Experimental Investigation on Thermal Flow Field Characteristics of a Direct Air-cooled System for a Large Power Plant

The PIV experiments were carried out on thermal flow field of a direct air-cooled system in the low speed wind tunnel for the first time.At the same time,the recirculation ratio at cooling tower of corresponding conditions was measured.After that the relationship between the thermal flow field structure and recirculation ratio under the cooling tower was discussed.The experimental results show that the thermal flow field structure has great effects on the average recirculation ratio under the cooling tower.As increasing with the coming wind velocity,the turbulent entrainment and mixing-up of vortex structure in the lee of cooling tower enhance as well,which causes recirculation ratio under cooling tower increase.Lengthening the height of wind wall or installing the frontal board to the platform can both ameliorate the thermal flow field structure of cooling tower,and the recirculation ratio under cooling tower can be decreased,so the effect of heat dispersion for air-cooled condenser can be improved.