Research On Air Conditioning Load Characteristics Of Air Handling Unit Special For Large Space

Compared with conventional single-building construction,large space buildings have high-altitude and large-volume geometric features,which make it easy to generate severe vertical temperature stratification during heating in winter.The upper air temperature is too high,which leads to an increase in useless heat consumption.The heat run energy consumption is significantly increased.In order to reduce the temperature gradient of large space in winter and save energy,this paper studies the applicability of a new type of air conditioning-air handling unit special for large space,in a large space.This paper investigates the current status of thermal environment such as infiltration air volume and vertical temperature distribution in the large space waiting room of a railway station in Wuhan.The measured data is used to verify the ContamW permeation wind model and the CFD airflow organization model.The permeate air volume and temperature gradient of typical space conditions were simulated.Then the air handling unit special for large space is taken as the research object,and the influencing factors such as air supply parameters,spacing and installation height are optimized.The airflow organization,thermal environment and load characteristics of the optimized design end system in large space are studied.Comparing the air handling unit special for large space system with the conventional stratified air-conditioning system,the DeST load simulation software compares the annual energy consumption of the two air conditioning system forms in different climate zones,and concludes the adaptability of the air handling unit special for large space system in different climate zone.Studies have shown that the vertical temperature difference of the air handling unit special for large space system is reduced by 1/3 when heating in winter,which can achieve good energy-saving effect;but in summer,the energy consumption is higher than that of the stratified air-conditioning system.Therefore,the system form is suitable for areas with a long heating period.When the area with the ratio of the number of days in the heating periodto the number of days in the cooling period is higher,the energy saving rate is higher.The air handling unit special for large space system is not suitable in hot summer and warm winter zone because it does not supply heating..Compared with the stratified air-conditioning system,when the chiller and gas boiler are used as the cold and heat sources,the energy consumption in Guangzhou of hot summer and warm winter zone increases by 2.8%,and the energy saving rate in Kunming of moderate zone is 18.9%.The energy saving rate of Wuhan of hot summer and cold winter zone is 9.5%,the energy saving rate in Tianjin of cold zone is11.2%,and the energy saving rate in Harbin of severe cold zone is 15.0%.This study has played a guiding role in the selection of air conditioning systems in large space and the optimization design of high-space air handling unit systems.