【正文】 out for pressor 2 is monly found in the industry ? The cooler creates additional volume and decreases the effectiveness of the antisurge control system Increased volume due to cooler ? The piping layout for pressor 2 can be acceptable if the additional volume does not create excessive dead time and lag in them ? Result Increased surge margins Energy waste Installing recycle valve upstream from cooler improves control response 169。 2022 Compressor Controls Corporation Menu Fwd Prev Rew ? Compressor has ideal piping layout for surge protection ? Minimum volume between the three flanges for all sections Recycle lines configured for optimum surge protection Minimum volume Section 2 Section 3 Section 1 Process Suction 169。 2022 Compressor Controls Corporation Menu Fwd Prev Rew ? Layout 1 has minimum volume between the flanges and is the best layout for antisurge control purposes Section 2 Section 3 Section 1 Process Suction Section 1 Section 2 Section 3 Suction Process Layout 1: Compressor with recycle lines optimally configured for antisurge control Layout 2: Compressor with coolers upstream of recycle takeoff ? When selecting layout 2 the residence time of the gas in the “surge” volume should be verified to check acceptable time delays are not exceeded ? These two piping layouts are most mon for antisurge control ? Layout 2 requires one cooler less and thus the capital investment is lower ? Layout 2 will require bigger surge control margins Which antisurge piping configuration do you choose??? 169。 2022 Compressor Controls Corporation Menu Fwd Prev Rew Analog controller SLL SCL 100% 0% Controller output 100% 0% ? Leading engineering contractor performed evaluation of execution time influence on ability to protect pressor from surge ? Dynamic simulation of pressor was built ? Digital controllers are pared against analog controller on simulation ? Analog controller has no execution time and is immediate ? Analog controller tuned for minimum overshoot ? Digital controllers get exact same tuning parameters ? Digital controllers get exact same disturbance Operating point Time Time Influence of controller execution time 169。 2022 Compressor Controls Corporation Menu Fwd Prev Rew Analog controller SLL SCL 100% 0% 100% 0% 100% Controller output Operating point Digital controller (2 executions per second) Time Time Time Time ? Compressor surged ? Large process upset would have resulted Analog vs. digital controller at 2 executions per second SLL SCL 0% 100% 0% Tuning same as analog controller 169。 2022 Compressor Controls Corporation Menu Fwd Prev Rew Controller output Operating point 100% 0% 100% 0% Time Time ? Compressor surged ? Large process upset would have resulted Analog vs. digital controller at 3 executions per second Digital controller (3 executions per second) SLL SCL Analog controller SLL SCL 0% 100% 0% Tuning same as analog controller 169。 2022 Compressor Controls Corporation Menu Fwd Prev Rew 100% 100% 0% 100% 0% Time Time ? Compressor almost surged ? Control system would have to be set up with bigger surge control margin Analog vs. digital controller at 10 executions per second Controller output Operating point SLL SCL Analog controller SLL SCL 0% 0% Tuning same as analog controller Digital controller (10 executions per second) 169。 2022 Compressor Controls Corporation Menu Fwd Prev Rew 100% 0% 100% 0% Time Time Controller output Operating point ? Response of CCC digital controller nearly identical to the analog controller ? Adding specialized response algorithm to PI control will allow even smaller surge margins Analog vs. digital controller at 25 executions per second Digital controller (25 executions per second) SLL SCL Analog controller SLL SCL 0% 100% 0% Tuning same as analog controller 169。 2022 Compressor Controls Corporation Menu Fwd Prev Rew Process HIC 1 Load 1 UIC VSDS Compressor 1 VSDS Compressor 2 1 LSIC 2 UIC out RSP Serial work out RSP 2 LSIC 1 MPIC Serial work Serial work Dynamic simulation: parallel pressors Suction 169。 2022 Compressor Controls Corporation Menu Fwd Prev Rew Simplified Diagram of Parallel LoadSharing Algorithms 169。 2022 Compressor Controls Corporation Menu Fwd Prev Rew Simplified Pamp。ID for Compressors Operating in Parallel 169。 2022 Compressor Controls Corporation Menu Fwd Prev Rew Simplified Diagram of Series Loadsharing Algorithms 169。 2022 Compressor Controls Corporation Menu Fwd Prev Rew Simplified Pamp。ID for Compressors Operating in Series The End