Evaluating the behavior of catalyst coated nut-coke in blast furnace conditions

For efficient blast furnace ironmaking, it is desired to have low reducing agent rate, primarily coke rate. Developing technology to improve reaction efficiency of the blast furnace is extremely important as it has the potential to allow a decrease in the reducing agent rate as well as CO2 emissions. The reaction efficiency of blast furnace can be improved by lowering the Thermal Reserve Zone (TRZ) temperature; which is also the starting temperature of coke gasification reaction. In present study, nut-coke has been coated with in-plant waste, consisting mainly of iron oxide and calcium oxide, as catalyst. There was a clear increase of 10 points in the reactivity of coated nut-coke. The coated nut-coke have been subjected to non-standard high temperature experiments simulating blast furnace conditions with reducing gas consisting of CO, CO2 and N2 to capture the effect of catalytic coating on the onset of gasification reaction. The high temperature experiments carried out advise the following: i) A drop of 100 °C in the reaction beginning temperature of catalyst coated nut-coke as compared to non-coated one ii) A typical calculation shows that the lowering of reaction beginning temperature corresponds to a potential carbon rate savings of about 2.5 kg/ton of hot metal (thm). Furthermore, in a trial conducted at blast furnace with charging catalyst coated nut-coke, it has been observed that the carbon rate during the trial period was 3 kg/thm lower than the base period. The findings of blast furnace trial agree with that of the experimental one.

The development of the modeling of the BHA for directional drilling

The article discusses the development of technology for directional drilling of oil and gas wells in the perspective of modeling downhole operations. The most significant mathematical models developed by Soviet and foreign scientists in the XX century are listed. An example of calculating the reaction on a bit based on the most widely used method of initial parameters is shown. In the process of a typical calculation of the deflecting force on the bit, it was possible to set the boundary conditions on the bottom hole assembly (BHA) supports in a natural form, using a well-known approach for calculating the deflection of the beam. The obtained results of calculations were applied in the construction of a simulation model for computer simulation based on a virtual program-simulator of the drilling directional wells. The simulating software allowed us to evaluate the effect of the Zenith angle of the well and the rigidity of the oriented layout on the deflecting force on the bit, the deflection of the turbo drill along the length from the bit to the nearest lower point of contact of the well wall.

Bearing Power Losses with Water-Containing Gear Fluids

Lubricants have a large influence on gearbox power losses. Recent investigations at a gear efficiency test rig have shown the high potential of water-containing gear fluids in drastically reducing load-dependent gear losses and temperatures. In this study, the bearing power losses with water-containing gear fluids were evaluated at a specific bearing power loss test rig explicitly and compared with mineral and polyalphaolefine oils. For all investigated lubricants, a Stribeck curve behavior of the load-dependent losses is observed. The water-containing gear fluids demonstrate lower no-load bearing losses and higher load-dependent bearing losses at higher rotational speeds. The comparison of measured bearing losses with typical calculation procedures showe partially large differences. The results underline the importance of having detailed knowledge of bearing losses when evaluating gear losses in gearboxes.

The method of assessment and formation the availability of the subsystem ensuring fitness for means of transport

In systems of means of transport operation in order to achieve appropriate completion of assigned transportation tasks it is necessary to maintain a required number of means of transport in the state of availability for carrying out of transportation task (roadworthy and stocked). In general, the processes of rendering vehicles roadworthy are connected to supplying them with fuel and operational materials, carrying out services and repairs, condition diagnostics. In the analyzed system of transport means operation, the processes are carried out in serviceability assurance subsystem SAS. In complex operation systems, the processes of rendering technical objects roadworthy are carried out at specifically designed technical infrastructure posts. The possibility of carrying out the assigned service and repair tasks depends on the availability and the number of such posts. The article presents the method of defining the operational availability and the number of technical infrastructure posts required for appropriate functioning of assigned service and repair task. Then typical calculation results are presented in charts prepared on the basis of data obtained from tests at existing transport means operation system.

Analysis and Study of Heat Transfer Resistance Inside and Outside the Reentry Capsule

According to the heat transfer characteristics inside and outside of the lunar-earth high-speed reentry capsule, a typical calculation model of heat conduction in external thermal protection system(TPS) coupled with internal radiation was established. The thermal properties of thermal resistance inside and outside the reentry capsule were analysed. The effects of thickness of the TPS, surface conditions and atmospheric pressures on the temperature were further explored. The results showed that atmosphere pressure was necessary to be controlled under 10Pa to ensure the safety temperature of the equipment and pipe. Based on the critical pressure, the configuration was optimized. The results provide detailed data for the system design of the lunar exploration, and also provide a reference for the thermal design of the atmospheric reentry spacecraft.

Method of Determining the Required Number of Technical Backup Area Posts

In complex operation systems, the processes of rendering technical objects roadworthy are carried out at specifically designed technical backup area posts. The article presents the method of defining the number of technical backup area posts required for appropriate functioning of assigned service and repair task. Then typical calculation results are presented in charts prepared on the basis of data obtained from tests at existing transport means operation system. The presented method makes it possible to analogically determine the minimum required number of posts for carrying out the assigned service and repair task for both a subsystem comprised of a group of units a given group of posts or an individual post in traffic maintenance and intervention subsystems.

New ART2/ART2A Algorithm Apply to Entire Real Number Field

In this paper, two shortcomings of standard ART2/ART2A algorithm were revealed through theoretical analysis: (1)Standard ART2/ART2A algorithm is only suitable for the case in the nonnegative real number field because of a limit of pretreating process in F1layer; (2)Even through all input patterns are shifted to the nonnegative real number field through coordinate transformation, the standard ART2/ART2A algorithm can not correctly recognize those patterns which have same phase, but different amplitudes. As a result, the standard ART2/ART2A algorithm is not quite suitable for universal pattern recognition. So this paper presented a new nonlinear transforming function in F1layer and a new competitive learning formula in F2layer for traditional ART2/ART2A algorithm. The applicable scope of the new ART2/ART2A algorithm is expanded to entire real number field from nonnegative real number field. The result of typical calculation example shows that the presented algorithm is effective.

Thermodynamic Performance Analyses of Mixed Gas-Steam Cycle (2): A Case Study of Aeroderivative Gas Turbine

There are a plenty of proposals to aim the gas turbine cycle thermal efficiency of 60%, such as “Steam-Cooled H-Tech. Combined Cycle”, “Methanol Conversion Regenerative Gas Turbine”, “Kalina Cycle” etc.*1, *2, *4, *5, *6, *7 This paper discusses the predicted performance behaviors of an assumed aircraft-derivative GT of 60MW, when applying into mixed gas-steam cycles like STIG, ISTIG(Intercooled Steam Injection GT) with reasonable minor modifications from the assumed gas turbine. By making case studies of steam-injected binary cycles according to the established analyses method in Part (1), typical calculation results for getting 60% efficiency are presented. The water-injected at LPC, ISTIG cycle is equivalent or superior to other improvement ideas, offering several features listed below. 1) Unnecessary to have a bottoming cycle, saving a lot of investment for the related equipment 2) Quick and stable response for changing duty load, by injecting metered water and steam without air holding vessels like water-cooled heat exchangers

A new analysis of recuperative gas turbine cycles

It is shown that the classical recuperator effectiveness is not an appropriate evaluation criterion for the gas turbine recuperator or a suitable independent thermodynamic parameter of the recuperative gas turbine cycle. Another parameter—the average heat transfer temperature difference in the recuperator—is recommended as the new criterion instead of the recuperator effectiveness. Therefore, the original classical analysis results of the recuperative gas turbine cycle are also inappropriate and it is necessary to give a new analysis. In this paper, the analytical expressions of the simple recuperative cycle efficiency and the optimum pressure ratio based on the new criterion are derived from general simplified assumptions. Some typical calculation results are also presented. With this new criterion, the optimum pressure ratio values for efficiency of a simple recuperative gas turbine cycle do not vary very much with the temperature ratio and are approximately equal to 3, much lower than the figures generally recognized before. A similar analysis for the recuperative gas turbine cycle with intercooler and reheater and an analysis ensuring approximately constant recuperator heat transfer area per unit power output are given also.