Real-time implementation of fault diagnosis to a heat exchanger

Abstract

The detection and isolation of faults in engineering systems has lately become of great significance. This paper is concerned with application of analytical fault detection techniques to a heat exchanger. The system is nonlinear and a velocity-based linearization is proposed before the residual generation, which is then realized using an observer, and parity relations. The problem of reasoning is treated by an approximate reasoning approach, called the transferable belief model. Its important feature is the ability to treat inconsistency in data by using more general belief functions. The system under consideration is controlled by programmable logic controller and supervised by supervisory control and data acquisition system. The procedure for implementation is designed with particular emphasis on industrial practice and the Ole for process control data access client/server technology is used for communication between sub-systems. r

A complete procedure for leak detection and diagnosis in a complex heat exchanger using data-driven fuzzy models

“…One can see that the four regressors defined in (9) are all involved in the rule-antecedents of the fuzzy model (11). This may allow a better understanding of the transfer behavior between the rule-premise inputs and the process water temperature.…”

“…The symptoms are generated with the aid of the identified nonlinear fuzzy model (11) that is run in parallel to the real process. Significant symptoms appear as differences between the estimated water temperatureT 34 (k) and the measured one T 34 (k).…”

“…This approach should reduce the effects of uncertainties on the FDD system and enhance its sensitivity to faults. Developing such models from physical laws and/or measurements is still of substantial interest [7][8][9][10][11]. An efficient method to obtain the required nonlinear dynamic models is to resort to models based on fuzzy logic reasoning.…”

An Experimental Study of Clogging Fault Diagnosis in Heat Exchangers Based on Vibration Signals

“…As described in reference [6], a single-chip microcomputer (SPCE061A) was utilized to construct an online monitoring and controlling system designed to detect the temperature at the inlet and outlet as well as that of the water vapor; it can also measure the flow rate and control the flow of both water and vapor. Stojan Persin et al [7] applied analytical fault detection techniques to do real-time fault diagnosis for an industrialscale pilot heat exchanger.An online monitoring and prediction system is proposed in reference [8], which explores the way in which this device monitors and predicts a heat exchangers performance, resulting in improved production efficiency of each individual unit, lower costs of production and maintenance, as well as a higher level of safety during production. The on-line performance monitoring of a shelland-tube type heat exchanger using steam and water has been developed on the basis of a theoretical model to monitor input and output process variables [9].…”

An Integrated FDD Approach for an Intensified HEX/Reactor

“…Among these models, the heat transfer coefficient will be assumed either constant or slowly decreasing. Many authors working in the field of process control and controllability prefer the constant parameter because of the computational simplicity, and a simplified dynamic model containing only one cell is often the case on application of fault detection and isolation, like sensor and/or actuator fault detection and isolation methods proposed in [19][20][21][22]. However, it is widely accepted that fouling influences the dynamics of overall heat transfer coefficient; thus constant value leads to some mismatch between the model and physical process, and this mismatch is usually handled as unstructured model uncertainties, like in [19].…”