基于前馈控制的某办公建筑供热系统改造及效果验证

Heating System Transformation and Effect Verification of an Office Building Based on Feedforward Control

供热系统能耗占据了建筑运行能耗的20%以上,供热系统的自动控制是系统节能的重要技术途径。传统的供热自动控制主要以反馈控制为主,存在着系统延迟的固有特性,节能效果有限。以实时负荷预测为基础,对控制参数进行动态调节的前馈控制是供热调控的新型技术手段:首先,分析管网和建筑的时间滞后等特性,建立供热系统的实际运行模型;然后,基于数据的供热量预测模型,依据从气象网站获取的未来气象参数预测值,计算未来时刻的预测热量值;最后,计算热量变化与供水温度、流量的关系,确定出下一个调控周期内电动阀门开度、水泵转速等参数。以北京市某办公建筑供热站节能改造项目为例,通过设置合理的测试方案,从调节效果和节能效果两方面分析了前馈控制系统的实际运行效果,最终得出前馈控制的运行方式具有按需控制和低延迟两大优越性,并从节电和节热两方面的分析发现,前馈控制系统具有很好的经济效益与环保效益。

The energy consumption of heating system accounts for more than 20% of the building operation energy consumption,and the automatic control of heating system is an important technical way of system energy efficiency.The traditional feedback control has the inherent characteristics of system delay,so the energy saving effect is limited.Feedforward control based on real-time load forecasting and dynamic regulation of control parameters is a new technical means of heating regulation:firstly,the time lag characteristics of pipe network and buildings are analyzed,and the actual operation model of heating system is established;then,based on the prediction model of heat supply based on data,the predicted heat value at the future time is calculated according to the predicted value of future meteorological parameters obtained from the meteorological website;finally,the relationship between heat change and water supply temperature and flow is calculated,and the parameters such as the opening of electric valve and the speed of water pump in the next regulation cycle are determined.Taking an energy-saving renovation project of an office building heating station in Beijing as an example,this paper analyses the actual operation effect of feedforward control system from two aspects of regulation effect and energy-saving effect by setting up a reasonable test scheme.Finally,it is concluded that the operation mode of feedforward control has two advantages:on-demand control and low delay.From the analysis of energy saving and heat saving,it is found that the feedforward control system has good economic and environmental benefits.