The energy equilibrium equation and discrete ordinate methods are combined to establish the one-dimensional steady heat transfer mathematical model of multi-layer thermal insulations （MTIs） in metallic thermal prote...The energy equilibrium equation and discrete ordinate methods are combined to establish the one-dimensional steady heat transfer mathematical model of multi-layer thermal insulations （MTIs） in metallic thermal protection systems. The inverse problem of heat transfer is solved by the genetic algorithm and data from the steady heat transfer experiment of fibrous thermal insulations. The density radiation attenuation coefficient, the albedo of fibrous thermal insulations and the surface emissivity of reflective screens are optimized. Finally, the one-dimensional steady heat transfer model of MTIs with optimized thermal physical parameters is verified by experimental data of the effective MTI conductivity.展开更多
Heat strain experienced by individuals wearing chemical protective clothing(CPC)is severe and dangerous especially in hot-humid environment.The development of material science and interdisciplinary studies including e...Heat strain experienced by individuals wearing chemical protective clothing(CPC)is severe and dangerous especially in hot-humid environment.The development of material science and interdisciplinary studies including ergonomics,physiology and heat transfer is urgently required for the reduction of heat strain.The aim of this paper was to study the relationship among clothing thermal properties,physiological responses and environmental conditions.Three kinds of CPC were selected.Eight participants wore CPC and walked(4 km/h,two slopes with 5%and 10%)on a treadmill in an environment with(35±0.5)℃ and RH of(60±5)%.Core temperature,mean skin temperature,heart rate,heat storage and tolerance time were recorded and analyzed.Physiological responses were significantly affected by the clothing thermal properties and activity intensity in hot-humid environment.The obtained results can help further development of heat strain model.New materials with lower evaporative resistance and less weight are necessary to release the heat strain in hot-humid environments.展开更多
Based on the heat transferring theory in the human-clothing-environment system, the heat insulation property and changing pattern of down jackets in relation to its down content is mainly dealt with. By the heated-man...Based on the heat transferring theory in the human-clothing-environment system, the heat insulation property and changing pattern of down jackets in relation to its down content is mainly dealt with. By the heated-manikin testing and the mathematical analysis to the testing data, the existence of the optimum down content is found. Furthermore the reason and mechanism of the relation between down content and clothing’s heat insulation property are explained.展开更多
Thermal protective clothing has been recognized as the primary shielding against emergency fire hazard and inflammable gas leakage. Therefore,the thermal response of human covered with thermal protective clothing unde...Thermal protective clothing has been recognized as the primary shielding against emergency fire hazard and inflammable gas leakage. Therefore,the thermal response of human covered with thermal protective clothing under high temperature is the key work to investigate the thermal insulation of thermal protective clothing. A coupling model composed of thermal protective clothing,air gap and human skin is established and the temperature of the micro-system is numerically solved via the finite element method( FEM).Especially,the heat transfer of air gap located between clothing and human skin considering conduction and radiation is established while the human skin layers involve the effect of blood perfusion. Then the effect of thermophysical properties( thermal conductivity and volumetric capacity) of fabric and thickness of fabric and air on the thermal response of the micro-system is elucidated and compared.The results indicate that the volumetric heat capacity of fabric is the key parameter to affect the thermal shielding performance of thermal protective clothing,and the thicker fabric thickness and air gap thickness can improve the thermal protective properties of the micro-system.展开更多
Background:Deep body temperature is a critical indicator of heat strain.However,direct measures are often invasive,costly,and difficult to implement in the field.This study assessed the agreement between deep body tem...Background:Deep body temperature is a critical indicator of heat strain.However,direct measures are often invasive,costly,and difficult to implement in the field.This study assessed the agreement between deep body temperature estimated from heart rate and that measured directly during repeated work bouts while wearing explosive ordnance disposal(EOD)protective clothing and during recovery.Methods:Eight males completed three work and recovery periods across two separate days.Work consisted of treadmill walking on a 1%incline at 2.5,4.0,or 5.5 km/h,in a random order,wearing EOD protective clothing.Ambient temperature and relative humidity were maintained at 24℃and 50%[Wet bulb globe temperature(WBGT)(20.9±1.2)℃]or 32℃and 60%[WBGT(29.0±0.2)℃]on the separate days,respectively.Heart rate and gastrointestinal temperature(TGI)were monitored continuously,and deep body temperature was also estimated from heart rate(ECTemp).Results:The overall systematic bias between TGI and ECTemp was 0.01℃with 95%limits of agreement(Lo A)of±0.64℃and a root mean square error of 0.32℃.The average error statistics among participants showed no significant differences in error between the exercise and recovery periods or the environmental conditions.At TGI levels of(37.0–37.5)℃,(37.5–38.0)℃,(38.0–38.5)℃,and>38.5℃,the systematic bias and±95%Lo A were(0.08±0.58)℃,(–0.02±0.69)℃,(–0.07±0.63)℃,and(–0.32±0.56)℃,respectively.Conclusions:The findings demonstrate acceptable validity of the ECTemp up to 38.5℃.Conducting work within an ECTemp limit of 38.4℃,in conditions similar to the present study,would protect the majority of personnel from an excessive elevation in deep body temperature(>39.0℃).展开更多
In this paper,the protective performance of woven fab-rics against heat radiation is studied from the view offabric structure.As indices reflecting the protective per-formance against heat radiation,the heat emissivit...In this paper,the protective performance of woven fab-rics against heat radiation is studied from the view offabric structure.As indices reflecting the protective per-formance against heat radiation,the heat emissivity andthe transmissivity of different fabrics are measured.It ispointed out that structure changes of common textiles af-fect their transmission to heat radiation while have littleinfluence on their absorption or reflection to heat radi-ation except fabrics surfaces are aluminized.Double-layer weave is proved to be an effective fabric weave forreducing the trasmissivity.It helps increase the densityand tightness while keeps the comfort of woven fabrics atthe same time.展开更多
In outdoor spaces, infants in strollers are significantly affected by thermal radiation from the ground surface due to their proximity to it. Infants are at increased risk of heat stroke while riding in a stroller. In...In outdoor spaces, infants in strollers are significantly affected by thermal radiation from the ground surface due to their proximity to it. Infants are at increased risk of heat stroke while riding in a stroller. Infants are less thermally adapted to their environment and can consequently be considered to need protective measures against thermal environments. In order to treat strollers as clothing, in the present study, experiments were conducted to clarify the thermal environment of an infant riding in a stroller. Using an infant thermal manikin, the clothing area factor fcl and the clothing thermal insulation I<sub>cl</sub> of the stroller were determined. The stroller clothing area factor fcl was 3.21 and the stroller clothing thermal insulation I<sub>cl</sub> was 0.47 clo. Therefore, it can be inferred that strollers have a pronounced effect on the body heat balance between an infant and their environment.展开更多
为探析调温服装领域的研究现状和发展趋势,本文基于文献计量法与文献综述法,以中国知网CNKI数据库和Web of Science核心合集数据库中相关文献为数据来源,通过VOSviewer和CiteSpace两款可视化软件,对调温服装研究的年发文量、发文作者、...为探析调温服装领域的研究现状和发展趋势,本文基于文献计量法与文献综述法,以中国知网CNKI数据库和Web of Science核心合集数据库中相关文献为数据来源,通过VOSviewer和CiteSpace两款可视化软件,对调温服装研究的年发文量、发文作者、发文机构、发文国家(地区)、关键词共现和聚类、关键词时间线等信息,进行科学知识图谱分析与描述性统计分析,以多维角度探索调温服装的研究热点与前沿。研究结果表明:2000年至今,国内外调温服装研究多应用于消防救援、医用防护、煤矿与隧道施工等处于极端工作环境的行业领域,且更加侧重于从人体生理反应数据对调温服装的性能进行优化,从服装逐步聚焦到着装者自身;调温方式、调温服装的性能评价、调温服装与人体生理指标的相互作用则是当前调温服装领域的研究热点;未来发展应以提升对轻量化、高效能的外源设备和新型调温材料的研发,建立健全相关的行业标准与生产技术规范,开展多维度的性能评价体系,立足于数智协同、研发多功能集成化的智能调温服装为主要方向。展开更多
Silica aerogel composites have promising applications in high-temperature heat storage insulation.However,the impact of high temperatures and moisture on their insulation performance remains unclear.To reveal the infl...Silica aerogel composites have promising applications in high-temperature heat storage insulation.However,the impact of high temperatures and moisture on their insulation performance remains unclear.To reveal the influences of high temperature and moisture absorption property on the heat transfer of silica aerogel composites,an experimental and numerical study was conducted to explore the micromorphology,thermophysical parameters,moisture absorption characteristics,and temperature response.The service temperature limit of the silica aerogel composite has been clarified.Measurements have conducted for the thermal conductivity,specific heat capacity,thermal diffusivity,specific surface area,density,porosity,and pore size distribution of the heated silica aerogel composite(at temperatures of 600,800,1,000,1,100 and 1,200℃).The moisture absorption characteristic curve at 20℃ has been obtained.Thermal testing of silica aerogel composites under varying heating temperatures and moisture content has been completed.Additionally,a numerical method has been developed to calculate the temperature curve of moist silica aerogel composites.The insulation performance of silica aerogel composite with varying moisture contents depends on the game between thermal conductivity and latent heat.Compared with the negative effect of the moisture content on insulation performance,the positive influence of moisture evaporation and heat absorption is dominant in situations involving temperatures higher than the phase transition temperature.展开更多
文摘The energy equilibrium equation and discrete ordinate methods are combined to establish the one-dimensional steady heat transfer mathematical model of multi-layer thermal insulations （MTIs） in metallic thermal protection systems. The inverse problem of heat transfer is solved by the genetic algorithm and data from the steady heat transfer experiment of fibrous thermal insulations. The density radiation attenuation coefficient, the albedo of fibrous thermal insulations and the surface emissivity of reflective screens are optimized. Finally, the one-dimensional steady heat transfer model of MTIs with optimized thermal physical parameters is verified by experimental data of the effective MTI conductivity.
文摘Heat strain experienced by individuals wearing chemical protective clothing(CPC)is severe and dangerous especially in hot-humid environment.The development of material science and interdisciplinary studies including ergonomics,physiology and heat transfer is urgently required for the reduction of heat strain.The aim of this paper was to study the relationship among clothing thermal properties,physiological responses and environmental conditions.Three kinds of CPC were selected.Eight participants wore CPC and walked(4 km/h,two slopes with 5%and 10%)on a treadmill in an environment with(35±0.5)℃ and RH of(60±5)%.Core temperature,mean skin temperature,heart rate,heat storage and tolerance time were recorded and analyzed.Physiological responses were significantly affected by the clothing thermal properties and activity intensity in hot-humid environment.The obtained results can help further development of heat strain model.New materials with lower evaporative resistance and less weight are necessary to release the heat strain in hot-humid environments.
文摘Based on the heat transferring theory in the human-clothing-environment system, the heat insulation property and changing pattern of down jackets in relation to its down content is mainly dealt with. By the heated-manikin testing and the mathematical analysis to the testing data, the existence of the optimum down content is found. Furthermore the reason and mechanism of the relation between down content and clothing’s heat insulation property are explained.
基金National Natural Science Foundations of China(Nos.51306095,51273097,51403112)China Postdoctoral Science Foundations(Nos.2014M561887,2015T80697)+1 种基金Qingdao Postdoctoral Application Research Funded Project,China(No.14-2-4-1-JCH)Qingdao Application Basic Research Funded Project,China(No.15-9-1-41-JCH)
文摘Thermal protective clothing has been recognized as the primary shielding against emergency fire hazard and inflammable gas leakage. Therefore,the thermal response of human covered with thermal protective clothing under high temperature is the key work to investigate the thermal insulation of thermal protective clothing. A coupling model composed of thermal protective clothing,air gap and human skin is established and the temperature of the micro-system is numerically solved via the finite element method( FEM).Especially,the heat transfer of air gap located between clothing and human skin considering conduction and radiation is established while the human skin layers involve the effect of blood perfusion. Then the effect of thermophysical properties( thermal conductivity and volumetric capacity) of fabric and thickness of fabric and air on the thermal response of the micro-system is elucidated and compared.The results indicate that the volumetric heat capacity of fabric is the key parameter to affect the thermal shielding performance of thermal protective clothing,and the thicker fabric thickness and air gap thickness can improve the thermal protective properties of the micro-system.
基金the Australian Government,managed by the National Security Science&Technology Centre within the Defence Science&Technology Organisation,and the US Government through the Technical Support Working Group within the Combating Terrorism Technical Support Office。
文摘Background:Deep body temperature is a critical indicator of heat strain.However,direct measures are often invasive,costly,and difficult to implement in the field.This study assessed the agreement between deep body temperature estimated from heart rate and that measured directly during repeated work bouts while wearing explosive ordnance disposal(EOD)protective clothing and during recovery.Methods:Eight males completed three work and recovery periods across two separate days.Work consisted of treadmill walking on a 1%incline at 2.5,4.0,or 5.5 km/h,in a random order,wearing EOD protective clothing.Ambient temperature and relative humidity were maintained at 24℃and 50%[Wet bulb globe temperature(WBGT)(20.9±1.2)℃]or 32℃and 60%[WBGT(29.0±0.2)℃]on the separate days,respectively.Heart rate and gastrointestinal temperature(TGI)were monitored continuously,and deep body temperature was also estimated from heart rate(ECTemp).Results:The overall systematic bias between TGI and ECTemp was 0.01℃with 95%limits of agreement(Lo A)of±0.64℃and a root mean square error of 0.32℃.The average error statistics among participants showed no significant differences in error between the exercise and recovery periods or the environmental conditions.At TGI levels of(37.0–37.5)℃,(37.5–38.0)℃,(38.0–38.5)℃,and>38.5℃,the systematic bias and±95%Lo A were(0.08±0.58)℃,(–0.02±0.69)℃,(–0.07±0.63)℃,and(–0.32±0.56)℃,respectively.Conclusions:The findings demonstrate acceptable validity of the ECTemp up to 38.5℃.Conducting work within an ECTemp limit of 38.4℃,in conditions similar to the present study,would protect the majority of personnel from an excessive elevation in deep body temperature(>39.0℃).
文摘In this paper,the protective performance of woven fab-rics against heat radiation is studied from the view offabric structure.As indices reflecting the protective per-formance against heat radiation,the heat emissivity andthe transmissivity of different fabrics are measured.It ispointed out that structure changes of common textiles af-fect their transmission to heat radiation while have littleinfluence on their absorption or reflection to heat radi-ation except fabrics surfaces are aluminized.Double-layer weave is proved to be an effective fabric weave forreducing the trasmissivity.It helps increase the densityand tightness while keeps the comfort of woven fabrics atthe same time.
文摘In outdoor spaces, infants in strollers are significantly affected by thermal radiation from the ground surface due to their proximity to it. Infants are at increased risk of heat stroke while riding in a stroller. Infants are less thermally adapted to their environment and can consequently be considered to need protective measures against thermal environments. In order to treat strollers as clothing, in the present study, experiments were conducted to clarify the thermal environment of an infant riding in a stroller. Using an infant thermal manikin, the clothing area factor fcl and the clothing thermal insulation I<sub>cl</sub> of the stroller were determined. The stroller clothing area factor fcl was 3.21 and the stroller clothing thermal insulation I<sub>cl</sub> was 0.47 clo. Therefore, it can be inferred that strollers have a pronounced effect on the body heat balance between an infant and their environment.
文摘为探析调温服装领域的研究现状和发展趋势,本文基于文献计量法与文献综述法,以中国知网CNKI数据库和Web of Science核心合集数据库中相关文献为数据来源,通过VOSviewer和CiteSpace两款可视化软件,对调温服装研究的年发文量、发文作者、发文机构、发文国家(地区)、关键词共现和聚类、关键词时间线等信息,进行科学知识图谱分析与描述性统计分析,以多维角度探索调温服装的研究热点与前沿。研究结果表明:2000年至今,国内外调温服装研究多应用于消防救援、医用防护、煤矿与隧道施工等处于极端工作环境的行业领域,且更加侧重于从人体生理反应数据对调温服装的性能进行优化,从服装逐步聚焦到着装者自身;调温方式、调温服装的性能评价、调温服装与人体生理指标的相互作用则是当前调温服装领域的研究热点;未来发展应以提升对轻量化、高效能的外源设备和新型调温材料的研发,建立健全相关的行业标准与生产技术规范,开展多维度的性能评价体系,立足于数智协同、研发多功能集成化的智能调温服装为主要方向。
基金supported by the National Natural Science Foundation of China(Grant Nos.:52006168 and 12102056).
文摘Silica aerogel composites have promising applications in high-temperature heat storage insulation.However,the impact of high temperatures and moisture on their insulation performance remains unclear.To reveal the influences of high temperature and moisture absorption property on the heat transfer of silica aerogel composites,an experimental and numerical study was conducted to explore the micromorphology,thermophysical parameters,moisture absorption characteristics,and temperature response.The service temperature limit of the silica aerogel composite has been clarified.Measurements have conducted for the thermal conductivity,specific heat capacity,thermal diffusivity,specific surface area,density,porosity,and pore size distribution of the heated silica aerogel composite(at temperatures of 600,800,1,000,1,100 and 1,200℃).The moisture absorption characteristic curve at 20℃ has been obtained.Thermal testing of silica aerogel composites under varying heating temperatures and moisture content has been completed.Additionally,a numerical method has been developed to calculate the temperature curve of moist silica aerogel composites.The insulation performance of silica aerogel composite with varying moisture contents depends on the game between thermal conductivity and latent heat.Compared with the negative effect of the moisture content on insulation performance,the positive influence of moisture evaporation and heat absorption is dominant in situations involving temperatures higher than the phase transition temperature.
