【作者】 张杰；

【导师】 魏衡华；

【作者基本信息】 中国科学技术大学 ， 控制理论与控制工程， 2011， 硕士

【摘要】 随着世界能源的日益短缺,节能问题已成为一个越来越迫切的问题。据相关统计,中央空调能耗约占建筑总能耗的50%,水系统的能耗占中央空调能耗的60%左右。中央空调的设计容量是系统的最大冷负荷,中央空调系统大部分时间是在部分负荷下运行,国内绝大多数的中央空调水系统采用定流量工作方式,在系统对冷量的需求发生变化时,水泵始终按照设计工况全速运行,水流量不能跟随实际负荷需求变化,导致水泵输送能耗浪费巨大。变流量是根据空调的实际负荷变化要求对水系统进行流量调节的方式,能够实现水流量跟踪实际负荷。本文通过对中央空调系统、水系统的工作原理的分析研究,对水泵进行变频调速以实现变水流量来满足部分负荷下空调区域对冷量的需求,在满足系统要求下最大限度的降低能耗,针对中央空调系统的三个子系统分别设计了变频控制方案。中央空调冷水系统是典型的非线性、时变、多变量的复杂系统,难以建立其精确数学模型,常规控制手段因对精确数学模型的强烈依赖性,难以在中央空调水系统中取得满意的控制效果,模糊控制不需要被控对象精确的数学模型,对各种干扰、噪声都有较强的抑制能力。本文中提出了基于模糊推理方法对PID控制器参数进行整定,设计出相应的自适应模糊PID控制器。仿真研究表明,自适应模糊自整定PID控制器既具有常规PID高精度的优点,又具有模糊控制快速、适应性强的特点,使被控对象具有良好的动、稳态特性。最后,针对合肥某公司生产车间的中央空调系统进行水系统改造,搭建了系统的硬件平台,利用Modbus协议实现了研华PAC与变频器之间的可靠通讯,降低了现场的干扰。在满足生产条件的基础上,取得了良好的节能效果。更多还原

【Abstract】 With the world energy shortage growth, energy issues have become an increasingly pressing issue. According to related statistics, central air-conditioning energy consumption accounts for about 50% of the total building energy consumption, the energy consumption of water system accounts for around 60% of the central air-conditioning energy consumption. The design capacity of the central air conditioning system is the maximum cooling load, but most of the time the system is running at part load. The majority time of central air conditioning water systems are working at constant flow mode, when the load changes, the pump is always running at full speed under design conditions, the water flow can not follow the actual load demand, resulting in huge energy wasted. Variable flow is based on the actual change requirements for water flow in air-conditioning load which means the system can track the actual load.In this article, through the analysis of working principle of central air conditioning system, water system, we proposed that frequency control for pumps can meet the demand for cooling capacity. The system will provide corresponding cooling capacity, to meet the system requirements to reduce energy consumption at the maximum. Design the scheme for three subsystem of the central air conditioning system.Cooling water system of central air conditioning is a typical non-linear, time-varying, multi-variable complex system, which is difficult to establish the accurate mathematical model, the conventional control method based on the precise mathematical model is difficult to obtain satisfactory control effect, because fuzzy control do not need precise mathematical model of controlled object, for all kinds of interference and noise have a strong suppression. This paper proposed a method based on fuzzy reasoning tuning PID controller parameters, to design appropriate adaptive fuzzy PID controller. Simulation studies show that the adaptive fuzzy self-tuning PID controller has both the advantages of high precision conventional PID, and also has quick, strong adaptability and characteristics of the fuzzy control. The result has a good dynamic and steady state characteristics.Finally, to renovation the water system of central air conditioning systems using in production plant in a company in Hefei. Modbus protocol can provide reliable communications between the Advantech PAC and the inverter, reducing the electromagnetic interference. When the production conditions are met, we can see that the energy saving achieved good results.更多还原