Experimental and numerical investigations of heat transfer characteristics of vertical falling film heat exchanger in data center cabinets

To reduce the energy consumption in data centers, this paper proposes a novel structure that integrates a cabinet with a vertical falling film heat exchanger in data center to perform natural evaporative cooling. First, an experimental setup is built to verify the heat and mass transfer characteristics of a falling film in a vertical tube and to obtain the mass transfer coefficient 0.05. Then, the characteristics of tube length direction and heat and mass transfer are analyzed using compiled user-defined functions for different parameters of moist air and water in the tube. The maximum growth rates of heat transfer coefficient and mass transfer rate are 67.65% and 55.23% at increasing inlet moist air Rema,i, respectively. Finally, the heat transfer characteristics of the falling film heat exchanger with staggered and in-line are compared for inlet air velocities in the range of 1-3.5 m center dot s(-1). The corresponding results demonstrate that the heat flow rate, heat transfer coefficient, and overall heat transfer performance P-EC of the staggered are better than those of the in-line as the inlet air velocity of the heat exchanger continues to increase. The maximum P-EC of the staggered heat exchangers is 40.07% higher than that of the inline heat exchangers.