H-16 ミストの蒸発冷却特性測定と制御方式の提案

抄録

Fine water mist sprays with average droplet diameters around 20 microns are being increasingly used as a means of cooling outdoor spaces such as rail platforms and shopping arcades. At high humidity there is higher risk of wetting people and the ground beneath mist nozzles. Control systems are often set to run above a set dry bulb temperature and below a set relative humidity. Experiments show that mist evaporation rates are related to the difference between the dry bulb and wet bulb temperatures, ΔT_<WB>. Changing operating parameters to include a minimum ΔT_<WB> can allow use at higher humidity levels. If a common 28℃, 70% condition is sufficient to prevent floor-wetting, then a condition of 28℃ with a ΔT_<WB> > 4.3K should still prevent floor-wetting. This would allow operation at 75% humidity near 39℃.