论文总字数：18334字

摘 要

为了能够节能减排,我们应该加强节能技术的运用。从而能够避免因为过度减排，而造成资源的浪费。怎么有用改进加热炉热效率,降低燃料消耗,减小装备损耗,削减烟气排放,是我们面对的首要而紧急的使命。在传热过程当中,必须应用到加热器，因此加热器在生产制造等产业中应用广泛。

目前，燃煤机组锅炉，特别是超临界参数的大容量锅炉，其锅炉排烟温度大都高出其设计温度。造成锅炉排烟温度普遍偏高的原因较多，其中，具有共性的问题是制粉系统掺入大量的冷一次风。 这是造成热一次风量减少、空气预热器换热效率降低（即吸热减少），并引起排烟温度偏高的一个重要原因。降低锅炉排烟温度是降低机组供电煤耗的重要途径之一，在锅炉排烟温度高于设计值时更是如此。目前， 通过减少制粉系统冷风掺入量来降低锅炉排烟温度的相关技术研究尚未见报道。 本课题“600万kCal/h炉空气加热器”的设计， 旨在通过该装置减少或取消制粉系统的冷风掺入量， 以消除该问题及其相关弊端，降低或调节锅炉排烟温度。

本空气加热器采用分体式的结构形式，以方便运输和安装，现场的安装工作量少。其核心部件是翅片。翅片管是一种通过内部工质汽-液相变和循环流动来传递热量的高效传热元件。翅片管式空气加热器是一种利用翅片管作为传热元件，回收蒸汽的热量，加热空气的装置。翅片管式空气加热器能够长时间在很高的温度下工作，并且能够承受很大的压力，在高腐蚀性的环境下也能坚持更久。

设计过程中，首先根据热平衡方程、蒸汽和空气的进、出口温度、流量，计算出传热量。然后通过选择热管规格及其结构参数，计算出总传热系数。最后确定热管的数量及其排列方式。在蒸汽和空气的流动压力降等各项指标满足设计的前提下，进行结构设计，设计出了本翅片管式空气加热器的施工总图和主要的零部件图。在结构设计过程中，热管采用水平放置的方式，通过对蒸汽和空气的中间间隔处进行相关的密封装置的设计，考虑了热管元件的可更换的特点，使得换热器的本体可以有较长时间的使用寿命。设计过程同时对装置内部的承重、强度等方面进行了考虑。

关键词： 翅片管， 空气加热器，过热蒸汽

Design 6 Million kCal/h Furnace Air Heater

Abstract

Energy saving and emission reduction is the need of changing the mode of production, but also a long-term goal of the sustainable development of chemical industry and the whole industry. It is the most important and urgent task for us to improve the heating efficiency, reduce the fuel consumption, reduce the equipment loss and reduce the smoke emission. In the heat transfer process, it must be applied to the heater, so the heater is widely used in manufacturing and other industries.

At present, the boiler, especially the super critical parameters of large capacity boiler, the flue gas temperature of the boiler is mostly higher than the design temperature. The boiler flue gas temperature is generally higher than the reasons, in which the common problem is the flour milling system mixed with a large number of cold air. This is caused by a reduction in the amount of heat, air preheater heat transfer efficiency is reduced (that is, heat absorption reduction), and cause high exhaust temperature is an important reason. Reducing boiler flue gas temperature is to reduce coal consumption of power supply units is an important way of in boiler flue gas temperature higher than the design value is even more so. At present, there is no report about the technology of reducing the flue gas temperature of the boiler by reducing the amount of cold air in the flour milling system. This topic "600 million kCal/h furnace air heater design aimed at by the device, reduce or cancel the pulverizing system of cold air incorporation, in order to eliminate the problems and defects, reduce or adjust the boiler exhaust gas temperature.

The air heater adopts integral structure to facilitate the transportation and installation, and the installation workload of the field is less. The core component is the fin. Fin tube is a kind of high efficient heat transfer element through the internal working fluid phase transition and circulation flow. The fin and tube type air heater is a device which uses the finned tube as the heat transfer element to recover the heat of the steam and heat the air. Fin tube type air heater can work for a long time at a high temperature, and can withstand a lot of pressure, in the high corrosive environment can persist longer.

In the design process, according to the heat balance equation of the air temperature and flow rate in the inlet and outlet, the heat transmission is calculated. Then by selecting heat pipe specifications and its structure parameters, the total heat transfer coefficient is calculated. Finally, the amount of heat pipe and its arrangement is determined. If all the indicators such as the flow pressure of the gas and air can meet the demands of the design, the general construction layout of the heat pipe air preheater and the drawing of the main parts are designed. In the process of structure design, heat pipe is placed upright. Designing the sealing device in the middle of the interval between the gas and the air can result in a longer service life of the heat exchanger, considering that some of the heat pipe elements are replaceable. In the process of the design, all factors, including the bearing and intensity of the device inside, are being considered.

Key words: Finned Tube , Air Preheater , Superheated Steam

目录

摘要 I

Abstract III

第一章 绪论 1

1.1 加热器种类介绍 1

1.2 空气加热器局限及方案选择 3

1.3 空气加热器使用注意事项 3

1.4 空气加热器内漏的原因 4

1.5 其他问题 5

1.6 空气加热器选材 5

1.7 结束语 6

第二章 600万kCal/h炉空气加热器的热力计算 8

2.1 原始参数 8

2.1.1 基本参数 8

2.1.2 热管参数 8

2.2 空气定性温度 9

2.3 过热蒸汽→饱和蒸汽段的热力计算及结构计算 10

2.3.1 空气定性温度 10

2.3.2 下，空气参数 10

2.3.3 空气的吸收热量 10

2.3.4 蒸汽定性温度 10

2.3.5 蒸汽放热量 11

2.3.6 蒸汽导热系数 11

2.3.7 蒸汽动力粘度 11

2.3.8 蒸汽工况密度 11

2.3.9 蒸汽Pr 11

2.3.10 对数平均温差 11

2.3.11 确定迎风面面积 及迎风面排数B 11

2.3.12 实际迎风宽度E 11

2.3.13 实际标准迎面风速 12

2.3.14 管内蒸汽的质量流速 12

2.3.15 蒸汽体积流速 12

2.3.16 管内雷诺数 12

2.3.17 管内蒸汽的Nu 12

2.3.18求管内换热系数： 12

2.3.19 求传热系数 12

2.3.20 求总传热面积 14

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