本文關(guān)鍵詞： 太陽(yáng)能儲(chǔ)熱材料 硝酸熔融鹽 膨脹石墨 錫粉　出處：《西安工程大學(xué)》2015年碩士論文　論文類(lèi)型：學(xué)位論文

【摘要】：化石能源的短缺及其使用帶來(lái)的環(huán)境污染問(wèn)題,嚴(yán)重制約著世界經(jīng)濟(jì)的發(fā)展,太陽(yáng)能作為一種接近無(wú)限的清潔型能源引發(fā)世界性關(guān)注,其中太陽(yáng)能熱發(fā)電是太陽(yáng)能開(kāi)發(fā)利用中最主要的一部分。但是太陽(yáng)能的使用受到晝夜交替、季節(jié)交替、天氣情況的變化存在不連續(xù)性、間歇性。為了在太陽(yáng)能輻射較強(qiáng)時(shí)將豐足的太陽(yáng)能存儲(chǔ),在太陽(yáng)輻射能較低的情況下釋放熱量,因此儲(chǔ)熱材料應(yīng)用而生。而且儲(chǔ)熱技術(shù)以及儲(chǔ)熱材料成為了太陽(yáng)能熱發(fā)電技術(shù)的關(guān)鍵因素。儲(chǔ)熱材料中熔融鹽儲(chǔ)熱材料被廣泛研究,其缺點(diǎn)熔融鹽的凝固點(diǎn)高,易造成管道堵塞,它腐蝕性和高溫下的化學(xué)穩(wěn)定性也是限制其應(yīng)用于主要因素。本文在研究了硝酸鉀、硝酸鈉為原料,以混合熔融法工藝制備樣品,通過(guò)添加膨脹石墨(Expanded Graphite,簡(jiǎn)稱EG)、金屬錫(Sn)和硝酸鋰來(lái)觀察復(fù)合熔鹽的熱性能變化,從而有效解決凝固性問(wèn)題、高溫化學(xué)穩(wěn)定性及其腐蝕性問(wèn)題。實(shí)驗(yàn)結(jié)果表明:膨脹石墨能有效提高熔融鹽的導(dǎo)熱性,添加量為質(zhì)量的5%為宜;金屬錫的加入對(duì)導(dǎo)熱系數(shù)、比熱容有較大的改善,但相容性差,不宜多添加;硝酸鋰能有效降低復(fù)合熔鹽的凝固點(diǎn),但其潮解嚴(yán)重,且價(jià)格昂貴,可以適量添加;硝酸鈉、硝酸鉀、硝酸鋰、膨脹石墨四者之間有良好的化學(xué)相容性,600℃以下相互之間不發(fā)生反應(yīng),無(wú)新的物相生成,滿足儲(chǔ)熱材料的要求。
[Abstract]:The shortage of fossil energy and the environmental pollution caused by its use seriously restrict the development of the world economy. Solar energy, as a kind of clean energy, has aroused worldwide concern. Solar thermal power generation is the most important part of solar energy development and utilization, but the solar energy is used by day and night alternates, seasons alternates, weather condition changes exist discontinuity. Intermittence. In order to store abundant solar energy when solar radiation is strong, heat is released when solar radiation energy is low. Therefore, the application of heat storage materials. And heat storage technology and heat storage materials have become the key factor of solar thermal power generation technology. The molten salt heat storage materials in heat storage materials have been widely studied, but its shortcomings are high solidification point of molten salt. It is easy to cause pipeline blockage, its corrosion and chemical stability at high temperature are also the main factors limiting its application. In this paper, potassium nitrate, sodium nitrate as raw materials, the mixed melting process to prepare samples. The thermal properties of the composite molten salt were observed by adding expanded graphite expanded graphite (EGN) and lithium nitrate to solve the solidification problem effectively. The experimental results show that expanded graphite can effectively improve the thermal conductivity of molten salt, and the appropriate addition amount is 5%; The addition of tin improves the specific heat capacity and the coefficient of thermal conductivity, but the compatibility is poor, so it is not suitable to add more. Lithium nitrate can effectively reduce the solidification point of the compound molten salt, but its moisture is serious, and the price is expensive, so it can be added in appropriate amount. There is no reaction between sodium nitrate, potassium nitrate, lithium nitrate and expanded graphite with good chemical compatibility below 600 鈩，

本文編號(hào)：1493948