臺灣博碩士論文加值系統

R290冷媒具有不會造成臭氧層的破壞並且為有較低全球暖化潛勢(GWP)值的良好特性；但R290屬於可燃性冷媒，因此可能會引起火災或爆炸。本論文以數值方法評估R290分離式空調機冷媒洩漏之安全性，數值模擬以ANSYS FLUENT套裝軟體模擬冷媒洩漏在室內空間的擴散情形，模擬過程中將洩漏位置分為兩種: (1)空調機外的輸送管與(2)空調機內蒸發器側邊的迴路彎管處；操作條件並考量壓縮機與排風扇的開啟與否等條件。本文並將數值模擬結果與文獻上的實驗濃度測量結果比對，結果顯示兩者的濃度分佈有相似趨勢，而研究結果亦顯示在開啟排風扇時對降低R290濃度有顯著的效果，另外並發現應盡量避免渦流的產生以免造成R290堆積導致其濃度升高的情況。

Refrigerant R290 possesses the characteristics of non-ozone layer depletion and low global warming potential (GWP). But, it belongs to the combustible refrigerant and it could cause a fire accident or explosion. This study used the numerical simulation to evaluate the safety of refrigerant leakage for a R290 air-conditioner. The CFD package software, ANSYS FLUENT, was employed to simulate the diffusion process of the leaking refrigerant within an indoor. During the CFD simulation, two leakage positions were considered: one was set at the pipe connector joining the inside and outside units, and the other was set at the return tubes of evaporator inside the indoor unit. In addition, the on and off of the compressor and the exhaust fan were also considered as the operating conditions. Comparing the numerical results with those of the experiment in literature, it can be found that both results had similar trend on the concentration distribution of R290. The numerical results also show that it is beneficial to lower the indoor R290 concentration when the exhaust fan was turned on. Moreover, avoiding the occurrence of flow circulation can reduce the accumulation of R290, causing that the rise of R290 concentration.

目錄

摘要 i
ABSTRACT ii
目錄 v
表目錄 vii
圖目錄 viii
第一章 緒論 1
1.1前言 1
1.2文獻回顧 5
1.3研究目的 6
第二章 數值模擬 7
2.1統御方程式 7
2.2數值方法 9
2.2.1 對流-擴散方程式的差分型式 9
2.2.2 壓力-速度耦合關係的處理 11
第三章 冷媒R290洩漏實驗 14
第四章 數值模擬之室內空間模型 18
4.1 基本假設與邊界條件設定 18
4.2數值模擬空間尺寸 21
第五章 結果與討論 23
5.1格點獨立分析 24
5.2案例分析 26
第六章 結論 40
參考文獻 41
符號彙編 43

[1] Designation and Safety Classification of Refrigerants, American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc,2008
[2] Jane Gartshore , &;quot;R32 for Air Conditioning- a low GWP, low flammable solution a low GWP, low flammable solution,&;quot; ACHPI 34,2012
[3] Tingxun Li, &;quot;Indoor leakage test for safety of R-290 split type room air conditioner , &;quot;international journal of refrigeration, vol. 40, 2014, pp.380-389.
[4] Martin Dieryckx，Next generation refrigerant for heat pump and air conditioning ，technology and economic assessment panel, vol. 2，2012.
[5] D. Colbourne and K.O. Suen, &;quot;Equipment design and installation features to disperse refrigerant releases in rooms—part I:experiments and analysis, &;quot; International Journal of Refrigeration, vol. 26, 2003,pp. 667–673.
[6] D. Colbourne and K.O. Suen, &;quot;Equipment design and installation features to disperse refrigerant releases in rooms—part II: determination of procedures, &;quot;International Journal of Refrigeration, vol.26,2003,pp.674-680
[7] Osami Kataoka, Masahito Yoshizawa and Taku Hirakawa, &;quot;Allowable Charge Calculation Method for Flammable Refrigerants, &;quot;Eighth International Refrigeration Conference, Purdue University, 2000, pp.383-390.
[8] IEC 60335-2-40, 2005. Household and Similar Electrical Appliances. Safety. Particular Requirements for Electrical Heat Pumps, Air-conditioners and Dehumidifiers. IEC, Geneva,Switzerland.
[9] Wang Zhang, Zhao Yang, Jin Li, Chang-xing Ren, Dong Lv,
Jie Wang, Xin Zhang and Wei Wu, &;quot;Research on the flammability hazards of an air conditioner using refrigerant R-290, &;quot;international journal of 41
refrigeration,vol.36,pp.1483-1494.
[10] ANSYS FLUENT 14.5 User’s Guide, ANSYS Inc. 2011.
[11] B.A. Younglove and J.F. Ely, &;quot;Thermophysical Properties of Fluids. ll. Methane,Propane,Isobutane,and Normal Butane, &;quot;American, 1987,pp.698-689.
[12] Yunus A.Cengel and John M.Cimbla, FLUID MECHANICS, New York: McGraw-Hill, 2006, pp.366-368
[13] 王文珊，新興冷媒與其應用產品發展研究，電子檢驗中心，台北，2013
[14] Quanyi Liua,,Hui Zhang,Yi Liu,Hong Huang,Xiaole Zhang,Zhipeng Li and Wei Yao, &;quot; Influencing factors of flammable refrigerants leaking in building air-conditioning system, &;quot;Procedia Engineering, vol.62, 2013,pp.648-654.
[15] Ryuichi NAGAOSA, Vikrant C. AUTE and Reinhard RADERMACHER, &;quot;A Risk Assessment for Leakages of Flammable Refrigerants into a Closed Space,&;quot; International Refrigeration and Air Conditioning Conference, Purdue,2012
[16] Quanyi Liu, Hui Zhang, Yi Liu, Hong Huang, Xiaole Zhang Zhipeng Li and Wei Yao, &;quot;Influencing factors of flammable refrigerants leaking in building. airconditioning system, &;quot;Procedia Engineering, vol.62,2013,pp.648-654.
[17] Dehua Cai, Guogeng He, Weier Tang, Liang Huang and Tengjiao Hai,
&;quot;The Simulation of the Leaking Distribution Characteristics of R290 Household Air-Conditioner, &;quot;11th IIR Gustav Lorentzen Conference on Natural Refrigerants, China, 2014, pp.1-13.
[18] Pham, H. and Rajendran, R., 2012, &;quot;R32 and HFOs as Low-GWP Refrigerants for Air Conditioning, &;quot; International Refrigeration and Air Conditioning Conference, Purdue, USA, July 16-19, Paper No. 2262, pp. 1-10.
[19] 王文珊，圖書館與養老院室內空氣品質之探討，碩士論文，國立台北科技大學冷凍空調工程所碩士班，台北，2014。