循环流化床(CFB)煤/焦气化反应的研究 Ⅰ.操作气速、固体循环速率对循环流化床气化反应的影响

报道了山西西山焦煤飞灰，在小型循环流化床气化反应器上，以二氧化碳为气化介质，在不同操作条件下（气速、固体循环速率）的气化反应。研究结果表明，ＣＯ出口浓度及碳转化率随着ＣＦＢ操作气速减小、固体颗粒循环速率的增加而增加。即在ＣＦＢ床中，提高气体、固体停留时间（床内固体颗粒浓度）有利于ＣＦＢ气化的进行。ＣＯ浓度及碳转化率沿床高的变化趋势与床内颗粒浓度分布一致。

Research on the gas desorption law of the consumingly destruct coal

To solve the issues of calculating gas loss quantity during sampling,simulated gas desorption process of the consumingly destruct coal with the assembly simulation testing device.Through an analysis of the simulation test datum using SPSS software, established a new formula that can be better description on gas desorption process,more accurate calculation of the gas loss quantity during sampling process,and calculating re- leasable gas quantity during a certain period.Aimed at the new formula,the best time of taking sample is confirmed 3 minutes for consumingly destruct coal,the computative error is less than 10%.Through experiment at laboratory and locale,the new formula could well describe consumingly destruct coal gas desorption law,and it has high calculation preci- sion of gas loss quantity in sampling and desorption quanlity.

Prevention of explosion in coal mine and management of coal mine gas

There are many problems in terms of safe coal production and the sound developmentof the coal industry.Accompanying the intensification and increasing efficiencyof coal production and the conducting of mining operations at deeper and more remoteareas of mines,the efficient recovery and utilization of Coal Mine Methane:(CMM) is animportant issue in improving and stabilizing the productivity in the coal mining industry withhigh levels of gas,where the incidence of gas outbursts is increasing.We plan to studyvarious aspects of the development of production technology and characteristics of themine site.This is to establish the technology for highly efficient coproduction coal and gasoperation rate.As a result,the productivity at the coal mine face will increase due to thereduction in gas emissions in the mining face.Effective use of recovered gas can be expectedto reduce global warming by reducing the amount of coal mine methane gas emissionin the air.

A triaxial creep model for coal containing gas and its stability analysis

Triaxial creep tests on CCG specimens were systematically performed using aself-made creep seepage experimental apparatus for determining the creep law of CCG.An improved triaxial creep model of CCG was established on the basis of a Nishiharamodel and another visco-elasto-plastic model,parameters of which were fitted on test data.Furthermore,the creep model is validated according to the result of triaxial creep experiments,and the outcome shows that the proposed triaxial creep model can properly characterizethe properties of various creep deformation phases of CCG,especially the acceleratingcreep phase.At the same time,the instability conditions of CCG were presentedbased on the discussion of the improved model's stability in terms of stability theories ofdifferential equation solution.

A new forecast model for the carbon-monoxide concentration in the upper corner of mining face

The CO gas in the upper comer along with the work of mining face in different coal-seam of Lingwu coal-field has deeply affected judgment for the degree of the coal spontaneous combustion and safety work. For this issue, a new calculation and forecast model of the carbon monoxide concentration in the upper comer of mining face was deduced for analyzing and calculating the date from the lab and test-in-place, during this course using the knowledge of heat transfer, fluid dynamics, and mathematics. The model took into account the characteristics of the coal spontaneous combustion, coal mining conditions, and other correlate factors, so the CO concentration of the upper comer safe under the normal condition, and it is in danger when the coal reached spontaneous combustion, which can be calculated accurately with the model and compared with the measured concentration with a tolerance of less than 12%.

Spontaneous coal combustion producing carbon dioxide and water

Gas products from the process of coal oxidization and spontaneous combustion have been studied at different temperatures with FTI spectroscopic tests. With temperatures rising to about 30~100 ℃, water and carbon dioxide gas were formed and from about 105~150 ℃, carbon monoxide was produced. Using the DFT B3LYP method with a 6-311G basis set, the reaction system, where spontaneous combustion between coal and oxygen occurs and produces water and monoxide, has been studied, with the geometric configuration for all stagnation points on the potential reaction energy surface optimized. With a frequency analysis and an IRC method, transient formations were tested. Our results indicate that in the reaction of coal oxidization and spontaneous com-bustion producing carbon dioxide and water, oxygen molecules attack carbon atoms of the terminal of the propyl alcohol group on the lateral chain of benzene rings, which causes this propyl alcohol group to produce the acid (-CH2-CH2-COOH) group and water. This acid group continues its break up into carbon dioxide and the (-CH2-CH3) ethyl group. We have come to the conclusion that this water-and-carbon dioxide-production reaction is spontaneous, based on the observation of the energy released by the reaction.

Theory and practice of integrated coal production and gas extraction

The integrated extraction of coal and gas combines coal mining with gas capture. Taking into account the gas deposition and flow conditions in the Chinese coal basins, this paper describes the status of the theory and key technologies of this integrated extraction system, and presents its application and practice in the Shaqu, Zhongxing, Fenghuangshan and Pingmei mines. Areas for further improvements in future studies are discussed, focusing in particular on the fundamentals of the extraction system to make it greener, more scientific, and more advanced in both the exploitation and utilization of coal and the gas in coal.

Seepage laws of two kinds of disastrous gas in complete stress-strain process of coal

The similarities and differences in seepage flow evolution laws of CH4 and CO2 during complete stress- strain process of samples were comparatively analyzed. The results show that the seepage flow evolution laws of CH4 and CO2 are extremely similar during the stress-strain process, showing that the character- istic first decreased and then increased. A mathematical model was also established according to the rela- tionship of seepage velocity and axial strain. However, due to the strong adsorption ability of CO2, the coal samples generated a more serious ''Klinkenberg effect'' under the condition of CO2. Owing to this, the CO2 seepage flow resulted into occurrence of ''stagnation'' phenomenon during the late linear elastic stage II. In the strain consolidation stage III, the increment rate of CH4 seepage velocity was significantly greater than that of CO2. In the stress descent stage IV, when the axial load reached the peak pressure of coal, the increment rates of CH4 seepage velocity presented a turning point. But the changing rate of CO2 seepage velocity still remained slow and a turning point was presented at one time after the peak of thestrain pressure, which showed an obvious feature of hysteresis.

Gas effusion of full-mechanized top coal caving in Jiaoping Mine Area

According to the gas observational data,the gas spatiotemporal distributions were analyzed in full-mechanized top coal caving in thick,hard and high-gas seams.The factors influencing gas effusion were researched and the rules of gas effusion under the special conditions were educed,for example,the underground pressure,the output inten- sity,the working surface advancement,and the amount of ventilation in the working face on gas effusion,and so on.The research results can be the base of forecasting gas effu- sion and controlling gas in these special conditions,which can guarantee the safety of highly efficient full-mechanized top coal caving.

Strategic deliberation on development of low-carbon energy system in China

In recent years, there have been considerable developments in energy provision with the growing improvements in energy supply security and support systems in China. However, China's energy system continues to retain a high-carbon feature where coal dominates energy production and consumption, which has led to the rapid growth of greenhouse gas emissions and associated serious environmental pollution. It has therefore become an important task for China to consider how to promote the low-carbon development of energy system. This paper summarized the basic trends and challenges for development of low-carbon energy system in China and studied the primary energy consumption and carbon emissions in different scenarios at 10-year intervals between 2010 and 2050. The analysis showed that controlling coal consumption will have an important influence on the control of total carbon emissions and of carbon emission peaking; promotion of non-fossil fuel energies will offer a growing contribution to a low-carbon transition in the medium and long term; the development of carbon capture, utilization, and storage will play a key role in realizing a deep decarbonization pathway, particularly after 2030; and the establishment of a low-carbon power system is crucial for the achievement of low-carbon energy transition. Finally, the strategic considerations and policy suggestions on the development of low-carbon energy systems in China are explored.

Forecast of coal spontaneous combustion with artificial neural network model based on testing and monitoring gas indices

Forecast is very important for preventing and controlling the disaster of spontaneous combustion （sponcom）. Gaseous products of coal, such as carbon monoxide, ethylene, propane and hydrogen, are commonly used as indicators to reflect its status quo of sponcom in coal mines. Nevertheless, since the corresponding relationship between the temperature and the indicators is non-linear and can＇t be depicted with simple mathematical formula, it is very difficult to diagnose and forecast coal sponcom by monitoring indicator gases＇ distribution. A forward feeding 3-layer artificial neural network （ANN） model is employed to express the corresponding relation between temperature and index gases of coal sponcom more accurately. A large amount of data from programmed temperature oxidation experiments were employed to train the network to gain the connection strength between nerve cells and to accomplish the model. It proved in real coal productions that the ANN model can forecast coal sponcom accurately.

Impact of renewable power market penetration on coal power generation capacity growth

Since renewable energy sources are growing in importance, how well they can penetrate the energy market for power generation will be a very important factor in the role the coal industry will play in the future. This paper examined the displacement of coal power plant capacity from 2010 to 2050 by renewables with respect to three drivers assumed under various conditions： the American Recovery and Reinvestment Act （ARRA）, Greenhouse Gas （GItG） policy, and varying plant capital cost cases. The results by 2050 illustrate that renewable market penetration captures anywhere from 1.9% to 6.4% of potential coal power generation capacity additions. Renewable power generation capacity additions is expected to outpace coal power plant additions by 89% with respect to ARRA in 2050, however with no GHG policy coal power generation capacity build-outs will outpace renewables by as high as 809%. Finally, coal power generation is still projected to be the largest single energy source contributor to the electricity market making up 28.0% of total available capacity, while renewables are expected to only make up 16.3% of total available capacity.