【Daily Question: Pump Equipment】Fill-in-the-blank question, February 9, 2019
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Rules for the fill-in-the-blank questions in bg2.png: 1. If both blanks are answered incorrectly, +2 wealth is awarded for active participation; if one blank is answered incorrectly and the other correctly, +5 wealth is given; if both blanks are answered correctly, +8 wealth is awarded. 2. If only one answer is provided, unless it is clear which question’s answer it is, a correct answer earns +5 wealth points, while an incorrect answer earns +2 wealth points; in all other cases, it counts as active participation and grants +2 wealth points. 3. Rewards for answers are available once per person only. 4. Each reply allows scoring for only one person. 5. The answer and its explanation will be visible after responding. 6. The reward is valid for 48 hours; no reward will be given if the deadline is passed. The student has won awards again; come by here every day. On the typical performance curves of centrifugal pumps, the variation of the flow-rate-efficiency curve is ( ), while the variation of the flow-rate-axis power curve is ( ). Answer: It increases gradually at first, then decreases gradually, reaching its maximum at the rated flow rate, with a monotonic increase
Rises to the highest point first and then declines/gradually increases
How do I say this thing? A curve that is generally higher in the middle and lower on the sides, with an upward trend where greater flow rate corresponds to greater shaft power
It increases gradually first and then decreases gradually, reaching its maximum at the rated flow rate, with a monotonic increase
The variation of the flow-efficiency curve is parabolic – rising first and then falling – while shaft power increases as flow rate increases
It increases gradually first, then decreases gradually, reaching its maximum at the rated flow rate, with a monotonic increase
Increased flow leads to improved efficiency; increased flow also results in higher shaft power
Initially, the flow rate is 0 and the efficiency is 0; as the flow rate increases, the efficiency increases as well； Beyond a certain point, the flow rate increases while efficiency decreases ； The curve is mountain-shaped. The greater the flow rate of a centrifugal pump, the greater its shaft power ； When the flow rate is 0, the shaft power is not 0, being approximately 60% of that under normal operation.
It increases gradually first, then decreases gradually, reaching its maximum at the rated flow rate; it increases monotonically
It increases gradually first, then decreases gradually, reaching its maximum at the rated flow rate, with a monotonic increase
It increases gradually first, then decreases gradually, reaching its maximum at the rated flow rate; it increases monotonically