Performance comparison of absorption heating cycles using various low-GWP and natural refrigerants

Vapor Liquid Equilibria of Binary Mixtures of 1-Butyl-3-methylimidazolium Triflate (C4mimTfO) and Molecular Solvents: n-Alkyl Alcohols and Water

“…In many industrial fields (e.g., chemical industry, food industry, or energy supply) low-temperature waste heat, with temperatures of about 330 K ≤ T ≤ 370 K, remains at the end of the process chain, with the heat being released in high amounts into the environment. , Absorption cycles (heat pumps, absorption chillers, or absorption transformers) are able to reuse this low grade waste heat economically, which results in an improvement of the primary energy efficiency. − …”

Thermodynamic Investigation and Comparison of Absorption Cycles Using Hydrofluoroolefins and Ionic Liquid

“…To build the absorption cycle models, some reasonable assumptions should be made for simplification: the system is in steady state; the refrigerants leaving the evaporator and condenser are both saturated; the solutions at the outlet of the generator and absorber are in phase equilibrium; the flow resistance, pressure losses, and heat losses are ignored; the throttling process is isenthalpic. , The absorption cycles using HFO/IL working fluids were modeled based on the following mass and energy balances in each component. ,, …”

“…To determine the outlet parameters after compression, the compressor isentropic efficiency was used: where η i is the isentropic efficiency, which was set as 0.7 in this study; , h 11,i is the ideal outlet refrigerant enthalpy in an isentropic compression.…”

Performance analysis of a single stage absorption heat transformer-based desalination system employing a new working pair of (EMIM) (DMP)/H2O

“…For NH 3 /H 2 O, the evaporation enthalpy of NH 3 is less than that of H 2 O. But on the other hand, the insignificant difference between the boiling temperatures of the two elements, besides the toxicity of NH 3 , stands as the main problems . For the reason of having sharp pressure curves leading to process pressures higher than 50 bar, the amount of consumed energy in pumps, instrumentation, and construction costs will increase.…”

“…But on the other hand, the insignificant difference between the boiling temperatures of the two elements, 32 besides the toxicity of NH 3 , stands as the main problems. 33 For the reason of having sharp pressure curves leading to process pressures higher than 50 bar, 25 the amount of consumed energy in pumps, instrumentation, and construction costs will increase. According to the literature, the COPs of some ionic liquids such as (EMIM)(DMP)/H 2 O, (MMIM) (DMP)/CH 3 OH, 34 and (BMIM)(DBP)/(CH 3 OH + H 2 O) 35 are quite close to LiBr/H 2 O systems.…”