Influence of crosswind on heller natural draft dry cooling tower and improvement measures

Abstract

With the risk of water resources increasingly heavier and the need of the inland development of the nuclear power, dry cooling tower in power plant with its excellent water conservation characteristics, gets more and more attentions from the countries all over the world, especially in coal-rich but water-short areas. There are mainly three dry cooling tower forms: the air-cooled condenser(ACC), the natural draft dry cooling tower with surface type condenser(Harman system) and the natural draft dry cooling tower with jet condenser(Heller system).The radiator of Heller dry cooling tower is fixed up vertically all around the tower. Its heat transfer performance is greatly affected by environmental conditions, especially the crosswinds. The study of the effects of the crosswinds to the flow and heat transfer performance is essential to the design and optimization of the air cooling tower. Hence, the effects of the crosswinds to the flow and heat transfer performance of the air cooling system are investigated by a hot state model experimental platform. A new method adding air leading plates all around the tower to eliminate or ease the adverse effect of the crosswinds is put forward. The results show that the cooling tower flow field and temperature field are in symmetry without crosswinds. The flow and heat transfer performance of Heller air cooling system in different locations will encounter varying degrees of influence under crosswinds. The total air flow rate and the total heat transfer rate are also influenced. Under high crosswinds, airflow from windward side will oppress that from tower side and leeside. Flow a round circular cylinder is also formed. At this time, radial wind speed and effective into tower wind speed are small in tower side and leeside, heat transfer effect is poorer. The worst parts of flow and heat are mainly in the tower side. The influence mechanisms of environmental crosswinds and the certainty of heat transfer deterioration parts point out the direction for the further precautions. Adding air leading plates all around the tower is a very effective windproof measure which can improve the operating conditions greatly, change negative effect to positive effect.