On line optimisation of maintenance tasks management using RTE approach

摘要

The efficiency of equipment units decreases depending on the time they have been operating due to fouling, formation of byproducts, catalysts deactivation etc. Therefore, periodical maintenance and/or cleaning is required to restore original conditions. This imposes a trade-off between shutdown and productivity improvement. When considering different production lines, the problem is usually addressed using mathematical programming (MINLP- Jain, and Grossmann, 1998, Georgiadis et al. 1999). The implementation of the decisions obtained in this way is unlikely to result in an optimal operation because of plant-model mismatch. Therefore, this work introduces both: simpler formulations (NLP and LP) and a procedure for the subsequent implementation of the discrete decisions involved in a real time environment. This methodology is an extension of the Real Time Evolution (RTE) approach for continuous processes (Sequeira et al., 2001b). The main advantages of the proposed approach are the robustness resulting from the use of on-line information and a scarce model dependency. An example illustrates the methodology from the planning stage to the on-line optimization including model mismatch and model uncertainty.