600mm厚料层操作制度的确立与工艺参数优化

通过对 6 0 0 mm厚料层生产工艺参数优化过程进行分析探讨后指出 :烧结矿中 Fe O含量不是对铁酸钙含量和形状产生影响的惟一因素 (碱度与原料条件不变 ) ,混合料水分的大小同样可以影响铁酸钙的含量和形状 ,而水分的大小及稳定程度又受热返矿量的大小和波动范围的制约 ,所以要达到理想的铁酸钙含量和形状 ,不仅要注意控制 Fe O含量 ,更要注意控制混合料水分和热返矿含量。

A method for predicting in-cylinder compound combustion emissions

This paper presents a method using a large steady state engine operation data matrix to provide necessary information for successfully training a predictive network, while at the same time eliminating errors produced by the dispersive effects of the emissions measurement system. The steady state training conditions of compound fuel allow for the correlation of time averaged in cylinder combustion variables to the engine out NO x and HC emissions. The error back propagation neural network (EBP) is then capable of learning the relationships between these variables and the measured gaseous emissions, and then interpolating between steady state points in the matrix. This method for NO x and HC has been proved highly successful.

Low Steam Condition Heat Generator Combined with Advanced Oxy-Fuel Combustion LNG Gas Turbine for Power Generation

We propose a novel concept for power generation that involves the combination of a LSCHG （low-steam-condition heat generator）, such as a light water nuclear reactor or a biomass combustion boiler, with an advanced closed-cycle oxy-fuel combustion gas turbine-a type of complex and efficient oxy-fuel gas turbine. In this study, a LSCHG is designed to heat water to saturated steam of a few MPa, to assist in the generation of the main working fluids, instead of a compressor used in the advanced oxy-fuel gas turbine. This saturated steam can have a lower pressure and temperature than those of an existing nuclear power plant or biomass-fired power plant. We estimated plant performances in LHV （lower heating value） basis from a heat balance model based on a conceptual design of a plant for different gas turbine inlet pressures and temperatures of 1,300 ℃ and 1,500 ℃, taking into account the work to produce O2 and capture CO2. While the net power generating efficiencies of a reference plant are estimated to be about 52.0% and 56.0% at 1,300 ℃ and 1,500 ℃, respectively, and conventional LSCHG power plant is assumed to have an efficiency of about 35% or less for pressures of 2.5-6.5 MPa, the proposed hybrid plant achieved 42.8%-44.7% at 1,300 ℃ and 47.8%-49.2% at 1,500 ℃. In the proposed plant, even supposing that the generating efficiency of the LNG system in the proposed plant remains equal to that of the reference plant, the efficiency of LSCHG system can be estimated 37.4% for 6.5 MPa and 33.2% for 2.5 MPa, even though the LSHCG system may be regarded as consisting of fewer plant facilities than a conventional LSCHG power plant.

The experimental study on combustion characteristics and emissions of a CMM fueled engine

In this paper, an experimental study on combustion characteristics and emissions of a single cylinder spark ignition engine fueled with coal-mine methane （CMM） is investigated under various loads. CMM is simulated by the compressed nature gas（ CNG）/nitrogen blend fuels. Based on experiment results, it is shown that under 0% - 35% nitrogen volume fraction in CNG/nitrogen blends, the maximum cylinder pressure, the maximum rate of pressure rise and the rate of heat release decrease, the flame propagation period increases, the center of heat release curve is closed to the top dead centre （TDC）markedly with the increase of nitrogen volume fraction. Meanwhile, the hydrocarbon （HC）, CO emissions increase, the NOx emission decreases apparently with the increase of nitrogen volume fraction.

Knock prediction for dual fuel engines by using a simplified combustion model

The present work used a methane-air mixture chemical kinetics scheme consisting of 119 elementary reaction steps and 41 chemical species to develop a simplified combustion model for prediction of the knock in dual fuel engines. Calculated values by the model for natural gas operation showed good agreement with corresponding experimental values over a broad range of operating conditions.

Effect of optimal aging treatment on magnetic performance and mechanical properties of sintered Nd-Fe-B permanent magnets

The magnetic performance and mechanical properties including hardness, brittleness, fracture toughness and strength characteristics of the as-sintered and the optimal aged Nd-Fe-B magnets were examined in this work. A new method of Vickers hardness indentation combined with acoustic emission was used to test the brittleness of the magnets.The results show that the magnetic properties of the magnets could be improved through aging treatment, especially the intrinsic coercive force. But it is accompanied by a decrease of strength and fracture toughness. Theoretical calculation confirms that acoustic emission energy accumulated count value could be used to characterize the material brittleness. The bending fracture morphologies of the as-sintered and the optimal aged Nd Fe B magnets were investigated with the emphasis on the relationship between mechanical properties and microstructure using a field emission scanning electron microscopy(FE-SEM). The research results indicate that the intergranular fracture is the primary fracture mechanism for both as-sintered and optimal aged Nd Fe B magnets. Aging treatment changes the morphology and distribution of the Nd-rich phases, reducing the sliding resistance between Nd_2Fe_(14)B main crystal grains and lowers the grain boundary strength, which is the main reason for the strength and fracture toughness decrease of the aged Nd-Fe-B magnets.

Investigation on Emission and Combustion with 100% Palm Kernel Methyl Ester as Fuel on VCR-DI-Diesel Engine

Methyl or ethyl esters of vegetable oils are the reliable alternative fuels for the petroleum diesel, because their properties are very nearer to the petroleum diesel. But the flash point and auto-ignition temperatures are very high for these esters. CR （compression ratio） is one of the parameter which influences the atomization and vaporization of fuel. It is also caused for improvement in the turbulence which leads to better combustion. In this work the single cylinder diesel engine was tested at different compression ratios i.e. 16.5：1, 17.5：1, 18.5：1, 19：1 with palm kernel methyl ester without modifications. On increasing compression ratio closeness of molecules of air increases and fuel is injected into that air caused for better combustion. The inbuilt oxygen of methyl or ethyl ester will participate in the combustion and causes for reduction of HC and CO. Better compression ratio for an engine with particular fuel provides satisfactory thermal efficiency and less environmental pollution. In the investigations, for palm kernel methyl ester, 18.5：1 compression ratio is preferable on single cylinder Dl-diesel engine.

The global oxygen budget and its future projection

Atmospheric oxygen （02） is the most crucial element on earth for the aerobic organisms that depend on it to release energy from carbon-based macromolecules. This is the first study to systematically analyze the global O2 budget and its changes over the past 100 years. It is found that anthropogenic fossil fuel combustion is the largest contributor to the current O2 deficit, which consumed 2.0 Gt/a in 1900 and has increased to 38.2 Gt/a by 2015. Under the Representative Concentration Pathways （RCPs） RCP8,5 scenario, approximately 100Gt （gigatonnes） of O2 would be removed from the atmosphere per year until 2100, and the O2 concentration will decrease from its current level of 20.946% to 20.825%. Human activities have caused irreversible decline of atmospheric O2. It is time to take actions to promote O2 production and reduce O2 consumption.

Effect of electrolyzed oxidizing water and hydrocolloid occlusive dressings on excised burn-wounds in rats

Objective: To study the efficacy of electrolyzed oxidizing water ( EOW ) and hydrocolloid occlusive dressings in the acceleration of epithelialization in excised burn-wounds in rats.Methods: Each of the anesthetized Sprague-Dawley rats (n = 28) was subjected to a third-degree burn that covered approximately 10% of the total body surface area. Rats were assigned into four groups: Group Ⅰ ( no irrigation), Group Ⅱ (irrigation with physiologic saline), Group Ⅲ ( irrigation with EOW ) and Group Ⅳ ( hydrocolloid occlusive dressing after EOW irrigation). Wounds were observed macroscopically until complete epithelialization was present, then the epithelialized wounds were examined microscopically. Results: Healing of the burn wounds was the fastest in Group Ⅳ treated with hydrocolloid occlusive dressing together with EOW. Although extensive regenerative epidermis was seen in each Group, the proliferations of lymphocytes and macrophages associated with dense collagen deposition were more extensive in Group Ⅱ, Ⅲ and IV than in Group Ⅰ. These findings were particularly evident in Group Ⅲ and Ⅳ.Conclusions: Wound Healing may be accelerated by applying a hydrocolloid occlusive dressing on burn surfaces after they are cleaned with EOW.

Average Droplet Diameter Measurement and Results for Fuel Aerosol Injected by Certain Types of the Turbojet Burners

Measurement of the diameter of the fuel aerosol droplet is very important in the design of new type burners and in diagnostic process. Diffraction method is one of the most useful measuring procedures in this case. An investigation setup is presented enabling the determination of the substituting drop diameter in fuel aerosol stream created by aeroengine injectors. The results obtained for K 108-767, K 108-012, 37.03.9595, 16.83.0310 types are presented.

In-situ characterization of metal nanoparticles and their organic coatings using laser-vaporization aerosol mass spectrometry

The development of methods to produce nanoparticles with unique properties via the aerosol route is progressing rapidly. Typical characterization techniques extract particles from the synthesis process for subsequent offiine analysis, which may alter the particle characteristics. In this work, we use laser-vaporization aerosol mass spectrometry （LV-AMS） with 70-eV electron ionization for real-time, in-situ nanoparticle characterization. The particle characteristics are examined for various aerosol synthesis methods, degrees of sintering, and for controlled condensation of organic material to simulate surface coating/functionalization. The LV-AMS is used to characterize several types of metal nanoparticles （Ag, Au, Pd, PdAg, Fe, Ni, and Cu）. The degree of oxidation of the Fe and Ni nanoparticles is found to increase with increased sintering temperature, while the surface organic-impurity content of the metal particles decreases with increased sintering temperature. For aggregate metal particles, the organic-impurity content is found to be similar to that of a monolayer. By comparing different equivalent-diameter measurements, we demonstrate that the LV-AMS can be used in tandem with a differential mobility analyzer to determine the compactness of synthesized metal particles, both during sintering and during material addition for surface functionalization. Further, materials supplied to the particle production line downstream of the particle generators are found to reach the generators as contaminants. The capacity for such in-situ observations is important, as it facilitates rapid response to undesired behavior within the particle production process. This study demonstrates the utility of real-time, in-situ aerosol mass spectrometric measurements to characterize metal nanoparticles obtained directly from the synthesis process line, including their chemical composition, shape, and contamination, providing the potential for effective optimization of process operating parameters.

System Design and Analysis of Hydrocarbon Scramjet with Regeneration Cooling and Expansion Cycle

A new expansion cycle scheme of the scramjet engine system including a hydrocarbon-fuel-based(kerosene)regenerative cooling system and supercritical/cracking kerosene-based turbo-pump was proposed in this paper.In this cycle scbeme,the supercritical/cracking kerosene with high pressure and high temperature is formed through the cooling channel.And then,in order to make better use of the high energy of the supercritical/cracking fuel,the supercritical/cracking kerosene fuel was used to drive the turbo-pump to obtain a high pressure of the cold kerosene fuel at the entrance of the cooling channel.In the end,the supercritical/cracking kerosene from the turbine exit is injected into the scramjet combustor.Such supercritical/cracking kerosene fuel can decrease the fuel-air mixing length and increase the combustion efficiency,due to the gas state and low molecular weight of the cracking fuel.In order to ignite the cold kerosene in the start-up stage,the ethylene-assisted ignition subsystem was applied.In the present paper,operating modes and characteristics of the expansion cycle system are first described.And then,the overall design of the system and the characterisitics of the start-up process are analyzed numerically to investigate effects of the system parameters on the scramjet start-up performance.The results show that the expansion cycle system proposed in this paper can work well under typical conditions.The research work in this paper can help to make a solid foundation for the research on the coupling characteristics between the dynamics and thermodynamics of the scramjet expansion cycle system.