离心泵瞬时启动过程的仿真

Simulation on performance of centrifugal pump during rapid startup period

为了更进一步研究高比转数大功率离心泵的瞬时工况,应用Flowmaster软件搭建离心泵运行模型,根据实际测量参数设置边界条件进行仿真并与试验结果进行对比,在可信的情况下,针对泵不同的启动方式进行仿真分析,量化了星-三角启动的优点.在此基础上,在不同阀门开度下,获得了离心泵的瞬时启动转速、流量、功率和出口压力的特性曲线,进而进行量纲一化分析.结果表明,星-三角启动属于缓慢启动方式,启动过程平缓,且整个过程中功率增长均匀,对设备冲击小;在离心泵的启动过程中,流量上升特性主要取决于电动机自身的启动特性,且在初期时上升缓慢,使流量达到稳定的时间大大滞后于转速达到稳定的时间;量纲为一的系数一直变化,与准稳态假设不符,从而得出离心泵启动时清晰的瞬态过程.

To further research instantaneous characteristics in the centrifugal pump during the startup period,first,the results simulated by the software Flowmaster was compared with the experimental results,and then the situation that pump started up by different ways was simulated and analyzed. It shows that star-delta starting is in favour of the pump compared to the direct-starting. Based on this,Flowmaster was used to simulate the instantaneous starting speed,flow rate,power and outlet pressure of the centrifugal pump with the different valve openings. At last,the non-dimensional analysis was carried out. The results show that the star-delta starting belongs to the slow-start and is better than the directstarting. In the start-up process of the centrifugal pump,flow rate characteristics are mainly determined by the motor starting characteristics and rise slowly at the beginning. The time that the flow rate reaches the stability from zero lags far behind the time that the rotating speed does. The dimensionless coefficient varies all the time and it can not be inconsistent with the quasi-steady state assumption.