Abstract
A fault diagnosis system using a signed directed graph (SDG) as a qualitative model of an objective plant has been developed for the purpose of assisting operators to decide a corrective action for abnormal situations arising in a large-scale chemical plant. A lot of manpower is required, however, to construct an SDG for a chemical plant because it comprises a number of pipeline networks of complicated structure.
This paper presents a systematic method to select state variables representing a pipeline network and algorithm to synthesize its SDG utilizing the mass balance, momentum balance, heat balance and component balances. This algorithm is implemented in a computer program which synthesizes an SDG of a given pipeline network from the CAD data and is successfully applied to a test plant in order to demonstrate its usefulness.
