共查询到20条相似文献,搜索用时 578 毫秒
1.
通过人工气候室实验研究基于虚拟现实技术(VR)构建的声光环境对人体热感觉、热舒适及生理参数的影响及性别差异,分析主观投票和生理参数间的相关性。结果显示:偏冷环境下(20℃),暖色调声光环境可将热感觉投票向中性校正,冷色调声光环境可加剧受试者冷感,使其更不舒适;中性环境下(25℃),声光环境对热感觉、热舒适的影响较小;声光环境联合作用效果强于单独作用效果;性别差异在热感觉、热舒适方面最为显著,声、光环境对男性热感觉、热舒适的影响略强于对女性的影响;人体热感觉、热舒适均与多种生理参数间存在显著相关关系。 相似文献
2.
3.
严寒地区夏季采用自然通风作为被动式降温手段,改善空气品质的同时减少能耗,其热舒适性会受到多因素影响。对严寒地区夏季自然通风条件下两种建筑布局的高校教学楼热环境进行实测,对影响热舒适的三种因素,温度、湿度以及受试者体重指数(bady mass index,BMI)进行调查研究,基于在室人员不同性别,进行差异性、相关性和显著性对比分析。结果表明:内廊式教学楼较中庭式教学楼有更好的热舒适性;操作温度与热舒适性密切相关,中性温度为27.96℃,其中男性为27.51℃,女性为28.26℃;相对湿度与操作温度负相关,且对热舒适性有较大影响;BMI与热舒适性呈现较低的相关性,其并不能明显影响热舒适性,但相同BMI下,男性热感觉略高于女性;利用Griffiths评价模型能准确预测严寒地区夏季舒适温度。 相似文献
4.
针对解决太阳能热利用过程中所面临的辐射强度不稳定、不连续和不均匀等关键问题,相变蓄热技术常与太阳能热利用系统耦合协同匹配,以实现稳定连续的热量输出。为了强化固液相变蓄热/放热过程、提高系统热储能效率,对金属泡沫内石蜡类相变材料(PCMs)在不同蓄热流体温度下的固液相变蓄热/放热特性开展了实验研究。设计并搭建了相界面可视化的蓄热/放热实验系统,实验过程中使用高清相机对相变过程中的相界面变化进行了记录。同时,通过在蓄热单元内部布置多个热电偶测点,对蓄热/放热过程中的温度变化规律进行了探究。实验结果表明,受自然对流影响,熔化过程中相界面由上至下变化;而凝固过程中由于初始时蓄热单元下部温度较低且存在自然对流,此时相界面自下而上变化。蓄热流体温度越高,熔化所需时间越短,与蓄热流体温度为65℃的工况相比,蓄热流体温度为85℃、80℃、75℃、70℃工况的完全熔化时间分别减少了56.0%、46.7%、15.4%和26.7%。当采用不同温度的流体进行蓄热工况时,相变材料内部温度呈现出具有明显差别的温升规律。尽管如此,当采用相同温度的换热流体进行放热工况时,相变材料的放热温度仍趋于一致。 相似文献
5.
通过将平均辐射温度引入到建筑热舒适性传热计算中的方法简化建筑热舒适性和能耗的相互关系及其计算公式 ,进行平均辐射温度和房间的有效温度分布情况对热舒适性的影响分析。用这种方法来比较在不同热辐射换热和对流换热工况下变墙面温度时建筑内的热舒适性。理论分析和辐射、对流换热及其结合工况的热舒适性测试数据结果分析表明 ,热舒适性可以用平均辐射温度和有效温度来表征。用平均辐射温度和有效温度分析计算热建筑舒适性的方法 ,在优化建筑热系统的设计时 ,也有非常重要的参考价值。 相似文献
6.
《节能》2016,(10)
为探究高校学生公寓春季室内热舒适状况,采用现场测试与问卷调查相结合的方法对兰州市某高校14间学生公寓室内热环境状况进行了现场调查研究,共获得181份有效人体热反应样本。运用统计分析法对受试者的热感觉、衣服热阻与操作温度进行了回归分析。结果表明,春季公寓内学生着装的平均服装热阻为0.689clo,90.1%的学生对室内20.4℃的平均温度表示接受;实测热中性温度为17.8℃,预测热中性温度为19.8℃,所期望的室内温度为18.7℃;80%的学生可接受的操作温度范围是17.7~22.1℃,其热接受温度下限比同属寒冷地区西安市的高3.2℃。该研究结果可为兰州高校学生公寓室内热环境的控制和制定其室内热舒适标准提供参考。 相似文献
7.
8.
9.
本文构建了一种可用于供暖和供冷两种工况的相变蓄能辐射地板系统,该系统包含蓄冷和蓄热两层石蜡相变材料,相变点分别为18℃和34℃,针对该相变地板蓄冷和蓄热层上下相对位置的变化,通过实验研究了在供暖水温45℃和供冷水温15℃两种工况下,这两种不同结构的相变地板的传热特性,以及相变层对找平层、地板层等结构层的影响。结果表明,该相变地板系统可用于供热和供冷两种工况,两种结构模式下,不同结构层在蓄能过程中温度变化特性均相近,但释能过程温度变化特性区别较大。结构的变化对实验箱体内气温在供暖时影响较大,而在供冷时影响不大。综合供冷供暖两种工况,从系统冷量和热量的传递结果考虑,蓄热层在上、蓄冷层在下的结构传热性能更优,可缓解地板温度过快下降带来的热舒适性差及结露问题。 相似文献
10.
工况下交联聚乙烯电缆绝缘材料的老化会导致其较预期相对较早达到寿命终点,威胁输电系统的可靠运行。采用热老化来模拟工况环境下电缆的老化过程,选取100 ℃、120 ℃和140 ℃和160 ℃ 4个不同的老化温度,在每个温度点选取6个老化阶段,研究不同老化温度和老化时间对XLPE电缆绝缘试样性能的影响。通过热重和拉伸测试研究电缆的热性能、机械性能及其结构随老化程度的变化,得到电缆绝缘试样的热老化活化能、起始分解温度、最快分解温度、终止分解温度、断裂伸长率和拉伸强度等参数。研究结果表明:活化能、起始分解温度、最快分解温度和断裂伸长率对电缆老化状态较为敏感;随着老化温度从100 ℃增加到160 ℃,这些参数均呈现先略微增大后迅速减小的趋势,说明XLPE电缆绝缘材料热老化在低温范围以结晶作用为主,而在高温范围以热裂解为主。 相似文献
11.
For optimum design of borehole thermal energy storage (BTES) and ground sources heat pump (GSHP) applications, determination of underground thermal properties is required. The design and economic feasibility (number and depth of boreholes) of these systems need thermal conductivity of geological structure, λ (W m?1 K?1), and thermal resistance of ground heat exchanger, R (K W?1 m). Thermal properties measured in laboratory experiments do not coincide with data of in situ conditions. Therefore, in situ thermal response test equipment has been developed and used in Canada, England, Germany, Norway, U.K., U.S.A. and Sweden to ensure precise designing of BTES systems. This paper describes the results and evaluations of the Adana continual thermal response test measurements. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
12.
In this paper, a thermal wave in the bath of superfluid helium II is measured by a new type of superconductor temperature sensor under different heat fluxes and bath temperatures, and at the same time, a thermal shock wave is also studied experimentally and theoretically. © 2001 Scripta Technica, Heat Trans Asian Res, 30(5): 419–425, 2001 相似文献
13.
First in situ determination of ground and borehole thermal properties in Latin America 总被引:5,自引:0,他引:5
The design of a ground heat exchanger for Underground Thermal Energy Storage (UTES) applications requires, among other parameters, knowledge of the thermal properties of the soil (thermal conductivity, borehole thermal resistance and undisturbed soil temperature). In situ determination of these properties can be done by installing a vertical borehole heat exchanger (BHE) and performing the so-called thermal response test (TRT). The present paper describes the results of a cooperative work between research groups of Chile and Argentina, which led to the first thermal response test performed in Latin America. A setup for implementing the TRT was prepared at the “Solar Energy Laboratory” of the Technical University Federico Santa Maria, Valparaiso, Chile. The test was realized over 9 days (24 June to 3 July 2003) while inlet and outlet fluid temperatures of the BHE and the ambient temperature were measured every minute. A comparison between conventional slope determination method, Geothermal Properties Measurement (GPM) data evaluation software based on numerical solutions to the differential equations governing the heat transfer processes and two variable-parameter fitting was performed in order to calculate the thermal conductivity and borehole thermal resistance. The detailed study of ground properties in different regions of Chile and Latin America (Argentina, Brazil) is a good precondition for future investigation and application of the Borehole Thermal Energy Storage (BTES) technology in the region. 相似文献
14.
This paper presents the results of a numerical and experimental study of phase change material (PCM) filled walls and roofs under real operational conditions to achieve passive thermal comfort. The numerical part of the study was based on a one-dimensional model for the phase change problem controlled by pure conduction. Real radiation data was used to determine the external face temperature. The numerical treatment was based upon using finite difference approximations and the ADI scheme. The results obtained were compared with field measurements. The experimental set-up consisted of a small room with movable roof and side wall. The roof was constructed in the traditional way but with the phase change material enclosed. Thermocouples were distributed across the cross section of the roof. Another roof, identical but without the PCM, was also used during comparative tests. The movable wall was also constructed as is done traditionally but with the PCM enclosed. Again, thermocouples were distributed across the wall thickness to enable measurement of the local temperatures. Another wall, identical but without the PCM, was also used during comparative tests. The PCM used in the numerical and experimental tests was composed of a mixture of two commercial grades of glycol in order to obtain the required fusion temperature range. Comparison between the simulation results and the experiments indicated good agreement. Field tests also indicated that the PCM used was adequate and that the concept was effective in maintaining the indoor temperature very close to the established comfort limits. Further economical analysis indicated that the concept could effectively help in reducing the electric energy consumption and improving the energy demand pattern. © 1997 by John Wiley & Sons, Ltd. 相似文献
15.
16.
Sverine Gomes Nathalie Trannoy Philippe Grossel Franoise Depasse Claudine Bainier Daniel Charraut 《International Journal of Thermal Sciences》2001,40(11):1794
The used Scanning Thermal Microscopy (SThM) probe is a thin Pt resistance wire acting as a heat source and as a detector simultaneously. Its energetic balance is investigated by the study of the temperature profile along the probe. A theoretical approach of the measurement, based on this investigation, is then proposed. Simulations with this modelling are shown to predict how the heat, electrically produced in the probe, is dissipated in the probe-sample system. In particular, it is shown that the steady-state of conduction losses to the thermal element support varies versus the thermal conductivity of the sample and can lead to bad interpretations of the measurement. 相似文献
17.
碳纤维作为一种被广泛应用的微纳米材料,对其导热性能的测量研究一直被作为对碳纤维性能研究的重要内容。在利用氦气的气体液化基础上搭建的超低温实验环境中,基于瞬态电热法对处于290到10 K温度内的碳纤维样品的导热性能进行研究。实验发现,当实验温度低于某一特定温度后,材料的热扩散率表现出与声子散射分析相反的实验结果。通过引入热扩散系数倒数这一理论研究声子热阻在低温下的变化,分析得出,当实验环境温度低于某一特定温度后,低温会造成碳纤维材料内的石墨微晶体结构发生变化,从而造成材料热扩散率下降。 相似文献
18.
本文对执行《公共建筑节能设计标准》(GB 50189-2005)中几个常见的重要问题进行探讨,包括围护结构热工性能参数分类、建筑朝向判别、外墙平均传热系数计算、地面和地下室热阻计算。 相似文献
19.