燃煤锅炉NOx排放特性及其燃烧优化

锅炉燃烧优化通常是降低NOx排放的首选方法.对某厂410 t/h锅炉NOx排放进行了试验研究,特别是锅炉运行参数对锅炉效率和NOx排放量的影响进行分析.提出在现行条件下,通过燃烧优化提高锅炉效率,减少NOx的排放方法.     

基于IMRAN的电站锅炉效率与NO_x排放模型

电站锅炉高效低NOx燃烧优化技术越来越受到人们的重视,而锅炉燃烧效率和NOx排放模型是高效低NOx燃烧优化的基础.从提高网络的泛化能力着手,对最小资源分配网络算法的隐节点删减策略进行改进,加入惩罚策略和合并策略,并把改进的MRAN算法应用到对电站锅炉NOx排放与效率的实时建模上.仿真结果表明,改进的MRAN算法除了具有一般MRAN算法的优点外,还具有比MRAN网络更加紧凑的结构.提出的网络算法具有多输出结构,可同时预测NOx排放与效率,适于用在电站锅炉的NOx排放与效率的燃烧实时整体优化中.     

基于人工神经网络和遗传算法的火电厂锅炉实时燃烧优化系统

大型燃煤电站锅炉燃烧效率的提高和污染气体的低排放对于节约能源和保护环境都有重要意义。通过燃烧优化可以提高锅炉效率、降低锅炉的氮氧化物排放、防止锅炉结焦和受热面爆管等，因而广泛得到应用。但目前燃烧优化方法往往采用现场试验方法，耗时费力，而且由于锅炉输入输出特性复杂。耦合性强，燃用煤种和操作条件变化较大，现场燃烧优化方法往往效果不佳。同时提出从DCS下载实时数据，利用人工神经网络对锅炉特性建模，并利用遗传算法实现操作参数的实时寻优。实践证明：这种方法能够实时地获得目前最佳的锅炉燃烧调整方式，对锅炉的节能降耗和降低环境污染都有重要意义。     

电站锅炉NOx排放与效率的响应特性模型

由于锅炉设备结构庞大，运行条件复杂，燃料性质多变差等因素，建立电站锅炉排放特性的函数模型难度极大．为满足锅炉高效低污染燃烧优化研究的需要，借助优化燃烧特性试验数据，建立了神经网络型与函数型的混合模型。算例表明：该模型能正确地描述电站锅炉NOx排放与效率的响应特性。图1表6参5     

直流锅炉风/煤比燃烧优化控制的研究

在分析风/煤比控制特性的的基础上,提出以炉膛辐射能信号最大为目标的寻优算法,将辐射能信号引入到锅炉送风控制回路,并在1台300 MW直流锅炉上进行了试验.结果表明:在维持正常燃烧工况下,进行实时燃烧优化策略能有效地改善机组的控制品质,提高机组的整体效率和减少NOx排放.     

基于智能算法的燃煤电站锅炉燃烧优化

基于Matlab人工智能工具包对某300MW燃煤电站锅炉进行了燃烧优化混合建模:利用BP神经网络建立了锅炉燃烧特性的BP神经网络模型,用以预测锅炉热效率和NO_x排放质量浓度.基于该模型,以锅炉热效率和NO_x排放质量浓度为目标,结合Matlab遗传算法工具包对锅炉进行燃烧优化,并采用权重系数法将多目标优化问题转化为单目标优化问题.结果表明:锅炉热效率和NO_x排放质量浓度校验样本的相对误差平均绝对值分别为0.142%和1.790%,该模型具有良好的准确性和泛化能力;权重系数法可根据实际情况,以锅炉热效率或NO_x排放质量浓度为优化重点选取相应的权重系数,对燃烧优化具有一定的指导意义.     

基于动态标杆值的电站锅炉燃烧控制优化

目前锅炉燃烧控制主要依靠人工手动调整，为解决运行经验差异导致锅炉燃烧性能差异的问题，提出了一种基于动态标杆值的电站锅炉燃烧控制优化方法。在建立燃烧模型的基础上，以归一化经济与环保指标得到综合效益因子作为寻优判据，对历史工况进行数据挖掘，实现全工况下基于动态标杆值的运行参数自主寻优和更新，使锅炉燃烧、污染物排放相互协调。该方法已于某燃煤电站成功实践，结果表明：在应用案例中，寻优推送后综合效益因子提高了4.34%,使得锅炉热效率和NO_x排放质量浓度相互协调更优。     

旋流器流量分配对燃气轮机燃烧性能的影响研究

目前锅炉燃烧控制主要依靠人工手动调整，为解决运行经验差异导致锅炉燃烧性能差异的问题，提出了一种基于动态标杆值的电站锅炉燃烧控制优化方法。在建立燃烧模型的基础上，以归一化经济与环保指标得到综合效益因子作为寻优判据，对历史工况进行数据挖掘，实现全工况下基于动态标杆值的运行参数自主寻优和更新，使锅炉燃烧、污染物排放相互协调。该方法已于某燃煤电站成功实践，结果表明：在应用案例中，寻优推送后综合效益因子提高了4.34%，使得锅炉热效率和NOx排放质量浓度相互协调更优。     

锅炉分级燃烧优化技术的研究

为减少锅炉燃烧所产生废气排放带来对环境的污染，达到高效低污染的可持续性发展要求，其技术改造和经济运行将愈显重要。建立了基于BP网络的模型及遗传算法的相应优化方法，进行了锅炉分级燃烧改造后的性能优化，可为锅炉的经济优化运行提供科学指导依据。图4参12     

燃烧优化指导系统在600MW机组节能减排中的应用

锅炉燃烧优化控制技术能在不进行锅炉设备改造的前提下,通过海量有效历史运行数据的训练,建立锅炉优化运行的数学模型,来提高锅炉运行效率及降低锅炉NO_x排放。介绍了Power Wizard电站锅炉燃烧优化系统软件以及在某600 MW机组锅炉的实际应用效果,为火电机组的节能减排提供了解决方法。     

船用中速柴油机性能的优化研究

为提升燃油系统电控化改造后4190ZLC-2船用中速柴油机的经济性能和排放性能,开展了燃油系统多参数优化试验;利用AVL FIRE软件对试验得到的经济性最优匹配参数下的柴油机高压工作过程进行了仿真计算;通过对燃烧室内三位流场的分析,提供进一步提高喷油压力和修改燃烧室形状的方案;再利用仿真计算得到喷油压力进一步提高后较优的燃烧室匹配方案。研究结果表明:喷油压力提高后,柴油机总体性能提高;为适应喷油压力的提高,燃烧室的深度和开口直径分别应该减小和增加,但燃烧室的深度太浅会造成燃烧不完全,导致油耗率上升。研究结果为该柴油机的燃烧系统改进提供了理论依据。     

电喷摩托车发动机的燃烧优化研究

介绍了电喷摩托车发动机燃烧过程优化的必要性以及自主研发的测试标定系统。电喷系统是实现发动机燃烧优化的有效技术平台；通过电喷发动机燃烧过程的优化标定，可以使电喷发动机的动力性、经济性和排放性能等综合能力得到充分应用和发挥。     

Exergy, exergoeconomic and environmental analyses and evolutionary algorithm based multi-objective optimization of combined cycle power plants

A comprehensive exergy, exergoeconomic and environmental impact analysis and optimization is reported of several combined cycle power plants (CCPPs). In the first part, thermodynamic analyses based on energy and exergy of the CCPPs are performed, and the effect of supplementary firing on the natural gas-fired CCPP is investigated. The latter step includes the effect of supplementary firing on the performance of bottoming cycle and CO₂ emissions, and utilizes the first and second laws of thermodynamics. In the second part, a multi-objective optimization is performed to determine the “best” design parameters, accounting for exergetic, economic and environmental factors. The optimization considers three objective functions: CCPP exergy efficiency, total cost rate of the system products and CO₂ emissions of the overall plant. The environmental impact in terms of CO₂ emissions is integrated with the exergoeconomic objective function as a new objective function. The results of both exergy and exergoeconomic analyses show that the largest exergy destructions occur in the CCPP combustion chamber, and that increasing the gas turbine inlet temperature decreases the CCPP cost of exergy destruction. The optimization results demonstrates that CO₂ emissions are reduced by selecting the best components and using a low fuel injection rate into the combustion chamber.     

直喷柴油机燃用二甲醚的试验研究

在直接喷射式柴油机上进行了燃用二甲醚的试验研究,对柱塞有效行程和柱塞直径、供油提前角、喷油压力、进气涡流比、喷嘴型式等燃烧系统主要参数对发动机功率和热效率的影响进行了研究,在燃料供给系统中增加燃油输送泵,消除了气阻,发动机可以在宽广的转速和负荷范围内稳定运行,发动机热效率比原机高３％ 。在优化燃烧系统参数的基础上对示功图和排放的测量及计算表明：二甲醚发动机最高爆发压力、最大压力升高率和 Ｎ Ｏｘ 排放均低于原机,烟度排放为０。试验结果显示了直喷式柴油机燃用二甲醚在降低排放方面的优越性能。     

An integrated approach for optimal design of micro gas turbine combustors

The present work presents an approach for the optimized design of small gas turbine combustors, that integrates a 0-D code, CFD analyses and an advanced game theory multi-objective optimization algorithm. The output of the 0-D code is a baseline design of the combustor, given the required fuel characteristics, the basic geometry (tubular or annular) and the combustion concept (i.e. lean premixed primary zone or diffusive processes). For the optimization of the baseline design a simplified parametric CAD/mesher model is then defined and submitted to a CFD code. Free parameters of the optimization process are position and size of the liner hole arrays, their total area and the shape of the exit duct, while different objectives are the minimization of NO_x emissions, pressure losses and combustor exit Pattern Factor. A 3D simulation of the optimized geometry completes the design procedure. As a first demonstrative example, the integrated design process was applied to a tubular combustion chamber with a lean premixed primary zone for a recuperative methane-fuelled small gas turbine of the 100 kW class.     

Development and characterization of a low-NOx partially premixed hydrogen burner using numerical simulation and flame diagnostics

The utilization of hydrogen as a fuel in free jet burners faces particular challenges due to its special combustion properties. The high laminar and turbulent flame velocities may lead to issues in flame stability and operational safety in premixed and partially premixed burners. Additionally, a high adiabatic combustion temperature favors the formation of thermal nitric oxides (NO). This study presents the development and optimization of a partially premixed hydrogen burner with low emissions of nitric oxides. The single-nozzle burner features a very short premixing duct and a simple geometric design. In a first development step, the design of the burner is optimized by numerical investigation (Star CCM+) of mixture formation, which is improved by geometric changes of the nozzle. The impact of geometric optimization and of humidification of the combustion air on NO_x emissions is then investigated experimentally. The hydrogen flame is detected with an infrared camera to evaluate the flame stability for different burner configurations. The improved mixture formation by geometric optimization avoids temperature peaks and leads to a noticeable reduction in NO_x emissions for equivalence ratios below 0.85. The experimental investigations also show that NO_x emissions decrease with increasing relative humidity of combustion air. This single-nozzle forms the basis for multi-nozzle burners, where the desired output power can flexibly be adjusted by the number of single nozzles.     

达欧Ⅱ排放的D6114Z_LQ9B型大功率柴油机性能开发

以D6114ZLQ9B型柴油机为例,通过对燃油系统、燃烧系统、增压系统等一系列改进,优化发动机的工作过程,使该机型性能良好,控制了NOx和颗粒PM等柴油车尾气污染物。其尾气污染物达到了欧Ⅱ排放标准。     

Active fuel design—A way to manage the right fuel for HCCI engines

Homogenous charge compression ignition (HCCI) engines feature high thermal efficiency and ultralow emissions compared to gasoline engines. However, unlike SI engines, HCCI combustion does not have a direct way to trigger the in-cylinder combustion. Therefore, gasoline HCCI combustion is facing challenges in the control of ignition and, combustion, and operational range extension. In this paper, an active fuel design concept was proposed to explore a potential pathway to optimize the HCCI engine combustion and broaden its operational range. The active fuel design concept was realized by real time control of dual-fuel (gasoline and n-heptane) port injection, with exhaust gas recirculation (EGR) rate and intake temperature adjusted. It was found that the cylinderto- cylinder variation in HCCI combustion could be effectively reduced by the optimization in fuel injection proportion, and that the rapid transition process from SI to HCCI could be realized. The active fuel design technology could significantly increase the adaptability of HCCI combustion to increased EGR rate and reduced intake temperature. Active fuel design was shown to broaden the operational HCCI load to 9.3 bar indicated mean effective pressure (IMEP). HCCI operation was used by up to 70% of the SI mode load while reducing fuel consumption and nitrogen oxides emissions. Therefore, the active fuel design technology could manage the right fuel for clean engine combustion, and provide a potential pathway for engine fuel diversification and future engine concept.     

均衡燃烧控制系统总体设计及关键技术问题研究

针对目前国内200MW机组锅炉燃烧运行过程中存在的问题，设计了均衡燃烧控制系统。根据系统的功能要求和变频器的控制方式，提出了系统总体设计方案，并针对实现该方案的关键--变频器的通信控制，简要讨论了采用主从式多机通信方式控制变频器输出的方法。     

Effective use of hydrogen sulfide and natural gas resources available in the Black Sea for hydrogen economy

In this article, we propose a novel system to effectively deploy an integrated fuel processing system for hydrogen sulfide and natural gas resources available in the Black Sea to be used for a quick transition to the hydrogen economy. In this regard, the proposed system utilizes offshore wind and offshore photovoltaic power plants to meet the electricity demand of the electrolyzer. A PEM electrolyzer unit generates hydrogen from hydrogen sulfide that is available in the Black Sea deep water. The generated hydrogen and sulfur gas from hydrogen sulfide are stored in high-pressure tanks for later use. Hydrogen is blended with natural gas, and the blend is utilized for industrial and residential applications. The investigated system is modeled with the Aspen Plus software, and hydrogen production, blending, and combustion processes are analyzed accordingly. With the hydrogen addition up to 20% in the blend, the carbon dioxide emissions of combustion decrease from 14.7 kmol/h to 11.7 kmol/h, when the annual cost of natural gas is reduced from 9 billion $ to 8.3 billion $. The energy and exergy efficiencies for the combustion process are increased from 84% to 97% and from 62% to 72%, respectively by a 20% by volume hydrogen addition into natural gas.