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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 ...
The Mollier enthalpy–entropy diagram for water and steam. The "dryness fraction", x , gives the fraction by mass of gaseous water in the wet region, the remainder being droplets of liquid. An enthalpy–entropy chart , also known as the H – S chart or Mollier diagram , plots the total heat against entropy, [ 1 ] describing the enthalpy of a ...
The steam thus produced is at the same temperature as the water below it. This is called saturated steam. If the steam is taken away from the boiler, in a pipe, and then further heat is applied to that steam, the steam can rise above the temperature of the water in the boiler. This heated-above-the-boiler-temperature steam is called "superheated".
A superheater is a device used to convert saturated steam or wet steam into superheated steam or dry steam. Superheated steam is used in steam turbines for electricity generation, in some steam engines, and in processes such as steam reforming. There are three types of superheaters: radiant, convection, and separately fired.
For the bubble to expand, the temperature must be raised slightly above the boiling point to generate enough vapor pressure to overcome both surface tension and ambient pressure. What makes superheating so explosive is that a larger bubble is easier to inflate than a small one; just as when blowing up a balloon, the hardest part is getting started.
In Steam and Water Circuit temperature of water is increased from room temperature to superheated steam temperatures. In temperature range of 200to 250°C (feed water), dissolved oxygen causes corrosion of components and piping.
The standard state of a material (pure substance, mixture or solution) is a reference point used to calculate its properties under different conditions.A degree sign (°) or a superscript Plimsoll symbol (⦵) is used to designate a thermodynamic quantity in the standard state, such as change in enthalpy (ΔH°), change in entropy (ΔS°), or change in Gibbs free energy (ΔG°).
However, if the temperature is changed to 1160 °R, the specific volume of the super heated steam would have changed to 0.2765 in 3 /lb, which is a 59% overall change. Knowing the specific volumes of two or more substances allows one to find useful information for certain applications.