- 期刊
液體蒸發過程帶參數的Gibbs自由能的變化
Change of Gibbs Free Energy with a Parameter of the System During the Process of Liquid Vaporizing
摘要
對於恒溫恒外壓下純物質液體(內部)蒸發，如果氣泡中沒有空氣，則當氣泡中液體的蒸氣壓小於或等於外壓時，體系的帶參數的Gibbs自由能G_p隨氣泡半徑r的增加而無界增加，液體不可能蒸發；當氣泡中液體的蒸氣壓大於外壓時，G_p隨γ有一極大值，氣泡長大須翻越一能峰，所以液體難於蒸發。如果氣泡中有空氣，則當氣泡中液體的蒸氣壓小於或等於外壓時，G_p隨γ有一極小值，G_p隨γ的增加和減小而無界增加，液體也不可能蒸發；當氣泡中液體的蒸氣壓大於外壓而小於某一壓力P_m時，G_p隨γ有一極小值和一極大值，氣泡長大先是進入一能穀，然後翻越一能峰，並且氣泡中液體的溫度或蒸氣壓越高，能峰越矮，液體蒸發越容易；當氣泡中液體的蒸氣壓達到P_m時，能峰的高度變為零，氣泡迅速膨脹而破裂，沸騰發生。氣泡中空氣越少，液體過熱程度越大。
並列摘要
For pure liquid evaporating under the condition of constant temperature and constant external pressure, if there is no air in a bubble, when the vapor pressure of the liquid in a bubble is less than or equal to the external pressure, the free enthalpy with a parameter of the system increases unlimitedly with the radius of a bubble γ increasing, liquid cannot evaporate; when the vapor pressure of the liquid in a bubble is greater than the external pressure, the free enthalpy of the system has a maximum with γ, the bubble must get across the energy peak during it grows up, so it is difficult for liquid evaporating. If there is air in a bubble, when the vapor pressure of the liquid in the bubble is less than or equal to the external pressure, the free enthalpy of the system has a minimum with γ, the free enthalpy of the system increases unlimitedly with the radius of the bubble γ increasing or decreasing, liquid cannot yet evaporate; when the vapor pressure of the liquid in a bubble is greater the external pressure and less than a certain pressure P_m, the free enthalpy of the system has a minimum and a maximum with γ, the bubble enters into an energy valu first, and then gets across an energy peak during it grows up, and the higher the vapor pressure or the temperature of the liquid in a bubble is, the shorter the energy peak is and the easier the evaporation of the liquid is, when the vapor pressure of the liquid in a bubble reaches P_m, the height of the energy peak vanishes, thus the bubble expands rapidly and breaks, and boiling occur. The less air in a bubble is, the more the liquid overheating is.