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研究生:熊世康
研究生(外文):Shih-Kong Shung
論文名稱:PartI:汽車空調舒適性提升之研究;PartII:LED散熱分析
論文名稱(外文):PartI:Improvement on Thermal Comfort in an Air-Conditioned Automobile Cabin; PartII:Analysis of LED Cooling
指導教授:溫志湧梁勝明
指導教授(外文):Chih-Yung WenShen-Min Liang
學位類別:碩士
校院名稱:國立成功大學
系所名稱:航空太空工程學系碩博士班
學門:工程學門
學類:機械工程學類
論文種類:學術論文
畢業學年度:96
語文別:中文
論文頁數:134
中文關鍵詞:熱舒適性散熱
外文關鍵詞:LEDPMVPPD
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PartI:
現代生活水平提昇,汽車也不再只是以往單純的代步工具,更多的功能、更好的品質、更舒適性空調皆為汽車發展的趨勢。本文中針對車艙內的熱舒適性做研究,以實驗結合數值模擬的方式建立一套可預測車艙內熱舒適性的可靠模擬方法。在實驗方面,將車艙內空調系統設定在25°C,實驗中對冷氣出風口在不同等級出風量時,量測出風口風速、出風口溫度、車艙內的相對濕度、車殼內溫度、車艙內玻璃溫度與車艙內各溫度監測點的溫度。在數值模擬方面,以GAMBIT建立非結構四面體的車艙網格。在不考慮化學反應、重力及輻射熱傳下,以SST (Shear-Stress Transport) K-ω紊流模式,配合上述實驗量測到的結果做為數值模型中的邊界條件,並利用商用套裝軟體FLUENT計算求解車艙內流場與溫度場。在熱舒適性方面,以Fanger所提出的熱舒適性指標PMV與PPD做熱舒適性分析。計算熱舒適性指標PMV與PPD所需要的參數可由數值模擬的車艙內流場得到風速與溫度,實驗得到相對濕度,乘客的衣服熱絕緣值與新陳代謝率計算求得。在結果方面,由模擬結果顯示出,當車艙內從空調啟動後降溫到25°C左右時,數值模擬所需要的時間約為580秒,實驗量測的時間約為600秒,兩者非常接近。在熱舒適性評估方面,當車艙內只有一駕駛員時,對該駕駛員而言,最佳溫度約在26°C左右;當車艙內有一位駕駛員和三位乘客時,坐在前座乘客座的人所需的最佳溫度會較其他三人高約1.4至1.7°C。除了以上出風口風扇鰭片固定的探討外,加入週期性上下擺動與左右擺動的出風口風扇鰭片邊界條件並對乘客的熱舒適性做分析,與空氣混合效率之優化。其結果顯示,當車艙內僅有一個駕駛員時,使用二級風量並使鰭片擺動可以提升駕駛員的熱舒適性,而當車艙內有四位乘客時,建議使用中級風量四級風並使風扇鰭片擺動以提升乘客的熱舒適性。

PartII:
發光二極體(Light-Emitting-Diode,LED)為新世代的照明與光源設備,與傳統白熾燈泡相比,具有低電壓、低電流、轉換損失低、熱輻射低、環保等優點。其產品應用廣泛,包含了一般照明,車用照明、可攜式產品的顯示器背光源(如手機、相機LCD)等,是未來政府積極推動的第三兆產業。雖然LED光源屬於冷光源,但事實上LED仍是一種高熱通量的發光元件。LED封裝體發光時依然有70~85%的餘熱,因此在極小的晶片面積下會產生高熱通量,故若散熱模組設計不佳,將導致溫度過高,進而使LED亮度減低、壽命降低、波長漂移,且因內部各元件的熱膨脹係數不均,易導致元件間承受過大機械應力而損毀。綜合上述,LED雖屬高效率的發光源,但隨著高照明的應用發展,LED發熱的功率也越來越高,LED散熱模組的設計也成為其應用上的關鍵技術之一。本文針對LED的散熱部分做實驗與模擬相互比對。在實驗部份,以LED裝置在散熱鰭片上,量測LED與鰭片各點的溫度;在數值模擬方面,以GAMBIT建立非結構四面體的散熱鰭片網格,在不考慮輻射的影響下,採用自然對流,將實驗量測所得到LED所產生的熱通量代入做為模擬上的邊界條件,利用商用套裝軟體FLUENT計算求解散熱鰭片周圍的流場與溫度場, 並擷取散熱鰭片的各點溫度。結果顯示,實驗所量測到鰭片的最高溫度為70°C左右,而數值模擬的鰭片最高溫度也是約70°C。兩者也相當接近。
PartI:
With the increasing demand of living standard nowadays, automobiles equipped with more functions, better quality and more comfortable air condition are a developing trend. In this study, by using experiment and numerical simulation, a robust simulation method for the prediction of thermal comfort in a cabin has been established. For the experimental part, the air conditioning system in the cabin was set at 25°C, and temperature, wind velocity at the fan, relative humidity, shell temperature, glass temperature and temperatures at some check points were measured under different fan level conditions. For the numerical simulation part, the mesh used was built in a tetrahedral unstructured grid by the Gambit software. Without regard to chemical reaction, gravity and radiant heat transfer, the boundary temperature and the wind velocity measured at the fans were used as inputs for the commercial software FLUENT with the K-ω turbulent model in order to calculate the flow field and temperature field inside the cabin. For the thermal comfort part, the PMV and PPD indicators introduced by Fanger were used to analyze the thermal comfort for the passengers in the cabin. The parameters involved in the PMV and PPD indicators can be obtained from numerical and experimental data. The parameter values of wind velocity and air temperature are obtained from numerical results, but humidity, and clothing insulation and activity level from experimental results. It is found that, in the case of an empty car, the required simulation time for cooling down to 25°C in the cabin is 580 seconds. This numerical cooling time is close to the experimental of 600 seconds. Our analysis of thermal comfort indicates that, when a driver seats in the cabin, the best temperature is about 26°C inside the cabin. While driver with three passengers seating in the cabin, the best temperature for the front-seat passenger is predicted to be 1.4 to 1.7°C higher than the others. In addition to the study of the fixed-blade fan case, we also analyze the air mixing efficiency and the thermal comfort of passengers using periodic swing-blade fans. The numerical results show that the second wind level of the fixed-blade fan or swinging-blade fans can improve the thermal comfort when only driver seats in the automobile cabin. However, for the case of four passengers seating in the automobile cabin, it is better to use the fourth wind level of the fixed-blade middle fan or swinging-blade fans to improve the thermal comfort.

PartII:
Light-Emitting-Diode (LED) is a modern lighting device. Compared with a traditional incandescent lamp, it has the advantage of low voltage, low current, low converting loss, low thermal radiation and low environmental pollution. LED products are used widely, including general lighting, auto lighting, back-lighted sources of LCD such as in cellular phones, and camera etc. It will be a sunrise industry which the government will actively support in the future. Though LED belongs to a cold light source, it is still a high heat flux lighting device. LED produces a 70%~85% heat loss when operated, and the produced high heat flux is concentrated on a small area of a chip. If the thermal module is not well designed, the corresponding high temperature will lead to reduction in LED brightness and life time and also drift of its wavelength. Beyond that, the coefficients of thermal expansion of internal elements are different. Hence, the elements will bear overloaded mechanical stresses and LED will fail. From the description above, LED belongs to an efficient light source. However, along with its development, the power of heating is getting higher; and the design of thermal module of LED becomes a key technology. In this study, we analyzed LED cooling by comparing the results of experiments and numerical simulations. In the experiment part, we attached LED to the fin and measured the temperature at some points on the LED and the heat sink. In the numerical simulation part, wet built the mesh in a tetrahedral unstructured grid by the Gambit software. The measured heat flux from the LED was inputted to the commercial software FLUENT in order to calculate the flow field and temperature field around the heat sink and get the surface temperature distribution of the heat sink, with the radiation heat transfer neglected. The result shows that the maximum temperature in the heat sink is about 70°C both in experiment and numerical simulation. The numerical simulation is in good agreement with the experimental measurement.
中文摘要 ……………………………………………………………I
英文摘要 ……………………………………………………………IV
致謝 …………………………………………………………………VIII
目錄 …………………………………………………………………IX
表目錄 ………………………………………………………………XIV
圖目錄 ………………………………………………………………XVII
符號說明 ………………………………………………………… XXIII
Part I 1~108
第一章 緒 論…………………………………………… 2
§1.1 前言 ………………………………………………… 2
§1.2 研究動機與方法 …………………………………… 3
§1.3 文獻回顧……………………………………………… 4
第二章 熱舒適性概論 …………………………………… 9
§2.1 人體與周圍環境的能量平衡方程式 ……………… 9
§2.2 衣服的熱絕緣值 …………………………………… 11
§2.3 PMV指標 …………………………………………… 12
§2.4 PPD指標……………………………………………… 13
§2.5 PPD指標與PMV指標對應關係…………………… 14
§2.6 求解PPD指標與PMV指標與最佳溫度…………… 14
第三章 數學模式與數值方法 …………………………… 16
§3.1 車艙外型與網格的建立 …………………………… 16
§3.2 數學模式 …………………………………………… 17
§3.3 數值方法 …………………………………………… 18
§3.4 UDF自訂函數 ……………………………………… 23
§3.5 邊界條件與收斂條件設定 ………………………… 24
第四章 實驗設備與方法 ………………………………… 27
§4.1 實驗車輛 …………………………………………… 27
§4.2 風速的量測…………………………………………… 28
§4.3 溫度的量測 ………………………………………… 28
§4.4 溼度的量測 ………………………………………… 29
第五章 結果與討論 ……………………………………… 30
§5.1 程式驗證 …………………………………………… 30
§5.2 空車時,車室內溫度、速度場的分析………………… 31
§5.3 有乘客時,車室內溫度、速度場的分析……………… 31
§5.4 風扇鰭片擺動程式驗證……………………………… 33
§5.5 風扇鰭片擺動時,車室內的溫度、速度分析………… 34
§5.6 熱舒適度(PMV&PPD)之分析……………………… 35
§5.7 風扇葉片擺幅 30、45、60度之比較………………… 37
第六章 結 論 …………………………………………… 39
參考文獻…………………………………………………… 41

Part II 109~133
第一章 緒 論…………………………………………… 110
§1.1 前言 ………………………………………………… 110
§1.2 研究動機與方法 …………………………………… 110
§1.3 文獻回顧……………………………………………… 111
第二章 數學模式與數值方法 …………………………… 113
§2.1 LED散熱鰭片外型與網格的建立……………………… 113
§2.2 數學模型 ………………………………………… 113
§2.3 數值方法 …………………………………………… 114
§2.4 邊界條件設定 ……………………………………… 114
第三章 實驗設備與方法 ………………………………… 116
§3.1 實驗用LED與散熱鰭片…………………………… 116
§3.2 溫度量測 …………………………………………… 116
§3.3 一維熱傳實驗………………………………………… 116
第四章 結果與討論 ……………………………………… 118
§4.1 Grid Independent Test ……………………………… 118
§4.2 一維熱傳實驗分析…………………………………… 118
§4.3 LED散熱實驗與模擬分析…………………………… 119
§4.4 ¼ model 最高溫度比較……………………………… 120
第五章 結 論 …………………………………………… 121
§5.1 結論 ………………………………………………… 121
§5.2 未來工作 …………………………………………… 122
參考文獻…………………………………………………… 123
自述 ………………………………………………………… 134
PartI:
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[3] G. Gan,“Evaluation of Room Air Distribution Systems Using Computational Fluid Dynamics,”Energy and Buildings, Vol.23,pp.83-93,1995.

[4] J. Kang and S. Park,“Development of Comfort Sensing System for Human Environment,”Mechatronics,Vol.8,pp.459-466,1998.
[5] J. Kang and S. Park,“Integrated Comfort Sensing System on Indoor Climate,”Sensors and Actuators, Vol. 82,pp.302-307,2000.
[6]T. Komoriya,“Prediction Method of Passenger’s Thermal Sensation by Numerical Simulation of Air Flow in an Automobile Passenger Compartment,”JSAE Review,Vol.16,pp. 315-315,1995.
[7] K. Kojima, Y. Adachi, S. Itoh, H. Ohtaki, and K. Watanuki,“An Estimate of Temperature in a Passenger Compartment by Numerical Simulation Using Linear Graph Theory,”JSAE Review,Vol.18,pp.205-205,1997.
[8] O. Kaynakli and M. Kilic,“An Investigation of Thermal Comfort inside an Automobile during the Heating Period,”Applied Ergonomics,Vol.36, pp.301-312,2005.
[9] H. Wang, C. Huang, Z. Liu, G. Tang, Y. Liu, and Z. Wang,“Dynamic Evaluation of Thermal Comfort Environment of Air-Conditioned Buildings,”Building & Environment,Vol.41,Issue 11,pp.1455-1610,2006.
[10] G. Gan,“Numerical Evaluation of Thermal Comfort in Rooms with Dynamic Insulation,”Building & Environment,Vol.35,Issue 5,pp.445-453,2000.
[11] M. C. G. da Silva,“Measurements of Comfort in Vehicles”,Measurement Science and Technology,Vol.13,pp. R61-R60,2002.
[12] F. Nicol,“Adaptive Thermal Comfort Standards in the Hot-humid Tropics,”Energy and Buildings,Vol.36,pp.628-637,2004.
[13] R. L. Hwang, T. P. Lin, and N. J. Kuo,“Field Experiments on Thermal Comfort in Campus Classrooms in Taiwan,”Energy and Buildings,Vol.38,pp.53-62,2005.
[14] M. Kilic, O. Kaynakli, and R. Yamankaradeniz, “Determination of Required Core Temperature for Thermal Comfort with Steady-state Energy Balance Method,” International Communications in Heat and Mass Transfer, Vol.33,pp.199-210,2006.
[15] M. S. Jang, C. D. Koh, and I. S. Moon,“Review of Thermal Comfort Design Based on PMV/PPD in Cabins of Korean Maritime Patrol Vessels,”Building and Environment, Vol.42,pp.55-61,2007.
[16] H. Chen, W. T. Chung, and S. M. Liang,“Numerical Simulation of Air Conditioning Flow Field in the Automobile Cabin,”the 12th National Computational Fluid Dynamics Conference,CFD12-2209,2005.
[17] H. Chen, W. T. Chung, and S. M. Liang,“Numerical Investigation of Air-Conditioned Flow Field in an Automobile Cabin with Parallel Unstructured Navier-Stokes Solver,”Int. Conf. on Parallel Comp. Fluid Dynamics 2006,”Busan,Korea,pp.335-338,2006.
[18] C. Chen, W. T. Chung, S. M. Liang,“Numerical Simulation of Air- Conditioned Flow Field in an Automobile Cabin,”Journal of Aeronautic, Astronautic and Aviation, Vol.38,No.4,pp.281-288,2006.
[19] H. Chen, W. T. Chung, S. M. Liang, and C. X. Liu, “Numerical and Experimental Study of Predicting Thermal Comfort in an Automobile Cabin,”the 11th National Conference on Vehicle Engineering,Taiwan,Da-Yeh University,Chang-Hua,November 2006.
[20] 梁智創, 張金龍, 洪宗義,“車內空調風口配置分析,”第十一屆車輛工程學術研討會,大葉大學機械與自動化工程學系,彰化, 2006.
[21] 王俊雄, 林顯群, 羅玉山, 周永泰, “房車內乘客舒適度之數值模擬,” 第十一屆車輛工程學術研討會, 大葉大學機械與自動化工程學系,彰化,2006.
[22] 鄭志堃,“汽車室內空調之三維熱傳分析,”碩士論文,機械工程學系,國立成功大學,台南,2006.
[23] 劉昶賢,“汽車座艙空調系統對乘客之舒適性研究,”碩士論文, 航空太空工程學系, 國立成功大學, 台南, 2007.
[24] J. Piquet, Turbulent Flows: Models and Physics, Springer-Verlag,New York,1999.
[25] S. V. Patankar,“Numerical Heat Transfer and Fluid Flow,”Hemisphere Publishing Corporation,New York,1980.
[26] Fluent 6.1 User’s Guide, Fluent Inc., Lebanon, NH, 2003.
[27] Fluent 6.2 User’s Guide, Fluent Inc., Lebanon, NH, 2005.
[28] Fluent 6.2 Tutorial Guide, Fluent Inc., Lebanon, NH, 2005.
[29] Gambit User’s Guide, Fluent Inc., Lebanon, NH, 2006.
[30] Gambit Tutorial Guide, Fluent Inc., Lebanon, NH, 2006.

PartII:
[1] 龔建銓, 陳令妮, 葉于瑛, 蔡鈺霞, 陳毓儒, 趙隆山, 呂宗蔚,“LED散熱分析,”中國機械工程學會第二十三屆全國學術研討會, 成功大學工程科學系,台南,2007.
[2] NICHIA公司“Thermal management design of LEDs”,Application Note, LA-KSE3110C, Oct. 31, 2003.
[3] 莊書豪, 張立民, 曹愷中, 郭宏賓,“LED背光模組散熱鰭片之模擬分析,”中國機械工程學會第二十三屆全國學術研討會, 中華醫事學院安全衛生工程系,中興大學機械工程系,中州技術學院機械與電腦輔助工程學系,台南,2007.
[4]
FLUENT6.2UDFManualhttp://202.41.85.84/doc/fluent6.2/help/pdf/udf/pdf.htm
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