Pseudo bond graph for fault detection and isolation of an industrial chemical reactor part I

Abstract

Model based supervision of process engineering plants is difficult due to the complexities arising out of the energetic couplings in the model. In this series of two papers, it is shown how the Bond Graph as a multidisciplinary and integrated tool can be used for dynamic modeling and Fault Detection and Isolation heal of process engineering including (energetic and chemical phenomena). In this first paper a pseudo Bond Graph model technique is applied to a pilot plant reactor equipped with a mono-fluid heating/cooling system. A modeling structure has been implemented according to the process sub-units reactor, jacket, supply system and heating/cooling system and validated through experimental observations. In the sequel of this paper, the use of Bond Graph techniques is proposed to indicate the appearance of undesirable product in the reaction mixture, so as to elaborate an efficient and sensitive method for early warning detection of runway. In the second part, the causal and structural proprieties of obtained Bond Graph are used not only to validate the model, but also to provide the computational algorithms to eliminate unknown variables from coupled thermo-chemical models and thus generate Analytical Relations (ARRs) in terms of measurements and parameters for online diagnosis.

Fault Diagnosis Algorithms by Combining Structural Graphs and PCA Approaches for Chemical Processes

“…A simple sketch of the process is shown in Fig. 7 and more details on the system description can be found in [4,19]. The CSTR is highly nonlinear with its state variables, volume of the water inside the tank and total enthalpy, being nonlinear functions of the input flows.…”

“…The relevant parameters of the reactor and jacket models are summarized in Table 2. In the previous researches [4,19], because of modular and functional aspect of the bond graph, a pseudo bond graph model of the system developed from the energy and mass balances has been presented as subsystems modeled separately. Thus to design a nonlinear FDI scheme, the SDG model must be constructed with the information obtained from coupled bond graph models in integral causality based on BG-SDG analog (see Table 1), as shown in Fig.…”

Particle filter based hybrid prognostics for health monitoring of uncertain systems in bond graph framework

“…For uncertain dynamic systems too, BG has been used extensively for modeling purposes and development of supervision techniques. This includes Fault Detection and Isolation (FDI) of complex systems [51], highly non-linear and complex thermo-chemical systems [52], non-linear mechatronic systems [53], intelligent and autonomous systems [54][55][56], industrial chemical reactors [57], hybrid systems [58] etc. In BG framework, the FDI is mainly based upon Analytical Redundancy Relations (ARRs) [59,60] or by usage of the algebraic observers [55,61].…”

Sliding Mode Observer-based Actuator Fault Reconstruction for a Continuous Reactor

“…This paper is focused on FDI, for FTC can refer to [1]. Researchers used existing approaches such the classic ones to develop their performance for new complex systems [2][3][4], or tried to find new approaches for performing fault diagnosis [5], [6], [7] and [8]. Applications of fault diagnosis approaches techniques to batch chemical processes are usually challenging, these depend on intrinsically unsteady operating conditions and their nonlinear dynamics.…”