摘要
西三线在西段工艺站场与西二线合建后,针对站场压缩机组既要联合运行又要独立运行的问题,提出了西三线负荷分配控制方案。该方案基于出口压力负荷分配控制原理,采用闭环控制方式,通过可编程逻辑PLC作为控制器,将负荷控制和负荷分配功能两层控制算法叠加,调节各台并联压缩机组的转速和防喘振阀的开度,进而控制各台压缩机组的工作点与喘振线在等距离的位置上。在满足出口压力的基础上,根据各台机组的能力对总负荷进行分配。根据计算公式,负荷分配控制器采集压缩机进出口压力、温度、差压等信号,计算工作点与喘振线的距离DEV值,通过其PID计算输出再经过软件加权平均送到各机的性能控制器输出控制压缩机组的转速。同时引入闭环PI控制、开环RT响应以及前馈防喘振控制,从而实现负荷分配功能。结果表明:该方案使各台机组均在正常区间内工作,控制各台压缩机组回流或放空造成的能量损失,使喘振风险降到最低,同时共同分担扰动。
Upon joint construction of gas compressor stations in western section of the 3rd West-to-East Gas Pipeline and the 2nd West-to-East Gas Pipeline, compressors in these stations are required to perform relevant operations both jointly and independently. Accordingly, control programs for load distribution in the 3rd West-to-East Gas Pipeline have been proposed. The program is based on closed-looped control over outlet pressures load distribution with PLC as controller to combine control algorithms for load control with load distribution to adjust rotation speeds of parallel compressors and apertures of the anti-surge valve. In this way, working points of all compressors can be maintained at equal distance with the surging line. In addition to satisfying requirements related to outlet pressures, total loads can be allocated in accordance with capacities of different compressors. In accordance with calculation formula, the load distribution controller may acquire data related to inlet and outlet pressures, temperatures, pressure differences and other signals of compressors to determine the DEV of working points and the surging line. Upon completion of PID calculation, weighted average of relevant results can be obtained by using relevant software before transmission of performance controller of compressors to control their rotation speeds. In addition, introduction of closed-loop PI control, open-loop RT response and feedforward anti-surge control may help to achieve load distribution objectives. Test results show the program can maintain all compressors within designed working extent to control backflows in these compressors and to reduce energy losses induced by blowdown. In addition to minimizing risks related to surging, the system can be deployed to share impacts of disturbance. （7 Figures, 1 Table, 8 References）
出处
《油气储运》
CAS
北大核心
2015年第5期538-543,共6页
Oil & Gas Storage and Transportation
关键词
西三线
压缩机组
负荷分配
联合运行
防喘振
3rd West-to-East Gas Pipeline, compressors, load distribution, joint operation, anti-surge
