Teaching Documents by Yasser A . Jebbar
This presentation talks about the CSC technologies that use mirrors to reflect and concentrate su... more This presentation talks about the CSC technologies that use mirrors to reflect and concentrate sunlight onto a receiver. The energy from the concentrated sunlight heats a high-temperature fluid in the receiver. This heat - also known as thermal energy - can be used in many applications.
Solar ponds (SP) represent one of the simplest methods for directly collecting solar irradiation ... more Solar ponds (SP) represent one of the simplest methods for directly collecting solar irradiation and converting it to thermal energy. There are several types of solar ponds. Based on the convection behavior of the saline solution in solar ponds, they may be classified into two main categories: convective and non-convective solar ponds. The applications of solar ponds are Air-Conditioning of Buildings, Generating Power, Desalination by Distillation, and Refrigeration.
Papers by Yasser A . Jebbar
International Journal of Heat and Technology, 2024
The thermal performance of a parabolic trough receiver (PTR) with hollow cylindrical inserts (HCI... more The thermal performance of a parabolic trough receiver (PTR) with hollow cylindrical inserts (HCIs) is numerically investigated. The HCIs are coupled in an axial manner and also radially joined to the interior of the PTR. Totally, eleven different internally hollow cylindrical receivers are examined and compared with the plain tube (PT). The lengths, thicknesses, and numbers of HCIs are tested at varied values, and all these tubes are examined under a constant inlet temperature of 300 K and mass flow rates in the range of 0.6-1.0 kg/s. ANSYS Fluent is the simulation software in this work. The developed model is validated with experimental correlations for PT case. The simulation findings demonstrated that the addition of HCIs may greatly enhance the uniformity of the temperature gradient between the wall of the PTR and the water. The optimum case of the HCIs has a length of 40 mm, a thickness of 2 mm, and a number of 15 inserts. This model recoded the higher ranges of Nusselt number (132-296), fraction factor (0.301-0.064), and thermal efficiency (41-79%). Also, the outlet temperatures of the PT and modified tube are increased from 300 K to 325.5 K and 339.7 K, respectively. As a result, this approach provides advantages over the utilization of interior fins, as it can be applied on the parabolic trough collector (PTC) without requiring any modifications to the PTR, which are associated with numerous operational challenges.
Fluid Dynamics & Materials Processing, 2024
This study includes an experimental and numerical analysis of the performances of a parabolic tro... more This study includes an experimental and numerical analysis of the performances of a parabolic trough collector (PTC) with and without cylindrical turbulators. The PTC is designed with dimensions of 2.00 m in length and 1.00 m in width. The related reflector is made of lined sheets of aluminum, and the tubes are made of stainless steel used for the absorption of heat. They have an outer diameter of 0.051 m and a wall thickness of 0.002 m. Water, used as a heat transfer fluid (HTF), flows through the absorber tube at a mass flow rate of 0.7 kg/s. The dimensions of cylindrical turbulators are 0.04 m in length and 0.047 m in diameter. Simulations are performed using the ANSYS Fluent 2020 R2 software. The PTC performance is evaluated by comparing the experimental and numerical outcomes, namely, the outlet temperature, useful heat, and thermal efficiency for a modified tube (MT) (tube with novel cylindrical turbulators) and a plain tube (PT) (tube without novel cylindrical turbulators). According to the results, the experimental outlet temperatures recorded 63.2°C and 50.5°C for the MT and PT, respectively. The heat gain reaches 1137.5 W in the MT and 685.8 W in the PT. Compared to the PT collector, the PTC exhibited a (1.64 times) higher efficiency.
THE 7TH INTERNATIONAL CONFERENCE ON APPLIED SCIENCE AND TECHNOLOGY (ICAST 2019), 2019
AUS, 2019
The Salinity Gradient Solar Pond (SGSP) can be an effective way of capturing and storing thermal ... more The Salinity Gradient Solar Pond (SGSP) can be an effective way of capturing and storing thermal energy from incident solar radiation. The concept of using the SGSP to provide cooling or heating air for buildings models is studied. The idea seems appealing for a number of reasons, the design study shows it to be technically feasible and provide in the cost of electricity. The simulation program in FORTRAN is designed to investigate the possibility of the SGSP for cooling and heating of the models of the buildings in Karbala city, Iraq (32.62° N, 44.03° E). The obtained results have been shown the SGSP could be used for the cooling and heating loads during all hours of the simulation time and to meet 100% of the cooling and heating air the SGSP needed is 4-5 times the area of the building model. Keywords: Salinity gradient solar pond, cooling and heating air, solar thermal energy, and FORTRAN Program. RESUMEN/ El estanque solar con gradiente de salinidad (SGSP) puede ser una forma efectiva de capturar y almacenar energía térmica de la radiación solar incidente. Se estudia el concepto de utilizar el SGSP para proporcionar aire de refrigeración o calefacción para los modelos de edificios. La idea parece atractiva por varias razones, el estudio de diseño muestra que es técnicamente factible y proporciona el costo de la electricidad. El programa de simulación en FORTRAN está diseñado para investigar la posibilidad del SGSP para enfriar y calentar los modelos de los edificios en la ciudad de Karbala, Iraq (32.62 ° N, 44.03 ° E). Los resultados obtenidos han demostrado que el SGSP podría usarse para las cargas de refrigeración y calefacción durante todas las horas del tiempo de simulación y para cumplir con el 100% del aire de refrigeración y calefacción que el SGSP necesitaba es 4-5 veces el área del modelo de construcción. Palabras clave: estanque solar con gradiente de salinidad, aire de refrigeración y calefacción, energía solar térmica y programa FORTRAN.
Thesis Chapters by Yasser A . Jebbar
The Solar Pond (SP) is used to store heat from the incident solar radiation. This technology is d... more The Solar Pond (SP) is used to store heat from the incident solar radiation. This technology is distinguished from other thermal storage technologies (e.g. a flat plate solar collector) by its ability to store thermal energy for more than 6 months, even in cloudy or rainy environments. Thus, this heat can be used in several applications, including heating and cooling buildings in winter and summer seasons, respectively. The absorbed solar radiation heats up the brine in the storage zone (bottom layer). Because this has the highest salt concentration, the hot brine cannot rise to the less-salty layer. Hence, the heat remains to accumulate at the bottom of the pond. A FORTRAN program is designed to analyze the thermal performance of the salt pond under the actual weather conditions of Karbala city, Iraq (such as ambient temperature, wind speed, relative humidity, and atmospheric pressure) and to find the appropriate depth of the prospective pond. The thermal conductivity of the pond is calculated using the numerical solution of the equilibrium equations implementing the Finite Differences Method (FDM), taking into account the loss of heat from the surface and bottom of the pond. Various models of buildings in Karbala city, Iraq are designed with different areas (100m2 and 1000 m2). Their thermal loads are calculated in addition to the amount of heat that can be withdrawn from the storage zone. Then the required areas of the used solar ponds in heating or cooling these buildings are determined. In Karbala city, Iraq the obtained results show that the maximum incident solar radiation is exceeded 7.7 kWh/m2/day in June and this result is in a good approximation with NASA’s data. The most effective factor in the SGSP performance is the amount of incident global radiation on the pond’s location. The SGSP can provide hot saline water with a temperature exceeding 70°C during June that in turn produces sufficient hot water to make the chiller and heater work properly. The cooling and heating air inside buildings need SP areas (4-5) times their floor areas.
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Teaching Documents by Yasser A . Jebbar
Papers by Yasser A . Jebbar
Thesis Chapters by Yasser A . Jebbar