In this article, Carl Knight – managing director of process steam and heat transfer specialist Fulton – looks at boiler sequencing control systems and how these intelligent controllers can optimise steam boiler installations to ensure energy efficient operation and improve boiler longevity.
Numerous processing facilities operate multiple steam boilers to meet the demands of their on-site processing equipment. However, if the steam boilers in these facilities are not optimised for efficiency, then the potential for any energy savings is not itself being fully optimised.
The use of an intelligent sequencing system for steam boiler installations provides redundancy, builds reliability and offers significant energy savings by automating start-up and shut-down procedures; controlling and optimising main steam header pressure or temperature; ensuring steam supply is controlled precisely for the required process; and balancing the load distribution across the boilers, all of which reduces extensive losses from repeated start/stop cycling of burners as much as is feasibly possible.
Steam boiler sequencing should be about more than simple on/off or start-up control. An intelligent sequencing system should also consider steam system load conditions and match this to the most efficient combination of boiler output according to process requirements.
Response to system loads and start-up times are also factors. For example, a boiler sequencing control system should be capable of monitoring when running too many or too few boilers is having a negative effect on efficiency and productivity. It should be able to monitor and pre-emptively predict a sudden surge in demand and hence boiler use by monitoring existing boiler demands, system pressures and flow rates; therefore starting/stopping boilers appropriately depending on process demand.
Additional factors include what happens in the case of boiler failure, sudden high steam loads and even lack of boiler availability due to servicing. A good sequencing system should take all these factors into consideration and manage the boiler operation automatically. With the result being that, despite the machine they are working on having just started a high-steam demand stage during its production process, the end user doesn’t notice that additional boilers had to be started.
Furthermore, benefits that can be achieved through the installation of an intelligent boiler sequencing system can include automation for start-up and shutdown of the boilers; better control of the main steam header pressure leading to more consistent pressure and therefore better steam quality (vitally important factors for sterilisation processes and accurate heat transfer rates); precisely-controlled process steam or hot water supplies; boilers operating at main header pressure or temperature and not maximum pressure or temperature; improved boiler longevity from complete load sharing; and improved fuel savings through eliminating idle time at low fire.
Suitable for up to four steam boilers, SCOPE from Fulton is a PLC-based intelligent boiler sequencing control system that optimises installations. It can be retrofitted to existing vertical and horizontal fuel-fired boiler installations, including Fulton’s own range of existing and planned products and those manufactured by other boiler OEMs.
But what about the future of boiler sequencing and the development of intelligent control systems using Cloud-based services?
Many processing facilities operate 24/7 so, to keep these facilities running consistently and efficiently, immediate action is often required and/or expected from the boiler manufacturer. By accessing its SCOPE intelligent sequencing system via Cloud-based systems, Fulton is already looking to incorporate remote accessibility for diagnostic- and service-related issues; and providing remote data for system improvements, which can be accessed by specialist engineers for diagnostics and clients for data review.
Fulton is also looking at the ability to perform certain maintenance procedures or service steam boilers remotely, no matter where in the world they are installed. This would help to reduce the environmental impact and costs associated with travel to/from site, savings that can be passed onto the client.
The future will therefore offer simple sequencing control of multiple boiler installations or a full boiler-house energy management system, accessible remotely by the manufacturer and client alike, to provide an efficient solution for everyone.
For further information on SCOPE email This email address is being protected from spambots. You need JavaScript enabled to view it., call +44 (0)117 972 3322 or click www.fulton.co.uk.
