Numerical Simulation And Optimization Design Of An Earth-air Heat Exchange Fresh Air System With Personalized Ventilation

Underground shallow soil because of its constant temperature throughout the year,with the characteristics of the "warm in winter and cool in summer".So rational utilization of the underground soil to cool the air is a low cost of the air conditioning technology.But due to the larger sites requirement,the technology is mainly geared to the needs of low density residential buildings in rural areas,promotion in extremely high-density city is limited.Compared with the traditional ventilation mode,personalized ventilation has a higher efficiency.By using the earth-air heat exchange technology combined with the personalized ventilation could improve indoor air quality and reduce the energy comsumption to a certain extent.Taking a typical office as an example in this paper,a personalized ventilation mode of earth-air heat exchange fresh air system was established by using commercial software Airpak of CFD.A research of the thermal comfort and the air quality of the work areas in the fresh air system of personalized ventilation under different fresh air volumes and different containment structures is carried on.It is concluded that the earth-air heat exchange fresh air system of personalized ventilation effectively reduces the demand for fresh air comparison with traditional ventilation.A mode of an office building in Tangshan was built by using DeST energy consumption simulation software.The simulation results show that the cooling load per unit area in summer is reduced by 8.55%,while heating load per unit area in winter is increased by 9.52% by using personalized ventilation.Ensuring the same inhaled air quality,40% fresh air volume was saved,and the length of the earth-air heat exchanger tube reduced by 10.45% with personalized ventilation.The optimization design on earth-air heat exchange fresh air system using personalized ventilation is carried out by the numerical simulation method,according to the analysis of the fresh air parameters and the personalized ventilation system and central air conditioning system’s influence on the thermal comfort of the workspace environment,some regular conclusions has been drawn,which gave some reference for applications and popularize of the earth-air heat exchange fresh air system using personalized ventilation.