儲熱槽的設計及使用方式均為影響太陽能熱水系統效率的重要因素，本研究採取市面上最常使用的無隔板儲熱槽，利用CFD軟體CFX模擬儲熱槽內部之熱流場，並結合能源系統模擬軟體TRNSYS以及台北、台中、高雄三地之TMY2氣象資料計算太陽能月負荷比及年負荷比，探討取負荷時段不補充冷水至儲熱槽對系統效率之影響。
有無補充冷水的差別在於起始溫度不同、取負荷時段冷熱水混合的問題，從結果可以發現不補充冷水的儲熱槽起始平均溫度比低，可以提升集熱器效率，而且更能充分使用到太陽熱能，減少輔助熱源所需提供的能量，讓整體效率有所提升，尤其是在太陽能豐沛的季節所帶來的效益最為明顯。
三個城市的研究結果皆顯示：只要取負荷時段不補充冷水至儲熱槽，太陽能熱水系統的效率可以顯著提高25%左右。

The design of the storage tank of a solar hot water system is an important factor that affects the efficiency of the system. In this study, the commercial non-partitioned storage tank is simulated by a CFD software CFX for the flow and temperature distributions in the tank. Then, the input and output of the tank are connected by the simulation software TRNSYS to complete the system simulation for estimating the system monthly and annual performances. The purpose of this study is to predict the system efficiency increase for no make-up water input during the night time when load is taking. The study is made for three representative cities of Taiwan, i.e. Taipei, Taichung and Kaohsiung.
The benefits of no make-up water input during the load taking period are two parts. Firstly, the collected solar energy can be completely utilized and the collector efficiency is higher on the next day owing to the low inlet temperature from the make-up water. Secondly, there is no mixing of hot water and the cold make-up water during the load taking period such that the auxiliary energy required is decreased. Therefore, the system efficiency (solar fraction) is increased.
The results of the present study indicate a system efficiency increase of about 25 % for all three representative cities by just without make-up water input during the load taking period.

論文審定書 i
誌謝 ii
摘要 iii
ABSTRACT iv
目錄 v
圖目錄 vii
表目錄 viii
符號說明 ix
第一章 緒論 1
第一節 前言 1
第二節 文獻回顧 2
第三節 研究動機與目的 3
第二章 基礎理論 4
第一節 系統簡介 4
第二節 TRNSYS 模組元件之理論分析 4
第三節 儲熱槽模型 7
第四節 儲熱槽之統御方程式 7
第三章 研究方法 12
第一節 研究方法與架構 12
第二節 TMY 2氣象資料 12
第三節 模擬軟體之運算方法 13
第四節 太陽能負荷比 ( Solar Fraction ) 14
第四章 結果與討論 18
第一節 TRNSYS 系統與 TRNSYS-CFX 系統之模擬結果比較 18
第二節 TRNSYS-CFD 系統之模擬結果討論 19
第五章 結論與未來展望 49
參考文獻 50

〔1〕 Gao, W., Liu, T., Lin, W. and Luo, C. "Numerical Study on Mixing Characteristics of hot Water inside the Storage Tank of a Solar System with Different Inlet Velocities of the Supply Cold Water, "Procedia Environmental Sciences, vol. 11, pp. 1153-1163, 2011.
〔2〕 Shue, N. S. "Numerical simulation of Large Solar Hot Water system in storage tank" NSYSU, Master Thesis, 2012.
〔3〕 Su, C.Y. "Numerical simulation of a Large Solar Hot Water System with a Stratification Storage Tank for Various Load time" NSYSU, Master Thesis, 2013.
〔4〕 Duffie, J. A. and Beckman, W. A., "Flat-Plate Collectors, " Solar engineering of thermal processes, Fourth Edition, New York, Wiley, pp. 236-321, 1980.
〔5〕 Klein, S. A., et al., "TRNSYS 16 User’s Manual," 1998.
〔6〕 Zeng, H. L. "The effect of hotinlet position of water storage of a large solar hot water system on the system performance " NSYSU, Master Thesis, 2016.
〔7〕 Ievers, S. and Lin, W. "Numerical simulation of three-dimensional flow dynamics in a hot water storage tank," Applied Energy, vol. 86, pp. 2604-2614, 2009.
〔8〕 Kuan, Y. C. "Numerical simulation study for the performance of a multi-tank large solar hot water system" NSYSU, Master Thesis, 2013.