New approaches to energy conversion by alternative working fluids

2007 ◽  
pp. 53-76
Author(s):  
Georg Alefeld
Keyword(s):  
Energy Conversion ◽  
Working Fluids ◽  
New Approaches

New approaches to solar energy conversion using Si/liquid junctions

1995 ◽  
Vol 38 (1-4) ◽  
pp. 279-303 ◽  
Author(s):  
Arnel M. Fajardo ◽  
Christoph D. Karp ◽  
C.N. Kenyon ◽  
Katherine E. Pomykal ◽  
Gary A. Shreve ◽  
...  
Keyword(s):  
Solar Energy ◽  
Energy Conversion ◽  
Solar Energy Conversion ◽  
New Approaches

New approaches to photovoltaic and photoelectrochemical energy conversion

2008 ◽  
Author(s):  
S. Ismat Shah ◽  
Hong-Ying Lin ◽  
Yinghong Miao ◽  
Meghan E. Schulz
Keyword(s):  
Energy Conversion ◽  
New Approaches

MODELLING PERFORMANCE OF OCEAN-THERMAL ENERGY CONVERSION CYCLE ACCORDING TO DIFFERENT WORKING FLUIDS

2016 ◽  
Vol 78 (11) ◽  
Author(s):  
Norazreen Samsuri ◽  
Sheikh Ahmad Zaki Shaikh Salim ◽  
Md Nor Musa ◽  
Mohamed Sukri Mat Ali
Keyword(s):  
Energy Conversion ◽  
Thermal Energy ◽  
Rankine Cycle ◽  
Developmental Model ◽  
Water Mixture ◽  
Ammonia Water ◽  
Working Fluids ◽  
Ocean Thermal Energy Conversion ◽  
Thermal Energy Conversion ◽  
Ocean Thermal Energy

Ocean Thermal Energy Conversion (OTEC) is a promising renewable energy technology with the concept to harness the energy stored at the surface seawater (SSW) and the cold deep seawater (DSW). The operation is based on the Rankine cycle, and involves at a minimum temperature difference of 20 K of the SSW and DSW to generate electricity. This research focuses on the economic efficiency of different working fluids used in the OTEC Rankine cycle. The various working fluids include ammonia, ammonia-water mixture (0.9), propane, R22, R32, R134a, R143a, and R410a. Most of the existing commercial OTEC systems use ammonia as the working medium despite its toxic nature. This study shows that the ammonia-water mixture still gives the best results in terms of heat transfer characteristics because of its greater transport properties and stability compared to other fluids. However, fluids such as propane and R32 can also be used as a substitute for ammonia-water mixture despite having slightly lower efficiency, because they are non-toxic and safer towards the environment. The same developmental model was used to present the proposed modified OTEC Rankine cycle, which shows a 4% increase in thermal cycle efficiency. This study reveals economically efficient and environmentally friendly working fluids.

Performance Analysis of 15 kW Closed Cycle Ocean Thermal Energy Conversion System With Different Working Fluids

2012 ◽  
Vol 135 (2) ◽  
Author(s):  
Jianying Gong ◽  
Tieyu Gao ◽  
Guojun Li
Keyword(s):  
Energy Conversion ◽  
Thermal Energy ◽  
Sea Water ◽  
Working Fluid ◽  
Closed Cycle ◽  
Working Fluids ◽  
Ocean Thermal Energy Conversion ◽  
Thermal Energy Conversion ◽  
Stable Operating ◽  
Ocean Thermal Energy

Closed cycle ocean thermal energy conversion (CC-OTEC) is a way to generate electricity by the sea water temperature difference from the upper surface to the different depth. This paper presents the performance of a 15 kW micropower CC-OTEC system under different working fluids. The results show that both butane and isobutane are not proper working fluids for the CC-OTEC system because the inlet stable operating turbine pressure is in a very narrow range. R125, R143a, and R32, especially R125, are suggested to be the transitional working fluids for CC-OTEC system for their better comprehensive system performance. Moreover, it is recommended that propane should be a candidate for the working fluid because of its excellent comprehensive properties and environmental friendliness. However, propane has inflammable and explosive characteristics. As for the natural working fluid ammonia, almost all performance properties are not satisfactory except the higher net output per unit sea water mass flow rate. But ammonia has relative broader range of the stable operating turbine inlet pressure, which has benefits for the practical plant operation.

Some New Approaches to ATPase Mechanisms in Energy Conversion

1975 ◽  
pp. 5-18
Author(s):  
Stuart J. Ferguson ◽  
William J. Lloyd ◽  
George K. Radda
Keyword(s):  
Energy Conversion ◽  
New Approaches
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