Combining a new baseboard radiator with a fan coil system for improving heating performance and reduce energy consumption

In the present work, the heating performance of a new system combined with a new modified baseboard radiator and fan coil is investigated. Using longitudinal fins with special geometry and also forced airflow at the end of the system causes that at the lower inlet water temperature compared with the conventional models, higher heat output rate be obtained. The heat output rate of the new modified system is obtained by experimental metrology based on the European Standard No. EN-442. Temperature and velocity distribution in the room space is done by simulation of the modified system in the Flovent software. Computational fluid dynamics (CFD) results are validated against experimental results and there is a good agreement between them. Also, the energy consumption of the system during the winter season is calculated in TRANSYS software. Experimental results show that the heat output rate of a new modified heating system with inlet water temperature in the range of 45–55°C is on average 4.17 times higher compared with the conventional model. CFD simulation also showed that the combined system provides good thermal comfort conditions. Energy consumption of the new system reduced about 13% compared with conventional models.     

Flower‐shaped ultra‐wideband fractal antenna

A flower‐shaped ultra‐wideband fractal antenna is presented. It comprises a fourth iterative flower‐shaped radiator, asymmetrical stub‐loaded feeding line, and coplanar quarter elliptical ground planes. A wide operating band of 12.12 GHz (4.58‐16.7 GHz) for S ₁₁ ≤ ? 10 dB is achieved along with an overall antenna footprint of 15.7 × 11.4 mm². In addition, other desirable characteristics, that is, omnidirectional radiation patterns, peak gain upto 5 dB, and fidelity factor more than 75% are achieved. A good agreement exists between the simulation and measured results. The obtained results illustrate that this antenna has wide operating range and compact dimensions than available structures.     

单管供暖系统散热器不热的原因及解决方法

当单管供暖系统部分散热器不热时,首先应排气,接着观察管道是否有堵塞或阀门故障,然后分析系统的定压情况及水压图,最后检查供暖系统设计是否合理,调试是否到位。     

计量收费后热网运行的特点及控制策略

随着热计量改革的进展,传统供热系统运行模式已经越来越不适用。本文介绍了在新的条件下,装配温控阀前后系统的特性变化,指出了与温控阀正确配备的控制设备;以及相应的热网运行特点和控制策略。     

乌鲁木齐的采暖热计量应用现状

对乌鲁木齐的采暖系统改造进行总体性的介绍，并且对当前应用最为广泛的几种分户热计量方式在乌鲁木齐实际工程中的运用进行了分析，以期达到为当前以及今后很长一段时间进行的供热改革提供借鉴。     

国内外供暖散热器新品精品及其选用

本文介绍了我国供暖散热器现状和发展方向以及国外散热器简况,并推荐了一些国内外供暖散热器新品精品供选用。     

世方豪庭热水集中供暖系统钢制散热器工程实例

本文从实际应用角度介绍了钢制板式散热器在世方豪庭项目成功使用的经验。在热水集中供暖系统中使用自动加药控制pH值的水处理装置,加强系统的运行管理(如严格控制失水量,实施非采暖季满水湿保养),可以对钢制散热器和系统起到阻蚀阻垢的作用。     

大空间对流散热器供暖的数值研究

采用CFD技术模拟了冬季室内在对流散热器供暖条件下的速度和温度分布,探讨了这种传统供暖方式在大空间建筑中的适用性,认为在一定建筑尺寸的大空间内仍可以保持相对均匀的上下温度分布,为大空间建筑散热器供暖的设计选择提供了理论依据     

散热器背面与墙距离对散热量的影响

通过实验研究给出了几种常用散热器距墙不同时的散热量，并经过分析指出：散热器紧贴墙面安装会使散热量降低；板式散热器在距墙３ｃｍ时散热量最大；柱型散热器距墙１～５ｃｍ时散热量无大变化。     

刍议散热器设计选型

列举了经常使用的各种散热器,分析其材质及使用条件,并从散热器施工安装形式、热媒水质、散热器材质、金属热强度及热价比等方面进行分析并指出了工程设计选用中应注意的事项.