Testing of crystallization inhibitors in industrial LiBr solutions

Concentrated lithium bromide (LiBr) solutions are used in absorption heat pumps for heating and cooling buildings. To increase the Carnot efficiency of heat pumps, it is necessary to decrease the lowest temperature of the cycle while keeping the high concnentration LiBr solution from freezing. By adding the appropriate additive, the crystallization temperature can be decreased to allow the enlargement of the operating range. As an attempt to test the behavior of several organophosphorous additives within industrial LiBr solutions, the freezing points of unused and used industrials solutions in the presence of these additives have been measured. The temperature stability of the tested additives has also been determined.