Study On Mechanism Model And Applicability Evaluation Of The New-type Displacement Ventilation

With the development of modern society, the increase in housing construction group, the improvement of housing tightness and a large number of high molecular compound used in interior decoration cause a large number of sick building. Meanwhile, in order to energy-saving, enhancement of air-conditioned room tightness and decline in the supply of fresh air lead to decline in air quality in the room. Precisely because of its high ventilation efficiency and ventilation efficiency, great advantages in the indoor air quality and energy-saving, displacement ventilation is widely used.In general, displacement ventilation outlet is installed on the floor or at the lower part of the room, both have defect in the air supply rate, supply air temperature and air distribution and occupy the effective space of the room lower part. To solve the above shortage, our research group ever devised the displacement ventilation system with high sidewall outlet which has a special structure and carried out theoretical and experimental research, and has obtained some regularity understanding on the outlet performance, air flow and thermal comfort evaluation. However, the mechanism model and applicability evaluation of the new displacement ventilation are to be further studied.Based on the work done by our research group, the writer did further experimental studies on the mechanism model and applicability evaluation of displacement ventilation system with high sidewall outlet, such as ventilation efficiency, thermal comfort analysis, air flow pattern designing. The up-fixing diffuser with low diffusion of ladder structure is more conducive to the room ventilation. Set indoor temperature, tested the velocity distribution of the non-isothermal air jet and the temperature field of the room under different conditions. Analyses the flow regulation of the non-isothermal air supply jet and the thermal plume, and establish theoretical analysis of boundary layer formation and development based on the boundary layer theory of air flow jet, correspondingly divide the room into the boundary layer region and the main area outside the boundary layer, analysis the momentum, quality and heat exchange between the boundary layer region and the main area outside the boundary layer, and explains the influence of coupling action on the thermal stratification based on the two factors of non-isothermal air supply jet and thermal plume, present the coupling mechanism of the new displacement ventilation. According to the requirements of comfort standards, by analyzing the experimental data of all the conditions, make an evaluation on thermal comfort of indoor thermal environment, determine parameters of the air supply that meet the requirements of comfort. Explains the influence of coupling action on the ventilation efficiency based on the two factors of non-isothermal air supply jet and thermal plume, present applicability evaluation of the new displacement ventilation. Preliminarily determine the airflow design for the new displacement ventilation, and provide a reference guide for engineering applications.