conversion de l'énergie thermique des mers
- Domaine
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- énergie énergie de la mer
- Date
Terme :
- conversion de l'énergie thermique des mers n. f.
Termes associés :
- conversion de l'énergie thermique océanique n. f.
- CETO
- conversion de l'énergie thermique des océans n. f.
- CETO
Traductions
-
anglais
Date :Définition
The extraction of useful energy from the oceans, using temperature differences between warm surface water (heated by absorption of solar energy) and colder, deep water to generate power.
Note :
Minimum temperature differences of 15 °C are needed in practical systems, and such temperature gradients are found in tropical ocean regions between latitudes of 10 °N and 10 °S. Low wind velocities must prevail for OTEC systems to be effective. Meaningful quantities of power have been generated in ocean areas where the temperatures range from between 25 ° and 30 °C at the surface to between 4°-7 °C at a depth of 750 metres. In the basic solar sea thermal power plant warm water is drawn into a broad diameter tube at the top of the system, where it produces steam under low pressure in the boiler module, and is cooled in the condenser by the intake of cold water at the base of the system. The efficiency of such a system (operating typically between 30°-5 °C) is calculated at 2-3 per cent. Such efficiencies are low compared with heat engines using conventional fuels, but since fuel costs are zero, and the system needs only to be designed for low working temperatures and pressures, the cost of power is reckoned to be economically feasible. Proposed practical operations include open cycle and closed cycle systems. Open cycle ocean thermal energy conversion units, such as the controlled flash evaporation process (CFE), rely on seawater as the working fluid to produce low pressure steam vapour which is harnessed to generate power. Closed cycle ocean thermal energy conversion units employ low boiling-point fluids, other than seawater itself, as working fluids in generating power. Examples of proposed closed cycle systems include the UMASS system (using ammonia and/or propane) and the CMU system (ammonia).
Termes :
- ocean thermal energy conversion
- OTEC