电网设备调度运行风险辅助评估研究

电网运行风险评估是保障其安全稳定运行的重要环节之一。对电网运行风险评估的概念及方法进行了介绍,根据长兴电网的基本运行情况,提出了电网设备调度运行风险辅助评估的概念。针对长兴电网设备运行的特点,通过蒙特卡洛模拟法进行了风险模拟,从而实现对风险的计算及定级。     

电子式互感器在洛川750 kV智能变电站的应用研究

电子式互感器是智能变电站的重要设备,从工程应用角度对电子式互感器的原理进行了简述,对洛川750kV智能变电站运行的电子式互运行情况进行了介绍,对运行中电子式互感器存在的问题进行了分析和归纳,并提出行之有效的应对方法,为电子式互感器的研究开发以及运行管理提供经验。     

负荷对电站锅炉运行参数影响特性分析及应达值的确定

运行参数对锅炉经济性的影响普遍采用偏差分析法进行分析,对锅炉各种运行参数的应达值而言其性质是不同的,在确定了应达值的基础上才能分析运行参数的偏差对锅炉经济性的影响。在分析了锅炉运行参数的静态特性后,对各类锅炉运行参数进行了分类,并分析了各类应达值的确定方法,为分析和提高电厂运行经济性提供了依据。     

大集控运行模式探索与实践

对传统集控运行模式的不足之处进行了分析与总结,指出大集控运行模式的主要特征,对新型运行模式下监控系统报警信息优化、状态检修信息平台构建两个关键问题进行了探索,并介绍了大集控运行模式的初步实践情况。     

ZN-65真空断路器故障分析及处理

对ZN-65型断路器在实际运行过程中出现的故障进行了详细分析,提出了解决的方案,并对改造后的运行情况进行了总结。阐述了真空断路器运行维护的技术措施。     

严寒地区太阳能-地源热泵与热网互补供暖运行方式研究

文章研究了严寒地区由太阳能-地源热泵与热网组成的互补供暖系统,在串联和并联两种运行方式下的性能情况。文章构建了两种运行方式下互补供暖系统的仿真模型,对该系统各部件进行了选型设计,对系统性能进行了仿真模拟并进行了经济性分析。结果表明:串联运行方式下互补供暖系统中地埋管换热器与土壤之间的最大换热效率比并联运行方式高19.8%,且串联运行方式下二者之间的换热总量要比并联运行方式高出9.44%;两种运行方式下埋管进出口水温均有下降;运行5 a后,并联运行方式下互补供暖系统的运行费用较串联运行方式下互补供暖系统略高,但从系统供暖能效及土壤温度的受扰动情况来看,并联式系统比串联式系统更具优势。     

石化企业蒸汽动力系统优化运行研究

建立了考虑设备启停费用的蒸汽动力系统多周期最优运行的混合整数线性规划模型,并将锅炉和汽轮机的模型根据实际运行情况进行了合理的线性化。利用规划软件LINGO进行优化求解,并通过实例证明了利用建立的模型,得到了合理的优化运行计划,节省了大量的运行成本。     

联合循环中余热锅炉与汽轮机的滑压运行

本文首先叙述了联合循环中蒸汽侧采用滑压运行的原因,接着对余热锅炉、汽轮机的滑压运行和联合循环的变工况性能进行了计算,论述了运行参数变化的特点,并与定压运行作了比较,从而说明采用滑压运行的合理性。     

闭式循环柴油机性能的试验研究

在闭式循环柴油机开式运行和闭式运行时,通过改变超重力旋转床的水流量,对吸收器的吸收特性及其闭式循环柴油机性能的影响进行了分析.恒定柴油机负载,改变混合进气中氩气的含量,分析了进气混合气中氩气含量对闭式循环柴油机性能的影响.在闭式运行时进行负荷试验,并与开式对比,对开式运行和闭式运行的油耗、系统压力等参数及柴油机运行状况进行了对比分析.     

三绕组变压器并联运行经济分析

结合运行实例 ,对三绕组变压器的两个绕组并联运行方式和三个绕组并联运行方式进行分析并得出了分析结论 ,可为运行部门选择经济的并联运行方式提供依据     

车用柴油机瞬态运行工况的性能标定优化方法研究

采集柴油机瞬态运行工况,使用频率统计方法分析瞬态运行工况分布并得到瞬态运行的权重工况,在此基础上进行权重工况的台架性能、排放优化试验得到性能考核指标的变化参数。根据权重工况的性能、排放优化规律进行瞬态运行工况性能优化试验,在考虑关键性能指标的trade-off规律情况下,最终完成瞬态运行工况性能优化试验,得到瞬态运行工况优化标定数据。     

考虑运行电抗与热平衡的电弧炉合理供电

首先综述了确定电弧炉运行电流的若干方法。然后,根据运行电抗电与工作电流的变化关系式推导出了几个特殊工作流。最后,从炼钢电弧炉的热平衡出发,综合考虑运行电抗的影响,推导出了更具一般性的最佳工作电流表达式。     

汽油发动机管理系统稳态工况参数标定方法研究

给出了汽油发动机管理系统稳态工况参数标定的步骤，详细论述了基准三维图工况节点选取和制取数据的方法；总结出工况分析法试验是选取各个节点的优化目标，进行三维图（ＭＡＰ）优化的有效手段。并给出了应用实例及试验结果。     

Parametric analysis of the proton exchange membrane fuel cell performance using design of experiments

Proton exchange membrane fuel cell (PEMFC) performance depends on different fuel cell operating temperatures, humidification temperatures, operating pressures, flow rates, and various combinations of these parameters. This study employed the method of the design of experiments (DOE) to obtain the optimal combination of the six primary operating parameters (fuel cell operating temperatures, operating pressures, anode and cathode humidification temperatures, anode and cathode stoichiometric flow ratios). In the first stage, this study adopted a 2^k−2 fractional factorial design of the DOE to determine whether these factors have significant effects on a response and the interactions between various parameters. Second, the L₂₇(3¹³) orthogonal array of the Taguchi method is utilized to determine the optimal combination of factors for a fuel cell. Based on this study, the operating pressure, the operating temperature, and the interactions between operating temperature and operating pressure have a significant effect on the fuel cell performance. Among them, the operating pressure is the most important contributor. When the operating pressure increases, it should simultaneously lower the effects of other factors. While both the operating temperature and pressure increase simultaneously with that, the other factors are at appropriate conditions, it is possible to improve the fuel cell performance.     

通用型水库群洪水补偿调度模型

建立了一般水库群洪水调度系统的数学模型,并提出了补偿调度的求解方法,补偿调度的基本思路是：首先根据各水库的入库洪水过程,按照各水库的洪水调度规程从上至下进行独立调洪计算,再与区间洪水合成防洪控制点的流量过程;若出现超载水量,则从两方面调整各水库的泄洪策略（拦蓄与预泄）,以达到避免或减少分洪水量的目的。所提出的通有型水库群洪水调度模型及补偿调度算法具有一般性,有利于编制开发通有型水库群洪水调度系统软件,其计算成果为制定人机交经方案提供了强有力的支持。     

Experimental analysis of dynamic characteristics on the PEM fuel cell stack by using Taguchi approach with neural networks

This study determines the optimum operating parameters for a proton exchange membrane fuel cell (PEMFC) stack to obtain small variation and maximum electric power output using a robust parameter design (RPD). The operating parameters examined experimentally are operating temperatures, operating pressures, anode/cathode humidification temperatures, and reactant flow rates. First, the dynamic Taguchi method is used to obtain the maximum and stable power density against the different current densities, which are regarded as the systemic inputs considered a signal factor. The relationship between control factors and responses in the PEMFC stack is determined using a neural network. The discrete parameter levels in the dynamic Taguchi method can be divided into desired levels to acquire real optimum operating parameters. Based on these investigations, the PEMFC stack is operated at the current densities of 0.4–0.8 A/cm². Since the voltage shift is quite small (roughly 0.73–0.83 V for each single cell), the efficiency would be higher. In the range of operation, the operating pressure, the cathode humidification temperature and the interactions between operating temperature and operating pressure significantly impact PEMFC stack performance. As the operating pressure increasing, the increments of the electric power decrease, and power stability is enhanced because the variation in responses is reduced.     

负荷扰动及工作水头对水电站小波动过渡过程的影响

为确定对小波动稳定性和调节品质最不利的工况,通过稳定域和数值计算分析小波动过渡过程最不利工况即控制工况的选取,研究了工况点的两个主要信息即工况点的负荷扰动以及工作水头对小波动稳定性的影响。实例应用结果表明,减负荷扰动越小,衰减度越小,调节品质越差;最小水头至额定水头之间的工况点的稳定性较额定水头至最大水头之间工况点的稳定性差,因而控制工况应该在最小水头至额定水头之间选择,对于低比转速水轮机,最小水头工况往往成为控制工况。     

Determination of acceptable operating cost level of nuclear energy for Turkey's power system

Generally, it is very difficult to assess the true operating cost of an electrical power unit in the countries where there is little or no operational experience. Since Turkey has no experience on operating a nuclear unit, operating costs of a nuclear unit is uncertain for use in generation expansion planning (GEP). Furthermore, there is a disagreement of whether it is cheap or not. In this study, an acceptable level of operating cost of nuclear units is determined for Turkey's power system. It is aimed to find a numerical value for nuclear operating cost at which nuclear is able to compete with other energy sources. Seven types of units are chosen as candidate units to the power system. Mixed-integer programming (MIP) is used as a mathematical model of generation expansion planning. The model consists of the cost function that minimizes the construction and operating costs and the reliability constraints. Adaptive simulated annealing genetic algorithm (ASAGA) is used for optimization algorithm to determine the types, times, and number of candidate units which meet forecasted demand within a pre-specified reliability criterion over the planning horizon from 2006 to 2025. In the case studies, a high level of nuclear energy operating cost is taken and then the cost is gradually lowered. Optimizations are made for each level of nuclear operating costs within four different scenarios and the quantities of nuclear capacity selected by optimizations are recorded. It is determined that, nuclear energy is able to compete with other energy sources when the operating cost is less than 210$/kWh yr or 2.4cent/kWh.     

Analytical model for predicting the effect of operating speed on shaft power output of Stirling engines

This paper is concerned with numerical predictions of relationship between operating speed and shaft power output of Stirling engines. Temperature variations in expansion and compression spaces as well as the shaft power output corresponding to different operating speeds were investigated by using a lumped-mass transient model. Effects of major operating parameters on power output were studied. Results show that as the operating speed increased, temperature difference between the expansion and compression spaces was reduced and as a result, the shaft work output decreased. However, the shaft power output is determined in terms of the shaft work output and the operating speed. When the operating speed was elevated, the shaft power output reached a maximum at a critical operating speed. Over the critical operating speed, the shaft power output decreased in high-speed regime. In addition, as air mass was reduced, either a decrease in thermal resistances or an increase in effectivenesses of the regenerator leads to an increase in the engine power.     

6110直喷式柴油机排放特性分析

测量了 6 110直喷式柴油机排气污染物 THC、CO、NOx 以及 PT的排放量 ,并分析了各种污染物的排放规律 ,对 THC排放与有效燃油消耗率 be、PT与 NOx 排放、SOF与 THC排放之间的关系做了研究。结果表明 6 110直喷式柴油机 THC和 CO的高排放区出现在小负荷工况 ;PT的高排放区出现在低负荷和高负荷工况 ;降低 NOx 排放的重点应放在小负荷工况和高速工况。柴油机的 be 与 THC排放随工况的变化表现出相似的变化规律。在较大的工况范围之内 ,PT和 NOx 排放之间存在折中关系 ;而在少数工况区域 ,PT和 NOx 排放之间存在一致性。 PT中的 DS与 NOx 排放之间始终存在着折中关系 ,而 SOF与 NOx 排放之间却存在着一定程度的一致性。在 THC的高排放工况 ,SOF也具有比较高的排放量