宿州地区HDD、CDD值的变化规律与分布特征

本文采用典型气象年法对宿州地区1986-2015年气象参数进行计算分析,得出HDD、CDD值。采用平均年法对HDD、CDD值的逐年变化规律与变化趋势及年分布特征进行了分析研究。定义了基于HDD/CDD值的冷热强度与程度的概念。结论如下:典型气象年宿州地区HDD、CDD值为2009.4℃·d和155.8℃·d。1月采暖度日数占全年采暖度日数1/4。7月制冷度日数占全年制冷度日数近1/2。HDD值在30年中呈下降趋势,冷强度极值增加,相同冷强度下的冷程度减小。CDD值呈上升趋势,热强度极值增加,相同热强度下的热程度增加。过渡月份异常天气的频次增多,冷热强度增大,16℃冷强度值为5.9℃·d与26℃热强度值为1.0℃·d。     

重庆地区农村住宅地面温度及防结露模拟研究

湿热地区农村住宅地面出现的潮湿问题,严重影响室内环境健康。本文研究了重庆地区农村住宅地面结露情况。利用DesignBuilder软件建立农村典型二层住宅模型,模拟了住宅分别使用普通水泥地面、低蓄热系数地面、架空通风地面时的全年地面温度与室内湿度,计算出地面结露时间及强度并进行比较。研究结果表明:重庆地区农村住宅地面结露主要集中在3月末至7月初,结露问题极为严重;低蓄热系数地面的防结露效果有限,不足以解决农村住宅地面结露问题;采用架空通风地面效果较好,可以基本解决地面结露问题;采取控制通风措施对于持续时间短、强度很低的地面结露可以起到缓解的作用,但不能解决持续时间长、强度大的结露问题。     

湿热地区毛细管地板供冷末端性能实测分析

选取重庆某住宅卧室进行实测分析,在供水温度为20、18、16℃,室外天气为晴天、多云、阴天(雨)工况下,研究毛细管地板供冷房间温度、地板供冷量、地板结露特征。供水温度为20、18、16℃时,室内最高温度27.6℃,最大供冷量分别为23、33、32 W/m2。开始结露时间为10:30—14:50之间,其中80%区域开始结露的时段为11:00—13:00之间,室内气流涡旋区最早出现结露。供水温度为18℃时,除湿能明显改变地板结露现象;供水温度为16℃时,除湿能改变大部分地板结露现象,室内气流涡旋区仍为结露区,但结露时间延后1h以上。地板结露区域与室内气流组织有关,毛细管铺设位置应避开房间气流漩涡区。     

墙体内保温体系冷桥部位结露分析

分别研究了胶粉聚苯颗粒保温砂浆、石膏板岩棉和高强水泥珍珠岩板这3种墙体内保温体系冷桥部位在夏热冬冷的杭州地区整个典型气象年采暖期间室外逐时温度、相对湿度和特定室内计算温度(18℃)、相对湿度(40%、50%、60%、70%)条件下,逐时的结露以及冷凝量情况;并根据整个采暖期间冷桥部位保温层受潮后的重量湿度增量是否超出允许值,依此来判定该部位保温材料的受潮破坏情况。并得出结论:在上述设定条件下,这3种内保温体系在室内较高湿度时会超过规范的允许值;使用胶粉聚苯颗粒保温砂浆内保温体系和高强水泥珍珠岩板内保温体系结露产生的冷凝水,一般不会超过规范要求;使用石膏板岩棉内保温体系容易受潮、结露,但是通过设置隔汽层能够使其得到较好的改善;在传热系数比较接近的条件下,高强水泥珍珠岩板内保温体系所占室内空间最大。     

航站楼暖通空调设计

<正>昆明气象分析和设计参数昆明地属我国北纬亚热带气候温和地区,冬无严寒,夏无酷暑,是我国著名的春城。从暖通空调系统设计方面而言,昆明的气象条件可以总结为以下几个特点。昆明为温和气候典型城市气候,年平均温度15℃,冬季平均温度8~10℃,夏季平均温度19~20℃。室外温度在15~22℃的时间超过4 000h。室外空气干球温度低于26℃的时间占全年时间的99%以上,而低于5℃的时间仅占全年时间的5%左右(图1)。夏季空调室外计算干球温度:26.2℃,湿球温度:20℃,焓值:66.95k J/kg,室外设计参数与空调房间室内设计参数基本相当(26℃,55%,63.3k J/kg),设计工况下,室外新风     

夹心保温墙体内部结露问题的模拟分析

在考虑建筑材料传热、传湿物性值随其自身温湿状态而变化的前提下,分别在严寒、寒冷、夏热冬冷及夏热冬暖4个典型地区的气象年内,对"三明治"式夹心保温墙体的内部结露情况进行了模拟计算。指出在严寒及寒冷地区采用这种保温方式的墙体存在发生内部结露甚至冻胀的危险,该结论对工程应用具有重要的参考价值。     

建筑外门窗抗结露性能设计

为了对建筑外门窗的抗结露性能进行直观有效的评价,本文依据GB/T8484-2020标准中建筑外门窗抗结露因子CRF的测试方法,分别绘制了CRF取值玻璃面板和试件框情况下的抗结露因子曲线,即室内环境温度为20℃,室外温度在-20℃到0℃范围内,不同抗结露因子的门窗产品存在结露风险的室内相对湿度,并将不同材质框型材、玻璃按照保温性能从低到高的顺序分别测试其抗结露因子,总结出取值范围,用于指导建筑外门窗产品的设计。     

楼地面潮湿的处理

每到夏季,一楼地面经常是湿淋淋的,倘若天气晴上几天,地面上就会出现斑渍。经过实践,我们摸索出了一套整改措施,在实际工程中取得了一定的效果。一、原因分析四川的空气湿度较大,年平均湿度为87%,夏季湿度为90%。湿度为96%以上的天气占整个夏季的2/3时间。年平均降雨量为1242.2mm,夏季占全年的80%。此时一楼地面、楼梯间好像泼上了水,到处都是湿淋淋的。这种现象是什么原因造成的呢?根据我们的调查,可分为两种。1.地面返潮由于虹吸现象,潮湿地基中的水分通过混凝土垫层和面层的毛细孔上升到地面,造成地面潮湿。2.结露空气中含有大量的水分,…     

民用建筑空调冷凝水管橡塑保冷厚度分析计算

采用表面温度法对民用建筑中非低温空调(送风温度逸15℃)冷凝水管橡塑材料的防结露最小保冷层厚度进行了分析计算.通过计算,得出了较干燥地区、 较潮湿地区的空调冷凝水管在不同管径下的保冷层最小厚度.根据计算结果,将空调冷凝水管的橡塑保冷层厚度按照较干燥地区、 较潮湿地区进行了简化,为工程师在图纸设计或制作招标技术标准时提供...     

高湿地区保温墙体防结露措施效果分析

为探究高湿地区复合保温墙体空气层、隔汽层两种防结露措施的效果,建立了以温度与相对湿度为计算驱动势的热湿耦合传递模型,并根据实验数据对模型进行了验证。进一步使用模型模拟了冬夏季高湿工况条件下,内外两种保温墙体内部的热湿变化情况。根据模拟结果得出,保温墙体在两种材料界面处具有较高的结露风险。在全年高湿地区,空气层可有效降低墙体内部的结露风险,隔汽层在此工况下防结露效果不佳。     

建筑热环境模拟分析用逐时相对湿度生成方法

分别采用对4次相对湿度、4次含湿量、4次露点温度以及4次湿球温度进行直线插值或3次样条插值等8种计算方法生成的逐时相对湿度,从统计学和能耗模拟两个角度,与实测值进行对比分析。分析结果表明,由4次含湿量（或露点温度）进行线性插值计算生成的逐时相对湿度与实测相对湿度吻合较好;并据此给出了由逐时相对湿度根据关联性计算生成逐时含湿量、湿球温度、露点温度的方法。     

重庆地区农村住宅地面的热湿状态

为全面改善农村住宅热湿环境,调查研究了重庆农村住宅常用地面在春夏季节的热湿状态。对农村住宅的调查和典型住宅地面的现场实测显示,农村住宅室内地面潮湿现象普遍,水泥地面的潮湿比例最高,6月份室内空气和地面的湿度最大,室内地面温度比空气温度低2℃左右,在潮湿天气,修建较早的住宅室内地面凝结时数比例接近60%。结果表明,农村住宅地面的热湿状态亟待改善。     

The h,x-diagram as a Representation of Measurements of Ranges of Comfort in a Long-Duration Test

It is well known that the inhabitants of dwellings use the room heating and ventilation to build up their own individual climatic zone in which they feel comfortable. To date individual measurements have been conducted to investigate these climatic zones, or line charts have been drawn up with a thermohygrograph in long-duration tests. Compared with the form of presentation used previously, the possibilities for evaluation have been substantially improved by the use of measured data-recording installations for the long-term investigation and presentation of results in the form of dots (temperature/humidity value pairs) in an h,x-diagram. The h,x-diagram is a type of psychrometric chart which is widely used in Germany. The advantage of this chart is that all thermodynamic properties of moist air can be determined without calculation. The dry bulb temperature, the wet bulb temperature, the dew point, the relative humidity, the humidity ratio, the specific enthalpy and the specific volume of moist air can be read directly from the diagram.     

Development of the typical meteorological database for Chinese locations

The typical meteorological database for 57 Chinese locations was developed for building simulations and air-conditioning design. The database consists of three parts: the typical meteorological years (TMY), the typical meteorological days (TMD) and the design temperature and humidity (DTH). The typical meteorological year (TMY) is the main part of the database. Because there are not data on solar radiation in the observations, a method to estimate solar radiation with dry bulb temperature difference, relative humidity, total cloud cover and wind speed was developed. Methodologies of interpolations were developed to produce 1 h data with the 3 h data. The global solar radiation on the horizontal surface was separated into direct and diffuse components with the Gompertz function. The typical meteorological day (TMD) consists of the monthly average values of dry bulb temperature, solar radiation, relative humidity, etc. for each hour of the day. The design temperature and humidity (DTH) was developed for the purpose of air-conditioning design. The frequencies of 2.5% and 5.0% were selected to decide the design temperature and humidity for the 57 Chinese locations.     

Investigation of moisture condensation on papermaking plant envelopes in high humidity environment by orthogonal analysis and CFD simulation

The objective of this study is to investigate the problem of moisture condensation on papermaking plant envelopes in high humidity environment. In this study, orthogonal experiment method is combined with CFD simulation to explore how moisture condensation varies with governing factors, such as the thermal parameters of building envelopes, temperature and humidity distributions or ventilation and air distribution. The criteria used by our work to determine whether the condensation will occur on envelopes are to calculate the temperature differences between the inner surface and the air dew point near the envelopes. Specifically, the temperature differences have a linear relationship with the governing parameters, and a first-order linear regression equation is derived, which is validated by data from investigation and measurement. This research provides theoretical support and measurement data for solutions of the envelope condensation problems and anti-condensation design of HVAC systems in papermaking plants.     

Temperature distribution inside ground for various surface conditions

An analysis is presented for the calculation of the daily and annual variations of the ground temperature distribution for various surface conditions, namely (i) dry sunlit surface, (ii) wet sunlit surface, (iii) dry shaded surface and (iv) wet shaded surface. For a wet surface the effect of moisture inside the ground has been taken into account globally. Numerical calculations have been performed for a typical hot summer day and a typical cold winter day (for the daily variation) and corresponding to the average meteorological data of the year 1974 (for the annual variation) at New Delhi. The temperature becomes constant at a depth of about 0.15 m for the daily variations while for the annual variations it becomes constant at a depth of about 4 m.     

An experimental study of a novel dew point evaporative cooling system

A novel dew point evaporative cooling system for sensible cooling of the ventilation air for air conditioning application was constructed and experiments were carried out to investigate the outlet air conditions and the system effectiveness at different inlet air conditions (temperature, humidity and velocity) covering dry, temperate and humid climates. The results showed that wet bulb effectiveness ranged between 92 and 114% and the dew point effectiveness between 58 and 84%. A continuous operation of the system during a typical day of summer season in a hot and humid climate showed that wet bulb and dew point effectiveness were almost constant at about 102 and 76%, respectively. The experiment results were compared with some recent studies in literature.     

Model-based moisture sorption stabilization in historical buildings

A novel air humidity control technique is proposed for preventing the moisture sensitive materials from varying their equilibrium moisture content, providing in this way more desirable environment conditions for preventive conservation of cultural heritage. The moisture content in artistic works or historical exhibits deposited in historical buildings is stabilized by means of a specific adjustment of the interior air humidity while the annual temperature variations in the interior are left almost unaffected. The proposed humidity control compensating for the impact of temperature changes on EMC variations is based on the application of sorption phenomena models while both the used models are not applied to estimate EMC but to suggest a prevention of its varying. Namely the Kelvin theory of micro-pore condensation and the Henderson model of moisture sorption are applied to determine the so-called equal-sorption humidity control. For long two implementations of this control – in a castle and archives collections – prove the ability of this control to stabilize the moisture content in the preserved exhibits at constant admissible level.     

水冷式表冷器传热研究(6):机器露点表达式的建立

建立了水冷式表冷器冷盘管表面平均热状态在干工况和湿工况下的数学表达式，通过理论和实验分析了各影响因素及影响程度。指出结构特性一定的表冷器，干工况下冷盘管表面平均热状态温度和进风干球温度、冷水初湿成线性关系；湿工况下在空调常用范围内，冷盘管表面平均热状态焓值和进风焓值，冷水初温成线性关系，且两种工况下冷盘管表面平均热状态温度（或焓值）都随迎面风速增大而增大，随水流速增大而减小。