问题 问答题 论述题

水轮机投入运转前和运行中应进行哪些项目检查?

答案

参考答案:

(1)定期测定水轮机轴的摆度以及轴承等处的振动。值班人员应定时了解、分析水轮机在不同水头、负荷下摆度和振动值的变化,是否超过规定值。并尽量避免在振动大、摆度大的负荷区运行。随时监听水轮机运行中的声音是否正常。

(2)水轮机的真空破坏阀应完好。

(3)接力器应无摆动和抽动现象,各油管路无渗漏油,调速环动作应灵活。

(4)导叶剪断销应完好,剪断销、各连杆的连接销钉应无上升现象。

(5)稀油润滑的导轴承,其油面、油位、油质应合格。轴承在运行中无异响,瓦温、油温正常,冷却水畅通,表计指示正确,无漏油、漏水,轴承密封良好。

(6)水润滑的橡胶轴承,润滑水应畅通,水压正常,轴承在运行中无异响,轴承密封良好。

(7)各种仪表如水压表、真空表、温度计等指示应符合运行要求。

(8)水轮机的辅助设备应定期切换、检查、维护,如供润滑水的泵、滤水器,气系统的气水分离器等应根据投入运行时间的长短进行定期切换、清扫工作。定期测定气泵或水泵的电动机绝缘,以保证水轮机的安全运行。

(9)为确保水轮机及所附设备的正常运行,延长设备的使用寿命,必须随时保持水轮机及其附属设备的清扫,定期对有关设备进行清扫工作。

阅读理解

第三部分:阅读理解

第一节:阅读下列短文,从每题所给的四个选项(A、B、C和D)中,选出最佳选项。

It is a beautiful day in June. The sun is hot. It's time to harvest strawberries (草莓),and the strawberry fields are full of people. These people are picking strawberry. They are not farmers, and they are picking fruit for fun. They can buy strawberries in a supermarket but it is cheaper to pick their own fruit. Strawberries from the farm are also flesher (更新鲜的). Most people also like to pick their own fruit because it is a pleasant way to spend the afternoon.       

One little boy is walking between the rows of plants. He is picking the strawberries and eating them as fast as he can. Two young women in pretty dress and high-heeled shoes(高跟鞋)are getting out of their car.  Now they are taking off their shoes. These women are taking a break from their work. They want to pick fruit and enjoy the sunshine.

56. What time of the year do the people in the passage pick strawberries?

A. Early spring.           B. Early autumn.          C. Early summer.        D. Early winter.

57. The people in the passage are picking fruit because they are ________ .

A. farmers working all day in the fields

B. looking for a pleasant way to spend the afternoon

C. poor and need the money

D. stealing the fresh fruit

58. The story implies (暗示)that strawberries in the supermarket are ______.    

A. larger                                                         B. less fresh                 

C. cheaper                                                       D. better for your health

填空题