锅炉三分仓空气预热器热力特性计算分析

论文总字数：25736字

摘 要

本文采用了陈欢设计的三分仓回转式空气预热器的计算程序，分析了三分仓空气预热器的热力特性。该计算程序按照三分仓回转式空气预热器的传热机理以及温度分布的特点，并考虑各个仓的漏风，从而建立出三分仓空预器微元体模型，并最终得出各个分仓的微分解析式，最后，利用迭代计算方法计算了金属热储存板的平均温度还有每个仓的流体平均温度。某1000MW锅炉三分仓回转式空气预热器的例子，结果表明这种计算方法具有比较高的精确度，每个仓的漏风效果都可以考虑到，而且可以进一步区分成更多数量的计算区域进行计算来满足不一样的工程要求，从而得到金属蓄热板的平均温度分布，为积灰问题和防止低温腐蚀提供了温度参考。

通过该计算程序对烟气侧参数变化、空气侧参数变化以及不同漏风对于传热、热空气温度和排烟温度的影响进行了计算分析。结果表明烟气侧参数进口烟温升高，排烟温度和热段空气温度都会升高，传热不变；烟气通道的流通截面积份额增加时，排烟温度下降、热空气温度会相应升高，传热增加。空气侧参数当一次风进口温度升高时，相应空气侧二次风进口温度升高，排烟温度升高，传热不变；空气侧参数一次风通道的流通截面份额增加时，对应的排烟温度还有热空气温度都相应降低。空气侧参数二次风进口温度升高时，热空气温度和排烟温度升高，空气侧参数二次风通道的流通截面份额增加时，对应的排烟温度还有热空气温度和排烟温度降低。当漏风增加时，进口烟温会相应变大，烟气速度升高，热空气温度升高，排烟温度升高，传热下降。

关键词：三分仓；微元模型；热力特性；传热；对流；漏风

Thermodynamic properties calculation and analysis of three-dimensional rotary air preheater in boiler

03012320 Zhang Guanhong

Supervised by Zhou Keyi

Abstract: Thermal dynamic calculation and analysis of tri-sectional rotary air heater in boiler was wrote in this paper, on account of the actual thermal dynamic calculation standard. A differential element model has been set up based on the heat transfer principle of rotary air heaters and the characteristic of temperature distribution, considering the influence of air leakage. And then the analytical expressions of each sector have been got. At last, the fluid temperature and the mean temperature on vertical section of metallic heat accumulation plate can be calculated by means of iteration based on the analytical expressions of each sector. When 1000MW tri-sectional regenerator is selected as computational object, the results indicate the new method has high precision, considering the influence of air leakage. And the calculation area can be divided as require to meet different demands of project. Also, this method can obtain the mean temperature field of the vertical section of metallic heat accumulation plate, which could provide temperature reference for analyzing low-temperature corrosion and ash deposition.

Parameters of gas, air side parameter changes and different air leakage for heat transfer and the influence of the temperature of hot air temperature and exhaust has carried on the calculation and analysis. Results show that the parameters of the flue gas side imported high temperature smoke, smoke temperature and hot air temperature will rise, heat transfer is same as the former; Flue gas channel share of the circulation area increases, the exhaust temperature drop, hot air temperature will rise accordingly, the heat transfer increases. Air side parameters when a wind inlet temperature increases, the corresponding air side secondary air inlet temperature rise, exhaust temperature, heat transfer; A wind channel the flow of air side parameters section share increases, the corresponding exhaust temperature and hot air temperature is reduced. Air side parameter secondary air inlet temperature, hot air temperature and exhaust temperature, secondary air channel the flow of air side parameters section share increases, the corresponding exhaust temperature and hot air temperature and exhaust temperature decrease. As air leakage increase import smoking temperature will get bigger, the flue gas velocity increases, the hot air temperature, exhaust temperature, heat transfer.

Key words: tri-sectional air preheaters; thermodynamic properties; infinitesimal model; heat transfer; convection; leakage

目 录

1绪论…………………………………………………………………………………………………………………………………………1

1.1引言……………………………………………………………………………………………………………………………………..1

1.2火电厂常用空气预热器………………………………………………………………………………………………………3

1.2.1管式空气预热器………………………………………………………………………………………………………………3

1．2.2回转式空气预热器…………………………………………………………………………………………………………4

1.2.2.1风罩回转式空气预热器……………………………………………………………………………………………….4

1.2.2.2受热面回转式空气预热器………………………………………………………………………………………......5

1.3火电厂常用空气预热器特点比较…………………………………………………………………………………….....6

1.4回转式空气预热器的结构………………………………………………………………………………………………......6

1.4.1机壳……………………………………………………………………………………………………………………………….....6

1.4.2转子…………………………………………………………………………………………………………………………………..6

1.4.3传热元件（受热面）………………………………………………………………………………………………………..6

1.4.4密封装置…………………………………………………………………………………………………………………………..7

1.4.5驱动装置…………………………………………………………………………………………………………………………..8

1.4.6吹灰及清扫装置……………………………………………………………………………………………………………....8

1.5三分仓回转式空气预热器在我国的运行现状…………………………………………………………………....8

2计算模型……………………………………………………………………………………………………………………………….....9

2.1物理模型……………………………………………………………………………………………………………………………...9

2.2微元体数学模型 ……………………………………………………………………………………………………....9

2.3区域划分及漏风影响………………………………………………………………………………………………………….10

2.4分区模型…………………………………………………………………………………………………………………………….10

2.5证明求解的唯一性……………………………………………………………………………………………………………..12

3三分仓回转式空气预热器的数值计算模型……………………………………………………………………….....13

3.1计算步骤…………………………………………………………………………………………………………………………….13

3.2参数选择…………………………………………………………………………………………………………………………….14

4三分仓回转式空气预热器热力计算的实例分析…………………………………………………………………..15

4.1计算结果及分析…………………………………………………………………………………………………………………15

4.2计算分析空气侧参数、烟气侧参数、不同漏风对于热空气温度还有排烟温度的影响…15

4.2.1计算分析烟气侧参数对于热空气温度、排烟温度的影响……………………..............16

4.2.2计算分析空气侧参数对于热空气温度、排烟温度的影响…………………….............16

4.2.3计算分析不同漏风对于热空气温度、排烟温度的影响………………………….............17

5结论与展望………………………………………………………………………………………………………………...............18

致谢…………………………………………………………………………………………………………………………………………..18

参考文献……………………………………………………………………………………………………………………………………19

锅炉三分仓回转式空气预热器热力特性计算分析

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