A two-layer fuzzy synthetic strategy for operational performance assessment of an industrial hydrocracking process

The operating performance may deteriorate from the optimal condition in industrial hydrocracking process due to changes in product requirements, equipment performance degradation, environmental noises, and random disturbances, etc. Therefore, it is necessary to carry out effective online operating performance assessment for it. In this paper, a two-layer fuzzy synthetic strategy is proposed for operating performance assessment of the hydrocracking process. First, an operating performance assessment index is constructed based on the concept of positive deviation of the quality variables. As there are many products in the process, an assessment system is further built based on the performance index. To calculate the indicators in the assessment index system in real-time, partial least squares is used for prediction. To solve the problem of limited labeled samples in the prediction, the process variables are classified into several subspace blocks according to their correlations with different key indicators. Then, a two-layer fuzzy synthetic evaluation strategy is designed to evaluate the actual operating performance of the hydrocracking process. The proposed strategy is finally illustrated with a series of cases on an industrial hydrocracking process in China.     

Estimation method for dynamic line rating potential and economic benefits

The determination of economic benefits of increasing transmission capability by dynamic line ratings is a multifaceted task. In addition, there are many parties concerned within the complex electricity markets. This paper suggests a method for the evaluation of economic feasibility and benefits, as well as for the minimum potential assessment of employing dynamic line ratings. The suggested deterministic method considers very conservative assumptions in order not to compromise the power system reliability, even though the method is intended for the power system planning and not for the operation purposes. The method is applicable for congested transmission connections between electricity market price areas and it is demonstrated with a distinct case study of congestion on the power transmission from Sweden to Finland. Despite the very conservative assumptions used in the ampacity calculation to be on the safe side, the method can clearly point out the motivation to consider the implementation of dynamic line ratings on congested transmission connections in order to relieve bottlenecks and provide benefits for the society.     

基于天文效应的流域性特丰水年预报方法及应用

针对造成水库特丰水年的天文条件问题,为了提高水库特丰水年预报结果的可信度,以国家电网公司调度区域内的15座大型水库特丰水年为研究对象,选用太阳黑子相对数、月球赤纬角2个天文因子,采用点聚图法,绘制水库年入库流量与太阳黑子关系分布图、水库年入库流量与月球赤纬角关系分布图、水库年入库流量天文效应区图,分析水库特丰水年在特定天文条件范围内的聚类关系,使15座水库特丰水年平均出现概率提高到正常出现概率的5.1倍。结果表明:水库的特丰水与太阳黑子、月球赤纬角密切相关,在特定的太阳黑子、月球赤纬角范围内高频率发生;基于流域同步性分析,从形成特丰水年的天文条件、天文周期、可公度结构等方面,预报2020年发生1964年型全国多流域水库特丰水、流域大洪水的概率大。     

一种面向用电信息采集系统的WSNs多信道MAC协议

由于无线传感器网络（WSNs）单信道介质访问控制（MAC）协议无法满足用电信息采集系统的数据量大和并发性强的特点,提出了一种面向分簇网络的多信道MAC协议.网络簇间通信采用多信道并行传输方式,簇内通信采用基于信道质量实时评估的自适应信道切换机制.基于OMNeT＋＋的仿真结果表明：与单信道MAC协议相比,该MAC协议可以有效提高网络吞吐量和抗干扰能力.     

35 MW循环流化床锅炉二次风机节能改造

循环流化床锅炉机组因其具有的优良特点适应中国国情而得到了迅速发展,但与煤粉锅炉相比,其特殊的燃烧方式使其必须采用高压头的一次风机与二次风机,造成流化床锅炉电站厂用电率较高。为了提高某135 MW循环流化床锅炉二次风机的效率,对该风机进行了技术改造,即通过在该风机原有叶片中间增加小叶片的方式来提升其效率。改造前后风机性能测试数据表明,改造后风机的流量与效率提升明显,其转速越低,风机性能提高幅度越大。     

含海水淡化负荷的可再生能源消纳技术研究综述

海水淡化作为一种可控、可时移负荷,具有一定的灵活调节能力,能够有效适应可再生能源发电的间歇性。海水淡化负荷消纳可再生能源的过剩发电量,在满足淡水供应的同时,提升电网接纳可再生能源的能力,对于电网“削峰填谷”提供良好的支撑作用。首先综述了海水淡化技术的发展现状,并对反渗透海水淡化技术的原理、能耗情况、运行成本进行分析。然后,将可再生能源与反渗透海水淡化技术结合的应用情况进行研讨。最后,阐述了海水淡化配合电网发展的必要性,并且针对具体实施机制给出建议。     

大型汽轮机通流部分改造效果综述及新技术应用

综述了20世纪90年代汽轮机通流部分改造效果。详细介绍了现今进行汽轮机通流部分改造所采用的新技术及其特点,为今后大型汽轮机通流部分的改造提供建设性意见。     

IGCC多联产系统工艺路线选择研究

以煤气化为核心的IGCC多联产系统集成了联合循环发电和化工品的生产,具有高效、环保等优势,得到广泛关注。由于系统的复杂程度及化工品生产和燃机发电对合成气的要求并不完全一致,多联产系统工艺路线的选择必须兼顾考虑。分析了IGCC多联产系统与常规IGCC电站的不同,并分别对IGCC及其多联产系统的气化技术、煤气净化技术、空分配置的选择原则进行分析,最后以实际IGCC多联产项目为例,给出了系统工艺路线的选择方案。     

基于有载自动调容配电变压器降损节能效益分析

在分析调容变压器降损节能原理的基础上,介绍了有载自动调容配电变压器的组成及工作原理,根据实测的典型日、月负荷数据,绘制了日、月负荷曲线,并对SZ11-M-T型有载自动调容型变压器与S11普通型配电变压器的动态功率损耗计算进行综合经济性比较,峰谷差异愈明显,峰谷轮换愈频繁,使用新型有载自动调容变压器节电效果愈显著。     

Application characteristics of heat storage material system

电储热技术是当前适应煤改电环保需求和清洁供暖发展趋势的一项新技术,各种温度级别的储热材料均存在,根据需求选择并制备材料,进而设计电热储能的系统结构成为储热研究关键内容。本文针对蓄热材料的热性能进行了应用特性研究,分析并提出一种蓄热材料温度体系,并对高温蓄热材料应用特点进行了系统设计分析与比较,提出一种基于特制氧化镁的电阻式蓄热系统设计方法,并分析其特点。