问题 问答题

简述燃烧系统故障的一般现象、原因和处理。

答案

参考答案:

燃烧系统故障的一般现象:

1.MK VI发出以下一个或多个报警:EXHAUST THERMOCOUPLE TROUBLE、EXHAUST THERMOCOUPLE OPEN TR IP、COMBUSTION TROUBLE、HIGH EXHAUST TEMPERATURE SPREAD TRIP、EXHAUST TEMPERATURE HIGH、EXHAUST OVER TEMPERATURE TR IP等。

2.至少有一个热电偶测量值明显失准或开路。

3.排气分散度S1、S2、S3数值大于正常运行值。

4.个别燃机排烟热电偶温度大于正常运行值。

燃烧系统故障的原因:

1.排气热电偶失灵或损坏。

2.燃烧室故障(燃烧室外壳裂开、导流衬套故障、过渡段故障、联焰管故障、窥视孔破裂或吹裂、火焰监测器或火花塞泄漏等)。

3.天然气管路泄漏或堵塞。

4.燃料喷嘴堵塞、松动、腐蚀。

5.天然气过热度不够,气中带有液体;天然气压力波动。

6.天然气控制阀GCV1,GCV2,GCV3调节不够灵敏或LVDT反馈不正确。

7.天然气清吹系统有故障。

8.透平叶片损坏,特别是第1级静叶损坏时现象更明显。

燃烧系统故障的处理:

1.若燃机发生跳闸,按跳闸处理方法处理。

2.观察燃机排烟情况,若发现异常,立即汇报值班长,向调度申请停机,情况严重时可立即手动紧急停机。

3.若确定是某支排气热电偶发生故障,应及时通知检修,经部主管领导同意后可采用并接故障热电偶至正常热电偶方法以避免机组不必要的跳闸。在并接故障热电偶前应对有关逻辑进行强制(典型的为L30SPT>0,L86TXT>0,L86TFB>0),并接完成后应先执行主复位命令然后解除上述逻辑强制。在燃机停机时更换故障热电偶。

4.遇到情况不明的燃烧系统故障报警,应立即向调度申请停机,汇报有关领导,配合检修根据GE有关技术规定进行燃烧系统的检查。

阅读理解

阅读理解。

     Mrs. Amatuli was my teacher in the fourth grade. One day at lunch time, I was getting ready to eat my

same old tuna fish (金枪鱼) sandwich and suddenly Mrs. Amatuli asked me if she could buy my sandwich

from me. She explained that, I could use the money to buy a hot lunch from the cafeteria.

     I was thrilled. I never bought my lunch at the cafeteria. It was too expensive for my family, and we always

carried our lunch and brought the bag back home to use again the next day. My sandwiches were either

bologna (大腊肠) or tuna fish. It rarely varied beyond that.

     You can understand my delight when I had the opportunity to buy a hot lunch.

     When we finished lunch that day, Mrs. Amatuli took me aside and said she wanted to explain why she had

bought my sandwich. I really didn't care why, but it gave me a few minutes of her precious attention so I was

very quiet as she explained. You see, she was Catholic and she told me that Catholics didn't eat red meat on

Fridays-they ate fish on Fridays.

     Oh, I couldn't wait to get home and tell my Mama that from now on I wanted tuna fish on Fridays. After,

my Mama understood why, she gladly fixed tuna fish for me on Fridays. She even fixed it on brown bread

because she knew Mrs. Amatuli liked brown bread. From then on, every Friday I could get in line with the

rest of the kids for a hot lunch. I didn't care how many of the kids complained about cafeteria food-it tasted

divine to me!

     I realize now that Mrs. Amatuli could have fixed herself a tuna sandwich of Friday. But she bought my

sandwich because she saw a little girl who was thrilled over the simple act of having a hot lunch.

     I will never forget her for her compassion and generosity and what I should do is follow her example.

1. Mrs. Amatuli bought the writer's sandwich because _____.

A. she was tired of cafeteria food

B. she hated getting in line with kids

C. she didn't eat red meat on Friday

D. she wanted to show care to the writer

2. What can we learn about the cafeteria food?

A. It was terrific.

B. It was terrible.

C. The writer enjoyed it.

D. Most kids were fond of it.

3. The underlined word "divine" in Paragraph 5 means _____.

A. perfect

B. sweet

C. unpleasant

D. special

4. Which of the following can best show the theme of this text?

A. It is hard to please all.

B. Better to give than to receive.

C. Love makes the world go around.

D. The more you offer, the more you are rewarded.

单项选择题