Heat Recovery Steam Generator (HRSG)

A specialized heat exchanger often used in power generation. These devices will produce steam for a specific process or to drive a steam turbine.

Turbine

A rotor-machine that is used to extract energy from high pressure, high temperature fluids via expansion across the turbine blades.

Combined heat and power (CHP)

Similar to a combined cycle process, CHP cycles are used to generate steam for functions beyond generating electricity. These functions can include space heating, process heating, or direct steam use.

Combined Cycle

A combined cycle system utilizes two or more thermodynamic cycles to recover energy from hot exhaust gas streams. These cycles often combine Brayton and Rankine cycles in series, through the use of a "heat recovery steam generator" or HRSG. This device is a large heat exchanger used to extract heat from exhaust gases to boil water in a Rankine cycle.

Rankine cycle

Also referred to as the steam cycle, the Rankine cycle utilizes the evaporation-condensation properties of a working fluid to drive a turbine. Water vapor, or steam, is often used as the working fluid for these processes. A pump is used to circulate the fluid through a boiler, where it is heated (or boiled) at a constant pressure into steam, after which it is expanded through a turbine for energy extraction.  It is a "closed" system, in that the working fluid is recycled.

Brayton cycle

A thermodynamic cycle that describes gas turbine engines. Inlet gas is brought to high pressure through a compressor, after which it is heated in a combustion chamber and expanded through a turbine for energy extraction. It is an "open" system, in that the working fluid is not recycled.

OPEC (Organization of the Petroleum Exporting Countries)

An intergovernmental organization whose stated objective is to "coordinate and unify the petroleum policies of member countries." It was created at the Baghdad Conference on September 10–14, 1960. Current members (with years of membership) include Algeria (1969–present), Angola (2007–present), Ecuador (1973–1992 and 2007–present), Iran (1960–present), Iraq (1960–present), Kuwait (1960–present), Libya (1962–present), Nigeria (1971–present), Qatar (1961–present), Saudi Arabia (1960–present), United Arab Emirates (1967–present), and Venezuela (1960–present). Countries no longer members of OPEC include Gabon (1975–1994) and Indonesia (1962–2008).

Crude Oil

A mixture of hydrocarbons that exists in liquid phase in natural underground reservoirs and remains liquid at atmospheric pressure after passing through surface separating facilities. Depending upon the characteristics of the crude stream, it may also include:

• Small amounts of hydrocarbons that exist in gaseous phase in natural underground reservoirs but are liquid at atmospheric pressure after being recovered from oil well (casinghead) gas in lease separators and are subsequently commingled with the crude stream without being separately measured. Lease condensate recovered as a liquid from natural gas wells in lease or field separation facilities and later mixed into the crude stream is also included;
  

• Small amounts of nonhydrocarbons produced with the oil, such as sulfur and various metals;
  

• Drip gases, and liquid hydrocarbons produced from tar sands, oil sands, gilsonite, and oil shale.
  
  Liquids produced at natural gas processing plants are excluded. Crude oil is refined to produce a wide array of petroleum products, including heating oils; gasoline, diesel and jet fuels; lubricants; asphalt; ethane, propane, and butane; and many other products used for their energy or chemical content.
  

Barrel

A unit of volume equal to 42 U.S. gallons.

Shock Absorbers

• A shock absorber or damper is a mechanical device designed to smooth out or damp a sudden shock impulse and dissipate kinetic energy.
• A dashpot is a mechanical device, a damper which resists motion via viscous friction. The resulting force is proportional to the velocity, but acts in the opposite direction slowing the motion and absorbing energy.
• In most dashpots energy is converted to heat inside the viscous fluid. In hydraulic cylinders the hydraulic fluid will heat up. In air cylinders, the hot air is usually exhausted to the atmosphere.

Water Tube Boilers:

• It is boiler with heat source outside the tube(shell side) and water to be heated is inside the tube.

Fire tube boilers:

• It is boiler with heat source inside the tubes and water to be heated is outside(shell side)

HRSG (Heat Recovery Steam Generators)

• HRSG is also a boiler which uses the heat rejected from other process or turbines to produce steam. Some HRSGs also have auxiliary firing facility.

Boiler

• A boiler is a closed vessel in which water or other fluid is heated under pressure.
• The hot fluid is then circulated out of the boiler for use in various purposes or heating applications.