Abstract: The general information and features of supercritical unit are illustrated. According to the engineering application situation, by comparing two feedforward methods, the new method application effect than classic control method, the response of unit’s load is much faster than before. It’s benefit to Automatic Generation Control (AGC). It’s hoped that the analysis and optimization can provide useful experience and lessons for the design of the supercritical boiler control to some extent.
Abstract: Investigation on the heat transfer and friction characters for fresh oil flowing inside three-dimensional internally finned tube (3-DIFT) was carried out with orthogonal experimental design method. Reynolds numbers varied from 30 to 800，Prandtl numbers 550 to 1000. The experimental results showed that low critical Reynolds numbers at the range of 100 to 200 were attained within all the experimental tubes, which indicated that 3-DIFT could obvious accelerate the transformation of high viscous fluid from laminar flow to turbulent flow. It offered a particular advantage to enhance the convective heat transfer of highly viscous fluid. Empirical equations on flow resistance and heat transfer were obtained using a least-squares regression. Compared with empty smooth tube, the maximal thermal performance factor for the turbulent flow within 3-DIFT could be enhanced up to 3.61. The optimization on shape of 3-DIFT for further augmentation heat transfer was also obtained.
Abstract: Hydrogen-air flame stability with different initial pressures is studied in a constant volume combustion cell. The schlieren flame images and the pressure curves are obtained under various initial pressures, equivalence ratios and initial temperatures. The results show that the time of the laminar flame stage is decreasing with the increasing initial pressure. The main reason of the rapid increasing pressure is whether the squish flame appears. The squish flame stage does not occur when the value of the initial pressure is very low. At this time, the varibility of the pressure is very low. The pressure oscillation occurs when the squish flame or the main flame transmits to the under wall surface. Meanwhile, under the different initial conditions, the time of the mixture combustion process stages is often different, and the flame stability is different. At the same time, the flame crtical radius is decreasing when the initial pressure is increasing.
Abstract: The microwave thermal conversion process of oil sludge was studied. It was found that the microwave thermal conversion process of oil sludge consisted of 5 stages: rapid heating, microwave drying, microwave hydrocarbons evaporation, microwave pyrolysis and microwave calcining. Using the residue produced from the microwave thermal treatment of oil sludge as a microwave absorbent can significantly accelerate the conversion. However, it does not show significant effect on the features of microwave thermal conversion. Meanwhile, the addition of residue at appropriate percentages increased oil recovery rate. The non-condensable gases consist of H2 and C1~C5 hydrocarbons. The recovered oil was mainly produced at microwave evaporation and microwave pyrolysis stages, consisting of 89% light oil and 11% heavy oil.
Abstract: The combustion efficiency and the gaseous emission of a 100 kWe MGT, designed for working with natural gas but fuelled with blends containing up to 10% of hydrogen is investigated. A critical comparison between experimental data and results of the CFD analysis of the combustor is discussed. The k-epsilon RANS turbulence model and the Finite Rate – Eddy Dissipation combustion model were used in the numerical computations. The chemical kinetic mechanisms embedded were the 2-step Westbrook and Dryer for methane oxidation, 1-step Westbrook and Dryer for hydrogen oxidation and the Zeldovich mechanism for NO formation. The experimental data and numerical computations are in agreement within the experimental accuracy for NO emissions. Regarding CO, there is a significant deviation between experimental and computational data due to the scarce predictive capability of the simple two steps kinetic mechanism was adopted. From a practical point of view, the possibility of using fuels with a similar Wobbe index was confirmed. In particular the addiction of 10 % of hydrogen to pure methane doesn’t affect the behavior of the micro gas turbine either in terms of NO or CO emissions.
Abstract: Looking into the future of aviation for commercial aircrafts there are various viable options for engine and associated propulsion technologies. The team had to eliminate some of the possible solutions. Superconducting electric motors were alleviated considering weight factors and lack of technology readiness to fly long range commercial jets. Even prop-fans were eliminated considering its limitation on stalling speed of fan and higher noise levels. To avoid such problems we went ahead with an integrated Turbofan engine.
Abstract: Several cracks were found on some actual floating roofs of a crude oil tank in the oil refinery located in southern Japan. We assumed that one of reasons would be due to thermal stress caused by temperature changes during the day. In order to consider whether the thermal stress could the cause damages on the floating roof, strain and temperature were measured on the actual floating roof by using optical fiber gauges. Furthermore, thermal stress analysis was carried out as effective analysis.
Abstract: To investigate the effect of laminar cooling parameters on temperature field and heat transfer coefficient, an experiment platform for analyzing laminar cooling is designed and made by the author. Making use of the equipment, the cooling experiments with the various cooling conditions have been carried. Based on the experimental results, the effects of different water flows and water temperature on cooling rate are presented in this study. And it can be found that adding impurities into cooling medium is an effective way to improving the cooling rate. The research achievements have a certain reference value for setting parameters in laminar cooling process of heavy plate.
Abstract: To make the treatment of seafood wastewater more economical and sustainable, this study aims to examine electricity generation from seafood wastewater in MFC reactor. By supplying the MFCs with seafood wastewater, the maximum power density of 291.6 mW/m2 and CE of 20.3 % could be obtained. The substrate loss was attributed to diffusion of molecular oxygen from the cathode to the anode, which led to substrate conversion through aerobic respiration rather than electricity-producing pathway. This study provides a conceptual demonstration of seafood wastewater for electricity production using MFC technology.
Abstract: This study is aimed at carrying out a finite element analysis on a roll cage of a vehicle used for student competitions around the world. The design process was carried out using a CAD package and analysis was done using finite element analysis software, ANSYS. Impact test was carried out on the roll cage under different conditions and the effect on the structural members are studied and discussed. The results are very much helpful and assure that the car is in safe condition in case of a crash or accident. Finite Element Analysis (FEA) is also carried out with the frame against torsional loading. Two different materials were considered for the analysis. The results of displacement of frame, nodal solution, element solution and bending moment are discussed.