An identification method for room temperature dynamic model based on analytical solution in VAV system

Abstract

Variable Air Volume (VAV) system is a typical time delay system with multiple variables, and it is difficult to build a dynamic response model for describing room temperature regulation process. This paper firstly proposes a novel model of dynamic response of room temperature based on the analytical solution of heat balance equation in VAV air conditioning zone. According to the solution, inertia time constant and magnification coefficient of room temperature response can be directly calculated by initial environmental parameters. The model is further extended to a Multi-Input Single-Output (MISO) model with airflow regulating actuators as input and room temperature as model output. Experimental studies are carried out to test practical supply airflow and room temperature response and corresponding model parameters are identified according to the measured data in the VAV experimental platform. The proposed identification method based on analytical solution is validated through simulation and compared with classical identification method. Results indicate that the proposed identification method could describe the room temperature dynamic characteristics of VAV system well, and it can be applied in control simulation and engineering application in future work.