Simulation Of The Air Curtain Ventilation With Deflector And Its Application In Environmental Control Of Greenhouse And Hoggery

The quality of indoor air quality is not only related to human health and work efficiency,but also related to agriculture,animal husbandry and other production environment.Air diffusion within spaces is an important factor affecting the indoor ventilation and air conditioning effect.Comprehensive utilization of the advantages of both airflow patterns,The supply air system of Air Curtain Ventilation is easy to install,and do not take up the space of occupied zone.Meanwhile,the Air Curtain Ventilation seems to be a promising airflow concept due to its better Indoor Air Quality and higher energy efficient,which is similar to the displacement ventilation system in certain extent.The baffle indoor can be a barrier for air flow,or can be a flow deflector.If we properly design the structure and size of the baffle and combine it with strip-type air inlet of the Air Curtain Ventilation,we can better create occupied zone airflow which can not only improve the indoor ventilation efficiency and indoor staff thermal comfort,but also can improve the agricultural environment,animal husbandry environment and other production environment labor productivity.Based on the literature research,theoretical analysis and numerical simulation,the authors studied The air curtain ventilation with deflector,and analyzed the effect of changing the deflector’s shape,size,installation height and air supply parameters for the indoor staff thermal comfort,greenhouse environment and hoggery environment.The studies shows that,compared with circular deflector,Horizontal straight deflector can guide air supply getting occupied zone and only a small part of the airflow is cut off by office desk and move downwards.If the width of the deflector is less than the width of vertical zone jet,the deflector cannot fully guide the air supply getting occupied zone and air supply will directly impact the ground.The Air Curtain Ventilation with deflector can make the head and foot temperature difference of indoor staff be small,resulting in "head cold feet warm" effect which is more comfortable for human.The ventilation effect and human thermal comfort of increasing the air supply temperature and velocity appropriately is the same with the effect of low temperature and low velocity conditions.The studies shows that,compared with wet-curtain cooling system,the air curtain ventilation with deflector in hoggery can make temperature,velocity and average air age more uniform.In summer,low temperature air can surround pig body.Meanwhile,the air age and temperature is low under the height of 1.1m.The air curtain ventilation with deflector’s air diffusion is better and saves more energy.Keeping the agricultural greenhouse cold load same,the air curtain ventilation with deflector and wet-curtain cooling system are applied to agricultural greenhouse and analyze the simulation results.On the height of crop,the air is fresh and the velocity is high.Under the wet-curtain system,the air flow from one side to the other side and air temperature and air age become high,while the velocity becomes low.Under the air curtain ventilation with deflector,the air diffusion is more uniform.