摘要现代气动技术广泛应用于汽车、电子、半导体、自动化等行业。气动元器件是组成气动系统的基本单元,为了设计出节能、低成本的气动系统,就必须准确的把握气动元件的流量特性。在对气动元件的流量特性的测试中,一般都使用音速流导C和临界压力比b来表示,即ISO6358国际标准组织草案,但该方法需要消耗大量的时间和气,并且其实验装置比较复杂。在文章中将国际标准草案与等温容器放气法测量气动元件的流量特性进行对比,总结出等温容器放气法的优势。50814
在此背景之下,参考了一种新的测试气动元件流量特性的方法—等温容器放气法。等温容器就是在容器中填充金属丝来增加气体状态变化过程中的热传递,因为其温度变化很小,因而近似看做等温。由于充放气过程几乎是等温过程,瞬态流量可以在等温容器充放气时的瞬态压力获得,此种方法能够测量稳态、非稳态的气体流动。而使用ISO6358的话,这种方法只能是逐一测量指定压力条件下的静态流量,需要逐点测量,所以测量时间长、耗气量大、且需要量程比非常高的流量计或几个流量计。与ISO6358国际标准草案相比,利用等温容器放气法测定气动元件的流量特性具有仿真实验装置简单、耗气量小、噪声小、能够测量瞬态流量特性等优点。
实验研究采用matlab和fluent软件进行建模与仿真,分别对两种仿真模型进行计算,旨在能独立的完成两个数学建模的建立,在仿真实验过程中研究容器的体积、填充的质量、丝径的差异对容器的温度特性的影响;并且最后对两种仿真模型得出的结果来进行对比分析,从而总结出那些容器的主要参数是影响等温容器性能的。
毕业论文关键字: 等温容器,流量特性,放气法,ISO6358
Abstract Modern pneumatic technology is widely used in automotive, electronics, semiconductor, automation and other industries. Pneumatic element is a basic unit composed of a pneumatic system. In order to design energy efficient, low-cost pneumatic system, it is necessary to accurately grasp the flow characteristics of pneumatic components. Pneumatic components on flow characteristics of the test, generally use sonic conductance C and critical pressure ratio b to indicate that the ISO6358 ISO draft, but the method needs to consume a lot of time and gas, and its experimental setup is more complex. In the article the draft international standard and isothermal containers deflated pneumatic components measured flow characteristics were compared. Summed isothermal containers discharge method advantage.
In this context, referencing to a new test method for flow characteristics of pneumatic components, isothermal containers discharge method. Isothermal container is filled with the wire in the vessel to increase the gas state in the heat transfer process of change, as the temperature changes very little, and therefore considered as isothermal approximation. Since the process of charging and discharging the gas is almost isothermal process, the transient flow can obtain from pressure transients when isothermal containers during charge and discharge gas, this method can measure the steady, unsteady gas flow. The use of ISO6358, then this method can only be measured by one static pressure conditions specified traffic. Test requires measuring point by point, so long measurement time, air consumption is large and requires a very high turndown ratio meter or several meters. Compared with the ISO6358 international draft standard, using the isothermal container deflated pneumatic components measured flow characteristics with simulation experimental setup is simple, low air consumption, low noise. Transient flow rate characteristics can be measured and so on.
Experimental study using matlab and fluent software for modeling and simulation. Software simulation models were calculated for both the purpose of completion of two independently established mathematical modeling. In the simulation of the process container volume, filling mass, wire diameter differences of the temperature characteristics of the container. And finally the two simulation models to the results of a comparative analysis, which concluded that the main parameters affecting container isothermal container properties.