Steam is used across multiple industries for its ability to transfer heat to drive chemical reactions, sterilize or disinfect objects and to maintain constant temperatures.

It is also used in jacketing and tracing of piping to maintain the uniform temperature in pipelines and vessels. Steam is used in piping for utility lines. Steam is a non-toxic antimicrobial agent. Steam, especially dry (highly superheated) steam, may be used for antimicrobial cleaning even to the levels of sterilization. Steam turbines are often used in the production of electricity.Īn autoclave, which uses steam under pressure, is used in microbiology laboratories and similar environments for sterilization. Engineers use an idealised thermodynamic cycle, the Rankine cycle, to model the behavior of steam engines. Condensation of steam to water often occurs at the low-pressure end of a steam turbine, since this maximizes the energy efficiency, but such wet-steam conditions must be limited to avoid excessive turbine blade erosion. The ability to return condensed steam as water-liquid to the boiler at high pressure with relatively little expenditure of pumping power is important. Steam engines and steam turbines use the expansion of steam to drive a piston or turbine to perform mechanical work. These locomotives were mostly used in places where there was a risk of fire from a boiler's firebox, but were also used in factories that simply had a plentiful supply of steam to spare. The locomotive's propulsion used pistons and connecting rods, as for a typical steam locomotive. This tank was filled by process steam, as is available in many sorts of large factory, such as paper mills. 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. In other industrial applications steam is used for energy storage, which is introduced and extracted by heat transfer, usually through pipes. 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. 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. 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. In electric generation, steam is typically condensed at the end of its expansion cycle, and returned to the boiler for re-use. 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 each case, water is heated in a boiler, and the steam carries the energy to a target object. 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 agriculture, steam is used for soil sterilization to avoid the use of harmful chemical agents and increase soil health. Temperature-entropy (T-s) diagram for steam. Pressure-enthalpy (p-h) diagram for steam. Steam charts are also used for analysing thermodynamic cycles.Įnthalpy-entropy (h-s) diagram for steam.

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 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. 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. When steam has reached this equilibrium point, it is referred to as saturated 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. Water vapor that includes water droplets is described as wet steam. 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.

2.3 Electricity generation (and cogeneration).

The medium steam