Research On The Optimization Of Air Distribution In Workplace Air Conditioning In Office Environment

In order to solve the problems of traditional air conditioning and ventilation,such as high energy consumption,poor air quality and comfort,station air conditioning system has been proposed.At present,the location of air supply outlet of air conditioning at partition station is mostly set to improve air quality,without considering the acceptability of the position of air supply outlet of human body.However,the position of the air supply outlet plays an important role in improving the thermal comfort of human body.Therefore,in this paper,according to the local thermal characteristics of human body,different air supply outlet forms are set up,and the thermal comfort of human body under the air supply is studied,and the air supply form with higher overall thermal satisfaction of human body is determined.Based on this air supply form,the air supply parameter range that can replace the background air supply is further explored to reduce the investment and operation cost of the air conditioning system.First of all,the literature shows that the head,chest,back and legs are local hot and cold sensitive parts of the body.For these parts,this study set up face bilateral air supply,chest bilateral air supply,head leg air supply and chest leg air supply four air supply forms.The variation of local and global thermal sensation of human body under four kinds of air supply was studied in a hot environment.The results show that the overall comfort of the subjects is greatly improved under bilateral chest air supply,and most of the subjects have a high acceptance of this air supply.Airflow stimulation on the face,chest and back of human body has a greater impact on the overall thermal sensation of human body,while airflow stimulation on the legs has a smaller impact.Local airflow stimulation can greatly improve the overall thermal comfort of human body,but the discomfort of human body is enhanced under facial airflow stimulation,and the feeling of blowing is directly proportional to the discomfort of human body.When the air supply can not eliminate the body heat,human discomfort will be enhanced.It can be seen that in order to ensure the overall comfort of the human body,the wind speed around the human body should be reduced as far as possible and reasonable air supply parameters should be determined in subsequent studies.Next,the influence of the size of the chest air supply outlet and the location of the indoor air return outlet on the indoor temperature and velocity distribution is studied by numerical simulation.The simulation results show that the temperature distribution in the station area is more uniform,the adjustable air supply volume range is larger,and the low-temperature air diffusion range is wider when the air supply outlet with a larger area is used for air supply.When the ceiling is used for air return,the temperature distribution in the vertical direction of the station area is uniform,and the temperature difference of the whole body is small.Therefore,in order to improve the overall comfort of human body,the air return design of the air conditioning system of the partition station should adopt the way of larger air supply area and ceiling air return.Finally,under the condition of no background air supply,the indoor thermal environment is studied under the condition of large air supply area and ceiling air return mode.The results show that the distribution of indoor air temperature and velocity is complex.Under the action of low-temperature air flow,heat source and buoyancy,indoor temperature is stratified.The higher the air supply speed,the greater the air supply volume,the more uniform the temperature distribution in the station area,and the lower the overall temperature difference of the human body.Indoor flow field distribution is mainly affected by air supply temperature and air supply volume.Through the study and analysis of the human body temperature difference,human chest wind speed,temperature distribution at different heights and PMV,the following air supply parameters are proposed: when the ambient temperature is thermal-neutral,the air supply volume of 144m3/h should be adopted,and the air supply temperature of 18℃～20℃ should be selected;The air supply volume of202m3/h is adopted and the air supply temperature of 22℃ is selected.When the ambient temperature is hot,that is,the indoor cooling load is large,the air supply volume of 202m3/h should be adopted,and the air supply temperature of 18℃~20℃ should be selected.When the air supply exceeds 220m3/h,no matter what the air supply temperature is,the air supply will have a blowing feeling on the human body,so the air supply should not exceed 220m3/h.In the range of the above air supply parameters,the indoor thermal environment can meet the requirements of human comfort,and the background air supply can be cancelled in the air conditioning system of the partition station,thus reducing the investment and operating cost of the air conditioning system of the station.