中国城市入炉生活垃圾热值分析

为分析垃圾热值与地理区域、季节、年份等的关系,选取国内有代表性的46座城市生活垃圾焚烧发电厂为研究对象,在收集和整理大量运营数据后,计算得到入炉生活垃圾的热值。研究结果表明:南方地区垃圾热值普遍高于北方,东南沿海经济发达地区的城市生活垃圾热值最高,其中广东、江苏和浙江入炉垃圾热值均在7 400 kJ/kg以上;四季分明的城市,春季和冬季城市生活垃圾热值明显低于夏季和秋季,不同季节入炉垃圾的热值最大相差8% ~ 22%;各城市生活垃圾热值逐年增长。     

高热值垃圾制备RDF成型特性及可行性

为高效能源化处理城市废物,文章提出了城市生活垃圾分质收集、分别处理、以废治废的新理念,即将高热值垃圾与其它废物联合制取RDF(垃圾衍生燃料)为工业应用提供能源;研究不同水分含量、不同塑料含量及不同附加物(生物质)对RDF成型特性的影响,对RDF制取过程进行部分能耗分析。结果表明:随着塑料含量增加RDF颗粒热值明显增大,但颗粒变得松散易破碎,堆积密度和颗粒长度降低,塑料含量小于50%为宜;随着含水率的增加热值有下降趋势,但利于颗粒压缩成型,堆积密度和颗粒长度降低,含水率控制在10%¹4%时,颗粒成型效果较好;锯末作为辅料制备的RDF成型效果比秸秆好。     

生活垃圾热值计算模型研究进展

垃圾热值是决定垃圾是否能采用焚烧处理,以及焚烧处理厂设计和运行的重要因素.经验模型是常用的获取热值的方法.梳理了国内外关于生活垃圾热值计算模型的研究,从热值的表示、计算模型的类型、建模方法、数据来源及样本大小等方面进行综述,发现热值表示方式在该研究领域不统一,建立模型的样本量小,缺乏普适模型,推广难,人工神经网络模型还...     

基于焚烧运行参数的垃圾热值软测量模型

在垃圾焚烧过程中,入炉垃圾热值的变化对燃烧的稳定性会产生很大的影响.针对在垃圾焚烧过程中垃圾热值难以在线测量的实际状况,采用基于小脑神经网络的垃圾热值预测模型,利用垃圾发电厂在线运行数据作为输入参数,实现垃圾热值的在线预测.研究表明,该软测量模型具有实时性好、能够预测垃圾热值整体变化趋势等优点.该模型初步应用于某垃圾发电厂,结果表明,其具有较好的实时性与准确度,在垃圾燃烧过程自动控制系统中具有较好的应用前景.     

陈腐垃圾处置及利用现状研究

综述了国内外陈腐垃圾的资源化利用现状以及潜在的处置技术,总结了垃圾填埋场陈腐垃圾特点和处置技术的相关研究,归纳了国内外垃圾填埋场开采陈腐垃圾过程生命周期评价的研究。针对陈腐垃圾与原生垃圾相比,含水率低、热值高、含大量似土壤类物质且富含营养元素,指出陈腐垃圾的处置途径为将分选后的一部分筛下物用于环境修复或作为建材,将另一部分筛上物进行能源化利用,具体可以将陈腐垃圾筛下物用于土壤修复、废水治理、作为营养土或者工程材料,都有其独特优势。同时,国内外现有的原生垃圾热处置技术都是筛上物的潜在处置手段,但是目前国内外相关研究仍较为匮乏。重点介绍了陈腐垃圾的几种潜在热处理方式,包括焚烧炉技术、水泥窑协同处置技术、热解气化技术,其中最具处理潜质的是热解气化技术。     

中伟实业集团

中伟实业集团经过多年的科技研发,针对国内生活垃圾成份复杂、含水率高、热值低的特点,开发了处理生活垃圾的立式转动炉排炉生产线。实现了混合生活垃圾无需添加任何燃料,完全连续自燃焚烧的独特工艺。增加烟气高温分解、停留时间,     

垃圾分类对垃圾焚烧炉运行性能影响的分析

针对2019年7月1日实施的《上海市生活垃圾管理条例》的相关规定,介绍了现行生活垃圾分类及处理方法,以及对垃圾焚烧的重要性。对某公司一台垃圾焚烧炉的运行工况进行了热工对比测试,分析了生活垃圾分类对垃圾热值以及垃圾焚烧炉运行性能的影响。     

分时收集条件下稻秸理化性状变化初步研究

以高茬(留茬高度50～60 cm)秸秆为对象,每间隔7 d采集秸秆样品一次,分析自然状态下留茬稻秸理化性状变化(含水率、热值及作物养分大、中微量元素含量等),同时记录气象资料(如雨日、雨量等),旨在为秸秆分时收集、秸秆热解或直燃能源化利用提供基础数据。结果表明,在温度较高、降雨较多季节,稻秸中钾、钙等营养元素被淋洗、秸秆灰分减少,含水率变化不大,热值、有机物质等损失较少,相关分析表明秸秆含水率与土壤含水量、空气湿度、风速等多重因素有关。初步结论:采用秸秆分时收集,可使秸秆中钾、钙等养分资源归还农田、降低秸秆灰分含量,且不影响秸秆热值。     

福州市生活垃圾分类现状调查与对策

分析了福州市在20多个条件较为成熟的小区开展生活垃圾分类收集处理试点屡告失败的原因。叙述了垃圾分类管理不到位,缺乏专项垃圾分类资金,缺乏大量生活垃圾分类专业指导工作人员,垃圾桶设计不美观,垃圾种类多,无明确标准,设施不够完善等各种垃圾分类困难的现实因素。提出了一些关于垃圾分类工作的建议。     

剩余垃圾与生物质混合制取RDF技术分析

介绍了源头分类后的剩余垃圾与生物质混合制取衍生燃料(RDF)的新技术.基于源头分类方式对沈阳市城市生活垃圾组分、热值等进行分析,探讨了废物衍生燃料技术在我国城市生活垃圾处理领域的应用前景.研究表明:沈阳市居民生活垃圾中的生物有机成分占总量的70%以上;剩余垃圾组分不到30%:剩余垃圾各组分物质热值均高于16 000 kJ/kg,其中塑料类组分的热值高达30 211 kJ/kg,剩余垃圾与生物质混合制取废物衍生燃料是一种可以有效综合利用我国城市生活垃圾与农村废弃生物质的新技术.     

Prediction of the physicochemical properties of woody biomass using linear prediction and artificial neural networks

This article aims at using Artificial Neural Networks (ANNs) and linear prediction to predict the physicochemical properties of woody biomass, including gross calorific value, carbon content, and oxygen content. By analyzing 43 data groups, it was found that Multilayer Feedforward Neural Network (MLFN) with 11 nodes is the best model for predicting the gross calorific value, with a root mean square (RMS) error of 0.85; General Regression Neural Network (GRNN) is the best model for predicting the carbon content, with an RMS error of 1.66; and linear prediction is the best model for predicting the oxygen content, with an RMS error of 2.11.     

Hard coal for energetic purposes: price–quality relationships; international coal market observations and Polish practice

Coal is the most abundant and commonly used energy carrier in the world. In coal-producing countries, coal is often the cheapest fuel for electricity and heat production. Prices of steam coals offered by exporters on international markets reflect current economic and market conditions and are also related to the prices of other fossil fuels like crude oil and natural gas. International coal-market observations and analyses lead to the conclusion that steam-coal prices depend only on heating value. In Polish practice, steam-coal prices are calculated using a price formula in which coal price is a function of three quality parameters: net calorific value, ash content and sulphur content, and a price of ‘basic’ or ‘reference’ coal (which means: coal of defined quality). This paper presents the results of international coal-market analyses of relationships between coal price and quality and describes the Polish coal-pricing system. A new solution, relevant to domestic coal mines and power plants, is presented to improve and simplify the conditions of bilateral settlements of coal deliveries.     

井眼方向控制设计的新方法

为了简化井眼方向控制设计的数学公式推导和施工参数求解,采用矢量代数方法对空间圆弧模型进行了再研究,推导出装置角、井眼方向矢量、井眼高边矢量、圆弧内法向矢量之间的矢量关系式。将圆弧井段参数计算中原来用三角函数表示的复杂公式用简单的矢量公式重新进行描述,极大地简化了有关的公式推导过程和计算。使用新的矢量公式对井眼方向控制方案设计参数求解问题进行研究,求出了全部9种已知设计条件下的设计方案的解,并给出判断初始装置角正负符号的新的、简单的判据。使用实际数据对设计方法进行测试,结果完全正确。给出的圆弧模型参数矢量计算公式,具有较强的几何直观性,比其他使用三角函数的相关公式更加简单,不仅可以用于解决井眼方向控制问题的求解,而且在圆弧型井眼轨道设计与计算的其他问题中都有应用价值。     

Prediction for the burnout of pulverized coal in a coal-fired power plant by combining proximate analysis,coal petrography,and pulverized-coal size distribution

Highly changeable coal quality, low combustion efficiency, and huge consumption of coal are the three common problems facing most of China’s coal-fired power plants. Proper prediction for the coal burnout in power boilers has important economic and environmental significance. By combining critical factors in proximate analysis, coal petrography, and the size distribution of pulverized coal, this article aims to propose a comprehensive method to predict the burnout of pulverized coal in power boilers. Results show that: (a) volatile content and calorific value are the two most important factors in proximate analysis, (b) the most important factors in coal petrography are the relative content of reactive and unreactive macerals and the mean and standard deviation of vitrinite reflectance, and (c) the 90–200-μm-size fraction is a particularly important factor in the size distribution of pulverized coal. Compared with any parameters or indices based on one of the three aspects in proximate analysis, coal petrography, and pulverized-coal size distribution, the synthetic index into which these critical factors are combined has a better significant correlation with coal burnout.     

等离子体气化熔融/垃圾处理系统

随着我国社会经济的发展,城市垃圾的产量快速上升。采用等离子体气化熔融技术来处理城市垃圾,能避免传统处理方式带来的二次污染问题,但由于我国城市垃圾含水量高、热值低等原因会造成等离子体炬电耗高的问题。本文结合气化熔融技术、回转式预热器、蓄热式燃烧以及余热回收等多项先进技术,理论上设计了一套日处理垃圾能力在10 ~ 30 t的等离子体气化熔融/垃圾处理系统。系统的减容率在95%以上,在充分利用垃圾中的能源的同时,将二噁英的排放控制在国家标准0.1 ng-TEQ/Nm³以内,减少重金属等二次污染物的排放,具有良好的经济性和环保性。     

甲醇燃料-地沟油双燃料燃烧热效率研究

甲醇燃料、地沟油以及甲醇燃料-地沟油加热装有20 kg水的铝锅进行实验研究。通过实验以及在模型计算下,改变双燃料的热值,分别分析相应的热效率变化规律。研究表明:双燃料热值低于18.85 MJ/kg时,双燃料热效率随着双燃料热值的增加而迅速增加;在双燃料热值高于18.85 MJ/kg时,双燃料热效率达到峰值38.31%,此后变化很小。理论计算热效率亦随着双燃料热值增加而增加;而双燃料热值在大于18.85 MJ/kg后,理论热效率值仍然缓慢增加且并未达到峰值。     

The properties of pellets from mixing bamboo and rice straw

Rice straw pellets are the main type of biomass solid fuel and have great potential as a bioenergy resource of the future in China. But it also showed important problems because of its high content of ashes and its low gross calorific value, reducing the possibility to be used in domestic heating. It was certified that mixing different types of biomass materials was helpful to improve the properties of pellets. To improve properties of rice straw pellets and investigate the effect of mixing bamboo and rice straw on the pellet properties, some properties of pellets, manufactured using different mixing ratio of bamboo and rice straw particles, were determined in this research. It can be concluded from this research that physical properties of all pellets meet the requirements of Pellet Fuels Institute Standard Specification for Residential/Commercial Densified except for bulk density of pellets, manufactured using mixing ratio (≤3:2) of bamboo and rice straw. The inorganic ash and gross calorific value of rice straw pellets cannot meet the requirement of Pellet Fuels Institute Standard Specification for Residential/Commercial Densified (8.0%) and the minimum requirement for making commercial pellets of DIN 51731 (>17,500 J/g). Both properties are improved through mixing bamboo particles and rice straw particles. It is significant that inorganic ash content and gross calorific value of pellets, manufactured using mixing ratio (≥3:2) of bamboo and rice straw, were lower than 8.0% and higher than 17,500 J/g, respectively. This also shows that mixing different biomass materials is an effective way to optimize properties of biomass solid fuel. All pellets after improvement are proposed as biomass solid fuel and have the potential to be developed as commercial pellets on an industrial scale in China.     

循环流化床锅炉水冷壁磨损研究进展

循环流化床（CFB）技术是低热值燃料利用领域最具有发展前景的技术,其特有的炉内气固流动结构引起了水冷壁磨损这一突出问题。本文综述了CFB锅炉水冷壁磨损研究的发展状况,首先从研究理论、易磨损位置及产生原因、影响因素、控制措施四个方面描述了CFB锅炉水冷壁磨损机理;然后介绍了磨损模型的发展历程,分析了相关模型的优缺点和适用性,着重强调了当前应用前景较广的CFB锅炉水冷壁磨损研究方法;最后,从热态环境构建、磨损模型修正、微观尺度结构描述、研究对象和人工智能方法五个方面为该领域的研究侧重点提出建议。     

An evaluation of South African fuelwood with regards to calorific value and environmental impact

The fuelwood commonly used in the Western Cape of South Africa, namely Acacia cyclops (Rooikrans), Acacia erioloba (Camelthorn), Eucalyptus cladocalyx (Blue gum), Pinus patula (South African pine) and Vitis vinifera (Vine stumps), was evaluated with regards to its calorific value and environmental impact when burned. Properties, such as density, ash content and elemental composition were determined and related to the calorific value. It could be demonstrated that the wood with the highest calorific value does not necessarily constitute the best option as fuelwood, if environmental factors are taken into account.