燃气输配技术论文怎么写(2)

  　摘要：
　　在城市燃气管网的设计过程中，水力计算是最关键的环节。本论文介绍了燃气管网水力计算的数学模型和求解方法，应用牛顿法解环形管网，很好的解决了燃气输配中的水力计算问题。
　　同时，在本论文中阐述了国内外燃气管网优化问题的发展现状，对应用于管网优化问题中的一些常用方法进行了比较与分析，指出了各常用算法的优缺点以及适用性，归纳总结出管网优化的发展趋势，给出了管径优化的目标函数，然后应用遗传算法对燃气输配管网进行了管径优化。优化结果表明，遗传算法适合于管道优化这一工程领域。

　　根据国内外燃气负荷研究的进展，从多角度对燃气负荷预测进行了分类。论文中提出了需要按燃气负荷预测的应用要求，燃气负荷变化特性等具体情况选择预测方法。在matlab环境下基于遗传算法的全局搜索和BP网络局部精确搜索的特性，对城市燃气管网短期负荷进行了预测。根据城市燃气负荷变化的特性，应用人工神经网络误差反向传播模型可以反映燃气负荷随机性、周期性及其变化趋势。通过采用遗传算法优化网络初始权重的方法，将遗传算法和即算法有机结合起来，为储气设施的设计与建设提供理论依据。在大连市锦绣小区燃气负荷预测中，以历史资料进行检验的结果证明了这种方法的有效性和可靠性。

　　国内外的各种管道泄漏检测方法大致可以分为硬件法和软件法两大类，本论文分析了各种检测技术的检测原理和优缺点，对各种检测方法进行了比较。将序贯概率比检验法（SPRT）应用到管道泄漏的在线故障诊断中，考虑描述其性能的两个参数-操作线和平均样本数函数，提出了将序贯概率比检测应用于管道泄漏判断的方法。实际应用表明，该方法克服了序贯概率比检测的原有缺点，用其进行管道泄漏检测提高了检测灵敏度和报警速度。

　　关键词：燃气管网；模拟优化；水力计算；短期负荷；泄漏检测

　　Abstract
　　The calculation of waterpower is the key step during the design of gas network of city.
　　Model and method of calculating waterpower of gas network are introduced in this paper. Thecalculation of distributing gas problem has been well solved by using Newton law.
　　The paper introduces simulation optimal calculation of development in pipeline design.
　　Hydraulic calculation formula and familiar solutions were adopted and sumed up bysummarization. Through compared to many techniques for pipe optimization, it offers that wemust make use of the adjust measures to local conditions and synthesis appliance of thedevelopment principle, which well applies to analyses and distribution manage. This paperestablishes the target function of pipe diameter optimization, and utilizes Genetic Algorithm tooptimize the diameters of gas networks. The result shows that Genetic Algorithm can apply topipeline optimization efficiently.

　　The present article forecasted the short load of the city gas pipe net under matlabenvironment which was founded on the global searching Genetic arithmetic and searching thepart of BP net in detail. According to the character of the city gas load, the randomicity,periodicity and the trend of the gas charge can be reflected by the application of BP ANN. GAsand BP ANNs algorithms were joined together and supplemented mutually by optimizing theinitial weight s of ANNs with GAs. It provided the academic evidence with design andconstruction of the storage gas. It proved that this method is efficient and credible by examiningthe historic data dunng the load forecasting of the city gas pipe net.

　　The research works about gas load in both domestic and abroad have been reviewed.
　　Based on statistics and modern optimization methods, literatures of gas load forecasting andpractice experiences were reviewed and induced, and categories of gas load forecasting havebeen made from different viewpoints. Forecasting method would be slected in accordance withapplication need and gas load variation characteristic.

　　The research achievements of pipeline leak detection at home and abroad in recent yearshas been reviewed. There are two main methods of leak detection, hardware method andsoftware method. The superiority and imperfections of every method in their performance andfields are discussed. The sensitivity of leaks detection method based on dynamic quantitybalance cannot satisfy the measuring requirement because of influences of errors andrequirements on false alarm and detection speed. The sequential probability ratio test （SPRT），one of hypothesis test methods, is analyzed and improved. In the experimental test, it is foundthat this method can overcome the SPRT's shortcomings, and it can improve the detectionsensitivity and detection speed.

　　Key Words: distribution pipeline; optimal and simulation; hydraulic calculation; short-load; leakage detection
　　目录
　　摘要
　　Abstract

　　1文献综述
　　1. 1水力计算的发展情况
　　1. 2管网的优化设计
　　1. 3管网负荷的预测
　　1 .4测漏技术的现状
　　1 .5本文研究背景
　　1. 6本文的主要研究内容

　　2水力计算
　　2. 1燃气管网的水力计算基本公式
　　2. 1 .1气体管段流量的基本方程
　　2.1.2管网水力计算简化公式
　　2. 2管网各段的计算流量
　　2. 3环状管网的水力计算
　　2. 3. 1环状管网的基本数据模型
　　2. 3. 2环状管网的计算步骤
　　2.3.3环状管网的平差计算
　　2. 3. 4实例计算
　　2. 4本章小结