【Daily Question】June 27-28: Application of the proportional law for centrifugal pumps (First 50 participants + 3–8 more points for each correct answer)
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This post was last edited by A Le on 2015-6-29 at 10:44. The Machinery Section has introduced the \"Question of the Day\" feature, which not only helps to foster an active atmosphere for technical discussions and guide the direction of such exchanges but also provides users with financial rewards, enabling them to experience various cool features. 【Daily Question】In practical applications of variable-frequency speed control, the proportional law may be used to estimate the performance of a centrifugal pump after frequency conversion. There is a pump currently in use, and its flow rate needs to be reduced to 80% of its current level, while the head remains unchanged. Then the speed needs to be adjusted to ( ). A. Above 80% speed B. 80% speed C. Below 80% speed Answer: A; for the explanation, see the best answer section. Requirements and tips for answering questions: Please reply with the answer you believe to be correct. If you provide a detailed explanation or analysis of the question or answer, an additional reward will be given. Extra rewards will be awarded if your answer is correct and your explanation is thorough and accurate. Feel free to answer the questions. Please note: We will close this thread after 24 hours, and at that time we will announce the best reply (the best assistance), as well as the answer and explanation. Do not submit answers repeatedly. As a reward for your effort, if you post a topic in this section within two days that provides a detailed explanation of the knowledge points related to this question, please reply or leave a comment in this post to inform us, and we will have a moderator award you + Charm. It is not allowed to simply copy and paste; original content is preferred, with at least some organization by the user along with personal insights. After registration, we will rank based on the content of the posts: the last-place contestant will receive +1 charm, the second-to-last +2 charm, and so on, with the highest score getting +5 charm. Other content: Call for weekly topics and daily questions (prizes for participation) [Mechanical Section] Collection of essential knowledge [Seeking manufacturer sponsors] (long-term campaign) [Rewards for recommending valuable content] Summary of daily questions and answers related to mechanical equipment for 2015
【Daily Question】In practical applications of variable-frequency speed control, the proportional law may be used to estimate the performance of a centrifugal pump after frequency conversion. There is a pump currently in use, and its flow rate needs to be reduced to 80% of its current level, while the head remains unchanged. Then the speed needs to be adjusted to (A). A. Above 80% speed B. 80% speed C. Below 80% speed
B. At 80% speed, the flow rate is proportional to the speed.
Guess and choose B; please explain the reason
In practical use of variable-frequency speed control, the proportional law may be employed to estimate the performance of a centrifugal pump after frequency conversion. There is a pump currently in use, and its flow rate needs to be reduced to 80% of its current level, while the head remains unchanged. Then the speed needs to be adjusted to (C). A. Above 80% speed B. 80% speed C. Below 80% speed
In practical use of variable-frequency speed control, the proportional law may be employed to estimate the performance of a centrifugal pump after frequency conversion. There is a pump currently in use, and its flow rate needs to be reduced to 80% of its current level, while the head remains unchanged. Then the speed needs to be adjusted to (B). A. Above 80% speed B. 80% speed C. Below 80% speed
In practical use of variable-frequency speed control, the proportional law may be employed to estimate the performance of a centrifugal pump after frequency conversion. There is a pump currently in use, and its flow rate needs to be reduced to 80% of its current level, while the head remains unchanged. Then the speed needs to be adjusted to ( ). A. Above 80% speed