A parabolic trough solar collector as a solar system for heating water: a study based on numerical simulation

This paper is an optical and thermal study of a small model of a parabolic trough solar collector (CTP), which will be used to heat tap water in the winter at Guemar, El-Oued province, Algeria. A mathematical model drawn from the energy balance equation applied to the absorber tube, this model was solved by the finite difference method. A computer program was developed to solve our problem. MATLAB was used as a tool for numerical simulation where it is used to calculate dynamic shifts at the level of the absorbent tube. The results are very honorable and encouraging, where the thermal efficiency of the concentrator had passed 61%, and the fluid temperature had passed 343 K

Estimating solar radiation according to semi empirical approach of Perrin de Brichambaut: application on several areas with different climate in Algeria

The solar energy reaching a given surface is directly dependent on the orientation thereof and the position of the sun. To get maximum energy from the sun, it is necessary a good solar receiver orientation towards the solar radiation where the solar radiation is perpendicular to the solar collector, so the knowledge of the sun's position over time is a very important thing. The intensity calculate of solar radiation received by an inclined surface is the primary objective of this paper. The study is based on the true solar time, the geographic and astronomical data on-site study. Matlab was the simulation tool, where a program was developed to calculate the daily global solar radiation collected by any geographical site depending on the semi-empirical model of PERRIN DE BRICHAMBAUT. The some applications on different places in Algeria, like El-Oued, Biskra, Blida and Oran in the day of March 21, June 21, September 21 and December 21, and the results obtained were confirmed by comparing them with the previously results published by the researchers is of great competence in this field. Keywords: solar energy, global solar radiation, inclined surface, simulation

Study of a solar air conditioning system with ejector

Air conditioning is one of the indispensable conditions of well-being in human life, so the face of this research to provide this basic necessity in remote areas and in desert places far from power grids. To achieve this goal, solar air conditioning has been adopted, where the compressor was replaced by an ejector, a parabolic trough solar collector and a small pump; this means that the solar air conditioner does not need a huge amount of electrical energy to operate. This paper is studding the thermodynamic cycles of this air conditioner as a function of changing the climatic conditions of Bouzaréah region in Algeria under several practical conditions of heat exchangers (Condenser, Evaporator and Generator). This study will allow the determination of the optical and thermal efficiency of the solar collector used as a solar thermal generator, refrigeration subsystem performance (COPEje) and system thermal ratio of the air conditioner, where the cooling load is estimated at 18 kW

Impact of natural charcoal blocks on the solar still output

Solar energy is an abundant energy in the earth globe. Solar distillation is one of the techniques that uses this energy to obtain portable water from ground or salt water. The purpose of our experimental study is to show that the blocks of natural carbon, that is to say the remains of a fire, can serve as an element for improving the performance of a solar still. For this, two similar solar stills were used, one is taken as reference SSR and the other modified still SSM contains carbon block. The results show that there is an improvement rate of 8%

Mechanical speed estimation of a DFIG based on the Unscented Kalman Filter (UKF)

This work proposes a new estimation technique for the doubly-fed induction generator (DFIG) variables. Researchers have designed numerous sensorless control strategies for the DFIG used either for mechanical speed, electromagnetic torque, or rotor position estimation. In this paper, an analysis of an Unscented Kalman Filter (UKF) will be presented as an observer for both rotor and stator currents, and mechanical speed, which are key information in DFIG control. The performance of the proposed observer has been validated in a 9 MW wind turbine under MATLAB/Simulink. Based on the results obtained, UKF is safely able to replace mechanically coupled sensors which have many disadvantages such as high cost, maintenance, and cabling requirements

Optimal tilt angle for photovoltaic panels in the Algerian region of El-Oued in the spring season: An experimental study

The tendency to exploit solar energy in the electricity production in Algeria is a priority and a major goal of the Algerian government, and for this reason it seeks to provide all the necessary capabilities to achieve this lofty goal. Photovoltaic electricity is one of the effective technologies for the solar electricity production, but before installing any photovoltaic panel, it is important to determine its optimal tilt angle, and based on this, this study allowed to show the optimal tilt angle of the photovoltaic panels in the Algerian region of El Oued in the spring season, and accordingly, two days (March 21st, 2023, and April 21st, 2023) were chosen to conduct this experimental study. Based on the obtained results, the optimal PV tilt angle for the month of March is 33° and 28° for the month of April. In addition, the greater the amount of solar radiation, the higher the efficiency and productivity of the PV panels, as the highest values for them (6.31 % and 62.17 W, respectively) were recorded on April 21st, 2023. The results of this study will contribute to the correct installation of photovoltaic panels in the Algerian region of El-Oued, especially if the photovoltaic panels are equipped with dual-axis solar tracking systems

Reynolds Horizontal and Vertical Test Bench from an Educational Point of View

The Reynolds Number Test Bench is a self-contained device that uses water to allow students to study laminar, turbulent flow regimes, and transition conditions. The vertical test bench does not allow a large number of students to see the experiment clearly, it only takes two people in front of the device to block the view of the rest of the students and this causes a problem. The idea of this work is to build a horizontal test bed that allows students to see the experience clearly and easily. The results obtained from our horizontal device are the same as that of the vertical bench

Dust Accumulation Effects on the Performance of Photovoltaic Panels: An Experimental Study in the Algerian Region of El-Oued

This paper examines the dust accumulation impact on the performance of photovoltaic panels in the Algerian region of El-Oued, where two similar photovoltaic panels were analyzed: a clean reference photovoltaic panel (PVr) and a dirty targeted photovoltaic panel (PVt) with 14.5 g/m² of dust. The data was collected on May 4th and 13th, 2022, through experimental works and numerical validation. The results show that dust significantly reduces the PV performance. On May 4th, 2022, the PVr produced 330.89 Wh, compared to 216.72 Wh for the PVt, with a difference of 34.65%. On May 13th, 2022, PVr generated 414.01 Wh, while PVt produced 271.16 Wh, with a difference of 34.67%. In terms of PV power generation, PVr reached maximum values of 52.82 W and 66.28 W on May 4th and 13th, respectively, compared to 34.5 W and 43.29 W for PVt. The PVr performance varied between 5.85% and 6.56%, while that of PVt was limited to 3.82% and 4.29%. These results highlight the importance of keeping photovoltaic panels clean to ensure optimal energy production, especially in desert environments like El-Oued,. Moreover, the study confirms that regular panel maintenance is essential to minimize power reduction due to dust and guarantee maximum panel efficiency

The efficiency of linear Fresnel reflectors in producing superheated steam for power plant drive

Solar energy is one of the most important sources of renewable energies, which is widely used in many fields, such as electricity production through direct production of superheated steam based on Linear Fresnel Reflector. This study aims to show the optical and thermal behavior of linear Fresnel solar reflectors field directed to the electricity production in El-Oued region at Algeria. Four days of different weather data have been selected to track the change in solar field performance. Numerical optical modeling has shown that the optical performance of the solar field has reached 53.60 %, while the thermal study based on the numerical solution of the energy balance equations of the receiver tube proved that the thermal efficiency was 37.3 % and the average thermal loss coefficient was limited between 5.72 and 5.98 W/m²K. As for the superheated steam temperature, the lowest value was recorded in December with a value of 501 K. The results obtained are very compelling and encouraging to invest in this low-cost technology