平板型太陽能集熱器為國內太陽能熱水器產業中最為常見太陽能利用裝置。集熱板主要是由歧管、吸收板面搭配選擇性吸收膜所構成；集熱板系統吸收太陽輻射能後轉換成可用熱能的過程中，太陽輻射光的角度、漫射比率、環境溫度及風速等因素皆會對其吸收、轉化的效率產生影響。ISO 9806：2013描述了一種準動態測試方法，來進行集熱系統吸收效率的測試。本研究利用準動態測試，在實際、多變的天氣條件下進行集熱板日照實驗，藉此評估集熱系統吸收太陽輻射光的效能表現。實驗模組為同一家台灣製造商生產之兩種不同型式的單鰭片單歧管平板型集熱板，差異在於歧管分別置於向陽面與背陽面，並搭配五種入口流體流量進行太陽輻射光日照實驗。
研究發現歧管置於向陽面的集熱板模組，在日照過程中，歧管因直接被日照光照射，故集熱板內部能量傳導的路徑相對較短，入口流量小時，其集熱系統在無熱散條件下的最佳效率最高，約0.66，隨著流量增加，逐漸下降至0.62；歧管置於背陽面的集熱板模組，內部能量是由吸收板被日照光照射後，藉由吸收板內部以及吸收板與歧管之間的焊接條進行熱傳導，入口流量小時，其集熱系統在無熱散條件下的最佳效率最低，約0.60，隨著流量增加至約一倍標準流量，其最佳效率達至高峰值，約0.63，爾後，又隨流量增加而逐漸下降。歧管置於向陽面的集熱板模組，因歧管直接接觸內部空氣層及其系統於集熱過程中的平均溫度較高，導致其集熱系統與環境之間的熱散程度較另一種集熱板模組較為嚴重。
一般常見的非循環集熱系統使用的情形，其系統平均溫度會比環境溫度高約5℃ ~ 10 ℃，表示系統會有明顯的熱散現象。故歧管置於背陽面的集熱板模組，其吸收日照光轉換成可用熱能的瞬時效率會比歧管置於向陽面的集熱板較佳，歧管置於向陽面的集熱板模組僅在入口流量小且系統與環境溫差小時，其系統效率略有優勢。

This study investigates the performance of the fin flat-plate solar collectors constituted of single tube and single fin. There are two different types of flat-plate collector (FPC) in this study. The first one, the FPC tube is mounted on the sunny side. The second one, the FPC tube is mounted on the back of the sunny side. ISO 9806:2013 performed a quasi-dynamic test (QDT) on FPC performance under variable and real weather conditions. Based on the QDT, two types of FPCs were tested with different inlet flow rates in Tainan, Taiwan for finishing the performance analysis.
The tube of the first FPC module was irradiated by the solar radiation directly, so the energy transferring path was comparetively shorter. At a small inlet flow rate, the optimal efficiency without heat loss (η0) of the FPC was almost 0.66. η0 decreased gradually as the inlet flow rate was increasing. In the second FPC module, solar radiation irradiates to the absorber plate of the FPC. The heat was transferred to the tube of the FPC via thermal conduction. At a small inlet flow rate, η0 of the second FPC was at most 0.60. As the flow rate was increasing, η0 increased gradually. There was a peak value of η0 when the inlet flow rate was increased to almost 1.0 of the standard flow rate stated in ISO 9806:2013. After the standard flow rate, η0 decreased as the flow rate was increasing. In the first FPC module, the tube of the FPC contacted the air layer inside the FPC system directly, so the mean temperature of the FPC was higher in the process of energy absorption. Therefore, the degree of heat loss of the first FPC is higher than the second FPC.
Under most actual weather, there is an obvious temperature difference between the FPC system and the surroundings. Performance and collection efficiency of the first FPC module is worse than the second one. The only advantages are appeared under the conditions of the small inlet flow rate and the small temperature difference between the system and environment.

[1] 經濟部能源局 & 財團法人台灣綠色生產力基金會 (2012)，建築節能應用技術手冊
[2] A GUIDE TO THE STANDARD EN 12975, “Quality assurance in Solar Heating and Cooling Technology：Thermal Performance”
[3] Adrian Bejan, “Convection Heat Transfer”, 4th Edition, John Wiley & Sons, p369-p379
[4] Bengt Perers (1993), “Dynamic method for solar collector array testing and evaluation with standard base and simulation programmers”
[5] Cooper (1969), “The Absorption of Radiation in Solar Stills”, Solar Energy, 12：333-346,
[6] Dimitrios I. Ladas, Ted Stathopoulos, “Wind effects on the performance of solar collectors on roofs”
[7] Hugh W.Coleman, and W.Glenn Steele, “Experimentation, Validation, and Uncertainty Analysis for Engineers”, 3th Edition
[8] INTERNATIONAL STANDARD, “Solar energy-Solar thermal collectors-Test methods”, ISO 9806：2013
[9] John A. Duffie, William A. Beckman (2006), “Solar Engineering of Thermal Processes”, 3th Edition, John Wiley & Sons, p11-p16
[10] J.W. Spencer (1971), “Fourier series representation of the position of the Sun”, 2(5)
[11] M.C. Rodríguez-Hidalgo, P.A. Rodríguez-Aumente, A. Lecuona, G.L. Gutiérrez-Urueta, R. Ventas (2011), “Flat plate thermal solar collector efficiency：Transient behavior under working conditions. Part I：Model description and experimental validation”, Applied Thermal Engineering 31：2394-2404
[12] M.C. Rodríguez-Hidalgo, P.A. Rodríguez-Aumente, A. Lecuona, G.L. Gutiérrez-Urueta, R. Ventas (2011), “Flat plate thermal solar collector efficiency：Transient behavior under working conditions part II：Model application and design contributions”, Applied Thermal Engineering, 31：2385-p2393
[13] S. Farahat, F. Sarhaddi, H. Ajam (2009), “Exergetic optimization of flat plate solar collectors”, Renewable Energy, 34：1169–1174
[14] Taiwan Accreditation Foundation, “測試結果量測不確定度評估指引：TAF-CNLA-G03(1) ”
[15] Tiago Osório (2011), “Solar thermal collectors under transient conditions：optical and thermal characterization based on the quasi-dynamic model”
[16] Viorel Badescu (2007), “Optimal control of flow in solar collectors for maximum exergy extraction”, International Journal of Heat and Mass Transfer,50：4311–4322
[17] Viorel Badescu (2006), “Optimum fin geometry in flat plate solar collector systems”, Energy Conversion and Management, 47(15-16)：2397–2413
[18] Ziqian Chen, Simon Furbo, Bengt Perers, Jianhua Fan, Elsa Andersen (2012), “Efficiencies of Flat Plate Solar Collectors at Different Flow Rates”, Energy Procedia, 30：65-72