Performance of Combined PV-Inverter System: Use of Amorphous and Crystalline Panels

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Carlos Armenta-Deu
Keyword(s):  
Theoretical Analysis ◽  
Energy Resource ◽  
Experimental Tests ◽  
Photovoltaic System ◽  
Maximum Deviation ◽  
Photovoltaic Modules ◽  
Pv Inverter ◽  
Pv Panel ◽  
System Use ◽  
Good Agreement

This paper is aimed at analyzing the performance of a combined PV-inverter system connected to an external load using either amorphous or crystalline photovoltaic modules. The analysis is based on previous theoretical analysis that uses the efficiency of the PV panel and of the DC/AC inverter as a key parameter. Different configurations using the same energy resource have been simulated to determine the efficiency of the PV panel, DC/AC inverter, and of the whole system. The theoretical process shows that the global efficiency of the photovoltaic system increased from 87.2% in the case of crystalline panels to 96% for amorphous ones. Experimental tests have been run to validate the theoretical analysis. A very good agreement between theoretical results and experimental data has been found within a standard deviation of σ = 0.633 and a maximum deviation of 1%.

scholarly journals Photovoltaic Cooling Utilizing Phase Change Materials

2020 ◽  
Vol 160 ◽  
pp. 02004
Author(s):  
Suhil Kiwan ◽  
Hisham Ahmad ◽  
Ammar Alkhalidi ◽  
Wahib O Wahib ◽  
Wael Al-Kouz
Keyword(s):  
Phase Change ◽  
Experimental Test ◽  
Phase Change Materials ◽  
Experimental Tests ◽  
Photovoltaic System ◽  
Cell Temperature ◽  
Average Cell ◽  
Solar Systems ◽  
Pv Panel ◽  
Change Material

A theoretical analysis based on mathematical formulations and experimental test to a photovoltaic system cooled by Phase Change Material (PCM) is carried out and documented. The PCM is attached to the back of the PV panel to control the temperature of cells in the PV panel. The experimental tests were done to solar systems with and without using PCM for comparison purposes. A PCM of paraffin graphite panels of thickness15 mm has covered the back of the panel. This layer was covered with an aluminum sheet fixed tightly to the panel frame. In the experimental test, it was found that when the average cell temperature exceeds the melting point temperature of the PCM, the efficiency of the system increases. However, when the cell temperature did not exceed the melting temperature of the PCM, the use of the PCM will affect negatively the system efficiency.

scholarly journals CFD Analysis of Elements of an Adsorption Chiller with Desalination Function

Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7804
Author(s):  
Karol Sztekler ◽  
Tomasz Siwek ◽  
Wojciech Kalawa ◽  
Lukasz Lis ◽  
Lukasz Mika ◽  
...  
Keyword(s):  
Experimental Tests ◽  
Maximum Deviation ◽  
Cfd Analysis ◽  
Adsorption Chiller ◽  
Structural Modifications ◽  
Numerical Tests ◽  
Computational Mesh ◽  
Flow Phenomena ◽  
Real Scale ◽  
Good Agreement

This paper presents the results of numerical tests on the elements of an adsorption chiller that comprises a sorption chamber with a bed, a condenser, and an evaporator. The simulation is based on the data and geometry of a prototype refrigeration appliance. The simulation of this problem is unique and has not yet been performed, and so far, no simulation of the phenomena occurring in the systems on a real scale has been carried out. The presented results are part of the research covering the entire spectrum of designing an adsorption chiller. The full process of numerical modeling of thermal and flow phenomena taking place in the abovementioned components is presented. The computational mesh sensitivity analysis combined in the k-ε turbulence model was performed. To verify and validate the numerical results obtained, they were compared with the results of tests carried out on a laboratory stand at the AGH Center of Energy. The results of numerical calculations are in good agreement with the results of the experimental tests. The maximum deviation between the pressure obtained experimentally and by simulations is 1.8%, while for temperatures this deviation is no more than 0.5%. The results allow the identification of problems and their sources, which allows for future structural modifications to optimize the operation of the device.

PHOTOINDUCED NONLINEAR OCTUPOLAR POLARIZATION: TRANSIENT AND PERMANENT REGIMES

1996 ◽  
Vol 05 (04) ◽  
pp. 653-670 ◽  
Author(s):  
CÉLINE FIORINI ◽  
JEAN-MICHEL NUNZI ◽  
FABRICE CHARRA ◽  
IFOR D.W. SAMUEL ◽  
JOSEPH ZYSS
Keyword(s):  
Theoretical Analysis ◽  
Second Harmonic ◽  
Experimental Results ◽  
Polar Field ◽  
Rotational Spectrum ◽  
Dual Frequency ◽  
One Dimensional ◽  
Ethyl Violet ◽  
Disperse Red 1 ◽  
Good Agreement

An original poling method using purely optical means and based on a dual-frequency interference process is presented. We show that the coherent superposition of two beams at fundamental and second-harmonic frequencies results in a polar field with an irreducible rotational spectrum containing both a vector and an octupolar component. This enables the method to be applied even to molecules without a permanent dipole such as octupolar molecules. After a theoretical analysis of the process, we describe different experiments aiming at light-induced noncentrosymmetry performed respectively on one-dimensional Disperse Red 1 and octupolar Ethyl Violet molecules. Macroscopic octupolar patterning of the induced order is demonstrated in both transient and permanent regimes. Experimental results show good agreement with theory.

scholarly journals Experimental Methods for Measuring the Viscous Friction Coefficient in Hydraulic Spool Valves

2021 ◽  
Vol 13 (13) ◽  
pp. 7174
Author(s):  
Massimo Rundo ◽  
Paolo Casoli ◽  
Antonio Lettini
Keyword(s):  
Friction Coefficient ◽  
Viscous Friction ◽  
Experimental Tests ◽  
Experimental Methods ◽  
Displacement Transducer ◽  
A Posteriori ◽  
Displacement Control ◽  
Spool Valves ◽  
The University ◽  
Good Agreement

In hydraulic components, nonlinearities are responsible for critical behaviors that make it difficult to realize a reliable mathematical model for numerical simulation. With particular reference to hydraulic spool valves, the viscous friction coefficient between the sliding and the fixed body is an unknown parameter that is normally set a posteriori in order to obtain a good agreement with the experimental data. In this paper, two different methodologies to characterize experimentally the viscous friction coefficient in a hydraulic component with spool are presented. The two approaches are significantly different and are both based on experimental tests; they were developed in two distinct laboratories in different periods of time and applied to the same flow compensator of a pump displacement control. One of the procedures was carried out at the Fluid Power Research Laboratory of the Politecnico di Torino, while the other approach was developed at the University of Parma. Both the proposed methods reached similar outcomes; moreover, neither method requires the installation of a spool displacement transducer that can significantly affect the results.

scholarly journals Different Techniques to Mitigate Partial Shading in Photovoltaic Panels

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3863
Author(s):  
Tiago Alves ◽  
João Paulo N. Torres ◽  
Ricardo A. Marques Lameirinhas ◽  
Carlos A. F. Fernandes
Keyword(s):  
Cell Model ◽  
Research Work ◽  
Experimental Tests ◽  
Operating Conditions ◽  
Pv System ◽  
Partial Shading ◽  
System Architectures ◽  
Pv Systems ◽  
Advantages And Disadvantages ◽  
Pv Panel

The effect of partial shading in photovoltaic (PV) panels is one of the biggest problems regarding power losses in PV systems. When the irradiance pattern throughout a PV panel is inequal, some cells with the possibility of higher power production will produce less and start to deteriorate. The objective of this research work is to present, test and discuss different techniques to help mitigate partial shading in PV panels, observing and commenting the advantages and disadvantages for different PV technologies under different operating conditions. The motivation is to contribute with research, simulation, and experimental work. Several state-of-the-artsolutions to the problem will be presented: different topologies in the interconnection of the panels; different PV system architectures, and also introducing new solution hypotheses, such as different cell interconnections topologies. Alongside, benefits and limitations will be discussed. To obtain actual results, the simulation work was conducted by creating MATLAB/Simulink models for each different technique tested, all centered around the 1M5P PV cell model. The several techniques tested will also take into account different patterns and sizes of partial shading, different PV panel technologies, different values of source irradiation, and different PV array sizes. The results will be discussed and validated by experimental tests.

Fluid Added Mass Effect in the Modal Response of a Pump-Turbine Impeller

2009 ◽  
Author(s):  
Eduard Egusquiza ◽  
Carme Valero ◽  
Quanwei Liang ◽  
Miguel Coussirat ◽  
Ulrich Seidel
Keyword(s):  
Natural Frequencies ◽  
Experimental Tests ◽  
Mass Effect ◽  
Added Mass ◽  
Mode Shapes ◽  
Pump Turbine ◽  
Modal Response ◽  
Surrounding Fluid ◽  
Turbine Impeller ◽  
Good Agreement

In this paper, the reduction in the natural frequencies of a pump-turbine impeller prototype when submerged in water has been investigated. The impeller, with a diameter of 2.870m belongs to a pump-turbine unit with a power of around 100MW. To analyze the influence of the added mass, both experimental tests and numerical simulations have been carried out. The experiment has been performed in air and in water. From the frequency response functions the modal characteristics such as natural frequencies and mode shapes have been obtained. A numerical simulation using FEM (Finite Elements Model) was done using the same boundary conditions as in the experiment (impeller in air and surrounded by a mass of water). The modal behaviour has also been calculated. The numerical results were compared with the available experimental results. The comparison shows a good agreement in the natural frequency values both in air and in water. The reduction in frequency due to the added mass effect of surrounding fluid has been calculated. The physics of this phenomenon due to the fluid structure interaction has been investigated from the analysis of the mode-shapes.

A Fuzzy Logic Controlled Single Axis Solar Tracking System

2015 ◽  
Vol 787 ◽  
pp. 893-898
Author(s):  
Suneetha Racharla ◽  
K. Rajan ◽  
K.R. Senthil Kumar
Keyword(s):  
Fuzzy Controller ◽  
Tracking System ◽  
Renewable Energy Sources ◽  
Energy Resource ◽  
Clean Energy ◽  
Energy Sources ◽  
Pv Panel ◽  
Solar Tracking ◽  
Simulation Results ◽  
Improved Performance

Recently renewable energy sources have gained much attention as a clean energy. But the main problem occurs with the varying nature with the day and season. Aim of this paper is to conserve the energy, of the natural resources. For solar energy resource, the output induced in the photovoltaic (PV) modules depends on solar radiation and temperature of the solar cells. To maximize the efficiency of the system it is necessary to track the path of sun in order to keep the panel perpendicular to the sun. This paper proposes the design and construction of a microcontroller-based solar panel tracking system. The fuzzy controller aims at maximizing the efficiency of PV panel by focusing the sunlight to incident perpendicularly to the panel. The system consists of a PV panel which can be operated with the help of DC motor, four LED sensors placed in different positions and a fuzzy controller which takes the input from sensors and gives output speed to motor. A prototype is fabricated to test the results and compared with the simulation results. The results show the improved performance by using a tracking system

scholarly journals Waste heat recovery from Refrigeration machine

2019 ◽  
Vol 9 (2) ◽  
pp. 185-190
Keyword(s):  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Sea Water ◽  
Waste Heat ◽  
Experimental Tests ◽  
Air Conditioner ◽  
Heat Exchanges ◽  
Refrigeration Machine ◽  
New System ◽  
Good Agreement

With the aim of saving energy and to reduce global warming effect, our work focuses on the valorization of the waste heat evacuated by the condenser of a refrigeration machine (air-conditioner) for the desalination of sea water. In this paper, the conception of a new system combining airconditioning and desalination is realized. The modelling of the heat exchanges of each part of the system is realized. To improve the performance of the system, various experimental tests are represented and discussed. Comparison between simulation and experimental results shows a good agreement and present a courageous motive for the system application.

Vibration Analysis for Piezoceramic Circular Plates with V-Notches. Part 1: Theory

2014 ◽  
Vol 30 (6) ◽  
pp. 603-609 ◽  
Author(s):  
C.-H. Huang ◽  
Y.-Y. Chen
Keyword(s):  
Theoretical Analysis ◽  
Transverse Vibration ◽  
Stress Singularity ◽  
Trigonometric Polynomials ◽  
Circular Plates ◽  
The Finite Element Method ◽  
Electrical Field ◽  
Ritz’S Method ◽  
Frequency Variations ◽  
Good Agreement

AbstractIn this paper the transverse vibration characteristics of piezoceramic circular plates with V-notches are investigated theoretically through use of the Ritz's method incorporated with the defined equivalent constants. The Ritz's method is employed with two sets of admissible displacement functions, algebraic-trigonometric polynomials and corner functions, to guarantee convergence sufficiently and represent the stress singularity, respectively. Moreover, the equivalent constants derived by comparing the characteristic equations of transverse vibration between isotropic and piezoceramic disks are applied to suspend the electrical field consideration regarding the piezoelectricity. With the aid of theoretical analysis, the non-dimensional frequency parameters of transverse vibration modes for completely free V-notching circular plates are exhibited; in addition, the frequency variations depending on various notch angles and depths are explored. Numerical calculations using the finite element method (FEM) are performed and the results are compared with the theoretical analysis. It is shown that the resonant frequencies predicted by theoretical analysis and calculated by FEM are in good agreement.

Vibrations of an Intermediately Supported U-Bend Tube

1975 ◽  
Vol 97 (1) ◽  
pp. 23-32 ◽  
Author(s):  
L. S. S. Lee
Keyword(s):  
Natural Frequency ◽  
Natural Frequencies ◽  
Experimental Tests ◽  
Bending Stiffness ◽  
Stiffness Ratio ◽  
Plane Vibration ◽  
Straight Beam ◽  
Out Of Plane ◽  
Straight Segments ◽  
Good Agreement

Vibrations of an intermediately supported U-bend tube fall into two independent classes as an incomplete ring of single span does, namely, the in-plane vibration and the coupled twist-bending out-of-plane vibration. Natural frequencies may be expressed in terms of a coefficient p which depends on the stiffness ratio k, the ratio of lengths of spans, and the supporting conditions. The effect of the torsional flexibility of a curved bar acts to release the bending stiffness of a straight beam and hence decrease the natural frequency. Some conclusions for an incomplete ring of single span may not be equally well applicable to the U-tube case due to the effects of intermediate supports and the presence of the supporting straight segments. Results of the analytical predictions and the experimental tests of an intermediately supported U-tube are in good agreement.

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