Advanced Materials Research Vols. 732-733

Abstract: In order to study the load pattern of crankshaft of hybrid ship main diesel engine, in this thesis, MAN B&W 5S60MC diesel engine model has been established using ADAMS software. The load pattern of crankshaft of diesel engine at variable load, and variable speed conditions due to the changes of assisted driving force have been calculated by the virtual prototype. The result shows that the influence of crankshaft load pattern is tiny when the diesel engine load is variable, but the influence of crankshaft load pattern is large when the diesel engine speed is variable. The research of hybrid ship sailing model study provides theoretical basis. The study provides theoretical foundation to the control model research of hybrid ship main diesel engine. It is helpful to improve the application process of hybrid ship.

Abstract: For recycling complementary energy efficiently, WMs latent heat of vaporization is made full use of in a free piston based organic rankine cycle exhaust gas energy recovery (ORC-FP) system. In this paper, the model of ORC-FP system has been established by the software GT-suite 7.0. Three sensitive factors (WMs gas ratio, piston damping coefficient and power WMs pressure) will be discussed by simulation results. The conclusions are shown as follows: Firstly, when WM state is 450K, 1.1MPa (Power WM) and 320K, 1.1MPa (Cooling WM) at inlet, the systems single cycle efficiency is highest about 69.21%, and the lowest is about 42.32%. Certain fluctuation of single cycle (SC) efficiency exists between two adjacent cycle, and the highest difference can reach 26.89%. Secondly, the systems total cycle (TC) efficiency decreases along with the increasing of damping coefficient (piston load). At the minimum piston damping coefficient (about 7500 N-s/m), the systems highest total cycle efficiency is 46.53%, and at the maximum (about 8750 N - s/m), the lowest total cycle efficiency is 35.66%. Thirdly, when damping coefficient is 7500 N-s/m, the higher pressure of WM is, the higher the systems total cycle efficiency is. In the pressure of 1.1MPa, the system reaches the highest efficiency which is about 46.53%, and in the pressure of 0.9 MPa reaches the lowest which is about 26.74%.

Abstract: The performance and application characteristic of various prime movers (gas turbines, gas engines and micro-turbines) were analyzed and compared; the criterion of selecting a DES prime mover was revealed and a method for designing the optimum capacity of a DES prime mover was given; The prime mover variable load characteristic, the impact of the start-stop and multi-station modular combination optimization are not fully considered, which will be the future research directions of DES configuration optimization .

Abstract: The effects of anti-scale, anti-corrosion and disinfection of circulating cooling water with electro-magnetic treatment and chemical treatment in the laboratory are compared. The applications of electro-magnetic treatment in power plants are summarized and discussed. The results of both experiments and applications in power plants show that the electro-magnetic treatment can be used in particular conditions, but the development of electro-magnetic treatment technology is immature. This technology used in circulating cooling water system in power plants should be further proved by more experiments and field applications.

Abstract: In order to investigate the influence of spray position on fuel air mixing quality, three-dimensional numerical simulation of the working process of a heavy-duty diesel was conducted. To quantitatively study the mechanism of the effect of spray position on fuel air mixing process, the deviation of spray centroid was introduced to describe the spray position change in combustion chamber. The results show that the gas intake swirl can affect the spatial distribution of spray in combustion chamber under three directions in cylindrical coordinate, in which the circumferential distribution is affected most. It then can be concluded that the spray can be limited to the vicinity of the combustion chamber axis. Better spray position, which is more helpful for the process of fuel air mixing and combustion, can be achieved by using optimal swirl, so that the power performance will be improved.

Abstract: This thesis introduces the working principle and structure of FWX series cyclone-static micro-bubble flotation column. It makes industrial test results analysis of the FWX series cyclone-static micro-bubble flotation column adopted by a gold mine, and come at valuable conclusions on the process design and equipment optimization through the analysis of experimental data.

Abstract: This paper presents a new fusion diagnosis based on rough set and BP neural network for the fault diagnosis of gas turbine. The frame is designed to fusion fault diagnosis, which is composed by three parts: the rough set data pre-processor, rough set diagnosis model and BP neural network diagnosis model. Aiming at the difficulty in getting adequate fault samples in fault diagnosis, rough set theory is first used to process the original data, establish the decision table and generate rules, which can eliminate the redundant information and build the rough set diagnosis model. After that, according to the optimal decision attribute pre-treated by rough set, BP neural network is designed for fault diagnosis, which can reduce the scale of neural network, improve the identification rate, and improve the efficiency of the whole fusion diagnosis system. Finally, an example of gas turbine generator sets fuel system is taken as a case study to demonstrate the feasibility and validity of the proposed method in this paper.

Abstract: The weight minimum and drive efficiency maxima1 of screw conveyor were considered as double optimizing objects in this paper. The mathematical model of the screw conveyor has been established based on the theory of the machine design, and the genetic algorithm was adopted to solving the multi-objective optimization problem. The results show that the mass of spiral shaft reduces 13.6 percent, and the drive efficiency increases 6.4 percent because of the optimal design based on genetic algorithm. The genetic algorithm application on the screw conveyor optimized design can provided the basis for designing the screw conveyor.

Abstract: According to the actual situation of heating furnace in Tianjin Tiangang United Co. Ltd, we designed a scientific and feasible solution of screw expanding power generator and auxiliary facilities matched, realized waste heat utilization of low-quality heat source from iron and steel industry exhausted, analyzed energy saving and environmental protection social benefit and good economic benefit that this solution have.

Abstract: In this paper, finite difference method and finite volume method are applied to incompressible viscous driven cavity flow problems, and their results are analyzed and compared. As for the finite difference method, second-order upwind and second-order central difference format are applied to the discretization of the convection and diffusion items respectively. For the finite volume method, three different ways are utilized to discretize the control equations: QUICK, second-order central difference and third-order upwind formats. The results show that computing time as well as calculation accuracy exponentially depends on Reynolds number, discrete formats and grid numbers.