Influencing sensitivities of critical operating parameters on PEMFC output performance and gas distribution quality under different electrical load conditions

2019 ◽  
Vol 255 ◽  
pp. 113849 ◽  
Author(s):  
Huicui Chen ◽  
Biao Liu ◽  
Tong Zhang ◽  
Pucheng Pei
Keyword(s):  
Operating Parameters ◽  
Electrical Load ◽  
Gas Distribution ◽  
Output Performance ◽  
Load Conditions

scholarly journals Evaluation of the Power Output Performance Improvement of a 2 MW Wind Turbine

2018 ◽  
Vol 201 ◽  
pp. 01005
Author(s):  
Jui-Hung Liu ◽  
Jien-Chen Chen ◽  
Wen-Jhen Lai ◽  
Wei-Niam Su
Keyword(s):  
Wind Turbine ◽  
Performance Improvement ◽  
Control Strategy ◽  
Surface Condition ◽  
Operating Parameters ◽  
Base Line ◽  
Output Performance ◽  
Cost Of Energy ◽  
Mean Wind Speed ◽  
Large Wind

This paper shows the possibility of the output improvement to a large wind turbine, so the operator can earn more and thus reduce the overall cost of energy. For a modern wind turbine certificated by IEC or DNV-GL guidelines, a 20 years design lifetime is a base line. However, the efficiency of the turbine will degrade after 8 or 9 years’ operating. Some components, especially the turning blade, the efficiency may vary due to the surface condition change. Meanwhile, the controller technology may also have been improved after years. So, the turbine can regain its original output or even have a better output performance through some adjustments. In this paper, a 2 MW wind turbine with different design and operating parameters like blade efficiency, wind direction alignment, high/low wind control strategy has been evaluated, then with the software DNV-GL BLADED simulation, to calculate the output differences and availability of the turbine. The result shown that a 3~5% yield annually can be obtained for each improved parameter in a 9 m/s mean wind speed situation.

scholarly journals A Control Scheme for Variable-Speed Micro-Hydropower Plants

2018 ◽  
Vol 10 (11) ◽  
pp. 4333
Author(s):  
Youping Fan ◽  
Dai Zhang ◽  
Jingjiao Li
Keyword(s):  
Output Power ◽  
Water Flow ◽  
Synchronous Generator ◽  
Automatic Regulation ◽  
Electrical Load ◽  
Relay Feedback ◽  
Generator System ◽  
Generator Output ◽  
Turbine Output ◽  
Load Conditions

The aim of this work was to design and build a control system to control the performance of the Pelton wheel and synchronous generator system at different upstream water flow and electrical load conditions. The turbine output power is determined by the upstream water flow and spear valve, whilst the generator output power is determined by the turbine output power and the electrical load. A spear valve is used to control the generator output power at different water and load conditions. An autotuning proportion integration (PI) arithmetic-based controller was built using a relay feedback tuning method. An on–off relay was used in the program in order to oscillate the system. The optimal PI gains can be estimated via the Ziegler–Nichols method. A fully open test was used to test the tuned PI gains. The performance of the original gains and the new tuned gains were discussed. A controller was used to maintain the frequency or voltage of the output power by automatic regulation of the turbine valve. The program could search for the maximum generation efficiency by entering the output current value of the generator into the program manually.

scholarly journals Analysis and Modeling of the Wear-Out Process of a Lithium-Nickel-Manganese-Cobalt Cell during Cycling Operation under Constant Load Conditions

Energies ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3899 ◽  
Author(s):  
Damian Burzyński ◽  
Robert Pietracho ◽  
Leszek Kasprzyk ◽  
Andrzej Tomczewski
Keyword(s):  
Ambient Temperature ◽  
Experimental Research ◽  
Discharge Current ◽  
Fuzzy Model ◽  
Constant Load ◽  
Operating Parameters ◽  
Half Cycle ◽  
Wear Process ◽  
Nickel Manganese ◽  
Load Conditions

This article describes the analyses of modeling the wear process of lithium-nickel-manganese-cobalt cells operating cyclically under constant load conditions. The main aging processes taking place in cells and the methodology of the modeling are discussed. The process of cell wear is examined, taking into account the influence of cyclic operating parameters (temperature, discharge current, and discharge depth). On the basis of the analyses carried out, a new function reflecting the influence of ambient temperature on the durability of the cell is proposed. A new fuzzy model of the wear process of the NMC 18650 type cell, depending on the parameters of the discharge half cycle, has been developed. The results of the model have been verified by experimental research.

Photo-induced degradation of a-Si:H thin film depending on electrical load conditions

2011 ◽  
Vol 7 (4) ◽  
pp. 323-325 ◽  
Author(s):  
Sang Hyun Park ◽  
Jun-Sik Cho ◽  
Kyung Hoon Yoon
Keyword(s):  
Thin Film ◽  
Electrical Load ◽  
Load Conditions

NUMERICAL ANALYSIS OF OPERATING PARAMETERS OF HYDRODYNAMIC THRUST BEARINGS LUBRICATED WITH MAGNETIC FLUID

Tribologia ◽  
2020 ◽  
Vol 291 (3) ◽  
pp. 43-51
Author(s):  
Marcin Szczęch ◽  
Wojciech Horak ◽  
Yuliia Tarasevych
Keyword(s):  
Comparative Analysis ◽  
Numerical Analysis ◽  
Numerical Simulations ◽  
Rheological Properties ◽  
Operating Parameters ◽  
Thrust Bearings ◽  
Bearing Load ◽  
Functional Features ◽  
Thrust Pad ◽  
Load Conditions

The paper presents the results of numerical simulations (CFD) of hydrodynamic thrust slide bearings lubricated with magnetorheological (MR) fluid. The analyses were carried out to evaluate the influence of the rheological properties of the lubricant, as well as the geometry of the bearing's thrust pad surface. Bearing load conditions were considered on the key functional features of the system, i.e. axial force and torque. The paper presents a comparative analysis of various geometries of thrust bearings and points out possible functional features of hydrodynamic thrust bearings lubricated with fluids with controlled rheological properties.

scholarly journals Big-Data-Mining-Based Improved K-Means Algorithm for Energy Use Analysis of Coal-Fired Power Plant Units: A Case Study

Entropy ◽  
2018 ◽  
Vol 20 (9) ◽  
pp. 702 ◽  
Author(s):  
Binghan Liu ◽  
Zhongguang Fu ◽  
Pengkai Wang ◽  
Lu Liu ◽  
Manda Gao ◽  
...  
Keyword(s):  
Power Plant ◽  
Energy Conservation ◽  
Power Plants ◽  
Energy Use ◽  
Reduction Method ◽  
Support Vector ◽  
Operating Parameters ◽  
Coal Consumption ◽  
Load Optimization ◽  
Load Conditions

The energy use analysis of coal-fired power plant units is of significance for energy conservation and consumption reduction. One of the most serious problems attributed to Chinese coal-fired power plants is coal waste. Several units in one plant may experience a practical rated output situation at the same time, which may increase the coal consumption of the power plant. Here, we propose a new hybrid methodology for plant-level load optimization to minimize coal consumption for coal-fired power plants. The proposed methodology includes two parts. One part determines the reference value of the controllable operating parameters of net coal consumption under typical load conditions, based on an improved K-means algorithm and the Hadoop platform. The other part utilizes a support vector machine to determine the sensitivity coefficients of various operating parameters for the net coal consumption under different load conditions. Additionally, the fuzzy rough set attribute reduction method was employed to obtain the minimalist properties reduction method parameters to reduce the complexity of the dataset. This work is based on continuously-measured information system data from a 600 MW coal-fired power plant in China. The results show that the proposed strategy achieves high energy conservation performance. Taking the 600 MW load optimization value as an example, the optimized power supply coal consumption is 307.95 g/(kW·h) compared to the actual operating value of 313.45 g/(kW·h). It is important for coal-fired power plants to reduce their coal consumption.

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