電解水產氫之電解液流場效應分析

Study on Flow Field of Electrolyte of Water Electrolysis

董成祥(Cheng-hsiang Tung)

指導教授 ： 洪勵吾

國立中央大學/工學院/能源工程研究所/碩士(2008年)

摘要

為了探討電解液流場對電解的效應，以磁石與沉水馬達使1m的KOH電解液產生一渦流與管流，搭配自行製作的電解槽進行電解，以實驗探討流場對電解時產生的影響。
渦流部分以0RPM~1100RPM的不同程度渦流，搭配電解電壓2V~5V。實驗結果顯示最大電流密度提升率約3.4%，發生在轉速100RPM時。轉速100RPM~轉速1100RPM之間電流密度不增反減，但在轉速400RPM會有ㄧ電流密度最低值。
管流部分以電解液體積流率0ml/s~65ml/s，搭配電解電壓2V~5V及正向流向與側向流向。由實驗結果可以知道，最大電流密度提升率約為23%，且可以發現任一電流密度都有最佳電解液體積流率，此外正向流向與側向流向無明顯差異。
渦流較管流最大差異在於產生的氣體無法順利排出電解槽內，因此形成比管流大上許多氣體造成的極化現象。

關鍵字

渦流 ； 管流 ； 極化 ； 電流密度 ； 水電解

並列摘要

In order to probe into the effect of electrolyte fluid field on electrolysis, magnetite and water pump are used to let 1M KOH electrolyte generating vortex and internal flow in the electrobath. The experimental results are discussed to understand the interaction between electrolyte fluid field and electrolysis.
At first, in the part of vortex flow, the vortex are ranged among 0RPM~1100RPM and the applied voltages are ranged among 2V~5V.When the rotation rate is 100RPM, the experimental results show that there is a maximum current density enhancement about 3.4%.In addition, as the rotation rate is among 100RPM and 1100RPM,the current density decreases. Moreover, at the rotation rate of 400RPM, the current density is minimum.
In the part of internal flow, the circulating rates of electrolyte are ranged among 0ml/s~65ml/s and the applied voltages are ranged among 2v~5v. The electrolyte flows in either parallel or normal to the electrodes. The experimental results show that there is a maximum current density enhancement about 23%, and the best circulating rate of electrolyte occurres for every current density. There are no difference in current density between parallel flow and crossed flow.
The biggest difference between vortex flow and internal flow is that the circulation generated by the vortex will drag the electrolysis gases from escaping from the electrobath, and this causes serious polarization phenomenon that does not occur in internal flow.

並列關鍵字

polarization ； vortex ； internal flow ； current densit

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