An overview of the progress of new working pairs in absorption heat pumps

Physicochemical and Thermodynamic Investigation of Ethanolic Solution of Phosphonium-Based Ionic Liquids─Measurements, Correlations, and Application to Absorption Cycles

“…(3) lower density and viscosity values; (4) promising values for both COP and f; ability of the refrigerator to operate in a wider temperature range (lower than 273.2 K); (6) no tendency of the ionic liquid to crystallize in the system and thermal stability of ionic liquids in a wide temperature range. An additional advantage of ionic liquid chemistry is their unique properties and the possibility of structure design, which opens a wide field for further exploration.…”

“…{Water + ammonia} is used in situations requiring lower temperatures. 6 When using an aqueous solution of lithium bromide, a significant operational issue is seen due to the crystallization of lithium bromide in the device circuit and its corrosiveness. The main problem with {ammonia + water} is its toxicity and explosiveness.…”

“…{Lithium bromide + water} is a suggested working mixture for absorption refrigeration devices when cold utility is required at temperatures equal to or higher than 5 °C. {Water + ammonia} is used in situations requiring lower temperatures . When using an aqueous solution of lithium bromide, a significant operational issue is seen due to the crystallization of lithium bromide in the device circuit and its corrosiveness.…”

Measurements of Thermophysical Properties of Ethanol + Hexamethyldisiloxane and Ethanol + Octamethyltrisiloxane Mixtures in the Temperature Range of 293–343 K at 100 kPa

“…Due to their nonisothermal phase change behavior and beneficial combination of individual properties, the use of zeotropic mixtures as working fluids in various thermodynamic cycle processes, like organic Rankine cycles (ORCs) or absorption heat pumps, increases constantly. 1 In Kalina processes, in particular, fluid mixtures are mainly used because here, compared to conventional water cycle processes, the boiling temperature is concentration-dependent and can be reduced significantly as a result. Because of this nonisothermal vaporization and the variability in temperature, fluctuating temperatures in the heat source can be compensated for according to Ibrahim and Klein.…”

Research on Thermodynamic Characteristics of the Saturated Flue Gas Waste Heat Recovery to Reduce Turbine Extraction Steam

“…Combined with the current research, it is difficult to match the appropriate cold source media to recover the saturated flue gas waste heat. Meanwhile, the utilization pathway of the saturated flue gas waste heat is affected by the temperature level. ,− The absorption heat pump can use dehumidification solutions as circulating media, which have strong hygroscopic properties, − and provide the stable cold source medium to recover flue gas waste heat. This paper proposes a saturated flue gas waste heat recovery system including an absorption heat pump and a direct-contact spray tower.…”