Simplified prediction models for acoustic installation effects of train-mounted equipment

Acoustic models of railway vehicles in standstill and pass-by conditions can be used as part of a virtual certification process for new trains.For each piece of auxiliary equipment,the sound power measured on a test bench is combined with meas-ured or predicted transfer functions.It is important,however,to allow for installation effects due to shielding by fairings or the train body.In the current work,fast-running analytical models are developed to determine these installation effects.The model for roof-mounted sources takes account of diffraction at the corner of the train body or fairing,using a barrier model.For equipment mounted under the train,the acoustic propagation from the sides of the source is based on free-field Green’s functions.The bottom surfaces are assumed to radiate initially into a cavity under the train,which is modelled with a simple diffuse field approach.The sound emitted from the gaps at the side of the cavity is then assumed to propagate to the receivers according to free-field Green’s functions.Results show good agreement with a 2.5D boundary element model and with measurements.Modelling uncertainty and parametric uncertainty are evaluated.The largest variability occurs due to the height and impedance of the ground,especially for a low receiver.This leads to standard deviations of up to 4 dB at low frequencies.For the roof-mounted sources,uncertainty over the location of the corner used in the equivalent barrier model can also lead to large standard deviations.

Construction Engineering,Equipment Installation,Construction Engineering

At present,with the development of society,China’s civil construction equipment installation engineering has many majors,complete catego-ries and high functional requirements.In particular,the installation of the equipment is a large amount of work,with a large number of types of work,with a strong degree of specialization,and also technically complex.In the construction of construction projects in China,the installation of engineer-ing equipment is a key control point of construction safety,and equipment installation has always been a key point that construction enterprises at-tach great importance to.The installation of engineering equipment will not only affect the overall progress of engineering construction,but also affect the quality of the project,therefore,the installation of construction equipment has played a vital role and has attracted increasing attention.Combined with the actual situation of construction enterprises,this paper briefly introduces some problems and solutions existing in the construction of construction enterprises.

Discussion on Question of Importing Large-scale Equipment from Other Countries by Installment

Successful cases have not been rare, that is to import funds accelerate hospital building by means of raising funds, borrowing, renting, jointing, and so on. The same characteristics is raising money at first and then working, and the investor will earn high proportional benefits. 'Importing funds' has solved some practical problems, but it also causes some negative effects, such as difficulty in management, being difficult to work, inequitable benefit allocation, little benefits earned by the hospital, a big venture, and so on.By means of installment, the hospital has imported much equipment, such as very expensive Magnetic Resonating Instrument (MRI), spiral CT, straight accelerator, ECT and so on. Connecting with practice, the authors has analyzed objectively the profits and the harm of importing equipment by installment. There are four reasons for applying installment: firstly, it solves the problem of shortage of funds of the hospital; secondly, it efficiently avoids the inconvenience resulted from the management by both jointing sides together; thirdly, it raises the investing earnings of the hospital; finally, it is advantages which are as follows. Importing large-scale foreign equipment from abroad by installment has not been popular in the native hospital, and there are not relatively regular and ripe rules to be followed. Moreover, because effective institution is required to act as an economic guarantor, an extra content of work will, be added to practice.The authors prefer that attentions should be paid to the five aspects in importing equipment by means of installment; selecting the suitable importing project, selecting a favorable cooperating partner and deciding suitable cooperating items; selecting an excellent company or institution to guarantee for the hospital, and grasping the practice of the contract.

One-Step-Installation of Offshore Wind Turbine on Large-Scale Bucket-Top-Bearing Bucket Foundation

In 2010,the first offshore wind turbine with integrated installation was established in Qidong sea area of Jiangsu Province,China,which led to the implementation phase of one-step-installation technique based on the design and construction of large-scale bucket-top-bearing (LSBTB) bucket foundation.The critical technique of LSBTB bucket foundation included self-floating towing,penetration with adjustment of horizontal levelness,removability and one-step-installation.The process of one-step-installation included the prefabrication of LSBTB bucket foundation in onshore construction base,installation and debugging of wind power,overall water transportation of foundation and wind power system,and installation of foundation and offshore wind turbine on the appointed sea area.The cost of one-step-installation technique was about 5 000 Yuan/kW,which was 30%-50% lower than that of the existing technique.The prefabrication of LSBTB bucket foundation took about two months.During the one-step-installation process,the installation and debugging of wind power and overall water transportation need about one to two days in sea area within 35 m depth.After the proposed technique is industrialized,the cost will be further reduced,and the installation capacity is expected to be up to 500 wind turbines per year.

Opening and Sharing of Large-scale Instruments and Equipment in Agricultural Research Institutes:A Case Study of Environment and Plant Protection Institute of Chinese Academy of Tropical Agricultural Sciences

The article introduces the main practices and achievements of the Environment and Plant Protection Institute of Chinese Academy of Tropical Agricultural Sciences in promoting the sharing of large-scale instruments and equipment in recent years,analyzes the existing problems in the management system,management team,assessment incentives and maintenance guarantee,and proposes improvement measures and suggestions from aspects of improving the sharing management system,strengthening management team building,strengthening sharing assessment and incentives,improving maintenance capabilities and expanding external publicity,to further improve the sharing management of large-scale instruments and equipment.

Construction Cooperation Strategy between Equipment Installation Engineering and Civil Engineering

As we all know,the construction and construction process of civil engineering projects are very complicated,so coordination and cooperation of different professions and types of work are required during construction.Based on this,the article focuses on the strategy of equipment installation engineering and civil engineering construction cooperation from different construction stages and hopes to help.

Key Points of Installation Technology and Analysis of Energy Saving Measures on HVAC Equipment

HVAC equipment is very concerned in the current equipment operation process.Its safety,reliability and comfort will have a greater impact on the production and life of common people.In some projects,there are some problems in the installation of HVAC equipment,such as imperfect installation scheme,low installation quality and random selection of equipment parameters.These seriously affect the normal operation of the equipment,and it is not easy to achieve energy saving of HVAC equipment.In the future installation of HVAC equipment,it is necessary to continuously optimize the HVAC equipment installation system,fully compare the reliability and feasibility of the equipment installation scheme,and strengthen the application of energy-saving technology of HVAC equipment.In this way,the use cost of the equipment can be reduced and the comprehensive quality of the equipment can be improved.Therefore,this paper discusses this further and puts forward reasonable suggestions.

Research of Personnel Operational Ability Evaluation of Large-scale Complex Equipment

The level of personnel operation ability determines the expected effectiveness of large-scale complex equipment. Firstly, this paper constructs the personnel operational ability evaluation index system and analyzes the data source of index. Secondly, the weight of index is determined and the fuzzy comprehensive evaluation model is proposed. Finally, results of instance analysis show that the evaluation model is feasible and effective.

大型发电设备装配场地的设计及安装

本文根据目前大型发电设备装配场地水平精度低,承载能力差,适应产品变化能力弱,可移动起吊设备挪位安装困难等问题,提出了新的建造技术方案,保证了后继电站三大主机设备优质、高效装配的需要。

基于线上线下教学的实践性教学研究

机电设备安装与调试课程的实践性较强,其内容包括机械设备的安装与调试和电气设备的安装与调试。实践性较强的课程单纯采用线上教学模式或者线下教学模式,教学效果都不是很理想。线上线下的教学模式融合了线上教学和线下教学的优点,有效弥补了传统教学模式下的缺陷。机电设备安装与调试课程采用了线上线下的教学模式,提高了教学效率和教学质量,取得很好的教学效果。在互联网信息化背景下的新型教学方式,可以在职业院校开设的其他实践课程中推广。

周期桁架结构设计及振动特性分析

为解决船舶动力系统低频振动噪声问题,本文基于声子晶体局域共振理论,设计了一种带周期振子桁架式浮筏结构。利用有限元法和Bloch理论,分析了周期振子桁架产生带隙的原因,讨论了振子质量、安装形式和桁架结构参数对带隙特性的影响规律,设计了周期振子桁架振动特性试验,探究了桁架结构振动传递特性。结果表明:振子质量越大,带隙宽度增加,胞元尺寸越大,带隙带宽减小;振子排列方式对带隙特性影响较小,增加振子数量,宽带特性显著;采用振子间隔安装方式,相较全安装方式,带隙特性变化较小,可有效减少振子数量。

瓦里安后装机GammaMedplus ix常见故障分析处理

日常使用瓦里安后装机时的故障主要为:网络传输故障,服务器故障、放射源驻留点故障,放射源卡等,其中最常见的为网络故障。本文归纳分析了瓦里安后装机GammaMedplus ix日常工作中4种常见的故障和处理方法,这几种方法在临床实际工作中有效且实用,可以较迅速解决日常工作中常见的一些故障。

制浆造纸设备精密放样测量及安装研究

随着制浆造纸工业快速发展,对设备精度要求越来越高,因此精密放样测量及安装成为关键的技术环节。为此,主要研究制浆造纸设备精密放样测量及安装的方法和技术。通过使用高精度的测量仪器和先进的测量技术,准确地测量出设备的尺寸和位置,确保设备的安装质量。经过实践证明,所提出的方法可以达到较高的测量精度和安装质量,有效提高制浆造纸设备的生产效率和产品质量。

煤矿井下机电设备的安装与维护

主要探讨了煤矿井下机电设备的安装与维护。分析了煤矿井下机电设备安装与维护对采煤工作的意义,指出了机电设备安装与维护中存在的问题,介绍了机电设备的安装流程和维护方法,旨在提高煤矿井下机电设备的安装与维护水平,确保煤矿采煤工作的顺利进行。

精密放样测量在造纸专业设备安装工程中的应用对策

在现代造纸技术朝着高速化、大型化的方向发展背景下,传统设备安装方法已经无法满足实际需求,因此,需要对全新的安装与放样测量方法展开研究。放样为精密工程测量中的主要工作,放样点位能够为工程施工提供重要基础,也会直接影响工程质量。随着新设备、新技术的不断发展,精密工程放样测量技术也在不断更新和发展,有效提高了工程的质量和效率。造纸行业中设备的安装要通过精密测量,假如前期无法根据设计精度安装,就会影响到后续部件安装,所以要严格执行标准规范,使用合理的测量措施对安装中的问题进行解决,保证施工能够顺利开展。将精密放样测量应用到造纸行业中,能够满足造纸专业设备的技术需求。

220kV变电站变压器现场安装技术

在220 kV变电站建设工程中,电气设备安装是极为重要的一环。变压器作为220 kV变电站的核心,安装过程较为复杂,安装精准度有着更为精确的规定,将其安装技术措施落到实处,是确保220 kV变电站正常投产投运的基础条件。

海上风电机组吊装技术研究

在海上风电产业大力发展的过程中,风电机组吊装作业成为制约海上风电场建设施工的关键环节之一,其中海域环境的复杂多变性、选用船舶设备的适应性、安装工艺流程的科学性等因素均决定着风电机组安装的成败。基于江苏启东某海上风电工程,充分考虑了工程海域的潮位、潮流特征等海洋气象环境的影响,选择并校核了风电安装船等船舶设备的性能适应性。同时在开阔海域下,探讨了施工前的准备作业以及风机吊装施工流程的优化,包括对塔筒、机舱、轮毂和叶片等附件预拼接作业进行了阐述,其中重点分析了塔筒吊装、机舱-轮毂组合体吊装以及风机叶片吊装的安装精度控制措施。该工艺流程有效保证了风机吊装作业满足设计和规范的要求,同时也提高了风机安装的施工精度与效率,旨在为后续海上风电工程的发展提供参考。

机械工程自动化设备安装技术研究

近年来,我国在经济建设和科学技术发展上取得了重大成果,带动了诸多行业的发展。工程自动化行业就是其中之一,基于自动化技术的相关机械设备也在各行业进行了大范围应用,并取得了良好的效果。文章围绕机械工程自动化设备安装技术进行了研究,分析了机械工程自动化设备的性能及常规安装流程,并重点阐述了机械工程自动化设备安装技术要点,包括组装自动化系统、机械设备焊接检测、机械设备安装调整等,旨在提高设备工作效率,减少故障和延长设备的使用寿命。

电厂电气二次设备安装及其质量控制探讨

在电厂建设中,电气二次设备的安装和质量控制是保障电厂安全稳定运行的重要环节,电气二次设备承担着监测、控制和保护电力系统的重要任务,它的质量也会与电厂的运行效率产生直接的关联。文中主要分析了电厂电气二次设备安装过程中的挑战,根据挑战还提出了有效的质量控制措施,希望可以为电厂建设提供有益的参考,使得电厂设备安装符合标准并能够可靠运行。