本文選題：太陽(yáng)能 + 多孔介質(zhì)��； 參考：《哈爾濱工業(yè)大學(xué)》2015年碩士論文

【摘要】：面對(duì)傳統(tǒng)能源供給短缺、不可再生和容易造成環(huán)境污染等弊病,世界各國(guó)致力于發(fā)展持續(xù)、高效、可再生的各類新能源,來(lái)解決傳統(tǒng)能源開(kāi)發(fā)利用帶來(lái)的問(wèn)題。太陽(yáng)能熱化學(xué)利用以其新穎、高效等特點(diǎn)成為新能源研究領(lǐng)域的重點(diǎn)。傳統(tǒng)的太陽(yáng)能熱化學(xué)轉(zhuǎn)化裝置由于有效氣體產(chǎn)量低、費(fèi)用高等缺點(diǎn)無(wú)法實(shí)現(xiàn)推廣,而多孔介質(zhì)太陽(yáng)能反應(yīng)器具有質(zhì)量輕、體表面積大等優(yōu)點(diǎn),使得其轉(zhuǎn)化效率較高,以其為載體的太陽(yáng)能熱化學(xué)轉(zhuǎn)化裝置成為近年來(lái)研究的重點(diǎn),對(duì)其進(jìn)行研究不僅具有重要的理論價(jià)值,更具有廣泛的工程應(yīng)用前景。因此,本文對(duì)高匯聚太陽(yáng)能流下多孔介質(zhì)反應(yīng)器內(nèi)甲烷水蒸氣重整制氫的熱化學(xué)反應(yīng)瞬態(tài)響應(yīng)特性開(kāi)展了數(shù)值研究。本文以表面涂有催化涂層的多孔介質(zhì)熱化學(xué)反應(yīng)器為研究對(duì)象,基于多孔介質(zhì)流動(dòng)及傳熱傳質(zhì)模型,將熱化學(xué)反應(yīng)機(jī)理與“局部非平衡假設(shè)”相耦合,建立了高匯聚太陽(yáng)能流下甲烷水蒸氣重整制取氫氣的熱化學(xué)瞬態(tài)反應(yīng)模型。首先,在無(wú)熱化學(xué)反應(yīng)的條件下,分析多孔介質(zhì)反應(yīng)器內(nèi)混合流體流動(dòng)及傳熱過(guò)程,重點(diǎn)研究各類關(guān)鍵因素對(duì)溫度場(chǎng)瞬態(tài)響應(yīng)特性的影響,為后續(xù)甲烷水蒸氣重整制取氫氣的熱化學(xué)反應(yīng)研究提供一定依據(jù)。然后,分別采用蒙特卡羅熱流和高斯熱流作為邊界熱源,選取典型工況,對(duì)多孔介質(zhì)反應(yīng)器熱化學(xué)反應(yīng)的溫度場(chǎng)及產(chǎn)物場(chǎng)的瞬態(tài)響應(yīng)特性進(jìn)行模擬研究。最后,針對(duì)邊界條件、多孔介質(zhì)物性和邊界輻射熱損失,著重研究其在瞬態(tài)熱化學(xué)反應(yīng)過(guò)程中對(duì)制氫效率的影響。研究結(jié)果表明,多孔介質(zhì)反應(yīng)器內(nèi)各點(diǎn)穩(wěn)態(tài)溫度和出口流體溫度均隨入口混合流體中甲烷相對(duì)含量的增加而升高,如甲烷含量升高50%,出口流體溫度升高約40K;在孔隙率0.66-0.93范圍內(nèi),出口流體溫度隨孔隙率減小而升高,氫氣相對(duì)產(chǎn)量升高,如孔隙率由0.9降低為0.7時(shí),出口流體溫度升高約60K,氫氣相對(duì)產(chǎn)量升高約8%;出口面氫氣產(chǎn)量隨固體骨架導(dǎo)熱系數(shù)的升高而增大,如導(dǎo)熱系數(shù)增加20%,氫氣產(chǎn)量增加約10%;混合流體入口流速降低,出口面氫氣相對(duì)產(chǎn)量升高,如入口流速減小0.025m/s,氫氣相對(duì)產(chǎn)量增大約6%;在不考慮邊界輻射熱損失的條件下,出口面氫氣產(chǎn)量較高,但實(shí)際工作環(huán)境下,由于入口壁面溫度較高,輻射熱損失對(duì)瞬態(tài)溫度場(chǎng)和產(chǎn)物場(chǎng)的影響較大,應(yīng)在考慮輻射熱損失的前提下,設(shè)法降低其影響。
[Abstract]:In the face of the shortage of traditional energy supply, non-renewable and easy to cause environmental pollution, countries all over the world are committed to the development of sustainable, efficient and renewable new energy to solve the problems brought about by the development and utilization of traditional energy. Thermochemical utilization of solar energy has become the focus in the field of new energy for its novel and high efficiency. The traditional solar thermochemical conversion device can not be popularized because of its low effective gas output and high cost, while the porous medium solar reactor has the advantages of light weight and large surface area, which makes its conversion efficiency higher. The solar thermochemical conversion device with solar energy as its carrier has become the focus of research in recent years. Its research not only has important theoretical value, but also has a wide range of engineering application prospects. Therefore, the transient response characteristics of thermal chemical reaction in a porous medium reactor for hydrogen production by steam reforming of methane with high convergent solar energy flow have been studied numerically in this paper. In this paper, a porous medium thermochemical reactor coated with catalytic coating is studied. Based on the porous media flow and heat and mass transfer model, the thermochemical reaction mechanism is coupled with the "local non-equilibrium hypothesis". A thermochemical transient reaction model for hydrogen production by steam reforming of methane with high convergent solar energy was established. Firstly, under the condition of no thermal chemical reaction, the flow and heat transfer process of mixed fluid in porous media reactor is analyzed, and the influence of various key factors on the transient response of temperature field is studied. It provides a basis for the study of the thermal chemical reaction of methane steam reforming to produce hydrogen. Then, Monte Carlo heat flow and Gao Si heat flux were used as boundary heat source, and the transient response characteristics of thermal chemical reaction temperature field and product field in porous media reactor were simulated. Finally, considering the boundary conditions, the physical properties of porous media and the heat loss of the boundary radiation, the effect of the porous media on the efficiency of hydrogen production during the transient thermal chemical reaction is studied. The results show that the steady state temperature and outlet fluid temperature in the porous media reactor increase with the increase of the relative content of methane in the inlet mixed fluid. If the methane content increases by 50, the outlet fluid temperature increases by about 40K, and the porosity ranges from 0.66-0.93. The temperature of outlet fluid increases with the decrease of porosity, and the relative yield of hydrogen increases, such as when the porosity decreases from 0.9 to 0.7, The outlet fluid temperature increases about 60K, and the relative hydrogen production increases by 8. The hydrogen production increases with the increase of the thermal conductivity of solid skeleton, such as the increase of the thermal conductivity by 20, the increase of the hydrogen production by about 10 percent, and the decrease of the flow rate at the inlet of the mixed fluid. The relative production of hydrogen on the outlet surface is increased, if the inlet velocity is decreased by 0.025 m / s, the relative production of hydrogen gas increases by about 6 parts. Without considering the boundary radiation heat loss, the output of hydrogen on the outlet surface is higher, but in the actual working environment, the temperature of the inlet wall is higher. The radiation heat loss has a great influence on the transient temperature field and the product field, so we should try to reduce the effect of radiation heat loss on the premise of considering the radiation heat loss.
【學(xué)位授予單位】：哈爾濱工業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TQ116.2

【參考文獻(xiàn)】

相關(guān)期刊論文 前4條

1 朱群志;;直接吸收太陽(yáng)輻射集熱器/熱化學(xué)反應(yīng)器的研究進(jìn)展[J];上海電力學(xué)院學(xué)報(bào);2013年02期

2 許達(dá);劉啟斌;隋軍;金紅光;;太陽(yáng)能與甲醇熱化學(xué)互補(bǔ)的分布式能源系統(tǒng)研究[J];工程熱物理學(xué)報(bào);2013年09期

3 許昌;劉德有;鄭源;郭蘇;嚴(yán)彥;;多孔介質(zhì)太陽(yáng)能吸熱器的非穩(wěn)態(tài)傳熱[J];華南理工大學(xué)學(xué)報(bào)(自然科學(xué)版);2011年03期

4 吳娟;龍新峰;;太陽(yáng)能熱化學(xué)儲(chǔ)能研究進(jìn)展[J];化工進(jìn)展;2014年12期

，

本文編號(hào)：2060274