目 录
摘 要 ...............................................................................................................................1
ABSTRACT...........................................................................................................................II
1 绪 论 .............................................................................................................................1
2 问题的提出及节能改造可行性分析 ...........................................................................2
2.1 原系统简介及存在问题 ...........................................................................................................2
2.2 节能改造的可行性分析 ...........................................................................................................2
2.2.1 中央空调的组成及工作原理...........................................................................................3
2.2.2 泵的特性分析与节能原理...............................................................................................4
3 节能改造的具体方案 ...................................................................................................7
3.1 改造需增加的设备及选型 .......................................................................................................7
3.2 变频器的控制方式 ...................................................................................................................7
3.3 主要控制电路设计 ...................................................................................................................9
4 变频节能技术框图及改造原理分析 .........................................................................12
4.1 对冷冻泵进行变频改造 .........................................................................................................12
4.2 对冷却泵进行变频改造 .........................................................................................................13
4.3 三菱 FR-F540-37K-CH 变频器主要参数的设定.................................................................13
5 变频器的选型 .............................................................................................................14
5.1 变频器的基本结构 ...................................................................................................14
5.2 变频器的分类及工作原理.........................................................................................16
5.3 变频器的选型 ..........................................................................................................16
6 PLC 硬件设计 ..............................................................................................................18
6.1 PLC 的型号选择........................................................................................................18
6.2 PLC 的 CPU 选择........................................................................................................19
6.3 I/O 模块的选择........................................................................................................20
7 PLC 软件设计 ..............................................................................................................21
7.1 编程软件的选择.......................................................................................................21
7.2 PLC 的程序框图........................................................................................................21
7.3 主要模块程序分析 ...................................................................................................22
7.3.1 冷冻水出回水和冷却水进出水的温度检测及温差计算程序 ................................22