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基于改进ESN的高炉煤气系统预测方法的研究
Study on the Prediction Method for Blast Furnace Gas System Based on Improved Echo State Network
【作者】 时飞飞;
【导师】 王伟;
【作者基本信息】 大连理工大学 , 控制理论与控制工程, 2009, 硕士
【摘要】 钢铁企业中能源介质的传输与转换的过程复杂,确保连续、安全和经济的能源供应是企业能源管理的重要任务。从钢铁企业能源的使用情况来看,副产煤气是能源优化调度的重点。由于高炉煤气(BFG)热值最低,生产过程复杂,产出波动大,一般情况下企业在对煤气调度和平衡调整不善时首先选择将BFG作放散处理,这势必造成大量有害气体对环境造成污染。因此对BFG产生量和消耗量进行科学预测,充分回收和利用BFG,可为制定合理的煤气使用计划提供依据,提高钢铁企业节能降耗的水平。本文以上海宝钢股份公司为研究背景,针对BFG系统的预测问题,将其系统中的产消用户分为非调节用户和调节用户,对不同类型用户采用不同的方法进行预测。对于非调节用户,提出一种带参数的改进回声状态网络(ESN)时间序列方法进行预测,同时根据最小均方差准则,以训练误差最小为目标,利用随机梯度下降法优化网络参数,并与其它几种常见神经网络的预测效果进行了比较,说明了该方法的优势。对于调节用户,则采用平均值法进行预测。对于BFG的受入量,由于其含噪水平较高,直接采用改进ESN方法进行预测,其效果不理想,为此提出一种基于经验模态分解(EMD)的除噪算法,在预测前首先对数据进行除噪。此外,分析了影响高炉煤气系统柜位升降的因素,采用ESN网络建立了高炉煤气系统柜位预测因素模型。在高炉煤气系统预测模型的基础上,本文研究开发了高炉煤气系统预测软件。该软件分为服务端和客户端,服务端每隔一定时间对高炉煤气系统(包括各个用户和柜位)进行预测,客户端则将实时数据和预测数据通过用户界面进行显示。仿真实验和高炉煤气系统软件运行均取得了较好的效果,表明了本文提出算法的有效性。
【Abstract】 The transportation and conversion process of energy in steel industry is relatively complicated. It is an important task for enterprise energy management to guarantee a continuous, safe and economical energy supply. At present, the byproduct gas is the key part of energy optimal scheduling problem. Blast furnace gas (BFG) is with the characteristics of least caloricity, complex generation process and output with big fluctuation, so it will usually be diffused firstly when poor energy scheduling and imbalance occurs, which will create much more harmful gas and degrade the environment. Therefore, the study on reliable prediction of the BFG generation and consumption and its recovery and reuse fully can provide scientific guidance for efficient utilization of the byproduct energy and improve the level to save energy in steel enterprise.In this paper, on basis of the background of Shanghai Baosteel, the generation and consumption users of the BFG system are divided into two types for the prediction problem, which are adjustable users and non-adjustable users, respectively. For non-adjustable users, an improved echo state network (ESN) prediction method with parameters is proposed firstly. Based on Least Mean Square (LMS) error criterion, the network parameters are optimized by stochastic gradient descent in order to achieve a minimized training error. Compared to other methods, such method brings about a better prediction performance. Secondly, an average method is used to predict adjustable users. Since the data of the BFG generation includes a series of noises in practice, the performance is unsatisfactory if using the improved ESN method directly. For resolving this problem, an approach based on empirical mode decomposition (EMD) is employed to implement the data de-noise before prediction. Based on analyzing the influence factors of gas holder level, prediction factor model of the BFG gas holder is built by the ESN method.An application software for the BFG system prediction is developed on the basis of the prediction method. This software consists of server and client terminal. The server predicts the BFG system which includes all users and gas holder at regular intervals and the client terminal presents the real-time data and predict data through the user interfaces. The prediction software has been applied in the Energy Center of Baosteel and the running results demonstrate the validity of the proposed method.
【Key words】 Blast Furnace Gas Prediction; Echo State Network; Parameters Optimization; Empirical Mode Decomposition;