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[en] Highlights: • Case study for 316 climate station conditions was carried out. • Strong linear dependence on total yearly DNI was found. • Simplified model shows accurate results in 12 latitudes worldwide. - Abstract: This paper proposes a simple method for estimating annual thermal performance of parabolic trough collectors (PTCs) based on a linear relation with annual DNI for a certain latitude. A case study with simulations for a novel concentrating solar collector in 316 locations for three operating temperature scenarios worldwide was carried out and showed promising results for the latitudes and continents investigated. For a certain latitude and mean operating temperature, the annual yield of a PTC was found to be linearly proportional to yearly DNI. The proposed method will serve as a simplified alternative to the steady-state and quasi-dynamic methods already used. Estimating performance based on yearly DNI can be used by design engineers to do quick preliminary planning of solar plants. Customers can also use this method to evaluate existing solar collector installations. A TRNSYS/TRNSED tool that uses a steady-state model has been developed to carry out the simulations and it has been validated against a PTC array at Technical University of Denmark (DTU). The results show that the simplified method can give reliable estimates of long-term performance of parabolic trough collectors.
[en] Technology roadmapping is a needs-driven technology planning process to help identify, select, and develop technology alternatives to satisfy a set of market needs. The DOE's Office of Power Technologies' Concentrating Solar Power (CSP) Program recently sponsored a technology roadmapping workshop for parabolic trough technology. The workshop was attended by an impressive cross section of industry and research experts. The goals of the workshop were to evaluate the market potential for trough power projects, develop a better understanding of the current state of the technology, and to develop a conceptual plan for advancing the state of parabolic trough technology. This report documents and extends the roadmap that was conceptually developed during the workshop
[en] Parabolic solar energy cooker was designed using locally available materials such as pieces of iron and plane mirrors. The diameter of the dish was 12 x 10-3 mm and pieces of glass mirrors were adhered to its concave surface using abro silicon gum as solar energy reflectors. The solar cooker was used to cook different food materials such as rice, bean, yam and stew between 11am and 3pm. The time taken to cook the food materials were measured and compared to the time it takes to cook similar food samples of the same quantity using kerosene and electric stove. It took the kerosene and electric stoves two hours, forty minutes (2.40) and two hours, ten minutes (2.10) respectively to cook beans with all the ingredients while the fabricated solar cooker took only one hour fifteen minutes. Due to high solar energy absorption capacity of the solar cooker and insolation rate, the study has reveled that it is faster, safer and takes less time to cook using cooker than either kerosene or electric stove.
[en] This paper focuses on optimising the use of additional oxidants in the photo catalytic degradation of a complex mixture of ten commercial pesticides. The CPC solar pilot plant used for the tests has 8.9 m2 of collector surface and a total volume of 247 L. Same TOC quantities of each pesticide were added to achieve the desired initial TOC concentration in all the experiments (from 5 to 100 mg of TOC per litre). Experiments were performed with H2O2 and S2OS8-2, but only peroxydisulphate was chosen for optimisation, because better results have been obtained with it. In addition to the consumption of the oxidant under different experimental conditions, the effect of peroxydisulphate and TOC concentrations was also evaluated. The mechanism of peroxydisulphate action is discussed with these results. The effect of reusing water and catalysts has also been studied. The results obtained from these experiments have been used to decide the dimensions and operating conditions of a solar photo catalytic plant, the final objective of which is the treatment of rin sates produced by washing pesticide containers. (Author) 37 refs
[en] We calculated the magnetic field dependency of hydrogenic donor binding energy in cylindrical quantum wires for both lateral parabolic potential and lateral inverse parabolic potential. We have worked in the effective mass approximation and variational calculation scheme. We have found that, for both confinements there is an abrupt change in binding energy with the magnetic field strength. The results are compared with each other and the square confinement
[en] This paper presents the theoretical analysis results of the relations between the geometric parameters of the reflector of a parabolic trough collector (PTC) system and the focal shape formed by the defocusing phenomenon of the non-parallel solar beam firstly. Then the effects of these designed parameters and the defocusing phenomenon on the comprehensive characteristics and performance of the whole process of the photo-thermal conversion in the PTC system were numerically studied and optimized, using a proposed three-dimensional integrated model combined the Finite Volume Method (FVM) with the Monte Carlo Ray-Trace (MCRT) method. It is revealed that the numerical results can be well explained by the theoretical analysis results, proving that the model and method used in the present study is feasible and reliable. It is also found that the comprehensive characteristics and performance are very different from some critical points determined by the defocusing phenomenon of the non-parallel solar beam. From these critical points, the optional ranges of the geometric parameters of the reflector are determined to collect the entire reflected beam from the reflector, with relative optimized performance. In addition, an improved description for the characteristics of the solar flux density distributions on the absorber tube is further presented. -- Highlights: • It is to present an analytical method or reference for designing more effective PTC. • Relations between the focal shape and the geometric parameters were analyzed. • Effects of the geometric parameters were studied by the FVM combined with the MCRT. • The comprehensive performance is mainly determined by the defocusing phenomenon. • Optional ranges of geometric parameters with optimized performance can be determined