Study On Fresh Air Cooling And Dehumidification Using Earth Energy

According to problems caused by traditional air condition (comfort, indoor air quality and high energy consumption), and based on the climatic characteristics and research status of cooling technology using tunnel wind, this paper analysed the feasibility of fresh air cooling and dehumidification technology using earth energy in hot summer and cold winter area. This technology has practical significance: improve the indoor environment, protect human health and reduce the energy consumption. It is beneficial to sustainable development and has great development potential.Outdoor meteorological condition and load characteristic of fresh air in hot summer and cold winter area were analysed firstly in this paper. The area has a typical hot and humid climate in summer, so cooling and dehumidification are need in fresh air handling. In addition, dehumidification is more important than cooling because that latent heat cooling take a huge account of fresh air load and energy consumption of dehumidification take a huge account of fresh air handling.Then, indoor ventilation requirement and fresh air dehumidification mode in hot summer and cold winter area were discussed. The humidity ratio indoor mainly comes from humid air outdoor. Fresh air from outdoor with a comfortable temperature and humidity value could meet the ventilation requirement of temperature and humidity. Fresh air cooling and dehumidification using earth energy is the perfect fresh air handling mode in summer in the area.Otherwise, ground temperature characteristics and heat transfer process between soil and air in Chongqing area were analysed. ground temperature tends to be stable at 19.5℃when the depth reach 9m. Dew point temperature of outdoor air in summer is higher than 19.5℃, thus, the earth energy could be used to cool and dehydrate fresh air outdoor. Intermittent ventilation is better than continuous ventilation because ground temperature get back in inaction period.Experimental data were processed and analyzed in the last part. The results show that: (1) the experimental system has nice persistence and stability and the exine of inner tube from 0~8m needs insulation to avoid Heat short-circuit; (2) the system has a nice environmental adaptability: cooling or dehumidification will take major place respectively when temperature or humidity is high; (3) the condensation of fresh air appear when the depth reach 4m and the experiment system has a better effect when intermittent operation.