增压富氧条件下碳颗粒燃烧特性的研究

对增压富氧条件下碳粒的燃烧速率进行了理论研究.主要考察了增压富氧条件下压力和粒径对碳粒燃烧速率的影响,以及常压下O2/CO2摩尔比对碳粒燃烧速率的影响.计算结果表明:增加气体压力能明显地提高碳粒的燃烧速率,但是当压力升高到一定程度后,继续升高压力对燃烧速率的影响逐渐减小.当粒径由75μm增加到175μm,碳的燃烧速率会...     

煤基化学链燃烧系统的化学反应性能研究

为了更有效地减少主要的温室气体CO2的排放量,在不添加额外的分离装置和消耗额外能源的情况下,急需找到一种可行的新型燃烧方式。基于零排放理念的化学链燃烧技术,它不仅能有效地富集高浓度的CO2,而且还将大幅提高能源的利用效率,实现多种污染物的协同控制。与煤焦反应时,铁基氧载体表现出高的反应程度,且尾气中CO浓度均较低,易于收集高浓度的CO2。这些都证实了煤基化学链燃烧技术的可行性以及其低排放特性。     

化学链燃烧过程中准东煤成灰特性实验

采用热重反应器对准东煤在不同条件下的成灰特性进行实验,研究了反应气氛、温度和铁矿石存在对准东煤成灰特性的影响。结果表明:化学链燃烧后的准东煤灰机械强度要高于空气直燃后的准东煤灰,且煤颗粒粒径越大,燃烧后煤灰的机械强度也越好;准东煤的成灰速率随着温度的升高而增加,且水蒸气气氛下的成灰速率要高于CO_2气氛;与传统燃烧方式相比,化学链燃烧过程中固留在煤灰中的钠含量较少,尤其是以水蒸气为气化介质的化学链燃烧过程。     

浸渍法制备的固态胺CO2吸附剂吸附性能

控制和减缓化石燃料电厂的CO₂排放对于缓解大气中CO₂浓度的持续上升具有重要意义。作为一种燃烧后CO₂ 捕集技术,固体CO₂吸附剂具有低能耗、弱腐蚀性、易再生等优点,在CO₂减排领域有着广泛的应用前景。介绍浸渍法制备的固态有机胺吸附剂对CO₂的吸附性能,着重介绍载体性质、有机胺负载量、温度和烟气含水量等因素对固态胺吸附剂吸附性能的影响,并对其机理进行了分析。此外,对比了不同固态胺吸附剂在75 ℃下对CO₂的吸附能力。分析认为,相对于其他类型的CO₂固体吸附剂,固态胺吸附剂较适用于从高温湿烟气中捕集CO₂。     

浸渍法制备的固态胺CO2吸附剂吸附性能

控制和减缓化石燃料电厂的CO2排放对于缓解大气中CO2浓度的持续上升具有重要意义.作为一种燃烧后CO2捕集技术,固体CO2吸附剂具有低能耗、弱腐蚀性、易再生等优点,在CO2减排领域有着广泛的应用前景.介绍浸渍法制备的固态有机胺吸附剂对CO2的吸附性能,着重介绍载体性质、有机胺负载量、温度和烟气含水量等因素对固态胺吸附剂吸附性能的影响,并对其机理进行了分析.此外,对比了不同固态胺吸附剂在75℃下对CO2的吸附能力.分析认为,相对于其他类型的CO2固体吸附剂,固态胺吸附剂较适用于从高温湿烟气中捕集CO2.     

烟气CO2捕集工艺过程关键问题分析

CO2的减排越来越受到国际社会的关注,应用于火电厂的烟气CO2捕集技术是实现大规模降低火电厂CO2排放的主要手段之一,而捕集工艺是CO2捕集技术的基础。从工艺设计角度出发,简述了胺基吸收法的烟气预处理与捕集吸收工艺,分析了精脱硫、烟气冷却、吸收速率、电厂适应性、运行控制及节能工艺等因素对CO2捕集系统性能的影响,为火电厂烟气CO2大规模捕集的了工艺设计提供参考。     

捕集并利用燃煤电厂二氧化碳生产高附加值产品的新工艺

二氧化碳矿化封存是将温室气体二氧化碳以固体碳酸盐形式永久封存起来,以减少大气中二氧化碳含量,减缓温室效应的一种新技术.文中阐述了近期矿化封存技术的最新发展情况并分析了未来发展的趋势,介绍了二氧化碳捕集与矿化一体化新工艺.二氧化碳捕集与矿化一体化新工艺可以克服以往工艺能耗高,效率低的缺点,同时还能生产有经济价值的副产品来降低CCS的成本.     

Modern State and Topical Issues of Studying Solid Fuel Particle Primary Fragmentation Processes as Applied to Biomass Combustion and Gasification in Fluidized and Dense Bed (Review)

It is shown that it is important to take into account the variation of particle sizes due to their fragmentation in fluidized bed biomass combustion. The present state of investigations into the fragmentation process is analyzed. It is shown that primary fragmentation, a process involving cracking and disintegration of initial fuel particles into two or more parts due to thermal stresses and growth of pressure in the particles during their rapid heating at the drying and devolatization stages is the most essential issue. Factors causing the cracking of fuel particles and the nature of this process are considered. The particle fragmentation quantitative characteristics and criteria are analyzed. It is shown that the particle critical diameter is the simplest criterion for estimating the susceptibility of different fuels to fragmentation. The main factors influencing the occurrence of primary fragmentation, namely, particle size, heating rate, bed temperature, and fuel characteristics, are considered. The list of fuel’s main characteristics affecting its primary fragmentation includes the volatiles content, porosity, moisture and ash content, susceptibility of particles to swelling or shrinking, and the organic part composition. Matters concerned with predicting primary fragmentation of fuels are considered. Information about the interrelation between the main characteristics of fuels, their susceptibility to primary fragmentation, and its nature is presented. In view of biomass properties and its combustion conditions, both of the primary fragmentation mechanisms, namely due to devolatization induced stresses and thermal stresses, are supposed to take place. It can be expected that the domination of one or another mechanism will depend on the combination of particle size and heating temperature. The lines of and methods for studying the nature of biomass particles primary fragmentation and its quantitative characteristics under different conditions are outlined. The data obtained as a result of such fundamental investigations will form the basis for elaborating methods for designing furnace devices and gasifiers operating on biomass taking into account the effect of particle fragmentation on the combustion, gasification, carryover, and heating surface contamination processes.     

分级燃烧降低煤粉炉NOx排放的化学机理及影响因素

再燃燃料在还原性气氛下对主燃区煤粉燃烧生成的氮氧化物的还原反应中 ,再燃燃料中产生了中间产物氰基、氨基和烃根等起到分解氮氧化物的作用。同一再燃燃料中烃类物质在燃料的贫富气氛中起到完全相反的作用。在实际应用中应使再燃区内处于弱还原性气氛下以保证再燃对降低NOx 生成所起的效果。同时最好采用气体燃料作为再燃燃料 ,并在保证达到NOx 排放水平的前提下尽量选取较高的空气过量系数 ,以同时降低飞灰中的含碳量和减轻高温腐蚀的程度     

水平燃料分级对煤粉炉燃烧特性影响的数值模拟研究

采用数值模拟的方法,对一台600 MWe燃烧褐煤的四角切向燃烧煤粉炉的燃烧与流动特性进行了研究,深入比较和了解水平燃料分级燃烧改造前后炉内燃烧与流动特性的不同,为该技术的进一步优化和燃烧调整提供依据。     

纳米二氧化钛复合材料应用于空调健康功能研究

本文对应用于空调换热器和过滤网上的纳米二氧化钛和银离子复合材料的健康功能进行了研究,结果表明,这种复合材料能够使空调换热器具有自清洁功能,能防止蒸发器和冷凝器发霉和被腐蚀。换热器和过滤网上均大量使用纳米二氧化钛和银离子复合材料后,空调的整机模拟真实环境杀菌和去除甲醛的能力较强。     

铋盐对二氧化锰化学改性的研究

在物理改性的基础上,利用铋盐对电解二氧化锰进行化学改性,制得用于可充碱性锌锰电池正极的改性二氧化锰材料,并对其可逆性及充放电容量进行了研究和讨论。结果表明,这种材料制备的电极,不仅内阻小,而且有高的充放电容量和好的循环寿命。     

基于带辅助搜索空间的改进二进制粒子群算法的微网经济负荷分配研究

研究了包括光伏电池、风机、微型燃气轮机、柴油发电机、燃料电池在内的微网的发电特性,考虑电压越限、功率平衡、微电源出力限制等约束条件,建立了以发电经济成本最小、环境成本最小的多目标微网经济负荷分配模型。针对二进制粒子群算法易"早熟"、容易陷入局部最优解的缺点,构造辅助搜索空间,改进二进制粒子群算法来求解该复杂非线性优化问题。对孤岛运行模式下的一个小型的含多种微电源的微网系统算例进行研究,仿真结果验证了模型的正确性和算法的有效性。     

Studying the Aerodynamics of the TPP-210A Boiler Furnace When It Is Shifted to Operate with Dry-Ash Removal and Vortex Fuel Combustion

To reduce the amount of nitrogen oxide emissions and achieve more reliable operation of the TPP-210A boiler, a process arrangement for firing Grade TR Kuznetsk coal that involves using straight-flow burners and shifting the boiler from slag-tap to dry-ash removal is developed. Owing to a large burner downward slope angle and special arrangement of burners and nozzles, four large vertical vortices rotating in opposite directions are produced in the furnace lower part, as a result of which the combustion products dwell for a longer period of time in the burning zone and more complete fuel combustion is achieved. For verifying the operability and efficiency of the proposed combustion arrangement, investigations on a boiler furnace physical model were carried out using a technique for visualizing fuel jets and secondary and tertiary overfire air jets. The fuel jet temperature boundaries in the course of jet propagation in the furnace model are also determined. The study results have shown that staged fuel combustion will be set up with using the proposed arrangement of burners and nozzles. In addition, large vertical vortices produced in the furnace lower part will help to achieve more efficient use of the dry bottom hopper heating surfaces, due to which lower coal combustion product temperature in the furnace upper part and smaller content of combustible products in fly ash will be obtained. Owing to low values of air excess factor at the pulverized coal burner outlet and gradual admission of air into the vortex zone through a few nozzles with intense inner recirculation of combustion products to the jet initial section, staged combustion of pulverized coal and low nitrogen oxide emissions will be secured. Owing to expansion of fuel jets, a rapid growth of mass in the fuel jet is achieved, which is obtained both due to ejection of the jet itself and due to forced admission of hot fuel gases from other jets. Investigations carried out on the physical model have confirmed that the proposed combustion arrangement features high efficiency and that a low content of nitrogen oxides in flue gases is obtained.