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1.
In this paper, the university teaching buildings in Chongqing are taken as study object, and the indoor thermal environment of classroom is studied with the ways of investigation and testing, in which the indoor thermal environment of classroom is characterized by two aspects: personal and impersonal. The accepted thermal environment range of the classroom in summer is obtained. The difference between predicted thermal sensation and measured one as well as the influence of air velocity on thermal sensation are analyzed. Some measures to improve indoor thermal quality are proposed. 相似文献
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为了充分利用热量资源避免低温危害,调整农业产业及品种布局,利用花生栽培物候观测资料,应用气候统计诊断分析方法,进行了沈阳市地区1971—2010年花生发育期的热量资源鉴定。结果表明,沈阳地区花生适宜播种期存在滞后现象,向后推迟7.6天。150天以上中晚熟花生品种苗期、成熟期及全生育期表现出不同程度的热量不足,苗期和全生育期有20%的年份热量不足,成熟期有10%的年份热量不足。为此,沈阳地区应选择生育期在140~150天的中晚熟花生品种,则有利于热量资源利用及免受低温冷害的威胁,从而确保稳定的收益。 相似文献
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对青海乡域4所典型中小学校10间教室冬季室内温湿度、风速、黑球温度等热环境参数进行现场测试,同时对420余名青少年学生的衣着情况、热感觉评价等进行了主观问卷调查。对测试和调查结果进行统计分析,得到实测和预测热中性温度分别为13.8和14.5℃,热期望温度为16.2℃,90%的学生感到满意的舒适温度范围为15.8~18.7℃。在当地寒冷的气候条件、学生衣着习惯、心理期望及生理特性等因素影响下,中小学生形成了对偏冷环境的适应性,提出可利用适应性PMV模型(aPMV)对中小学生平均热感觉进行准确预测。可为乡域中小学教室冬季热环境设计提供依据。 相似文献
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Thermal adaptation after earthquake is analyzed under the special condition of destructed houses and fundamental facilities.Field investigation and questionnaire survey were carried out after Wenchuan earthquake.The thermal adaptation model is also used to study the capacity variation of thermal adaptation.Through the comparison with the thermal adaptation under the common condition,it shows the thermal adaptation under the special condition has improved.And the causes for the changes are analyzed. 相似文献
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Thermal environment in urban public space is considered as an important factor affecting thermal comfort of human beings. In the whole year, thermal environment in public space of the city in hot-summer and cold-winter zone changes dramatically, which has an effect on human thermal comfort. In this study, three typical public spaces including street, park and square of Changsha were selected for a long-term experiment of thermal environment. Based on the analysis of four significant thermal environment parameters-air temperature, relative humidity, global temperature and wind speed, seasonal characteristics of thermal environment in urban public space were obtained. The results show that the characteristics of urban thermal environment are determined by natural climate, while the physical structure of a city has essential impact on the changes of local outdoor thermal environment. Affected by plants (trees) and water (Xiangjiang river) air temperature of the street along the street is much lower, relative humidity is higher and solar radiation is weaker in most of the year. Compared to the street along the river, air temperature of the square is higher and solar radiation is stronger. 相似文献
6.
Yan Zhijun 《保鲜与加工》1989,(2)
The building cold and hot loads calculation method for design-ers is spread and used in our country.There are total 301 kinds of commonwalls and roofs,which are classified as 6 types respectively.The cold loadtemperature tables are compiled for designers.With the development of build-ing science,there will be many new types of wall construction without classi-fication.This is inconvenient for fhis new calculation method to be spread.Inthis paper,a new method of wall classification is developed according to theprinciple of fuzzy colony discernment.We have got satisfactory result in com-parison with the result gained by load calculation method.This method invo-lves only algebra calculation and comparison calculation,such as taking bigger,taking smaller etc.,so it is simple and easy for designers to use. 相似文献
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The influence of applying different heat transfer models coupled different data processing methods on determining the ground thermal properties and borehole resistance is analyzed and studied in allusion to constant heating flux method of thermal response test. Results indicate that the calculated thermal properties and borehole resistance are different when applying line heat source model and cylindrical heat source model respectively; volume specific heat barely affects the unknown thermal conductivity, but affects the borehole resistance. Three-parameter estimation has good credibility in determination of thermal properties and borehole resistance. However, the stability of three-parameter estimation on the determination of thermal diffusivity is not good. Finally, the approach of three parameters estimation coupled the line heat source model and cylindrical heat source model is proposed to determine the thermal properties and borehole resistance based on the analysis of the minimum average error on the two heat transfer models. 相似文献
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Impacts of natural ventilation on indoor thermal environment for residential housing 总被引:2,自引:0,他引:2
A typical residential housing in Chongqing is taken as an example, which is with worse natural climate conditions and absent of wind resource. A feasibility study on improving the thermal environment by natural ventilation is analyzed based on the i d chart. By the on site tests,the indoor thermal comfort is evaluated based on the PMV PPD methodology. Better natural ventilation can not only save the building energy consumption, but also improve indoor thermal environment, especially in the rain and transition seasons, even in the urban area with poor wind resource. 相似文献
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采用自然干燥(15℃)、热风干燥(45℃、55℃、65℃)、流化床干燥(45℃、55℃、65℃)对初始湿基含水率21.2%的稻谷进行降水处理,选取适当水分间隔测量稻谷导热系数和爆腰率,得到不同干燥工艺条件下的导热系数与含水率的拟合曲线、导热系数与爆腰率的拟合曲线,并对降水速率与爆腰增率、导热系数与爆腰率做相关分析。结果表明,降水速率与爆腰增率,导热系数与爆腰率都存在极显著相关性。干燥工艺影响稻谷降水速率,产生不同爆腰率,改变内部结构进而影响导热系数测量值。随爆腰率增大,导热系数呈非线性递增。流化床干燥对稻谷导热系数测量造成的影响大于薄层热风干燥。低温薄层热风干燥稻谷的导热系数最接近自然干燥处理值。 相似文献
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Analyses the thermal environment parameters from physiological aspect and from psychological aspect respectively. Introduces the conception of thermal comfort of human body from heat balance aspect. Presents some measures to improve indoor thermal environment and advance thermal comfort of human body. Analyses the influence of indoor thermal environment on thermal comfort of human body and some questions on the aspect of this research, also puts forward some advices. 相似文献
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《保鲜与加工》2003,(10):81-83
The thermal efficiency of the fast gas water heaters is an important index sign to reflect the efficiency of its utilization for energy resources,the executing of the signs and standers of utilization for energy resources of gas equipments will put forward some very high request with the objectivity to it. This index sign is tested and defined under the single experimental condition.But that is different in practice.The water heaters work under the various conditions and the changes of the thermal efficiency parameters are inevitable.Therefore the thermal efficiency evaluation for the fast gas water heaters can not carry through with the thermal efficiency which is tested under the single condition and the all-year average thermal efficiency should be adopted.Aiming at the orderliness about the changeful thermal efficiency of the fast gas water heaters which work under the different conditions,we do a flood of experiment research and scientific theoretic analysis ,and bring forward a new evaluation means for the thermal efficiency,that is the all-year average thermal efficiency should be adopted in evaluation.This paper also introduces the calculational methods of the all-year average thermal efficiency detailedly. 相似文献
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Numerical analysis on the thermal performance of several kinds of composite wall construction 总被引:1,自引:0,他引:1
According to climatic characteristics of the hot summer and cold winter zone, P. R. China and considering the different forms of interior and exterior insulation, different thickness of insulation, different materials of insulation and different forms of the main wall, this paper developed a physical model and a mathematic model, calculated the characteristics of materials and wall construction. It used the software Fluent to analyze thermal performance of different types of walls, to compare the interior and exterior surface temperature. The results of simulation show that under the condition of the same continuous temperature-wave, there are basically irrelative between the external surface average temperature and wall constructions. Compared among those construction with the same index of thermal inertia and heat transmission coefficient, but the different insulation-form, it shows that the exterior insulation has more attenuation and longer delay time than interior insulation ,and the interior surface has less fluctuations of temperature, stronger resistance against wave changes in outdoor temperature and better thermal stability. Under the same main wall material with different insulation materials, it shows that the heat transfer coefficient and thermal inertia can’t be used to comprehensively value the effect of thermal insulation, and the materials with more temperature attenuation have better energy-saving materials performance. 相似文献
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Xu JingFeng 《保鲜与加工》2005,(3):13-18
With the attention to the comfort degree of living environment, the phenomenon of making use of the PMV -PPD index within the ISO7730 standard to evaluate the indoor thermal comfort degree is more and more widespread. Many papers about indoor thermal environment are based on the PMV - PPD index as the reference or basis to research and analyze. But few people understand and pay attention to the application range of the PMV - PPD index. So some people misuse and abuse the PMV index and deduce some inaccurate conclusions. In this thesis, based on the analysis of the process of deducing PMV equation, the phenomenon that PMV index is different from the fact in the high temperature condition is explained; furthermore the application range of the PMV equation is confirmed. So to obtain the scientific and reasonable evaluation and conclusion in the process of research of the thermal comfort degree can be ensured. 相似文献
16.
刚性陶瓷瓦热防护系统概率设计分析方法 总被引:2,自引:0,他引:2
针对高超声速飞行器中广泛应用的陶瓷瓦热防护系统,结合有限元法和蒙特卡洛模拟建立了其概率热分析系统,提出了刚性陶瓷瓦热防护系统尺寸概率设计方法。建立了刚性陶瓷瓦热防护系统的二维有限元模型,考虑了热传导系数、比热容和表面辐射率等材料属性参数以及热防护系统各层厚度的不确定性,得到系统温度场的概率分布特性和系统热防护性能对各参数的灵敏度,并对系统的热可靠性进行了评估。算例表明:文中提出的方法对热防护系统设计过程中合理确定陶瓷瓦厚度和在保证系统性能的前提下有效减轻重量具有指导价值。 相似文献
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Sludge adhesion on the inside wall of drying equipments may affect sludge drying performance. Effects of drying conditions on sludge adhesion were investigated by thermal drying experiments. It was found that sludge water content was the main important factor impacting sludge adhesion quantity. When sludge water content decreased with thermal drying, the adhesion quantity increased. The adhesion quantity reached the maximum value when sludge water content decreased to about 60%. The further drying reduced the adhesion quantity gradually. The heating temperature had almost no impact on sludge adhesion when the heating temperature was no higher than 120℃, while the adhesion quantity increased with the increasing heating temperature when the heating temperature was higher than 120℃. Conduction heating would lead to more sludge adhesion compared with convection heating. Rough heating interface would also help sludge adhesion. 相似文献
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A series of experiments were carried out on the coke sprayed with ZBS of Anyang and Kunming Iron & Steel Co.,Ltd on the reaction electrical furnace.The microstructure of coke before and after spraying with ZBS were investigated with SEM and HY-4 Automatic microdensitometer.Coke reaction index and coke strength reaction were investigated according to the GB/T4000-1996.The results are as follows:Compared to original coke sample,the pore space become relatively little and small,and the coke hole rate is reduced.The ZBS carbide with brilliant white rib formed around the gap,existed in the coke reacted 2 hours,and it can improve CSR.ZBS can obviously improve coke thermal properties.The worse coke thermal properties are,the bigger the margin improved by ZBS are. 相似文献
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The characteristics of EPDM waterproofing membrane are analyzed. Due to the effect of heat and oxygen, aging occurs to EPDM waterproofing membrane with a protective layer to some extent. And the decline of mechanical properties and plasticizer migration are particularly outstanding, resulted in a reduction in service life of the material. Unaged and aged samples were tested by SEM and FTIR. Furthermore, by using accelerated thermal aging and thermal analysis kinetic method, mode of EPDM waterproofing membrane between performance indicators and service life under certain conditions was established to predict its service life, which provides technical support for architectural design, building construction and material research. 相似文献