第29卷第8期工程熱物理學(xué)報Vol 29. No82008年8月JOURNAL OF ENGINEERING THERMOPHYSICSAug,2008二乙二醇二甲醚液相導(dǎo)熱系數(shù)實(shí)驗(yàn)研究劉云飛吳江濤許曉飛劉志剛西安交通大學(xué)動力工程多相流國家重點(diǎn)實(shí)驗(yàn)室,陜西西安710049)要本文利用瞬態(tài)單熱線法對溫度區(qū)間233~373K、壓力區(qū)間01~30MPa的二乙二醇二甲醚(DMDE)的導(dǎo)熱系行了實(shí)驗(yàn)研究,為替代燃料研究提供了基礎(chǔ)數(shù)據(jù),導(dǎo)熱系數(shù)測不確定度為±2%.實(shí)驗(yàn)數(shù)據(jù)擬合成導(dǎo)熱系數(shù)關(guān)于溫度和壓力的方程,實(shí)驗(yàn)數(shù)據(jù)與擬合方程計算值的最大偏差為-256%,平均絕對偏差為091%關(guān)鍵詞二乙二醇二甲醚;導(dǎo)熱系數(shù);瞬態(tài)熱線法中圖分類號:O621.24文獻(xiàn)標(biāo)識碼:A文章編號:0253-231X(2008)08-1287THERMAL CONDUCTIVITY OF DIETHYLENE GLYCOLDIMETHYL ETHER IN LIQUID PHASELIU Yun-Fei WU Jiang- Tao XU Xiao-Fei LIU Zhi-Gang(State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an Jiaotong University, Xi'an 710049, ChinaAbstract In order to provide the urgent thermophysical data for the research of alternative cleanfuels, using transient hot-wire method, the thermal conductivity of liquid diethylene glycol dimethyether were measured over the temperature range from 233 to 373 K and pressure range from 0.1 to 30Key words DMDE; thermal conductivity; transient hot-wire methd 83MPa. The uncertainty of the thermal conductivity was estimated as #2%. The experimental resultswere correlated as a function of temperature ande. The maximum and the average absolutedeviation of the experimental values from the calculated values were-26% and 0.91%, respectively0引言很多文獻(xiàn)中都有論述B4,其基本的工作方程為現(xiàn)有的研究表明,二乙二醇二甲醚(DMDE)含氧△Tu(0=4Xht+xhn()()量高,是一種潛在含氧燃料添加劑,可提高燃燒性能,降低毒性尾氣排放;另外,DMDE在有機(jī)合成中有式中,A和a分別介質(zhì)的導(dǎo)熱系數(shù)和熱擴(kuò)散系數(shù);多種用途,因此開展DMDE熱物性研究是非常必△Td為熱線的理想溫升;q為單位長度線熱源的加要的。根據(jù)文獻(xiàn)調(diào)查,DMDE的導(dǎo)熱系數(shù)研究非常缺熱量;t為加熱的時間;7為熱線的半徑;C=乏,除了R. Burgdorf曾測量了298.15K和323,15e=1.718.,為歐拉常數(shù).巾式(1)可知,熱線的理K常壓下DMDE的導(dǎo)熱系數(shù)外,未見其它相關(guān)報道.想溫升與加熱時間的對數(shù)呈線性關(guān)系因此可以從線因此,本文對DMDE的導(dǎo)熱系數(shù)開展了實(shí)驗(yàn)研究,性回歸的斜率得到被測流體的導(dǎo)熱系數(shù),并且從截距可以得到流體的熱擴(kuò)散系數(shù),進(jìn)而可以得到其比1實(shí)驗(yàn)原理定壓熱容。實(shí)驗(yàn)原理采用的理想模型,在實(shí)際測量過液體的導(dǎo)熱系數(shù)測量有多種方法,而瞬態(tài)熱線程中有許多因素需要考慮,需要對實(shí)測溫升采取法是目前公認(rèn)的測址流體導(dǎo)熱系數(shù)最好的方法,具些必要的修正,具體內(nèi)容可參見文獻(xiàn)有精度高、測址速度快的優(yōu)點(diǎn),其測量原理是對在無限大介質(zhì)中處于熱平衡的無限長的線熱源施加欣2導(dǎo)熱系數(shù)測量系統(tǒng)沖熱流,線熱源的溫度隨即產(chǎn)生變化,根據(jù)溫升-時整個測量系統(tǒng)主要由高低溫恒溫槽、溫度測量間的關(guān)系,就可以得到液體的導(dǎo)熱系數(shù),具體原理在系統(tǒng)口中國煤化工制系統(tǒng)以及一些收稿日期:200801-15;修訂日期:20080526CNMHG基金項(xiàng)目:全國優(yōu)秀博士論文作者專項(xiàng)資金(No.200540);教育部新世紀(jì)優(yōu)年計劃( NO, NCET-05-0836)作者簡介:劉云飛(1982-),男,內(nèi)紫古赤峰人,碩上,主要從事導(dǎo)熱系數(shù)實(shí)驗(yàn)研究及其數(shù)值模擬工程熱物理學(xué)報配套的設(shè)備組成。恒溫槽的的控溫范圍為210~500快速、穩(wěn)定的低壓電路開關(guān)切換功能,標(biāo)準(zhǔn)電阻是上K,其中低溫槽用酒精作為恒溫介質(zhì),恒溫范圍為海正陽儀表廠生產(chǎn)的BZ3C型直流電阻器,標(biāo)稱值190~320K,高溫槽的恒溫介質(zhì)為201-10#甲基硅1歐姆,等級為0.002級,電阻器的年變化量不超過油,恒溫范圍為243~420K.在導(dǎo)熱系數(shù)測量過程0.0%.整個系統(tǒng)通過GPIB總線連接到工控機(jī),中,恒溫槽的溫度波動度小于±5mK/30min.溫可以很好地實(shí)現(xiàn)采集的自動化度測量采用F700B(313~383K)、 Agilent3458A數(shù)字多用表(223~313K)和2592的標(biāo)準(zhǔn)長桿鉑電阻溫度計.導(dǎo)熱系數(shù)溫度測量的不確定度為±10mK,關(guān)于溫度測量的詳細(xì)說明可參見文獻(xiàn)同6Kcythley 2400瞬態(tài)單熱線法導(dǎo)熱系數(shù)測量裝置由裝置本體和ExperimentalKeithley kResistan數(shù)據(jù)采集系統(tǒng)兩個部分組成,裝置本體如圖1所示,使用的壓力和溫度范圍分別為0~30MPa和Standard Resistance200~470K,該裝置本體除了電路部分,金屬部分全部采用316不銹鋼材料,設(shè)計壓力為40MPa.壓Keythley 2010力腔體的密封采用耐腐蝕的聚四氟乙烯.在滿足要圖2數(shù)據(jù)采集系統(tǒng)求的前提下,本文盡可能地減小了裝置的容積,以System of dat.減少被測流體的充灌量,實(shí)測容積約為40mL,熱絲采用直徑20μm,長度約85mm的鉑絲,鉑絲通壓力控制系統(tǒng)主要由2PB-05平流泵組成,使用過聚四氟乙烯支架固定,在鉑絲上、下末端10mm的壓力范圍是0-~42MPa處各焊接一根同樣粗細(xì)的鉑絲引出作為測壓引線裝置的檢定采用甲苯作為標(biāo)準(zhǔn)物質(zhì),具體檢定過程見參考文獻(xiàn)4].檢定結(jié)果表明,不同溫度下得到的甲苯導(dǎo)熱系數(shù)值與文獻(xiàn)提供的標(biāo)準(zhǔn)值之間的偏差3210小于1%,最大偏差為0.87%,最小偏差為-0.06%平均絕對偏差為0.48%,實(shí)驗(yàn)結(jié)果表明本實(shí)驗(yàn)裝置準(zhǔn)確可靠3實(shí)驗(yàn)結(jié)果及分析實(shí)驗(yàn)使用的二乙二醇二甲醚由上海滬試化工廠生產(chǎn),化學(xué)純。本文在233~373K的溫度范圍內(nèi)每隔20K測量了01MPa~30MPa的液相二乙二醇二甲醚的導(dǎo)熱系數(shù).實(shí)驗(yàn)結(jié)果見表1將實(shí)驗(yàn)數(shù)據(jù)擬合成導(dǎo)熱系數(shù)關(guān)于溫度和壓力的方程,方程形式如下1.抽真空管2.進(jìn)液管3.PTFE支架4.彈簧5.電壓引線A=∑∑aT"P6.容器7.鉑絲8.銅墊圈9.法蘭10.PTFE墊圈=0j=011.密封件12.套筒13.引出線式中,導(dǎo)熱系數(shù),Wm-1K-1;T-溫度圖1實(shí)驗(yàn)裝置圖K;p-壓力,MPaFig 1 Experimenetal apparatus of transient hot-wire擬合得到的式(2)中的系數(shù)a在表2中列出數(shù)據(jù)采集系統(tǒng)主要由 Keithley2010數(shù)字多用式(2)不具有外推性,適用于溫度區(qū)間23373表、 Keithley2400數(shù)字源表、 Keithley7001開關(guān)系K、壓力區(qū)間01~30MPa的DMDE液相導(dǎo)熱系統(tǒng)、標(biāo)準(zhǔn)電阻、電阻箱、和工控機(jī)等組成,如圖2所數(shù)的計算.實(shí)驗(yàn)數(shù)據(jù)與擬合方程偏差如圖3所示示。兩個 Keithley2010數(shù)字多用表,一個用來測量實(shí)驗(yàn)值與公式(2)計算值的最大偏差為-256%,平標(biāo)準(zhǔn)電阻兩端的電壓,從而可以得到通過熱絲的電均絕中國煤化工中給出了2815流;另一個用來測量熱絲兩端電壓。 Keithley2400K數(shù)字源表可提供穩(wěn)定的電壓源,同時可以通過計算驗(yàn)CNMH④值的偏差分別為機(jī)直接調(diào)節(jié)電壓大小. Keithley7001開關(guān)系統(tǒng)提供1.12%和425%,可見實(shí)驗(yàn)結(jié)果相互吻合良好劉云飛等:二乙二醇二甲醚液相導(dǎo)熱系數(shù)實(shí)驗(yàn)研究表1DMDE導(dǎo)熱系數(shù)實(shí)驗(yàn)數(shù)據(jù)Table 1 Thermal conductivity of DMDE溫度壓力線功率導(dǎo)熱系數(shù)偏差溫度壓力線功率導(dǎo)熱系數(shù)偏差T5P8m28m△0A22m2Nmx△2313.5010.10.14801.5089313.650.1477234.3315002934313.6845.00.1493234.1435.00.17040000313.8635.00.5760.149408250.1703314.1470.6220.14970.0582313.76810.00.4910.15141.000710.00.8240.15080.6004234.7350.17180.000031384410.00.6220.15080.60040.17370.0576313.78020.00.15490.15530.909234.00620.00.-0.2304313.79420.00.15480.58483.71430.0313.88233.960.175231416930338130.00.2278314.13430.00.6220.160614529253.9070.10.1646-0.1214333.7280.10.1329253.9720.10.6490.16410.4248333.98300.543-1.39910.7020.16420.364133.7240.10.5432.1:324253.7915.00.1670333.9335.00.502253.8820.7020.1667333.7890.50216595254,2875334.1115.00.1360254.08710.00.1694333.97710.00.16920.4154334.15510.010.00.7570.16970.7720333.95710.00.1381254.10320.00.7020.17220.2328333.60120.00.5020.14132.48450.7020.4075333.83120.00.5430.14112.5553017220.232833398820.00.5430.1410255700.1720333.94630.00.5430.1455-2.47990.2294333.94030.005430.1458254,41130.0-0.0574334.02430.00.14621448125353.6150.1273.7950.6070.16220.3092353.9715.0274.125500.16220.3092353.628500.1295273.6955.00.16200.123353.830.5140.12961.726827392910.00.6560.16320.3054353.905.00.4750.132417679274.18210.0-0.3056353.67010.00.4751.381427408310.00.7050.1834353.97610.00.514176791.1330353.95820.00.5140.13752.0787734353.940.13727082736200.5141.1105353.9630.4380.131.1569273.7830.1702353.58230.00.13960.6070.1698353.9990.5140.1399293.9350.0.15250.7162373.7950.10.3820.11010.6130.2606374.1790.10.4160.11020.6130.19533742920.10.4510.111105430293.604500.9640373.7215.00.4510.1140-0.34970.6140.1542-0.8997373.8305.00.11400.26250.15400.9646373.740.4880.1141026220.15740.0000373.92610.00.4510.11710.67850.157901904373.65210.00.11700.93140.2542294.112200.16319282373.588200.4161.1139373.84920.00.451-0.564293.92320.00.6620.7426373.69520.00.4880.402694.02130.00.16670.6643373.713H0.7943294.05030.00.6620.16690.7850373.921中國煤化工294.2070.8170.724373878CNMHGAA=(入xp-λa),xp是實(shí)驗(yàn)值,l是公式(2)的計算值1290工程熱物理學(xué)報表2式(2)中的系數(shù)a4Table 2 Coefficient aig of eq ( 2)123791x103.10525×10-2-401151×10-39.47577×10-54.12683×104.01613×10-5961789×10-755325×10-7132585×10-73.21955×10-9-1.72155×10-91.01118×10-914428×10-10-3.55441x10從圖中可以看到,相同溫度下DMDE的導(dǎo)熱系數(shù)隨壓力的增大而增大,相同壓力下導(dǎo)熱系數(shù)隨溫度的升高而減小。4結(jié)論本文利用瞬態(tài)單熱線法,對溫度區(qū)間233~373240260280300320340360K、壓力區(qū)間01~30MPa的二乙二醇二甲醚的導(dǎo)熱系數(shù)進(jìn)行了實(shí)驗(yàn)研充,將實(shí)驗(yàn)數(shù)據(jù)擬合成了導(dǎo)熱圖3DMDE導(dǎo)熱系數(shù)實(shí)驗(yàn)值與計算值的偏差系數(shù)關(guān)于溫度和壓力的方程,實(shí)驗(yàn)數(shù)據(jù)與方程計算Fig3 Deviations of experimental data from eq (2)值的最大偏差為-2.56%,平均絕對偏差為091%計算出相同溫度下導(dǎo)熱系數(shù)實(shí)驗(yàn)數(shù)據(jù)的平均參考文獻(xiàn)值擬合成相同壓力下導(dǎo)熱系數(shù)隨溫度變化的曲線,如圖4所示,同理,計算出相同壓力下導(dǎo)熱系數(shù)實(shí)(1朱新寶,王甫全二乙二醇二甲醚的合成與應(yīng)用江蘇化驗(yàn)數(shù)據(jù)的平均值,擬合成相同溫度下導(dǎo)熱系數(shù)隨壓01,29(力變化的曲線,如圖5所示ZHU Xinbao, WANG Fuquan. Systhesis and Applicationof Diethylene Glycol Dimethyl Ether. Jiangsu ChemicalIndustry.2001,29(4):38-412 Burgdorf R, Xocholl A, Arlt W, et al. Thermalphysi-cal Properties of Binary liquid Mixtures of Polyether andn-alkane at 298. 15 and 323. 15 K: Heat of Mixing, HeatCapacity, Viscosity, Density and Thermal Conductivity.0°Fluid Phase Equilibria, 1999,(164): 225-2550.23]Healy JJ, de groot J J, Kestin J. The Theory of the0.11Transient Hot-Wire Method for Measuring Thermal Con-ductivity, Physica, 1976, 82C: 392-408T/K4宋琳豐碳酸二甲酯與碳酸二乙酯導(dǎo)熱系數(shù)的實(shí)驗(yàn)研究圖4DMDE的導(dǎo)熱系數(shù)溫度關(guān)系碩上論文].西安:西安交通大學(xué),2007Fig 4 Thermal conductivity of DMDE as a functionSONG Linfeng. Experimental Research of Thermal Con-ductivity of Dimethyl Carbonate and Diethyl Carbonatein the Liquid Phase: [Master Thesis]. Xi'an: Xi'an Jiao-0.18tong University, 2007阿]吳江漭.高梢度流體熱物性測試系實(shí)驗(yàn)系統(tǒng)的研制及二甲醚熱物理性質(zhì)的研究:博上論文.西安:西安交通大學(xué),2003-°a3kKo25KwU Jiangtao. Development of the New ThermophysicalProperties Measurement System and Research of Ther-mophysical Properties of Dimethy Ether: [Ph D. Thesis]△273KV293KXi'an: Xi'an Jiaotong University, 2003◇33K<333K☆373K6吳江濤,劉志剛,潘江高精度流體熱物性測試試驗(yàn)系統(tǒng)的研制.西安交通大學(xué)學(xué)報,2004,38(9):937-942LIU Zhigang. PAn Jiang. Developmen圖5DMDE的導(dǎo)熱系數(shù)壓力關(guān)系中國煤化工 Measurement SysteFig 5 Thermal conductivity of dMDE as afunction of pressureCNMHGan Jiaotong Univer-