Experimental researches on characteristics of vapor–liquid equilibrium of NH3–H2O–LiBr system

An improved system of NH3–H2O–LiBr was proposed for overcoming the drawback of NH3–H2O absorption refrigeration system. The LiBr was added to NH3–H2O system anticipating a decrease in the content of water in the NH3–H2O–LiBr system. An equilibrium cell was used to measure thermal property of the ternary NH3–H2O–LiBr mixtures. The pressure–temperature data for their vapor–liquid equilibrium (VLE) data were measured at ten temperature points between 15–85 °C, and pressures up to 2 MPa. The LiBr concentration of the solution was chosen in the range of 5–60% of mass ratio of LiBr in pure water. The VLE for the NH3–H2O–LiBr ternary solution was measured statically. The experimental results show that the equilibrium pressures reduced by 30–50%, and the amount of component of water in the gas phase reduced greatly to 2.5% at T=70 °C. The experimental results predicted much better characteristics of the new ternary system than the NH3–H2O system for the applications.