Centralised Automation and Control System How a Centralised Automation and Control System Improves Plant Efficiency
In their mission to establish a centralised automation and control system for their sugar and cogeneration (power) plant, an Indian sugar manufacturer implemented an InduSoft Web Studio-based HMI/SCADA system with Honeywell PID loop controllers, and notably improved their plant efficiency.
While most industries rely on external power sources to fuel their operations, sugar manufacturers can produce their own power in a process called ‘cogeneration’. As part of the process of producing sugar from sugar cane, by-products such as bagasse — a left-over fibre from the crushing and extraction process — can be employed as an ecofriendly fuel for power cogeneration. The bagasse can be incinerated to fuel a boiler furnace, which can be used to produce electricity.
The power, produced by the furnace can be used in the production of more sugar cane juice — a net positive energy gain. Historically, sugar mills in India were permitted to produce only the energy they needed for their own operations. Most Indian companies, therefore, adopted the practice of installing inexpensive boilers and turbines, which were notoriously inefficient. They typically would operate only during the sugar season. After all, why to invest money in an expensive, efficient system, when there is little scope for a return on that investment?
In the mid-1990s, the Indian Ministry of Power began permitting companies to generate surplus energy. The energy could then be exported to the state electricity board or to other manufacturers, which in turn subsidises production costs, promotes competition, and makes electricity more plentiful for everyone. RRB Sugar Mills is one of the India’s largest sugar producers, with a cane-crushing capacity of 400 Tons of Cane per Day (TCD). When exportation of energy was permitted, many plants, including RRB Sugar, began looking for ways to raise the efficiency of their power plants. At its Wategaon, India, facility, RRB installed backpressure turbo-alternators with two high-pressure boilers, a turbine generator and a backpressure turbine generator.
This required a new control system, and InduSoft Web Studio was chosen to develop an HMI/SCADA system that would ensure an efficient plant. Although the system was initially installed only to control the boilers, it worked so satisfactorily that RRB expanded it also to control the entire sugar-making and wastewater processes.