运行性能优化系统在火电厂600 MW机组上的应用

简述了北仑电厂二期600MW机组的基于DCS系统的运行性能优化系统。通过对机组运行参数及性能参数进行耗差分析,试系统对运行人员进行实时的调整指导,使机组运行的经济性得以提高,有利于电厂的节能降耗。

锅炉性能优化系统“SOAP”降低氮氧化物排放应用试验

"SOAP"性能优化系统,是由运行关键参数监测设备和性能优化软件两部分组成。该系统突破传统优化理念,以试验设计和专家系统为核心,利用人工智能神经网络、统计回归分析和模糊数学理论建立多输入变量与多目标之间的非线性数学模型,对锅炉性能进行全面优化,找出通过燃烧调整降低锅炉氮氧化物排放量的关键参数。

锅炉性能优化系统在680MW超超临界机组的应用

以某电厂超超临界680MW机组锅炉为研究对象,对锅炉运行可调参数进行全面优化试验,取得反映该锅炉运行特性的数据,利用锅炉性能优化系统(SOAP)对试验数据进行筛选,通过人工智能神经网络技术建立优化运行数学模型,全面协调和优化锅炉系统的运行经济性与可靠性指标,创建该锅炉系统各种负荷下的最佳运行方式。

混合构架下医院信息系统的ORACLE性能优化

ORACLE数据库是现在各大中型医院的主要数据库系统。随着医院信息化的深入,现在的医院信息系统的架构已不是单一的一种架构,而是C/S架构与B/S架构及基于中间件的多层架构共存的混合架构。这种混合架构下的医院信息系统,对ORACLE数据库的优化提出新研究内容。本文结合医院信息系统的实例入手,从综合角度较全面提出一种混合架构下的医院信系统ORACLE性能优化的方法及技巧。

基于激光冲击的航空发动机风扇性能优化设计

航空发动机风扇性能是整个发动系统的核心,为了优化航空发动机的性能,提出一种基于激光冲击的航空发动机风扇性能优化系统设计方案。系统采用嵌入式设计技术,采用激光冲击技术进行航空发动机风扇性能相关参数检测,进行航空发动机风扇智能控制算法设计。结合传感器分布式检测技术进行航空发动机风扇转动状态测试,对航空发动机风扇性能优化系统的模块设计包括AD模块、智能信息处理模块、集成控制模块、激光冲击时钟控制模块、中断模块以及复位模块组成,采用激光冲击进行发动机风扇性能的智能监测和状态模式识别,结合ADSP-BF537进行发动机风扇性能检测的数据分析和智能控制,实现系统硬件设计。测试结果表明,设计的航空发动机风扇性能优化系统能实时监测风扇状态特征,提高对发动机风扇的远程智能控制能力。

某商用车冷却系统一维数值分析与性能优化

利用一维数值分析与整车热平衡试验解决某车型发动机出水温度过高的问题。以整车许用环境温度为评价指标,考虑发动机台架热平衡数据为边界,搭建整车冷却系统换热分析模型并基于整车热平衡试验进行标定。通过分析得出风量是影响许用环境温度的主要因素,从风扇性能优化与空气侧流通条件改善两方面提高某车型许用环境温度。结果表明:外特性最大扭矩点工况下,新型无轮毂风扇提高许用环境温度2.5℃;前下挡网结构优化与空滤器右置方案分别提高许用环境温度1.7℃和2.4℃,经过优化该车许用环境温度满足设计要求。

建筑设计知识库——以楼梯间详图知识库及给排水系统的自动性能优化知识库为例

建筑行业信息化升级需从其源头——设计端提供统一的信息化模型。文章介绍的建筑设计知识库,提出了建筑设计行业数智化转型的解决方案,一方面可以帮助建筑行业从源头建立信息化模型,一方面可以帮助建筑设计企业完成从项目导向产品导向的生产模式的转变。本文将通过楼梯间详图知识库及给排水系统的自动化性能优化知识库为例具体阐述建筑设计知识库的架构与实现。

基于SPSA的蒸汽发生器液位MPC系统性能优化方法研究

核电厂蒸汽发生器(SG)液位变化过程具有强非线性且存在“虚假水位”现象,传统SG液位控制系统多采用固定参数比例-积分-微分(PID)控制器,但传统PID控制方法不具备自优化、自适应、自学习等能力,使得控制系统性能难以达到并保持最佳。为提高机组瞬态响应能力以及核电厂的稳定性、安全性和经济性,提出了一种基于并行摄动随机逼近(SPSA)算法的模型预测控制(MPC)方法。该方法采用MPC系统代替传统PID控制系统,并利用SPSA实现液位控制系统参数的整定优化,从而实现SG液位控制系统的性能优化。通过仿真试验验证了本方法能够有效提高SG液位控制参数的整定效率以及控制系统稳定性。

Performance optimization of electric power steering based on multi-objective genetic algorithm

The vehicle model of the recirculating ball-type electric power steering (EPS) system for the pure electric bus was built. According to the features of constrained optimization for multi-variable function, a multi-objective genetic algorithm (GA) was designed. Based on the model of system, the quantitative formula of the road feel, sensitivity, and operation stability of the steering were induced. Considering the road feel and sensitivity of steering as optimization objectives, and the operation stability of steering as constraint, the multi-objective GA was proposed and the system parameters were optimized. The simulation results show that the system optimized by multi-objective genetic algorithm has better road feel, steering sensibility and steering stability. The energy of steering road feel after optimization is 1.44 times larger than the one before optimization, and the energy of portability after optimization is 0.4 times larger than the one before optimization. The ground test was conducted in order to verify the feasibility of simulation results, and it is shown that the pure electric bus equipped with the recirculating ball-type EPS system can provide better road feel and better steering portability for the drivers, thus the optimization methods can provide a theoretical basis for the design and optimization of the recirculating ball-type EPS system.

LISP-PCHORD:An Enhanced Pointer-Based DHT to Support LISP

Aiming to efficiently support theLocator/Identifier Separation Protocol(LISP),in this paper,we present an enhanced pointerbased DHT mapping system:LISP-PCHORD.The system creates a pointer space to build ontop of standard DHTs.Mappings within thepointer space are(Endpoint Identifiers(EID),pointers) where the pointer is the address ofthe root node(the physical node that stores themappings) of the corresponding(EID,RoutingLocators(RLOCs)) mappings.In addition toenabling architectural qualities such as scalability and reliability,the proposed LISP-PCHORDcan copy with flat EIDs such as self-certifyingEIDs.The performance of the mapping systemplays a key role in LISP;however,DHT-basedapproaches for LISP seldom consider the mismatch problem that heavily damages the system performance in terms of lookup latency.In order to mitigate the mismatch problem andachieve optimal performance,we propose anoptimization design method that seeks an optimal matching relationship between P-nodes(nodes within the pointer space) and the physical nodes on the basis of the given lookuptraffic matrix.In order to find the optimal matching relationship,we provide two solutions:a linear programming method and a geneticalgorithm.Finally,we evaluate the performance of the proposed scheme and compare itwith that of LISP-DHT.

Prediction of Cracking Gas Compressor Performance and Its Application in Process Optimization

Cracking gas compressor is usually a centrifugal compressor. The information on the performance of a centrifugal compressor under all conditions is not available, which restricts the operation optimization for compressor. To solve this problem, two back propagation (BP) neural networks were introduced to model the performance of a compressor by using the data provided by manufacturer. The input data of the model under other conditions should be corrected according to the similarity theory. The method was used to optimize the system of a cracking gas compressor by embedding the compressor performance model into the ASPEN PLUS model of compressor. The result shows that it is an effective method to optimize the compressor system.

Mobile Internet Applications：Impact on Future Wireless Communications System

Based on the analysis of application status in real network,the trace model of some typical mobile Internet applications data is given and their impact on 2G/3G network is discussed in this paper.Furthermore,in order to support the mobile Internet application efficiently in future,the issues including the impact on the Long Term Evolution (LTE-A) system and some potential solutions for performance optimization are studied.Based on the trace data model of IM traffic,the performacne evaluaiton of LTE-A system shows that some specific configuration machanisms can play an important role in improving network system efficiency in the case of IM traffic.

Parameter design and performance analysis of zero inertia continuously variable transmission system

In order to solve the problem of weak power performance of vehicle equipped with continuously variable transmission(CVT) system working under transient operating conditions, a new CVT equipped with planetary gear mechanism and flywheel was researched, a design method of transmission parameter optimization was proposed, and the comprehensive matching control strategy was established for the new transmission system. Fuzzy controllers for throttle opening and CVT speed ratio were designed, and power performance and fuel economy of both vehicles respectively equipped with conventional CVT system and new transmission system wrere compared and analyzed by simulation. The results show that power performance and fuel economy of the vehicle equipped with new transmission system are better than that equipped with conventional CVT, thus the rationality of the parameter design method and control algorithm are verified.

Performance Analysis and Framework Optimization of Open Source Cloud Storage System

More and more embedded devices, such as mobile phones, tablet PCs and laptops, are used in every field, so huge files need to be stored or backed up into cloud storage. Optimizing the performance of cloud storage is very important for Internet development. This paper presents the performance evaluation of the open source distributed storage system, a highly available, distributed, eventually consistent object/blob store from Open Stack cloud computing components. This paper mainly focuses on the mechanism of cloud storage as well as the optimization methods to process different sized files. This work provides two major contributions through comprehensive performance evaluations. First, it provides different configurations for Open Stack Swift system and an analysis of how every component affects the performance. Second, it presents the detailed optimization methods to improve the performance in processing different sized files. The experimental results show that our method improves the performance and the structure. We give the methods to optimize the object-based cloud storage system to deploy the readily available storage system.

Attitude control allocation strategy of high altitude airship based on synthetic performance optimization

This paper presents a method for solving the attitude control problem of high altitude airship (HAA) with aerodynamic fin and vectored thruster control. The algorithm is based on the synthetic optimization of dynamic performance and energy consumption of airship. Firstly, according to the system overall configuration, the dynamic model of HAA was established and the HAA linearized model of longitudinal plane motion was obtained. Secondly, using the classic PID control theory, the HAA attitude control system was designed. Thirdly, through analyzing the dynamic performance of airship with fin or vectored thruster control, the synthetic performance index function with different weighting functions was determined. By means of optimizing the obtained performance index function, the attitude control of high altitude airship with good dynamic performance and low energy consumption was achieved. Finally, attitude control allocation strategy was designed for the airship station keeping at an altitude of 22 km. The simulation experiment proved the validity of the proposed algorithm.

Simulation and Optimization of Furrow Irrigation by the Model SASlS： Sensibility to the Spatial and Temporal Weighted Factors

The surface irrigation systems are the most used not just in Brazil, but in the whole world mainly due to the economy of energy and its operation easiness; however, these systems present low levels of performance, usually, as a consequence of inadequate design and management. Thus, the objective of this research was to develop a tool capable to make possible the simulation and optimization of the continuous flow furrow irrigation performance, making successive simulations of the advance phase and respective prognostics of the performance parameters of the irrigation system. The proposed model is denominated SASIS, ＂Software Applied to Simulation of the Surface Irrigation＂, and had its validation tested for different field conditions. In this paper, the simulation and the optimization of the furrow irrigation by the model SASIS are evaluated regarding to the spatial （4） and temporal （0） weighted factors, which account for the nonlinear variation in the surface and subsurface flow profiles. The analysis of the sensitivity of simulation of the advance phase in the irrigation identified ranges of combinations between spatial and temporal weighted factors of the surface and subsurface flow profiles, resulted in acceptable discrepancies between simulated and measured advance time. Also it was verified that conjugated effect of these weighted factors on the simulation of the advance phase was greater than the effect of the temporal weighted factor. The model presents effective mechanisms in the accomplishment of countless simulations, in a discharge strip understood between the minimum and the maximum allowable values, aiming to determine the relationship between discharge and water application efficiency, deep percolation and runoff rates, and consequently to optimize the performance of the furrow irrigation systems with continuous flow.

Energy Saving for Automatic Train Control in Moving Block Signaling System

With rapid development of the railway traffic, the moving block signaling system （MBS） method has become more and more important for increasing the track capacity by allowing trains to run in a shorter time-headway while maintaining the required safety margins. In this framework, the tracking target point of the following train is moving forward with its leading train. This paper focuses on the energy saving tracking control of two successive trains in MBS. Nonlinear programming method is used to optimize the energy-saving speed trajectory of the following train. The real-time location of the leading train could be integrated into the optimization process. Due to simplicity, it can be used for online implementation. The feasibility and effectiveness are verified through simulation. The results show that the new method is efficient on energy saving even when disturbances present.

TBM Construction Process Simulation and Performance Optimization

Long tunnel excavation with tunnel boring ily affected by uncertainties and needs to be adjusted machine （TBM） is a complex and stochastic process. It is eas- according to specific geological conditions in different tunnel sections, which makes the construction scheduling and management difficult. Based on the rock mass classification, this paper estimates the penetration rate. Using the rate, a cyclic network simulation （CYCLONE） model of TBM boring system is established, and the advance rates under different geological conditions are determined. Then, the impact of different cutter head thrust, which is chosen in reasonable range according to previous experiences, on pro- ject schedule is analyzed. Moreover, the simulation model of mucking system is built to determine the number of muck trains and rail intersections reasonably, regarding the efficiency of muck loading and material transporting. Based on the interaction and interrelation between TBM boring system and mucking system, the combined CY- CLONE model for the entire tunneling process is established. Then reasonable construction schedule, the utilization rate of working resources, and the probability of project completion are obtained through the model programming. At last, a project application shows the feasibility of the presented method.

Study on load performance of electric motor system used in hybrid electric vehicle

The performance of the power assist, global optimization solved by dynamic programming （DP） method, Chery and Insight control strategies are analyzed using the mild parallel hybrid electric vehicle （PHEV） model based on Insight structure. The influence of the four control strategies to the load power of the electric motor system used on parallel hybrid electric vehicle is studied. It is found that 80 percent of the motor load power points are under 1/5 of the electric peak power. The motor load power of the power assist control strategy is distributed in the widest range during generating operation, and the motor load power of the global optimization control strategy has the smallest one.

Investigation of the performance of the dish/stirling solar thermal electricity system

A dish/stifling solar thermal electricity system consists of two parts： a dish solar concentrator and a Stifling engine. For optimizing the system, in this paper, the mathematical model for concentrator design was established and the effects of those design parameters of concentrator, such as the size and intensity of the focal point, the receiver temperature, on the efficiency of the Stifling engine and output power were numerically simulated. The results of the simulation revealed a close relationship between power and efficiency because of power losses, and there was a maximum for the engine efficiency and power with increasing solar radiation because there was a peak value of system efficiency with increasing receiver temperature. So, in view of our Stifling engine, the 450 rim angle and 6m focal length are optimal design for concentrator and the 800℃receiver temperature is best.