Detecting cracks in reciprocating compressor valves using pattern recognition in the pV diagram

The impact of cracks on the performance of photovoltaic modules

“…The result is confirmed by the T-test value which is less than the threshold value 2.58. Moreover, when a parallel to busbars crack affects 2 solar cells with approximate broken area less than 82mm 2 have no significant effect on the amount of power generated by the PV module. Fig.…”

“…Such loads induce mechanical stresses into the components of the PV module, especially into the crystalline solar cell [1]. The resulting cracks in silicon solar cells reduce the power output of the PV modules [2]. The amount of this degradation is usually relatively small, if measured directly after the crack initiation.…”

“…Electroluminescence (EL) imaging method is used to scan the surface of the PV modules, the light output increases with the local voltage so that regions with poor contact show up as dark spots [6]. The thermography technique is simpler to implement, but the accuracy of the image is lower than with the EL technique, and does not allow the estimation of the area (in mm 2 ) that is broken in the solar cells [7]. Therefore, the image technique used in this work is based on EL imaging method which also is illustrated and discussed briefly in the work of Berardone et al [8] and Spataru et al [9].…”

A parametric study on the dynamic response of reciprocating compressor with a revolute clearance joints

“…Because the valve is installed on the outside of the reciprocating compressor, it is convenient to detect and install the valve. Kurt Pichler, et al [1] investigated fault detection in reciprocating compressor valves under varying load conditions and Pichler K., Lughofer E., Pichler M., et al [2] detected cracks in reciprocating compressor valves using pattern recognition in the pV diagram. Reciprocating compressor movement mechanism is mainly slider crank mechanism, for Paulo Flores and his team did a lot of research in the mechanism with joint clearance [3][4][5], which the multi clearance, the clearance of the moving pair and the contact impact detection are considered respectively.…”

A New Engine Fault Diagnosis Method Based on Multi-Sensor Data Fusion

“…In these kinds of methods, a computer program is designed to simulate the reasoning and decision-making process of human experts to diagnose faults. Other fault diagnosis methods, such as machine learning [8,9] and signal processing [10][11][12], where there is a comparison of frequency analysis and SVM (support vector machine) classifiers in [11,12], are also widely used in practical applications [13,14]. There are also fault diagnosis methods in multi-sensor networks.…”