Room temperature and humidity decoupling control of common variable air volume air-conditioning system based on bilinear characteristics

Variable air volume(VAV)air-conditioning(AC)systems are widely employed to achieve a comfortable room thermal and humid environment depending on its better regulation performance and energy efficiency.In the single coil VAV AC system,conventional proportional-integral(PI)control algorithm is usually adopted to track the set-points of the room temperature and humidity by regulating the supply air flow rate and the chilled water flow rate,respectively.However,the control performance is usually not good due to the high coupling of the heat and mass transfer in the air-handling unit(AHU).A model-based control method is developed to realize the decoupling control of the room temperature and humidity according to the bilinear characteristics of the temperature and humidity variation.In this control method,a bilinear room temperature controller is used to track the room temperature set-point based on the real-time cooling load,while a room humidity controller is used to track the room humidity set-point depending on the real-time humidity load.The control performance was validated in a simulated VAV AC system.The test results show that comparing with the conventional PI control,the room temperature and humidity are controlled much more robustly and accurately by using the proposed model-based control method.

大空间VAV空调系统室内温度优化控制的探讨

本文在深入分析大空间VAV空调系统室内温度控制方法的基础上,得出由于室内垂直温度梯度的影响,传统的通过检测室内回风管温度作为室内温度的控制依据的控制方法具有一定的不合理性。本文利用PHOENICS软件对一大空间商场VAV空调系统进行了模拟,依据模拟结果,通过采用温度修正的优化方法对回风温度检测值进行优化,使得温度检测值与实际需求温度值更贴近,降低了VAV空调系统的运行能耗,达到节能的目的,风机可节能25.4%。

模糊Smith-PID控制器在空调房间温控系统中的应用

为了解决变风量(VAV)空调房间温度控制系统中非线性、滞后等缺点,采用一种模糊Smith-PID控制策略,通过水域温度控制实验进行验证,并与常规Smith算法在不同温度下的稳定性、鲁棒性等进行比较研究,同时论证了模糊Smith-PID控制算法在空调房间温控系统中的实用性和有效性。实验结果表明,模糊Smith-PID控制算法可使温度控制精度在±0.5℃,验证了该算法的优越性。

基于MATLAB的空调房间温控系统的仿真研究

针对空调房间温度的非线性变化纯滞后惯性大等突出问题,建立了一个空调室温控制模型。根据这一模型提出了一种模糊Smith-PID最优控制策略,使用MATLAB对空调房间温度的模型失配时鲁棒特性、抗干扰特性、动态特性等进行仿真研究。结果表明:模糊Smith-PID控制效果均优于常规PID和传统Smith-PID控制,响应快、抗干扰性强、鲁棒性好,并能使房间温度控制在给定温度±0.1℃附近,超调几乎为零,是一种实用而简便的控制方法。