Seasonal Variation in Air Temperature and Relative Humidity on Building Areas and in Green Spaces in Beijing, China

The cooling and humidifying effects of urban parks are an essential component of city ecosystems in terms of regulating microclimates or mitigating urban heat islands(UHIs).Air temperature and relative humidity are two main factors of thermal environmental comfort and have a critical impact on the urban environmental quality of human settlements.We measured the 2-m height air temperature and relative humidity at the Beijing Olympic Park and a nearby building roof for more than 1 year to elucidate seasonal variations in air temperature and relative humidity,as well as to investigate the outdoor thermal comfort.The results showed that the lawn of the park could,on average,reduce the air temperature by(0.80±0.19)℃,and increase the relative humidity by(5.24±2.91)% relative to the values measured at the building roof during daytime.During the nighttime,the lawn of the park reduced the air temperature by(2.64±0.64)℃ and increased the relative humidity by(10.77±5.20)%.The park was cooler and more humid than surrounding building area,especially in night period(more pronounced cooling with 1.84℃).Additionally,the lawn of the park could improve outdoor thermal comfort through its cooling and humidifying effects.The level of thermal comfort in the park was higher than that around the building roof for a total of 11 days annually in which it was above one or more thermal comfort levels(average reduced human comfort index of 0.92)except during the winter.

CORRELATION BETWEEN PEAK INTENSITY OF EXTREME AFTERNOON SHORT-DURATION RAINFALL AND HUMIDITY AND SURFACE AIR TEMPERATURE IN SOUTHEAST COAST OF CHINA

Using hourly rainfall intensity, daily surface air temperature, humidity and low-level dew point depressions at55 stations in the southeast coast of China, and sea surface temperature from reanalysis in the coastal region, this paper analyzes the connection between peak intensity of extreme afternoon short-duration rainfall(EASR) and humidity as well as surface air temperature. The dependency of extreme peak intensity of EASR on temperature has a significant transition. When daily highest surface temperature is below(above) 29°C, the peak rainfall intensity shows an ascending(descending) tendency with rising temperature. Having investigated the role of moisture condition in the variation of EASR and temperature, this paper discovered that the decrease of peak rainfall intensity with temperature rising is connected with the variation of relative humidity. At higher temperatures, the land surface relative humidity decreases dramatically as temperature further increases. During this process, the sea surface temperature maintains basically unchanged, resulting in indistinct variations of water vapor content at seas. As water vapor over land is mainly contributed by the quantitative moisture transport from adjacent seas, the decline of relative humidity over land will be consequently caused by the further rise of surface air temperature.

The relationship between indoor air quality(IAQ)and perceived air quality(PAQ)-a review and case analysis of Chinese residential environment

Due to the majority of time people spent indoors,indoor air quality is not only critical to people’s health,comfort,but can also significantly influence occupants perception on indoor environment.Air quality is closely related to many factors including thermal parameters,pollutant concentrations,and ventilation performance.However,the current building indoor air quality evaluation method is based the objective measurement of indoor parameters,without considering occupants’subjective perception.This paper is aimed at summarizing a profound review on the PAQ evaluation method.Comparisons among various PAQ evaluating methods with advantages,similarities and differences were conducted.Analysis of literatures about indoor air quality in Chinese residential buildings field is also summarized,and discussion on the subjective influence of temperature and relative humidity,venti-lation performance,volatile organic compounds(VOCs)concentration,and particulate matters on perceived air quality is carried out.

Control Means and Data Analysis of Environmental Factors of Facility Watermelon in Beijing Area

In this study, the environmental indicators(including temperature, light, air relative humidity and CO_2 concentration) of facility watermelon in Beijing area were monitored with US350 environmental sensor during the whole growth period. The results showed that in the solar greenhouses in Beijing area, the average air temperature was in the range of 10.67-29.95 ℃ during the whole growth period of watermelon, the average soil temperature ranged from 16.92 to 35.10 ℃, the average light intensity changed from 268.37 to 13 842.60 lx, the average air relative humidity ranged from 52.40% to 94.26%, and the average CO_2 concentration was in the range of 455-631 ml/m^3; and in the spring greenhouses in Beijing area, the variation range of average air temperature was 14.05-29.84 ℃ during the whole growth period of watermelon, the average soil temperature ranged from17.47 to 28.12 ℃, the average light intensity was in the range of 55.80-12 858.64 lx, the average soil moisture content ranged from 18.19%-34.56%, the variation range of average air relative humidity was 20.72%-96.26%, and the average CO_2 concentration was in the range of 351-544 ml/m^3.

On the Relationship between Climatic Variables and Pressure Systems over Saudi Arabia in the Winter Season

The synoptic circulation over Saudi Arabia is complicated and frequently governed by the effect of large-scale pressure systems. In this work, we used NCEP–NCAR global data to illustrate the relationship between climatic variables and the main pressure systems that affect the weather and climate of Saudi Arabia, and also to investigate the influence of these pressure systems on surface air temperature（SAT） and rainfall over the region in the winter season. It was found that there are two primary patterns of pressure that influence the weather and climate of Saudi Arabia. The first occurs in cases of a strengthening Subtropical High（Sub H）, a weakening Siberian High（Sib H）, a deepening of the Icelandic Low（Ice L）, or a weakening of the Sudanese Low（Sud L）. During this pattern, the Sub H combines with the Sib H and an obvious increase of sea level pressure（SLP） occurs over southern European, the Mediterranean, North Africa, and the Middle East. This belt of high pressure prevents interaction between midlatitude and extratropical systems, which leads to a decrease in the SAT,relative humidity（RH） and rainfall over Saudi Arabia. The second pattern occurs in association with a weakening of the Sub H, a strengthening of the Sib H, a weakening of the Ice L, or a deepening of the Sud L. The pattern arising in this case leads to an interaction between two different air masses： the first（cold moist） air mass is associated with the Mediterranean depression travelling from west to east, while the second（warm moist） air mass is associated with the northward oscillation of the Sud L and its inverted V-shape trough. The interaction between these two air masses increases the SAT, RH and the probability of rainfall over Saudi Arabia, especially over the northwest and northeast regions.

高效空气源热泵式烤房优化设计

针对普通燃煤烤房能源消耗大、污染环境和生物质燃料烤房存在较大的安全隐患等问题,对普通烤房进行改造,引入空气源热泵系统,利用流体力学软件FLUENT对烤房不同气流形式结构、装烟室地面分风坡结构、加热室底部导流板结构的烘烤过程进行数值模拟,以获得烘烤性能最优的烤房结构形式;同时对温湿度控制系统进行设计,以实现烤房温湿度的精准调控,最后开展节能应用效果和温湿度操控性能正交试验。试验结果表明:所设计的空气源热泵烤房与普通燃煤烤房和生物质燃料烤房相比,能源消耗减少,平均烘干1 kg烟叶可分别节约0.77元和0.35元,烟农节能增收成效显著;在温湿度调节上更加准确灵敏,烟叶烘烤质量明显提高。

风幕精准送风参数制丝线对温湿度模拟研究

随着卷烟制丝加工技术进步和对烟草品质的需求,环境温湿度对制丝加工过程质量有重要影响。为了保持制丝生产线上的烟丝水分和温度的稳定性,论文提出一种风幕隔离方法阻止烟丝输运过程中水分蒸发并维持温度稳定,主要研究风幕送风参数对制丝车间和制丝线温湿度影响,计算结果显示在制丝线上能够有效地形成均匀的风幕,且风幕未端风速大于0.5m/s,风幕的存在能够有效地保持烟丝水分蒸发和温度的稳定,保证烟丝的品质。

智能雨水晾衣监测装置研究

智能雨水晾衣监测装置采用单片机作为主要控制芯片,由温湿度传感器、风速传感器、雨滴传感器、光敏传感器获取外界的信息。传感器所采集到空气温湿度、风力大小、光照强度以及是否正在下雨等信息,由单片机处理后对步进电机进行控制,实现防水布的伸出与收缩。装置可以选择自动避雨和手动避雨两种模式。设计电路采用仿真软件在电脑上进行仿真,极大地减少设计成本,直观地发现装置设计的缺点,也能更好地验证该装置的正确性。

纺织车间定向均流送风口结构设计及其送风性能

为改善某纺织工厂细络联车间温湿度的稳定性及均匀性,提出了一种适用于细络联车间的定向均流送风口,并与复合式混流送风口对比。利用ANSYS Fluent软件对不同送风口下限定区域流场进行数值计算,通过速度、温度、相对湿度及其分布偏差系数评价两者送风效果。在此基础上搭建实验台,验证模拟的正确性。结果表明:当定向均流送风口应用在不同设备布置情况下,可通过调节对开式叶片角度进行风量调节,实现相对湿度调节以达到工艺需求;可通过转动均流导板将气流送至目标区域,实现对设备区域的定向送风。复合式混流送风口和定向均流送风口的速度分布偏差系数均值分别为0.2093和0.0889,温度分布偏差系数均值分别为0.0152和0.0083,定向均流送风口送风效果更好。

基于ENVI-met的广州街区温湿环境模拟

为研究华南湿热气候地区城市小区的温湿环境特征,基于微气候模式(ENVI-met)模拟广州市海珠区中山大学小区冬夏季温湿场的分布特征,并结合气象自动站连续监测资料进行检验订正,结果表明:(1)不同季节街区温湿场空间分布特征存在一定差异,白天水体和植被覆盖区为高湿和低温区;(2)ENVI-met模式能够较好预测小区微尺度温度和湿度环境,冬季温度和湿度实测值日变化幅度稍高于模拟值,夏季温度模拟值日变化幅度大于实测值;(3)冬夏季温度经过多项式函数拟合订正及冬季湿度经过指数函数和夏季湿度经过幂函数拟合订正后RMSE分别降至0.8℃以下和2.5%以下;MAPE分别降至0.26%和2.6%以下,模拟结果与实测值基本一致。研究结果表明ENVI-met可应用于城市小区规划建设。

基于改进人工神经网络的直膨空调系统建模与仿真

为了提高基于人工神经网络(ANN)模型的变速直膨式空调系统运行稳定性,提出一种在原有ANN模型的基础上额外接入房间干球与湿球温度作为输入信号的改进ANN模型。根据能量守恒和质量守恒原理,分别建立房间干球与湿球温度数学模型,并通过MATLAB/Simulink分别仿真运行以两种ANN模型作为解耦元件的空调系统在10次干湿球温度阶跃变化下的运行特性。基于改进ANN模型的控制系统均将干湿球温度控制到新设定值的时间平均减小44.4%,最大减小61.4%,且风机和压缩机的最大动态偏差减小的次数达到85%,平均减小18.0%,最大减小52.4%。因此,基于改进ANN模型控制可以有效提升直膨式空调系统温湿度同时控制的稳定性与灵敏性。

长江中下游地区Venlo型温室空气温湿度以及黄瓜蒸腾速率模拟研究

根据温室能量和质量平衡的物理学原理,建立了一个以温室外气候条件(太阳辐射、温度、湿度、风速等)为驱动变量,以温室结构、温室覆盖材料、温室内作物(高度、叶面积指数)为参数的温室小气候模拟模型,并利用上海Venlo型温室的三季试验数据对模型进行了检验。结果表明:模型能较好地预测中国长江中下游地区Venlo型温室内夏季和冬季空气温度、湿度以及作物蒸腾速率。模型对该地区夏干季节(2001年8月,三伏天)、夏湿季节(2002年6月下旬至7月中旬,梅雨季节)和冬季(2002年1月27日～2月5日)温室内空气温度、湿度以及作物蒸腾速率预测值与实际观测值的决定系数(R2)和标准误(SE)分别为:0.89,0.75,0.52;1.1℃,4.4%,0.040g·m-2·s-1;0.80,0.84,0.77;1.5℃,4.4%,0.018g·m-2·s-1;0.84,0.59,0.73;1.6℃,6.0%,0.012g·m-2·s-1。该研究为进一步探讨温室环境的优化调控提供了理论依据和决策支持。

长江下游防虫网覆盖塑料大棚内温湿度模拟

为了对防虫网覆盖塑料大棚内空气温度和相对湿度进行预测,该文根据能量平衡和质量平衡原理,建立了以塑料大棚外气象要素(太阳辐射、温度、相对湿度、风速、气压)为驱动变量,以塑料大棚结构(容积、表面积、通风窗面积、棚内地表面积)、覆盖材料(塑料薄膜透光率、防虫网目数)、小白菜(叶宽、叶面积指数)等为参数的塑料大棚内温湿度模拟模型,并根据试验观测资料对模型进行了检验。结果表明:模型能较好地预测长江下游地区防虫网覆盖塑料大棚内温度和相对湿度。模型对该地区夏季晴天、多云天和阴天覆盖防虫网塑料大棚内温度预测值与实测值的决定系数(R2)分别为0.93、0.92和0.87,回归估计标准误差(RMSE)分别为1.3、1.4和0.9℃,相对误差(RE)分别为5.8%、6.5%和4.1%;夏季晴天、多云天和阴天大棚内相对湿度预测值与实测值的R2分别为0.91、0.90和0.89,RMSE分别为4.1%、4.7%和3.2%,RE分别为4.8%、5.6%和3.8%。模型的建立也为防虫网覆盖塑料大棚结构优化和管理提供参考。

南方塑料大棚冬春季温湿度的神经网络模拟

利用浙江省慈溪市草莓塑料大棚和南京信息工程大学农业气象试验站番茄塑料大棚的小气候观测数据及气象站资料,建立3个以棚外辐射、温度、相对湿度和风速为输入变量,棚内温度和相对湿度为输出变量的BP神经网络预测模型。结果表明,3个模型气温训练值与实测值的均方根误差(RMSE)都在2℃以内,相对误差都在4%左右;相对湿度训练值的RMSE都在7个百分点以内,相对误差不超过7%。利用此模型得到的气温预测值与实测值的RMSE都在2℃左右,冬季气温的相对误差较大,春季通风和不通风模型气温的相对误差不超过6%;相对湿度预测值的RMSE都在7个百分点以内,相对误差不超过9%。说明所建BP神经网络模型对于不同季节、不同通风条件、不同作物的大棚温湿度模拟都有较高的精度,能够满足棚内温湿度的预测要求,且对温度的模拟精度高于对相对湿度的模拟。

MTCLIM模型(山地小气候模拟模型)的研究现状及其潜在应用

MTCLIM模型是许多生态、生理模型的分析工具。它能解释模型的结果 ,分析一些生态、水文过程在不同气候条件下的变化趋势 ,也是其它模型的辅助管理工具 ,辅助建立不同环境条件下的生态管理方案。本文介绍了该模型的基本原理及其各变量较详细的计算方法 ,概述其研究历史及发展现状 ,及模型应用的几个重要方面及其发展趋势。

蒸发冷却技术在纺织空调改造中的应用

探讨蒸发冷却技术在纺织空调改造中的应用效果。以山东某纺织厂3#与4#车间空调系统为例,测试并分析了两车间原有空调系统存在的问题,采用蒸发冷却技术分别对其进行了改造,在原有风道的基础上增加蒸发式冷气机送风,实现了车间风量平衡和车间有效加湿,最终使车间的温湿度满足了生产要求。认为:蒸发冷却技术是一种较好的实用技术,可应用于车间空调系统的改造。

基于温湿度控制的红外热风联合干燥机设计与试验

为提高热风干燥热效率和干燥均匀性,设计了一款基于温湿度控制的红外热风联合干燥机,分析了气流分配室作为干燥机的关键部件对腔室内部流场分布的影响规律。结构仿真中,以气流控制方程和标准kε湍流模型为理论模型,利用CFD软件对气流分配室内腔进行数值模拟分析,得到气流在气流分配室内腔的流动特征,对原物理模型的腔体厚度H进行结构优化,进行了试验验证。结果表明,加入均风板可以显著提高气流分配室内气流速度偏差比和速度不均匀系数;优化后腔体厚度H=100 mm的气流分配室能够很好解决出风口气流分布不均的现象,出风口速度偏差比和速度不均匀系数分别由44.9%和30.2%降低至7.2%、7.0%。验证试验结果表明,平均速度相对误差为4.21%,速度不均匀系数相对误差为1.4%,速度偏差比的最大误差为1.48%,说明结构设计合理,均化气流的效果明显。以鲜面条为研究对象,对该机性能进行试验,得到此红外热风联合干燥时间(50 min),比单一热风干燥的时间缩短了16.7%。

高温高湿环境室内围护结构表面结露的分析

某些室内环境因空气温度高湿度大,造成外围护结构尤其是玻璃幕墙内表面结露。通过采用现场实测、理论计算和数值模拟相结合的方法对高温高湿室内围护结构表面结露进行分析,发现空调送风口与幕墙之间的距离与送风口的出风角度是主要影响因素。当风口与玻璃幕墙间距在0.2-1.1 m,出风角度在30°-45°时,基本可避免玻璃幕墙上出现大面积结露;出风角度为16°时,风口与外墙的间距越大,越有利于避免外围护结构结露;出风角度大于45°时,风口与外墙的间距越小,结露区域面积越小。

织造车间双露点空气处理的节能应用

探讨织造车间采用双露点空气处理的节能效果。阐述了双露点大小环境送风系统的原理。以郑州某织造车间为例,对比了双露点大小环境送风系统与传统单露点送风系统的送风量和制冷量。结果表明:双露点送风系统相对于传统的送风系统送风量减小约16.35%,两者所需制冷量基本相同。认为:双露点空气处理的节能性较好。

基于水热因子的玉米物候模拟

对锦州14 a玉米各生育期特征及其与气候因子的关系分析表明:同品种玉米的物候期相近,变化在2 d左右,而吐丝期到成熟期所需日数变化较大,为6 d或以上;玉米各生育期的影响因子不同,气温与湿度对玉米出苗期、三叶期和七叶期的影响显著,播种期到七叶期的积温占整个生育期积温的20%,并与同期的空气湿度累积量呈显著二次曲线相关(R2=0.91)。积温与空气湿度累积可较好地模拟玉米播种期至七叶期和玉米的总生育期。