输水管道系统气体特性与水流冲击截留气团研究

Research on gas properties and current rush to interception air-mass in delivery pipeline system

通过试验与理论相结合的方法,对输水管道系统气体特性与水流冲击截留气团进行了研究.研究表明,决定气团主要性质的气体多方指数n在输水管道系统发生水力过渡过程时存在较为显著的变化,并非单一常数,从而提出了相应的四过程:即压缩子过程1、膨胀子过程2、膨胀子过程3和压缩子过程4.在压缩子过程4与膨胀子过程2中,气体多方指数n取值为1.4～1.6;而在压缩子过程1与膨胀子过程3中,气体多方指数n取1.15.气体多方指数n的取值对压力水流冲击截留气团的结果有一定影响,n值越小,水流冲击截留气团的压力越大;反之越小.

According to the experimentation and the theory, research on gas properties and current rush to interception airmass in the delivery pipeline system are made . The studies indicated that the gas thermal insulation coefficient determining primary properties of the air-mass changes apparently instead of a single constant when hydraulic transition process happens . So four appropriate processes are given,namely sub-process 1 of compressing, sub-process 2 of inflating, sub-process 3 of infiating, and sub-process 4 of compressing. In the sub-process 2 of inflating and sub-process 4 of compressing, the gas thermal insulation coefficient is 1.4 ～ 1.6, and is 1.15 in other two processes. The value of gas thermal insulation coefficient has definitely influence on the result of the analytic root of current rush to interception air-mass in the delivery pipeline system. The more small gas thermal insulation coefficient is, the more great the press of current rush to interception air-mass is, and and vice versa.