Large engineering plants(LEPs)have certain unique features that necessitate a maintenance strategy that is a combination of both time and condition based maintenance.Although this requirement is appreciated to varying...Large engineering plants(LEPs)have certain unique features that necessitate a maintenance strategy that is a combination of both time and condition based maintenance.Although this requirement is appreciated to varying degrees by asset owners,applied research leading to a systematic development of such a maintenance strategy is the need of the day.Such a strategy should also adopt a wholesome"systemic"approach so that the realization of the overall objectives of maintenance is maximized.E-maintenance has several potential benefits for large engineering plants.In this paper,a three pronged strategy is suggested for the successful implementation of e-maintenance for LEPs.Firstly,an integrated condition and time based maintenance framework is proposed for LEPs.Secondly,reference is drawn to models for condition and time based maintenance at systemic levels.As a part of the ab initio development of a condition monitoring system for a LEP,one of the characteristics of the condition monitoring system,namely,predictability,is discussed in detail as a sample for a systemic study.Thirdly,emphasis is laid on the information and expertise available in the domain of plant design,operation and maintenance and the same is tapped for incorporation in maintenance decision making.展开更多
Monitoring data from the Three Gorges Project show that the resulted tensile stresses are mainly distributed within the front section of the internal anchoring section which is often measuring 2.5 m in length. The com...Monitoring data from the Three Gorges Project show that the resulted tensile stresses are mainly distributed within the front section of the internal anchoring section which is often measuring 2.5 m in length. The composition of two early strength cement grout mixes marked as R_3350 and R_7350 was successfully developed to accelerate anchoring facilities installation and to reduce its intervention with the shiplock construction. It was measured that the ground water pH value in the sidewall slopes of the permanent navigation shiplock during the construction period was close to 8. Based on those characteristics it is concluded that the groundwater is weakly corrosive to steel material and will appear as non-corrosive to the steel wire strands embedded in the cement grout set. The advanced model of 3 MN unbonded anchor cables with double anti-corrosion protection(including the corrugated pipe) is developed to meet the needs of stabilizing the high sidewall rock slopes of the permanent navigation shiplock on the Three Gorges Project.展开更多
Xinjiang Shawan county, the third phase of the cadres and workers to raise building project, building size, frame shear structure, high-rise residential area is 75000 square metres underground garage, in order to ensu...Xinjiang Shawan county, the third phase of the cadres and workers to raise building project, building size, frame shear structure, high-rise residential area is 75000 square metres underground garage, in order to ensure the engineering quality and company's interests, and achieved good social benefits, our company in this project construction scheme and measures, combined with design units in advance, clear design and content;The establishment of sand plant, concrete mixing station, plastic steel window processing plant, greatly reduce the construction cost;In order to solve the problem of cold shrinkage and dry shrinkage of concrete, wG-CMA compensation shrinkage concrete technology is adopted. In view of the scale and progress requirements of the project, strengthen management and technical personnel configuration and level requirements, strengthen personnel assessment and technical quality schedule control, strengthen material management, civilized construction, so as to ensure quality, speed up progress, reduce construction costs, and achieve good economic and social benefits.展开更多
Today,with nonstop improvement in computational power,Large-Eddy Simulation(LES) is a high demanding research tool for predicting engineering flows.Such flows on high pressure condition like diesel engines is extensiv...Today,with nonstop improvement in computational power,Large-Eddy Simulation(LES) is a high demanding research tool for predicting engineering flows.Such flows on high pressure condition like diesel engines is extensively employed in ground and marine transportation,oblige the designer to control and predict toxic pollutants,while maintaining or improving their high thermal efficiency.This becomes one of the main challenging issues in decades.In the present work,numerical investigation of diffusion flame dynamics is performed in the near-field of high-Reynolds jet flow on high pressure condition encountered in diesel engine applications.This work discusses the implementation of Partially Stirred Reactor(PaSR) combustion model by the approaches of large eddy simulation(LES).The simulation results show that LES,in comparison with Reynolds-Averaged Navier-Stokes(RANS) simulation predicts and captures transient phenomena very well.These phenomena such as unsteadiness and curvature are inherent in the near-field of high Reynolds diffusion flame.The outcomes of this research are compared and validated by other researchers' results.Detailed comparisons of the statistics show good agreement with the corresponding experiments.展开更多
文摘Large engineering plants(LEPs)have certain unique features that necessitate a maintenance strategy that is a combination of both time and condition based maintenance.Although this requirement is appreciated to varying degrees by asset owners,applied research leading to a systematic development of such a maintenance strategy is the need of the day.Such a strategy should also adopt a wholesome"systemic"approach so that the realization of the overall objectives of maintenance is maximized.E-maintenance has several potential benefits for large engineering plants.In this paper,a three pronged strategy is suggested for the successful implementation of e-maintenance for LEPs.Firstly,an integrated condition and time based maintenance framework is proposed for LEPs.Secondly,reference is drawn to models for condition and time based maintenance at systemic levels.As a part of the ab initio development of a condition monitoring system for a LEP,one of the characteristics of the condition monitoring system,namely,predictability,is discussed in detail as a sample for a systemic study.Thirdly,emphasis is laid on the information and expertise available in the domain of plant design,operation and maintenance and the same is tapped for incorporation in maintenance decision making.
文摘Monitoring data from the Three Gorges Project show that the resulted tensile stresses are mainly distributed within the front section of the internal anchoring section which is often measuring 2.5 m in length. The composition of two early strength cement grout mixes marked as R_3350 and R_7350 was successfully developed to accelerate anchoring facilities installation and to reduce its intervention with the shiplock construction. It was measured that the ground water pH value in the sidewall slopes of the permanent navigation shiplock during the construction period was close to 8. Based on those characteristics it is concluded that the groundwater is weakly corrosive to steel material and will appear as non-corrosive to the steel wire strands embedded in the cement grout set. The advanced model of 3 MN unbonded anchor cables with double anti-corrosion protection(including the corrugated pipe) is developed to meet the needs of stabilizing the high sidewall rock slopes of the permanent navigation shiplock on the Three Gorges Project.
文摘Xinjiang Shawan county, the third phase of the cadres and workers to raise building project, building size, frame shear structure, high-rise residential area is 75000 square metres underground garage, in order to ensure the engineering quality and company's interests, and achieved good social benefits, our company in this project construction scheme and measures, combined with design units in advance, clear design and content;The establishment of sand plant, concrete mixing station, plastic steel window processing plant, greatly reduce the construction cost;In order to solve the problem of cold shrinkage and dry shrinkage of concrete, wG-CMA compensation shrinkage concrete technology is adopted. In view of the scale and progress requirements of the project, strengthen management and technical personnel configuration and level requirements, strengthen personnel assessment and technical quality schedule control, strengthen material management, civilized construction, so as to ensure quality, speed up progress, reduce construction costs, and achieve good economic and social benefits.
文摘Today,with nonstop improvement in computational power,Large-Eddy Simulation(LES) is a high demanding research tool for predicting engineering flows.Such flows on high pressure condition like diesel engines is extensively employed in ground and marine transportation,oblige the designer to control and predict toxic pollutants,while maintaining or improving their high thermal efficiency.This becomes one of the main challenging issues in decades.In the present work,numerical investigation of diffusion flame dynamics is performed in the near-field of high-Reynolds jet flow on high pressure condition encountered in diesel engine applications.This work discusses the implementation of Partially Stirred Reactor(PaSR) combustion model by the approaches of large eddy simulation(LES).The simulation results show that LES,in comparison with Reynolds-Averaged Navier-Stokes(RANS) simulation predicts and captures transient phenomena very well.These phenomena such as unsteadiness and curvature are inherent in the near-field of high Reynolds diffusion flame.The outcomes of this research are compared and validated by other researchers' results.Detailed comparisons of the statistics show good agreement with the corresponding experiments.
