Comparison Between Heat Pipe and Direct Heat Exchange Solar Louvre Collectors

International concern about the environmental implications of climate change coupled with increasing demand for energy to fuel modern society has lead to growing interest in using renewable energy sources as alternatives to conventional sources. The work presented in this paper compares two types of solar collector integrated into louvred shading devices. In addition to protecting glazed spaces in buildings from excessive solar gain, the collector would provide the flexibility to produce systems customized for collecting heat over a temperature-range appropriate to particular building services applications at various climates/locations. This would allow considerable savings to be made in primary energy consumption and lead to a reduction in global warming impact. Two solar absorbers, based on different techniques of heat exchange, were tested experimentally. The first was based on a direct heat exchange technique, and the second used heat pipe technology. Various comparisons were made and it was concluded that the heat pipe solar louvre collector was the preferred device.     

循环水泵冷却水管腐蚀失效分析

循环水泵冷却水管发生严重腐蚀失效。通过ICP对管材进行成分分析,确定材料并无成分缺陷。再通过对腐蚀产物进行能谱分析和XRD扫描,发现Cl-可能是引起腐蚀失效的重要原因,而Cl-很有可能来自冷却水。因此建议改善冷却水质并改用耐Cl-腐蚀的材料制作冷却水管。     

利用污水管道处理生活污水试验研究

本文针对污水管道系统管径大，距离长，污水在当中输送时间长等特点和环境污染现状，提出充分利用污水管道巨大空间的如下设想；采用前置高负荷生物接触氧化渠和在沿途的污水提升泵站中注入空气的管道生化反应工艺，从而有机污染物质在输送过程中得到部分降解，并且进行了模拟试验和研究。     

人工湿地植物处理污水的试验研究

为了选择适合在中国四川地区生长的湿地植物，作者在四川省成都市１９９３年１０月２日－１１月１９日的深秋季节进行了湿地系统处理模拟污水的盆栽静态试验，以研究多种湿地植物在自然环境条件下对污染物的去除情况。试验发现，灯蕊草，芦苇，菖蒲这三种植物在１４天内均能去除模拟水样中的ＣＯＤｃｒ，其中，芦苇的去除率为３８％，菖蒲的去除率为４１％，灯蕊草的去除率为４２～４６％。这三种植物同时也能污水的ｐＨ从３．５调节     

Modeling of Fluid Flow and Heat Transfer in a Copper Based Heat Sink Application

With the trend towards increasing the speed of processors in smaller sized of computers, there has been considerable interest in heat sink technologies with higher levels of performance and further miniaturization. This work addresses the fundamental heat transfer augmentation question of how to design a copper-based heat sink, when the overall dimensions of the bottom plate or fan are specified. A three-dimensional finite-volume model has been developed and applied to investigate flow and conjugate heat transfer in the copper-based heat sink. The model was produced with the commercial program FLUENT, which allows this nonlinear, highly turbulent problem to be simulated using the k-ε turbulence model. The theoretical model developed is validated by comparing the model predictions with available experimental data. The thermal performance and temperature distribution for the heat sink were analyzed and a procedure for optimizing the geometrical design parameters based on less space occupation and more efficient heat transfer coefficient is presented. Several design examples with different types of cooling methods and manufacturing processes have been analyzed. The reliability and effectiveness in heat spreading of those has been compared. It has been shown that the copper-based heat sink with louvered fins (case No.3) has an optimum design configuration.     

新型杀菌剂双季铵盐BQAS性能试验研究

新型杀菌剂双季铵盐以其低毒、性能优良而受到广泛的关注。以自制的N,N-二甲基十二烷基叔胺和1,4-二溴丁烷为原料合成产物双季铵盐(BQAS)。对双季铵盐BQAS的杀菌性能及缓蚀性能研究表明,双季铵盐对SRB和TGB的杀灭能力均优于1227,双季铵盐在有氧中性水介质中表现出一定的缓蚀性能,并具有较强的杀菌能力,是一种吸附成膜型缓蚀剂。     

Performance of a small-scale solar-powered adsorption cooling system

In this study, an experimental investigation on the performance of a small-scale residential-size solar-driven adsorption (silica gel-water) cooling system that was constructed at Assiut University campus, Egypt is carried out. As Assiut area is considered as hot, arid climate, field tests for performance assessment of the system operation during the summer season are performed under different environmental operating conditions. The system consists of an evacuated tube with a reflective concentration parabolic surface solar-collector field with a total area of 36 m², a silica gel-water adsorption chiller of 8 kW nominal cooling capacity, and hot and cold water thermal storage tanks of 1.8 and 1.2 m³ in volume, respectively. The results of summer season field test show that under daily solar insolation varying from 21 to 27 MJ/m², the solar collectors employed in the system had high and almost constant thermal efficiency. The daily solar-collector efficiency during the period of system operation ranged from about 50% to 78%. The adsorption chiller performance shows that the chiller average daily coefficient of performance (COP) was 0.41 with the average cooling capacity of 4.4 kW when the cooling-water and chilled-water temperatures were about 31°C and 19°C, respectively. As the chiller cooling water is cooled by the cooling tower in the hot arid area, the cooling water is at a higher temperature than the design point of the chiller. Therefore, an experiment was carried out using the city water for cooling. The results show that an enhancement in the chiller COP by 40% and the chilling power by 17% has been achieved when the city water was 27.7°C.     

陶瓷过滤器除尘性能试验研究

分析了陶瓷过滤器的除尘机理,设计了用于试验的陶瓷管过滤器,针对陶瓷过滤器的效率、动态滤尘特性、清灰效果进行了相关试验,所得数据表明：陶瓷管的初始阻力较大,除尘效率可达到99.99%以上;陶瓷管的残余阻力较高但增长缓慢;综合考虑30ms的脉冲宽度以及0.6MPa清灰压力下效果最好,0.5MPa的清灰压力也完全可以满足清灰的要求;建议使用风速在1m/min或低于1m/min。     

温度冲击试验设备实现途径及热负荷分析

结合试验指标要求,对温度冲击试验设备实现途径进行分析比较,选择两箱式作为试验设备的实现方式;对设备组成结构及制冷、加热流程进行阐述,并对温度冲击试验过程中两种制冷状态下的热负荷进行了分析计算。     

气田含油污泥焚烧性能优化实验

焚烧法是气田含油污泥处理的主要方法。文章分析了气田含油污泥的性质和特性,气田含油污泥处理方法及存在问题,对气田含油污泥焚烧性能优化机理、提高旋转窑焚烧炉工艺参数进行了研究。结合现场实际情况,提出了以降低污泥含水率在30%以下和控制焚烧炉预热温度500℃以上为主要措施的解决思路。     

Evaluation of the Use of Artificial Neural Networks for the Simulation of Hybrid Solar Collectors

Abstract

In the last decade, Artificial Neural Networks (ANNs) have been receiving an increasing attention for simulating engineering systems due to some interesting characteristics such as learning capability, fault tolerance, speed and nonlinearity. This article describes an alternative approach to assess two types of hybrid solar collector/heat pipe systems (plate heat pipe type and tube heat pipe type) using ANNs. Multiple Layer Perceptrons (MLPs) and Radial Basis Networks (RBFs) were considered. The networks were trained using results from mathematical models generated by Monte Carlo simulation. The mathematical models were based on energy balances and resulted in a system of nonlinear equations. The solution of the models was very sensitive to initial estimates, and convergence was not obtained under certain conditions. Between the two neural models, MLPs performed slightly better than RBFs. It can be concluded that similar configurations were adequate for both collector systems. It was found that ANNs simulated both collector efficiency and heat output with high accuracy when “unseen” data were presented to the networks. An important advantage of a trained ANN over the mathematical models is that convergence is not an issue and the result is obtained almost instantaneously.     

一种高压油管焊接质量评价方法

阐述了高压油管疲劳破坏的原理及危害,建立高压油管焊接质量评价力学模型,通过有限元分析技术对其许用位移输入进行计算,并结合应变测量技术,利用电动振动台,对高压油管焊接处的疲劳特性进行了试验验证。结果表明,此高压油管焊接质量评价方法是可行的,有限元分析技术和应变测量技术的结合使用,保证了试验的安全性和结果准确性,此外,利用电动振动台进行疲劳耐久试验,操作方便简单,成本相对较低,具有通用性。     

管道生物好氧反应器模型动力学研究

本文针对污水管道生化反应器进行力学模型研究，分析了有机物降解规律，并给出了在一定试验条件下的动力学参数。     

无缝钢管厂外排废水治理方案

针对无缝钢管厂酸洗废水pH值低、氧化铁含量高等特殊性,采用分散治理回收与集中处理回收相结合的技术方案。使处理后的水回用于生产,并采用一水多用、重复利用和循环利用的技术,提高了重复用水率,基本上实现“零排放”。     

村镇供水管网优化设计探讨

如何合理确定村镇供水管网敷设方案,关系到整个供水系统的安全性和可靠性。通过生成树变化法,将环状管网转化成树状管网,确定供水管网中最短供水路线,再计算最短供水路线下的最低综合费用、供水系统的经济管径,以确定最优管道敷设方案。根据该方法对四川省某镇供水系统进行了设计。     

放射性废树脂聚合物水泥固化的试验研究

聚合物水泥用于放射性废离子交换树脂水泥固化工艺,利用其防水性能抑制废树脂的溶胀,降低水泥固化体中放射性核素^137Cs、^90Sr浸出率,提高了废树脂包容率和处置的安全性。     

压裂返排液生物处理实验研究

从油田压裂返排液中筛选出EB系列菌种,可高效降解压裂返排液中的高分子和有机污染物。考察了振荡时间、温度、接种量、菌种混合比例等对压裂返排液COD去除率的影响。结果表明:48h振荡、25℃、10%接种量、菌种EB1和EB2按1∶1比例混合是较佳应用条件。EB复合菌种的应用范围较广,其pH值适用范围为6～9,矿化度适用范围为3 000～20 000mg/L。该研究提高了压裂返排液生物处理技术规模化应用的可行性。     

摆管淋水试验装置的校准方法探讨

文中简述了摆管淋水试验装置的基本结构及其常见的校准方式,对其中的“摆角校准”这一技术难点提出了可行的解决方案并作了较详尽的说明分析。     

电气浮法处理钻井废水实验研究

对电气浮法处理模拟钻井废水进行了实验研究,分析了工艺参数(电气浮时间、电极间距、电气浮后静止停留时间、废水温度和电流密度)对电气浮法处理效果的影响。实验结果表明,电气浮法处理钻井废水受许多因素的影响,掌握这些因素对电气浮处理的影响规律,有助于合理选取最佳参数,达到既高效又节能地处理钻井废水的效果。研究结果表明:最佳电气浮时间为10min,电极间距推荐选用1.0cm,电气浮后静止停留时间选用5min,废水适宜处理温度为30～50℃,选择电流密度小、电气浮处理时间长的组合工艺能达到最佳处理效果。     

套管喷旋流技术在热交换器中的应用

套管式空气预热器的传热元件是由两根不同直径的管子套在一起组成,外管由高温烟气获取热量,充分利用排烟余热,内管中通入冷空气,内外管通过对流和辐射的传热方式实现热量传递,是一种结构简单、换热效率高的新型空气换热器。