300MW汽轮机采用最新通流技术改造的结构分析

介绍了上海汽轮机厂对上世纪80年代引进美国西屋公司的300 MW亚临界汽轮机进行通流部分改造的方案。改造后机组采用先进的AIBT通流技术,结构部件进行了较大的优化,如调节级逆流改为顺流的优化、高压蒸汽室的优化,整体高压内缸的全新设计优化等。机组投运后表明,改造对提升机组性能有明显的效果,机组运行稳定、灵活,热经济性得到提高。

火电厂1000MW汽轮机通流技术改造

汽轮机是火力发电机组重要的组成部分,其性能的好坏直接影响发电的质量和效率,但是在火电厂1000MW汽轮机通流部分还存在一定的问题。针对火电厂1000MW汽轮机通流技术改造进行分析,剖析改造效果。

GE公司汽轮机通流技术的进展

本文叙述ＧＥ公司在改进汽轮机性能方面的一系列新的通流设计的特点。讨论了这些新特点对新机组和现有机组改造所带来的好处。此外，本文还讨论了用开发新设计概念的最近产生的三维粘性ＣＦＤ分析规范：叙述了为验证ＣＦＤ规程及用新设计特点后对效率收益所作的预测而进行的实验室试验规划。最后，讨论了ＧＥ公司为使先进的气动设计显著缩短周期而开发的新的独特的现代化通流设计自动化和优化工具。

基于透平通流化技术的BPRT机组提效改造

本文研究了基于透平通流化技术的BPRT机组提效改造项目,该机组是高炉鼓风机和高炉煤气余压透平发电装置的高炉二次能源回收装置。通过建立透平效率监测平台,发现机组运行效率低,影响了能耗,采取了一系列措施来提高透平运行效率。具体措施包括建立透平效率监测平台、学习对标锭鑫钢铁BPRT改造项目、优化透平设计等。通过这些改进,透平机组的运行效率提升至83%。还优化了透平效率监测平台,实现了机组效率的实时监控和报警提示功能。该项目的创新点在于首次引入效率监测管理理念,建立了大型用能设备的在线效率监测平台,为类似机组的改造提供了借鉴。

基于轴承跨距限制的高中压通流宽负荷提效技术研究及应用

从通流型式的选择、高效叶型的选型、回热系统的优化、叶型端壁的优化、通流汽封技术、精细化通流能力选型设计优化以及回热系统设计原则分析等几方面对基于轴承跨距限制的高中压通流宽负荷提效技术进行研究。基于轴承跨距限制的高中压通流宽负荷提效技术可迅速推广到同类型机组的升级改造应用当中,推动了国内1000MW等级汽轮机的优化升级进程。

基于通流CFD方法的涡轮可控涡设计研究

为进一步实现高性能涡轮精准气动设计、提升涡轮效率,基于Euler方程通流计算流体力学(computational fluid dynamics,CFD)技术发展了控制叶排出口环量的涡轮可控涡设计方法。设计方法通过时间推进法求解二维流动方程,采用具有TVD性质的三阶精度Godunov格式,时间方向按显式-隐式交替求解。损失系数通过模型计算后在径向重新分布,在给定叶排出口环量分布后涡轮气动设计开始进行。利用设计方法对某型航空发动机单级涡轮进行了自由涡和可控涡设计,并利用三维CFD方法验证气动性能。通过对比分析,可以发现设计方法可以有效实现可控涡设计。相比三维模拟结果,通流结果流量误差在0.2%左右,膨胀比误差在-0.02左右,效率误差不超过0.77%;可控涡设计比自由涡设计效率更高,转子叶根反力度更高,叶排根部二次流和流动分离更弱、损失更低。

高压100MW汽轮机通流改造技术及热力性能试验分析

针对目前在运高压100MW机组经济性差的问题，东方汽轮机厂采用现代化通流技术对其进行改造以达到节能降耗的目的，先后在山西霍州发电厂，新疆玛纳斯发电厂实施了现代化改造。改造后按照ASME PTC6．0进行了热力鉴定试验，均达到了预期效果，本文主要介绍东方汽轮机厂在对新疆玛纳斯发电厂100MW机组改造后的热力试验情况。

亚临界煤电机组增容提效技术及性能考核试验

为助力国家“双碳”目标的如期实现,对煤电机组进行升级改造已成为国家在能源电力领域的重要举措。以某电厂一台亚临界600 MW煤电机组为例,针对增容提效改造目标,采用先进的AIBT通流改造技术和辅机节能技术对机组实施改造,并对增容提效改造后的煤电机组进行性能考核试验,对比分析改造前后机组的热经济指标。结果表明:机组容量从600 MW增容至630 MW,额定负荷下热耗率降至7726.03 kJ/(kW·h),比改造前降低了500.17 kJ/(kW·h),低于改造目标值;供电标准煤耗降至289.68 g/(kW·h),较改造前降低了7.5%。该亚临界600 MW机组的增容提效改造案例可为煤电机组的安全节能升级改造提供借鉴和参考。

东汽第八代300MW汽轮机设计技术特点

东汽第八代300MW汽轮机在消化吸收国外先进技术的基础上，采用当代先进的通流技术和结构设计技术，通过理论分析和试验研究，解决了原机组存在的问题，提高了机组的经济性、可靠性和安全性。文章详细介绍了东汽第八代300MW汽轮机的设计技术特点。

超临界600MW机组汽轮机升参数改造

为了提高某电厂引进型超临界600MW机组汽轮机运行的经济性,采用第三代高效冲动式汽轮机通流技术,结合提升主蒸汽参数、进排汽流道优化和汽封结构优化等措施对该汽轮机进行改造。热力性能试验结果表明:改造后汽轮机的效率和热耗率优于设计值,达到了国内先进水平。

优秀组织者代表发言 把企业的目标转化为科技工作者自觉的行动

东汽从上个世纪80年代末开始，开展“讲、比”活动至今已经23年了，在这23年中，“讲、比”与东汽精神形成了精神动力，使来自五湖四海的科技工作者扎根山区，创造出了自主研发成功世界首创的一百万超超临界通流技术和建厂从没有过亏损的神话。一代又代科技工作者成长起来，我也从“讲、比”活动的参加者转变为了组织者。

超超临界机组汽轮机热力性能优化设计探讨

基于第三代通流技术,研究超超临界机组汽轮机新一代通流技术;结合二次再热技术,选取相关参数进行研究分析。结果表明:采用新一代通流技术和二次再热技术,机组的热力性能得到提高,汽轮机效率提高0.5~1.0百分点。

大型单轴1350 MW机组的设计研究

目前,660 MW、1000 MW等级超超临界机组已相继在火电厂投产,为获得更好的经济效益,对1350 MW等级机组进行了设计与应用研究,从相关技术方案、材料、通流、末级叶片等方面确定了一系列设计方案,通过方案比选和优化设计,所研制的1350 MW机组比常规机组在进汽参数、机组效率、安全性和经济性等方面有了明显提高,为我国大型汽轮机的设计和制造提供了借鉴。

GPSA:A Greedy Pull-based Scheduling Approach for P2P Live Streaming under Heterogeneous Environments

Pull-based P2P live streaming is a promising solution for the large scale streaming systems, like PPStream, PPlive, due to its high scalability, low cost and high resilience. However, they usually suffer from bad delay performance. In this paper, we seek to improve the delay performance under ensuring video display quality stemming from chunk scheduling. And so we model Pull-based chunk scheduling problem as a multi-objective optimization problem to minimize the video delay and maximize video display quality in the environment of heterogeneous upload bandwidths, heterogeneous and dynamic propagation delays. Finally we put up with a greedy Pull-based scheduling approach(GPSA) to solve the optimization problem. The evaluation shows GPSA can outperform two classical chunk scheduling approaches and adapt to dynamic variance of propagation delays.

A two-stage short-term traffic flow prediction method based on AVL and AKNN techniques

Short-term traffic flow prediction is one of the essential issues in intelligent transportation systems(ITS). A new two-stage traffic flow prediction method named AKNN-AVL method is presented, which combines an advanced k-nearest neighbor(AKNN)method and balanced binary tree(AVL) data structure to improve the prediction accuracy. The AKNN method uses pattern recognition two times in the searching process, which considers the previous sequences of traffic flow to forecast the future traffic state. Clustering method and balanced binary tree technique are introduced to build case database to reduce the searching time. To illustrate the effects of these developments, the accuracies performance of AKNN-AVL method, k-nearest neighbor(KNN) method and the auto-regressive and moving average(ARMA) method are compared. These methods are calibrated and evaluated by the real-time data from a freeway traffic detector near North 3rd Ring Road in Beijing under both normal and incident traffic conditions.The comparisons show that the AKNN-AVL method with the optimal neighbor and pattern size outperforms both KNN method and ARMA method under both normal and incident traffic conditions. In addition, the combinations of clustering method and balanced binary tree technique to the prediction method can increase the searching speed and respond rapidly to case database fluctuations.

Integrated LOBS/GMPLS Network Testbed

In the context of dynamic telecommunication traffic requirement, experimental prototypes and testbeds have been vital and challenging steps towards achieving practical OBS networks. This paper presents the novel integrated LOBS/GMPLS network testbed. Dynamic interworking technologies between GMPLS network and LOBS network and potential survivability schemes in this multilayer network are investigated by experimentally evaluating the TCP and popular streaming media service performance over an integrated LOBS/ GMPLS testbed.

A framework for interoperability of BPEL-based workflows

With the prevalence of service-oriented architecture （SOA）, web services have become the dominating technology to construct workflow systems. As a workflow is the composition of a series of interrelated web services which realize its activities, the interoperability of workflows can be treated as the composition of web services. To address it, a framework for interoperability of business process execution language （BPEL）-based workflows is presented, which can perform three phases, that is, transformation, eonformance test and execution. The core components of the framework are proposed, especially how these components promote interoperability. In particular, dynamic binding and re-composition of work-flows in terms of web service testing are presented. Besides, an example of business-to-business （B2B） collaboration is provided to illustrate how to perform composition and conformance test.

Effects of behavioral characteristics of taxi drivers on safety and capacity of signalized intersections

Comparative analyses were conducted to compare the effects of the behavioral characteristics of the drivers of taxis and private cars on the capacity and safety of signalized intersections. Data were collected at sixteen signalized intersections in the Nanjing area in China. The risk-taking behaviors of the drivers of taxis and private cars were compared. The results suggest that 19.9% of taxi drivers have committed at least one of the identified risky behaviors, which is 2.37 times as high as that of the drivers of private cars(8.4%). The traffic conflicts technique was used to estimate the safety effects of taxis and private cars. The overall conflict rate for taxis is 21.4% higher than that for private cars, implying that taxis are more likely to be involved in conflicts. Almost all of the identified traffic conflicts can be attributed to certain levels of risk-taking behaviors committed by either taxi drivers or the drivers of private cars, and taxi drivers are more likely to be at fault in a conflict. Failure to yield to right-of-way and improper lane change is the leading causes of the conflicts in which taxis are at-fault. The research team further studied the effects of taxis on the queue discharge characteristics at signalized intersections. The results show that the presence of taxis significantly reduces both start-up lost time and saturation headways. The effects of taxis on saturation flow rates are dependent on the proportion of taxis in the discharge flow, and the saturation flow rates increase with the increase in the proportion of taxis. The adjustment factors for various proportions of taxis for different turning movements are then calculated to quantitatively evaluate the effects of taxis on the capacity of signalized intersections.

Flavor-Changing Bottom-Strange Associated in the Littlest Higgs Model with T-parity at the ILC

In the littlest Higgs model with T-parity(LHT) the mirror quarks induce the special flavor structures and some new flavor-changing couplings,which could greatly enhance the production rates of the flavor-changing processes. We in this paper study some bottom and anti-strange production processes in the LHT model at the International Linear Collider(ILC),i.e.,e^+e^-→bs andγγ→bs.The results show that the production rates of these processes are sizeable for the favorable values of the parameters.Therefore,it is quite possible to test the LHT model or make some constraints on the relevant parameters of the LHT through the detection of these processes at the ILC.