循环冷却系统实验装置的优化设计
【摘 要】
冷却塔是一种重要工业循环用水装置，它利用不同温度的空气和水两种介质通过直接接触和间接接触方式来降低水温以达到循环用水的目的。在大型中央空调系统中，由冷却塔和冷水机组组成的空调水系统的能耗约占整个空调系统能耗的55%左右，其中冷却塔子系统的耗电量占整个系统耗电里的15%左右，而目前的空调冷却塔系统的设计是按全年最不利工况进行设计的，如何改善其工作状况，实现节能的目的，具有重要意义。由于整个暖通空调系统是按最大负荷设计，而空调系统大多数时间内处于部分负荷状况下运行，如果能根据负荷在线找出空调系统的最佳工作点，并通过控制系统实现能量最佳匹配，将大幅度地降低空调系统能耗。
本文通过分析冷却塔系统中各个主要设备的能耗特点，提出了对冷却塔系统节能的优化方案，使得冷却塔组在任何工况下运行都能保持最佳的运行状态，从而起到节能的效果。本文中通过控制风机台数并配以风阀启闭及变流量下全塔组配水为关键的节能技术，辅以塔体优化、设计及检测等方面的科技进步，以此将成本降到最低并且充分发挥冷却水的冷却潜力提高循环使用率从而使节能效益最大化，达到节能减排的目的。研究出一种控制简单、能耗小、散热面积利用充分的冷却控制方法，通过搭建模型，模拟一台冷却塔组来实现上述控制方法。本实验台加入了PLC装置，对当下冷却塔组进行仿真控制，配合目前流行的自动化设备，通过传感器的数据采集等，对冷却塔组的整体结构、换热面积、循环水流速等相关因素进行设计和改善，真正实现了自动控制。同时进行冷却塔组实验平台的模型搭建、选型，通过更多的实验数据来增强节能冷却塔组的说服力。
关键词：冷却塔；节能；PLC；自动控制系统
循环冷却系统实验装置的优化设计
【Abstract】
Cooling tower is an important industrial water recycling device, two media using different temperatures of air and water through direct contact and indirect contact method to lower the water temperature to achieve the purpose of circulating water. Air-conditioning water system by the cooling tower and chiller energy consumption accounts for about 55% of the energy consumption of the entire air conditioning system, and cooling tower subsystem power consumption accounted for about 15% of the overall system power consumption in a large central air conditioning system while the design of air-conditioning cooling tower system is designed according to theannual most unfavorable conditions, The significance of how to improve their working conditions and to achieve the purpose of energy saving as great philosophically asit is scientifically. Best match of the entire HVAC system is designed according to the maximum load, while the air-conditioning system is running under partial load conditions most of the time. According to the load-line to find out the optimum operating point of the air-conditioning systems, and air conditioning energy consumption will be reduced by adjust the system to achieve energywill significantly.
Based on the analysis of energy consumption for cooling tower systems in each of the major equipment characteristics, presents system optimized scheme for energy saving of cooling tower, cooling tower set running under any condition to maintain top running condition, thereby making the energy-saving effect. This article by controlling the fan number and with a tower under wind valve and variable flow water distribution as a key set of energy-saving technology, supplemented by Tower optimization, design and testing, the scientific and technological progress, to minimize the cost and fully realize the potential cooling of cooling water increasing the recycling rate in order to maximize energy efficiency, achieve the goal of energy conservation and emission reduction.
循环冷却系统实验装置的优化设计
Developed a simple control, small power consumption, heat dissipation area full of cooling control method by building a model that simulated a cooling tower set to achieve the control method. The bench joined the PLC device, on the current cooling tower simulation control group, with the current popular automation equipment, via the sensor data acquisition, of cooling tower in the overall structure, heat transfer area, circulating water flow rate and other factors related to design and improve true automation. Parallel model of cooling tower experimental platform construction, selection, by group of more experimental data to enhance the energy efficiency of cooling towers of persuasion.
Key words: Cooling Tower;Energy Conservation;PLC;Automatic Control System
循环冷却系统实验装置的优化设计
目录
1 绪论 .............................................................. 1
1.1 背景及意义 ................................................ 1 1.2 冷却塔 .................................................... 2 1.3 优化设计内容 .............................................. 3
2 冷却系统实验装置的设计 ............................................ 4
2.1 冷却塔类型的选择 .......................................... 4
2.1.1 横流塔与逆流塔的对比 ................................. 4 2.1.2 开式塔与闭式塔的选择 ................................. 5 2.1.3 小结 ................................................. 5 2.2 冷却塔单个塔体的尺寸选择 .................................. 6 2.3 冷却系统的配水 ............................................ 6
2.3.1 用小孔代替喷头 ....................................... 7 2.3.2 管道的选择 ........................................... 7 2.3.3 溢流槽的设计 ......................................... 7 2.4 填料的设计 ................................................ 8 2.5 风机的选型 ............................................... 10
2.5.1 风机的H-Q曲线 ...................................... 10 2.5.2 风机的参数简介 ...................................... 10 2.6 冷却系统实验装置的箱体设计 ............................... 11
2.6.1 箱体选材 ............................................ 11 2.6.2 箱体设计 ............................................ 12 2.7 箱体基本电气设备选型 ..................................... 15
2.7.1 电源 ................................................ 15 2.7.2 继电器 .............................................. 16 2.8 本章小结 ................................................. 16
3 控制回路的设计 ................................................... 18
3.1 进水温度控制方案的设计 ................................... 18
3.1.1 方案一：利用恒温混水阀又名恒温阀/恒温控制阀 ......... 18 3.1.2 方案二：利用阀门+远程控制阀头 ....................... 19 3.1.3 方案三：利用电加热棒+混合阀 ......................... 20 3.1.4 方案四：电力调整器+加热器 ........................... 21
循环冷却系统实验装置的优化设计
3.1.5 小结 ................................................ 21 3.2 进出水温度的测量 ......................................... 21 3.3 流量的测量和控制 ......................................... 23
3.3.1 水泵的选型 .......................................... 23 3.3.2 流量计的选型 ........................................ 25 3.3.3 连接 ................................................ 27 3.4 温控仪的选型 ............................................. 27 3.5 控制方案的设计 ........................................... 29 3.6 控制箱箱体控制设备及电气设备的布置图 ..................... 29
4 冷却水系统模型实验平台实验 ....................................... 32
4.1 实验一 变工况性能测试实验 ............................... 32
4.1.1 流量一定，改变温度 .................................. 33 4.1.2 温度一定，改变流量 .................................. 34 4.1.3 流量温度同时改变 .................................... 34 4.2 实验二 温度PID控制实验 ................................. 35
5 结论与展望 ....................................................... 38 致 谢 ............................................... 错误！未定义书签。 参考文献 ............................................................ 40