Papers by Keyword: Mass Balance

Abstract: In this article, the mass and heat balance calculations of underground coal gasification process for thin coal seams in faulting zones of Lvivskyi coal basin (Ukraine) are defined. The purpose of the research is to establish regularities of heat and mass balance changes in faulting zones influence due to usage air and oxygen-enriched blast. A comprehensive methodology that included analytical calculations is implemented in the work. The output parameters of coal gasification products for the Lvivvyhillia coal mines are detailed. The heat balance is performed on the basis of the mass balance of underground coal gasification analytical results and is described in detail. Interpretations based on the conducted research and investigation are also presented. Conclusions regarding the implementation of the offered method are made on the basis of undertaken investigations. According to conducted research the technology of underground coal gasification can be carry out in the faulting zone of stable geodynamic and tectonic activity. The obtained results with sufficient accuracy in practical application will allow consume coal reserves in the faulting zones using environmentally friendly conversion technology to obtain power and chemical generator gas, chemicals and heat.

Abstract: The closed bay formed by a tidal power plant on the west coast of Korea has caused water quality to change due to nutrient increase and salinity alternation. The nutrients of the inner bay are often kept a balance with the aid of the outflow at the mouth of the bay. Hence it is necessary to minimize the environmental effects by forecasting the potential environmental changes caused by a tidal power construction. Seasonal observations of mass balance in the inner and outer Garolim Bay were performed. The low quality nutrients released from sediments, land and river were more dominant than the nutrients released from the outer bay in the study area. It was observed that the tidal power plant construction made water exchange ratio 57%.Various mitigation strategies such as water gates were studied so that the water exchange rate can be reduced. The change in the water exchange ratio is significantly reduced as the cross-section and the number of water gates is increased. The water exchange ratio was decreased by 8%, which increased nutrients in the inner bay. Results of numerical the nutrients decreased with the 7% increase in the inflow while the decrease in outflow discharges. However, it is considered only 0.2% increase in the entire mass balance of Garolim Bay relatively inadequate to mitigate the environmental impact.

Abstract: The common mass balance has limited use in any gravitational condition. In this paper, we describe the simple design of a mass balance which is independent to the gravitational condition. Based on the Hookes Law, the balance is constructed by attaching the object being measured in the middle of two fixed end springs. The mass of the object is deducted from the frequency of the mechanical oscillation of the object. The performance of mass balance has been tested using four different mass loads (ranging from 15.28 g to 27.50 g) in three different gravitational conditions (0G, 1G and 2G) during parabolic flight. Our field testing resulted in the independency of the oscillation frequency of the mass on the gravitational conditions.

Abstract: The problems of computer model simulation of CаO-SiO2-Al2O3 system are considered. The crystallization scheme and sets of microstructure elements are analyzed for the fields of liquidus CaO, 3CaO*SiO2, 3CaO*Al2O3. The concentration fields both with individual set of microstructure elements and the fields without the unique crystallization scheme and microstructure set were found. The crystallization stages for given compositions are illustrated by the mass balance diagrams.

Abstract: Taking Sebei gas field as an example, this paper sorts hydrostatic pressure test data over the years and summarizes the reasons that the formation pressure drop curve generates a straight line, up-warping and recurvation from the perspective of water invasion, perforation adding, layer adjusting, sand burying, and sand control as well as inter-layer interference and inter-well interference, with typical wells analyzed and explained. On this basis, two kinds of mass balance correction models which have taken the offset of the pressure drop curve into account are proposed to calculate the dynamic reserves of gas wells with different offset shapes of pressure drop curves. Practical result shows the simple concept and strong practicality of this method, which provides an effective method for the accurate calculation of dynamic reserves of such gas reservoir.

Abstract: Fate of mercury (Hg) in a modern sanitary municipal solid waste (MSW) landfill in Guiyang, China was investigated to assess the potential lost of Hg to ambient environment through different pathways. Mercury content in MSW, leachate, and mercury airborne emission rate through the surface and the vent pipe system were determined. A mass balance calculation showed that, roughly 0.67% of Hg entered into the landfill each year was lost into the surrounding environment, which was dominated by the pathway of working face (98.47%), then soil covers (1.28%), leachate (0.22%) and landfill gas vent pipes (0.03%).

Abstract: Mercury distribution and stable isotope composition in solid samples of two coal-fired power plants in Guizhou province were determined. Results shown electrostatic precipitator (ESP) has mercury removal efficiency between 29.53% to 58.41%, and wet flue gas desulfurization (WFGD) between 12.29% to 58.60%, mercury removal efficiency of ESP and WFGD mainly depends on the coal properties. Most mercury (70% to 88%) in coal was captured by the combination of ESP+WFGD. Mercury in fly ash and gypsum were much heavier in isotope composition compared to the coal, hints mercury escaped into atmosphere was enriched in lighter mercury isotopes.

Abstract: Caragana Korshinskii Kom is a widely grown deciduous shrub in the region of inner magnolia. A full utilization of its useful components holds great potential for cellulosic ethanol production in an efficient and economic way. The remaining residues after protein extraction contain 29.02% cellulose and 19.61% hemicellulose, offers a potential feedstock for cellulosic ethanol production. Fermentable capability of hydrolysate derived from pretreated biomass is strongly dependent on pretreatment methods. In this work, three hydrolysis methods (alkaline hydrolysis, acid hydrolysis and acid-alkali hydrolysis) were compared by its digestibility. Alkali pretreatment could help greatly to cellulose degradation. The conversion percentage of cellulose and hemicellulose was increased to 1.43% and 13.01%, respectively. Without any nutrient addition, hydrolysate from alkaline pretreated biomass showed relative fermentable capability by Candida Tropicalis with a final ethanol concentration of 5.4 g/L. A mass balance of the whole process integrating protein extraction and cellulosic ethanol production indicated that 1000kg C. Korshinskii Kom leaves will produce 154 kg crude proteins, and the residues will produce 18 kg ethanol.

Abstract: Based on the absorption principle of desulfurization process by sodium-calcium dual-alkali scrubbing method, the paper researches the computational model of gas balance, seriflux balance, and the circulating amount of seriflux, defines the equivalent relation between the data input and output, and develops a mass balance calculation software by Visual Basic 6.0. The software can be used for designing and equipment-selecting by employing the outcome of the computation. It can also do optimization and analysis of operation parameter. From the economic point of view, it is convenient for designers to choose the optimization parameter.

Abstract: The determination of a spacecraft’s mass properties is critical during its conceptual design phase. Obtaining reliable mass property information, early in the design of a spacecraft, could prevent design mistakes that can be extremely costly in the development process. The process of the determination of the mass properties consist in a systematic work, that include the taking part of all the sub systems or design teams that conforms the preliminary tasks for the design of the communications satellite. The VX-SAT project is a system engineering exercise, realized in the China Academy of Space Technology (CAST) like training for the future designs in communication satellites for the Bolivarian Agency of Space Activities (ABAE) in Venezuela. This paper aim to show an analysis of the procedures in the calculation of the mass properties in communication satellite using suitable software’s and the importance of the process to collect the mass budget information to get the more reliable results. Also includes an overview of the VX-SAT system, the preliminary design of the structure requirements and finally the methods used to the analysis of the general determination of the mass properties with its results.