空调翅片管换热器研究进展

本文介绍了目前国内外空调行业普遍采用的翅片管换热器的研究情况,通过对平片、波纹片、开缝及百叶窗片强化翅片管换热器的研究进展介绍,指出了目前翅片管换热器研究的不足,展望了研究方向。     

浅谈管壳式换热器

本文介绍了管壳式换热器的基本原理和结构以及简单的设计方法,详细讲解了管壳式换热器中固定管板式换热器、浮头式换热器、u型管式换热器的结构及特点．为管壳式换热器的结构选择提供了参考。     

换热网络回路的识别技术

依据夹点理论通常会产生以最大限度地回收系统能量为综合目标的换热网络综合,同时会产生一些闭合的匹配回路,这些回路会产生多余的匹配单元、增加设备投资;当被控制参量产生波动时,波动会在回路中产生振荡,影响网络的稳定运行,增加控制难度。对这些回路的识别与打开人们已作了大量的工作,但大多是以亿工分析与识别为基础的,不利于大型拓扑网络的分析与综合。文中利用图论中的基本原理对换热网络综合过程中回路的识别与打开进     

On-line preconcentration and GFAAS determination of trace metals in waters

An on-line separation preconcentration system coupled to electrothermal (graphite furnace) atomic absorption spectrometry was developed. A miniature column packed with iminodiacetic acid ethyl cellulose (IDAEC) was inserted into the loop. A peristaltic pump was used to deliver solutions. A flow of air was driven into the packed column, evacuating it between sample loading, washing and elution. The retained analyte was introduced on-line to graphite furnace using countercurrent elution with HNO₃. The system was applied for the determination of V, Co and Pb in medicinal mineral water samples, and nickel in sea water samples. The detection limits (3σ) were 0.058, 0.022, 0.067, 0.062 μg/l for Co, Pb, V, and Ni, respectively. The R.S.D. (n=5) was <5% at 0.4–1.0 μg/l concentration range.     

离子交换法从APT结晶母液中回收钨酸钠

用弱碱大孔离子交换树脂Ｄ３５４在微酸条件下吸附母液中钨，用１０％的苛性钠进行解吸好可获得浓钨酸钠溶液。该法简单而经济。