Abstract: In response to the problems of low collection efficiency and energy waste in food waste pretreatment workshops, in combination with the actual case of a harmless treatment plant for food waste in a certain county，the computational fluid dynamics (CFD) technology was employed to carry out numerical simulation of the airflow organization in the workshop. By establishing a 1∶1 physical model (workshop dimensions was 66.65 m× 34.50 m×13.40 m), the influence of ventilation frequency and air outlet layout on the air flow distribution were compared and analyzed under four working conditions with varying numbers of open discharge doors (0-3 doors). Results showed that exhaust vents was concentrated at a height of 6.00 meters from the center, and the supply air outlet (at a height of 2.50 meters) had insufficient air volume and its location was unreasonable, which caused significant dead zones at the 1.50 meters personnel breathing height on the first floor, and the dead zone was the largest under condition 4 (three doors all open). The mechanical supply air volume was only designed to be 50% of the exhaust air volume, and the supply air cannot penetrate the equipment-obstructed areas, resulting in insufficient air turbulence. By adjusting the positions of the supply/exhaust vents and increasing the proportion of low-altitude air supply, it is possible to reduce ineffective ventilation while meeting the requirement that the wind speed in the door opening be greater than or equal to 0.3 m/s. This also helps to decrease the equipment footprint and energy consumption.

Key words: computational fluid dynamics (CFD), odor collection, food waste, airflow organization, numerical simulation