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IMPACT OF WIND ENERGY CONVERSION SYSTEMS FOR DISTRIBUTED GENERATION. By, Shikha T.S,Bhatti and D.P.Kothari. This novel work :. 1. Introduces a new concept of amplifying the wind speed before it comes in contact with the rotor blades of a savonius turbine by using a convergent nozzle.
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IMPACT OF WIND ENERGY CONVERSION SYSTEMS FOR DISTRIBUTED GENERATION By, Shikha T.S,Bhatti and D.P.Kothari
This novel work: 1. Introduces a new concept of amplifying the wind speed before it comes in contact with the rotor blades of a savonius turbine by using a convergent nozzle. 2. Emphasizes on the improvement of the efficiency these commercially unsuccessful rotors. 3. Verifies the nozzles characteristics with the help of a research program involving wind tunnel tests of five different models. 4. Analyses the important nozzle dimensions
DISTRIBUTED GENERATION – A TURN FOR THE BETTERDistributed resources are:1. Uniquely portable, flexible, diversifiable, controllable, and accountable to end-users. 2. Avoid many of the hidden costs of centralisation and entail less risk.3. Enable utilities to increase capacity in small increments.
4. Reduce delivery costs and make more efficients use of existing grid. 5. Avoid T and D losses and risk of failure.6. Lower technical risks and increase reliability.7. Entail environmental and social benefits. New modified rotor can be conveniently built in small units (Distributed generation)
UNSUCCESFUL BUT PROMISING - SAVONIUS WIND TURBINEPrinciple of operation: A simple savonius turbine
Required modifications: Use of concentrating nozzle with savonius rotor in two different positions
A four bladed savonius rotor with a convergent nozzle A six bladed savonius rotor with a convergent nozzle
IMPORTANT NOZZLE PARAMETERS1. Length of nozzle (L,cms)2. Outlet to inlet area ratio (A2 /A1, Ratio)Experimental set up:Five nozzle models (Different outlet area ) fabricated and tested outside wind tunnel in following conditions:1. controlled wind velocity at the inlet of the nozzle.
2. outlet of nozzle left open to the atmosphere.3. Tests conducted for three different lengths of the nozzle.4. Nozzle placed at different distances from the wind tunnel outlet. .
RESULTSTable: Average amplification of wind velocity for different models
ANALYSIS OF PERFORMANCE CHARACTERISTICS Area versus velocity ratio
CONCLUSION1. The six-bladed rotor turns out to have an optimum design.2. Use of nozzles with six-bladed rotor enhances the power extraction at low wind speeds.3. The new improved rotor using a convergent nozzle can outperform existing ones by a significant margin.
4. The amplification rate thus also becomes constant after a fixed distance from the wind tunnel.5. Calculations indicate that this rotor will draw 2 to 3 times as much wind as conventional windmill of same swept area. 6. The ideal power coefficient and hence efficiency can be enhanced to a good extent.