ)熱材料,組建相應(yīng)的蓄熱裝置結(jié)構(gòu),研究裝置的傳熱特性和強(qiáng)化傳熱效果。為提高系統(tǒng)整體傳熱效率,針對(duì)裝置中煙氣熱導(dǎo)率較低的問(wèn)題,分別設(shè)計(jì)了盤(pán)管式和波紋管式兩種蓄熱裝置。盤(pán)管結(jié)構(gòu)能在較小的尺寸范圍內(nèi)延長(zhǎng)煙氣的行駛路徑,增加接觸時(shí)間,提高傳熱速率;波紋管結(jié)構(gòu)能增大換熱接觸面積、增強(qiáng)流體擾動(dòng)以強(qiáng)化傳熱,且相變材料的體積填充比大,材料利用率高。建立了盤(pán)管式余熱回收蓄熱裝置結(jié)構(gòu)模型,根據(jù)理論計(jì)算經(jīng)驗(yàn)公式,初步確定了結(jié)構(gòu)單元特征和尺寸,簡(jiǎn)化模型后進(jìn)行三維建模,利用Fluent軟件對(duì)蓄熱裝置的放熱過(guò)程進(jìn)行數(shù)值模擬研究,模擬換熱過(guò)程中蓄熱裝置內(nèi)的溫度場(chǎng)分布、液相率分布,各監(jiān)測(cè)點(diǎn)監(jiān)測(cè)面的溫度變化等,分析了不同導(dǎo)熱油入口流速、蓄熱裝置初始溫度和自然對(duì)流對(duì)系統(tǒng)充放熱性能的影響,得出最佳的工況條件。計(jì)算了相變材料選用NaNO3-46KNO3和LiNO3時(shí)的裝置蓄熱量分別為0.481MWh和0.508MWh。根據(jù)結(jié)構(gòu)中相關(guān)部件的合理化分析,對(duì)蓄熱裝置中各單元結(jié)構(gòu)和尺寸進(jìn)行優(yōu)化,為盤(pán)管式蓄熱裝置的實(shí)際應(yīng)用提供參考。建立了波紋管式蓄熱裝置的單管二維數(shù)學(xué)模型,與相應(yīng)尺寸光管單元模型的充放熱過(guò)程進(jìn)行對(duì)比分析,比較波紋管的強(qiáng)化傳熱效果。并在25mm管徑條件下,模擬了充放熱過(guò)程中儲(chǔ)熱單元溫度場(chǎng)分布、相界面移動(dòng)規(guī)律、監(jiān)測(cè)點(diǎn)溫度變化趨勢(shì)和相變材料蓄熱量等,分析了不同波節(jié)間距和波節(jié)高度對(duì)蓄熱單元充放熱性能的影響,得到最佳波節(jié)高度和波節(jié)間距尺寸參數(shù)。經(jīng)過(guò)計(jì)算得到在最佳結(jié)構(gòu)參數(shù)下的波紋管蓄熱裝置整體蓄熱量為66978kJ,為波紋管式余熱回收蓄熱裝置在工程實(shí)際中的應(yīng)用提供一定的參考價(jià)值。
[Abstract]:With the rapid development of industry and the improvement of human living standards, energy demand has been on the rise. Because of unreasonable exploitation and utilization, the problem of energy shortage has appeared all over the world, but the phenomenon of energy waste is still very serious, so it is very important to adopt reasonable and effective methods to improve energy efficiency. Energy storage technology can store solar energy and industrial waste heat in the form of heat energy, alleviate the space and time difference between energy supply and use, and become an effective means to improve energy efficiency. The research of energy storage technology mainly includes the research of heat storage material and heat storage device structure. Due to the low thermal conductivity of most heat storage materials, the overall heat transfer efficiency of the heat storage device is low, so it is very important to find suitable means to enhance the heat transfer efficiency of the system. In this paper, NaNO3-46KNO3,LiNO3, adipic acid, which is common in medium and high temperature heat storage materials, is selected as phase change storage material, and the corresponding heat storage device structure is constructed to study the heat transfer characteristics and enhanced heat transfer effect of the device. In order to improve the overall heat transfer efficiency of the system, two kinds of heat storage devices, coil type and corrugated tube type, were designed to solve the problem of low thermal conductivity of flue gas in the device. The coil structure can prolong the running path of flue gas, increase the contact time and increase the heat transfer rate in the small size range, and the corrugated tube structure can increase the heat transfer contact area and enhance the fluid disturbance to enhance the heat transfer. The volume filling ratio of phase change material is large and the material utilization ratio is high. The structure model of coil type waste heat recovery and storage device is established. According to the empirical formula of theoretical calculation, the characteristics and dimensions of the structure unit are preliminarily determined, and the three-dimensional modeling is carried out after simplifying the model. The heat release process of heat storage device is simulated by Fluent software. The temperature field distribution, liquid phase rate distribution and temperature change of monitoring surface in the heat storage device during heat transfer process are simulated, and the inlet velocity of different heat conduction oil is analyzed. The effects of the initial temperature and natural convection of the heat storage device on the system's heat filling and releasing performance are discussed. The optimal operating conditions are obtained. The heat storage of the device with NaNO3-46KNO3 and LiNO3 is calculated as 0.481MWh and 0.508MWh. respectively. According to the reasonable analysis of the relative parts in the structure, the structure and size of each unit in the heat storage device are optimized, which provides a reference for the practical application of the coil type heat storage device. The two-dimension mathematical model of the corrugated tube type heat storage device is established. The heat transfer enhancement effect of the corrugated tube is compared with that of the corresponding size light tube unit model. Under the condition of 25mm pipe diameter, the temperature field distribution of heat storage unit, the law of phase interface movement, the temperature change trend of monitoring point and the heat storage of phase change material during heat filling and exothermic process are simulated. The effects of different pitch spacing and pitch height on the heat storage unit are analyzed and the optimum parameters of pitch height and pitch size are obtained. The overall heat storage capacity of the corrugated tube heat storage device under the optimum structural parameters is 66978kJ, which provides a certain reference value for the application of the corrugated tube heat recovery device in engineering practice.
【學(xué)位授予單位】：武漢理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類(lèi)號(hào)】：TB34;TK115

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 王霞;王利恩;;熔融鹽儲(chǔ)熱技術(shù)在新能源行業(yè)中的應(yīng)用進(jìn)展[J];電氣制造;2013年10期

2 鄧靜;;回轉(zhuǎn)窯高溫?zé)煔庥酂岬幕厥绽肹J];科技風(fēng);2013年09期

3 付路軍;董發(fā)勤;楊玉山;何平;;二元脂肪酸/SiO_2復(fù)合相變儲(chǔ)能材料的制備與表征[J];功能材料;2013年04期

4 凌空;封永亮;陶文銓;;帶環(huán)狀翅片管式相變儲(chǔ)熱器的數(shù)值模擬[J];工程熱物理學(xué)報(bào);2012年08期

5 周衛(wèi)兵;張磊;朱教群;孫正;程曉敏;;硬脂酸/膨脹石墨復(fù)合相變儲(chǔ)熱的動(dòng)力學(xué)研究[J];武漢理工大學(xué)學(xué)報(bào);2012年07期

6 李元元;程曉敏;俞鐵銘;;Sn-Zn合金相變儲(chǔ)熱材料的熱循環(huán)穩(wěn)定性[J];特種鑄造及有色合金;2012年07期

7 白松;;單管程浮頭換熱器中波形膨脹節(jié)的設(shè)計(jì)[J];石油化工設(shè)備技術(shù);2012年01期

8 郭茶秀;劉樹(shù)蘭;;固-液相變傳熱強(qiáng)化過(guò)程研究進(jìn)展[J];廣州化工;2011年12期

9 李利民;莊春龍;張洪宇;鄧安仲;李勝波;;焓法模型求解相變傳熱問(wèn)題有效性分析[J];后勤工程學(xué)院學(xué)報(bào);2011年03期

10 李麗莎;閆全英;;相變圍護(hù)結(jié)構(gòu)的研究及發(fā)展[J];材料導(dǎo)報(bào);2010年S2期

相關(guān)碩士學(xué)位論文 前2條

1 俞鐵銘;Sn-Bi-Zn-Cu-Pb多元合金中溫相變儲(chǔ)熱性能研究[D];武漢理工大學(xué);2012年

2 歐陽(yáng)梅;針翅管式相變蓄熱換熱性能的數(shù)值模擬[D];重慶大學(xué);2009年

，

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