Technology Projects > Energy and Fresh Water > Introduction

Introduction


The main area of focus of the group is the utilization of the ocean resources to find alternative technologies for fresh water and renewable energy. Currently the group is working on three specific areas, fresh water production using low temperature thermal desalination (LTTD) process and energy production using two distinctly different processes, Ocean Thermal Energy Conversion and Wave Energy. 

     The Group is committed to develop technologies for producing high quality clean drinking water and energy from the ocean. Technologies like Low Temperature Thermal Desalination (LTTD) using coolant water discharge from thermal power plant, wave energy using floating devices such as Backward Bent Ducted Buoy (BBDB), ocean current turbine development, solar desalination, heat exchangers for LTTD and ocean thermal energy conversion are the focal areas of research. Apart from the aspect of technology development, the group has taken initiative in transferring the LTTD technology to the society through industrial partnership.

Energy & Fresh water: 
The program focuses on developing technologies for tapping renewable energies and generating fresh water from the ocean. A small rating Backward Bent Ducted Buoy was studied and its field trials are under progress. Operation of the LTTD plant principle is also suitable for power plant cooling water discharge where the temperature difference around 10oC is available. The setup of such experimental waste heat desalination plant is under progress at NCTPS, Chennai.


Objectives: 
To generate 2 - 3 lakh litres per day freshwater using the Low Temperature Thermal Desalination technology by utilizing the waste heat at North Chennai Thermal Power Plant. 
Development of turbines towards OTEC/Wave Energy to run LTTD plants or run small loads or increase efficiency of wave energy plants. 
Theoretical and experimental studies on components like heat ex-changers for desalination and energy conversion.
To install a floating Wave powered device to power loads like a small rated Reverse Osmosis or to meet the lighting requirements of small islands. 
Generation of theoretical, experimental and field data, for optimization of components and suitable adoption towards commercialization of extraction of renewable energies and fresh water including solar desalination.


Desalination by LTTD process: 
The phenomenon of the variation in the ocean water temperature with an increase in depth is used in the Low Temperature Thermal Desalination (LTTD) to flash evaporate the warm water at low pressure and condense the resulting vapor with the deep sea cold water. Starting from a small laboratory based 5 m 3/day capacity scale model, the group has successfully commissioned one 100 m 3/day capacity land based plant at Kavaratti and one 1000 m 3/day capacity floating barge based desalination plant off the coast of Chennai.

The group has successfully commissioned the LTTD process for power plants where huge amounts of warm water are discharged continuously from the plant. A demonstration plant is being set-up at North Chennai Thermal Power Station and continuously generating fresh water is being used by the power plant. Establishment of similar plant at Tuticorin Thermal Power Station with 2 x 1 MLD capacity is under progress.

NIOT has successfully demonstrated 1000 m 3 / day barge mounted desalination plant 40 km off Chennai coast in March 2007. Efforts are on to establish large scale offshore desalination plant off Chennai around 1000 m water depth.

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Backward Bent Ducted Buoy (BBDB)
157 mm Gorlov turbine model made from Rapid prototype machine

 

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300 mm helical turbine made of steel reinforced blades