基于模糊控制的中央空调控制系统设计

发布时间：2018-10-30 15:15

【摘要】：改革开放以后我国社会经济的快速发展，越来越多的现代化建筑拔地而起，在为人们提供了舒适的学习工作环境的同时，建筑巨大的能耗问题也引起了社会的关注，据有关部门的调查显示，在智能建筑中，中央空调占了建筑能耗的50%以上，水系统的耗能又占到了空调能耗的60%左右,这对于建筑的运营成本形成了巨大的压力，也不符合我国提出的节能减排的基本政策，因此提高空调整体的运行效率，提高能源的利用率是当今社会所面临的重要课题。国内的中央空调水系统大都是采用定流量的运行方式，，水泵按照设计全速运行，不能根据系统冷量的实际需求改变流量，造成了巨大的能耗问题。本文分析了中央空调及其水系统的工作原理，提出了变频调速来实现变流量的控制以达到水系统的水流量按照实际负荷来调整的目的，提出了水系统的变频控制方案。针对中央空调水系统所具有非线性、多变量、易受干扰的特点，以及难以建立准确的数学模型的问题，常规PID控制很难达到令人满意的控制效果。结合模糊控制所具有的无需准确数学模型，抗干扰能力强的特点，提出了模糊PID控制，并且设计了模糊PID控制器。在进行了大量的仿真验证后，模糊PID控制器在控制中央空调冷冻水温度上比常规PID控制具有更好的效果，其不仅具有常规PID的控制精度，还具有模糊控制响应迅速、抗干扰强的特点。最后对系统的硬件及软件进行了介绍，采用了西门子S7-200PLC作为主控制器，选用西门子MM440变频器来实现水泵的变频控制，介绍了系统主程序及其控制子程序的设计，并对能够达到的节能效益进行了分析。
[Abstract]:With the rapid development of China's social economy since the reform and opening up, more and more modern buildings have emerged from the ground. While providing people with a comfortable learning and working environment, the huge energy consumption problem of the building has also aroused the attention of the society. According to the investigation conducted by relevant departments, in intelligent buildings, central air conditioning accounts for more than 50% of building energy consumption, while water system energy consumption accounts for about 60% of air conditioning energy consumption. This creates a huge pressure on the operating costs of buildings. It is also not in line with the basic policy of energy saving and emission reduction proposed by our country. Therefore, it is an important task facing the society to improve the overall operating efficiency of air conditioning and the efficiency of energy utilization. The domestic central air conditioning water system mostly uses the fixed flow operation mode, the pump runs according to the design full speed, cannot change the flow rate according to the system cold quantity actual demand, has caused the huge energy consumption question. In this paper, the working principle of central air conditioning and its water system is analyzed, and the variable flow control is put forward to achieve the purpose of adjusting the water flow of water system according to the actual load, and the frequency conversion control scheme of water system is put forward. In view of the nonlinear, multivariable and easily disturbed characteristics of central air conditioning water system and the difficulty of establishing accurate mathematical model, conventional PID control is difficult to achieve satisfactory control effect. Combined with the characteristics of fuzzy control, which does not need accurate mathematical model and has strong anti-interference ability, fuzzy PID control is proposed and fuzzy PID controller is designed. After a lot of simulation, the fuzzy PID controller has a better effect than the conventional PID control in controlling the chilled water temperature of central air conditioning. It not only has the control precision of conventional PID, but also has the quick response of fuzzy control. The characteristic of strong anti-interference. Finally, the hardware and software of the system are introduced. Siemens S7-200PLC is used as the main controller, Siemens MM440 inverter is selected to realize the frequency conversion control of the pump, and the design of the system main program and its control subprogram is introduced. The efficiency of energy saving is analyzed.
【学位授予单位】：青岛科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TP273;TB657.2

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