摘 要

冶金烧结带冷机由于排烟含尘高、温度高，热量浪费较大，所以炉体热效率较低，一般烧结带冷机出口烟气温度大约在350℃左右，烧结带冷机热效率很低，本课题结合国家节能减排的大政方针，沿着科研与生产相结合的原则，进行余热生产锅炉用给水，提高系统的热效率。本课题工艺参数为：热流体为冶金烧结带冷机废气，含尘量lt;1g/Nm³,废气流量为250000Nm³/h，废气进口温度为150℃，要求废气出口温度为100℃，生产1.2MPa的锅炉给水55吨/h，给水进口温度为30℃。

本课题设计首先查阅了国内外对烧结带冷机出口烟气的回收利用以及塑料管式冷却器方面的资料与文献，了解了该课题大致的设计研究内容、流程、注意事项等。然后，在仔细研读该设计课题的内容和要求的基础上，先后进行了热力计算、结构计算、阻力计算以及校核计算，保证设计出的塑料管式冷却器的正确性。最后，根据计算校核结果，利用AutoCAD 软件做出该冷却器的结构图。

本课题的设计主要参照了《热管与热管换热器》、《锅炉原理》、《传热学》、《流体力学》、《热力发电厂》。在烟气的流动压力降以及水动力循环等各项指标满足设计的前提下，综合考虑各种因素，选用合理的结构，以求满足各种要求。总之，本次设计结果满足任务书的设计要求，在安全性和经济性及环保要求方面有较好的结果。

关键词 ： 余热回收 塑料管式冷却器 设计

Design of Plastic Pipe Cooler for High Dust Flue Gas

Abstract

Metallurgical sintering with a cold machine due to high smoke dust, high temperature, heat a greater waste, the furnace thermal efficiency is low，General sintering with a cold machine outlet flue gas temperature about 350 ℃ or so, sintering with cold machine thermal efficiency is very low,This topic combined with the national energy conservation and emission reduction policy, along the combination of scientific research and production principles，The waste heat is used to produce boiler feed water to improve the thermal efficiency of the system.The technological parameters of the subject are as follows: the hot fluid is the waste gas of the metallurgical sintering zone, the dust content is lt;1g/Nm³, the exhaust gas flow rate is 250000Nm³/h, the exhaust gas inlet temperature is 150 ℃, the exhaust gas outlet temperature is 100 ℃, Boiler feed water 55 tons/h, feed water inlet temperature of 30 ℃.

The design of the subject first reviewed the domestic and foreign on the sintering with the export of cold flue gas recovery and plastic pipe cooler aspects of the information and literature, to understand the subject of the general design research content, processes, precautions and so on. Then, on the basis of carefully studying the contents and requirements of the design subject, the thermodynamic calculation, structural calculation, resistance calculation and checking calculation were carried out to ensure the correctness of the designed plastic tube cooler. Finally, according to the calculation results, using AutoCAD software to make the structure of the cooler.

The design of this topic mainly refers to the "heat pipe and heat pipe heat exchanger", "boiler principle", "heat transfer", "fluid mechanics", "thermal power plant". In the flue gas flow pressure drop and the hydrodynamic cycle and other indicators to meet the design of the premise, taking into account a variety of factors, choose a reasonable structure, in order to meet the various requirements. In short, this design results meet the design requirements of the task book, in terms of safety and economy and environmental requirements have better results.

Key words: waste heat recovery；plastic tube cooler；design

目 录

摘要......................................................I

ABSTRACT.......................................................II

第一章 绪论.......................................................1

1.1 课题背景....................................................1

1.2 烧结带冷机出口烟气的余热利用................................2

1.2.1 冶金烧结工艺..........................................2

1.2.2 烧结工艺的意义........................................3

1.2.3 烧结带冷机的余热回收..................................3

1.3 塑料管式冷却器..............................................5

1.4课题研究的意义跟目的. .......................................6

第二章 高含尘烟气塑料管式冷却器的设计.........................7

2.1 课题的设计内容及设计要求....................................7

2.2 拟作的工作..................................................7

2.3设计工作中需要考虑的问题. ...................................7

第三章 塑料管式冷却器热力计算..................................9

3.1 原始参数....................................................9

3.2 塑料管原件的基本选择........................................9

3.2.1 塑料管型式............................................9

3.2.2 塑料管的几何尺寸......................................9

3.3 计算传热量Q ................................................9

3.3.1 烟气的定性温度......................................9

3.3.2 烟气传至给水的热量 ..................................10

3.4 水出口温度及对数平均温差. ............................11

3.4.1 水出口温度.........................................11

3.4.2 对数平均温差. ....................................11

3.5 确定迎风面积及迎风面管排数.........................12 3.5.1 确定迎风面积. ............................................12

3.5.2 迎风面管排数.......................................12

3.6 求总传热系数............................................12

3.6.1 管束最小流通截面积..............................12

3.6.2 流体最大质量流速.................................13

3.6.3 求雷诺数.........................................13

3.6.4求流体的换热系数...................................13

3.6.5 求每米长塑料管管外表面积. .........................14

3.6.6 求污垢热阻及管壁热阻.............................14

3.6.7 求总传热系数......................................14

3.7 求加热侧总传热面积......................................14