جستجوی مقالات مرتبط با کلیدواژه « انرژی تجدید پذیر » در نشریات گروه « مکانیک »

The present study was conducted to optimally select equipment for a grid-connected photovoltaic solar power station using the method of analytical hierarchy process (AHP) and the Expert Choice software. AHP is one of the most widely used multi-criteria decision-making tools. Criteria and sub-criteria such as efficiency, price, number of years of warranty, and amount of equipment were considered. For selection of optimal equipment using the AHP method, realized in Expert Choice, pairwise comparison is made between the sets for weighting once the hierarchical levels, including the goal, criteria, sub-criteria, and alternatives (intended equipment), are specified. As the sets are weighted, the compatibility of judgments is analyzed, which must be less than 0.1. The research addressed the equipment available over the market in Iran. Given the measures considered here, 500W Mono Trina Solar was selected as the best panel, and 25KW Growatt MID KTL3-X was the best inverter. The other alternatives were assigned the next priorities based on the corresponding weights. Moreover, sensitivity analysis was made on the main criteria, and the effect of parameter weight on the alternatives was assessed.

Limited access to fresh water sources has raised water shortage as a crisis. Therefore, solar desalinations have received special attention today. A stepped solar desalination device which has 28 steps with a height of 30 mm, a width of 110 mm and a length of 840 mm has been designed, built and used in this research. In order to increase the daily production rate, the device has been tested and optimized in 4 different modes: first mode) simple, second mode) with phase change material (PCM), third mode) with Hybrid Nano phase change material (NPCM), fourth mode) with Hybrid NPCM under magnetic field. The phase change material and Hybrid Nano phase change material have been used as a source of thermal energy storage to continue the desalination of water when the sun sets. After conducting the tests, it was found that the fourth mode of the test, i.e. the Hybrid Nano phase change material under the magnetic field, had a 98% increase in the production rate compared to the simple mode.

In the present study, a novel tri-generation system is proposed. The system produces heat, electric power, and cooling water using concentrated solar cells alongside thermoelectric coolers. The simulation of the system is performed analytically. A zerodimensional model for thermoelectric cooler is applied and the thermal resistance network model is used for a more accurate simulation of the cooling system of the concentrated solar cells. The results indicate that the system can deliver 270 kW electrical power and 2 kg/s of cold water flow in 10℃ and 10 kg/s of hot water flow in 50℃ using 1000× CPV panels with an overall surface area of about 2 m2 which are divided into 1×1 cm pieces. The parametric study conducted on the system for different hours of the day shows that solar radiation has a minimal effect on the output cold water temperature, but it strongly affects the generated power.

The purpose of this research is to determine the amount of equipment used in the design of the photovoltaic solar power plant with a capacity of 200 kW. In this research conducted by PVsyst software, 500 w MonoTrina solar panel with 400 pieces, 25kw Growatt MID KTL3-X inverter with 8 pieces, which are arranged in 40 rows and 10 panels in each row. The optimal panel installation angle was 35 Degree °and the optimal azimuth angle was 0 Degree (case study: Qazvin city). According to the considered space and the designs made, including the percentage of permissible losses in cable calculations, the length and cross-sectional area of the DC side cable made of copper and aluminum are 800 meters, 16 and 25 mm square respectively, the length and cross-sectional area . AC side cable made of copper and aluminum is determined to be 100 meters, 16 and 25 mm square, respectively. The amount of total annual production energy of the desired point was determined by considering the losses, which was about 337.1 megawatt hours per year.

Coasts and harbors can be considered huge sources of energy, which can be seen in the form of waves, tides and constant surface or underwater currents, due to the temperature difference between different points. Energy production in this way does not involve pollution. These power plants can generate energy throughout the year. In this study, finite element method has been used to model the generator as one of the most accurate simulation methods for the desired calculations, which can be used on shores, ports and ship hulls, and the oscillating movements of water waves can be easily converted into energy. Lightning. In this paper, the mechanism of this type of generator is modeled and simulated. The simulation results showed that the implementation and construction of these generators have good efficiency and high economic efficiency. Reliable simulation tools are essential for studying the performance and viability of wave energy devices, as experiments are both costly and difficult. In particular, the ability to survive in nonlinear waves is one of the biggest challenges to wave energy, and since waveforms and dynamics are highly dependent on the model, each device must be studied separately with approved instruments. To take. In this study, the design of the generator including rotor, stator and wiring will be fully investigated. For this purpose, first the mathematical relations related to the generator are stated and at the end, the analytical design of a generator example will be examined. In this study, the finite element method has been used as one of the most accurate simulation methods for the calculations.

In this paper, the thermodynamic performance of a solar assisted high temperature heat pump with water heating application is investigated. The comprehensive simulation and analysis of energy and exergy was done by Haysis and MATLAB software. This analyzes produce some convincing results due to the use of environmentally friendly and environmentally friendly energy sources. Thermodynamic analysis in thermal energy systems is very important due to the identification of high-consumption equipment and determining the location and level of inefficiency of the system equipment. According to the results of the system energy, among the equipment of the P100 pump system and the HX1 heat exchanger, it has the lowest and the highest energy consumption, respectively. 2.09 and 22669.11 kW. Also, the exergy analysis shows that the highest amount of exergy of currents with 367092 kW is related to the input flow of the tank and the highest exergy destruction of the equipment is 15563 kW related to the solar collector. This exergy destruction of the solar collector with temperature changes throughout the year with the lowest destruction in July at the rate of 14342 kW and the highest exergy destruction of 15678 kW relates to the month of June. Among the rotating equipment, the most exergy destruction is related to the k101 compressor of the water heat transfer cycle.

One of the most important steps in using any renewable energy source is to accurately estimate it. Universal solar radiation is generally measured on a horizontal surface, while the maximum amount of solar radiation is a collision on a sloping surface. However, in order to take full advantage of solar radiation on collector surfaces, conventional fixed solar systems, both solar photovoltaic and flat panel solar collectors, are installed on sloping surfaces. In this study, the HDKR model has been used to estimate the radiant energy on the horizontal and sloping surfaces of solar collectors. In this regard, using MATLAB software, the amount of energy received by the solar collector throughout the year was investigated. The results of this study show that in the Ahvaz International Airport station, in terms of average monthly, the highest amount of direct radiation for clear skies is related to June with 206 kWh / m2 and the lowest amount of radiation for February is 113 kWh / m2. Square meters.

Initially, adding B5 to diesel fuel was led to reduce CO emissions and fuel consumption and increase torque and brake power. In the next step, alumina and silica nanoparticles were added separately to the diesel-biodiesel fuel at 30, 60, 90 and 120 ppm. The results showed that SiO2, compared to Al2O3, improved the performance and reduced emissions which resulted in 21.6% increase in brake power at 90 ppm, 8.1% decrease in CO2, 56.16% decrease in CO, 3.05% decrease in fuel consumption and a very slight increase of 0.57% and 0.6% in NOX and NO, respectively. Then SiO2_Al2O3 composite samples with different ratios were added to diesel-biodiesel fuel. Among the nanocomposites, B5Al60Si60 had the highest power and torque, resulting in a 1.44% increase in torque and a 1.64% increase in brake power compared to diesel fuel and a reduction of 39.21%, 9.9%, 10, 6.9% and 6.85% in CO, CO2, NO and NOX, respectively. A multilayered neural network with one and two hidden layers and two types of sigmoid activation and hyperbolic tangent were used to analyze the results. The MSE and R values for brake power, CO, CO2, NO, NOX and torque were 21.10 and 0.9905, 1414/75 and 0.9910, 0.0009 and 0.9940, 3.94 and 0.9965, 0.00079919, and 0.9905 respectively. In total, the best network is that with the sigmoid activation function and the hidden layer.

Today's energy consumption is increasing in developing countries. Most countries generate electricity from fossil fuels. Combined cycle plants produce 1 kg of 660 g of carbon dioxide gas. In study Firouzkouh province of Tehran province has been studied to use a small turbine to supply electricity to greenhouses. According to the study, Firuz Mountain has a wind density142 (w / m2) at a height of 10 meters from the ground. In this The wind speed is 5.6 m/s. Due to the wind speed and wind density in the Firoozkouh region, wind turbines of 10 and 5 kW have been used for further investigation. The 10 and 5 kW Hummer turbines produce 2394 and 1532 watts, respectively, with respect to the region's wind velocity, respectively. To reduce greenhouse costs, it is possible to invest in wind energy, while taking advantage of the environmental benefits of dispersed production and reducing the cost of greenhouse products in the long run. The reviews of this paper show that turbines 10 and 5 kilowatts of hammer in the Firoozkooh area and 10 meters high for installation and use.