Novel Burner Concept for Premixed Surface-Stabilized Combustion

2012 ◽  
Author(s):  
V. N. Kornilov ◽  
S. Shakariyants ◽  
L. P. H. de Goey
Keyword(s):  
Thermal Power ◽  
Operating Conditions ◽  
Flammability Limits ◽  
Load Range ◽  
Simple Method ◽  
Lean Premixed Flames ◽  
Pressurized Combustion ◽  
Burning Rates ◽  
Micro Turbine ◽  
Operating Window

Surface-stabilized combustion is credited with high burning rates, extended lean flammability limits, wide modulation range and other advantages. This makes it an attractive technology for compact low-emission combustors. The experimental gas turbine surface burners reported to this date are produced from compressed and sintered Fe-Cr-Al fiber mats. The authors have developed a new concept of surface burner fabricated by braiding ceramic cords around a ceramic frame. This simple method produces a basket-type surface suitable for stabilizing lean premixed flames over a broad range of operating conditions. The use of ceramics extends possibilities for operation at very high inlet temperatures with reduced risks of material sintering and oxidation. This paper presents test results with an experimental burner on a pressurized combustion rig with optical access. The experiments were performed under the following conditions: inlet temperatures of 22–740 C, pressures of 1–3 bar, thermal power between 4 kWTh and 32 kWTh and equivalence ratios of 0.28–0.95. Measurements of flue gas composition and pressure drop are also reported in the paper. The operating window for low-NOx and low-CO combustion is analyzed. With the demonstrated performance, the burner could cover the operating envelope of a 3 kWe recuperated micro turbine [1]–[2] with no pilot and no staging. This would also limit NOx to <40 ppm @ 0% O2 within the micro turbine load range of 100% to 50%.

scholarly journals Selection of Heat Pump Capacity Used at Thermal Power Plants under Electricity Market Operating Conditions

Energies ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 226
Author(s):  
Milana Treshcheva ◽  
Irina Anikina ◽  
Vitaly Sergeev ◽  
Sergey Skulkin ◽  
Dmitry Treshchev
Keyword(s):  
Electric Power ◽  
Heat Pump ◽  
Heat Load ◽  
Power Plants ◽  
Thermal Power ◽  
Heat Pumps ◽  
Operating Conditions ◽  
Energy Resources ◽  
Thermal Power Plants ◽  
Maximum Heat

The percentage of heat pumps used in thermal power plants (TPPs) in the fuel and energy balance is extremely low in in most countries. One of the reasons for this is the lack of a systematic approach to selecting and justifying the circuit solutions and equipment capacity. This article aims to develop a new method of calculating the maximum capacity of heat pumps. The method proposed in the article has elements of marginal analysis. It takes into account the limitation of heat pump capacity by break-even operation at electric power market (compensation of fuel expenses, connected with electric power production). In this case, the heat pump’s maximum allowable capacity depends on the electric capacity of TPP, electricity consumption for own needs, specific consumption of conditional fuel for electricity production, a ratio of prices for energy resources, and a conversion factor of heat pump. For TPP based on combined cycle gas turbine (CCGT) CCGT-450 with prices at the Russian energy resources markets at the level of 2019, when operating with the maximum heat load, the allowable heat pump capacity will be about 50 MW, and when operating with the minimum heat load—about 200 MW.

Design Point for Predicting Year-Round Performance of Solar Parabolic Trough Concentrator Systems

2013 ◽  
Author(s):  
Men Wirz ◽  
Matthew Roesle ◽  
Aldo Steinfeld
Keyword(s):  
Operating Conditions ◽  
Transfer Model ◽  
Parabolic Trough ◽  
Specific System ◽  
Simple Method ◽  
Operating Condition ◽  
Average Efficiency ◽  
Design Point ◽  
Yearly Average ◽  
Solar Field

Thermal efficiencies of the solar field of two different parabolic trough concentrator (PTC) systems are evaluated for a variety of operating conditions and geographical locations, using a detailed 3D heat transfer model. Results calculated at specific design points are compared to yearly average efficiencies determined using measured direct normal solar irradiance (DNI) data as well as an empirical correlation for DNI. It is shown that the most common choices of operating conditions at which solar field performance is evaluated, such as the equinox or the summer solstice, are inadequate for predicting the yearly average efficiency of the solar field. For a specific system and location, the different design point efficiencies vary significantly and differ by as much as 11.5% from the actual yearly average values. An alternative simple method is presented of determining a representative operating condition for solar fields through weighted averages of the incident solar radiation. For all tested PTC systems and locations, the efficiency of the solar field at the representative operating condition lies within 0.3% of the yearly average efficiency. Thus, with this procedure, it is possible to accurately predict year-round performance of PTC systems using a single design point, while saving computational effort. The importance of the design point is illustrated by an optimization study of the absorber tube diameter, where different choices of operating conditions result in different predicted optimum absorber diameters.

Gas Cooling and Humidification: Design of Packed Towers from Small-Scale Tests

1950 ◽  
Vol 163 (1) ◽  
pp. 41-53 ◽  
Author(s):  
W. F. Carey ◽  
G. J. Williamson
Keyword(s):  
Operating Conditions ◽  
Total Heat ◽  
Small Scale ◽  
Water Cooling ◽  
Packed Tower ◽  
Simple Method ◽  
Worked Example ◽  
Gas Cooling ◽  
Heat Method ◽  
Working Out

On plants in which gases are processed, the gases are often brought into direct contact with water—usually in packed towers. The purpose may be to cool a hot gas, to increase the humidity of a gas, or, in the well-known special case of water-cooling towers, to cool water by contact with atmospheric air. These processes involve simultaneous transfers of sensible heat and water vapour, and existing methods of analysis are complex and laborious, except for the cooling of water, for which Merkel's total-heat method has long been available. Merkel's approximate solution offers the engineer a simple method of working out, for any operating conditions, the amount of heat transferred and the “driving force” available for transferring it. The present paper generalizes the total-heat method and, with a permissible sacrifice in accuracy, preserves the essential simplicity of the water-cooling treatment for gas-cooling and humidification processes. To complete the design of a packed tower, a knowledge is required of the characteristics of the packing. Information obtained in small towers is given for a number of packings, and a worked example shows how to apply the method of treatment, and the packing data presented, to the design of a large plant tower.

Characterization of a Piezoelectric Membrane for MEMS Power

2001 ◽  
Author(s):  
K. Bruce ◽  
R. Richards ◽  
D. Bahr ◽  
C. Richards
Keyword(s):  
Thin Film ◽  
Power System ◽  
Combustion Engine ◽  
Thermal Power ◽  
Operating Conditions ◽  
Mechanical Power ◽  
Central Component ◽  
Carnot Cycle ◽  
Modular Architecture ◽  
Micro Power

Abstract Work toward the development of a thin-film piezoelectric membrane generator is presented. The membrane generator is the central component of a new MEMS power generation system, the P3 micro power system. The P3 micro power system is based on a two-dimensional, modular architecture, in which the individual generic modules or unit cells each have all the functions of an engine integrated. Each unit cell is an external combustion engine, in which thermal power is converted to mechanical power through the use of a novel thermodynamic cycle that approaches the ideal vapor Carnot cycle. Mechanical power is converted into electrical power through the use of a thin-film piezoelectric membrane generator. This paper introduces the concept of the thin-film piezoelectric membrane generator, and describes its design and fabrication. Results of a study to characterize the performance of the piezoelectric membrane generator under expected operating conditions are presented. Current prototypes of the membrane generator are shown to be capable of producing a peak power of 0.1 milliWatts at a voltage of 0.5 Volts.

Novel Combined Power and Cooling Thermodynamic Cycle for Low Temperature Heat Sources, Part II: Experimental Investigation

2003 ◽  
Vol 125 (2) ◽  
pp. 223-229 ◽  
Author(s):  
Gunnar Tamm ◽  
D. Yogi Goswami
Keyword(s):  
Low Temperature ◽  
System Analysis ◽  
Waste Heat ◽  
Thermal Power ◽  
Experimental System ◽  
Thermodynamic Cycle ◽  
Operating Conditions ◽  
Working Fluid ◽  
Water Mixture ◽  
Theoretical Simulation

A combined thermal power and cooling cycle proposed by Goswami is under intensive investigation, both theoretically and experimentally. The proposed cycle combines the Rankine and absorption refrigeration cycles, producing refrigeration while power is the primary goal. A binary ammonia-water mixture is used as the working fluid. This cycle can be used as a bottoming cycle using waste heat from a conventional power cycle or as an independent cycle using low temperature sources such as geothermal and solar energy. An experimental system was constructed to demonstrate the feasibility of the cycle and to compare the experimental results with the theoretical simulation. Results showed that the vapor generation and absorption condensation processes work experimentally, exhibiting expected trends, but with deviations from ideal and equilibrium modeling. The potential for combined turbine work and refrigeration output was evidenced in operating the system. Analysis of losses showed where improvements could be made, in preparation for further testing over a broader range of operating conditions.

scholarly journals Automatic and Online Detection of Rotor Fault State

2018 ◽  
Vol 7 (1) ◽  
pp. 43 ◽  
Author(s):  
Ali Ouanas ◽  
Ammar Medoued ◽  
Salim Haddad ◽  
Mourad Mordjaoui ◽  
D. Sayad
Keyword(s):  
Induction Motor ◽  
Dimensional Space ◽  
Operating Conditions ◽  
Online Detection ◽  
K Nearest Neighbor ◽  
Simple Method ◽  
Important Place ◽  
Motor Test ◽  
Wide Range ◽  
Fault State

In this work, we propose a new and simple method to insure an online and automatic detection of faults that affect induction motor rotors. Induction motors now occupy an important place in the industrial environment and cover an extremely wide range of applications. They require a system installation that monitors the motor state to suit the operating conditions for a given application. The proposed method is based on the consideration of the spectrum of the single-phase stator current envelope as input of the detection algorithm. The characteristics related to the broken bar fault in the frequency domain extracted from the Hilbert Transform is used to estimate the fault severity for different load levels through classification tools. The frequency analysis of the envelope gives the frequency component and the associated amplitude which define the existence of the fault. The clustering of the indicator is chosen in a two-dimensional space by the fuzzy c mean clustering to find the center of each class. The distance criterion, the K-Nearest Neighbor (KNN) algorithm and the neural networks are used to determine the fault type. This method is validated on a 5.5-kW induction motor test bench.Article History: Received July 16th 2017; Received: October 5th 2017; Accepted: Januari 6th 2018; Available onlineHow to Cite This Article: Ouanas, A., Medoued, A., Haddad, S., Mordjaoui, M., and Sayad, D. (2017) Automatic and online Detection of Rotor Fault State. International Journal of Renewable Energy Development, 7(1), 43-52.http://dx.doi.org/10.14710/ijred.7.1.43-52

scholarly journals Evaluation of active sludge and aquatic ferns usage for removal of zinc in a biological wastewater treatment system

2019 ◽  
pp. 39-44
Author(s):  
Amir Hajiali ◽  
Lacramioara Diana Robescu
Keyword(s):  
Ph Value ◽  
Reaction Times ◽  
Treatment Method ◽  
Operating Conditions ◽  
Industrial Scale ◽  
Reactor Performance ◽  
Solution Ph ◽  
Active Sludge ◽  
Simple Method ◽  
Aquatic Fern

In this research capability of biological treatment method via active sludge and aquatic fern evaluated in different operating conditions and they were optimized in order to remove Zn (II). A simple reactor performance for treatment of model and real wastewater on laboratory and semi-industrial scale was investigated. This refining process proceeded with special attention to the effect of solution pH-value, pollutant concentration, absorbent concentration and reaction time. The batch semi-industrial scale reactor represented over 90 % removal efficiency under pH-value of 6 and 5-5.5 for aquatic ferns and active sludge, respectively. Effective reaction times represented various durations for aquatic ferns and active sludge with respect of 120 minutes and 90 minutes. The two biological masses had the best performances with 6 g/l for aquatic ferns and 5 g/l for active sludge. In the presence of 5 ppm of Zn (II) as the objective heavy metal, both absorbents had over 93.2 % removal efficiencies. While obviously laboratory-scale attempts introduced higher acceptable reduction efficiencies via this economic applicable treatment method. Additionally, economic considerations clarified feasibility of this recommended simple method.

scholarly journals Environmental Characteristics of Modern Systems of Domestic Use of Fuel. Part 2. Pollutants Formation by Natural Gas Combustion in Atmospheric Burners: Experimental Studies

2020 ◽  
Vol 63 (5) ◽  
pp. 450-461
Author(s):  
B. S. Soroka ◽  
V. V. Horupa
Keyword(s):  
Thermal Power ◽  
Experimental Studies ◽  
Environmental Indicators ◽  
Gas Pressure ◽  
Operating Conditions ◽  
National Academy Of Sciences ◽  
High Concentration ◽  
Hydrocarbon Gases ◽  
Absolute Level ◽  
Toxic Emissions

The Gas Institute of the National Academy of Sciences of Ukraine performs comprehensive studies of the formation of toxic emissions in the flame of atmospheric burners and beyond the visible burning cones (“rich” primary flame). The experiments are based on the proven significant content of harmful substances in the combustion products of gas fuel in household appliances and on direct contact of consumers with gas emissions during the operation of the stoves. A methodology for the experimental researches of the harmful emissions formation has been proposed while the computerized firing rig serving as the diagnostic facility has been developed for studying the combustion of hydrocarbon gases in the burners of household stoves. Carbon oxides CO and nitrogen oxides NO and NO2 are considered as toxic emissions, while the primary air excess coefficient and the heat load of the burner are considered as variable parameters. Under operating conditions of a gas stove, its variable characteristics are the gas pressure in front of the nozzle of the atmospheric burner and its thermal power. When optimizing the design of burners, the determinant value of the stability of burning, energy and environmental indicators of fuel combustion is the coefficient of excess of primary air λpr at a given gas pressure before the burner. The influence of this coefficient on the formation of CO, NO, NO2 is established, and the possibility of emissions with a high concentration of nitrogen dioxide is proved. Since the concentration of [NO] decreases with an increase in λpr, and the absolute level of [NO2] concentrations is not significantly affected by the value of λpr, it is determined that the proportion of [NO2] concentration in the [NOx] = [NO] + [NO2] compound increases with an increase in the primary air excess coefficient.

scholarly journals Design and Thermo-Economic Comparisons of an Absorption Air Conditioning System Based on Parabolic Trough and Evacuated Tube Solar Collectors

Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3198 ◽  
Author(s):  
Adil Al-Falahi ◽  
Falah Alobaid ◽  
Bernd Epple
Keyword(s):  
Air Conditioning ◽  
Thermal Power ◽  
Lithium Bromide ◽  
Operating Conditions ◽  
Coefficient Of Performance ◽  
Parabolic Trough ◽  
Solar Absorption ◽  
Pumping System ◽  
Economic Analyses ◽  
Evacuated Tube

Solar absorption cycles for air conditioning systems have recently attracted much attention. They have some important advantages that aid in reducing greenhouse gas emissions. In this work, design and thermo-economic analyses are presented in order to compare between two different collector types (parabolic trough and evacuated tube) by water–lithium bromide absorption systems, and to select the best operating conditions. Generally, the system consists of three major parts. The first part is the solar field for thermal power conversion. The second part is the intermediate cycle, which contains a flashing tank and pumping system. The third part is the water lithium bromide absorption chiller. A case study for a sports arena with 700–800 kW total cooling load is also presented. Results reveal that a parabolic trough collector combined with H2O–LiBr (PTC/H2O–LiBr) gives lower design aspects and minimum rates of hourly costs (USD 5.2/h), while ETC/H2O–LiBr configuration give USD 5.6/h. The H2O–LiBr thermo-economic product cost is USD 0.14/GJ. The cycle coefficient of performance COP was in the range of 0.5 to 0.9.

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