Utility management is a large part of the oil and gas industry and boiler management and steam balancing is often an overlooked factor for upstream and downstream processing. Steam optimization helps to reduce boiler loads, streamlines process efficiency and enables service providers to not only meet the demands of customers but also exceed them at reduced cost margins.
Emerson’s Fuaad Moosa shared a story with me where he was asked to put together a proposal for a steam optimization study. The producer’s objective was to perform an assessment on their multiples sites wherein the utilities or steam was connected to a common network. Their requirement was to be able to get a better understanding of the steam management and identify areas for improvement in terms of load balancing and efficiency of the boilers across these different sites.
The complex has 4 existing trains with a fifth train under construction. The study scope includes the three trains within the complex. These plants have tie-ins on the process and the utilities side, and they are controlled by a common distributed control system (DCS) from a single control room. This complex is self-sufficient with energy, including steam, electricity, and mechanical power requirements. The facility is connected to the local grid, maintaining stable frequency. While there is some excess power generation capacity, no power is usually exported to the grid.
Fuaad noted that the overall process design for the utilities is a complex one, and difficult to operate and control due to the significant interactions between the various components of the system. The engineering, operations, and maintenance staff has identified various improvement opportunities in the utilities operations. The purpose of the proposed study was to review and evaluate the opportunities, implement immediate remedies where possible, identify additional improvements, and summarize recommendations into a concrete implementation plan.
The most immediate objective was to seek ways to improve the utilities cost effectiveness to meet energy and water reduction targets, while improving the overall reliability and availability of the complex. This is all part of the company’s long term commitment to sustainability and to the adaptation of the ISO 50001 Energy Management Standard.
Key steps to the study include:
- Assist in examining the possibility of optimizing operations further, with a focus on instrumentation, control, and energy management technologies.
- Conduct field surveys of the processes, interview plant personnel, examine current operating methods, and review current and historical operating data.
- Provide recommendations related to equipment, operating methods, and control strategies, and would estimate the cost and benefit that could be realized through completing the enhancements.
- Provide verification and quantification of the opportunities already identified, and uncover possible additional improvements.
- Determine root causes of current problems and immediate solutions will be implemented where possible.
- Provide short-term solutions that will not disrupt plant process conditions to be implemented.
- Provide long-term solutions that could be implemented at a planned shutdown.
Expected improvements include:
- Better control of existing equipment existing within the Steam / Utility environment within the complex e.g., de-superheaters, condensers
- Stabilization of steam header control
- Utility instrumentation that includes measurement devices as well as final control elements
- Letdown station pressure control tuning and control strategy improvements
- Excess air control improvements
- Potential field improvements for letdown desuperheaters
- Coordinated control of the steam and power balance
- Ongoing Energy Management System
- Opportunities to enhance monitoring with wireless technology
Fuaad explained that due to the complexity of the plants and their highly interactive nature, a detailed dynamic simulation would need to be performed at the end to verify and demonstrate the performance of the new coordinated control strategies.
The project is ongoing and we hope to provide an update as it progresses.