| With the development of the fresh air market,a variety of indoor air purification equipment and fresh air purification equipment have emerged,and the pipeline free fresh air system has gradually occupied a place in the industry.A small apartment in Jinan as the research object in this paper.In order to make better use of the advantages of the pipeline-free fresh air system,the selection,installation and use of the pipeline-free fresh air system were analyzed by using simulation and experiment methods.First of all,in this paper,the market demand of our country and the present situation of housing construction of real estate companies were analyzed to determine that the pipeline free fresh air system is a new wind system suitable for China's national conditions and for the domestic market.Compared with the traditional tubular fresh air system and air purifier,the pipe-free fresh air system has obvious advantages,including simple installation,no damage to indoor decoration,less space occupation,no secondary pollution,and sufficient oxygen content in the room.A variety of technical measures for purifying fresh air had been analyzed to get the conclusion that the traditional filtering and purifying methods with high safety performance still occupy an important position in the fresh air industry.Next,for the design of mainframe and outlet of the pipeline-free fresh air system,four air supply schemes were put forward in this paper,and three dimensional models corresponding to the four schemes were simulated by FLUENT.By comparing and analyzing the formaldehyde mass fraction distribution map,the velocity vector map,the average mass fraction of formaldehyde curve and the average mass concentration curve of particulate matter in indoor space,the best ventilation scheme was obtained.It provides theoretical guidance for the design and use of the fresh air mainframe and outlet of the pipeline-free fresh air system.Then,the optimal air supply velocity was simulated and analyzed when the pipeline-free fresh air system is in operation.In this paper,four kinds of wind speed conditions were putforward,and the formaldehyde mass fraction distribution map,the cloud map of particle concentration distribution,the velocity vector map,the velocity distribution cloud map the average mass fraction of formaldehyde curve and the average mass concentration curve of particulate matter obtained by FLUENT simulation and then combination of purification effect and human comfort were analyzed.The results show that the optimal range of air speed was obtained and the rational suggestions for the use of the system were provided.Finally,the test bench was built.The curve of the average concentration of formaldehyde with time was measured by formaldehyde analyzer.One is the typical cross section of four air supply schemes under certain wind speed.The other is several typical sections under four wind speeds using the same air supply scheme.The experimental data were analyzed to obtain the best air supply scheme and the optimal range of wind speed,and the results were compared with the simulation results,and the results show that,the simulation results are in agreement with the experimental results.In this paper,the airflow field of indoor formaldehyde and air mixture and the dispersion phase of particulate matter were studied to reflect the ability of the system to purify indoor air.It has a certain theoretical significance for guiding the reasonable installation and use of the pipeline free fresh air system.At the same time,the purification of formaldehyde and particulate matter can also indirectly reflect the purifying effect of the system on other indoor states and other types of pollutants.The conclusion obtained by FLUENT simulation was verified by experiment,which could further reflect the performance of the system and ensure the use of users. |
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