· An improved lignite pre-drying using a supplementary steam cycle is proposed. • Thermodynamic and economic analyses are quantitatively conducted. • Lower exergy destruction and better matched energy level are obtained. •
Consulta
Abstract Lignite is an important fuel for power generation in many parts of the world. In conventional lignite-fired power plants, the high moisture content of lignite can result in low thermal plant efficiencies. Drying the lignite prior to combustion in the boiler is thus an
Consulta
· The fragmentation and pulverization properties of lignite in the different drying processes were investigated in this study. Lignite particles were dried at different temperatures (100, 140, and 180°C), particle sizes (6–25 mm) and drying time (0–60 min), and the parameters of fragmentation index ( S f ) and pulverization ratio ( β )
Consulta
:Thermal Power PlantsIntegration of Evaporative DryersLignite-Fired · The system boundary includes the lignite mining, transportation, lignite crushing and combustion, lignite drying, lignite compression, the hot flue-gas
Consulta
The lignite dryer adopts a new technology of crushing the lignite and then drying it by rotary dryer. That Makes the drying process realized continuous, industrialized and automated. The diameter of the drying drum of our company ranges from Φ1.9 meters to Φ3.4 meters, and the length ranges from 24 meters to 40 meters.
Consulta
· Drying experiments at three different temperatures (120, 200, and 280 C) in nitrogen atmosphere were carried out. The drying curves in Fig. 2 show that X daf decreases with the prolongation of drying time. For the drying curves at 200 and 280 C, the rate of X daf reduction was rapid at the beginning of drying, and the weight change
Consulta
· Low-temperature and humid drying experiments [temperatures of 20–30 °C; relative humidity (RH) of 40–60%] were conducted to investigate the drying shrinkage of lignite at low temperatures. The moisture content and volume variations of lignite during low-temperature drying were measured to analyze the change in the water content and
Consulta
:Reduction-oxidationStretching Vibration · Under exposed conditions, the volume shrinkage of saturated coal is significant, and continuous drying can lead to cracking and serious crushing as the
Consulta
:Volume ShrinkageLignite · When evaporative dryers are integrated within power plants, the waste heat of power plants can be used to dry lignite, thereby increasing the efficiency of
Consulta
· The drying process of lignite changes its average pore diameter; therefore, the combustion performance can be improved by adjusting the pore structure of lignite during the drying process. Furthermore, it is recommended to dry lignite at 230 °C to reduce energy loss during the drying and combustion processes and improve the
Consulta
input through co-firing dry lignite are modeled. The cases of thermal share substitution examined are those of 10, 20 and 30% of the initial input. The steam extracted from lignite pre-drying in each case is used as a heating medium in the power plant’s feed water
Consulta
· Air-dried raw lignite was crushed using a lab-scale roll crushing mill and screened into the one specific required size fraction, i.e., −1.25 +0.71 mm using a standard sieve. Shengli lignite was characterized by high
Consulta
· The sludge was completely dried by the drying oven at 105 [19], and was ground and crushed. Then, it was passed through an 850 μm sieve to remove the coarse particles, and finally kept in a
Consulta
· Two primary techniques can be employed to dry lignite: evaporation drying and non-evaporation drying [4], [5], Prior to the experiment, the coal was crushed and sieved to achieve a particle size ranging from 40 to 80 mesh. The coal was stored in
Consulta
· In this study, the pore structure variation and fractal dimension of Shengli lignite in the drying process (150 ~ 500 °C) were investigated. The pore structure of lignite samples, including specific surface area, average pore diameter and pore shape etc., were obtained by N 2 adsorption/desorption at 77 K. And two fractal dimensions D 1 and D
Consulta
:Volume ShrinkageLignite · According to common practice, the rotary indirect drying method, the mill drying as well as the fluidized bed drying concept are the most prominent for lignite
Consulta
· Section snippets Materials The lignite sample used in this study was collected from Mengdong mining area. After being crushed and screened, 25–13 mm and 13–6 mm lignite samples were used in this study. Table
Consulta
· The effects of thermal pretreatment on pyrolysis behavior of Shengli lignite were investigated in a fixed bed reactor. In comparison with raw coal, the thermally pretreated coal has lower content
Consulta
· Upgradation of the rank of lignite is mandatory for its effective utilization as a potential energy source. Microwave drying is being explored in the present work as an effective upgradation technique. The effects of operating variables such as sample mass, particle size and sample thickness were investigated. The work also attempts to compare
Consulta
· Symbols as in Figure 3 Formation of free radicals: R. M. Carr et al. 4 3 ly U C o U C iz 2 30 1 , los -- ----- 1 ~ 0 48 96 144 192 240 0 Oxidation time ( hr) Figure 6 Changes in spin concentration on exposure of nitrogen-flowdried New Vale lignite to
Consulta
:Publish Year:2014Power PlantsSignificant volume shrinkage and drying cracking of high-water-content lignite will occur during low-temperature drying. To determine the variation behaviors of the drying shrinkage rate and desicc
Consulta
· But Tang et al. [6] found mesopore volume of Shengli lignite decreased in the drying process (150e500 C) show a "V" shape variation trend, and the turning point was 200 C. Anyhow, the previous
Consulta
· Lignite is a gelatinous porous medium that contains moisture [33], [34], [35], which causes structural damage during drying and the fragmentation of lignite into small particles as the moisture content decreases. It is believed that a change in moisture content is the principal cause of volume change, and that shrinkage leads to cracking.
Consulta
· While, in the LPDPP, the moisture content of the dried lignite fed into the boiler is reduced to 15.0% (wet basis). The temperature of the exhaust flue gas decreases to 130 C and the boiler efficiency can reach 93.7%. The details of the components of the dried.
Consulta
Lignite Fluorite Ore Metal Powder Steel Slag Ball Press Coal Briquette Machine US$1,900.00 / Piece 1 Piece (MOQ) View More 1992,is a professional manufacturer specializing in the production of mineral beneficiation equipments,sand and stone crushing
Consulta
· The raw lignite is dried with an exit temperature after drying of approximately 70 to 85 C. The dried raw lignite is then crushed. This crushing of the dried raw lignite is performed in an air-swept roller mill, in which the crushing and cooling of the lignite particles is brought about by the inflowing cold and/or ambient air to a
Consulta
· The U.S. Department of Energy (DOE) and Great River Energy are testing a new coal-drying technology that could dramatically reduce the emissions of Coal Creek Station, a 1,092-MW lignite-fired
Consulta
· enter a compaction crushing state [13– 16]. e crushing of coal is affected by its strength, local particle size, and impact energy [17–2 1]. e coal loading process leads to com-
Consulta
· The crushing strength (CS) of single lignite particle, based on the definition in this paper, shows no clear dependence on drying temperature. The drying temperature might affect the moisture content in the sample, thus affecting the CS .
Consulta
· Lignite-fired boilers can benefit greatly from applying open coal pulverizing systems. • The benefits include marked coal-savings, enhanced coal combustion and water recovery. • A novel superheated-steam-drying open-pulverizing-system was proposed for
Consulta
Trituradora de piedra vendida por proveedores certificados, como trituradoras de mandíbula/cono/impacto/móvil, etc.
OBTENER COTIZACIÓN