Subcooled Water Pool Research Articles

Numerical Simulation of Steam Jet Condensation Through a Triple Nozzle Submerged into a Subcooled Water Pool

Submerged steam jet condensation is widely applied in many industrial fields due to its high heat and mass transfer efficiency during the process of direct contact condensation (DCC). The injection of steam into a water pool usually passes through an array of nozzles. It is important to understand the interaction between neighboring jets from different nozzles. In this paper, two thermal resistance models for DCC are implemented into the computational fluid dynamics code ANSYS Fluent through a user-defined function. The triple steam nozzle cases, in which the inlet pressure ranges from 0.1 to 0.6 MPa, were investigated to understand the interaction of nozzles and their configuration as well as their mechanisms. The distributions of temperature, velocity, volumetric fraction, and pressure fields were analyzed for different cases. Furthermore, the plumes of steam jets always attract each other toward the center of the plumes, and when the inlet pressure is over 0.3 MPa, the mixing of neighboring steam plumes will occur. In addition, the location where the peak value occurs for the parameters of steam velocity, pressure, and temperature, etc. is getting closer and closer to the center of the flow domain. In addition, the curve of the pressure along the centerline of the nozzle verified the existence of compression and expansion of steam inside the plume.

Oxidation of molten zirconium-containing droplet in water

During a severe accident in light water reactors, the molten reactor core (corium) falls into a water pool in the form of a jet. Complex interactions may occur between the melt and coolant known as molten fuel–coolant interactions (FCI), including energetic coolant evaporation and metallic melt (e.g., Zr and Fe) oxidation. This may further lead to steam and hydrogen explosions, which are both substantial safety risks for nuclear power plants.The heat of reaction and hydrogen production during oxidation can influence the progress and severity of the accidents. For example, the reaction heat may prolong the liquid state of corium, potentially leading to high-intensity explosions, whereas the generated hydrogen can create a combustible atmosphere, increasing the risk of hydrogen explosion. Therefore, this study evaluates the hydrogen production and oxidation degree of molten metallic droplets falling into a water pool to improve the FCI models for the risk evaluation of severe accident safety. The MISTEE-OX facility at KTH, which has been primarily built to study steam explosions is modified to investigate oxidation during FCI and provide experimental data on the oxidation behaviour of metallic droplets (Zr/Fe) quenched in a subcooled water pool. The dynamics of the falling droplets and generated bubbles are recorded using a high-speed camera, and the total volume of the bubbles is measured using a graduated cylinder. This study presents preliminary experimental results of the oxidation between Zr/Fe droplets and water, as well as recent improvements in measurement methods and facility upgrades. Our research findings are useful to enhance the knowledge of the oxidation process in FCI phenomena and validate the related mechanistic models in FCI codes.

EXPERIMENTS ON FLOW AND HEAT TRANSFER CHARACTERISTICS OF STEAM CONDENSATION IN SUBCOOLED WATER POOL

We report experiments of steam condensation in water pool for various steam mass flux (53-133 kg/ m<sup>2</sup>s) and water subcoolings (15-65°C). The process is visualized using high-speed imager, and the images are processed for bubble parameters and interfacial heat transfer. The bubble is observed to undergo a cyclic motion of growth, necking, and separation for the conditions studied. The flow transits towards chugging at higher subcoolings and low vapor mass flux. The heat transfer coefficient increases with vapor mass flux and liquid subcooling. The heat transfer coefficient is estimated to be 0.049-0.89 MW/m<sup>2</sup>K for oscillating regime, while relatively higher values (0.94-1.4 MW/m<sup>2</sup>K) are determined during chugging.

Influence of Noncondensable Gas–Dust Mixture on Direct Contact Condensation of Steam at Atmospheric Pressure

Abstract At the Department of Civil and Industrial Engineering (DICI) of the University of Pisa, an experimental research program, funded by International Thermonuclear Experimental Reactor (ITER) Organization, concerning steam direct condensation in a flux containing also noncondensable gas and dust, was carried out. This mixture of fluids and dust is injected into the ITER pressure suppression tanks during a loss of coolant accident (LOCA) in the Vacuum Vessel. The aim of the research program is to determine the steam condensation efficiency in such conditions. Experimental tests were performed injecting this mixture in a tank partially filled with water. Alumina was used to simulate the actual dust present in the ITER Vacuum Vessel. Mass flow rates, temperature, and pressure of the different fluids involved were recorded during the tests. The steam condensation into the subcooled water pool at a temperature ranging between 318 and 369 K was investigated to determine the condensation regimes occurring during the mixture injection. The values of the fraction of the energy absorbed by water, dust, and metallic structures of the heat losses and of the average heat transfer coefficient were determined considering pure steam, steam-dust and steam-air–dust injection. The average heat transfer coefficient, determined calculating the steam jet surfaces by means of image elaboration, was compared with empirical correlations.

An experimental study of steam turbulent jet condensation & upward propagation of thermal plume into sub-cooled water pool

Supersonic steam’s axial injection into water in a cylindrical vessel (1 m high and 24 cm in diameter) was achieved through a nozzle of 6 mm diameter, located at the center of the vessel. Optical examinations were determined through a steam jet to find out condensation rate, which was allied with the steam mass flux (295–672 kg/m2/s) while leaving the nozzle’s exit. The Reynolds number (i.e., 41,000–73,610) has been estimated based on most swollen section of the steam’s jet. Further beyond the condensation zone, the steam, that has been condensed, progresses into a condensed steam plume, which is surrounded by the sub-cooled water. Particle Image Velocimetry (PIV) has been applied to focus region through the mid axis of the heated water plume along a vertical plane of 100 mm × 100 mm cross sections till 400 mm from the nozzle. Central upward averaged velocity profile of the condensed water thermal plume has been evaluated at 295 and 672 kg/m2s, both have hinted the exponential decrease of mean axial velocity when the plume travels vertically upward. The radial velocity distribution of the mean axial velocity across the radial dispersal of the jet, has been obtained as self-preservable and the mean axial velocity attained the Gaussian profile by incorporating appropriate grading of axial distance and mean velocity. Other significant aspect of the current work is to apply the buoyant scaling evolved from the single-phase non-condensing upward thermal plumes to the condensed upward plume through the relations of volume flow, momentum and buoyant being computed from the steam jet operating conditions. The source values of physical dimensionless parameters such as Reynolds number (Reo), Plume Richardson number (Ripo), entrainment coefficient (αo), buoyant vertical scale (Bo) have been evaluated. Based on the radial spread of the velocity profiles along the vertical distance from the condensation region, the dynamics of the thermal and the jet propagation has been highlighted through the evaluation of the dimensionless buoyant parameters along the downstream of the plume. The present experimental measurements obtained for condensed single-phase plume are compared with the experimental results of the non-condensed single-phase thermal plume to signify the vitality of the dimensionless parameters derived from non-condensed plumes.

Effect of diameter and inclination of steam injection pipe on chugging dynamics in direct contact condensation

Low mass flux of steam and high degree of subcooling are the prominent factors for occurrence of unstable direct contact condensation, commonly known as chugging, when steam is injected into a subcooled water pool. Such an arrangement is typically used in the pressure suppression pool of the primary containment vessel in a boiling water reactor. With an attempt to identify the conditions of minimum pressure oscillations during the chugging regime, the present study investigates the effect of internal diameter (0.5–1 in.) and inclination (8.75˚) of steam injection pipe on steam bubble dynamics, pressure transients and heat transfer characteristics at different steam mass flow rates (5–25 kg/hr) and submergence depths of steam pipe (1–13 cm) within the water pool. The study reveals that the condensation cycle time decreases with a decrease in the internal diameter of the pipe. Furthermore, the frequencies of fluctuations in the interfacial area of the steam bubble and pressure transients in the steam pipe exhibit an increasing trend with an increase in steam mass flow rate and a decrease in internal diameter of the steam injection pipe. The chugging frequencies in the inclined and vertical orientation of steam injection pipe lie within the range of 0.5–3 Hz. The average heat transfer coefficient increases with an increase in the internal diameter of pipe and steam mass flow rate. The amplitude of pressure oscillations has decreased significantly whereas heat transfer coefficient has increased marginally upon changing the orientation of steam injection pipe from vertical to inclined. Therefore, smaller diameter and inclined orientation of steam injection pipe are favourable for mitigation of pressure oscillations in applications of direct contact condensation.

Numerical simulation of air discharged in subcooled water pool

Turbulent jet discharges in subcooled water pools are essential for safety systems in nuclear power plants, specifically in the pressure suppression pool of boiling water reactors and In-containment Refueling Water Storage Tank of advanced pressurized water reactors. The gas and liquid flow in these systems is investigated using multiphase flow analysis. This field has been extensively examined using a combination of experiments, theoretical models, and Computational Fluid Dynamics (CFD) simulations. ANSYS CFX offers two approaches to model multiphase flow behavior. The non-homogeneous Eulerian-Eulerian Model has been used in this work; it computes global information and is more convenient to study interpenetrated fluids. This study utilized the Large Eddy Simulation Model as the turbulence model, as it is better suited for non-stationary and buoyant flows. The CFD results of this study were validated with experimental data and theoretical results previously obtained. The figures of merit dimensionless penetration length and the dimensionless buoyancy length show good agreement with the experimental measurements. Correlations for these variables were obtained as a function of dimensionless numbers to give generality using only initial boundary conditions. CFD numerical model developed in this research has the capability to simulate the behavior of non-condensable gases discharged in water.

An experimental study on quenching of metallic spheres in seawater

Motivated by quenching of melt droplets and debris particles in seawater during a hypothetical severe accident of light water reactors (LWRs), the quenching process of stainless-steel spheres in a seawater pool was investigated in the present study. The polished spheres were pre-heated up to 1000℃ in an induction furnace with inserted atmosphere, and then immersed into the subcooled water pool in a chamber made of transparent quartz. A thermocouple was embedded in the center of the sphere to measure the history of the sphere’s temperature, while a high-speed camera was employed to record the quenching process and vapor film dynamics. Quantitative data, e.g. film thickness and oscillation, of the vapor film evolution during the quenching process were obtained through an image processing program developed on the MATLAB platform.The experimental results indicated that the quenching rate was higher in seawater than in deionized water, and the vapor film collapsed at a temperature higher than the Leidenfrost temperature in deionized water. The trend appeared more significant with increasing subcooling of water. The comparison of the quenched spheres suggested the surface of the sphere in seawater achieved higher degree of discoloration and roughening than that in deionized water, probably due to the additives of salt which change water properties. The image processing and analysis revealed that the vapor film had different thickness profile along the upper and lower hemispheres, and the averaged film thickness was smaller in seawater than in de-ionized water during the stage of stable film boiling. The vapor film was thinning and oscillating with time, and its fluctuations appeared different frequencies and amplitudes at the upper and lower locations, which may explain the mechanism of the earlier collapse of vapor film in the quenching process of a high-temperature sphere in seawater.

Modeling of horizontal steam injection in a water pool

A comprehensive understanding of the direct contact condensation (DCC) phenomena of steam discharged into a subcooled water pool is essential for the nuclear engineering field. DCC is the most rapid and efficient way to condense high-pressure and high-temperature steam with simple engineering systems. However, the pressure oscillation due to the rapid condensation and small length and time scales of turbulent two-phase flow make the investigation of DCC phenomena challenging either by experiments or with numerical simulations.This paper presents the computational fluid dynamics (CFD) simulations of the small-scale separate effect test facility (SEF-POOL) experiment of Lappeenranta-Lahti University of Technology (LUT University). In the SEF-POOL test, the steam was injected using the orifice of a diameter of 16 mm. All simulations were performed by employing the compressible two-phase solver of OpenFOAM which was based on the Eulerian–Eulerian two-fluid approach. The interfacial heat transfer between steam and water was modeled by using the Nusselt number formulation of Coste (2004). The Rayleigh–Taylor interfacial (RTI) area model of Pellegrini et al. (2015) was applied for the interfacial area modeling. In this work, the formation and collapse of the steam bubbles are studied using the extended pattern recognition based image analysis algorithm. The pattern recognition (PR) algorithm is based on the video material recorded during the SEF-INF2 experiment of the SEF-POOL test facility.The presented study show that if the two-phase interface is rough and smear into the subgrid scale, the interfacial area density calculation solely with the volume fraction gradient is inadequate for predicting rapid condensation rates. Results indicate that rapid and high interfacial accelerations in DCC trigger interfacial instabilities which increased the interface roughness and total interfacial area consequently. Thus, interfacial area modeling with the RTI increased the total interfacial heat transfer rate in the simulations. The achieved results exhibit that the selected modeling approach captured the rapid bubbling condensation oscillation mode of the SEF-POOL test. Presented results demonstrate that image analysis and pattern recognition have great potential in thermal-hydraulic research that can be beneficial for direct contact condensation and phase-interface dynamics model development.

Experimental analysis of direct contact condensation during vertical injection of steam onto a subcooled water pool

Experiments have examined the phenomenon of direct contact condensation when steam is injected vertically into the subcooled water pool. The investigation is carried out by varying the steam mass flow rate and submergence depth of the steam injection pipe in the range of 10–50 kg/h and 1–13 cm, respectively. The behavior of the bubble that appeared at the pipe outlet, transient heat transfer coefficient, pressure variation in the steam injection pipe, and its associated frequency have been analyzed. The images captured by high-speed camera showed different bubble shapes. The overall cycle time of bubble evolution has decreased with an increase in the mass flow rate and increased with an increase in the pipe submergence depth. The time-averaged heat transfer coefficient increased with an increase in the mass flow rate and decreased with the rise of the pipe submergence depth. The pressure drop within the steam injection pipe shows the parabolic variation with an increase in the mass flow rate and is slightly influenced by the submergence depth due to changes in interfacial structures within the pipe. The peak frequency associated with the pressure has increased with an increase in the mass flow rate and decreased with an increase in the pipe submergence depth at higher mass flow rates. The fast Fourier transform of interfacial area of the larger bubble at the pipe outlet shows that the first peak frequency lies between 0.5 and 5 Hz, and the second peak frequency lies in the range of 25–30 Hz.

Entraining of dust and steam flux in water pool: experimental and numerical simulations of vapor condensation and dust deposition

This paper deals with experimental tests of steam condensation in a water pool at atmospheric pressure and temperature in the range 15-100 °C. The activity is performed in the frame of a research program, funded by the ITER organization, for the study of dust deposition, produced in the ITER Vacuum Vessel and entrained by the steam and non condensable gas into the Pressure Suppression Tanks in the case of a Loss of Coolant Accident. The steam condensation into a subcooled water pool has been investigated to characterise the condensation regimes occurring during dust deposition tests. The dust distribution on the tank walls strongly depends on the steam jet length and on the effective heat transfer coefficient. Few grams of dust reduce the water transparency, therefore separated tests without dust overcome this drawback. Measurements of the lengths and surfaces of the steam jets (which permit to calculate effective average heat transfer) have been performed by means of image analyses and have been compared with theoretical correlations. The comparison showed a good agreement between the experimental data and theoretical correlations. Useful data have been obtained for implementing numerical models of dust deposition and for understanding the dust distribution on the tank wall obtained in the experimental tests.

An Experimental Study of Steam Turbulent Jet Condensation & Upward Propagation of Thermal Plume into Subcooled Water Pool

An Experimental Study of Steam Turbulent Jet Condensation & Upward Propagation of Thermal Plume into Subcooled Water Pool

Experimental Investigation of the Transient Pool Boiling Heat Transfer on the Quenching of Vertical Rodlet in Water

Abstract Quenching is an important phenomenon when the emergency core cooling system is put into operation during loss of coolant accident (LOCA) in a nuclear reactor. In this study, an experimental apparatus is designed and constructed with the purpose of conducting transient pool boiling experiments with quenching method for zirconium (Zr-4) cylindrical test samples. Three thermocouples are inserted in the test sample to investigate the effect of axial distance on the minimum film boiling temperature. The Zr-4 rodlet is heated up to a temperature well above the minimum film boiling temperature (up to 600 °C), and then plunged vertically in a quiescent pool of subcooled water. A data acquisition system is used to record the temperature history of the embedded thermocouples. Data reduction is performed by an inverse heat conduction code to calculate the surface temperature and corresponding surface heat flux. A visualization study is conducted to record the quench behavior of the test sample by using a high-speed camera. It is found that the minimum film boiling temperature decreases with the axial distance, while temperature at critical heat flux (CHF) is relatively insensitive to the axial distance. The film boiling heat transfer coefficient decreases with surface temperature, and seems to be independent of axial distance. The quench front is observed to originate from the bottom and move upward. It is found that the quench front velocity remains nearly constant in the lower region of the test sample, and significantly increases in the upper region.

Systematic experimental investigation on the characteristics of molten lead-bismuth eutectic fragmentation in water

In this study, to enhance the understanding of the thermo-hydraulic characteristics during the direct contact of molten lead-bismuth eutectic (LBE) and water, a series of visualized fragmentation experiments were conducted by releasing molten LBE into a subcooled water pool using the VTMCI (Visualized Thermo-hydraulic characteristics in Melt-Coolant Interaction) facility developed at Sun Yat-Sen University. The parameter effects, including melt temperature, water subcooling, boiling mode, penetration velocity, nozzle diameter and melt mass, on the fragmentation process and debris properties are studied in detail. A new correlation is developed by fitting the experimental data, which can simultaneously consider the effect of melt temperature, water subcooling, penetration velocity and nozzle diameter, to predict the average fragment size. The maps to predict the fragment sphericity and debris porosity based on the experimental results are established.

Numerical analysis of sub-atmospheric steam condensation in suppression tank with SIMMER IV code

Abstract One of the key safety components for nuclear fusion plants is the suppression tank, which is designed to protect the Vacuum Vessel (VV) against accidental pressurization events, e.g. Loss Of Coolant Accident (LOCA). In this framework the attention is focused on the Vacuum Vessel Pressure Suppression System (VVPSS), made of water tanks in which the pure steam, or eventually mixed with incondensable gases, is injected and consequently the overpressure is dumped profiting of Direct Contact Condensation (DCC). The design constraints of fusion reactor dictate that the pressure resulting (long-term) from any accidental or baking condition should be always kept lower than 0.15 MPa. The study of the phenomena evolving during DCC in LOCA conditions is the major novelty, especially in consideration of the lack of similar studies in the available literature. In this context, a wide series of experimental tests was carried out at Pisa University (UNIPI), Department of Civil and Industrial Engineering (DICI), in a Small Scale Test Facility (SSTF), designed and instrumented for investigating DCC at sub-atmospheric pressure, by varying water pool temperature, pressure and steam mass flow rate. The adoption and assessment of suitable numerical codes, to reliably simulate such a cutting-edge multiphase multicomponent scenario, have a crucial role for contributing to the phenomena understanding and for possible safety analysis of full-scale components. On this basis, a preliminary evaluation of the cartesian three-dimensional SIMMER IV code capabilities in simulating DCC at sub-atmospheric conditions was carried out, taking as reference one UNIPI test. SIMMER IV code was able to set up precise initial low-pressure boundary conditions and simulate superheated steam condensation in subcooled water pool, with condensation efficiency comparable to the experimental one. Moreover, SIMMER IV code predicted a longitudinal steam plume dimension and injected steam velocity consistent with experimental data.

Numerical Simulation of Vapor–Bubble Collapse—Heat Transfer and Nonlinear Dynamics Issues

Abstract In this work, we compute the dynamics of a spherical vapor-bubble in an infinite pool of subcooled water during bubble collapse using our semi-analytical method. The main contribution of this work is to bring out the dynamics of nonmonotonic bubble collapse describing heat transfer characteristics and nonlinear dynamics. The dynamics shows the variation of radius with time for collapsing vapor bubble at different subcooling ΔTsub of 1.40 K to 35 K. The present approach accurately determines the bubble radius decreasing with time and has been compared with our experimental results, the experiment from literature, the other theories, and correlations. As it is noted that the literature lacks steady-state analysis of oscillating bubble collapse, we also report the steady-state analysis and the bifurcation analysis of bubble collapse at a pressure of 1.0 atm to check the stability of bubble collapse. The effect of ΔTsub and initial bubble radius R0 on dynamics of bubble collapse has been analyzed. The collapse of big bubbles involves with the bubble oscillations because of a large contribution of liquid inertia and the collapse of very small bubbles essentially occurs in heat transfer regime.

Oxidation of molten zirconium droplets in water

Zirconium, which is used as the cladding material of nuclear fuel rods in LWRs, can react with steam in the case of a core meltdown accident. This results in the release of hydrogen which poses a significant risk of hydrogen explosion. Oxidation of Zr occurs either during the core degradation when the steam flows over the hot fuel rod surfaces or during an FCI when molten corium falls into a water pool (e.g. in the lower head). An experimental study was performed at the MISTEE-OX facility at KTH to observe and quantify the oxidation of molten zirconium droplets in a water pool. During the experimental runs, single droplets of molten zirconium were discharged into a subcooled water pool and the dynamic events were recorded using a high-speed camera. The bubble dynamics indicate a process of cyclic oxidation and hydrogen release from the rear periphery of a droplet while it is quenched in the water. The debris (solidified state of the droplet) after each run was collected for compositional and microstructural analysis via SEM/EDS. The obtained data were employed to estimate the oxidation fractions of the droplets and the results revealed several interesting insights into the oxidation phenomenon of the Zr melt. The water subcooling was observed to have a significant influence on the oxidation: the degree of oxidation decreased with increase in the water subcooling. Furthermore, the degree of oxidation was also influenced by the depth into the debris, forming compounds whose oxygen content decreases from the outer surface towards the core of the debris. Therefore, the qualitative and quantitative results presented in this paper are important in the context of developing a phenomenological understanding of the oxidation behaviour of zirconium melt during the FCI as well as to improve and validate the currently available models implemented in the state-of-art steam explosion codes.

Experimental study on the condensation of sonic steam in the underwater environment

Abstract Steam jet condensation is of great importance to pressure suppression containment and automatic depressurization system in nuclear power plant. In this paper, the condensation processes of sonic steam jet in a quiescent subcooled pool are recorded and analyzed, more precise understanding are got in direct contact condensation. Experiments are conducted at atmospheric pressure, and the steam is injected into the subcooled water pool through a vertical nozzle with the inner diameter of 10 mm, water temperature in the range of 25–60 °C and mass velocity in the range of 320–1080 kg/m2s. Richardson number is calculated based on the conservation of momentum for single water jet and its values are in the range of 0.16–2.67. There is no thermal stratification observed in the water pool. Four condensation regimes are observed, including condensation oscillation, contraction, expansion-contraction and double expansion-contraction shapes. A condensation regime map is present based on steam mass velocity and water temperature. The dimensionless steam plume length increase with the increase of steam mass velocity and water temperature, and its values are in the range of 1.4–9.0. Condensation heat transfer coefficient decreases with the increase of steam mass velocity and water temperature, and its values are in the range of 1.44–3.65 MW/m2°C. New more accurate semi-empirical correlations for prediction of the dimensionless steam plume length and condensation heat transfer coefficient are proposed respectively. The discrepancy of predicted plume length is within ± 10% for present experimental results and ± 25% for previous researchers. The discrepancy of predicted condensation heat transfer coefficient is with ± 12%.

Parametric investigation of film boiling heat transfer on the quenching of vertical rods in water pool

The present study explores the effects of liquid subcooling, material properties and surface conditions on the film pool boiling heat transfer using stainless steel (SS), zirconium (Zr), and Inconel-600 rods. Vertical quenching experiments were performed in subcooled and saturated distilled water pool at atmospheric pressure. Surface characterization results (microscope images, surface roughness, and water contact angle) were obtained to characterize the morphology of the substrate surface of the test samples. A visualization study was carried out using a high-speed camera to observe the phenomenon of quench front axial propagation in addition to the instability of the vapor-liquid interface. Embedded thermocouples are used to measure the change in temperature of the test samples with time. An inverse heat conduction code was used to determine the surface temperature and the corresponding heat flux curves. The effects of liquid subcooling, thermal properties of the substrate, and surface conditions on the minimum film boiling temperature (Tmin) were investigated. The lower kρcp and the porous surface of the Zr test sample disturb the flow of the vapor during film boiling. This along with the lower contact angle of the Zr surface resulted in a higher Tmin value compared to the other two test samples. A generalized correlation was developed and compared to various existing correlations. The effects of liquid subcooling, surface roughness, and thermal properties of the substrate materials were taken into account in developing the correlation. The average error estimated for the generalized correlation is 1.5% and the root-mean-square error is 9.3%.

Numerical simulation of bubble formation and condensation of steam air mixture injected in subcooled pool

Bubble formation and condensation of steam-air mixture vertically injected in a subcooled water pool was simulated, combining thermal phase change model into the two continuous phase free surface model of ANSYS CFX 17.1. Continuous surface force model was used to calculate surface tension force and the influence of non-condensable gas was accounted for by component transportation equation and assumption of interface temperature equal to saturation temperature at local partial steam pressure. The thermal phase change model includes an experimental correlation for liquid side sensible heat transfer. Based on available experiment data from literatures, singular pure steam bubble and steam-mixture bubble in a pool were first simulated to see the predictability of the proposed method and then, the same method was applied to the bubble formation, detachment and condensation process of injected steam air mixture from a nozzle. Bubble dimeter, water subcooling and non-condensable gas concentration studied range from 4.9mm to 50mm, 12K to 40K, and 0 to 31.5% respectively. The results of the computations indicate that the present method can predict very well the bubble formation and condensation both for pure steam case and with non-condensable gas.