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Steam is water vapor (water in the gas phase), often mixed with air and/or an aerosol of liquid water droplets. This may occur due to evaporation or due to boiling, where heat is applied until water reaches the enthalpy of vaporization. Steam that is saturated or superheated (water vapor) is invisible; however, wet steam, a visible mist or ...
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 ...
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 thermodynamic system. [2] A typical chart covers a pressure range of 0.01–1000 bar, and temperatures up to 800 degrees Celsius. [3] It shows enthalpy in terms of internal energy , pressure and ...
The quantitatively described steam quality (steam dryness) is the proportion of saturated steam in a saturated water/steam mixture. In other words, a steam quality of 0 indicates 100% liquid, while a steam quality of 1 (or 100%) indicates 100% steam. The quality of steam on which steam whistles are blown is variable and may affect frequency.
The high-pressure liquid enters a boiler, where it is heated at constant pressure by an external heat source to become a dry saturated vapour. The input energy required can be easily calculated graphically, using an enthalpy–entropy chart (h–s chart, or Mollier diagram), or numerically, using steam tables or software. Process 3–4
Up to 99.63 °C (the boiling point of water at 0.1 MPa), at this pressure water exists as a liquid. Above that, it exists as water vapor. Note that the boiling point of 100.0 °C is at a pressure of 0.101325 MPa (1 atm), which is the average atmospheric pressure. Water/steam data table at standard pressure (0.1 M Pa) T °C.
Superheater. 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.
The specific heat of the human body calculated from the measured values of individual tissues is 2.98 kJ · kg−1 · °C−1. This is 17% lower than the earlier wider used one based on non measured values of 3.47 kJ · kg−1· °C−1. The contribution of the muscle to the specific heat of the body is approximately 47%, and the contribution ...