Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/2392
標題: 一個螺旋狀熱交換器之熱傳性能
Heat Transfer Performance of a Spiral Heat Exchanger
作者: 陳世豪
Chen, Shih-Hao
關鍵字: spiral heat exchanger
螺旋式熱交換器
effectiveness
second-law efficiency
Reynolds number
熱效率
第二定律效率
雷諾數
出版社: 機械工程學系所
引用: 1.J.Y. San, W.M. Worek, Z. Lavan, “Second-law analysis of a two- dimensional regenerator”, Energy, Vol. 12, pp. 485-496, 1987. 2.N.E. Wijeysundera, J.C. Hartnett, S. Rajaseker, “The effectiveness of a spiral coil heat exchanger”, International Communications in Heat and Mass Transfer, Vol. 23, pp. 623-632, 1996. 3.J.Y. Jang, M.T. Wang, “Transient response of cross flow heat exchangers with one fluid mixed”, Heat and Fluid Flow, Vol. 8, pp. 182-186, 1987. 4.J.Y. San, C.L. Jan, “Second-law analysis of a wet cross flow heat exchanger”, Energy, Vol. 25, pp. 939-955, 2000. 5.P. Naphon, S. Wongwises, “A study of the heat transfer characteristic of a compact spiral coil heat exchanger under wet-surface conditions”, Experimental Thermal and Fluid Science, Vol. 29, pp. 511-521, 2005. 6.T.J. Rennie, V.G.S. Raghavan, “Numerical studies of a double-pipe helical heat exchanger”, Applied Thermal Engineering, Vol. 26, pp. 1266-1273, 2006. 7.J.R. Burns, R.J.J. Jachuck, “Condensation studies using cross- corrugated polymer film compact heat exchanger”, Applied Thermal Engineering, Vol. 21, pp. 495-510, 2001. 8.P.K. Sahoo, Md.I.A. Ansari, A.K. Datta, “A computer based iterative solution for accurate estimation of heat transfer coefficients in a helical tube heat exchanger”, Journal of Food Engineering, Vol. 58, pp. 211-214, 2003. 9.T.J. Rennie, V.G.S. Raghavan, “Experimental studies of a double-pipe helical heat exchanger”, Experimental Thermal and Fluid Science, Vol. 29, pp. 919-924, 2005. 10.D.G. Prabhanjan, G.S.V. Raghavan, T.J. Rennie, “Comparison of heat transfer rates between a straight tube heat exchanger and a helically coiled heat exchanger”, International Communications in Heat and Mass Transfer, Vol. 29, pp. 185-191, 2002. 11.B.A. Qureshi, S.M. Zubair, “Second-law-based performance evaluation of cooling towers and evaporative heat exchangers”, International Journal of Thermal Sciences, Vol. 46, pp.188-198, 2007. 12.S. Wongwises, M. Polsongkram, “Condensation heat transfer and pressure drop of HFC-134a in a helically coiled concentric tube-in-tube heat exchanger”, International Journal of Heat and Mass Transfer, Vol. 29, pp. 4386-4398, 2006. 13.C.Y. Park, P. Hrnjak, “Effect of heat conduction through the fins of a microchannel serpentine gas cooler of transcritical system”, International Journal of Refrigeration, Vol. 30, pp. 389-397, 2007. 14.V. Kumar, S. Saini, M. Sharma, “Pressure drop and heat transfer in tube-in-tube helical heat exchanger”, Chemical Engineering Science, Vol. 61, pp. 4403-4416, 2006. 15.A. Gupta, S.K. Das, “Second law analysis of crossflow heat exchanger in the presence of axial dispersion in one fluid”, Energy, Vol. 35, pp. 664-672, 2007. 16.S.Y. Wu, X.F. Yuan, Y.R. Li, L. Xiao, “Energy transfer effectiveness on heat exchanger for finite pressure drop”, Energy, Vol. 32, pp. 2110-2120, 2007. 17.R. Yun, Y. Kim, C. Park, “Numerical analysis on a microchannel evaporator designed for air-conditioning systems”, Applied Thermal Engineering, Vol. 27, pp. 1320-1326, 2007. 18.T.L. Ngo., Y. Kato, K. Nikitin, T. Ishizuka, “Heat transfer and pressure drop correlations of microchannel heat exchangers with S-shaped and zigzag fins for carbon dioxide cycles”, Experimental Thermal and Fluid Science, Vol. 32, pp. 560-570, 2007. 19.林俊憲,“一個蛇形管式交叉流熱交換器之性能測試”,碩士論文,中興大學機械系,2008。 20.J.Y. San, G.S. Lin, K.L. Pai,“Performance of serpentine heat exchanger: Part I-Effectiveness and heat transfer characteristics”, Applied Thermal Engineering, Vol. 29, pp. 3081-3087, 2009. 21.白凱莉,“一個蛇行熱交換器之熱效率與第二定律效率之分析”,碩士論文,中興大學機械系,2008。 22.J.Y. San, K.L. Pai,“Performance of a serpentine heat exchanger: Part II-Second-law efficiency”, Applied Thermal Engineering, Vol. 29, pp. 3088-3093, 2009. 23.W.M. Kays, A.L. London, Compact Heat Exchanger (3rd edition ), Mcgraw-Hill,1984. 24.A Bejan, Advanced Engineering thermodynamics, John Wiley and Sons,1988.
摘要: 本研究進行一個螺旋式熱交換器之模擬分析,並測試一個此熱交換器實驗模型之熱傳性能,分析模式採一維之熱傳模式,管內流體考慮為混合之狀態,其流動方向為螺旋型式,而管外流體為不混合之狀態,其流動方向為由熱交換器之徑向均勻向外流出。研究中利用電腦模擬分析計算管內流體出口之無因次溫度,將其代入公式後,即可獲得熱交換器之熱效率與第二定律效率。分析之結果顯示,於一個固定之熱傳單位數(Ntu)下,當兩流體之整體熱容率比值(Ct*)等於1時,其熱效率為最低;而Ct*愈趨近於零或無窮大時,其熱效率愈趨近於最高值。相反地,當Ct*值於1附近時,且Ntu值為固定時,其第二定律效率為最大。除此之外,將兩相同之螺旋熱交換器經逆向串聯後,其熱效率與第二定律效率值均會明顯優於單一熱交換器之性能。實驗量測乃針對一個具五圈螺旋管之熱交換器模型進行氣體側(管外)熱對流係數(h)與摩擦因子(f)之量測,所考慮雷諾數(Re)之範圍為353~2593,所得之數據並加以迴歸分析,結果顯示,f值與(Re-300)之-0.393次方成正比,而Nu值則會與[(Re/1000)+8]之3.169次方成正比。
The heat transfer performance of a spiral heat exchanger was numerically and experimentally investigated. In the analysis, a one-dimensional heat transfer model was used. The tube flow is mixed and it flows spirally from the inlet to the outlet. The flow outside the tube is unmixed and it flows radially from the centerline of the spiral tube toward outside. The non-dimensional temperature of the tube flow was evaluated and it yielded the effectiveness and second-law efficiency of the heat exchanger. For a fixed Ntu value, as the ratio of flow heat capacity rates (Ct*) is 1.0, the effectiveness is at the minimum. As the Ct* approaches zero or infinity, the effectiveness would approach the maximum. Conversely, for a fixed Ntu value, as the Ct* value nears 1.0, the second-law efficiency is at the maximum. The effectiveness and second-law efficiency of two heat exchangers in overall-counterflow arrangement appears to be much higher to those of a single heat exchanger. In the experiment, the gas-side (outside the tube) convective heat transfer coefficient (h) and Darcy friction factor (f) of a test model with a five-lap spiral tube was measured. The Reynolds number was in the range 353-2593, The result shows that the f value increases with the (Re-300)^(-0.393).The Nu value increases with the (Re/1000+8)^(3.169).
URI: http://hdl.handle.net/11455/2392
其他識別: U0005-3107200921202600
文章連結: http://www.airitilibrary.com/Publication/alDetailedMesh1?DocID=U0005-3107200921202600
Appears in Collections:機械工程學系所

文件中的檔案:

取得全文請前往華藝線上圖書館



Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.