Thermal Comfort Of Indoor Environment And Performance Optimization Of Air Conditioning System Based On Chilled Beams

With the development of architectural design,it is a trend that the use of the large area of glass curtain wall as a peripheral protective structure,especially apply to office buildings.It is particularly critical and important that development and application of energy-saving and green indoor air conditioning system suitable for office curtain wall building.At the same time,the more times the office staff stay,the higher requirements for indoor environment are.Office indoor environment quality will affect not only the health of office staff,but also the efficiency of office staff.In order to meet the development of this era,indoor air conditioning system need to have the characteristics of energy-saving,comfortable and healthy.This paper mainly studies the chilled beams conditioning system composed of active chilled beams,floor convection and fresh wind system.This chilled beams conditioning system has been used in office buildings in China,but it is still in the primary stage of research.Active chilled beams is very suitable for office buildings,since it has energy-saving,environmental protection,comfort,health and many other advantages.With the use of floor convection can effectively eliminate the heat load by the glass curtain wall,improve the thermal comfort of office staff.In this paper,we study the airflow organization state and thermal comfort of open office by field determination method and CFD numerical simulation method.The related researches show as following:(1)Using field measurement gets the position coordinates and numbering of the glass curtain wall,the floor convection,the active chilled beams and the station in open office.We measure the environment parameters of the glass curtain wall,the brick wall,the floor convection,the active chilled beams and the station were respectively determined in the winter and summer working conditions.Furthermore,the sound environment of open office was also measured.It can be found through the measurement,the thermal environment and the sound environment of this open office are in a relatively comfortable state.(2)We did a simple questionnaire survey for the office staff who is in the representative station during the field measurement in the winter and summer working conditions.It can be more in-depth understanding of the actual operation of this chilled beams conditioning system.In the end,we combined result of questionnaire with the result of field measurement,and get a preliminarily understood of the good thermal comfort of the staff in the office.(3)Simplified the open office,built the physical model and set boundary condition.Furthermore,we used air speed,temperature,PMV index and PPD index,in the numerical simulation,as evaluation indexes to explore the winter and summer working conditions’ indoor environment and thermal comfort of office staff.The reliability of the boundary conditions of the set physical model is verified by the compare of numerical simulation and field measurement data.We believed that the numerical simulation can solve the problems of the practical project.(4)In order to verify the operation status of the chilled beams conditioning system under extreme weather conditions in the open office,the boundary conditions of the glass curtain wall are modified in the winter and summer working conditions.By means of numerical simulation,we improved and optimized the chilled beams conditioning system of open office under extreme weather condition(5)There are condensation problems when using the chilled beams conditioning system in the summer working conditions.This paper summarized the possible causes of condensation for chilled beams conditioning system,and optimization of fresh wind system,dynamic operation and condensate water system to slove the condensation of chilled beams conditioning systemThis paper provides some methods to slove the condensation of chilled beams conditioning system,provides some guidance for the actual operation of the chilled beams conditioning system under extreme weather conditions,and provide evidences for the application of this chilled beams conditioning system in office curtain wall building.