High-temperature Facility Research Articles

High-temperature Calibration Facility for Calibrating Multihole Pressure Probes

High-temperature Calibration Facility for Calibrating Multihole Pressure Probes

Mastering of production of lead-free ecologically clean free-machining steels

Both in the domestic and world steel industry alternative ecologically clean free-cutting steels, having cutting machinability characteristics and mechanicalproperties, comparable with lead-containing steels, but voided of their drawbacks,are actively searched. First ofall the alternative steels should not be not so ecologically harmful. Scientific and technological aspects of lead-free free-machining steels production, alloyed by bismuth, calcium, tin, boron and nitrogen presented. Solubility of bismuth in iron and iron alloys with chromium, manganese, nickel, tungsten, vanadium, cobalt,phosphor, sulphur, aluminum, carbon and other elements at the temperature of 1550–1650 ºСdetermined. Parameters of interaction of the first and second order calculated. Study of bismuth behavior and tin spherical samples in 40X steel melt accomplished. The study done at the high temperature facility with controlled atmosphere and X-ray TV observation system. Simulation of phase compositions multicomponent alloys of steel АВЦ40ХГНМaccomplished by application of a program package FactSage. Within the study,a production technology of lead-free, ecologically clean free-machining, steels elaborated and masteredat OJSC “Zlatoust electro-metallurgical works”. Free-machining corrosion-resistant steels (АВЦ19ХГН, АВЦ40Х, АВЦ40ХГНМ, АВЦ12Х18Н10, АВЦ40Х13, АВЦ14Х17Н2) alloyed by bismuth and calcium, steels (АО40Х, АО30ХМ) alloyed by tin, and steels (А38ХГМАРand А30ХМАР) containing BN were the objects of the study. The steels samples were in the form of forged billet of 10, 20 and 80 mm diameter and ingots of 18 and 500 kg (round 345 mm). Steel quality characteristics determined such as mechanicalproperties in longitudinal and cross directions of ingots, uniformity of distribution of fusible elements, carbon and Sulphur along the axis zone and in billet transverse sections. Pictures of ingots macrostructure by height and section obtained. Estimation of hardenability and steel contamination by non-metallic inclusions, austenitic grain size, steel machinability by cutting, surfacequality of re-worked billet and steel macrostructure accomplished. Comparable ecological studies of atmosphere contamination during the steel alloying also accomplished.

Development of a high temperature facility for study of aerosol emission behavior of combustible materials

Aerosol size and number/mass size distribution are vital parameters for evaluating their effect on human health and the environment. To study the aerosol emission behavior of a material, a high temperature facility has been designed. Combustible materials like biomass, wood, agricultural residue as well as commercially used material like graphite can be burnt and characterized using this facility. In the present work, nuclear grade graphite has been tested in the facility, which can attain a maximum furnace temperature of 1350 °C with an air flow rate of 25 lpm. A cooling and dilution mechanism was incorporated to lower the temperature of the aerosol-laden gas to the desired value for aerosol size measurement using spectrometers. Isokinetic sampling has been ensured using a specially designed probe. Losses due to thermophoresis, condensation and coagulation, etc. have also been calculated and are found to less than 5%.

Determination of temperature dependences of Young's modulus and internal friction of fuel cladding by resonance method

We study elastic characteristics and internal friction of fuel claddings to improve computer codes for VVER-1000 fuel rods. We analytically described elastic characteristics of cladding material and obtained coefficient of the form of the first longitudinal frequency numerically. We described new measuring module for automatic acquisition data. We’ve established temperature dependences of Young’s modulus and internal friction via high-temperature facility and developed electronic module and noted maximum of these characteristics at the temperature 1160 K. It can be explained by the destruction of the texture in the material of claddings.

Experimental Study of the Characteristics of Heat Transfer in an HLMC Cross-Flow around Tubes

The process of heat transfer in a heavy liquid-metal coolant (HLMC) cross-flow around heat-transfer tubes has not been thoroughly studied yet. Therefore, it is of great interest to carry out experimental studies for determining the heat-transfer characteristics in lead coolant cross-flow around tubes. It is also interesting to explore the velocity and temperature fields in an HLMC flow. To achieve this goal, experts of the R.E. Alekseev Nizhny Novgorod State Technical University performed work aimed at experimental determination of the temperature and velocity fields in high-temperature lead coolant cross-flows around a tube bundle. The experimental studies were carried out in a specially designed high-temperature liquid-metal facility. The experimental facility is a combination of two high-temperature liquid-metal setups, i.e., FT-2 with a lead coolant and FT-1 with a lead-bismuth coolant, combined by an experimental site. The experimental site is a model of the steam generator of the BREST reactor facility. The heat-transfer surface is an in-line tube bank of diameter 17 mm and wall thickness of 3.5 mm, which is made of 10H9NSMFB ferritic–martensitic steel. The temperature of the heat-transfer surface is measured with thermocouples of diameter 1 mm installed in the walls of heat-transfer tubes. The velocity and temperature fields in a high-temperature HLMC flow are measured with special sensors installed in the flow cross-section between rows of heat-transfer tubes. The characteristics of heat transfer and velocity fields in a lead coolant flow were studied in different directions of the coolant flow: the vertical (“top-down” and “bottom-up” (Beznosov et al., 2013, “Experimental Studies of Thermal Hydraulics of a HLMC Flow Around Heat transfer Surfaces,” Proceedings of the 21st International Conference on Nuclear Engineering, ICONE21, Paper No. ICONE21-15248)) and the horizontal directions. The studies were conducted under the following operating conditions: the temperature of lead was t=450–500°C, the thermodynamic activity of oxygen was a=10−5–100, and the lead flow through the experimental site was Q=3–6 m3/h, which corresponds to coolant velocities of V=0.4–0.8 m/s. Comprehensive experimental studies of the characteristics of heat transfer in a lead coolant cross-flow around tubes have been carried out for the first time, and the dependences Nu=f(Pe) for a controlled and regulated content of the thermodynamically active oxygen impurity and sediments of impurities have been obtained. The effect of the oxygen impurity content in the coolant and characteristics of protective oxide coatings on the temperature and velocity fields in a lead coolant flow have been revealed. This is because the presence of oxygen in the coolant and oxide coatings on the surface, which restricts the liquid-metal flow, leads to a change in the characteristics of the wall-adjacent region. The obtained experimental data on the distribution of the velocity and temperature fields in an HLMC flow permit studying the heat-transfer processes, and on this basis, create program codes for engineering calculations of HLMC flows around heat-transfer surfaces.

Temperature measurements in a rapid compression machine using anisole planar laser-induced fluorescence

Advanced combustion processes induced by self-ignition mechanisms in piston engines, such as Homogeneous Charge Compression Ignition (HCCI), especially need an accurate spatio-temporal temperature information because their phenomenology therefore their performances highly depend on the thermal conditions. The objective of this study is to measure the temperature distribution inside a rapid compression machine (RCM) along the compression stroke using anisole planar laser induced fluorescence. The present paper gives a new insight into the interpretation of RCM autoignition data. It also brings useful information for kinetics-related combustion research and combustion modeling. The anisole planar laser-induced fluorescence (PLIF) technique is applied, in order to observe the formation and the evolution of temperature heterogeneities in the combustion chamber prior to the auto-ignition process. Anisole is used as a novel tracer species, and the fluorescence signal's dependence on parameters, such as temperature, pressure and bath gas composition, is quantified in a high-pressure, high-temperature facility. Calibration of the fluorescence signal is defined under RCM-related temperature and pressure conditions and a protocol is proposed for post-processing of the PLIF image sequences, allowing the quantitative field temperatures to be determined at successive instants following compression. In order to gain a better understanding of the mixture process, Particle Image Velocimetry (PIV) measurements are analysed under the same conditions. The correlation between thermal and aerodynamic phenomena is determined. The temperature field is found to be non-uniform, with hot and cold centre positions resulting from recirculation inside the chamber, combined with heat transfer effects from the chamber wall.

Waste Polystyrene (PS-6) Plastic Conversion into Liquid Hydrocarbon Fuel by Using HZSM-5 Catalyst with Thermal Degradation Process

Polystyrene is a thermoplastic substance, which is in solid (glassy) state at room temperature, but flows if heated above its glass transition of about 100 oC (for molding or extrusion),and becomes solid again when cooled. Pure solid polystyrene is a colorless, hard plastic with a limited flexibility. It can be cast into molds with fine detail. Polystyrene can be transparent or can be made to take on various colors. Polyester is one of the most widely used plastics, the scale several billion kilograms per year. Polystyrene and polystyrene materials have become to the concern topics about that very high temperature and sophisticated facility needs to apply to speed up the degradation process. The process of degradation could eradicate the polystyrene materials from the environment and save the atmosphere from defect air pollution. Catalytic and thermal degradation of waste polystyrene have been studied in a glass fiber reactor and. HZSM-5 catalyst used accelerates the reaction and increase the production yield. Temperature is used 120 oC to 400 oC. Polystyrene melting temperature is 260 oC. Also polystyrene made by p-Xylene it has benzene ring. Analytical instrument are (GC/MS) used for produce fuel it has lots of benzene compound, aliphatic alkane and aliphatic alkenes. GC/MS trace the hydrocarbon range before thermal degradation C3-C28 and after degradation is range C6-C18 because catalyst help to degrade the polyester long chain to short chain hydrocarbon. ASTM standard test is showing fuel sulfur content also less then EPA standard

Fluoranthene laser-induced fluorescence at elevated temperatures and pressures: implications for temperature-imaging diagnostics

The objective of this study is to develop a quantitative measurement of temperature from fluoranthene fluorescence under conditions with elevated temperatures and pressures. Absorption and fluorescence of fluoranthene are studied in a pressure and temperature range of 0.1–4 MPa and 473–873 K for the two excitation wavelengths of 266 and 355 nm. The influence of thermodynamic parameters such as pressure, temperature and gas composition is characterized in a high-pressure and high-temperature facility. When increasing the pressure, the vibrational relaxation mechanisms are favored, which involves an increase of the fluorescence quantum yield. Concerning the temperature effect, the fluorescence decreases with increasing temperature, this is explained by efficient radiative mechanisms of intersystem crossing. The quenching effect is strongly efficient in air, with a fluorescence evolution described by the Stern–Volmer relation. Over the temperature range studied, the fluorescence quantum yield decreases exponentially by two orders of magnitude. From the temperature dependence of fluoranthene fluorescence in different ambient gases for 266 and 355 nm excitation, the potential temperature measurements in homogeneously and inhomogeneously seeded systems are suggested: the single-color detection technique, the single-excitation two-color detection technique and the dual-excitation wavelength technique.

Marangoni convection in molten salts

Marangoni convection is involved in many technological processes. The substances of industrial interest are often governed by diffusive heat transport and their physical modelling is limited with respect to the Prandtl number Pr. The present paper addresses this deficiency. Studies were made on molten salts having Pr values in an intermediate range well below that of the typically employed organics. Since some of the selected species have a relatively high melting point, a high-temperature facility which allows studying thermocapillary convection at temperatures in excess of 1,000°C was built. The results presented here were obtained in a cylindrical geometry, although the equipment that was built is not restricted to this configuration because of its modular construction. Modelled after some applications, the fluid was heated centrically on top. The bulk was embedded in a large thermostatically controlled reservoir so as to establish the lower ambient reference temperature. A characteristic size of the experimental cell was chosen such that, on the one hand, the dynamic Bond number Bo did not become too high; on the other hand, the liquid had to have a certain depth to allow particle image velocimetry. The complicated balance between body forces and thermocapillary forces in the case of intermediate Bo was found to result in a distinct local separation into a bulk motion governed by natural convection with a recirculating Marangoni flow on top. In contrast to low viscosity organics, the vapour pressure of which increases considerably with decreasing Pr, high values of the Marangoni number can be reached. Comparisons of the topology of Marangoni vortices between molten salts with 2.3 ⩽ Pr ⩽ 6.4 and a silicone oil with Pr typically one order of magnitude higher suggest that the regime of non-negligible heat diffusion is entered.

Measurement of exhaust gas recirculation rate by laser-induced fluorescence in engine

The objective of this study is to measure by planar laser-induced fluorescence the exhaust gas recirculation (EGR) rate in the combustion chamber of an optical engine to quantify the stratification phenomena used in the new combustion strategy. From the results obtained in a high pressure–high temperature (HP–HT) facility, the tracer chosen for this aim is 3-pentanone. This paper presents a quantitative measurement of the EGR rate in the engine and a post-processing model with a correction and calibration procedure by considering the influence of temperature and pressure on the absorption cross-section and the 3-pentanone fluorescence quantum yield from the results established in the HP–HT facility. The stratification phenomena are quantified by using 3-pentanone fluorescence for two different configurations of EGR introduction in the engine. The local fluorescence measurements in the HP–HT facility are also compared with planar fluorescence measurements in the optical engine.

VAPORIZATION AND OXIDATION OF LIQUID FUEL DROPLETS AT HIGH TEMPERATURE AND HIGH PRESSURE: APPLICATION TO N-ALKANES AND VEGETABLE OIL METHYL ESTERS

Vaporization and oxidation of liquid fuel droplets are basic mechanisms in spray combustion for various industrial applications. In this work, coupled effects of temperature and pressure on n-alkane droplet vaporization are investigated in experiments conducted in a high-pressure and high-temperature gasification facility equipped with the fiber-suspended droplet technique. The influence of temperature and pressure on n-heptane and n-decane vaporization rates is particularly emphasized with regard to critical conditions of the liquid fuel. Characteristics of n-alkane droplet vaporization, and heating and vaporization times are compared with those of vegetable oil methyl esters—biofuels used in diesel engines. Finally, chemical species formed during the oxidation of these biofuels are identified by gas chromatography in oxidation experiments performed in a jet-stirred reactor. The influence of temperature, pressure, and equivalence ratio on regulated and unregulated pollutants is discussed. Emissions of pollutants obtained during biofuels oxidation are compared with those identified during the oxidation of a synthetic diesel fuel.

High-temperature neutron reflectometry of liquid metal-ceramic interfaces

Neutron reflectometry has been used to study liquid metal-ceramic interfaces in situ. A high-temperature facility designed and commissioned for use on the SURF reflectometer at the ISIS beamline, Rutherford Appleton Laboratory, is described. Results from a study of two Sn-Ti alloys on sapphire up to 1173 K are presented and the interfacial composition established by interpretation of the recorded reflectivity profiles. Overall the results are in good agreement with previously published work inferred from the analysis of solidified structures and the neutron reflection technique, established as a unique method for the high temperature analysis of buried solid/liquid interfaces.

High temperature neutron reflection spectroscopy of liquid metal/ceramic interfaces

A high temperature facility to study liquid metal–ceramic interfaces via neutron reflection spectroscopy is described. Preliminary results from a study of sapphire/Sn and sapphire/Sn–3 wt% Ti samples up to 1000°C are presented. Results show that the interface generally consisted of a patchy mixed metal/metal oxide surface rather than discreet layers. A study of Ti segregation proved inconclusive although further investigation is required. Overall the technique is suitable for the characterisation of metal–ceramic interfaces at high temperature.

Ultrasonic-induced Cavitation Studies in Pb-Bi Alloy 500–1500 F

Abstract Cavitation studies have been conducted in lead-bismuth alloy (70 percent lead-30 percent bismuth) at 500 and 1500 F (260–816 C) with a vibratory device utilizing a piezoelectric crystal transducer unit and high-temperature cavitation facility. Test materials subjected to the cavitation environment were Types 304 and 316 stainless steel, two tantalum alloys, Mo-1/2Ti and Cb-1Zr in two heat-treat conditions. At 500 F tantalum alloys were most cavitation-resistant based on mean depth of penetration, although the Mo-1/2Ti and the two stainless steels were nearly as good. At 1500 F both tantalum alloys were still the best, followed by Mo-1/2Ti, Cb-1Zr (cold-worked) and 316 stainless steel in that order. The Cb-1Zr (annealed) and 304 stainless steel were the least cavitation resistant. Thus, as expected, the relative advantage of the refractory alloys at high temperature is indicated. For all materials the cavitation damage at 1500 F was greater than that at 500 F, as expected. Qualitative and quantitative correlations between the cavitation damage data and the mechanical properties of the materials are presented. Corrosion effects were negligible.