问题 问答题 简答题

简述燃油泄漏试验的过程?

答案

参考答案:

通过来自于DCS人机接口(MMI)的“启动泄漏试验”信号启动泄漏试验,发出“LTIV”开指令,并启动一个计时器。因此启动泄漏试验必须具备下列条件:

A).进油关断阀已关闭。

B).所有火检显示无火信号存在。

C).来自MMI的启停泄漏试验信号不存在。

D).油源压力正常信号存在。

e).油母管泄漏试验故障信号不存在。

f).所有燃烧器OBTV阀已关和MFT复位按钮已操作。

g).回油关断阀已关信号存在。

当这些条件都满足,发出的“启动燃油泄漏试验”信号将启动泄漏试验周期,并发出开泄漏试验隔离阀指令,允许燃油进入油母管。

收到启动泄漏试验信号,就启动一个1分钟的计时器,而且提供一个当瞬间启动信号消失时,以维持输出的自锁。这个输出也提供“油母管泄漏试验1已启动”信号给调节控制,并给出一个开泄漏试验隔离阀1分钟周期的信号,在1分钟周期内,假如无泄漏,就允许把燃油母管的油压充至油源压力。

由“与”门的输出检测1分钟计时器周期的结束,由于LTIV阀的信号被撤销,并且这个逻辑检查“燃油母管压力》X”信号,这个信号是由调节控制系统的设定值信号,若达到了所设定的压力值即不小于“X”值,则试验程序继续进行,否则试验程序被取消。

由“与”门的输出检测3分钟计时周期的结束,此逻辑检查“燃油母管压力》Y”信号,这个设定值比X值低,是由调节控制系统提供的。如果达到了压力设定值,并确定该系统没有泄漏,就把触发器发至“置位”状态,并发出“油泄漏试验1满意”信号,如果“燃油母管压力》Y”信号没出现,就发出一个”油泄漏试验失败”信号,试验程序被取消。触发器的“置位”状态和“油泄漏试验1满意”信号由触发器保持,直到发出“MFT动作”信号为止。

油泄漏试验2:由于泄漏试验2要求打开回油闭锁阀,所以在炉膛吹扫完成和发出“NOMFT”信号后,才能启动这个试验。

在“油母管泄漏试验允许条件满足”信号和“NOMFT”信号都出现后,且成功的完成泄漏试验1,将启动泄漏试验2。逻辑给出一个10秒周期的开回油闭锁阀信号,这样减少了完成试验1所需要的油母管压力。当10秒结束后,回油闭锁阀关闭,系统检查阀门已关后,向调节系统发出一个油母管泄漏试验已启动信号。

调节控制系统提供一个“油母管压力=Z1”的信号给BMS。接着启动一个5分钟计时器,计时结束后,BMS检查“油母管=Z2”信号是否满足。如果满足,置位S/R触发器,发出“油母管泄漏试验2成功”信号,允许打开燃油主安全关断阀。如果所提供的其他允许条件都满足的话,就可以进行油点火。

如果Z2值不在所要求的限制内,BMS把这个信号看作逻辑“0”,发出“油母管泄漏试验2失败”信号。(油母管压力Z1、Z2值在调试时确定)。

单项选择题 A1/A2型题
阅读理解

阅读理解。

     While it is impossible to live completely free of stress, it is possible to prevent stress as well as reduce

its effect when it can't be avoided. The US Department of Health and Human Services offers the following suggestions for ways to deal with stress.

     ◆Try physical activity

     When you are nervous, angry or upset, try releasing the pressure through exercise or physical activity. Running, walking, playing tennis, and working in your garden are just some of the activities you might try.

     ◆Take care of yourself

     You should make every effort to eat well and get enough rest. If you easily get angry and can't sleep

well enough, or if you're not eating properly, it will be more likely that you will fall into stressful situations

. If stress repeatedly keeps you from sleeping, you should consult a doctor.

     ◆Make time for yourself

     Schedule time for both work and entertainment. Don't forget, play can be just as important to your

overall well-being as work. You need a break from your daily routine to just relax and have fun. Go

window-shopping or work on a hobby. Allow yourself at least a half hour each day to do something you

enjoy.

     ◆Make a list of things to do

     Stress can result from disorganization and a feeling that "there's so much to do, and not enough time".

Trying to take care of everything at once can be too much for you and as a result, you may not achieve

anything. Instead, make a list of everything you have to do, then do one thing at a time, checking off each

task as it is completed. Set out to do the most important task first.

1.Which of the following statements shows that you have fallen into stressful situations?

A. You can't sleep well all the time.        

B. You have a break after work.

C. You always feel happy and relaxed.      

D. You only do one thing at a time.

2. According to the passage, how do you make a list of things to do?

A. Try to take care of everything at once.    

B. Do one thing at a time.

C. Only do the most important thing.      

D. Have a break from your work.

3. Why does the writer write this passage?

A. To give opinion.    

B. To give suggestions.

C. To make a request.  

D. To ask for advice.

4.What is the best title for the passage?

A. How to Deal with Stress?              

B. How to Make Time for Yourself?

C. How to Take Care of Yourself?        

D. How to Make a List of Things to Do?

5.Which of the following would be the advice to deal with stress according to the passage?

A. just lie in bed for a rest        

B. always listen to pop music

C. insist on doing work        

D. make a list to do things one by one