西北寒冷地区浅层地道风系统性能实验研究

EXPERIMENTAL STUDY ON PERFORMANCE OF EARTH-AIR HEAT EXCHANGER SYSTEM IN COLD REGION OF NORTHWEST CHINA

为探究地道风技术在中国西北严寒地区的应用潜力,该文以兰州某浅层地道风项目为研究对象,对其典型工况性能进行实测,分析不同工况下的换热性能与节能效果。结果表明,兰州地区-2.0 m浅层土壤夏季6—9月份平均温度17.7℃,冬季12—3月份平均温度4.5℃,6、7、12、1月份具有较强的换热潜力。兰州地道风系统夏季不易出现冷凝水,出口新风温度皆处于室内舒适温度范围内,无需进行二次降温;冬季地道风系统的出口温度和湿度曲线变化更为平缓。12、1月份使用地道风预热,热泵COP可提升28.1%~30.3%,降低能耗22.0%~23.3%。模拟结果表明地道风系统换热效率受地域与季节变化影响较小。

In order to explore the application potential of earth-air heat exchanger technology in the severe cold regions of Northwest China,this paper takes a earth-air heat exchanger system in Lanzhou as the research object,conducts actual measurement of its typical working conditions and analyzes the heat transfer performance and energy-saving effects under different working conditions.The results show that the average temperature of 2.0 m shallow soil in Lanzhou is 17.7℃from June to September in summer.The average temperature from December to march in winter is 4.5℃.June,July,December and January have strong heat exchange potential.In Lanzhou,condensed water is not easy to occur in the earth-air heat exchanger system in summer.The outlet fresh air temperature is within the indoor comfortable temperature range,so there is no need for secondary cooling.The change of outlet air temperature and humidity curve of earth-air heat exchanger in winter is more gentle.In December and January,using the earth-air heat exchanger for preheating,the heat pump COP can be increased by 28.1%-30.3%,and the energy consumption can be reduced by 22.0%-23.3%.The simulation results show that the heat transfer efficiency of earth-air heat exchanger system is less affected by regional and seasonal variation.