Desublimation of flowing vapor with a thermal resistance between the coolant and the heat sink surface

Results are shown of a study concerning the desublimation of water vapor flowing between parallel plates, with a finite coefficient of heat transfer between coolant and heat sink surface.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 24, No. 3, pp. 419–424, March, 1973.     

Study of entrainment of drops of coolant by wet vapor in a heat-pipe vaporizer

Expressions are obtained to describe the performance of a heat pipe in a regime of wet vapor flow. The analytical results are experimentally confirmed.Notation Q heat flow - q heat flux in the vaporizer - T temperature - P pressure - S surface area - length - r radius - G mass velocity - y mass moisture content - n number of droplets - V volume - N_ca calculated concentration - v axial linear velocity - d diameter - volume moisture content - a inclination of heat pipe - m mass velocity from a unit surface area - F force - w radial velocity - I intensity of beam - K permeability - N parameter - slip coefficient - g gravitational constant - distribution parameter - variance - x, y, z coordinates - C constant - attenuation efficiency factor - friction coefficient - attenuation factor of medium referred to a unit surface area - n=S_d/S_s coefficient of heat-flow transformation - k heattransfer coefficient in the heat-pipe condenser Indices liquid - w wick - hp heat pipe - ef effective value - cap capillary structure - d drop - v vapor - f flow-rate value - s vaporizer - cond condenser - e free-falling - ar arithmetic mean value - a adiabatic zone - b light beam Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 42, No. 1, pp. 11–20, January, 1982.     

Performance of return-flow channels in fluidized-bed equipment

Overflow of free-flowing materials into a fluidized bed from an upright channel in countercurrent gas filtration is investigated. Equations for calculating the weight rate of flow of the free-flowing material and the critical counterpressure are proposed.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 17, No. 3, pp. 423–428, September, 1969.     

Evaluation of coolant power losses in a thermal plasma arc reactor

Coolant power losses, associated with the operation of a research prototype plasma arc reactor, have been studied experimentally and are described herein. These power losses were measured in four separate fluid-cooled plasma arc reactor zones while plasma power input levels were increased from 4.8 to 13.7 k W. During this increase, all other controllable variables, such as plasma gas flow rate and coolant fluid flow rate were held constant. As operating power levels were increased, the coolant power losses in all four fluid-cooled zones of the plasma arc reactor also increased. However, the relative distribution of power losses changed significantly as the plasma power input levels were increased.     

Growth of vapor locks in channels of small diameters

The results of an analytical investigation into the ejection of liquid from channels by vapor locks formed in these are presented. The theoretical results are compared with experiment.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 25, No. 3, pp. 440–444, September, 1973.     

Design of a heat pipe with separate channels for vapor and liquid

The design of a limited rate heat pipe with individual channels for vapor and liquid is discussed.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 34, No. 6, pp. 988–993, June, 1978.     

Management of cracks and defects in engineering equipment

Abstract

The management of cracks and defects in engineering equipment is becoming an increasingly important decision that plant engineers and management are faced with. As plant equipment ages, an increasingly significant problem is reliability. By early detection and assessment, cracks can be monitored and repaired if it is required to do so. This paper provides an overview of the general technique that is employed in the evaluation of defects or cracks, whether real or postulated, in plant equipment. Also included is a brief outline of assessments of defects along with various case studies.     

New reference data on the thermodynamic properties of sodium vapor

Based on our previously published semiempirical equation of state derived using the results of new precision spectroscopic measurements, tables of reference data are compiled on the thermodynamic properties of sodium vapor and their root-mean-square deviations (errors) in the temperature range from 700 to 2500 K at pressures from the saturation line to 3 MPa     

Corrosion inhibitor for the chemical decontamination of primary coolant systems of nuclear power plants

Radiation field reduction in the primary heat transport (PHT) system of water-cooled reactors can be achieved by ‘dilute chemical decontamination (DCD)’ process. The corrosion behaviour of carbon steel has been studied in the absence and presence of different concentrations of cinnamaldehyde in 4.76 mM L⁻¹ of citric acid for different immersion times (6 h and 24 h) at 30 °C using weight loss, potentiodynamic polarization and impedance measurements. Cinnamaldehyde has given an inhibition efficiency of about 90% at 15.15 mM L⁻¹ and inhibition efficiency is decreased to 82% when duration of immersion increased from 6 h to 24 h. Electrochemical studies follow the same trend as those observed in weight loss measurements. The formation of the adsorbed inhibitor film on the carbon steel was further confirmed by FTIR studies.     

Ultra-precision engineering in lithographic exposure equipment for the semiconductor industry

The developments in lithographic tools for the production of an integrated circuit (IC) are ruled by 'Moore's Law': the density of components on an IC doubles in about every two years. The corresponding size reduction of the smallest detail in an IC entails several technological breakthroughs. The wafer scanner, the exposure system that defines those details, is the determining factor in these developments. This review deals with those aspects of the positioning systems inside these wafer scanners that enable the extension of Moore's Law into the future. The design of these systems is increasingly difficult because of the accuracy levels in the sub-nanometre range coupled with motion velocities of several metres per second. In addition to the use of feedback control for the reduction of errors, high-precision model-based feed-forward control is required with an almost ideally reproducible motion-system behaviour and a strict limitation of random disturbing events. The full mastering of this behaviour even includes material drift on an atomic scale and is decisive for the future success of these machines.     

Computer modeling of the deformation of elements of operating power equipment with damages

We consider the results of computer modeling of the deformation process of a collector with damages under in-service conditions with regard for the elastoplastic character of deformation and the real geometry of the collector and crack-like defects. We also establish the probable causes of damage initiation.     

化学气相沉积法制备Ta2O5薄膜的研究进展

Ta2O5是重要的介电材料和光波导材料.从前驱体的选择方面综述了化学气相沉积法制备Ta2O5薄膜的研究进展,说明了五卤化钽和Ta金属有机化合物对CVD过程的影响,对这两类前驱体的优缺点进行了比较和评述,讨论了Ta2O5的生成机理,并对其发展方向作了简要的展望.     

Laws of vapor bubble growth in the superheated liquid volume (thermal growth scheme)

The mathematical formulation of the heat-input-controlled vapor bubble growth in an infinite volume of uniformly heated liquid is described. Using the dimensional theory, the structure of the solution was analyzed qualitatively. A historical survey of theoretical works devoted to the considered problem is presented. Asymptotic solutions are obtained and studied systematically. The results of the complete analytical solution of the problem and formulas for the calculation of the bubble growth rate in the whole domain of possible variations in regime parameters are presented. The conclusion is made that the influence of permeability of the interface has a significant effect on the bubble growth rate. It is shown that the Plesset-Zwick formula, which is commonly accepted in computational practice, is not applicable at both small and large Jakob numbers and its good agreement with the experiment is determined to a large extent by a combination of the imperfectness of the theoretical analysis and the experimental error. The conclusion is made that, for many liquids, the ultimately achievable value of the dimensionless superheating parameter (Stefan number) can exceed unity. In this case, the regularities in the bubble growth acquire some features unexplored to date.     

The theory of the growth of vapor bubbles in a metastable liquid

The growth of a single bubble and a system of vapor bubbles in the initial state in thermal and mechanical equilibrium with a liquid has been considered. Linear and nonlinear solutions have been derived, and the effects of the radial inertia, viscosity of the liquid, interphase heat and mass exchange, and the conditions of the tightness of bubbles on the development of the process have been studied on their basis.     

Low-cost DSP-based equipment for the real-time detection of transients in power systems

A novel solution for the real-time detection of transients in power systems is presented. It relies on a simple and robust algorithm, which analyzes the signal in the time domain, does not involve high computational burdens, does not require a high amount of memory, and has been implemented on a low-cost DSP. Experimental results showing the very good system performance are provided.