高压加热器停用时最佳调整方法的探讨

针对电厂高压加热器(简称高加)投入率较低的问题,采用最优化技术,找出高加停用时的最佳运行参数,从而使机组的经济性达到高加停用时的最优值,对指导生产具有一定的意义。     

转子定参数和滑参数启动模拟的对比分析

汽轮机在启动过程中发生复杂的非稳态传热现象。以某汽轮机转子为研究对象,借助有限元方法模拟计算并对比分析了在定参数和滑参数两种启动方式下,转子温度场和应力场随时间的变化过程。结果表明在定参数启动过程中,转子表面温度变化比滑参数启动更为快速和剧烈,同时,将会导致较大的热应力峰值,带来更多的寿命损耗。而提高转子体的初始温度可降低应力峰值大小。该计算分析结果对汽轮机机组的启动和运行具有一定的参考意义。     

中间再热锅炉的启动旁路系统与再热器的安全性问题

启动旁路系统是电站锅炉向高参数、大容量发展过程中产生的新课题。本文认为,启动旁路系统是锅炉在启动和事故情况下的一种调节和保护系统。在设计启动旁路系统时,不能以事故情况下再热器的安全问题作为主要考虑因素,而应该以启动(尤其是滑参数启动)时,如何解决锅炉供汽和汽机用汽     

600 MW超临界火力发电机组高加泄漏风险预控及操作

600 MW超临界火力发电机组中的高压加热系统对于机组的效率、经济性有非常重要的作用,一旦高加系统发生故障,轻则导致机组效率降低、重则导致机组停机甚至设备损坏。因此,在机组运行过程中,有效的监视高加系统及相关参数等,可以及时的判断出高加是否存在故障,并做好风险防范,把高加泄漏故障消除于最初状态,使得机组经济性及安全性得到极大的保障与提升,对于同类机组有一定的借鉴意义。     

142 MW螺旋管高压加热器的研制开发

介绍了 142MW螺旋管高加的设计结构及参数的确定 ,叙述了该高加制造关键零件的工艺及关键节点的技术保证措施 ,分析了关键零件的测试结果和技术改进方法 ,得出该高加开发试制成功的结论     

生活垃圾焚烧发电项目再热技术以及热力系统的设计研究

本文介绍了再热技术在生活垃圾焚烧发电领域的应用情况以及国内外再热机组应用现状,讨论了余热锅炉蒸汽参数的选择比较并提出了推荐的蒸汽参数,讨论了汽轮机回热系统是否带高加和除氧器的滑压与定压运行问题。提出了汽轮机回热系统带高加运行和除氧器采用滑压运行方式,有利于提高机组的经济性。     

超超临界机组主给水泵移至高加出口方法研究

针对超超临界机组高压加热器(简称高加)汽水两侧压差急剧升高后所带来的问题,提出了一种降低汽水两侧压差的方法即将主给水泵的位置由高压加热器进口移动到高压加热器的出口,并以某电厂1 000MW超超临界机组为例,对主给水泵位置变化后所带来的问题进行了研究,并提出了相应的应对措施。研究结果表明,主给水泵位置变化后,高加汽水两侧压差大幅度降低到9.5MPa,并且对主给水泵的启动和运行不会带来影响。     

引进型300MW机组装设2×5%MCR启动疏水旁路的实践

针对高低压二级串联旁路在引进型300MW机组上功能不能充分发挥的情况，另在机侧设置5%MCR启动疏水旁路，现已通过试运行，除高加危急疏扩有些问题，需要处理外，其余情况良好。     

AP1000核电二回路高压加热器疏水管路布置优化

为提高核电机组的经济性,研究了AP1000核电机组二回路高压加热器(后面简称高加)疏水管路布置,利用EBSILON平台搭建5种不同的疏水管路布置方案仿真模型,分析不同方案的热经济性。分析得出TMCR工况下7号高加疏水自流到6号高加,6号高加疏水至前置泵出口的布置方案的热经济性最好,供电热耗减少7.09J/(kW·h),若机组长期变负荷运行,建议采用7号高加疏水至前置泵出口,6号高加疏水自流到除氧器的布置方案。     

高压加热器疏水自动化的节能

一、前言 我厂一期工程共有两台ZJ—110G型高压加热器(简称高加)。自1986年投运至今五年来,高加一直处在假水位(实际是无水位)运行状态,使得高加疏水带汽,不仅浪费了加热蒸汽,还会影响除氧器的正常运行。高加疏水自动化的投入,可以使高加保持一定的低水位,杜绝疏水带汽,达到节能降耗的目的。本文主要介绍我厂高加疏水自动调节系统的更改方案与投试经验。     

火电机组高压给水加热器动态过程的数值分析

通过对高压加热器的动态数值仿真计算,分析了高压加热器泄漏和汽轮机负荷增大对高压加热器的特征参数,如给水出口温度、抽汽管道压损、疏水温度和疏水水位的影响,以及在疏水水位相同时、不同运行状态下的高压加热器各特征参数的差异;分析了高压加热器泄漏和汽轮机负荷增大对高压加热器给水管热应力的影响。结果表明:单纯凭借疏水水位的升高不能判定高压加热器是否发生泄漏,需要根据其他特征参数的变化来判断引起疏水水位的升高的是否是由泄漏引起的。图5表1参4     

新技术在600MW高压加热器制造中的应用

600MW高压加热器在制造工艺上采用了先进的管板深孔钻、管子与管板液压胀接等先进技术,保证了产品设计制造质量。     

高压给水加热器泄漏的动态仿真与故障特征提取

通过对高压加热器的动态数值仿真计算,分析了高压加热器泄漏时对其运行参数,如给水出口温度、抽汽管道压损、疏水温度以及疏水水位的影响,并由此提取了表征高压加热器泄漏时的故障特征量,为完善建立高压加热器故障知识库并对其进行泄漏故障的早期诊断奠定了基础。     

采暖锅炉供水应注意的几个问题

本文从锅炉供水点、水泵的选择上，介绍应注意的几个问题，同时要考虑管网系统压力差。在热源、管网布局以及系统流量影响压力差上要特别注意。     

蛇形管高压加热器用于1 000 MW二次再热机组的可行性分析

随着1 000 MW二次再热机组设计参数越来越高、采用传统单列U形管高压加热器也越来越受到限制,当前新上二次再热机组不得不采用双列U形管高压加热器,从而使得主给水系统复杂、运行困难。结合U形管高压加热器,对比分析了新型高压加热器(即蛇形管高加)技术特点及国产化现状,指出在1 000 MW二次再热机组应用蛇形管高压加热器是可行的,并具有结构及系统简单、热适应性好、可靠性高等优势,推荐在同类工程中应用,为适应末来更高参数超超临界机组的高压加热器制造技术发展打下基础。     

Exergetic analysis of solar concentrator aided natural gas fired combined cycle power plant

This article deals with comparative energy and exergetic analysis for evaluation of natural gas fired combined cycle power plant and solar concentrator aided (feed water heating and low pressure steam generation options) natural gas fired combined cycle power plant. Heat Transfer analysis of Linear Fresnel reflecting solar concentrator (LFRSC) is used to predict the effect of focal distance and width of reflector upon the reflecting surface area. Performance analysis of LFRSC with energetic and exergetic methods and the effect, of concentration ratio and inlet temperature of the fluid is carried out to determine, overall heat loss coefficient of the circular evacuated tube absorber at different receiver temperatures. An instantaneous increase in power generation capacity of about 10% is observed by substituting solar thermal energy for feed water heater and low pressure steam generation. It is observed that the utilization of solar energy for feed water heating and low pressure steam generation is more effective based on exergetic analysis rather than energetic analysis. Furthermore, for a solar aided feed water heating and low pressure steam generation, it is found that the land area requirement is 7 ha/MW for large scale solar thermal storage system to run the plant for 24 h.     

新型核电机组启停及给水系统控制策略

  目的  采用研究、分析和归纳的方法,得到机组启停、给水、旁路的控制策略。  方法  参考项目经验,借鉴核电常规岛和火电机组的先进设计理念,对机组工艺系统的设备进行优化,相应优化控制策略,主要考虑“机组启停和旁路系统”和“给水系统”控制策略优化。  结果  研究机组启停控制策略2个方案;给水控制策略5个方案;旁路控制策略3个方案。  结论  “机组启停控制策略”采用方案一,控制策略较简单,较方案二耦合少,经济性较合理。“给水系统控制策略”采用方案二（母管制）控制方案合理,经济性好,系统运行安全;“旁路控制策略”采用方案一,方案一经济性好,保护控制逻辑完善。     

A water heater using very high‐temperature storage and variable thermal contact resistance

This paper describes the role of thermal contact resistance in a high‐temperature sensible heat storage water heater using cast iron as a storage material. An experimental set‐up consisting of a cast iron cylinder and a stainless‐steel tube running through its centre was fabricated and tested. The experimental data were compared with a theoretical model. It was observed that the variation in thermal contact resistance between the cast‐iron blocks and the tube with temperature plays a dominant role in extracting the heat at a reasonably constant temperature. The contact resistance between two contacting surfaces was modelled as the composite of two parallel resistances: one due to the points where two surfaces contact each other and the other due to a gap between the surfaces, which is often air filled. An approximate contact resistance prediction was obtained by assuming the resistance due to the air gap modulated by a correction factor which accounts for the contacting surface area. Based on the results from the experimental set‐up and theoretical modelling, a prototype storage water heater using cast‐iron blocks as the storage material was designed, fabricated and tested. Copyright © 2001 John Wiley & Sons, Ltd.     

Exergetic utilization of solar energy for feed water preheating in a conventional thermal power plant

This communication is based on exergy concept for the utilization of solar thermal energy in a Rankine cycle‐based fuel‐fired thermal power plant (FFTPP). It has been shown that solar thermal energy as an aided source for feed water preheating helps to reduce the exergy loss in feed water heater (FWH) of Rankine cycle and develops more work than that could have been produced in a solar thermal power plant (STPP). It has been found that this enhancement in work increases for low‐pressure FWHs. For further illustration, a case study has been carried out of a typical 50 kW STPP and a 220 MW FFTPP. The effect of utilizing the same input solar thermal energy of typical STPP, if used as an aided source in a 220 MW FFTPP for feed water preheating is investigated. The work output of STPP is 59.312 kW, while the extra work output of FFTPP by using solar thermal energy of STPP is 90.27 kW. It has been found that the efficiency of work conversion of aided solar thermal energy in FFTPP is higher than the efficiency of work conversion in STPP. Copyright © 2009 John Wiley & Sons, Ltd.     

Dynamic behaviour analysis of a heat recovery steam generator during start‐up

This work presents an analysis of the dynamic behaviour of a HRSG (heat recovery steam generator) during start‐up. A calculation program based on a quasi‐steady method is constructed. A typical high‐pressure HRSG is designed conceptually and analysis is performed to examine the influence of the gas inlet condition of the HRSG on its start‐up behaviour. Effects of the gas turbine operation mode and the gas bypass are analysed. In addition, the water level control during start‐up, which is one of the most important facts in the real plant operation, is simulated. Through a parametric calculation, the effect of the control parameters on the start‐up behaviour is analysed and examples of optimum control are demonstrated. Copyright © 2000 John Wiley & Sons, Ltd.