变风量空调系统的建模与智能控制研究

【作者】 于长雨；

【导师】 樊卫华；

【作者基本信息】 南京理工大学 ， 控制理论与控制工程， 2008， 硕士

【摘要】 随着人们生活水平的提高和科技的发展,空调系统已成为人们生活中不可缺少的一部分,但是与此同时带来的能源消耗问题也变得越来越引人注目。变风量(variable airvolume,VAV)空调系统作为目前最具节能潜力的空调系统已经逐渐成为大型中央空调系统应用发展的趋势。VAV空调系统中通常采用的是多个PID控制回路联合工作的方式。但由于空调系统本身的强耦合、非线性等特点,PID控制往往难以达到满意的控制效果。因此有必要研究VAV空调的控制技术以提高其系统性能。本文在对VAV空调系统运行过程分析基础上,对VAV空调系统的建模和控制策略进行了研究,主要结果与创新点在于:首先给出了空调房间对象模型以及VAV空调送风侧系统整体模型,为VAV空调系统控制策略的研究和分析建立了基础。其次针对PID控制器在室温控制中应用中的不足,将模糊控制技术引入到室温控制器设计中,设计了模糊PID控制器,并对其在VAV系统中的应用效果及对其它控制环路的影响进行了仿真研究。结果表明,与传统的PID控制器相比,模糊室温控制器不仅在室温控制精度上获得了更好的控制效果,而且在系统的稳定性及节能性方面也更有优势。最后基于送风侧系统的模型,将模糊控制思想引入到送风侧系统协调控制中,设计了模糊协调控制策略。仿真结果表明,模糊协调控制策略比传统协调控制策略在稳定性和节能性上都有更好的效果。本文所研究的模糊智能控制方法,在VAV空调系统的室温控制以及系统协调控制中都获得了较好的控制性能和节能效果,对智能控制在VAV空调控制系统中的应用进行了有益的探索。更多还原

【Abstract】 With the development of technology and improvement of living standard, air conditioning systems have become an important part of daily life, and their energy consumption drew more and more attention. Variable air volume (VAV) system gradually became the trend of large air conditioning system become of its great potential of energy conservation. Control system in VAV system is usually consisted by multiple PID control loops. But because the air conditioning system is a system of strong coupling and nonlinear, PID controller can hardly achieve satisfied performance. So it is necessary to study new control technologies to improve the performance of VAV system.The modeling and control strategies of VAV system are studied based on analysis of its operation process in this thesis, the main achievements are as follows:Firstly, conditioned zone model and VAV air side system model are proposed which establish the fundamentals of the study and analysis of VAV system control strategies.Secondly, fuzzy control technology is introduced to zone air temperature controller design because of the deficiency of PID controller on this aspect; a fuzzy-PID is designed. Simulations are done to obtain its performance as well as its influences on other control loops. The results demonstrate that fuzzy-PID control unit not only improve the control precision when compared to the traditional PID control but also shows its advantages on system stability, energy conservation.Finally, on the basis of VAV air side system model, fuzzy controller is applied to coordinated control of air side system. The simulation results show that fuzzy coordinated control strategy can achieve better performance as well as saving energy compared to traditional coordinated control strategy.Fuzzy intelligent control method investigated in this thesis achieve good control performance when applied in zone air temperature control and coordinated control in VAV system, which is a benefiting explore in applying intelligent control to VAV system.更多还原