Development of ammoniated salts. Thermochemical energy storage systems: Phase IB. Final report, February--September 1977

Physical properties of NH/sub 4/Cl 3NH/sub 3/

“…By measuring the rate at which the oscillations of the spring decay (see Fig. 3 for typical data output), it is possible to determine the viscosity of the liquid under study from the equation "np = 37.04 6 + 0.148, (1) where n and p are the viscosity and density of the liquid, respectively, and 6, the logarithmic decrement, is the rate of decay Of the spring oscillation. The constants 37.04 and 0.148 were determined by calibration with liquids of known viscosity and density under the appropriate pressure of argon.…”

“…Introduction The~compound NH4CI'3NH3 is an attractive candidate for use in thermochemical heat pump/storage systen... This is principally because it is a liquid at temperatures above 5°C and consequently possesses a heat transfer coefficient approximately 50-fold greater than comparable solid ammoniates, e.gi MgCl2"6NH3 or CaCl2'8NH3.1 Furthermore, the rate of the ammon'iation reaction iS4Cl(l) + 3NH3(9) t NH4C>3NH3 (1) appears to be an order of magnitude greater than-that of the solid ammoniates.l While preliminary investigations of NH4CI-3NH3 yielded encouraging results regarding its use in haat pump systems, it was not possible to make detailed system design and performance studies because nothing was known about the physical properties (viscosity, surface tension, and density). Because of the high dissociation pressure of NH4C1-3NK3 -the equilibrium NH3 pressure over NH4CI *3NH3 is ~ 5 atm at 25°C z (Fig.…”