Advanced Materials Research Vols. 805-806

Abstract: The gathering system for peripheral pattern in oil field, some wells must be shutdown because of the high backpressure of well, which due to the influence of pipe deformation, blockage, wax precipitation, water volume, crude oil physical property, scale deposit and so on. There in no report about the diagnosis method of reason for high backpressure. This paper defined the wells position in the peripheral pattern by means of the diagnosis method that is node point pressure-temperature method. It can judge if there is block up in pipeline by pressure drop per hectometer of water, and also if the designed pipe standard can match the operating conditions. The diagnose methods proposed can make sure the reasons of well high backpressure, then, the resolve schemes can be obtained.

Abstract: Based on the Structure and wind load force characteristics of the vehicle mounted extensible mast system, a test method for the wind load simulation of the system was designed. According to the thin wall part structural feature, a method that adding lateral tension at the flanges of the mast was used to simulate wind load. Calculation method of the theoretical wind load force was given, and the transformation formulas between loading force needed and theoretical wind force was put forward, as well the control method of the test based on PID control algorithm was described. Simulation of the force condition under trapezoidal load was given by ANSYS. The results showed that using the load scheme designed, the distribution of stress and strain was almost the same as continuous load, as well as the value and position of the maximum stress and strain.

Abstract: Mainly introduce MP424 high-speed data acquisition system and realize data acquisition, processing and display by way of compiling corresponding upper computer software with LabVIEW software. Acquire spark advance angle and fuel injection advance angle signals and compare with experimental model further. The results present that this data acquisition system is feasible.

Abstract: We accomplished a study on variation of tooth body stresses under three various pitch conditions in thread meshing connection, but also analyzed the effects of pitch variations on the stress distribution of the whole connecting thread. The results show that variable-pitch connection can effectively improve the uniform bearing capacity of tooth bodies and the overall bearing capacity of connecting thread, which is of great value for the improvement and optimization of structure design of threaded casing.

Abstract: Taking a small diesel engine as the prototype, emission researches for its structural features and different uses are carried out. Obvious differences of emissions for the same diesel engine using different test cycles are shown. By analyzing the test result, it has been found that the weighting factor of each mode is only part of the factors for the large differences of the emission values. The contributions of individual modes are used to analyze the mechanism of changing emissions of the diesel engine and it is found that reducing NO_X of the full load for the mobile non-road diesel engine is the key to reach emission standard; for the fixed diesel engine, CO emission must be controlled at the same time. It has been found that it is necessary to take different combustion optimization parameters or measures to reduce the emission of the diesel engine according to the different uses of small diesel engine engines.

Abstract: Three-dimensional numerical study is performed for heat transfer and resistance characteristics as well as comprehensive performance of two kinds H-type (single and double) finned tube. It is found that the heat transfer and resistance characteristics as well as comprehensive performance of H-type finned tube are influenced by the Reynolds number of gas. With the growth of Reynolds number, the air-side Nusselt number rises gradually and the heat transfer performance gets better and better, whereas the air-side Euler number drops step by step until close to a fixed value. The comprehensive performances of both single H-type finned tube and double ones are weaken progressively. When Reynolds number value is same, the convective heat transfer, pressure drop, air-side Nusselt number and Euler number of single H-type finned tube are bigger than those of double ones. The single H-type finned tube expression is much better than double ones in comprehensive performance and heat transfer.

Abstract: High pressure (HP) fuel pipeline is one of the major components of Combination Electronic Unit Pump (CEUP) diesel fuel injection system and has significant contribution in building up of high pressure required during fuel injection cycle. A MATLAB numerical model of pressure wave inside HP fuel pipeline of CEUP system using damped wave equation has been developed in MATLAB to study and simulate pressure wave propagation through fuel pipeline at various operating conditions of diesel engine. Finite Difference method has been applied to model and simulate pressure equation at various equidistant locations of fuel pipeline. Dynamic variations of fuel properties as a function of varying pressure have also been incorporated. The MATLAB model has been validated by comparing simulated pressures with those of experimentally validated AMESim numerical model of CEUP fuel injection system. Quantitative comparisons were also done using Root Mean Square Error (RMSE) and Index of Agreement (IA). Results show that MATLAB numerical model is quite accurate especially at low cam rotational speeds and low cam angles.

Abstract: To improve fuel economy, an Organic Rankine Cycle (ORC) system is proposed to recover waste heat from heavy-duty diesel engines. R123 and R245fa were selected as working fluids. Extensive numerical simulations were conducted to find thermal efficiency of the system under different evaporation pressures, mass flow rates of working fluids and temperature of engine exhaust gases. Results show that the system thermal efficiency was increased with the increase in evaporation pressure for both R123 and R245fa. Efficiency of R123 system was found to be greater than that of R245fa system. For Rankine cycle with both R123 and R245fa, mass flow rate range varied with the evaporation pressure. Limited by evaporation rates and thermal decomposition of the working fluid, the range of mass flow rates in R245fa system was narrower than the R123 system. The thermal efficiency with different temperatures of engine exhaust gases was similar under the fixed evaporation pressure.

Abstract: Based on the heat-transfer principle of air pre-heater, the influence mode of the changes of the air flow, the flue gas flow, the air leakage in different locations, to the temperature of the hot air and the exhausting gas was researched. The problem of a pulverized coal fired boiler, No.2, of a Thermal Power Plant, which the deviation of exhausting flue gas temperature increased to an abnormal extend when the boiler load rise up quickly was analyzed, the fault position and fault reason were located exactly, and the fault was eradicated by equipment maintenance at last. The results of this study have a certain significance to solve similar problems.

Abstract: Experimental study on the catalytic activity of Cu&Fe molecular sieve catalyst with different N_SR on NOx conversion efficiency, and explore the influence of temperature and airspeed to ammonia storage characteristics, analysis the relationship between the ammonia storage amount and the NOx conversion efficiency. The experimental result shows that: The catalytic activity can be more than 90% when the catalyst at 300°C-400°C, and an appropriate increase in N_SR can improve the NOx conversion efficiency. The influence of temperature on the characteristics of the reservoir ammonia greater than the airspeed, At 200°C-250°C, the NOx conversion efficiency and the amount of ammonia storage linear relationship. Use dynamic variable gain feedback control SCR system urea injection system, which effectively control the ammonia leak to make it satisfy China-V emission regulations.