湿空气的湿度计算及其在干燥热工中的应用

<正>在干燥室内利用热气体借对流作用传热给砖坯,砖坯得到热量后将水分蒸发为潮气排出室外,气体在整个干燥室内起着充当热能交换和水汽传递的媒介物。砖瓦干燥热工中常将这种媒介物称为介质。最常     

一种求解湿空气温度和相对湿度的CFD算法

以往在用计算流体力学 (CFD)方法计算空气温度时 ,仅考虑空气显热 ,导致计算温度与实际情况相差较大。提出一种考虑潜热的计算房间温度和相对湿度的CFD方法 ,将两种计算结果进行了比较 ,发现前者的计算结果较后者约高 0 .5～ 1℃。     

“浅析烧结砖干燥和焙烧的用风量”学习探讨

<砖瓦世界>和<砖瓦>两个杂志于2008年第5期同时刊登了"浅析烧结砖干燥和焙烧的用风量"一文(写法上作了些微调,内容基本相同;但表1中100℃时的饱和绝对湿度:<砖瓦世界>写成了599.17,而<砖瓦>写成588.17,这是一个较大变动).两杂志对照拜读了一下,现谈点粗浅的心得和联想,请同仁们批评指正.     

湿空气相对湿度的一种计算方法

利用工程热力学的基本知识推导了计算式，并与传统的计算方法进行了比较。新计算式形式简单，物理意义明确，计算较准确。     

摩尔在干燥热工中的应用

1摩尔 摩尔(mol)是用于计量物质的量的国际制基本单位.它是指一个系统的物质的量,而该系统中所含的单元数与0.012kg碳的原子数目相等.0.012kg碳所含的原子数目是6.02×1023个,这个数叫做阿佛加德罗数或阿佛加德罗常数.     

浅析烧结砖干燥和焙烧的用风量

烧结砖瓦从坯体干燥到烧结成型一刻也离不开风(空气)。在干燥时,靠风在传递热量的同时把砖坯中的水汽带走以烘干砖坯。在焙烧时依靠风在传递热量的同时把燃料烧起来使达到泥料的烧结温度,把干坯烧成砖瓦。     

适用于计算机程序计算的湿空气计算方法

本文旨在提出一种适用于计算机程序计算的湿空气状态参数计算方法。本文通过采用最小二乘法对饱和水蒸气压力试验数据进行分段二次多项式拟合,由此得出一个分段计算函数,并提出建立在此分段函数基础上的湿空气状态参数计算方法。通过与已有经验公式及实验数据对比表明此方法具有较高的计算精度。经过实践证明,此方法适用于编写需要进行湿空气计算的相关计算机程序。     

一种简便实用的湿空气性质计算方程

根据文献数据对几个蒸汽压力经验方程、水汽化潜热方程等进行数理统计处理，给出了几个经验方程，并运用这些经验方程建立了一种简便实用、精确度高的湿空气性质计算方程。     

读“浅析烧结砖在干燥和焙烧时的用风量”心得

在《砖瓦》和《砖瓦世界》两个杂志于2008年第5期同时刊登了“浅析烧结砖在干燥和焙烧时的用风量”一文（写法上作了些微调,内容基本相同;但表1中100℃时的饱和绝对湿度：《砖瓦》写成588．17,而《砖瓦世界》写成了599．17,这是一个较大变动）。两杂志对照拜读了一下,现谈点粗浅的心得和联想,请同仁们批评指正。     

串联热阻叠加原理在建筑热工计算中的应用

在建筑热工计算中，确认构成传热过程的各环节后，利用串联热阻叠加原理可免去繁琐的推导。应用串联热阻叠加原理分析了平行的无限大平面，遮热板的遮热效果，计算了带封闭阳台房间封闭部分的基本耗热量。     

湿空气绝热节流系数计算及讨论

基于修正的PR方程(MPR方程)与压缩因子方程,将焦耳-汤姆孙系数的计算转化为压缩因子在等压条件下对温度的偏导数的计算,提出了一种计算湿空气绝热节流系数的方法.对该方法进行了验证,首先计算了饱和湿空气的压缩因子,与相关文献的数据进行了比较;其次计算了不同压力、不同温度下氧气的焦耳-汤姆孙系数,与基于实验数据的经验公式的计算值进行了比较,结果均表明此方法具有较高精度.最后分析了温度、压力及含湿量对湿空气绝热节流系数的影响,并比较了MPR方程和PR方程的计算结果.     

正压送风量的一种计算方法

针对装有正压送风系统的高层建筑，分析了影响正压送风量分配状况的因素，这些相关因素包括送风部位，同时开门楼层数和开门门洞的风速。提出了以门开启时通过门洞的空气流足以阻挡着火层或有烟层烟气流的水平扩散为基础的正压送风量计算公式。     

变风量多分区空调系统新风量计算

介绍了变风量多分区系统的区域新风需求、新风分布、通风效率和单/双通道多分区循环系统,借鉴ANSI/ASHRAE标准62.1-2004提出的系统新风量计算方法给出了变风量多分区空调系统的新风量计算方法.该方法有助于在新风节能方面拓展设计思路.     

温湿度独立控制系统中最小新风量计算方法研究

通过对全面通风方程的分析,对实测数据和计算数据进行比较,验证了全面通风方程用于求解室内含湿量的正确性。并将此方程应用于温湿度独立控制系统最小新风量的求解中,通过引入预除湿时间,解决了原有最小新风量求解方法的不足。通过数据比较,分析了预除湿时间以及送风含湿量对最小新风量的影响,认为只有综合考虑最小新风量、预除湿时间及送风含湿量才能实现温湿度独立控制系统的优化设计。     

由等效显热比计算空调送风量的方法

在已往的工业建筑设计中，新风量一般是按照送风量的百分数计算，所以很容易确定新回风混合状态点。但在民用建筑设计中，新风量是由人员密度和吸烟状况等因素确定的，无法按照送风量的百分数计算，故新回风混合状态点无法事先确定，这就使送风量的计算十分不便。介绍了一种由等效显热比计算空调送风量的方法，此方法能够大大简化送风量的计算工作。     

Influence of air humidity and the distance from the source on negative air ion concentration in indoor air

Although negative air ionizer is commonly used for indoor air cleaning, few studies examine the concentration gradient of negative air ion (NAI) in indoor environments. This study investigated the concentration gradient of NAI at various relative humidities and distances form the source in indoor air. The NAI was generated by single-electrode negative electric discharge; the discharge was kept at dark discharge and 30.0 kV. The NAI concentrations were measured at various distances (10-900 cm) from the discharge electrode in order to identify the distribution of NAI in an indoor environment. The profile of NAI concentration was monitored at different relative humidities (38.1-73.6% RH) and room temperatures (25.2+/-1.4 degrees C). Experimental results indicate that the influence of relative humidity on the concentration gradient of NAI was complicated. There were four trends for the relationship between NAI concentration and relative humidity at different distances from the discharge electrode. The changes of NAI concentration with an increase in relative humidity at different distances were quite steady (10-30 cm), strongly declining (70-360 cm), approaching stability (420-450 cm) and moderately increasing (560-900 cm). Additionally, the regression analysis of NAI concentrations and distances from the discharge electrode indicated a logarithmic linear (log-linear) relationship; the distance of log-linear tendency (lambda) decreased with an increase in relative humidity such that the log-linear distance of 38.1% RH was 2.9 times that of 73.6% RH. Moreover, an empirical curve fit based on this study for the concentration gradient of NAI generated by negative electric discharge in indoor air was developed for estimating the NAI concentration at different relative humidities and distances from the source of electric discharge.     

湿球温度与饱和焓值经验关系式

利用空气调节手册中提供的湿空气物性数据,探讨并分别建立了标准大气压下湿球温度与饱和焓的函数关系式以及非标准大气压力（６５￣１１０ｋＰａ）下通用的经验解析式。认为公式具有足够的精度,或供工程设计计算使用。     

湿空气热物理性质计算方程

依据二元组分混合气体的性质，推导建立了由空气温度、压力和相对湿度表达的湿空气热物理性质的计算方程。     

Modeling the effect of hygroscopic curtains on relative humidity for spaces air conditioned by DX split air conditioning system

The use of hygroscopic materials for moisture buffering is a passive way to moderate the variation of indoor humidity. Through absorption and desorption, surface materials in the indoor environment, such as curtains, carpets and wall paper, are able to dampen the moisture variations. The moisture buffering capacity of these materials may be used to improve the relative humidity of the indoor environment at reduced energy costs.The objectives of this paper are threefold. The first objective is to derive a theoretical model for the transient moisture transfer between a curtain system and the indoor air for the case where the curtain is placed in front of a wall. The second objective is to conduct experiments inside environmental chambers to validate the theoretical model and to test the ability of curtains to moderate indoor humidity. It is shown that the experimental results for the curtain moisture uptake and the relative humidity inside the chamber compared well with the model simulation results. The third and final objective is to test and evaluate the model under “real environment conditions” for a case study of a hygroscopic cotton curtain, placed in a “typical” office space in the city of Beirut with an area of 25 m² that uses direct expansion (DX) air conditioning system. It is found that hygroscopic curtains maintain humidity of less than 65% during part load operation compared to the upper limit of 70% relative humidity when no curtain is used. On the other hand, it is found that the energy use, as determined by the daily electrical power consumption of the DX system, is almost the same for the two cases, (with and without a curtain), where approximately 20 kWh of energy input is required 13 kWh of sensible energy and 7 kWh of latent energy.