Advanced Materials Research Vols. 1070-1072

Abstract: Organic Rankine cycle is an effective way to recover low-grade heat energy. In order to improve system performance, for low-temperature waste heat of 120°C and R245fa,R600a,R227ea organic working fluid, using Aspen Plus software conducted simulation by changing the evaporation temperature. Results from these analyses show that decreasing the evaporation temperature, increasing thermal and exergy efficiencies, evaporating pressure, at the same time reduce steam consumption rate.

Abstract: Ship coating should be at the right temperature and good ventilated environment. Setting reasonable hang radiant panel for the ship spraying workshop, in the form of radiation heating combined with mechanical air supply to achieve suitable temperature and wind speed. Using the CFD method, by the STAR-CCM+ software, we can simulate the radiation heating workshop space and solid piece. It is concluded that the surrounding air velocity distribution, and observe the change of the temperature field, getting the suitable temperature and air velocity distribution for ship hull surface spraying. Then it can improve the quality of coating.

Abstract: The research and development situation of liquid nitrogen coil-wound heat exchanger were discussed in view of heat exchange in gas purification field in petrol-chemical industry. The basic designing methods and the multi-stream heat exchange process were illustrated by the cryogenic and high pressure crossing heat exchange equipments of liquid nitrogen coil-wound heat exchanger with multi-stream and multiphase flow, including Three-stream back-cooling heat exchanger in first stage, Four-stream back-cooling heat exchanger in second stage, Five-stream back-cooling heat exchanger in third stage, Multi-stream main back-cooling coil-wound heat exchanger etc. A series of coil-wound heat exchangers with different mixed fluids and different applications were described. The winding structure characteristics and the work principles of the spiral pipe bundles were elaborated to give references for the scientific design and calculation of coil-wound heat exchanger in cryogenic field. The important research directions and the critical scientific problems were forecasted.

Abstract: In order to simplify the model of diesel engine working process in Hardware-In-the-Loop simulation system and improve its real time operating performance, a quasi-dimensional model of diesel engine working process based on a new phase divided spray mixing model was formulated and developed. The software MATLAB/Simulink was utilized to simulate the diesel engine working process. The good agreement between experimental results and calculated results indicates that the quasi-dimensional model of diesel engine working process is reliable for predicting power, fuel consumption and emissions of diesel engine. It is concluded that the quasi-dimensional model of diesel engine working process was greatly simplified and the real time operating performance of simulation system was obviously improved by using this phase divided spray mixing model.

Abstract: The spark plug ion current signal carries abundant information about the engine combustion process. Real-time acquisition of the spark plug ion current signal can effectively extract the characteristic parameters, then enhance the power, fuel economy and emissions of the engine. The paper analyzed the influence factors of ion current, designed an acquisition and analysis system of spark plug ion current signal, and mainly studied the influence of spark plug gap and bias voltage on ion current signal in a six-cylinder four-stroke gas engine. The results show that the bias voltage and the spark plug gap have a great impact on the spark plug ion current signal. The ion current signal intensity is directly proportional to the bias voltage applied cross the spark plug, and inversely proportional to the spark plug gap. Results also indicates that the ion current is directly proportional to the mobility and concentration of charged particles in burned gas plasma.

Abstract: This paper reviews and summarizes recent developments in hydrogen and gasoline mixtures powered engine research. According to the hydrogen and gasoline injection location, engine can be divided into three categories: hydrogen intake port injection, gasoline direct injection; Hydrogen direct injection, gasoline intake port injection; hydrogen and gasoline intake port injection. Different gasoline and hydrogen injection location determines the engines have different advantages. Follow an overview of spark ignition engine using hydrogen and gasoline mixtures, general trade-off when operating engine on hydrogen and gasoline mixtures are analyzed and highlights regarding accomplishments in efficiency improvement and emissions reduction are presented. These include estimates of efficiency potential of hydrogen and gasoline engines, fuel economy and emissions.

Abstract: This paper addresses the physicochemical characteristics of petroleum based diesel, coal based diesel and blended diesel (volume ratio of petroleum based diesel and coal based diesel 1:1), the power performance, fuel economy and exhaust emission with the three kinds of fuel were investigated on an engine test bench. The results show that: without any change in the diesel engine, when the engine fueled with coal based diesel power slightly upgraded, fuel consumption rate change little, exhaust smoke decrease obviously compared with using petroleum based diesel, that means coal based diesel is a kind of low-pollution alternative fuel for diesel engine.

Abstract: We studied the shutdown state of natural gas engine on a modified GW4B13 direct injection engine. The result shows that when the engine is cold, high speed hold a dominant factor, causing the engine spends longer time shutting down than the time under the hot engine situation; stop position of the engine is normal distribution, and the majority of the stop position is located before the top dead center between 70° to 90°; when the stop position before the top dead center 90° and 120 ° , the engine spends shortest time, less than 0.3s, reaching the target speed, i.e. the idle speed 400rpm.

Abstract: Because of discontinuity of the shape, the piston rod of rapping device is liable to occur stress concentration phenomenon, leading to fracture of the piston rod. At work, the maximum stress of piston rod which took place in the cross section of the geometric mutations varied with the change of the fillet radius, under the same load, it analyzed the influence of different fillet radius on fracture of the piston rod via ANSYS/LS-DYNA finite element. The results showed that it can meet the requirements when the fillet radius was 5 mm.

Abstract: Based on the practical experience of turbine unit installation, combined with the project quality management theory, analyzed the impact factors of turbine installation quality, explored the quality control content, and formed a more perfect of quality control methods system ultimately. The application of the methods in the SDIC Power Plant team turbine unit installation achieved the good results, and it became the reference for the same or related industry.