In the process of tunneling of tunnel boring machine (TBM), different geological conditions often correspond to different working conditions, and the randomness of geological conditions also causes the order of occurr...In the process of tunneling of tunnel boring machine (TBM), different geological conditions often correspond to different working conditions, and the randomness of geological conditions also causes the order of occurrence of each working condition to be different. Under the conversion of different working conditions, this makes the vibration of different types of cutterheads different. How to choose the appropriate type of cutterhead according to different geological conditions is very important for saving engineering cost and increasing cutterhead life. In view of the above situation, this paper proposes a stability evaluation method during the TBM tunneling process to select the appropriate cutterhead type. Firstly, the corresponding relationship between geology and working conditions is established according to different geological conditions, and the input loads corresponding to geological conditions are obtained. Then, it is substituted into the dynamic model of the cutterhead system, the vibration response boundaries of each degree of freedom are obtained by solving. And the average value of the maximum boundary amplitude of each degree of freedom is taken to represent the extreme vibration of the cutterhead under the corresponding working conditions. Finally, by comparing the fluctuation of the ultimate vibration amplitude of each type of cutterhead in the process of working condition conversion, the results are as follows: when the transition between homogeneous strata and composite strata is normal and there is no large turning and deviation correction, the vibration response of the two-part cutterhead is the smallest, and the two-part cutterhead is the best choice. Otherwise, the five-part cutterhead is the best choice, while the stability of the integrated cutterhead is the worst.展开更多
This paper summarized the pressure control methods used in 16 large-scale production facilities in China for vaccines against foot-and-mouth disease virus and highly pathogenic avian influenza virus.We presented the p...This paper summarized the pressure control methods used in 16 large-scale production facilities in China for vaccines against foot-and-mouth disease virus and highly pathogenic avian influenza virus.We presented the pressure control modes,with their characteristics,of the"constant supply"mode-variable exhaust air volume system and the"constant supply"mode-constant exhaust air volume system.This paper analyzed the influence of common problems(e.g.,pressure reference zero drift,positive pressure reversal and failure to restore the original normal working conditions after working condition conversion)on system stability during pressure control in BSL-3 large-scale production facilities and their solutions,providing references for the design and implementation of similar construction projects under the new situation.展开更多
基金National Natural Science Foundation of China(Grant No. 51875076) NSFC-Liaoning United Key fund (Grant No. U1708255).
文摘In the process of tunneling of tunnel boring machine (TBM), different geological conditions often correspond to different working conditions, and the randomness of geological conditions also causes the order of occurrence of each working condition to be different. Under the conversion of different working conditions, this makes the vibration of different types of cutterheads different. How to choose the appropriate type of cutterhead according to different geological conditions is very important for saving engineering cost and increasing cutterhead life. In view of the above situation, this paper proposes a stability evaluation method during the TBM tunneling process to select the appropriate cutterhead type. Firstly, the corresponding relationship between geology and working conditions is established according to different geological conditions, and the input loads corresponding to geological conditions are obtained. Then, it is substituted into the dynamic model of the cutterhead system, the vibration response boundaries of each degree of freedom are obtained by solving. And the average value of the maximum boundary amplitude of each degree of freedom is taken to represent the extreme vibration of the cutterhead under the corresponding working conditions. Finally, by comparing the fluctuation of the ultimate vibration amplitude of each type of cutterhead in the process of working condition conversion, the results are as follows: when the transition between homogeneous strata and composite strata is normal and there is no large turning and deviation correction, the vibration response of the two-part cutterhead is the smallest, and the two-part cutterhead is the best choice. Otherwise, the five-part cutterhead is the best choice, while the stability of the integrated cutterhead is the worst.
基金supported and financially funded by the National Key R&D Program of China:Source identification,monitoring and integrated control of indoor microbial contamination(No.2017YFC0702800).
文摘This paper summarized the pressure control methods used in 16 large-scale production facilities in China for vaccines against foot-and-mouth disease virus and highly pathogenic avian influenza virus.We presented the pressure control modes,with their characteristics,of the"constant supply"mode-variable exhaust air volume system and the"constant supply"mode-constant exhaust air volume system.This paper analyzed the influence of common problems(e.g.,pressure reference zero drift,positive pressure reversal and failure to restore the original normal working conditions after working condition conversion)on system stability during pressure control in BSL-3 large-scale production facilities and their solutions,providing references for the design and implementation of similar construction projects under the new situation.
