Ventilation Mode And Control Research Of Underground Parking Ventilation System

In order to make the air quality of underground parking meet hygiene standards and reduce the energy consumption of the ventilation system, we need to design reasonable ventilation, ventilation airflow organization and system operating mode.The design ventilation directly affects the indoor air quality and energy consumption. At present, the designing standards of underground parking ventilation system both at home and broad are different, and there are more factors effecting vehicle exhaust emissions. By comparing the common method and empirical equation of calculating the underground parking ventilation, it is not reasonable to use the uniform ventilation design standard and volume times method, unit index method to calculating the ventilation. We should design the ventilation by diluted concentration method.The common airflow organization forms of underground parking ventilation are mainly mechanical exhaust and mechanical supply, mechanical exhaust and natural supply, no-duct inductive ventilation. There are different ventilation effects between different forms of ventilation systems. With an actual underground parking for objects, the three ventilation forms above are simulated in Airpak. Through indoor velocity field, Carbon monoxide field and airflow organization indicators, ventilation properties of three ventilation forms above are compared and studied. It is indicated that the ventilation properties of no-duct inductive ventilation is the best.Because the energy consumption is proportional to the ventilation size, and the vehicle frequency is changed with the time, using variable air volume ventilation system can reduce energy consumption. At present, the common control methods of variable air volume ventilation system are mainly intermittent control, double speed fan and variable frequency control. By the example of the underground parking for an office building, the three control methods above are compared from the average concentration of Carbon monoxide and economic performance. At last, feedforward and fuzzy PID control are used in variable air volume ventilation system. Use the software matlab and simulink to simulation the ventilation system based on feedforward and fuzzy PID control. The result demonstrates that the control effect of feedforward and fuzzy PID control be superior to traditional PID control with better Response performance and anti-interference performance.