Experimental investigation on a loop thermosyphon with evaporative condenser for free cooling of data centers.

Integrating evaporative cooling with loop thermosyphon can significantly improve the free cooling ability. In this paper, a loop thermosyphon with evaporative condenser is investigated experimentally. The mist water flow out of a single nozzle is observed and analyzed. The performance and annual free cooling potential of the system are investigated, compared with conventional loop thermosyphon. The results show that the evaporative cooling effect of the locations below the horizontal level of the nozzle is more significant due to gravity. With the increase of horizontal distance from the nozzle, the temperature decreases and then increases and the optimal distance is 200–400 mm. The heat capacity of LTEC increases with the increase of indoor and outdoor temperature difference while it decreases with the increase of humidity. Evaporative cooling can enhance the heat transfer of LTEC by 7%–33% compared with loop thermosyphon with conventional condenser, and this value is larger for smaller indoor and outdoor temperature difference and higher indoor temperature. LTEC can expand the annual free cooling time by 7%–14% compared with LTCC and the effect is more significant in regions with drier weather. • Loop thermosyphon with evaporative condenser (LTEC) is studied experimentally. • Temperature field and flow field of the water spray out of a single nozzle are analyzed. • The distance with the best evaporative cooling effect is 200–400 mm from the nozzle. • The heat transfer of LTEC is 7%–33% larger than LTCC. • The annual free cooling time of LTEC is 7%–14% larger than LTCC. [ABSTRACT FROM AUTHOR]