基于STM32的中央空调水控制系统的研究与实现

发布时间：2019-04-13 21:10

【摘要】：目前国家及企业对建筑能耗愈加重视,中央空调占据建筑能耗的60%以上,而水系统是中央空调系统中的重要组成部分,因此降低中央空调水系统的能耗将会减少整个建筑能耗。现有的中央空调水控制系统中冷却水以及冷冻水往往单独控制,各自以最大设计负荷运行;冷却水循环过程中,不考虑天气等因素,持续开启冷却塔风机;楼层支管系统控制方式简单,造成能源浪费;冷冻水循环过程中,冷冻水泵的变频调速控制算法简单,控制效果不理想。针对目前中央空调水控制系统中存在的不足,论文对中央空调水系统进行研究,主要工作如下:(1)设计了一套基于STM32的具有远程监控功能的分布式中央空调水控制系统,并完成了硬件电路的设计以及PCB绘制与调试,为中央空调水控制系统的研究构建了基础平台。搭建远程服务器,通过使用组态软件WINCC,编写中央空调水系统的远程监控界面,远程服务器通过以太网与控制系统上层的核心控制板连接,实现远程监控功能。整个控制系统由三层构成,上层为核心控制板;中间层的冷却水泵控制板、冷冻水泵控制板、冷却塔控制板以及楼层支管控制板;下层为水泵、传感器等现场设备。核心控制板通过RS-485电路将冷却水系统与冷冻水系统集成在一起,根据中央空调负荷的变化,通过变频的方式调节水泵转速,从而调节冷却水以及冷冻水流量。冷却塔控制板根据环境温度的变化控制冷却塔风机的启停;楼层支管控制板根据各支管回水温度改变支管阀门开度,减少能源浪费,同时提高了室内用户的舒适性。(2)冷冻水循环是一个非线性、时变、大滞后的复杂过程,在Simulink中对冷冻水系统进行模糊PID算法仿真,相较传统的PID算法,新的算法提高了控制的实时性和控制精度。(3)系统相关实验验证。在对系统硬件电路各模块进行单独测试的基础上对整个系统进行联合调试,实验结果表明,系统运行状况良好,节能效果好,满足设计需求。
[Abstract]:At present, the state and enterprises pay more and more attention to building energy consumption, central air conditioning accounts for more than 60% of the building energy consumption, and water system is an important part of the central air conditioning system. Therefore, reducing the energy consumption of the central air conditioning water system will reduce the energy consumption of the whole building. The cooling water and freezing water in the existing central air conditioning water control system are usually controlled by the maximum design load, and the cooling tower fan is opened continuously in the cooling water cycle process, regardless of the weather and other factors. The control mode of floor branch system is simple, resulting in waste of energy, and in the course of freezing water cycle, the control algorithm of variable frequency speed regulation of frozen water pump is simple and the control effect is not satisfactory. Aiming at the deficiency of central air conditioning water control system, this paper studies the water control system of central air conditioning. The main work is as follows: (1) A distributed central air conditioning water control system with remote monitoring function based on STM32 is designed. And completed the hardware circuit design and PCB drawing and debugging, for the central air conditioning water control system to build a basic platform. The remote server is built and the remote monitoring interface of the central air conditioning water system is programmed by using the configuration software WINCC,. The remote server is connected with the core control board in the upper layer of the control system through Ethernet to realize the remote monitoring function. The whole control system is composed of three layers, the upper layer is the core control board, the middle layer is the cooling pump control board, the freezing pump control board, the cooling tower control board and the floor branch control board, and the lower layer is the field equipment such as water pump, sensor and so on. The core control board integrates the cooling water system with the refrigerated water system through the RS-485 circuit. According to the change of the central air-conditioning load, the speed of the pump is adjusted by frequency conversion, so as to adjust the cooling water and the chilled water flow. The control plate of cooling tower controls the start and stop of cooling tower fan according to the change of ambient temperature; The floor branch control panel changes branch valve opening according to the return water temperature of each branch, reduces energy waste and improves the comfort of indoor users. (2) Frozen water cycle is a nonlinear, time-varying and large lag complex process. Compared with the traditional PID algorithm, the new algorithm improves the real-time performance and control precision of the frozen water system simulated in Simulink by fuzzy PID algorithm. (3) the related experimental verification of the system is carried out. On the basis of testing each module of the hardware circuit of the system, the whole system is debugged. The experimental results show that the system works well, the energy-saving effect is good, and meets the design requirements.
【学位授予单位】：西安建筑科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU83;TP273

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