第三章过程流体机械活塞式压缩机概述.ppt

级次 公称压力MPa 压力损失 实际压力MPa 实际压力比 Ⅰ 0.1 0.27 0.05 0.08 0.095 0.2196 3.07 Ⅱ 0.27 0.8 0.035 0.06 0.2606 0.848 3.25 内止点时： 综合来看，活塞力比较均匀，所以选取的d和S是合理的，以上有关计算有效。 今有一台单级单作用的往复活塞压缩机，名义进气压力为0.1MPa，名义排气压力为0.4MPa，活塞行程为300mm，曲轴的转速为n=400r/min，相对余隙容积为0.15，容积流量为40m3/min，气体绝热指数为1.4，膨胀过程指数为1.25，其温度系数、压力系数、泄漏系数三者之积为0.91，进、排气过程相对压力损失分别为3%，8%。 试计算：（1）此压缩机的气缸直径；（圆整到整数mm） （2）按绝热过程考虑，需配置电机的功率。 （电机的余度取为10%，机械效率取为95%） （1）求解气缸直径 又 其中 (2)求解电机功率 解：两级压缩 作业3 各级吸入温度为 各级排气温度为 对于空气压缩机 三级压缩 第一级进气压力100kPa，排气压力为 第二级进气压力353kPa，排气压力为 第三级进气压力1246kPa，排气压力为4400kPa 各级吸入温度为 各级排气温度为 往复活塞压缩机 - 简介 往复活塞压缩机是各类压缩机中发展最早的一种，公元前1500年中国发明的木风箱为往复活塞压缩机的雏型。18世纪末，英国制成第一台工业用往复活塞空气压缩机。20世纪30年代开始出现迷宫压缩机，随后又出现各种无油润滑压缩机和隔膜压缩机。50年代出现的对动型结构使大型往复活塞压缩机的尺寸大为减小，并且实现了单机多用 * Air is a gaseous envelope that surrounds the earth exerting pressure on everything. Actual air pressure depends on your location relative to sea level * Compress is defined as to press together or force into a smaller space; condense Air is a colorless, odorless, tasteless gaseous mixture consisting mainly of nitrogen (78%) and oxygen (21%) When controlled, compressed air can be used to perform work * Compressed Air is stored energy... The energy contained in compressed air within the balloon is equal to the energy required to inflate it. If the volume of a given amount of air decreases, the pressure will increase. With a positive displacement compressor, compressed air is obtained by forcing air into a smaller volume. During its flight, the balloon dissipates energy - the same energy required to fill it * For energy: Compressed air is an excellent source for storing and transmitting energy in order to do work. For process requirements: Compressed air required as an active part of a process (e.g. chemical, pharmaceutical, fermentation, etc.) Behind water, gas, and electricity compressed air is considered the Fourth Utility * Energy from compressed air is used to power pneumatic production equipm