【摘要】 本文从最基本的热力学关系式出发,推导出溴化锂水溶液液相熵的积分方程式和汽相熵的表达式,通过数值计算的方法,求出一系列状态点的参数值,然后在T—S座标系中描绘出等浓度线群和两组等压线群。计算液相熵值时,首先假定溶液经历等浓度过程,计算出一组等浓度线,然后利用溶液的状态方程求出一系列状态点的参数值,根据这些参数在同一图上作出等压线。计算汽相熵值时假定溶液汽液两相平衡时压力较低,可以引用理想气体的比热关系式,因此可推导出汽相熵的表达式,据此表达式可以描绘出一组汽相等压线。描绘出溴化锂水溶液的T—S图以后,以一个实际的吸收式制冷循环作为例子,说明在该图上的表示情况。更多还原

【Abstract】 In this paper, two entropic formulas of LiBr water solution were derived, basing on several original thermodynamics equations. One is the integrated equation of entropy for liquid phase, he other is the entropic expression for vapour phase. Through numerical calculation, the parameters of condition points are obtained, then, a group of isoconcentration curves and two groups of isobaric curves are drawn in T-S coordinate system. To calculate the entropy of liquid phase, supposing that the concentration of solution was constant in the process of calcuation, a group of isoconcentration curves are obtained. Parameters of equilibrium points were calculated by the equilibrium e equation of solution, and a group of isobaric curves were plotted. In calculation of vapour phase entropy, assuming that the equilibrium pressure of liquid-vapour is so small that the specific heat equation of ideal gas could be used, the entropic expression of vapour phase could be derived and a group of isobaric curves could be plotted. A refrigeration cycle is shown in the diagram as an example to use it for a practical absorption refrigeration process.更多还原