无症状高原反应域低气压环境下人体热舒适研究

发布时间：2018-06-06 06:05

本文选题：无症状反应高度低气压环境 + 热舒适　；参考：《西安建筑科技大学》2008年博士论文

【摘要】： 舒适健康的室内环境对人们的工作、生活及工艺过程有着积极的意义。目前国内外的研究大都是基于常压环境展开的,PMV-PPD指标是基于稳态环境中人体本身接近于舒适状态下、以欧美国家的受试者为研究对象得出的。在历年的设计与应用中表明,气候条件、地理位置、生活习惯、建筑形式、采暖空调系统的形式乃至经济发展水平等均会对人体的热舒适有重要影响。气候条件包括空气温度、相对湿度、空气流速、空气压力等因素,特别是空气压力,在诸如低压低氧的高原环境中,人体的生理反应以及与周围环境之间的热交换都会发生变化,PMV指标在不同大气压力条件下的适用程度有待于进一步探讨。本文在国家自然科学基金委(项目编号50778091)的支持下,对低气压环境中人体热舒适进行了研究。本文重点研究海拔3000m以下的无症状高原反应范围内的人体热舒适相关问题,在此范围内,低压低氧会引起人体生理机能的一些适应性变化,但不致发生病理上的改变(海拔3000m以上的区域首先应解决的是高原反应及高原病的防治问题,这往往需要通过生理学或医学的手段实现)。本文的主要研究内容如下: (1)低气压环境下人体与周围环境热平衡的理论研究人体热平衡与环境因素有关,低气压对人体热平衡的影响,主要表现在:在低气压环境中因空气密度的改变,人体与周围环境的对流换热系数和传质系数发生变化,导致人体的散热特性改变;根据人体生理学研究成果,低气压可使空气中氧分压力降低,引起呼吸功能的改变,从而导致呼吸散热量发生变化;低气压下人体的能量代谢发生适应性改变,使人体的自身产热量发生变化。本文研究了低气压环境下人体对流换热量的变化,在低气压条件下对流换热减弱,而蒸发换热加强。基于刘伊斯关系式进行热质比拟,给出了低气压环境中蒸发散热的新的表达式。作者同时研究了与人体生理有关的呼吸散热和新陈代谢率的变化,在前人研究的基础上,重点探讨了低气压环境对人体呼吸和新陈代谢率的影响。给出了低气压环境中人体的热平衡方程式,并进一步分析了低气压环境中影响PMV的各影响因素。 (2)无症状反应高度内低气压环境下人体热舒适的实验研究基于正交试验分析,重点研究了在代表性服装热阻和活动水平条件下,温度、压力、风速等因素对人体平均热感觉MTS的影响程度,获得了热舒适与各个参数的关系。对热舒适的影响从大到小的排列顺序为:温度＞压力＞风速,即在低气压环境中,大气压力对人体热舒适有直接而重要的影响。作者采用了平均热感觉和热中性温度来考察不同压力下人体热感觉的变化。实验表明,在低气压环境下,人体的热中性温度是降低的,并进行了人体与周围环境条件下的换热分析。为进一步分析各个因素之间的关系,作者进行了平行实验分析,对比分析了相关因素对人体热感觉的影响。空气温度和平均辐射温度升高时,MTS均会增加;在低压环境中着厚重衣服、当人体处于接近舒适状态时,室内微风速(＜0.3m/s)对人体的热感觉影响很小;而在接近舒适的环境中,相对湿度对MTS的影响较小。本文还对比了不同压力工况下PMV与受试者平均热感觉投票值MTS,结果表明,在低气压环境中PMV的预测值及随大气压力的变化趋势与人体的实际热感觉存在着偏差。此外,对人体的生理指标进行了测试,采用t—检验:双样本等方差假设及两个正态总体均值的假设检验方法对测得的人体各生理指标数据进行分析,得出了压力因素影响人体各生理指标的显著程度及影响趋势。 (3)无症状反应高度内低气压环境中人体热感觉预测模型的建立在常压环境中广泛采用的PMV指标计算极其复杂,必须在计算机上迭代求解,这对工程应用极为不利。更为重要的是,PMV指标预测低气压环境中的人体热感觉时,与人体的实际热感觉存在偏差。本文采用量纲分析法,将低气压环境中影响热舒适的主要因素无因次化,并结合本文的实验数据,建立了无症状反应高度内低气压环境中人体热感觉预测模型。
[Abstract]:The comfortable and healthy indoor environment has a positive significance to people's work, life and process. At present, most of the research at home and abroad is based on the ambient pressure environment. The PMV-PPD index is based on the human body itself near the comfort state in the steady state and the subjects of the European and American countries as the research object. The application shows that climate conditions, geographical location, living habits, architectural forms, heating and air conditioning system and even the level of economic development will all have an important impact on the thermal comfort of the human body.
Climate conditions include air temperature, relative humidity, air flow velocity, air pressure and other factors, especially air pressure. In the plateau environment such as low pressure hypoxia, the physiological response and heat exchange between the human body and the surrounding environment will change. The application of the PMV index under different pressure conditions needs to be further discussed.
Under the support of National Natural Science Foundation of China (Project No. 50778091), this paper studies the thermal comfort of human body in low pressure environment. This paper focuses on the related problems of human thermal comfort within the range of asymptomatic plateau response below 3000m altitude. In this range, low pressure and hypoxia will cause some adaptive changes in human physiological function. There are no pathological changes (above 3000m above sea level), which should be solved first in the plateau response and the prevention of high altitude diseases, which often need to be realized by physiological or medical means.
The main contents of this paper are as follows:
(1) theoretical study on thermal balance between human body and surrounding environment under low pressure environment
The heat balance of human body is related to the environmental factors. The effect of low pressure on human heat balance is mainly manifested in the change of the heat transfer coefficient and mass transfer coefficient of the body and the surrounding environment in the low pressure environment, which leads to the change of the heat transfer characteristic of the human body; according to the research results of human physiology, the low pressure can make the air in the air. The decrease of oxygen pressure causes the change of respiratory function, which leads to the change of respiratory heat dissipation, and the energy metabolism of human body is changed under low pressure, which makes the body's own heat production change.
In this paper, the changes of convective heat transfer in human body under low pressure are studied. The convection heat transfer is weakened under low pressure and the heat transfer is strengthened. A new expression of evaporation and heat dissipation in low pressure environment is given based on the Liu Yi equation.
The authors also studied the changes in respiratory heat dissipation and metabolic rate related to human physiology. On the basis of previous studies, the author focused on the effects of low pressure environment on human respiration and metabolic rate. The heat balance equation of human body in low pressure environment was given, and the effects of PMV in low pressure environment were analyzed. Sound factors.
(2) experimental study of human thermal comfort under low pressure environment with asymptomatic response height
Based on the orthogonal test analysis, the influence of the temperature, pressure, wind speed and other factors on the average thermal sensation MTS of the human body is studied under the conditions of the thermal resistance and the activity level of the representative clothing, and the relationship between the thermal comfort and the parameters is obtained. The sequence of thermal comfort from large to small is temperature > pressure > wind speed, that is, the low gas pressure ring. Atmospheric pressure plays a direct and important role in human thermal comfort.
The authors used the average thermal sensation and the thermal neutral temperature to examine the changes in the thermal sensation of the human body under different pressures. The experiment showed that the heat neutral temperature of the human body was reduced in the low pressure environment and the heat transfer analysis under the environment of the human body and the surrounding environment was carried out.
In order to further analyze the relationship between the various factors, the author carried out a parallel experiment and analyzed the influence of the related factors on the human body's thermal sensation. When the air temperature and the average radiation temperature rise, the MTS will increase; in the low pressure environment, the heavy clothes, when the human body is near the comfortable condition, the indoor breeze speed (< 0.3m/s) is to the person. The thermal sensation of the body is very small, while in a comfortable environment, relative humidity has little effect on MTS.
The average thermal sensation voting value of PMV and the subjects MTS under different pressure conditions is also compared. The results show that there is a deviation between the predicted value of PMV and the change trend with the atmospheric pressure in the low pressure environment with the actual thermal sensation of the human body.
In addition, the physiological indexes of the human body were tested. The t test, double sample variance hypothesis and the hypothesis testing method of two normal population mean values were used to analyze the physiological index data of the human body, and the significant degree and influence trend of the pressure factors affecting the physiological indexes of the human body were obtained.
(3) prediction model of human thermal sensation in low pressure environment with asymptomatic response height
The PMV index, which is widely used in atmospheric environment, is extremely complex and must be solved iteratively on the computer. It is extremely unfavorable for engineering applications. More importantly, the PMV index predicts the thermal sensation of human body in low pressure environment, and there is a deviation from the actual thermal sensation of the human body. This paper uses the dimensional analysis method to influence the heat in low pressure environment. The main factors of comfort are dimensionless. Combined with the experimental data in this paper, a predictive model of human thermal sensation in low pressure environment with asymptomatic response height is established.
【学位授予单位】：西安建筑科技大学
【学位级别】：博士
【学位授予年份】：2008
【分类号】：R188

【引证文献】