1 SEC.
Pd
100%
D
A
Pd
A C B
D 0 100%

Qs
DPo
A C B
D
0 100%源自DPcA C BD
Performance curves are usually very flat near surge操作曲线靠近喘振线 Even small changes in compressor pressure differential cause large flow changes压缩机压差的微小变化也会引起较 大的流量变化 The speed of approaching surge is high; in only 0.4 seconds, DPO dropped by 14%, with a 2% change in DPc 到达喘振线的时 间为0.4秒。
hr DEV < 0
DEV = 0
- Operating Point
DEV > 0 qr
[File Name or Event] Emerson Confidential 27-Jun-01, Slide 7
2
Surge margin Or Surge Control Line SCL
The approach to surge is fast快速到达喘振点
• Flow and Pressure Transmitters流量及压力变送器 • Piping Layout配管布置 • Antisurge Control Valve防喘振控制阀
[File Name or Event] Emerson Confidential 27-Jun-01, Slide 4
[File Name or Event] Emerson Confidential 27-Jun-01, Slide 9
Flow Measuring Devices流量测量装置
Selection Criteria: Repeatability & Minimal Delays 选择原则：重复性及最小 延迟 Knowing the flow is essential to determine distance between Operating Point and SCL 流量是决定操作点与SCL 间距的关键参数

Process & Compressor Control过程及压缩机控制
– – – – – – –
[File Name or Event] Emerson Confidential 27-Jun-01, Slide 2
Objectives of Anti-Surge Control 防喘振控制的目标
0
[File Name or Event] Emerson Confidential 27-Jun-01, Slide 8
Managing the high speed of approaching surge处理到达喘振线的高速

Increase overall system speed of response wherever feasible 尽可能 的提高系统的响应速度
hr
CCC’s Method CCC的方法 – The antisurge controller must provide a distance to SLL that is invariant of change in inlet conditions防喘振控制器必须提供到SLL的距离，该距离不随入口 条件变化 – Non-linearity in the SLL can be accommodated using a function based on piecewise characterization通过分段特性提供非线性的SLL – This will lead to safer control yet reducing the surge control margin which means 这使实现安全控制的同时减小喘振控制的边缘:
The Surge Control Line (SCL)喘振控制线 Distance between Operating Point and SCL操作点与SCL间距
• • Maximize the Compressor Operating Zone压缩机操作区最大化 Minimize the Surge Margin减少喘振边缘
– Transmitters变送器 – System Volumes系统体积 – Valves阀门
• DVC ODV Tier
• Optimized Actuation System优化的执行机构系统

Specialized Control Responses特定的控制响应
– Automated open loop (Recycle Trip)自动的开环控制 – Adaptive surge control line – closed loop control 变化的喘振控制线闭环控制 – Control loop decoupling控制回路解耦
机控制要解决的主要问题
机的性能特性图最大化
– Maximize the Compressor Performance Map使压缩
– Location of Surge Limit Line喘振线的位置 – High Speed of Approaching Surge达到喘振的速度 – Control Loop Considerations控制回路的考虑
•Develop Surge Control Line
•Develop Control Actions to maximize operating zone
Actual available operating zone
Minimum speed
Qs,
[File Name or Event] Emerson Confidential 27-Jun-01, Slide 5
•
CCC parameter: DEV = d - surge margin • Benefit: One standard surge parameter in the plant. No operator confusion好处：工厂中只有一个标准的喘振参数。
DEV > 0 DEV = 0 DEV < 0 Good Recycle Line Bad
• • • Flow and Pressure Transmitters流量及压力变送器 Piping Layout配管布置 Antisurge Control Valve防喘振控制阀

Basic Antisurge Control System基本的防喘振控制系统
– – – – Surge Control Line - PI Control - Closed Loop Control传振控制线-PI控制-闭环控制 Surge Testing喘振测试 Recycle Trip - Open Loop Control循环测试-开环控制 Tight Shut-off Line-严密关断线
Blow-off or recycle放弃或在循环 Discharge Throttling出口流量调节 Suction Throttling入口流量调节 Adjustable guide vanes可调节的导向叶片 Speed Variation速度变化 Interacting Antisurge and Performance Loops防喘振回路及性能回路的关联 Loop Decoupling回路解耦
vol
Location of the Surge Limit Line (SLL)
喘振线的位置
Basics – The better we can measure the distance to surge, the closer we can operate to it without taking risk目的是准 确找出喘振线的位置，以使操作尽量接近喘振线 – The Surge Limit Line (SLL) is not a fixed line. The SLL changes depending on the compressor inlet conditions: Tsuction, Psuction, Mol. Weight, ratio of specific heats, k喘 振线不是固定线。位置取决于压缩机入口的温度压力， 气体的分子量，及绝热系数。 – Most compressor OEM’s use a prediction大多数的压 缩机厂上使用预测。
Maximizing theCompressor Performance Map
使压缩机的性能特性图最大化
Compressor Risking Surge Recycle Valve is Open
Rprocess,2
Operating Point 2
Rc
Adding control margins
Anti-Surge Control 防喘振控制
Compressor Control压缩机控制

Objectives of Antisurge Control防喘振控制的目标 Major Challenges of Compressor Control压缩机控制要解决的主要问题
– – – – Maximize the Compressor Performance Map使压缩机的性能特性图最大化 Location of Surge Limit Line喘振线的位置 High Speed of Approaching Surge达到喘振的速度 Control Loop Considerations控制回路的考虑