Towards the improvement of thermal efficiency in lignite‐fired power generation: Concerning the utilization of Polish lignite deposits in state‐of‐the‐art IGCC technology

Integrated coal Gasification Combined Cycle (IGCC) is the most advanced technology for coal‐fired power generation. The two‐stage entrained flow gasification process allows for the use of a wide range of coal, as long as the gasification temperature is above the ash melting point of a used fuel. In this gasification technology, lignite, which often has a low ash melting point, can be preferably utilized. However, ash fluidity is also another importance, because the behaviour of molten slag can diminish a stable ash discharge from a gasifier. As the eligibility of coal ash properties is a considerable factor, water physically and chemically kept in lignite (30 – 60% in mass) attributes to deteriorating gasification efficiency, because it causes significant heat loss and increasing oxygen consumption. Developing a thermal evaporative lignite drying method will be a necessary attempt to apply lignite to the coal gasification process. For those preceded objectives, coal and ash properties and drying characteristics of several grades of Polish lignite, extracted from Belchatow and Turow deposits, have been experimentally investigated in a preliminary study evaluating the applicability and consideration for its utilization in state‐of‐the‐art clean coal technology, IGCC. This paper particularly discusses the eligibility of Polish lignite from the perspective of the fusibility and fluidity of ash melts and the fundamental drying kinetics of lignite in superheated steam in the light of water removal. The viscosity of ash melts is measured at high temperature up to 1700 °C. In the drying tests, the significant influence of structural issues, because of the provenance and origin of lignite on the drying characteristics, was found by applying the method of sensitivity analysis of physical propensity. This paper concludes that the investigated Polish lignite has characteristics favourable for utilization in IGCC technology, once the precautions related to its high moisture have been carefully addressed. Copyright © 2016 John Wiley & Sons, Ltd.     

固体生物质燃料灰熔融性测定方法的研究

通过分析GB/T 219和欧盟生物质燃料相关标准中灰熔融性测定方法的异同,研究并建立了我国固体生物质燃料灰熔融性的测定方法。     

煤灰熔融温度计算公式的研究

依据172组商业用煤分析数据,对7种经验公式的准确性和适用性进行了检测;在此基础上,进一步对煤灰酸碱比与ST和FT关系进行了分析,采用分段拟合的方法,推导出利用煤灰酸碱比计算ST和FT的一组关系式,预测结果与实测值具有较好的一致性,且关系式适用范围较广,可对实际工作起到指导作用。     

助熔剂对型煤灰熔融特征温度的影响

研究了高灰熔点型煤灰成分与灰熔融特性的关系,考察了Fe2O3, MgO, CaO和固体水玻璃助熔剂对型煤灰熔融温度的影响. 结果表明,碱性氧化物与灰中所含矿物质在高温下易形成低共熔混合物,能有效降低型煤灰熔融温度. 加入等量(11%, w)的MgO, CaO及固体水玻璃、Fe2O3,流动温度分别下降了22.0, 58.8, 81.2和91.9℃. 通过三元相图及XRD分析揭示了物相组成变化和矿物晶体的存在形式. CaO, 固体水玻璃和Fe2O3适宜的添加量分别为11%, 9%和9%. CaO和固体水玻璃对型煤还具有粘结和促进气化作用,更适合作为助熔剂.     

The effect of halloysite additive on operation of boilers firing agricultural biomass

The paper presents results of investigations on using halloysite as an additive in biomass-fired boilers. It has been shown that in the case of a few different agricultural biomasses the halloysite addition increased the ash sintering temperature to the values noted for coals. This is an effect of bonding sodium and potassium in the form of chlorides and other compounds. In practical terms the halloysite additive may reduce slagging and fouling of boiler heating surfaces as well as deteriorate the agglomeration processes in fluidized beds. Moreover, addition of halloysite reduces the amount of KCl and NaCl present in ash (and therefore in ash deposits) thus decreasing the rate of high temperature corrosion.     

煤灰熔融性的研究

本文从化学和矿物角度，对我国３７个煤灰样品及在此基础上配制的３０个煤灰样品的熔融性进行了研究。结果表明，利用煤灰熔融温度的变化规律，采用配煤方法可以改变和控制煤灰的熔融温度，达到煤的最佳利用效果。     

低灰熔融性神华煤干煤粉气化

神华煤具有灰分低、硫含量低、挥发分高、发热量高、水含量高的特点,但灰熔融性低于1200℃。采用Shell气化炉加工低灰熔融性神华煤时,出现了气化炉膜式水冷壁不挂渣,合成气冷却器结垢严重,干合成气飞灰过滤器滤芯频繁断裂,碳转化率低,CO变换催化剂失活等问题。通过在气化原料煤中掺混10%左右的高灰分、高灰熔融性的神华乌海高硫煤,使混合原料煤的灰熔融性高于1250℃。配煤后彻底解决了上述问题,装置运行良好。     

特殊场合下的温度测量技术

对于测量条件恶劣，不能用常规传感器实现的特殊场合，如高温强腐蚀性介质、真空、高温熔体及核辐射条件下的温度测量，必须开发特种专用传感器。本文阐述了钨铼热电偶等特种温度传感器的特点、性能及应用，并着重探讨了当前测温领域热点问题。铝液、铜液及熔盐等高温溶体连续测温；高温渗碳、真空粉末治金烧结炉(气)等强还原性气氛下的温度测量：流化床等流动粉体等高温强磨损条件下的温度测量技术等。实践证明，新开发的特殊场合下专用温度传感器，不仅与国际接轨，替代进口产品，而且还可以打入国际市场。     

不同添加剂对生物质灰分及床料的熔融性影响

使用灰熔点法,分析Al2O3、高岭土、CaO对稻草、麦秸秆与河砂及煤灰混合物的熔融性质的影响,研究结果表明灰熔点法在预测添加剂对生物质灰分与床料熔融粘结改善方面具有较强的适用性。煤灰与两种生物质混合物的灰熔点要高于河砂与两种生物质灰分混合物的灰熔点,麦秸秆与床料混合后的灰熔点要高于相同奈件下稻草与床料混合后的灰熔点,三种添加剂对提高生物质灰与煤灰、河砂混合物的灰熔点结果从高到低依次是Al2O3,高岭土,CaO。     

湘钢二烧二期工程上马后合理炉料结构研究

通过对湘钢高炉可能使用的几种炉料结构的熔滴性能和还原性能的试验研究表明,湘钢二烧二期工程合理的炉料结是采用78％烧结矿＋15％澳矿＋7％球团矿。