Advanced Materials Research Vols. 986-987

Abstract: Based on one company’s engineering of constructing underground coal pipeline above goaf, calculation analysis the influence of residual subsidence deformation and stress distribution of the coal pipeline engineering. The mining subsidence make the underground coal pipeline bearing not only the earth pressure of upper, lower and lateral, but also the result of the subsidence deformation include of vertical and horizontal in-plane bending moment. Based on this, put forward the anti-deformation technical measures to build new coal pipeline and provide scientific basis for anti-deformation design.

Abstract: External surface cracks can occur in cylindrical vessels due to damage and propagate in the manufacturing process and during service life. Most of research focuses on stress intensity factors for surface cracks with low aspect ratios, i.e., a/c ≤1.0. Situation may well arise where the aspect ratio of cracks is larger than one. An external longitudinal surface crack is assumed to be subjected to different types of hoop stress distributions acting perpendicular to the crack faces. The stress intensity factors (SIFs) along the crack front were determined through the three-dimensional finite element method. Then these results are used to compute approximate values of SIFs in the case of complex loadings by employing both the superposition principle and the power series expansions of the actual hoop stresses. It is found that the maximum stress intensity factor for external surface cracks with high aspect ratio occurs at different point to that with low aspect ratio.

Abstract: Impact load of perforation will result in strong vibration of downhole string, string operated such as bending fracture accidents. Considering the clearance between string and casing, using space beam and spring element to solve the nonlinear contact problems between oil jacket, established the numerical model of string structure dynamic response analysis in horizontal well. Extracting downhole perforation pressure wave monitoring data, using the finite element software ANSYS, analyzed the dynamic response of the tubing under perforation of detonation shock wave impact, got the displacement of the tubing、acceleration time history. The results show that, without packer, the maximum Mises equivalent stress in the end of the string, the deformation and stress changes in deflecting section of the tubing string are bigger than in vertical Wells.

Abstract: In this paper, the desorption temperature of adsorption bed in typical weather condition is studied though the solar adsorption refrigeration experiment with conditions of different weather. The results showed that: the better the weather condition is, the higher the highest temperature of the adsorption bed is, so the better the effect of desorption is. No matter in cloudless sunny or partly cloudy sunny conditions, the desorption temperature of adsorption bed can reach 93.4°C, and the amount of desorption also will be larger; however, in cloudy weather conditions, desorption temperature can reach 88.5°C, and desorption quantity is relatively fewer than it in cloudless sunny days.

Abstract: Integral impeller is the key component in aviation, aerospace and other fields, and the deformation has an important effect to the machining quality and precision of the integral impeller. Because of the complexity of the geometry and surface curvature changes for the integral impeller, and the semi suspended state during the processing, force analysis and control technology for the deformation have become the key and difficulty to realize high quality processing. In this paper, the situation about the blade machining with the finite element analysis is introduced, and the factors about the blade machining deformation is also summarized. The deformation of a single cutter location point are computed and analyzed with finite element method, and the application problems to the machining deformation with the finite element are presented.

Abstract: The measurement of deformation of one diesel engine water cooling cylinder liner under free condition and assembly load case is carried out by V-INCOMETER testing system. The basic principles of radial deformation for this cylinder liner are obtained through the test data Fourier transformation. And the affect principles of cylinder liner original distort, which results from mechanical machining and heat treatment process, to the cylinder liner assembly deformation are carried out.

Abstract: It is magnificent to find the center of the coupling after many calculations, test and optimization. It presents a check based on looking methods and determine the centering of this calculation method after repeatedly overhaul of a 200mw extraction condensing steam turbine adjusting center practice. The effectiveness of its application in practice can duration, and the average time and its consumption of money could be reduced to 1/3, 1/3 and 1/5of its original, illustrates the adjustment process issues which should pay attention to,and provides technical reference for the safe operation of the same type of rotating machinery .

Abstract: Inadequacy was discussed of using acid dew point temperature (ADT) as safe low limitation of exhaust gas temperature on the background of waste heat deep utilization of flue gases. Concept of limited corrosion dew point (LCT) was presented based on corrosion property of ordinary carbon steel and binary phase equilibrium of H₂SO₄-H₂O system,. Calculation formula of LCT was solved by establishing fugacity equation of H2O with a fixed concentration and constant pressure. The results show that LCT lies during 68-84°C when volume percentage of H₂O vapor varies from 6-12% which is in line with that of exhaust gas of boiler. The maximum relative error of the calculated data is 1.43% in contrast to reported data. Ordinary carbon steel in contact with flue gas with its surface temperature above LCT will not occur obvious corrosion and wet soot deposition through observation of experiment on site. It is available for exhaust gas temperature to decline below ADT but above LCT in process of deep utilization of waste heat of flue gas.

Abstract: In order to design a reasonable safe power control system and realize the automated management of offshore drilling system, this paper analyzes the electric system features and grid configuration of drilling platform; power station design and short circuit calculation; electrical power system electroplax selection. This system adopts oceanographic engineering software EDSA for construction and parameter input and conducts short-circuit calculation for modeling and simulation. The electric system design and short-circuit calculation can be examined by simulation result and real platform.

Abstract: New type of energy-saving conductor which can obviously reduce the transmission losses was recently developed in power project. However, considering ice-coating and galloping in winter, it is necessary to investigate its ice accretion characteristic compared with conventional conductor. Research was conducted by icing wind tunnel test. Ice mass and ice shape of conductor with different diameter were examined. There is no clear advantage on the ice-coating resistance capability of energy-saving conductor with small diameter, while for conductor with larger diameter, energy-saving conductor’s ice-coating resistance capability is better than conventional conductor. The test result is helpful for choosing suitable type of large diameter conductor in high and ultra-high voltage transmission project.