Application Research Of Wet Film Direct Evaporative Cooling In Ventilation And Cooling High Temperature Industry Building

Direct evaporative cooling (abbreviation: DEC) technology with its energy efficiency, environment protective and economical advantage has wide application perspective. The principle, classification, equipment exploit, application field, present research condition and the study meaning of evaporative cooling are systemic introduced in this paper. Theory study on the heat and mass transfer of the wet film direct evaporative cooling is carried on, and based on these, control equations which include mass, dynamic, and energy conservation equations are established.The temperature in industry building is usually higher, because of the characteristic of the production;some poisonous and noxious matter will be brought out in the production process also. As some standards such as GBZ1—2002 was put forward, the way of nature ventilation in cooling air in industry building has can not be achieved the demand of pertinent standards already, but the investment and operation expense is higher to use the traditional mechanical refrigeration, and the air quality is poor also. DEC air conditioner shows particularly advantage because of itself characteristic in this field. Organic pad(CELDEK) DEC air conditioner experimental table and climatic room are constructed, imitate the application of DEC used in industry building, and ventilate , cool down the air in the room with the method of positive pressure air supply. The performance parameters were measured in different conditions, and corresponding data are obtained.Use the professional software ID-DiaGram1.3.5, Origin 7.0 analyze the original data and performance diagram, the result indicate that, for the DEC air conditioner, Δt(air temperature difference between in inlet air temperature and outlet air temperature of DEC ), Δd(water vapor difference between in inlet air and outlet air of DEC),E(cooling efficiency of the DEC air conditioner) etc, are interrelated with the performance parameters t₁(dry bulb temperature of the inlet air),t_s(wet bulb temperature of the inlet air) , RH₁ (relative humidityof the inlet air ) , G(value of supply air) etc, and exist some laws between them. Compared with different thickness of the pad and the value of v (velocity of the inlet air) , as well as to increase efficiency of the DEC when we design the equipment, we should consider the volume of the equipment, if the v is reduced too small for just to increased the efficiency, the result must be that the equipment is bulkiness and the investment is high, and if the v is too high, the result is that the resistance of the equipment is too large, the operation cost of the equipment will be improved also.The result of the experiment also indicate that, application the directive evaporative cooling in the industry building field is feasible, and satisfy the regulations such as GBZ1— 2002 required. Compared with the traditional mechanical refrigeration equipment and natural ventilation, the DEC technology is more energy efficiency, environment protective and economical, and the effect is more perfect. Climatic condition out of the door is given for the application of direct evaporative cooling air conditioner in industry building in the paper, and especially discuss its use in the high temperature, high relative humidity area. In addition, for the humidity of the outlet air of the DEC air conditioner is too high, the paper gives a simple and feasible method to resolve it.Finally, used the NPV(Net Present Value) method, in allusion to practical engineer project, the paper compared DEC air conditioner system with traditional mechanical refrigeration system, and gain the result, it showed that, DEC air conditioner system is more energy efficiency, economical than the traditional mechanical refrigeration system.