【作者】 王震；

【导师】 刘京；

【作者基本信息】 哈尔滨工业大学 ， 土木工程， 2023， 硕士

【摘要】 个性化舒适加热系统是人体热舒适领域的重要研究方向。当人们处于-20℃左右的极低温环境时,面临着冷暴露带来的各种危害,此类型的情景包括复合冰壳结构建筑中的游客、从事冷库或食品加工行业的工人等。这种情况下,从热源、安全、美观和节能角度考虑,传统的供热方式已经不再适用。个性化舒适加热系统为解决这一问题提供了新的思路,因此本文通过客观实验、主观实验、数学建模和CFD模拟四种手段实现了极低温环境下人体热舒适和个性化加热的实验与模拟研究。研究成果可作为极低温环境下的个性化加热方法,可用于预测极低温环境下人体热生理参数、评估人体热舒适、个性化加热技术的测试与开发。主要工作和研究成果如下:首先,完成了极低温环境下人体热舒适与个性化加热实验。利用低温实验室营造-20℃左右的极低温环境,设置了9个实验工况,对低温实验室的升温特性、个性化加热设备的加热特性和人体周围热环境的升温特性进行了测试;同时测量了受试者的皮肤温度,并收集了主观调查问卷,进而分析出了不同实验工况对热生理参数和热舒适的影响。结果表明,暖风机+限制箱工况是一种适用于极低温环境的高效个性化加热技术,其矫正能力CP高达38.3℃。其次,建立了整体-局部热舒适评价模型和基于热生理参数的热舒适评价模型。根据人体热舒适实验得到的整体/局部热舒适投票和整体/局部热感觉投票,通过多元线性回归方法建立了整体-局部热感觉/热舒适评价模型,得到了极低温环境下各部位热感觉/热舒适占整体热感觉/热舒适的权重因子;此外还建立了基于皮肤温度/皮肤温差的热舒适评价模型。与国内外现有的热舒适评价模型相比,本文所建立的热舒适评价模型在适用性和准确性方面表现出一定优势。随后,建立了基于Stolwijk的一维人体体温调节模型,并确定使用该模型计算热舒适的方法。参考Stolwijk的人体体温调节模型,根据研究需要建立了由被动系统和主动系统构成的一维人体体温调节模型;并使用人体热生理实验数据对模型进行了验证,结果表明,体温调节模型会低估部分身体部位的皮肤温度,但总体上模型的准确性可以接受;此外,利用人体体温调节模型结合热舒适评价模型计算了人体热舒适,确定了具体的计算方法。最后,提出了瞬态环境下人体体温调节模型结合CFD模拟的方法,并应用该方法对暖风机+限制箱工况进行了优化。将复杂的虚拟人体几何模型处理后加入到整体几何模型中,在此基础之上对暖风机+限制箱工况及其优化工况进行了数值模拟研究,分析了不同工况下的温度场、流场分布特点,并对热舒适进行了评估。结果表明,通过优化暖风机的送风温度和送风高度,改善了暖风机+限制箱工况存在的问题,达到了预期优化目标,同时还实现了22%的节能率。更多还原

【Abstract】 Personal comfort heating systems have emerged as a crucial research area in the field of human thermal comfort.When individuals are exposed to extremely low temperature environments around-20°C,they encounter various hazards due to cold exposure.Such scenarios may include visitors in buildings with composite ice shell structures and workers engaged in cold storage handling or food processing industries.In such cases,traditional heating methods are no longer applicable in terms of heat source,safety,aesthetics,and energy savings.The personal comfort heating system offers a new solution to this problem.This study presents experimental and simulation research on human thermal comfort and personal heating in an extremely low temperature environment through four approaches: objective experimentation,subjective experimentation,mathematical modeling,and CFD simulation.The research outcomes can be utilized as a personal heating method in extremely low temperature environments,and can be used to predict human thermal physiological parameters,evaluate human thermal comfort,and test and develop personal heating technology in extremely low temperature environments.The primary work and research findings are outlined below:First,the human thermal comfort and personal heating experiments in an extremely low temperature environment were completed.Nine experimental working conditions were set up to test the heating characteristics of the low-temperature laboratory,the heating characteristics of the personal heating equipment and the heating characteristics of the human thermal environment by using the lowtemperature laboratory to create an extremely low temperature environment around-20°C.The skin temperature of the subjects was also measured,and subjective questionnaires were collected.Further,the effects of different experimental working conditions on thermal physiological parameters and thermal comfort were analyzed.The results showed that the airwarmer with confinement box condition was an efficient personal heating technology for extremely low temperature environments with a Corrective Power of up to 38.3℃.Second,the overall-local thermal comfort evaluation model and thermal comfort evaluation model based on thermal physiological parameters were established.According to the overall/local thermal comfort votes and overall/local thermal sensation votes obtained from human thermal comfort experiments,the overall-local thermal sensation/thermal comfort multiple linear regression method was used to establish the suitable evaluation model,and the weight factor of thermal sensation/thermal comfort of each body part in extremely low temperature environments accounted for the overall thermal sensation/thermal comfort was obtained;in addition,the thermal comfort evaluation model based on skin temperature/skin temperature difference was also established.Compared with the existing thermal comfort evaluation models at domestic and overseas,the thermal comfort evaluation model established in this paper exhibited certain advantages in terms of applicability and accuracy.Subsequently,a one-dimensional human thermoregulation model based on Stolwijk model was established and a method for calculating thermal comfort using this model was determined.Referring to Stolwijk’s model of human thermoregulation,a one-dimensional human thermoregulation model consisting of a passive system and an active system was developed according to the research needs.The model was validated using human thermophysiological experimental data,and the results showed that the thermoregulation model would underestimate the skin temperature of some body parts,but the overall accuracy of the model was acceptable.In addition,human thermal comfort was calculated using the human thermoregulation model combined with the thermal comfort evaluation model,and the specific calculation method was determined.At last,the human thermoregulation model in transient environments was combined with computational fluid dynamics(CFD)to optimize the working condition of airwarmer with confinement box.A complex virtual human geometry model was incorporated into the overall geometry model.Using numerical simulation,the working condition of airwarmer with confinement box and its optimized working condition were studied,and the temperature and flow field distribution characteristics were analyzed under different working conditions.Thermal comfort was evaluated based on these results.The results showed that by optimizing the air supply temperature and height of the airwarmer outlet,the issues related to the working condition of airwarmer with confinement box were addressed,and the desired optimization target was achieved,while it also achieved a 22% energy saving rate.更多还原