Study On The Influence Of Local Isothermal Airflow For Human Thermal Comfort And Air Conditioning Energy Consumption

Building energy efficiency is the trend of modern building development,the purpose is to pursue the construction of low energy consumption and high comfort,that is,to feel comfortable indoor staff,but also reduce building energy consumption and reduce the cost of building use.There are many ways to improve the thermal comfort of the human body,in which local thermal environment regulation is an effective means.At present,the study of local thermal comfort has variable temperature seats,station air supply and other forms,most of the study is carried out local non-isothermal air flow regulation,non-isothermal airflow on the local thermal comfort has significantly improved,but this station air conditioning costs High,and the use of the process can not be a good way to reduce air conditioning energy consumption in the transformation of the building is limited.Air conditioning environment plus local isothermal air supply adjustment method can solve the thermal comfort and air conditioning energy consumption.In this paper,through the numerical simulation and thermal comfort test,to study the local isothermal airflow on the human body when the head of the thermal reaction,and the regulation of this energy-saving analysis.In this paper,numerical simulation software is used to simulate the indoor steady-state environment of ordinary wall-mounted air conditioner.By changing the air conditioning air temperature and desktop fan blowing speed and other border conditions,analysis of the human body around the thermal environment changes.The relationship between the temperature field,velocity field,and the human body thermal comfort index PMV were analyzed in different working conditions,and the relationship between local isothermal airflow and human thermal comfort was studied.And then the local hair test: air conditioning to create a 26 ℃(hot neutral)and28 ℃(partial heat)at the background temperature,the subject of local hair test,the hair part of the head,the local wind speed of 0.3m / s and 0.5 m / s.Experiments in the use of subjective questionnaires in the form of subjects with the air flu and hot feeling.During the course of the experiment to monitor the impact of human thermal comfort important physiological indicators,such as skin(head)temperature and core temperature.By analyzing the numerical simulation results and experimental results,it is foundthat when the local wind speed is less than 0.5m / s,the body air flu decreases with the increase of the ambient temperature and increases with the local airflow.The body heat sensation decreases as the wind speed increases and the ambient temperature decreases.The variance analysis showed that the ambient temperature and the blowing speed had a significant effect on the overall thermal sensation(P <0.05).In this experiment,the effect of the blowing rate on the thermal sensation of the human body was greater than the ambient temperature.Under the experimental conditions,the relationship between human body thermal sensation and air flu is negatively correlated.The temperature of the human body was found to have a significant effect on the ear temperature and head temperature,and the fluctuation range of the ear temperature decreased with the increase of the temperature in the environment when the local wind speed was constant.When the ambient temperature is constant,the ear temperature and the head temperature decrease with the increase of the local airflow,and the change of the ear temperature is small and kept within the normal range.By increasing the local airflow,you can make the ambient temperature of 28 ℃ when the body’s thermal comfort index to 26 ℃ambient temperature level.The energy consumption analysis of the adjustment measures to increase the local isothermal airflow in the air-conditioned environment shows that the energy saving rate of the air-conditioning energy consumption in the experimental environment can be significantly reduced by using the local isothermal airflow under the premise of ensuring the thermal comfort.Up to 20.15%,the energy efficiency of such measures is reduced with the decrease of latitude,but the energy saving will increase with the decrease of latitude.