问题 问答题 简答题

水轮发电机组机械部分有哪些保护?

答案

参考答案:

水轮发电机组机械部分一般设有下列事故保护:

(1)推力、上导、下导、水导轴承温度过高;

(2)采用橡胶导轴承的冷却水中断;

(3)机组过速保护;

(4)压油装置事故油压下降保护;

(5)摆度过大、振动过大保护;

(6)主轴密封水压(或流量)过低;

(7)冷却水流量过低;

(8)推力、上导、下导、水导轴承油位异常;

(9)压油装置(集油箱、漏油箱)油位异常;

(10)顶盖水位异常;

(11)大轴补气装置动作;

(12)顶盖真空破坏阀动作;

(13)钢管压力安全阀动作。

(14)剪断销剪断保护装置;

(15)轴承油槽油混水保护。

单项选择题 案例分析题
阅读理解

阅读理解。

     Vampires (吸血鬼)

     Vampire stories go back thousands of years. The acts we now associate with vampires, such as rising

from the grave and drinking blood, were popularized by Eastern European stories. 

     Most early cultures created stories to explain things they didn't understand. For example, hair and nails

continue to grow after people die, which has already been proved possible by modern science.

     These facts were unknown to most people in the 19th century, however. As a result, the legends

surrounding such mysteries were kept alive.

     Count Dracula

     In 1897, Irish writer Bram Stoker's novel Dracula was published, spreading the vampire stories to a mass

audience. In the hovel, the Count Dracula of Transylvania, a 500-year-old vampire, has drunk his country

dry and must move to England in search of new victims. Dracula means "son of the dragon" or "son of the

devil" in Romania.

     Werewolf

     The story of a half-man, half-wolf beast is as old as that of vampires, and almost as varied. In most

werewolf stories, however, a beast would silently enter settlements at night and steal a young child or an

animal.

     The most common explanation of werewolf stories is that the beast was usually an ordinary wolf. The

genetic disorder, which causes too much body hair, may also have helped to popularize the story.

     Frankenstein

     This is a fictional scientist created by British writer Mary Shelly in 1818. Dr. Frankenstein lives m a castle

and is so addicted to making living beings from parts of dead bodies that he refuses to marry.

     The story of Frankenstein may have been planted in Shelly's mind since she visited Castle Frankenstein in

Germany, where an alchemist (炼术士) tried to do experiments with the aim of making people live longer.

     The Invisible Man

     In H.G.Wells' 1897 story, a young scientist called Griffin, manages to make himself invisible. But he

cannot find a way to become visible again. He then wants to make use of his super power but finally has

gone mad. Wells' tale owes a great debt to Greek philosopher Plato's book Republic.

1. The best title for this passage should be ____.

A. Origins of Ghosts

B. Tales of Horror

C. Exciting Stories

D. Science Fictions

2. The people in the 19th century did NOT know ____.

A. why vampires drank blood

B. why dead people rose from the grave

C. that vampires always kept their nails

D. that hair could continue to grow after people died

3. What do most of the werewolf stories have in common according to the passage?

A. The beast often silently entered settlements at night and stole a little child.

B. The werewolf was in genetic disorder, so it had a lot of body hair.

C. An ordinary wolf would enter settlements at night and steal a child.

D. The beast was sometimes a half-man and sometimes a half-wolf.

4. Which of the following statements is right about Frankenstein and The Invisible Man?

A. They were produced based on the writers' real experience.

B. They were the producers of science and technology.

C. They were not well suited to their surroundings.

D. They were folk legends in the writers' homeland.