Journal of Liaoning Petrochemical University
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Leak Detection and Localization of Pipelines Based on LMD and LSTSVM
Shi Changqing,Lang Xianming,Zhang Lin,Li Ping
Abstract492)   HTML    PDF (9821KB)(163)      
In fluid pipeline leak detection and location, noise in the pressure signal collected both ends of the pipeline will affects the accuracy of leak detection and the error of leakage location. To reduce the noise interference an improved local mean decomposition (LMD) signal analysis method is proposed. The production functions (PF) that were related to the leak signal can be exacted, and it was necessary to know the characteristics of leak signals or noise in advance. According to the cross⁃correlation function, there is a significant peak between the measured signals which are decomposed into a number of PFs. These reconstructed principles PF components were obtained, and a wavelet analysis was used to remove the noise in the reconstructed signal. On this basis, the signal features were extracted according to the time⁃domain feature and waveform feature, which were input into Least Squares Twin Support Vector Machine (LSTSVM), LSTSVM to distinguished different working conditions. According to the reconstructed signal after wavelet de⁃noising, the time delay estimate of the negative pressure signal at the end of the pipeline is obtained by the cross⁃correlation function, and the leak location was ultimately calculated by combining the time delay with the leak signal propagation velocity. A leak simulation for pipeline was proposed , where the collected data of the different working conditions was processed. The experimental results show that the proposed method can effectively identify different working conditions and accurately locate the leakage point.
2019, 39 (6): 84-90. DOI: 10.3969/j.issn.1672-6952.2019.06.015
Experimented Study on the Influence Factors of Spontaneous Imbibition in Ultra Low Permeability Fractured Reservoir
Liu Changli,Liu Xin,Zhang Lina,Chen Zhenlong
Abstract809)      PDF (2099KB)(262)      
        Water flooding development has become the only way for the ultra low permeability fractured reservoir development. However, due to the problems of reservoir micro fracture development, serious heterogeneity and critical water, resulting the water flooding recovery was low.Spontaneous imbibition oil production is an important way of oil production in this kind of reservoir, on the basis of the use of indoor experiment, the salinity of injected water, core permeability, oil saturation, surfactant, oil viscosity and temperature in a low permeability fractured reservoir were studied systematically. Experimental results show that when the environment formation water salinity is less than the mainland core layer water salinity, or joining a surface active agent could significantly improve spontaneous imbibition effect. as the permeability and oil saturation increased and the crude oil viscosity decreased; capillary imbibition became stronger and the ultimate imbibition recovery is greater; the increase of temperature can increase the initial imbibition rate, but the ultimate imbibition recovery is basically the same, the temperature is not the direct acting factors about imbibition effects in ultra low permeability fractured reservoir.
2017, 37 (3): 35-38. DOI: 10.3969/j.issn.1672-6952.2017.03.008
 
A New Aggregated Method for Interval Multi Attribute Group Decision
ZHENG Guiling, SUN Liang, QI Xiaoyan, ZHANG Lina, YE Tianyu
Abstract425)      PDF (1802KB)(312)      
Because of complexity, many aggregated methods for interval multiattribute group decision are difficult to general decision makers, a new way has been proposed in this paper. This method puts forward basic interval conception to aggregation and provides direct solution schematically. It is easier and more intuitive. Finally, as compared with the results of literature method, this has been demonstrated as an effective method.
2013, 33 (4): 99-104.
Checking the Bone Density by Medical Image Based on Alternate Pattern of Random Walk
ZHANG Ling-yu, JI Yu-bo
Abstract475)      PDF (455KB)(243)      
A kind of method with using of vertebra medical image to deal with image key data was presented. First, used of the method of piecewise linear transform to stretch gray level of image for enhancing contrast ratio between target area and background area or reducing the detail in the target area. Second, used of information of pixel gray level to set up weighing chart, choose target seed pixels and background seed pixels, and then make use of rand-walk algorithm to divide up image so that receive edge of contour line. At last, unit area pixel average gray-level in the range of edge contour line was computed. Through comparing gray value of unit area in the region with bone density which can be gotten from physic testing, the bone density may be received in the checked region.
2010, 30 (4): 54-58. DOI: 10.3696/j.issn.1672-6952.2010.04.016
Fischer-Tropsch Wax Graft With MAH
HUANG Wei, CONG Yu-feng, ZHANG Ling, GENG Pin
Abstract339)      PDF (155KB)(195)      
In the presence of the initiator benzoyl peroxide (BPO), maleic anhydride (MAH) was grafted onto a kind of H-1 type fischer-tropsch wax by melt grafting process to improve the hardness and other indicators of Fischer-Tropsch wax. The experimental results show that, when the reaction lasted for 20 min at the reaction temperature of 140 ℃, the amount of maleic anhydride (MAH)was 5.0 g and the amount of initiator (BPO)was 4.0 g, the grafting rate reached 1.53% while the product's penetration degree was 1.6(0.1 mm). From the infrared spectroscopy (IR), we can see that MAH had been successfully grafted to the fischer-tropsch wax.
2009, 29 (3): 5-7.
C5 Petroleum Resin Modification as Pour Point Depressant for Diesel
YU Hong-bo, CONG Yu-feng, LIAO Ke-jian, ZHANG Ling, SUN Feng-jiao
Abstract430)      PDF (546KB)(292)      
The pour point depressant for diesel was prepared by firstly making modifacation of C5 petroleum resin with maleic anhydride, and then modified with octadecanol. Four factors were studied on the influence of freezing point and cold filter plugging point, which are, respectively, the amount of maleic anhydride and initiator, the time of reaction, the temperature of reaction. The result shows that, the best depression capacity of pour point depressant for diesel is acquired with the amount of maleic anhydride is 15%,and the amount of the initiator is 1.0%, and the temperature is 180 ℃ and the time is 3.0 h.
2009, 29 (1): 25-27.
Preparation of Horniness Oxidized Wax by Catalytic Oxidation
LIAO Ke-jian,ZHANG Ling,CONG Yu-feng,SUN Feng-jiao,YU Hong-bo
Abstract485)      PDF (132KB)(363)      
The catalytic oxidation experiments were carried out to prepare the horniness oxidized wax from paraffin wax and polyethylene. The results show that good products can be obtained under the following conditions: reaction temperature 170 ℃, reaction time 7 h, mass ratio of paraffin wax and polyethylene 7∶3, the amount of catalyst 0.01%, the amount of additive 1.0%, the air flow 0.20 m3/h. acid number of the product was 9.82 mg(KOH)/g, saponification number is 79.19 mg(KOH)/g, penetration is 9.2 (0.1 mm), melting point was 87.4 ℃, index of refraction(75 ℃ ) was 1.453 6. As compared with natural hard wax(carnauba wax),their properties were quite similar each other.
2008, 28 (4): 24-26.
Establishment and Dynamic Simulation of the Virtual Prototype of Excavator Work Device
ZHANG Lin-yan, DENG Zi-long, ZHANG Hong-liang, FU Yue
Abstract409)      PDF (230KB)(316)      
The software Pro/E was adopted to create a three-dimensional physical model of the virtual prototype of a single bucket backhoe hydraulic excavator work device. The model was transferred into ADAMS to build a virtual prototype of the work device. A work cycle of excavator work device, as well as the tangential force, the normal force and the gravitational force of the materials was successfully simulated by using the function step. With the simulation, load-time curves of three hinge points whose articulated stresses are more complex were obtained. The research has provided the basis for the design of the excavator devices.
2008, 28 (3): 46-49.