The specialized equipment utilized in long-line tunnel engineering is evolving towards large-scale,multifunctional,and complex orientations.The vibration caused by the high-frequency units during regular operation is ...The specialized equipment utilized in long-line tunnel engineering is evolving towards large-scale,multifunctional,and complex orientations.The vibration caused by the high-frequency units during regular operation is supported by the foundation of the units,and the magnitude of vibration and the operating frequency fluctuate in different engineering contexts,leading to variations in the dynamic response of the foundation.The high-frequency units yield significantly diverse outcomes under different startup conditions and times,resulting in failure to meet operational requirements,influencing the normal function of the tunnel,and causing harm to the foundation structure,personnel,and property in severe cases.This article formulates a finite element numerical computation model for solid elements using three-dimensional elastic body theory and integrates field measurements to substantiate and ascertain the crucial parameter configurations of the finite element model.By proposing a comprehensive startup timing function for high-frequency dynamic machines under different startup conditions,simulating the frequency andmagnitude variations during the startup process,and suggesting functions for changes in frequency and magnitude,a simulated startup schedule function for high-frequency machines is created through coupling.Taking into account the selection of the transient dynamic analysis step length,the dynamic response results for the lower dynamic foundation during its fundamental frequency crossing process are obtained.The validation checks if the structural magnitude surpasses the safety threshold during the critical phase of unit startup traversing the structural resonance region.The design recommendations for high-frequency units’dynamic foundations are provided,taking into account the startup process of the machine and ensuring the safe operation of the tunnel.展开更多
With the development of electronic equipment to high accuracy, high density, high frequency, and atrocious ser- vice environment, the functional surface in this type of equipment has increasingly serious problems,
The matters of equipment optimization development are usually discrete,fuzzy and non-quantitative.It is difficult directly to optimize the equipment development with a mathematical model.A set of methods for designing...The matters of equipment optimization development are usually discrete,fuzzy and non-quantitative.It is difficult directly to optimize the equipment development with a mathematical model.A set of methods for designing the equipment optimization development with six dimensions and eight main elements is established based on the theory and method of standardization.The top-tier design space of systematic development of equipment is built up by the relations of basic models,series and model spectrums.The relations of time and space for equipment optimization development are established.The design processes of a six dimension systematic space are expounded.The connotation of each plan in the main system space is analyzed.A design method for an entire equipment is established with standardization theory.The coordinating design methods of equipment technical system and the optimization design methods of equipment integration are discussed.The design methods for universalization and serialization of components and parts are established.The design methods of equipment optimization development highlight the relations of the basic model of platform,the serialization of platform basic models,the modularization of equipment functions,the model spectrum of variant equipment,and the universalization and serialization of components and parts.展开更多
A new type of impedance-balanced ship equipment foundation structure based on the principle of impedance balancing using a“discontinuous panel-vibration isolation liquid layer-foundation structure”is proposed to sol...A new type of impedance-balanced ship equipment foundation structure based on the principle of impedance balancing using a“discontinuous panel-vibration isolation liquid layer-foundation structure”is proposed to solve the problem of poor low-frequency vibration isolation of the foundation under unbalanced excitation of shipboard equipment.Based on the finite element method,the influence of characteristic parameters of the foundation panel structure on its vibration reduction characteristics under unbalanced excitation is explored.The results show that the vibration isolation level of the impedance-balanced foundation is 10 dB higher than the traditional foundation in the low-frequency band of 10-500 Hz when subjected to combined excitation of concentrated force and moment.Increasing the thickness of the impedance-balanced foundation panel can enhance the isolation effect.Increasing the number of sub-panels can effectively reduce the vibration response of the foundation panel and enhance the isolation performance of the foundation.The connection stiffness between sub-panels has a small effect on the isolation performance of the foundation.展开更多
The type of pinion and rack vertical shiplifts has been developed in recent a couple of years in the construction of dams.But the design methods and methodologies have rarely been discussed in literature.The Xiangjiab...The type of pinion and rack vertical shiplifts has been developed in recent a couple of years in the construction of dams.But the design methods and methodologies have rarely been discussed in literature.The Xiangjiaba shiplift is the second shiplift of this type following the Three Gorges shiplift.Being aimed at the technological rationality of the design in synthetically considering security,economy and applicability,this paper presents the research results of some vital issues relating the design of the Xiangjiaba shiplift,including the determination of design water depth of ship chamber based on fluid numeral computation and physical model test,the optimum design of general layout of main equipments and the civil structure of the Xiangjiaba shiplift,the finite element method(FEM) analysis of stress,vibration modes and the buckling of ship chamber,antiseismic research and the design of structures and mechanisms of the shiplift and the optimum design of driving mechanisms.This research provides the theoretical basis for the design of the Xiangjiaba shiplift.The design principles and research methods are valuable for the design of the same type of shiplifts.展开更多
Selecting the optimal one from similar schemes is a paramount work in equipment design.In consideration of similarity of schemes and repetition of characteristic indices,the theory of set pair analysis(SPA)is proposed...Selecting the optimal one from similar schemes is a paramount work in equipment design.In consideration of similarity of schemes and repetition of characteristic indices,the theory of set pair analysis(SPA)is proposed,and then an optimal selection model is established.In order to improve the accuracy and flexibility,the model is modified by the contribution degree.At last,this model has been validated by an example,and the result demonstrates the method is feasible and valuable for practical usage.展开更多
Combined with equipment activities such as combat readiness,training, exercises and management, it is proposed that the design of equipment in-service assessment subjects should follow the principles of combination, s...Combined with equipment activities such as combat readiness,training, exercises and management, it is proposed that the design of equipment in-service assessment subjects should follow the principles of combination, stage and operability. Focusing on the design of equipment in-serviceassessment subjects, a design method for in-service assessment subjects basedon the combination of trial and training mode is proposed. Based on theactual use of high-equipment use management and training and the established indicator system, the army’s bottom-level equipment activity subjectsand bottom-level assessments are combined. The indicators are mapped andanalyzed. Through multiple rounds of iterations, the mapping relationshipbetween in-service assessment indicators and military equipment activitysubjects is established. Finally, the equipment activity subjects whose data iscollected (reflecting the underlying assessment indicators) are generated inservice assessment subjects. The orthogonal test method is used to optimizethe samples in the assessment subjects to form an in-service assessmentimplementation plan. Taking a certain type of armored infantry fightingvehicle as an example, the sample optimization design of the initially generatedin-service assessment subjects is analyzed. It provides methods and ideas tocarry out in-service assessment work.展开更多
We carried out researches on the syllabus design for the specialty of electromechanical equipment maintenance & management in vocational college. Our researches involve the following aspects: (1) The training obje...We carried out researches on the syllabus design for the specialty of electromechanical equipment maintenance & management in vocational college. Our researches involve the following aspects: (1) The training objective of the specialty; (2) the curriculum system; (3) The teaching methodology; and (4) Field training.展开更多
Characteristic period is an important parameter of the seismic design response spectrum.There is important theoretical significance and engineering application value to the study of the characteristic period of seismi...Characteristic period is an important parameter of the seismic design response spectrum.There is important theoretical significance and engineering application value to the study of the characteristic period of seismic design response spectrum of ultra high voltage(UHV)electrical equipment.In this paper,1448 horizontal earthquake records within the world scope including the United States and Japan for Site Class Ⅲ were analyzed.Results show that both magnitude and epicentral distance have great influence on the characteristic period.About80% of characteristic periods of strong earthquake records are about 0.9s.Statistical analysis was conducted on the seismic hazard assessment results of 312 projects of China in recent years,and it is found that about 70% of characteristic periods are about 0.9s.Combined with the related code comparison and analysis,it is suggested that the characteristic period of the seismic design response spectrum of UHV electrical equipment should select 0.9s in order to effectively guarantee the seismic safety of UHV electrical equipment.展开更多
Objective The evaluation index of medical equipment's economic benefit is based on the usage of medical equipment,the traditional data collection method is time-consuming,laborious and not entirely accurate.The us...Objective The evaluation index of medical equipment's economic benefit is based on the usage of medical equipment,the traditional data collection method is time-consuming,laborious and not entirely accurate.The usage of medical equipment is obtained by designing data query statements from the HIS system.Methods First the charging items are in correspondence with the device's name included,second fees and other relevant data are extracted from charging module in HIS.Through a rough estimate of the recovery period and an increase or decrease ratio,the economic benefit of the medical equipment can be analyzed.Results Through the method of the benefit analysis of the medical equipment,we can clearly find out the different economic benefit of the equipment,and finally analyze the reasons.Conclusion Practice has proved that,this methad,it can greatly reduce human,material resources required in data collection and improve the accuracy of the data.It can help hospital managers timely to grasp the operating costs of medical equipment and other information,and also provide scientific data for hospital managers when they purchase reasonable medical equipment.展开更多
Since the excessive capacity in steelmaking and continuous casting at present,and the limited development margin of CC technology and equipment in scale,the further development must be made in a profound and detailize...Since the excessive capacity in steelmaking and continuous casting at present,and the limited development margin of CC technology and equipment in scale,the further development must be made in a profound and detailized way.This paper enumerates the items of CC technology and equipment,which need to be detailized from several aspects such as roll arrangement design,equipment design and production operation,and it points out that detailization is the future direction of CC technology and equipment.The items in roll arrangement design include eliminating periodic meniscus fluctuation by adjusting space between rolls reasonably;taking special measures to avoid dangerous regions of casting speed,in order to reduce the center porosity and centerline crack of slab;optimizing the major radius and the length of outer arc of caster before straightening point to avoid dangerous region of casting speed.The items in equipment design include choosing a suitable structure of support and guiding roll according to the concrete conditions of caster;according to bulging shape of slab,thinking more about restriction of shell to bulging force, discussing the force on rollers,optimizing split roll to support slab;safety factor should be considered together with calculation method of the bearing nominal static load.The items in aspects of continuous casting operation include the delicacy division and the function-positioning of operation modes for CC machine due to the consideration of dynamic soft reduction;monitoring and controlling system of CC machine must be further detailized to improve the stability of production operation and slab quality.In addition to the three aspects mentioned above,this article points out many other items also,such as homogenization of secondary cooling of slab,quality control of surface and internal of slab,and so on.This article emphasizes,some key technologies need to be researched also,and all these researches will never stop.展开更多
This article, based on investigation and analysis, existed anaerobic fermentation equipment, with a view to the production of high-latitude area, pointed out the thought of exploiting efficient anaerobic fermentation ...This article, based on investigation and analysis, existed anaerobic fermentation equipment, with a view to the production of high-latitude area, pointed out the thought of exploiting efficient anaerobic fermentation equipment, including: the settting independent equipment of acidogenic phase and methanogenic phase; the applying conbination of AF and UASB in methanogenic phase; adopting efficient sludge inverse flowing equipment and the technique of flora enrichment, and efficient method of saving energy and thermal retardation; adopting autocontrol which could make the equipment run efficiently and stably.展开更多
In view of the low level testability of armored equipment,the important significance of armored equipment testability growth is discussed in this paper.The failure mode effects and criticality analysis( FMECA) method ...In view of the low level testability of armored equipment,the important significance of armored equipment testability growth is discussed in this paper.The failure mode effects and criticality analysis( FMECA) method to realize testability growth is introduced.Centering on the testability growth demands of new armored equipment,the deficiencies of traditional FMECA are analyzed.And an enhanced FMECA( EFMECA) method is proposed.The method increases the analysis contents,combines the information before the failure occurrence and impending failure modes together organically.Then the failure symptoms is analyzed,the failure modes and effects is determined,and the state development trend is predicted.Finally,the application of EFMECA method is illustrated by the example of the failure mode of typical armored equipment engine.展开更多
The numerous environmental protection equipments for desulfuration,denitration,and precipitation have been installed in the domestic coal-fired power plants,while the investment and energy consumption of the units inc...The numerous environmental protection equipments for desulfuration,denitration,and precipitation have been installed in the domestic coal-fired power plants,while the investment and energy consumption of the units increase correspondingly.To reduce the operational cost and initial investment as much as possible,the working processes of the environmental protection equipments are optimized in the design and some new technologies are adopted for energy saving.These technologies include the SCR,SNCR,combined SCR and SNCR for denitration device,system without gas-gas heater design for desulfuration,desulfuration system without bypass,booster fan and induced draft fan integrated,stack and cooling tower integrated and so on.However,such measures may cause some new problems during the operation of the equipment.The problems are summarized and analyzed thoroughly and the feasible methods are provided to solve them,which could decrease the operational risk of units.The present discussion can also improve the further design of environmental protection equipments to ensure the long-term steady operation of the units.展开更多
基金Smart Integration Key Technologies and Application Demonstrations of Large Scale Underground Space Disaster Prevention and Reduction in Guangzhou International Financial City([2021]–KJ058).
文摘The specialized equipment utilized in long-line tunnel engineering is evolving towards large-scale,multifunctional,and complex orientations.The vibration caused by the high-frequency units during regular operation is supported by the foundation of the units,and the magnitude of vibration and the operating frequency fluctuate in different engineering contexts,leading to variations in the dynamic response of the foundation.The high-frequency units yield significantly diverse outcomes under different startup conditions and times,resulting in failure to meet operational requirements,influencing the normal function of the tunnel,and causing harm to the foundation structure,personnel,and property in severe cases.This article formulates a finite element numerical computation model for solid elements using three-dimensional elastic body theory and integrates field measurements to substantiate and ascertain the crucial parameter configurations of the finite element model.By proposing a comprehensive startup timing function for high-frequency dynamic machines under different startup conditions,simulating the frequency andmagnitude variations during the startup process,and suggesting functions for changes in frequency and magnitude,a simulated startup schedule function for high-frequency machines is created through coupling.Taking into account the selection of the transient dynamic analysis step length,the dynamic response results for the lower dynamic foundation during its fundamental frequency crossing process are obtained.The validation checks if the structural magnitude surpasses the safety threshold during the critical phase of unit startup traversing the structural resonance region.The design recommendations for high-frequency units’dynamic foundations are provided,taking into account the startup process of the machine and ensuring the safe operation of the tunnel.
文摘With the development of electronic equipment to high accuracy, high density, high frequency, and atrocious ser- vice environment, the functional surface in this type of equipment has increasingly serious problems,
文摘The matters of equipment optimization development are usually discrete,fuzzy and non-quantitative.It is difficult directly to optimize the equipment development with a mathematical model.A set of methods for designing the equipment optimization development with six dimensions and eight main elements is established based on the theory and method of standardization.The top-tier design space of systematic development of equipment is built up by the relations of basic models,series and model spectrums.The relations of time and space for equipment optimization development are established.The design processes of a six dimension systematic space are expounded.The connotation of each plan in the main system space is analyzed.A design method for an entire equipment is established with standardization theory.The coordinating design methods of equipment technical system and the optimization design methods of equipment integration are discussed.The design methods for universalization and serialization of components and parts are established.The design methods of equipment optimization development highlight the relations of the basic model of platform,the serialization of platform basic models,the modularization of equipment functions,the model spectrum of variant equipment,and the universalization and serialization of components and parts.
基金funded by the National Natural Science Foundation of China(Grant Numbers.U2006229 and 52101351)。
文摘A new type of impedance-balanced ship equipment foundation structure based on the principle of impedance balancing using a“discontinuous panel-vibration isolation liquid layer-foundation structure”is proposed to solve the problem of poor low-frequency vibration isolation of the foundation under unbalanced excitation of shipboard equipment.Based on the finite element method,the influence of characteristic parameters of the foundation panel structure on its vibration reduction characteristics under unbalanced excitation is explored.The results show that the vibration isolation level of the impedance-balanced foundation is 10 dB higher than the traditional foundation in the low-frequency band of 10-500 Hz when subjected to combined excitation of concentrated force and moment.Increasing the thickness of the impedance-balanced foundation panel can enhance the isolation effect.Increasing the number of sub-panels can effectively reduce the vibration response of the foundation panel and enhance the isolation performance of the foundation.The connection stiffness between sub-panels has a small effect on the isolation performance of the foundation.
文摘The type of pinion and rack vertical shiplifts has been developed in recent a couple of years in the construction of dams.But the design methods and methodologies have rarely been discussed in literature.The Xiangjiaba shiplift is the second shiplift of this type following the Three Gorges shiplift.Being aimed at the technological rationality of the design in synthetically considering security,economy and applicability,this paper presents the research results of some vital issues relating the design of the Xiangjiaba shiplift,including the determination of design water depth of ship chamber based on fluid numeral computation and physical model test,the optimum design of general layout of main equipments and the civil structure of the Xiangjiaba shiplift,the finite element method(FEM) analysis of stress,vibration modes and the buckling of ship chamber,antiseismic research and the design of structures and mechanisms of the shiplift and the optimum design of driving mechanisms.This research provides the theoretical basis for the design of the Xiangjiaba shiplift.The design principles and research methods are valuable for the design of the same type of shiplifts.
文摘Selecting the optimal one from similar schemes is a paramount work in equipment design.In consideration of similarity of schemes and repetition of characteristic indices,the theory of set pair analysis(SPA)is proposed,and then an optimal selection model is established.In order to improve the accuracy and flexibility,the model is modified by the contribution degree.At last,this model has been validated by an example,and the result demonstrates the method is feasible and valuable for practical usage.
文摘Combined with equipment activities such as combat readiness,training, exercises and management, it is proposed that the design of equipment in-service assessment subjects should follow the principles of combination, stage and operability. Focusing on the design of equipment in-serviceassessment subjects, a design method for in-service assessment subjects basedon the combination of trial and training mode is proposed. Based on theactual use of high-equipment use management and training and the established indicator system, the army’s bottom-level equipment activity subjectsand bottom-level assessments are combined. The indicators are mapped andanalyzed. Through multiple rounds of iterations, the mapping relationshipbetween in-service assessment indicators and military equipment activitysubjects is established. Finally, the equipment activity subjects whose data iscollected (reflecting the underlying assessment indicators) are generated inservice assessment subjects. The orthogonal test method is used to optimizethe samples in the assessment subjects to form an in-service assessmentimplementation plan. Taking a certain type of armored infantry fightingvehicle as an example, the sample optimization design of the initially generatedin-service assessment subjects is analyzed. It provides methods and ideas tocarry out in-service assessment work.
文摘We carried out researches on the syllabus design for the specialty of electromechanical equipment maintenance & management in vocational college. Our researches involve the following aspects: (1) The training objective of the specialty; (2) the curriculum system; (3) The teaching methodology; and (4) Field training.
基金founded by the Earthquake Science and Technology Spark Plan of China(XH12063)
文摘Characteristic period is an important parameter of the seismic design response spectrum.There is important theoretical significance and engineering application value to the study of the characteristic period of seismic design response spectrum of ultra high voltage(UHV)electrical equipment.In this paper,1448 horizontal earthquake records within the world scope including the United States and Japan for Site Class Ⅲ were analyzed.Results show that both magnitude and epicentral distance have great influence on the characteristic period.About80% of characteristic periods of strong earthquake records are about 0.9s.Statistical analysis was conducted on the seismic hazard assessment results of 312 projects of China in recent years,and it is found that about 70% of characteristic periods are about 0.9s.Combined with the related code comparison and analysis,it is suggested that the characteristic period of the seismic design response spectrum of UHV electrical equipment should select 0.9s in order to effectively guarantee the seismic safety of UHV electrical equipment.
文摘Objective The evaluation index of medical equipment's economic benefit is based on the usage of medical equipment,the traditional data collection method is time-consuming,laborious and not entirely accurate.The usage of medical equipment is obtained by designing data query statements from the HIS system.Methods First the charging items are in correspondence with the device's name included,second fees and other relevant data are extracted from charging module in HIS.Through a rough estimate of the recovery period and an increase or decrease ratio,the economic benefit of the medical equipment can be analyzed.Results Through the method of the benefit analysis of the medical equipment,we can clearly find out the different economic benefit of the equipment,and finally analyze the reasons.Conclusion Practice has proved that,this methad,it can greatly reduce human,material resources required in data collection and improve the accuracy of the data.It can help hospital managers timely to grasp the operating costs of medical equipment and other information,and also provide scientific data for hospital managers when they purchase reasonable medical equipment.
文摘Since the excessive capacity in steelmaking and continuous casting at present,and the limited development margin of CC technology and equipment in scale,the further development must be made in a profound and detailized way.This paper enumerates the items of CC technology and equipment,which need to be detailized from several aspects such as roll arrangement design,equipment design and production operation,and it points out that detailization is the future direction of CC technology and equipment.The items in roll arrangement design include eliminating periodic meniscus fluctuation by adjusting space between rolls reasonably;taking special measures to avoid dangerous regions of casting speed,in order to reduce the center porosity and centerline crack of slab;optimizing the major radius and the length of outer arc of caster before straightening point to avoid dangerous region of casting speed.The items in equipment design include choosing a suitable structure of support and guiding roll according to the concrete conditions of caster;according to bulging shape of slab,thinking more about restriction of shell to bulging force, discussing the force on rollers,optimizing split roll to support slab;safety factor should be considered together with calculation method of the bearing nominal static load.The items in aspects of continuous casting operation include the delicacy division and the function-positioning of operation modes for CC machine due to the consideration of dynamic soft reduction;monitoring and controlling system of CC machine must be further detailized to improve the stability of production operation and slab quality.In addition to the three aspects mentioned above,this article points out many other items also,such as homogenization of secondary cooling of slab,quality control of surface and internal of slab,and so on.This article emphasizes,some key technologies need to be researched also,and all these researches will never stop.
基金Supported by National Natural Sciences Foundation(20040224001)
文摘This article, based on investigation and analysis, existed anaerobic fermentation equipment, with a view to the production of high-latitude area, pointed out the thought of exploiting efficient anaerobic fermentation equipment, including: the settting independent equipment of acidogenic phase and methanogenic phase; the applying conbination of AF and UASB in methanogenic phase; adopting efficient sludge inverse flowing equipment and the technique of flora enrichment, and efficient method of saving energy and thermal retardation; adopting autocontrol which could make the equipment run efficiently and stably.
文摘In view of the low level testability of armored equipment,the important significance of armored equipment testability growth is discussed in this paper.The failure mode effects and criticality analysis( FMECA) method to realize testability growth is introduced.Centering on the testability growth demands of new armored equipment,the deficiencies of traditional FMECA are analyzed.And an enhanced FMECA( EFMECA) method is proposed.The method increases the analysis contents,combines the information before the failure occurrence and impending failure modes together organically.Then the failure symptoms is analyzed,the failure modes and effects is determined,and the state development trend is predicted.Finally,the application of EFMECA method is illustrated by the example of the failure mode of typical armored equipment engine.
文摘The numerous environmental protection equipments for desulfuration,denitration,and precipitation have been installed in the domestic coal-fired power plants,while the investment and energy consumption of the units increase correspondingly.To reduce the operational cost and initial investment as much as possible,the working processes of the environmental protection equipments are optimized in the design and some new technologies are adopted for energy saving.These technologies include the SCR,SNCR,combined SCR and SNCR for denitration device,system without gas-gas heater design for desulfuration,desulfuration system without bypass,booster fan and induced draft fan integrated,stack and cooling tower integrated and so on.However,such measures may cause some new problems during the operation of the equipment.The problems are summarized and analyzed thoroughly and the feasible methods are provided to solve them,which could decrease the operational risk of units.The present discussion can also improve the further design of environmental protection equipments to ensure the long-term steady operation of the units.