Controller Design And Realization Of Air Handling Unit Of Constant Temperature And Humidity Air Conditioning

Constant temperature and humidity air-conditioning is widely applied in industry,science research even high-class mansion.However,due to the system complicity of the constant temperature and humidity air-conditioning,the strong coupling of air temperature and humidity regulation,and the high requirement on the control ability of air control it is very hard to design the controller of air handling unit.In order to achieve the high precision adjustment of the air temperature and humidity,decreasing energy consumption,this thesis designs an air handling unit controller of constant temperature and humidity air-conditioning,by using Simulink to simulate the main parts of air handling unit,including cooling coil,heating device,humidification device,air valve and other devices.The thesis designs the controller by using Fuzzy PID,simulates the air-moderate process of constant temperature and humidity air-conditioning and verifies the effect of Fuzzy PID controller.Meanwhile,in order to make the simulation more realistic,the fresh air data about temperature and humidity are real data,which is chosen form meteorological record of Shenyang city on the day of September 1st 2015.The constant temperature and humidity air-conditioning takes primary return air system,changeable ratio between fresh air and return air to meet the requirements on the quality of air and to reduce the consumption of energy.Furthermore,we not only succeeded simulating air handling unit of constant temperature and humidity air-conditioning,but also achieved the goal of simulating hardware in the loop.We also realized Fuzzy PID by the embedded technology,realized the communication between the embedded controller and the computers by designing serial communication circuit,and designed the display circuit by LCD screen as the human machine interface.By analyzing the simulation result both the Simulink and hardware in the loop simulation,the Fuzzy PID has been proved to be capable to control the constant temperature and humidity air-conditioning air handling unit efficiently and moderate the temperature and humidity of the fresh air in accuracy.Meanwhile,Fuzzy PID controller has succeeded in controlling the air valve,it can adjust the ratio of fresh air and return air according to the conditions and requirements of quality of air.In this way,we can both be energy saving and high precision controlling.