Experimental research of the cross walls effect on the thermal performance of wet cooling towers under crosswind conditions

This paper describes a hot model test of natural draft wet cooling towers (NDWCTs) to investigate the effect of cross walls on the thermal performance of NDWCTs under crosswind conditions. The hot model test can simulate the actual operation of a prototype tower by operating a model tower at steady state conditions while varying the temperature and flow rate of the incoming hot water along with the crosswind velocity. Cross walls of two shapes at different setting angles were installed in the rain zone and tested under various operating conditions. The results show that crosswinds degrade the NDWCT performance below a critical crosswind velocity Vcr, but improve the performance above Vcr. Increasing water flow rate and inlet water temperature can raise Vcr. Installing cross walls can improve the NDWCT performance. At low crosswind velocities, the solid wall leads to better NDWCT performance than the porous wall. However, the opposite effect is obtained at high crosswind velocities. At all crosswind velocities, the cross wall at a setting angle of 0° results in higher performance than that at 45°, regardless of cross wall shapes. Moreover, the cross wall at 45° degrades the NDWCT performance under high crosswind conditions.

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► Hot model test of natural draft wet cooling towers (NDWCTs) with cross walls.
► Crosswinds degrade NDWCT performance below a critical crosswind velocity, but improve performance above critical velocity.
► Increasing water flow rate and inlet water temperature can raise critical velocity.
► Solid wall leads to better performance than porous wall under low crosswinds, while opposite effect is obtained under high crosswinds.
► Cross walls at setting angle of 0° result in higher performance than those at 45° under all crosswind conditions.