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Life span and overall performance enhancement of Solar Photovoltaic cell using water as coolant: A recent review
摘要： In today’s world, as electricity consumption is increasing, people are more dependent on electricity. Solar Photovoltaic system is one method to generate electricity. The conversion efficiency of solar photovoltaic panel depends on atmospheric condition and reflection. The operating temperature of photovoltaic module plays an important role in performance of PV system as efficiency of PV system decreases when temperature module increases. The operating photovoltaic cells at high temperature degrades the material of it in long time. Operating solar photovoltaic at lower temperature will increase its lifespan. This will reduce module surface area by increasing overall output power. Researchers have proposed and tested several cooling techniques for the panel. One of the most common and effective way to cool PV module is used of water as coolant. In this paper, efforts made by various researchers to cool down solar photovoltaic module to increase the efficiency using water application have been discussed. The application of water on front surface, rear surface, both front and rear surface have been reviewed extensively. The performance of module by immersion in water also have been reported.
关键词： Nanofluids,Electrical conversion efficiency,Solar Photovoltaics,Thermal conductivity,Overall efficiency
更新于2025-09-12 10:27:22
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Solar steam generation enabled by bubbly flow nanofluids
摘要： Plasmonic nanofluids are recently explored to promote steam generation, showing great promise of such fluids for solar thermal applications. However, plasmonic nanoparticles are opaque and the nanofluids require high mass concentration to achieve efficient evaporation, which in turn leads to parasitic light absorption for the underlying particles. In this work, we introduce bubbles into dilute plasmonic nanofluids to enhance solar water evaporation. The dynamic bubbles not only act as light scattering centers to extend the incident light pathway and amplify solar flux, but also provide large gas-liquid interfaces for moisture capture as well as kinetic energy from bubble bursting to improve vapor diffusion. The coupling effect between plasmonic heating and bubbly-flow humidification results in a steam generation rate of 0.72 kg m?2 h?1 under two-sun, which is about three-time higher than that of the pure water. A series of experiments under different light intensities, concentration of nanofluids, gas flow rates as well as photothermal materials such as carbon nanotubes (CNTs) and magnetic Fe3O4 nanoparticles are also conducted to verify the concept. It is concluded that all the nanofluids enhance the steam generation process, and the bubbly flow nanofluids can be further improved the performance. This work provides an original insight on the bubbly flow nanofluids for solar vapor generation, and stands for a basis to design scalable solar evaporators from accessible raw materials.
关键词： Solar energy,Bubbly flow,Plasmon heating,Steam generation,Nanofluids
更新于2025-09-11 14:15:04
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Photovoltaic–thermal (PV/T) technology: a comprehensive review on applications and its advancement
摘要： Over the most recent couple of decades, tremendous consideration is drawn towards photovoltaic–thermal systems because of their advantages over the solar thermal and PV applications. This paper intends to show different electrical and thermal aspects of photovoltaic–thermal systems and the researches in absorber design modification, development, and applications. From the previous review articles, it has been concluded that the heat energy exhausted from the PV module can be further utilized in different ways and helps in achieving better efficiency. Furthermore, the types of photovoltaic–thermal systems such as air collector, water collector, and combi system, coupling with heat pump and their application to buildings are also stated. This paper also discussed certain design aspects like modifications in the flow channel by adding fins, thin metallic sheets, roll-bond absorber, and porous media and the effect of these modifications on the hybrid system’s efficiency. Furthermore, the use of the latest technologies such as nanofluids, thermoelectric generators, and phase-change materials improves the overall system performance. The role of soft-computing techniques is forecasting the impact of various parameters on the photovoltaic–thermal system is also discussed.
关键词： Phase-change materials (PCM),PV/T combi,Thin metallic sheets (TMS),Nanofluids
更新于2025-09-11 14:15:04
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Alternative designs of parabolic trough solar collectors
摘要： Parabolic trough collector (PTC) is the most established solar concentrating technology worldwide. The conventional parabolic trough collectors are used in various applications of medium and high-temperature levels. However, there are numerous studies which investigate alternative designs. The reasons for examining different PTC configurations regard the thermal efficiency increase, the reduction of the manufacturing cost and the development of more compact designs. The objective of this review paper is to summarize the existing alternative designs of PTC and to suggest the future trends in this area. Optical and thermal modifications are examined, as well as the use of concentrating thermal photovoltaic collectors. The optical modifications include designs with secondary concentrators, stationary concentrators and strategies for achieving uniform heat flux. The thermal modifications regard the use of nanofluids, turbulators and the use of thermally modified receivers with insulation, double-coating and radiation shields. The concentrating thermal photovoltaics are systems with flat or triangular receivers which can operate in low or in medium temperature levels with the proper alternative designs. It has been found that there are many promising choices for designing PTC with higher thermal performance and lower cost. The conclusions of this work can be used as guidelines for future trends in linear parabolic concentrating technologies.
关键词： Nanofluids,Solar energy,Alternative design,Secondary reflector,Parabolic trough collector,Thermal enhancement
更新于2025-09-09 09:28:46
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Can Nanofluids Lead to Commercial Usage in Solar Engineering
摘要： The efficiency concept has been the major concern of specialists and analysts in the vital flied of energy. The energy efficiency corresponds with the productivity of resources consumption since there is a worrying limitation on the fossil fuel reserves of the earth. Although the price of fuel has been diminished significantly in recent years, the constraint of its availability in not-too-far future has put the pressure on the governments to intend toward the renewable energies more than ever. Furthermore, nobody can really estimate that what would be occurred in the global economic market in the next years. Solar energy considered as one of the most reliable and available sources of energy which can be renewed continuously. That is why the different technologies, i.e. PV and thermal systems, have been developed and studied yet. Apart from the improvements which originated from design and technology progress, the appearance of nanotechnology caused significant advancement in solar engineering similar with the other fields of study. There are numerous researches on the field of solar energy with the applications of nanotechnology. For instance, currently the solar energy can be observed in heating, cooling, power generation, energy storage, transportation, medical etc. As long as nanotechnology proposed, the solar engineers has made their efforts to enhance the performance of solar systems and achieve the higher efficiencies. In the case of solar collector systems, nanomaterial’s can be added into absorber surfaces or heat transfer fluids which would result in enhancement of thermal and optical properties of the systems. Nanomaterial’s categorized as follows: Organic: fullerene, nanotube, electrospun nanofibers Inorganic: metal, metal oxides, quantum dots hybrid. Based on the application, nanomaterial’s can be mixed with the fluids which called Nanofluids. In other words, the suspension of nanoparticles in liquids considered as Nanofluids. Common liquids as the base fluid are water, ethylene, glycol and oil and the nanoparticles which have been used in literatures for dispersing in base fluid include carbon nanotube, alumina, titanium dioxide, silver, copper, graphite, etc. Nanofluids are made by mechanical (one-step or two-step) or chemical methods [1]. The synthesis is the main process which involved in preparation of the Nanofluids. On the other hand, the combination of nanomaterial’s with phase change materials (PCMs) known as Nano composites. Each type of Nanofluids or Nano composites exhibits the special properties. For example, the Nanofluids are more applicable in solar collectors for power generation and Nano composites are preferably considered in thermal storage projects i.e. heat or cold storage which would provide the industrial or domestic requirements of different climates. The hybrid systems exploit the most benefits of nanomaterials for simultaneous power generation and thermal storage. Furthermore, using the PCMs can increase the operating time of the system during the night or cloudy situations. Nanofluid phase change materials (NPCMs) have opened a new field of study for researchers. In fact, a NPCM is a liquid in which nanoparticles that change phase are added in order to enhance the thermal properties of this fluid. Despite the fact that all researches have been conducted theoretically and experimentally in all around the world, prove that the application of Nanofluids would lead to enhancement of optical and thermo-physical (conductive and convective) behaviour of solar systems, the applications of Nanofluids limited to the noncommercial projects [2]. Two main reasons interfere with the aim of commercializing Nanofluids application for solar power generation or solar thermal storage. Firstly, the results of remarkable achievements of numerous researchers show an inconsistency in some cases and therefore, the uncertainty of the results may necessitate more detail studies to overcome some ambiguities. Secondly, it is obvious that the optical and thermal properties of Nanofluids would be enhanced rather the base fluids, however, their application issues including durability, sedimentation, agglomeration, viscosity problems, some design complexities and operating costs have not been studied exactly and sufficiently. Hence it seems there would be a rather long way to achieve the exact, clear and unique results to smooth commercializing of Nanofluids applications in solar engineering.
关键词： Nanotechnology,Thermal Storage,Solar Energy,Nanofluids,Solar Engineering
更新于2025-09-09 09:28:46