三分仓空预器防堵技术措施及系统改造方案分析

提高燃烧所需空气温度,有利于着火和燃烧,减少锅炉不完全燃烧热损失。电站锅炉空预器就是利用锅炉尾部烟道中排放的烟气热量来加热炉膛中燃烧所必需的空气,通过提高空气热量来充分使用烟气余热以及降低锅炉排烟温度的一种热交换装备,它提高了锅炉效率,是锅炉运行中不可或缺的一部分。腐蚀、堵灰、漏风和电流波动及事故停机是空预器运行中最主要的问题,将直接影响到锅炉的燃烧和效率以及送、引风机的功耗,严重时还会造成风机失速和机组带不到满负荷等严重后果。受热面回转式空预器结构紧凑、轻便,占地面积相对较小,因此随着大型电站锅炉蒸汽参数和机组容量逐渐增大,现在基本都选择采用回转式空预器。现介绍常见的三分仓容克式回转空预器防堵技术措施及系统改造方案,以解决空预器堵塞导致系统阻力上升的问题,可为锅炉的经济运行提供参考。     

空预器堵塞的原因分析及调整对策

空预器是火力发电厂锅炉中重要的辅机设备之一,主要作用是利用高温烟气来加热锅炉燃烧所需要的空气,其原理是通过连续转动的散热片,在烟气低温区域缓慢地载着传热元件旋转,使流入预热器的热烟气和冷空气完成热交换。空预器回收了烟气热量,降低了排烟温度,因而提高了锅炉效率;同时由于燃烧所需空气温度提高,有利于燃料的着火和燃烧,减少了燃料不完全燃烧的热损失。现对某厂空预器堵塞的原因及预防措施进行分析。     

循环流化床锅炉燃烧系统烟气氧含量控制

循环流化床锅炉(CFBB)具有燃煤效率高、燃料适应性广等诸多优点而广泛应用于电厂及其他工业生产过程中。通过分析循环流化床锅炉的燃烧任务与控制特点,发现锅炉燃烧系统是一个具有多参数、非线性的、时变且多变量紧密耦合的系统,其中烟气氧含量控制的好坏更是提高锅炉燃烧效率,节能环保的关键。为使锅炉运行始终保持在最佳燃烧点,可以采用带有氧量校正的串级送风调节系统或带氧量校正的送风调节系统。同时在负荷变化的过程中,为保证送风量始终略大于燃料量,采用燃料、送风的双交叉限制措施。最后,通过在某热岛中心项目所用的490t/h循环流化床锅炉上实施,验证了此烟气氧含量控制方案。     

循环流化床锅炉富氧燃烧改造探讨

通过分析富氧燃烧的理论依据,讨论了CFB锅炉结合富氧燃烧的技术优势。以国内某670t/h带外置床CFB锅炉为例,讨论了锅炉富氧燃烧技术改造的方案,并讨论了改造后的运行调整方式。     

SHP—A型锅炉二次燃烧器

本市职工技协服务中心锅炉节能专业队,根据多年从事锅炉专业的实践经验,研制成功高效率节能装置——锅炉二次燃烧器。 本装置是利用燃煤和燃油锅炉正常燃烧后,所产生的烟气中一切可燃物质与蒸汽在高温下分解出来的氢、氧元素发生化学反应,生成水煤气和部分甲烷、乙烯使之再次燃烧。同时加二次风助燃,使煤气充分而稳定地燃烧。     

燃气轮机分布式能源技术在导热油余热锅炉项目中的应用

文中介绍了燃气轮机分布式能源技术,具体为燃气轮机与余热直燃机相结合的系统、燃气-蒸汽联合循环系统和燃气轮机与余热锅炉结合的系统。并以华峰集团有限公司重庆华峰分布式能源项目为实例,阐述燃气轮机与余热锅炉结合的系统中的燃烧系统、热力系统、电力系统、环保排放及主要技术经济指标等,分析该项目的意义。     

锅炉风机的变频调速与节能

为了保证锅炉炉膛内的燃料连续不断燃烧,必须不间断地向锅炉炉膛内供应足够量的助燃空气,同时将燃烧后产生的高温烟气通过受热面、烟道及除尘器等设施降温后排入大气;要完成这一燃烧过程,蒸发量在60万大卡/h以上的锅炉一般都采用机械强制通风,随着燃烧工艺、温度、煤种、气候等因素的变化,需随时对炉膛的进出风量进行调节,以改变炉膛的燃烧工况。传统的调节方法是改变风道挡板开度以改变管路的阻力。这种方法电机的功率输出没有变,因此浪费能源较多。经我们研究后,决定在不改变原传动设备与结构的基础上,对三相交流异步电机加装变频调速器进行调速控制。该变频调速技术是通过改变交流电机的供电频率来调节电机的转速,以调节风机转速来替代调节风道挡板开度。电机转速和风机排风量的有关公式如下:     

浅析余热锅炉受热面管腐蚀原因

介绍了腐蚀性烟气对余热锅炉受热面管的腐蚀情况,并详细论述了由于复杂的烟气成分引起的余热锅炉低温腐蚀、高温腐蚀以及电化学腐蚀,并分析其形成机理及预防措施,结果表明余热锅炉在烟温高于或低于酸露点时均存在低温腐蚀现象。     

电动钻机动力系统冗余设计

针对目前电动钻机柴油发电机组动力系统运行成本高、柴油燃烧污染环境、电源单一的问题,提出采用柴油发电机组动力系统+工业高压电网动力系统的冗余供电设计方案,在工业高压电网覆盖的钻井区域采用工业高压电网动力系统为钻机供电,节约供电成本,减少环境污染.在工业高压电网无法覆盖的偏僻钻井区域采用柴油发电机组动力系统为钻机供电.柴油...     

燃煤发电机组烟气余热回收影响因素及系统优化

针对重庆松藻电力有限公司三号燃煤发电机组排烟温度高、除尘效率低、锅炉热效率低等问题,文章从该燃煤发电机组烟气回收影响因素入手,从工艺技术路线确定、受热面布设方案选择等多角度比较论证,为该发电厂确定烟气余热回收利用系统的优化方案。经理论分析,优化后的系统可明显降低燃煤发电机组的排烟温度,保证了机组运行的环保价值与经济价值。     

Parametric simulation and performance analysis of a solar gas turbine power plant from thermodynamic and exergy perspectives

Using solar energy in gas turbine cycles is a new method that can improves the efficiency of gas turbines. Placing a solar receiver before a combustion chamber can raise the temperature of the air coming into the chamber and reduce the consumption of fuel in the chamber. The system that combines a solar energy receiver with a gas turbine cycle is technically called a “solar gas turbine”. The goal of this paper is the parametric simulation and performance analysis of a gas turbine cycle equipped with a solar receiver from thermodynamic and exergy aspects of view. The selected parameters in this study, include the pressure ratio of compressor, the temperature of gases at the turbine inlet and the direct normal irradiance. The obtained results indicate that the fuel consumption of this combined system is reduced by using a solar receiver and the temperature of gases entering the combustion chamber increased. The reduction of consumed fuel, in turn, reduces the rate of exergy destruction in the combustion chamber. Another important point is that the solar receiver itself has the least amount of exergy destruction. The net power generated by a solar gas turbine cycle is 10 % higher than that produced by a simple gas turbine cycle. Also, the studies show that the electrical efficiency of a solar gas turbine cycle is about 41 % higher than the simple gas turbine cycle.

     

Investigation of nonlinear numerical mathematical model of a multiple shaft gas turbine unit

The development of numerical mathematical model to calculate both the static and dynamic characteristics of a multi-shaft gas turbine consisting of a single combustion chamber, including advanced cycle components such as intercooler and regenerator is presented in this paper. The numerical mathematical model is based on the simplified assumptions that quasi-static characteristic of turbo-machine and injector is used, total pressure loss and heat transfer relation for static calculation neglecting fuel transport time delay can be employed. The supercharger power has a cubical relation to its rotating velocity. The accuracy of each calculation is confirmed by monitoring mass and energy balances with comparative calculations for different time steps of integration. The features of the studied gas turbine scheme are the starting device with compressed air volumes and injector’s supercharging the air directly ahead of the combustion chamber.     

小型风力-压缩空气储能系统研究概述

小型压缩空气储能系统是分布式能源系统的重要组成部分，是弥补新能源发电系统波动性和随机性的一种有效方法。通过查找国内外相关文献，对小型压缩空气储能系统的关键部件进行综述，得到小型压缩空气储能技术和释能技术的发展方向。基于当前研究现状，得出结论：首先为了提高系统效率要解决耦合后功率不匹配问题，其次为满足风力发电机组空间受限的特点应对压缩空气进行一体化设计，最后对压缩空气关键技术进行总结，并给出了有待解决问题的研究方案。     

催化燃烧与旋转回热耦合的燃气轮机性能分析

低热值燃气总量巨大,种类繁多,很大一部分由于热值过低无法点火燃烧,常直接排入大气,造成能源浪费,加剧环境污染。为了利用这部分低热值燃气,提出一种催化燃烧与旋转回热耦合的新型燃气轮机系统,把催化燃烧室和高温换热器两个部件融合于一个部件中。相比传统燃气轮机,该燃机具有独特的优势:以低热值燃气为主燃料,采用催化燃烧;旋转回热保证了催化燃烧反应持续发生;结构布局更加紧凑。分析这种新型燃气轮机系统的热力循环特点,计算100 k W级新型燃机的热力性能,研究旋转周期等参数对性能的影响。结果表明:在使用甲烷浓度为2%的低浓度燃气时,透平入口温度保证在1 030~1 200 K,燃机能正常工作,从理论上证明了该新型系统是可行的;不同旋转周期之间系统运行的热力参数变化在3%以内,呈现准周期性;旋转周期之内系统运行的热力参数呈现波动变化;旋转周期减小,燃机输出功率和热效率降低,其波动性也降低。     

军用车辆动力系统技术特点及发动机选型研究

介绍了军用车辆动力系统的组成及使用要求,同时对其所用发动机的技术特点进行了阐述,并对其选型过程进行了重点研究。与转子发动机及燃气轮机进行了对比,内燃机具有高效、高可靠性、高耐久性及成本低廉等优势。对内燃机经选型后的改装过程进行了研究,最后对其进行了展望。     

基于气-液相变的等压压缩空气储能方法研究

风能和太阳能等可再生能源具有间歇性和不稳定性的特点,不能大规模接入电网。压缩空气储能作为大规模储能技术可以调节电网负荷,削峰填谷,解决上述问题。目前压缩空气储能系统的压缩空气都是在体积恒定的容器中储存,压缩空气在释放时经过减压阀节流减压至预定的较低压力,浪费了大量的有用能,导致系统效率低,压缩空气利用率低。等压压缩空气储能通过保持压缩空气在储存和释放时压力的恒定,解决系统效率低的问题。基于质量守恒和能量守恒定律,建立压缩空气的热力学模型,采用基于气-液相变的等压方法,系统效率提高了12.18%。     

Influence of gas turbine specification and integration option on the performance of integrated gasification solid oxide fuel cell/gas turbine systems with CO2 capture

We investigated key design features of the integrated gasification solid oxide fuel cell/gas turbine (IG-SOFC/GT) system including carbon dioxide capture. Two different types of system configurations that depend on the carbon dioxide capture scheme (pre- and oxycombustion captures) were examined. Research focus was given to the effect of the gas turbine specification on the performance of the entire system. IG-SOFC/GT systems using two different gas turbines were analyzed, and their performances were compared. A parametric analysis was carried out to further understand the performance comparison. We found that the net system efficiency was not very sensitive to the turbine inlet temperature and the pressure ratio. As a result, similar net efficiencies were observed between the systems using two gas turbines with quite different specifications. In addition, a revision of the system layout was investigated and it was found that the power capacity of the system could be increased and the system efficiency could also be slightly enhanced by supplying nitrogen separated from the air separation unit to the fuel cell rather than to the gas turbine combustor.     

基于大小气缸与大小活塞的新型发动机系统性能预测分析

为提高现有内燃发动机的热效率,在分析斯特林发动机以及常规发动机特点的基础上提出基于大小气缸与大小活塞的带回热器的新型发动机系统.气体在该新型发动机系统的小气缸中受到压缩,压缩的过程中喷入水雾以便降低压缩功耗.压缩后的气体在回热器中受到初步加热后进入大气缸,与喷入大气缸中的燃料混合、燃烧并做功,做功后的气体在回热器中放热后被排入大气.在对系统深入分析的基础上,建立新型发动机系统的性能计算模型.利用数学模型,计算该新型发动机系统热效率在不同压缩比、不同的最高工作温度以及不同的活塞效率条件下的变化规律,并与相同条件下的常规奥托循环与狄塞尔循环的热效率进行对比.结果表明,这种新型发动机系统比常规发动机具有更高的热效率,最多可以提高20%以上.而且新型发动机系统的效率还随着回热器的效率增加而增加,增幅可以接近10%.     

气动系统节能方法研究进展综述

针对影响气动系统效率的主要因素,从提高压缩空气制气效率、余热利用、分压供气、减少泄漏和残余能量回收再利用等节能手段,介绍了当前国内外气动系统节能的主要技术进展和新的研究成果,并进一步分析了各种节能方法的特点,提出了未来气动系统节能技术的研究重心和发展方向。有助于为探索新的节能理论和方法提供启发,推动行业技术进步。     

An experimental study on combustion efficiency of low grade anthracite in AFBC

This is the basic study to develop a fluidized bed combustion boiler which can use low grade anthracite. In this study, the anthracite of about 3400 kcal/kg was burned in the bench scale non-recycling atmospheric fluidized bed combustor of 200mm diameter and 2215mm height with the static bed height of 250mm and the combustion temperature range of 800–950°C. During the combustion, the effect of factors such as the superficial gas velocity in bed, the air ratio, the coal supply location and the coal particle size on the combustion efficiency, the elutriation ratio and the unburned carbon content both in elutriated ash and in drained ash was thoroughly analyzed. When the superficial gas velocity in bed is 0.7～2.2m/s, the air ratio is 1.0～1.6 and coal supply locations are 300,500 and 700mm above the air distributor, the combustion efficiencies range from 66% to 83.5% for the mean coal particle size of 0.209mm, and from 71% to 88% for the case of 0.265mm. The combustion efficiency decreases as the superficial gas velocity in bed and the air ratio increase. The lower the coal supply location is, the better the combustion efficiency becomes in general.