FABRIC STRATIFICATION MANIFOLDS FOR SOLAR WATER-HEATING

The level of thermal stratification that can be maintained in forced-f low, direct solar water-heating systems using a fabric manifold is stu died in a 372-liter tank with an inlet flow rate of 0.07 1/s. A rib-kn it, lightweight, spun-orlon acrylic is the most effective manifold mat erial in a comparative study of 13 synthetic and natural fabrics. Ther mal stratification (or more appropriately mixing) in the tank equipped with this acrylic manifold is compared to the level of stratification achieved using a rigid, porous manifold and a conventional drop-tube inlet. Initial tank temperature profile, temperature of the water ente ring the tank, and test duration are varied in three testing schemes. Comparison of vertical temperature profiles and height-weighted energy stored in the tank indicate that under realistic operating conditions , the fabric manifold is 4 percent more effective than the rigid manif old, and 48 percent more effective than the conventional drop-tube inl et.