已知某离心泵性能曲线如图1- 117所示(图中虚线是该泵输油时性能)。若用此泵输水时，管路特性方程为h= 30+0.02Q2，输油时管路特性方程为h，=30+0.04Q2 (单位Q:L/s.h:m)。试肯定:(1)用台泵在输水管路中输水时 ，其工作点流量和扬程各为几? (2)用一台泵在输油管路中输油时的流量(Q.)扬程(H、)为几? (3)若坚持输油时的流量Q、不低于输水时的流量Q,试剖析从泵或管路装置上可采取哪些措施。
9. 已知某离心泵在转速n= 2900r/min 下的性能曲线可用方程H=40-0.01Q2(单位H:m;Q:m2/h)来表示,管路系统的阻力性能曲线可用L=15+0.04Q?(单位H:m;Q:m'/h)来表示。当管道输水量为15m2/h时:
10.有一分支管路如图1-118所示，泵前管路1的活动阻力损失为0.04Q ;泵后管路2和管路3的活动阻力损失分别为0. 05Q和0.1Qf(Q以L/s计:活动阻力以m计)。系的性能参数见表1- 15.试画出分支管路的安装特性.肯定系的流量和扬程以及各管路中的流量。
It is known that the performance curve of a centrifugal pump is shown in figure 1-117 (the dotted line in the figure is the performance of the pump during oil delivery). If this pump is used for water delivery, the pipeline characteristic equation is h = 30 + 0.02q2, and the pipeline characteristic equation is h, = 30 + 0.04q2 (unit Q: L / S.H: m). Try to determine: (1) when a pump is used to deliver water in the water pipeline, what are the flow and head at its working point? (2) What is the flow (Q.) head (h,) when one pump is used to deliver oil in the oil pipeline? (3) If the flow Q during oil transportation is not lower than that during water transportation, try to analyze what measures can be taken from the installation of pump or pipeline.
9. It is known that the performance curve of a centrifugal pump at speed n = 2900r / min can be expressed by equation H = 40-0.01q2 (unit: H: m; Q: m2 / h), and the resistance performance curve of pipeline system can be expressed by L = 15 + 0.04q? (unit: H: m; Q: M '/ h). When the water delivery capacity of the pipeline is 15m2 / h:
(1) With outlet throttling regulation, what is the pressure head of throttling loss?
(2) If variable speed regulation is adopted, what speed should the pump be adjusted?
10. There is a branch pipeline, as shown in figure 1-118. The flow resistance loss of pipeline 1 in front of the pump is 0.04q; The flow resistance losses of pipeline 2 and pipeline 3 behind the pump are 0.05q and 0.1qf respectively (q is calculated in L / s: flow resistance is calculated in M). See table 1-15 for the performance parameters of the system. Try to draw the device characteristics of the branch pipeline, and determine the flow and head of the system and the flow in each pipeline.
