1,720,985 research outputs found
Passive sustainability strategies in traditional Gaziantep residences: a critical report on historical development
Full text linkIn recent years, the increase in the need for energy and the rapid depletion of energy resources have revealed that energy control in buildings is of vital importance. This situation requires energy efficiency not only in new buildings but also in existing building stocks. For this reason, passive strategic measures affecting thermal comfort and energy efficiency in historical buildings built in Gaziantep in the late 18th and early 19th centuries have been evaluated in this study. First, the cultural, technological and natural images of the region that are effective in the development of these strategies were identified. The reflection of these images on architectural design and the parameters affecting energy use as a result were revealed. In order to examine the effect of passive strategy measures in the spaces, a field study was carried out on a selected Gaziantep traditional residential building. For the field study, measurements were taken from the selected building and the street every hour during the day. These measurements have been made under the following conditions: sunny inside the courtyard, sunny outside the courtyard, shade inside the courtyard and shade outside the courtyard. Afterwards, all measurements have been compared. As a result, it is concluded that the courtyard systems that form the cultural, technological and natural image of the region have a great effect on thermal comfort. © The Author(s) 2024
Impacts of Ground Slope on Main Performance Figures of Solar Chimney Power Plants: A Comprehensive CFD Research with Experimental Validation
No full textGeometric parameters in solar chimney power plants are numerically optimised for the purpose of better power output figures. Several parameters have been investigated in the pilot plant such as chimney height and diameter, collector diameter and slope, and slenderness. However, ground slope has not been studied to date despite its perspicuous impact on turbulent flow. In this study, the impacts of the different slope angles of the ground, where the solar radiation is absorbed through the collector, on the main performance parameters of the system are numerically analysed through a reliable CFD software ANSYS FLUENT. By considering the actual geometric figures of the pilot plant, a 3D model is constructed through DO (discrete ordinates) solar ray tracing algorithm and RNG k-epsilon turbulence model. For the solar intensity of 1000 W/m(2), the maximum velocity inside the system is found to be 14.2 m/s, which is in good accordance with the experimental data of 15.0 m/s. Starting from 5 m inside the collector, the chimney inlet heights are reconfigured 0.209, 0.419, 0.625, 0.838, and 1.04 m, respectively, and when the ground slope is 0.1, 0.2, 0.3, 0.4, and 0.5 degrees, the changes in the performance output of the system are investigated. For the reference case which refers to the horizontal ground, the maximum air velocity is determined to be 14.2 m/s and the power output is 54.3 kW. However, when the ground slope is made 0.5 degrees, it is observed that the maximum velocity increases by 37% to 19.51 m/s, and the power output is enhanced to 63.95 kW with a rise of 17.7%. Sloping ground is found a key solution to improve the turbulent effects inside the plant, thus to enhance the electrical power output
Life cycle cost and carbon footprint analysis of CuO–Al2O3/water hybrid nanofluids in thermoelectric vaccine refrigerators
Full text linkThis study investigates the application of a CuO–Al 2 O 3 /water hybrid nanofluid as a coolant in thermoelectric vaccine refrigerators, aiming to enhance heat dissipation from the Peltier module’s hot side. A 35-L cooling cabinet was utilised, and experimental comparisons were made using water and a 2% CuO–Al 2 O 3 /water hybrid nanofluid. Results show that the vaccine cabinet reaches the target temperature of 4 °C in 990 s with nanofluid, compared to 1200 s with water. The system’s energy consumption was reduced by 18.3%, and carbon emissions decreased by 12.3% over a 15-year lifespan, highlighting its environmental benefits. Despite similar coefficients of performance (COP), the nanofluid system demonstrates enhanced efficiency, shorter cooling times, and long-term sustainability advantages. These findings support the adoption of hybrid nanofluids in thermoelectric cooling applications for energy-efficient and environmentally friendly refrigeration systems
Sustainable insulation technologies for low-carbon buildings: From past to present
Full text linkBuilding facade insulation technologies have evolved from primitive thermal barriers to high-performance, multifunctional systems that enhance energy efficiency and indoor comfort. Historical insulation methods, such as thick masonry walls and timber-based construction, have gradually been replaced by advanced materials and innovative facade designs. Studies indicate that a significant proportion of a building’s heat loss occurs through its external walls and windows, highlighting the need for effective insulation strategies. The development of double-skin facades (D-SFSs), adaptive facades (AFs), and green facades has enabled substantial reductions in heating and cooling energy demands. Materials such as vacuum insulation panels (VIPs), aerogels, and phase change materials (PCMs) have demonstrated superior thermal resistance, contributing to improved thermal regulation and reduced carbon emissions. Green facades offer additional benefits by lowering surface temperatures and mitigating urban heat island effects, while D-SF configurations can reduce cooling loads by over 20% in warm climates. Despite these advancements, challenges remain regarding the initial investment costs, durability, and material sustainability. The future of facade insulation technologies is expected to focus on bio-based and recyclable insulation materials, enhanced thermal performance, and climate-responsive facade designs. This study provides a comprehensive review of historical and modern facade insulation technologies, examining their impact on energy efficiency, sustainability, and future trends in architectural design
Passive sustainability strategies in traditional Gaziantep residences: a critical report on historical development
Full text linkIn recent years, the increase in the need for energy and the rapid depletion of energy resources have revealed that energy control in buildings is of vital importance. This situation requires energy efficiency not only in new buildings but also in existing building stocks. For this reason, passive strategic measures affecting thermal comfort and energy efficiency in historical buildings built in Gaziantep in the late 18th and early 19th centuries have been evaluated in this study. First, the cultural, technological and natural images of the region that are effective in the development of these strategies were identified. The reflection of these images on architectural design and the parameters affecting energy use as a result were revealed. In order to examine the effect of passive strategy measures in the spaces, a field study was carried out on a selected Gaziantep traditional residential building. For the field study, measurements were taken from the selected building and the street every hour during the day. These measurements have been made under the following conditions: sunny inside the courtyard, sunny outside the courtyard, shade inside the courtyard and shade outside the courtyard. Afterwards, all measurements have been compared. As a result, it is concluded that the courtyard systems that form the cultural, technological and natural image of the region have a great effect on thermal comfort
Assessment of glass
No full textEspecially for new-generation buildings, since esthetic appearance as well as thermal comfort is essential, glass materials have been widely used as building materials in buildings. Due to its superior optical properties, it is preferred in buildings, especially in window areas. On the other hand, the heat losses and gains and light transmission rates from the glass used in the building envelopes and especially in the window areas are very effective on the energy efficiency of the buildings. Therefore, innovative glass technologies are developed and used in new smart buildings. In this context, the most preferred glass technologies are laminated glass and tempered glass for the building envelope. For window areas, it can be listed as low emissivity glasses, high-technology glasses, vacuum glasses, glasses with phase change materials and insulated glasses.The use of new-generation glass technologies instead of traditional glass technologies provides significant benefits to users regarding economic, environmental, and social effects. © 2024 Elsevier Ltd. All rights reserved
Design and experimental investigation of a thermoelectric vaccine cabinet integrated with photovoltaic and nanofluids
Full text linkVaccines are one of the most effective methods used to prevent many lethal and infectious diseases from past to present. Generally, storage temperatures of vaccines are between 2 and 8 degrees C. Keeping the vaccines in this temperature range and ensuring reach the end user without deterioration is very important in order to prevent the vaccines from losing their effectiveness. In this regard, various cooling systems are used. One of the devices used to ensure the cold storage of vaccines is a thermoelectric device. Thermoelectric devices attract attention as an energy-efficient technology, as well as their compact structure, silent and vibration-free operation, and suitability for automation. In this study, the design and manufacturing of a photovoltaic solar energy-driven, nanofluid-integrated thermoelectric vaccine cabinet was carried out and its performance data were experimentally examined. The capacity of the vaccine cabinet is 200 vaccine vials and 200 ready-to-use syringes, as well as the battery and inverter parts. In experiments carried out at two different outdoor temperatures, heat removal from the hot surface of the thermoelectric cooler with different refrigerants were examined. In addition, the effects of using fans were also investigated while the heat swept from the surface was transferred to the environment with the help of a water-to-air heat exchanger. In the experiments carried out for a total of 8 different cases, the highest average coefficient of performance value obtained during the experiments was 1.19. Experimental results show that vaccine storage temperatures can be reached under the prepared operating conditions
Methods of fabrication of bionanocomposites
No full textPetrochemical-based plastic packaging materials that cannot be biodegradable and remain intact in nature for many years and the continuous proliferation of these materials as waste has become an international problem. As a result of this problem, bionanocomposites produced from biodegradable materials represent a new class of nanosized materials with various uses, from various daily uses to food packaging applications. It consists of a biobased component and at least one-dimensional nanosized particles. It differs from nanocomposites with fundamental differences such as preparation methods, functions, biodegradability, biocompatibility, and obtaining methods. In the presented study, the production methods of bionanocomposites are explained with some examples obtained by these methods. Generally, there are four main production methods: in situ intercalative polymerization, solution intercalation, template synthesis, and melt intercalation. With these methods, bionanocomposites can be produced that are homogeneously dispersed and provide major enhancements in mechanical, thermal and water vapor barrier characteristics compared to base polymers. It is capital to use the appropriate method and to make the correct synthesis according to the base polymer used and the type of nanoparticle added, to obtain a homogeneous and nonagglomerated bionanocomposite synthesis. © 2022 Elsevier Ltd. All rights reserved
Performance analysis of solar chimney power plant with waste heat integration on the ground
No full textAlthough the solar chimney power plant is a solar energy system, it can produce electricity 24 hours a day and the performance of the system can be increased with additional energy sources in cases where solar radiation is low. By integrating waste heat into the system, energy can be provided to the system during hours when there is no sun and the temperature of the air in the system can be increased. Thus, the continuous vacuum effect of the chimney can be used for electricity generation. At a solar radiation of 400 W/m2 and an ambient temperature of 294 K, the waste heat of the gas power plant at a temperature of 816.9 K is analysed with a 3D CFD model under continuous conditions. In the study based on the Manzanares pilot plant geometry, it is seen that the power output of the system, which gave a power output of 20.68 kW in the reference case, increased by 63.47% to 33.807 kW with the waste heat supplement. It is seen that the system gives a power output of 14.016 kW for the same climatic conditions during the hours when there is no sun.</p
Optimised performance of a thermally resistive PV glazing technology: An experimental validation
No full textCuce, Erdem/0000-0003-0150-4705Thermally resistive PV glazing (TRPVG), which is a recently developed technology for low/zero carbon buildings, is in the centre of interest worldwide as a consequence of multifunctional benefits of this novel product such as remarkably better thermal insulation performance compared to conventional PV and other fenestration technologies in market, clean energy generation, self-cleaning, sound insulation, UV and IR absorption, etc. in this study, thermal insulation performance of TRPVG is numerically optimised through a well-known CFD software ANSYS FLUENT. Optimisation is based on determining the optimum inert gas (argon) thickness (tau) behind the amorphous silicon (a-Si) PV module which yields to minimum overall heat transfer coefficient (U-value) for the entire structure. For a typical case (tau = 16 mm), CFD results are compared with the experimental data derived from the standardised co-heating tests, and a good accordance is achieved. CFD results are also compared with the findings of thermal resistance approach, which assumes heat conduction takes place in the inert gas medium only. the results reveal that natural convection effects become notable for the values of tau over 10 mm. in other words, tau stands as a parameter that needs to be optimised for its values greater than 10 mm. For the typical TRPVG sample with tau = 16 mm, the overall U-value from the CFD research is determined to be 1.19 W/m(2)K, which is in good agreement with the experimental data. the optimised value of tau for the TRPVG structure introduced is determined to be 20 mm, which guarantees the minimum total heat transfer rate (Q) across the glazing and maximum temperature difference between internal and external glazing surfaces. (C) 2019 the Authors. Published by Elsevier Ltd.TUBITAK (The Scientific and Technological Research Council of Turkey)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [216M531]The corresponding author gratefully acknowledges the financial support of TUBITAK (The Scientific and Technological Research Council of Turkey) through the project grant of 216M531
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