问题 问答题 简答题

锅炉送风调节系统投入的质量指标有哪些?

答案

参考答案:

(1)锅炉稳定运行时,调节系统应能保持送入炉膛的氧量在给定值的±5%范围内;

(2)调节系统工作稳定,执行器不应频繁动作;

(3)送风机挡板开度阶跃改变5%时,调节系统应能使送入炉膛氧量在1min内恢复稳定。

(4)送风量给定值改变5%时,调节系统应能在30S内稳定在新的给定位置;

(5)对以锅炉负荷为前馈信号的送风调节系统,当改变额定负荷的5%燃料量时,调节系统应在2min内消除扰动。

阅读理解

Can you swim? Do you like swimming? Yes? Well, how can you learn to swim? I think the best way is to go into the water and learn. I’m afraid you’ll never learn to swim just by reading books about swimming or looking at others swimming. It’s the same with the English study. We must practice, practice and practice.

Listening and speaking are very important for beginners. The children in English-speaking countries first listen to others. Then they try to imitate and speak. We can listen to English programs on radio. You may just understand a few words. It doesn’t matter. Just be relaxed, try to catch every word. Somebody may be a good listener. But he dare not speak. He’s afraid of making mistakes. You know we sometimes make mistakes when we speak Chinese. Don’t be afraid. We must be brave. If you really want to learn English well, you must try to speak with everyone as long as he knows English. Whether you know him or not is not important, when there’s nobody to talk with, you can talk to yourself in English. It’s interesting and also a good way to practice your spoken English. Remember, the more you speak, the fewer mistakes you’ll make.

Reading and writing are more important for senior school students. First we must choose the books we’re interested in. A lot of reading will improve your language sense. This is the most important.

Keep writing English diaries. We can also write English articles. You may even post them to English magazines. Don’t be afraid of failure. Failure is the mother of success.

Easier said than done. Well, let’s do more practice from now on. I’m sure you’ll learn English well in this way.

小题1:You can learn to swim by_______.

A.reading books about it

B.looking at others swimming

C.having lessons on it

D.going into the river and learning小题2:We should learn English by _______.

A.listening and speaking

B.reading and writing

C.both A and B

D.swimming小题3:What will you do with mistakes when you speak?

A.Don’t make mistakes.

B.Study hard

C.Try not to speak English

D.Don’t be afraid.小题4:What’s more important for senior school students?

A.listening

B.speaking

C.reading and writing

D.learning小题5:We can listen to English ______, according to the passage.

A.by train

B.on the radio

C.every minute

D.now and then

单项选择题