A commentary has been published: Discussion: "PulverizedCoal Firing of Marine WaterTube Boilers: Following Upon an Appreciation of the Results Secured in the Stationary PowerPlant Field With Pulverized Coal, a Series of Tests Were Conducted to Determine the Value of This Method of Firing to Marine Boilers" (Stillman, T. B., 1928, Trans. ASME, 4950(3), p. 031066)
To explore methods of reducing NOx emission from pulverized coal boilers, the effects of injecting ammonia solution and pyrolysis gas into the furnace on NOx emission were experimentally investigated on a 75 t/h pulverized coal boiler. Results show that the deep air staging with 30% separated over fire air (SOFA) creates a high temperature and strong reducing atmosphere in the reducing zone ...
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.
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 ...
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 ...
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 ...
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 ...
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 ...
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 ...
The Chinese national standard GB/T [7] exhibits the experimental specification for coal calorific measurement using the bomb X. Zhang et al. Laserinduced breakdown spectroscopy (LIBS ...
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 ...
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...
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
Calorific value. Calorific value, measured in British thermal units or megajoules per kilogram, is the amount of chemical energy stored in a coal that is released as thermal energy upon combustion. It is directly related to rank; in fact, the ASTM method uses calorific value to classify coals at or below the rank of highvolatile bituminous (above that rank, coals are classified by fixed ...
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 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.
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.
The basis low calorific value received by raw coal, MJ/kg. 1. Introduction. ... Hightemperature DTF can quantitatively obtain the change in conversion proportion of in the combustion process of pulverized coal. However, the simulated atmosphere in a DTF is not representative of the complex gas environment in the furnace caused by the rotating ...
The new equation is at least as effective in predicting calorific values for a set of 1004 coals as equiv. equations derived for 6 subsets of the coals. On the whole, the distributions of differences between obsd. and calcd. calorific values are skewed to only a small extent. About 86% of the differences lie between 300 and +300 Btulb.1.
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 ...
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.
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 ...
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 ...
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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