Practical challenges faced with implementing a Dynamic Compressor Selection program

A previous paper described the development of a compressed air control system called REMS-DCS (Real-time Energy Management System for Dynamic Compressor Selection). This system dynamically selects compressors based on their efficiency and position within the compressed air network. REMS-DCS was empirically tested and the results verified with existing off the shelf simulation models as well as historic compressed air data for a platinum mining operation. Results indicated a high level of confidence with accurate simulations and outputs as well as electrical savings opportunities. The project was approved for implementation with funding support from Eskom-IDM (Integrated Demand Management). Upon implementation, immediate practical challenges became apparent. All compressors had to be upgraded with Programmable Logic Controllers (PLC) and the necessary field instrumentation for condition and efficiency monitoring. REMS-DCS requires accurate input data for simulations. All flow and pressure transmitters had to be verified and acceptable field ranges mapped to ensure quality decision making. Client policies did not allow REMS-DCS writing privileges to the PLCs that control the demand valves at the various POD (Points of Delivery). This created challenges to optimise the predetermined valve pressure set point arrays in the PLC´s without direct REMS-DCS control. Numerous other challenges were faced during the commissioning and performance assessment of this novel technology. This paper describes how these challenges were mitigated and how the project´s electricity savings target of 3.33 MW was achieved successfully.