大容量电站锅炉过热器再热器温度偏差原因及防止对策

本文分析了电站锅炉过热器、再热器发生超温爆管的各种原因,并提出了防止汽温偏差过大的对策。文中总结了多年来在解决电站锅炉过、再热器超温方面的科研成果,并列举了若干国产及进口大容量电站锅炉过、再热器超温爆管问题的实例及解决办法。     

姚孟电厂进口2×300MW机组汽水系统的技术特点及改进措施

姚孟电厂进口机组汽水系统设计合理、设备性能良好,取得了令人满意的运行效果,深受用户好评.本文在充分肯定姚孟电厂进口机组整体性能的基础上,深入分析了锅炉启动系统热态启动性能不良的原因并提出了改进方案;深入分析了锅炉再热汽温采用喷水减温方式对机组经济性的影响及改用摆动燃烧器调温的可行性和经济性.图2表1参4     

350MW超临界墙式切圆锅炉汽温偏差试验研究及分析

近年来,350MW超临界墙式切圆锅炉得到逐步推广,该炉型普遍存在汽温偏差较大的问题,部分锅炉汽温偏差过大,影响其安全、经济运行。基于某厂350MW超临界墙式切圆锅炉汽温偏差分析及调整解决措施,提出解决该问题的主要应对思路,可供同类问题参考。     

锅炉低负荷下SCR入口烟温提升方案对比研究

为了解决燃煤电站锅炉在中低负荷时,由于SCR入口烟温低于SCR催化剂最佳反应温度范围而导致SCR效率低以及氨逃逸率增加而引起空气预热器的堵灰等问题,以广东某电厂600MW机组锅炉为研究对象,在50%THA、60%THA和70%THA工况下通过热力计算对比分析了4种不同的烟温提升方案,结果表明:给水旁路和省煤器出口水旁路再循环方案调节能力不足,不具备可行性;当所需SCR入口烟温调节幅度在0℃～40℃范围内,省煤器烟气旁路方案有较好的调节能力,但排烟温度会升高,需耦合使用低温省煤器改造等手段消除排烟温度升高带来锅炉效率下降的影响;而省煤器分级改造虽受预留空间及改造费用的影响,但具有明显的烟温调节能力,当移除面积小于原省煤器的50%时,SCR脱硝系统其进口烟温调节幅度在0℃～40℃范围内,又能满足在高负荷下正常运行,且不至于使排烟温度升高,对锅炉运行的经济性不会产生影响。     

东方自主开发型300MW循环流化床锅炉的床温控制

引进型300MW循环流化床锅炉中，采用了外置式换热器的布置方式，这样的设计能够有效的调节炉膛床温，但由此带来了结构复杂、控制系统繁琐等诸多问题，使锅炉运行的掌控难度加大。而东方自开发300MW循环流化床锅炉方案中，与引进型方案最大的不同之处就在于取消了外置式换热器的布置，并采用了东方传统的炉内布置屏式受热面的布置型式，使锅炉整体布置大为简化，运行的控制也得到简化。本锅炉方案一经推出，就得到了国内外广大用户的青睐，但运行中如何对床温进行调节是目前许多用户担心的问题。本文主要从保证床温均匀性和防止床层超温两个方面，介绍了东方自主开发型3000MW循环流化床锅炉床温的控制技术。     

菏泽1025 t/h W型火焰锅炉的技术特点

菏泽发电厂1 025 t/h锅炉是从英国MBEL公司进口的W型火焰锅炉,简要分析介绍了该锅炉的有关技术特点、系统配置以及调试、运行状况.     

700℃四角切圆П型锅炉烟温偏差优化控制

为了研究700℃锅炉的烟气热偏差特性,采用计算流体力学的方法对1台700℃等级四角切圆П型锅炉展开数值模拟研究。基于商用的CFD软件,分析了700℃锅炉的烟气热偏差特性和形成机理,研究了燃尽风的反切和燃尽风的速度偏置对炉内速度场、温度场的影响,重点针对炉膛出口附近的速度分布和温度分布,进行烟气热偏差优化控制。结果表明:当分离燃尽风(SOFA)反切25°时,炉膛出口烟温偏差为63.23 K;相对于反切0°,烟温偏差的降幅达到51.43 K;当右侧SOFA风的速度与左侧SOFA风的速度比值为1.3∶1时,炉膛出口烟温偏差为39.31 K,相对于SOFA风没有偏置时,烟温偏差降低了23.92 K。     

660MW超超临界塔式锅炉优化设计

在总结660 MW超超临界Ⅱ型锅炉和1 000 MW超超临界塔式锅炉的设计经验及实际运行情况,比较Ⅱ型锅炉和塔式锅炉的主要特点的基础上,结合具体工程要求和容量等级,对660 MW超超临界塔式锅炉的汽水流程、燃烧系统、汽温偏差、空气预热器等方面进行了设计优化,研制了660 MW超超临界塔式锅炉,并通过了实际运行机组的验证.     

大容量高效锅炉受热面壁温测点布置方法

本文结合国内首台1000MW双切圆π型二次再热锅炉受热面壁温运行情况,分析现有壁温测点布置存在的问题,总结得出各受热面壁温测点布置原则及方法,为后续锅炉受热面壁温测点布置提供依据。     

略谈东锅DG35/3.82-17型循环流化床锅炉的改进和优化

本文介绍了DG35/ 3 82 - 17型循环流化床锅炉结构及其在石狮热电厂运行情况 ,深入分析热态运行的主要特点 ,同时指出运行中存在的过热汽温偏高、风帽磨损等问题 ,并对该型锅炉提出了改进和优化设计的意见。     

华能珞璜电厂W型火焰锅炉的特点分析

华能电力公司从国外引进多台W型火焰型锅炉。华能珞璜电厂锅炉采用的是STEIN公司技术,由于在结构上是瘦高型,比其他几台锅炉高10m左右,燃烧器采用直流缝隙式,单台燃烧功率小,侧墙风量小,再热器减温水采用喷水调节。和华能另外几个厂的W型火焰锅炉在性能上相比,其燃烬特性、结渣特性、调峰特性和温度特性等都较为良好,有着鲜明 的特点。在W火焰锅炉这一炉型中,该锅炉是设计较为成功的炉型。     

Improving Steam Boiler Operation by On-Line Monitoring of the Strength and Thermal Performance

The operation of steam boilers with high efficiency requires control of thermo-hydraulic and strength parameters in the on-line mode. During operation under transient conditions, there are significant temperature differences over the circumference of the horizontal pressure vessels. This occurrence is caused by the different values of heat transfer coefficients on the inner surface of the boiler drum in the water and steam region. Large thermal stresses can occur in partially filled horizontal vessels. This takes place in large steam generator drums, superheater headers, and steam pipelines. The paper presents a method for determination of thermo-flow parameters for steam boilers. This method allows performing the calculations of the boiler furnace chamber and heating flow rates absorbed by superheater stages. These parameters are important for monitoring the performance of the power unit and determining the degree of the furnace chamber slagging. Knowledge of these parameters allows determining the degree of the furnace chamber slagging. The calculation can be performed in online mode and use to monitoring of steam boiler. The presented method allows to the operation of steam boiler with high efficiency.     

Prediction of silica carry-over and solubility in steam of boilers using simple correlation

Silica content of the boiler water is critical for steam turbines and scaling of boiler heat transfer surfaces. Silica (SiO₂) can volatilize with the steam in sufficient concentrations to deposit in steam turbines leading to scale formation on boiler surfaces. In this work, a simple correlation is presented to predict silica (SiO₂) solubility in steam of boilers as a function of pressure and water silica content. The solubility of silica in steam directly depends on both the density and temperature of steam. With decreasing temperature and density, solubility of silica reduces. As the pressure affects steam density which has a strong bearing on steam temperature, it has an important effect on the solubility of silica in steam. The proposed correlation predicts the solubility of silica (SiO₂) in steam for pressure up to 22,000 kPa and boiler water silica contents up to 500 mg/kg. The predictions from the proposed correlation have been compared with reported data and found good agreement with average absolute deviation being around 4%. This simple-to-use correlation can be of immense practical value for the engineers to have a quick check on silica (SiO₂) solubility in steam of boilers as a function of pressure and water silica content at various conditions without performing any experimental measurements. In particular, personnel dealing with the utility boilers would find the proposed approach to be user friendly involving no complex expressions with transparent calculations.     

IGCC系统关键部件的选择及其对电厂整体性能的影响——(2)余热锅炉篇

由于气化炉类型不同,合成气冷却器副产蒸汽的数量和品位不同,导致在应用于某些类型气化炉的IGCC系统时,优化后采用的余热锅炉在限定排烟温度的条件下,不能满足设计的节点温差.采用GT PRO软件,将目前几种主要型式余热锅炉配置到气化炉的IGCC系统中,通过对全厂技术和经济性能的模拟和比较,以选取最优的余热锅炉配置.     

大容量高参数D型锅炉的结构特点和关键技术

论述大容量高参数D型锅炉的设计以及此锅炉在总体布置和结构设计上的突出特点。重点分析锅炉各主要部件的重力传递体系、对流管束和侧水冷壁的力学稳定性、D型锅炉热膨胀系统和锅筒胀管结构等有别于其它类型锅炉的设计难点,并为解决这些难点在设计中所采取的关键技术。该型锅炉具有结构紧凑、体积小和重量轻等优点,可被用于发电、供汽和其它工业用途,特别是可在石化工业中广泛应用。     

D型锅炉的设计结构特点及其发展

D型锅炉以其结构紧凑 ,占地小 ,安装周期短 ,运行维护方便等特点 ,在国内石油化工系统得到了广泛的应用。早期该型锅炉全部为进口 ,自哈尔滨锅炉厂有限责任公司为扬子石化公司设计制造的国内首台D型锅炉投运之后 ,国产D型锅炉在国内市场所占的份额在逐年增加 ,本文以哈锅为扬子石化、齐鲁石化提供的两台D型锅炉为例 ,介绍了D型锅炉的结构特点及国内D型锅炉的发展情况。随着我国能源结构的调整 ,D型锅炉将会得到更广泛的应用。     

某小型燃煤工业锅炉的节能改造分析

通过对某锅炉的运行现状分析,发现存在运行热效率低、锅炉出力低、排烟温度高、炉渣含碳量高等问题,采取余热利用、锅炉风室改造、水处理设备改造及加强管理人员和锅炉操作人员培训等措施,锅炉热效率提高了11.41％,吨汽耗煤量降低了9.90％,锅炉出力提高了8.63％.     

Application of an empirical model in CFD simulations to predict the local high temperature corrosion potential in biomass fired boilers

To gain reliable data for the development of an empirical model for the prediction of the local high temperature corrosion potential in biomass fired boilers, online corrosion probe measurements have been carried out. The measurements have been performed in a specially designed fixed bed/drop tube reactor in order to simulate a superheater boiler tube under well-controlled conditions. The investigated boiler steel 13CrMo4-5 is commonly used as steel for superheater tube bundles in biomass fired boilers. Within the test runs the flue gas temperature at the corrosion probe has been varied between 625 °C and 880 °C, while the steel temperature has been varied between 450 °C and 550 °C to simulate typical current and future live steam temperatures of biomass fired steam boilers. To investigate the dependence on the flue gas velocity, variations from 2 m·s⁻¹ to 8 m·s⁻¹ have been considered. The empirical model developed fits the measured data sufficiently well. Therefore, the model has been applied within a Computational Fluid Dynamics (CFD) simulation of flue gas flow and heat transfer to estimate the local corrosion potential of a wood chips fired 38 MW steam boiler. Additionally to the actual state analysis two further simulations have been carried out to investigate the influence of enhanced steam temperatures and a change of the flow direction of the final superheater tube bundle from parallel to counter-flow on the local corrosion potential.     

富氧燃烧技术用于链条燃煤蒸汽锅炉的合理性和可行性

在分析了富氧燃烧技术特点的基础上,根据某单位5台链条蒸汽锅炉的实际运行情况,从提高炉膛温度、锅炉出力、锅炉热效率及减少污染物排放的实际需要和比较成熟的富氧燃烧技术两方面,论述了富氧燃烧技术用于20t／h链条蒸汽锅炉改造的合理性和可行性。     

The service life of steam boiler drums

The occurrence of cracks in steam boilers made in the Federal Republic of Germany, the Soviet Union and the German Democratic Republic led to a detailed investigation of the state of steam boiler drums in Czechoslovakia, and to an analysis of the computing methods used in operation. The properties of the material—particularly resistance to high-cycle fatigue, low-cycle fatigue and thermal fatigue—were studied on 15223 (cf ASTM A302) steel, a grade which is most frequently used in Czechoslovakia for the production of high-pressure steam boiler drums. This made it possible to plot a limit fatigue life for boiler drums made from this steel.