Water Spray Nozzle Research Articles

Comprehensive numerical and experimental analysis the impact of employing vortex generators on evaporative cooling process

Reduced energy usage is an important concern in vapor compression cooling systems, particularly in hot climates. These systems function poorly in hot weather and consume a lot of electricity. Evaporative condensers use the cooling impact of evaporation to facilitate the process of heat rejection and thereby increase energy efficiency. This work evaluates the impact of employing vortex generators on the performance of an evaporative condenser. The analysis is performed using a validated numerical model, a commercial CFD code. The proposed vortex generators are parallel plates with sinusoidal and zigzag patterns. Dry air enters a channel equipped with four vortex-generating plates and water spray. The incoming dry air cools due to the two-phase heat transfer during air contact with the sprayed water droplets, and the cooled air with the proper humidity level exits the channel. The investigated parameters include longitudinal nozzle position, inlet air flow rate, pitch, and the height of the vortex generator plates in two sinusoidal and zigzag modes and the obtained results are compared with the plain channel model. Greater inlet air velocity resulted in superior output temperatures and pressure drops, yet lower outlet relative humidity and water mass percentage. According to the findings, the air pressure drop and outlet dry temperature are raised by 152 % and 5 %, respectively, when the incoming air velocity is altered from 0.4 to 0.6 m. s−1 (50 % growth), and the nozzle position is moved from X = 1.35 m to X = 1.85 m (37.04 % change) from the channel entrance, while the relative humidity and water mass fraction are decreased by 19 % and 11 %, respectively. Additional research revealed that the vortex flow level is lower when the nozzle is positioned farther away from the plates, and the water spray's impact on lowering the local air temperature in vortex-flowing areas is more substantial when it is positioned closer to the plates. Furthermore, increasing wave height and pitch values of vortex generators result in a more extensive air pressure drop in the channel, and vice versa. This means that, at a fixed pitch, a higher plate wave height raises the amount of vortex flows. According to the findings, sinusoidal vortex plates have better efficiency than the zigzag ones, and in a channel equipped with water spray, the use of vortex plates before the water spray nozzles lowers the dry temperature at the outlet by about one °C compared to that of the plain channel.

An empirical study on thermal efficiency and dusty moisture removal efficiency using enthalpy wheel in industrial waste incineration plant

In this work, an empirical study is conducted on the waste heat recovery and moisture removal performance of an enthalpy wheel installed in an industrial waste incineration plant. The enthalpy wheel made of a metal mesh is placed in parallel with the wet scrubber of the incineration plant to exchange heat with high-temperature exhaust at 200 °C. In the enthalpy wheel, exhaust gas and external air exchange heat in the form of a counter flow, and the condensation effect is maximized by installing a water-spray nozzle at the inlet of the enthalpy wheel. Empirical data were collected over 100 days spanning July to October. To evaluate the performance of the enthalpy wheel, thermal efficiency, moisture removal efficiency, and dust removal efficiency were tested under high-temperature humid conditions. In some results, the overall thermal efficiency reached peaked at 61.2 %. Regarding moisture removal performance, the average moisture removal rate was 493 kg/h, affording an efficiency of 49.2 %. In terms of dust removal performance, the average dust removal efficiency was 79.6 %.

Watertight insertion of heavy sliding doors in exterior walls

The joints around heavy terrace doors are considered a weak point in rain-exposed façades, as it is vulnerable to defects in design and construction. The insertion process of heavy sliding doors is a notable challenge. Design recommendations from manufacturers as well as national advisory agencies are currently lacking. This paper presents a full-scale laboratory study on the water tightness of heavy sliding doors with joints waterproofed according to five different solutions. The door assembly is mounted in a pressurized cabinet with water spray nozzles to simulate wind-driven rain. The interior side of the joint around the door is monitored for moisture leaks at steadily increasing pressure levels. It was found that leaks most often occur in the corners of the frame. Sealant mounted before the door itself was hoisted in place tended to be twisted or distorted as the door was adjusted in the frame, spoiling the waterproofing. A common feature of the most watertight solutions was that the sealant was mounted after the door itself was fastened to the frame. The sealant should be continuous, flexible, mounted in a single plane, and preferably be accessible during the assembly process. Waterproofing recommendations for the design and insertion of sliding doors should account for practical challenges brought on by the heavy weight.

Research on Fog Guns for Dust Reduction at Coal Field – Roșiuța Quarry

Abstract In order to comply with the provisions of the normative acts in the field of air quality (STAS 12574/1987 - maximum allowed concentrations of sedimentable powders [1]), it was proposed to build a water mist dedusting facility within the coal deposit to stop the dust emissions at the source. The installation must ensure long-term operation in harsh conditions, with resistance to wear and minimal maintenance: operating time 12-14 hours/day, 365 days/year. The dedusting plant is composed of the water house, the distribution network, the fog production plants and the electricity supply plant. The process used to create the mist is based on the use of high pressure pumps. The equipment consists of fog guns equipped with high-pressure water spray nozzles and dispersion fans that are purchased fully equipped including a remote control installation; 6 spray guns were provided.

Study on orientation and number of water spray nozzles for scientific experimental application

In dry climates, evaporative cooling techniques are frequently used in place of air-conditioners to increase energy efficiency and reduce installation costs. An evaporative nozzle is a type of evaporative cooling technique. Evaporative nozzle spraying is a technique that is used in a variety of applications, including cooling and humidification. The performance of evaporative spray nozzles with a number ranging from 2 to 8 nozzles has been examined in terms of nozzle combinations, orientations (horizontal and vertical), and Reynolds numbers ranging from 13000 to 83000. In general, the results show that relative humidity is inversely proportional to the Reynolds number. Furthermore, the nozzle numbers are proportional to the relative humidity. As the number of nozzles in a vertical arrangement increases from 2 to 8, the relative humidity rises to 90%. For 8 spray nozzles, the vertical arrangement produces 7.4% higher outlet relative humidity than the horizontal arrangement. The current investigation’s highest relative humidity is 90%, which occurs for 8 nozzles in the vertical direction at Reynolds number 13300. Moreover, the horizontal and vertical correlations were developed to predict the outlet relative humidity with respect to the nozzle orientation.

Experimental study on the combined effects of obstacles and local water mist on gas explosion for maritime safety

A variety of experimental configurations including different water mist obstacles, are used to investigate the combined effects of obstacles and water mist upon the gas explosion. The results demonstrate the 8 μm water mist can significantly inhibit the deflagration, while both 45 μm and 80 μm water mists exhibit the opposite effect under all the locally distributed positions of water spray nozzle without obstacles inside the vessel. When considering the obstacles, the 45 μm water mist starts to mitigate the deflagration and its mitigation effect is more significant than that induced by the 8 μm water mist. What's more, the 80 μm water mist can slow down the flame propagation speed while it would still lead to the gas explosion. Additionally, there remains unchanged about the effect of locally spraying 8 μm water mist upon deflagration at the initial stage of flame development as varying the position of obstacles, while the effects of mitigating deflagration by 45 μm and 80 μm water mist are decreased. The results will make contributions to design the arrangement of equipment and water mist configuration on the offshore platform or NG-fueled ship's engine room so as to mitigate the gas explosion accident. • An experimental study is conducted to analyze inhibitory effects of locally spraying water mist. • The inhibitory effects of different sizes and spray positions of water mist are presented. • The combined effects of obstacles and locally spraying water mist on deflagration explosion are presented. • The results are suitable for water mist arrangement on offshore platforms and ships engine rooms.

내구 연한을 연장하기 위한 위생 배관 및 열교환기 전열 튜브의 부식 특성에 관한 연구

his paper seeks to determine corrosion characteristics between different materials used for pipes in building HVAC systems. Typically, the life span of a building correlates to the amount of damage to its components. Therefore, material selection is a very important issue when it comes to extending the life of the building or improving its function. This study focuses on the corrosion characteristics between different materials used for heat exchangers (in recapturing surplus heat) and pipes used in HVAC. A chamber is prepared with salt water spray nozzles, measuring the corrosiveness at assigned intervals between pipes of different materials: copper, steel, brass and titanium. In summary, the steel pipes exhibited the severest corrosion, followed by copper where corrosion was evident in the later stages of the experiment. Small amounts of corrosion was found in brass while titanium resulted in no corrosion at all.

Large eddy simulation of smoke blocking by water sprays in a tunnel fire

This study presents a large eddy simulation (LES) of smoke blocking by water sprays in tunnel fires to investigate the effect of water sprays on the characteristics of the smoke flow. This study uses an LES solver – FireFOAM. In addition, fire experiments using a 1/10 scale model tunnel with two water spray nozzles are conducted to validate the LES results. The length of the model tunnel is 12 m, the height and width are 0.5 m, respectively, and the heat release rate of the fire is 7.38 kW (2.33 MW in full scale). Each spray nozzle operates at a pressure of 0.3 MPa, and the volume median diameter of spray droplets is 226 μm. First, a grid sensitivity analysis on the gas temperatures under free-burn conditions is performed. A 1.25 cm uniform mesh is chosen in the tunnel domain for all subsequent simulations. Then, FireFOAM predictions are validated against experimental data on the distribution of water spray mass flux under conditions without the fire and the gas temperatures measured under conditions with and without the water sprays. The water spray mass flux and gas temperatures predicted by FireFOAM show good agreement with the measurements. Next, the characteristics of the smoke flow are investigated in the presence of the water sprays. It is found that the water sprays block part of the smoke flowing under the ceiling and force it to descend to the ground. The descended smoke flows back in the lower part of the fire zone, and a vitiated air layer is formed. The vitiated air layer is composed of the smoke flowing back and fresh air drawn from the portal. On the other hand, some smoke leaks through the water spray zone and flows along the ceiling on the portal side. It is also found that the spray cooling delays the propagation of the leaked smoke toward the tunnel portal. Furthermore, it is quantitatively shown that the buoyant flow stratification destroyed by the water sprays becomes thermally and chemically stabilized again on the portal side, for the specific case under this study. Last, the smoke blocking performance is quantified based on the mass flow rates of the smoke flowing under the ceiling in the fire zone and the smoke flowing back toward the fire. A comparison of the smoke blocking rates between the predictions (time dependent: 40–50%) and measurements (steady: 39.4%) shows good agreement.

Experimental and numerical study of water sprayed turbulent combustion: Proposal of a neural network modeling for five-dimensional flamelet approach

Owing to the increasing worldwide demand for natural gas, the development of a large submerged combustion vaporizer is required. Its burner is equipped with a water spray nozzle to reduce nitrogen oxides, and a practical simulation method is required for the optimal design. The non-adiabatic flamelet approach can predict the combustion emissions and is useful for reducing simulation costs. However, as the number of control variables increases, the database requires larger memory and cannot be dealt with by general computers. In this study, an artificial neural network (ANN) model based on a five-dimensional flamelet database, which includes the effects of heat loss and vapor concentration by sprayed water evaporation, is developed. Furthermore, large eddy simulations (LESs) for turbulent combustion fields with and without water spray are conducted employing flamelet generated manifold (FGM) approach with this ANN model, and the validity is investigated. For comparison, a lab-scale burner equipped with a water spray nozzle is manufactured, and combustion experiments with and without water spray are conducted. The results show that CO, NO, temperature, and reaction rate of progress variable predicted by the present ANN model are in good agreement with those of a five-dimensional flamelet database. In the condition without water spray, the flame behavior predicted by the LES employing the FGM/ANN approach is in good agreement with that employing the conventional FGM approach, while indicating much lower memory, although there appeared some quantitative discrepancies in the temperature against the experiment probably partially because of the insufficiency of the FGM approach for the present complex flame structure. In the condition with water spray, the LES employing the FGM/ANN approach is able to capture the effect of the water spray on the flame behavior in the experiment, such that the water spray decreases the temperature, which causes the decrease in NO but increase in CO.

Numerical Simulations of Water Spray on Launch Pad During Rocket Launching

This paper compares the cooling effect on the launch pad with two different levels of water cooling system used in the Long March 7. The rocket plume model is set up based on the three-dimensional Navier–Stokes equations solved by the realizable turbulence model. The Eulerian dispersed phase (EDP) model is employed to describe the injected cooling water. Comparing with test data, the validity of the above models is verified, respectively. On this basis, the temperature distributions on the launch pad with two different levels of water spray system are investigated. The results show that the overall temperature of the launch pad drops significantly with the first-level water spray system. However, because the rocket plume blows most of the injected water away, the temperature of the central area barely decreases. When using the second-level water spray system, the central temperature is reduced obviously, but the cooling area of a single water spray nozzle is limited. Under the influence of plume, the closer to the central zone, the smaller the area that each water spray nozzle can cool.

Numerical analysis of the effect of horizontal distance between a water mist nozzle and ignition source on reduction in heat release rate

A numerical study on the effect of horizontal distance between a water spray nozzle and a fire on fire suppression was conducted using fire dynamics simulator (FDS) 6.5.2. This study focuses on the application of a water mist system to special fire areas such as the electrical rooms in nuclear power plant. A small compartment was modeled, with an n-Heptane pool as fuel, a water mist nozzle, and a door opening. Four horizontal distance conditions were applied to investigate the relationship between the horizontal distance and fire suppression time. It was determined that the fire suppression time for the different horizontal distance conditions could be well expressed as a power function of the normalized horizontal distance between the water mist nozzle and n-Heptane pool. Also, sensitivity analyses of cell size, droplets size distribution (DSD), and droplets per second (DPS) were conducted for each horizontal distance condition.

Continuing Results for Effervescent Aerosol Salt Water Spray Nozzles Intended for Marine Cloud Brightening

Marine Cloud Brightening (MCB) by effervescent spray atomization of mixed sea water brine with air is a candidate for solar radiation management to compensate for global warming. We discovered that the flow from mixing tee nozzle described earlier had occasional unstable slug flow. A new design that adding rotational swirl to the salt brine as it is mixed into the air stabilized the nozzle flow and no longer showed slug flow in spray pictures. Flow equations were developed for the relatively low speed of sound of a choked flow mixed brine and air nozzle. Experimental mixed flow measurements with 300b pressure and a 200 μm diameter nozzle and calculations using perfect gas, and isotropic processes equations compared well with the chocked flow equations. Analysis in EXCEL of particle sizers measurements from both a scanning mobility particle sizer (SMPS) and an aerodynamic particle sizer (APS) showed production of many nanometer sized particles estimated as usable for MCB. A small number of micron sized particles were also always present but with about 90% of the sprayed mass. This is a first report with good data over the complete size range. The micron sized particles measured were similar to the measurements of earlier reports which reported no nanometer sized particles. We hypothesize that many nano-particles are always produced by liquid-air effervescent sprays, but earlier, were not observed because SMPS instruments were not available. The presence of the large mass percentage of large particles in the spray may cause problems by evaporative cooling preventing the rise of the MCB particles. We suggest future systems design with an impactor filter to remove the large particles. Calculations combining increased brine concentration, lower pressure, and larger nozzle area showed that significant reductions in required power and number of nozzles could be realized. An EXCEL model is developed to calculate flow from experimental analysis equations and compare with mixed choked flow equations. Solving with the model predicted the power required and the number of nozzles required to produce 1015 particles/s. The model showed that increasing brine concentration strongly lowered total power. Lowering pressure decreased power and increased number of nozzles. Increasing nozzle area lowered the number of nozzles. This model predicted that, at 300b pressure and 200μm diameter nozzle as the experiment but using an increased brine concentration of 0.1 instead of 0.032 would require only 115 nozzles instead of 358 and power of 146 kw instead of 493 kw. Combining increased brine concentration, lower pressure, and larger nozzle area, the model predicted that with a 1 mm diameter nozzle at 30b pressure and salt concentration of 0.2, the nozzle count and power required would drop to only 24 nozzles and power of 28 kw. Whether extending the model to these conditions is valid is not known but suggests further development should be investigated. Filtering out and reusing the 90% or greater large particles mass sprayed combined with the lower power advantage of higher brine concentration is suggested for future systems.

Numerical simulations of water spray on flame deflector during the four-engine rocket launching

This paper aims to study on the cooling effect with two types of water spray nozzle on the flame deflector during the four-engine launch vehicle take-off. To accurately simulate the two-phase flow of the rocket gas with multispecies and the water spray, the three-dimensional compressible Navier-Stokes equations, discrete ordinates methods and realizable k-Ɛ turbulence model are used to establish the rocket supersonic plumes impact model. The Eulerian dispersed phase (EDP) model was used to simulate the water spray into the exhaust gas. The accuracy and effectiveness of the gas-liquid flow model are verified by a good agreement between simulation results and experimental data. On this basis, a series of numerical simulation studies under different water injection position are performed. The results show that the high temperature regions, along the axis of engines on the deflector plate, have no significant temperature decreasing effect by water spray from the nozzles mounted on the apex of the deflector, and the high temperature converts a large quantity of water into vapor near the plume boundary, which would decrease the flow conductivity. With the cooling spray nozzle fixed directly to the deflector plate, the temperature decrease effect is obvious and the effect of thermal shock on deflector plate induced by exhaust plume is reduced, so that it can prevent the flame deflector from thermal ablation. The study results provide indepth information and engineering guidance for designing the water spray systems and increasing the safety of the launch process.

Numerical study on performance improvement of air-cooled condenser by water spray cooling

Water spray cooling is an efficient way to enhance heat transfer of the air-cooled condenser (ACC) of power generating unit under high ambient temperatures. Taking the air-cooled 300 MW power generating unit as object, the flow and temperature fields of ACC with water spray cooling were analyzed by numerical simulation with experimental validation. Based on the air flow field inside ACC cell, an improved water spray nozzles arrangement was proposed to enhance the cooling capacity. The inlet air temperature and back pressure of turbine were compared with that under the original nozzles arrangement. The water consumptions including that of water droplets pre-cooling evaporation in air flow, liquid film evaporation on the finned tube bundles, and drainage of redundant water were obtained. The influences of water spray rate, spray direction and nozzles distance on cooling performance were investigated. The results showed that the improved nozzles arrangement is expected to provide efficient cooling performance and significant reduction in back pressure of the objective power generating unit. The improved nozzles arrangement with upward spray direction and nozzles distance of 0.8 m can be applied to the design of water spray system in ACC. In addition, the obtained redundant drainage water under various ambient conditions provided the evidence for spray water rate optimization.

Numerical modelling of the interaction between water sprays and hot air jets - Part II: Two-phase flow simulations

The paper presents a comprehensive set of numerical simulations performed to examine the current Computational Fluid Dynamics (CFD) capabilities in the prediction of the interaction of a water mist spray with a vertical upward jet of hot air within an Eulerian-Lagrangian framework. The experimental tests considered herein are described by Zhou [Proceedings of the Combustion Institute, 2015]. The spray is a 30° full cone water mist spray emerging from a nozzle that delivers a water flow rate of 0.084 lpm at a pressure of 750 kPa. The vertical jet of hot air at 205∘C is issued from a 72 mm-diameter nozzle placed at 560 mm below the water spray nozzle. Three exit velocities of 3.3, 4.2 and 5.3 m/s were examined. Gas phase simulations (described in the companion paper, Part I) have allowed to determine a set of parameters (e.g., cell size of 4 mm and modified Deardorff model for the turbulent viscosity) that are suitable for the water mist spray simulations. Moreover, it is shown here that a prescribed complex spray pattern with a full discharge angle of 60° is required in order to match water spray profiles in the nozzle near-field. The three regimes of spray-jet interaction (i.e., water spray dominated, vertical jet dominated or equal influence of the spray and the vertical jet) are qualitatively well captured by the numerical simulations. However, the location of the interaction boundary is underestimated by up to 26%. This could be partially attributed to modelling aspects related to, for example, turbulent dispersion or turbulence inflow conditions of the droplets. Uncertainties in the experimental measurements must also be considered.

Enhancement in free cooling potential through PCM based storage system integrated with direct evaporative cooling (DEC) unit

The present work reports the enhancement in free cooling potential using a modified cooling system compared to the conventional free cooling system. The proposed modified system is a novel pilot scale model packed with spherically encapsulated phase change material in a cylindrical tank along with water spray nozzles (direct evaporative cooling unit) at the inlet of the tank. The experiments were conducted in Bangalore, a city located in south India that possesses moderate/temperate climate throughout the year. Considering the local ambient conditions, an organic phase change material with the phase transition temperature range of 25.6–27.1 °C was used in the present study. Significant reduction in total charging duration and enhancement in heat transfer rate was achieved through the hybrid cooling system. The reduction in charging duration of 28.7% and 34.8% was observed for the proposed hybrid cooling system at heat transfer fluid (HTF) inlet velocities of 2 and 1.5 m/s respectively. It is observed from the results that in the experiments conducted with conventional free cooling system at 1 m/s HTF velocity, the phase change material (PCM) placed in the last two rows of the storage tank did not reach its end freezing temperature even after 10 h of experimentation due to the low heat transfer rate, whereas in the experiments conducted with the modified free cooling system, the storage tank is completely charged at all HTF velocities. It is construed from the results that the integration of evaporative cooling unit along with phase change material based free cooling system aids the chosen phase change material to completely solidify at a faster rate and augments the thermal performance of the storage unit. The proposed system can be operated as a single stand-alone cooling system to meet the cooling demand of the buildings or it can be integrated with the mechanically operated HVAC systems to achieve energy efficiency in the overall cooling system.

P.4.b.014 - The prevalence of posttraumatic stress disorder and mental health of Korean Vietnam War veterans 40 years after the war

The public health impact of particulate matter in ambient air with a size of 2.5 μm or smaller (PM2.5) has been of great concern. It is well known that PM2.5 is much more harmful to human health than coarse particles. To remove PM2.5, most air purifiers on the market have been equipped with a high efficiency particulate air (HEPA) filter. Under the circumstances that generate PM2.5 aerosols at high concentrations such as during indoor cooking or in work places, HEPA-grade filters are neither durable nor applicable because of their high replacement cost. Thus, a large number of cooks and workers are exposed to intensive emissions of PM2.5 without proper filtration. In this paper, we introduce a novel concept to remove PM2.5 without HEPA filters. A key idea is to use the condensational growth of particles. Once the particles have grown to a few micron, they are much easier to remove because of their increased inertia. Based on this, we developed the first prototype of a filter-free particle filtration unit consisting of an air saturator (equipped with water spray nozzles), a condenser in which humid air is cooled down to a supersaturation state and thereby allows particles to grow by condensation, and a multi-nozzle-impactor assembly for collecting the grown particles downstream of the condenser. We started with a small-scale model, and then demonstrated that a large-scale prototype could remove organic, inorganic, and metallic ultrafine particles with a collection efficiency of larger than 80% at a volume flow rate of 50–92 L/s.

Optimization of the Water Spray Nozzle, Refrigerant Charge Amount and Expansion Valve Opening for a Unitary Ice Maker Using R-404A

R-502, which had long been used as the refrigerant of a unitary ice maker, has been replaced by R-404A due to ozone depletion. In this study, the refrigeration cycle of a unitary ice maker was optimized using R-404A. The optimization was accomplished through a search for the proper refrigerant charge amount and the opening of the expansion valve. For the present ice maker having 24 ice cups, the optimum charge amount was 580[Formula: see text]g and the optimum valve opening was “0”. At this configuration, the ice making time was 12[Formula: see text]min 55[Formula: see text]sec, ice production was 4.46[Formula: see text]kg/h and COP was 0.439. After the initial start-up period, both condensation and evaporation temperature gradually decrease with time. As ice builds up in the cup, the heat transfer performance of the evaporator decreases, which results in the decrease of the evaporation and condensation temperature. Through CFD and relevant experiments, optimum nozzle slit width and nozzle to cup distance were obtained.

Design of a small scale iron and manganese removal system for Copperbelt University’s borehole water

The study aimed at designing and performance testing of a suitable small scale Iron and Manganese removal system for Copperbelt University’s Borehole water. Materials for the filtration system were locally sourced within the Copperbelt province of Zambia. Tests were carried out on borehole water and system filtered water. The results show that the system performed relatively well on reducing Iron and Manganese from groundwater. The model constructed was a small scale version of an Up-flow filtration system. Evaluation showed performance efficiencies of 81.67% and 32% on iron and manganese removal respectively. The Up-flow design is better because water takes relatively more time to pass through the filter increasing contaminant removal capacity. The aerator tray was good but retention time for air was not sufficient and could be made better. Based on the results from the lab scale model a full scale Prototype was proposed and designed. Selecting the most applicable design largely depends on economical availability of materials, ease of construction and operation all this in relation to system efficiency. The Up-flow design in this study can be improved with respect to (i) the sedimentation tank for the settlement of oxidized iron and manganese by improving retention time of water (ii) spray nozzle to increase the surface area for aeration of water. Additionally, a substitute aerator tray with cascades to increase retention time for aeration is proposed. Furthermore, based on the model and literature review of similar designs, the sand layer depth should be at least 20 cm.

Analysis of the Slab Temperature, Thermal Stresses and Fractures Computed with the Implementation of Local and Average Boundary Conditions in the Secondary Cooling Zones

Abstract The numerical simulations of the temperature fields have been accomplished for slab casting made of a low carbon steel. The casting process of slab of 1500 mm in width and 225 mm in height has been modeled. Two types of boundary condition models of heat transfer have been employed in numerical simulations. The heat transfer coefficient in the first boundary condition model was calculated from the formula which takes into account the slab surface temperature and water flow rate in each secondary cooling zone. The second boundary condition model defines the heat transfer coefficient around each water spray nozzle. The temperature fields resulting from the average in zones water flow rate and from the nozzles arrangement have been compared. The thermal stresses and deformations resulted from such temperature field have given higher values of fracture criterion at slab corners.