RESUMO
This research examines the optimal 3D geometric parameters and shape of empty diffusers to enhance the mass flow rate of the HAWT rotor plane using a detailed parametric study. Previous works have investigated the use of diffusers to augment turbine power output; however, different curvature surfaces and the effects of all associated angles have not been considered for a thorough evaluation. This work mainly focuses on analyzing the effect of opening angles (2° to 22°), inlet shroud angles (8° to 24°), flange height ratios, flange angles (0° and 15°), and shape of the diffuser as well as flanges on velocity, pressure at the diffuser entry, and through the diffuser section at a wind speed of 4.5 m/s. At an inlet-shroud angle of 24° and an opening angle of 8°, with a diffuser flange height-throat diameter ratio of 0.3, the system achieved an 82.9% increase in flowrate. The diffuser with an inlet shroud-side lower stepped flange showed an optimum velocity of 9.12 m/s (maximum) and 8.2 m/s (average), resulting in a 102.66% and 82.2% increase in velocity, respectively. The percentage increase in velocity of the present study is 92.61%, compared with the previous maximum increase in rate of 53.8%, and then an increase in velocity of 38.81% was obtained. The optimum speed occurred at 0.175 m from the inlet section of the diffuser, indicating where the turbine should best be located. The CFD results from this work were validated with experimental data from the literature, showing a good agreement between the two. Integrated diffuser-turbine system simulation and experimental work with field tests are recommended as a way forward.
RESUMO
Bioenergy is now recognized to be capable of providing the vast majority of predicted future renewable energy supply. Biomass is currently considered a common and commonly used renewable energy source. This study depends upon the investigation of khat waste using Aspen Plus software, which is required for creating environmentally friendly energy sources capable of improving our access to energy and economic sustainability. The outcome of the study is to understand the characteristics of the pyrolysis process without conducting a time-consuming, expensive, and complex procedure. The results of the investigation will be useful in determining the best feedstock for the formation of biofuel. Aspen Plus software simulates several ash-free organic components, including carbon, oxygen, nitrogen, hydrogen, and sulfur, with results like 45.72 % for carbon, 5.84 % for hydrogen, 0.43 % for nitrogen, and 38.56 % for oxygen. The production of biofuel is affected by processing parameters such as temperature and total mass flow rate. During reactions with the same mass but different temperatures, the bio-oil declined from 600 °C to 800 °C, while the maximum gas emission climbed quickly and the biochar reduced. In addition, it was recovered from Khat waste and proved to have an energy efficiency of 80.75 % and a net energy capacity of 134.25 kW. In addition, the High heating value (HHV) can be obtained from Khat waste is 19.38 MJ/kg, and low heating (LHV) can be 18.12 MJ/kg. We have been able to realize it using the Institute of Gas Technology formula based on ultimate analysis. The results show that Khat produces more oil than other wastes. As a result, all Khat waste is naturally occurring and Khat waste usually contains less nitrogen and no sulfur when used as fuel, which is an air pollutant reducing and protecting the environment.
