內(nèi)燃機(jī)余熱回收溫差發(fā)電器多參數(shù)數(shù)值模型及優(yōu)化設(shè)計(jì)
本文選題:溫差發(fā)電器 + 數(shù)值模型。 參考:《天津大學(xué)》2016年碩士論文
【摘要】:能源與環(huán)境是人類面臨的重大課題,開發(fā)新能源和充分利用低品位能源、廢熱能源具有重大意義。內(nèi)燃機(jī)所產(chǎn)生的能量中,大約有30%的能量以廢熱形式由尾氣排出,溫差發(fā)電技術(shù)可以利用半導(dǎo)體熱電轉(zhuǎn)換材料直接將熱能轉(zhuǎn)換為電能,容易在汽車發(fā)動(dòng)機(jī)上進(jìn)行布置且環(huán)境友好,可以有效回收內(nèi)燃機(jī)排氣中的余熱。鑒于國(guó)內(nèi)、外在溫差發(fā)電器建模方面存在的缺陷,本文基于熱力學(xué)定律和FLUENT UDF基本理論,建立多參數(shù)三維溫差發(fā)電器數(shù)值模型。論文主要工作如下:首先建立多參數(shù)三維溫差發(fā)電單偶數(shù)值模型,此模型所考慮參數(shù)包括變物性參數(shù)、幾何參數(shù)、維度、陶瓷片、外部溫度和流動(dòng)參數(shù)、可逆參數(shù)和不可逆參數(shù)。其中,可逆參數(shù)主要包括塞貝克效應(yīng)和帕爾貼效應(yīng),不可逆參數(shù)包括傅立葉效應(yīng)、焦耳效應(yīng)、湯姆遜效應(yīng)、空氣間隙熱損失、接觸熱阻和接觸電阻。其次,驗(yàn)證了本文所建數(shù)值模型正確性。分析不同熱端溫度和不同對(duì)流換熱系數(shù)條件下,溫差發(fā)電單偶性能隨電流的變化趨勢(shì);重點(diǎn)分析變物性參數(shù)、湯姆遜效應(yīng)、空氣間隙熱損失對(duì)模型的影響。結(jié)果顯示:輸出功率和轉(zhuǎn)化效率的變化趨勢(shì)與之前的數(shù)學(xué)模型模擬結(jié)果相一致,但是,最大效率電阻并不符合之前的數(shù)學(xué)模型所得出最大效率電阻與內(nèi)阻相等的結(jié)論,而是有一定的漂移;物性參數(shù)對(duì)數(shù)值模型的影響最大,不可忽略;考慮湯姆遜效應(yīng)可以提高模型的精度;空氣間隙熱損失僅影響溫差發(fā)電器的轉(zhuǎn)化效率,而對(duì)輸出功率的影響可以忽略。然后,基于所建模型,從溫差發(fā)電單元的長(zhǎng)度、截面面積影響兩個(gè)方面,對(duì)溫差發(fā)電單偶結(jié)構(gòu)做出優(yōu)化設(shè)計(jì)。結(jié)果顯示:存在最優(yōu)長(zhǎng)度使得輸出功率和轉(zhuǎn)化效率均得到最優(yōu)值;最大輸出功率隨橫截面積的增大而增大,但轉(zhuǎn)化效率隨橫截面積的增大而減小。最后,將溫差發(fā)電單偶數(shù)值模型擴(kuò)展到溫差發(fā)電模塊層面,利用該數(shù)值模型對(duì)溫差發(fā)電模塊與熱交換器進(jìn)行了模擬分析和優(yōu)化設(shè)計(jì),為溫差發(fā)電技術(shù)回收發(fā)動(dòng)機(jī)排氣余熱提供依據(jù)。結(jié)果顯示:根據(jù)換熱器表面溫度合理的布置不同材料的溫差發(fā)電模塊,可以提高輸出功率。
[Abstract]:Energy and environment are important tasks for human being. It is of great significance to develop new energy sources and make full use of low grade energy and waste heat energy. About 30% of the energy generated by internal combustion engines is discharged by exhaust gas in the form of waste heat. Thermoelectric power generation technology can directly convert heat energy into electric energy by using semiconductor thermoelectric conversion materials. Easy to arrange on the automobile engine and environment friendly, can effectively recover the waste heat in the exhaust gas of the internal combustion engine. In view of the defects in the modeling of the external thermoelectric generator in China, based on the laws of thermodynamics and the basic theory of fluent UDF, the numerical model of the multi-parameter three-dimensional thermoelectric generator is established in this paper. The main work of this paper is as follows: firstly, a multi-parameter three-dimensional thermoelectric single-couple numerical model is established. The parameters of the model include variable physical parameters, geometric parameters, dimensions, ceramic chips, external temperature and flow parameters. Reversible and irreversible parameters. Among them, reversible parameters mainly include Sebek effect and Partier effect, irreversible parameters include Fourier effect, Joule effect, Thomson effect, air gap heat loss, contact thermal resistance and contact resistance. Secondly, the correctness of the numerical model is verified. The variation trend of single couple performance with current under different hot end temperature and different convection heat transfer coefficient is analyzed, and the effects of variable physical parameters, Thomson effect and air gap heat loss on the model are analyzed. The results show that the variation trend of output power and conversion efficiency is consistent with the simulation results of previous mathematical models, but the maximum efficiency resistance does not accord with the conclusion that the maximum efficiency resistance and the internal resistance obtained from the previous mathematical model are equal. But there is a certain drift; physical parameters have the greatest influence on the numerical model, can not be ignored; considering the Thomson effect can improve the accuracy of the model; air gap heat loss only affects the conversion efficiency of thermogenerators, The effect on output power can be neglected. Then, based on the model, the structure of thermoelectric unit is optimized from two aspects: the length of thermoelectric unit and the influence of cross-section area. The results show that the maximum output power increases with the increase of cross-sectional area, but the conversion efficiency decreases with the increase of cross-sectional area. Finally, the single and even numerical model of thermoelectricity generation is extended to the thermoelectricity generation module, and the simulation analysis and optimization design of the thermoelectricity generation module and heat exchanger are carried out by using the numerical model. It provides the basis for the recovery of engine exhaust heat by thermoelectric technology. The results show that according to the surface temperature of heat exchanger, the output power can be increased if different materials are reasonably arranged.
【學(xué)位授予單位】:天津大學(xué)
【學(xué)位級(jí)別】:碩士
【學(xué)位授予年份】:2016
【分類號(hào)】:TM913;TK403
【參考文獻(xiàn)】
相關(guān)期刊論文 前10條
1 喻紅濤;張志豐;邱清泉;張國(guó)民;;基于ANSYS的溫差發(fā)電器性能[J];電工技術(shù)學(xué)報(bào);2014年07期
2 程富強(qiáng);洪延姬;祝超;;碲化鉍溫差發(fā)電模塊構(gòu)型優(yōu)化設(shè)計(jì)[J];高電壓技術(shù);2014年05期
3 董衛(wèi);張慶;吳仲武;楊良化;姚海濤;;PZT與TeBi半導(dǎo)體材料熱電轉(zhuǎn)換特性的對(duì)比分析[J];熱科學(xué)與技術(shù);2014年01期
4 舒歌群;賈琦;田華;孫秀秀;許曉菲;;內(nèi)燃機(jī)排氣余熱回收溫差電單偶的模擬分析[J];天津大學(xué)學(xué)報(bào)(自然科學(xué)與工程技術(shù)版);2014年02期
5 鄧亞東;殷淑娥;詹衛(wèi)煒;蘇楚奇;;汽車尾氣溫差發(fā)電裝置熱場(chǎng)數(shù)值模擬分析[J];武漢大學(xué)學(xué)報(bào)(工學(xué)版);2014年01期
6 楊素文;肖恒;歐強(qiáng);茍小龍;;廢熱式溫差發(fā)電器性能仿真[J];計(jì)算機(jī)仿真;2012年11期
7 張?jiān)骑w;任曉江;張眾杰;;內(nèi)燃機(jī)熱平衡仿真研究現(xiàn)狀與展望[J];內(nèi)燃機(jī)與配件;2011年09期
8 杜群貴;;Influence of Structure Parameters on Performance of the Thermoelectric Module[J];Journal of Wuhan University of Technology(Materials Science Edition);2011年03期
9 楊雙亮;張紅;許輝;;車用溫差發(fā)電裝置換熱性能的數(shù)值模擬研究[J];低溫與超導(dǎo);2011年05期
10 劉彬;梁虹;陳研;張紅光;;發(fā)動(dòng)機(jī)余熱回收技術(shù)的研究現(xiàn)狀及發(fā)展趨勢(shì)[J];小型內(nèi)燃機(jī)與摩托車;2011年02期
相關(guān)碩士學(xué)位論文 前2條
1 梁虹;有機(jī)朗肯循環(huán)在柴油機(jī)尾氣余熱利用方面的應(yīng)用研究[D];北京工業(yè)大學(xué);2011年
2 屈健;低溫差下半導(dǎo)體溫差發(fā)電器設(shè)計(jì)與性能研究[D];同濟(jì)大學(xué);2006年
,本文編號(hào):2014653
本文鏈接:http://sikaile.net/kejilunwen/dongligc/2014653.html