Gas Compressor Units Research Articles

Aerodynamic drag of tube bundles with the helical-shaped tubes

The paper is devoted to the experimental studies of the aerodynamic drag of staggered bundles of helical tubes in order to create highly effective heat exchangers with reduced weight and size. The researches of the aerodynamic drag of staggered bundles of helical tubes at their airflow were carried out on an experimental setup, which is an open-circuit wind tunnel of rectangular cross section and conducted by the method of physical modeling in an isothermal flow, using the data of the drainage selection of static pressures before and after the bundle. The influence of geometric characteristics of helical tubes and parameters of their placement in the bundle on the aerodynamic drag is shown. The comparison of the aerodynamic drag of the bundles of helical and plain tubes of the same outside diameter depending on the incident velocity was conducted. The research results can be used in developing recuperative heat exchangers having high heat-aerodynamic efficiency and applied in thermal power engineering, petrochemical industry, gas compressor units of the gas transportation system ofUkraine. The obtained results can be the basis for aerodynamic calculations in the design of new heat exchangers of helical tubes.

Elastic deformation of the bearing surface of a radial sliding bearing turbocharger

The methodology of studying the elastic deformation of the bearing surface at the simultaneous action of forces, gradually aris­ing from start to stop, is proposed on the example of the operation of the journal thrust bearing of turbocharger of the gas compressor unit turbine. For that, the mathematical model was used, which describes the balance and deformation of spatially curved element, its external and internal geometry. The methodology of numerical solution of the problem is based on the combined application of the continuation method and Newton-Kantorovich method.The problems, which arise in the operation of plain thrust bear­ings of the compressors of turbo generators are described in the pa­per, the analysis of the literature on this subject is given. It is shown that, as a rule, local problems, describing any separate process, are still considered in the problems of friction. In this respect, it was pointed out that the process of friction is inseparably linked with the large number of load factors, which have not yet been considered simultaneously. During the description of the methodology, its sense was outlined, the ways of setting the possible loads, which can be applied or taken away during the bearing operation were shown. The possibility of investigating the bearing surface with a non-circular (oval) geometry of the axial line was shown on the example of the plain thrust bearing of the turbocharger. The research results are presented in the form of diagrams, which show the values of some characteristics of the stress-strain state of the bearing surface of the plain journal bearing of the turbocharger with specific physical and geometrical characteristics in dimensionless quantities.

Possible Reasons for Instability in the Performance Properties of Tr-22 s Mineral Turbine Oil when Used in Gas Compressor Units

It has been experimentally established that the instability in the performance properties of Tp-22 s mineral turbine oil is due to the different catalytic activities of the original base stocks used to produce the commercial oil. The catalytic activity factor shows by how many times iron (the catalyst) increases the oxidation rate of the oil. A higher catalytic activity factor for the original base stock means poorer performance properties for the commercial oil obtained from it. Introducing additives into the composition of the mineral base stock that block the catalytic effect of iron makes it possible to reduce the catalytic activity factor.

Structure, composition, and control algorithms of high-efficiency electric drives of gas-compressor units

The structure and composition of electric drives used in gas-compressor units are considered. The key requirements and peculiarities of controlling the efficiency of electrically driven gas-compressor units and the structure and algorithms of their control systems are analyzed.

ТеплообміН пучкіВ труБ З рівнорозвиненоЮ поверхнеЮ

Наведено результати експериментальних досліджень конвективного теплообміну шахових пучків труб з рівнорозвиненою поверхнею в діапазоні зміни чисел Рейнольдса від 5000 до 70000. Запропоновано узагальнену залежність для розрахунку конвективних коефіцієнтів тепловіддачі таких пучків. Показано, що коефіцієнт Сq при числі Рейнольдса в рівнянні подібності залежить від геометричних характеристик пучків та труб.

Methodology and tools for neuro-fuzzy prediction of the status of electric drives of gas-compressor units

Results of development and implementation of integrated systems for monitoring and predicting the technical condition of electric gas-compressor units are presented. Operational factors affecting the reliability of the engines with synchronous motor drive are revealed. Hardware is proposed that is based on smart sensors, and results of computer simulation of operation of electric-driven gas turbo-compressors are given.

Magnetic Memory Testing and Intensity Failure Analysis of Fractured Bolt of Cylinder Head on Hydrogen Gas Compressor

Along with the wide application of pressure energy, large scale reciprocating compressor unit is becoming one of the necessary key equipments in petrochemical industry. The reciprocating compressor has complicated structure and it is very difficult to carry out measurement & analysis to the operation status of various components. Above all, as the most important fastener of the compressor, once fracture of cylinder head bolt of the reciprocating compressor occurs, major disaster will occur. Metal magnetic memory testing technology is a nondestructive examination technology based on magneto-mechanical effect principle. Specific change of leakage magnetic field will occur in stress & deformation concentrated region under combined action of alternate work load and geomagnetic field, macroscopic cracking can be detected and stress concentration and early state damage can be evaluated by utilizing this specific change, We carried out on-site examination on the fractured bolt of cylinder head of hydrogen gas compressor unit in refinery of certain petrochemical corporation with latest metal magnetic memory testing technology. On the basis of intensity analysis and dynamic load calculation to cylinder head bolt of the reciprocating compressor, we analyzed the cause of bolt fracture by using metal magnetic memory testing technology and drew out the magnetic memory signal distribution characteristics of the bolt and its fracture. We verified the correctness of testing result of the metal magnetic memory technology on cylinder head bolt and its fracture with metallographic examination technology; furthermore, we studied the reliability of bolt fatigue crack & fracture analysis and investigation of accident cause by using magnetic memory characteristic distribution signal.

Inspection of rotor disks of HPT and LPT of TK-10-4 gas-compressor units by the ultrasonic flaw detection method

The special features of diagnosing disks of gas turbines of gas-compressor units by the ultrasonic flaw detection method are considered. The efficiency of detecting crack-type defects in disks of HPT and LPT rotors under the first tooth of fir-tree slots of the disks in the area of trapezoidal grooves for tightening plates is shown. The application of the ultrasonic flaw detection method substantially increases the reliability of crack detection.

Numerical modeling of ventilation process and thermal status of the noise-heat protective housing of a gas-turbine plant on parallel computers

We study the thermal status of a noise-heat protective housing (NHPH), where a gas turbine plant (GTP) is located. The analysis of thermal conditions requires consideration of heat transfer caused by radiation emitted by the heated elements of the housing. In this paper, a mathematical model is proposed to calculate the rate and temperature of the air flow inside the NHPH, as well as the temperature of the NHPH wall-material, making allowance for radiation heat transfer. A parallel algorithm is designed for solving the cluster gas dynamic problem. The optimization problem is solved by applying the parallel domain decomposition method. Calculations are made for the NHPH of one of the available of gas-compressor units. The results confirm that the heat transfer caused by radiation should be taken into account in the solution of a solid-state thermal conductivity problem for NHPH walls. There is good agreement between the calculated temperatures and the temperatures measured at certain points on the external surface of NHPH walls.

Experimental Investigation «Dry» Gas-Dynamic Seals Used for Gas-Compressor Unit

This paper describes the high-speed test bench of NAU «KhAI», experimental assembly used for testing the plain bearings and «dry» gas-dynamic seals for the gas-compressor unit, and also DGS control measuring panel and information acquisition system. The basic results of the research are given below.

Modelling and Simulation of a Complete Supercritical Fluid Extraction Plant with Countercurrent Fractionation Column

The most complete dynamic model to date of a supercritical fluid extraction (SFE) plant is presented and experimentally validated. The SFE flowsheet is modularly organized into a set of detailed sub-models of the main unit operations, including the extraction packed column, the supercritical solvent heat exchanger, the product recovery and solvent regeneration column, and the solvent make-up. The modules are interconnected through appropriate boundary conditions that establish continuity of mass, momentum, and energy. The present model significantly improves our previous modeling efforts by, among other features, including the gas compressor unit, extending the operation of the whole plant to nonisothermal conditions, and upgrading the packed column model for reflux mode operation. The SFE model was validated against experimental data for the fractionation of edible oil mixtures by supercritical carbon dioxide. Good agreement was obtained between experimental and predicted results; moreover, the model correctly predicts the trends with different operating and design parameters.

Technological data analysis for pre-emergency situations at gas compressor units

Special features of mathematical models used to describe time dependencies of technological parameters of gas compressor unit (GCU) are analyzed during pre-emergency operation of GCU; the models are developed on the basis of the method of grouped arguments. Principal feasibility for well-timed identification of GCU being in pre-emergency situation is demonstrated.

Стартер-генераторный комплекс газотурбинного двигателя газоперекачивающего агрегата

A starter-generator complex is offered for starting of gas turbine engine generating of electric power, using one asynchronous electric machine and the automatic switching of electrical customers of gascompressor unit on a feed from the starter-generator complex

Automated monitoring system for drive motors of gas-compressor units

The present-day techniques for design and development of the embedded systems for monitoring and prediction of a technical condition of MW electrically driven units are examined with a case study at synchronous machines at gas-compressor stations. The statistical analysis of damageability and operational factors of aging of the insulation at stator windings of gas-compressor unit motors is cited. The example of an automated monitoring system for the STD-12 500 synchronous motor, based on innovative electric equipment and an automated process control system (APCS), is shown.

Analysis of methods and assessment criterions of technical state gas-compressor units

In the article we have observed perspective methods of diagnostic gas-compressor units at various stages of their maintenance phase and the optimal and informative assessment criterion of their technical state.

Testing of discs of turbine rotors of gas compressors with the dye penetrant nondestructive testing technique

The special features of diagnostics of turbine discs of ΓTK-10-4 gas compressor units tested by the dye penetrant flaw detection method are considered. It is shown that disc blades must be dismantled and carefully mechanically cleaned, the spots in discs where such flaws as cracks are generated most often being analyzed, thereby reducing the searching and detection time.

Determination of dynamic stability regions of a synchronous motor of a gas compressor unit for different field control laws

A system of nonlinear differential equations for the synchronous electric drive of gas compressor units has been obtained in vector-scalar form. A technique has been developed for determining the dynamic stability regions of a synchronous motor for various algorithms of the field control.

Numerical forecasting surge in a piping of compressor shops of gas pipeline network

This paper presents a method of forecasting stable operation of gas compressor unit (GCU) centrifugal supercharger (CFS) installed on a piping of compressor shops servicing gas pipelines. The stability of superchargers operation is assessed in relation to the phenomenon of surge. Solution of this problem amounts to the development and numerical analysis of a set of ordinary differential equations. The set describes transmission of gas through a compressor shop as a fluid dynamics model with lumped parameters. The proposed method is oriented to wide application by specialists working in the gas industry. The practical application of this method can use all-purpose programming and mathematical software available to specialists of gas companies.

Сomplex and protection vibrokontrolyu gas compressor units "visa-pc"

Writers wanted to introduce and develop complex “Viza-PC” which meant for dimensioning and reflecting operation vibrofactors, forming the signal for tolerance buildup in system automatic control gascompressor unit.

Some Features of High-Temperature Oxidation of Aluminide Coatings on Alloy TsNK-7P

Special features of high-temperature oxidation of aluminide coatings (slip-deposited Al – Si and ion-plasma-deposited VSDP-11) on alloy TsNK-7P are considered. The kinetics of the oxidation process, the element composition, and the microhardness of coatings with different thicknesses are described. Results of thermal fatigue tests of alloy TsNK-7P with aluminide diffusion coatings are presented. It is shown that the VSDP-11 coating ensures a higher heat resistance and thermal fatigue strength on alloy TsNK-7P than the Al – Si coating and can replace the latter on turbine vanes of gas compressor units.