臺灣博碩士論文加值系統

近年隨著工業的發展，人類對能源的需求與日俱增，節能裝置以及再生能源的開發已是全世界關注的議題。有機朗肯循環(organic Rankine cycle, ORC)是用於低溫熱源發電的技術，用於工業廢熱回收、太陽能以及地熱發電等等領域。工廠排放的廢熱低於230°C被定義為低階廢熱，因無法有效再次運用於製程通常被排放於環境。本文針對低階廢熱回收之有機朗肯循環系統進行熱力分析，分別使用R134a、R1234yf、R227ea、R245fa、丙烷作為工作流體進行系統最大熱效率及淨輸出功的分析。於三個熱源溫度100°C、150°C、200°C以及四個狹點溫差5°C、10°C、15°C、20°C的條件下以迭代的方式計算熱傳量，分別利用蒸發壓力及蒸發溫度探討其對系統性能的影響並找出最佳參數。結果顯示當熱源溫度200°C時R245fa具有最高的淨輸出功505.5kW以及系統熱效率15%。以硬焊型板式熱交換器作為熱交換器模型，根據上述條件所得之最佳點計算總傳熱面積並計算熱交換器建設成本；結果表明熱源溫度越高所需的建設成本越低，在熱源溫度150°C、200°C時使用丙烷作為工作流體時具有最低的建設成本。

As industry develops, there is an increasing demand on energy. The development of energy-saving devices and renewable energy have been emerging issues around the world. Organic Rankine cycle, ORC, is a technique to generate power from low temperature heat sources. ORC is used in recycling industrial waste heat, solar energy and geothermal power generation. Waste heat below 230°C is called low-grade waste heat. Low-grade waste heat cannot be efficiently reused in process, so it is usually exhausted into the environment. In this research, we perform thermodynamic analysis on low-grade waste heat recycling ORC systems. R134a,R1234yf, R227ea, R245fa, and Propane are used as working fluids and their max system thermal efficiency and net power output is calculated. We discuss the effect of different evaporation pressure and evaporation temperature to the system performance with different conditions of three heat source temperatures, 100°C, 150°C,and 200°C, and four pinch point temperature differences, 5°C,10°C,15°C, and20°C by iteration methods to find the optimum parameters. The result shows that R245fa has the highest net work output of 505.5kW and system thermal efficiency of 15% at heat source temperature of 200°C. In this research, we use brazed plate heat exchangers as example. We use the optimum conditions to calculate the total heat transfer area and evaluate the constructing costs of the heat exchanger. It is found that the higher heat source temperature, the lower cost it needs. When the propane is used as working fluid, the lowest cost can be achieved with heat source temperature at 150°C、200°C.

緒論 1
1.1研究背景 1
1.2文獻回顧 2
1.3研究動機與目的 3
1.4論文架構 4


理論基礎 6
2.1有機朗肯循環系統 6
2.1.1工作原理 6
2.1.2熱力學方程式8
2.2工作流體篩選9


研究方法 14
3.1研究架構 14
3.2分析方法 6
3.2.1模擬條件與參數 16
3.2.2計算流程 17
3.2.3熱交換器狹點計算模型 17
3.3最佳化評估方式建立 21
3.3.1分析流體種類與操作範圍 21
3.3.2淨輸出功及熱效率 24
3.3.3熱交換器成本估計 27


結果與討論 33
4.1蒸發參數對系統性能的影響 33
4.1.1蒸發壓力對系統性能的影響 45
4.1.2蒸發溫度對系統性能的影響 56
4.1.3狹點溫差對最佳系統性能的影響 63
4.1.4最佳蒸發參數 67
4.2狹點溫差對熱交換器成本的影響 69


結論與未來工作 71
參考文獻 73

[1] B. F. Tchanche, G. Lambrinos, A. Frangoudakis, and G. Papadakis, ``Low-grade heat con- version into power using organic rankine cycles--a review of various applications,'' Renew- able and Sustainable Energy Reviews, vol. 15, no. 8, pp. 3963–3979, 2011.

[2] F. Vélez, J. J. Segovia, M. C. Martı́n, G. Antolı́n, F. Chejne, and A. Quijano, ``A techni-
cal, economical and market review of organic rankine cycles for the conversion of low-grade
heat for power generation,'' Renewable and Sustainable Energy Reviews, vol. 16, no. 6, pp. 4175– 4189, 2012.

[3] S. Quoilin and V. Lemort, ``Technological and economical survey of organic rankine cy- cle systems,'' 2009.
[4] ``105 年能源統計手冊,'' 經濟部能源局, 2016.

[5] C. Vetter, H.-J. Wiemer, and D. Kuhn, ``Comparison of sub-and supercritical organic rank- ine cycles for power generation from low-temperature/low-enthalpy geothermal wells, con- sidering specific net power output and efficiency,'' Applied Thermal Engineering, vol. 51, no. 1, pp. 871–879, 2013.

[6] C. He, C. Liu, H. Gao, H. Xie, Y. Li, S. Wu, and J. Xu, ``The optimal evaporation temper- ature and working fluids for subcritical organic rankine cycle,'' Energy, vol. 38, no. 1, pp. 136– 143, 2012.

[7] I. H. Aljundi, ``Effect of dry hydrocarbons and critical point temperature on the efficien- cies of organic rankine cycle,'' Renewable Energy, vol. 36, no. 4, pp. 1196–1202, 2011.

[8] D. Wang, X. Ling, H. Peng, L. Liu, and L. Tao, ``Efficiency and optimal performance eval- uation of organic rankine cycle for low grade waste heat power generation,'' Energy, vol. 50, pp. 343–352, 2013.
[9] ``2015 各國平均電價比較,'' 台灣電力公司, 2016.

[10] E. Lemmon, M. Huber, and M. McLinden, Refprop 9.0, nist standard reference database 23, version 9.0 2010.

[11] J. M. Calm and G. Hourahan, ``Refrigerant data update,'' HPAC Engineering, vol. 79, no.
1, pp. 50–64, 2007.

[12] A. Mota-Babiloni, J. Navarro-Esbrı́, Á. Barragán, F. Molés, and B. Peris, ``Drop-in energy performance evaluation of r1234yf and r1234ze (e) in a vapor compression system as r134a replacements,'' Applied Thermal Engineering, vol. 71, no. 1, pp. 259–265, 2014.

[13] H. Xu, N. Gao, and T. Zhu, ``Investigation on the fluid selection and evaporation paramet- ric optimization for sub-and supercritical organic rankine cycle,'' Energy, vol. 96, pp. 59– 68, 2016.

[14] R. Turton, R. Bailie, W. Whiting, J. Shaeiwitz, and D. Bhattacharyya, Analysis, synthesis and design of chemical processes. Pearson Education, 2012, ISBN: 9780132618731.

[15] Chemical engineering, https://www.chemengonline.com/pci.