ANALYTICAL AND EXPERIMENTAL STUDY OF THERMOSYPHON SOLAR WATER HEATERS.

A theoretical analysis of thermosyphon type solar water heaters is presented. The analysis extends the work available in the literature by considering the work available in the literature by considering transient environmental conditions (insolation and ambient temperature) and the possibility of drawoff of hot water from the storage tank. The differential equation which describes the fluid temperature profile in the collector as a function of time and location is solved using a collector loss coefficient determined from a four node transient collector model (glass cover, collector 'deck' and fluid, back insulation, pan). A four node model of the storage tank is used including the possibility of hot water drawoff for domestic use. Given the environmental operating conditions and a physical description of the system the analysis yields collector inlet and outlet temperatures, collector circulating flow rate, nodal and mean storage tank temperatures and collector efficiencies.