Integrated dynamic decision analysis of gas drying plant: sensitivity analysis

摘要

The plant referred to in this paper is located downstream from an exhausted natural gas field now employed as a backup lung to meet heavy consumption demands during the winter. The risk analysis of a plant through a procedure that combines logico-probabilistic and phenomenological features allows identification not only of the alternative seuqnces (e.g., duration of the flare-off). The complete panorama of infomation thus provided opens the way to all the more detailed examinations needed to enable informed decisions to be taken with a view, for example to improving the plant itself. Since the aim of this study was to simulate plant improvements designed to minimise the risk of the plant being shut down through the spurious intervention of its protection systems, the most significant transients were analysed in detail. This analysis showed that the probability of the top event "flare-off exceeding the fixed acceptable limit" was 4.08 10~4. IDDA was used to demonstrate that simple modification of the plant would be sufficient to reduce the probability of excessive pressure in the drying columns to 8.25 centre dot 10~(-10).