E. A. Dancy
1984
Citations
0
Influential Citations
3
Citations
Journal
Solar Energy
Abstract
Abstract Trisodium phosphate dodecahydrate can be considered for solar heat storage if it is used as a saturated solution rather than as pure material. However, even with a saturated solution it is necessary to take certain precautions to avoid deterioration of the heat storage capacity: either a cold finger must be used to maintain the presence of dodecahydrate crystal nuclei at all times or the temperature must not be allowed to exceed the liquidus temperatures for prolonged periods (e.g. 48 hr) or ∼85°C for brief periods, these treatments leading to the subsequent appearance of a lower hydrate. Enthalpy was measured as a function of temperature (to 85°C) and concentration (72–87% dodecahydrate), and the thermal cycling behavior of solutions was studied. Since crystalline trisodium phosphate dodecahydrate (as purchased or separating from solutions having Na P ⋍ 3 ) does not conform to the formula Na3PO4·12 H2O, being more correctly considered as an alkaline complex salt approximating NaPO4·12 H2O· 1 9 to 1 4 NaOH, the role of the Na P ratio is examined in the context of heat storage in a saturated solution.