Hydrogen compressors perform specific functions in the technical system of crude oil processing. The authors characterize consequences of wear margin loss of the compressor, present design solutions of hydrogen piston compressor and divide its construction into functional units. The compressor fault analysis is based on post repair documentation of compressors maintained according to their service life, and making use of technical diagnostics applied to 21 compressors, covering the last 20 years. The analysis distinguishes the loss of compressor wear margin due to loss of functional unit wear margin and due to damage to a compressor component. Faults typical of hydrogen compressor elements have been described. Besides, the authors estimate fault risks for selected elements and risks of wear margin loss of selected functional units. Statistical data are given in tables and bar charts. The analysis outcome indicates the need to implement methods and tools for diagnosing the cylinder unit, comprising several functional units.Keywords: refinery, hydrogen compressors, piston machine faults, fault analysis, diagnostic of reciprocating compressors ANALIZA USZKODZEŃ TŁOKOWYCH SPRĘŻAREK WODORU UŻYTKOWANYCH W RAFINERIACH Streszczenie Opisano zadania sprężarek wodoru w systemie technicznym przetwarzania ropy naftowej. Scharakteryzowano następstwa utraty potencjału eksploatacyjnego sprężarki. Przedstawiono rozwiązania konstrukcyjne tłokowych sprężarek wodoru użytkowanej w rafinerii. Analizę uszkodzeń sprężarek przeprowadzono w oparciu o badania dokumentacji poremontowej, obsługiwanych według resursu oraz z wykorzystaniem metod diagnostyki, 21 sprężarek z ostatnich 20 lat. W analizie uwzględniono fakt, że w przypadku sprężarek obsługiwanych według resursu podczas remontu po upływie z góry ustalonego czasu użytkowania wymieniane są elementy sprężarki, których potencjał eksploatacyjny nie został jeszcze wyczerpany. Stwierdzono około 500 przypadków utraty potencjału eksploatacyjnego analizowanych sprężarek. W analizie rozróżniono utratę potencjału eksploatacyjnego sprężarki z powodu utraty potencjału eksploatacyjnego danego zespołu funkcjonalnego sprężarki i z powodu uszkodzenia elementu sprężarki. W artykule zamieszczono opisy wybranych uszkodzeń wybranych elementów sprężarki. Oszacowano ryzyko uszkodzenia wybranych elementów i ryzyko utraty potencjału eksploatacyjnego wybranych zespołów funkcjonalnych. Dane statystyczne zestawiono w formie tabel i wykresów słupkowych. Stwierdzono, że: elementom można przypisać charakterystyczne dla sprężarek uszkodzenia; liczba przypadków utraty potencjału sprężarki zależy od składu sprężanego gazu; największy udział procentowy w uszkodzeniach elementów mają pierścienie uszczelniające zaworów oraz sprężyny dociskowe zaworów; największe ryzyko jest związane z uszkodzeniami pierścieni tłokowych jako elementów oraz łożysk (w tym wodzika) jako zespołów funkcjonalnych, z uwagi na poważne w skutkach uszkodzenia wtórne; największy udział procentowy mają zawory jako zespoły funkcjonalne, z na...

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PurposeThe lack of integrity of the piston machine combustion chamber manifests itself in leakages of the working fluid between the piston and the cylinder liner, at valves mounted in the cylinder head and between the head and the liner. An untight combustion chamber leads to decreased power output or efficiency of the engine, while leaks of a fluid may cause damage to many components of the chamber. The actual value of working chamber leak is a desired and essential piece of information for planning operations of a given machine.Design/methodology/approachThis research paper describes causes and mechanisms of leakage from the working chamber of internal combustion engines. Besides, the paper outlines presently used methods and means of leak identification and states that their further development and improvements are needed. New methods and their applicability are presented.FindingsThe methods of leak identification have been divided into diagnostic and non-working machine leak identification methods. The need has been justified for the identification of leakage from the combustion chamber of a non-working machine and for using the leakage measure as the value of the cross-sectional area of the equivalent leak, defined as the sum of cross-section areas of all leaking paths. The analysis of possible developments of tightness assessment methods referring to the combustion chamber of a non-working machine consisted in modelling subsequent combustion chamber leaks as gas-filled tank leak, leak from another element of gas-filled tank and as a regulator of gas flow through a nozzle.Originality/valueA measurement system was built allowing the measurement of pressure drop in a tank with the connected engine combustion chamber, which indicated the usefulness of the system for leakage measurement in units as defined in applicable standards. A pneumatic sensor was built for measuring the cross-sectional area of the equivalent leak of the combustion chamber connected to the sensor where the chamber functioned as a regulator of gas flow through the sensor nozzle. It has been shown that the sensor can be calibrated by means of reference leaks implemented as nozzles of specific diameters and lengths. The schematic diagram of a system for measuring the combustion chamber leakage and a diagram of a sensor for measuring the cross-sectional area of the equivalent leak of the combustion chamber leakage are presented. The results are given of tightness tests of a small one-cylinder combustion engine conducted by means of the set up measurement system and a pre-prototype pneumatic sensor. The two solutions proved to be practically useful.

The quality of company asset management is significantly dependent on the quality of a system for asset wear margin identification. A pipeline–machine subsystem may be an essential part of assets in many production companies. It is necessary to build models of pipeline–machine subsystems and models of a system for the identification of subsystem wear margin. The method used consists of a decomposition of desired characteristics of an enterprise into desired characteristics of a pipeline–machine subsystem. Methods for the identification of real characteristics of a subsystem depend on the character of subsystem operation. In this study, hydrodynamic and thermodynamic models of the subsystem are built. Tests are conducted on industrial and laboratory objects. The boundaries of the subsystem are defined and changes in pressure, temperature and mass flow rate in the pipeline are presented. Causes of changes in the mentioned quantities are described. Desired characteristics of the subsystem resulting from decomposition are described. The presented methods of determining efficiency for steady working conditions and open flow use hydrodynamic and thermodynamic models. Energy efficiency of the subsystem is decomposed into efficiencies of main elements of the subsystem. A method is proposed for determining the subsystem’s energy efficiency in the case of the flow into a closed vessel. It is possible to determine the hydraulic efficiency of the subsystem components: the suction pipe, the discharge pipe and the machine. The efficiency of the machine determined by the hydrodynamic method is complementary to the efficiency obtained by the thermodynamic method. The machine set efficiency is composed of hydraulic efficiency of the machine; mechanical efficiency of the machine, the gearbox and motor; and electric efficiency of the motor. Hydraulic efficiency of the pipeline is related to substitute measure of wear margin—the coefficient of resistance. Pressure drop is a diagnostic symptom. Thermal efficiency of the heat exchanger is related to a substitute measure of wear margin—the coefficient of heat penetration. Temperatures and mass flow rate in the heat exchanger are diagnostic symptoms. It is possible to determine the capacity and efficiency of subsystems with one side closed—such as those filling hydrophore and gas vessels.

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