Papers by Keyword: Power Output

Abstract: A solar chimney power plant (SCPP) sometimes also called 'solar updraft tower' is a part of the solar thermal group of indirect solar conversion technologies, utilizing a combination of solar air collector and central updraft tube or chimney to generate a solar induced convective flow which drives pressure staged turbines to generate electricity. In this paper the performance of a solar chimney power plant (SCPP) is evaluated if established in the Kota region of Rajasthan in India. Kota has high intensity of solar radiation with more than 270 sunny days in a year. To investigate the theoretical performance evaluation of the solar chimney power plant in Kota region, total energy generation and average power output for every ten minute interval has been calculated on the basis of solar radiation and temperature data provided by Centre for wind energy Technology (C-WET) available for the period from June 2011-May 2012 for every ten minute interval. Subsequently day wise and month wise calculations have been performed for energy generation and power output for the year June 2011 - May 2012. Further, annual average power output of SCPP is calculated at Kota for different sets of dimensions of SCPP and assuming different values of collector efficiency. Power produced at the plant established in Kota region is compared with power output estimated by J. Schlaich by their experience gained from prototype of SCPP in Manzanares, Spain. Land area required for solar chimney power plant if installed in Kota region of Rajasthan India is calculated for 200 MW capacity plant.

Abstract: The micro power generators that depend on converting the ambient energy into usable electrical energy for portable electronic devices have attracted much attention in recent years. A novel microfluidic power generator which is based on reverse electrowetting in a microchannel geometry was presented by Tom Krupenkin and J. Ashley Taylor. This generator overcomes the defects such as low output and low resource utilization of traditional energy converters. Understanding the parameters influencing output of this generator is a key to enhance the power output of it. This paper discussed the effects of factors on generator output by numerical simulation. The results show that promising performance of REWOD-based power generator can be achieved by choosing a thinner dielectric film with high dielectric constant and high break strength, and increasing the droplet oscillation frequency.

Abstract: By analyzing the parallel hybrid electric vehicle mode, the optimization of output power to fuel engine and electric motor is discussed. The fuzzy logical rules are proposed by fuzzy control theory. According to the system required power and battery SOC, the engine output power and the motor output power are optimized. The results show that the optimization method based on fuzzy logical can effectively reduces fuel consumption and can well control the battery SOC changes.

Abstract: Stirling engine has the characteristics of diversification of heat source and high thermal power conversion efficiency. It has broad application prospects in using low-grade energy, such as solar energy, biomass emergy and industrial waste heat. In this paper, Schmidt Method used in the Stirling engine working cycle is analyzed theoretically, and the Stirling engine power output is calculated. The effects of temperature and the average cycle pressure on the output characteristics of the system are analyzed. Theoretical calculations show that the output characteristics can be improved significantly by adjusting the heating temperature and the average cycle pressure. An experiment station is then designed and constructed for the research on Stirling engine power output characteristics. Experimental results show that by improving pre-charge pressure in the working chamber with low temperature conditions, the system can achieve higher power output and thermal efficiency. Pre-charge pressure in the working chamber is adjusted to 2MPa, when the heater tube wall temperature reaches 650 °C, the output power exceeds 1750W, and the effective efficiency will be 23.3%.

Abstract: Computational Fluids Dynamics was performed to simulate the performance of torque and output power of wind turbine. Propeller of wind turbine is made by sandwich composite. The composite is combination of ramie fiber with Albizia wood as a core. FLUENT is used to perform simulation of propeller at different wind speeds. The wind speeds ranges from 3 to 5 m/s at coastal area of Kwaru, Bantul, Yogyakarta. Spallart-Almaras method uses to simulate the torque and power output at different Reynold Number. The simulation result shows that the torque of rotor ranges from 25 to 75 Nm, power outputs range from 50 to 240 W and power output coefficients are lay between 0.35 to 0.40 for wind speed from 3 to 5 m/s which is typical in coastal area of Indonesia.

Abstract: The general cycle model of a class of external combustion engines is established in which the influence of the multi-irreversibilities mainly resulting from the linear heat-loss model between the high and low heat reservoir, and the irreversible adiabatic processes. Some important parameters such as the power output, efficiency and the temperatures of the working substance are calculated and some important characteristic curves are given. The results obtained in this paper may provide some theoretical guidance for the optimal design of the Carnot, Brayton, Braysson and some new heat engines.

Abstract: Cell temperature can reach as high as 70 oC while working, using only photovoltaic battery in the solar plane will result in a waste of energy. Combined with the wing configuration, a hybrid energy design method with higher efficiency is presented: photovoltaic cells will be distributed on the wing surface and photothermal cells will be arranged in the wing box section. The back of photovoltaic battery can be used as high temperature heat source and the lower wing surface can be a low temperature cooling source. Through the research of photovoltaic cells maximum power output, the envelope method ensures the output power, improves the power tracking reliability, and reduces difficulty in the design. The structure design of thermoelectric battery P-N junction is optimized by using the maximum power and maximum power to-mass ratio as objective function. The optimal solution of P-N junction structure of a certain type thermoelectric battery is given for acquiring maximum power-to-mass ratio.

Abstract: PEM Fuel Cell (PEMFC) system plays an important role in a future hydrogen economy. Numerical modeling is useful to evaluate and optimize PEM fuel cell system. Therefore, this paper developed an integrated numerical model for predicting the power output of PEMFC system and optimizing system operation parameters to achieve the maximal output power. The developed numerical model integrated the models of fuel cell stack itself and its auxiliary systems, which were quantitatively described and analyzed with calculation equations. Furthermore, the newly developed numerical model was applied to a PEMFC powered scooter to estimate the output power a PEMFC system and optimize the operation conditions parameters of its auxiliary systems based on optimization algorithm. This validates that the developed integrated numerical model is useful and reliable for predicting the net output power and achieving maximal net output power through optimizing the operating parameters of a PEMFC system.

Abstract: The experimental studies of output power performances of a vertical-axis-wind-turbine (VAWT) had been conducted in suction-type low speed wind tunnel with various free stream velocity. Torque and rotation speed of blades were measured by using torque meter and optical detector to analyze the effect of blade-section shape on the performance of wind turbine. The test model of experiments in the research was H-rotor VAWT. Three shapes of the NACA 4-digital series blade-section, NACA0022, NACA6404, and NACA6422 were taken in this work. Effects of thickness and camber of blade-section, blade numbers, and blade setting angles on the performance of VAWT have been analyzed in detail. The results show that NACA6422 blade-section has rotation speed of 42% higher than that of NACA0022 when the free stream velocity is below 12 m/s and the blade numbers are 4-blade type. Wind turbines with NACA6422 blades also showed that about 10% higher output power than that of NACA0022 blades among the tested range of free stream velocity. Results indicated that wind turbine with blades of anti-symmetric and thick blade-section was generally more suitable for applying to VAWT. All results of this study can be used the optimization design of VAWT blades in further.

Abstract: The overall performance of any solar energy project largely depends upon the available solar radiations, inclination and orientation of solar collectors. Presented in this paper is the analytical study on optimum tilt angles and lifetime differential savings for a distributed 200 kW grid connected mono-crystalline solar PV system operating at Khatkar Kalan, Punjab, India. The optimum tilt angles for monthly, seasonally and yearly basis is carried out by searching the values of tilt angle for which electric power output is maximum for a particular day or a specific period using energy conversion model. The results reveal that the yearly optimum tilt angle for the SPV plant at Khatkar Kalan is 36° which is 4.58° higher than the latitude angle. The power output from the array increases with increase in angle of tilt for winter months whereas the trend is reverse for the summer months. In winter months the maximum power output is achieved for the array surface with a tilt of angle 13° - 23° higher than the local latitude while for summer months the maximum power output is achieved at 16° lower than the latitude angle. The optimum tilt angles maximizing monthly power output for south facing surface shows that the monthly optimum tilt angle varies from 15° to 55°. Also the parametric analysis for some influential factors such as latitude of location and reflectivity of ground surface is explored.