The brinesiphon: a homolog of the thermosiphon driven by induced salinity and downward heat transfer

Abstract

The basis of a novel method for passive solar water heating homologous to the thermosiphon but driven by induced salinity, which causes a fluid to circulate without the need for a mechanical pump and with inverse natural convection (downward heat transfer), is outlined. The brinesiphon, like the thermosiphon, operates by harnessing the tendency of a less dense fluid to rise above a denser fluid, resulting in fluid motion through a collector, but with two exceptions: first, the buoyancy is controlled by induced salinity gradients rather than thermal gradients, and second, as a result, natural convection is in the opposite direction than that in the homologous thermosiphon concept; i.e., hot fluid flows down, and cold fluid rises. A brinesyphon may be more suitable for solar domestic water heating systems than the thermosiphon because the direction of flow allows downward transfer from a solar collector to a lower storage tank without any type of mechanical pumping system.