LNG Processes
In liquefied natural gas (LNG) facilities, our optimization experience shows that capacity and availability depend on coordination between the process, compressors, refrigeration-system capacity, and the constraints imposed by feed-gas pipeline capacity. The limiting constraint can shift with ambient conditions, season, and operating configuration, resulting in:
- Production below the actual capacity of the facility;
- Increased energy consumption and process variability;
- Frequent operator intervention to manage constraints and redistribute loads.
Enero Solutions embeds its advanced control, adaptive control, and optimization strategies directly within the control system to continuously identify the active constraint and automatically adapt operating conditions.
This approach makes it possible to:
- Maximize production based on the active constraint, whether it comes from the compressors, their drivers, the refrigeration system, heat exchangers, or available pipeline capacity.
- Maximize availability and prevent cascading trips by incorporating trip constraints into the control strategy and, following the loss of a compressor or train, automatically keeping the redundant line in operation without causing a sympathetic trip;
- Reduce variability and energy consumption by operating closer to the technical limits of the facility when production must be maximized, or by targeting the optimum efficiency point when capacity is constrained by the market or the gas network.
Pipelines
Pipeline operation requires the coordination of multiple pump stations operating in series, particularly during flowrate or product changes, start-ups, and shutdowns. Inadequate coordinated pipeline control can result in:
- Excessive pressure and flow variability during normal operation, increasing cyclic loading on the pipeline and its equipment;
- Overpressure, cavitation, and localized flow reversal during transitions, placing excessive stress on check valves, pumps, control valves, and other critical equipment;
- Interactions between pressure controllers at different stations, reducing the hydraulic stability of the pipeline and increasing average pump power consumption;
- Accelerated degradation of critical equipment and reduced leak-detection system performance, directly degrading pipeline integrity programs.
As part of its optimization work, Enero Solutions combines control valve performance verification, calibration, and optimization, control loop PID tuning, and the development, in collaboration with operating teams, of advanced control, adaptive control, and decoupling strategies embedded directly within the control system to coordinate pumps, variable-speed drives, valves, and network constraints.
This optimization approach makes it possible to:
- Reduce variability and stabilize the pipeline operation
- Automate and coordinate start-ups, shutdowns, and production changes
- Automatically adapt the control strategy to different operating conditions
