Lippong Tan

Experimental investigation of power generation from salinity gradient solar pond using thermoelectric generators for renewable energy application

Low grade heat (<100°C) is currently converted into electricity by organic rankine cycle (ORC) engines. ORC engines require certain threshold to operate as the organic fluid generally boils at more than 50°C, and fails to operate at lower temperature. Thermoelectric generators (TEGs) can operate at very low temperature differences and can be good candidate to replace ORC for power generation at low temperatures. In this paper, the potential of power generation from TEG and salinity-gradient solar pond (SGSP) was investigated. SGSP is capable of storing heat at temperature up to 80°C. The temperature difference between the upper convective zone (UCZ) and lower convective zone (LCZ) of a SGSP can be in the range of 40°C 60°C. This temperature difference can be used to power thermoelectric generators (TEG) for electricity production. This paper present result of a TEG system designed to be powered by the hot and cold water from the SGSP. The system is capable of producing electricity even on cloudy days or at night as the SGSP acts as a thermal storage system. The results obtained have indicated significant prospects of such system to generate power from a low grade heat for remote area power supply.

Passive flow heat exchanger simulation for power generation from solar pond using thermoelectric generators

Renewable energy is becoming an important source of energy due to the rise in crude oil prices and the increase in greenhouse effects due to burning of fossil fuels. With only finite source of fossil fuel and exponential increase in the demand of power be

Theoretical analysis to determine the solar concentration limit with passive cooling of solar cells

This re search was conducte d to de te rmine the limiting values of the ge ome tric concentration whe n use d with solar thermal system (the rmoe lectric ge nerator) (TEG) to maintain desir ed hot and cold side te mpe ratures for powe r ge neration. An optimum heat sink fin gap is conside re d to achieve maximum heat transfer rate using passive cooling. A theore tical mode l is de ve lope d for de termining the optimum solar concentration using a the rmoe lectric ge nerator sandwiche d be twee n the targe t p late and passive cooling heat sink. The rmal resistance and Seebeck coefficie nt of a thermoe lectric ge nerator unde r conside ration is ex pe rimentally de te rmine d. Heat flow path for this syste m is de fine d and e nergy balance e quations are establishe d. A computer mode l is de ve lope d to solve the en ergy balance equations and find the optimum value s for geome tric conce ntration and hot & cold side tempe rature of thermoe lectric ge nerator. It was obse rve d that for the specific configuration of heat sink and thermoe le ctric ge ne rator in a sy stem, the tre nd of te mperature differe nce be twee n the hot and cold sides re main the same at diffe rent heat input conditions. The optimum ge ome tric conce ntration for solar radiation inte nsity of 800 W/m2 and heat sink fin le ngth of 0.15m is pre dicte d to be 13. The the ore tical mode l is capable of optimizing the values of geome tric conce ntration for desire d hot side or cold side tempe rature .

Experimental study of a sustainable hybrid system for thermoelectric generation and freshwater production

The paper presents a sustainable hybrid system, which is capable of generating electricity and producing freshwater from seawater using low grade heat source. This proposed system uses low grade heat that can be supplied from solar radiation, industrial waste heat or any other waste heat sources where the temperature is less than 150°C. The concept behind this system uses the Seebeck effect for thermoelectricity generation via incorporating the low boiling point of seawater under sub-atmospheric ambient pressure. A lab-test prototype of the proposed system was built and experimentally tested in RMIT University. The prototype utilised four commercial available thermoelectric generators (Bi2Te3) and a vacuum vessel to achieve the simultaneous production of electricity and freshwater. The temperature profiles, thermoelectric powers and freshwater productions were determined at several levels of salinity to study the influence of different salt concentrations. The theoretical description of system design and ...