问题
多项选择题
汽轮机叶轮变形的原因主要有（）。
A.机组超出力运行或通流部分严重结构，致使隔板前后压差过大
B.运行中汽缸与转子的热膨胀控制不好，出现过大的胀差，引起隔板与叶轮摩擦
C.运行中推力瓦磨损，导致隔板与叶轮摩擦引起变形
D.运行中汽压过低，长期运行
答案
参考答案：A, B, C
搜题请搜索小程序“爱下问搜题”
汽轮机叶轮变形的原因主要有（）。
A.机组超出力运行或通流部分严重结构，致使隔板前后压差过大
B.运行中汽缸与转子的热膨胀控制不好，出现过大的胀差，引起隔板与叶轮摩擦
C.运行中推力瓦磨损，导致隔板与叶轮摩擦引起变形
D.运行中汽压过低，长期运行
参考答案：A, B, C
ss at all. The poor ant, almost tired out, was still bravely doing her best when a bird saw her. Moved with pity, the bird threw her a blade (叶片) of grass, which supported her like a boat, and thus she
reached the bank again. While she was resting and drying herself in the grass she heard a man coming near. He was walking along barefooted and carrying a gun in his hand. As he saw the bird he wished to kill her, and he would certainly have done so, but the ant bit him in the foot just before he raised his gun to 
fire. He stopped to see what had bit him, and the bird immediately flew away. It w
as an animal much weaker and smaller than herself that had saved her life. 
he water pushed her