Thermochemical Heat Storage – System Design Issues

The study of properties of composite adsorptive materials “silica gel – crystalline hydrate” for heat storage devices

“…According to [1], the working pairs CaCl 2 -H 2 O, SrBr 2 -H 2 O, Na 2 S-H 2 O, MgCl 2 -H 2 O could be promising for the accumulation of thermal energy. They allow realizing the energy storage density of 1.9-2.7 GJ/m 3 of crystalline hydrate.…”

“…However, the irreversible hydrolysis of magnesium chloride at an elevated temperature required its replacement by 13X zeolite [4]. In the Netherlands, a solar installation for the heat supply of residential buildings, including an adsorption module has been developed [1]. As a heat-accumulating material along with massive salts, zeolite and silica gel were tested.…”

Trouton’s Rule for Vapor Sorption in Solids

“…Examples of salt hydrates that could be used for heat storage are Na 2 S·5H 2 O (cf. [1][2][3][4]) and K 2 CO 3 ·1 1 ⁄2H 2 O [5], but there are many other candidate reactions [6][7][8][9]. Selecting a suited salt hydrate depends on a number of its properties, which are obtained from experimental data.…”

“…virtually loss-free and therefore particularly suited for long-term storage. Figure 1 is a sketch of a system for thermochemical heat storage (THS), designed for seasonal storage of excess solar heat in summer for later use in winter [4]. For heat storage, heat from solar collectors of, e.g., 80-90 °C, is transferred to a hot water storage tank.…”

“…Selection criteria are, for instance, a high heat storage density at favorable operating temperatures, sufficient output power, cycling stability, and low costs and low toxicity [1][2][3][4][5][6][7][8][9]. Examples of salt hydrates that could be used for heat storage are Na 2 S·5H 2 O (cf.…”