考虑热传递的真空容腔压力响应研究  

Impact of Heat Transfer on Pressure Response in Vacuum Chamber of Pneumatic Vacuum System

作　　者：郭钟华[1] 李小宁[1] 香川利春[2] 

机构地区：[1]南京理工大学机械工程学院,南京210094 [2]东京工业大学精密工学研究所

出　　处：《真空科学与技术学报》2015年第1期74-78,共5页Chinese Journal of Vacuum Science and Technology

基　　金：国家自然科学基金资助项目(51305202);江苏省自然科学基金资助项目(BK20130764)

摘　　要：针对气动真空系统中容腔的压力响应,以往的经验方法没有研究温度变化带来的影响。而在真空发生器回路的容腔抽吸过程中,容腔内空气温度的变化会对压力响应曲线产生影响。本文围绕真空发生器回路和具有一定容积的抽吸容器,改进经验方法,建立了考虑热传递的真空抽吸模型。为了研究真空抽吸过程中传热系数,使用间接测量法("停止法")测得了容腔内温度的变化量,得出了无量纲努塞尔数随抽吸时间的变化曲线。以等温容器抽吸法获得的真空发生器流量特性为基础,使用定努塞尔数传热模型对真空容腔压力响应进行了仿真。通过比较仿真和实验结果可知,考虑热传递的真空容腔压力响应模型能较好地表示真空容腔内压力的变化。The impact of heat transfer on the pressure response in vacuum chamber of the pneumatic vacuum system was approximated, modeled, simulated and measured to modify the conventional pressure-response curve, empirically for- mulated with assumption of adiabatic pumping of the vacuum chamber. The time-dependent temperature in the vacuum chamber in the pumping was evaluated in an indirect method （stop method）, and the dimensionless Nusselt number and heat transfer ratio were derived. The pressure response was simulated with the newly-developed heat transfer model, in which Nusselt number was assumed to be a constant, and on the basis of the static flow-rate characteristics of the ejector. The fairly accurate, temperature-dependent pressure response in the vacuum chamber was obtained by comparing the sim- ulated and measured results.

关 键 词：气动真空系统 容腔 压力响应 传热系数 

分 类 号：TH138[机械工程—机械制造及自动化]