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[en] This guide presents the vision of the professionals of the AFPG (the French professional association of geothermal energy) for a good design of moderate-temperature (inferior to 30 C) water loop based on geothermal energy or BETEG in order to meet thermal needs (heat and cold) at the scale of several buildings while sharing geothermal capture systems. The authors first present the BETEG, its associated geothermal resources, its different production modes, its ability to share energy among buildings, its ability for evolution and modularity, its potential in the valorisation of thermal storage, its control. It describes the various equipment and their components: capture device, sharing device, production device, control device. Its describes the principle of a moderate-temperature water loop (communication, supply, storage, valorisation, decentralisation of production), briefly presents some characteristics of an application depending on its scale, and evokes the assessment and definition of energetic needs. Then, other aspects of an operation are addressed: legal framework of an energy network, operation planning, intervener and funding, and regulatory framework of surface geothermal energy. Some cases are finally presented as returns on experience
[en] In this study, a corrosion failure analysis of a heat transport pipe was conducted, as the result of a pinhole leak. Interestingly, the corrosion damage occurred externally in the pipeline, resulting in severe thickness reduction near the seam line. Also, while a stable magnetite protective film formed on the inner surface, the manganese oxide formation occurred only on the outer surface. The interior and exterior of the pipe were composed of ferrite and pearlite. The large manganese sulfide and alumina inclusions were found near the seam line. In addition, the manganese sulfide inclusions resulted in grooving corrosion, which progressed in the seam line leading to the reduction in the thickness, followed by the exposure of the alumina in the matrix to the outer surface. To note, the corrosion was accelerated by pits generated from the boundaries separating the inclusions from the matrix, which resulted in pinhole leaks and water loss
[en] This publication aims at proposing a detailed analysis of costs of four surface geothermal technologies: vertical geothermal probes, geothermal energy on aquifer, horizontal sensors, and geothermal baskets. It first presents the adopted methodology, some general hypotheses (studied examples, heat pumps, comparative solutions for heating, energy costs, hypotheses for cooling, aids and loans), and the four technologies with their specific hypotheses. Results are presented for the different building sectors: individual housing, collective housing, and office building
[en] This paper deals with the development proposal of a heating system for maintaining a required temperature of a microscopic biological sample, which are located within the detection area of the microscope. The need for maintaining a specific temperature of a biological sample is given by the viability of the microorganism what is related to the temperature of their internal medium. Meeting the conditions for changing or maintaining the required temperature is especially necessary in cases such as monitoring the growth of microorganisms and within the temperature-dependent mutations. In this paper, several alternatives are presented, while the best possible design of the heating element is investigated through thermal simulation analysis. Consequently, the proposal for an appropriate control algorithm for the selected heating system and its arrangement is given together with its verification within the experimental sample of the microscope.
[en] In recent years, studying on energy production processes has been more popular by the sharp increasing trend of energy consumption and loss. One of the effective ways considered for energy loss avoidance in power generation system is using heat loss of power cycles to provide demanded heat for industrial units. Employing auxiliary cycles and compressed air energy system alongside main power production cycle improves the produced power and performance of combined heat and power systems. In this study, a novel combined heat and power system with Brayton cycle as the main power production unit using wind renewable energy, compressed air energy system, and Rankine and organic Rankine cycles is proposed and simulated for residential approaches. All parts of model are validated via the previous published researches and the performance of proposed system in different operating conditions is investigated in detail energetically and exergetically. Results show the acceptable performance of proposed system in peak times as well as low load hours. The increase of gas turbine expansion ratio brings more first and second law efficiencies, while more irreversibility is created by compressor compression ratio increase. In addition, produced power and irreversibility have linear trend by inlet air mass flow rate beside no change in the first and second law efficiencies. Demanded mass flow rate of fuel, Rankine, organic Rankine cycle, and heating system are directly affected by inlet air mass flow rate and overall thermal efficiency can be increased by simultaneous turbine and compressor pressure ratio increase.
[en] In Britain, residential properties are predominantly heated using gas central heating systems. Ensuring a reliable supply of gas is therefore vital in protecting vulnerable sections of society from the adverse effects of cold weather. Ahead of the winter, the grid operator makes a prediction of gas demand to better anticipate possible conditions. Seasonal weather forecasts are not currently used to inform this demand prediction. Here we assess whether seasonal weather forecasts can skilfully predict the weather-driven component of both winter mean gas demand and the number of extreme gas demand days over the winter period. We find that both the mean and the number of extreme days are predicted with some skill from early November using seasonal forecasts of the large-scale atmospheric circulation (r > 0.5). Although temperature is most strongly correlated with gas demand, the more skilful prediction of the atmospheric circulation means it is a better predictor of demand. If seasonal weather forecasts are incorporated into pre-winter gas demand planning, they could help improve the security of gas supplies and reduce the impacts associated with extreme demand events. (letter)
[en] Energy conservation continues to play a crucial role in social and economic development. With the remarkable increase in oil prices and exploring solutions for the replacement of fossil fuels, an ecofriendly energy resource has become the priority among more and more people. Keeping the intension for reducing the global warming impact and looking for alternative clean source of energy, solar energy applications such as solar thermal systems, solar water heating and cooling are becoming energy-efficient designs. One of the widely used applications of solar energy is solar water heating systems. Low-cost solar water heaters can cover the domestic needs for water in the range of 100–200 l per day. Solar water heating systems are generally more efficient and advantageous in hot areas. However, the application of solar water heating is still a challenge in winter and sub-zero conditions, having low solar irradiance. In such conditions, solar water heating system cannot produce enough energy, which drives a need for evaluating system component design and improves its performance during low ambient conditions. In this study, detailed design methods for solar water heater components are discussed for cold regions like North Dakota, USA. The type of system chosen in this study is natural circulation-based solar water heating system. The study will also compare the experimental data with previously conducted numerical analysis.
[en] An upgraded infrared imaging system has been installed at the stellarator TJ-II as a diagnostic tool of the Neutral Beam Injection heating. Thermographic analysis of the beam-wall interaction areas can be used to estimate the beam power lost through reionization and shine-through mechanisms in Neutral Beam heated plasmas. Three different Regions of Interest inside TJ-II vacuum vessel have been determined whose thermographic analysis will be applied to the study of beam related processes. The optical conditions required for each application have been used to define the specifications of the IR camera. Optimization of the optical design has been carried out by means of the optical simulation code ZEMAX. The IR window size has been increased to maximize the fraction of the field of view that is free from vignetting. The system has been fully commissioned and is now operative, routinely providing thermographic data of the regions of interest during the last TJ-II experimental campaign. The IR diagnostic is described in detail and its applicability to study beam power deposition on different targets is discussed.
[en] A first article notices that the 2018 revival of the thermal solar market is due to the support of the Heat Fund, to the call for territorial projects, and to restructuring efforts made by the sector. It also notices that there is still a lot to be done for the development of skills. A professional then gives her opinion about the role for the energy-carbon label for the development of thermal solar installations. The second article presents the dynamic commissioning arrangement (MESD) which has been developed by a professional body to support the management of a solar installation by its commissioner, and is now part of the Heat Fund arrangement. The third article addresses the combined solar system (SCC) which is designed to heat individual and collective housing and to produce domestic hot water by using solar energy: Germany is a leader in this sector, and, despite some debate about defects, the performance and liability of this technology are keeping on improving. The next article evokes examples in Corsica, Brittany, and Centre-Val-de-Loire regions which illustrate possibilities of development at the regional level through increase of financing supports, and derogations. The last article discusses the role of Info Energy Spaces which have been created as proximity services in all French districts to provide free public consultancy, with extended missions, but with the essential necessity of a continued State financial support
[en] The stability of α-, (β+γ)- and δ-tocopherols present in rice bran oil at different heating temperatures has been evaluated. For this purpose, samples of rice bran oil from chemical and physical refining processes in Brazilian industries were studied. The oils were submitted to cabinet drying without air circulation in the absence of light at 100 ºC, 140 ºC and 180 ºC. The samples were taken before heating and after 48, 144, 240, 336, 432, 576, 768, 1008 and 1368h of heating. The analyses of tocopherols were made by high performance liquid chromatography, with a fluorescence detector. It was determined that α-tocopherol was the compound with the fastest degradation rate at the three heating temperatures. The highest degradation rate of tocopherols in both oils occurred at 180 ºC. Among the tocopherols studied, α tocopherol presented the lowest stability, followed by (β+γ)- and δ-tocopherols.
[es]La estabilidad de los tocoferoles α-, (β + γ) - y δ presentes en los aceites de salvado de arroz a diferentes temperaturas de calentamiento fueron evaluadas. Para ello, se utilizaron muestras de aceite de salvado de arroz proveniente de los procesos de refinación química y física de industrias brasileñas. Los aceites fueron sometidos a 100 ºC, 140 ºC y 180 ºC, en cabinas de secado sin circulación de aire, bajo ausencia de luz. Las muestras fueron tomadas antes de la calefacción y después de 48, 144, 240, 336, 432, 576, 768, 1008 y 1368 h de calentamiento. El análisis de tocoferoles fue realizado por cromatografía líquida de alta eficacia, con detector de fluorescencia. Se observó que el α-tocoferol fue el compuesto con degradación más rápida en las tres temperaturas de calentamiento. La mayor tasa de degradación de los tocoferoles, en ambos aceites, ocurrió a la temperatura de 180 ºC. Entre los tocoferoles analizados, α-tocoferol presentó menor estabilidad, seguido por los (β + γ) - y δ-tocoferoles