Evaluation of the controllability of multi-family building with radiator heating systems: A frequency domain approach

Abstract

For multi-family buildings with radiator heating system (MFBRHS) in China, on-demand heating is an important route to achieve energy saving, emission reduction, and improve user satisfaction. The current researchs are mainly focused on load forecasting and achieving heat balance by adjusting supply temperature or flow rate. However, the time-delay of disturbances factors and control parameters caused by the building envelopes and hydraulic coupling of the network is often ignored, which results in the failure to truly achieve heat balance. In this paper, a linearization method is proposed for the MFBRHS, and the frequency domain approach was employed as an analytical tool to gain a deeper understanding of the dynamic characteristics of the system. The results show that the selected building is equivalent to a low-pass filter. The average response speed of supply temperature and flow rate is slower than that of the solar radiation and outdoor temperature, which indicates that each control parameter should be delayed for adjustment to truly achieve heat balance. Additionally, the uncertainty of the building envelope only affects the magnitude of the disturbances while has a limited effect on its response speed.