Efficient Air Supply And Smart Ventilation System In Nearly Zero Energy Buildings

Nowadays,people have very high standard about the indoor air quality,the energy consumption of ventilation system and the comfort requirements.This project mainly focus on the human micro environment.,including the indoor air quality and the comfort of the fresh air supply.In order to describe the indoor air flow and the energy transfer,we use the(computational fluid dynamics)CFD model to create a dynamic model of the human thermodynamic circumstance.And by using the Finite Volume Method to divide the computing domain into thousands of grids,then integrate them to get the high level of indoor environment model.Then we can get the airflow field,temperature field and other relative results.Compared to the traditional ventilation control algorithm,this project chose the adaptive fuzzy PID control algorithm to control the airflow rate,CO2 concentration and other parameters.As we can see the experimental results,this kind of control algorithm is much better than the traditional PID control,not only in the stability but also the less response time to reach the desired airflow level.And we also use the moveable diffuser to supply air right to the occupant breathing zone.By using a Arduino board,we can easily control the diffuser movement,and it also equipped with infrared sensors to detect the existence of occupant in the working station.If the infrared sensor detect the occupant working in one of the working station,the diffuser will move quickly to the head of the occupant and at the same time,the supply airflow volume will be changed according to the number of occupants in the experimental room.In this project,we use an office of Norwegian University of Science and Technology as an experiment room,the ventilation in that building is the traditional constant air volume system.By installing the smart ventilation experiment equipment in the room,we get the real airflow rate I several conditions and also get the CO2 concentration in the micro environment under different circumstances.From the data we get,we find that this smart ventilation system supply less fresh air to the occupant breathing zone and can also maintain the air quality comfort for the occupant.And compared to the other ventilation systems,it can save much more energy and need more response time to reach the desired air volume level.