結合風能與太陽能發電研究

Abstract

本文預期結合風能與太陽能來做為一小型發電系統並驗證發電系統的可行性，本文以兩相熱虹吸迴路來做為實驗迴路的基礎模型。在實驗中探討對太陽能發電輸入功率(蒸氣速度)、冷凝器冷水溫度、蒸發器液填充比以及冷凝器蒸發器間相對高度差的效應，風能發電中探討模擬風源提供不同風速情況下對系統發電性能的影響，以及探討結合發電如何影響發電量與發電效率。本文並選用FC-72介電液為工作流體。實驗參數的設定範圍如冷凝器冷水溫度從10℃到30℃、蒸發器液填充從60%到80%、冷凝器蒸發器間相對高度從10cm到15cm、風速從啟動風速到10 m/s與蒸汽速度從啟動風速到12 m/s。 風能發電實驗結果顯示，發電量因為風速增加而近似線性增加，並以一經驗式來描述輸出功率與風速間之關係。在太陽能發電實驗中發現冷凝器中的冷水溫度增加會大幅提高輸出電功率與發電效率。較高的蒸發器液填充比，系統會有較好的發電性能。最佳的填充比80%，對於輸出電功率與發電效率都有相當多的改善。實驗結果也發現，冷凝器蒸發器間相對高度差對於發電性能的影響輕微。 此外，結合能源發電的總發電量與發電性能明顯高於能源單獨發電量總和許多。只有在低結合風速時，冷凝器冷水溫度對總發電量仍有相當大的影響。

In this study an experiment is carried out to investigate the feasibility of a small-scale power generation system from combined solar and wind energy. A model test loop is established basically in the form of a two-phase closed loop thermosyphon. Effects of the input power (vapor speed), cooling water temperature in the condenser, liquid fill ratio in the evaporator and relative elevation between the condenser and evaporator for solar power and effects of the wind speed from simulated wind source for wind power are examined in detail. Besides, how the output electric power and electric power generation efficiency affected by interaction of the combined energy sources are inspected. FC-72 dielectric liquid is selected as the working fluid. Tests are conducted for the cooling water temperature in the condenser varied from 10 to 30 ,℃℃ liquid fill ratio in the evaporator from 60 % to 80 %, condenser-evaporator relative elevation from 10 to 15 cm, the wind speed from a cut-in velocity to 10 m/s, and the vapor speed from a cut-in velocity to 12 m/s. The obtained experimental data for the power generation from the wind energy show that the output electric power increases approximately linearly with the wind speed. An empirical correlation is proposed to delineate the relationship between the output power and wind speed. For the power generation from the solar energy only, an increase for the cooling water temperature in the condenser significantly raises the output electric power and electric power generation efficiency. Higher liquid fill ratio in the evaporator results in better power generation performance. However, an optimal liquid fill ratio exists. For the ratio of 80 %, the output electric power and electric power generation efficiency are significantly improved. The power generation performance depends only slightly on the relative elevation between the condenser and evaporator for most experimental cases. We also note that the total power output and the electric power generation efficiency from the combined energy sources are noticeably higher than the total of that generated from the individual energy sources. The cooling water temperature in the condenser considerably influences the power generation performance only at low wind speed.