登录

  • 登录
  • 忘记密码?点击找回

注册

  • 获取手机验证码 60
  • 注册

找回密码

  • 获取手机验证码60
  • 找回
毕业论文网 > 毕业论文 > 理工学类 > 热能与动力工程 > 正文

热管式空气预热器设计毕业论文

 2022-07-02 10:07  

论文总字数:25055字

摘 要

能源是我们人类社会生存与发展的物质基础。随着全球人口的爆炸式增长和全球经济的高速发展,能源消费也持续增加。世界面临着巨大的能源挑战,工业领域的节能减排显得尤为重要。

本设计“3500Nm3/h热管空气预热器设计”正是基于这样的现实背景,设计一台整体式热管空气预热器,以回收锅炉排放烟气的余热,加热空气,提高进入热风炉的助燃空气的温度,从而节约热风炉的煤气消耗量,达到提高能源利用率和节能减排的目的。

本热管式空气预热器采用整体式的结构形式,以方便运输和安装,现场的安装工作量少。其核心部件是整体式重力热管。热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。热管式空气预热器是一种利用热管作为传热元件,回收烟气的热量,加热空气的余热回收装置。它可以有效地避免烟气的低温露点腐蚀,并且具有传热面壁温可控,流体流动阻力小,结构紧凑,烟气侧和空气侧都能有效施加强化传热措施,传热元件可更换,维修费用低等一系列优点。

设计过程中,首先根据热平衡方程、烟气和空气的进、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。在烟气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,设计出了本热管式空气预热器的施工总图和主要的零部件图。在结构设计过程中,热管采用竖直放置的方式,通过对烟气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: 空气预热器 热管 设计

The boiler with

Heat Pipe Air Preheater

Abstract

Energy is the material foundation of our survival and development of human society. With the explosive growth of the world's population and the rapid development of global economy, energy consumption is also increasing. World's energy issue faces enormous challenges, so in the field of industry, energy conservation and emissions reduction is particularly important.

“ The boiler with heat pipe air preheater” is designed, based on the realistic background. As an integral part of the heat pipe, air preheater is designed to recycle the waste of the flue gas from the boiler, and in effect, to heat the air and to raise the temperature of the combustion air entering the boiler. As a result, the gas consumption is remarkably reduced. Thanks to that, the goal of improving energy efficiency, energy conservation and emissions reduction can be achieved.

The heat pipe air preheater possess an integral structure, which enables convenient transportation and on site installation. Its core component is a monolithic gravity heat pipe. Heat pipe is a kind of efficient heat-transfer element, which transfers the heat through the interval variable vapor-liquid phase, by circulating and floating. The heat pipe air heater is a kind of recovering unit, which uses heat pipes as transferring-heat elements to recover flue gas heat and heat the air. It can effectively help to avoid the corrosion at the dew point in low temperature. Besides that, it has other important advantages: it controls side wall temperature, the resistance of heat transfer fluid flow is insignificant, the structure is compact, heat transfer enhancements on the gas side and air side can be effectively installed, the heat transfer components are replaceable, and the maintenance cost is low.

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: Air Preheater ;Heat Pipe ;Design

目 录

摘 要....................................................................................................................Ⅰ

ABSTRACT ……………………………….…….......................................................Ⅲ

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

1.1锅炉烟气余热分析..............................................................................1

1.1.1 火力发电节能现状..............................................................................1

1.1.2 锅炉烟气特性..........................................................................1

1.1.3 锅炉烟气余热回收方法..........................................................1

1.1.4 其他行业的节能................................................................

1.2 锅炉换热设备.....................................................................................2

1.2.1 锅炉换热设备工作要求..........................................................2

1.2.2 锅炉换热设备类型与选择......................................................2

1.2.3 整体式热管换热器..............................................................................3

1.3 热管与热管空气预热器.................................................................................3

1.3.1 热管简介..............................................................................................3

1.3.2 热管的工作原理..................................................................................3

1.3.3 热管的基本特性..................................................................................4

1.3.4 热管空气预热器的结构形式..............................................................4

1.3.5 热管空气预热器的主要特点..............................................................5

1.4 热管空气预热器的余热回收技术.................................................................6

1.4.1 烟气余热回收预热技术......................................................................6

1.4.2 双预热技术..........................................................................................6

1.4.3 自身预热技术......................................................................................6

1.5 小结.................................................................................................................7

第二章 热管空气预热器热力计算..............................................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 计算传热量.................................................................................................9

2.2.1 空气侧定性温度及参数......................................................................9

2.2.2 冷空气实际获得热量....................................................................9

2.2.3 烟气放出热量.................................................................................9

2.3 烟气侧出口温度及对数平均温差....................................................10

2.3.1 烟气出口温度................................................................................10

2.3.2 烟气侧定性温度及参数....................................................................10

2.3.3 对数平均温差.............................................................................11

2.4 确定迎风面积及迎风面管排数.........................................................11

2.4.1 烟气侧迎风面积与空气侧迎风面积....................................11

2.4.2 迎风面宽度....................................................................................11

请支付后下载全文,论文总字数:25055字

您需要先支付 80元 才能查看全部内容!立即支付

企业微信

Copyright © 2010-2022 毕业论文网 站点地图