A cooling pond is a man-made body of

water Water is an inorganic compound with the chemical formula . It is a transparent, tasteless, odorless, and Color of water, nearly colorless chemical substance. It is the main constituent of Earth's hydrosphere and the fluids of all known liv ...

primarily formed for the purpose of cooling heated water or to store and supply cooling water to a nearby

power plant A power station, also referred to as a power plant and sometimes generating station or generating plant, is an industrial facility for the electricity generation, generation of electric power. Power stations are generally connected to an electr ...

or industrial facility such as a petroleum refinery,

pulp and paper mill A paper mill is a factory devoted to making paper from vegetable fibres such as wood pulp, old rags, and other ingredients. Prior to the invention and adoption of the Fourdrinier machine and other types of paper machine that use an endless belt, ...

, chemical plant, steel mill or

smelter Smelting is a process of applying heat and a chemical reducing agent to an ore to extract a desired base metal product. It is a form of extractive metallurgy that is used to obtain many metals such as iron, copper, silver, tin, lead and zin ...

Overview

Cooling ponds are used where sufficient land is available, as an alternative to

cooling tower A cooling tower is a device that rejects waste heat to the atmosphere through the cooling of a coolant stream, usually a water stream, to a lower temperature. Cooling towers may either use the evaporation of water to remove heat and cool the ...

s or discharging of heated water to a nearby

river A river is a natural stream of fresh water that flows on land or inside Subterranean river, caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. A river may run dry before reaching the end of ...

or coastal bay, a process known as “once-through cooling.” The latter process can cause

thermal pollution Thermal pollution, sometimes called "thermal enrichment", is the degradation of water quality by any process that changes ambient water temperature. Thermal pollution is the rise or drop in the temperature of a natural body of water caused by h ...

of the receiving waters. Cooling ponds are also sometimes used with air conditioning systems in large buildings as an alternative to cooling towers. The pond receives

thermal energy The term "thermal energy" is often used ambiguously in physics and engineering. It can denote several different physical concepts, including: * Internal energy: The energy contained within a body of matter or radiation, excluding the potential en ...

in the water from the plant's

condensers __NOTOC__ Condenser may refer to: Heat transfer * Condenser (heat transfer), a device or unit used to condense vapor into liquid. Specific types include: ** Heat exchanger#HVAC and refrigeration air coils, HVAC air coils ** Condenser (laboratory), ...

during the process of energy production and the thermal energy is then dissipated mainly through

evaporation Evaporation is a type of vaporization that occurs on the Interface (chemistry), surface of a liquid as it changes into the gas phase. A high concentration of the evaporating substance in the surrounding gas significantly slows down evapora ...

and

convection Convection is single or Multiphase flow, multiphase fluid flow that occurs Spontaneous process, spontaneously through the combined effects of material property heterogeneity and body forces on a fluid, most commonly density and gravity (see buoy ...

. Once the water has cooled in the pond, it is reused by the plant. New water is added to the system (“make-up” water) to replace the water lost through evaporation. A 1970 research study published by the U.S. Environmental Protection Agency reported that cooling ponds have a lower overall electrical cost than

s while providing the same benefits. The study concluded that a cooling pond will work optimally within 5 degrees Fahrenheit of natural water temperature with an area encompassing approximately 4 acres per megawatt of dissipated thermal energy.

Examples

* Lake Anna is a cooling pond in

Virginia Virginia, officially the Commonwealth of Virginia, is a U.S. state, state in the Southeastern United States, Southeastern and Mid-Atlantic (United States), Mid-Atlantic regions of the United States between the East Coast of the United States ...

, which provides cooling water for the North Anna Nuclear Generating Station. This pond has recreational uses such as fishing, swimming, boating, camping, and picnicking as well as being a cooling pond for the nuclear plant. * The cooling pond at the Chernobyl Nuclear Power Plant (Pripyat, Ukraine) has abundant wildlife, despite the radiation present in the area. There are some accounts of wels catfish ''(Silurus glanis)'' growing up to 350 pounds and having a lifespan of up to 50 years in the area. * The Columbia Energy Center in Pacific, Wisconsin is a coal fired power plant with a capacity of 1000 MW. A dual cooling system is used for heat rejection that consists of a cooling pond and two cooling towers. The pond and towers are connected in a parallel arrangement to help dissipate thermal energy at expedited rates. * In 1994 the reactor at Yongbyon Nuclear Scientific Research Center, North Korea, was under U.S scrutiny and its nuclear fuel rods were taken out of the reactor and placed in the facility's cooling pond. The fuel rods have since been removed. * At the 2.05 MW Ashford A power station Kent, UK, cooling water for the oil-fired engines was obtained from, and returned to, cooling water ponds. The principal cooling mechanism in the ponds was by convection from the water surface. * At the 89 MW Back o’ the’ Bank power station in Bolton UK the cooling water was cooled in 4 spray ponds. The small size of the spray droplets improved the heat transfer, increased evaporation, and led to more effective cooling. Each cooling pond had a capacity of 0.75 million gallons per hour (0.95 m³/s). Make up water was abstracted from the nearby River Tonge. In about 1950 a hyperbolic reinforced concrete cooling tower was built with a capacity of 2.5 million gallons per hour (3.15 m³/s), with cooling range of 15 °F (8.3 °C). However, there were complaints that operation of the cooling tower let to problems with ice in cold weather as water vapour from the tower froze as fine particles. * In 1963 the UK's

Central Electricity Generating Board The Central Electricity Generating Board (CEGB) was responsible for electricity generation, transmission and bulk sales in England and Wales from 1958 until privatisation of the electricity industry in the 1990s. It was established on 1 Januar ...

(CEGB) was researching the possibility of using warmed cooling water from power stations to support fish-farming both for recreational use and for food. At Grove Road power station in London water was cooled in wooden natural draft cooling towers and fell into cooling water ponds. The CEGB introduced carp ( Cyprinus carpio), grass carp, silver carp and Tilapia into the cooling water ponds; the fish grew rapidly in the warm water (up to 27 °C). * Zaporizhzhia Nuclear Power Plant, Ukraine, has massive cooling ponds with additional water spray.

References

{{pond * Cooling technology Ponds Water pollution

Overview

Examples

See also

References