Analysis into Abnormal Factors Affecting the Ash Discharge Amount of Thermal Power Plant

2013 ◽  
Vol 664 ◽  
pp. 1012-1017
Author(s):  
Gang Chen ◽  
Wei Su ◽  
Tian Shen Chen

An ash yield experiment and a coal ash component analysis with the same coal sample at different temperatures showed that when a coal sample burned in a boiler furnace whose temperature was higher than 815 ° C, part of the salts (eg, sulfate) and oxides (eg, SO3) would continue to be decomposed, resulting in the actual ash yield of the coal sample decreasing compared with the theoretical ash discharge rate. At the same time, the analysts pointed out that the moisture loss and its representative defects of the as-fired coal sampling machine system, the dust removal efficiency fluctuation of the electrostatic precipitator, and the measurement deviation of the as-fired coal quantity also caused the actual ash discharge rate to be on is low side.

The normative method (NM) of thermal boiler calculation, which has been confirmed and refined multiple times, contains the structure of ideas and methods retained and adapted during the transition to digital technologies. As applied to the analysis of thermal processes in the boiler furnace with flare furnaces, this required the transformation of a large array of initial and reference data, which cannot be used unchanged in digital technologies, including computer-assisted. This applies to graphical and tabular data, which occupy up to 80% of the NM volume. The main regulatory elements of the digital model in this case are the temperature of adiabatic combustion of the fuel, the coefficient of attenuation of radiation by the combustion medium, the degree of emissivity of the furnace taking into account the size of the radiating layer, the coefficient of thermal efficiency of the furnace wall pipings, the resulting Boltzmann number and the final calculated value of the gas temperature at the exit from the furnace. The use of specific data for a boiler with D = 400 t/h made it possible to clarify the structure of analytical dependencies, as well as the magnitude of deviations from the standard values in the final temperature values. The paper presents a developed transition to dependencies accounting for the thermal power of the boiler and the type of fuel. The digital model adaptation to the boiler conditions with all types of fuel in use made it possible to determine the average deviations of the final parameters. Quantitatively, the entire material corresponds to the normative data, is presented digitally and corresponds methodically to the Mathcad-15 package. In contrast to acclaimed works in this area, all factors affecting the heat balance are represented by approximations taking into account temperature variability.


2013 ◽  
Vol 724-725 ◽  
pp. 1306-1309
Author(s):  
Peng Fei Nie ◽  
Hong Yu Zhang ◽  
Yang Wang

This paper introduces the phenomenon of stack rainout in the wet flue gas desulphurization system for the thermal power plant units without GGH,analyzes the factors affecting rainout of wet stack and finds out the main causes resulting in stack rainout of wet flue gas desulphurization for Wangtan Power Plant without GGH,such as low temperature after the flue gas desulfurizationinsufficient diffusion capability of flue gas flowthe blockage of mist eliminatorpoor operation of electrostatic precipitatorinadequate combustion of boilerhigh speed of flue gas flow in the stackthe effect of climate. Also it is analyzed that the mist eliminator equipment and ensuring the efficient operation of electrostatic precipitator may relieve the phenomenon of stack rainout.


2021 ◽  
Vol 11 (6) ◽  
pp. 2691
Author(s):  
Nataša Ćuković Ignjatović ◽  
Ana Vranješ ◽  
Dušan Ignjatović ◽  
Dejan Milenić ◽  
Olivera Krunić

The study presented in this paper assessed the multidisciplinary approach of geothermal potential in the area of the most southeastern part of the Pannonian basin, focused on resources utilization. This study aims to present a method for the cascade use of geothermal energy as a source of thermal energy for space heating and cooling and as a resource for balneological purposes. Two particular sites were selected—one in a natural environment; the other within a small settlement. Geothermal resources come from different types of reservoirs having different temperatures and chemical compositions. At the first site, a geothermal spring with a temperature of 20.5 °C is considered for heat pump utilization, while at the second site, a geothermal well with a temperature of 54 °C is suitable for direct use. The calculated thermal power, which can be obtained from geothermal energy is in the range of 300 to 950 kW. The development concept was proposed with an architectural design to enable sustainable energy efficient development of wellness and spa/medical facilities that can be supported by local authorities. The resulting energy heating needs for different scenarios were 16–105 kW, which can be met in full by the use of geothermal energy.


2010 ◽  
Vol 7 (4) ◽  
pp. 1254-1257 ◽  
Author(s):  
K. H. Shivaprasad ◽  
M. M. Nagabhushana ◽  
C. Venkataiah

Ash, an inorganic matter present in coal is amenable for dissolution using suitable reagents. Thus the dissolution of ash and its subsequent removal reduces the release of many toxic elements into the environment by coal based industries. Removal of ash also enhances the calorific value. In the present investigation an attempt has been made to reduce the ash content of raw coal obtained from nearest thermal power by using hydrochloric acid, sulfuric acid and sodium hydroxide. A series of leaching experiments were conducted on coal of different size fractions by varying the parameters like concentration, temperature and time of leaching. The results indicate that it is possible to remove nearly 75% of ash from coal sample by leaching.


2019 ◽  
Vol 109 ◽  
pp. 00119
Author(s):  
Volodymyr Yemelianenko ◽  
Vitalii Pertsevyi ◽  
Oleksandr Zhevzhyk ◽  
Iryna Potapchuk ◽  
Oleksandr Lutai

Analysis of the perspectives of the coal fuel for thermal power plants is carried out. The necessity of the experimental study for temperature measurement in the boiler furnace. The results of the experimental study are presented: temperature change over time at the burner outlet for different constant pressure value of the backlighting gas, dependence of the temperature at the burner outlet from the backlighting gas pressure for constant concentration value of pulverized coal in coal-air mixture, dependence of the temperature at the burner outlet from the concentration of pulverized coal in coal-air mixture for constant value of the backlighting gas pressure, temperature measurements for constant backlighting gas pressure value, constant value of the concentration of pulverized coal in coal-air mixture when plasmatron is switched and operates for some time range. The results of the study could be applied to the solid fuel treatment for different thermal units.


2013 ◽  
Vol 594-595 ◽  
pp. 527-531
Author(s):  
Mohamad Ezad Hafez Mohd Pahroraji ◽  
Hamidah Mohd Saman ◽  
Mohamad Nidzam Rahmat ◽  
Kartini Kamaruddin ◽  
Ahmad Faiz Abdul Rashid

Millions tons of coal ash which constitute of fly ash and bottom ash were produced annually throughout the world. They were significant to be developed as masonry brick to substitute the existing widely used traditional material such as clay and sand brick which were produced from depleting and dwindling natural resources. In the present study, the coal ash from coal-fired thermal power plant was used as the main raw material for the fabrication of cementless unfired lightweight brick. The binder comprising of Hydrated Lime (HL)-activated Ground Granulated Blastfurnace Slag (GGBS) system at binding ratio 30:70, 50:50 and 70:30 were used to stabilize the coal ash in the fabrication process of the brick. Foam was used to lightweight the brick. The compressive strength and ambient density were evaluated on the brick. The results indicated that the brick incorporating HL-GGBS system achieved higher strength of 20.84N/mm2 at 28 days compare to the HL system with strength of 13.98N/mm2 at 28 days. However, as the quantity of foam increase at 0%, 25%, 50%, 75% and 100%, the strength and density for the brick decreased.


2013 ◽  
Vol 67 (2) ◽  
pp. 293-298 ◽  
Author(s):  
C. Keating ◽  
D. Cysneiros ◽  
T. Mahony ◽  
V. O'Flaherty

In this study, the ability of various sludges to digest a diverse range of cellulose and cellulose-derived substrates was assessed at different temperatures to elucidate the factors affecting hydrolysis. For this purpose, the biogas production was monitored and the specific biogas activity (SBA) of the sludges was employed to compare the performance of three anaerobic sludges on the degradation of a variety of complex cellulose sources, across a range of temperatures. The sludge with the highest performance on complex substrates was derived from a full-scale bioreactor treating sewage at 37 °C. Hydrolysis was the rate-limiting step during the degradation of complex substrates. No activity was recorded for the synthetic cellulose compound carboxymethylcellulose (CMC) using any of the sludges tested. Increased temperature led to an increase in hydrolysis rates and thus SBA values. The non-granular nature of the mesophilic sludge played a positive role in the hydrolysis of solid substrates, while the granular sludges proved more effective on the degradation of soluble compounds.


1975 ◽  
Vol 39 (4) ◽  
pp. 562-566 ◽  
Author(s):  
W. J. Whalen ◽  
P. Nair

In the carotid body (CB) of the anesthetized cat tissue Po2 (Pto2) measured with a micro O2 electrode averaged about 65 mmHg at normal arterial pressure (mean = 96 mmHg). Pto2 correlated significantly with the hematocrit of the arterial blood but not with % saturation. When arterial pressure was reduced (mean = 58 mmHg) by bleeding Pto2 fell significantly. Phentolamine injection (1 mg/kg iv) at the reduced pressure caused Pto2 to rise significantly. At normal arterial pressure blowing moistened O2 over the CB did not affect Pto2 if the electrode tip was about 90 mum into the CB. At a reduced pressure (and blood flow) the sensitive depth increased to about 301 mum, and to about 600 mum when flow was stopped. We concluded that a) the increased chemoceptor discharge usually seen with hemorrhage is due to reduced Pto2; b) the reduction in Pto2 is probably due to reduced blood flow which is, in turn, caused partly, at least, by sympathetic nervous system activity; c) O2 content, rather than Po2, may determine chemoreceptor discharge rate; and d) there are no barriers in the CB which are impermeable to O2.


2020 ◽  
Vol 2 (1) ◽  
pp. 3
Author(s):  
Katerina Lazarova ◽  
Silviya Boycheva ◽  
Marina Vasileva ◽  
Denitza Zgureva ◽  
Tsvetanka Babeva

In this study, solid waste from coal combustion in thermal power plants (TPPs) was used for the synthesis of zeolite Na-X samples. They were prepared by the long-term alkaline atmospheric conversion of coal ash collected from the electrostatic precipitators in the TPP “AES Galabovo”. When used in the form of thin films/layers, the optical detection of volatile organic compounds (VOCs) is possible due to a change in their reflectance spectra and color. In order to improve the sensing properties of synthesized zeolites, they were wet milled for 60 s and both milled and unmilled zeolites were used as dopants for the niobium oxide matrix in the form of thin films deposited by the spin-coating method on a silicon substrate. The surface morphology and structure of both zeolite powders were studied by scanning electron microscopy, while their size was determined by dynamic light scattering (DLS) spectra. Optical constants (refractive index, n, and extinction coefficient, k) and the thickness of the films were calculated from reflectance measurements. The change in the reflection coefficient ∆R of the films was determined from measured reflectance spectra prior to and after exposure to probe acetone molecules. An increase in the reaction of the films with milled zeolites to acetone, compared to the samples with unmilled zeolites, is demonstrated.


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