A Compressible Transient Model of the Solar Chimney and Heat Collector

2013 ◽  
Vol 283 ◽  
pp. 15-21 ◽  
Author(s):  
Gang Li ◽  
Hui Lan Huang ◽  
Hua Zhang ◽  
Jian Bin Liu ◽  
Xiang Chen
Keyword(s):  
Fluid Pressure ◽  
State Equation ◽  
Ideal Gas ◽  
Solar Chimney ◽  
Transient Model ◽  
Heat Collector ◽  
Solar Chimney Power Plant ◽  
Improved Model ◽  
The Given ◽  
Good Agreement

The compressible transient model of solar chimney power plant system was proposed. It was added to the pressure equation and the ideal gas state equation basis on the heat balance equation for the solar collector model. The air flow station can be easily calculated with the improved model. The results of dynamic changes of the total pressure difference calculated in the model were in good agreement with the given actual measured values in references. The solar chimney model was considered the influence of fluid pressure on the density. The influence of the structural chimney on the chimney efficiency was analyzed with the established model. It was shown that the chimney efficiency changes significantly with the chimney height and its diameter. The chimney efficiency was decreased with a convergent chimney shape while increased with the divergent one. When the tilt angle of chimney reached a peak and then further increased, the chimney efficiency was the constant. These results will provide the important reference to improving the system efficiency.

Raman Gas Analyzer (RGA): Natural Gas Measurements

2016 ◽  
Vol 70 (10) ◽  
pp. 1770-1776 ◽  
Author(s):  
Dmitry V. Petrov ◽  
Ivan I. Matrosov
Keyword(s):  
Natural Gas ◽  
Chromatographic Analysis ◽  
Operating Principle ◽  
Gas Analyzer ◽  
Time Stability ◽  
Gas Measurements ◽  
Improved Model ◽  
The Given ◽  
Good Agreement

In the present work, an improved model of the Raman gas analyzer (RGA) of natural gas (NG) developed by us is described together with its operating principle. The sensitivity has been improved and the number of measurable gases has been expanded. Results of its approbation on a real NG sample are presented for different measurement times. A comparison of the data obtained with the results of chromatographic analysis demonstrates their good agreement. The time stability of the results obtained using this model is analyzed. It is experimentally established that the given RGA can reliably determine the content of all molecular NG components whose content exceeds 0.005% for 100 s; moreover, in this case the limiting sensitivity for some NG components is equal to 0.002%.

Numerical Study on Enhanced Paraffin/Air Heat Transfer with Extended Surface

2012 ◽  
Vol 501 ◽  
pp. 376-381
Author(s):  
Yan Zhou ◽  
Wen Juan Zheng ◽  
Xi Yan Fan ◽  
Jun Chao ◽  
Qing Ling Li
Keyword(s):  
Heat Transfer ◽  
Heat Storage ◽  
Numerical Study ◽  
Solar Chimney ◽  
Release Capacity ◽  
Vertical Heat ◽  
Heat Collector ◽  
Extended Surface ◽  
Solar Chimney Power Plant ◽  
Air Flow Velocity

The extended surface is used to enhance paraffin/air heat transfer because of the paraffin’s poor thermal conductivity, and the heat storing and releasing capacity of paraffin heat storage layer with variety of extended surface are compared by numerical simulation. The results show that: the heat storage layer with vertical rectangular fin extended surface has stronger ability on the heat storage and release, and can more effectively improve the air flow velocity in the solar chimney power plant system with vertical heat collector. Due to the restrictions of manufacturing, the heat storage and release capacity is stronger when the heat storage layer surface area with vertical rectangular fin is from 3.4 times to 5.8 times compare to the flat-plate heat storage layer.

Analytical Thermal Analysis of Solar Chimney Power Plant

2010 ◽  
Author(s):  
Mohammad O. Hamdan
Keyword(s):  
Power Plant ◽  
Analytical Model ◽  
Numerical Data ◽  
Ideal Gas ◽  
Second Law ◽  
Solar Chimney ◽  
Solar Plant ◽  
Solar Chimney Power Plant ◽  
Plant Power ◽  
Monotonic Relation

An analytical model and a thermodynamics study of the steady airflow inside a solar chimney are performed in this paper. A simplified Bernoulli equation combined with fluid dynamics and ideal gas equation are modeled and solved using EES solver to predict the performance of a solar chimney power plant. The analytical model is validated against an experimental and numerical data available in the literature. The developed analytical model is used to evaluate the effect of geometric parameters on the solar plant power generation. The analysis is showing that the height and diameter of the tower are the most important physical variables for the solar chimney design. The collector area has minimal effect on second-law efficiency but strong effect on harvested energy. The second law efficiency has non-monotonic relation with the turbine head.

Unsteady Conjugate Numerical Simulation of the Solar Chimney Power Plant System with Vertical Heat Collector

2011 ◽  
Vol 704-705 ◽  
pp. 535-540 ◽  
Author(s):  
Yan Zhou ◽  
Xiao Hui Liu ◽  
Qing Ling Li
Keyword(s):  
Numerical Simulation ◽  
Power Plant ◽  
Solar Radiation ◽  
Output Power ◽  
Maximum Output Power ◽  
Maximum Output ◽  
Solar Chimney ◽  
Air Velocity ◽  
Heat Collector ◽  
Solar Chimney Power Plant

A new kind of solar chimney power plant system combining chimney and heat collector was designed. Paraffin was chosen as the material of energy storage layer and the unsteady conjugate numerical simulation of the system was done by Fluent software. The operation condition of the system was simulated when the solar radiation value was changed with time according to the actual situation. Simulation results showed that: with the increase of solar radiation, flow velocity of the air and the maximum output power increased. At twelve o'clock, the air velocity could reach 1.24 m/s and output power was 122W. Due to the energy storage effect of phase change materials, the system had output power of 1.3W at night. Moreover because of the continuous work of the heat storage layer, in the same condition of solar radiation, the air velocity and maximum output power increased with the system operation days extended.

Performance analysis of a solar chimney power plant system in two Algeria regions

2021 ◽  
pp. 1-26
Author(s):  
Sellami Ali ◽  
Benlahcene Djaouida ◽  
Abdelmoumène Hakim Benmachiche ◽  
Zeroual Aouachria
Keyword(s):  
Power Plant ◽  
Performance Analysis ◽  
Solar Chimney ◽  
Plant System ◽  
Solar Chimney Power Plant

scholarly journals Quantitative Shape-Classification of Misfitting Precipitates during Cubic to Tetragonal Transformations: Phase-Field Simulations and Experiments

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1373
Author(s):  
Yueh-Yu Lin ◽  
Felix Schleifer ◽  
Markus Holzinger ◽  
Na Ta ◽  
Birgit Skrotzki ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
Phase Field ◽  
Phase Field Model ◽  
Invariant Moments ◽  
Plane Normal ◽  
Plane Shape ◽  
Formation And Evolution ◽  
The Given ◽  
Good Agreement

The effectiveness of the mechanism of precipitation strengthening in metallic alloys depends on the shapes of the precipitates. Two different material systems are considered: tetragonal γ′′ precipitates in Ni-based alloys and tetragonal θ′ precipitates in Al-Cu-alloys. The shape formation and evolution of the tetragonally misfitting precipitates was investigated by means of experiments and phase-field simulations. We employed the method of invariant moments for the consistent shape quantification of precipitates obtained from the simulation as well as those obtained from the experiment. Two well-defined shape-quantities are proposed: (i) a generalized measure for the particles aspect ratio and (ii) the normalized λ2, as a measure for shape deviations from an ideal ellipse of the given aspect ratio. Considering the size dependence of the aspect ratio of γ′′ precipitates, we find good agreement between the simulation results and the experiment. Further, the precipitates’ in-plane shape is defined as the central 2D cut through the 3D particle in a plane normal to the tetragonal c-axes of the precipitate. The experimentally observed in-plane shapes of γ′′-precipitates can be quantitatively reproduced by the phase-field model.

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