问题 问答题 简答题

机组降负荷过程停运一台磨煤机,操作过程对机组运行有哪些影响?

答案

参考答案:

1)停磨过程中,减小煤量抽粉过程中,由于磨里有存煤,实际进入炉膛煤量比实际煤量多,实际煤水比短时间内失调,会造成中间点温度升高,汽压、汽温升高。

2)磨停运后,短时间内会造成煤量减少过多,造成过调,负荷短时间内会降得过快。

3)停运磨如果是上层磨,停完后由于火焰中心降低,燃烧恢复正常后会造成汽温降低;反之,停下层磨,由于上层煤量增多,汽温会稍微上升。

完形填空

首字母填空(10小题*1=10分)

Lots of people in the world like listening to folk songs. A folk song is a song that is “from the p 小题1:”. Every c 小题2: has folk songs. Usually, they are quiet, simple songs. People often sing them with just a g 小题3: of a few other instruments. Some folk songs are so o 小题4: that no one knows who wrote them or when they were written. Other folk songs are by songwriters who are interested in people’s l 小题5: and experiences. Woody Guthrie was one of those songwriters.

Woody Guthrie was born in a very small town in Oklahoma in 1912. Guthrie first learned to play the guitar from his grandfather in 1917. He soon began to p 小题6: with other people in the area. Step by step, people liked his music.

In 1929, the economy was bad. Many people were not working, and there were many poor people. Guthrie began to travel around the country looking for work. Guthrie became interested in singing about people and their p 小题7: during this period.

In the winter of 1940, Guthrie decided to go to New York. On his way, he created “This Land is Your Land.” The song talks about places and things people love. The last line of the song says, “This land was made for you and me.” These words tell people that e 小题8: is equal.

Woody Guthrie died in 1967, but his music l 小题9: on. His music is an important part of American h 小题10: and culture. And to this day, people love to sing the folk songs written by him.

单项选择题 B1型题