吸收式动力循环工质R245fa+DMF体系汽液相平衡实验研究

Measurement of Vapor-Liquid Equilibria of a Potential Working Pair of Absorption Power Cycle——1,1,1,3,3-Pentafluoropropane+N,N-Dimethyl Formamide

根据前人对有机Rankine循环和吸收式制冷循环的研究,本文选出了一组有潜力的吸收式动力循环工质R245fa+DMF。利用外循环可视汽液相平衡(VLE)测定装置,本文测定了温度293.15~353.15 K,压力15~700 kPa条件下R245fa+DMF体系的VLE数据。利用逸度系数法中的PR、SRK状态方程,活度系数法中的NRTL、Wilson模型,本文对体系的VLE数据进行了关联。偏差评价表明,NRTL模型能够较好描述该体系在实验温度压力下的VLE数据。从p-x图上可以看出,该体系呈现对Raoult定律较强的负偏差,显示R245fa和DMF具有很好的亲和性。因此,R245fa+DMF的组合具有成为吸收式动力循环工质对的潜力。

The vapor-liquid equilibrium(VLE) data for R245fa+DMF system were determined by a visible recycle equilibrium device at the temperature 293.15~353.15 K and the pressure 15~700 kPa.The system VLE data were correlated by the state of equations of PR and SPK,and the activity coefficient models of NRTL and Wilson to obtain the binary parameters of the system.The average and maximum relative deviation analysis shows that VLE data for R245fa+DMF system can be well calculated by NRTL equation.So NRTL equation can well describe the VLE data of system under the experimental temperature and pressure.The experimental data show that the R245fa+DMF are potential working pair option for absorption power cycle.