Based on Newton’s second law and the thermal network method,a mechanical thermal coupling model of the bearing rotor system of high-speed trains is established to study the interaction between the bearing vibration a...Based on Newton’s second law and the thermal network method,a mechanical thermal coupling model of the bearing rotor system of high-speed trains is established to study the interaction between the bearing vibration and temperature.The influence of lubrication on the vibration and temperature characteristics of the system is considered in the model,and the real-time relationship between them is built up by using the transient temperature field model.After considering the lubrication,the bearing outer ring vibration acceleration and node temperature considering grease are lower,which shows the necessity of adding the lubrication model.The corresponding experiments for characteristics of vibration and temperature of the model are respectively conducted.In the envelope spectrum obtained from the simulation signal and the experimental signal,the frequency values corresponding to the peaks are close to the theoretical calculation results,and the error is very small.In the three stages of the temperature characteristic experiment,the node temperature change of the simulation model is consistent with the experiment.The good agreement between simulation and experiments proves the effectiveness of the model.By studying the influence of the bearing angular and fault size on the system node temperature,as well as the change law of bearing lubrication characteristics and temperature,it is found that the worse the working condition is,the higher the temperature is.When the ambient temperature is low,the viscosity of grease increases,and the oil film becomes thicker,which increases the sliding probability of the rolling element,thus affecting the normal operation of the bearing,which explains the phenomenon of frequent bearing faults of high-speed trains in the low-temperature area of Northeast China.Further analysis shows that faults often occur in the early stage of train operation in the low-temperature environment.展开更多
为贯彻落实碳达峰碳中和(简称“双碳”)目标,促进低碳产业发展,国家采取一系列碳减排政策推动能源系统低碳转型。构建了考虑碳减排收益的电-热耦合系统低碳扩展规划模型,同时考虑到系统中具有的大量源-荷不确定性,基于信息间隙决策理论(...为贯彻落实碳达峰碳中和(简称“双碳”)目标,促进低碳产业发展,国家采取一系列碳减排政策推动能源系统低碳转型。构建了考虑碳减排收益的电-热耦合系统低碳扩展规划模型,同时考虑到系统中具有的大量源-荷不确定性,基于信息间隙决策理论(information gap decision theory,IGDT)构建鲁棒低碳规划模型与机会低碳规划模型。采用IEEE-13节点配网和32节点热网组成的能源系统测试算例对模型进行对比验证,分析了鲁棒模型的风险规避特点以及机会模型的寻求收益特点,验证了IGDT方法在不确定信息并不充足时仍然能够量化不确定性,且能根据规划决策者不同的风险偏好在预期的投资成本范围内求得相应的最优规划结果。同时,对比了碳减排收益对两种低碳规划模型的影响,分析了两种模型的不确定性与碳减排收益的关系。最后,分析了储能配置对低碳规划的影响。算例结果证明了储能配置可有效降低两类规划模型的投资成本,即储能投资对规划决策者的风险偏好选择不敏感。展开更多
基金supported by the National Key R&D Program of China(No.2020YFB2007700)the National Natural Science Foundation of China(Nos.11790282,12032017,12002221,and 11872256)+1 种基金the S&T Program of Hebei Province of China(No.20310803D)the Natural Science Foundation of Hebei Province of China(No.A2020210028)。
文摘Based on Newton’s second law and the thermal network method,a mechanical thermal coupling model of the bearing rotor system of high-speed trains is established to study the interaction between the bearing vibration and temperature.The influence of lubrication on the vibration and temperature characteristics of the system is considered in the model,and the real-time relationship between them is built up by using the transient temperature field model.After considering the lubrication,the bearing outer ring vibration acceleration and node temperature considering grease are lower,which shows the necessity of adding the lubrication model.The corresponding experiments for characteristics of vibration and temperature of the model are respectively conducted.In the envelope spectrum obtained from the simulation signal and the experimental signal,the frequency values corresponding to the peaks are close to the theoretical calculation results,and the error is very small.In the three stages of the temperature characteristic experiment,the node temperature change of the simulation model is consistent with the experiment.The good agreement between simulation and experiments proves the effectiveness of the model.By studying the influence of the bearing angular and fault size on the system node temperature,as well as the change law of bearing lubrication characteristics and temperature,it is found that the worse the working condition is,the higher the temperature is.When the ambient temperature is low,the viscosity of grease increases,and the oil film becomes thicker,which increases the sliding probability of the rolling element,thus affecting the normal operation of the bearing,which explains the phenomenon of frequent bearing faults of high-speed trains in the low-temperature area of Northeast China.Further analysis shows that faults often occur in the early stage of train operation in the low-temperature environment.
文摘为贯彻落实碳达峰碳中和(简称“双碳”)目标,促进低碳产业发展,国家采取一系列碳减排政策推动能源系统低碳转型。构建了考虑碳减排收益的电-热耦合系统低碳扩展规划模型,同时考虑到系统中具有的大量源-荷不确定性,基于信息间隙决策理论(information gap decision theory,IGDT)构建鲁棒低碳规划模型与机会低碳规划模型。采用IEEE-13节点配网和32节点热网组成的能源系统测试算例对模型进行对比验证,分析了鲁棒模型的风险规避特点以及机会模型的寻求收益特点,验证了IGDT方法在不确定信息并不充足时仍然能够量化不确定性,且能根据规划决策者不同的风险偏好在预期的投资成本范围内求得相应的最优规划结果。同时,对比了碳减排收益对两种低碳规划模型的影响,分析了两种模型的不确定性与碳减排收益的关系。最后,分析了储能配置对低碳规划的影响。算例结果证明了储能配置可有效降低两类规划模型的投资成本,即储能投资对规划决策者的风险偏好选择不敏感。
