摘 要
本设计对锅炉液位的控制方案进行了简单地介绍，并对其设计方案存在的问题进行分析。论述了改进方案的特点，消除了“虚假水位”的影响。
本文还介绍了锅炉汽包水位的动态特性，单冲量、双冲量、三冲量控制方案的特点及工程中需注意的问题，着重介绍了汽包三冲量控制方案。
通过对锅炉汽包液位动态特性的分析，介绍了基于51单片机的液位控制系统的软硬件组成，并成功地运用到实际系统中，大大降低了使用成本，提高了系统的性价比，取得了良好的控制效果。
关键词：汽包水位；串级三冲量控制；单片机；汽包水位；动态特性；控制方案；单冲量；双冲量；三冲量
Abstract
The methods of the boiler liquid level were introduced simplely in the paper and exsiting questions of the methods in the designing were anylied. Improving methods’ feature was descriped and faulse liquid level’s effection was eliminated.
The paper introduced the dynamic characteristics of the level of boiler bubble. The characteristics of automatic control schemes with one variable or two variables or three variables were discussed,as well as some problems concerned in engineering. The automatic control scheme of boiler bubble with three variables was recommended specially.
According to analyzing the boiler liquid level＇s dynamic characteristics,this paper introduces the liquid level control system of boiler based on single chip computer,including the software and the hardware.This system was used in practice successfully,reduced the cost greatly,increased the ration of the performance and the cost,and achieved good control effect.
Key words:boiler liquid level;impulse three and serial control;single chip computer;dynamic characteristics; automatic control schemes;one variable;two variables;three variales
目 录
1.引言： .................................... 1 2.锅炉的传热和水循环过程原理 ................. 1 2.1锅炉的传热过程原理 ....................... 1 2.2锅炉的水循环过程原理 ..................... 3 3.锅炉基本工艺过程分析 ....................... 5 4.锅炉汽包水位动态特性分析 ................... 5 4.1给水流量作用下的动态特性 ................. 6 4.2汽包水位在蒸汽扰动下的动态特性 ........... 7 5.锅炉液位的控制方案的选择 ................... 9 5.1单冲量控制系统 ........................... 9 5.2双冲量控制系统 .......................... 10 5.3三冲量控制系统 .......................... 11
河南理工大学毕业设计（论文）说明书
5.3.1三冲量控制方案I--前馈（蒸汽流量）加反馈（液位、给水流量）控制方案 ..................... 11 5.3.2三冲量控制方案II--蒸汽流量前馈-给水流量串级控制系统 ............................... 12 5.4几种控制方案的比较 ...................... 13 5.5工程中需要注意的问题 .................... 15 5.5.1关于汽包液位测量的问题 ............... 15 5.5.2给水阀的选择问题 ..................... 16 5.5.3给水流量和蒸汽流量的选择.............. 16 6.系统实现 ................................. 17 6.1硬件实现 ................................ 17 6.1.1输入模块设计 ......................... 32 6.1.2键盘/显示模块设计 .................... 36 6.1.3报警模块设计 ......................... 38 6.1.4输出模块设计 ......................... 39 6.2软件设计 ................................ 42 7.应用 ..................................... 42
河南理工大学毕业设计（论文）说明书
8.结束语 ................................... 46 9.致谢信 ................................... 47 10.参考文献................................. 48