張華玲++姚大軍++洪詩堯



摘要:
服裝熱阻是影響人體熱舒適的重要因素之一,夜間睡眠狀態下的被服系統總熱阻包括人體所穿服裝熱阻與整個床褥系統熱阻。針對低氣壓環境,目前,尚缺乏被服熱阻實驗數據,也沒有可參考的被服系統總熱阻的理論計算模型。以人體睡眠狀態被服系統總熱阻計算方法為依據,引入氣壓修正項對相關參數進行修正,建立了適用于低氣壓環境的被服系統總熱阻的修正計算模型,并用模型計算了冬夏典型被服系統總熱阻,分析了氣壓減小對總熱阻的影響,發現冬夏季被服系統總熱阻均隨大氣壓力降低而升高,增加百分比最大值均為42%,且均出現在被子覆蓋率為23.3%的條件下,當海拔低于3 000 m時,由被子覆蓋率引起的被服系統總熱阻增加系數不超過0.05。
關鍵詞:
低氣壓環境;病人;被服系統總熱阻;壓力修正;計算模型
Abstract:
Clothing thermal resistance is a key factor that affects the thermal comfort of human body. The total thermal resistance of bedding and clothing system in sleeping at night includes the clothing system resistance and the body of the mattress system. In the low pressure environment, there is still a lack of experimental data and calculation model of thermal resistance, with no reference to theory models. In this paper, based on calculation method of the total thermal resistance of bedding and clothing system in sleeping, the calculation model of total thermal resistance in low pressure environment is established by the introduction of pressure correction of related parameters. The typical total thermal resistance both summer and winter is calculated using the model. The variation rules of total thermal resistance caused by the pressure reducing is obtained. At altitude of less than 3000m, the increasing coefficient of total thermal resistance of bedding and clothing system caused by the coverage ratio of blanket is not more than 0.05. The total thermal resistances both winter and summer increase with atmospheric pressure decreasing. There is a same maximum percentage of 42% under the condition of 23.3% of blanket coverage.
Keywords:
low pressure environment; patients; total thermal resistance; pressure correction; calculation model
目前,人體熱舒適研究主要關注于日間不同活動水平[14],服裝熱阻取決于人體所穿的衣物及所帶配飾,主要采用ASHRAE手冊中給出的計算方法[5]。夜間睡眠狀態下的被服系統總熱阻除了所穿衣物熱阻外還包括整個床褥系統的熱阻,文獻[5]給出的公式計算睡眠狀態下的人體總熱阻將會存在較大的誤差,Lin等[6]給出了常壓下人體睡眠狀態被服系統總熱阻計算模型,并給出了不同材質與厚度床褥系統熱阻在常壓下的實驗測試值。研究低氣壓下的人體睡眠狀態熱舒適,首先需要計算或測試低氣壓環境床褥系統的熱阻,但目前還未見文獻給出基礎數據。……