变频调速在污水提升泵上的节能应用

概述变频调速控制原理 ,介绍了污水处理厂在污水提升泵上应用变频调速 ,分析了采用变频调速可达到的显著的节能效果。     

变频调速供水系统的节能控制

变频调速供水系统在居住小区、高层建筑得到大量采用。本文分析了变频调速供水系统在不同控制策略下的节能效果 ,提出了采用变压变流量变频调速控制的新模式。并结合工程实际 ,提出了实施方案。     

单变频器控制一用一备水泵的策略分析及其应用

介绍采用1台变频器控制应用于一用一备的2台凝泵变频调速控制热井水位的可行性及控制策略分析,比较各种方案的优劣,以及变频调速的节能情况和应用效果.     

空压机变频调速在铁路系统的应用和节能效果

铁路系统广泛使用的空压机应用变频调速技术改造控制方法效益明显。对机务、车辆部门空压机工作特性和存在问题进行分析 ,提出变频调速系统的改进方法 ,认为对铁路系统空压机采用变频调速技术 ,可以显著地改善空气压缩机的供风质量和节约电能。     

变频调速节能技术在我厂的应用

1变频调速的优点在水泥行业中，有许多设备、工艺过程及生产线，都需要采用调速控制装置。调速方法有许多种，如：调压调速，电磁转差离合器调速，串级调速，改变极对数调速，变频调速等。其中变频调速是众多方法中较好的一种。它的优点是无附加转差损耗，效率高，调速范围宽，     

深井直接供水变频调速控制系统的探讨

本文在对深井直接供水系统压力变化分析的基础上，说明了该系统变频调速控制的必要性，阐述了变频调速供水原理，并提出了深井直接供水变频调速控制的效益分析。     

变频调速技术的发展及其在电力系统中的应用

从电力半导体、控制技术和主电路拓扑结构等方面综述了变频调速技术的发展历史和现状,并总结了在变频控制中的主要控制技术;分析了高压变频调速技术的发展动态和几种实现方案的技术特点对比情况;指出变频调速技术在未来的发展趋势。最后介绍了变频调速技术在电力系统中节能降耗、改善工艺和控制性能等方面的应用。     

变频调速控制器与节电

本文阐迷了变频调速控制器的性能，电机调速的几种方式和变频调速的节电特性及其在热电联供电站锅炉燃烧控制中的应用。表明用变频调速节电效果十分显著。     

轧机循环供水的节能改造与应用

本文针对水泵运行特点，提出采用变频调速技术进行分档调速和控制，节电效果明显，并实现无人值守。     

应用变频调速技术节能降耗成果显著

我公司是福州市工业企业中的创利大户,但同时也是用电大户。公司在满负荷生产情况下,日用电量在30万kWh左右。因此降低成本,节能降耗是我公司节能工作中的一个重点。随着变频技术的不断发展特别是大功率晶体管和大功率可控硅问世以来,大功率的变频技术得到广泛应用。采用变频调速技术,能够准确、直观地控制电机转速并且可以实现采用计算机的自动化控制,起到了节能降耗,提高经济效益的重要作用。从1997年开始,组织实施应用变频调速技术,投入资金150万元,陆续在循环水泵、发酵罐和干燥塔等设备上采用变频调速技术,两年多来实际效果显著,为公…     

Control relevant modeling of planer solid oxide fuel cell system

This paper provides two types of control relevant models of planer solid oxide fuel cell system with different details. Dynamic models of system components which include heat exchanger, reformer and after-burner are also provided along with the necessary formulation of a fuel cell connected in parallel with a capacitor. Steady-state and dynamic simulations of fuel cell system for both types of models are performed. The results indicate that both models are comparable in predicting stack voltage at lower current load. But, the discrepancy in the stack voltage, power and temperature of different components become more prominent at higher current load.     

The equivalent model of controller in synchronous frame to stationary frame

The system controlled in synchronous frame is commonly used. However, it is a problem how to transform the controller in synchronous frame to stationary frame. This paper deduces the stationary frame equivalent model of arbitrarily controller in synchronous frame. The equivalent model can reflect the control performance of the input signal at different frequency accurately. The unified frequency-domain model of the overall system can be established using the equivalent model, and the guidance for frequency analysis and stability analysis can be provided. Theoretical derivation and simulation results verify the correctness and generality of the equivalent model.     

Effect of frame material on the creep of solid oxide fuel cell

During long term operation at high temperature, creep is inevitable and can cause damages and cracks, which should be decreased to ensure the stack integrity. A strain based creep damage model is used to predict the creep damage behavior of a planar solid oxide fuel cell (SOFC). It demonstrates the maximum creep damage locates at the corner of glass-ceramic (GC) facing the frame after 50 000 h creep. The effect of frame material on the creep is studied. By increasing the creep parameter B of frame, the creep and damage in the cell and GC are decreased. This indicates the frame with a larger creep parameter can alleviate the interaction between components and decrease the deformation of the system. It recommends to use frame materials which have creep parameters larger than 1.3752 × 10⁻¹⁵ MPa^-nh⁻¹ besides CTEs closed to the cell to compensate and mitigate the creep and damage of SOFC system.     

Study on the degradation mechanism of the frame for membrane electrode assembly in proton exchange membrane fuel cell

The membrane electrode assembly (MEA) in the proton exchange membrane (PEM) fuel cell needs to be encapsulated by a frame to improve its assembly strength and sealing performance. However, irreversible degradation usually occurs to invalidate the frame and cause the fuel cell fail. In this study, a series of experiments are conducted to simulate operating environment in the fuel cell, and degradation mechanism of the frame is explored. Changes of tensile strength, peeling strength, shearing strength, and bending strength are adopted to evaluate the frame stability, and effects of temperature, water, and acid on these indexes are quantified. It is found that the peeling strength has the most significant decline, which is the primary failure form of the frame. Acid solution provides the main contribution to this failure. In acid solution, hydrogen ions and water molecules permeate the frame, resulting in rapid degradation and separation of the bonding interface. This study reveals the degradation process of the frame for the first time, and helps enhance our understanding of the frame failure.     

PG9171E燃气轮机排气框架的冷却及故障分析

某300MW燃气—蒸汽联合循环电站由两台100MW等级的燃气轮机发电机组、一台100MW蒸汽轮机发电机组及两台立式、无补燃、单压余热锅炉组成。燃气轮机是由美国GE公司提供的PG9171E机组。由于燃气轮机的燃烧和排气温度都相当高,因此,对热部件来说有一套高效的冷却系统是相当重要的;     

轨道激励频率对转向架侧架动应力影响的研究

采用车辆动力学和有限元分析技术,应用车辆动力学有限元集成模型,以轨道垂向不平顺为研究对象,获得侧架轨道垂向不平顺激励下的动态载荷与激励频率的对应关系,而后将动力学仿真获得的侧架弹簧承台面上的9组垂向载荷一时间历程作为栽荷边界条件施加到侧架有限元模型上,使用结构动力学分析方法分析轨道垂向不平顺激励频率对侧架动应力的影响。研究结果表明,9．25—16．67m之间的轨道波长对侧架关键部位的最大动应力影响比较大。因此,考虑轨道激励频率对车辆零部件动应力的影响是很必要的。     

HX_N5型机车转向架构架研制

介绍了HXN5型机车转向架主要参数,构架的结构设计、材料要求及试制、试验情况。     

CKD7F型机车转向架构架的改进

对资阳机车有限公司出口越南的第1批CKD7F型机车转向架构架裂纹原因进行了分析,在第1、2批现车构架局部补强的基础上对第3、4批CKD7F型机车转向架构架进行了改进设计,说明了新构架的结构组成及局部结构改进情况。有限元分析结果和机车实际运用情况表明,新构架的改进非常成功。     

数字化机务段的构架研究

提出了数字化机务段的概念和内函 ,数字化机务段系统的体系框架及技术体系框架 ,描述了数字化机务段的主体内容及相互之间的关联。     

转向架构架柔度对构架垂向动态载荷影响的分析

运用刚-柔耦合动力学方法,通过有限元软件ANSYS和多体动力学软件SIMPACK,分别考虑构架刚性、柔性,建立两种完整机车动力学模型。在改变直线上机车运行速度、一系垂向刚度值以及使机车通过曲线段等多种工况下,对基于弹性变形的构架动态载荷进行分析,为进一步对构架疲劳寿命分析提供依据。研究结果表明,相对构架刚性处理,考虑构架柔性可以改善构架一系垂向动态载荷,但一系垂向力主频范围较刚性处理时要宽。另外,基于刚-柔耦合计算方法对柔性构架研究具有借鉴意义。