无蜗壳风机空气动力性能解读及其应用

介绍了无蜗壳风机与常用有蜗壳风机之间的结构差异、性能测试方法与性能计算的区别。通过性能试验发现,无蜗壳风机配置在空调机组内时,不同于有蜗壳风机可直接按其名义风量、压力选取,两者存在一定的差异。以对无蜗壳风机的理解和试验结果为基础,对风机室的设计提出了相应建议。认为使用无蜗壳风机时,必须配置风机室,尽量采用该风机性能曲线的中段区域参数。     

基于ECR400型风机盘管性能影响因素实验研究

对以ECR400型为代表的风机盘管在不同运行工况下的性能在焓差实验室内进行了实际测试。分别得到在夏季制冷工况及冬季制热工况下,不同室内空气温度、风机盘管供水温度、供水流量以及风机盘管送风量等对风机盘管性能的影响。实验结果表明:室内空气温度、风机盘管供水温度、供水流量等对风机盘管制冷(热)与除湿性能都有显著影响,送风量的变化对风机盘管除湿性能的影响较小。本实验结论对风机盘管的设计选型及运行维护具有一定的指导意义     

高海拔隧道主风机的选型研究

通风机的性能受诸多因素的影响,风流密度是一重要影响参数。文章在鹧鸪山通风基础参数调查的基础上,根据相似比定律,研究了高海拔地区风流密度对通风机工作性能的影响。研究表明,高海拔地区,风机的实际工作风压和风机的电机功率随风流密度的降低而降低。高海拔条件下,进行风机的选型时,应根据相似比定律对计算风压和功率进行修正。建议风机安装后对风机性能进行现场测试,拟合风机的工作性能曲线,为运营机电控制提供依据。     

无蜗壳风机的特性研究

实验表明,自制叶轮的性能已达国外同类产品的性能水平。分析了影响无蜗壳风机性能的多种因素,探索了无蜗壳风机的使用条件及其应用于空调箱的可行性。     

双级变幅式专用风机吊装臂架系统的技术原理及应用

本文分析了现有风机吊装工况的特点和现有产品的技术瓶颈,提出了双极变幅式专用风机吊装臂架系统设计。通过有限元分析和作图法分析对比,双极变幅式臂架系统大幅提高了风机安装微动性能和就位高度以及起重性能,并经过试验得到验证。     

空气源热泵风机性能对结霜的影响

分析了空气源热泵在制热运行时风机性能对结霜的影响。通过对风机性能的模拟，分析了在制热运行结霜工况下由于风量变化所引起的蒸发温度变化、霜层厚度变化以及制热量的变化，以指导空气源热泵的风机选型。     

消防排烟风机常规性能测试装置分析

为满足不同规格尺寸的消防排烟风机在实验室可靠地进行常规性能检测需求,对采用C型风管进气试验方式对消防排烟风机常规性能检测装置进行了分析与研究。分析了装置研究的背景和C型风管装置的详细构成以及使用的测试系统,利用装置多次测试消防排烟风机的常规性能。结果表明,该装置符合相关标准要求,系统稳定,测试数据精确,智能化测试采集速度快,对消防排烟风机生产企业自行研制设计常规性能试验装置具有参考作用。     

风机盘管机组风量测试技术方案优化设计和分析

围绕风机盘管机组的性能要求,阐述智能化自动控制风洞式空气焓值风机盘管性能测试系统的组成,对额定风量检测的要求进行了详细的分析,采用涡街式流量计取代喷嘴,将平衡风机设计优化,满足标准实验工况的检测要求。     

风机在大同二电厂脱硫系统中的应用

通过风机在大同二电厂脱硫系统中的应用,介绍了脱硫系统中典型的两种风机———增压风机和氧化风机的设备结构和性能特点,探讨和分析了选择风机类型的主要参数,得出了该电厂风机应用和选择成功的结论,可供同类工程参考。     

刍议轮窑与干燥室专用节能风机

本文介绍了近１０年来出现的心用节能风机和干燥室送热节能风机，并对各种型号的节能风机进行了分析，重点介绍了“ＺＦＪ系列轮窑高温防腐节能风机”及“ＧＳＪ系列干燥达热节能风机”的性能特点。     

Untersuchungen zur Genauigkeit von magnetisch induktiven Betondeckungsmessungen

Assessment of the accuracy of concrete cover measurements using Eddy Current devices The use of non‐destructive testing in civil‐engineering (NDT‐CE) is well established to assess as‐built drawings for existing structures as well as for quality assurance of new buildings or in case of concrete repair. To gain reliable results the choice of the appropriate testing method in combination with the correct data assessment is essential. Hence this article starts with the basics of the two typical testing methods for concrete cover measurement with high precision. Methods based on Eddy Current and based on Radar are different. The strengths and limitations of both methods are presented. In the second part the achievable accuracy of concrete cover measurements using Eddy Current will be assessed for the most important parameters that have been varied in a wide range. It is shown how results are influenced by an improper input of the diameter or by the effect of neighbored rebars. At the end of the article it is shown how the deviation of the results can be minimized using the internal neighboring rebar correction of some of the devices. This article does not intend to be a product test rather the influence parameters of measurements close to reality will be identified and quantified how the accuracy of concrete cover measurements is affected.     

基坑开挖对邻近任意角度建筑物影响的有限元分析

实测结果表明,邻近基坑的建筑物与基坑边互不垂直时,基坑开挖将导致墙体同时发生挠曲变形与扭转变形。三维有限元分析表明,对与基坑边成一定角度的建筑物,当其跨越坑外沉降槽最低点或沉降曲线上凸区域时,建筑物所产生的扭转变形最为显著。随着建筑物与基坑距离的变化和建筑物纵墙与基坑边之间夹角的变化,当建筑物位于天然地面沉降挠曲程度较大的位置时,建筑物的挠曲变形对墙体拉应变起主要作用,墙体最大拉应变发生在建筑物纵墙垂直于基坑边,即纵墙与基坑边相互垂直时是建筑物的最不利位置;而当建筑物位于天然地面挠曲程度较小的位置时,墙体的拉应变源于挠曲变形与扭转变形的共同作用,纵墙墙体的最大拉应变将发生在与基坑边成一定角度的建筑物纵墙上,此时纵墙与基坑边垂直并不是建筑物的最不利位置。     

ÖBB Steyrtalbrücke – Belastungsprobe und Langzeitmessungen

ÖBB Steyrtalbridge – Load test and long term measurements At km 65,621 of the railroad track between Linz and Selzthal the Steyrtalbridge was rebuilt in the years 2013 and 2014. The essential design criterion from the client ÖBB Infrastruktur AG was the endeavor of an optimized bridge under consideration of life‐cylce‐cost, which among other things despite a bridge length of 182 m can be designed without high‐maintenance breather switches. Based on the current standards and certain design flexibilities, which are allowed in the codes special ways and techniques were used to calculate the rail tension. With this results of the rail‐structure‐interaction it was possible to design without breather switches. As consequence of the assumptions in the planning process it was necessary to make comprehensive measurements which shall give information of the real behavior of the bridge and compare them with the assumptions and results of the static calculation. Therefor static and dynamic load test were performed before opening to regular traffic. In addition long term measurements were carried out to evaluate the load‐bearing behavior over time and to confirm the calculation approaches for the verification of the rail‐structure‐interaction. In this article the planning of the monitoringsystem, the implementation and results of the load test and the following long term measurements are illustrated.     

Zustandsuntersuchung und Instandsetzung am Hauptdach des Hauses der Kulturen der Welt in Berlin

The main roof of the ”Haus der Kulturen der Welt“ in Berlin Which is very well‐known on account of its history and striking structural design – was to be inspected by the author to determine its condition and analysed with regard to the durability of the existing liquid synthetic sealant. The roof structure consists of a biaxial, curved area‐covering structural element with circumferential edge beams of pre‐stressed lightweight concrete. This is the result of the reconstruction between 1984 and 1987 following a partial collapse of the then Berlin Congress Hall in 1980. The very thin roof shell is also made of lightweight concrete and, like the edge beams, has a polyurethane‐based spray‐on seal that was specially developed for this purpose as protection against the ingress of moisture. The reason why this, at the time, novel type of seal was chosen was that it should take into account the fact that the roof design urgently needed some kind of protection against moisture that had to compensate the expected changes shape and crack movements of the roof with no damage. The following article reports on the nature, scope and main results of the analysis of the condition of the roof seal, edge beams and abutments. It will also describe the repair recommendations resulting from the investigations, which form the basis of the execution of work at the present point in time. Apart from presenting the technical principles and special features of the building that have to be taken into account during any repairs, the special features of the execution will also be addressed.     

Beurteilung der Tragfähigkeit von geschädigten Stahlbetonbrücken auf der Grundlage der Ergebnisse einer Bauwerksprüfung

Structural Reliability Assessment of Damaged Reinforced Concrete Bridges on the Basis of the Results from a Bridge Inspection The regular bridge inspection is of high importance for the reliable use of the infrastructure. This paper describes and explains a method with supports the engineers of a bridge inspection in the assessment of the damaged bridges during or directly after the inspection. Based on this initial estimate the urgent measures i.e. a lower permitted bridge class can still be carried out before more detailed inspections and calculations have been done. The reliability analyses for the damaged bridges are carried out using first order and second order reliability method (FORM and SORM). The probability of failure, p_f or the safety index, of the system respectively are the main results of the calculation procedure. This paper shows the approach and the application with an example. Particularly in the communal sector the method can be helpful, because it can not be assumed that in all cases the regular bridge inspections and the appropriate maintenance have been carried out.     

Bewertung einer alten genieteten Stahlbrücke – Die Bösebrücke in Berlin

Evaluation of an old riveted steel bridge – The Böse‐Bridge in Berlin, Germany. This report is about the recalculation of the Böse‐Bridge in Berlin which was built between 1912 and 1916. A special feature of this three‐bayed truss arch bridge is the nickel steel used in the main bay. Different models have been used to recalculate the main structure, the truss nodes and the carriageway slab. The static analysis is based on the semi‐probabilistic concept. As a result of this recalculation the construction was classified to have the bridge capacity 30‐30 according to DIN 1072. Finally, this report concludes by determining the remaining lifetime depending on the concept of the Wöhler curves.     

捕捉“光线”——解读葡萄牙“梅莉德斯周末住宅”

本文以阿雷斯·马特乌斯兄弟设计的梅莉德斯周末住宅的院子为线索,通过其与冈卡罗·伯内设计的“阿维罗大学的校长楼”进行比较,揭示了“光线”是其设计的核心。这为我们研究葡萄牙建筑提供了更为全面的视野。但更为重要的是,文章表明了类型学的方法论在中国大规模快速建造的今天更具现实意义。     

Feldversuche mit dem Brückenklappverfahren

Field Tests with the Balanced Lift Method As a counterpart to the lowering arch construction method the “balanced lift method” for bridge girders is suggested. The bridge girders can be built in combination with the pier using climbing forms in a vertical position. Therefore, during the production no bending stresses are generated in the girders. Thus, the balanced lift method allows lower costs and a shorter construction time than the traditional balanced cantilever method. The span of the bridge girders is reduced by the compression struts or tension ties which results in substantial savings in construction materials compared to the balanced cantilever method for bridge construction. The proposed method will be especially advantageous for bridges with high piers. The range of the span length for the application of the balanced lift method ranges between 50 m and 250 m.     

Entwicklung eines baupraktischen Näherungsverfahrens zur Beurteilung der Zuverlässigkeit von Massivbrücken auf der Grundlage der Ergebnisse von Bauwerksüberprüfungen

Im vorliegenden Teil 2 des Beitrags wird die Entwicklung des baupraktischen Näherungsverfahrens für die Beurteilung der Zuverlässigkeit von Massivbrücken im Rahmen der RI‐EBW‐PRÜF vorgestellt. Wesentlicher Inhalt ist dabei die Modellierung der Modellunsicherheit Bauwerksprüfer, da die Bewertung der Mängel und Schäden an einem Brückenbauwerk durch den jeweiligen Bauwerksprüfer einen entscheidenden Einfluss auf die Zustandsbewertung hat. Zudem wird auf die Dimensionsanalyse von Grenzzustandsfunktionen näher eingegangen, da damit bei geschickter Normierung eine allgemein gültige Anwendung des Verfahrens erreicht werden kann. Die Anwendung des Verfahrens erfolgt mit einem Software‐Tool, das abschließend vorgestellt wird. In Teil 1 des Beitrags wurden die Grundlagen des Verfahrens sowie die Entwicklung der veränderten stochastischen Material‐ und Geometrieparameter infolge Schädigung behandelt. Development of an Approximation Procedure for a Structural Reliability Assessment of Reinforced Concrete Bridges on the Basis of the Results from Bridge Inspection Part 2 of the paper shows the development of the approximation procedure for the reliability assessment of reinforced concrete bridges according to RI‐EBW‐PRÜF. An essential part of this is the development carried out by the model uncertainty bridge inspector, as the respective bridge inspector's individual assessment of the damage of a bridge has a decisive influence on the condition evaluation. Furthermore, the dimensional analyses of ultimate limit states are shown, as the general use of the developed methodology can be achieved with an ingenious standardization. The application of the procedure with the developed software tool is presented in conclusion. Part 1 of the two papers describes the basics of the methodology and shows the development of the stochastic models for the material and geometry parameters which have changed as a result of damage.     

Museumsinsel Berlin – Geotechnische Untersuchungen für die Grundinstandsetzung und Ergänzung des Pergamonmuseums

Museum Island in Berlin – Geotechnical investigations for the overhauling and completion of the Pergamon Museum. Overhauling the Pergamon Museum on the Museum Island in Berlin is a particularly complex task concerning geotechnics. On the one hand the substratum and ground water conditions in the area concerned are very inhomogeneous and on the other hand the Pergamon Museum and its neighbouring museums are especially valuable buildings worthy of protection. The initial target of the geotechnical investigation programme was to further safeguard the substratum and ground water conditions. Here systematic investigation of the substratum was carried out based on old historical drillings in order to enable the use of innovative special civil and underground engineering procedures. Furthermore it was necessary to investigate the foundation situation of the existing buildings. The planning objective is the technical and cost‐effectively optimized choice of the required geotechnical measures for the intended overhaul and refurbishment of the Pergamon Museum.