本文選題：石墨烯 + 氧化石墨烯��； 參考：《西南石油大學(xué)》2017年碩士論文

【摘要】：目前,強(qiáng)化傳熱手段的創(chuàng)新,主要集中在新型換熱器的開發(fā),提高換熱效率,降低能量損失,減小設(shè)備體積。雖然換熱設(shè)備不斷完善,但是由于以水、醇、油為代表的傳統(tǒng)純液體換熱工質(zhì)導(dǎo)熱系數(shù)低,換熱體系仍很難達(dá)到高負(fù)荷有效換熱的要求。因此,研究者們開始嘗試從換熱工質(zhì)著手,研究納米流體的換熱性能,希望攻克強(qiáng)化傳熱領(lǐng)域的這一技術(shù)瓶頸。其中,石墨烯具有超高的導(dǎo)熱系數(shù),丙二醇作為一種無(wú)臭無(wú)毒且生物可降解性的綠色換熱介質(zhì),逐步替代乙二醇。因此,本文從高效性和環(huán)保性出發(fā),制備了一種高效綠色的分散體系1,2-PG/RGO納米流體,并分析研究了其熱性能。本文具體研究?jī)?nèi)容總結(jié)如下:(1)在強(qiáng)酸性條件下,以石墨為原料,以高錳酸鉀作為氧化劑,合成氧化石墨烯GO,在無(wú)水乙醇中,以水合肼為還原劑,合成石墨烯RGO;采用兩步法,以1,2-丙二醇為基液,制備1,2-PG/RGO納米流體和1,2-PG/GO納米流體。然后,使用拉曼光譜、X射線衍射、掃描電子顯微鏡、透射電子顯微鏡對(duì)樣品進(jìn)行表征;最后,采用靜置沉降實(shí)驗(yàn)、Zeta電位實(shí)驗(yàn)、分散穩(wěn)定性分析儀研究納米分散體系的分散穩(wěn)定性,實(shí)驗(yàn)結(jié)果表明1,2-PG/RGO體系的分散穩(wěn)定性優(yōu)于1,2-PG/GO體系。(2)采用KD2-Pro熱特性分析儀,測(cè)定1,2-PG/RGO納米流體導(dǎo)熱系數(shù),實(shí)驗(yàn)結(jié)果表明隨著RGO微粒體積濃度的升高,1,2-PG/RGO體系的導(dǎo)熱系數(shù)不斷增大。溫度升高,低體積濃度下,體系導(dǎo)熱系數(shù)減小,較高體積濃度下,體系導(dǎo)熱系數(shù)增大。在40℃溫度條件下,1.0%體積分?jǐn)?shù)的1,2-PG/RGO體系導(dǎo)熱系數(shù)值可達(dá)0.276 W/(m·K),比基液1,2-PG提高了 28.37%。(3)采用紫外-可見光分光光度計(jì)和MATLAB分別測(cè)定與計(jì)算了 1,2-PG/RGO納米流體的吸光度、透射率、消光系數(shù)以及太陽(yáng)能吸收分?jǐn)?shù),結(jié)果表明1,2-PG/RGO體系展現(xiàn)出全波段吸收特性,體積分?jǐn)?shù)越大,光吸收性能越好。對(duì)于體積份額為0.02%的1,2-PG/RGO納米流體,入射光光程為0.34cm時(shí),可達(dá)到90%的太陽(yáng)能吸收分?jǐn)?shù)。(4)測(cè)定了不同條件下1,2-PG/RGO納米流體的粘度,分析實(shí)驗(yàn)數(shù)據(jù)可知,隨著體積濃度的升高,體系粘度值降低。剪切速率較小時(shí),1,2-PG/RGO體系表現(xiàn)出剪切稀釋特性,剪切速率較高時(shí),表現(xiàn)出牛頓流體的特性。(5)通過(guò)Fluent軟件,仿真模擬1,2-PG/RGO納米流體在自然對(duì)流狀態(tài)下的熱量傳遞過(guò)程,發(fā)現(xiàn)RGO納米微粒的添加在一定程度上改善基液的自然對(duì)流換熱�；谝陨涎芯�,1,2-PG/RGO納米流體可以考慮作為設(shè)備換熱體系或者太陽(yáng)能集熱系統(tǒng)的工作介質(zhì)。
[Abstract]:At present, the innovation of heat transfer enhancement mainly focuses on the development of new heat exchanger, improving heat transfer efficiency, reducing energy loss and reducing equipment volume. Although the heat transfer equipment has been improved continuously, it is difficult for the heat transfer system to meet the requirement of high load and effective heat transfer due to the low thermal conductivity of the traditional pure liquid heat transfer medium represented by water, alcohol and oil. Therefore, the researchers began to try to study the heat transfer performance of nanofluids from the perspective of heat transfer fluids, hoping to overcome this technical bottleneck in the field of enhanced heat transfer. Among them, graphene has a high thermal conductivity, propylene glycol as a odorless and biodegradable green heat transfer medium, step by step to replace ethylene glycol. Therefore, based on the high efficiency and environmental protection, a kind of high efficient green dispersion system (1hpPG- RGO) was prepared, and its thermal properties were studied. The specific research contents of this paper are summarized as follows: under strong acid conditions, graphene oxide (GOO) was synthesized by using graphite as raw material and potassium permanganate as oxidant. In anhydrous ethanol, hydrazine hydrate was used as reductant to synthesize graphene RGO.Two-step method was used. In this paper, 1 ~ (2) -PGR _ (R) nano-fluid and 1 ~ (2) -PGR _ (-go) nano-fluid were prepared by using 1 ~ (2) -propanediol as the base solution. Then, the samples were characterized by Raman spectrum X-ray diffraction, scanning electron microscope and transmission electron microscope. The dispersion stability of nanometer dispersion system was studied by dispersion stability analyzer. The experimental results showed that the dispersion stability of 1o 2-PGR / RGO system was better than that of 1H 2-PGR / RGO system. (2) the thermal conductivity of 1nc-PGR / RGO nano-fluid was measured by KD2-Pro thermal analysis instrument. The experimental results show that the thermal conductivity of the system increases with the increase of the volume concentration of RGO particles. With the increase of temperature, the thermal conductivity of the system decreases at low volume concentration, and increases at higher volume concentration. At the temperature of 40 鈩，

本文編號(hào)：1844137