问题 问答题 简答题

水冷壁爆管的现象、处理。

答案

参考答案:

现象:

1>严重时,爆管处有明显的爆破声和喷汽声,炉膛负压变正,给水流量不正常的大于蒸汽流量,汽包水位迅速下降,难以维持水位,燃烧室内有泄漏响声;

2>如果爆管,炉膛压力急剧升高,孔洞及不严密处向外喷烟、汽水;

3>汽包压力、蒸汽流量、排烟温度下降,两侧烟温差增大;

4>烟道及引风机入口负压变小,引风机电流上升;

5>旋风分离器进、出口烟温下降,料腿回料温度低;

6>床压增大,床层压差增大,床料板结,流化不良,床温分布不均,底灰排放困难。

处理:

1>如发现泄漏,未发生MFT且能维持汽包正常水位时,降压,保持低负荷运行,汇报值长,申请停炉;

2>检查并注意损坏情况是否迅速扩大,密切监视水位,汽温,床温及底灰排出情况,调整炉膛负压、床压.视情况联系汽机增开给水泵;

3>燃烧不稳定及时投油助燃。投油前布袋除尘器走旁路。

4>若水冷壁严重损坏,发生MFT、锅炉已灭火或加强进水后难以维持汽包水位时应紧急停炉;

5>一次风维持在最小流化风量,加强排渣;

6>维持一台引风机运行,消除炉内蒸汽;

7>停炉时,布袋除尘器应切为旁路运行,防止泄漏物造成布袋堵塞或寿命降低;

8>停炉后,继续上水维持水位。如给水耗量太大,水位维持困难可停止上水。停止上水后,禁止开启省煤器再循环;

9>尽快将炉内床料排出炉膛,以防止床料结块;

10>待炉内水蒸汽基本消失后,停运引风机,开通烟道自然通风。

阅读理解

阅读理解。

     Elizabeth Blackwell was born in England in 1821, and moved to New York City when

she was ten years old. One day she decided that she wanted to become a doctor. That

was nearly impossible for a woman in the middle of the nineteenth century. After writing

many letters asking for admission(录取) to medical schools, she was finally accepted by

a doctor in Philadelphia. She was so determined that she taught school and gave music

lessons to get money for the cost of schooling.

     In 1849, after graduation from medical school, she decided to further her education in

Paris. She wanted to be a surgeon(外科医师) , but a serious eye problem forced her to

give up the idea.

     Upon returning to the United States, she found it difficult to start her own practice because

she was a woman. By 1857 Elizabeth and her sister, also a doctor, along with another

woman doctor, managed to open a new hospital, the first for women and children. Besides

being the first woman physician and founding her own hospital , she also set up the first

medical school for women.

1. Why couldn't Elizabeth Blackwell realize her dream of becoming a surgeon?_____

A. She couldn't get admitted to medical school

B. She decided to further her education in Paris

C. A serious eye problem stopped her

D. It was difficult for her to start a practice in the United States

2. What main obstacle(障碍) almost destroyed Elizabeth's chances for becoming a doctor?_____

A. She was a woman

B. She wrote too many letters.

C. She couldn't graduate from medical school.

D. She couldn't set up her hospital.

3. How many years passed between her graduation from medical school and the

opening of her hospital?_____

A. Eight years

B. Ten years

C. Nineteen years

D. Thirty-six years

4. According to the passage, all of the following are "firsts" in the life of Elizabeth Blackwell

except that she ______.

A. became the first woman physician

B. was the first woman doctor

C. and several other women founded the first hospital for women and children

D. set up the first medical school for women

5. Elizabeth Blackwell spent most of her lift in _______.

A. England

B. Paris

C. the United States

D. New York City

单项选择题