Towards Operational Optimisation of Complex Industrial Processes — An Introduction

Complex industrial processes such as paper making, steel making and magnetic material making are energy intensive. The production structure of these processes was designed a long time ago when the cost of energy was low. However, in recent years the cost of energy has been significantly increased and the profitability of these production systems are facing new challenges in terms of copying with ever increased energy cost. On the other hand, these complex industrial processes are operated via networked control systems, namely the distributed control systems (DCS) and programmable logic control (PLC). DCS/PLC realises required control action for various units in these complex industrial processes and they are key units that link high level management to low level real-time control. For example, the production planning and scheduling are linked to either DCS or PLC so as to realise set points control of each control loops along production lines. In this context, a large volume of process datum is now available from DCS/PLC system. Therefore, plant-wide operational optimisation should be addressed using a number of approaches. In terms of production structure, detailed energy and system auditing should be carried out in order to optimise the system and its instrumentation design. As for the DCS/PLC system, it is important to develop novel and user friendly hardware and software so that fast reaction speed of DCS/PLC system can be obtained to facilitate the operational optimisation that aims at optimising product quality, production efficiency and energy consumption. In this feature issue, we organised three papers on the above aspects. The first paper addresses energy saving approach for paper making processes using energy auditing and system analysis tools with datum from DCS/PLC systems. The second paper looks into the novel development of DCS/PLC structure and software architecture so as to realise advanced control and optimisation algorithms. The third paper investigates issues related to an effective software system so as to increase equipment utilisation and to minimise production costs for a magnetic material making process. It is expected that these papers would provide readers with some highlights on novel developments on operational optimisation for complex industrial processes.