Search results
Results from the WOW.Com Content Network
The temperature will remain constant while it is at constant pressure underneath the saturation dome (boiling water stays at a constant of 212F) until it reaches the saturated vapor line. This line is where the mixture has converted completely to vapor. Further heating of the saturated vapor will result in a superheated vapor state.
Superheated steam was widely used in main line steam locomotives. Saturated steam has three main disadvantages in a steam engine: it contains small droplets of water which have to be periodically drained from the cylinders; being precisely at the boiling point of water for the boiler pressure in use, it inevitably condenses to some extent in the steam pipes and cylinders outside the boiler ...
When steam has reached this equilibrium point, it is referred to as saturated steam. Superheated steam or live steam is steam at a temperature higher than its boiling point for the pressure, which only occurs when all liquid water has evaporated or has been removed from the system.
In thermodynamics, vapor quality is the mass fraction in a saturated mixture that is vapor; [1] in other words, saturated vapor has a "quality" of 100%, and saturated liquid has a "quality" of 0%. Vapor quality is an intensive property which can be used in conjunction with other independent intensive properties to specify the thermodynamic ...
This pressure is given by the saturated vapour pressure, and can be looked up in steam tables, or calculated. [9] As a guide, the saturated vapour pressure at 121 °C is 200 kPa, 150 °C is 470 kPa, and 200 °C is 1550 kPa. The critical point is 21.7 MPa at a temperature of 374 °C, above which water is supercritical rather than superheated ...
Below that temperature, a water vapor bubble will shrink and vanish. Superheating is an exception to this simple rule; a liquid is sometimes observed not to boil even though its vapor pressure does exceed the ambient pressure. The cause is an additional force, the surface tension, which suppresses the growth of bubbles. [4]
The saturated liquid curve is the curve separating the subcooled liquid state and the two-phase state in the T–s diagram. [1] When used in a power cycle, the fluid expansion depends strongly on the nature of this saturation curve: A "wet" fluid shows a negative saturation vapor curve.
At this pressure, the condensation temperature of the water vapor at the heat exchanger will be 390 K. Taking into account the boiling point elevation of the salt water we wish to evaporate (8 K for a saturated salt solution), this leaves a temperature difference of less than 8 K at the heat exchanger. A small ∆T leads to slow heat transfer ...