数据挖掘技术在火电厂优化运行中的应用

火电机组运行优化目标值的合理确定是实施机组性能诊断和优化运行的前提和基础，是电站运行优化的关键。采用传统方法确定的优化目标值往往不能正确反映机组的实际运行状态。充分利用火电厂生产运行的大量历史数据，提出了数据挖掘的火电机组运行优化方法，将模糊关联规则应用于火电厂运行优化目标值的确定。以某300MW机组历史数据为基础，运用这一方法得到各典型工况下的最优值以指导实际运行。试验结果表明，基于数据挖掘的火电厂运行优化目标值确定方法可以提高机组运行效率，降低污染物排放。     

锅炉给水泵优化运行的探讨

对电厂锅炉给水泵优化运行进行分析比较,建立一套优化运行系统,用以指导给水泵运行,从而达到降低厂用电量的目的。     

机组经济运行管理系统在电厂的应用

针对某发电厂实施的机组经济运行管理系统项目,总结了实施的重要阶段,详细介绍了机组经济运行管理系统,可为此类项目在国内的实施提供经验借鉴。     

Time-length calibration method of large data mining of photovoltaic power plants

When analyzing photovoltaic plant’s output characteristics, the time interval and the time length of data need to be considered. At present, there is no exact theoretical basis of the time length of data. In the case of a certain time interval, the selection of the time length of data is of great significance for the analysis of extracting photovoltaic characteristics. This paper takes a feature mining of fluctuation degree and generated energy according to cluster analysis. On the basis of this, a definition of “daily performance coefficient” is given to characterize data characteristics. The optimum sample size estimation of daily performance coefficient based on principles of probability and statistics is taken to obtain the time length of data under different permissible errors. As a criterion that best meets the objective situation for selecting the statistical properties of the random variable, maximum entropy principle from information entropy theory provides the time length of data-determining method with no other constraints. Based on information entropy theory, taking the issue of storage capacity configuration in Photovoltaic (PV)-storage system as an example, this paper studies the relation between storage capacity demand and the time length of data and the relation between information entropy and the time length of data. In this way, the time length of data for PV-storage system’s operating characteristic analysis is determined.     

Design exploration of three-dimensional transverse jet in a supersonic crossflow based on data mining and multi-objective design optimization approaches

The information in the three-dimensional transverse injection flow field is very important for the design of a scramjet combustor, and it should be explored by using the data mining and multi-objective design optimization methods. In the current study, the three-dimensional Reynolds-averaged Navier–Stokes (RANS) equations coupled with the two equation SST k-ω turbulence model has been utilized to simulation the transverse injection flow field with a freestream Mach number 3.75, and the influence of the turbulence model on the flow field properties has been evaluated as well. At the same time, three grid scales have been employed to perform the grid independency analysis, and the predicted results have been compared with the available experimental data in the open literature in order to carry out the code validation process. Further, the effect of the injector geometric configuration on the mixing efficiency of the transverse injection flow field has been investigated, and four different configurations have been considered in the current study, namely the square port, the diamond port, the equilateral triangular port and the circular port. The obtained results show that the case with the square injection port can obtain the largest mixing efficiency, and it can offer the rapidest near-field mixing between the injectant and the air. At last, the transverse injection flow field with the square injection port has been optimized by the surrogate-based evolutionary algorithm, and the relationships between the design variables and the objective functions have been explored by the variance analysis method. It is shown that the jet-to-crossflow pressure ratio has a high remarkable impact on the total pressure recovery efficiency, as well as the number of the injection ports on the drag force performance. The drag force increases with the increase of the number of the injection ports due to the deeper penetration of the rear jets.     

锅炉经济性分析及最优氧量的确定

在锅炉送风及炉膛压力控制系统中,氧量设定值的改变会导致锅炉热损失及送风机电耗的改变,从而影响电站经济性.针对机组运行状态发生改变后的氧量最优值更新问题,提出了改进的增量式模糊数值型关联规则挖掘算法,并以 1 台300 MW 机组为例进行了分析.结果表明:这种新的挖掘算法与传统的数据挖掘方法相比,具有良好的快速性,效率可提高4～16倍,大大减少了候选项集的数目,因而大量减少了重复计算的费用.该方法确定的氧量最优值可有效降低机组供电煤耗效率,并可提高机组运行经济性.     

自适应预报方法在时间序列数据挖掘中的应用

介绍了用于工业月产值的时变参数自适应多步预报两种方法,是处理一类时间序列数据挖掘的实用较好方法,具有一定的推广应用价值。     

电站锅炉运行参数对经济性的影响

本文针对某电站锅炉,进行了燃烧调整试验,分析了运行参数对锅炉效率的影响,提出了合理的运行工况。为电站锅炉经济运行提供参考。     

Performance improvement of centrifugal compressors for fuel cell vehicles using the aerodynamic optimization and data mining methods

Centrifugal compressors are one of the most important auxiliary components in polymer electrolyte membrane fuel cell vehicles, which tend to operate at a narrow area with low specific speed. Here, the optimal design goals of centrifugal compressors are investigated on the basis of a lumped model for fuel cell systems. A three-dimensional multi-objective and multi-point aerodynamic optimization and data mining method for centrifugal compressors named ODM is presented via integrating a multi-island genetic algorithm, Reynolds-Average Navier-Stokes solver technique and self-organization map based data mining technique. Data mining indicates that compressor geometry would move to a small inlet diameter ratio and a narrow region of the outlet width ratio. Based on the optimization results, a centrifugal compressor for 100 kW fuel cell stack is manufactured. The experimental results show that the improvement of isentropic efficiency near low mass flow has been achieved, which indicates that the proposed ODM is effective in the performance improvement of centrifugal compressors for fuel cell vehicles.     

安康水电站水轮机运行性能优化途径

安康水电站近年水轮机过流部件损坏严重,影响电站安全运行。分析其原因,主要是运行工况欠佳、水轮机补气效果不好等原因所致。应采取改善运行工况,改进补气措施、提高检修水平等技术措施,以达到优化水轮机运行性能的目的。     

电站运行优化决策支持系统及优化值的确定

在电站运行优化的目标分析的基础上，依照决策支持系统(DSS)的结构及其设计思想，对电站运行优化决策支持系统(OODSS)的结构进行探讨，重点对运行优化的关键性难题——优化目标值的确定问题进行深入研究，在传统方法的基础上提出基于数据开采技术的新方法，并利用决策支持系统解决半结构化问题的优势提出进一步的综合性解决方案。图2表2参5     

电站凝汽器运行状态监测智能决策系统研究

凝汽器系统是电站凝汽式汽轮机的重要辅助设备,其运行状态的优劣对汽轮机组的安全性与经济性都有很大影响。针对某火力发电厂凝汽器系统,设计了将故障诊断和性能优化融合在一起的状态监测智能决策系统软件。该软件具有两大特色：一是性能优化与故障诊断的结合;二是故障诊断采用模糊神经网络与专家推理串行连接的模式。主要介绍了系统的组成、接口及其特点。该软件已在运行中得到了成功应用。     

A new self-scheduling strategy for integrated operation of wind and pumped-storage power plants in power markets

Competitive structure of power markets causes various challenges for wind resources to participate in these markets. Indeed, production uncertainty is the main cause of their low income. Thus, they are usually supported by system operators, which is in contrast with the competitive paradigm of power markets. In this paper, a new strategy for increasing the profits of wind resources is proposed. In the suggested strategy, a Generation Company (GenCo), who owns both wind and pumped-storage plants, self-schedules the integrated operation of them regarding the uncertainty of wind power generation. For presenting an integrated self-schedule and obtaining a real added value of the strategy, participation of the GenCo in energy and ancillary service markets is modeled. The self-scheduling strategy is based on stochastic programming techniques. Outputs of the problem include generation offers in day-ahead energy market and ancillary service markets, including spinning and regulation reserve markets. A Neural Network (NN) based technique is used for modeling the uncertainty of wind power production. The proposed strategy is tested on a real wind farm in mainland, Spain. Moreover, added value of the strategy is presented in different conditions of the market.     

万丰热电厂厂区水煤浆系统的优化与运行

介绍了万丰热电厂220t／h油炉改烧水煤浆的卸、储、运系统设计特点及设备选型和系统运行情况,同时针对水煤浆的特点和该锅炉运行要求,对系统中的管路布置、储罐局部设计、回流系统和运行方法等进行了优化设计和改进,应用证明这些改造方法对提高系统的安全可靠运行是十分有效的。     

Multicarrier energy systems: Optimization model based on real data and application to a case study

Multicarrier energy systems are increasingly used for a number of applications, among which the supply of electricity, heating, and cooling in buildings. The possibility of switching between different energy sources is a crucial advantage for the optimal fulfillment of the energy demand. The flexibility of these systems can benefit from the integration with smart grids, which have strong variations in time during their operation. The energy price is the parameter that is usually considered, but also the primary energy factor and the greenhouse gases emissions need to be accounted. This paper presents an application of an operational optimization method for a multicarrier energy system, based on real data–driven model and applied to different countries. The generation plant of a hospital is considered as case study, coping with multiple energy needs by relying on different conversion technologies. The optimal operation of the system shows a wide range of variability, depending on the chosen objective function, the hour of the day, the season, and the country. The results are affected mostly by the energy mix of the electricity supplied from the power grid, which has a direct influence on the primary energy consumption and the greenhouse gases emissions and an indirect influence on the electricity prices.     

基于排污权交易的石化企业蒸汽动力系统运行优化研究

针对以往石化企业蒸汽动力系统的节能减排仅局限于企业自身,提出基于排污权交易的蒸汽动力系统多周期运行优化模型。以操作、减排和排污权交易总费用为目标函数,增加排污总量约束,并采用线性变化参数的粒子群优化算法求解,通过企业与企业之间排污权的交易,来达到减排降耗的目的。工程实例研究结果表明,该企业的排污量超过允许排污额度277.86t,如将减排效率提高至91.8%以上,则可将排污权卖出。该模型的提出为企业管理者提供了全新的理论依据。     

基于改进粒子群优化算法的动态数据校正技术研究

动态数据校正是根据过程模型的数据校正机制降低测量值中离群点的影响,消除随机误差,使得到的估计校正值满足能量守恒和质量守恒定律.提出了一种基于不确定知识的粒子群优化算法的动态数据校正和离群值检测方法,改进的算法在粒子群优化算法的基础上引入不确定知识,在粒子寻优迭代过程中限定粒子的搜索中心和搜索范围,提高了粒子可信度,克服了粒子早熟问题,使得粒子以更快、更有效的方式向最优值靠近.连续搅拌反应槽系统(CSTR)仿真实验证明了改进方法的有效性.     

Parallel operation characteristics of PEM fuel cell and microturbine power plants

This paper reports on the dynamic behavior of a 250 kW proton exchange membrane fuel cell power plant (PEM FCPP) and a 250 kW microturbine (MT) when operating in parallel. A load sharing control scheme is used to distribute the load equally between the PEM FCPP and the MT. For stand alone operation of a PEM FCPP, a set of batteries or ultracapacitors are needed in order to satisfy the power mismatch during transient periods. Using MT in parallel with the PEM FCPP helps in eliminating the need for storage devices. Models for the PEM FCPP and the MT with power, voltage and speed controls are used to determine the dynamic response of the system to a step change in the load. Simulation results indicate viability of parallel operation of the PEM FCPP and the MT. These results are obtained using MATLAB^®, Simulink^®, and SimPowerSystems^®.     

Risk‐based optimal distribution of power reserves in wind power plants

This paper employs the Conditional Value‐at Risk, largely used in financial risk management, to specify the power reserve capacity of a wind power plant (WPP) under a risk metric. Evidences are shown here that other popular, simpler measure, the Value‐at Risk, is inappropriate for that specification. Under this risk‐based reserve metric, two programs are approached to optimally distribute a reserve request in a WPP subject to a given confidence level in the commitment. The most exhaustive of the two is a two‐level formulation including a solution to the load power flow (LPF) in the WPP. By solving these two programs, for comparison with interior‐point and heuristic solvers, conclusions are drawn. Notably, that a Pareto optimality occurs for stringent reserve requests; that putting off‐line generators is financially more profitable than partial curtailments to respond to low reserve requests; and that in these cases accounting for losses through LPF‐based optimization seems unnecessary. Copyright © 2016 John Wiley & Sons, Ltd.