Steam Jet Research Articles

Evaluation of affected region by steam jet on surrounding environment

Evaluation of affected region by steam jet on surrounding environment

Experimental Study on Condensation of Steam Jet Injection in Submerged Condition

Experimental Study on Condensation of Steam Jet Injection in Submerged Condition

Experimental Investigation of Pressure Oscillation in Steam Jet Condensation Through a Sparger in Stagnant Water

Experimental Investigation of Pressure Oscillation in Steam Jet Condensation Through a Sparger in Stagnant Water

ОСОБЛИВОСТІ МУЗЕЙНОЇ РЕСТАВРАЦІЇ ПОЛИВ’ЯНИХ КЕРАМІЧНИХ ПЛИТОК ЦЕРКОВНОЇ ПІДЛОГИ ХІІ СТ. З М. БУСЬК

For the first time in the article the analysis and systematization of twin ceramic tiles of the XII century from the city of Busk is performed. Metric characteristics, technology of tile execution and its watering, installation technology are determined. A restoration program has been developed and work on the monument has been practically implemented. During the chemical-technological studies of two samples it was found that the mineral composition of lime-sand solution consists of quartz sand, slaked lime, organic additives and the mineral masicot, which corresponds to the chemical formula PbO, and lead oxide Pb2O. Thus, during the princely era to create a strong solution add protein, resulting in the formation of casein, over time in this solution could function organisms (which would feed on microcasein), so to prevent the formation of microorganisms added antiseptic - lead oxide. Analysis of brown ceramic glaze showed that this color is formed by mixing the tops of oxide forms of calcium and pork, as well as quartz sand, clay raw materials and feldspar. Yellow ceramic glaze was the result of the presence of a significant amount of lead oxide in the charge. Green ceramic glaze was formed due to the presence of a copper element in the silicate matrix.Fluorescent glow is characteristic of yellow and greenish coating. This effect is achieved due to the addition of a mixture of wood and bone ash (phosphorus). Yellow-green ceramic glaze is stronger than brown.. This was reflected in the state of preservation of the decorative surface of the tiles, and is also a consequence of the fact that the yellowish ceramic glaze was more homogeneous due to the lead content. In contrast, brown ceramic glaze was less robust due to the additional introduction of Fe2O3 oxide into the charge. The program of restoration of finishing tiles consists of several stages: photo-fixation of the monument before restoration; execution of measurement drawings and cartograms of losses; part of the ceramic tiles that were in a critically unstable state was strengthen the solution KSE-100; performing samples for chemical analysis; cleaning of the ceramic tiles from pollution by means of compresses of distilled water and a cotton swab; cleaning ceramics from crosslinked organic contaminants by steam jet method; structural strengthening of ceramics with silicon-organic solution KSE-300; injection of cracks with mineral solution to prevent further destruction of the monument; lassing additions; elaboration of a reverse arrangement method of arranging floor tiles. The process of structural strengthening lasted three times in two weeks. After total impregnation of the tiles with silicon-organic solution, they were covered with a film to allow deeper penetration of the substance and slow evaporation. This method allowed to evenly impregnate the ceramic tiles and prevent the formation of zones of film stress on the surface of the works. The main axis of the restoration program was the stabilization of the archeological site from further destruction. All found ceramic tiles had significant damage and cracks, and this is a source of destruction of the object. Therefore, during the restoration it was decided to inject the cracks with the author's mineral solution. The result of conservation measures - managed to stabilize the monument, stop its destruction and give the object an expositional appearance. Ceramic tiles of the church floor are a valuable Ukrainian cultural heritage of the XII century. Their technology of execution and installation testifies to a high level of handicraft skill. The importance of ceramic floor tiles for Ukrainian science and art has led to a frugal approach to conservation, adherence to the vector of quality stabilization of ceramic and irrigated materials. The developed concept of museum arrangement of ceramic tiles will allow to continue historical and chemical-technological research.

Experimental Investigation on the Pressure Oscillations Induced by Subsonic Steam Jets Under Different Vessel Pressures

Experimental Investigation on the Pressure Oscillations Induced by Subsonic Steam Jets Under Different Vessel Pressures

Experimental Investigation of Pressure Oscillation in Steam Jet Condensation Through a Sparger in Stagnant Water

Experimental Investigation of Pressure Oscillation in Steam Jet Condensation Through a Sparger in Stagnant Water

Analysis on helium stratification erosion by vertical steam jet using the CUPID code

This paper presents a validation of a computational fluid dynamics (CFD) code (CUPID) for predicting the erosion of helium stratification by a vertical steam jet. For the validation of CUPID, CFD grade experimental data obtained from the PANDA facility in the framework of the OECD/NEA HYMERES-2 project was used. To predict the stratification erosion phenomena appropriately, the turbulence model and radiative heat transfer model need to be employed as major physical models. Therefore, the standard k–ε turbulence model, including the buoyancy term, was applied, and a sensitivity study was carried out to investigate the effect of buoyancy production in the turbulence dissipation rate equation on the predicted helium concentration. Additionally, a radiative heat transfer model (P-1) was implemented by applying the appropriate parameter for the calculation, and the predicted gas temperature distributions with and without radiative heat transfer were compared. First, the physical models were validated for a baseline test case in which the vertical steam jet did not interact with any flow obstacles. Then, a second validation was carried out as a blind benchmark calculation where the experimental data were released after the calculation results had been submitted. The CUPID calculations for the helium concentration and gas temperature were very close to the measured data and showed that the analysis models can be used to accurately predict the gas mixing phenomena in the containment.

Numerical investigation on thermal hydraulic characteristics of steam jet condensation in subcooled water flow in pipes

Because of the high efficiency of heat and mass transfer, the direct contact condensation of the steam jet in subcooled water has been widely used in various industrial processes. Based on the previous experiments, this paper has established the numerical model and simulation method to describe the condensation of saturated steam discharging into the subcooled water in the pipe through the nozzle. Within the frame of the Euler-Euler two-fluid model, the heat and mass transfer in the condensation phase change of steam is calculated by the thermal phase-change model. When the steam pressure at the nozzle inlet increases from 150 kPa to 450 kPa, the steam plume gradually transforms from contraction cone to expansion-contraction cone. The length of the steam plume increases linearly from 0.59de to 3.07de. The condensation heat transfer coefficient based on the volume of the two-phase region gradually decreases from 4847.01 MW/m3K to 1988.16 MW/m3K. By analyzing the distribution of thermal-hydraulic parameters along the nozzle central axis, it is found that the expansion-contraction steam plume channel accelerates the steam jet to a supersonic state. The total pressure decreases suddenly at the nozzle outlet, and the water phase dynamic pressure causes the total pressure to rapidly increase to the maximum at the end of the gas-liquid two-phase region. When the steam pressure at the nozzle inlet is 450 kPa, the Ma number and maximum total pressure are up to 1.43 and 1228.2 kPa, respectively.

Combustion of kerosene sprayed with a jet of superheated steam

In the present work, the effect of forced air supply on the combustion process of liquid hydrocarbons was studied using diesel fuel as an example. The content of the flame intermediate components and temperature distribution along the flame symmetry axis were studied using an atmospheric burner in which liquid fuel is atomized by a steam jet. The gas composition of equilibrium combustion products and heat release were also investigated. The influence of the excess air ratio in the combustion chamber of the burner device on the thermal and environmental characteristics was shown.

Study of dispersed composition of spray during atomization of water-fuel emulsion with a superheated steam jet

Using the method of direct shadow photography the dispersed composition of fuel spray was studied when water-fuel emulsion is sprayed with the superheater steam jet. For emulsions with a mass water content of 5 and 10%, the characteristic droplet size in the flow is 1–2 μm and sufficient for effective combustion.

Design features of a high-vacuum steam jet pump and some results of its tests

This paper presents an original design of a high-vacuum steam jet pump in which a heater made of a heating cable is immersed in a working fluid located in a stainless steel boiler. At the same time, the boiler itself is vacuum isolated from the pump housing. There is also a heater made of a heating cable in a stainless steel shell, made in the form of a spiral and immersed in a working fluid. Such an arrangement of the heater is possible only when a liquid with a homogeneous chemical composition and a low saturated vapor pressure is used as a working fluid in high-vacuum pumps.

Experimental study of heat transfer in the complex space of small steel containment with a steam jet

Compared with large reactors, the internal structure of small reactors is more compact, and the heat capacity is smaller. The experiments were carried out under various jet velocities, sizes, and horizontal locations to study the heat transfer phenomenon caused by steam jet in a small containment with a complex structure. The results show that the overall temperature distribution in the containment is the same under different jet flow factors. Below the break, the temperature increases with height, and above the break, maintaining the same temperature without thermal stratification. The higher the jet velocity, the higher the overall temperature. As the size of the break increases, the jet velocity decreases, and the circulation in the containment slows down, resulting in the temperature rises. There is no significant difference in temperature field with various jet horizontal locations.

A novel solar assisted multigeneration system devoid of external utilities for drought adaptation considering water-exergy nexus analysis

• A sustainable solar multigeneration system was proposed to adapt to climate change. • Comparative thermodynamic, cost, risk, and environmental analysis were conducted. • The system offers 13 times less water withdrawal than conventional power plants. • Exergetic efficiency of the eco-friendly system can reach up to 74.37% • The novel system manages to generate products at a cost rate of 0.017 $.MWh −1. Conventional steam-driven multigeneration systems contribute to environmental damage by losing significant freshwater and emitting greenhouse gases. Here, a novel solar-powered steam jet ejector-based multigeneration system independent of external cold utilities is proposed for climate change adaptation. A Rankine cycle, an organic Rankine cycle, and a reverse osmosis desalination unit are fully integrated for clean power, cooling, and freshwater production employing. The thermo-mathematical model was evaluated considering thermodynamic efficiencies, annual costs, exergorisk, and global warming potential in a stand-alone and comparative framework. The water utilization of the hot utility was compared with two traditional fossil fuels by conducting a water-exergy nexus analysis. The analytical results showed that most of the total exergy destruction (73%) occurred in the solar collectors. The proposed system had 0.0171 $.MWh −1 cost of energy and an exergy efficiency of 57.29 % by employing R11. Compared to a natural gas-fired utility, the proposed solar-powered system reduced freshwater withdrawal, and consumption by 16 and 13 times, respectively. The system could achieve the exergetic efficiency of 74.37 % with the cost of energy of 0.013 $.MW −1 in a parametric model. Finally, R365mfc emerged as the optimal fluid for the proposed system by satisfying all performance criteria.

Jet impingement in high-energy piping systems, part I: Characteristics and model evaluation

Under postulated pipe rupture accidents in nuclear power plants (Loss-of-Coolant Accident or LOCA), jet impingement can occur where the high-energy fluid is discharged and cause damage to the surrounding structures, systems, and components (SSCs). As a part of addressing the potential non-conservatisms in the Standard model ANSI/ANS-58.2 (1988), the current work investigates characteristics of jet impingement in high energy piping systems as in nuclear power plants including pressure distribution within jets, pressure on target, and critical mass flux and performs model evaluation. The pressure prediction using ANSI/ANS-58.2 (1988) as well as critical mass flux models are evaluated using the experimental data available in literature. An organized experimental database with different inlet fluid conditions including subcooled water, saturated water/two-phase (0 ≤ x < 0.7), and saturated steam (x ≥ 0.7) is compiled for data analysis and model evaluation. It is found that a power law can be used to correlate the dimensionless static and stagnation pressures at the center of the free jets, while either a power law or an exponential function can be used to correlate the dimensionless stagnation pressure at the center of the targets in impinging jets. The difference in stagnation pressure between free and impinging jets is negligible for saturated steam and saturated water/two-phase jets, but it is significant for subcooled water jets. From model evaluations, the stagnation pressure within the saturated steam jets can generally be predicted well by the Standard model. Although stagnation pressures at far distances (z* > 3.3) can be underestimated, the dimensionless pressures at these axial locations are below 0.07. For saturated water/two-phase jets, the stagnation pressure can be predicted well using the Standard model for the large-scale test data (D > 0.28 m) but are underestimated at some axial locations for the medium- and small-scale test data (D < 0.15 m). Significant overestimation in stagnation pressure is observed for subcooled water jets with high degree of subcooling, which is because the critical mass flux is overestimated using Homogeneous Equilibrium Model (HEM). For subcooled water jets with low degree of subcooling, HEM underestimates the data. Different from HEM, Henry-Fauske model always overpredicts the experimental data, where the degree of overestimation increases as the degree of subcooling decreases. The critical mass flux for saturated steam jets and saturated water/two-phase jets can be predicted well by isentropic expansion model and HEM, respectively.

Jet impingement in high-energy piping systems, part II: Model improvement and guidance development

The Standard model in ANSI/ANS-58.2 (1988) has been widely employed in the design and safety analysis of nuclear power plants for jet impingement under postulated pipe rupture accidents. However, the potential non-conservatisms presented in Standard Review Plan (2015) need to be addressed when evaluating this model. The current work aims to improve the model on jet prediction including jet geometry and stagnation pressure, as well as to address the potential non-conservatisms. Based on the model evaluation results in Part I, new correlations for the jet core length and stagnation pressure in subcooled water and saturated water/two-phase jets are implemented to replace the existing correlations in the Standard model. It is shown that the revised code with the newly developed correlations predicts the stagnation pressure generally higher or conservatively for all conditions investigated.On the potential blast wave effect, the current work develops an approach to quantify the over-static and reflected pressures using the equivalent weight of TNT approach in literature. To employ this approach, the released energy in the equivalent of TNT needs to be determined from jet impingement. This energy is calculated using the vessel burst energy concept with conservative assumptions in the current work. For jet geometry, dynamic models to predict the jet spreading angle for saturated steam jets are compared with the Prandtl-Meyer angle for under-expanded supersonic jets. It is found that the jet spreading angle for saturated steam jets in the Standard model generally agrees with the dynamic model in literature for a wide range of initial vessel stagnation pressure conditions. Regarding the pressure distribution within jets, it is confirmed that edge-peaking pressure profiles can be observed for saturated steam jets at far distances from the break plane (z > 3.3 D); however, the dimensionless pressures at these locations are generally less than 0.07. Regarding the jet dynamic loading effect, the literature review suggests that dynamic amplification and resonance of impinged downstream structures and components might not occur for jet impingement in nuclear power plants.

Experimental study of the hydrodynamics of a supersonic steam jet impinged on a wall in vertical and oblique orientations

Experimental study of the hydrodynamics of a supersonic steam jet impinged on a wall in vertical and oblique orientations

The study of the effect of forced air supply on the combustion of liquid fuel dispersed by superheated steam

In the present work, the effect of forced air supply on the combustion process of liquid hydrocarbons was studied using diesel fuel as an example. The content of intermediate components of the flame and the temperature distribution along the flame symmetry axis were studied using an atmospheric burner with liquid fuel atomizing by a steam jet. The gas composition of equilibrium combustion products and the heat release were investigated. The influence of the excess air ratio in the combustion chamber of the burner device on the thermal and environmental characteristics was shown.

Simulations of PANDA and SPARC experiments on containment atmosphere mixing caused by vertical gas injection

Several experiments of interaction of air or steam jet with a horizontal helium rich layer in a closed vessel representing a NPP containment, which were performed in PANDA and SPARC experimental facilities, are simulated on the local instantaneous scale using the Unsteady Reynolds Averaged Navier Stokes approach. Axisymmetric two-dimensional and three-dimensional numerical models of cylindrical vessels are developed, and the effects of numerical domain reduction are studied. The mixing process is simulated as a single-phase flow with common momentum and energy equations. Consequently, an additional term accounting for enthalpy diffusion due to compositional changes is implemented into the energy equation. Included gas species mass fractions are considered as passive scalars and are calculated using the transport equation. However, the term describing the molecular diffusion cannot be neglected and had to be added to the diffusion equation implemented in the default OpenFOAM computational fluid dynamics code that was used. The k-ε turbulence model with additional turbulence generation and dissipation due to buoyancy is used for turbulence modelling. The comparison of simulation and experimental results shows that the improved physical model is able to successfully describe the phenomena in several experiments performed in different facilities with different initial and boundary conditions.

Performance comparison of different heat pumps in low-temperature waste heat recovery

The recovery of low-temperature waste heat can greatly reduce the fossil energy consumption, among whose technologies heat pumps show excellent energy saving effect and environmental friendliness. There are four commercial types of heat pumps, the absorption heat pump (AHP), absorption heat transformer (AHT), steam jet pump (SJP) and mechanical heat pump (MHP). To compare the energy performance of the four types of heat pumps in low-temperature waste heat recovery (WHR), simulation models for these heat pumps are established by Aspen Plus. The heat demand of the user side is described by a heat ratio (the ratio of the user side heat demand to the waste heat). The energy performance of four kinds of heat pumps in low-temperature WHR is compared and analyzed by the coefficient of performance (COP), exergy efficiency and annual savings of standard coal. The results show that when the heat ratio is higher than about 0.5, the MHP has the best energy performance. When the heat ratio is lower than about 0.5, the AHT is the best, for it can not only meet the heat demand of the user side, but make full use of the waste heat source as well. The performance of SJP is always better than that of AHP. Combined with qualitative economic analysis, it is recommended that the SJP is a good choice when HR is higher than about 0.7, otherwise the AHT is a suitable choice. This study can provide references for choosing a suitable heat pump in the low-temperature WHR.

Erratum to: Conductivity Sensors Based System Development and Application to Investigate the Interfacial Behaviour between Supersonic Steam Jet and Water

Erratum to: Conductivity Sensors Based System Development and Application to Investigate the Interfacial Behaviour between Supersonic Steam Jet and Water