The combustion efficiency of a coal is often measured in terms of burnout. In this study, the ash tracer method [21], [22] was adopted to determine the burnout of the tested coals. The burnout can be expressed as (1) Burnout (%) = A s h u c − A s h r c A s h u c (1 − A s h r c 100) × 100 where Ash uc and Ash rc stand for ash contents in the unburned char and the raw coal, respectively.
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1. Introduction. Aimed at addressing climate change caused by CO 2 emissions, the consumption ratio of coal has been decreasing in China, while its total consumption is still on the rise. The power generation industry relies heavily on coalfired power, which is responsible for more than 50% of the total coal consumption in primary energy production (Gopan et al., 2015; Lasek et al., 2013; Lv ...
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The volume flow of gas into boiler Bgas. Calculation example In this paper, a coal and gas dualfired boiler is taken as an example. On the basis of measured data, the method proposed above is applied to calculate the pulverized coal mass flow. Detailed data and calculation result are shown in Table 1.
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Considering an injection rate of 100 kg/t of pig iron, when a coal with a calorific value of 7500 kcal/kg is replaced by another one with 7700 kcal/kg, the fuel rate change is 4 kg/t of pig iron ...
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The average measurement errors for carbon, hydrogen, volatile, ash, heat values is %, %, %, % and .07MJ/kg, respectively, and all of these measurement accuracies have totally ...
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As a result, the values from this study were smaller by % for the calibration line and by % for the validation line in nearinfrared spectroscopy. The RMSE average values for calorific values were calculated to be less than 1%. Keywords: laserinduced breakdown spectroscopy (LIBS); coal; sulfur; calorific value; multivariate data ...
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A numerical model of a tower boiler burning low calorific value and highalkali coal was established; based on the jet rigidity of the flow field in the furnace, the effects of air velocity and air volume flow on the combustion of highalkali coal and NOx emissions were studied. The optimal parameters obtained by numerical simulation are applied to a typical experimental boiler. The ...
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Pulverized coal synonyms, Pulverized coal pronunciation, Pulverized coal translation, English dictionary definition of Pulverized coal. coal dust. Translations. English: coal dust n polvere f di carbone. Italian / Italiano: polvere f di carbone.
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When there was no condition to test the coal calorific value in the industry, the net calorific value of coal could be calculated according to the empirical formula [30]. By contrasting the net calorific values of coal obtained by experience formula and experiment, LIU and JU [31] found that the deviation was less than 5%. It was shown
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Heating value and vitrinite reflectance are both rank parameters (section ); although, as noted in section, calorific value is related to the maceral content as well as the coal rank. Grindability and particle size are also related ( section ), with particle size being a function of the grindability of the coal and the energy ...
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The fuel is a hard coal with an average calorific value around of MJ/kg. Fig. 1. Firing system of a frontal pulverized coalfired boiler
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The adiabatic bomb calorimeter and the isothermal bomb calorimeter are two standard methodologies defined by GB/T [3], ISO 1928 2009 (E) [4] and ASTM D586513 [5]. In bomb calorimetry, coal burns in a bomb, and the heat of combustion is transferred to water outside the bomb wall.
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Fig. 1, Fig. 2 show V * /V * ′, which is appropriate value for the Qfactor, as a function of coal particle heating rate for different coal the CPD model, the result for Adaro coal could not be obtained because of the divergence in the simulation. This is considered to be caused by that the properties of Adaro was out of range for the correlation.
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The minimum average relative error (RE) of the predictive values for the validation samples was %, and the average error of the proposed model for the calorific value quantitative analysis was MJ kg −1.
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the input of sulfur, hydrogen, total water and analytic water; the high calorific value, low calorific value and cartridge calorific value of coal can be calculated automatically [910]. The difference between high calorific value and low calorific value lies in whether the water in fuel combustion products is liquid or gaseous. Water is liquid ...
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Characteristics of pulverized coals have significant influence on the spontaneous combustion and explosion processes. This paper presents an experimental and theoretical framework on physicochemical characteristics of coal and their interrelations from spontaneous combustion and explosion perspectives. The chemical properties, morphology, bulk density, particle size, and specific surface area ...
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Calorific value is an essential fuel parameter during the process of energy utilization. Fortyfour coal samples with different calorific values were quantitatively analyzed by laserinduced breakdown spectroscopy (LIBS) in this paper. The influences of different spectral preprocessing methods such as smoothing, standard normal variate transformation (SNV), multiplicative scatter correction ...
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Lowrank coal (calorific value below 5,100 kcal/kg) and mediumrank coal (5,1006,100 kcal/kg) dominate current Indonesian coal production. Coal reserves are estimated to be about % for lowrank coal and around % for mediumrank coal. The country's power plants use both types of coal as fuel. Basically, coal calorific value is one ...
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It uses coke and auxiliary injectants like pulverized coal (PC) to generate the reductants and energy needed. However, coke production causes considerable energy consumption and greenhouse emissions and accounts for a big portion of pig iron production costs [1]. Also, coking coal resource is gradually depleted on the earth.
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The average measurement errors for carbon, hydrogen, volatile, ash, heat values is %, %, %, % and .07MJ/kg, respectively, and all of these measurement accuracies have totally ...
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Densephase pneumatic conveying of pulverized coal experiments with superficial gas velocity ranged from m s −1 to m s −1 were carried out on the selfestablished 50 mm industrial pipe facility. The fluctuations of pressure, solid velocity, solid concentration and the average crosssection concentration were analyzed in terms of relative standard deviation (RSD), powder ...
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The realtime quantitative analysis of the calorific value of pulverized coal particle flow is important for the efficient and clean combustion of coal. Herein, a piezoelectric vibratory feeder produced a continuous flow of pulverized coal particles, which were detected by laserinduced breakdown spectroscop
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The heating value (or energy value or calorific value) of a substance, usually a fuel or food (see food energy), is the amount of heat released during the combustion of a specified amount of it.. The calorific value is the total energy released as heat when a substance undergoes complete combustion with oxygen under standard chemical reaction is typically a hydrocarbon or other ...
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34 Gudimella Tirumala Srinivas et al.: Efficiency of a Coal Fired Boiler in a Typical Thermal Power Plant s [( ) ( )]2 1 4 3 100 f f w h h h h w GCV × − + − = × × (3) Here GCV f is the gross calorific value of the coal (kJ/kg), whose measurement is based on mass of coal for which hoppers are mounted over the boilers on calibrated load cells [15].
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Pulverized coal absorbs part of the heat to increase its own internal energy, enhancing the char performance and accelerating the achievement of the volatile matter combustion temperature; furthermore, the calorific value needed to reach the ignition temperature is guaranteed. 51 In the pyrolysis stage, WOS has a dominant effect on pulverized ...
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The pulverized coal preheatingcombustion test platform for peak shaving (Fig. 1) consists of a PreCFB, a combustion chamber and auxiliary design load of the test platform is 1 MW, the primary air with a low air equivalence ratio carries the pulverized coal particles into the PreCFB for gasification and partial combustion, generating hightemperature preheated fuel.
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Pulverized coal power plants are broken down into four categories, with operating temperatures and pressures as a function of the steam temperature and pressure: •. Subcritical pulverized coal (SubCPC) plants, below the critical point of water (540°C and 170220 bar), have an operating efficiency <38%. •.
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The coal consumption in our country mainly lies in coalfired power stations and industrial boilers. 1 Since the temperature change in the furnace influences combustion, slagging, corrosion, and so on, 2 the accurate analysis of the temperature level and its distribution in the furnace will predict the slagging in the furnace and improve the saf...
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The pulverized coal was dried at three selected temperatures of 25 °C, 75 °C and 110 °C, and the moisture and porosity of the pulverized coal particles were measured. Based on the porosity range obtained from the measurement, 3D steady numerical simulation of combustion in tangentially coalfired furnace was conducted by use of Fluent Software.
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The given values are for fuels with the given density. The variation in quality may give heating values within a range 5 10% higher and lower than the given value. Also the solid fuels will have a similar quality variation for the different classes of fuel. 1 Btu (IT)/lb = MJ/t = J/kg = kcal/kg = kWh/kg.
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According to the peak shape of the DTG and DSC curves, the combustion process of pulverized coal can be divided into two stages: (1) The volatile escaping and homogeneous combustion stage (260410 °C); the organic components in coal undergo a small amount of easytobreak small molecular sidechain pyrolysis at about 320 °C, perform a fast ...
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Modern boilers powder the coal to a very fine dust so that while burning, it is almost like a fluid stream. The size of the coal particles is in the range of 75 microns. This means every particle comes into contact with the air. The loss due to unburned carbon is only in the range of % or less making the boilers very efficient.
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A material supplier from Belgium would like to produce limestone powder for his custome...
India is rich in various mineral resources and it is an important mineral processing market
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