Study On Influence Factors Of The Working Performance Of Dry-wet Combined Tandem-type Hybrid Cooling Tower

As a common equipment for cooling process fluid,the cooling tower has the outstanding feature of high cooling efficiency but a large water consumption problem,and is widely used in industry and air-conditioning systems of building.Due to the energy saving and emissions reduction,much attention has been paid to the improvement of working efficiency of the cooling tower,which has been the mainstream trend of cooling tower development.But in recent years,the energy shortage and high industrial consumption is the basic condition of our country.That the country vigorously promotes energy-saving and emission reduction makes the research on cooling efficiency,energy consumption and water consumption of cooling tower receive much concern.So this paper studies a combined-type cooling tower that strings finned tube bundles and bare tube bundles together with packing.The paper also compare the working performance of combined-type cooling tower with normal closed cooling tower’s while they are processing the cooling water with low temperature under 40℃.First of all,this paper changed air volume,spray water and cooling water flow of the dry-wet combined tandem-type hybrid cooling tower,and studied the influence of these three factors on heat transfer performance and resistance performance of hybrid cooling tower.At the same time,the influence of these three factors respectively on performance of wet,spray and dry area of the hybrid cooling tower was analyzed.Finally,under the best conditions compared with the performance of closed cooling tower,the improvement of heat transfer performance and the increase of energy consumption of hybrid cooling tower were examined.The result indicates,the air resistance of dry-wet cooling tower increases with the wind speed,which is greater than that of counter flow.The heat exchange of the hybrid cooling tower increases and then decreases with the increasing wind speed,and the best condition happens at the speed of 3.5 m/s.The heat exchange increases and then decreases with the spray water density during 8-16 m~3/(m~2·h).The synthesized heat exchange reach optimal performance for spray water density of 14 m~3/(m~2·h).The heat transfer capacity in the finned tubes dry area accounts for about 34.06%in all heat transfer capacity.The air resistance of dry-wet cooling tower increases with the spray water density,which is greater than that of counter flow.Under parallel flow,the water resistance in cooling tower was 25 k Pa,which in dry area was 15 k Pa,accounting for60%.Under conuter flow,the water resistance in cooling tower was 20 k Pa,which in dry area was 14 k Pa,accounting for 70%.