Based on K ε two equation turbulence model,the air distribution and contamination field under different conditions was numerically simulated in a vector flow cleanroom.Special mesh system was introduced to deal wit...Based on K ε two equation turbulence model,the air distribution and contamination field under different conditions was numerically simulated in a vector flow cleanroom.Special mesh system was introduced to deal with the quarter circle shaped inlets.Model experiments were also made.By analysis of numerical as well as experimental results,we made some predictions about flow characteristics,contaminant control effect and ventilation performance of this energy saving cleanroom.It has been proved that the vector flow can meet class 100 of Fed. St.with 13 to 12 conventional air change per hour,and reduce layer height and simplify air clean system.展开更多
Cleanroom software engineering has been proven effective in improving software development quality while at the same time increasing reliability. To adapt to large software system development, the paper presents an ex...Cleanroom software engineering has been proven effective in improving software development quality while at the same time increasing reliability. To adapt to large software system development, the paper presents an extended the Cleanroom model, which integrates object-oriented method based on stimulus history, reversed engineering idea, automatic testing and reliability assessment into software development. The paper discusses the architecture and realizing technology of ECM.展开更多
Keeping pressure gradient is an excellent approach to prevent the reveal of </span><span style="font-family:"white-space:normal;">airflow direction and cross infection in manufacturing ...Keeping pressure gradient is an excellent approach to prevent the reveal of </span><span style="font-family:"white-space:normal;">airflow direction and cross infection in manufacturing circumstances of ph</span><span style="font-family:"white-space:normal;">armaceutical cleanrooms, thus how to keep cleanroom’s pressure is critical. In </span><span style="font-family:"white-space:normal;">the paper, we study a positive pressure pharmaceutical cleanroom system wh</span><span style="font-family:"white-space:normal;">ich is composed by a cleanroom and an airlock. We divide the system’s disturbances into step disturbance, ramp disturbance and sine wave disturbance. </span><span style="font-family:"white-space:normal;">We design its pressure gradient control strategies, including CAV control, PI</span><span style="font-family:"white-space:normal;">D control and active-disturbance-rejection-control. We build the system’s mod</span><span style="font-family:"white-space:normal;">el and make simulations based on Matlab/Simulink software platform. Re</span><span style="font-family:"white-space:normal;">sults show that active-disturbance-rejection-control algorithm has good capabilities for shorter responding time and lower overshot of the pressure gradient. The results reveal that active-disturbance-rejection-control method has good control performances in responding time, accuracy and disturbance rejection.展开更多
This summary has introduced the development process of clean technology, and demonstrated the current status and development of cleanroom and relevant environment technology at home and abroad.
文摘Based on K ε two equation turbulence model,the air distribution and contamination field under different conditions was numerically simulated in a vector flow cleanroom.Special mesh system was introduced to deal with the quarter circle shaped inlets.Model experiments were also made.By analysis of numerical as well as experimental results,we made some predictions about flow characteristics,contaminant control effect and ventilation performance of this energy saving cleanroom.It has been proved that the vector flow can meet class 100 of Fed. St.with 13 to 12 conventional air change per hour,and reduce layer height and simplify air clean system.
文摘Cleanroom software engineering has been proven effective in improving software development quality while at the same time increasing reliability. To adapt to large software system development, the paper presents an extended the Cleanroom model, which integrates object-oriented method based on stimulus history, reversed engineering idea, automatic testing and reliability assessment into software development. The paper discusses the architecture and realizing technology of ECM.
文摘Keeping pressure gradient is an excellent approach to prevent the reveal of </span><span style="font-family:"white-space:normal;">airflow direction and cross infection in manufacturing circumstances of ph</span><span style="font-family:"white-space:normal;">armaceutical cleanrooms, thus how to keep cleanroom’s pressure is critical. In </span><span style="font-family:"white-space:normal;">the paper, we study a positive pressure pharmaceutical cleanroom system wh</span><span style="font-family:"white-space:normal;">ich is composed by a cleanroom and an airlock. We divide the system’s disturbances into step disturbance, ramp disturbance and sine wave disturbance. </span><span style="font-family:"white-space:normal;">We design its pressure gradient control strategies, including CAV control, PI</span><span style="font-family:"white-space:normal;">D control and active-disturbance-rejection-control. We build the system’s mod</span><span style="font-family:"white-space:normal;">el and make simulations based on Matlab/Simulink software platform. Re</span><span style="font-family:"white-space:normal;">sults show that active-disturbance-rejection-control algorithm has good capabilities for shorter responding time and lower overshot of the pressure gradient. The results reveal that active-disturbance-rejection-control method has good control performances in responding time, accuracy and disturbance rejection.
文摘This summary has introduced the development process of clean technology, and demonstrated the current status and development of cleanroom and relevant environment technology at home and abroad.
