scholarly journals Procedure for the quantification of the degradation index of Photovoltaic Generators

2021 ◽  
Vol 2 (2) ◽  
pp. 47-53
Author(s):  
Proenza Y. Roger ◽  
Camejo C. José Emilio ◽  
Ramos H. Rubén
Keyword(s):  
Mathematical Model ◽  
Power Generation ◽  
Solar Energy ◽  
Operating Conditions ◽  
Energy Research ◽  
Degradation Index ◽  
Starting Point ◽  
Santiago De Cuba ◽  
Photovoltaic Generators ◽  
The Mathematical Model

A procedure is presented for the quantification of the degradation index of Photovoltaic Generators, based on the quantification of the operational losses inherent in the system, which allows maintaining the nominal operating conditions and by the warranty terms of the photovoltaic generator. A photovoltaic generator connected to the network with a nominal power of 7.5 kWp, installed in the Solar Energy Research Center of Santiago de Cuba, is used to evaluate and validate the procedure. The starting point is the mathematical model of the photovoltaic generator, then the operational losses of the photovoltaic generator are quantified and the mathematical model is adjusted to real conditions, through a polynomial adjustment.  The results obtained show that the photovoltaic generator presents deviations in terms of the nominal power generation, because the operational losses are 7% with respect to the values ​​given by the manufacturer.

scholarly journals Fault Diagnostic Methodology for Grid-Connected Photovoltaic Systems

2021 ◽  
Vol 2 (2) ◽  
pp. 10-30
Author(s):  
Proenza Y. Roger ◽  
Camejo C. José Emilio ◽  
Ramos H. Rubén
Keyword(s):  
Mathematical Model ◽  
Fault Diagnosis ◽  
Solar Energy ◽  
False Alarm ◽  
False Alarm Rate ◽  
Real System ◽  
Photovoltaic Systems ◽  
Energy Research ◽  
Santiago De Cuba ◽  
The Mathematical Model

This research focuses on the design of a fault diagnosis methodology to contribute to the improvement of efficiency, maintainability and availability indicators of Grid-Connected Photovoltaic Systems. To achieve this, we start from the study of the mathematical model of the photovoltaic generator, then, a procedure is performed to quantify the operational losses of the photovoltaic generator and adjust the mathematical model of this to the real conditions of the system, through a polynomial adjustment. A real system of nominal power 7.5 kWp installed in the Solar Energy Research Center of the province of Santiago de Cuba is used to evaluate the proposed methodology. Based on the results obtained, the proposed approach is validated to demonstrate that it successfully supervises the system. The methodology was able to detect and identify 100% of the simulated failures and the tests carried out had a maximum false alarm rate of 0.22%, evidencing its capacity.

scholarly journals Performance Evaluation of a Gravity-Assisted Heat Pipe-Based Indirect Evaporative Cooler

Energies ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 200 ◽  
Author(s):  
Krzysztof Rajski ◽  
Jan Danielewicz ◽  
Ewa Brychcy
Keyword(s):  
Mathematical Model ◽  
Heat Pipe ◽  
Cooling Capacity ◽  
Operating Conditions ◽  
Coefficient Of Performance ◽  
Mass Transfer Processes ◽  
Air Cooler ◽  
Evaporative Cooler ◽  
The Mathematical Model ◽  
Further Development

In the present work, the effects of different operating parameters on the performance of a gravity-assisted heat pipe-based indirect evaporative cooler (GAHP-based IEC) were investigated. The aim of the theoretical study is to evaluate accurately the cooling performance indicators, such as the coefficient of performance (COP), wet bulb effectiveness, and cooling capacity. To predict the effectiveness of the air cooler under a variety of conditions, the comprehensive calculation method was adopted. A mathematical model was developed to simulate numerically the heat and mass transfer processes. The mathematical model was validated adequately using experimental data from the literature. Based on the conducted numerical simulations, the most favorable ranges of operating conditions for the GAHP-based IEC were established. Moreover, the conducted studies could contribute to the further development of novel evaporative cooling systems employing gravity-assisted heat pipes as efficient equipment for transferring heat.

The Study on Heating Running Schemes of Solar Energy Combined with Municipal Heating

2013 ◽  
Vol 790 ◽  
pp. 160-164
Author(s):  
Yong An Ao ◽  
Gang Li ◽  
Wei Xin Kong ◽  
Qi Feng
Keyword(s):  
Mathematical Model ◽  
Solar Energy ◽  
Water Temperature ◽  
Solar Collector ◽  
Heat Load ◽  
Environmental Benefits ◽  
Combination System ◽  
Save Energy ◽  
The Mathematical Model ◽  
Heat Amount

The research, based on combination system of solar energy and municipal heating network, studied the running scheme of combination system of solar energy and municipal heating network through ways of experiments and theoretical calculation of the mathematical model. Firstly, the research established mathematical model of heat equilibrium of the combination system of solar energy and municipal heating network; secondly, keeping the indoor heat load steady, compared the dynamic heat load provided by solar collector with that needed by heated room at the same time,determined time spans of the network stopping service and the heat load added by the network within 24 h. In the research we took a heating period in a typical room in Shenyang for example, under the conditions of low temperature floor radiant with heating index standard of 50W/ m2 and 50°C of the average supplied water temperature, 40 °C of the return water temperature, calculated and verified the established mathematical model. The results include: when the heat load provided by solar collector is greater or less than the heat needed by the room, how many heat amount should be supplied by the running network and the amount of water flow within the network pipes correspondingly, and how long the network runs or stops. The final conclusions include: whether the running scheme of the combination system can save energy? the conditions of energy saving in running a combination system, and whether the system can bring environmental benefits.

Research on the Convergence Condition of Iterative Solution for the Mathematical Model of Reservoir Power Generation Optimization

2020 ◽  
Author(s):  
Anqi Tan ◽  
Senlin Chen
Keyword(s):  
Mathematical Model ◽  
Power Generation ◽  
Iterative Process ◽  
Iterative Solution ◽  
Scheduling Optimization ◽  
Convergence Conditions ◽  
Generation Scheduling ◽  
Solution Convergence ◽  
Calculation Results ◽  
The Mathematical Model

<p>Discrete differential dynamic programming algorithm is widely used in reservoir power generation dispatching, but the problem of "dimensional disaster" still exists, and there are different degrees of limitations such as premature convergence and uncertainty of convergence. In the existing monographs and literature, there is little research on the algorithm itself. The iterative solution convergence conditions, initial parameters, and initial trajectory selection of the mathematical model for reservoir power generation scheduling optimization have important effects on the iterative process and results. The convergence conditions directly determine when the iterative process converges and its calculation results. In this paper, the solution convergence conditions are studied. Based on the calculation results of the mathematical model of reservoir power generation scheduling optimization, the method of iteratively solving the convergence conditions when different state quantities are used as control factors is systematically studied. Shuibuya Hydropower Station Scheduling results show that using this method to determine the termination step size can shorten the calculation time and obtain an optimization result close to the ideal value, avoid the randomness of the convergence process of the iterative solution, and improve the accuracy of the DDDP algorithm and the efficiency of the target value.</p>

Study on Control Characteristics of Driving and Lifting System for Logistics and Loading Machinery

2012 ◽  
Vol 268-270 ◽  
pp. 1517-1522 ◽  
Author(s):  
Guo Jin Chen ◽  
Ting Ting Liu ◽  
Ni Jin ◽  
You Ping Gong ◽  
Huo Qing Feng
Keyword(s):  
Mathematical Model ◽  
Dynamic Characteristics ◽  
Optimization Design ◽  
Integrated System ◽  
Operating Conditions ◽  
Control Methods ◽  
Lifting System ◽  
The Mathematical Model ◽  
Power Match

The logistics and loading machinery is the typical hydromechatronics integrated system. How to solve the reasonable power match in the driving and lifting process of the logistics and loading machinery, we need to establish the mathematical model of the driving and lifting system, and analyze their control characteristics. Aiming at the load requirements for different operating conditions, this paper studies respectively the dynamic characteristics of the driving and lifting system. Through simulation and computation, the control methods and strategies based on the best performance are proposed. That lays the foundation for the optimization design of the logistics and loading machinery.

scholarly journals Analysis of the Problem of Staff Allocation to Work Stations

2019 ◽  
Vol 1 (1) ◽  
pp. 545-550
Author(s):  
Marek Krynke ◽  
Krzysztof Mielczarek ◽  
Alan Vaško
Keyword(s):  
Mathematical Model ◽  
Production Line ◽  
Production Capacity ◽  
Organization Of Work ◽  
Machine Operation ◽  
Staff Allocation ◽  
Starting Point ◽  
Personnel Allocation ◽  
The Mathematical Model

Abstract The proper organization of work is to set the workflow to the slightest effort of man and machine operation to obtain maximum results. The article presents the problem of the allocation of personnel that occurs in a real company. The mathematical model for this issue was formulated. An algorithm solving the problem of personnel allocation is presented. The proposed analysis is a starting point for determining the production capacity and load of each workstation, which is particularly important when using multi-station work and balancing the production line.

scholarly journals The Mathematical Model and Numerical Study of Heat and Mass Transfer Processes in the Combustion Chamber of Diesel-Generator Units with a Valve-Inductor Generator

2020 ◽  
pp. 611-625
Author(s):  
Dmitriy V. Guzei ◽  
Andrey V. Minakov ◽  
Vasiliy I. Panteleev ◽  
Maksim I. Pryazhnikov ◽  
Dmitriy V. Platonov ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Mass Transfer ◽  
Combustion Chamber ◽  
Heat And Mass Transfer ◽  
Operating Conditions ◽  
Diesel Generator ◽  
Transfer Processes ◽  
Mass Transfer Processes ◽  
Actual Geometry ◽  
The Mathematical Model

The mathematical model of heat and mass transfer processes in the combustion chamber of diesel generator units with valve inductor generators has been developed. The mathematical model takes into account the actual geometry of the combustion chamber and the operating conditions of the diesel engine. A study of the main characteristics of a diesel generator in a wide range of modes of operation has been carried out. In addition to energy characteristics, environmental parameters have been considered

Mathematical Model of Oceanographic Buoy Solar Energy Power Source Design Based on Double Batteries

2013 ◽  
Vol 740 ◽  
pp. 782-786
Author(s):  
Guo Liang Zou ◽  
Xin Nan Lou
Keyword(s):  
Mathematical Model ◽  
Solar Energy ◽  
Power Supply System ◽  
Supply And Demand ◽  
Power Source ◽  
Supply System ◽  
Rainy Weather ◽  
The Mathematical Model ◽  
Engineering Projects ◽  
Rainy Days

To implement the objective of steady operation of the marine observation buoy system on the sea throughout the year,based on energy balance between supply and demand, this paper presents the mathematical model of solar energy power supply system derived from double batteries switching technology. The batteries are divided into main batteries and auxiliary batteries. The main batteries are used regularly and the auxiliary batteries are used in periodic rainy weather. The main advantage of this model is that the capacity of auxiliary batteries can be dynamic calculated based on the numbers of maximum continuous rainy days and minimum intervals between rainy days. The batteries capacity is sufficient but not redundant. This design project has been tested on marine buoy and the accuracy of the model is splendid for most engineering projects.

A New Reactor Concept for Efficient Solar-Thermochemical Fuel Production

2013 ◽  
Vol 135 (3) ◽  
Author(s):  
Ivan Ermanoski ◽  
Nathan P. Siegel ◽  
Ellen B. Stechel
Keyword(s):  
Solar Energy ◽  
High Efficiency ◽  
Packed Bed ◽  
Operating Conditions ◽  
Packed Bed Reactor ◽  
Reactive Material ◽  
Starting Point ◽  
Wide Range ◽  
Solar Thermochemical ◽  
The U.S

We describe and analyze the efficiency of a new solar-thermochemical reactor concept, which employs a moving packed bed of reactive particles produce of H2 or CO from solar energy and H2O or CO2. The packed bed reactor incorporates several features essential to achieving high efficiency: spatial separation of pressures, temperature, and reaction products in the reactor; solid–solid sensible heat recovery between reaction steps; continuous on-sun operation; and direct solar illumination of the working material. Our efficiency analysis includes material thermodynamics and a detailed accounting of energy losses, and demonstrates that vacuum pumping, made possible by the innovative pressure separation approach in our reactor, has a decisive efficiency advantage over inert gas sweeping. We show that in a fully developed system, using CeO2 as a reactive material, the conversion efficiency of solar energy into H2 and CO at the design point can exceed 30%. The reactor operational flexibility makes it suitable for a wide range of operating conditions, allowing for high efficiency on an annual average basis. The mixture of H2 and CO, known as synthesis gas, is not only usable as a fuel but is also a universal starting point for the production of synthetic fuels compatible with the existing energy infrastructure. This would make it possible to replace petroleum derivatives used in transportation in the U.S., by using less than 0.7% of the U.S. land area, a roughly two orders of magnitude improvement over mature biofuel approaches. In addition, the packed bed reactor design is flexible and can be adapted to new, better performing reactive materials.

Improving the Performance of a Two Way Flow Control Valve, Using a 3D CFD Modeling

2014 ◽  
Author(s):  
Emma Frosina ◽  
Adolfo Senatore ◽  
Dario Buono ◽  
Michele Pavanetto ◽  
Micaela Olivetti ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Flow Control ◽  
Fluid Dynamic ◽  
Control Valve ◽  
Operating Conditions ◽  
Cfd Modeling ◽  
Flow Control Valve ◽  
Development Costs ◽  
Definition Of ◽  
The Mathematical Model

The paper introduces a methodology aimed to optimize the performance of hydraulic components; in particular the design of a new two way flow control valve studying the valve internal fluid-dynamic behavior will be introduced. The methodology is based on the definition of a CFD tridimensional fluid-dynamic model. In fact, the model can help engineers to develop the best geometry, to optimize the valve performance, reducing the prototyping requirement and finally the time-to-market and, consequently, the development costs. At first, the original spool internal geometry has been evaluated and studied to tune the mathematical model and to validate it comparing its results with the data obtained through an experimental campaign. Then, the same approach has been applied to investigate several different internal spool geometries to define the best one in all operating conditions. A limited number of solutions have been prototyped and tested to verify the mathematical model predictions, in order to find the best configuration whose performances are consistent with the assigned objective for the component.

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