Zhengfang Wang

China University of Petroleum, Tsingtao, Shandong Sheng, China

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Publications (9)0 Total impact

  • Yiyuan Cheng · Zhengfang Wang
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    ABSTRACT: Laser quenching and nitriding treatment has been performed on 35CrMoA steel, and the microstructure, hardness and wear resistance of laser quenching/nitrided layer were investigated by means of OM, XRD and TEM, microhardness tester and wear equipment compared with the gas nitrided layers. The results show that both nitrided layer consisted of ε, γ′, and Cr2N. The content of ε-Fe3N is higher in the laser quenching/nitrided white layer while the content of the brittle δ-Fe2N is lower than that of the gas nitrided layer. Especially the Cr2N particles are much finer. Spherical particles of cementite were formed in lower strip bainite. The scratch in worn surface of laser quenching/nitrided layer is shallow, but the gas nitriding worn surface has the deep plow furrow and flaking. After laser quenching/nitriding treatment, the depth of the nitrided layer increases, and hardness and wear resistance were improved dramatically.
    No preview · Conference Paper · Jan 2011
  • Zhengfang Wang · Shuling Liu · Shiwei Li
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    ABSTRACT: Corrosion is a serious problem in atmospheric distillation unit when the plant refines high-acid crude oil from Shengli Oil Field. How to measure and predict the corrosion and related factors is a significant task in refinery. The GM (1, 1) model can only predict the sequence of exponential law, scribe the monotonic change event. We take acid values as a sample, use the data from the first to 6th month, and establish GM (2, 1) model and Verhulst model to predict the data from 7th to 9th month. For the GM (2, 1) model, the maximum relative error is 11.8%, the mean relative error is 7.2%, and the mean relative error of prediction data is 13.2%. For the Verhulst model, the maximum relative error is 7.0%, the mean relative error is 3.1%, and the mean relative error of prediction data is 10.6%. The conclusion is that the Verhulst model is better than DGM model and the Verhulst model can be used for corrosion pate prediction.
    No preview · Article · Nov 2009
  • Zhengfang Wang · Weiqiang Wang · Hui Qi
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    ABSTRACT: Corrosion is serious on the first atmospheric distillation unit when the plant processes high-acid crude oil from Shengli oil field. Measured the corrosion pate on the top of atmospheric distillation tower with electric resistance probe every two month, monitored sulfur value, salt value, salt value after desalt, acid value in crude oil, iron ion in product container and pH value in cooling water every month. Created grey data sequence with equal weight whitenization and stepwise ratio generation method, carried on grey correlation analysis, calculated absolute, relative and synthetic degree of incidence, carried on predominance analysis too. The conclusion is that the main factor to corrosion is acid value, and then is salt value after desalt, pH value, content of salt, sulphur value and iron ion value. Getting rid of salt from crude oil as possible is benefit to equipment, and monitoring salt value after desalts, pH value could predict corrosion.
    No preview · Conference Paper · Aug 2009
  • Zhengfang Wang · Yong Wang · Weiqiang Wang · Chuanyi Lu · Chaowen Li
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    ABSTRACT: Shengli refinery plant process Middle-east crude oil, the equipment is exposed to wash erosion seriously. The elbow on the entrance of the atmospheric distillation tower top exchangers always leak for eroding. Measured the thickness of elbow by ultrasonic thickness meter every month, find the accumulating generation operator of remnant thickness is quasi smooth sequence, established GM (1, 1 ) model with grey system theory, detected the error with relative error, model passed error check, is eligible. Used full data to create improved GM (1, 1) model to predict elbowdasias thickness in the future. The elbow life can reach to 24 month, but can not reach to 36 month. Select place to measure thickness by experience is out of truth. Use Fluent to emulate fluid field can help to find the place to monitor.
    No preview · Conference Paper · Apr 2009
  • Source
    Zhengfang Wang · Yong Wang · Weiqiang Wang · Hui Qi · Jian Zhang · Qingkun He
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    ABSTRACT: Shengli refinery plant process middle-east crude oil, the equipment is exposed to wash erosion seriously. The elbow on the entrance of the atmospheric distillation tower top exchangers always leak for eroding. Measured the thickness of elbow by ultrasonic thickness meter every month, established GM (1, 1) model with grey system theory, the average relative error is 1.8959%, model passed error check, is eligible. Adding a number 100 to the thickness of the elbow, then subtract it from the result, established improved GM (1, 1) model, and the average relative error is 1.3084%, increased prediction precision. Used full data to create improved GM (1, 1) model to predict elbowdasias life. Predicted the thickness of elbow in the future, the elbow life can reach to 24 month, but can not reach to 36 month. It shows that the grey system model is feasible; the improved full data GM (1, 1) model can be used for long-term forecasting and is more accuracy.
    Preview · Conference Paper · Mar 2009
  • Zhengfang Wang · Weiqiang Wang · Yiyuan Cheng · Yuhua Chen · Dawei Qu
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    ABSTRACT: Exchangers on the top of distillation tower exposed to wash erosion seriously when Shengli refinery processed Middle-east crude oil. Used grey system theory, aimed at general tube-shell exchangers and helix-baffled structure, tube of 20 carbon steel with TH847 coating, 20 steel aluminizing, 316L and dual phase steel, carried on grey decision. For exchangers rebuilding project, grey target decision shows that helix-baffled exchangers with 20+TH847 coating tube is the best preference plan, while grey incidence decision shows that the helix-baffled structure with 20 carbon steel aluminizing tube is the preferential plan. In general, helix-baffled structure is better than general contractures, should adopt advanced manufacture technology to lower the fabricate difficulty.
    No preview · Article · Feb 2009
  • Zhengfang Wang · Shuling Liu · Hui Qi · Shiwei Li
    [Show abstract] [Hide abstract]
    ABSTRACT: Corrosion is a serious problem on the first atmospheric distillation unit when the plant refines high-acid crude oil from Shengli Oil Field. To measure and predict the corrosion and related factors is significant tasks in refinery. The GM(1,1) model only can predict the sequence of exponential law, scribe the monotonic change event. Took acid value as sample, used the data from the first to 6th month, established GM(2,1) model and Verhulst to predict the data from 7th to 9th. For the GM(2,1) model, the maximum relative error is 11.797%, the mean relative error is 7.2269%, and the mean relative error of prediction is 13.2006%. For the Verhulst model, the maximum relative error is 7.0037%, the mean relative error is 3.1402%, and the mean relative error of prediction is 10.5732%. the conclusion is that the Verhulst model is better than DGM model and can be used for corrosion prediction.
    No preview · Conference Paper · Jan 2009
  • Zhengfang Wang · Weiqiang Wang · Yong Wang · Yiyuan Cheng · Dawei Qu
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    ABSTRACT: The exchangers on the top of distillation tower exposed to wash erosion seriously when Shengli refinery processed Middle-east crude oil. Considered the heat transfer efficiency, manufacture fee, maintenance fee, manufacture difficulty and safety in exchangers rebuilding project, established mathematics model with grey system theory, and carried on grey decision. Grey incidence decision shows that the helix-baffled structure with 20 carbon steel aluminizing tube is the preferential plan, then is helix-baffled structure with 20+TH847 tube, common structure with 20 carbon steel aluminizing tube, common structure with 20+TH847 tube. In general, helix-baffled structure is better than general contractures, should take action to lower the fabricate difficulty of helix-baffled exchangers.
    No preview · Article · Jan 2009
  • Zhengfang Wang · Yong Wang · Jan Zhang · Dawei Qu · Xiuhua Liu
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    ABSTRACT: Corrosion exacerbated on atmospheric distillation unit when Shengli plant refined high-sulfur and high-acid crude oil imported from Middle-east. Measured the corrosion pate on the top of atmospheric distillation tower with electric resistance probe and monitored sulfur value, salt value, salt value after desalt, acid value in crude oil and iron ion in product container every month. Carried on grey correlation analysis, calculated absolute, relative and synthetic degree of incidence, carried on predominance analysis too. The conclusion is that the main factor to corrosion is salt value after desalt, and then is content of iron ion, salt, acid and sulphur. Getting rid of salt from crude oil as possible is benefit to protect equipment, monitoring salt value after desalt or content of iron ion to adjust the quantity of water, ammonia and corrosion inhibitor added into oil is feasible.
    No preview · Conference Paper · Nov 2008

Publication Stats

15 Citations

Top Journals

Institutions

  • 2009
    • China University of Petroleum
      Tsingtao, Shandong Sheng, China
    • Shandong University
      • Institute of Biomedical Engineering
      Chi-nan-shih, Shandong Sheng, China
  • 2008-2009
    • China University of Petroleum
      Ch’ang-p’ing-ch’ü, Beijing, China