Why does a steam turbine need vacuum?
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Why does a steam turbine need vacuum?
Vacuum applies to steam turbines because the pressure of saturated vapour above available cooling water is well below 1 bar (typically 17 mbar at 15°C ambient). These shortcomings are examined and used to explain the anomalous response of a turbine to a copious supply of cold winter cooling water.
What is meant by vacuum efficiency in steam condenser?
Vacuum Efficiency in Condenser. VACUUM EFFICIENCY : It is defined as the ratio of actual vacuum in condenser as recorded by the vacuum gauge to the ideal vacuum. Vacuum efficiency is also defined as the ratio of the partial pressure of steam to the measured condenser pressure.
What is the effect of high vacuum in condenser?
When a vacuum exists in the condenser, atmospheric air will leak into the condenser shell through flanges and other leakage points raising the condenser pressure. Dissolved gas in the water used to raise the steam will also enter the condenser along with the steam, but will not condense.
How does a vacuum condensate system work?
With the vacuum pump installed on the feed unit, the condensate returns under vacuum directly to the feed tank. It is stored under vacuum until required by the boiler water level control. Finally, note that eliminating your system’s vacuum return pumps will likely increase operating and fuel costs.
Why vacuum is created?
In general, a vacuum is created by starting with air at atmospheric pressure within a chamber of some sort. As molecules are removed, there are fewer other molecules for a given molecule to collide with the distance becomes longer and longer as the pressure is reduced.
Why do we need vacuum in condenser?
The removal of air and other noncondensable gases from the condenser shell side is required for proper heat transfer from steam to cooling water in the condenser and, thus, to maintain high vacuum in the condenser.
How vacuum is created in the main condenser?
Water is used to condense steam back to liquid water in any form of boiler system, whether on board ship or in power plants. In other words, the specific volume of water at a given pressure is many times lower than that of steam. This enormous reduction in volume creates the vacuum inside the condenser.
Why space is a vacuum?
The vacuum of outer space is not caused by the expansion of the universe, but is caused by gravity. There would still be things like vacuum fluctuations, gravity, and dark matter, which can’t be sucked out. With that said, outer space is very close to empty compared to earth’s atmosphere.