回热式给水泵汽轮机优化配置研究

针对回热式给水泵汽轮机系统中的功率协调问题,分析了进汽节流调节、排汽补汽调节和发电机调节3种配置方案的控制方法与特点。以1000MW超超临界二次再热机组为研究对象,建立机组全范围仿真模型,研究了上述3种方案的热力性能差异。结果表明:随机组负荷的增加,小汽轮机与给水泵的功率差值先增大后减小,在70%THA工况附近达到最大值19.3MW;进汽节流调节方案节流损失较大,经济性最差;排汽补汽调节方案可减少进汽节流,提高给水温度,但增加了抽汽过热度,经济性优于节流调节;发电机调节方案经济性最佳,在低负荷下节能效果更加显著。     

超超临界MC系统运行特性及优化研究

MC系统利用回热式小汽轮机能够降低中间再热机组的抽汽过热度。以MC系统为研究对象,建立了主汽轮机和小汽轮机相互耦合的全工况数学模型,基于Labview开发仿真试验平台,以试验为基础提出了系统优化方法。结果表明:MC系统中回热式小汽轮机随负荷降低存在做功溢出,需通过进汽节流来实现主机与小汽轮机相互协调;背压辅助调节功率的优化方法能够有效减少回热式小汽轮机进汽节流,从而提高MC系统的经济性。     

基于流型判别准则的排汽焓的准确在线监测方法

随着信息计算机技术发展,对大型汽轮发电机组进行性能在线监测及分析成为可能.机组能耗率和干度是两个被监测的重要指标.通过对已往的汽轮机变工况计算方法分析,提出以汽轮机末级抽汽或次末级抽汽(过热蒸汽状态)为计算起点的汽轮机的顺序变工况核算方法.根据初始假定的末级流量和现场实际的末级前热力状态和背压,用汽轮机变工况流型判别准则,判别级的流型,然后从末级前参数开始顺序进行一次级的变工况核算,得到新的排汽焓和排汽干度,最后算得机组的能耗率和排汽焓(或排汽干度).这样既不用流量测量,也不用排汽干度测量,就能准确地在线监测机组能耗率和排汽干度.     

1 000 MW机组不同BEST级数下变工况回热特性研究

为了寻找抽汽背压式汽轮机(back pressure extraction steam turbine,BEST)最佳的级数方案,以配置BEST的二次再热机组为设计基础,保持总回热级数不变,BEST级数从4级增加到8级,对比不同BEST级数下机组的可行性、变工况特性及热经济性.结果表明:从BEST功率相对给水泵功率的裕...     

1350MW二次再热发电机组热力系统设计分析

综合考虑锅炉侧和汽轮机侧的设计协调,构建了1 350 MW二次再热机组原则性热力系统。针对不同给水泵汽轮机配置进行了计算与分析,定量分析了背压抽汽式与凝汽式小水泵汽轮机两方案对再热蒸汽流量、机组热耗和回热加热器设计等的影响。结果表明:额定工况下,背压抽汽式给水泵汽轮机系统的一、二次再热器蒸汽流量分别比凝汽式系统小266 t/h和289 t/h,从而有利于锅炉对流受热面设计;背压抽汽式系统的4号、5号加热器进汽温度相比凝汽式系统分别降低350℃和297℃,有利于加热器设计和运行。但背压抽汽式系统比凝汽式系统机组热耗高约为6 kJ/kWh。部分负荷下的计算结果表明背压抽汽式系统一、二次再热蒸汽流量仍小于凝汽式系统,机组热耗相比凝汽式系统仍稍高。     

船用湿汽轮机逆顺序混合法的热力核算及除湿性能分析

结合船用单缸大功率喷嘴调节湿汽轮机的结构特性,分析建立详细的压力级和调节级逆顺序混合算法,并以此建立整机调节级和压力级的耦合算法,利用已有的设计数据验证所提出算法的有效性并分析湿度对末几级叶片的水蚀特性。在整机热力耦合算法中考虑汽轮机级间抽汽的除湿方式,比较不同抽汽位置和抽汽量对各级排汽湿度的影响。结果表明,级间抽汽除湿方式能够有效降低汽轮机内湿度,防止叶片侵蚀发生。最优抽汽位置和抽汽量,各级输出功率可以得到保证,抽汽后级的排汽湿度也明显下降。     

供热式汽轮机工况图的系统及参数修正方法

现有的供热式汽轮机工况图,主要是在额定的主蒸汽参数、再热蒸汽参数、排汽参数及抽汽压力下得到的,并且认为回热系统的状态正常。而汽轮机实际运行中,这些参数并不总是保持其额定值不变,同时回热系统状态也不可避免地要偏离设计值,且还存在着过热器和再热器的喷水减温。此时,为了得到电功率与主蒸汽流量及抽汽量之间的关系,就不能直接查取汽轮机的工况图,而必须对其进行修正。给出了在汽轮机回热系统状态及主蒸汽参数、再热蒸汽温度、汽轮机排汽压力以及抽汽压力偏离设计值时的一种修正方法,并以某C330/262-16.7/0.49/538/538型汽轮机为例进行了修正计算。所提出的修正方法对于在实际运行中依据主蒸汽流量和抽汽流量预测汽轮机电功率,具有一定的指导意义。     

1000 MW超超临界汽轮机蒸汽参数的优化及讨论

探讨了1000 MW超超临界汽轮机组的参数及运行方式.外高桥三期2×1000 MW汽轮机为上汽(SIEMENS)机型,采用补汽阀调频及过负荷调节.以压力条件作为划分定压和滑压的判据,最高冷却水温条件下,功率≤1000 MW时不开补汽阀;其它水温下能在功率＞1000 MW且p＜27MPa时尽可能进行滑压运行;它采用≥3D弯管等,降低造价,降低再热系统压降时,降低冷却水温度,单独设汽动给水泵汽轮机的凝汽器,降低进入主凝汽器的蒸汽流量及热负荷,以降低机组平均背压和端差等,机组运行性能因而提高.     

利用回热抽汽控制参与风电系统调频方法研究

随着风力发电在电力系统中发电比例的提升,风速的波动性所带来的风功率的随机波动性给电力系统调频带来了新的挑战,在不增加系统装机容量的前提下,如何提高现有火电机组的调频能力应对大规模风电并网具有较重要的意义。本文通过对再热式汽轮机的并网运行进行了仿真研究,证明了汽轮机在带负荷运行中,回热系统的抽汽量变化会影响汽轮机的功率,回热系统的抽汽效应对汽轮机频率调节有显著影响。并且,本文还重点讨论了低风速风电功率欠发时,火电机组处于高负荷运行工况下,回热系统抽汽效应对汽轮机频率调节的影响。因此,在高渗透率风电的电网系统中,通过调整回热抽汽量是一种能够提高汽轮机调峰调频出力的可行方法。     

凝结水节流调节回热系统变化量的热平衡建模与能效分析

基于热平衡原理,推导并证明了凝结水节流调节处于稳态时机组做功变化量、吸/放热变化量的定量测算模型。以某超临界600MW机组为研究对象,在75%设计工况下计算机组凝结水节流调节时凝结水份额节流1%与5%的经济性,对比算例可知:在工况一定情况下,凝结水节流调节会使除氧器与低压加热器抽汽份额减少,从而使汽轮机汽量增加而提升负荷,且由于回热系统效果变差导致机组经济性下降,且随着凝结水份额节流量的不断增加,凝结水节流调节提升的负荷不断增加而机组经济性不断降低。     

Areal evolution of PV systems

If a large amount of the future penetration of PV systems is imaged, it is likely that they densely concentrate in a certain area. It may not be a simple aggregation of individually optimized system, but a different system image may result by the total optimization of an area. The author frames this new question as the problem of “Areal Evolution” or “PV-AREA”. The following two cases are dealt with and their concrete concepts are given: (1) PV systems for community, (2) global-scale utilization of PV systems.     

HS-510型发动机的改进设计

本文介绍了HS—510型发动机的改进过程。通过改进使其功率提高和燃油经济性改善。同时也说明一个产品只有不断地改进和完善，才能满足社会进发展的需要。     

1台1 025 t/h液态排渣锅炉的设计和运行特点

介绍了1台1025t/h液态排渣锅炉汽水系统、燃烧系统和控制系统等设计和运行的若干特点,对国内同类型锅炉的设计和运行具有指导意义。     

计算机辅助计量管理系统

计算机辅助管理系统研制开发的必要性以及国内外概况,并对系统开发的最终目标、功能及其意义进行了阐述.     

光伏系统蓄电池组不均衡性的故障分析及排除

蓄电池组是光伏系统的重要设备,其故障往往导致光伏系统不能正常运行。光伏系统蓄电池组的故障多数因其不均衡所致。文章分析了蓄电池组因不均衡性导致的故障,提出了故障预防措施和故障排除方法。     

Operation strategy of residential centralized photovoltaic system in remote areas

Photovoltaic (PV) systems have found fairly wide application in remote isolated area. However, each individual PV system usually supplies energy only to one consumer. In such a case we have several consumers that each one of them uses a stand-alone PV system. This situation would expose such stand-alone systems to transient excessive loads larger than the power generated by the PVs, and then the battery is bound to discharge even during the day. For overcoming this problem, we suggest an autonomous centralized PV system, comprising one battery bank and plural subsystems connected to each other. From solar radiation data and load profiles, the performance of the PV centralized system is simulated by using a time step scheme. The advantages of this system are found to be the large charging rate of power, high efficiency, and low cost compared with conventional individual PV systems and hybrid systems. In addition, the economic study shows that the life cycle cost and the price of kilowatt hour generated in the centralized system is lower than that for the individual systems.     

板坯连铸机冷却水系统的完善与应用

针对北方某厂板坯连铸机生产状况，对其软水冷却系统、设备净环水冷却系统和二次喷淋浊环水冷却系统进行了研究分析，提出了冷却水系统的完善方案，解决了连铸水系统的稳定性，避免了频繁开停泵对连铸水系统高压电机的冲击及冬季长时间停机或检修造成设备和管道系统内部滞水而冻结，提高了事故处理的灵活性和环境适应性。     

Sustainable electricity generation for rural and peri-urban populations of sub-Saharan Africa: The “flexy-energy” concept

Access to energy is known as a key issue for poverty reduction. Electrification rate of sub-Saharan countries is one of the lowest among the developing countries. However, this part of the world has natural energy resources that could help raising its access to energy, then its economic development. An original “flexy-energy” concept of hybrid solar PV/diesel/biofuel power plant, without battery storage, is performed in this paper. This concept is developed in order to not only make access to energy possible for rural and peri-urban populations in Africa (by reducing the electricity generation cost) but also to make the electricity production sustainable in these areas. For landlocked countries like Burkina Faso, this concept could help them reducing their electricity bill (then their fuel consumption) and accelerate their rural and peri-urban electrification coverage.     

Optimal sizing of stand-alone hybrid systems based on PV/WT/FC by using several methodologies

This paper presents a comparative study of four sizing methods for a stand-alone hybrid generation system integrating renewable energies (photovoltaic panels and wind turbine) and backup and storage system based on battery and hydrogen (fuel cell, electrolyzer and hydrogen storage tank). Two of them perform a technical sizing. In one case, the sizing is based on basic equations, and in the other case, an optimal technical sizing is achieved by using Simulink Design Optimization. The other two methods perform an optimal techno-economical sizing by using the hybrid system optimization software HOMER and HOGA, respectively. These methods have been applied to design a stand-alone hybrid system which supplies the load energy demand during a year. A MATLAB-Simulink model of the hybrid system has been used to simulate the performance of hybrid system designed by each method for the stand-alone application under study in this work. The results are reported and discussed in the paper.     

热力系统控制可容错性分析与应用研究

根据系统可控性和可观测性理论，通过对控制系统中元(部)件冗余性、冗余度的分析，研究故障系统可容错的条件，对稳压器压力控制系统进行可容错性定量分析；通过分析控制系统的部件对系统的静态性能、动态性能的影响程度，容错控制系统的部件重要度分析，确定引起控制系统故障的关键部件。