Residents living in the cold areas such as Harbin generally experience a residence time of approximately 6 months in chilly winter without frequent natural ventilation. To find out the influence of a short period of v...Residents living in the cold areas such as Harbin generally experience a residence time of approximately 6 months in chilly winter without frequent natural ventilation. To find out the influence of a short period of ventilation on the indoor formaldehyde concentration inside a new building, an investigation was conducted for the instance of twice ventilation in a day through window opening. The results showed that the initial concentration of formaldehyde was 3.53 -8. 48 times as high as the concentration after 10 min ventilation. After closing the window, the indoor formaldehyde concentration increased with time and followed an exponential equation of C = C0 exp（ - b ＊ t） ＋ （ a ＋ Cu, ） [ 1 - exp（ - b ＊ t） ] with correlation coefficient （ R^2 ） of 0. 945 - 0. 999, based on the statistical analysis of 14 groups of measurement data. The developed equation can be used to estimate the emission rate of indoor formaldehyde sources and the air exchange rate of the test room simultaneously.展开更多
Natural ventilation effects in high and large space buildings of tropical areas greatlya ffect the air conditioning energy consumption.Aiming at nearly zero energy building design,thisp aper mainly contributes to prov...Natural ventilation effects in high and large space buildings of tropical areas greatlya ffect the air conditioning energy consumption.Aiming at nearly zero energy building design,thisp aper mainly contributes to provide theoretical basis and reference for thermal comfortable air conditioning system design of high and large space buildings.Taking a theatre in Hainan as study object,a newly composite enhanced natural ventilation system is proposed by integrating theu nderground tunnel-based earth to air heat exchange system and the solar chimney.Ventilationq uantity,air velocity and air temperature field,human vertical temperature gradient differenceu nder24simulation working conditions are considered and analyzed by using ANSYS Fluent.Fort he underground tunnel,results show that Group Two with double underground tunnels and side airs upply location shows its advantages in cooling effects and air supply uniformity.Then for the solar chimney,results show that the solar radiation intensity contributes to larger difference int ransmission power and leads to different cooling effects.On the whole,the system under workingc ondition No.7with120m long,side air supply,double underground tunnel and20m high,1mw ide,0.6°absorber plate angle solar chimney shows its priority in better comprehensive performance.展开更多
The high frequency ventilation(HFV)can well support the breathing of respiratory patient with 20%-40%of normal tidal volume.Now as a therapy of rescue ventilation when conversional ventilation failed,the HFV has been ...The high frequency ventilation(HFV)can well support the breathing of respiratory patient with 20%-40%of normal tidal volume.Now as a therapy of rescue ventilation when conversional ventilation failed,the HFV has been applied in the treatments of severe patients with acute respiratory failure(ARF),acute respiratory distress syndrome(ARDS),etc.However,the gas exchange mechanism(GEM)of HFV is still not fully understood by researchers.In this paper,the GEM of HFV is reviewed to track the studies in the last decades and prospect for the next likely studies.And inspired by previous studies,the GEM of HFV is suggested to be continually developed with various hypotheses which will be testified in simulation,experiment and clinic trail.One of the significant measures is to study the GEM of HFV under the cross-disciplinary integration of medicine and engineering.Fully understanding the GEM can theoretically support and expand the applications of HFV,and is helpful in investigating the potential indications and contraindications of HFV.展开更多
In recent years,rapid urban development has led to capsule hotels,sleep pods,and other tiny sleeping spaces that adapt to people’s fast-paced lives,achieving maximum functionality with a very small footprint.However,...In recent years,rapid urban development has led to capsule hotels,sleep pods,and other tiny sleeping spaces that adapt to people’s fast-paced lives,achieving maximum functionality with a very small footprint.However,due to the small space,human metabolic pollutant(such as CO_(2))is more likely to accumulate,and the air is not easily circulated.In this paper,a full-size experimental platform is set up with three types of ventilation modes to explore the exclusion efficiency of metabolic pollutants and the overall distribution of age of air under these ventilation modes.The conclusions showed that the mean values of metabolic pollutant exclusion rates for the different ventilation modalities varied very little across the spatial dimensions of the confined space but varied considerably in the area around the head.The double-side attached ventilation method was the most effective in removing human metabolic pollutants,especially in the head region(CN≥0.92),while the single-wall attached ventilation method had the best air exchange efficiency(η≥0.85).This suggests an inconsistent distribution of CO_(2) and age of air,which is contrary to general common sense.The conclusions of this paper can guide the design of ventilation for tiny sleeping spaces.展开更多
基金Sponsored by the Scientific and Technically Key Project of Heilongjiang Province(Grant No.GC04C213).
文摘Residents living in the cold areas such as Harbin generally experience a residence time of approximately 6 months in chilly winter without frequent natural ventilation. To find out the influence of a short period of ventilation on the indoor formaldehyde concentration inside a new building, an investigation was conducted for the instance of twice ventilation in a day through window opening. The results showed that the initial concentration of formaldehyde was 3.53 -8. 48 times as high as the concentration after 10 min ventilation. After closing the window, the indoor formaldehyde concentration increased with time and followed an exponential equation of C = C0 exp（ - b ＊ t） ＋ （ a ＋ Cu, ） [ 1 - exp（ - b ＊ t） ] with correlation coefficient （ R^2 ） of 0. 945 - 0. 999, based on the statistical analysis of 14 groups of measurement data. The developed equation can be used to estimate the emission rate of indoor formaldehyde sources and the air exchange rate of the test room simultaneously.
基金Sponsored by the National Natural Science Foundation of Guangdong Province(Grant No.2020A1515011092)the Open Projects Fund of KeyL aboratory of Ecology and Energy-saving Study of Dense Habitat(Tongji University),Ministry of Education(Grant No.2020030105)。
文摘Natural ventilation effects in high and large space buildings of tropical areas greatlya ffect the air conditioning energy consumption.Aiming at nearly zero energy building design,thisp aper mainly contributes to provide theoretical basis and reference for thermal comfortable air conditioning system design of high and large space buildings.Taking a theatre in Hainan as study object,a newly composite enhanced natural ventilation system is proposed by integrating theu nderground tunnel-based earth to air heat exchange system and the solar chimney.Ventilationq uantity,air velocity and air temperature field,human vertical temperature gradient differenceu nder24simulation working conditions are considered and analyzed by using ANSYS Fluent.Fort he underground tunnel,results show that Group Two with double underground tunnels and side airs upply location shows its advantages in cooling effects and air supply uniformity.Then for the solar chimney,results show that the solar radiation intensity contributes to larger difference int ransmission power and leads to different cooling effects.On the whole,the system under workingc ondition No.7with120m long,side air supply,double underground tunnel and20m high,1mw ide,0.6°absorber plate angle solar chimney shows its priority in better comprehensive performance.
基金the Natural Science Foundation of Hunan,China(No.2020JJ4159)the Research Foundation of Education Bureau of Hunan,China(No.19A093)+1 种基金the Interdisciplinary Program of Shanghai Jiao Tong University(No.YG2019ZDB08)the Significant Special Project form Ministry of Science and Technology of China(No.2021YFC0122500)。
文摘The high frequency ventilation(HFV)can well support the breathing of respiratory patient with 20%-40%of normal tidal volume.Now as a therapy of rescue ventilation when conversional ventilation failed,the HFV has been applied in the treatments of severe patients with acute respiratory failure(ARF),acute respiratory distress syndrome(ARDS),etc.However,the gas exchange mechanism(GEM)of HFV is still not fully understood by researchers.In this paper,the GEM of HFV is reviewed to track the studies in the last decades and prospect for the next likely studies.And inspired by previous studies,the GEM of HFV is suggested to be continually developed with various hypotheses which will be testified in simulation,experiment and clinic trail.One of the significant measures is to study the GEM of HFV under the cross-disciplinary integration of medicine and engineering.Fully understanding the GEM can theoretically support and expand the applications of HFV,and is helpful in investigating the potential indications and contraindications of HFV.
基金This study was jointly funded by Shaanxi Provincial Overseas Scholars Scientific and Technological Activities Selection Project(2022-005)Shaanxi Provincial Key R&D Program International Science and Technology Cooperation Program Project(2023-GHZD-28),and The Youth Innovation Team of Shaanxi Universities.
文摘In recent years,rapid urban development has led to capsule hotels,sleep pods,and other tiny sleeping spaces that adapt to people’s fast-paced lives,achieving maximum functionality with a very small footprint.However,due to the small space,human metabolic pollutant(such as CO_(2))is more likely to accumulate,and the air is not easily circulated.In this paper,a full-size experimental platform is set up with three types of ventilation modes to explore the exclusion efficiency of metabolic pollutants and the overall distribution of age of air under these ventilation modes.The conclusions showed that the mean values of metabolic pollutant exclusion rates for the different ventilation modalities varied very little across the spatial dimensions of the confined space but varied considerably in the area around the head.The double-side attached ventilation method was the most effective in removing human metabolic pollutants,especially in the head region(CN≥0.92),while the single-wall attached ventilation method had the best air exchange efficiency(η≥0.85).This suggests an inconsistent distribution of CO_(2) and age of air,which is contrary to general common sense.The conclusions of this paper can guide the design of ventilation for tiny sleeping spaces.
