相关试题
【单选题】
受热面酸洗后进行钝化处理的目的是___。
A. 在金属表面形成一层较密的磁性氧化铁保护膜
B. 使金属表面光滑
C. 在金属表面生成一层防磨保护层
D. 冲洗净金属表面的残余铁屑
【单选题】
过热器前受热面长时间不吹灰或水冷壁结焦会造成___。
A. 过热汽温偏高
B. 过热汽温偏低
C. 水冷壁吸热量增加
D. 水冷壁吸热量不变
【单选题】
炉膛负压摆大，瞬间负压到最大，一、二次风压不正常降低，水位瞬时下降，气压、气温下降说明此时发生___。
A. 烟道面燃烧
B. 吸、送风机入口挡板摆动
C. 锅炉灭火
D. 炉膛掉焦
【单选题】
水冷壁、省煤器、再热器或联箱发生泄漏时，应___。
A. 紧急停炉
B. 申请停炉
C. 维持运行
D. 节日停炉
【单选题】
发生烟道再燃烧事故，当采取措施无效时应___。
A. 立即停炉
B. 申请停炉
C. 保持机组运行
D. 向上级汇报
【单选题】
随着运行小时增加，引风机振动逐渐增大的主要原因一般是___。
A. 轴承磨损
B. 进风不正常
C. 出风不正常
D. 风机叶轮磨损
【单选题】
风机串联运行的主要目的是___。
A. 提高风压
B. 提高风量
C. 提高效率
D. ／
【单选题】
标准煤的发热量为___。
A. 20934千焦
B. 25120.8千焦
C. 29307.6千焦
D. 12560.4千焦
【单选题】
锅炉三冲量给水自动调节系统中，___是主信号。
A. 蒸汽流量
B. 给水流量
C. 汽包水位
D. 蒸汽压力
【单选题】
风机的工作点是管路特性曲线和风机___的交点。
A. Ｑ－Ｐ特性曲线
B. Ｑ－η特性曲线
C. Ｑ－Ｎ特性曲线
D. /
【单选题】
20号钢的导汽管允许温度为___。
A. ＜450℃
B. ＝500℃
C. ＞450℃
D. /
【单选题】
锅炉煤灰的熔点主要与灰的___有关。
A. 组成成分
B. 物理形态
C. 硬度
D. 可磨性
【单选题】
温度不变时，过热蒸汽的焓随压力增大而___。
A. 增大
B. 减小
C. 不变
D. 先增大后减小
【单选题】
汽包锅炉点火初期是一个非常不稳定的运行阶段，为确保安全，___。
A. 应投入锅炉所有保护
B. 应加强监视调整
C. 应加强联系制度
D. 应加强监护制度
【单选题】
锅炉在正常运行过程中，在吹灰器投入前将吹灰系统中___排净，保证是过热蒸汽，方可投入。
A. 凝结水
B. 汽水混合物
C. 空气
D. 过热蒸汽
【单选题】
在锅炉蒸发量不变的情况下，给水温度降低时，过热蒸汽温度升高，其原因是___。
A. 过热热增加
B. 燃料量增加
C. 加热热增加
D. 加热热减少
【单选题】
就地水位计所指示的水位高度, 比汽包的实际水位高度___。
【单选题】
在监盘时，如看到风机因电流过大，或摆动幅度大的情况下跳闸，___。
A. 可以强行启动一次
B. 可以在就地监视下启动
C. 不应再强行启动
D. 请求领导决定
【单选题】
在允许范围内，尽可能保持高的蒸汽温度和蒸汽压力，则使___。
A. 锅炉热效率下降
B. 锅炉热效率提高
C. 循环热效率提高
D. 汽轮机效率提高
【单选题】
汽水混合物进入旋风分离器的速度越高，汽水分离效果___
【单选题】
汽包锅炉进行超水压试验，压力为汽包工作压力的___
A. 1.1倍
B. 1.25倍
C. 1.5倍
D. 1.2倍
【单选题】
在达到最佳过量空气系数前，增加风量，锅炉机械不完全燃烧损失___
A. 增加
B. 不变
C. 减小
D. 变化不大
【单选题】
风机要求关门启动的原因是：___
A. 减小风压的波动
B. 减小启动时的电流
C. 减小对另一台风机的影响
【单选题】
造成锅炉部件寿命老化损伤的因素，主要是疲劳、蠕变___。
A. 磨损
B. 低温腐蚀
C. 高温腐蚀
D. 腐蚀与磨损
【单选题】
当锅炉负荷突然增大时，汽包水位会___。
A. 上升
B. 下降
C. 先迅速下降后上升
D. 先迅速上升后下降
【单选题】
机组大小修后锅炉应做锅炉水压试验，一般只做___试验。
A. 汽包工作压力
B. 过热器工作压力 C.1.05倍过热工作压力 D.1.08倍过热器压力
【单选题】
壁温小于580℃的过热器管的用钢材为___。
A. 20号钢
B. 15CrMo
C. 12Gr1MoV
D. 2Cr12WMoNbVB
【单选题】
高压锅炉安全门定值的规定是___
A. 控制安全门为额定压力的105%，工作安全门为额定压力的108%
B. 由总工程师确定
C. 控制安全门为额定压力的108%，工作安全门为额定压力的105%
D. 应高于工作压力
【单选题】
锅炉腐蚀除了烟气腐蚀和工质腐蚀外，还有___。
A. 汽水腐蚀
B. 应力腐蚀
C. 硫酸腐蚀
D. 电化学腐蚀
【单选题】
锅炉大小修后的转动机械须进行不少于___试运行，以验证可靠性。
A. 10min
B. 30min
C. 2h
D. 8h
【单选题】
___的特点是挥发分高、含碳量低，易点燃，火焰长。
A. 矸石煤
B. 无烟煤
C. 贫煤
D. 褐煤
【单选题】
在锅炉热效率试验中___工作都应在试验前的稳定阶段内完成。
A. 受热面吹灰、锅炉排污
B. 试验数据的确定
C. 试验用仪器安装
D. 试验用仪器校验。
【单选题】
所有高温管道、容器等设备上都应有保温层，当室内温度在25℃时，保温层表面的温度一般不超过___。
A. 40℃
B. 50℃
C. 60℃
D. 30℃
【单选题】
工作介质温度在540～600℃的阀门属于___。
A. 普通阀门
B. 高温阀门
C. 超高温阀门
D. 低温阀门
【单选题】
物质的温度升高或降低___所吸收或放出的热量称为该物质的热容量。
【单选题】
绝对压力就是___。
A. 容器内工质的真实压力
B. 压力表所指示的压力
C. 真空表所指示压力
D. 大气压力
【单选题】
水在汽化过程中，温度___，吸收的热量用来增加分子的动能。
A. 升高
B. 下降
C. 既不升高也不下降
D. 先升高后下降
【单选题】
一定压力下，水加热到一定温度时开始沸腾，虽然对它继续加热，可其___温度保持不变，此时的温度即为饱和温度。
【单选题】
油品的危险等级是根据___来划分的，闪点在45℃以下为易燃品，45℃以上为可燃品，易燃品防火要求高。
A. 闪点
B. 凝固点
C. 燃点
D. 着火点
推荐试题
【单选题】
He works hard every day to make more money, but he ___ his health, time with his family, and the hobbies he once love D.
A. neglects
B. reminds
C. ceases
D. Declines
【单选题】
I asked a passenger sitting beside me if our train was the Westlake Express train, and he said he ___ of it.
A. not even heard
B. had not even heard
C. even not heard
D. ever had not heard
【单选题】
Whatever you say in the paper has to ___ your own thinking; hence simply repeating the professor’s opinions or whatever is in the readings will not get you very far.
A. ignore
B. arouse
C. reflect
D. release
【单选题】
We are sorry to know that they did not succeed ___ the project for lack of necessary funds.
A. to fulfill
B. to have fulfilled
C. in fulfilling
D. with fulfilling
【单选题】
It is surprising that fewer students were prepared to undertake the ___ to hand in written work on a regular basis, or to study over long periods.
A. engagement
B. commitment
C. authority
D. aspiration
【单选题】
Emily felt hurt and ___ by a close friend who had borrowed a considerable sum of money to pay for a house and then took it as a gift, never thinking of giving back the money.
A. conflicted
B. curbed
C. swollen
D. betrayed
【单选题】
In 1988 the old system was ___ in the country and a new system was introduced to take effect in 1990.
A. transmitted
B. abolished
C. assumed
D. compensated
【单选题】
We should not ___ ourselves to the classroom. We should go out of the classroom, see the world and talk to others as much as we can.
A. entertain
B. confine
C. assign
D. involve
【单选题】
I have always been grateful ___ Fred __the generous and helpful information when I was at the crossroads.
A. to … for
B. to … with
C. for … with
D. for … to
【单选题】
I think we both need to ___ the past, be happy about what we had for a time, learn from our experiences, and move on from there.
A. let go of
B. give authority to
C. make sense of
D. keep up with
【单选题】
My brother and I managed to ___ with each other and we soon made peace after a week’s quarrel.
A. heal
B. reconcile
C. respond
D. advocate
【单选题】
The two robbers in a stolen car tried to ___ a police roadblock (路障), but faile D.
A. break in
B. break off
C. break up
D. break through
【单选题】
Because of his long illness, Lee’s English level had dropped, but he was determined to ___ the other students by working harder.
A. put up with
B. catch up with
C. get along with
D. fill up with
【单选题】
We appreciate your efforts in making changes in your schedule and think that this new arrangement is now ___ to us.
A. agreeable
B. sustainable
C. portable
D. indispensable
【单选题】
The woman who died in a car crash last Saturday in the suburbs has been ___ as Kate Johnson, a 25-year-old office clerk.
A. justified
B. identified
C. notified
D. classified
【单选题】
My nephew failed in the College Entrance Examination, and we were all very sorry that he did not ___ to the university.
A. take it
B. get it
C. make it
D. succeed it
【单选题】
Almost half of that group will experience stress ___ enough to call for professional help.
A. tense
B. moderate
C. bearable
D. intense
【单选题】
If you grow too fast your entire economy could completely shut down and bring growth to a(n) ___.
A. halt
B. cease
C. peak
D. epidemic
【单选题】
I tried my best to drive inside in order to avoid the edges that might make me ___ the steep slope.
A. slip down
B. settle down
C. bring down
D. turn down
【单选题】
When the driver heard that there was a bomb on the bus, he immediately ___ to the side of the highway and radioed the police.
A. put out
B. took off
C. pulled over
D. slipped off
【单选题】
She was very ___ to become a manager in our customers’ office, but finally accepted our offer.
A. eager
B. intelligent
C. ridiculous
D. reluctant
【单选题】
In the race, it looked as if he would be the first, but then another young man who was close behind him put on speed and ___ by a few seconds.
A. beat him for it
B. beat him to it
C. beat him up
D. beat it to him
【单选题】
It is really helpful to have someone like you that we can ___ and count on during difficult times.
A. lean on
B. get to
C. hang on
D. get by
【单选题】
Women have a greater ability to ___ names with faces than men do, and they are also better at recalling lists.
A. associate
B. compare
C. engage
D. involve
【单选题】
He was always ready to help others and managed to ___ his friends ____being hurt.
A. expose … to
B. confine …to
C. restrict … from
D. shield … from
【单选题】
Older people are less likely to be ___ their negative emotions (情绪) and more likely to focus on the positive.
A. reserved for
B. caught up in
C. beat up to
D. counted on
【单选题】
I don’t have any bandage, so I have to ___ pressure to the wound to keep the bleeding down.
A. apply
B. involve
C. fulfill
D. establish
【单选题】
It is important that whichever candidate (候选人) is picked the loser should accept the defeat ___.
A. in advance
B. with great pride
C. with good grace
D. in large part
【单选题】
___ that new homes cost more than older homes, but that is not true across the country anymore.
A. It used to be
B. It is used to be
C. It used to being
D. It is used to being
【单选题】
The boss ___ his employees to work longer hours as the company is dreadfully short of staff at present.
A. called on
B. signed up
C. cared for
D. set up
【单选题】
The president’s visit and ___ discussions led to a plan that aimed to improve the trade relations between the two countries.
A. emerging
B. subsequent
C. consequent
D. Submerging
【单选题】
The author ___ his general idea mainly through statistics and results obtained from a survey (调查) about auto customer services in the United States.
A. assumes
B. engages
C. illustrates
D. represents
【单选题】
People in this town starved, several buildings were bombed and crime ___ because you had to steal to eat.
A. eroded
B. reflected
C. released
D. soared
【单选题】
Olympic recognition for bodybuilding (健美) remains ___ since some argue that bodybuilding is not a sport because the actual contest does not involve the same sort of efforts as “real” sports.
A. controversial
B. conventional
C. characteristic
D. influential
【单选题】
Tom tried to justify his absence from the meeting by ___ that he had been ill that day.
A. admitting
B. advocating
C. claiming
D. citing
【单选题】
___ the huge financial benefits, biological companies have been rushing to set up laboratories and new research projects.
A. Aware
B. Aware of
C. Not aware
D. Not aware of
【单选题】
Unfortunately, ___ lack of funds, the studies he began just two months ago, had to be ended early.
A. out of
B. in addition to
C. owing to
D. to begin with
【单选题】
With a good command of English, he soon got ___ to working with British people.
A. accustomed
B. consistent
C. relevant
D. responsible
【单选题】
What needs to be ___ here is that language and culture interact, and that understanding of one requires understanding of the other.
A. altered
B. stressed
C. aroused
D. committed
【单选题】
Policies and organizations must be created to meet workers’ hopes, and to ___ new problems that inevitably arise between workers and managers.
A. compromise
B. ensure
C. undermine
D. resolve
