摘要能源作为人类社会生存和发展的三大支柱之一长久以来扮演着不可替代的角色。 而锅炉作为一种有效的高消耗能源利用方式广泛应用于人类社会的生产和生活中，同 时也在人类能源利用的发展过程中获得了不断的改进。然而，传统燃煤锅炉排烟温度 高，燃料热利用率低，造成能源的大量浪费，严重威胁着人类对燃料资源的利用前景。 事实上，在过量空气系数合理的条件下锅炉是具有回收一定量的排烟热损失的能力 的。因此，降低锅炉排烟热损失，提高锅炉热效率就显得非常重要了。83975

基于这一现状，本课题在原有 SHS200-4。5/432-Q D 型自然循环锅炉基础上,选择 并布置合适的烟气冷凝式省煤器。在建立锅炉热力系统模型后，采用热力与烟气阻力 计算方法校核锅炉各受热面吸热量、烟气流速和工质进出口温度等主要参数。基于锅 炉安全经济运行的标准要求，比较分析不同的方案，对锅炉的结构进行合理地调整和 优化。

通过上述的计算与分析，本课题所设计的冷凝式燃气锅炉在一定程度上提高了热 效率,且符合锅炉安全经济运行的标准。

毕业论文关键词：冷凝式省煤器；热力计算；烟气阻力计算；热效率

Abstract Energy has long played an irreplaceable role in human society as one of the three pillars of the survival and development。 As an efficient way of high consumption of energy, the boilers are widely used in production and life of human society and gain continuous improvement in the development of human energy use at the same time。 However, the temperature of exhausted smoke of the traditional coal-fired boilers is high, thus causing the low heat utilization rate of fuel and huge waste of energy。 It has been a serious threat to prospect of human use of fuel resources。 In fact, on account of reasonable excess air coefficient, the boiler can recover a certain amount of heat loss caused by flue gas emission。 Therefore, it is very necessarily important to reduce the heat loss of boilers’ smoke exhaustion so as to improve the thermal efficiency of boilers。

Based on this reality, the topic selects and arranges a suitable flue gas condensing economizer based on the original SHS200-4。5/432-Q D-type natural  circulation boiler。 After establishing boiler thermal system model, proofread major parameters of  each heating surface with method of thermal and flue gas resistance calculation, such  as absorbed heat, flow velocity of flue gas, temperature of working medium at the entrance and the exit and so on。 Based on the standard requirements of safe and economic operation of boiler, compare and analyze different designs so as to adjust and optimized the structure of the boiler in a reasonable way。

By the above calculation and analysis, the condensing natural gas boiler designed in the topic has improvement in thermal efficiency to some degree and complies with a standard of safe and economic operation。

keywords: Condensing economizer; Thermal calculation; Calculation of gas resistance; Thermal efficiency

目 录

第一章 绪论 1

1。1 引言 1

1。2 冷凝式燃气锅炉的国内外研究现状 1

1。3 研究课题的主要内容 2

第二章 锅炉冷凝换热方案的确定 4

2。1 冷凝式锅炉强化换热方式 4

2。2 冷凝式锅炉冷凝式换热器的选型 4

第三章 锅炉部件热力计算与分析