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Go to Editorial ManagerIn this proposed study, all environmental factors affecting the aboveground and buried pipes, such as solar radiation and temperature, and soil temperature, have been studied on the characteristics of flow inside the aboveground and underground pipelines by building a mathematical model using MATLAB based on energy balance equations. From the mathematical model, the effect of solar radiation on the aboveground section of the pipeline is significate. During March and an inlet temperature of 34 °C, the pipeline outlet fluid temperature will rise to 50 °C. Other parameters affecting the aboveground section of the pipeline, such as ambient temperature and wind speed, have a much smaller effect on the fluid temperature, and the temperature difference is approximately 4 °C between the highest and lowest pipeline outlet fluid temperature. The result for the underground section of the pipeline showed that the main affecting parameter on the fluid temperature is the burry depth of the pipeline, the deeper the pipeline depth the lower the temperature variation and the lower fluid temperature can be seen, at 1 meter of bury depth the minimum and maximum fluid temperature was 18 °C and 36 °C respectively, and at 5 meters of bury depth, the minimum and maximum fluid temperature was 26 °C and 31 °C respectively. This study also checks different process parameters. Some of these are fluid flow, pipe diameter, and pipe material. The effect of the fluid flow and pipe diameter has a similar impact on the fluid temperature (while fixing all the other parameters), the higher the fluid flow or the smaller the pipe diameter resulted in a better heat transfer and more considerable temperature difference, and vice versa. The final process parameter, pipe material, had little to no effect on the fluid temperature variation.
In this paper, a theoretical study of the conventional solar-still system integrated via the design of heat recovery of air exhausted from the air conditioner condenser employing heat exchangers (WHRUs) was conducted. This study aims to improve desalination performance by compensating for the non-existence of sunlight during the night. A comparison was made between the desalination performance in the event of exposure to solar radiation and its performance in the case of exposure to the system (WHRUs). It was found that the (WHRUs) system has a minimal impact on the production of the conventional desalination rig during the night period, as the highest cumulative productivity in the presence of the (WHRU S ) reached (2.15 kg) in August. In contrast, the productivity dependent on solar radiation was (4.58 kg) for the same month, with the most significant percentage of improvement reaching (31.91 %).
In the present research, a Matlab program with a graphical user interface (GUI) has been established for studying the performance of a solar tower power plant (STPP). The program gives the ability for predicting the performance of STPP for different tower dimensions, ambient operating conditions and locations. The program is based on the solution of a mathematical model derived from the heat and mass balance for the tower components. The GUI program inputs are; tower dimensions, solar radiation, ambient temperature, pressure, wind velocity, turbine efficiency, emissivity and absorptivity for collector and ground and thermal conductivity and thickness for ground. However, the GUI program outputs are; temperature and pressure differences across the collector and tower, velocity in the tower, density of air in collector outlet, mass flowrate of air, efficiency for collector and tower, the overall efficiency and output power of STPP. The effect of the geometrical dimensions of STPP and some climatic variables on the plant performance was also studied. The results show that the output power increases with increasing the collector diameter, chimney diameter and solar radiation by an increasing of 0.282 kW/m, 0.204 kW/m and 0.046 kW/(W/m2) respectively.
The thermal performance of an absorption refrigeration system powered by solar pond heat was studied, simulated, and evaluated under the climatic conditions of Basra, Iraq. The simulation used MATLAB to solve the heat and mass transfer equations within the three layers of the solar pond (assuming NaCl as the salinity gradient medium) and linked them via a heat exchanger to the absorption refrigeration system to determine the temperatures supplied to the absorption cycle. The absorption cooling system operates on a lithium bromide-water pair and contains an internal heat exchanger between the generator and absorber with an assumed efficiency of 80%. The simulation was conducted over several months of the year, from March to October, and daily climatic variables such as solar radiation and ambient temperature specific to Basra were considered, allowing the system's performance to be evaluated under realistic climatic conditions. The objective was to evaluate the coefficient of performance (COP) of absorption refrigeration systems and demonstrate the feasibility of using solar ponds as a sustainable heat source for cooling in hot regions. The study demonstrated the feasibility of operating an absorption refrigeration system using the thermal energy stored in the lower layer of the solar pond, while maintaining good thermal stability in that layer throughout the day, especially in areas with high solar radiation, such as Basra. The simulation model was developed entirely in MATLAB using fundamental physical equations that describe each component of the solar pond and absorption refrigeration system, without relying on pre-existing components or tables. This provides greater modeling flexibility and a deeper understanding of system behavior under hot climate conditions.
The solar chimney is a natural draft device that uses solar radiation to provide upward momentum to the in-flowing air, thereby converting the thermal energy into kinetic energy through an air turbine which in turn can be converted into electrical energy. The main parts of the solar chimney power plant are a large circular solar collector, a tall chimney, and an air turbine. In this paper, a theoretical study was performed to evaluate the performance of a solar chimney power plant system in Basrah City, where sunny days and solar radiation are high. A mathematical model was developed to study the effect of various parameters on the output power of the solar chimney. I1 was found that the output power depends strongly on the chimney tall and the difference between the collector air temperature and the ambient air temperature as well as the outside heat transfer coefficient, which essentially depends on the wind speed.
Solar desalination uses solar radiation to convert saline or seawater into clean water and is increasingly crucial due to growing pollution from industrial and automotive sources. Although solar stills offer a sustainable solution, they face challenges in terms of production efficiency. This study presents a new structural design for solar stills, which incorporates advanced insulation materials, a well-designed distillate channel, and an inclined base to enhance productivity. The research explores how different climatic conditions such as wind speed, solar radiation, and atmospheric humidity affect solar still performance. Seven experimental setups were evaluated, comparing traditional inclined stills with advanced closed-loop systems. The results demonstrated that closed-loop systems improved productivity by 28.6% compared to open-loop systems. Additionally, moderate wind speeds increased productivity by 20.82%, while partial cloud cover and light rain decreased productivity by 52.15% and 12.9%, respectively. However, light rain also enhanced condensation efficiency by cooling the glass surface. This study highlights the importance of incorporating environmental factors into the design and optimization of solar still systems for improved performance.
The desalination market is gradually growing as a result of the significant water scarcity in various regions throughout the world. Concentrated solar power (CSP) can be used to power distillation, which is an effective method for addressing water shortages in areas where there is both a severe lack of water and abundant direct normal irradiation. CSPs are ideal candidates for the advancement of desalination technologies due to their capacity to produce both thermal and electricity energy. This review article offers a comprehensive of the current status of cutting-edge CSP-desalination systems. The paper reviews previously published studies conducted by researchers in the field of multi-effect desalination using concentrated solar collectors, and they are classified into two main types. Exclusively freshwater generation and freshwater / electricity cogeneration. In addition, the paper reviews conventional desalination. This review illustrates that there are numerous prospective methods for integrating desalination systems into CSPs. Potential areas for future investigation in CSP-desalination systems. In particular, the most significant obstacles to be surmounted are lowering the costs and efficiency improvements of solar repayment and desalination equipment. A potential method to expedite the commercialization of these plants is to develop innovative strategies that optimize thermal efficiency and reduce costs. Environmental factors (solar radiation intensity, ambient temperature and wind speed) and design factors (solar field area, number of mirrors, number of stages, steam temperature, steam quantity and pressure) are the main effective parameters that affect the distilled water production process. In general, the CSP desalination systems are environmentally and technically appealing; however, there remains substantial progress to be made in order for these plants to be commercially viable.
Solar power systems, also known as photovoltaic (PV) systems, are widely used as a clean and sustainable energy source worldwide. However, these systems can be affected by various factors that contribute to dust accumulation, which have been grouped into five categories: module characteristics, environmental factors, climatic conditions, exposure situations, and soiling properties. Dust accumulation can significantly impact photovoltaic modules' efficiency and power output, leading to a decrease in electricity generation. Airborne dust reduces the intensity of solar radiation by scattering and absorbing it, especially in hot and dry regions such as southern Iraq. This study provides an updated overview of the process of dust accumulation on photovoltaic modules south of Iraq. Moreover, it illustrates the methods used to measure dust accumulation and the performance of solar PV under soiling. Furthermore, it exemplifies the sources of the soiling generation. Additionally, it demonstrates the composition and size of dust particles. Finally, future research perspectives are discussed, and a thorough investigation of the impact of dust is suggested in all regions of Iraq and even in all countries of the world, especially those interested in clean energy. This research aims to understand the effect of dust soiling on PV performance. The outcome of this research will help design the PV module system while considering the most effective method to reduce or prevent dust accumulation in specific areas.
The panel absorbed solar radiation and majority of this radiation is transform into a heat, and it is usually wasted and useless. At higher cell temperature, the current out of the cell has an unnoticeable rise, but the voltage value will drop significantly, resulting in a reduction in maximum power produced. The cooling method is therefore beneficial to keep the panel at the operation temperature. A simulation model is developed using COMSOL Multiphysics software version 3.5 software to investigate the enhancement in performance of a PV water cooling module (PVW module) based on a passive and simple cooling technique using a wetted cotton porous wick attached on the PV panel's back side and compare with uncooled PV panel (PVREF module). Unsteady, laminar and 2-D, the flow in the proposed modules is assumed. The input parameters were taken from a real weather condition was perform in Najaf-Iraq. The effect of variation of mass flow rate is also studied in the present work. Good agreement was obtained for PVREF module with previously researches.