A p−V Diagram Based Fault Identification for Compressor Valve by Means of Linear Discrimination Analysis

The pressure-volume diagram (p−V diagram) is an established method for analyzing the thermodynamic process in the cylinder of a reciprocating compressor as well as the fault of its core components including valves. The failure of suction/discharge valves is the most common cause of unscheduled shutdowns, and undetected failure may lead to catastrophic accidents. Although researchers have investigated fault classification by various estimation techniques and case studies, few have looked deeper into the barriers and pathways to realize the level determination of faults. The initial stage of valve failure is characterized in the form of mild leakage; if this is identified at this period, more serious accidents can be prevented. This study proposes a fault diagnosis and severity estimation method of the reciprocating compressor valve by virtue of features extracted from the p−V diagram. Four-dimensional characteristic variables consisting of the pressure ratio, process angle coefficient, area coefficient, and process index coefficient are extracted from the p−V diagram. Principal Component Analysis (PCA) and Linear Discriminant Analysis (LDA) were applied to establish the diagnostic model, where PCA realizes feature amplification and projection, then LDA implements feature dimensionality reduction and failure prediction. The method was validated by the diagnosis of various levels of severity of valve leakage in a reciprocating compressor, and further, applied in the diagnosis of two actual faults: Mild leakage caused by the cracked valve plate in a reciprocating compressor, and serious leakage caused by the deformed valve in a hydraulically driven piston compressor for a hydrogen refueling station (HRS).

Dynamic Analysis for a Reciprocating Compressor System with Clearance Fault

In order to explore the failure mechanism of a reciprocating compressor system with clearance fault, we implemented a computational framework whereby a simulation model of the mechanism is established using ADAMS software in this paper, and a typical reciprocating compressor model is introduced to validate the design model. In this work, the joint clearance faults between the crankshaft and linkage, between the linkage and crosshead, and in both locations are taken into account computationally. These faults are one of the major causes of vibration. Through dynamic calculation and analysis of a system with clearance fault, the simulated results show that these clearance faults directly influence the vibration. The larger the gap size, the more severe the vibration and the higher the amplitude of the vibration. Furthermore, the clearance number also affects the vibration greatly.

DEVELOPMENT OF THE COMBINED RESERVOIR OF MIXTURE OF TECHNICAL COMBUSTIBLE LIQUIDS AS COMPONENT OF ENVIRONMENT PROTECTION TECHNOLOGY

In this study the development, analysis and description of the sche­me of environment protection technology for the oil storage were carried out. The proposed scheme is provided for the utilization of vapors of technical combustible liquids stored at the enterprise, namely diesel fuel, gasoline and motor oil, formed during the manifestation of the phenomena of small and large reservoir breathing in significant quantities. Set of initial data and the mass hour­ly emission of such vapors into the en­vironment were obtained according to an improved approach. Development of a high-pressure storage reser­voir for such vapors as the executive device of environmental protection technology for the oil storage according to an improved approach was carried out. Parameters of the reciprocating compressor, which distills the mixture of such vapors from the low-pressure storage reservoir to the high-pressure sto­rage reservoir, compressing them, was selected. Calculation of the reservoir wall thickness ba­sed on the theory of strength of closed solid shells was carried out taking into account the mechanical properties of the wall material, namely steel 60, and the value of the pressure of the gaseous fluid in it. Magnitudes of weight of the deve­loped reservoir and the cost of materials for its manufacture were determinated. Design of a combined reservoir for the ac­cu­mu­lation of a volley of a mixture of such vapors with a system of intermediate cooling of the mixture after its compression by a reciprocating compressor and the pos­sibility of heating the condensate in the reservoir was de­ve­loped.

application based comparison of statistical versus deep learning approaches to reciprocating compressor valve condition monitoring

This paper presents a vibration-based condition monitoring approach for early assessment of valve wear in an industrial reciprocating compressor. Valve seat wear is a common fault mode that is caused by repeated impact and accelerated by chatter. Seeded faults consistent with valve seat wear are installed on the head-side discharge valves of a Dresser-Rand ESH-1 industrial reciprocating compressor. Due to the cyclostationary nature of these units a time-frequency analysis is employed where targeted crank angle positions can isolate externally mounted, non-invasive, vibration measurements. A region-of-interest (ROI) is then extracted from the time-frequency analysis and used to train a suitably sized convolutional neural network (CNN). The proposed deep learning method is then compared against a similarly trained discriminant classifier using the same ROIs where features are extracted using texture and shape image statistics. Both methods achieve > 90% success with the CNN classification strategy nearing a perfect result.