问题 问答题

试述惰气发生装置的补充燃烧工况?

答案

参考答案:

惰气发生装置的补充燃烧工况是当热介质锅炉的烟气含量超过时采用的工况。在这种工况下,将来自锅炉的烟气和新鲜空气混合,作为燃烧空气。一般将燃烧空气的含氧量调整到10%-16%范围内,因为含氧量低于10%时,火熄不能维持。因为该工况下燃烧室的含氧量低于新鲜空气的含氧量(24%),所以,采用这种工作方式生产惰气可以节约省燃油。

阅读理解

第二部分阅读理解(共20小题;每小题2分,满分40分

A

Sam and Joe were astronauts. There was once a very dangerous trip and the more experienced astronauts knew there was only a small chance of coming back alive. Sam and Joe, however, thought it would be exciting though a little dangerous. “We’re the best men for the job,” they said to the boss. “There may be problems, but we can find the answers.” “They’re the last people I’d trust,” thought the boss. “But all the other astronauts have refused to go.”

Once they were in space, Joe had to go outside to make some repairs. When the repairs were done, he tried to get back inside the spaceship. But the door was locked. He knocked but there was no answer. He knocked again, louder this time, and again no answer came. Then he hit the door as hard as he could and finally a voice said, “Who’s there?” “It’s me! Who else could it be?” shouted Joe. Sam let him in all right but you can imagine that Joe never asked to go on a trip with Sam again!

36. Most of the astronauts were unwilling to go on a trip because _______.

A.there was little chance of being selected      B.they weren’t experienced enough

C. they thought they might get killed         D. it wasn’t exciting enough

37. Why were Sam and Joe chosen?

A. The boss wanted them to get more experience.

B. The boss trusted them more than anyone else.

C. They were the last people who wanted to go.

D. They were the only men who offered to go.

38 Joe didn’t want to work with Sam again probably because he thought Sam _______.  

A. was very slow and possibly deaf     B.didn’t know how to operate the door

C. was less experienced than he was   D. didn’t know how to do repairs

39. The writer tells this story to _______.

A. show the dangerous side of the astronauts’ life   B. make people laugh

C. show the funny side of the astronauts’ life     D. make people think

选择题