Advanced Materials Research Vols. 805-806

Abstract: The vivid expression of entity models in the virtual circumstance is directly related to the facticity and immersion of the virtual environment. To build the virtual maintenance training system for Cummins M11 diesel engine, this paper primarily designed the functions of the system, studied the constructing and optimizing techniques of 3D models. Using EON platform, these 3D models were secondarily constructed to achieve the pre-designed functions, and realize the real-time interactive simulation. The experiments show that synthetically using these VR constructing techniques can overcome the limitations of single modeling method, and brilliantly make the simulation environment more realistic and familiar to the trainees, achieving good training results.

Abstract: This paper establishes quality evaluation systems of complete sets of equipment for water treatment based on defining the notion and analyzing the development and characteristic of water treatment equipment industry and complete sets of equipment. 24 unit operations and corresponding equipment in water treatment were chosen and determined as independent devices of complete sets of equipment for water treatment. Four-layer, which is destination layer, criterion layer, feature layer and index layer, of quality evaluation system are established. 26 quality items are selected according to wastewater treatment practice and some national & industrial standard. Evaluation index describes what index is needed to evaluate quality of complete sets of equipment for water treatment. Evaluation methodology describes how to conduct evaluation of selected indexes. Evaluation rule describes when and in what condition the evaluation was conducted. This work will standardize product quality of complete sets of equipment for water treatment and promote healthy development of environmental protection equipment industry.

Abstract: This article analysis the relationship between BBD inlet and outlet tube mill separator blockage and the boiler's safety-economy, finds out the cause of the separator blockage, puts forward the corresponding reform scheme, then the retrofit scheme after implementing separator blockage problem.

Abstract: The simulation method was used to study the fuel supply and injection characteristics of diesel top clearance plunger pump. The results show that the top clearance plunger pump relative advance of fuel supply is larger than that of the traditional plunger, and it can achieve the purpose of injection advance when the oil pump operate at 600~1000rpm. Through optimizing the structure of top clearance plunger, the amount of the injection advance can become larger and the advanced range of speed is increased. After optimized, the BSFC (Brake Specific Fuel Consumption) is 4.3% lower than that before when the diesel engine matched the top clearance plunger, which shows its advantage especially in working at high-speed.

Abstract: The effects of multiple injections coupled with medium EGR (25% - 30%) on heavy duty diesel engine were investigated. Injection timing and mass were adjusted with different injection strategies (main-post and pilot-main) to study the influence of these parameters on combustion and emissions. The mechanism of soot emission reduction was discussed. Results indicate that, at fixed total injection quantity and EGR rate, NOx is reduced, while soot is decreased followed by an increasing with increasing post injection quantity; NOx nearly kept constant and soot declined before rising with lager main-post interval. Optimum post injection could accelerate soot oxidation rate. Pilot injection has no positive impact on NOx, while soot decreases with less pilot fuel mass and lager pilot-main interval. Optimum pilot injection could be beneficial for a better mixture property. The acceleration of soot oxidation rate is the basic reason of soot emission reducing by multiple injections.

Abstract: The thermodynamic cycle analysis of diesel engines using the engine cycle simulation programs is feasible. The comparison of dual and LIVC miller cycles engine fueled with ED10 diesel/ethanol blends on temperature and emissions are investigated by simulation. From the comparison, +0.85 EIVC miller cycle is a selection for an optimizing point of miller cycle ratio, i.e, the intake valve timing of the engine is good for NO emission, SOOT emission and the engine power output. The difference of EIVC and LIVC miller cycle was studied. The results show the tendency of performance with EIVC miller cycle is similar to that of LIVC miller cycle. But the peak cylinder combustion temperature of EIVC miller cycle become lower relative to LIVC miller cycle, which lead to slightly lower NO emission and slightly higher SOOT emission for EIVC miller cycle.

Abstract: The paper assessed the fire risk of the summer tyres marks Kormoran on the base of thermogravimetric analysis complemented by the analysis and determination of the carbon monoxide (CO) concentration in the decomposition products. Thermogravimetric analysis was performed in an atmosphere of air with flow rate of 4 l/min. During the thermal analysis, the samples were loaded with temperatures from 20 to 550 °C, in the first case by rate of heating 5 °C/min and in second case by 10°C/min. The results of thermal analysis shown that the thermal decomposition of the samples at a heating rate of 5 °C/min started at 320 °C and from the temperature of 370 °C thermal decomposition pass intensively. At a heating rate of 10 °C/min, thermal decomposition of the samples started at 360 °C, from the temperature of 420 °C thermal decomposition pass intensively. The measured concentrations of CO in combustion gases showed that the thermal decomposition of tyres is accompanied by a significant release of gas. The results also shown that the thermal decomposition of the investigated tyres coupled with the release of CO starts at temperatures around 320 °C. That temperature cannot be considered as safe in the medium and long-term exposure.

Abstract: A new unpowered decanter system was designed to lift the decanting sink only by the dynamic provided by liquid level difference. The system arranged the float tank pools symmetrically in both ends of the decanting sink. The system was run by the difference of liquid level between float tank pool and reaction pool. When the level difference got small, the float tank would rise and hence lift up the decanting sink in the reaction pool to up above the liquid level; when the level difference got large, the float tank no longer received the buoyance so the decanting sink would float in the reaction pool and decant. The testing results of the experiment device showed that by means of difference of liquid level to lift the decanting sink was feasible. The new system is simple in structure, so that the construction and maintenance cost is not high. It also does not consume electricity. It provides a new decanter model.

Abstract: Recently, 3D printing technology has obtained the rapid development which brings immeasurable changes. It is considered to be one of the main marks of the third industrial revolution. The shares of Avic Heavy Machinery co., Ltd (600765) involving 3D printing technology continuously hardened six times in January 2013.Taking it as an example, we expound the connotation and advantages of 3D printing technology seriously and also elaborate the background of 3D printing technology. In addition, by analyzing its operation ability, profitability and growth capacity, we find the shares of Avic Heavy Machinery co., Ltd (600765) hardened on account of 3D concept hype, and not its performance. Then we describe the existing problems in the development of 3D printing technology in our country. Finally we give some corresponding suggestions to the development of 3D printing technology from three angles.

Abstract: A three dimensional fluid flow model was set up in this paper, based on the computational fluid dynamics (CFD) and the elasticity theory. Using the finite volume method, a 120° bend was taken as a research object to simulate the erosion to the wall of fluid with sparse particles, finally, to determine the most severe wear areas.At the same time, the distribution of two-phase flows pressure and velocity was analyzed in 45° and 90° bends, then tracked the trajectory of the particles. The results show that the 90°bend has the smallest wear area and particle distribution or combination property is the best.