问题 问答题 简答题

回转空预器的故障的常见原因及处理方法?

答案

参考答案:

a.机械部分故障,转子与外壳卡死,电机热电偶动作

b.电气故障跳闸

处理方法

a.如跳闸前无过电流现象,将跳闸开关拉回停止位置,重新合闸一次,重合闸成功一次则继续运行,并汇报值长,查明原因,重合闸不成功或电机过电流应立即停止,投入盘车,盘车投不上时应人工(手动)盘车,并汇报有关人员

b.汇报值长,将负荷降到150MW,调整燃烧,停运一套或两套制粉系统运行c.停运跳闸侧的空预器所对应的一次风机,送风机,引风机,停运一次风机时应注意运行磨煤机联锁切换,防止一次风机停运导致磨煤机跳闸,该项操作应在空预器跳闸后10分钟内完成,否则电气联锁动作,跳该侧引送一次风机及其对应的磨煤机并导致RB动作

d.关闭故障侧空预器入口烟气挡板和出入口一二次风门,开启冷风联络门,必要时投入空预器吹灰

e.立即联系检修进行处理

f.两台空预器同时停运,强合不成功应立即停炉并进行盘车

阅读理解

阅读理解。

     It could not have been easy to see the tiny swimmer, but a group of scientists claimed to have discovered

the world's tiniest fish. The little creature was found recently in an Indonesian swamp (沼泽).

     For now, the fish is known as Paedocypris progenetica. It has a transparent, or see-through, body. Its head

doesn't have a skeleton (骨架), leaving its brain vulnerable (脆弱的) to its surroundings. The fish, which is

female (雌性的), can grow to be only 7.9 millimeters or (0.31 inches) long, about the size of a large mosquito

(蚊子).

     Maurice Kottelat, a fish expert from Sweden, led the team of researchers that made the discovery. Kottelat

and his team reported their discovery in the Proceedings of the Royal Society, a British scientific journal.

     "You don't wake up in the morning and think today we will find the smallest fish in the world," said Kottelat

in an interview. He and his team were most excited by the possibility of having discovered the world's smallest

vertebrate. "What's important is finding a complete backbone in a body so small," said Kottelat. All fish, reptiles

(爬行动物), birds, and mammals (including humans) are vertebrates.

     It wasn't long after Kottelat's announcement that another researcher challenged the claim with a discovery

of his own. Fish expert Ted Pietsch, a researcher at the University of Washington, says that he has discovered

a fish that is smaller than Kottelat's discovery.

     According to Pietsch, the male Photocorynus spiniceps is a tiny ocean fish measuring only about a quarter

inch. That would actually make Pietsch's fish the world's smallest vertebrate. Kottelat's would come in at a

close second. When Pietsch got in touch with Kottelat to mention the fish, four of which he keeps in his office-

Kottelat did not argue. He kindly gave the title of "world's smallest vertebrate" over to Pietsch's unique fish.

     "So our little fish is only the smallest freshwater vertebrate," Kottelat wrote. "Now I wait until the next

smallest fish is discovered."

1. Pietsch's fish is shorter than Kottlelat's by about _____. [ ]

A. 0.01 inches

B. 0.06 inches

C. 0.1 inches

D. 0.31 inches

2. The underlined word "vertebrate" probably means "_____". [ ]

A. a creature in an ocean

B. a fish in fresh water

C. an animal that can swim

D. an animal with a backbone

3. Which statement is TRUE according to the text? [ ]

A. Kottlelat's fish still keeps the record of the smallest fresh water vertebrate so far.

B. Pietsch's record of discovery of the world's smallest fish was soon broken by others.

C. Kettlelat didn't admit that Pietsch's fish was even smaller than his.

D. All fish, reptiles, amphibians, birds and humans share the same ancestor.

4. Which question doesn't seem to be answered so far according to the text? [ ]

A. Is fish a vertebrate animal?

B. What's the world's smallest fish indeed?

C. What is the smallest freshwater vertebrate?

D. What size is Pietsch's fish?

填空题