Implementation of Gas Control Algorithm in EASTPCS

In this paper, gas control on EAST in open and closed loop is discussed and its implementation into EASTPCS （plasma control system for the experimental advanced supercon- ducting tokamak） is introduced. Using a model to describe the plasma density response to the gas puff command, a gas simulation server （simserver） using MATLAB simulink tools and real time workshop was built up. Proper operation of the gas control algorithm was verified using this simserver. The simulation results suggested that the gas control can be applied in the next EAST campaign.

Study on comprehensive gas control techniques and practice in coal mines

The origins and main control methods of gas in coal seams were introduced cursorily, and the processes that need to be done in controlling gas, which includes prediction of gas emissions, drainage systems, the means of prevention of gas outbursts, and some suggestions were put forward. The characteristic of different gas emissions and the corresponding counter measures were presented, and ＆ case study of simultaneous extraction of coal and gas in Xieyi Coal Mine was carried out by coal mining and gas extraction without coal-pillar. The field application shows that gas drainage ratio in panel 5121（0） averages about 90% and reaches as high as 95~/0, which will give beneficial references to gas control in coal mines.

Enhancement of a foaming formulation with a zwitterionic surfactant for gas mobility control in harsh reservoir conditions

This work presents the design of a robust foam formulation that tolerates harsh reservoir conditions(high salinity,high divalent ion concentration,high temperature,light oil,and hydrocarbon injection gas)in a sandstone reservoir.For this,we selected anionic Alpha Olefin Sulfonate(AOS)surfactants and studied their synergistic effects in mixtures with zwitterionic betaines to enhance foam performance.The laboratory workflow used to define the best formulation followed a de-risking approach in three consecutive phases.First,(phase 1)the main surfactant(AOS)was selected among a series of commercial candidates in static conditions.Then,(phase 2)the betaine booster to be combined with the previously selected AOS was chosen and their ratio optimized in static conditions.Subsequently,(phase 3)the surfactant/booster ratio was optimized under dynamic conditions in a porous medium in the absence and the presence of oil.As a result of this study,a mixture of an AOS C14-C16 and cocamidopropyl hydroxysultaine(CAPHS)was selected as the one having the best performance.The designed formulation was proven to be robust in a wide range of conditions.It generated a strong and stable foam at reservoir conditions,overcoming variations in salinity and foam quality,and tolerated the presence of oil.

The control of coal mine gas and coordinated exploitation of coal bed methane in China

Based on the characteristics of the coalfield geology and the distribution of coalbed methane (CBM) in China,the geological conditions for exploiting the CBM and drainingthe coal mine gas were analyzed,as well as the characteristics of CBM production.Bycomparing the current situation of CBM exploitation in China with that in the United States,the current technology and characteristics of the CBM exploitation in China were summarizedand the major technical problems of coal mine gas control and CBM exploitationanalyzed.It was emphasized that the CBM exploitation in China should adopt the coalmine gas drainage method coordinated with coal mine exploitation as the main model.Itwas proposed that coal mine gas control should be coordinated with coal mine gas exploitation.The technical countermeasure should be integrating the exploitation of coal andCBM and draining gas before coal mining.

Characteristics of mining gas channel expansion in the remote overlying strata and its control of gas flow

The technology of pressure relief gas drainage is one of the most effective and economic for preventing gas emissions in underground mines.Based on current understanding of strata breakage and fracture development in overlying strata,the current study divides the overlying strata into the following three longitudinal zones in terms of the state of gas flow:a turbulent channel zone,a transitional circulation channel zone and a seepage channel zone.According to the key strata discrimination theory of controlling the overlying strata,the calculation method establishes that the step-type expansion of the mining gas channel corresponds to the advancing distance of working face,and this research also confrms the expanding rule that the mining gas channel in overlying strata follows the advancing distance of mining working face.Based on the geological conditions of Xinjing Coal Mine of Yangquan,this paper researches the expanding rule of mining gas channel as well as the control action of the channel acting on the pressure relief flow under the condition of the remote protective layer,and got the distance using inversion that the step-type expanding of mining gas channel is corresponding to the advancing distance of working face,which verifes the accuracy and feasibility of theoretical calculation method proposed in this study.The research provides the theoretical basis for choosing the technology of pressure relief gas drainage and designing the parameters of construction.

Novel Oxygen Storage Components Promoted Palladium Catalysts for Emission Control in Natural Gas Powered Engines

A three-way catalyst comprised novel oxygen storage components for emission control in natural gas powered engines was prepared. The addition of novel oxygen storage components to the Pd/γ-Al2O3 catalysts resulted in improved activities of the fresh and aged catalyst by lowering the light-off temperature for methane in natural gas engines exhaust.

Gas dynamic control of properties of welded joints from high strength alloyed steels

Gas dynamic control in welding with consumable electrode in conditions of two-jet gas shielding and its impact on the processes in the welding area and properties of the welded joints from high strength alloyed steel 30HGSA is considered in the paper. The results of a comparative experimental study of controlling the properties of welded joints by changing the gas dynamics of the active shielding gas are given. The impact force of a shielding gas jet on the drop of the electrode metal is 12 times higher in conditions of two-jet gas shielding than in those of single jet shielding. It is found that gas dynamics of the active shielding gas jet determines the formation of the welded joints, their chemical properties and the properties of the welded joints from high strength alloyed steels. The consumable electrode welding method with two-jet gas shielding provides controlled dynamics in the welding area and allows controlling the transfer of the electrode metal, chemical composition of the weld, stabilizing the welding process, it ensures higher mechanical properties of the welded joints.

Foaming supramolecular surfactants for gas mobility control in naturally fractured carbonate reservoirs at high temperature,salinity,and hardness

Oil production and mainte nance are essential issues in naturally fractured reservoirs because they are the largest and most productive on earth.However,they present early water and gas channeling but could be remediated by using foaming agents to control these phenomena through blocking channeling areas.In Mexico these reservoirs have pressure up to 5,500 psi,high temperature up to 200℃,salinity up to400,000 ppm,and hardness up to 250,000 ppm;due to these thermodynamic conditions,there has been no available technology to form stable enough foams.In this work,a foaming supramolecular surfactant with the capability to chelate Ca^(2+)ions is examined.As a result,surfactant monomers are bridged by captured Ca^(2+)cations leading to the formation of high-molecular-weight oligomers,which significantly increment the viscosity of the solution improving the foam stability,and since at this manner the Ca2+cations are no longer available to precipitate as components of solid salts,the foaming supramolecular surfactant also performs as antiscalant.These observations are explained through quantum theoretical modeling.The foam is stable,effectively blocking the gas channels,whereas in presence of oil the foam is broken leading the oil to pass into the wellbore.The characteristic rheological properties of the foam allow its injection into the formation at a range of flow rates,foam qualities,and shear stress to achieve the flooding and the blocking of a variety of fractured carbonate formations,and the change of the wettability of the matrix,which is a desirable behavior in a huff and puff process,as reported in a previous publication about a successful pilot test of this foam.

Division of Gas Accumulation System and Laws Controlling Distribution of Natural Gas in Typical Petroliferous Basins of China

Considering the existing problems of the petroleum system, this paper bringsforward the concept of natural gas accumulation system and presents the dividing principles. Thendetailed statistics on the accumulation factors of the 32 typical natural gas accumulation systemsin China and studies on the laws controlling distribution of gas are collected. The research showsthat the petroleum accumulation system is the basic unit controlling petroleum generation, migrationand accumulation. Generating intensity, generating amount, accumulating efficiency and migrationdistance plays an important role in the distribution of natural gas. Through analysis on results ofresources evaluation, discovered reserves and residual reserves, potential areas in middle-scaledpetroliferous basins in China are forecasted in this paper. Ordos, Sichuan, Tarim and Qaidam basinsare found out to be the main basins developing and enriching gas accumulation systems.

Performance Enhancements in the EAST Digital Plasma Control System

The EAST plasma control system （PCS） is in continuous development to satisfy the EAST experimental requirements. In order to realize low latency and distortion-free signal transmission between PCS and servo systems such as the poloidal field power supply, in-vessel coil power supply and real-time scope, reflective memory boards （RFM） were applied. The new hardware layout and enhanced performance are reported. Newly implemented PCS control algorithms for gas control and real-time data display are also presented.

A new design of foam spray nozzle used for precise dust control in underground coal mines

In order to improve the utilization rate of foam,an arc jet nozzle was designed for precise dust control.Through theoretical analysis,the different demands of foam were compared amongst arc jets,flat jets and full cone jets when the dust source was covered identically by foam.It is proved that foam consumption was least when an arc jet was used.Foam production capability of an arc jet nozzle under different conditions was investigated through experiments.The results show that with the gas liquid ratio(GLR)increasing,the spray state of an arc jet nozzle presents successively water jet,foam jet and mist.Under a reasonable working condition range of foam production and a fixed GLR,foam production quantity increases at first,and then decreases with the increase of liquid supply quantity.When the inner diameter of the nozzle is 14 mm,the best GLR is 30 and the optimum liquid supply quantity is0.375 m^3/h.The results of field experiments show that the total dust and respirable dust suppression efficiency of arc jet nozzles is 85.8%and 82.6%respectively,which are 1.39 and 1.37 times higher than the full cone nozzles and 1.20 and 1.19 times higher than the fiat nozzles.

Running Control Mode for In-Duct FGD with No-Bypass Design

The desulfuration system in the second phase project of Sanhe Power Plant is the first such system that adopts in-duct FGD with no-bypass design by domestic power plants.Different from that of the conventional FGD with bypass design,a running control mode,which is important for the security of the absorbing tower within the designed ranges,shall be made to ensure the flue gas temperature and dust concentration at the inlet of the absorbing tower.The stable running of the system shows that the control mode is feasible.

Utilisation of transparent synthetic soil surrogates in geotechnical physical models: A review

Coal extraction in Huainan area is basically characterized by one of typical multi-seam mining conditions observed in China, where coal is mined in soft seams characterized by high gas content, high stress, low permeability and difficult geological conditions. The average mining depth in Huainan area is 875 m and continues to increase by 15-25 m annually. The rise in mining depth increases the risk of coal and gas outbursts and makes it more difficult to control outburst risk in Huainan coalmines. This paper reviews the main achievements（e.g. theories, technologies and equipment） in outburst control in Huainan, and tries to analyze some key challenging issues, and to present associated strategies to address these issues.It suggests that the outburst control in Huainan must take a combination approach of both regional and localized control in which the former plays a dominant role. Other outburst prevention principles include（1） non-outburst seams protecting outburst seams,（2） less outburst-prone seams protecting strong outburst-prone seams,（3） stress-releasing mining, and（4） the combination of ground and underground gas drainage（the model is dubbed as ＂walking on two legs＂）. The paper concludes that we should conduct fundamental researches on outburst mechanism, and develop outburst control technologies and equipment to ensure safe and efficient coal mining of deep coal resources in Huainan area.

The viability of using gasoline-integrated biodiesel-diesel mixtures in engines as a solution to greenhouse gas emissions:a review

The implementation of alternative fuels,such as biodiesel,in engines has been shown to be a feasible strategy to control greenhouse gas(GHG)emissions.The blending of biodiesel with diesel can reduce emissions of carbon monoxide(CO)and carbon dioxide and reduce soot formation.Nonetheless,biodiesel combustion comes with low thermal efficiency,elevated emissions of nitrogen oxides(NOx)and carbon deposition issues.Recently,the addition of gasoline to diesel-biodiesel blends has been proposed to compensate for the downsides of biodiesel combustion.In the current review,the viability of using this ternary fuel blend in engines is thoroughly reviewed.The review first assesses the environmental and health issues caused by conventional fuels,mitigation schemes to control GHG emissions and alternative fuels as a decarbonizing technology.The combustion and emissions characteristics of diesel-bio-diesel-gasoline mixtures are discussed in detail.Finally,the status,challenges and prospects of applying the alternative fuel mixture in engines are appraised.This work has revealed that the mixing of gasoline with diesel-biodiesel blends brings about elongated ignition delay,increased heat release rate and in-cylinder pressure at high loads.Additionally,by adding gasoline,the combustion duration is shortened and soot,CO and unburned hydrocarbon emissions are suppressed,while NOx emissions are slightly increased.Combustion stability is found to be partially disrupted in the presence of gasoline whereas fuel economy(at medium and high loads)is improved by the addition of gasoline.To support the wider deployment and commercialization of this fuelling strategy in the transportation sector,favourable legislation and/or fiscal incentives are needed in countries around the world.This would encourage researchers,fuel producers and engine manufacturers alike to solve challenges such as biodiesel feedstock costs,fuel quality,fuel storage management and engine warranty issues.

Fuel poverty and low carbon emissions: a comparative study of the feasibility of the hybrid renewable energy systems incorporating combined heat and power technology

Fuel poverty is most prevalent in North East England with 14.4%of fuel poor households in Newcastle upon Tyne.The aim of this paper was to identify a grid connected renewable energy system coupled with natural gas reciprocating combined heat and power unit,that is cost-effective and technically feasible with a potential to generate a profit from selling energy excess to the grid to help alleviate fuel poverty.The system was also aimed at low carbon emissions.Fourteen models were designed and optimized with the aid of the HOMER Pro software.Models were compared with respect to their economic,technical,and environmental performance.A solution was proposed where restrictions were placed on the size of renewable energy components.This configuration consists of 150 kW CHP,300 kW PV cells,and 30 kW wind turbines.The renewable fraction is 5.10%and the system yields a carbon saving of 7.9%in comparison with conventional systems.The initial capital investment is$1.24 million which enables the system to have grid sales of 582689 kWh/a.A conservative calculation determined that 40%of the sales can be used to reduce the energy cost of fuel poor households by$706 per annum.This solution has the potential to eliminate fuel poverty at the site analyzed.