Thermal Comfort Of Human Body In Miniature Building Based On Local Thermal Sensation

In recent years,under the double background of the global population explosion and limited land resources,as well as the energy consumption and environmental pollution problems,the real estate field is facing unprecedented great challenges in its development process.In the process of creating a resource-saving society,the direction of housing innovation is comfort,energy saving,and miniaturization.In addition,building energy saving is also the development trend of modern architecture.The research and design of micro-buildings should not only meet the basic living needs but also achieve the efficiency of maintaining human comfort and green energy saving.Local thermal sensation has a great influence on human thermal comfort in micro-buildings,which is worth further study.At present,the research on the effect of local stimulation on overall comfort is relatively shallow,as most of the research on local thermal comfort heat transfer mode is relatively simple.Human comfort analysis and energy consumption research are still not clear.Therefore,in the case of three different heat transfer modes(convection,conduction,radiation)stimulation,this paper carries out eight kinds of local stimulation on different parts of the human body,by using the influence relationship between skin temperature and thermal sensation,the sensitivity of human body parts is explored,and the thermal response of local stimuli acting on different parts of the human body and the influence law on thermal comfort are explored,providing theoretical guidance for the selection of parts in the energy saving experiment.And based on analyzing the differences between different parts of the human body,the thermal environment control mode is adjusted,and the sensitive parts are intermittently supplied with air heating according to the entry and exit of personnel for the transitional space with a small number of users and a small area(such as foyer,corridor,etc.).As a consequence,the indoor thermal comfort of the human body with minimal energy consumption is achieved.First of all,in order to obtain the relationship between local and global thermal sensation,25 sensitive body parts were selected for local research in this paper.The local and overall thermal sensation,thermal comfort,thermal acceptability,thermal expectation,and the changes of skin temperature are analyzed in different parts stimulated by different heat transfer methods.The results show that,under the premise that the heat levels received by different parts of the body per unit skin area are the same,the differences produced by three different heat transfer methods after stimulation have similar rules as that before stimulation,in which the temperature variation amplitude is high-temperature convection>high-temperature conduction>high-temperature radiation,room temperature convection>room temperature conduction,low-temperature conduction>low-temperature convection>low-temperature radiation.Secondly,through the statistical analysis of the questionnaire,the sensitive trend of the thermal sensation voting mean was ranked like that:head-neck>torso>upper limb>lower limb,the adaptability and stability of the head-neck,and trunk to temperature changes are better than those of the limbs.The rank of discomfort was:head-neck>upper limb>torso>lower limbs,the discomfort of the head-neck,and upper limbs is more prominent,and the air supply to the trunk and lower limbs will have a weak influence,so it can be used as a local heating method to improve human comfort.Under the experimental conditions,correlation analysis showed that there was a strong correlation between local skin temperature and local thermal sensation,which had a very significant relationship,and the correlation was weaker in women than in men.There is a negative correlation between local skin temperature and local thermal comfort.In this experimental environment,regression fitting analysis showed that there was an obvious linear relationship between the overall average thermal sensation voting value TSV of different genders and different heat transfer modes and its corresponding average body surface temperature.In the thermal neutral state,the average neutral temperature of the male body surface was higher than that of the female body surface;Under the same environment,Women’s average thermal sensation and average thermal discomfort are always higher than men’s.This shows that under the same working conditions,female body parts show higher sensitivity;Compared with men,women show more heat tolerance and are more receptive to slightly hotter environments,while women are more likely to feel cold discomfort when faced with cold stimuli.Finally,in order to verify the site sensitivity obtained in the local stimulation experiments of different heat transfer modes,the human body parts were optimized into three highly sensitive experimental parts,namely head-neck,abdomen and feet.The energy-saving comparison experiment was conducted with the traditional air conditioning position,in the optimized energy-saving building space thermal environment,the energy consumption of the human body thermal comfort under the working condition of different height(different height of human body and traditional air conditioning position)by using two kinds of heat sources with different power is compared and analyzed.The results show that when the low-grade heat source is 1000W,the head-neck as the local heating part has the best effect both in terms of the powerful effect and the time spent to achieve thermal comfort,the energy consumption is 12.88kJ;When the high-grade heat source is 2000W,the effect of choosing the abdomen as the local heating part is the best,the energy consumption is 55.12kJ;The energy consumption of head-neck,abdomen and feet as local heating parts under the two heat sources is much lower than that of traditional air conditioning positions.In conclusion,this paper studies the effects of different heat transfer stimuli on human thermal comfort from both subjective and objective perspectives.The sensitivity of body parts and the energy-saving effect of the parts of the air supply are analyzed.The conclusion can provide an important reference value for the future study of the human body using different heating and cooling methods in the micro-building,and its local thermal sensation and human thermal comfort.It also provides a theoretical basis for the study and design of high comfort and low energy consumption indoor thermal environment of micro-buildings.