Simulation and Algorithm Optimization of VAV Air Conditioning Room Temperature Model

With the rapid development of intelligent buildings, the research and development of VAV air-conditioning systems have become the focus of attention. This article mainly studies the temperature control loop of the VAV air-conditioning room, and optimizes the control effect of the temperature control loop of the air-conditioning room by combining intelligent algorithm and PID control. At the same time, a fuzzy PID controller is designed. Fuzzy PID control is added to the temperature control loop of the air-conditioning room. Matlab/Simulink is used for modeling and simulation. The experimental results show that the fuzzy PID control effectively improves the stability of the indoor temperature. The resulting maximum dynamic deviation is smaller, the adjustment time is shorter, and the interference resistance is better, which has certain theoretical significance for improving the comfort of the VAV system air-conditioned room.

I. Introduction

The VAV air-conditioning system was born in the United States in the 1960s. It has the characteristics of low energy consumption and flexible control and is widely used. Because the air supply system of the VAV air-conditioning system is composed of a complex pipe network, there are branches of each pipe network. And there are nonlinearities, large hysteresis and coupling between the branches of the pipe network. When the load or set value of an air-conditioned room in the VAV air-conditioning system changes, in order to maintain a stable indoor temperature, the terminal device will control the air volume of the room to adapt to this change. At this time, the total air volume of the air duct changes (or duct The static pressure value changes), it will inevitably affect the air intake of other air-conditioned rooms and cause the room temperature to change, breaking the dynamic balance of the entire VAV air-conditioning system. It is necessary to change the fan speed to make the system enter the next steady state point. If the control strategy of each loop is used improperly, the dynamic characteristics of each loop in the VAV air-conditioning system may become worse, and the indoor temperature may overshoot or even oscillate when disturbed.