首站进、出口压力pZ1或pQ1稍有下降,对整条管道系统的输气量都会有较明显的影响。The slight decrease of inlet and outlet pressure pZ1 or pQ1 in the first station will have a more obvious impact on the gas transmission capacity of the whole pipeline system,而输气管的终点压力pZ,即使在较大范围内变化,对整个系统输气量的影响也不大。However, the terminal pressure pZ of the gas pipeline, even if it changes in a large range, has little impact on the gas delivery volume of the whole system.