【Daily Question: Pump Equipment】Short Answer Question 2019.2.16
Thread Content
Rules for short-answer questions on bg2.png: 1. For incorrect answers, +2 wealth is given for active participation; for answers that are somewhat reasonable but not specific enough, +5 wealth is awarded; answers that are correct receive +8 wealth. 2. Rewards for answers are available once per person only. 3. Each reply allows scoring for only one person. 4. The answer and its explanation will be visible after responding. 5. The reward is valid for 48 hours; no reward will be given if the deadline is missed. The student has won another award; come by here every day. The performance curve of a centrifugal pump includes curves showing the relationship between flow rate and head, efficiency, net positive suction head, and shaft power. Briefly describe which curves change when only the specific gravity of the fluid increases, and how they change. Answer: The flow rate-shaft power curve rises in a linear proportion to the increase in specific gravity, while the other curves remain unchanged
The head and efficiency remain unchanged, while the shaft power increases and the net positive suction head decreases
Friend, it’s not a true/false question; it’s a short-answer question: lol
This is too difficult; just answer randomly: cavitation will decrease, shaft power will increase, efficiency will rise, and head will decrease
Head, efficiency, and cavitation remain unchanged; shaft power increases
The head decreases, efficiency drops significantly; however, the shaft power increases
The flow rate–shaft power curve increases in proportion to the increase in specific gravity, while the other curves remain unchanged.
N = density * g * H * Q; as the density increases, the shaft work increases linearly. The remaining curves remain unchanged.
Don’t rush; take your time. Parameters such as flow rate versus head, flow rate versus efficiency, and flow rate versus net positive suction head are almost inherent properties of the pump itself, and are less affected by external factors (with the exception of changes in viscosity). On the other hand, flow rate versus shaft power is directly related to the density of the medium, and the shaft power will increase
Flow rate and shaft power vary proportionally, with everything else remaining constant (provided viscosity remains unchanged)