管壁当量粗糙度对集中供热管网设计的影响

针对大型热网设计参数较多的情况,在排除已知的或预先给定的设计参数以后,研究了管壁当量绝对粗糙度K与集中供热管网阻力损失的关系,以及不同的K值对水力计算结果的影响。

试论靖边油区地面集输管网优化技术的应用

本文深刻讨论研究了油气集输管网的参数结构,并对其优化问题提出了建议。本文作者总结了现在常使用的一些基础的水力计算模型,比较了一些输管路水力模型。对各种流量下管流的持液率和压降进行了计算,提出了优化条件的前提。

多热源区域供热系统的环网和调节

本文继2002年第2期《区域供热》中“谈城市区域供热系统多热源联网供热”一文之后,根据我公司铁南热网80年代末引进芬兰的供热技术、我公司的运行实践及吸收国内外的先进经验,作者认为:为优化多热源区域供热系统的设计及可靠的运行,建议多热源联网供热系统最好采用间接连接的环型管网。同时本文重点分析了多热源联网供热系统调节的特点,并提出四种可供选择的调节模式。

Heat Transfer and Flow Analysis in Loop Heat Pipe with Multiple Evaporators Using Network Model

Thermal performance of a loop heat pipe with two evaporators and two condensers was examined using a lumped network model analysis. Thermosyphon-type vertical loop heat pipe and capillary-pump-type horizontal loop heat pipe were calculated by examining the change of heating rate of two evaporators. Calculation results showed that the vapor and liquid flow rates in the loop heat pipe and the thermal conductance of the heat pipe changed significantly depending on the distribution ratio of the heating rate of the multiple evaporators. The thermal performance of the vertical loop heat pipe with two evaporators was also examined and experimental results of flow direction and thermal conductance of the heat pipe agreed with the analytical results. The lumped network model analysis is therefore considered accurate and preferable for the practical design of a loop heat pipe with multiple evaporators.