Because of the multiple problems on high energy consumption and unbalanced thermal comfort caused by the traditional ventilation system,a new concept of ventilation-stratum ventilation has been proposed,which sends th...Because of the multiple problems on high energy consumption and unbalanced thermal comfort caused by the traditional ventilation system,a new concept of ventilation-stratum ventilation has been proposed,which sends the fresh air to the breathing zone directly.In this paper,the local air distributions of the displacement ventilation and the stratum ventilation in a model office were measured.The air ages in the breathing zone for the displacement ventilation and stratum ventilation were compared with the tracer gas concentration decay method.The decay curves of tracer gas concentration for these two ventilation systems in the breathing zone were obtained,and the air ages were calculated.The experimental results show that the stratum ventilation system can offer lower air age for four mechanically ventilated cases in the breathing zone,and it can also provide better thermal comfort,which renews the air of breathing zone more quickly and reduces the energy consumption in some degree.The experimental investigation provides a theoretical basis for the application of stratum ventilation system.展开更多
Nowadays,the world is short of energy source,and larger proportion of building energy consumption is occupied by air conditioning system. It is urgent that not only importance should be attached on energy saving but a...Nowadays,the world is short of energy source,and larger proportion of building energy consumption is occupied by air conditioning system. It is urgent that not only importance should be attached on energy saving but also arcology energy technology based on green and sustainable thought should be advocated. Considering the ever growing energy consumption of residential buildings,intermittent ventilation is a solution to saving energy consumption and improving indoor thermal comfort. Aiming at reducing indoor air temperature by intermittent ventilation and decrease energy consumption of air conditioning system,with the help of DeST (Designer's Simulation Toolkit) this paper analyzes the characteristics of air conditioning load and year round air conditioning time in Chongqing located in hot summer and cold winter zone,obtains the amount of energy consumption saved at different ventilation rates,and recommends suitable ventilation rate in hot summer and cold winter zone.展开更多
In order to study the effects of ventilation modes and outlet height on the airflow field of a nursery piggery,computational fluid dynamics (CFD) technology was used to simulate the wind speed and temperature of an ex...In order to study the effects of ventilation modes and outlet height on the airflow field of a nursery piggery,computational fluid dynamics (CFD) technology was used to simulate the wind speed and temperature of an experimental pig house in the cold northern region.This study was conducted with simulation and a comparative analysis of transverse ventilation,longitudinal ventilation and roof air intake modes.Furthermore,the effects of the air outlet height of 0.7,0.6 and 0.5 m with the roof air inlet mode on the environment in the pig house were studied.Field experiments verified the model of roof air intake model.The results showed inadequate ventilation in both the vertical and horizontal ventilation.However,the airfield gradients were less variable and more balanced when using the rooftop air intake mode.The variation of outlet height significantly affected nursery pig houses’ airflow velocity and temperature.Roof air inlet mode with an outlet height of 0.7 m was better than the other two.The normalized mean square error (NMSE) of air velocity and temperature was less than 0.01,and the simulation analysis could genuinely reflect the distribution of the airflow field in the nursery.展开更多
在积水入渗试验中,气阻效应会阻碍渗流并影响湿润锋的形态.针对不同通气条件下湿润锋的气阻效应,进行了无通气、中部通气10k Pa、20k Pa以及底部通气20k Pa 4种不同工况下的土柱入渗试验,通过埋设传感器以及外部拍照两种方式,动态监测...在积水入渗试验中,气阻效应会阻碍渗流并影响湿润锋的形态.针对不同通气条件下湿润锋的气阻效应,进行了无通气、中部通气10k Pa、20k Pa以及底部通气20k Pa 4种不同工况下的土柱入渗试验,通过埋设传感器以及外部拍照两种方式,动态监测了湿润锋运移过程并进行了对比.结果表明:温度传感器和外部监测对湿润锋位置的捕捉吻合度良好,湿度传感器对湿润锋的响应略早,而体积含水率传感器的响应则滞后;通气气压大小对湿润锋有显著影响,相同通气压力下,通气位置不同对初期入渗影响较大,对湿润锋达到底部总体时间影响较小.研究成果对湿润锋动态监测以及揭示通气阻渗机理具有重要参考价值.展开更多
目的比较无创通气间歇期氧气驱动雾化、无创通气间歇期空气驱动雾化、无创通气同时空气驱动雾化对慢性阻塞性肺疾病急性加重(AECOPD)患者雾化过程中二氧化碳分压、氧饱和度(SpO_(2))及心率的动态变化及治疗效果的影响。方法根据随机对...目的比较无创通气间歇期氧气驱动雾化、无创通气间歇期空气驱动雾化、无创通气同时空气驱动雾化对慢性阻塞性肺疾病急性加重(AECOPD)患者雾化过程中二氧化碳分压、氧饱和度(SpO_(2))及心率的动态变化及治疗效果的影响。方法根据随机对照研究的方法将99例需使用无创通气及雾化吸入治疗的慢性阻塞性肺疾病急性加重患者根据计算机产生的随机数字表随机分为对照组、观察一组、观察二组各33例,对照组给予无创通气间歇期氧气驱动雾化吸入,观察一组给予无创通气间歇空气驱动雾化,观察二组给予无创通气同时空气驱动雾化,记录雾化0、5、10、15 min和雾化结束5、10、15 min的经皮二氧化碳分压(PtCO_(2))、SpO_(2)及心率变化。记录治疗前至治疗第7天每天早晨动脉血气PaCO_(2)、PaO_(2)数值,记录三组住院时间。结果三组雾化过程中PtCO_(2)对比结果显示,时间主效应和时间组别交互效应差异均有统计学意义(P<0.001),且对照组PtCO_(2)数值与时间呈线性关系(F=10.166,P=0.003),随时间变化呈上升状态;观察一组各时间点PtCO_(2)数值与时间呈线性关系(F=10.544,P=0.003),随时间变化呈下降状态;观察二组各时间点PtCO_(2)数值与时间呈线性关系(F=20.003,P<0.001),随时间呈下降状态。再分别对三组每个时间点PtCO_(2)数值进行多样本方差分析,对照组雾化15 min PtCO_(2)高于观察一组、观察二组;观察一组、观察二组均与对照组雾化前后PtCO_(2)差值(dPtCO_(2))差异有统计学意义(P<0.05);对三组雾化结束观察期每个时间点PtCO_(2)数值进行多样本方差分析,结果显示三组雾化结束0 min PtCO_(2)、雾化结束5 min PtCO_(2)差异有统计学意义(P<0.05),雾化结束10 min PtCO_(2)、雾化结束15 min PtCO_(2)三组差异无统计学意义(P>0.05);三组雾化过程中SpO_(2)对比显示三组时间组别交互效应差异均有统计学意义(P<0.05)。且观察一组各时间点SpO_(2)数值随时间呈下降趋势。对照组雾化10 min SpO_(2)、雾化15 min SpO_(2)高于观察一组和观察二组;三组均能使动脉血气中PaCO_(2)随治疗时间的增加而好转(P<0.05)。结论三种雾化治疗方式均能取得良好的治疗效果,但无创通气间歇期氧气驱动雾化会使雾化过程中PtCO_(2)及SpO_(2)上升;无创通气间歇期空气驱动雾化会使雾化过程中PtCO_(2)及SpO_(2)下降;无创通气同时空气驱动雾化使雾化过程中PtCO_(2)下降及保持SpO_(2)平稳,因此无创通气同时空气驱动雾化是相对更加安全的雾化吸入方式,值得临床推广。展开更多
文摘Because of the multiple problems on high energy consumption and unbalanced thermal comfort caused by the traditional ventilation system,a new concept of ventilation-stratum ventilation has been proposed,which sends the fresh air to the breathing zone directly.In this paper,the local air distributions of the displacement ventilation and the stratum ventilation in a model office were measured.The air ages in the breathing zone for the displacement ventilation and stratum ventilation were compared with the tracer gas concentration decay method.The decay curves of tracer gas concentration for these two ventilation systems in the breathing zone were obtained,and the air ages were calculated.The experimental results show that the stratum ventilation system can offer lower air age for four mechanically ventilated cases in the breathing zone,and it can also provide better thermal comfort,which renews the air of breathing zone more quickly and reduces the energy consumption in some degree.The experimental investigation provides a theoretical basis for the application of stratum ventilation system.
基金Projects(2006BAJ02A02-05,2006BAJ01A05-06-04) supported by the National Key Technologies R & D Program of China
文摘Nowadays,the world is short of energy source,and larger proportion of building energy consumption is occupied by air conditioning system. It is urgent that not only importance should be attached on energy saving but also arcology energy technology based on green and sustainable thought should be advocated. Considering the ever growing energy consumption of residential buildings,intermittent ventilation is a solution to saving energy consumption and improving indoor thermal comfort. Aiming at reducing indoor air temperature by intermittent ventilation and decrease energy consumption of air conditioning system,with the help of DeST (Designer's Simulation Toolkit) this paper analyzes the characteristics of air conditioning load and year round air conditioning time in Chongqing located in hot summer and cold winter zone,obtains the amount of energy consumption saved at different ventilation rates,and recommends suitable ventilation rate in hot summer and cold winter zone.
基金Supported by the National Natural Science Foundation of China(32072787)。
文摘In order to study the effects of ventilation modes and outlet height on the airflow field of a nursery piggery,computational fluid dynamics (CFD) technology was used to simulate the wind speed and temperature of an experimental pig house in the cold northern region.This study was conducted with simulation and a comparative analysis of transverse ventilation,longitudinal ventilation and roof air intake modes.Furthermore,the effects of the air outlet height of 0.7,0.6 and 0.5 m with the roof air inlet mode on the environment in the pig house were studied.Field experiments verified the model of roof air intake model.The results showed inadequate ventilation in both the vertical and horizontal ventilation.However,the airfield gradients were less variable and more balanced when using the rooftop air intake mode.The variation of outlet height significantly affected nursery pig houses’ airflow velocity and temperature.Roof air inlet mode with an outlet height of 0.7 m was better than the other two.The normalized mean square error (NMSE) of air velocity and temperature was less than 0.01,and the simulation analysis could genuinely reflect the distribution of the airflow field in the nursery.
文摘在积水入渗试验中,气阻效应会阻碍渗流并影响湿润锋的形态.针对不同通气条件下湿润锋的气阻效应,进行了无通气、中部通气10k Pa、20k Pa以及底部通气20k Pa 4种不同工况下的土柱入渗试验,通过埋设传感器以及外部拍照两种方式,动态监测了湿润锋运移过程并进行了对比.结果表明:温度传感器和外部监测对湿润锋位置的捕捉吻合度良好,湿度传感器对湿润锋的响应略早,而体积含水率传感器的响应则滞后;通气气压大小对湿润锋有显著影响,相同通气压力下,通气位置不同对初期入渗影响较大,对湿润锋达到底部总体时间影响较小.研究成果对湿润锋动态监测以及揭示通气阻渗机理具有重要参考价值.
文摘目的比较无创通气间歇期氧气驱动雾化、无创通气间歇期空气驱动雾化、无创通气同时空气驱动雾化对慢性阻塞性肺疾病急性加重(AECOPD)患者雾化过程中二氧化碳分压、氧饱和度(SpO_(2))及心率的动态变化及治疗效果的影响。方法根据随机对照研究的方法将99例需使用无创通气及雾化吸入治疗的慢性阻塞性肺疾病急性加重患者根据计算机产生的随机数字表随机分为对照组、观察一组、观察二组各33例,对照组给予无创通气间歇期氧气驱动雾化吸入,观察一组给予无创通气间歇空气驱动雾化,观察二组给予无创通气同时空气驱动雾化,记录雾化0、5、10、15 min和雾化结束5、10、15 min的经皮二氧化碳分压(PtCO_(2))、SpO_(2)及心率变化。记录治疗前至治疗第7天每天早晨动脉血气PaCO_(2)、PaO_(2)数值,记录三组住院时间。结果三组雾化过程中PtCO_(2)对比结果显示,时间主效应和时间组别交互效应差异均有统计学意义(P<0.001),且对照组PtCO_(2)数值与时间呈线性关系(F=10.166,P=0.003),随时间变化呈上升状态;观察一组各时间点PtCO_(2)数值与时间呈线性关系(F=10.544,P=0.003),随时间变化呈下降状态;观察二组各时间点PtCO_(2)数值与时间呈线性关系(F=20.003,P<0.001),随时间呈下降状态。再分别对三组每个时间点PtCO_(2)数值进行多样本方差分析,对照组雾化15 min PtCO_(2)高于观察一组、观察二组;观察一组、观察二组均与对照组雾化前后PtCO_(2)差值(dPtCO_(2))差异有统计学意义(P<0.05);对三组雾化结束观察期每个时间点PtCO_(2)数值进行多样本方差分析,结果显示三组雾化结束0 min PtCO_(2)、雾化结束5 min PtCO_(2)差异有统计学意义(P<0.05),雾化结束10 min PtCO_(2)、雾化结束15 min PtCO_(2)三组差异无统计学意义(P>0.05);三组雾化过程中SpO_(2)对比显示三组时间组别交互效应差异均有统计学意义(P<0.05)。且观察一组各时间点SpO_(2)数值随时间呈下降趋势。对照组雾化10 min SpO_(2)、雾化15 min SpO_(2)高于观察一组和观察二组;三组均能使动脉血气中PaCO_(2)随治疗时间的增加而好转(P<0.05)。结论三种雾化治疗方式均能取得良好的治疗效果,但无创通气间歇期氧气驱动雾化会使雾化过程中PtCO_(2)及SpO_(2)上升;无创通气间歇期空气驱动雾化会使雾化过程中PtCO_(2)及SpO_(2)下降;无创通气同时空气驱动雾化使雾化过程中PtCO_(2)下降及保持SpO_(2)平稳,因此无创通气同时空气驱动雾化是相对更加安全的雾化吸入方式,值得临床推广。
