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In the present study, the effects of inlet air cooling on compound cycle performance in a diesel gas turbine engine system where waste heat is used in the composite power system in the sustainable energy system were investigated thermodynamically. The effects of the inlet air cooling the system that enhances power production and the resulting thermal efficiency values were analyzed based on various operational variables gas turbine pressure ratio, diesel engine compression ratio, gas turbine inlet and fresh air inlet temperatures, etc. . The energy losses in each system component were determined and the second law efficiency of the system was determined based on the introduced operational parameters. The gas turbine unit in the model included a gas generator with two compressors and a high-pressure turbine, and a low-pressure power turbine running on a separate shaft. The diesel engine and gas-generator exhaust gases were mixed and expanded in a low-pressure turbine, leading to the production of power with the waste energy. In the cycle, an intake air cooler, an intercooler and a recuperative air pre-heater were used. In the intake air cooling cycle, the power increase was around 15% when the pressure rate of the low-pressure compressor was 3.5. Natural gas was used as fuel in the thermodynamic model. The cycle irreversibilitywas used in the calculations based onthe thermodynamic concepts.

AbstractIn this study, a novel solar tower-based gas turbine-driven multi-generation plant is proposed and analyzed in detail with energy, exergy, economic, and environmental impact analysis. A multiobjective optimization is performed by incorporating all performance indicators simultaneously. The proposed plant consists of an intercooling-regenerative-reheat solarized gas turbine cycle as the primary power cycle of a multi-generation plant for the first time. Two organic Rankine cycles are used to utilize waste heat of intercooling section and exhaust of gas turbine. To produce the multi-generation products of power, cooling, industrial process heating, fresh water, floor heating, green hydrogen, domestic hot water, hot air for food drying, and greenhouse heating, power cycles are integrated with a multi-effect desalination, a double-effect absorption refrigeration cycle, an electrolyzer, a drying hot air unit, a greenhouse heater, and an industrial process heater. A rigorous parametric analysis is performed to reveal the effects of variations of decision variables on the plant performance. At the optimum conditions, energy efficiency, exergy efficiency, average unit product exergy cost, and emission savings values are determined as 57.23%, 40.7%, 0.08315 $/kWh, and 948.7 kg CO2/h, respectively. Moreover, proposed plant can produce 1962 kW power and 3.353 kg/h hydrogen in addition to other utilities with a system cost rate of 0.05134 $/s and 3226 kW exergy destruction rate.

Solidity is one of the main factors that influence the performance of a wind turbine. The solidity of an H-Darrieus wind turbine is optimized in terms of blade number, chord length, and rotor radius to get the maximum power coefficient using Taguchi L16 (4^3) array. Power coefficient values are calculated by the Double Multiple Stream Tube model by in house built MATLAB code according to Taguchi orthogonal array. The maximum power coefficient is found as 0.4728 for the two-bladed rotor with a chord length of 0.2 m and a radius of 2 m. Relation of maximum power coefficient respect to blade number, chord length, and rotor radius is derived. Predicted mean values of the maximum power coefficient are in agreement with calculated values. Furthermore, an equation for the maximum power coefficient is obtained for rotor solidity. Derived equations can be useful to estimate the maximum power coefficient values of H-Darrieus wind turbines.

Abstract The main goal of this study is to investigate the effect of boiler design by smoke tube addition on combustion characteristics and emissions in a small scale pellet boiler. In this context, flame/smoke tube pellet-fuelled boilers with two different constructions were designed, manufactured and tested. In the design of the boilers, the first passes of gases without smoke tubes (Boiler-1) and with smoke tubes (Boiler-2) were considered. The effect of different gas passes of the boilers on flame temperature, flue gas temperature, thermal efficiency, and flue gas emissions of O2, CO, CO2 and NOx were investigated and results were compared with each other. The results showed that adding smoke tubes to the first pass of the boiler decreased the average flue gas temperatures from 87.6 °C to 76.9 °C. The thermal efficiency of the Boiler-2 geometry reached a value of 92.3% and was nearly 1.3% higher than the Boiler-1 geometry. CO emissions increased up to 205 ppm from 166 to 371 ppm by addition of smoke tubes to the first pass of the Boiler-1. It was observed that smoke tubes addition to the first pass of the boiler did not affect the NOx emissions significantly, which were about 45–47 ppm.

Biogas is one of the most attractive renewable resources due to its ability to convert waste into energy. Biogas is produced during an anaerobic digestion process from different organic waste resources with a combination of mainly CH4 (~50 mol/mol), CO2 (~15 mol/mol), and some trace gasses. The percentage of these trace gases is related to operating conditions and feedstocks. Due to the impurities of the trace gases, raw biogas has to be cleaned before use for many applications. Therefore, the cleaning, upgrading, and utilization of biogas has become an important topic that has been widely studied in recent years. In this review, raw biogas components are investigated in relation to feedstock resources. Then, using recent developments, it describes the cleaning methods that have been used to eliminate unwanted components in biogas. Additionally, the upgrading processes are systematically reviewed according to their technology, recovery range, and state of the art methods in this area, regarding obtaining biomethane from biogas. Furthermore, these upgrading methods have been comprehensively reviewed and compared with each other in terms of electricity consumption and methane losses. This comparison revealed that amine scrubbing is one the most promising methods in terms of methane losses and the energy demand of the system. In the section on biogas utilization, raw biogas and biomethane have been assessed with recently available data from the literature according to their usage areas and methods. It seems that biogas can be used as a biofuel to produce energy via CHP and fuel cells with high efficiency. Moreover, it is able to be utilized in an internal combustion engine which reduces exhaust emissions by using biofuels. Lastly, chemical production such as biomethanol, bioethanol, and higher alcohols are in the development stage for utilization of biogas and are discussed in depth. This review reveals that most biogas utilization approaches are in their early stages. The gaps that require further investigations in the field have been identified and highlighted for future research.

Abstract Biomass materials are renewable sources that abundant worldwide due to natural plants and living organisms. Lignocellulosic biomass can be categorized as hardwood, softwood, agricultural wastes, and grasses. Agricultural residues those which of them have importance due to being produced in huge amounts in the worldwide annually. Food wastes and agricultural wastes are utilized either alternative use such as generating energy, fuels or disposal. However, disposal of these residues is follow out either scraping or burning way. This study aims to convert industrial agricultural origin biomass by using hydrothermal carbonization method to carbon-based material having high conductivity for use in supercapacitor production by using different activating chemicals. Hydrothermal carbonization was applied to different biomass samples such as nutshell, hazelnut shell, and corn cob. The elemental analysis of the obtained biochar was carried out and it was determined that the highest source of biomass was corn cob. The selected biochar has been chemically activated with different chemicals such as KOH, NaOH, H3PO4 and, ZnCl2. Advanced carbonization of activated biochar was carried out at 500, 600, 700 and 800 °C with 1, 1.5 and 2-h retention times. The resulting carbon-based products were mixed with KBr and identical pellets were prepared and their electrical conductivity values were measured. Electrical conductivity results, NaOH-800 °C-2h and ZnCl2-700 °C-1.5 h obtained from the process prepared from the biocidal pellets were determined to have the highest conductivity value. Brunauer–Emmett–Teller (BET) and Scanning Electron Microscope (SEM) analyses of the samples with the highest conductivity values were performed and surface morphologies were examined.

The ATLAS Inner Detector is a composite tracking system consisting of silicon pixels, silicon strips and straw tubes in a 2 T magnetic field. Its installation was completed in August 2008 and the detector took part in data- taking with single LHC beams and cosmic rays. The initial detector operation, hardware commissioning and in-situ calibrations are described. Tracking performance has been measured with 7.6 million cosmic-ray events, collected using a tracking trigger and reconstructed with modular pattern-recognition and fitting software. The intrinsic hit efficiency and tracking trigger efficiencies are close to 100%. Lorentz angle measurements for both electrons and holes, specific energy-loss calibration and transition radiation turn-on measurements have been performed. Different alignment techniques have been used to reconstruct the detector geometry. After the initial alignment, a transverse impact parameter resolution of 22.1+/-0.9 ��m and a relative momentum resolution ��p/p = (4.83+/-0.16) \times 10-4 GeV-1 \times pT have been measured for high momentum tracks. 34 pages, 25 figures