南京热电厂5号锅炉技术改造

南京热电厂5号炉长期存在锅炉效率偏低等问题。由于原来汽机额定负荷为110 MW,锅炉负荷一直未超过355 t/h。在机组出力提高至135 MW的同时,锅炉出力必须恢复到400 t/h。为提高锅炉运行的安全性和经济性,决定对5号炉进行一整套的技术改造。改造前后试验结果表明:5号炉技术改造大大提高了锅炉运行的经济性和安全性。5号炉技术改造的成功经验可以为同类型机组技术改造提供参考依据。     

锅炉燃用低热值水煤浆遇到的问题及解决办法

介绍了万丰热电厂水煤浆锅炉改烧低热值混煤水煤浆后锅炉负荷下降的情况及解决办法。对两种水煤浆燃烧所需的送风量及烟气量的计算表明,引风出力不足是引起锅炉负荷下降的主要原因。为此进行了尾部烟道改造,减少烟气阻力;增加一台引风机,加大引风量。改造效果显著,锅炉负荷由166 t/h提高到176 t/h。     

发电厂锅炉引风机节能改造

武汉凯迪公司自主研发的生物质直燃循环流化床锅炉,试验锅炉为240 t/h循环流化床锅炉,每台炉配备两台电机功率800 kW的型号为Y6-40-26F引风机,单台引风机锅炉平均负荷170 t/h,为满足汽机接带负荷,需要启动两台引风机,运行方式不经济,通过技术改造,可实现节能目的。     

某锅炉出力不足及排烟温度高改造

锅炉自投运以来,因炉膛和高温过热器管隙等处结焦严重,额定240 t/h煤粉锅炉实际只能在160 t/h左右运行;设计排烟温度135℃实际运行时达到了190~210℃。改造后该炉在目标出力200 t/h下长周期稳定运行,排烟温度降至130℃,炉膛内基本不结焦,锅炉整体效率提高约6.5%。     

锅炉技术改造及性能试验

某热电厂安装3台SHF-35-39/450型沸腾炉,为了提高经济效益,将沸腾炉改为循环流化床锅炉,改造后,由于锅炉采用平面流分离器,分离效率低,锅炉存在达不到额定出力等问题.又对1号锅炉进行了第二次技术改造,锅炉出力由35 t/h提高到42 t/h,达到设计要求.     

SHL6.5—13—A型锅炉送风装置的节能改造

一、SHL6.5—13—A型锅炉简介 SHL6.5—13—A型锅炉,系重庆锅炉总厂产品,该炉为双横汽包,链条炉排。按近似贫煤的混合烟煤设计,适用Ⅱ、Ⅲ类烟煤及混合煤。 该炉燃烧设备采用厂标6.5t/h、10t/h、20t/h锅炉通用化设计的鳞片式链条炉排。这种型式炉排具有漏煤损失小,运行稳定可靠,不停炉可调换炉条等优点。 炉排由24型齿轮变速箱带动,借助四档转速来改变炉排运转速度,以适应负荷及燃烧调整的需要。     

增压风机运行方式优化及经济性分析

通过试验确认低负荷时引风机出口烟气能克服脱硫系统的沿程阻力,当锅炉总风量低于1 700t/h以下时,脱硫系统停运增压风机,保持动叶全开,引风机适当增加出力,可满足锅炉和脱硫系统安全稳定运行,显著降低了厂用电耗.取得了良好的经济效果.为防止其对锅炉运行产牛影响,在设计控制逻辑时采取了相应的预防措施.,对炉瞠负压波动大、引风机失速、烟气泄漏等方面的问题进行了分析,提出了解决问题的可行性方案,能够保证锅炉的稳定运行.     

35t／h链条炉节能综合改造

在我国的许多地方小型火电厂中,目前运行着数十台某锅炉厂产的35t/h链条炉.该炉设计煤种为无烟煤,设计热效率为78%但在我们所调查的河北、河南、山西的十多个电厂的二十几台该型炉中,没有一台锅炉的运行达到了设计情况,其运行热效率多数仅在70%左右,且部分锅炉还达不到额定出力,长期在低负荷下运行.经过对这些锅炉的运行情况观察我们发现,它们存在着一个共同的问题,就是炉渣含碳量都很高,多数在40%以上,有的甚至高达55%.进一步分析发现,造成上述现象的原因基本上是相同的,主要是由于锅炉本身结构存在着不足,     

甘蔗渣锅炉燃烧装置的节能改造

我国很多地区都采用固定炉排烧生物质燃料的锅炉,这些锅炉大都存在炉排易结渣、燃烧效率低、因燃烧故障事故停炉多等问题。通过对某糖厂85 t/h甘蔗渣锅炉燃烧装置进行改造,彻底解决了该甘蔗渣锅炉炉排堆渣结焦现象,提高了锅炉燃烧效率,解决了因炉排结焦停炉事故的发生,达到了较好的节能效果。     

链条锅炉节能降耗综合改造

链条锅炉煤种适应性差,不适于单烧无烟煤及结焦性强和低发热量的劣质煤;燃烧不完全使锅炉出力不足;对负荷适应力差,运行不稳时,炉渣含碳量高;结构复杂炉排、侧密封故障多,司炉劳动强度大。针对以上问题,本文主要介绍通过加装分层给煤装置、改进炉拱、炉排及侧密封结构等来改善配风,强化煤质引燃和燃尽,从而增加锅炉出力,提高热效并降低烟尘排放：某20t／h锅炉经改造后,锅炉热效率提高10％左右,每小时耗煤量减少0．2t,机械不完全燃烧损失降低8％,气体不完全燃烧损失降低0．41％,节能减排效果较为明显。     

Experimental studying of a small combined cold and power system driven by a micro gas turbine

A small combined cold and power (SCCP) system is presented. An experimental study of the performance of the SCCP system is described. The gas fuelled SCCP system uses a micro gas turbine generator set and an absorption chiller. The test facility designed and built is also described. The rated electricity power of the micro gas turbine generator is about 24.5 kW at the experimental conditions. When exhaust gas from the micro gas turbine is used to drive the absorption chiller, the rated cooling capacity is 52.7 kW without supplying fuel to burn in the absorption chiller and 136.2 kW with supplying about 78.9 kW LPG fuel to burn in the absorption chiller, respectively. Primary energy rate (PER) and comparative saving of primary energy demand are used to evaluate the performance of the SCCP system. PER of the SCCP system decreases rapidly with the decrease of electric power output when the electric power output is less than 10 kW. The calculated results also show that comparative saving of primary energy demand of the SCCP system decreases with the decrease of electric power output and the SCCP system do not save primary energy comparing to conventional energy system when the electric power output is less than 10 kW.     

DZL58-1.25/130/70型链条炉低负荷下的燃烧优化

链条炉低负荷运行时,存在热效率低、燃烧不完全等问题。燃烧优化可以达到节能减排的目的。本文认为链条炉的煤层厚度、炉排行进速度通过试验方法进行优化,是链条炉低负荷运行时实现燃烧优化的因素之一。结合在线仪表或采用烟气、煤质分析设备进行实际工况的热平衡测试,以烟气过量空气系数、炉渣含碳量、飞灰可燃物含量、热效率作为评判指标寻求优化值并在低负荷运行时执行。选用一台DZL58-1.25/130/70型链条炉在60%额定负荷运行时进行了煤层厚度、炉排行进速度的优化试验,得到优化数值并在运行中得到应用,使该链条炉低负荷运行时热效率有所提高,达到很好的燃烧优化效果。     

内燃机冷热电联产系统设计点性能分析

简介内燃机冷热电联产系统的发展现状,总结了发电用内燃机在设计点工况下主要参数的现有分布范围:排气温度约为450~600℃,排气流量基本上与额定功率呈线性关系,发电效率一般在33%~45%。对联产系统不同形式的能量输出、联产系统经济效率等进行分析研究,表明联产系统回收的能量主要来自排气和冷却水,排气回收能量一般高于冷却水回收能量。与热电联产系统相比,由于制冷比供热困难,冷热电联产系统的经济效率较高。     

First and second law thermodynamic analysis of a single and dual-stage ignition biomass downdraft gasifier

The dual-stage ignition biomass downdraft gasifier is an enormous tar reduction technology as against a single-stage ignition biomass gasification. Exergetic analysis of the system guides toward a possible performance enhancement. In dual-stage gasification, around 67.76% of input exergy is destructed in the several components, while 9.16% is obtained as a useful exergy output and 24.34% is found to be as a useful energy output there. The entire unit was assessed with a progressively rising electric load from 15.24 kW to 38.86 kW. The enhanced producer gas quality comes from 57% combustible gas with a higher heating value of 6.524 MJ/Nm³ and tar content of 7 mg/Nm³ after the paper filter, whereas the biomass consumption rate is 58 kg/h at the greatest load with the grate temperature of 1310–1370 °C. The samples of exhaust gas emissions are obtained environmentally favorable. The results even described that the dual-stage ignition biomass downdraft gasifier has significantly greater energetic and exergetic efficiency as compared to the single-stage gasifier.     

Techno‐economic analysis of renewable energy source options for a district heating project

With the increased interest in exploiting renewable energy sources for district heating applications, the economic comparison of viable options has been considered as an important step in making a sound decision. In this paper, the economic performance of several energy options for a district heating system in Vancouver, British Columbia, is studied. The considered district heating system includes a 10 MW peaking/backup natural gas boiler to provide about 40% of the annual energy requirement and a 2.5 MW base‐load system. The energy options for the base‐load system include: wood pellet, sewer heat, and geothermal heat. Present values of initial and operating costs of each system were calculated over 25‐year service life of the systems, considering tax savings due to depreciation and operating costs, and salvage value of equipment and building and resale price of land in the cash flow analysis. It was shown that the natural gas boiler option provided less expensive energy followed by the wood pellet heat producing technologies, sewer heat recovery, and geothermal heat pump. Among wood pellet technologies, the grate burner was a less expensive option than powder and gasifier technologies. It was found that using natural gas as a fuel source for the peaking/backup system accounted for 37% of the heat production cost for the considered district‐heating center. The results show that the cost of produced heat from wood pellet grate burner is well comparable to that of the natural gas boiler. Emissions of the systems are also calculated in this study. It is shown that the natural gas boiler for the base‐load heat production would produce more than 4300 tonnes of GHG emission per year, while wood pellet burning systems are GHG neutral. Sensitivity analysis on various inputs to the economic model has been carried out. It was shown that 20% increase in capital cost of the natural gas base‐load system or 1% decrease in wood pellet price inflation would make the wood pellet grate burner economically preferable to the natural gas boiler. Copyright © 2009 John Wiley & Sons, Ltd.     

燃用非设计煤种链条炉排锅炉过热蒸汽超温改造

DHL 35—450/3.82—AⅡ型链条炉排锅炉因燃用非设计煤种,导致炉内燃烧恶化,炉膛出口出现大量炽热粒子冲刷过热器,使得过热蒸汽超温,锅炉出力下降。针对上述问题,提出了评价粒子流冲刷过热器所引起的传热影响的计算方法和炉拱改造方案,并采用CFD技术,对炉拱改造前后的炉内流场进行了模拟与对比。研究结果表明,通过改造炉拱,改善了炉内燃烧工况,炉内火焰充满度高,形成了"α"火焰,消除粒子流,使锅炉性能得到优化。     

10 MW级深冷液化空气储能发电系统自动启动控制方法研究

以10 MW级深冷液化空气储能发电系统为研究对象,简要介绍了技术原理、系统构成、主要设备及工艺流程,并从自动控制视角,分别设计了储、释能阶段的启动方法。基于该自动启动方法,可完成储能阶段空气净化及压缩、空气液化、储热和蓄冷子系统的联合运行以及释能阶段储热、蓄冷和膨胀发电子系统的联合运行,实现了储能阶段自动达到额定出液量及释能阶段自动满足额定发电量的需求,提高了能量型机械储能系统对电网负荷变化的响应速度。     

城市生活垃圾焚烧炉的仿真

以天津双港垃圾焚烧发电厂的日处理垃圾400t／d往复移动式炉排垃圾焚烧炉为对象，结合垃圾热解燃烧特性，建立了综合数学模型并进行了仿真计算。首先在额定工况下计算了垃圾料层内温度分布、挥发分和固定碳燃烧情况，炉膛出口烟温T1和烟气含氧量随时间的变化。然后计算了在垃圾性质突变和炉排速度阶跃改变两种情况下T1随时间的变化。计算结果显示：模型特性与实际焚烧炉特性十分符合，现该模型已用于实际的仿真培训系统。图11表3参1     

Exergy analysis,parametric analysis and optimization for a novel combined power and ejector refrigeration cycle

A new combined power and refrigeration cycle is proposed, which combines the Rankine cycle and the ejector refrigeration cycle. This combined cycle produces both power output and refrigeration output simultaneously. It can be driven by the flue gas of gas turbine or engine, solar energy, geothermal energy and industrial waste heats. An exergy analysis is performed to guide the thermodynamic improvement for this cycle. And a parametric analysis is conducted to evaluate the effects of the key thermodynamic parameters on the performance of the combined cycle. In addition, a parameter optimization is achieved by means of genetic algorithm to reach the maximum exergy efficiency. The results show that the biggest exergy loss due to the irreversibility occurs in heat addition processes, and the ejector causes the next largest exergy loss. It is also shown that the turbine inlet pressure, the turbine back pressure, the condenser temperature and the evaporator temperature have significant effects on the turbine power output, refrigeration output and exergy efficiency of the combined cycle. The optimized exergy efficiency is 27.10% under the given condition.