By analyzing the gas expansion process from the upstream chamber via an orifice and a very rapid-opening ultra-high vacuum(UHV)gate valve to downstream one,the standard pressure analytical model basedon the dvnamic va...By analyzing the gas expansion process from the upstream chamber via an orifice and a very rapid-opening ultra-high vacuum(UHV)gate valve to downstream one,the standard pressure analytical model basedon the dvnamic vacuum calibration apparatus in millisecond range developed by Lanzhou Institute of Physics(LIP)is deduced theoretically and corrected by real gas characteristics and temperature changes.According to the Kuudsen criterion,there is no free molecular fow regime in the area in front of the orifice during the gas expansion,so the chocked fow approximation is adopted to reduce the difficulty of numerical computation Under this anproxiuatiou and the full opening of the rapid valve,the standard pressure expression is calculated theoretically,and the upstream chamber pressure and temperature changes are obtained by numerical simulation during the gas expansion from 100 kPa to 10kPa.Also,experiments are performed using capacitance diaphragmgauges(model CDG045Dhs),The uncertainties between the measured pressure and the simulated and theoretical ones are 10%and 4.65%,respectively,which indicates that the apparatus can generate predictable pressure changes in the millisecond rauge and the conceptual model can better approximate the calibration results.Einally,the orifice conductance,and the correction factors of real gas characteristics and temperature change to the standard pressure are calculated accordins to the simulation results:the corrected staudard pressure expression is obtained.展开更多
吸尘器在欧盟环保设计法规No 666/2013和能效标签法规EU No 665/2013自2014年9月1日实施后,近期又有新的进展和研究发现。本文在梳理吸尘器欧盟能效标签和环保设计法规的现状和更新的基础上,结合扫地机器人IEC国际标准等标准制修订以及...吸尘器在欧盟环保设计法规No 666/2013和能效标签法规EU No 665/2013自2014年9月1日实施后,近期又有新的进展和研究发现。本文在梳理吸尘器欧盟能效标签和环保设计法规的现状和更新的基础上,结合扫地机器人IEC国际标准等标准制修订以及消费者对产品性能认知的角度,对吸尘器和扫地机器人性能标准化和欧盟法规的挑战进行简要阐述,并提出吸尘器和扫地机器人性能标准化建议和参考意见。展开更多
基金the National Natural Science Foundation of China(No.61501212)。
文摘By analyzing the gas expansion process from the upstream chamber via an orifice and a very rapid-opening ultra-high vacuum(UHV)gate valve to downstream one,the standard pressure analytical model basedon the dvnamic vacuum calibration apparatus in millisecond range developed by Lanzhou Institute of Physics(LIP)is deduced theoretically and corrected by real gas characteristics and temperature changes.According to the Kuudsen criterion,there is no free molecular fow regime in the area in front of the orifice during the gas expansion,so the chocked fow approximation is adopted to reduce the difficulty of numerical computation Under this anproxiuatiou and the full opening of the rapid valve,the standard pressure expression is calculated theoretically,and the upstream chamber pressure and temperature changes are obtained by numerical simulation during the gas expansion from 100 kPa to 10kPa.Also,experiments are performed using capacitance diaphragmgauges(model CDG045Dhs),The uncertainties between the measured pressure and the simulated and theoretical ones are 10%and 4.65%,respectively,which indicates that the apparatus can generate predictable pressure changes in the millisecond rauge and the conceptual model can better approximate the calibration results.Einally,the orifice conductance,and the correction factors of real gas characteristics and temperature change to the standard pressure are calculated accordins to the simulation results:the corrected staudard pressure expression is obtained.
文摘吸尘器在欧盟环保设计法规No 666/2013和能效标签法规EU No 665/2013自2014年9月1日实施后,近期又有新的进展和研究发现。本文在梳理吸尘器欧盟能效标签和环保设计法规的现状和更新的基础上,结合扫地机器人IEC国际标准等标准制修订以及消费者对产品性能认知的角度,对吸尘器和扫地机器人性能标准化和欧盟法规的挑战进行简要阐述,并提出吸尘器和扫地机器人性能标准化建议和参考意见。
