Influence of Radiation Properties of Combustion Products on the Reliability of the Combustion Zone in Power Plants

2018 ◽  
Author(s):  
E.V. Toropov
Keyword(s):  
Combustion Zone ◽  
Power Plants ◽  
Combustion Products ◽  
Radiation Properties

scholarly journals INFLUENCE OF HEATING OF A GAS-AIR MIXTURE ON THE CHARACTERISTICS OF COMBUSTION OF FUEL GASES

2021 ◽  
pp. 83-90
Author(s):  
Alyona Shilova ◽  
◽  
Nikolay Bachev ◽  
Roman Bulbovich ◽  
◽  
...  
Keyword(s):  
Low Temperature ◽  
Flame Front ◽  
Power Plants ◽  
Combustion Products ◽  
Concentration Limit ◽  
Low Temperature Combustion ◽  
K Value ◽  
Stable Position ◽  
Excess Air ◽  
External Heating

For a stable position of the flame front in the combustion chambers of gas turbine power plants, the fresh gas-air mixture must be heated to the ignition temperature during the entire operation process. With air excess coefficients in the interval between the upper and lower concentration limits, reverse currents from the zone of developed combustion successfully cope with this task. When organizing low-temperature combustion near the lean limit, the contribution of reverse currents to heating the fresh gas-air mixture turns out to be insufficient and additional external heating of the components in special heaters with exhaust gases from the turbine is required. The temperature characteristics of the fresh gas-air mixture at the inlet to the chamber and in the zone of return currents, as well as combustion products in the developed flame zone, were obtained from the solution of the energy balance equations. The modes of low-temperature lean combustion with excess air coefficients exceeding the lower concentration limit α = 2 are considered. The calculations were carried out for two values of the ejection coefficient in the zone of reverse currents K = 0.14 and K = 0.30. A K value of 0.14 was obtained using empirical relationships. The value K = 0.30 was obtained from the condition that during stoichiometric combustion, the gas-air mixture is heated completely by reverse currents. It is shown that with an increase in the excess air ratio to ensure a stable position of the flame front, the role of external heating of components increases.

scholarly journals The radiation properties of burning clouds of metal dust. 3. Modification of the emission spectrum

2021 ◽  
pp. 100-105
Author(s):  
V.G. Shevchuk ◽  
N.I. Poletaev ◽  
А.V. Nimich ◽  
G.L. Shyngarov
Keyword(s):  
Emission Spectrum ◽  
Emission Spectra ◽  
Combustion Products ◽  
Decomposition Temperature ◽  
Boron Compounds ◽  
Dust Clouds ◽  
Radiation Properties ◽  
Local Modification ◽  
Yellow Region ◽  
Metal Dust

In this work we studied the emission spectra of the combustion products of low-volume dust clouds (V = 5 L) from aluminum (ASD-4), as well as clouds from mixed compositions of aluminum with inorganic powdery oxidizing agents (NaNO3, NaCl, Na2CO3·10H2O, Sr(NO3)2, Ba(NO3)2, KNO3, CuSO4, CuSO4·10H2O) and combustible (B, AlB2, Cu). This article discusses the possibilities of purposeful modification of the emission spectrum of the base composition using various inert and optically active dispersed additives that shift the maximum of the emission spectrum of the fuel composition to the region of longer waves or cause a local change in the emission spectrum in the corresponding spectral regions. In the course of the experiments, it was revealed that the introduction of additives into the basic composition of dispersed fuel does not significantly change the dynamic characteristics of the suspension. However, the additives lead to a decrease in temperature (by about 100–200°K in the presence of an additive up to 25% by weight) and to a corresponding shift in the maximum of the radiation spectrum. The possibility of a significant local modification of the spectrum in the yellow region with the help of inorganic additives to the fuel of sodium salts with a low decomposition temperature (additives Na2CO3·10H2O) was shown experimentally. Boron additives and boron compounds (B, AlB2) leads to a significant increase in the luminosity of the flame in the green region of the spectrum with a maximum radiation in the range Δλ = 530 ÷ 580 nm. The article presents the lighting characteristics (luminous intensity, light sum) of large clouds (V ≥ 10 m3) of mixed compositions based on PAP-2 aluminum powder. It was found that the introduction of inorganic additives to the base fuel does not lead to a noticeable change in the lighting characteristics, but somewhat increases the time of the cloud glow both in the visible and infrared parts of the spectrum.

scholarly journals RESEARCHES OF ECONOMIC INDICATORS OF WORK MODERNIZED RAH-98

2017 ◽  
pp. 27-34
Author(s):  
Yo.S. Mysak ◽  
M.F. Zayats ◽  
T.I. Rуmar
Keyword(s):  
Natural Gas ◽  
Power Unit ◽  
Power Plants ◽  
Combustion Products ◽  
Fuel Oil ◽  
Stable Mode ◽  
Load Variation ◽  
Mode Of Operation ◽  
Two Stages ◽  
Efficiency And Reliability

An analysis of the existing methods and schemes of heating the air by combustion products in the tailings of the heating boiler indicates that such measures provide an opportunity to increase the efficiency and reliability of power plants, as well as increase the efficiency of boiler plants. This paper considers the results of the study of the economic performance of the modernized RAH-98 boiler TGMP-314 A 300 MW on natural gas in the range of load variation of the power unit 160–260 MW and on the fuel oil in the range of load variation of the power unit 200–260 MW. Experiments were carried out at a stable mode of operation of the boiler in two stages: for the off and for the included scheme of suction environment from the seals of RAH. The average increase in the efficiency of the boiler is 0.35 % gross during operation of the boiler, both on natural gas and on fuel oil in the specified range of loads. Absorption of air in RAH for loads of the power unit 160–260 MW for the included circuitry is reduced by 7 % on average compared to the disconnected circuit. Bibl. 10, Fig. 5.

scholarly journals Research Summary on the Processing, Mechanical and Tribological Properties of Aluminium Matrix Composites as Effected by Fly Ash Reinforcement

Crystals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1212
Author(s):  
Alaa Mohammed Razzaq ◽  
Dayang Laila Majid ◽  
Uday M. Basheer ◽  
Hakim S. Sultan Aljibori
Keyword(s):  
Composite Materials ◽  
Fly Ash ◽  
Power Plants ◽  
Bottom Ash ◽  
Metallic Matrix ◽  
Weight Fraction ◽  
Combustion Products ◽  
Coal Waste ◽  
Matrix Composites ◽  
Coal Combustion Products

Fly ash is the main waste as a result of combustion in coal fired power plants. It represents about 40% of the wastes of coal combustion products (fly ash, boiler ash, flue gas desulphurization gypsum and bottom ash). Currently, coal waste is not fully utilized and waste disposal remains a serious concern despite tremendous global efforts in reducing fossil fuel dependency and shifting to sustainable energy sources. Owing to that, employment of fly ash as reinforcement particles in metallic matrix composites are gaining momentum as part of recycling effort and also as a means to improve the specifications of the materials that are added to it to form composite materials. Many studies have been done on fly ash to study composite materials wear characteristics including the effects of fly ash content, applied load, and sliding velocity. Here, particular attention is given to studies carried out on the influence FA content on physical, mechanical, and the thermal behavior of Aluminium-FA composites. Considerable changes in these properties are seen by fly ash refinement with limited size and weight fraction. The advantage of fly ash addition results in low density of composites materials, improvement of strength, and hardness. It further reduces the thermal expansion coefficient and improve wear resistance.

scholarly journals Тoxicity of exhaust gasessolid fuel boiler KE-25-14S

2020 ◽  
Vol 22 (1) ◽  
pp. 77-84
Author(s):  
M. S. Ivanitskiy
Keyword(s):  
Power Plants ◽  
Negative Impact ◽  
Thermal Power ◽  
Hazard Index ◽  
Combustion Products ◽  
State Regulation ◽  
Best Available Technologies ◽  
The Impact ◽  
National Environmental ◽  
Practical Recommendations

The article deals with the implementation of the new national environmental legislation, which provides for the division of all energy enterprises into 4 categories depending on the degree of negative impact on the environment, the introduction of technological rationing, implemented on the principles of the best available technologies, provided that they are technically possible to use them, and the differentiation of state regulation measures in the field of environmental protection. Within the framework of this approach, the values of the total index of harmfulness (toxicity) of combustion products formed during the burning of Berezovsky coal of the B2 grade (enrichment class P) were determined by numerical experiments in order to assess the impact on the environment of emissions from low-power boilers KE-25-14C. The total emission hazard index is determined by taking into account the contribution of specific hazard indicators of combustion components represented by nitrogen oxides, sulfur dioxide, carbon monoxide, ash particles, vanadium pentaoxide and benz(a)pyrene. The private contribution of the considered pollutants to the total toxicity of emissions in the implementation of combustion regimes with moderate and large chemical underburning of fuel is established. Practical recommendations are given for using the results of the study as input data for setting technological standards for boilers of thermal power plants in the process of approval and obtaining a comprehensive environmental permit, and for developing a program to improve the environmental efficiency of energy enterprises.

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