The Change Of Human Thermal Response Under The Vertical Tower Fan And The Application Of Thermal Comfort Model

With the improvement of people's living standards,it is more and more significant to properly regulate the indoor environment,meet the requirements of human thermal comfort and building energy conservation.In the existing indoor environment control,the fixed temperature and humidity regulation is often used as the main control method in the room.At relatively high room temperature conditions in summer,the increase of wind speed can reduce the thermal sensation of the human body,and reduce some of the indoor cooling to achieve energy saving at the same time.Existing researches on the influence of wind speed on human thermal comfort mainly focus on ceiling fans or floor shaking fans.Moreover,regulating human thermal sensation through wind speed is rarely applied in practical environment.In order to explore the difference of flow characteristics between the existing main fans,this paper firstly carried out the actual test of common fans,the structure and flow characteristics of the vertical tower fan,the floor shaker fan and the ceiling fan are compared;The test results show that the wind field of the vertical tower fan is more concentrated,the turbulence intensity of it is lower,the frequency of it is higher,and is relatively more energy-efficient,which is suitable for long-term sitting in office environment.So,this paper uses vertical tower fan to control wind speed,and designs experiments for human thermal reaction changes under different temperatures and wind speeds,and explored the changes of human subjective parameters and skin temperature with environmental parameters under the action of vertical tower fan.Based on this experiment,partial correlation analysis of the main influencing factors of human thermal response is conducted in this paper.The analysis results show that under uniform environment,temperature and wind speed are the main factors affecting human thermal response,and there is a significant correlation between them and subjective thermal response parameters.At room temperature of 24~28°C,the thermal sensation of men is generally higher than that of women,and the lower the temperature,the greater the difference.In this experiment,the effects of height,weight,age,and clothing thermal resistance on the subjective thermal response of the human body did not show significant differences.On the other hand,in this paper,the changes of skin temperature in the experiment are analyzed.As the wind speed increases,the skin temperature will decrease.Therefore,when the temperature and wind speed change simultaneously,the hand thermal neutral temperature value in this study is lower than the hand thermal neutral temperature value when there's only temperature changes.Based on the results of partial correlation analysis,this study uses temperature and wind speed as the main influencing factors in the human thermal response prediction model,the prediction model of the thermal sensation vote,the acceptability of wind speed,and the feeling of the air circulation are given.The effect of polynomial on temperature and wind speed is the best data fitting.In the model,the relationship between TSV/AWS/FAC and wind speed is a quadratic function,which also indicates that the greater the wind speed,the greater the variation of TSV/AWS/FAC caused by the same wind speed variation,and the relationship between temperature and subjective parameters in the model is linear or quadratic function.In this paper,the TSV value of this experiment is compared with the research results of other existing fans.The comparison shows that the vertical tower fan can better reduce the thermal sensation of the human body under the same temperature and wind speed environment.After that,the paper verifies the prediction model by verifying data.The verification results show that the determination coefficients are above 66%,and the accuracy of the prediction method is high.The analysis shows that the correlation coefficient between the human thermal sensation and the acceptability of wind speed is-0.728,and the correlation coefficient with the feeling of air circulation is-0.685,and the correlation is significant.There is a significant correlation between the acceptability of wind speed and the feeling of air circulation,and the quadratic function fitting is optimal.Based on the prediction model of human thermal response under the vertical tower fan and the existing thermal sensation prediction model by skin temperature,this paper proposes environmental dynamic regulation methods which is suitable for individual environment and multiple environment: in the individual environment,the fixed temperature and humidity control can be classified into different types by considering the factors of season,building location and building type,etc.When skin temperature is input,the body's thermal sensation can be predicted according to skin temperature,and then the environment can be controlled by thermal sensation.In a multi-person environment,fan control can be added in each office to adjust the difference between individuals,and the background temperature can be adjusted according to the number and size of fans.In order to improve its applicability,this paper proposes two methods for correcting the model.The first is the self-learning correction method,which allows the model to continuously self-correct according to the value of human input;the other is the individual physiological parameter correction method based on the human body's heat balance equation,which modifies the individual's height,weight,age,gender,the clothing thermal resistance and the activity status.This paper adopts such a control method in the actual office environment to verify the requirements of comfort,and put forward the prospects for future applications.