Solving model of temperature and humidity profiles in spray cooling zone

Publication date: October 2017
Source:Building and Environment, Volume 123
Author(s): Chen Huang, Jiao Cai, Zhifen Lin, Qianru Zhang, Yezan Cui
Spray cooling technology is being increasingly used to improve the outdoor high temperature environment owing to its energy efficient and environmentally friendly characteristics. However, it is difficult to quantitatively analyze the temperature and humidity distribution in the spray environment due to the uncertainty of the outdoor environment. Based on the moist air theory combined with the heat and mass transfer model of droplets, this study established an analytical model to analyze the effect of spray cooling on the environment temperature and humidity patterns. The developed model can be used to calculate the temperature drop and humidity increase rates under different conditions. The data collected at the Shanghai Expo Axis is used to validate the established model, which shows good agreement with the experiment results. On the basis of these experimental conditions, the temperature drop and humidity increase rates are calculated under different spray pressures, droplet diameters, and airflow rates in the spraying area. It is found that the best spray pressure is 3 MPa when both the cooling effect and the economic feasibility are considered. Second, smaller droplet sizes and lower airflow rates lead to better cooling effect. Third, the local environment humidity has a greater cooling effect compared to the environment temperature. Additionally, this study offers critical analysis of the environment parameters that influence the cooling effect and the cost of the spray cooling system.