What is relative expansion?

The relative expansion (also called strain) divided by the change in temperature is called the material’s coefficient of linear thermal expansion and generally varies with temperature.

What is thermal expansion turbine?

Steam turbines have a known thermal expansion, where the rotor and stator follows a different trajectory during warming up. This phenomenon may lead to less power production due to the high vibrations or even lead to complete turbine shutdown to avoid the parts being severely damaged.

How does steam expand?

When water is heated it evaporates, which means it turns into water vapor and expands. At 100℃ it boils, thus rapidly evaporating. And at boiling point, the invisible gas of steam is created. The opposite of evaporation is condensation, which is when water vapor condenses back into tiny droplets of water.

What happens when steam expands?

As the steam expands to fill the cylinder, it cools down, loses pressure, and gives up its energy to the piston. The steam isn’t a source of energy: it’s an energy-transporting fluid that helps to convert the energy locked inside coal into mechanical energy that propels a train.

Why does matter expand when heated?

All three states of matter (solid, liquid and gas) expand when heated. Heat causes the molecules to move faster, (heat energy is converted to kinetic energy ) which means that the volume of a gas increases more than the volume of a solid or liquid.

Under what condition is differential expansion zero?

Under what condition its value is zero? The difference in expansions of different substances when they are heated through the same range of temperature is called the differential expansion. Water pipes burst in winter, why? In winter, when water trapped in a pipe cools further from 4oC – 0oC, it freezes.

How is alignment influenced by thermal expansion?

Results show that thermal expansion has an influence on shaft alignment due to difference of alignment values when hot and cold conditions, namely 0.025 mm (gap) and 0.071 mm (offset.) in vertical plane then-0.025 mm (gap) and-0.069 mm (offset.) in horizontal plane.

What is the expansion ratio of steam?

1700:1
The expansion ratio of steam at 100o C (212o F) is 1700:1, but as the volume of water used to cool the upper layer is small, the expanded volume is still relatively small (in comparison to the contraction of the upper layer).