Research On New Inhibitors For Lithium Bromide Absorption Chiller

Lithium bromide absorption chiller has been applied widely in recent years, since it has many excellent characteristics, such as high thermal efficiency, wide heat sources, low energy consumption and zero release. To increase the thermal efficiency, triple-effect and multi-effect refrigeration cycles have been developed. In the triple-effect chiller, the maximum working temperature is 180℃ and the concentration of lithium bromide solution is concentrated. Lithium bromide solution is an aggressive medium, and may cause serious corrosion on carbon steel, copper and cupronickel under conditions of triple-effect and multi-effect cycles. This problem has limited the development of lithium bromide absorption chiller.The inhibition effects of PMA/SbBr₃, E-Mo, PWA, PWVA and PWVA/Sb₂O₃ on corrosion resistance of carbon steel, copper and cupronickel in 55%LiBr+0.07mol/L LiOH solution are studied by weight loss test, electrochemical measurements and physical detection technologies, such as SEM, XRD, EPMA and IR. The results indicate that PMA/SbBr₃, PWA, PWVA and PWVA/Sb₂O₃ can retard both anodic and cathodic reactions of carbon steel, copper and cupronikel in 55%LiBr+0.07mol/L LiOH solution, and behave as mixed inhibitors. E-Mo just inhibit anodic reactions, and can be classified as anodic inhibitor.PMA/SbBr₃ complex inhibitor shows excellent inhibition performance on carbon steel in 55%LiBr+0.07mol/L LiOH solution at high temperature. It can also inhibit the corrosion of copper and cupronickel effectively. At experimental temperatures, the thermodynamic equation of corrosion reaction of carbon steel in 55%LiBr+0.07mol/L LiOH solution with PMA/SbBr₃ inhibitor is lnk=11.447-3561.4/T and the apparent activation energy of the corrosion reaction is 29.61 kJ/mol. The apparent activation energy of the corrosion reaction is increased by the addition of PMA/SbBr₃ inhibitor, which means that the corrosion of carbon steel is retarded in the presence of PMA/SbBr₃ inhibitor.E-Mo inhibitor can be obtained by adding 20 mg/L 2-propenoic telomer into 55% LiBr solution, in which the solubility of Li₂MoO₄ can be increased to 850 mg/L. E-Mo inhibitor has excellent inhibition performance on carbon steel in 55%LiBr+0.07mol/L LiOH solution. Especially, when solution temperature is higher than 180 ℃, the inhibition efficiency is still very high. Even when the solution temperature is 240 ℃, the corrosion rates of carbon steel is only 33.07 μm/a, and inhibition efficiency is 91.5%. E-Mo can also inhibit the corrosion of copper and cupronickel. Under experimental condition, the relationship between corrosion...