一种新型的织物热湿传递性能测试仪

研制一种新型的织物热湿传递性能测试仪，燕在模拟人体出汗的条件下，对组合双层织物与模拟皮肤之间的水汽分配，温度和热流的动态变化进行了测试，根据水汽分压、温度和热流曲线，计算出热湿传染系数，可以用来评价织物的热湿传递性能。     

微孔膜防水透湿织物热湿传递中织物表面凝结

试制了一种织物微气候仪，模拟人体和服装之间的微气候，测量其中的温度和相对湿度。研究是否在织物里表面产生凝结，为进一步研究织物的热湿传递提供实验依据。测试装置由计算机控制，操作方便，实验时间短。本装置实验结果与ASTME96—00测试的透湿量相比较，对防水透湿织物的湿传递表征具有明显的优势。此外，本文从水蒸汽凝结和Kelvin公式，分析研究了微孔膜防水透湿织物热湿传递中发生表面凝结的现象。     

苎麻织物的组织和纬密对热湿性能的影响

本利用统计方法，探讨了苎麻织物组织、纬密的变化对织物导热系数、热阻、温冷感、保暖率和透湿量的影响。研究结果表明，苎麻织物在夏季服用时，基热湿性能以斜纹组织、设计纬密为213根／10cm的织物为最佳。     

真丝薄型织物热湿性能与其结构参数关系的探讨

本文使用非稳态下织物传热传湿测试装置，对Ｌ２７（３１３）正交设计试制的真丝电力纺试样．进行了纯热阻、湿阻及热湿交互作用下的热阻、湿阻测定。并按测试结果建立了真丝薄型织物热湿性能与其结构参数间的多元线性回归方程。结果表明，织物厚度是影响薄型织物热阻、湿阻的一个显要因素；热、湿交互作用下织物的热、湿值小于纯热、湿条件下的热、湿阻值。为薄型织物热湿性能设计提供了参考．     

织物热湿传递测试装置

自制了织物湿阻和热阻测试仪,探讨了服装面料的透湿性能,通过关联度分析,可知厚度是影响湿传递性能的最主要因素,另外,尝试用传感器来监视测试所用人造皮肤的出汗情况。     

苎麻织物的组织和纬密对热湿性能的影响

本文利用统计方法,探讨了苎麻织物组织、纬密的变化对织物导热系数、热阻、温冷感、保暖率和透湿量的影响。研究结果表明,苎麻织物在夏季服用时,其热湿性能以斜纹组织、设计纬密为213根/10cm 的织物为最佳。     

微孔膜防水透湿织物热湿传递中织物表面凝结

试制了一种织物微气候仪,模拟人体和服装之间的微气候,测量其中的温度和相对湿度,研究是否在织物里表面产生凝结,为进一步研究织物的热湿传递提供实验依据。测试装置由计算机控制,操作方便,实验时间短。本装置实验结果与ASTME96-00测试的透湿量相比较,对防水透湿织物的湿传递表征具有明显的优势。此外,本文从水蒸汽凝结和Kelvin公式,分析研究了微孔膜防水透湿织物热湿传递中发生表面凝结的现象。     

织物表面性能对其湿传递性能影响

将实验用织物进行了亲水性和拒水性整理,使用织物微气候仪,利用汽态湿传递和液态湿传递方法研究了织物表面性能对其湿传递性能的影响。实验结果表明,织和的水汽湿传递性能和织物表面性能无关,而织物液态湿传递性能却主要决定于织物的表面性能。在织物液态湿传递过程中,影响其传递性能的主要因素是织物的芯吸效应。     

微风环境下机织物的湿渗透机理

测量和分析了几种中长涤粘机织物在相近厚度不同透气量以及相近透气量不同厚度情况下的透湿情况．研究发现,在微风环境里,相近厚度织物的透湿量随着其透气量的增大有减小趋势．由此得出一个假设,毛细管吸附作用在织物的透湿中起着重要的作用,透气量太大时单位面积内的毛细孔数减少,对水分子的吸附量小,所以吸湿量小．因此,织物的透湿过程描述为导湿则更加确切．另外,在透气量相近时,透湿量随厚度增加而略有减小,主要原因是由于织物微孔中纤维材料的表面积很大,水分子在传递过程中受到很大的吸附力,从而使得较厚的织物的导湿能力下降．     

针织物热湿舒适性能的测试方法和综合评判

介绍了我院研制的一系列织物静态、动态热湿舒适性能的测试仪器和评判指标,提出有关针织物热湿舒适性的静、动态综合评判观点和方法,并就原料对针织物热湿舒适性能的影响进行了研究．     

围护结构热湿耦合传递模型及简便求解方法

为了预测围护结构内的温度和湿度分布,以连续变量,相对湿度和温度为驱动势,考虑热传递与湿传递之间的耦合作用,建立了围护结构热湿耦合传递非稳态模型,并提出了基于多物理场耦合仿真模拟软件COMSOL的热湿耦合传递模型简便求解方法。通过对比新建模型模拟结果与HAMSTAD标准验证实例,验证了模型及求解方法的准确性。     

Development of experimental study on coupled heat and moisture transfer in porous building envelope

A new facility was presented which can expediently and cheaply measure the transient moisture content profile in multi-layer porous building envelope. Then, a common multi-layer porous building envelope was provided, which was constructed by cement mortar-red brick-cement plaster. With this kind of building envelope installed in the south wall, a well-controlled air-conditioning room was set up in Changsha, which is one of typical zones of hot and humid climate in China. And experiments were carried out to investigate the temperature and moisture distribution in multi-layer building envelope in summer, both in sunny day and rainy day. The results show that, the temperature and humidity at the interface between the brick and cement mortar are seriously affected by the changes of outdoor temperature and humidity, and the relative humidity at this interface keeps more than 80% for a long-term, which can easily trigger the growth of mould. The temperature and humidity at the interface between the brick and cement plaster change a little, and they are affected by the changes of indoor temperature and humidity. The temperature and humidity at the interface of the wall whose interior surface is affixed with a foam plastic wallpaper are generally higher than those of the wall without wallpaper. The heat transfer and moisture transfer in the envelope are coupled strongly.     

墙体内热湿耦合过程的时域递归展开算法

利用时域递归展开算法对墙体内热湿耦合传递方程进行求解。以木板为例,应用该算法进行了热湿耦合传递的分析计算,在时间域和空间域上分别运用递归展开法和控制容积法进行离散,从而得到递归形式的线性方程组,运用MATLAB软件对这一过程进行求解。计算结果与有限差分算法、解析解计算结果以及实验数据吻合良好,表明该算法能够用于求解多孔介质热湿耦合传递模型。时间步长的改变对计算结果影响较小,可通过增加时间步长方法来减少工作量。     

Effects of heat treatment on the microstructures and mechanical properties of a new type of nitrogen-containing die steel

Nitrogen can increase the strength of steels without weakening the toughness and improve the corrosion resistance at the same time. Compared with conventional nitrogen-free die steels, a new type of nitrogen-containing die steel was developed with many superior properties, such as high strength, high hardness, and good toughness. This paper focused on the effects of heat treatment on the microstruc-tures and mechanical properties of the new type of nitrogen-containing die steel, which were investigated by the optimized deformation process and heat treatment. Isothermal spheroidal annealing and high-temperature quenching as well as high-temperature tempering were ap-plied in the experiment by means of an orthogonal method after the steel was multiply forged. The mechanical properties of nitro-gen-containing die steel forgings are better than the standard of NADCA #207-2003.     

Analysis of the effects of the heat of sorption on the process of heat transfer in moisture exchange across a membrane

A theoretical study has been conducted to investigate the effects of mass transfer on heat transfer in moisture exchange across a membrane and a mathematical model describing the heat transfer process with consideration of the heat of sorption was established. A dimensionless variable, Ψ =JLλ /δ (T ₁₀−T ₂₀), which controls the effect of the heat of sorption on the heat transfer in membrane process, was obtained through theoretical analysis, and the effects of Ψ on the heat transfer process were analyzed. Results showed that in the case that the temperature gradient and mass transfer are in the same direction, the effective heat flux changes the direction at Ψ=1. For Ψ<1, the heat transfers from high to low temperature sides through the membrane, and the total thermal resistance increases with increasing the moisture flux across membrane or reducing the temperature difference between the bulk flows on the two sides of membrane. For Ψ>1, the overall effect of the heat and mass transfer is that the effective heat flux points from low to high temperature sides and the total thermal resistance decreases with increasing the mass flux or reducing the temperature difference. In the case that the temperature gradient and mass transfer are in the opposite directions, the existence of the heat of sorption acts to enhance the heat transfer from high to low temperature sides, causing a reduced total thermal resistance, and the greater the mass flux or the smaller the temperature difference, the smaller the total thermal resistance. Supported by the National Natural Science Foundation of China (Grant No. 50576040)     

粮食热、湿性能测定的研究

粮食的温度和含水率(湿度)是安全储粮的重要指标。不合理的储藏方式,会使粮食品质劣变速度加快,甚至会霉烂变质。因此,了解掌握不同粮食的各种物性参数,是保管好粮食的有利因素。本文是属于粮仓热湿性能专题研究的一部分,着重对各种粮食不同物性参数进行了系统测定,找出了相互之间的关系,整理、绘制了图表和计算公式,介绍了测定方法,为粮食在保管过程中热湿性能提供了理论依据。     

极端热湿地区围护结构热湿耦合传递模型

极端热湿地区常年高温多雨,为了准确预测围护结构内的温度和湿度分布,模拟高温、高湿和高太阳辐射对围护结构的影响,建立了适用于极端热湿地区的围护结构热湿耦合传递模型,在边界条件中加入太阳辐射和雨水负荷对传热传湿的影响,考虑了随材料含湿量不断变化的材料物性参数。为了求解模型,提出了基于计算机软件COMSOL的模型求解方法,利用MATLAB计算方程组不断变化的系数,并确定了软件容差和网格的设置条件：相对容差推荐设定在0.001,绝对容差设定为0.000 1,网格按极细化划分。通过对比HAMSTAD标准实例验证了模型的准确性。     

铸造式折板换热器的设计与性能的测定

在综合折板式、板式、螺旋板式、板翅式换热器的基础上设计了一种新型换热器———铸造式折板换热器 .实验测定结果表明 :该换热器具有阻力小、传热系数大、流体分配均匀等优点