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Paweł Lindstedt and Rafał Grądzki

A Synthetic Method for Examination of Potential Reliability and Safety Level Demonstrated by Technical Facilities During Their Lifetime

The paper presents fundamentals for an innovative method that takes advantage of diagnostic information defined with participation of an expert. (presented as a score of points). Defined number of points is assigned to each signal change, depending on the signal value and the moment when the change occurs, whilst the number of points is preliminary defined by an expert. The proposed innovative method consists in the use of signals represented by the scores to determine combined status equations [3, 5] for parameters of the adjustment control state and technical state (equations 3 and 4) and then parameters of reliability and safety (equations 5 and 6). Such an approach enables continuous monitoring of the reliability and safety states of facilities during their lifetime. The presented approach may prove to be extremely useful as it unambiguously presents wear and tear of the facilities and enables to predict when the facilities should be repaired (overhauled).

Open access

Paweł Lindstedt and Rafał Grądzki

Model for Blade Diagnosis in a Working Rotor Machine Employing the Method of Virtual Elimination of Stochastic Environment

This paper presents the bases of a new method of monitoring technical condition of turbomachine blades during their operation. The method utilizes diagnostic models such as a quotient of amplitude amplification and a phase shift of a diagnostic signal y(t) which is a result of blade operation as well as a signal x(t) of blade environment while a blade tip approaches a sensor, amplitude amplification and phase shift of these signals while the blade tip moves away from the sensor.

The adopted diagnostic models indirectly take into account the existing environment of a blade, represented by the signal x(t), without the need to measure it [13, 15]. Thus, the model is sensitive to the changes in technical condition of blades and practically insensitive to a change in environment. The suggested method may prove very important in diagnostics of rotor blades during turbomachines operation (compressors, turbines etc.).

Open access

Paweł Lindstedt and Rafał Grądzki

A Synthetic Method to Investigate Reliability and Safety Potential of a Technical Facility During its Operation

The paper presents presumptions to an innovative way intended to bring down each diagnostic information, even if it has been provided with participation of an expert, to the form that can be expressed in a conventional manner by the corresponding score of points. Each change of the signal (depending on its value and the moment when it appears) is associated with the score that has been already established by experts. The proposed innovative method consists in utilization of the obtained signals to find out parameters of the current settings and the technical status (equations 3, 4) and the safety and reliability of the object (equations 5, 6) with application of the combined status equations [3,5]. It will enable to perform continuous monitoring and prediction of the reliability and safety of the facility during its lifetime. The described method may prove to be extremely useful as it exhibits the overall deterioration of the facility in an unambiguous and synthetic manner and makes it possible to predict future operation status of the facility and, in consequence, to schedule appropriate maintenance operations (adjustments, repairs, overhauls).

Open access

Rafał Grądzki, Karol Golak and Paweł Lindstedt

Abstract

An important problem in the operation of gas pipelines is the identification of accidental gas leakage from the damaged pipeline. It is the hardest when the leakage is small. A disadvantage of prior methods is that with their use is only possible to identify and locate significant outflow with only a low accuracy. In proposed method of identifying the gas flow will be used a new signal from the corrective element “r” attached to the tested pipeline and calculated from it and mass flow rate signals auto and cross power spectral density Sxx, Syy, Srr, Sxy, Sxr, Syr. Using the power spectral density signals allows for transition from the signal diagnostic to the parameter diagnostic which is more effective. Assumptions methods will be verified at the experimental station.

Open access

Grądzki Rafał and Lindstedt Paweł

Abstract

The paper presents fundamentals of an innovative diagnostic method using operation information (imported in the form of dimensionless number of points). This process consists in the fact that for any change in the signal (depending on the signal value and the time when the change occurs) appropriate number of points determined by the by experts is assigned. The existing methods of assesing the operability include summing of all the points and then determining the current state and maintance level [10]. The proposed method uses these signals expressed in the form of points to determine the coupled interaction equations [3] defining parameters of the control and technical states, which are the basis for the assessment of the plant’s operability. In addition, the changes in control and technical states can be used to identifiy the parametric and momentary failures, and thus for the continuous monitoring of plants operability [7].

Open access

Grądzki Rafał, Golak Karol, Lindstedt Paweł and Bartoszewicz Błażej

Abstract

This article applies diagnosing issues outflows of gas pipelines using specialized research equipment - equalizers. Variant with only two measuring devices (equalizers), arranged on the inlet and outlet of the pipeline, and the standard pressure transducers and flow rate were considered. The signals from the system and research equipment (equalizers) are the basis for the development of new method to test outflow of gas pipeline, which is based on the quotient of the power spectral density of signals generated by the equalizer (diagnoser) and signals measured using standard pressure transducers and flow rate. Possible use to analysis the signals power will allow go from signal diagnostic for more effective parametric diagnostic.