- FAN Haodong;SHAN Xiongfei;ZHANG Man;DING Yi;YANG Hairui;LYU Junfu;JIN Yan;QIN Shuning;College of Electrical and Power Engineering,Taiyuan University of Technology;Department of Energy and Power Engineering,Tsinghua University;SDIC Power Holdings Co.,Ltd.;
In the biomass thermal conversion technology,fluidized bed combustion technology has gradually become a research hotspot due to its unique advantages.However,in practical application,the problems of slagging and fouling often occur on the heating surface,which seriously affect the operation cycle of biomass circulating fluidized bed boiler unit.The mechanism of slagging and fouling of biomass circulating fluidized bed boiler were expounded,and the phenomenon of fouling and slagging in actual boiler and the engineering countermeasures were pointed out.The characteristics of biomass fuel are the decisive factors that lead to slagging and fouling of fluidized bed unit.The selection of fuel with low alkali metal content and bed material with similar composition with outer covering layer can effectively reduce the slagging and fouling degree during the combustion process of biomass fuel.The furnace temperature has a direct impact on the slagging,and when the air distribution plate of the biomass fluidized bed unit is evenly distributed,the temperature can be reduced.In the design of a biomass fluidized bed boiler unit,slagging and fouling can be inhibited by increasing the velocity of primary airflow,rationally arranging the heating surface of the boiler,and stagger arrangement of the low-temperature heating surface and high-temperature heating surface of the tail flue.When the biomass circulating fluidized bed boiler is mixed with high-parameter coal-electric boiler,the content of alkali metal substance after fuel mixing is reduced,which effectively reduces the degree of slags and contamination of boiler unit,and provides guidance for the high reliability operation of the biomass circulating fluidized bed boiler.
2020 S1 v.26 [Abstract][OnlineView][Download 135K] - LI Peng;LIU Yuanjie;WANG Huifang;LIU lei;LI Kezhong;HOU Xiangsheng;State Key Laboratory of Coal-based Low-carbon Energy,Enn Technology & Development Co.,Ltd.;
During the pyrolysis or gasification of caking coal,a certain amount of colloids will be produced,which may cause coking in the furnace and lead to blockage of the outlet of the slag discharge pipe. Therefore,it is necessary to achieve destruction of caking coal. The common methods of caking destruction were discussed,and the prospect of destruction technology was put forward. The major methods of caking destruction include pre-oxidation,mixing,mechanical breaking and additive method. Pre-oxidation is efficient for the caking destruction of bituminous coal,and is the most intensively investigated. In the process of pre-oxidation,oxygen-containing functional groups in coal increase,aliphatic hydrogen decreases,the degree of micropores and crosslinking increases,and the fluidity of coal is lost in the process of heating,so as to reduce the formation of colloids,and thus achieve viscosity breaking. Generally,the higher the temperature,oxygen content,pre-oxidation temperature and time,the more favorable to break the viscosity. The mixing method and additive method mainly reduce the overall cohesiveness by adding non-viscous substances,so as to achieve the viscosity breaking. However,the degree of viscosity breaking is limited by the unit capacity of gasification,and it is also greatly affected by raw materials. Mechanical breakage prevents coal sample from sticking during gasification by stirring,which has the advantage of simple process,but can only be used in fixed bed,and the handling capacity is difficult to meet the needs of large-scale industrial production. In the future,a variety of methods can be coupled to break the limitations of single technology,and efficient composite breaking technology can be developed. For example,the combination of basic compound addition method and pre oxidation method can reduce the coal cohesiveness,and the basic compound can also play a catalytic role in the gasification process.
2020 S1 v.26 [Abstract][OnlineView][Download 850K] - NING Yongan;DUAN Yihang;GAO Ningbo;QUAN Cui;National Energy Shendong Coal Group Co.,Ltd.;School of Energy and Power Engineering,Xi'an Jiaotong University;
With the large-scale promotion of coal gasification technology,the storage and production of coal gasification slag become larger and larger,which has caused serious environmental pollution and waste of land resources,and has adversely affected the sustainable development of coal chemical enterprises. The utilization of coal gasification slag is of great significance for realizing the circular development of the coal chemical industry. The generation of gasification slag and its environmental problems,and the basic characteristics of coal gasification slag were introduced. Based on the elemental composition of coal gasification slag,the research progress on utilization of coal gasification slag at home and abroad was reviewed,including the carbon element( preparation of activated carbon,adsorbent,etc.),aluminum element( preparation of polyaluminum chloride flocculants,alumina,etc.),silicon( preparation of mesoporous materials),and the use of gasification slag in construction and building materials. Based on the above analysis,it is proposed that large-scale utilization of coal gasification slag( utilization of building materials,etc.) is the main disposal method. However,the key factor restricting the development of this method is the residual carbon in the coal gasification slag. Therefore,cost-effective separation and enrichment technology of residual carbon is a key technology to promote the comprehensive utilization of coal gasification slag.
2020 S1 v.26 [Abstract][OnlineView][Download 1466K] - ZHANG Hui;LAI Zhibin;HE Hongxiang;LIU Ye;RUAN Yongfang;WU Changjun;HUANG Xuelin;Huangpu Customs Technical Center;China Certification & Inspection Group Guangdong Co.,Ltd.;
China is the largest coal producing and consuming country in the world. The coal industry has become the largest emission source of toxic and harmful substances in China,which is one of the main causes of many environmental problems in China. With more and more attention paid to environmental protection,the emission standard of trace elements in coal combustion has been improved,and the processing and utilization of trace elements in coal has also got a new understanding. In view of the shortcomings of the traditional analysis methods of trace elements in coal,such as the consumption of more chemical reagents,long detection cycle and complex post-processing,the research and application status of the determination of some trace elements in coal by atomic fluorescence spectrometry were summarized. It is concluded that the method has the advantages of low cost,convenient operation and high accuracy,and can be applied to the determination of some trace elements in coal. In this paper,the principle and development status of atomic fluorescence spectrometry( AFS) for determination of trace elements in coal were discussed,and the future research and ability direction of determination of trace elements in coal were prospected. It is considered that through the optimization and discussion of atomic fluorescence spectrometry analysis technology,combined with precise automation and intelligent equipment,it can be widely used in the determination of trace elements in coal.
2020 S1 v.26 [Abstract][OnlineView][Download 142K] - ZANG Jingkun;CHENG Wei;Mining College,Guizhou University;National & Local Joint Laboratory of Engineering for Effective Utilization of Regional Mineral Resources from Karst Areas;Guizhou Key Laboratory of Comprehensive Utilization of Nonmetallic Mineral Resources;
Coal is the most abundant fossil energy in the world. However,the combustion process will be accompanied by the emission of harmful gases such as sulfur oxides,which will have a negative impact on the ecological environment and human health. Compared with the traditional physical and chemical desulfurization technology,coal microbial desulfurization technology has advantages such as clean and efficient,which is of great significance for improving the utilization of high sulfur coal and alleviating air pollution. In this article,the occurrence of sulfur in coal and the biological removal mechanism of inorganic sulfur and organic sulfur,and desulfurization methods including microbial leaching and microbial pretreatment-flotation were discussed in detail. Besides,a comparative analysis of the key factors( coal particle size,microbial species and microbial growth environment) affecting microbial growth and desulfurization efficiency was carried out,and the main problems and development trends of microbial desulfurization technology were proposed to provide scientific reference for the development of clean and efficient microbial desulfurization technology.
2020 S1 v.26 [Abstract][OnlineView][Download 950K] - WANG Haitang;LIU Liguo;XIONG Rihua;National Institute of Clean-and-Low-Carbon Energy;State Key Laboratory of Water Resource Protection and Utilization in Coal Mining;
Coal chemical industry has the bottleneck problems of " water shortage,high water consumption and high discharge",among which the discharge of production wastewater is large and the treatment difficulty is great,especially the treatment of the concentrate after the terminal membrane filtration is particularly problematic. Under the background of zero discharge of industrial wastewater advocated by the state,the water quality of concentrated liquid of coal chemical industry and the urgency of near zero discharge treatment were analyzed.The technical methods of minimum liquid discharge of membrane concentrate of coal chemical industry at home and abroad were introduced,and the principle and advantages and disadvantages of different technologies respectively were analyzed. At last,the development trend of membrane concentrate near zero emissions was prospected. The technology of near zero discharge treatment includes membrane separation technology,thermal evaporation technology and natural evaporation technology. Membrane separation technology mainly includes high efficiency reverse osmosis,ultra-high pressure reverse osmosis,electrodialysis,DTRO,positive osmosis,vibration membrane technology,etc. Thermal evaporation technology mainly includes multi-effect evaporation technology,mechanical compression re-evaporation technology,film distillation technology,etc. Natural evaporation technology mainly includes evaporation pond and forced natural evaporation technology. The efficient reverse osmosis combined with MVR has wide application prospect. On this basis,how to further reduce the energy consumption of thermal evaporation,realize the separation of crystal salt,provide processing efficiency,as well as the further development of high salt and pollution resistant reverse osmosis membrane,become the future development trend.
2020 S1 v.26 [Abstract][OnlineView][Download 123K] - TIAN Yanfeng;Shendong Coal Preparation Center;
In view of the problem of single product structure in the no-fines coal washing system of Shangwan coal preparation plant the index and washability of fine coal were studied,through the industrial test of dry separation of the fine coal screening test and floating-sinking test.The results show that the ultra-low ash products can be produced by pre-sieving the fine coal with 6 mm size or by grading the fine coal with 6 mm size.The yield of ultra-low ash products is 32.29% in the 0-25 mm fine coal.After dry separation,the yield of gangue is 0.74%,and the water content of clean coal is about 0.1% lower than that of raw coal.
2020 S1 v.26 [Abstract][OnlineView][Download 3693K] - WANG Zhenlong;CHN Energy Shendong Coal Preparation Center;
In order to improve the market competitiveness of commercial coal and reduce the operation cost in Halagou coal preparation plant,in view of the change of raw coal quality and the current severe coal market situation,the problems of fine coal separation system and the coarse and fine slime treatment system were analyzed,and the production organization mode was optimized with adjusting separation granularity of flapping screen,reducing the separation lower limit of lump coal system,increasing the coarse coal,improving the mixing effect of chemicals and reducing the moisture content of fine coal slime. After the transformation,Halagou coal preparation plant has improved the processing capacity and flexibility of the production system,and solved the problems restricting the system production.The moisture content of commercial coal is reduced by 1%,and the annual increment of variety coal is about two hundred thousand ton per year.The medium,medicament,power and materials are greatly reduced,and the economic benefits are considerable.
2020 S1 v.26 [Abstract][OnlineView][Download 472K] - QIAO Xiaoli;ZHANG Tao;Shigetai Coal Preparation Plant,CHN Energy Shendong Coal Preparation Center;Dispatching Command Center,CHN Energy Shendong Coal Preparation Center;
The gangue is easy to be slimed in Shigetai coal preparation Plant.In recent years,with the increase of the amount of final coal and secondary slime,the quality of the circulating water becomes worse,and the concentration of overflow water and mud content increase.It is necessary to add excessive medicament.The kinds of medicament were selected by settlement test,and the system of selecting medicament was usually further demonstrated on the spot.Finaly,the suggestions for improvement were put forward.After transformation,the rationality of reagent addition scheme is improved.Through combining action of pipeline mixer and reagent system,the upper limit of fine coal washery is raised from 35% to 45%,and the quality of circulating water and quality of blended coal are improved.
2020 S1 v.26 [Abstract][OnlineView][Download 99K] - PAN Yuejun;CHN Energy Shendong Coal Preparation Center;
Aiming at the problems of instability and poor treatment effect in coal slurry system of Buertai coal preparation plant,the mineral composition in coal slurry system was analyzed by XRD to determine the function of each component in coal slurry and find out the reasons for the difficulty of settling coal slurry water in Buertai coal preparation plant so as to select the reagent adding scheme to improve the treatment efficiency of coal slurry water.The results show that the coal samples in Buertai coal preparation plant contain a certain amount of montmorillonite,which makes the slime water difficult to settle.Because some coal samples contain part of pyrite and feldspar in the top and bottom plates,the top and bottom plates of some coal samples are gray or yellowish,the ratio of raw coal should be changed to select the treatment agent according to the composition of coal slime.
2020 S1 v.26 [Abstract][OnlineView][Download 1125K] - XU Lianhang;LI Wenxiu;WANG Dapeng;CHN Energy Shendong Coal Group;Institute of Chemical Engineering and Technology,China University of Mining and Technology;
Heavy medium separation is an effective method to separate coarse slime. In order to further improve the heavy medium separation process of coarse slime,the samples of heavy medium separation process were collected systematically. According to the national standard method,the particle size composition and density composition of the samples were measured,the separation accuracy and medium migration rule of the heavy medium of coal slime were analyzed,and suggestions for further improvement were given in combination with the technological process of coal preparation plant. The results show that the lower limit of heavy medium separation of slime can reach 0.125 mm,and gangue enters into cleaned coal mainly through grading. The heavy medium yield of <0.045 mm was 80.16%,and the particle size of the suspension was slightly coarser with the qualified medium of clean coal as the suspension. The main way of medium loss is product removal,accounting for more than 70% of the total loss,the main reason of medium loss is the poor effect of arc sieve and the working condition of magnetic separator is not ideal. It is suggested that the heavy medium separation process of coal slime should be optimized by further controlling the particle size of medium,replacing arc sieve with high frequency sieve and returning centrifuge liquid to the sorting system.
2020 S1 v.26 [Abstract][OnlineView][Download 714K] - LIU Chunlong;Shanxi Xiaohuigou Coal Industry Co.,Ltd.,China Coal Energy Co.,Ltd.;
Aiming at the problem of high clean coal ash content and poor separation effect of CSS separator in Xiaohuigou Coal Preparation Plant,influencing factors of CSS separator were analyzed,and the best separation condition was explored by adjusting the drum water and feed concentration of CSS separator,so as to achieve good separation effect of CSS separator. The experiment shows that the CSS separator in Xiaohuigou Coal Preparation Plant has the best sorting effect in the condition of feeding concentration less than 500 g/L and the top water flow 35 m3/h.
2020 S1 v.26 [Abstract][OnlineView][Download 100K] - ZHENG Yupeng;HE Jianbin;CHN Energy Shendong Coal Preparation Center;
Slime dewatering recovery is an important link in coal preparation plant. With the increase of the mechanization degree of coal mining and coal preparation,the amount of slimeand recovery of fine coal products increase greatly,which makes it difficult to treat coal slime water,recover coal slime from water and realize solid-liquid separation,so that the hourly capacity of fine coal slime treatment equipment can't meet the design requirements. In this paper,the existing problems of the pressure filter in Halagou coal preparation plant are analyzed. In view of the existing problems,the improving efficiency strategy of pressure filter in Halagou coal preparation plant was put forward from working parameters and feed properties. Finaly,effect of pressure filter was estimated. The results show that the main problems of coal preparation plant are high fine slime,high water content and high concentration of filtrate from pressure filter. The average discharge time of pressure filter is shortened from 150 s to 120 s,and the hourly processing capacity of single pressure filter is increased from 45 t to 56 t. The average moisture of fine coal slime discharged by pressure filter is reduced by 1%,and the qualified rate of discharge moisture of pressure filter is increased from 43% to 89%.
2020 S1 v.26 [Abstract][OnlineView][Download 451K] - ZHANG Xiaojun;PAN Yuejun;CHN Energy Shendong Coal Preparation Center;
Coal slime solidification can solve the problem of high water content in coal slime,realize comprehensive and continuous utilization of coal slime. By studying the forming conditions of Daliuta and Shigetai coal slime,effect of pressure and binder on compressive strength and falling strength of briquettewere studied.The results show that the optimum conditions of coal slurry molding are as follows:10% water addition,25 MPa molding pressure,8% binder addition. Briquette production can greatly improve the utilization efficiency of coal slime and avoid environment. The briquette made from coal slime has good waterproof performance,good burning effect and low price,and its strength meets the requirement of industrial boiler.
2020 S1 v.26 [Abstract][OnlineView][Download 93K] - ZHANG Lei;KANG Xuegang;SHI Yawen;ZHAO Yifei;Daliuta Coal Preparation Plant,CHN Energy Shendong Coal Preparation Center;
In order to summarize the experience of slime water treatment in Shendong Mining Area,methods on reducing pressure of slime water treatment were summarized,such as exploring the reagent system,optimizing the process of reducing secondary slime and reducing the washing of primary slime. Slime water in Shendong mining area has high sliming characteristics,and it is difficult to deal with. Optimization of reagent system can greatly reduce the consumption of reagent. Full mixing of slime water and reagent can greatly reduce the cost of reagent. Optimization of reasonable process system can reduce the amount of secondary slime in the system. Pre-separation pulverization can greatly relieve the pressure of slime water,but the economic benefit is not necessarily increased. According to the characteristics of slime water in Shendong Mining Area,the main research direction of slime water treatment research is to explore the process of reducing secondary slime and de-pulverizing before separation.
2020 S1 v.26 [Abstract][OnlineView][Download 231K] - HE Jianbin;PAN Yuejun;CHN Eergy Shendong Coal Preparation Center;
In view of the problems such as the high content of fine coal slime and the serious sludging in Buertai coal preparation plant,the compound settling test of coal slime water flocculants and coagulants was carried out with the coal slime water from the pulverized coal system produced,and the chemical addition scheme for coal slurry treatment was studied. The results showthat TDX1215 flocculant and TDN2109 flocculant have the best compound effect.When the dosage of flocculant and coagulant are 8 g/t and 32 g/t respectively,the turbidity of supernatant is 48 NTU at the lowest and the p H is lower.For this reason,the alkaline water tends to be neutral,and is conducive to the field treatment of coal slurry and equipment maintenance.
2020 S1 v.26 [Abstract][OnlineView][Download 2327K] - DONG Lijing;CHN Energy Shendong Coal Preparation Center;
Aiming at the problems of poor treatment effect of fine slime,high water content of product and high turbidity of filtered effluent in Baode coal preparation plant,the combined treatment of coarse and fine slime and one-stage concentration two-stage recovery process were studied to apply to the slime water treatment system of Baode coal preparation plant.The recovery rate of each particle size and the feed concentration of each particle size of screen before and after the combined treatment were compared and analyzed. The results show that after combined treatment,the moisture content of plate and frame filter press and screen centrifuge decrease,and the moisture content of coarse and fine slime decreases by 2.03%,the recovery rate of screen centrifuge and < 0.045 mm fine slime increase by 11.89% and12.90%,respectively.The total moisture content of commercial coal can be reduced by 0.4% when it is mixed with blended coal.The pressure of slime water treatment system is relieved by reducing feed volume of concentration tank and slime volume,improving the screen recovery rate.
2020 S1 v.26 [Abstract][OnlineView][Download 206K] - CHEN Yinmin;ZHANG Xiaojun;CHN Energy Shendong Preparation Center;
Aiming at the problem on cracking of sieve side plate of Kangweide 12'×30' vibrating screen,main beam break of screen,loose of sieve plate and motor damage in Bulianta coal preparation plant,ANSYS finite element method was used to analyze the statics and dynamics of the vibrating screen,and the model was modified and designed by parametric modeling. The results show that the support position of main beam and connection position for side plate are the maximum stress area of the screen. The maximum value is 38.159 MPa,which is much lower than that of the ordinary steel 235 MPa,and the structural strength meets the requirements. The stiffness of the structure is 327 667.9 N/mm. The stiffness and strength of the equipment are in line with the safe range,and the side plate cracking is not due to the static problem,but also needs the dynamic analysis.
2020 S1 v.26 [Abstract][OnlineView][Download 3005K] - XUE Hongwei;SU Cuihua;Shangwan Coal Preparation Plant,CNN Energy Shendong Coal Preparation Center;
Based on the complex production technology and large scale of coal preparation plant,that the coal preparation equipment is various,power supply and distribution system equipment and facilities,production,inspection and maintenance process shutdown power supply process are complex.Especially for the traditional shutdown operation process involving more personnel,more process steps,more hidden links,more paper records,record filling is not standard phenomenon,there are safety risks and low efficiency.With the advance of intelligent construction of coal preparation plant,through research,demonstration and implementation,supported by information technology and Internet technology,the research and development and application of digital power distribution system have been carried out.After the implementation and application of the system,the practical problems is solved,and the safety management ability and work efficiency are really improved.
2020 S1 v.26 [Abstract][OnlineView][Download 2841K] - HAN Zibin;CHN Energy Shendong Coal Preparatin Center;
At present,the control system of coal preparation plant is often limited to the local control and regulation of feed rate and density. In the application of this method,the quality of clean coal is mainly determined by the suspension density and liquid level of the medium barrel. Combined with the process flow of Shendong Coal Preparation Plant of national energy group,the mathematical model of control system is established. Density control is very important in the separation of heavy media,and there is a coupling relationship between this parameter and liquid level. It is very important to control the liquid level of heavy medium,which is difficult to control. Considering that medium density and liquid level are dynamic,variable separation method is established based on fuzzy control,and fuzzy controller of density and liquid level is designed. The fuzzy control strategy of coupling liquid level and density is established to achieve good suspension density control effect. On this basis,through the dynamic model of dense medium cyclone,the control of dense medium separation process is studied,and the simulation analysis is carried out under the operating conditions by using Simulink simulation software. The results show that the density control has reached the expected precision level,and there is no overshoot in the liquid level regulation,which is close to the actual experience. The system can effectively suppress interference and meet the requirements of medium control in heavy medium separation.
2020 S1 v.26 [Abstract][OnlineView][Download 1761K] - XUE Hongwei;GAO Pan;Shangwan Coal Preparation Plant,CNN Energy Shendong Coal Preparation Center;
For industrial control system and the application of intelligent monitoring system is divided difference with convenience,low resource utilization and other secondary'In order to strengthen the intelligent monitoring system of artificial Intelligence technology,reduce industrial control systems and intelligent monitoring system were divided the application of redundancy.On the basis of Hione intelligent integration platform,by associating the intelligent monitoring system and were AI technology with industrial control,the linkage problem between industrial control system and intelligent monitoring system is solved.The solution of this problem can not only improve work efficiency and resource utilization rate,but also help to accelerate the intelligent construction of coal preparation plant.
2020 S1 v.26 [Abstract][OnlineView][Download 3677K] - ZHANG Xuemei;ZHAO Xiaodong;WEI Linhui;LI Dong;MA Qinghua;HAO Jingyuan;Xi'an Siyuan University,Energy & Chemical Engineering Research Center;Beijing Deqin Technology Development Co.,Ltd.;College of Chemical Engineering,Xi'an Jiaotong University;
In order to study the judgment method of curve error of experimental results,the sample was made from balls of a briquette plant in northern Shaanxi,and 11 pieces of the half-rank histograms( 37 points on each histograms) of coal vitrinite reflectance were measured.The histograms were transformed into Psedo-Strength Index( PSI) by using the best active lazy ratio diagram and the relationship between coal metamorphism and lazy components,and the abnormal points and abnormal curves of 11 curves were determined. The results show that it is impossible to determine which PSI are abnormal curves and should be eliminated according to the size of abnormal points or the number of abnormal points whose error exceeds 3σ. Therefore,it should first calculate the arithmetic mean of all 37 points on the PSI distribution curve to establish the arithmetic mean curve,then calculate Euclidean distance,distance arithmetic mean,distance average error,distance standard error,and distance limit error to determine the abnormal PSI curve. Because the absolute value of Euclidean distance error of 11 PSI curves is less than 3σ of distance limit error,it is determined that there are no abnormal curves in 11 PSI curves.
2020 S1 v.26 [Abstract][OnlineView][Download 316K] - HU Zhenguang;GAO Zeng;DONG Kun;ZHANG Wanlin;ZHAO Haijun;Shenhua Guohua Electric Power Research Institute Co.,Ltd.;
In order to make the coal samples representative,the sampling scheme and performance test process of sampling system were discussed in power plant A.The shortcomings of power plant sampling evaluation were pointed out through analyzing sampling unit division and number of necessary sub samples.It is found that main factors of inaccurate sampling evaluation are unsuitable selection of recommended formula and index,the coal mining capacity of performance test only 1 000 t,and unenforced adaptability evaluation of Carboniferous coal after the sampling precision test of Shenhua blended coal.Coal power enterprises should pay attention to the design and evaluation of sampling scheme,control the process of sampling performance test,and ensure the scientific and accurate sampling.
2020 S1 v.26 [Abstract][OnlineView][Download 124K] - WANG Huixin;CHEN Zhiyuan;WANG Yonghong;ZHAO Xia;CHEN Qianlin;YANG Yuan;AO Xianquan;Guiyang North Water Control Co.,Ltd.;Laboratory of Guizhou Coalfield Geology Bureau;College of Chemistry and Chemical Engineering,Guizhou University;School of Chemistry and Materials Science,Guizhou Normal University;
Calorific value is an important criterion for evaluating the quality and power of coal. Based on the calorific value of coal and industrial analysis testing data of Guizhou,using the explore and correlation analysis functions of SPSS statistical software,through the correlation analysis between the calorific value and industrial analysis index of Guizhou,and on this basis,after multiple regression analysis,multiple regression model was derived between calorific value and industrial analysis index of Guizhou coal,detected the forecast effect of the prediction model.Results show that this prediction model has higher forecasting precision,the model can be used to forecast and check the calorific value of coal in Guizhou.
2020 S1 v.26 [Abstract][OnlineView][Download 119K] - GAO Yunfei;CHN Energy Shendong Coal Group Co.,Ltd.;
In order to study the determination of nitrogen in coal,the main differences between the national standard and the international standard of nitrogen in coal by semi-micro Kjeldahl method and gasification method in detail was introduced,and the revision direction of the Chinese national standard was discussed. There are still some differences between the national standard and ISO standard for the semi-micro Kjeldahl method,and for some differences,the ISO standard can be considered and verified by experiments. However,some differences,such as catalysts and mixed alkali solutions,need to be further tested whether adopts the ISO standard.For semi-micro gasification method,there are many differences between national standard and ISO standard.Some of these differences,such as fluxing agent and bulking agent,absorbent solutions,etc.,are still difficult if ISO standards are adopted.
2020 S1 v.26 [Abstract][OnlineView][Download 101K] - ZHANG Lei;SHI Yawen;KANG Xuegang;Daliuta Coal Preparation Plant,CHN Energy Shendong Coal preparation Center;
In order to clarify the short-term coal quality control direction of different coal types,the binary linear regression analysis of moisture,ash content,as received basis low calorific value of commercial coal in Daliuta coal preparation plant living well system was conducted based on SPSS software. The results show that there is a strong linear correlation between the total moisture and dry ash content of commercial coal in the movable well system,and the correlation coefficients are all above 0.99. The calorific value constant of the received basis is different in different periods,and the influence degree of the total water coefficient and dry basis ash coefficient on the low calorific value of the as received basis is different.The average total moisture and average dry basis ash content of the ultra-low ash and Shenhua excellent mixture have different influence on the received basis low calorific value. The correlation between the average dry basis ash content of blended coal and the low calorific value constant of as received basis is also poor,while the average total moisture of mixed coal has a certain correlation with the low calorific value constant on the received basis. Under certain production conditions,the moisture content of the product is difficult to further reduce,and the ideal calorific value can be obtained through ash control.
2020 S1 v.26 [Abstract][OnlineView][Download 868K] - LU Jianwen;WANG Hong;LU Peishan;FU Lijun;Information Service Center of Baotou Iron & Steel Group Co.;Coal Coking Chemical Company of Baotou Steel Union Co.,Ltd.;Technology Center of Baotou Steel Union Co.,Ltd.;
As the main raw material of blast furnace,coke plays a crucial role in the process of heating,reducing agent and skeleton.The quality of coke directly affects the quality of iron.In this study,a multi-layer neural network based method for coke quality index prediction was proposed.The Extreme Gradient Boosting Trees( EGBT) were employed to analyze the correlation of the influenced factors first,based on which the training sample was constructed,and then the multi-layer neural network was proposed for coke quality index prediction.The statistical results of the experiments and the practical application show that the proposed method exhibits satisfied accuracy in practical production process.
2020 S1 v.26 [Abstract][OnlineView][Download 1864K] - LU Maorong;WANG Qingzhao;Guodian Coal Quality Supervision and Inspection Co.,Ltd.;
In order to verify whether the " Automatic Instrument method for the Determination of Total Moisture in Coal" can replace the current GB/T 211—2017 " Determination of Total Moisture in Coal",28 lignite coal samples and 4 long-flame coal samples were tested simultaneously. The precision and accuracy of the two methods were measured according to GB/T 18510—2001" Guidelines for the Validation of Alternative Methods of Analysis for Coal and Coke". The variance of repeated determination of " Automatic Instrument Method for the Determination of Total Moisture in Coal" is 0.016 45,and the variance of repeated determination of the GB/T 211 B1 is 0.019 35.The precision of " Automatic Instrument method for the Determination of Total Moisture in Coal" is higher than that of GB/T 211 B1.The standard deviation of difference between results of"Automatic Instrument method for the Determination of Total Moisture in Coal"and the results of GB/T 211 B1 method is 0.150 4,and the statistic tcwas 0.370 2,indicating that any bias in the test is significantly less than the maximum allowable bias. The results show that the precision and accuracy of the automatic instrument method for determination of total moisture in coal are consistent with the GB/T 211 method in the determination of total moisture in lignite and long-flame coal. " Automatic Instrument method for the Determination of Total Moisture in Coal"can replace the current GB/T 211—2017.
2020 S1 v.26 [Abstract][OnlineView][Download 122K] - ZHANG Lei;KANG Xuegang;SHI Yawen;Daliuta Coal preparation Plant,CHN Energy Shendong Coal Preparation Center;
In order to clarify the necessity of improving coal quality,the trend of energy demand of the next 15 years in China was forecasted using GDP and energy intensity,the trend of coal demand combined with energy structure was estimated. Taking coal quality of Daliuta coal perparation plant as an example,the influence of moisture and ash content on the calorific value were studied,and the necessity of improving coal quality combined with quality requirements of coal uses were analyzed.The main means of decreasing coal moisture and ash and improving coal quality were discussed.Finally,suggestions based on problems of Shendong coal separation and processing were put forward.With the improvement of coal quality requirements in the future,chemical coal preparation and microwave technology are likely to be used in coal production.
2020 S1 v.26 [Abstract][OnlineView][Download 109K] - FANG Peiwen;GONG Zhiqiang;ZHANG Man;YANG Hairui;China Petroleum Pipeline Engineering Corporation;College of New Energy,China University of Petroleum (East China);State Key Laboratory of Power Systems,Department of Energy and Power Engineering,Tsinghua University;
The pyrolysis experiments of microalgal biomass at 400-800 ℃ were conducted in a vertical tube furnace to study the influence of temperature on the pyrolysis char. Besides,the scanning electron microscope( SEM),laser particle size analyzer,CHNS/O elemental analyzer,X-ray fluorescence spectrometer( XRF),X-ray diffractometer( XRD) and inductively coupled plasma mass spectrometry( ICP) were used to examine the physical and chemical characteristics of the pyrolysis char under different temperatures. Results show that with the increase of pyrolysis temperature,char production rate of microalgae and residue reduced,C/H and C/O of pyrolysis char become bigger,the average particle diameter decreases firstly and then increases,and the specific surface area rises firstly and then decreases. The promotion of temperature is beneficial to carbon and graphite structure formation of pyrolytic char,while the sintering will occur,and the void structure can be damaged when the temperature is too high. Finally,the concentration of heavy metal elements in pyrolysis char of microalgae and the residue is at clean level.Pyrolysis process can reduce the potential ecological threat of pyrolysis of heavy metals effectively.
2020 S1 v.26 [Abstract][OnlineView][Download 2736K] - ZANG Xuejing;WANG Xueyun;GUO Liangyuan;DU Gang;China Coal Research Institute;Coal Chemistry Branch of China Coal Research Institute;State Key Laboratory of Coal Mining and Clean Utilization;
In order to obtain a suitable and accurate gasification kinetic model,the applicability of five different gasification kinetic models for Shenmu long flame coal was introduced and studied. The gasification kinetics of Shenmu long flame coal in CO_2 atmosphere was analyzed by using NETZSCH STA 409 PG thermobalance and isothermal method. The relationship between carbon conversion rate and time was determined by random pore model( RPM),unreacted shrinkage core model( SCM),brewing model( BM),Homogeneous model( HM)and modified volume model( MVM) fitted,analyzed and compared. Correlation coefficient R2 was used to test the consistency between fitting results and experimental results,and it was found that the accuracy of the five models was in order from high to low: brewing model> modified volume model > homogeneous model > unreacted shrinkage core model > random pore model,and brewing model was more suitable for the kinetics simulation of CO_2 gasification reaction of Shenmu long flame coal. According to the Arrhenius formula,the activation energy and the pre-exponential factors of different models were obtained and compared. The R2 test result was in order from high to low: random pore model > unreacted shrinkage core model > brewing model > homogeneous model > modified volume model. The experimental results showed that the fitting effect of 900 ℃ and 1 000 ℃ is generally better than that of 800 ℃ . In the fitting of gasification model,the mixed model is the most suitable. In the analysis of activation energy,the random pore model is the best fit. The range of CO_2 gasification activation energy predicted by different models is between 61-143 k J/mol,which is basically consistent with the results reported in relevant literatures.
2020 S1 v.26 [Abstract][OnlineView][Download 963K] - PU Jianwei;PU Jianquan;Northwest Electric Power Design Institute Co.,Ltd.,China Power Engineering Consulting Group;
At present,rapping motor or manual rapping is mostly used to treat coal blocking in coal hopper of power plant,and coal blocking in raw coal hopper is mainly related to external moisture of raw coal and inclination angle of raw coal hopper. In order to prevent coal blocking,the proper inclination angle is selected for the design of raw coal hopper,and the system design of reducing the external moisture of raw coal is added to make external moisture always lower than 8%. Based on this,a new type of coal hopper anti blocking system was studied,and the gasification system scheme was empirically analyzed. The purified flue gas after the induced draft fan of the wind and smoke system is used as the gas source of the gasification device to gasify the raw coal,which not only ensures the fluidity of the coal,prevents the occurrence of arch blocking coal,but also avoids the risk of raw coal spontaneous combustion caused by air as the gas source. The scheme does not increase the explosion-proof risk of the coal pulverizing system on the basis of utilizing the waste heat of the boiler. The design of annular gasification plate makes the whole flue gas and raw coal particles can be better mixed to obtain lower external moisture of raw coal.
2020 S1 v.26 [Abstract][OnlineView][Download 1161K] - SHI Huijuan;ZHOU Qi;ZHANG Zhang;MAO Yu;Clean Combustion and Flue Gas Purification Key Laboratory of Sichuan Province;Dongfang Electric Group Dongfang Boiler Co.,Ltd.;
In order to suppress the bad fouling occurred on the devices when burning Wucaiwan coal,the sodium migration proportion and effect of additives on sodium volatilization were studied.Sodium contents were measured by the combination method of dilute hydrochloric extraction and 600℃low-temperature ashing,and the sodium release proportion in coals were tested at different temperatures with different additives and percentages.Results show that Na_2O content is 0.391%,and sodium release proportion increases to 37.20%when the ashing temperature ascendes to 815℃.Sodium release proportion will be descended efficiency when taking SiO_2,Al_2O_3,Kaolin,SiO_2/Al_2O_3=5∶1(Si Al),SiO_2/Al_2O_3/Fe_2O_3=75∶15∶1(Si Al Fe),SiO_2/Al_2O_3/MgO=75∶15∶1(Si Al Mg) which have SiO_2or Al_2O_3as additives with national standard ashing.Kaolin can significantly reduce release proportion of sodium,and release proportion gradually decreases with the increase of kaolin content.The sodium release proportion reduces much when the additive is Al_2O_3at 4%and Si Al Fe or Si Al Mg at 6%,and CaCO_3/CaO affectes the sodium release proportion little.
2020 S1 v.26 [Abstract][OnlineView][Download 392K] - ZHAO Yabin;JIA Xiangru;YANG Guofang;HUO Xinguang;SONG Changzhong;College of Energy and Power Engineering,Inner Mongolia University of Technology;
In order to explore the mixed combustion characteristics of biomass and coal gangue,the TG-DTG method was used to conduct a mixed combustion experiment on sunflower stalks,corn stover,and coal gangue. The Friedman method was used to calculate the combustion reaction kinetic parameters. The analysis of the test results show that adding a small amount of biomass to the coal gangue can significantly reduce the reaction activation energy,affect the activation factor,and improve the combustion of coal gangue; with the increase of the biomass content,the ignition index,flammability index and comprehensive combustion index all increase. The mixed sample is easier to ignite,the flame is more stable,and the comprehensive combustion characteristics are better; the mixed combustion of sunflower stalks and corn stalks with coal gangue respectively has similar effects on activation energy,both from reducing activation energy and affecting activation energy change trends. Improve the combustion of mixed samples; when the biomass ratio is low,the effect of sunflower stalks on the activation energy of mixed combustion is greater than that of corn stalks.
2020 S1 v.26 [Abstract][OnlineView][Download 2899K] - LI Xie;WANG Xinyu;HUANG Yaji;XU Fubin;GUO Xiaogang;ZHU Zihao;LU Ruijie;LIU Xiaodong;DAI Weibao;CHEN Guoqing;CHN Energy Taizhou Power Generation Co.,Ltd.;Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education,Southeast University;Guodian Science and Technology Research Institute Co.,Ltd.;
In view of the serious high temperature hot corrosion of the water wall of a 1 000 MW dual tangential coal-fired boiler,based on the Fluent 19.2,the numerical simulation method was used to simulate the combustion of the furnace. It is found that the area with high CO volume fraction behind the furnace side wall is consistent with the actual corrosion area. In order to explore the influence of wall-attached-air on the combustion of dual tangential circle boiler furnace,a circumferential seam type wall-attached-air system was installed on both sides of the boiler. By changing the wall attached air volume,the temperature field,oxygen volume fraction field,CO volume fraction field and various flue gas parameters at the furnace outlet were analyzed,and the influence of the wall-attached-air system on the furnace combustion was explored. The simulation results show that when the wall-attached-air rate is less than 1%,properly increasing the wall air has obvious effect on reducing the volume fraction of CO on the near side wall,but when the air volume of the wall-attached-air is greater than 1%,the effect does not change much,and the temperature near the wall rises obviously,and the outlet mass concentration of NO_xalso increases. The results show that the volume fraction of CO the near side wall of the main combustion zone can not be effectively reduced when the wall-attached-air rate is 0. 5%. The mass concentration of NO_xat the outlet of condition 4 increases by more than10% compared with the original condition when the wall-attached-air rate is 2%. The combination effect of conditions 3 and 4 with wallattached-air rate of 1% and 1.5% respectively are the best. In the actual retrofit of power plant,additional wall attached air system should be installed on the basis of the layout in this paper,and the total wall-attached-air rate should be between 1% and 1.5%.
2020 S1 v.26 [Abstract][OnlineView][Download 2386K] - YUAN Wenjie;JIA Xiaoping;LI Nan;SUN Xianbin;ZHAO Pengbo;Jiangxi Yichun Jingneng Thermal Power Co.,Ltd.;Huaneng Clean Energy Research Institute Co.,Ltd.;State Key Laboratory of Coal Based Clean Energy;
A circulating fluidized bed( CFB) boiler of the 165 t/h unit had problems such as high carbon content in bottom ash and fly ash,low boiler thermal efficiency and limited peak load and so on,combustion optimizing was carried out to solve these problems. The results show that the low load operation condition of the boiler is improved by adding circulating ash discharge system. Under 80 t/h load,the bed temperature of the boiler increases from 724℃ to 861℃,the average carbon content in bottom ash and fly ash decreases from24.85% to 5.65%,the boiler thermal efficiency of the boiler increases by 3.27%,the NO_x emission remains stable and the SO2 increases slightly. Combustion optimization also enhances the peak load regulation capacity of the boiler. The safe load is reduced from 80 t/h to60 t/h. The annual production cost can be saved by 44.64 million yuan.
2020 S1 v.26 [Abstract][OnlineView][Download 768K] - DU Yuliang;CHN Energy Shengdong Coal Company;
In order to optimize the pilot scale test bench of activated coke fixed bed reactor,CFD numerical calculation method was used to optimize the structure of activated coke fixed bed reactor. The porous medium model was used to simulate the active coke layer,and the standard deviation coefficient of velocity in SCR system was introduced as the main evaluation standard. Three different fixed bed reactors were analyzed and calculated,and the relatively optimal structure model was obtained,which effectively improved the velocity uniformity of flue gas entering the active coke layer. The basic physicochemical properties of typical activated coke were characterized by elemental analysis,industrial analysis,BET,SEM and surface functional group content analysis. The no removal test was carried out on a boiler flue gas treatment capacity of 500 m3/h,and the change curve of no removal rate with time was obtained. The sharp point appeares in the original no removal curve of fixed bed reactor,which is supposed to be caused by flue gas short circuit. The no removal curve of the optimized fixed bed reactor decrease steadily and slowly,without any sharp point,which proves that the flue gas fully contactes with the active coke bed.This regression test proves that the optimization of activated coke reactor based on CFD is feasible. The results show that the inlet pipe is connected to the whole inlet cross section,and the louver rectifier plate is installed in front of the active coke layer,which can significantly improve the uniformity of the inlet velocity of the active coke,strengthen the contact between the flue gas and the active coke bed,and improve the reaction efficiency. The most important evaluation index of speed uniformity in structural optimization is δV,and the smaller δV,the better speed uniformity is.
2020 S1 v.26 [Abstract][OnlineView][Download 1828K] - LIU Bin;ZHANG Changhong;China Huaneng Clean Energy Technology Research Institute Co.,Ltd.;Liaoning Shenmeihongyang Thermal Power Co.,Ltd.;
In-service CFB boilers has problem of poor load-carrying capacity,high bed temperature and unstable feed-back.The factors affecting on CFB boiler bed temperature and output were presented,and characteristics of air cap and central cylinder,etc.were deeply analysed.The results show that the reasonable air cap structure,the small hole wind speed and the central cylinder structure have great influence on the bed temperature and load capacity of the boiler.The structure design of reclaimer has direct influence on the normal operation of the system,and has little influence on the bed temperature and load capacity of the boiler.In the process of optimization design of boiler reconstruction,reasonable design should be carried out according to different kinds of coal in order to ensure the stable operation of the boiler.
2020 S1 v.26 [Abstract][OnlineView][Download 100K] - LI Wenhua;Zhejiang Zheneng Wenzhou Power Generation Co.,Ltd.;
Flue gas denitrification is the key technology of environmental protection operation of thermal power units in China,and SCR denitrification is the mainstream technology. SCR denitrification process needs to consume a certain amount of catalyst. In order to save costs and improve economic benefits,domestic power plants began to use domestic catalysts gradually. However,compared with imported products,it was found that the service life of domestic catalysts was shorter in the case of pipeline blockage,which was mainly caused by ammonia leakage and corrosion of pipelines. In this paper,aiming at the problem of partial blockage of air preheater caused by high ammonia local escape rate in SCR denitrification unit of a power plant,the actual operation of the plant was statistically analyzed by using big data,and it was found that there was uneven ammonia injection. According to the analysis results of big data,the test adjustment scheme was puts forward,and field equipment was adjust according to the scheme. The operation results show that the ammonia injection quantity is more uniform,and the local ammonia escape phenomenon basically disappears.
2020 S1 v.26 [Abstract][OnlineView][Download 255K] - BAI Tao;JIN Zhiping;School of Electric Power,Civil Engineering and Architecture,Shanxi University;
The formation and treatment scheme of colored plume were and studied,different enviromental fators were analysed for treatment scheme of colored plume. Ruselts show that the direct heating technique can reduce the energy consumption at higher ambient temperature,the direct condensation technique can reduce the energy consumption at lower ambient temperature. The condensation and reheat technique can reduce the treatment cost of colored plume.
2020 S1 v.26 [Abstract][OnlineView][Download 1602K] - LU Rongchun;MIAO Miao;KONG Hao;ZHANG Man;YANG Hairui;Shenhua Fujian Energy Co.,Ltd.;State Key Laboratory of Power Systems,Department of Energy and Power Engineering,Tsinghua University;
Taking the retrofit of Jinjiang thermal power plant 2×260 t/h CFB boiler flue gas ultra-low emission as an example,the existing ultra-low emission technologies of dry desulfurization and wet desulfurization was compared and analyzed. The results show thatthe safety of ammonia desulfurization technology is low,and the application of activated coke desulfurization technology in China is not mature. Compared with CFB dry desulfurization technology,limestone-gypsum wet desulfurization technology has some disadvantages,such as unable to completely remove SO3,Hg and other heavy metals,high investment,operation and maintenance costs,and large land occupation. Combined with the existing desulfurization technology of calcium injection in the furnace,CFB dry desulfurization technology after the furnace has better technical and economic advantages,and has the characteristics of multi-pollutant collaborative removal,no waste water,white( blue) smoke emission and other advantages. It is the most suitable technology for ultra-low emission transformation of CFB boiler flue gas desulfurization in this project. The technology is suitable for comprehensive control of ultra-low emission from flue gas desulfurization of CFB boiler.
2020 S1 v.26 [Abstract][OnlineView][Download 594K] - ZHANG Jun;CHEN Ou;LUO Zhigang;YANG Jianhui;LIU Guodong;Beijing Guodian Longyuan Environmental Engineering Co.,Ltd.;
By the end of 2018,in addition to some regions,domestic thermal power units have basically completed the transformation of ultra-low emission.The ultra-low emission puts forward new requirements for the total amount control of ammonia injection in thermal power units.Due to the problems such as low control accuracy and large delay in the traditional control mode,it is difficult to achieve stable emission of NO_xat the chimney,or excessive ammonia injection is made to keep the NO_xbelow the standard at the chimney,resulting in blockage of catalyst and air preheater,affecting the life and use of the device,and increasing the operation cost of the system.Through the big data analysis method,linear regression,shallow neural network,decision tree regression and extreme random tree regression were used in this paper to analyze the influence of boiler load,furnace total air volume,coal supply,primary air,secondary air,burn out air and other measuring points on the chimney NO_x.The results show that extreme random tree regression has good prediction effect on training set,verification set and cross validation set.Among the measuring points used for analysis,the total air volume,ammonia flow rate,inlet flue gas pressure,inlet flue gas temperature,inlet NO_xconcentration,boiler load,primary air velocity of each burner and coal feeding amount of each pulverizer have great influence on NO_xat the general discharge outlet.When it is necessary to accurately control the total discharge NO_xunder ultra-low emission control,these measuring points should be considered.However,the influence of O2 concentration at inlet,oxygen content at economizer outlet,secondary air volume at left and right sides of boiler,and burnout air volume of front and rear walls have little influence on NO_xat total discharge outlet,which can be ignored when establishing prediction model.On this basis,more than 70 points with the most important influence are selected to predict the chimney NO_x.Compared with the actual measurement data,the prediction accuracy and characteristics of various big data algorithms are analyzed.The comparison results show that the predicted total exhaust NO_xvalue of extreme random tree analysis model is in good agreement with the actual measured value,which can achieve good prediction effect.
2020 S1 v.26 [Abstract][OnlineView][Download 2923K] - MENG Luowei;Yichang Dongyangguang Thermal Power Co.,Ltd.;
The flue gas circulating fluidized bed desulfurization and dust removal process has a great advantage in the ultra-low emission reconstruction of large-scale CFB boiler. In the actual operation process,there are some abnormal phenomena and faults such as large flue gas resistance,high power consumption rate,wall sticking and bed collapse.In the process of ultra-low emission transformation of CFB boiler,the experiences and deficiencies of similar projects were summarized. In the design stage,the selection of key parameters and induced draft fan,the transformation of pre dust remover,the feeding position of circulating ash and system layout were optimized.The control of parameters such as Ca ∶ S,tower pressure,tower temperature,dust hopper level and denitration in the furnace were optimized. After a long time of operation practice,the standard discharge is stable and reliable,and the Ca ∶ S in the furnace is reduced.The calcium injection and COA denitration system in the desulfurization absorption tower are in standby state,and good safety,economic and social benefits have been achieved.
2020 S1 v.26 [Abstract][OnlineView][Download 1712K] - BAI Jiliang;LI Bin;ZHU Jinqi;HAN Ping;WU Wanzhu;XIAO Xianbin;Guoshen Company of CHN Energy;National Engineering Laboratory of Biomass Power Generation Equipment,North China Electric Power University;
The carbon content of fly ash is an important indicator that affects the thermal efficiency of the boiler and the economy operation of the units. An improved BP neural network model based on the Levenberg-Marquardt algorithm was established to predict the carbon content of fly ash in a 150 MW CFB boiler,including a parent model and three sub-models. The parent model selected seven parameters such as the technical analysis and low calorific value of coal as input parameters. The sub-models investigated the coal quality deviation parameters on other input parameters of the parent model. The improved BP neural network was used to train the samples to predict the carbon content of fly ash.The training results were compared with the results obtained by traditional polynomial regression methods or empirical methods. The results show that the correlation coefficient R2 of BP neural network,Polynomial linear regression,and Polynomial nonlinear regression are 0.957 1,0.605 1,0.766 7,respectively,and the relative mean error RME are 4.84%,17.02%,12.46%,respectively. The improved BP neural network model has higher prediction accuracy and better generalization ability for fly ash carbon content.
2020 S1 v.26 [Abstract][OnlineView][Download 1026K] - SUN Liqun;ZHANG Guoxin;China Huadian Engineering Co.,Ltd.;
Aiming at problems occurred during the operation of boiler flue gas denitrate urea direct injection technology,the paper analyzes the material consumption,urea decomposition rate and byproducts. This paper also analyzes the existing urea direct injection technology and urea hydrolysis technology route,and finds out the optimum technical route for urea direct injection reformation. Practice shows that the urea catalytic hydrolysis technology of urea direct injection,denitration system has been greatly improved reliability of ammonia,material consumption,urea decomposition rate and the impact on the boiler tubes are greatly optimized,energy-saving renovation investment payback period is about 1 to 2 years.
2020 S1 v.26 [Abstract][OnlineView][Download 827K] - ZHANG Jun;CHEN Ou;LUO Zhigang;YANG Jianhui;LIU Guodong;Beijing Guodian Longyuan Environmental Engineering Co.,Ltd.;
By the end of 2018,domestic thermal power units except some areas have basically completed the renovation.In this paper,the operation data of a domestic power plant before and after the ultra-low emission renovation were analyzed in detail,and the characteristics and application of the current mainstream ultra-low emission technology route were analyzed.The parameters of ultra-low emission renovation of denitrification system were analyzed from five aspects: basic conditions of unit,denitrification efficiency and NO_x emission,ammonia injection rate of denitrification system,pressure drop of denitrification system and catalyst activity.Changes and possible problems after ultra-low emission renovation was analyzed.
2020 S1 v.26 [Abstract][OnlineView][Download 2633K] - CHEN Hanzhang;GAO Hongtao;Shenhua Hollysys Information Technology Co.,Ltd.;
In recent years,with the increasing demands for environmental management from the the state,many new policies and regulations have been implemented,which have raised higher requirements for pollution emission enterprises' self-management. Enterprises have gradually become the main body of environmental protection,transforming from the original forced environmental protection entities into the active protection ones. Particularly,management of the large coal enterprises controlled by the central authorities is challenging because these enterprises spread all over the country and involve in multi-industry sectors and are usually characterized with huge pollution and high environmental risks. Therefore,the central enterprise needs to construct a pollution source monitoring system that is suitable to its own characteristics,supporting the internal environmental management through information technology.
2020 S1 v.26 [Abstract][OnlineView][Download 1873K] - LI Meng;LI Lingqian;SU NANDing;GUO Baitang;GUO Yueyang;Henan Coal Science Research Institute Detection Technology Co.,Ltd.;Pingdingshan Dazhuang Mining Industry Co.,Ltd.;Henan Yueyang Energy Conservation Technology Co.,Ltd.;
The flue gas emission of coal slime drying system affects the normal production of coal washing enterprises,and decides whether the problems of high dust content,easy formation of wet smoke plume and unused waste heat of flue gas can be solved. According to the source of flue gas dust,the formation mechanism of wet smoke plume and the utilizing ways of flue gas waste heat,the technology of dust removal,mist elimination and waste heat cascade utilization of the flue gas in the coal slime drying system were studied with flue gas removed by spraying,the wet smoke plume eliminated by means of the flue gas direct cooling and pre-washing technology,and the waste heat recovered by the gas-liquid direct contact heat exchange technology. The flue gas treatment system equipment integrating the technology of dust removal,mist elimination and waste heat cascade utilization were developed. Taking Pingdingshan Dazhuang Mine Industrial Co.,Ltd.as an example,a spray system was installed in the original desulfurization tower,and the flue gas of the coal slime drying system was washed with circulating water in a film form to reduce the dust content in the flue gas. Meanwhile,the direct contact heat transfer between spray water and flue gas reduced the flue gas temperature,condensed the moisture in the flue gas,and reduced the moisture content of the flue gas. After sedimentation,the spray water entered the plate heat exchanger through the floating circulating pump,and the recovered heat was used for heating or making hot water for bathing. The cooled circulating water entered the spray system from the top of the desulfurization tower,and so on. The results show that after the transformation of the flue gas treatment system,the dust concentration decreases from35 mg/m3 to 27 mg/m3,reducing by 22.86%,and the moisture content decreases from 10.22 g/kg to 4.69 g/kg,reducing by 54.11%.The waste heat utilization is 1 233 k W,and the annual power consumption is reduced from 1 284 500 k Wh to 96 300 k Wh,the annual power saving is 1 188 100 k Wh,which is equivalent to 365.93 tons of standard coal. The annual electricity cost is reduced by 712 900 yuan.The implementation of the project has effectively reduced the dust and white mist emissions during the flue gas emission of coal slime drying system in the coal washing industry,realized the cascade utilization of flue gas waste heat,and reduced the corrosion and blockage of the water pump and heat exchanger during operation.
2020 S1 v.26 [Abstract][OnlineView][Download 721K] - CUI Dongfeng;YAN Jianchao;WEI Ran;Hangzhou Environmental Protection Research Institute of China Coal Technology & Engineering Group;
Aiming at problem of the low temperature of flue gas in coal-fired industrial boilers and the low efficiency of denitration using SCR and SNCR processes,a combination of bag dust removal,gas-phase oxidation,liquid-phase absorption and wet electric dust removal was proposed for flue gas purification treatment of coal-fired industrial boilers. Taking the design of a coal-fired industrial boiler flue gas purification system as an example,the composition and design parameters of bag type dust removal,denitration reaction,simultaneous desulfurization and denitrification,wet electric dust removal,slurry pressure filtration,electrical control,and automatic control system were introduced with the proposed process flow,and the environmental benefit analysis was performed based on the test results.After more than one year of application,the results show that the flue gas purification system is stable and reliable.The actual average emission concentration of SO2 is 31 mg/Nm3,NO_x is 42 mg/Nm3,and particulate matter is 6.5 mg/Nm3,all of which are better than those required by the national and local governments.
2020 S1 v.26 [Abstract][OnlineView][Download 287K] - WANG Xiaolei;TONG Shenglu;ZHANG Yulong;National Instituteof Clean-and-Low-Carbon Energy;China Energy Investment Co.,Ltd.;State Key Laboratory of Water Resource Protection and Utilization in Coal Mining;College of Mechanical and Electrical Engineering,Shandong University of Science and Technology;
In view of the existing problems in the current mine water pretreatment process,the project proposes the cyclone separation + ceramic membrane process for treatment of pulverized coal particles,suspended solids,etc. in the high concentration mine water,and has carried out a pilot test in a coal mine of Ningxia coal industry of China Energy Investment Corporation. The parameters of different diameters of hydrocyclones,parallel groups of hydrocyclones and underflow diameter were optimized. Results show that the comprehensive treatment effect of two hydrocyclones with 50 mm underflow diameter of 10 mm is the best with water production flow rate 6.96 m3/h and the solid removal rate 54%. The turbidity of water from hydrocyclone after filtrated by ceramic membrane is less than 1 NTU,which meets the requirements of reuse or advanced treatment. The process of " cyclone + ceramic membrane" is effective in treating 0.5%-1.0% high concentration mine water,without any chemicals,with low cost and small land,which is suitable for underground application.
2020 S1 v.26 [Abstract][OnlineView][Download 1709K] - LIU Hongguo;ZHANG Fang;WANG Jun;Shenhua Funeng Power Generation Co.,Ltd.;Beijing Cohorzon Jntellectual Property Ltd.;
Zero discharge of desulfurization wastewater in thermal power industry is the only way to realize clean production in thermal power industry.The technology is rapid development and iteration.In order to embed patent application into enterprise technological innovation,it's necessry to carry out forward-looking patent layout and mining in this field in advance,give play to the guiding role of patent navigation in the cultivation of high-value patents of enterprises,and enhance the core competitiveness of enterprises.The technical route and hot spot distribution of desulfurization wastewater zero discharge technology were discussed,and the patent application situation of head water treatment research unit from the perspective of patent was analyzed. Finaly,suggestions on patent mining and layout of patentable technology fields were put forward.The results show that compared with the international advanced companies,the number of patent applications and authorizations in domestic water treatment industry are more,but mainly concentrated on utility model and appearance patents.The patent stability is poor,and there is an obvious gap in the layout of patents involving core inventions of technology and process.It is necessary to pay attention to the use of patent navigation technology,study and judge the development trend of the industry,determine the optimized technology research and development path,strengthen the international and domestic patent layout of core technology,avoid risks and win competitive advantages.
2020 S1 v.26 [Abstract][OnlineView][Download 1452K] - XIONG Yingying;ZHANG Xin;CUI Chaoxian;Department of Power Engineering,Shanxi University;
With the rapid development of China's economy,the process of urban construction is accelerating,large-scale renovation activities emerge in an endless stream,and a large number of outdoor buildings are generated. However,simple landfill incineration will do harm to the living environment and human health. In recent years,the emerging pyrolysis technology of waste has attracted much attention because of its harmless resource reduction. The thermogravimetric experiments of outdoor construction waste containing lime were analyzed using thermal analyzed. It was concluded that different heating rate,TG-DTA curve under different atmosphere and the calculation of reaction kinetics of three factors including the reaction activation energy Ea,kinetic mechanism function f( α) and refers to the former factor A.The results show that under different temperature rising rates,the pyrolysis of samples starts at about 125 ℃,and when the temperature rises to about 160 ℃,the complete pyrolysis basically reaches equilibrium,and the pyrolysis is decomposed into endothermic process. According to Kissinger method,the activation energy Ea of the decomposition reaction was 33.36 k J/mol,and the log value of predactyl factor A( lg A) was 1. 12 min-1. According to Ozawa method,the decomposition reaction activation energy Ea is 35. 36 k J/mol,lg A was1.07 min-1. The experiment can be represented by a three-dimensional solid surface reaction R3 model.
2020 S1 v.26 [Abstract][OnlineView][Download 1401K] - DUAN Xuelei;FENG Bo;PEI Haowei;MA Lin'ge;JOW Jinder;LI Yonglong;National institution of Clean-and-Low-Carbon Energy;
As a common component of fly ash,the phase change of iron oxide will occur in the process of dual-atmosphere thermogravimetric determination of fly ash carbon content.In order to study the influence of the presence of iron oxides on the determination of the carbon content of fly ash by the dual atmosphere TG method,XRD and TG-MS were applied to study the influence mechanism of iron oxide and the reduction process of different forms of iron oxide.The results show that the presence of iron oxides will undergo a reduction reaction with carbon in the inert atmosphere above 565 ℃,the iron oxides are reduced by unburned carbon to form elemental iron and in the oxidation atmosphere,the elemental iron is partially oxidized through the air atmosphere,which results in a lower measurement result of carbon content.All forms of iron oxide undergo a stepwise reduction reaction with carbon,and ferric oxide is easier to be reduced by carbon.The maximum reduction weight loss at 950 ℃ is 4.5%.When the iron oxide content in the fly ash is less than 8.53%,the dual-atmosphere thermogravimetric method has a reliable measurement result for the determination of carbon content,which is suitable for the determination of most fly ash in China.
2020 S1 v.26 [Abstract][OnlineView][Download 1388K] - PAN Haibin;WEI Guanghong;ZHAO Zhihong;QUAN Yongsheng;JIANG Long;Jinglong Power Plant Co.,Ltd.;North China Electric Power Research Institute Co.,Ltd.;
In order to alleviate the low comprehensive utilization of fly ash in coal-fired power plants in Northwest China,and to better guide the formulation of comprehensive utilization policies of coal-fired power plants in Northwest China,a coal-fired power plant in North China was selected to evaluate the way and scope of comprehensive utilization of fly ash.through the detection of various properties of fly ash,the local industrial and transportation conditions,so as to provide guidance for the comprehensive utilization of fly ash.The fly ash of the coal-fired power plant can be used for filling and soil restoration,but the soil environment monitoring and agricultural products collaborative monitoring should be strengthened.Due to incomplete combustion of the boiler,the fly ash does not meet the preparation conditions of ceramsite,and it can be used for making silicate products such as bricks and for road subgrade construction.It has the potential to extract carbon particles and magnetic beads,but not to extract Al2 O3 and Si O2.It meets the requirements of radioactivity,and the use way is not restricted by reflection.It can be used for the preparation of new materials such as environmental adsorption,and can be transported to Beijing,Tianjin and Hebei province carried by railway. Through testing and analyzing the physical and chemical properties of fly ash in Northwest China,and formulating reasonable local policy guidance can guide and improve the comprehensive utilization status of fly ash in Northwest China.
2020 S1 v.26 [Abstract][OnlineView][Download 829K] - ZHANG Wei;CCTEG Beijing Huayu Engineering Co.,Ltd.;
To explore the reasonable development and utilization of coal resources and water safety water supply technology solutions,influence of mining subsidence were predicted by coal mining of caving mining method,strip mining,colloid paste filling mining and coal pillar( no drivage mining for integration),and the effect of mining method on water resources in water source areas was analysed. The maximum subsidence area of coal mining subsidence was predicted by analysing method of caving mining,strip mining,colloid paste filling mining and no( no drivage mining for integration) coal pillar mining. Combined with the regional hydrogeological conditions and water table depth of Quaternary Salawusu formation aquifer,the subsidence seeper was calculated caused by different extraction methods,and its impact on water resources was analysed. It suggests that the cementing paste filling mining method should be adopted to reduce the subsidence value after mining,so as not to form permanent water accumulation area and protect the water resources.
2020 S1 v.26 [Abstract][OnlineView][Download 1037K] 下载本期数据