Solar thermal heat engines for water pumping: An update
ABSTRACT Solar thermal-driven heat engines for water pumping have been previously reviewed for some authors in the past century. However, some devices have not been treated as metal hydride-based systems or the pumping subsystems of solar thermal-driven reverse osmosis desalination systems. Following the typical classification given in the previous literature, in this work an update of the solar heat engines for water pumping based in thermodynamic methods (conventional and unconventional) is presented. Besides small remarks about systems previously quoted by other authors, new designs found in the literature are described. In general, the main characteristics of these systems is their low efficiency, low power output and, in the case of unconventional designs, its simplicity. This work in conjunction with previous review papers make up reference point for the knowledge of the use of solar thermal energy for liquid pumping purpose.
Conference Paper: A sensitive cell neuron model based on chaos[Show abstract] [Hide abstract]
ABSTRACT: The research in the high sensitivity of the biological sensorium has been the blank in the work of NN (neural network). According to the analyzing results of chaotic theory, the chaotic system has an extremely high sensitivity and resolving power. Based on the application of chaotic theory to measuring, this paper proposes a concept of the sensitive chaotic cell neuron (SCCN) and a mathematical model for SCCN. Like the biological sensorium, the SCCN can get a high sensitivity and resolving power to feeble signals. The simulation results show the high sensitivity of SCCN to the feeble signalsSignal Processing Proceedings, 2000. WCCC-ICSP 2000. 5th International Conference on; 02/2000
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ABSTRACT: The aim of this paper is to identify and evaluate potential areas of technical improvement to solar-powered desalination systems that use reverse osmosis (RO). We compare ideal with real specific energy consumption (SEC) to pinpoint the causes of inefficiency. The ideal SEC is compared among different configurations including a batch system driven by a piston, and continuous systems with single or multiple stages with or without energy recovery in each case. For example, to desalinate 1 m of freshwater from normal seawater (osmotic pressure 27 bar) will require at least 0.94 kWh of solar energy; thus in a sunny coastal location, up to 1850 m of water per year per m (m/m) of land covered by solar collectors could theoretically be desalinated. For brackish water (osmotic pressure 3 bar), 11570 m/m of fresh water could theoretically be obtained under the same conditions. These ideal values are compared with practically achieved values reported in the literature. The practical energy consumption is found to be typically 40−200 times higher depending on feed water composition, system configuration and energy recovery. For state-of-the-art systems, energy losses at the various steps in the conversion process are quantified and presented with the help of Sankey diagrams. Improvements that could reduce the losses are discussed. Consequently, recommendations for areas of R&D are highlighted with particular reference to emerging technologies. It is concluded that there is considerable scope to improve the efficiency of solar-powered RO system.Desalination and Water Treatment - DESALIN WATER TREAT. 01/2011; 35:14-32.
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ABSTRACT: The research developments with renewable energy source water pumping systems (RESWPSs) are reviewed in this paper. The reported investigations are categorized into five major groups as follows: (i) solar photovoltaic water pumping systems (SPWPSs), (ii) solar thermal water pumping systems (STWPSs), (iii) wind energy water pumping systems (WEWPSs), (iv) biomass water pumping systems (BWPSs) and (v) hybrid renewable energy water pumping systems (HREWPSs). More than a hundred published articles related to RESWPSs are briefly reviewed. Additionally, the limitations with RESWPSs and further research needs are described. This paper concludes that renewable energy sources (RESs) play a vital role in reducing the consumption of conventional energy sources and its environmental impacts for water pumping applications.Renewable and Sustainable Energy Reviews 25:351–370. · 5.63 Impact Factor