提高机组低负荷运行经济性的讨论

针对大机组低负荷运行工况，从运行角度讨论提高机组运行的经济性。     

提高国产200MW机组的经济性

简述四川电力系统２００ＭＷ机组在节能改造方面所做的工作，分析供电煤耗偏高原因以及提高国产２００ＭＷ机组的经济性应着重抓好的工作。     

浅析机组压负荷调峰对厂用电率及供电煤耗的影响

随着我省大容量新机组不断投产发电，我省用电峰谷差逐年不断增加，大机组压负荷调峰已成了不可避免的问题，本文分析了机组压负荷调峰对厂用电率和煤耗上升的影响。     

秸秆锅炉驱动超超临界机组给水泵汽轮机经济性分析

以新建超超临界1000 MW机组为例,探讨了采用燃烧秸秆的高压锅炉代替汽轮机抽汽驱动给水泵汽轮机的可行性,并给出燃烧秸秆锅炉蒸汽系统的基本流程.在对机组变工况计算的基础上,分析了采用秸秆锅炉后机组煤耗率的变化以及能够获得的经济效益和环保效益.     

基于技术-经济-环境多因素的燃煤电厂运行经济性评价

根据火电厂燃煤机组的运行状况,全面考虑技术、经济、环境等多种因素,在计算机组的能量费用、非能量费用和环境污染费用后,构建燃煤电厂运行经济性综合评价指标的数学模型.以某国产600 MW机组为例,对燃煤电厂运行经济性综合评价指标进行了分析和计算,表明用运行经济性综合评价指标来取代电厂的供电煤耗率来衡量电厂运行经济性可行且更合理.     

燃机与锅炉耦合系统提高电厂供电效率的研究

为提高火力发电厂的供电效率,提出燃机与锅炉机组的耦合系统,并建立该耦合系统性能计算模型。经过对耦合系统性能的预测分析可知:排烟温度对系统的性能影响较大,在设定的130℃排烟温度条件下,耦合了燃机的电厂效率提高,供电煤耗降低。在一定的最高燃机工作温度条件下,进入锅炉机组总风量与流经燃机的空气流量与之间的比值有最佳值。以燃机最高工作温度700℃为例,耦合系统可以提高机组效率0.5%以上,其发出的功率可以增加电厂供电量超过4%,在考虑了机组热效率以及低温腐蚀等因素以后,除了抵消风机电耗以外,最佳的供电量增加幅度为1.64%,此时对应着最佳的锅炉机组总风量与流经燃机空气流量的比值,其大小为4.29。     

降低国产200WM燃煤机组供电煤耗的探讨

国产２００ＭＷ机组安全可靠性差，稳定经济性差，供电煤耗水平参差不齐比较突出。本文结合邢台发电厂６台国产２００ＭＷ机组１９９３年供电煤耗和各项参数及设备运行过程中存在的问题，运用等效热降法等理论计算相应的节能潜力，对国产２００ＭＷ燃煤机组供电煤耗的最好水平作进一步的探讨，从而得到国产２００ＷＭ燃煤机组供电煤耗最好水平可达到３６８ｇ／ｋＷ．ｈ的结论，并且提出实现最好水平的几点建议。     

大型火电机组低负荷运行经济性研究

随着电力建设的快速发展和供需关系趋于平衡,火电机组利用小时数逐年下降,机组长期处于低负荷的"非经济负荷区"运行.文中分析研究了湖南省火电机组低负荷运行现状及对经济性的影响,从优化机组设备运行方式、加强设备技术改造等方面提出了提高低负荷运行经济性的有效措施.     

320MW机组锅炉加装低温省煤器的经济性研究

对某台320MW机组锅炉在尾部烟道加装低温省煤器,利用烟气余热加热机组凝结水,以降低电袋复合除尘器入口烟温。试验结果表明:加装低温省煤器后,汽轮机热耗率下降40.3kJ/(kW.h),机组供电煤耗降低1.425g/(kW.h);进入电袋复合除尘器的烟气温度降至130℃左右,满足进入脱硫装置排烟温度≤150℃的要求,同时消除了锅炉两侧烟道的烟温偏差,使机组可在任何负荷下安全运行。     

Simulating the transients in a load node with a triple-wound transformer at different voltage levels

The transient processes in the load node of a power system, which contains powerful induction motors and triple-wound transformers, are simulated. A technique for transient calculation using direct-current synthetic schemes of electric circuits (Dommel’s algorithm) is presented. A dynamic model of an induction motor in the phase domain and a model of a triple-wound transformer based on inductively coupled branches are used taking into account the transformation of voltage levels. It is shown that the mutual influence of different voltage levels in the circuits can be investigated in the phase domain, within one model, and in the course of one simulation process. As an example, we consider a 110/35/10-kV load node that contains an induction motor, a static load, and a reactive power-compensation device in the form of a capacitor on the low-voltage side, as well as power-transmission lines on the medium-voltage side. Dommel’s algorithm makes it possible to investigate various types of nonlinear elements in the system and does not impose any restrictions on the waveform and harmonic composition of signals in the model. The algorithm also allows one to change the parameters and configuration of the timing constraints, which increases the range of the modes considered. When simulating the load node in this domain, various types of asymmetry and complex faults can be considered. The model of the induction motor is highly flexible and yields good results when calculating the dynamic modes.     

高原环境下110 kV城网迎峰过冬的可行性研究

针对高寒地区特殊的气象条件,研究了110 kV城网中提高导线温度的可行性及提高导线温度后主变的过载能力,并给出了计算依据和结果。线路试运行结果表明,将导线允许温度从70℃提高到80℃时,除部分配套金具不能满足要求外,主变及其他均能安全运行。     

某超超临界1000 MW机组锅炉满负荷瞬间灭火原因分析及处理

针对某超超临界1 000 MW机组锅炉满负荷瞬间灭火问题,通过锅炉灭火时间点前后的燃烧工况、湿式捞渣机密封水液位以及锅炉满负荷冷灰斗密封挡板标高沉降等数据复原跟踪分析,发现燃烧工况差使部分未燃尽煤粉所形成焦块直接落入炉底水封使密封水中固体颗粒物增加,造成本身存在设计缺陷的液位测量元件被埋,信号失真无法正常联锁补水导致炉底水封破坏,是造成锅炉满负荷瞬间灭火和机组跳闸的主要原因。对此,通过调整入炉煤粉细度,改进捞渣机液位测量元件测量桶底部结构,优化补水程序判断条件,有效防止了锅炉炉底水封破坏带来的安全风险。此结果可为配置同类型湿式捞渣机的锅炉机组提供借鉴。     

高原环境下110kV城网迎峰过冬的可行性研究

针对高寒地区特殊的气象条件,研究了110 kV城网中提高导线温度的可行性及提高导线温度后主变的过载能力,并给出了计算依据和结果.线路试运行结果表明,将导线允许温度从70℃到80℃时,除部分配套金具不能满足要求外,主变及其他均能安全运行.     

不同电价机制下含光伏发电的家庭负荷调度经济性研究

随着分布式能源的日益发展,分布式能源在未来能源互联网构架中将占有重要的作用。对不同电价机制下含光伏发电的家庭负荷调度问题进行了研究。首先,通过一系列数学变换,建立了能用LINGO直接求解含光伏发电的家庭负荷调度问题的非线性混合整数规划模型。然后,以此模型为基础,以固定电价、分时电价和实时电价3种电价机制为研究对象,对多种电价机制下含光伏发电装置和固定电价机制下无光伏发电装置的家庭负荷调度问题的经济性进行了比较和分析。仿真结果表明,实时电价机制不仅能够显著降低电费,而且能够积极响应新能源补贴政策。     

Enlarged thermal deaerators with a horizontal column for large units at nuclear power stations

We describe the new enlarged deaerators for 1000-MW power units and for a BN-800 power unit equipped with an enlarged-volume tank with one horizontal deaeration column.     

Experience gained at the Ural Turbine Works with retrofitting steam turbine units for thermal power stations

Examples of projects on retrofitting, modernizing, and renovating steam turbine units at thermal power stations implemented with participation of the Ural Turbine Works are given. Advanced construction and layout solutions were used in implementing these projects both on the territory of Russia and abroad.     

A Multi-objective Shuffled Bat algorithm for optimal placement and sizing of multi distributed generations with different load models

In this paper a new and efficient hybrid multi-objective optimization algorithm is proposed for optimal placement and sizing of the Distributed generations (DGs) in radial distribution systems. A Multi-objective Shuffled Bat algorithm is proposed to evaluate the impact of DG placement and sizing for an optimal improvement of the distribution system with different load models. In this study, the ideal sizes and locations of DG units are found by considering the power losses, cost and voltage deviation as objective functions to minimize. Furthermore, the study is verified with voltage dependent load models like industrial, residential, commercial and mixed load models. The feasibility of the proposed technique is verified with the 33 bus distribution network and also the qualitative comparisons against a well-known technique, known as Non-dominated Sorting Genetic Algorithm II (NSGA-II) is done and results are presented.     

An investigation of thick PZT films for sensor applications: A case study with different electrode materials

Lead zirconate titanate (PZT) is a piezoelectric material that can sense or respond to mechanical deformations and can be used in ceramic micro-electro-mechanical systems (C-MEMS). A thick-film paste was prepared from a pre-reacted PZT powder (PbZr_0.53Ti_0.47O₃) and thick-film technology (screen-printing and firing) was used to deposit the PZT layers on LTCC tapes and on alumina substrates. The microstructural, electrical and piezoelectric characteristics of the thick PZT films on relatively inert alumina substrates and on LTCC tapes were studied. Preliminary experiments indicated that due to the interaction between the printed PZT layers and the LTCC substrates during firing the electrical characteristics deteriorate significantly. To minimise the influence of substrate-film interactions different electrode materials and the use of additional intermediate layers as a barrier were evaluated. The dielectric permittivities, dielectric losses, and piezoelectric coefficients (d ₃₃) were measured. The dielectric permittivities of the thick films fired on LTCC substrates were lower (210 with gold electrodes and 430 with silver electrodes) than those measured on alumina substrates (500). The piezoelectric coefficients d₃₃ were measured with a Berlincourt piezometer. The d ₃₃ values measured on the LTCC substrates were relatively low (60–80 pC/N) compared with the values obtained for the alumina substrates (around 140 pC/N). The lower dielectric constants and piezoelectric coefficients d ₃₃ of the films on LTCC substrates are attributed to the formation of phases with a lower permittivity. This was a result of the diffusion of SiO₂ from the LTCC into the active PZT layer. The diffusion of silica was confirmed by the SEM and EDS analyses.     

A software system used for load distribution at a combined heat and power plant with the complex mix of the equipment and complex schemes of heat and electric power supply

The authors describe various approaches to construction of an algorithm for the solution of the problem of load distribution at a combined heat and power (CHP) plant with the complex mix of the equipment and complex schemes of heat and electrical energy supply on the basis of which the software system has been developed. Methods of obtaining energy characteristics of the equipment used for solving the problem of load distribution were studied. The results of the implementation of the software system for load distribution at the CHP-23 plant belonging to OAO Mosenergo are given. Realization of recommendations on maintaining an operational mode of the equipment with due regard for its optimal loading makes it possible to obtain fuel savings of up to 1%.