A Multi-node Human Thermal Response Model Based On Different Convective Environments

To further evaluate the thermal comfort of this kind of thermal environment and carry out subsequent system control strategy research,Establishing mechanism for evaluating and predicting the human thermal response to the environment created by these new convective air conditioning technologies has become one of the key topics of current research.Multi-node human thermal response model has attracted more and more attention due to its excellent performance in non-uniform and unsteady environments.Most of the existing multi-node human thermal response models take into account the influence of different temperature factors on body temperature regulation in non-uniform and unsteady environments.They are often used in thermal environments with smaller air velocity and have lower prediction accuracy in larger wind speed environments.Based on the existing models,the heat transfer calculation between human body and environment in different convective environments is revised from the aspects of local convective heat transfer coefficient on skin surface,average radiation temperature and clothing thermal resistance.A multi-node thermal reaction model for human body in convective environments with different wind speed is established and solved numerically by using MATLAB programming.The validity of the model under different convection conditions is verified by literature validation.The validation results are as follows:(1)When validating the model under steady-state convective heat transfer conditions,the average skin temperature is selected as the validation value,and the predicted value of the model is validated with the experimental results in natural convection and mixed convection environments.The predicted value is basically within the range of the standard deviation of mean addition or subtraction of the experimental measurements;When comparing the predicted value of local skin temperature with the experimental measurements in forced convection environments,it is found that the prediction errors of local temperature of head,upper arm,abdomen and lower leg are between-1 oC and 1 oC,especially the prediction errors of head and abdomen are less than 0.5 oC,while the prediction errors of limbs are larger in some conditions,such as foot working condition 1 or even more than 1.5 oC.(2)The results of validation of the model under transient convective heat transfer conditions show that in the sudden change of low wind speed and temperature environment,the maximum difference between the predicted core temperature of the model and the measured sample range is 0.2 oC,and the maximum deviation of the average skin temperature is about 0.5 oC.In the high-temperature-blowing and lowtemperature-blowing conditions,the predicted value of trunk part agrees better with the measured values than limbs.The deviation between the predicted value and the measured value of the local skin temperature is about 0.5 oC,and the deviation of the partial time interval of the leg is about 1 oC.In conclusion,when validating the model under different working conditions,the prediction deviation of most parts of the model is small,and the deviation of a small number of end parts is large under some working conditions,but the skin area of these parts accounts for a small proportion,which is acceptable as a whole.It shows that the human thermal response model based on convective environment can predict physiological parameters such as skin temperature under different convective conditions.The research in this paper can provide some reference for the thermal comfort evaluation and system control strategy of human body in this kind of environment.