摘 要

随着我国近年来工业的飞速发展，使得我国的经济力量得到巨大的提升，但工业化带来的环境问题与能源的浪费问题也变得更加突出。在我国以火力发电为主的电能供应体系中，绝大数电厂都依赖着燃煤锅炉来产生蒸汽，但锅炉尾部所产生烟气中往往携带着大量热量被白白排放到大气中，造成了能源的浪费，因此，在燃煤锅炉尾部加装低温省煤器，来有回收利用烟气中的热量是十分必要的。本设计对我国锅炉电厂进行了分析，从国内外的一些案例出发，探讨了锅炉机组加装低温省煤器的必要性。在查阅了相关的论文之后，提出对低温省煤器设计的一些设想，并尝试使用了PVC材料来作为省煤器中的换热管材料，同时也通过查阅资料等方法解决了省煤器设计中存在的问题。本设计为吸收热量1500kW的低温省煤器，烟气进口温度为150℃，出口温度为100℃，含尘量为10。冷却水流量为30t/h，水进口温度为30℃，工作压力为0.2MPa。换热器选用PVC材料光管，在省煤器中竖直布置，依靠上下挡板固定。设计过程首先对管子横排数进行假设，并根据换热量求得水的出口温度，根据迎风面求出纵排管数，然后求出整个过程的压力降，最终对管子的工作温度与强度进行校核，获得满足要求的相关设计参数，并利用画图软件来将其绘制成机械图纸。最终对设计中存在的一些问题提出了思考总结，并对新材料制成的低温省煤器未来的发展提出了大胆合理的假设。

关键词：低温省煤器 高含尘烟气 塑料管材 结构设计

Design of 1500kW Low Temperature Economizer for High Dust Flue Gas

Abstract

With the rapid development of China's industry in recent years, China's economic strength has been greatly improved, but the environmental problems and energy waste caused by industrialization have become more prominent. Is given priority to with thermal power power supply system in our country, most power plants are dependent on coal-fired boiler to generate steam, but often in the boiler tail flue gas generated by carrying a large amount of heat is released into the atmosphere, causing the waste of energy, therefore, mounted at the end of the coal-fired boiler of low temperature economizer, to recycle the heat in flue gas is very necessary. This design analyzes the boiler power plant in China, and discusses the necessity of adding low temperature coal economizer to the boiler unit from some cases at home and abroad. After check the related papers, this paper puts forward some proposals to the design of low temperature economizer, and try to use the PVC material as the heat exchange tube economizer, but also access to information and other methods to solve the problems that exist in the economizer design. This design for the 1500 kw heat absorption of low temperature economizer, the flue gas inlet temperature is 150 ℃, outlet temperature is 100 ℃, dust content of 10. The cooling water flow rate of 30 t/h, and the water inlet temperature 30 ℃, pressure is 0.2 MPa. The heat exchanger is made of PVC material, which is arranged vertically in the economizer and fixed by upper and lower baffles. First of all, the tube row number hypothesis, and according to the heat transfer for the outlet temperature of water, according to the windward side and the vertical tube row number and the pressure drop of the whole process, meet the requirements of related design parameters, and drawing software is used to draw them into mechanical drawings. In the end, some problems in the design are considered and summarized, and the future development of low temperature coal economizer made of new materials is put forward with bold and reasonable assumptions.

Key Words: Low temperature economizer; Heat exchange; Power plant boiler; Energy saving

目 录

摘要……………………………………………………………………………………I

ABSTRACT…………………………………………………………………………II

第一章 绪论 …………………………………………………………………………1

1.1 低温省煤器研究背景 …………………………………………………………1

1.2 国内外的研究现状及存在问题 ………………………………………………2

1.3 低温省煤器研究的目的和意义 ………………………………………………2

1.4 加装低温省煤气需考虑的问题 ………………………………………………3

1.5 设计思路及研究方法 ………………………………………………………3

第二章 低温省煤器热力计算……………………………………………………5

2.1 设计课题题目 …………………………………………………………………5

2.2 工艺参数 ………………………………………………………………………5

2.3 设计流程 ………………………………………………………………………5

2.4 数据校核………………………………………………………………………12

第三章 结论…………………………………………………………………………17

3.1设计总结 ………………………………………………………………………17

3.2前景展望 ………………………………………………………………………17

参考文献 ……………………………………………………………………………19

致谢……………………………………………………………………………………21

1. 绪论

1.1 低温省煤器研究背景

近年来，我国的电力供应系统不断优化，发展至今形成了以火力发电为主，风力，水力，太阳能，核能等其他新型发电方式并存的电力供应体系^[1]。据2017年最新的报告显示，我国的火力发电供电比占全国总产电值的70%以上，甚至在部分时间段内，能够超过80%。分析其主要原因，由于我国近年来工业的快速发展，需要大量的电力支撑，而我国作为煤炭资源大国，必然会以火力发电为主，来保证我国GDP的稳步上升^[2]；此外，受到日本核电泄露事故影响，核能发电在全球范围内饱受质疑，而我国的核电技术并不算成熟，核电比率一直难以上升；最后，由于国家政策对火力发电在环保方面的高要求，加上技术的不断成熟，火力发电系统的环境友好性日益上升，火力发电的污染水平自2011年新规定发布以来，已经逐渐降低到能够接受的水平^[3]。

在我国的火力发电厂的锅炉机组中，大多以600MW以上的全面国产化的大容量、高参数的环保机组为主，技术上不断地替换小型机组，同时环保程度达标的超临界机组也在不断发展^[4]。