The filter fits tightly on vac to provide a good seal. 2.4 Electricity generation (and cogeneration).Steam is traditionally created by heating a boiler via burning coal and other fuels, but it is also possible to create steam with solar energy. Water vapor that includes water droplets is described as wet steam. As wet steam is heated further, the droplets evaporate, and at a high enough temperature (which depends on the pressure) all of the water evaporates and the system is in vapor–liquid equilibrium. When steam has reached this equilibrium point, it is referred to as saturated steam. Superheated 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. Steam tables contain thermodynamic data for water/saturated steam and are often used by engineers and scientists in design and operation of equipment where thermodynamic cycles involving steam are used. Additionally, thermodynamic phase diagrams for water/steam, such as a temperature-entropy diagram or a Mollier diagram shown in this article, may be useful. Steam charts are also used for analysing thermodynamic cycles.Įnthalpy-entropy (h-s) diagram for steam. Pressure-enthalpy (p-h) diagram for steam. Temperature-entropy (T-s) diagram for steam. In agriculture, steam is used for soil sterilization to avoid the use of harmful chemical agents and increase soil health. Steam is used in various chemical processes as reactant, especially in the petrochemical industry. Steam cracking of long chain hydrocarbons produces lower molecular weight hydrocarbons for fuel or chemical applications. Steam reforming produces syngas or hydrogen. Steam's capacity to transfer heat is also used in the home: for cooking vegetables, steam cleaning of fabric, carpets and flooring, and for heating buildings. In each case, water is heated in a boiler, and the steam carries the energy to a target object. Steam is also used in ironing clothes to add enough humidity with the heat to take wrinkles out and put intentional creases into the clothing.Įlectricity generation (and cogeneration) Īs of 2000 around 90% of all electricity was generated using steam as the working fluid, nearly all by steam turbines. In electric generation, steam is typically condensed at the end of its expansion cycle, and returned to the boiler for re-use. However, in cogeneration, steam is piped into buildings through a district heating system to provide heat energy after its use in the electric generation cycle. The world's biggest steam generation system is the New York City steam system, which pumps steam into 100,000 buildings in Manhattan from seven cogeneration plants. Energy storage ĭespite the resemblance to a boiler, note the lack of a chimney and also how the cylinders are at the cab end, not the chimney end. In other industrial applications steam is used for energy storage, which is introduced and extracted by heat transfer, usually through pipes. Steam is a capacious reservoir for thermal energy because of water's high heat of vaporization.įireless steam locomotives were steam locomotives that operated from a supply of steam stored on board in a large tank resembling a conventional locomotive's boiler. This tank was filled by process steam, as is available in many sorts of large factory, such as paper mills. The locomotive's propulsion used pistons and connecting rods, as for a typical steam locomotive.
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