Systems automation company GE Intelligent Platforms expects to see significant demand in the South African market for its US-developed distributed control system (DCS) steam cycle solution for power plants, which was launched last month, global energy industry manager Bill Pezalla tells Engineering News.
The steam cycle solution combines proven and comprehensive capabilities, providing coordinated control of the boiler, boiler auxiliaries and turbine auxiliaries, along with preconfigured, customisable control strategies and screens, he explains.
The system has a set of unique preconfigured templates with complete control strategies and screens, which can easily be tailored to a specific plant’s needs.
It also contains libraries representing control strategies, control elements and visualisation elements, allowing the user to manually instance and tie objects in the libraries together to form complete, customised appli- cations, using simple user interfaces and without the need to reprogram the solution.
GE believes this technology could make a difference to how power plants in South Africa are run and is currently negotiating with a number of possible customers, he says.
The solution can be installed on new plants but, at this stage, the company aims to enable plants with older boilers to make use of this modern technology.
“The DCS technology can be used on any size plant, which will further increase demand, as it enables small and medium-sized boilers to make use of technology that could previously only be used on large systems,” Pezalla adds.
GE’s engineers have worked with boilers for many years and have extensive knowledge of different types of power plants and their equipment. This has allowed the company to simplify the control of boilers by enabling operators to drag and drop the technology on a computer screen for easy installation.
“Our DCS isn’t new, but the fact that we reduced the logic down to enable it to be rapidly installed is a new concept,” he says.
Power plants are running for longer with shorter maintenance outages and the advantage of GE Intelligent Platforms’ DCS is that it is an open system that works with any type of boiler and can be implemented during a short maintenance outage, Pezalla explains.
The speed of system implementation results in increased uptime, which, in turn, increases production.
“When boilers are controlled manually, the process will not be as exact as when it is controlled by an automised system. Automising the process improves its efficiency with regard to manpower and the amount of fuel and water that is used,” Pezalla says.
By leveraging the system’s combustion control algorithms, a high level of precision and accuracy can be maintained, which leads to more efficient boiler operations, he notes.
The solution also allows real-time control to ensure the uniform loading of fuel sources and greater uniformity in air flow, he adds.
Meanwhile, operators can easily measure and analyse combustion and emissions, as the solution delivers a holistic view of the efficiency metrics and provides actionable insight to assist in decisions to increase the levels of energy production while reducing fuel consumption.
By using this system, fuel use can be reduced by 3% to 5% and system implementation time can be reduced by 50 % to 80%, Pezalla points out.
Further, the system’s drum-level control algorithms automatically respond to varying steam loads and pressure variations, which assists in ensuring that boilers operate within the correct safety parameters.
Boiler safety is also increased through the careful tuning and precise control of all steps of the process, such as purging the furnace before fuel firing and automated burner sequencing, including pilot and main flame light-offs as well as by avoiding repeat purging and reinitiation of the start-up sequence.
Meanwhile, the GE solution ensures smooth and consistent steam production with fossil fuels and biomass fuels by handling variations in the quality and moisture content of fuels with its advanced British thermal unit combustion compensation algorithms, which reduce carbon monoxide emissions.
Consistent steam production is also beneficial, as inconsistent steam can cause fan blades to fatigue and break, he says.
Boiler damage is prevented by maintaining water levels to avoid low water conditions, which could damage the boiler or lead to an explosion, says Pezalla.