不同制冷剂/离子液体工质对的吸收式制冷循环性能分析

In order to find new alternative pairs, 19 kinds of refrigerant/ionic liquid working pairs were used in the single-effect absorption refrigeration cycle and the performance of the cycle was analyzed. Firstly, non-random two-liquid activity coefficient model was utilized to correlate the experimental phase equilibrium data of the studied pairs to validate the reliability of the model. Secondly, thermodynamic model of absorption refrigeration cycle was established based on the conservation of mass and energy. Finally, the effects of the outlet temperature of absorber and generation temperature on solution mass flow, coefficient of performance and exergy efficiency of the system were discussed. The results show that the mass flow of solution is an important factor affecting the system performance. The performance of the system has obvious difference due to the different working pairs. Fluorinated alkanes with shorter carbon chains are more easily dissolved in ionic liquid, which is conducive to improve the performance of the system. In addition, the coefficient of performance of the system increases with the decrease of the absorber outlet temperature and the increase of the generator outlet temperature. For the studied substances, five working pairs including NH₃/[omim]BF₄, NH₃/[hmim]BF₄, H₂O/[bmim]Tf₂N, R32/[emim]Tf₂N and R161/[hmim]Tf₂N have higher coefficient of performance. NH₃/[omim]BF₄ is the best, and the maximum coefficient of performance is 0.62. Moreover, the maximum value of the exergy efficiency increases by 1.39 times when the evaporation temperature increases by 2 ℃. The exergy efficiency increases sharply firstly and then decreases gradually with the increase of evaporation temperature, and the exergy efficiency decreases with the increase of the condensation temperature.