Cycle Performance Of Absorption Power Cycle And Vapor-Liquid Equilibrium Research Of R245FA Binary System

As an advanced energy technology which can effectively utilize the low-grade energy, the absorption power cycle has been caught a lot of attention in the past a few decades. However the research of its working fluids has always been neglected. So based on the previous working fluids research about organic Rankine cycle and absorption refrigeration cycle and the concept of sub-cycle coupling, this work did some research on the working fluids selection in the three parts:According to previous investigation on Organic Rankine Cycle (ORC) and absorption refrigeration cycle, this work has chosen three potential working pairs for absorption power cycle. They are1,1,1,3,3-Pentafluoropropane (R245fa)+N, N-Dimethylformamide (DMF)/diethylene glycol dimethyl ether (DMEDEG)/N-methyl-2-pyrrolidone (NMP).Second, in order to test the absorption character between the solute and the absorbents, this work build up a experimental system to test the vapor-liquid equilibrium data of the three system. 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 show that VLE data for R245fa-DMF system can be well calculated by NRTL equation. At the same time, we all also discussed the pressure variation in the absorption process, the relationship between temperature and activity coefficient, deviation of three systems from Raoult’s law and the different affinity within the three systems. In addition, the relationships of the affinity and the solubility have been analyzed on the basis of the molecule structure and the hydrogen bond interactions between R245fa and absorbents.Finally, base on the concept of sub-cycle coupling and chemical engine, a new mathematical model has been raised to calculate the efficiency of absorption power cycle. Ten test samples of working fluids have been put in the cycle simulation program to validate the model. At the same time, the thermophysical properties of these working fluids together with the result of the simulation have also been discussed. This work investigated how the vaporization and the affinity between the power cycle working fluids and absorbents can influence the cycle efficient. On the basis of the new model and the simulation result, this work proposed some relating regularities between the thermophysical properties of the working fluids and the cycle performance.