Computed Performance Characteristics of Electrofluid Dynamic Colloid Generators

1971 ◽  
Vol 93 (2) ◽  
pp. 183-191
Author(s):  
J. E. Minardi
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Power Output ◽  
Applied Voltage ◽  
Electric Breakdown ◽  
Infinite Plane ◽  
Two Dimensional ◽  
Gas Velocity ◽  
Dynamic Generator

The effects of the electric breakdown limitation on the power output of an electrofluid dynamic generator operating with colloids are studied. The study is performed for both an axisymmetric cylinder of charge and a two-dimensional (Cartesian) slab of charge between infinite, plane, parallel electrodes. The ratio of radius to length or width to length varies from zero to infinity, thus both the so-called slender channels (reference [9]) and broad channels (reference [2]) as well as the intermediate geometries are studied. Normalized power (the value of which is basically limited by electric breakdown) is presented as a function of normalized gas velocity and normalized applied voltage. Also presented is a normalized power per unit mass flow rate as a function of the normalized velocity and voltage. A single chart is sufficient to cover all geometries because the normalized power includes a geometric factor which can be determined from an auxiliary curve to account for the particular geometry.

Experimental Investigation of a Flat Plate Photovoltaic/Thermal Collector

2018 ◽  
Author(s):  
Mohamad Modrek ◽  
Ali Al-Alili
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Power Output ◽  
Electrical Power ◽  
Solar Thermal ◽  
Pv Panel ◽  
Solar Thermal Collectors ◽  
Electrical Power Output ◽  
Electrical Output

Photovoltaic thermal collectors (PVT) combines technologies of photovoltaic panels and solar thermal collectors into a hybrid system by attaching an absorber to the back surface of a PV panel. PVT collectors have gained a lot of attention recently due to the high energy output per unit area compared to a standalone system of PV panels and solar thermal collectors. In this study, performance of a liquid cooled flat PVT collector under the climatic conditions of Abu Dhabi, United Arab Emirates was experimentally investigated. The electrical performances of the PVT collector was compared to that of a standalone PV panel. Moreover, effect of sand accumulation on performance of PVT collectors was examined. Additionally, effect of mass flow rate on thermal and electrical output of PVT collector was studied. Electrical power output is slightly affected by changes in mass flow rate. However, thermal energy increased by 22% with increasing flow rate. Electrical power output of a PV panel was found to be 38% lower compared to electrical output of PVT collectors. Dust accumulation on PVT surface reduced electrical power output up to 7% compared with a reference PVT collector.

A physics-based turbocharger model for automotive diesel engine control applications

2018 ◽  
Vol 233 (7) ◽  
pp. 1667-1686 ◽  
Author(s):  
Kang Song ◽  
Devesh Upadhyay ◽  
Hui Xie
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Turbine Rotor ◽  
Variable Geometry ◽  
Gas Velocity ◽  
Euler’S Equations ◽  
Variable Geometry Turbine ◽  
Euler's Equations ◽  
Compressor Power

Control-oriented models of turbocharger processes such as the compressor mass flow rate, the compressor power, and the variable geometry turbine power are presented. In a departure from approaches that rely on ad hoc empirical relationships and/or supplier provided performance maps, models based on turbomachinery physics and known geometries are attempted. The compressor power model is developed using Euler’s equations of turbomachinery, where the gas velocity exiting the rotor is estimated from an empirically identified correlation for the ratio between the radial and tangential components of the gas velocity. The compressor mass flow rate is modeled based on mass conservation, by approximating the compressor as an adiabatic converging-diverging nozzle with compressible fluid driven by external work input from the compressor wheel. The variable geometry turbine power is developed with Euler’s equations, where the turbine exit swirl and the gas acceleration in the vaneless space are neglected. The gas flow direction into the turbine rotor is assumed to align with the orientation of the variable geometry turbine vane. The gas exit velocity is calculated, similar to the compressor, based on an empirical model for the ratio between the turbine rotor inlet and exit velocities. A power loss model is also proposed that allows proper accounting of power transfer between the turbine and compressor. Model validation against experimental data is presented.

scholarly journals Off-Design Performances of an Organic Rankine Cycle for Waste Heat Recovery from Gas Turbines

Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1105 ◽  
Author(s):  
Carlo Carcasci ◽  
Lapo Cheli ◽  
Pietro Lubello ◽  
Lorenzo Winchler
Keyword(s):  
Gas Turbine ◽  
Mass Flow Rate ◽  
Air Temperature ◽  
Mass Flow ◽  
Flow Rate ◽  
Power Output ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Ambient Air ◽  
Air Mass

This paper presents an off-design analysis of a gas turbine Organic Rankine Cycle (ORC) combined cycle. Combustion turbine performances are significantly affected by fluctuations in ambient conditions, leading to relevant variations in the exhaust gases’ mass flow rate and temperature. The effects of the variation of ambient air temperature have been considered in the simulation of the topper cycle and of the condenser in the bottomer one. Analyses have been performed for different working fluids (toluene, benzene and cyclopentane) and control systems have been introduced on critical parameters, such as oil temperature and air mass flow rate at the condenser fan. Results have highlighted similar power outputs for cycles based on benzene and toluene, while differences as high as 34% have been found for cyclopentane. The power output trend with ambient temperature has been found to be influenced by slope discontinuities in gas turbine exhaust mass flow rate and temperature and by the upper limit imposed on the air mass flow rate at the condenser as well, suggesting the importance of a correct sizing of the component in the design phase. Overall, benzene-based cycle power output has been found to vary between 4518 kW and 3346 kW in the ambient air temperature range considered.

Experimental investigation and optimization of a low-temperature thermoelectric module with different operating conditions

2019 ◽  
Vol 16 (3) ◽  
pp. 368-376
Author(s):  
Dipak Sudam Patil ◽  
Rachayya R. Arakerimath ◽  
Pramod V. Walke
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Power Output ◽  
External Load ◽  
Thermoelectric Module ◽  
Load Resistance ◽  
Operating Conditions ◽  
Content Type ◽  
Heater Temperature

Purpose This paper aims to present an experimental investigation and optimization of a low-temperature thermoelectric module to examine the influence of the main operating conditions. Design/methodology/approach In this work, a comparison was made by varying the various operating parameters such as heat source temperature, the flow rate of the cold fluid and the external load resistance. A Taguchi method was applied to optimize the parameters of the system. Three factors, including the external load resistance, mass flow rate of water (at the heat sink side) and heater temperature (at the heat source side) along with different levels were taken into account. Analysis of variance was used to determine the significance and percentage contribution of each parameter. Findings The experimental results show that the maximum power output 8.22W and the maximum conversion efficiency 1.11 per cent were obtained at the heater temperature of 240°C, the cold fluid mass flow rate of 0.017 kg/s, module temperature difference of 45°C and the load resistance of 5 O. It was observed that the optimum parameter levels for maximum power output determined as 5 O external load resistance, 0.17 kg/s mass flow rate of water and 240°C heater temperature (A1B3C3). It reflects that these parameters influence on the optimum conditions. The heater temperature is the most significant parameter on the power output of the thermoelectric module. Originality/value It is clear from the confirmation test that experimental values and the predicted values are in good agreement.

Power Enhancement of Gas Turbine Plant by Intake Air Fog Cooling

2015 ◽  
Vol 3 (1) ◽  
Author(s):  
J. P. Yadav ◽  
Bharat Raj Singh ◽  
Onkar Singh
Keyword(s):  
Gas Turbine ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Power Output ◽  
Gas Turbines ◽  
Ambient Air ◽  
Summer Season ◽  
Ambient Conditions ◽  
Power Enhancement

Although gas turbines are known as constant volume machines, but its performance considerably depends upon the ambient air temperature and mass flow rate. During summer season the density of the air decreases which affects the mass flow rate and ultimately the power output of a gas turbine is reduced. In order to overcome this situation several techniques are already in the practice and one of the most effective and economical is adopting the inlet fog cooling, and this technique basically enhances the power output of the machine. The cooling of ambient air by fog cooling up to wet bulb temperature increases the mass flow rate on account of increase in air density, as a result it ultimately increases the power output of a gas turbine. Fogging is applied with consideration of relative humidity of ambient air not only during summer season but also during dry days of summer season in order to increase the power output of gas turbine. This paper describes the effect on percentage enhancement of power out adopting various fuel options with low and high humidity ambient conditions. The result indicates the potential increase in the power output up to 14%. It is also observed that the total cost of power production increases due to increase in fuel consumption on account of enhanced power output. Thus the best suitable selling cost of power should be selected to compensate the increased investment on fuel cost.

scholarly journals Geothermal Power: Factors affecting the performance of Binary Plants

2015 ◽  
Vol 2 ◽  
pp. 32-49
Author(s):  
Izabela Domanski ◽  
Matthew Cappadona ◽  
Oliver Fuller ◽  
Zeb Krix
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Power Output ◽  
Power Plants ◽  
Plant Performance ◽  
Factors Affecting ◽  
Binary Cycle ◽  
Well Depth ◽  
And Performance

A meta-study is conducted investigating the effect of plant parameters on the power output and efficiency of geothermal binary cycle power plants. Production well depth, geofluid temperature and mass flow rate are the parameters considered. An increase in mass flow rate is shown to increase both power output and efficiency. It is shown that a distinction can be made between two basic types of binary plants based off of mass flow and performance data. The well depth is shown to have no effect on plant performance. In addition, condenser parameters were investigated and the highest efficiency condenser system is determined.

Numerical Study on Three-Dimensional Wall Effects of Flat Micro Nozzle

2011 ◽  
Vol 339 ◽  
pp. 276-282
Author(s):  
Jun Jie Tong ◽  
Ji Wen Cen ◽  
Jin Liang Xu
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Stokes Equations ◽  
Numerical Study ◽  
Three Dimensional ◽  
Numerical Results ◽  
Two Dimensional ◽  
Wall Effects ◽  
Micro Nozzle

The FLUENT6.1 software is applied to simulate the supersonic flow in micro convergent-divergent nozzle which is fabricated from flat silicon wafers. The simulation is complemented by parallel computing steady 2-D and 3-D Navier-stokes equations to study the three-dimensional wall effects on temperature and velocity inside the micro nozzle. Also the performances of fluent mass coefficients and thrust force efficiencies are studied. It is observed by the study that three-dimensional wall effects are not negligible in flat micro nozzle. The velocity of fluid in three-dimensional nozzle is less than the corresponding velocity of fluid in two-dimensional nozzle significantly, while the temperature of fluid in three-dimensional nozzle is much higher than the corresponding temperature of fluid in two-dimensional nozzle. The mass flow rate and thrust at the exit of 2-D nozzle are greater than the corresponding mass flow rate and thrust at the exit of three-dimensional. With the throat Renaults being increased, the corresponding differences between two-dimensional numerical results and three-dimensional numerical results decreased accordingly. Two-dimensional numerical results can not correctly predict the actual mass flow rate and thrust at the exit of micro nozzle.

Numerical Study of Axial Turbine Flow With Variable Gas Property

2004 ◽  
Author(s):  
Yufeng Yao ◽  
Ian G. Amos
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Power Output ◽  
Gas Turbines ◽  
Numerical Study ◽  
Performance Characteristics ◽  
Accurate Analysis ◽  
Blade Row ◽  
Property Model

Aerodynamic performance characteristics and flow details of industrial gas turbines have been evaluated by using a computational fluid dynamics code with a variable gas property model. Systematic simulations have been carried out first to study numerical effects, notably grid resolution and domain size dependency, followed by applications on a warm air turbine rig and an industrial engine. Studies of the turbine rig are focused on the stage performance characteristics and the results agree with the test data fairly well. It is also found that the variable gas property has little influence on the flow half a chord downstream of the rotor trailing edge, where the conditions of the next turbine stage are determined. Further studies on a 3-stage turbine reveal the influence of the variable gas property model. When the gas properties are made constant with respect to the first blade row conditions, the mass flow rate is the same as when using the variable gas property model, however the exit total temperature is over-predicted by about 15 Kelvin. There is also an over-prediction of turbine power output of 0.6%. Simulations using a constant gas property of averaged value or at the last blade row over-predict the mass flow rate by 0.5% and 1% respectively. Downstream on the blade surface and near the exit, they under-predict the temperature and the power output. The predicted efficiency from the various simulations is found to be less influenced than the parameters discussed above, with a difference of about 0.25%. As a conclusion, it is necessary to include the variable gas property effect in 3D calculations of industrial gas turbine flow to achieve an accurate analysis of the flow and performance.

Experimental Study on the Performance of the Single Screw Expander Prototype by Optimizing Configuration

2012 ◽  
Author(s):  
Wei Wang ◽  
Yu-ting Wu ◽  
Guo-dong Xia ◽  
Chong-fang Ma ◽  
Jing-fu Wang ◽  
...  
Keyword(s):  
Experimental Data ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Power Output ◽  
Consumption Rate ◽  
Experimental Results ◽  
Thermodynamic Efficiency ◽  
Single Screw ◽  
Gas Consumption

Improving thermodynamic efficiency of prime movers is the key issue for efficient utilization of low temperature heat resources. Because of many good characteristics, the single screw expander is perhaps a good choice. Precisions in manufacture and assembly are very important factors to the performance of single screw expanders. In this paper, experimental results of the first single screw expander prototype made by ourselves was analyzed and reported for the first time. From the experimental data, the power output of the prototype was about 5kW, but the gas consumption rate was above 105kg/kWh, so the shaft efficiency was only 34% or so. The results indicated that internal leakage was very serious. Hence, the second single screw expander prototype was manufactured. The gap between gate rotor and shell of the new prototype was reduced. The gap is about 0.02mm. From the new experimental data, the mass flow rate was significantly decreased. However, the power output was only 1.4kW. So, the gas consumption rate was even more than the first prototype. The reason of bad experimental results may arise from the too large friction between screw, gate rotor and shell in the case of small gap. So, we manufactured the third single screw expander prototype, which is 0.04mm in gap. From the experimental data, the maximum power output was about 4.5kW, but the mass flow rate was decreased sharply. So the gas consumption rate was about 60kg/kWh, and the shaft efficiency was about 60%. The result indicated that the performance of the single screw expander was remarkable improved by optimizing its configuration.

Thermal and Economic Analysis of Gas Turbine Steam Injection Plant

2006 ◽  
Author(s):  
Sepehr Sanaye ◽  
Vahid Mahdikhani ◽  
Ziaeddin Khajeh Karimeddini ◽  
Gholamreza Sadri
Keyword(s):  
Combustion Chamber ◽  
Gas Turbine ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Power Output ◽  
Steam Injection ◽  
Nox Emissions ◽  
Gas Turbine Exhaust ◽  
Turbine Exhaust

Steam injection into gas turbine combustion chamber increases the power output and lowers the NOx emissions. Steam may be produced in a heat recovery steam generator (HRSG), using gas turbine exhaust gases. Steam which is usually injected with pressure of combustion chamber, increases the mass flow rate flowing through turbine and decreases the combustion temperature, hence, lowering the amount of NOx emissions. This power augmentation method is usually used for gas turbines with power outputs in range of 2–50 MW with one pressure level in HRSG. In this paper the optimum design parameters of the above mentioned system is obtained for the above range of gas turbine power output. For doing this task an objective function is introduced which contains the economic and thermal characteristics of the system. This objective function is minimized when gas turbine exhaust temperature, compressor pressure ratio, isentropic efficiency of compressor and turbine, fuel mass flow rate (natural gas), inlet air mass flow rate, and the amount of injected steam mass flow rate vary.

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