2017年06期目次

  • Progress and suggestion on desulfurization and denitrification technology for coke oven flue gas

    WANG Yan;ZHANG Yang;GUO Shanshan;BAI Xiaoyan;ZHOU Qi;WANG Zhizheng;Coal Chemistry Branch of China Coal Research Institute;Graduate School of China Coal Research Institute;State Key Laboratory of High Efficient Mining and Clean Utilization of Coal Resources;

    SO_2 and NO_x emission status and the main influencing factors of pollutant concentration in coking industry in China were analyzed.This paper also compared the process principle,desulfurization and denitrification efficiency and their advantages and disadvantages of the desulfurization technology( i.e.,ammonia desulfurization,limestone-gypsum desulfurization,double alkali desulfurization,Mg O desulfurization,spray drying desulfurization and circulating fluidized bed desulfurization),denitrification technology( low NO_x combustion technology,SCR denitrification,oxidation denitrification) and integrated desulfurization and denitrification technology( active coke desulfurization and denitrification and LCO desulfurization and denitrification).The route selection,flue gas emission,secondary pollution and others problems were summarized.It is pointed out that the pollution control of coke oven flue gas should effectively integrate the source control,low nitrogen combustion and ending purification,and the coke oven management level and the application of new technology should also be strengthened.

    2017 06 v.23;No.112 [Abstract][OnlineView][HTML全文][Download 1082K]

  • Quality requirements of coke oven gas for production of industrial methanol

    XIONG Chu'an;ZHANG Jinyong;ZHANG Hongsen;School of Environment and Chemical Engineering,Heilongjiang University of Science and Technology;Baotailong New Materials Co.,Ltd.;

    The technology of coke oven gas to methanol is a characteristic integrated utilization process of coke oven gas in China,which shows important significance to both the mass production and environmental protection by implementing resource utilization of coke oven gas and reducing the emission of pollutant.Based on the National Key R & D Program of China 'study on the criterion of key technology in cycle linkage of private industry',the comparative studies between the enterprises survey and literature reports were carried out and the effects of main impurities,such as oxygen content,sulfide,ammonia,benzene,naphthalene,hydrogen cyanide,tar and dust on the subsequent process of methanol were analyzed.As expect,the quality requirements of coke oven gas for industrial methanol production are proposed,which is useful to guide the process management and quality control in coke production and coke oven gas purification for enterprises,and thus,providing qualified raw material gas for methanol production.

    2017 06 v.23;No.112 [Abstract][OnlineView][HTML全文][Download 102K]

  • Research progress and prospect of acid-alkali demineralization with activated carbon

    WU Qian;LIANG Daming;WANG Peng;XIE Wei;Coal Chemistry Branch of China Coal Research Institute;Beijing Key Laboratory of Coal Based Carbon Materials;National Energy Technology and Equipment Lab of Coal Utilization and Emission Control;

    Based on different raw materials and minerals of different formulation,the paper provided reference for selection of demineralization method and formulation for demineralization process. The acid-alkali demineralization method selection,main factors affecting the demineralization effect and activated carbon performance were principally introduced.In addition,the process and mechanism of acid-alkali demineralization were briefly concerned.Finally,the future research direction of the acid-alkali demineralization with activated carbon was prospected.It is mainly pointed out that the mechanism of de-ashing of the acid-alkali chemical ash removal agent should be studied deeply to realize the accurate removal of inorganic minerals in the activated carbon. The research of deep ash-removal process on coal-based activated carbon is the development trend of alkali-acid washing.

    2017 06 v.23;No.112 [Abstract][OnlineView][HTML全文][Download 137K]

  • Current situation and prospects of power coal dry separation technology in China

    XIA Yunkai;LI Gongmin;Tangshan Shenzhou Manufacturing Co.,Ltd.;Hebei Dry Coal Processing Equipment Engineering & Research Center;

    In view of the problems of wet process in coal preparation,technical features and advantages of different deshaling equipment were compared. Application progress of various coal dry separation process and technology was also introduced,and technical characteristics and future development direction of different coal dry separation process and equipment were discussed. The objective of power coal dry separation is to enhance clean coal product heating value and remove its refuse rock and sulfur content. There are many advantages such as no product moisture increase and low processing cost. With the new processes of classified separation,lump coal dry separation,fine coal dry separation,dual quality upgrading of pre-drying and dry separation process and air dense medium separation,process flowsheet of coal dry preparation plants can realize custonized design,which makes up for the limitation of traditional single FGX dry coal cleaning process and equipment. It will be an inevitable tendency for the future dry coal preparation plant designers to develop high efficient,large scale,low energy consuming,lower efficient separation bottom size type dry separation process and equipment,and high-efficient,economical,large scale coal preparation plants.

    2017 06 v.23;No.112 [Abstract][OnlineView][HTML全文][Download 143K]

  • Characteristics and cleanliness class of coal seam in Yuanbaoshan open-pit coal mine

    HE Bao;LI Zhennan;College of Mining Engineering,Liaoning Technical University;

    In order to use the coal from Yuanbaoshan open-pit coal mine reasonably and cleanly,the coal quality was analyzed based on general geology,characteristics of coal-bearing strata and coal physico-chemical property.The type,industrial properties and utilization approaches of such coal were determined. According to the new coal resource potential evaluation of the proposed coal cleanliness class scheme grade 6,the cleanliness of this mining area coal seam was drew primarily from the aspects of ash,sulfur,F and As contents.The results show that clarain and durain are the main lithotypes of the mining area coal.Huminite is the main maceral of this mining area coal.The low ash,medium sulfur and high volatile contents,as well medium calorific value of No.2 lignite are the typical coal characteristics in this mining area.The cleanliness class of main coal seam 5 and 6 is Ⅲ-Ⅳ,which belongs to the better-medium clean coal. The cleanliness class of the mining area coal is Ⅳ,which belongs to the medium clean coal.Because of its medium calorific value,poor thermal stability,great chemical reactivity with CO_2,higher tar yield and medium cleanliness,the quality of this lignite is thought be better.The lignite can be used as a raw material for combustion,gasification and coking with a greater economic value.

    2017 06 v.23;No.112 [Abstract][OnlineView][HTML全文][Download 118K]

  • Recleaning of coal flotation tailings desliming and floatability evaluation

    REN Ruichen;CHEN Kang;WANG Guoliang;LI Caixia;ZHENG Zhongyu;DONG Jiaqi;Mineral Processing and Utilization Design Institute,Liaoning Technical University;College of Mining Engineering,Liaoning Technical University;Liaoning Key Laboratory of Mineral Processing,Liaoning Technical University;

    In order to solve the problem of large amount,low ash and high content of heterogeneous fine mud of coal flotation tailings from a coal preparation plant of Kailuan Group,desliming experiment was conducted using small taper angle hydrocyclone group installed in series of φ150 mm,φ75 mm,φ50 mm,φ10 mm.Through sequential evaluation experiment the hydrocyclone group before and after as well as all levels of the underflow coal slime were evaluated.The results show that all levels of the underflow ash are less than raw fine coal.Withφ10 mm hydrocyclone,the ash difference between underflow and overflow is 11. 15%; the removal rate of less than 0.015 mm high ash content fine slime is 19.73%; the ash yield of fine coal after desliming decreases 2. 73% indicating high effective of hydrocyclone group desliming.The floatability of the raw fine coal is extremely difficult-to-float; after desliming it is promoted to be difficult-to-float. The mixed underflow of φ75 mm and φ50 mm,and underflow of φ10 mm are less difficult-to-float.When ash content of cleaned coal is 11. 50% or less,the yield of the clean coal after desliming is 8.91% higher than before( 19. 21%); the mixed yield of the clean coal from separating flotation is 31. 48%( 12. 27% increase),which means the desliming is able to improve the flotability of fine coal.

    2017 06 v.23;No.112 [Abstract][OnlineView][HTML全文][Download 257K]

  • Experimental study on preparation of gasification coal water mixture with char

    HE Hongxing;DU Liwei;ZHANG Guiling;WANG Xuewen;China Coal Research Institute Company of Energy Conservation;National Coal Water Mixture Engineering Technology Research Center;State Key Laboratory of Coal Mining and Clean Utilization;National Energy Technology and Equipment Laboratory of Coal Utilization and Emission Control;

    To increase the mixture concentration of char,the coal water mixture for gasification was prepared using char and lignite as raw materials.The slurry characteristics were tested by means of traditional process,classified grinding and gap-graded process. The results show that the highest concentration of char and lignite are 55. 58% and 47. 38% respectively prepared by traditional process. The highest concentration of char and lignite are 58. 13% and 51. 59% respectively of slurry prepared by classified grinding process with a thickness ratio of 85 to 15.As well,the highest concentration is 61. 36% prepared by gap-graded process with mass ratio of char and lignite of 7 to 3 and char thickness ratio of 6 to 4.It meets the design requirements that improves fluidity and stability obviously.

    2017 06 v.23;No.112 [Abstract][OnlineView][HTML全文][Download 105K]

  • Heat and mass transfer of coal particles pyrolysis based on weight loss curve

    ZHANG Xuhui;CHEN Zan'ge;WU Peng;TENG Jilin;ZHANG Peilin;NARI Group Corporation ( State Grid Electric Power Research Institute);Beijing Guodian Futong Science and Technology Development Co.,Ltd.;

    To improve the applicability and accuracy of heat and mass transfer model,the coal pyrolysis model was built based on the thermal weight loss curve to replace the DEAM model.The heat and mass transfer process of coal particles were described by equation of heat conduction and mass conservation,the model was validated by the testing pyrolysis weight loss platform of coal particle. The results show that the average relative deviations of the exhalation of 4 mm,8 mm,12 mm coal volatile are 6.21%,5.11%,4.92% respectively under the condition of ambient temperature 900 ℃ and the flow velocity of carry gas 0.06 m/s.The average relative deviations of the exhalation of 4 mm coal volatile are 6.21%,5.54%,5.20%,under the condition of ambient temperature 900,750,650 ℃ and flow velocity of carry gas 0.06 m/s.

    2017 06 v.23;No.112 [Abstract][OnlineView][HTML全文][Download 337K]

  • Analysis on retention of alkali metals in updraft biomass gasifier

    WANG Jianwei;LIU Ning;ZANG Hongyu;LI Longzhi;School of Mechanical and Electronic Engineering,Shandong University of Science and Technology;

    A novel device was designed allowing direct combustion and updraft gasification combustion with peanut shell,cotton stalk and corn stalk particles as feeds. The alkali metals content in the flue gas produced from the device in the direct combustion and updraft gasification combustion processes was tested. The experimental results show that the alkali metals content in updraft combustion process is much lower than that in the direct combustion process,although there is a difference in the alkali metals content among these three fuels.It illustrates that the updraft gasifier has a unique filter retention effect on volatile alkali metals using biomass as feedstock,which can effectively alleviate the alkali metals corrosion of the downstream heat equipment.Therefore,updraft biomass gasifier is a better alternative coal renewable energy utilization equipment.

    2017 06 v.23;No.112 [Abstract][OnlineView][HTML全文][Download 136K]

  • Velocity field of cold model gasifier with top-setting seven-nozzle

    PENG Baozai;LIU Zhen;GUAN Qingliang;FANG Xinhui;LI Wenhua;National Institute of Clean-and-Low-Carbon Energy;

    In order to investigate the flow field of the top-setting seven-nozzle gasifier,a model gasifier was designed based on the similarity principle with the height of 4 000 mm and the diameter 800 mm based on industrial dry-coal fed gasifiers.The velocity fields were measured using PDA for the top-setting seven-nozzle scheme and top-setting single-nozzle scheme,respectively. The results indicate that the top-setting single-nozzle scheme has a center-jet flow field,but the top-setting seven-nozzle scheme is of a plug-flow like field with much less axial velocity degradation along the radial direction.In addition,the center velocity of the top seven-nozzle scheme reduces more dramatically than that of the top-setting single-nozzle scheme resulting in fewer short-way particles.The top-setting seven-nozzle scheme has much smaller reflux zone and better gas-solid mixing effects that the top-setting single-nozzle scheme. The calculated reflux ratio of particles near the nozzle exit positions of the top-setting seven-nozzle scheme is higher than that of the top-setting single-nozzle scheme,which indicates that the top-setting seven-nozzle scheme can effectively enhance the gas-solid mixing and improve the carbon conversion efficiency.

    2017 06 v.23;No.112 [Abstract][OnlineView][HTML全文][Download 305K]

  • Research on acceleration test of MEEP chain life under simulated operating conditions

    HE Yuzhong;HE Haitao;YAO Yuping;LEI Huihui;Zhejiang Feida Environmental Science & Technology Co.,Ltd.;

    In order to improve the life and reliability of moving-electrode type electrostatic precipitator( MEEP) for efficiently capture the PM_(2.5) dust in flue gas,this article studied the wear,fatigue and service life of MEEP's drive chain under simulated operating conditions on a home-made chain test-bed furnace.The related factors affecting the furnace performance were systematically investigated by the aspects of temperature,dust environment,load force,working hours etc.The experimental results show that the inner surface of sub-roller,the outer surface of sleeve and pin are found undergo significant wear,and they are mainly caused by abrasive wear and accompanied by fatigue wear.In addition,the test chain can meet the designing requirements for eight years under operating condition criteria,and the elongation of chain can be less than 1%.

    2017 06 v.23;No.112 [Abstract][OnlineView][HTML全文][Download 196K]

  • Application of Gieseler fluidity on coal coking field

    ZHAO Qi;Coal Chemistry Branch of China Coal Research Institute;State Key Laboratory of High Efficient Mining and Clean Utilization of Coal Resources;National Energy Technology & Equipment Laboratory of Coal Utilization and Emission Control;

    In order to promote the effective using of Gieseler fluidity in coal coking field,the test method,standard and main equipment application of Gieseler were briefly introduced.Discussions concerning the use of Gieseler fluidity in coal coking field,such as distinguishing of abnormal coking coal,identifying the change of bondability of easily oxidized coal,accurate recognition of coking coal's caking property,controlling the quality of coke and coal blending method of gasification coke were systematically summarized.αmax-R coal blending method in gasification coke production was discussed.This paper also put forward the coal coking field should use the advantage of Gieseler and guide the rational utilization of coking coal.The equipment that suit for coal properties and test standard should be paid more attentions.

    2017 06 v.23;No.112 [Abstract][OnlineView][HTML全文][Download 132K]

  • Ash melting behavior of coal and biomass in reducing atmosphere

    ZHANG Guanjun;Institute of Thermal Power Technology,China Datang Corporation Science and Technology Research Institute;

    In order to reveal ash melting characteristics of coal and biomass during the high-temperature thermal conversion process,the influence of biomass addition on ash melting characteristictemperatures was investigated by ash fusion temperature test and high-temperature on-line XRD analysis.The mineral phase decomposition,reduction and phase transformation were investigated,and the changes of silicate species were verified by SiO_2-CaO binary phase diagram. The results show that the addition of wheat straw significantly reduces the ash melting characteristic temperatures; the softening and deformation temperature shows a monotonically decreasing trend. When the biomass mass fraction reaches 50%,the ash flow temperature and hemisphere temperature go to be the lowest value.The high silicon content of the biomass leads to a high ΔT_(FT-DT)value; while the high K_2O content leads to a lower DT value.At high temperature range,carbonates and sulfates decomposition reactions occurre,iron oxides and sulfates are reduced to metallic iron and sulfides,simple oxides and SiO_2 will form silicates.The ash melting characteristic temperature largely dependes on the amorphous material formation rate and its softening rate.

    2017 06 v.23;No.112 [Abstract][OnlineView][HTML全文][Download 257K]

  • Coal-fired chemical looping combustion with hematite and ilmenite oxygen carriers

    LI Yanbing;ZHANG Shuai;LIU Qiusheng;SUN Ping;Shenhua Guohua ( Beijing) Electric Power Research Institute Co.,Ltd.;

    To screen the low-cost and high-efficient oxygen carrier that is suitable for coal-chemical-looping combustion process,lowcost and environmentally friendly hematite and ilmenite with different chemical composition and structure properties were adopted as the nominated oxygen carriers to investigate their reaction performance in a lab-scale fixed-bed reactor.Results show that higher reaction temperature is effective to enhance the coal gasification reaction rate and reaction performance of both two oxygen carriers,resulting in the CO_2 concentration and carbon conversion being improved by different degrees.However,excessive reaction temperature is easy to cause the sintering and agglomeration on these two oxygen carrier particles,and eventually inhibits the conversion of coal gasification products.Compared to the performance of hematite,ilmenite shows a better pore structure and reaction performance,higher CO_2 capture efficiency and carbon conversion efficiency could be achieved,and therefore is more suitable for coal-chemical-looping combustion process.

    2017 06 v.23;No.112 [Abstract][OnlineView][HTML全文][Download 539K]

  • Influence of tertiary air arrangement on low-NOx combustion characteristics for a "W" type flame boiler

    LAN Yanxu;WANG Hui;QIU Fugang;SUN Lushi;WANG Ben;YU Jie;WANG Ke;XU Linlin;Shajiao A Power Station of Guangdong Yudean Group Co.,Ltd.;State Key Laboratory of Coal Combustion,Huazhong University of Science & Technology;Wuhan Huayu Combustion and Energy Engineering Technology Co.,Ltd.;

    In order to meet the increasingly stringent of low nitrogen emission standards,research on low nitrogen combustion characteristic of the down-fired"W"type boiler is an urgent task.In this study,a down-fired with lean coal boiler was taken as test object.On the basis of the boiler characteristics,the numerical simulation study was performed in different tertiary air arrangements of burner,and the effects of combustion and NO_x emissions were analyzed. Firstly,the original boiler conditions were analyzed by numerical method,and it was compared with the actual operation datum.In Down-fired boiler,low-NO_x combustion design was performed by the comparison of parameters of different tertiary air arrangements to ensure the optimum tertiary air arrangement. The numerical simulation results show that the arrangement of tertiary air has a great influence on the combustion and NO_x formation in the furnace.The amount of NO_x produced by arrangement mode one or two is more than 800 mg/Nm~3,and the carbon content of fly ash produced by arrangement mode three is up to 6.85%.High temperature area near the water wall of arrangement mode four could easily lead to slagging.The above four arrangements all have defects.The arrangement mode five is the best arrangement,which produces low content of NO_x ( 762 mg/Nm~3),and the carbon content of fly ash is 4.51%,as well the temperature distribution is reasonable.

    2017 06 v.23;No.112 [Abstract][OnlineView][HTML全文][Download 385K]

  • Effects of combustion conditions on the characteristics of fly ash and slag in coal-fired power plants

    WEI Shaoqing;TIAN Xiuqing;YANG Fengling;CHENG Fangqin;Jinneng Changzhi Co-generation Co.,Ltd.;Shanxi Collaborative Innovation Center of High Value-added Utilization of Coal-related Wastes,Shanxi University;Shanxi Province Engineering Research Center of Clean Coal Combustion for Power Generation ( Under Preparation);

    In order to expand the comprehensive utilization of fly ash and slag from power plant,in this paper,fly ash and slag produced from combustion of low volatile coals in different types of boilers under different conditions were studied.To investigate the effectofcombustion conditionson the characteristics of fly ash and slag,the physical and chemical characteristics were analyzed by inductively coupled plasma( ICP),X-ray diffraction( XRD),physical adsorption instrument( BET),thermogravimetric analysis( TG-DTG) and scanning electron microscopy( SEM),etc.The results show that the effects of coal variety and boiler type on physicochemical propertiesof fly ash and slag are obvious,while the effects of operatingload of same type boiler onchemical composition,mineral matters and microscopic morphology of fly ash and slag are negligible.The characteristics of fly ash and slag are different,which is due to the difference of PC,CFB and WFB combustion temperature and the influence of coal quality.

    2017 06 v.23;No.112 [Abstract][OnlineView][HTML全文][Download 420K]

  • Dissolution rate of Al2O3 of ash and slag from circulating fluidized bed boiler

    WU Haibin;XUE Fangbin;CUI Yanwei;YANG Fengling;Shanxi Rui En Ze Technology Co.,Ltd.;Institute of Resources and Environmental Engineering,Shanxi University;Changzhi City Economic Development Research Institute;

    In order to investigate the activity of fly ash and slag derived from the burning process of coal gangue and further extend their application,the chemical compositions of ash and slag from circulating fluidized bed boiler( CFB) was analyzed. The effect of burning temperature and particle size on the Al_2O_3 dissolution of ash and slag was studied by 20% hydrochloride acid( HCl) leaching and ultrafine activating.The results show that the contents of Al_2O_3 and SiO_2 in the ash and slag are 25% and 35%,respectively.In addition,the dissolution of Al_2O_3 decreases with the increase of burning temperature of coal gangue in CFB. The dissolution of Al_2O_3 exceedes 52% when the burning temperature is 800-900 ℃.While the dissolution of Al_2O_3 decreases to 26%-40% when the burning temperature increases up to 900 ℃.The dissolution of Al_2O_3 could be increased from 68% to 93% when the particle size decrease from 198 μm to 74 μm.

    2017 06 v.23;No.112 [Abstract][OnlineView][HTML全文][Download 124K]

  • Pollutant emission performance of additive-upgraded high-sulfur coal in CFB combustion

    LIANG Bin;LIU Zhongpan;WU Qiong;ZHENG Yuangang;BAI Haolong;SONG Hua;WANG Chuanzhi;LAN Tian;Yankuang Group Co.,Ltd.;Yankuang Technology Co.,Ltd.;

    A technology was proposed to upgrade the high-sulfur coal by utilizing the composite chemical additives.The technology aimed at achieving SO_2 emission no higher than the base-coal when it was co-fired with the additive-upgraded high sulfur( AUHS) coal.Furthermore,when the AUHS was co-fired with the base-coal,the SO_2 produced from both the base-coal and high sulfur coal could be reduced to meet the strictest emission standard,e.g.ultra low emission standard( i.e. < 35 mg/Nm~3).To validate the technologic concept,experimental tests with a base-coal,a high-sulfur coal and their blend were combusted in a 1 MW pilot circulating fluidized bed( CFB) test facility.The results show that the SO_2 emission is almost same as that of base-coal when 30% high-sulfur coal co-fired with the additives.Further experiments demonstrate that co-firing the additive-containing high-sulfur coal with a blend of high sulfur coal and base-coal( total high sulfur coal is 30%) with an overall stoichenmistric ratio of 2.5 reduces the SO_2 emission to 21.5 mg/Nm~3.It is lower than the current national ultralow emission standard of 35 mg/Nm~3.The in-situ sulfur removal efficiency is 98.8%.In addition,the additives used to upgrade the high sulfur coal also inhibit the production of other gaseous pollutants,such as N_2O,NH_3,HCN,HCl,HF,CH_4 and CO reflected by the lower emissions of these pollutants.The investigation confirms that the technology presenting in this study is one of the most effective and economic solutions for clean utilization of high sulfur coals.

    2017 06 v.23;No.112 [Abstract][OnlineView][HTML全文][Download 282K]

  • Preparation of metallurgical grade alumina by calcination of crystalline aluminum chloride

    GUO Qiang;XIAO Yongfeng;WANG Baodong;SUN Qi;National Institute of Clean-and-Low-Carbon Energy;

    In order to prepare qualified metallurgical grade alumina by calcination of crystalline aluminum chloride,the effect of calcination temperature and time of crystalline aluminum chloride on the decomposition rate and the physical properties of alumina was studied by laboratory static experiment.The results show that the calcination temperature and time are 250 ~ 350 ℃ and 0.5 ~ 3 h at low temperature region,and the calcination temperature and time are 1 000 ~ 1 100 ℃ and 15 ~ 60 min at high temperature region.A small amount of water vapor was introduced into the roasting process to benefit the decomposition of crystalline aluminum chloride.By characterization of the physical properties of alumina,it is found that the particle size and specific surface area of the alumina products obtained by the two-step process are higher than the one-step method.With the increase of the calcination temperature,the particle size and specific surface area of the alumina decreases.In addition,the particle size of the alumina increases with particle size of crystalline aluminum chloride.

    2017 06 v.23;No.112 [Abstract][OnlineView][HTML全文][Download 391K]

  • Emission characteristics and controlling of NOx in lean coal-fired boiler of the 330 MW unit

    YANG Wei;LI Wenxiu;GUO Fude;YANG Fengling;ZHANG Kai;CHENG Fangqin;Jinneng Changzhi Co-generation Co.,Ltd.;Shanxi Collaborative Innovation Center of High Value-added Utilization of Coal-related Wastes,Shanxi University;Shanxi Province Engineering Research Center of Clean Coal Combustion for Power Generation ( Under Preparation);Beijing Key Laboratory of Emission Surveillance and Control for Thermal Power Generation,North China Electric Power University;

    The field experiments of low-NO_x combustion system were conducted in a 330 MW lean coal-fired boiler.Testing investigation of NO_x emissions was performed before and after furnace exit and SCR.At the same time,the concentration of NO_x varying with the depth of the tail flue and boiler load was examined.The results show that concentration of NO_x in the furnace outlet is maintained about 600 mg/m~3.The concentration of NO_x is related to the sampling location,thus the stationing of section in the field test should be reasonable.The emission of NO_x will be less than 50 mg/m~3 under the different load with the control of low-NO_x and SCR.The denitration efficiency of the SCR system is good under normal running condition.However,there are some problems,such as large consumption of ammonia,catalyst blockage,abrasion and low-NO_x efficiency at low load.The study suggests that the power generation unit should combine SNCR with SCR,and increasing the residence time of the ammonia in the system can improve the denitration efficiency and avoid ammonia escaping.

    2017 06 v.23;No.112 [Abstract][OnlineView][HTML全文][Download 413K]

  • Decrease of hardness of the coal water slurry gasification black ash water system

    WANG Xiaolei;CHEN Quan;TONG Shenglu;HUO Weidong;National Institute of Clean-and-Low-Carbon Energy;

    In order to solve the problem of scaling and clogging of coal water slurry gasification black ash water system,the present status and processing mechanism of system were analyzed,and studies were carried out by simulating and a lab-scale device experiment. The treatment effects of two schemes of NaOH+CO_2 and Ca(OH)_2+Na_2CO_3 were verified,and the dosage of reagent was checked.The technical guidance was provided for a field pilot test,and effective and feasible modification methods were found.The experimental results show that the two treatment schemes of NaOH+CO_2 and Ca(OH)_2+Na_2CO_3 have good treatment effect.Two schemes both could reduce the hardness to less than 300 mg/L.This can meet the requirements of ash water reuse.The costs of NaOH+CO_2 and Ca(OH)_2+Na_2CO_3 schemes are 2. 38 and 1. 62 Yuan/t respectively.

    2017 06 v.23;No.112 [Abstract][OnlineView][HTML全文][Download 203K]

  • Analysis on the retrofitting engineering of ultra-low pollutant emissions for a 1 000 MW ultra-supercritical coal-fired power plant

    ZHOU Chaoyang;School of Power and Mechanical Engineering,Wuhan University;

    The retrofitting engineering of ultra-low pollutant emissions in coal-fired power plants in China has being carried out to further reduce SO_2,NO_x and dust emissions to alleviate their effects on serious fog and haze weather.The state of the art on the Selective Catalytic Reduction( SCR) flue gas denitrification,wet flue gas desulfurization( WFGD) and dry electrostatic precipitator( ESP) in a 1 000 MW ultra super critical coal fired power plant was firstly analyzed,and a retrofitting solution of ultra-low pollutant emissions was proposed and carried out with the integrated combination of the increasing capacity of SCR,low-low temperature electrostatic precipitator with high frequency power source,the improving efficiency of wet flue gas desulfurization and the synergistic dedust of the desulfurization absorption tower.The performance tests of the unit were carried out to measure the removal efficiencies of the SCR,WFGD and low-low temperature EPS before and after the retrofitting engineering of ultra-low pollutant emissions.The results show the concentrations of the dust,SO_2 and NO_x at the inlet of the chimney are 4.0 mg/m~3,21.5 mg/m3 and 38.2 mg/m~3,respectively,which are lower than the standards of ultra-low pollutant emissions.The amounts of the dust,SO_2 and NO_x emissions are further reduced by 543 tons,2 633 tons and 634 tons every year after the engineering retrofitting and it significantly improves the local air quality.

    2017 06 v.23;No.112 [Abstract][OnlineView][HTML全文][Download 150K]

  • Comparison of different systems for waste heat recovery from flue gas in a 1 000 MW power plant

    YANG Fuxin;TAN Houzhang;ZHANG Junjie;JING Changcai;DONG Kun;WANG Shunsen;School of Energy and Power Engineering,Xi'an Jiaotong University;Shenhua Guohua ( Beijing) Electric Power Research Institute Co.,Ltd.;

    To recover the waste heat from flue gas and lower the temperature of the flue gas,four systems are proposed by using a low temperature economizer for energy saving based on the energy cascade utilization principle in a 1 000 MW power plant. The efficiencies of these systems are obtained by using the matrix method.Comparing the typical system of waste heat recovery that the economizer is located after the air preheater; the system of flue gas bypass of the air preheater has advantages and the standard coal consumption reduction is increased from 1.85 g/k Wh to 3.14 g/k Wh.

    2017 06 v.23;No.112 [Abstract][OnlineView][HTML全文][Download 196K]
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