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In the present investigation, 75Cr3C2-25NiCr coating was deposited on T91 boiler tube steel substrate by high velocity oxy-fuel (HVOF) process to enhance high-temperature corrosion resistance. High-temperature performance of bare, as well as HVOF-coated steel specimens was evaluated for 1500 h under cyclic conditions in the platen superheater zone coal-fired boiler, where the temperature was around 900 °C. Experiments were carried out for 15 cycles each of 100 h duration followed by 1 h cooling at ambient temperature. The performance of the bare and coated specimens was assessed via metal thickness loss corresponding to the corrosion scale formation and the depth of internal corrosion attack. The uncoated boiler steel suffered from a catastrophic degradation in the form of internal oxidation attack and thickness loss. The 75Cr3C2-25NiCr coating showed good adherence to the boiler steel during the exposures with no tendency for internal oxidation.

The numerical simulation of the methanol synthesis process by using HT-L pulverized coal gasification is studied in the work. Pulverized coal gasification are simulated by Aspen Plus industrial systems flower software, and the optimum condition can be gained by calculation. The pulverized coal entrained-flow gasifier adopts the minimization method of Gibbs free energy. Under the given conditions of 1500°C and carbon conversion of 99%, when coal flow volume is 3265.87 kg/h and the ratio of air and coal is 4:1, the content of effective gas is maximal, and also the content of effective gas increased with increasing of the pressure.

Chlorine additives are often used to improve the combustion performance of pulverized coal injection (PCI) in blast furnace. The influence of chlorine additives on pulverized coal combustion rate was analyzed and the micrograph of unburned pulverized coal (UPC) was observed by SEM in order to analyze the influence mechanism of chlorine additives. The results show that proper addition amount of CaCl2, NaCl, MgCl2and FeCl3respectively promotes pulverized coal combustion in different degrees. The average size of UPC is smaller and the micrograph becomes irregular when the chlorine additives are increased. While beyond the appropriate addition amount, the combustion rate of PCI reduces. During the combustion process of pulverized coal with chlorine additives, HCl is produced which prevents the combustion process.

The static crucible method was employed to effects of different additions and coal mixing ratios on burning rate. The optimal amount was 4% and mixing ratio was Semicoke-Jincheng coal=7:3. XRD and TGA techniques were used to characterize combustion process. The combustion-supporting mechanism was that Mn7+(CO-)7 weakens the bridged bond binding force among carbon structure units and changes lattice structure. Heat storage preparation time is shortened which accelerates pulverized coal combustion.

A method for judging the gray property of flames based on spectral analysis and the two-color method for determining the temperature and emissivity of flame has been demonstrated. A calibrated spectrometer system was used for the data acquisition of the radiation intensity profile of a flame over a range of wavelengths (200 – 1100 nm). The wavelength range that meets the gray body assumption, in which the emissivity can be assumed as a constant, can be determined from the emissivity profile obtained by spectral analysis and the two-color method. Then the temperature and emissivity of the flame and their relative mean square deviations were calculated within that range. Experiments were conducted on pulverized coal-fired flames in a commercial 300MW boiler furnace. The results show that the coal-fired flame can be assumed as gray body between 500 nm and 1000 nm, and the temperature and emissivity calculation results of coal-fired flames are found to be in reasonable agreement with results using other methods from the literature.

Typical combustible particle coal has been analyzed by using turbulence-chemistry interaction models to realize which models are more accurate and reasonable on pulverized coal MILD combustion. Three turbulence-chemistry interaction models are examined: the Equilibrium Mixture Fraction/PDF (PDF), the Eddy Break Up (EBU), the Eddy Dissipation Concept (EDC). All of three models can give a suitable prediction of axial velocity on combustible particle coal MILD combustion because turbulence-chemistry interaction models have little influence on flow field and flow structure. The Eddy Dissipation Concept model (EDC), based on advanced turbulence-chemistry interaction with global and detailed kinetic mechanisms can produce satisfactory results on chemical and fluid dynamic behavior of combustible particle coal MILD combustion, especially on temperature and species concentrations.

The character of the Fly ash of Circulating Fluidized Bed Boiler (CFB Fly ash) is greatly different from that of Pulverized coal furnace for its high unburned carbon. In order to make effective use of CFB Fly ash in concrete, carbon content was decreased by simulated fluidized bed combustion in laboratory and a series of concerned experiments were carried out on CFB Fly ash. The experimental results indicate that CFB modification Fly ash is possible to be used in concrete to partially replaced cement. It is a valuable reference for CFB Fly ash technical engineers.

Methane and carbon dioxide of different pressures were absorbed by the anthracite coal for 5 hours in high pressure reactor. When adsorption experiment was completed, pressure is reduced quickly. The content of pulverized coal which was produced by releasing gas quickly, was used to reflect capacity of gas adsorption. The result showed that the content of pulverized coal which was produced by adsorbing CH4 was higher than that was produced by adsorbing CO2 on the same coal under the same pressure. Langmuir isotherm and Freundlich isothermal can describe coal methane adsorption. Freundlich isothermal can be a good description of coal carbon dioxide adsorption.

Based on a 300MW Oxy-fuel pulverized coal boiler,this paper established a dynamic mathematical model of air separation system distillation column, and compiled simulation procedure with the Fortran language on the platform of IMMS. With distillation column as the object of the research, it carried on a disturbance experiment about the outlet air flow of purifier and extractable volume of liquid nitrogen in lower tower. The results demonstrate that when the outlet air flow of purifier decreases, the nitrogen purity in gas is reduced by 0.39%, and the oxygen purity in liquid is reduced by 1.5%;when the outlet air flow of purifier is constant and extractable volume of liquid nitrogen decreases, the nitrogen purity in gas is increased by 0.2%, and the oxygen purity in liquid is increased by 0.06%.

With the conceptual design 300MW oxy-combustion of pulverized coal boiler for the study, according to its working principle, we divide the whole boiler into several subsystems, and complete the dynamic and static simulation model based on the IMMS platform. The results show that, the established model is stable, the trend of the dynamic characteristics is reasonable, and the error is within the permissible range, which provides a reference for the simulation of the oxy-combustion of pulverized coal boiler as a whole.

In the present research work, adding a certain amount of coke dry quenching(CDQ) dust to pulverized coal used in blast furnace is proposed for efficient utilization of resources and reducing smelting cost. The properties of coal blends and coal/dust blends were investigated by using long tube tester and the device of thermogravimetry (TG). Important results were obtained by experimental researches about explosibility and combustion performance. According to optimum blending ratio of coal B in coal blend (around 50%), burnout of coal/dust blends decreases after adding CDQ dust in the range 5% to 10% to blends. However, all of them are more than 80%, which can meet production requirements. In the case of adding about 8% of CDQ dust to coal blend, combustion efficiency is better and safety injection can be realized.

It presents the compressor gas-cooler of a 300 MW Oxy-fuel pulverized coal fired boiler and established the simulation model of the cooler by the mechanism analysis method. On the simulation platform, the heat transfer performance and dehydration properties of cooler are studied on different pressure conditions. The simulated experiments show that when the flue gas inlet pressure is greater than the design pressure, with the increase of pressure, heat exchange performance of gas-cooler will declines; the water separation amount increases initially and then decreases subsequently.

The effects of Ca-based sulfur catcher on sulfur fixing were investigated by experiments. The results indicate that sulfur capture efficiency of CaO is the maximum when n(CaO)/n(S) ratio is equal to 2.5. Moreover, the influences of Cr2O3 on sulfur-fixing of CaO were studied when n(CaO)/n(S) ratio is equal to 2.5. The results indicate that addition of Cr2O3 can improve the sulfur capture efficiency of CaO, and efficiency of CaO is the best when Cr2O3 is added to 0.5%. This is because that Cr2O3 can be oxidized to CrO2. On the one hand, the oxides of chromium can catalyze the reaction of sulfur-fixing. On the other hand, CrO2 can react with SO2 to form Cr2(SO4)3. These also can improve the sulfur capture efficiency of Ca-based sulfur catchers.

Ball mills with double inlets and outlets (BMDIO) are widely equipped in milling systems of thermal power plants because of BMDIOs’ vantage on being able to pulverize various raw coal. In this paper, dynamic characteristics of mill’s coal level were studied by pulverizing coal mechanism analysis. Furthermore, models for filled level of mill were obtained with mathematical Equations. The nonlinear, strong coupling and large lag features of BMDIO’s dynamic characteristics were demonstrated by the model for level of materiel constructed in this paper. And, the model would be become the available theory basis for the calculation of pulverized coal into furnace and design of combustion in fossil-fired thermal unit.

In this paper, a computational fluid dynamics (CFD) model of a 600 MW opposed swirling coal-fired utility boiler has been established to numerically study the NOx emission characteristics under different ratios of over fire air (OFA) and modes of in-service burner layers. The current CFD model had adopted a chemical percolation devolatilization (CPD) model and been validated by comparing the simulated results with the experimental data. The numerical simulation results show that, with increasing the ratio of OFA, the carbon content in fly-ash increase somewhat linearly and the NOx emission reduce significantly, and the OFA ratio of 30% is optimal with higher burnout of pulverized coal and lower NOx emission. The different in-service burner layer modes have different influences on the residence time of the pulverized-coal particles, effect of air staging in the burner region and flue gas temperature at the exit of the lower furnace. Stopping the upper burner layers can increases the residence time of the pulverized-coal particles, resulting in the reduction of the carbon content in the fly ash and the increase of the pulverized-coal burnout. The flue gas temperature at the exit of the lower furnace can also decrease, which would be helpful to reducing the slagging tendency on the surfaces of the platen superheaters.

The flow measurement of primary air is very important for thermal power plants to maintain the safe state of operation. For direct firing pulverizing system, the measuring is essentially affected by pulverized coal particles. Abrasion and occlusion would bring great trouble to the measurement. Many measuring methods are invalid under that circumstance. Lots of efforts have been made to find appropriate ways to measure the flow of primary air containing pulverized coal. Venturi tube had been successfully used to measure the flow of air. If a venturi tube is used to measure the flow velocity of primary air, the differential pressure goes higher with the increase of the concentration of pulverized coal in the primary air. The neglect of the affection of pulverized coal on the measuring would result in remarkable deviation. With the aids of coal flow rate, a method of using venturi tube to measure the velocity of primary air containing pulverized coal was established. The affection of pulverized coal on flow measuring of primary air cannot be ignored.

This work makes thermodynamic analysis and optimization for the coal-based Fischer-Tropsch (FT) process. The thermodynamic analysis results show that under standard conditions the maximum effective carbon conversion is 50% from raw coal (CH0.8O0.1) to hydrocarbon products, and at least 50% carbon is converted into CO2emission in the coal-based FT process. Subsequently, a new coal-based FT synthesis process is proposed to get minimum water consumption, minimum wastewater emission and maximum energy efficiency. The process contains a pulverized coal gasification unit, water-gas-shift unit and iron-based FT synthesis unit with 50% CO2selectivity. The H2/CO molar ratio of fresh syngas to the FT synthesis unit is 0.5. The carbon and water footprints analysis results indicate that the effective carbon conversion from raw coal to hydrocarbon products is about 46.0%, and it only consumes 0.102 molar water and generates 0.032 molar wastewater when converts 1 molar coal to hydrocarbon products in the process.

A new non-pressure waste heat recycling system was designed and arranged on KHSS0.5-0.7-AⅡ industrial coal-fired boiler to decrease the exhausted gas temperature about 35°C, improve the boiler efficiency about 3.2%. Results showed that this system can avoid low-temperature sulfur corrosion and operate in normal and intermittent water supply condition safely and economically.

In order to solve the problem of that the boiler burns inferior coal but cannot guarantee the combustion stability, the rich-lean burner divides primary wind pulverized coal airflow into two stocks of airflows containing different amounts of pulverized coal and sends the airflows into coal-fired furnace for improving the ignition characteristics. By the numerical simulation of the pulverized coal flow characteristics in an elbow bias-oriented rich-lean burner, regarding the “concentration ratio” and “speed difference” as the standard of evaluating the separation characteristic of the burner, considering the influence of the partition plate length, bias current stopper height and primary wind velocity to the separation effect of pulverized coal so as to provide technical assistances for the elbow bias-oriented rich-lean burner’s practical application and improvement.

Aimed at improving the utilization of pulverized coal, high-temperature heat pipe technology was introduced into lignite carbonization.Under the design of power of 10kw semi-industrial pulverized coal carbonization test equipment, Fugu lignite coal as raw material to investigate the operating characteristics of the device and carbonization characteristics. Experimental result shows that the high temperature heat pipes heat steadily and meet the temperature requirement of low-temperature carbonization. With the extension of the holding time, the semi-coke fixed carbon content increasing, but volatile matter vice versa, however, holding time above 60 minutes, the effect of carbonization is not obvious, and the best carbonization time is 30 ~ 60 minutes. The length of the holding time has little effect on gas composition, the content of H2 and CH4 are relatively higher than the rest gas, (H2 + CH4) gas accounted for 70% of the total, the heating value remains at 18.76 ~ 19.22MJ/m3, belongs to medium-high value gas, could provide for industrial and civilian use.

China is rich in coal-bed methane (CMB) resources, and has a vast exploitable volume, but the surface gathering system is not perfect. In order to solve the problems of high degree of difficulty in surface gathering system design and lower economic efficiency caused by the characteristics of CBM gas field geographically remote, more wells, large water production in single well and gas containing pulverized coal etc, we studied the select method of the piping material of CBM, process and the treatment technologies of produced water in F block of the southern Qinshui Basin. Finally, the first phase production can reach 6 × 108m3/a and the central processing plant size is 10 × 108m3/a in the F block. The application of this study not only reduced the capital investment but also met the requirement of good environmental protection. This gathering process design can be applied to other development and construction of CBM gas fields.

Experimental study of changing and blending combustion of Shenhua coal on boiler operation was carried out, while the furnace slagging during the experiment, the coal pulverizing system adjustment and the boiler operation oxygen control issues were analyzed. The results show that: the boiler can operate in safety blending Shenhua coal and Zhungeer coal with the ratio of 7:3 based on the strengthening laboratory analysis of coal as fired, the safety and economy of the boiler and coal pulverizing system can be ensured with the pulverized coal fineness R90 in 30%, and selecting the lower mill combinations and setting the coal pulverizer outlet temperature at 73°C, the reasonable exhaust gas oxygen content should be 4.0%, and the boiler thermal efficiency has an 1% increase compared with the condiation of burning inferior Shanxi bituminous coal, the nitrogen oxide emissions are significantly reduced.

To deal with the problem of energy waste in High-pressure gas relief of pulverized coal injection in the blast furnace, designed a flywheel compressor which consists of an energy storage mechanism and a power mechanism. It is used for recycling and reusing the energy released by the high-pressure nitrogen gas in pulverized coal mixing. It is a safe and an energy saving equipment without motor driving. In this paper, the model of the flywheel compressor was established in Solidworks and Fluent to simulate the flow field, then basic dimensions of the compressor was conducted, and structural design and optimization were completed at last.

The present status and challenges of blast furnace (BF) ironmaking technology are analyzed, and the developing targets of the contemporary BF ironmaking process are mentioned. The significance and function of high blast temperature and oxygen enriched-pulverized coal injection for BF are described. The key technologies of high blast temperature is discussed and evaluated emphatically. Promoting blast temperature and improving oxygen enrichment ratio, as well as enhancing pulverized coal injection rate which are important guarantee for saving fuel consumption, reducing operation cost, and realizing sustainable development. There are broad developing prospects of contemporary BF process under the condition of high blast temperature and low fuel ratio ironmaking technologies are applied.

Coal additives can promote coal burning and improve the utilization of coal, thus effectively saving coal resources. Coal additive was found to improve coal calorific value obviously by the tests of coal calorific value with two kinds additives, the maximum of calorific value could be increased by 19% , which indicated that the additives promoted coal combustion . By comparing the experimental data , when added directly , it was the most efficient to improve combustion heat for the dose group of 1% coal formulations. while immersed added, it was 0.5% dose formulations to improve coal combustion heat the most efficiently. The effect of immersed added was better than that of added directly. Through SEM micrographs analysis of coal sample experiments, surface roughness and angle were outstanding for not added coal additives. There are similar in shape of pulverized coal comparing the direct added additive with not added additive. The morphology of coal samples changed while dipping additives on them, coal was partially eroded , spherical trend , which increased the surface area, it was helpful for burning.

The foundation backfill materials with pulverized coal ash and admixture gypsum fly ash were studied. The laboratory experiments were designed to determine its compaction characteristics, compressibility, intensity and bearing capacity of foundation with different mixture ratio. Dry density and strength property of fly ash with different water content were analysed. The result shows that the modulus, strength and foundation bearing capacity all have been greatly improved when gypsum was added into fly ash The proper mix proportion of the gypsum fly ash is very suitable for engineering application and this research provides a scientific reference for the similar projects.

The combustion stability of pulverized coal is very essential for utility boilers. That is the key issue to keep the operation of the whole power-generation unit in a safe state. The amount of volatile matter is used to anticipate the combustion state of pulverized coal. As a widely accepted concept, higher volatile matter content would result in more stable combustion state. But in some cases, the coal with high volatile matter content led to poor combustion states, even resulted in the flameout of the burner. More method is needed to judge the coal and to predict the combustion stability. With research on the approximate analysis of the coal composition, the heat value of volatile matter was calculated. Such heat value varies obviously for different kinds of coal. The ratio of the heat value of volatile matter to the heat value of fixed carbon is supposed to describe the combustion stability of pulverized coal. The application of the method judges the coal better than using the amount of volatile matter alone.

The problems of the high exhaust gas temperature in the biomass boiler which moves normally are analyzed, and the anti-balance method to get the boiler efficiency is used to get the relationship between the exhaust gas temperature and the boiler efficiency. Greater exhaust gas heat loss, smaller the boiler efficiency. According to 35t/h biomass grate boiler, the factors which affect exhaust gas temperature are analyzed and summarized

According to the structure and working principle of rotary air preheater,the heat transfer calculation model is set up with reasonable simplification. Combining with the design parameters of the rotary air preheater of a 400 t/h pulverized coal boiler unit ,the results of practical calculation show that the said thermodynamic calculation method not only has higher precision of calculation,but also can get the temperature distributions of the gas, air and heat surface in each cross-section of the rotary air preheater. The result of numerical simulation calculation tallies well with the original designed data. It can be used for the heat calculation both two-sectorial and three-sectorial air heater; it can be used for performance analysis of the regenerative air heater.

In a closed pulverized coal preparation system, a special device must be installed to vent flames and pressure during unexpected dust explosions. A vent flame arrestor is a key element in this device, which helps prevent a dangerous second explosion by venting flames. Traditional vent flame arrestors are designed with mounting metal fiber or rock fiber on both the sides and the top of the arrestor to cool dust flames and arrest burning dust during an explosion. This type of arrestor is widely used, but their application is still problematic, even for St1 dust at low reduced pressure (Pred). To solve these problems, we designed two types of flameless venting devices. The first is intended for St1 dust explosion venting at Pred 0.07 MPa, and was modified from an original device by adopting a labyrinth-like structure in the interior space to successively reduce the strength of the dust flame. The second is intended for St1 dust explosion venting at 0.07 < Pred 0.18 MPa, and was modified from the first type by adding a special suppressant in the interior space to make the dust flames cooler than the ignition point of the dust. Our experiments confirmed that our designs yield improved efficiency of flameless venting devices, leading to safer vent flame arrestors.

In this paper, the test fuel is organic waste water slurry, which can be mixed to by organic waste water and pulverized coal. The organic waste water comes from chamfor Papermaking Company of Jiangsu province. Theoretically, we introduce the structure retrofit of the 75t/h Circulating Fluidized Bed Boiler of chamfor Papermaking Company in detail. It is the first industrial application that coal organic waste water as fuel to burn in circulating fluidized bed boiler in China. To get more reasonable boiler structure transformation scheme and more accurate data, we need carry lots of experiments.

In this paper, the present status and challenges of blast furnace (BF) ironmaking technology are analyzed, and the developing tendencies of the modern BF ironmaking technology are mentioned. The significance and function of high blast temperature and oxygen enriched-pulverized coal injection for BF ironmaking are described. The key technologies of high blast temperature, oxygen enriched, and pulverized coal injection (PCI) are discussed and evaluated emphatically. Promoting blast temperature and improving oxygen enrichment ratio, as well as enhancing PCI rate which are important guarantee for saving fuel consumption, reducing operation cost, and realizing sustainable development. There are broad developing prospects of modern BF process under the condition of high blast temperature and low fuel ratio ironmaking technologies are applied.

A thermal model was established for the study about influence of collapse phenomenon on unburned pulverized coal in COREX melter gasifier. In the model, the ore was simulated by wax, the coke and lump coal were simulated by maize, UPC is simulated by pulverized coal. The results showed that too high blast temperature could lead to collapse in the model, and under normal or collapsing furnace state, UPC is dispersed or aggregated distribution in packed bed. According to this experimental results and the previous research results, the suggestions about COREX were given at last. Keywords: COREX melter gasifier; pulverized coal injection; unburned pulverized coal; physical experiment

The widely used technologies of Selective Catalytic Reduction (SCR), Non-selective Catalytic Reduction (SNCR) and hybrid SNCR-SCR for coal-fired boiler in China are reviewed. The technical characteristics of different processes and transformation methods are compared. Analysis is made about the advantages of each technology and the major problems in the retrofitting. The proposal for the corresponding problems is presented. Reference is provided for coal-fired boiler denitrification transformation in China.

With calcium carbonate and barium carbonate as desulfurizers, combustion desulphurization experiments of coal water slurry and pulverized coal were respectively done in the ZCL. The results show that desulfurization efficiency in coal water slurry is prior to the same pulverized coal. The desulfurization characteristic of desulphurizing coal water slurry was analyzed by comparing the desulfurization efficiency of coal water slurry and pulverized coal. The reaction atmosphere in the boiler is different from the pulverized coal because of water evaporation ,and the CO content was lower ,so the decomposing rate for desulphurization products was reduced,after water evaporated ,it formed microstructures which was considered as favorable to the desulfurization rate .

Accurate measurement of the concentration of pulverized-coal in various pipes as a guidance to proper control plays a key role in assuring safe and economic operation of a pulverized coal-fired boiler during the combustion process. Experimental studies are carried out on the measurement of a lean mass flow in a pneumatic conveying pipeline using electrical capacitance tomography (ECT). A cyclone separator is employed in this system where the sensors are placed in order to compensate the inhomogeneity of the sensor sensitivity. The distribution of void fraction in radial direction, the average void fraction and the wavy characteristics are analyzed. The feasibility and reliability of the method are verified by the experimental results.

China is a big agricultural country, which had many kinds of biomass resources. Biomass energy belongs to clean energy, it was available to achieve zero co2 emissions and substitute fossil fuels such as coal, oil and gas to be an important energy. Through the transformation of 35t/h coal-fired CFB boiler, which based on material and circulated carrier, burning biological energy, changed boiler from consuming one-time energy to the regenerative energy, which saved coal and prevented waste from directly emitting into the atmosphere to pollute the environment. It would save energy and increase the local farmers additional income by sell stem, which followed the trend of the national development strategy. The test data show that: this transformation of boiler is very successful, indicate that we can transform some original polluted boiler which consume coal to some degree and provide some experimental methods for these transformations.

Hydrocyclone is widely used in grading size in 3 ~ 250 μ m classification or separation assignments and grading size less than 15 μ m enrichment or clarification assignments. Now almost having no concentrator don't use hydraulic cyclone. Small diameter hydrocyclone of diameterΦ10 mm can classify ultrafine pulverized coal . So the application of two phase fluid theory and cyclone technology base on the principles of design,Design and manufacture a variety of small diameter hydrocyclone. After practice has proved. Sorting coal superfine particle effect is good. and can be used for sorting other mineral.

Based on the heat-transfer principle of air pre-heater, the influence mode of the changes of the air flow, the flue gas flow, the air leakage in different locations, to the temperature of the hot air and the exhausting gas was researched. The problem of a pulverized coal fired boiler, No.2, of a Thermal Power Plant, which the deviation of exhausting flue gas temperature increased to an abnormal extend when the boiler load rise up quickly was analyzed, the fault position and fault reason were located exactly, and the fault was eradicated by equipment maintenance at last. The results of this study have a certain significance to solve similar problems.

The worse coal quality cause low center flame temperature in furnace, low combustion stability, high carbon content in fly ash and slag. The refractory belt installed in primary combustion zone can reduce the heat absorption capacity of water wall and improve the average temperature to steady ignition and high efficient combustion. For conforming the area of refractory belt better, the equation was founded by thermal computational methods and analyzing the different influence to the area of refractory belt.

The optimum temperature within the reagent injection zone is between 900 and 1150°C for the NOX reduction by SNCR (selective non-catalytic reduction) in coal-fired utility boiler furnaces. As the load and the fuel property changes, the temperature within the reagent injection zone will bias from the optimum range, which will reduces significantly the de-NOX efficiency, and consequently the applicability of SNCR technology. An idea to improve the NOX reduction efficiency of SNCR by regulating the 3-D temperature field in a furnace is proposed in this paper. In order to study the new method, Computational fluid dynamics (CFD) model of a 200 MW multi-fuel tangentially fired boiler have been developed using Fluent 6.3.26 to investigate the three-fuel combustion system of coal, blast furnace gas (BFG), and coke oven gas (COG) with an eddy-dissipation model for simulating the gas-phase combustion, and to examine the NOX reduction by SNCR using urea-water solution. The current CFD models have been validated by the experimental data obtained from the boiler for case study. The results show that, with the improved coal and air feed method, average residence time of coal particles increases 0.3s, burnout degree of pulverized coal increases 2%, the average temperature at the furnace nose decreases 61K from 1496K to 1435K, the NO emission at the exit (without SNCR) decreases 58 ppm from 528 to 470 ppm, the SNCR NO removal efficiency increases 10% from 36.1 to 46.1%. The numerical simulation results show that this combustion adjustment method based on 3-D temperature field reconstruction measuring system in a 200 MW multi-fuel tangentially fired utility boiler co-firing pulverized coal with BFG and COG is timely and effective to maintain the temperature of reagent injection zone at optimum temperature range and high NOX removal efficiency of SNCR.

According to the 2012s workover treatment statistic in the Hancheng block, the eastern Ordos gas field, the workover caused by pulverized coal accounts for 41.8% of the total, which has seriously affected the continuous and stable drainage. This is one of the main factors which constraint coalbed methane production yield. In this paper, geological factors including the composition of coal petrography, the mechanical strength of coal petrography and coalbody structure destruction and engineering factors including drilling, fracturing and drainage were analyzed to study on the controlling factors on the output of pulverized coal. We conclude that the determinant on output of pulverized coal is the nature of coal seam, however engineering factors cause the output of pulverized coal directly. The root-mean-square amplitude attribute analysis was first used to display the mechanical strength of coal seam. Based on the result, we made the prediction about the possibility of the output of pulverized coal and divided the studying area into four grades. The research on the controlling factors and the prediction of the output of pulverized coal could provide the basis for the prevention and comprehensive treatment of pulverized coal.

This paper evaluates the results of two recent studies of advanced amine-based, post-combustion CO2 capture plant designs. The first study was conducted by the IEA Greenhouse Gas R&D Programme (IEA GHG), while the second study was conducted by Parsons for the US DOEs National Energy Technology Laboratory (NETL). Fluors improved monoethanolamine (MEA) process, known as the Econamine FG PlusSM technology, is utilised for both studies. Cost and performance estimates for both pulverized coal and natural gas-fired combined cycle plants are summarized. Differences between the design bases and assumptions for the two studies are discussed. The Econamine FG PlusSM technology, as an improved process in amine-based post-combustion CO2 capture described in this paper is leading to lower increases in the cost of electricity (COE). Both the DOE/Parsons and IEA GHG studies show that the increase is now down to 42 to 43% from as high as 60 to 70% indicated from previous studies for PC plants with CO2 capture.

O2/CO2combustion technology is an effective method to capture and store coal-fired boiler flue gas CO2. With a 300MW subcritical pulverized coal boiler as the research subject investigated, Fluent numerical simulation software is used to simulate the process of pulverized coal combustion both in air and O2/CO2conditions. The comparative analyses are made both in the former conditions, such as the combustion characteristics of pulverized coal, the influence of oxygen volume fraction, the effect of the secondary air temperature on the temperature field in the furnace of pulverized coal boiler. As for the following results of the pulverized coal combusted in the O2/CO2condition, compared with the results in the air condition, its time of ignition is delayed, and the combustion temperature is low and the central position of flame rises. With the increasing percentage of the oxygen volume and the rising temperature of secondary air, the time of ignition speeds up, which improves the overall furnace temperature level and transferring capability of the radiation heat.

The comparative study of numerical results on pulverized coal combustion process with CFD has become an important measure for direct engineering practice. In this paper, a combustion facility was simulated numerically with the Fluent code to investigate the process of coal combustion. Firstly, geometric models, grid and boundary type were established in the Gambit. Secondly, required models, physical properties and working conditions were chosen in the solver. Then, the important diagrams of each component displayed distinctly in the post professor. The simulation results showed that the rules of the volatile releasing and combustion processes of coke could provide important references to improve the combustion of the pulverized coal.

A tangentially fired boiler with twin furnace is tested to analyze the effect of such factors as primary air velocity,air distribution mode, over fired air,oxygen content on NOx and boiler efficiency during boiler combustion adjustment,providing reference for boiler operation optimization and reducing NOx emissions.

The ash deposition and the gas velocity affect the exhaust gas temperature of a CFB boiler. The surface contamination in a CFB boiler is quite different from that one in the pulverized coal boiler. It is suggested that the surface contamination in a CFB boiler should be determined according to the ash content in the fuel as well as the cyclone collection efficiency. The effect of the gas velocity on the surface contamination is very important. The lower gas velocity causes more serious contamination, leading to the higher exhaust gas temperature. The staged tube arrangement should be employed. And the gas velocity should be designed higher to enhance the self-cleaning ability. Anyway, the soot blower should be designed in the CFB boiler convective heating surface. The ratio of the practical contamination coefficient to the design one, k,is the strong function of gas velocity, wy, which was expressed as: k=1+exp(6.8-wy)

The preparation of pellets with taking the iron concentrate and titanium concentrate as the raw materials, the pulverized coal as the reducing agent and the CMC as the binder were researched in this paper. It was deduced from the orthogonal experiment results that the impact of quantities of binders on the compressive strength is the greatest, carbon ratio takes the second place, water content takes the third place, and pressure the least; the impact of the water content on the drop numbers is the greatest, pressure takes the second place, carbon ratio takes the third place and quantities of binders the least. Suitable parameters of forming process are ore ratio is 1:1, quantities of binders is 2.5%, carbon ratio is 18%, water content is 8% and pressure is 16 MPa.

Coal Bottom Ash (CBA) is a by-product from the generation of electricity using pulverized coal; Tanjung Bin power plant in Malaysia is a coal-based power plant that generates tonnes of bottom ash daily without known economic value that ends up in the ash pond. Due to the problems associated with the disposal ash pond in terms of cost and environmental impact, attention has now been focused on how best to utilize this waste. This paper present the recent development achieved on the utilization of bottom ash from Tanjung Bin power plant Malaysia in concrete development; physical and chemical properties, workability and fresh concrete properties as well as the strength development of Tanjung Bin bottom ash.

In drainage and mining of the coal bed methane(CBM),pump valve jams caused by the settlement of pulverized coal particles directly affect the normal production of the coal bed methane(CBM).From the study of the pulverized coal particle size,this paper summarizes the law of the pulverized coal particle size change in various stages of the coal bed methane(CBM) production well drainage and ming.By analyzing the pulverized coal particle velocity distribution along the pump cylinder,the viewpoint that the pulverized coal particle has a higher axial velocity in the central part of the settlement and has a lower velocity near the wall surface is put forward to.Based on the theory,the motion track equation of the pulverized coal particle can be got by calculation.Under the condition of considering buoyancy,fluid resistance and pressure drag,instant drop speed of the pulverized coal in water is calculated.