Heating-only fan coil(HFC)is one of the suited end users,which is not only compact but also highly efficient.And the major factors affecting the heat dissipation performance of HFC include leakage through coil bypass,...Heating-only fan coil(HFC)is one of the suited end users,which is not only compact but also highly efficient.And the major factors affecting the heat dissipation performance of HFC include leakage through coil bypass,distance between fan and coil,fan structure and air inlet type.Under natural air convection or forced,experimental studies were made on the effects of these factors upon the heat dissipation performance of HFC.The results show that:1)After reducing the leakage through coil bypass,the heat dissipation of HFC increases 16.9% under natural convection,and increases 8.3% under forced convection.2)After the distance between fan and coil be raised from 23.2cm to 41.7cm,the heat dissipation of HFC decreases 21.3% under natural convection,but increases12.8% under forced convection.3)After changing the fan structure,the heat dissipation of HFC increases 41.8% under natural convection,and the heat dissipation per motor power increases 96.1% under forced convection.4)The heat dissipations of HFC with round pass,slit and strip type of air inlet are different,whose proportion is about 100%,110%,136% under natural convection,and 100%,105%,116% under forced convection.展开更多
本文提出按照FANS(Future Air Navigation Systems)概念在中国实施以卫星为基础的未来通信、导航和监视(CNS)系统的成本/效益分析。文中对中国民用航空飞机进行了分类、统计,对未来发展进行了预测,并在一定假设的基础上对实施未来CNS系...本文提出按照FANS(Future Air Navigation Systems)概念在中国实施以卫星为基础的未来通信、导航和监视(CNS)系统的成本/效益分析。文中对中国民用航空飞机进行了分类、统计,对未来发展进行了预测,并在一定假设的基础上对实施未来CNS系统的成本和效益进行了估算。结果表明,效益成本比约为2.6:1,从而证明FANS方案不仅在技术上先进,能克服现有航行系统的缺点,而且在经济上也有明显效益。展开更多
The article is devoted to the study of the issues of determining the patterns of changes in air pressure along the length of a pneumatic transmission pipeline for raw cotton at different flow parameters and different ...The article is devoted to the study of the issues of determining the patterns of changes in air pressure along the length of a pneumatic transmission pipeline for raw cotton at different flow parameters and different pipeline diameters. Theoretical studies have proved the reduction of static and total pressure along the line of pneumatic cotton transportation. The dependence of the pressure change on the diameter of the transport line and the aerodynamic drag of the pipeline is obtained. The results obtained are recommended for use in the design of raw cotton pneumatic transport systems.展开更多
The field tot of performance of mine main fan is going to become an independance requirement of coal mlue progressively and to be taken seriously. According to the fan-house with air gate closed to the fan inlet, this...The field tot of performance of mine main fan is going to become an independance requirement of coal mlue progressively and to be taken seriously. According to the fan-house with air gate closed to the fan inlet, this paper analyses the influence of the rapid changing air flow field upon field test and puts forward a reasonable test scheme.展开更多
基金Supported by National11th Five-Year Plan Major Scientific and Technological Issues of China(2006BAJ01A04)
文摘Heating-only fan coil(HFC)is one of the suited end users,which is not only compact but also highly efficient.And the major factors affecting the heat dissipation performance of HFC include leakage through coil bypass,distance between fan and coil,fan structure and air inlet type.Under natural air convection or forced,experimental studies were made on the effects of these factors upon the heat dissipation performance of HFC.The results show that:1)After reducing the leakage through coil bypass,the heat dissipation of HFC increases 16.9% under natural convection,and increases 8.3% under forced convection.2)After the distance between fan and coil be raised from 23.2cm to 41.7cm,the heat dissipation of HFC decreases 21.3% under natural convection,but increases12.8% under forced convection.3)After changing the fan structure,the heat dissipation of HFC increases 41.8% under natural convection,and the heat dissipation per motor power increases 96.1% under forced convection.4)The heat dissipations of HFC with round pass,slit and strip type of air inlet are different,whose proportion is about 100%,110%,136% under natural convection,and 100%,105%,116% under forced convection.
文摘本文提出按照FANS(Future Air Navigation Systems)概念在中国实施以卫星为基础的未来通信、导航和监视(CNS)系统的成本/效益分析。文中对中国民用航空飞机进行了分类、统计,对未来发展进行了预测,并在一定假设的基础上对实施未来CNS系统的成本和效益进行了估算。结果表明,效益成本比约为2.6:1,从而证明FANS方案不仅在技术上先进,能克服现有航行系统的缺点,而且在经济上也有明显效益。
文摘The article is devoted to the study of the issues of determining the patterns of changes in air pressure along the length of a pneumatic transmission pipeline for raw cotton at different flow parameters and different pipeline diameters. Theoretical studies have proved the reduction of static and total pressure along the line of pneumatic cotton transportation. The dependence of the pressure change on the diameter of the transport line and the aerodynamic drag of the pipeline is obtained. The results obtained are recommended for use in the design of raw cotton pneumatic transport systems.
文摘The field tot of performance of mine main fan is going to become an independance requirement of coal mlue progressively and to be taken seriously. According to the fan-house with air gate closed to the fan inlet, this paper analyses the influence of the rapid changing air flow field upon field test and puts forward a reasonable test scheme.
