Research on the distribution of smoke in tunnels is significant for the fire emergency rescue after an operating metro train catches fire. A dynamic grid technique was adopted to research the law of smoke flow diffusi...Research on the distribution of smoke in tunnels is significant for the fire emergency rescue after an operating metro train catches fire. A dynamic grid technique was adopted to research the law of smoke flow diffusion inside the tunnel when the bottom of a metro train was on fire and to compare the effect of longitudinal ventilation modes on the smoke motion when the burning train stopped. Research results show that the slipstream curves around the train obtained by numerical simulation are consistent with experimental data. When the train decelerates, the smoke flow first extends to the tail of the train. With the decrease of the train's speed, the smoke flow diffuses to the head of the train. After the train stops, the slipstream around the train formed in the process of train operation plays a leading role in the smoke diffusion in the tunnel. The smoke flow quickly diffuses to the domain in front of the train. After forward mechanical ventilation is provided, the smoke flow inside the tunnel continues to diffuse downstream. When reverse mechanical ventilation operates, the smoke in front of the train flows back rapidly and diffuses to the rear of the train.展开更多
Continuous and dynamic measurements of human respiratory parameters are very important for vital diseases of respiratory system during mechanical ventilation. This paper analyzed the structure and mechanical propertie...Continuous and dynamic measurements of human respiratory parameters are very important for vital diseases of respiratory system during mechanical ventilation. This paper analyzed the structure and mechanical properties of the human respiratory system, and designed an active intervening monitoring micro system for it. The mobile mechanism of the micro system is soft and earthworm-like movement actuated by pneumatic rubber actuator, the measurement and therapy unit of the system is an extensible mechanism with sensors in the front. The micro monitoring system can move in respiratory tract and measure the respiratory parameters in bronchium continuously. Experiments had been done in swine＇s respiratory tract, the results proved that the micro robot system could measure the respiratory parameters in real-time successfully and its movement was smith in swine＇s respiratory tract.展开更多
Earth tempering of stable air has attracted great attention as a sustainable air conditioning method in pig houses. At summer time air cooling of income air strongly reduces heat stress and required ventilation rate. ...Earth tempering of stable air has attracted great attention as a sustainable air conditioning method in pig houses. At summer time air cooling of income air strongly reduces heat stress and required ventilation rate. At winter time heating costs can be reduced. The effect of air condition using geothermal energy was investigated in a farrowing house. Underneath the foundation of the farrowing house 88 non perforated ribbed tubes （diameter： 20 cm） were piped in a depth of 1.6-2.0 m. Over a period of 12 month following data were recorded at hourly intervals and analyzed： outside air temperature, as well as air temperature in the air supply duct and in the compartments. Incoming air （supply duct） was heated up to 20 ℃ during winter time and in summer time cooled by up to 15 ℃ compared to the outside air temperature. In contrast to the outside air diurnal variation, temperature fluctuations of the incoming air were reduced by 90%. Due to cooling of the incoming air at summer time the stable inside temperature could be limited to maximal 29 ℃（maximum outside temperature was 35℃）. Earth-tube heat exchangers with non perforated ribbed tubes were very efficient for air conditioning in farrowing houses. They were a cost effective supplement for sustainable cooling and heating of farrowing houses.展开更多
To explore the spatial-temporal evolution law of rock mass temperature in high geothermal roadway during mechar^ical ventilation, a series of experiments were conducted based on the physical simulation test system of ...To explore the spatial-temporal evolution law of rock mass temperature in high geothermal roadway during mechar^ical ventilation, a series of experiments were conducted based on the physical simulation test system of thermal and humid environment in high geothermal roadway, which is a method independently developed by China University of Mining and Technology. The results indicate that during ventilation, the disturbed region of the temperature extends gradually from shallow area to deep area in the surrounding rock mass of the roadway. Meanwhile, the temperature increases as the exponential function from shallow area to deep, with steady decrease of the temperature gradient and heat flux. As the ventilation proceeds, the relationship between dimensionless temperature and dimensionless time approximately meets Hill function.展开更多
In a golf course located at El Kantaoui, Sousse, Tunisia, this study was carried out over a sandy soil grassy sward to investigate the effects of mechanical aeration （perforation of the sward with an aerators machine...In a golf course located at El Kantaoui, Sousse, Tunisia, this study was carried out over a sandy soil grassy sward to investigate the effects of mechanical aeration （perforation of the sward with an aerators machine called ＂Vertidrain＂） on its compaction and hydraulic conductivity. For this purpose, many soil cores were extracted using a 1.6 e.g. m effective width Verti-Drain aerator equipped with hollow spades spaced 65 e.g. mm apart. Aeration was performed at a rate of 350 holes/m2. Soil resistance to penetration and permeability were determined at the initial state before aeration as well as 10, 20, and 30 days after aeration. Compared to the initial state, the results showed that mechanical aeration greatly affects the grassy sward ground by reducing its resistance to penetration as 35% and 43% decrease in penetration resistance were noticed at 5 e.g. cm depth 10 and 20 days after aeration, respectively. Also, resistance to penetration decreased by 41% and 48% at 15 e.g. cm depth during the same two periods of time with a relatively constant moisture content. However, soil resistance to penetration at 5 and 15 e.g. cm depths only decreased by 21% and 26%, respectively. Regarding the soil hydraulic conductivity measured after aeration, a significant improvement at the 1% level with the method of variance analysis, was observed compared to that at the initial state （4.9 e.g. cm hl）. Indeed, the hydraulic conductivity was 12.5, 13, and 14.1 e.g. cm h-1 10, 20, and 30 days after aeration, respectively.展开更多
The content of contribution is to analyse suggested renovation of school building in term of energy performance and indoor environment quality. There were three selected variants of possible reno ration of school buil...The content of contribution is to analyse suggested renovation of school building in term of energy performance and indoor environment quality. There were three selected variants of possible reno ration of school building. At first, it was installation of equipment for heat recovery into existing mechanical ventilation system. There were further evaluated possibilities how to use glass atrium or ground air-heat exchanger in mechanical ventilation system. These suggested variants were analysed in field of energy performance, namely in term of impacts on heat demand for space heating in order to keep required parameters of indoor environment quality according to standard STN EN 15251 （operative temperature, relative air humidity, air change rate）. The analysis was elaborated by using energy simulation tool Design Builder in order to evaluate yearlong operation of buildings.展开更多
As an important life support treatment, mechanical ventilation is usually adopted in clinics. With the development of the res-piratory diagnostic and treatment technologies, air flow dynamics of mechanical ventilation...As an important life support treatment, mechanical ventilation is usually adopted in clinics. With the development of the res-piratory diagnostic and treatment technologies, air flow dynamics of mechanical ventilation is usually referenced in the evaluation of pulmonary status and assessment of respiratory therapy. In order to improve the ventilation efficiency and provide a reference for pulmonary diagnostics, in this paper, a new mathematical model of mechanical ventilation system was set up. Furthermore, a prototype mechanical ventilation system for an artificial simulating lung was designed and experimentally studied. Lastly, in order to improve the ventilation efficiency and provide a reference for pulmonary diagnostics, the air flow dynamics of the mechanical ventilation system was illustrated through simulation and experimental studies. The study can be helpful to the optimization of the mechanical ventilation system.展开更多
基金Project(U1134203)supported by the Major Program of the National Natural Science Foundation of ChinaProject(51105384)supported by the National Natural Science Foundation of China
文摘Research on the distribution of smoke in tunnels is significant for the fire emergency rescue after an operating metro train catches fire. A dynamic grid technique was adopted to research the law of smoke flow diffusion inside the tunnel when the bottom of a metro train was on fire and to compare the effect of longitudinal ventilation modes on the smoke motion when the burning train stopped. Research results show that the slipstream curves around the train obtained by numerical simulation are consistent with experimental data. When the train decelerates, the smoke flow first extends to the tail of the train. With the decrease of the train's speed, the smoke flow diffuses to the head of the train. After the train stops, the slipstream around the train formed in the process of train operation plays a leading role in the smoke diffusion in the tunnel. The smoke flow quickly diffuses to the domain in front of the train. After forward mechanical ventilation is provided, the smoke flow inside the tunnel continues to diffuse downstream. When reverse mechanical ventilation operates, the smoke in front of the train flows back rapidly and diffuses to the rear of the train.
文摘Continuous and dynamic measurements of human respiratory parameters are very important for vital diseases of respiratory system during mechanical ventilation. This paper analyzed the structure and mechanical properties of the human respiratory system, and designed an active intervening monitoring micro system for it. The mobile mechanism of the micro system is soft and earthworm-like movement actuated by pneumatic rubber actuator, the measurement and therapy unit of the system is an extensible mechanism with sensors in the front. The micro monitoring system can move in respiratory tract and measure the respiratory parameters in bronchium continuously. Experiments had been done in swine＇s respiratory tract, the results proved that the micro robot system could measure the respiratory parameters in real-time successfully and its movement was smith in swine＇s respiratory tract.
文摘Earth tempering of stable air has attracted great attention as a sustainable air conditioning method in pig houses. At summer time air cooling of income air strongly reduces heat stress and required ventilation rate. At winter time heating costs can be reduced. The effect of air condition using geothermal energy was investigated in a farrowing house. Underneath the foundation of the farrowing house 88 non perforated ribbed tubes （diameter： 20 cm） were piped in a depth of 1.6-2.0 m. Over a period of 12 month following data were recorded at hourly intervals and analyzed： outside air temperature, as well as air temperature in the air supply duct and in the compartments. Incoming air （supply duct） was heated up to 20 ℃ during winter time and in summer time cooled by up to 15 ℃ compared to the outside air temperature. In contrast to the outside air diurnal variation, temperature fluctuations of the incoming air were reduced by 90%. Due to cooling of the incoming air at summer time the stable inside temperature could be limited to maximal 29 ℃（maximum outside temperature was 35℃）. Earth-tube heat exchangers with non perforated ribbed tubes were very efficient for air conditioning in farrowing houses. They were a cost effective supplement for sustainable cooling and heating of farrowing houses.
基金Project(2014-6121)supported by Fundamental Research Funds for the Central Universities,ChinaProject(51504236)supported by the National Natural Science Foundation of ChinaProject supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions,China
文摘To explore the spatial-temporal evolution law of rock mass temperature in high geothermal roadway during mechar^ical ventilation, a series of experiments were conducted based on the physical simulation test system of thermal and humid environment in high geothermal roadway, which is a method independently developed by China University of Mining and Technology. The results indicate that during ventilation, the disturbed region of the temperature extends gradually from shallow area to deep area in the surrounding rock mass of the roadway. Meanwhile, the temperature increases as the exponential function from shallow area to deep, with steady decrease of the temperature gradient and heat flux. As the ventilation proceeds, the relationship between dimensionless temperature and dimensionless time approximately meets Hill function.
文摘In a golf course located at El Kantaoui, Sousse, Tunisia, this study was carried out over a sandy soil grassy sward to investigate the effects of mechanical aeration （perforation of the sward with an aerators machine called ＂Vertidrain＂） on its compaction and hydraulic conductivity. For this purpose, many soil cores were extracted using a 1.6 e.g. m effective width Verti-Drain aerator equipped with hollow spades spaced 65 e.g. mm apart. Aeration was performed at a rate of 350 holes/m2. Soil resistance to penetration and permeability were determined at the initial state before aeration as well as 10, 20, and 30 days after aeration. Compared to the initial state, the results showed that mechanical aeration greatly affects the grassy sward ground by reducing its resistance to penetration as 35% and 43% decrease in penetration resistance were noticed at 5 e.g. cm depth 10 and 20 days after aeration, respectively. Also, resistance to penetration decreased by 41% and 48% at 15 e.g. cm depth during the same two periods of time with a relatively constant moisture content. However, soil resistance to penetration at 5 and 15 e.g. cm depths only decreased by 21% and 26%, respectively. Regarding the soil hydraulic conductivity measured after aeration, a significant improvement at the 1% level with the method of variance analysis, was observed compared to that at the initial state （4.9 e.g. cm hl）. Indeed, the hydraulic conductivity was 12.5, 13, and 14.1 e.g. cm h-1 10, 20, and 30 days after aeration, respectively.
文摘The content of contribution is to analyse suggested renovation of school building in term of energy performance and indoor environment quality. There were three selected variants of possible reno ration of school building. At first, it was installation of equipment for heat recovery into existing mechanical ventilation system. There were further evaluated possibilities how to use glass atrium or ground air-heat exchanger in mechanical ventilation system. These suggested variants were analysed in field of energy performance, namely in term of impacts on heat demand for space heating in order to keep required parameters of indoor environment quality according to standard STN EN 15251 （operative temperature, relative air humidity, air change rate）. The analysis was elaborated by using energy simulation tool Design Builder in order to evaluate yearlong operation of buildings.
基金supported by the National Natural Science Foundation of China(Grant No.51575020)
文摘As an important life support treatment, mechanical ventilation is usually adopted in clinics. With the development of the res-piratory diagnostic and treatment technologies, air flow dynamics of mechanical ventilation is usually referenced in the evaluation of pulmonary status and assessment of respiratory therapy. In order to improve the ventilation efficiency and provide a reference for pulmonary diagnostics, in this paper, a new mathematical model of mechanical ventilation system was set up. Furthermore, a prototype mechanical ventilation system for an artificial simulating lung was designed and experimentally studied. Lastly, in order to improve the ventilation efficiency and provide a reference for pulmonary diagnostics, the air flow dynamics of the mechanical ventilation system was illustrated through simulation and experimental studies. The study can be helpful to the optimization of the mechanical ventilation system.
