问题 问答题 简答题

400V电源中断的现象、原因是什么?

答案

参考答案:

现象:

(1)400V电压指示消失;

(2)DCS报警;

(3)所有运行中的低压电气设备跳闸;

(4)若GGH备用电机联动成功,GGH维持运行;

(5)增压风机跳闸,旁路挡板突开。

原因:

(1)400V工作段故障,备用未投;

(2)脱硫低压变故障;

(3)6KV母线故障,备用电源未投;

(2)立即汇报值长、通知主机、要求恢复电源;

(3)立即确认联锁保护动作,复位各跳闸设备;

(4)恢复各个系统(阀门)处于备用状态,等待电源恢复;

(5)电源恢复后,立即对各搅拌器进行盘车,盘车成功,恢复搅拌器运行;若盘车不动,联系检修处理;

(6)电源恢复后,立即启动工业水泵、工艺水泵对运行过的浆液设备、管道进行彻底冲洗,确认管道未造成堵塞;

(7)短时恢复电源,请示值长,分别启动各个系统,恢复FGD运行。

连线题
阅读理解

 In the eyes of dog lovers, the dog is man’s best friend. But for much wildlife, loose dogs may be a dangerous enemy, according to a study by a biologist from Utah State University in the US.

Based on much existing research and their own case studies, Julie Young of Utah State University and four other scientists conclude that loose dogs may represent a huge danger to wildlife, especially endangered species, by hunting down or worrying them and by spreading diseases. They also found that dogs, their worldwide numbers around 500 million, can cause more damage to wildlife and livestock(牲畜) than wolves and other enemies of these animals.

Young gave examples from the US state of Idaho, where research showed the presence of dogs reducing some deer populations. On the Navajo American Indians’ reservation in northeastern Arizona, packs of loose dogs are chasing livestock. They have killed populations of small animals such as rabbits and act as a disease carrier for rabies(狂犬病) among people and other animals, she said. Loose dogs also were to blame for distemper outbreak leading to a die-off of endangered black-footed ferrets in northwestern Wyoming in the 1980s.

The phenomenon is not just limited to US; it’s a global problen. Julie Young once studied three endangered species in central Asia: wild sheep, gazelles and antelope. The rate of injury and death to these animals by loose dogs was very high. In another case, Young found that dogs, not wolves, as originally suspected, were responsible for a large number of livestock killings in the mountainous Basque country between Spain and France.

Authors of the new study said the problem is likely to worsen as communities expand. Then how to deal with it?

Indeed, in many countries, leash(拴狗的皮带) laws permit punishment of dog owners whose pets chase wildlife. But lawbreakers are rarely punished because the police lack both people and money.

Young has low-cost solutions to the problem for dog lovers, though. They include public dog-training programs and vaccinating (预防接种) dogs against rabies and other illnesses.

小题1:. What is the main point of Julie Young’s study?

A.Many species are endangered because they are killed by loose dogs.

B.Wild dogs are immune to many diseases.

C.Wolves are still the greatest enemy of livestock.

D.Loose dogs pose a great danger to wildlife.小题2:. Which of the following statements about loose dogs is TRUE according to the research?

A.There are around 500 million loose dogs around the world.

B.The black-footed ferrets in northwestern Wyoming were once the main food source of local loose dogs.

C.The problem caused by loose dogs is the most serious in the US.

D.People used to think that wolves, rather than loose dogs killed livestock in the Basque country.小题3:. Which of the following is among Julie Young’s solutions to the trouble caused by loose dogs?

A.More strict leash laws

B.Public dog-training programs.

C.Vaccinating people against rabies and other illnesses.

D.More support from the police.小题4:. What is the main point of the article?

A.A global disaster caused by loose dogs.

B.What makes the dog man’s greatest friend.

C.The problem of loose dogs and the possible solutions.

D.The danger of the increasing numbers of dogs.