Results 1 - 10 of 527
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[en] Results of investigation of characteristics of the pulse power optical emitter based on magnetoplasmatic compressor are given. Dependence of an energy flux density of radiation on the energy put in the discharge, in approach a Planck radiation law is shown
[en] In the present paper, heat exchange tube resistance to an acoustic field, is studied particularly in the case where the tubes are to be located either at the suction or discharge end of a compressor or upstream from a sonic relief valve or even mounted between these two elements. The aim is to estimate the stress levels involved with a view to arriving at a tube lifetime assessment, from which could be derived a preliminary design calculation method to be used by the design engineering teams at preliminary project stage
[fr]On etudie la resistance a un champ acoustique, des tubes d'echangeur de chaleur, particulierement dans le cas ou les tubes sont places soit a l'extremite d'aspiration ou de decharge d'un compresseur ou en amont d'une soupape de securite sonique ou meme montes entre ces deux elements. Le but final est d'estimer les niveaux impliques de contraintes pour arriver a evaluer la duree de vie des tubes, qui pourrait etre derivee d'une methode de calcul preliminaire utilisable par les equipes d'ingenierie dans l'etape preliminaire du projet
[en] Processes occurring in a plasma flow generated by a magnetoplasma compressor (MPC) during the formation of the compression zone are discussed. The paper presents results of measurements of the spatial distribution of the electric current in the plasma flow, the temporal and spatial (along the flow) distributions of the plasma density, and the profiles of the velocity of individual flow layers along the system axis. The spatial distribution of the electromagnetic force in the flow is analyzed. It is shown that the plasma flow is decelerated when approaching the compression zone and reaccelerated after passing it. In this case, the plasma flow velocity decreases from ν = (2–3) × 107 cm/s at the MPC output to ν < 106 cm/s in the region of maximum compression and then again increases to 107 cm/s at a distance of 15–17 cm from the MPC output. In some MPC operating modes, a displacement of the magnetic field from the compression zone and the formation of toroidal electric current vortices in the plasma flow after passing the compression zone were detected
[en] In the budget of any industrial complex, maintenance of rotating machines is a considerable factor which might be widely reduced when deciding a maintenance policy ''according to the state of things'' or ''estimated''. For Eurodif shop of Tricastin compressors where these combine with structures and are subjected to internal and external excitation, definition of a vibratory close-following and its implementation set up various problems which are investigated in this paper
[fr]Dans le budget de tout complex industriel, l'entretien des machines tournantes constitue un poste important qui peut etre reduit dans les proportions considerables en adoptant une politique d'entretien ''suivant etat'' ou ''previsionnelle''. Pour les compresseurs de l'usine EURODIF du Tricastin qui sont integres aux structures et qui sont soumis a des excitations interieures et exterieures, la definition du suivi vibratoire et sa mise en oeuvre ont pose un certain nombre de problemes qui sont examines dans cette communication
[en] Noise sources at gas compressor facilities include the enclosure/building housing a gas engine and compressor, the ventilation openings, doors and windows for the enclosure, the engine air intake and exhaust, and a cooler. Accurate predictions of the noise levels inside the enclosure, the breakout noise from open windows and doors and ventilation, as well as the transmission through the walls, is necessary in order to determine cost effective noise mitigation for the facility. In order to accurately predict the sound breakout from these facilities it is necessary to know the acoustic absorption of the interior of these equipment enclosures. Although the acoustic absorption data of the wall systems may be available, the absorption attributable to the non-enclosure surfaces, the equipment and fittings, is not usually known and is difficult to predict. Since piping, instrumentation and mechanical equipment often take on a typical arrangement, shape, volumetric density and material composition, it is useful to know the typical acoustic absorption attributable to these items. In this study, reverberation time (RT) measurements were taken at 2 decommissioned gas compressor facilities in order to determine the absorption characteristics of the enclosure. The RT was measured according to ASTM C423-02a. The overall absorption coefficient of a compressor enclosure with a solid liner was found to be similar to that of steel decking. Fittings within the enclosure did not increase the high frequency absorption of the enclosure. It was concluded that room modes, structural vibrations, and fittings may serve to increase the effective absorption at frequencies below 630 Hz. Because of the small dimensions of the enclosure, low-frequency response of the room affected the reliability of the data below 160Hz. Structural vibration of the enclosure was investigated, and may considerably influence the noise breakout from the enclosure apart from the interior acoustical considerations. 4 refs., 1 tab., 2 figs.
[en] The main objective of these studies is characterization of dense xenon plasma streams generated by magnetoplasma compressor (MPC) in different operational regimes. Optimization of plasma compression in MPC allows increase of the plasma stream pressure up to 22...25 bar, average temperature of electrons of 10...20 eV and plasma stream velocity varied in the range of (2...9)x106 cm/s depending on operation regime. Spectroscopy measurements demonstrate that in these conditions most of Xe spectral lines are reabsorbed. In the case of known optical thickness, the real value of electron density can be calculated with accounting self-absorption. Estimations of optical thickness were performed and resulting electron density in focus region was evaluated as 1018 cm-3.
[en] The two-dimensional MHD-flow of the ideal plasma in a channel of the magnetoplasma compressor (MPC) with an axial hole in the central electrode (divertor) is numerically simulated. The steady-state regime of the flow is obtained. The influence of finite and periodical density perturbation at the entry of the channel on the compressional flow properties is investigated. It is shown that the flow is stable under such perturbations
[en] Highlights: • The unsteady superposition characteristics of two moving incident shockwaves for R718 vapor flows coupled with condensing are intensively studied, which have not been reported before. • Remarkable supercharging abilities (high boosting pressure ratio) and remarkable superheating ability are achieved from the two superpositing moving shockwaves, as could be fully used for vapor recompression in multi-effect distillation technology (MED) for brine water treatment. • The stagnated feature of the supercharged driven stream with ultra-high temperature between two refractive contact faces, makes a much longer time for PMT to detect when superposition-shock tube used for chemical reactions research. - Abstract: Although the positive values of the fundamental gas-dynamic derivative of R718 near vapor-liquid equilibrium line ensures no occurrence of the non-classical behavior like rarefaction shock waves, the occurrence of the homogenous condensations due to rarefaction waves must be taken into account when using the moving shocks and rarefaction waves in wave devices. In this article, the superposition behaviors such as shockwave refraction and reflection of two moving incident shocks for R718 vapor flows near this the vapor-liquid equilibrium zone, have been intensively studied. And the supercharging characteristic of two superposition moving incident shocks for R718 vapor flows achieves remarkable high boosting pressure ratios of about square of those of one primary equal-intensity shock. This inspiring result could be fully used for vapor recompression in multi-effect distillation technology (MED) for brine water treatment.