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 ...
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 ...
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 ...
In this paper, a calorific value detection method based on NIRSXRF fusion spectroscopy is proposed, which utilizes NIRS to detect organic functional groups and XRF to detect inorganic ashforming elements in coal.
FC and FR have been calculated from the equations (1), (2): (1)FC = 100 (M + VM + A) (2)FR=FC/VM. Hard coal and coal sludge, which is waste from flotation coal enrichment, and fly ash, from cocombustion of hard coal and coal sludge 65%/35% A 1, and from cocombustion of agro biomass and forest biomass 20%/80% A 2, come from one of the ...
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.
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...
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.
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.
The time required for the LIBS measurement process (see Table 1) depends on the frequency and number of scans. In this study, the frequency and number of scans are set to 4 spectra per second and 196 spectra per sample, respectively, resulting in 49 s for LIBS measurement. ... Improved measurement of the calorific value of pulverized coal ...
error (ARE), and the standard deviation (SD) of this method for predicting the calori c value of coal are fi MJ kg−1, % and MJ kg−1 respectively. The measurement repeatability...
Two coals, bituminous (American Baily Pittsburgh No. 6) used in Israeli utilities and lignite (brown coal Hambach) used in German power plants, have been investigated in this study. The results show that the combined TG/DSC method can provide a much better understanding of the chemical reactivity of coals in the combustion process.
recovered fuel (SRF). RDF had only two classes depending only on the calorific value, moisture and ash content, in contrast to 125 SRF classes. These SRF classes are based on three properties where each of the properties has five classes for the net calorific value, the chlorine content, and the mercury content [8].
A hyphenated model was proposed to improve the accuracy of calorific value. ANN and GA were employed for identifying the calorific value in 86 coal samples, and the AAE was MJ/kg [95]. The SVR method based on KCV was proposed for quantitative analysis of 44 coal samples, and the MSE of calorific value was (MJ/kg) 2 [78].
To reduce the cost of electricity production, lowquality coal with low calorific value is used and mixed with various types of coal in Korea. Coal is roughly composed of 69% carbon, 15% oxygen, % coal ash, 5% hydrogen, % nitrogen, % sulfur, and % other components.
The calorific value of coal mainly depends on the content of combustible organic elements and ash, and is a comprehensive indicator of coal quality. It is of great significance to quickly obtain the calorific value of coal entering the boiler for the optimal control of coal blending and combustion in thermal power generation. However, the measurement repeatability of LIBS for the coal ...
Ammonia (NH3), as a derivative of hydrogen and energy carrier, is regarded as a lowcarbon fuel provided that it is produced from a renewable source or a carbon abated process of fossil fuel. Cofiring ammonia with coal is a promising option for pulverized coalfired power plants to reduce CO2 emission. Applying the cofiring in an existing pulverized coalfired boiler can achieve satisfying ...
The measurement repeatability meets the requirements of the Chinese national standard. This calorific value measurement technology based on NIRSXRF is safe, fast, and stable, providing a new way to optimize and control the utilization process of coal in coal washing plants, power plants, coking, and other industries.
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
Pulverized Coal Combustion. PCC technology is a widely utilized technology to generate energy from fossil fuel, especially coal [15]. In this technology, pulverized coal is injected to combust in a furnace in the presence of a controlled level of air. The heat generated is used to produce highpressure steam driving a steam turbine to ...
The interaction between the optical thickness and the radiation pulsation of pulverized coal particles during the combustion process is studied to learn the influences of turbulent particle combustion on radiative heat transfer.
Introduction. In 2014, the share of electricity produced in the world from coal combustion was % [1]. While this share will need to be drastically reduced in the coming decades to reach the current CO 2 emission targets, it is nonetheless important to keep on increasing the efficiency of the existing assets worldwide in order to limit their global environmental impact.
There has been little research on volatile releasing characteristics of pulverized coals under moderate or intense lowoxygen dilution (MILD) oxycombustion (MO) conditions. For the first time, volatile releasing characteristics of bituminous coal and semianthracite under both MILD aircombustion (MA) and MO conditions were investigated using a flatflame assisted entrained flow reactor. Both ...
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 ...
However, in traditional oxyfuel combustion systems, the ASU and CO 2 compression and purification unit (CPU) are carried out at high pressure, but the fuel combustion unit (pulverized coal boiler or fluidized bed boiler) is operated at atmospheric pressure, the unbalanced distribution of system pressure results in a large amount of energy loss ...
Though several factors affect the calorific value, including the type of coal, particle size, and environmental conditions [2530]. The scope of this work is limited to explore the effect of environmental factors (temperature, humidity, and air flow) on low grade coal pulverized to obtain average particle size of 213 μm, according to ...
A numerical simulation procedure is proposed for analyzing the partial replacement of pulverized coal injection by hydrogen, oxygen, and blast furnace gas (BFG) injections mixed with pulverized coal (PCI) within the tuyeres of large blast furnaces. The massive use of hydrogenrich gas is extremely interesting for ironmaking blast furnaces in the context of netzero carbon hot metal production.
from coal combustion are primarily sulfur dioxide (SO 2), with a much lower quantity of sulfur xide (SO 3) and gaseous sulfates. These compounds form as the organic and pyritic sulfur in the coal are oxidized during the combustion process. On average, about 95 percent of the sulfur present in bituminous coal will be emitted as gaseous SO x
range of coal with variable ash content and calorific values [2], whi le operational requirements are becoming tighter due to economic pressure s and environmental emission s regulations [3] .
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 ...
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%. •.
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 ...
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.
At present, coalfired power plants mainly involve pulverized coal combustion and a great amount of coal combustion solid residue continues to be formed from power plants. Querol et al. [2] have estimated the worldwide production of coal ash to exceed 550 × 10 6 tonnes/year. Fly ash is defined as the fraction of fine ash particles that is ...
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.
© DZCrusher - كل الحقوق محفوظة
