消失模工艺铸造耐热铸铁风帽

采用消失模工艺铸造耐热铸铁沸腾燃烧炉风帽。RTSi-5．5耐热铸铁采用中频感应炉熔炼，铸造工艺为多个铸件排成长列，每只砂箱埋二层铸型，生产效率高；采用浇注系统补缩，补缩效果好；铸件表面质量明显改善。     

Real-time comparison of a number of predictive controllers

Many model predictive control (MPC) algorithms have been proposed in the literature depending on the conditionality of the system matrix and the choice of its cost-function. This paper presents the newer MPC schemes such as extended predictive control (EPC) and shifted MPC as well as other well known forms. The control performance of these controllers are compared using two systems that are slow and fast reacting. The closed-loop responses are compared and the differences and similarities are explained on the basis of the structure of the control schemes. Disturbance rejection and the tracking of various setpoint trajectories are performed with good closed-loop results from all the controllers. It was found that the controllers that were specifically designed to reduce the system matrix ill-conditionality such as EPC and generalized predictive control provided better control performance when compared to other MPC methods.     

Software‐defined networking approach for enhanced evolved packet core network

The evolved packet core (EPC) network is the mobile network standardized by the 3rd Generation Partnership Project and represents the recent evolution of mobile networks providing high‐speed data rates and on‐demand connectivity services. Software‐defined networking (SDN) is recently gaining momentum in network research as a new generation networking technique. An SDN‐based EPC is expected to introduce gains to the EPC control plane architecture in terms of simplified, and perhaps even software‐based, vendor independent infrastructure nodes. In this paper, we propose a novel SDN‐based EPC architecture along with the protocol‐level detailed implementation and provide a mechanism for identifying information fields exchanged between SDN‐EPC entities that maintains correct functionality with minimal impact on the conventional design. Furthermore, we present the first comprehensive network performance evaluation for the SDN‐based EPC versus the conventional EPC and provide a comparative analysis of 2 networks performances identifying potential bottlenecks and performance issues. The evaluation focuses on 2 network control operations, namely, the S1‐handover and registration operations, taking into account several factors, and assessing performance metrics such as end‐to‐end delay (E2ED) for completion of the respective control operation, and EPC nodes utilization figures.     

5G核心网服务化架构研究

随着软件定义网络(SDN)和网络功能虚拟化(NFV)技术在移动核心网的应用,传统4GEPC正逐渐实现软硬件解耦,并将以服务化架构(SBA)为目标进行自我重构。文章主要分析研究5GCSBA架构的相关技术、特点及重要功能,为运营商核心网向5GCSBA架构的演进部署提供参考。     

东芝三菱高压变频器在电厂600MW发电机组给水泵上的应用

本文简单介绍了大功率高压变频器在600MW机组电厂给水泵的应用。也简要介绍了该变频器的特点,以及在EPC项目中重点解决的一些难题。整个工程采用EPC方式,包括液力耦合器的改造和空水冷却器。     

杨房沟水电站EPC模式下工程变更管理

在工程建设发展的今天,EPC总承包模式是大势所趋。杨房沟水电站开创了国内百万千瓦级大型水电站EPC模式建设的先河。EPC模式下的变更管理是一项重要的管理工作,从工作界面划分、设计深度、招标范围、风险转移等方面,对该工程EPC模式下的工程变更管理进行了思考和总结,希望为类似工程提供有益参考。     

水电工程EPC项目设计监理工作探讨——以杨房沟水电站设计监理为例

目前,工程建设领域在大力推行EPC建设模式和全过程咨询服务,新的建设模式对工程建设监理和技术咨询提出了更高的要求,也为工程咨询行业发展提供了契机。结合杨房沟水电站设计监理工作,对EPC模式下的设计监理工作进行探讨,介绍了杨房沟水电站EPC项目设计监理工作内容、职能定位、工作方式、工作成效和存在的主要问题。设计监理作为总承包监理的重要组成部分,具有设计管理、设计审查和设计咨询3个方面的职责,组织机构和制度建设是做好的设计监理工作的基础,采用现场工作和后方工作相结合的方式,充分利用网络视频、BIM系统进行设计监理,可以大大提高工作效率。另外,还对EPC模式下设计监理工作提出了建议,可为同类工程提供参考。     

大型水电工程总承包跨越式发展浅论

在国家加快推行工程总承包建设大环境下,推行大型水电工程总承包建设模式是必然趋势。介绍了杨房沟水电站总承包建设管理3 a来所取得的成效;针对该水电站建设管理中存在的组织结构调整、总承包内部管理体系建设推进缓慢,复合型人才严重缺乏,考核激励机制不完善等问题,探讨了大型水电工程总承包跨越式发展思路与方法;提出了加快企业转型、推动技术创新应用、转变监理服务理念等建议。可为类似工程推进总承包建设管理提供借鉴。     

Research on structural compatibility of eco-porous concrete and vegetation

To investigate the structural compatibility of eco-porous concrete (EPC) and vegetation, a simulation method (sand penetration coefficient) of structure compatibility between the eco-porous concrete (EPC) and vegetation was put forward. Furthermore, the relation between sand penetration coefficient and pore characteristics were analyzed, and the technology of acquiring equivalent pore size was optimized. The results present that the new simulation method, characterized by sand penetration coefficient, can effectively assess the ability of eco-porous concrete (EPC) to allow the root system to pass through. In addition, the real pore structure shape by “rubbing technology” can be easily and quickly obtained.     

Analysis of synergy degree and its influencing factors in hydropower EPC project management

The use of engineering procurement construction (EPC) mode is currently a trend in hydropower engineering construction. The clarification of the internal relationship between hydropower EPC projects and the realization of synergy has great significance in improving management efficiency and implementation effect. In this work, a three-dimensional system and a system model of hydropower EPC project management synergy are constructed. The mechanism and factors that influence the degree of management synergy are analyzed on the basis of management synergy theory. Furthermore, the evaluation index system and the degree of synergy model are established, and grey relational analysis is utilized to identify the key factors that affect the synergy degree. Thus, this study aims to facilitate the hydropower EPC project management synergy, provide a quantitative method for synergy degree evaluation, and propose corresponding promotion strategies. Results show that the order degree of each subsystem presents a steady upward trend. Specifically, the order degree of the subsystem at the trial operation stage is low, which is the major restriction on the further improvement of the synergy degree of EPC project management. The key factors in improving the synergy level of hydropower EPC project management are mainly concentrated in the information and organization synergy subsystems, including the construction degree of information platform, the performance of functions, the timeliness of information transfer, and the functions of the information platform.