七氟丙烷（HFC-227ea）的热力学性质研究

【作者】 王跃武；

【导师】 陈则韶； 胡芃；

【作者基本信息】 中国科学技术大学 ， 工程热物理， 2006， 硕士

【摘要】 根据蒙特利尔议定书的要求，氯氟烃类物质(CFC)和含氢氯氟烃类物质(HCFC)将被禁用，HFC-227ea(1，1，1，2，3，3，3-Heptafluoropropane)是最近提出的一种对大气臭氧层无害的制冷工质，是CFC12和CFC114可能替代物之一，其混合物被认为可替代R22和R502。 本文选用MBWR(Modified Benedict-Webb-Rubin)方程为HFC-227ea的pVT状态方程，并以文献提供的大量精确的pVT实验数据为基础，拟合了适用于HFC-227ea的pVT状态方程，给出了拟合参数值。该方程适用压力从0.03MPa至53MPa，密度从2.9kg／m3至1800kg／m3，温度从204K至473K。该方程计算HFC-227ea的pVT数据与实验数据比较：气相压力平均绝对值偏差0.296％，饱和蒸气压平均绝对值偏差0.213％，液相密度平均绝对值偏差0.148％。并根据熵、内能及焓等物性参数的微分关系式，利用拟合出的HFC-227ea的pVT状态方程及比热容的关系式，推导HFC-227ea的热力学性质(焓、熵、比热)的计算方程，计算了在广阔温度、压力范围的HFC-227ea的焓、熵、比热值，给出了HFC-227ea的压焓图(p-H图，温度245-455K，压力0.03-10MPa，密度2.1500kg／m~3)和温熵图(T-s图，温度235-450K，压力0.0015-20MPa，密度0.2-1400kg／m~3)，以及定压比热曲线图(C_P-T图，温度280-460K，压力1-5MPa)。描述了HFC-227ea在整个热力学面上的一些热力学性质。更多还原

【Abstract】 According to the revisions of the Montreal Protocol, CFCs and HCFCs will be phased out. At the present, HFC-227ea(1, 1, 1,2, 3, 3, 3- Heptafluoropropane) isconsidered as a harmless refrigerants to ozone layer and a possible alternative refrigerant to replace CFC12 and CFC114, and blends containing HFC-227ea are potential alternatives to R22 and R502.MBWR(Modified Benedict-Webb-Rubin) equation of state was selected asthe pVT eqution of state for HFC-227ea. Based on pVT experimental data of HFC-227ea published in literature, we fitted a pVT equation of state for HFC-227ea, and determined the adjustable coefficients of the pVT equation for HFC-227ea. This equation is suitable for conditions of the pressure from 0.03MPa to 53MPa, density from 2.9kg/m3 to 1800kg/m3, and temperature from 204K to 473K. The average absolute deviations of this equation for gaseous phase pressure, vapor pressure and liquid density are 0.296%, 0.213% and 0.148%, respectively. And then according to the differential relationship of entropy, internal energy and enthalpy, pVT equation of state for HFC-227ea and the ralionship of specific heat, we deduced the calculation equation of thermodynamic properties(enthalpy, entropy ,specific heat)of HFC-227ea, calculated the enthalpy ,entropy, specific heat of HFC-227ea, and given pressure-enthalpy chart(p-H chart, temperature 245-455K, pressure 0.03-10MPa, density 2-1500kg/m3), temperature-entropy chart(T-s chart, temperature 235-450K, pressure 0.0015-20MPa, density 0.2-1400kg/m3), specific heat at constant pressure graphical chart(C_p-T chart, temperature 280-460K, pressure l-5MPa) of HFC-227ea. We described some thermodynamic properties over the entire thermophysical surface.更多还原