Experimental Study On The Regularity Of Displacement Ventilation System With High Sidewall Outlet

In the modern society, as the time of people working and learning in indoor gradually increase, the requirements to the indoor working environmental has also gradually increased. Displacement ventilation as its advantages in the aspects of thermal comfort,indoor air quality and energy-saving is of being extensive research and application at domestic and abroad.Displacement ventilation outlet is usually installed at the lower part of the room or floor layouts, both occupy the effective space of the room lower part, and in some cases caused the layout of the outlet difficult. To solve the shortage of the traditional displacement ventilation, our research group ever devised the displacement ventilation system with high sidewall outlet, and the displacement ventilation with a special structure outlet was conducted in the form of the theoretical and experimental research. The results show that: the system performances higher ventilation efficiency than the traditional mixed-mode ventilation, and has a higher commitment of the cooling load than the traditional displacement ventilation.Based on the work done by our research group, the writer did further experimental studies on the displacement ventilation system with high sidewall outlet. The experimental model is based on a typical office room, under the different forms of diffuser physical configuration, the writer respectively conducted some conditions with summer indoor set temperature, transition season indoor set temperature and winter set indoor temperature under different load rates. The author tested the velocity distribution of the non-isothermal air jet and the temperature field of the room. According to the requirements of comfort standards, by analyzing the vertical temperature difference and the air speed at the 0.1m ground of all the conditions, determined parameters of the air supply that meet the requirements of comfort. And also using the ventilation jet non-dimensional velocity change curve, analyses the combination jet flow regulation and its influence on the ventilation efficiency, explains the influence of coupling action and indoor set temperature on the ventilation effect based on the two factors of supply air velocity and heat source intensity, and presents the influence of diffuser physical configuration on the ventilation effect .The results of the analysis showed that: the impact of the supply air jet on the air temperature around itself is weaker. The change of the ventilation efficiency is controlled by the coupling action of the supply air jet and the thermal plume. The diffuser with ladder velocity distribution effectively improves the indoor ventilation efficiency, and the ventilation efficiency can also improved with the increasing of indoor set temperature. Thus provides a meaningful reference to the design and practical application of the displacement ventilation system.