Thermodynamic properties and performance evaluation of [EMIM] [DMP]‐H ₂ O working pair for absorption cooling cycle

Abstract

The combination of ionic liquid-refrigerant based [EMIM][DMP]-H 2 O as an alternative working pair for single effect vapor absorption cycles (VACs) is assessed and optimized by using energy and exergy based performances. Thermodynamics properties of binary mixture of [EMIM] [DMP]-H 2 O like Dühring's (P-T-x1) and h-T-X1 plots are computed from the activity coefficient based non-random two-liquid model (NRTL) model. Further modeling and simulation of VACs are accomplished in open source Scilab as mathematical programing software and used to ascertain the optimal generator temperature established on energetic and exergetic COP. Optimal results include an extensive range of temperatures like T e from 2.5 to 15 C and T a and T c from 30 to 45 C. Simulation of the single effect VAC with SHE by using [EMIM][DMP]-H 2 O mixture at T e = 10 C, T g = 100 C, T a = 30 C, and T c = 40 C were evaluated and compared with the 5 working fluids. Simulation outcomes depicted greater COP of 0.82 for [EMIM][DMP]-H 2 O in comparison with NH 3-H 2 O, EMISE-H 2 O, [EMIM][BF4]-H 2 O and nearly equal to LiBr-H 2 O (COP = 0.83). In addition, the effect of T g on the COP, ECOP f , and composition are compared and optimized for the evaporation temperature range from 2.5 to 15 C, T a /T c from 30 to 45 C and cooling water (CW) flow in series and parallel. Additionally, the optimal T g exhibited distinction based on energy and exergy analysis. Thus, it resulted in optimized performances of [EMIM] [DMP]-H 2 O that can be suitable to replace corrosive aqueous LiBr in VACs.

Thermodynamic performance of absorption‐compression hybrid refrigeration cycles based on lithium nitrate+1‐butyl‐3‐methylimidazolium nitrate/water working fluid

“…Comparable COP was achieved for [EMIM][DMP]/H 2 O and a largely wider operating temperature range was found for [MMIM][DMP]/H 2 O, in comparison with LiBr/H 2 O. Ayou 10 studied an absorption heat transformer cycles with [EMIM][BF 4 ]/TFE and [BMIM][BF 4 ]/TFE. Results revealed that higher gross temperature lift was achieved and the disadvantages of crystallization and corrosion issues were improved compared to conventional LiBr/H 2 O. Takalkar 11 also assessed and optimized the thermodynamic performance for single‐effect cycles based on [EMIM][DMP]/H 2 O. Results depicted a larger COP in comparison with H 2 O/NH 3 and comparable to LiBr/H 2 O. Zheng 12 reviewed the recent researches on imidazolium ILs‐based working fluids regarding to status of thermophysical properties measurement, the thermodynamic performance and future prospect assessments of absorption cycle using IL‐based working fluids.…”