20-06-2012, 03:06 PM
SOLAR UPDRAFT TOWER PLANT
SOLAR UPDRAFT TOWERPLANT.pptx (Size: 1.51 MB / Downloads: 72)
INTRODUCTION
The present energy production is damaging the environment and is non- sustainable.
Remedy- building of nuclear power plant
Unacceptable risk.
High cost.
Less availability of nuclear fuel.
Solar updraft tower
Sensible technology.
Uses renewable energy.
Accessible to the technologically less developed countries.
An updraft solar power plant utilizes a combination of solar air collector and central updraft tube to generate electricity.
THE COLLECTOR
Usually 2 -6 meters height from ground.
Top surface is covered by glass or plastic film glazing.
Opened at its periphery for continuous air flow.
Height of the collector is more towards the base of the tower.
Heating effect increased by green house effect.
Water filled black tubes are used for additional thermal storage.
Stored thermal energy in the water tubes can be used during the night (24 hr power generation).
THE TOWER
Tower is a pressure tube with low friction loss.
Efficiency of the plant is proportional to the tower height.
Updraft of air in the tower is approximately proportional to rise of air temperature in the collector.
Air velocity at the bottom of tower reaches about 15m/s.
THE TURBINE
Shrouded pressure staged turbine.
Static pressure is converted to rotational energy.
Speed of air before and after turbine is almost same.
Output is proportional to product of change in pressure and volume flow per unit time.
There is no much change in velocity of air.
Maximum output obtained when pressure drop at turbine is 80% of total pressure drop.
CONCLUSION
Works on a simple proven principle.
As thermodynamic efficiency of plant increases with tower height, such plants have to be large to become cost competitive.
No consumption of costly fossil fuels. Especially beneficial for developing countries.
No ecological harm .
The plant consists of concrete and glass which are made from sand and stone. thus they can be even constructed in desert areas.