Coal Storage Research Articles

A Brief Talk on Coal Dust Suppression

Coal dust is the solid micro-particles which are generated during coal mining, transportation, storage and processing dispersed into the air. Coal dust not only poses a great threat to the environment, but also poses a serious threat to the health of workers engaged in related industries. So, developing technical and scientific tools that are efficient, safe, practical and convenient to prevent dust and explosion, protect the environment and health and safety of employee and promote safe production in the community have become the top priorities in the industry.

System of Adsorption of CO2 in Coalbed

Carbon capture and storage (CCS) has been observed as an alternative measure to mitigate emissions from greenhouse gases. CCS systems separate CO2 during the process of converting fuel and transport to the facilities where they are stored, e.g., under geological formation conditions. Capture and sequestration technologies are now widely used in different industries. CO2 capture is currently a costly and energy-consuming technology. The costs obviously depend on the size of the plant and the type of fuel used. Generally, capture systems are categorized into three categories: pre-combustion, post-combustion, and oxy-fuel combustion. The saline aquifer, depleted oil, and gas fields are large-capacity storage sinks. The coalbeds also provide as a substitute to geological storage. One of the main advantages of coal storage is renewable methane fuel and coal desulfurization. The studied coal reserves are located in Candiota, State of Rio Grande do Sul, Brazil. These are the largest coal deposits in the country, with a reserve of 1 billion tons. This work will represent a study on CO2 storage in Candiota coalbed system. The use of a synthetic CO2 cylinder with a flow of 0.2 L /min varies the time of contact with the coalbed. The results from the volatile matter increase by 11%. The results of the ultimate analysis exhibited an 8% increase for carbon and oxygen after 60 minutes of CO2 flow in the coalbed. On the other hand, there was a reduction of 32% for sulfur. The resultant phenomena occur due to the adsorption capacity of CO2, where the compounds are released from the pores of coal

Three-dimensional Numerical Analysis of Stress and Deformation of Soft Soil-pile group-pile Cap System under Coal Pile Load

In order to study the stress and deformation characteristics of adjacent pile cap system under the action of coal pile load in soft soil site, taking a large coal storage field in Malaysia as the specific engineering background, based on the large finite element numerical computing platform ABAQUS, the three-dimensional nonlinear numerical model of pile foundation and soft soil site under the action of pile coal load is established to consider the spatial stiffness effect, the stress deformation analysis and safety evaluation of pile group foundation pile foundation for a given site are carried out. It can provide guidance and reference for the design and practice of related engineering.

Experimental and numerical investigation of the effect of temperature patterns on behavior of large scale silo

Abstract With the requirement of environmental protection, reinforced concrete silos with large diameter for coal storage were built. In view of less literatures on the effect of temperature patterns, this paper presents the experimental study and 3D FEM simulation of a reinforced concrete silo with 136.5 m in diameter and 19.35 m in height. The stresses of circumferential and vertical steel bars were measured by the vibrating string strain gauges installed under different circumstances of temperature patterns due to sunshine and season changing. The data were collected and transmitted with GPRS transmission system for a period of more than 1000 days. Meanwhile, finite element model was built by ABAQUS software, in which the Drucker-Prager elasto-plastic criterion and the elasto-plastic damage model were used to modify the nonlinearity of soil and reinforced concrete. The test data agree well with the numerical simulation results. The effect of temperature patterns on silo wall was scrutinized. The results of this paper provide a crucial basis for the design of large scale silos.

Contamination by Coal Dust in the Neighborhood of the Tarragona Harbor (Catalonia, Spain): A Preliminary Study

Background: In February 2017, some buildings of La Pineda (Catalonia, NE Spain) a rather small town, located near to the Tarragona harbor, were affected by a contamination episode that dirtied external walls, windows, doors and floors of these buildings with a black dust. This study was aimed at assessing the origin of the black dust appeared in the buildings. Methods: Black dust samples were collected in the railings of balconies, windows, and exterior doors of two buildings in La Pineda, as well as in the ground of the breakwater of the Tarragona harbor, at few meters from the open air coal storage area. Elemental analysis of the black dust (C, N, H and S) was performed. A daily sample of PM10 was also collected and analyzed for five consecutive days. Results: The total carbon content of the collected dust was 25.8%, 29.4% and 33.9% in the two buildings of La Pineda and the breakwater, respectively. In turn, the contribution of carbon from carbonates was 0.0%, 1.3% and 5.1%, in the samples of the two buildings and the breakwater, respectively. PM10 showed levels between 18 and 39 µg/m3, with mean and median levels of 29 µg/m3. Conclusion: The elemental analysis indicated that the two black dust samples collected in the two buildings of La Pineda were similar to the sample collected at the breakwater of the port of Tarragona, showing a common origin: The bulk coal storage area of Tarragona harbor. Because information on the human health risks derived from the important activities conducted in the port of Tarragona is currently non-existent, an exhaustive assessment of all pollutants involved in the activities of the port is strongly recommended.

MODIFIKASI UNIT CV 507 DENGAN MENAMBAHKAN BYPASS CHUTE DAN PENYARING (SCREEN SIZER) SEBAGAI PEMISAH UKURAN BATUBARA

Abstract This study discussed about modifying coal storage units which function to separate large size coal, pack stones, which causes the carrying capacity of coal to ships or stock piles not to reach maximum capacity. This is due to the inability of the CV507 line to load coal in accordance with design capacity Shiploader 2 which is 6000 tons / hour maximum. the operational and financial impacts caused by large coal or pack stones can cause the unit to disassemble to be disrupted or damaged and the capacity is not optimal. The current target set is the loading of coal loads can exceed 1,350,000 tons per month. The method used in identifying cases is reviewed from the QCDSMP method (Quality, Cost, Delivery, Safety, Morale, Productivity) used in the company, and analysis of the cause of this case using the Fish Bone method to determine dominant cause factors. From the results it is known that the most dominant causative factor is the Method, where there must be a separation process between large and small coal in the Screen Sizer before the Auxiliary Screen, so that the coal according to the screen size is directed directly to CV508 without passing through the large Auxiliary Screen and big coal (oversize) through the Auxiliary Screen process to be separated so as not to enter to the ship by modifying the CV507 unit.

Fugitive emission rates assessment of PM2.5 and PM10 from open storage piles in China

An assessment of the fugitive emission rates of PM2.5 and PM10 from an open static coal and mine storage piles. The experiment was conducted at a large union steel enterprises in the East China region to effectively control the fugitive particulate emissions pollution on daily work and extreme weather conditions. Wind tunnel experiments conducted on the surface of static storage piles, and it generated specific fugitive emission rates (SERs) at ground level of between ca.10-1 and ca.102 (mg/m2·s) for PM2.5 and between ca.101 and ca.103 (mg/m2·s) for PM10 under the u*(wind velocity) between ca.3.0 (m/s) and 10.0 (m/s). Research results show that SERs of different materials differ a lot. Material particulate that has lower surface moisture content generate higher SER and coal material generate higher SER than mine material. For material storage piles with good water infiltrating properties, aspersion is a very effective measure for control fugitive particulate emission.

Environmental Impact of Conventional Power Plant in Normal and Accidental Conditions

THE PREVENTION and simulation of chemical leakage has become one of the most important topics in the fields of environmental protection and process safety. Thermal Power plants are the major source of generation of electricity for any developing country. A power plant can affect the environment during its construction and its operation. These effects, or impacts, can be either temporary or permanent. A power plant and its auxiliary components (e.g. natural gas pipelines, water intakes and discharge, coal delivery and storage systems, new transmission lines and waste disposal sites) occupy space on the ground and in the air, use water resources, and, in most cases, emit pollutants into the air. Before construction of any electric facility it is required to study its impact on the environment. The environmental impact study shall cover the impact of the plant on the environmental in case of normal operation and accident condition through air. This paper covers the analysis of the meteorological parameters and calculate the concentration of pollutants emitting from two stacks of Electric Station-Power Plant, Damanhur, Egypt by simulating seasonal dispersion of pollutant. This plant uses mainly natural gas as fuel. The most likely pollutants emitted from the stack of the plant are nitrogen oxides, carbon monoxide, sulfur oxides, and particulate matter. For normal emission the AirPacts module was used in the Simplified Approach for Estimating Impacts of Electricity Generation (SIMPACTS) to calculates the physical impacts and the associated damage costs for the following types of pollutants namely,sulfur dioxide (SO2), nitrogen oxides (NOx), carbon monoxide (CO). For risk assessment, the Hybrid Single-Particle Lagrangian Integrated Trajectory (ALOHA) Model was used with different scenarios. Through this study, dispersion models are derived for nitrogen dioxide and methane concentrations for different scenarios, which result from the fuel combustion process , to determine the distance to a defined toxic endpoint and develop a prevention/emergency response program accordingly.

Analysis and Research on Control Technology of Large Mining Height Fully Mechanized Face and Roadway Surrounding Rock

Coal is important basic energy and important raw materials, the development of coal industry to support the rapid development of the national economy. In the 1950s and 1960s, the proportion of coal in China's primary energy production and consumption structure accounted for 90% and 80% respectively, and the proportion of coal in 2004 was 75.6% and 67.7% respectively. In recent years, with the rapid development of fully mechanized mining equipment manufacturing technology, fully mechanized mining equipment to heavy, strong and automated, so that the reliability of the equipment is guaranteed, a strong impetus to the development of large mining technology, new round of coal mining technology revolution, the current in the East, Jincheng and other mining areas have been the first in the thick coal seam f = 1.5-5 use of large mining height fully mechanized mining equipment, to achieve the highest efficiency, the lowest cost of tons of coal. The main points of this paper are: in the production of coal enterprises to improve the competitiveness of the coal market. Conditions and conditions of coal storage conditions should be allowed to give priority to the use of large mining and mining methods.

Dustfall design of open coal yard in the power plant-a case study on the closed reconstruction project of coal storage yard in shengli power plant

This thesis, based on the closed reconstruction project of the coal storage yard of Shengli Power Plant which is affiliated to Sinopec Shengli Petroleum Administration, first makes an analysis on the significance of current dustfall reconstruction of open coal yard, then summarizes the methods widely adopted in the dustfall of large-scale open coal storage yard of current thermal power plant as well as their advantages and disadvantages, and finally focuses on this project, aiming at providing some reference and assistance to the future closed reconstruction project of open coal storage yard in thermal power plant.

Profit Allocation of Hybrid Power System Planning in Energy Internet: A Cooperative Game Study

The rapid development of Energy Internet (EI) has prompted numbers of generators to participate, leading to a hybrid power system. Hence, how to plan the hybrid power system and allocate its profit becomes necessary. In this paper, the cooperative game theory is introduced to discuss this problem. We first design the basic structure of EI, and point out the object of this study—coal power plant-wind farm-photovoltaic power station-energy storage provider (CWPE) alliance. Subsequently, average allocation strategy (AAS), capacity-based allocation strategy (CAS) and Shapley value allocation strategy (SAS) are proposed, and then the modified disruption propensity (MDP) index is constructed to judge the advantages and disadvantages of the three schemes. Thirdly, taking a certain area of A Province as an example, the profits of CWPE under three strategies are calculated respectively. Finally, by analyzing individual rationality and collective rationality of cooperative game and the MDP index of the three profit allocation schemes, we find that SAS is the most stable.

The analysis of heavy metal in leaching liquid of coal

In this paper, heavy metals in coal were extracted by pure water to simulate the leaching effect of natural precipitation or artificial rainfall on outdoor storage of coal. The results show that the leaching liquid pH was slightly declining, and Cu, Zn, Pb, Cd were in μg/L level, far less than the hazardous waste identification standard of GB5085.3-2007. It suggests that leaching liquid was less harmful to environment when coal was immersed by big amount of water. In the case of spray or precipitation less, the pH drop was more obvious, leaching of heavy metals more, and the general elution of the initial dissolution of the most obvious. Although the amount of small but more toxic, the relevant management should be alert to its harmful.

Characterization of nanoscale rockmechanical properties and microstructures of a Chinese sub-bituminous coal

Microstructures and geomechanical properties are of key importance in coal mining, coal bed methane production and CO2 storage in deep coal seams. Full characterization of the microstructures needs multiscale methods and accurate mechanical data to avoid geohazards (e.g. coal seam layer collapse, fault reactivation or methane leakage). However, standard methods (i.e. acoustic, seismic or USC tests) measure only cm-km bulk properties, while it is clear that the nano-micrometre scale coal heterogeneity plays a vital role. Thus, we used the SEM, microCT, and NMR to characterized the microstructure of a Chinese sub-bituminous coal, and measured nanoscale geomechanical properties via nanoindentation tests and compared the results with the traditional acoustic method. We found that such coal had few cleats, while nanopores constituted the main pores. Furthermore, clear heterogeneity in geo-mechanical properties was observed and mapped, which was not reflected in the bulk acoustic measurements (which provide only averaged data). Such small scale heterogeneity, however, clearly highly correlated with the morphology of the sample, where the mineral phase in the coal had higher indentation moduli (up to 60 GPa for well consolidated), while the coal matrix had lower indentation moduli (lower than 6 GPa). We conclude that such nanoscale rockmechanical property was highly correlated with the morphology of the microstructure; and importantly, it is necessary to measure geomechanical coal properties at small scale to appreciate their large variation and highly heterogeneous character, and to reliably assess and eventually reduce the risk of geohazards.

Experimental and numerical study of coal dust ignition by a hot particle

This work studies the ignition of a layer of brown coal dust by hot metal particles experimentally and numerically. The experiments establish the limits of the flaming ignition of gas and ignition delay times when the parameters of solid fuel and metal particles varied in a wide range. The particle size of coal ranged from 0.1 to 1 mm; the shapes of the metal particles were sphere, disk, and cube; their initial temperature varied between 1000 and 1400 K. A mathematical model was developed for describing the processes involved in heat and mass transfer as well as chemical reactions around the local heat source. The results of the numerical simulation are in good agreement with the experimental data: boundaries of the flaming ignition of coal; coal ignition delay times; three modes of flaming ignition of coal with the ignition zone of volatiles located in the vicinity of the hot particle. The mathematical model is good at predicting the ignition conditions during interaction between a hot metal particle and a layer of coal dust. The model can also be used for developing the promising technology of steam boiler start-up by highly reactive coal instead of flammable liquid combustion. Another application is the development of fire prevention guidelines for tightening fire safety management at productions deal with coal mining, transportation, storage, processing, and combustion. Finally, the paper includes the analysis of limitations for the practical use of the predictive mathematical model in thermal power engineering and fire safety management.

Wind Power Development and Energy Storage under China’s Electricity Market Reform—A Case Study of Fujian Province

This paper, based on the Fujian provincial 500 kV grid and part of the 220 kV grid and the key power plants, including hydro, coal, nuclear, gas, wind and pumping and storage hydro powers (PSHP) connected to the grid, constructs an independent electricity market model. Using data that are very close to reality about coal fired power production costs, along with data about power plants’ technical constraints, this paper studies the effect of wind power on Fujian’s provincial electricity market. Firstly, the paper analyzes the relationship between wind speed and wind power output and the effects of short-term power output fluctuation on frequency modulation and voltage regulation. Secondly, under supposition of the production costs following quadratic functions, the paper analyzes the effects of changes in wind power output on the electricity supply costs under optimal power flow. Thirdly, using the bidding model in the Australian Electricity Market Operator for reference and supposing that, in a competitive market, coal fired power plants can bid 6 price bands according to their capacity, the paper analyzes effects of wind power on electricity prices under optimal power flow, the stabilizing effects of PSHP and the minimum PSHP capacity needed to stabilize the electricity market. Finally, using a daily load curve, this paper simulates the electricity prices’ fluctuation under optimal power flow and PSHP’s stabilizing effect. The results show that, although PSHP has a large external social welfare effect, it can hardly make a profit. In the end, this paper puts forward some policy suggestions for Fujian province’s wind and nuclear power development, PSHP construction and electricity market development.

Nanoscale rock mechanical property changes in heterogeneous coal after water adsorption

Rock mechanical properties are of key importance in coal mining exploration, coal bed methane production and CO2 storage in deep unmineable coal seams; accurate data is required so that geohazards (e.g. layer collapse or methane/CO2 leakage) can be avoided. In this context it is well established that coal matrix swelling due to water adsorption significantly changes the coal microstructure. However, how water adsorption and the associated with microstructural changes affect the mechanical properties is only poorly understood, despite the fact that micro-scale mechanical properties determine the overall geo-mechanical response as failure initiates at the weakest point. Thus, we measured nanoscale rock mechanical properties via nanoindentation tests and compared the results with traditional acoustic methods on heterogeneous medium rank coal samples in both dry and brine saturated conditions. The microscale heterogeneity of the rock mechanical properties was mapped and compared with the morphology of the sample (measured by SEM and microCT). While the nanoindentation tests measured decreasing indentation moduli after water adsorption (−60% to −66%), the traditional acoustic tests measured an increase (+17%). We concluded that acoustic tests failed to capture the accurate rock mechanical properties changes for the heterogeneous coal during water adsorption. It is thus necessary to measure the coal rock mechanical properties at the microscale to obtain more accurate data and reduce the risk of geohazards.

Technological Solutions for Processing Closed Coal Mines by Open Pit Method

The main sources of environmental pollution are: pollution from the residual effects of working out of mine fields by underground method; pollution from secondary mining of mine fields by the open method. The pollution of the environment from the underground mining of mine fields is mainly due to the erosion of the surface of the ditches caused by collapse of the underground workings, spontaneous combustion of the remaining coal reserves and exit of poison gases SO2 and CO to the surface through the cracks from the lower horizons of the worked-out mine fields. This makes actual the research of technological possibilities of harmful emissions reducing when quarrying underground mines’ fields. The environment deterioration from conducting open pit mining operations in the underground mine fields is caused by the technological processes of quarrying (preparation of rock for excavation, excavation, transportation of rocks and coal, dumping), by the objects of the open pit infrastructure (industrial site, transport communications, trenches and other workings, coal storage and rock dumps). The main direction of eliminating the negative environmental consequences of underground mining is the localization or complete isolation of the underground mines influence’ on the surface.

Development of technology of pulverized coal injection in Ukraine’s blast furnaces in variable liquid and gas dynamic conditions

The aim of the work is to study the features of the use of pulverized coal (PCI) in the conditions of the blast furnace (BF) No. 5 of Metinvest Holding Ltd (Ukraine). The complex for the preparation and use of pulverized coal includes: a coal unloading and storage area; coal mixing section; coal sampling unit; plot of coal sorting and preparation; installation of drying and grinding coal raw materials, installation for the injection of pulverized coal into the BF. It is shown that the use of rational modes of loading and forming portions of the charge, the choice of rational slag mode allowed to increase the annual consumption of pulverized coal on average up to 130 kg / t of pig iron even in the conditions of variable load of BF and when working on coke of reduced quality. During the research, an operational monitoring of the condition of the lining of the BF shaft was carried out using the indications of the thermocouple of the lining and the body of the refrigerators. The determination of the thermal loads of the cooling system made it possible to develop measures to adjust the distribution of the charge components along the radius and circumference of the furnace. The temperature of the peripheral gas flow along the entire height of the furnace is reduced by an average of 13%, the irregularity of the peripheral temperature is reduced by 11%. The stability of the cooling system and the smooth operation of the blast furnaces.

煤矿机电设备节能技术探索研究

我国煤炭储存丰富，煤炭资源在我国经济发展中长期成作为主要能源。而煤炭规模化的生产主要依靠机械设备。根据实际负荷，通过对设备电流频率的改变，实现了对机电设备运行速度的控制，根据实际需求调节设备的运行状态，实现煤矿开采的节能目的。本文通过节能技术的应用现状及其原理进行分析，详细阐述了变频节能技术在煤矿机电设备中的应用以及发展前景，以期促进煤矿采集业的发展。 China, as a country with abundant coal storage, has made outstanding contribution to the eco-nomic development of our country. The large-scale production of coal relies mainly on mechanical equipment. According to the actual load, the current frequency of the equipment is changed to control the running speed of the electromechanical equipment. The operation status of the equipment is adjusted according to the actual needs so as to realize the energy saving goal of coal mining. This paper analyzes the application status and principle of energy-saving technology, elaborates the application of frequency-conversion energy-saving technology in coal mine electromechanical equipment and its development prospect in order to promote the development of coal mining industry.

Deep-hole water injection technology of strong impact tendency coal seam—a case study in Tangkou coal mine

The implementation of coal-seam water injection can change the physical and mechanical properties of coal, can improve the coal storage limit, prevent and control rock burst, prevent coal and gas outburst, and reduce dust concentration in underground operations. However, there are still many shortcomings such as the poor sealing effect and the lack of coal seam permeability. In order to study coal softening through water injection and its effect of reducing the coal’s impact tendency, we examine the impact tendency, coal seam injection, water injection additive, water injection hole sealing, and coal seam stress-relief effect of coal seam on LW5304 experimentally and through engineering application. The results show that this method can be used to reduce the coal’s impact tendency, if the samples are soaked. Triton X-100 additive can effectively reduce the polarity of water and the surface tension, while improving the coupling effect of water and coal and the wettability of coal. The “pure polyurethane + cement slurry + cement mortar” sealing process can be used to avoid water injection leaking. The water content of LW5304 coal seam is 3.2~4.2% after water injection, and the average increase of moisture content is 1~2.5%. In addition, the number of coal-stress early warning is reduced, and micro-seismic monitoring shows that the average energy is reduced as well. Therefore, water injection in coal seam is considered a good method for relieving stress.