Modeling of a loop thermosyphon supplying solar energy to a desalination boiler

A new concentrated solar desalination system based on a two-phase working fluid with volumetric solar absorption is under development. This system promises to improve overall solar to thermal efficiency and reduce parasitic power by taking advantage of the passive flow circulation of a loop thermosyphon. To predict system performance, a two-phase loop thermosyphon model was developed around well-validated, two-phase frictional pressure drop correlations. The model was used to analyze pressure drops and resulting fluid saturation temperatures throughout the loop. Good agreement was found between the predicted fluid mass flow rate and that measured in a lab-scale prototype loop thermosyphon. The model continues to be developed and will be validated against a larger-scale prototype system.