问题 问答题 简答题

调速系统在空负荷下为什么维持不了额定转速?是什么原因?

答案

参考答案:

因为汽轮机启动后,在主汽门全开,真空正常负荷为零的情况下,调速系统保持不了额定转速。其原因是调速汽门关不严或调速系统不正常而引起的,大致有以下几点:

①调速汽门接触不严密,阀门与阀门座间隙太大。

②调速系统连杆尺寸安装不正确。

③调速器连杆,油动机,错油门等卡住。

④传动杆或错油门连接处松驰。

⑤传动杠杆与蒸汽室温度相差达大,热膨胀不一致,而使错油门阀不在空负荷位置上。

单项选择题
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Recently, a  professor of philosophy in the United States has written a book called MoneyandtheMeaningofLife. He has discovered that how we deal with money in our day­to­day life has more meaning than we usually think. One of the exercises he asked his students to do is to keep a record of every penny they spend for a week. From the way they spend their money, they can see what they really value in life.

He says that our relation with others often becomes clearly defined when money enters the picture. You might have wonderful friendship with somebody and you think that you have a very good friend. But you will know him only when you ask him to lend you some money. If he does, it brings something to the relationship that seems stronger than ever before. Or it can suddenly weaken the relationship if he doesn't. This person may say that he has a certain feeling, but if it is not carried out in the money world, there is something less real about it.

Since money is so important to us, we consider those who possess a lot of it to be very important. The author interviewed some millionaires in researching his book.

Question: What is the most surprising thing you have discovered about being rich?

Answer: The most surprising thing is why people give me so much respect. I am nothing. I do not know much. All I am is rich.

People just have an idea of making more and more money, but what is it for? In his book, the professor uncovered an important need in modern society: to bring back the idea that money is an instrument rather than the end. Money plays an important role in the material world, but expecting money to give happiness may be missing the meaning of life.

小题1:The author seems to believe that asking your friend to lend you some money ________.

A.is a good way to test your friendship

B.will do harm to your friendship

C.will strengthen your friendship

D.is a good way to break off your friendship小题2:What can we learn about the millionaire from his answer in the interview?

A.He does not feel that he is well educated.

B.He does not think that he is a very important person.

C.He does not think that being rich is worth so much attention.

D.He does not consider himself to be very successful.小题3:What does the American professor of philosophy want to explain in his book?

A.Money is an end.

B.Money is a means.

C.Money is everything.

D.Money is unimportant.小题4:Which of the following might the author disagree with?

A.Money is important in modern society.

B.The meaning of life does not completely lie in money.

C.Wealth will surely bring the owner happiness

D.Happiness is not necessarily the result of wealth.