Modeling And Control Simulation Of Variable Air Volume Air Conditioning System Based On MATLAB

With the development of society,people’s living standards are constantly improving,and people’s requirements for the comfort of work and living environment are also constantly improving.Therefore,air conditioning has become an indispensable part of people’s life and work.However,the extensive use of air conditioners also results in high energy consumption.In response to the national energy conservation and emission reduction policies,engineers began to study how to reduce the energy consumption of air conditioners while ensuring comfort.Due to the high energy consumption of the traditional constant air volume air conditioning system,it has been difficult to meet the needs of social development.Therefore,the variable air volume air conditioning system has gradually become the focus of engineers.This paper takes the VAV variable air volume air conditioning system as the research object,and introduces the basic theoretical knowledge,structural composition and working principle of the variable air volume air conditioning system.The characteristics of each typical link in the air conditioning system are analyzed,and the mathematical model of the main components of the air handling unit such as heater,humidifier and surface cooler is established.Use computer simulation software to test and verify it,and obtain its dynamic characteristics.And the main links of the air conditioning system are packaged,which provides a basis for technicians to carry out experimental simulation.The temperature adjustment of the air-conditioned room is realized by changing the air supply temperature and air volume.This paper takes the indoor temperature control as the research object.The transfer function between the air supply volume and the air-conditioning room load is established,and the transfer function of the sensor,the damper actuator,and the terminal device is also constructed.In order to prevent the two controllers from interfering with each other,the cascaded PID algorithm control is adopted in this paper,aiming at the characteristics of the control complexity of the variable air volume air conditioning system.Because the traditional PID control has low precision and poor stability,it is necessary to further optimize the control system.With the development of intelligent algorithms,more and more intelligent algorithms are applied to PID parameter tuning.Therefore,this paper combines the advanced intelligent algorithm with the traditional PID control to improve the control effect.In this paper,the gray wolf intelligent algorithm is used to optimize the control system,the air supply temperature control is set as the main controller,the air volume controller is set as the secondary controller,and the optimization results of the intelligent algorithm are assigned to the parameters of the PID controller to achieve the optimum Excellent control effect.At the same time,in order to prevent overshooting,a fitness function is designed.Finally,use Simulink to simulate it.Compared with the simulation results,the control system optimized using the gray wolf intelligent algorithm has better stability and anti-interference performance than the traditional PID control.The simulation experiment verifies that the control method designed in this paper has a better control effect compared with the traditional control method,and also meets people’s basic needs for thermal comfort.It plays a certain reference role for the intelligent control of VAV variable air volume air conditioning system.