In the present study, a suitable composition of parameters has been obtained to provide an efficient process cooling flue gas with complete condensation water vapour from air-water mixture on film in co-current upward flow tube direct contact heat and mass exchanger. The results showed that value irrigation density depends velocity initial content should be calculated empirical equation. active pipe height also For example, if is 11%, 20.8 m/s channel not exceed 0.460 m. heating limit...

The present study is devoted to the modeling, design, and experimental of a heat pipe exchanger utilized as recuperator in small air conditioning systems (airflow ≈ 300–500 m3/h), comprised individually finned pipes. A thermal model was developed, based on available correlations. Based previous works authors, refrigerant R404A recognized best working fluid with 20% filling ratio. An engineering analysis parametric calculations performed aid computational concluded 20 rows pipes staggered...

Knowledge of flame–wall interaction helps in the understanding flame phenomena near a wall and extinction. In present work different characteristics were measured square, narrow quenching channels. A propane/air mixture was employed direct visualization used to observe behavior under conditions. Flame propagation velocity determined during downward propagation. As expected, close condition it found be lower than that adiabatic conditions values predicted by theory. The dead space appeared...

The conducted experimental studies of the linear compressor concerned cooling capacity, efficiency, and Energy Efficiency Ratio (EER). Linear performance tests were carried out for supply voltage 190–265 V frequency in range 45–65 Hz, which allowed to be tested outside its typical operating range. Modulation was achieved using an inverter. full characteristics a presented. results compared with reciprocating similar displacement volume, lower EER values by average 38% pressure ratio above...

Following the quantitative determination of dust cloud parameters, this study investigates flame propagation through cornstarch clouds in a vertical duct 780 mm height and 160 × square cross section, gives particular attention to effect small scale turbulence intensity on characteristics. Dust suspensions air were produced using an improved apparatus ensuring more uniform distribution repeatable concentrations testing duct. The dispersion-induced was measured by means particle image...

In this paper, the influence of swirl number on mixing two confined coaxial jets is analysed.The generator a set fixed vanes located in annular nozzle.Different trailing edge angles result numbers ranging from 0.14 to 0.95.Numerical model validated using non reactive benchmarks.Low, intermediate and large swirling injectors are simulated contrast flow pattern.The presence Inner Recirculation Zone associated high plays an important role heat mass transfer since promote gradients with minimum...

Plate fin-tube heat exchangers are widely used in air conditioning and refrigeration systems other industry fields. Various errors made the manufacturing process can result formation of an gap between tube fin. Several numerical simulations were carried out for a symmetric section plate exchanger to study influence on transfer under periodic flow conditions. Different locations sizes spanning 1/2 circumference considered range airflow velocities. Velocity temperature fields cases with...

The present study numerically investigates the propagation of a laminar premixed flame front in two-dimensional tubes with sudden contraction and isothermal cold walls. Navier–Stokes equations species are solved single-step overall reaction model for stoichiometric propane/air mixture. finite volume method is applied investigating behavior during passage through various diameters. These investigations show that can enter smaller diameter tube from wider one propagate stable manner all...

Computational Fluid Dynamics has been used to study the mixing and combustion of two confined jets whose setup operating conditions are those benchmark Roback Johnson. Numerical model solves 3D transient Navier Stokes for turbulent reactive flows. Averaged velocity profiles using RNG swirl dominated k-epsilon have validated with experimental measurements from other sources non case. The is Probability Density Function. Bearing in mind annular jet number over 0.5, a vortex breakdown appears...

The interaction of two confined coaxial jets has been studied using Computational Fluid Dynamics. Annular jet flows over 8 flat blade swirl generator. Numerical simulation uses RNG k-ε turbulence model. These models are suitable for turbulent dominated flows. Intermediate injector simulated and the flow patterns non-reactive reactive cases contrasted. Low swirling injectors do not promote fluid to turn near center chamber, resulting larger mixing zones with weak gradients. Whereas large...

The results of experimental investigations heat transfer and a friction factor in an air channel the minichannel exchanger are presented.The main aim analysis was to examine influence geometrical parameters fin shape with two geometries on flow characteristics channel.The test rig designed monitor airflow during cooling by exchanger.The conducted range 1-5 m/s.The temperature evaporation refrigeration system set at 288.15 K.The energy balance carried out.A numerical model describes through...

The results of numerical investigations heat transfer and pressure drops in a channel with 30° helical micro-fins are presented. main aim the analysis is to examine influence height on heat-flow characteristics channel. For tested pipe diameter 12 mm, micro-fin varies within range 0.05–0.40 mm (with 0.05 steps), which equal 0.4–3.3% its diameter. was performed for turbulent flow, Reynolds numbers 10,000–100,000. working fluid water an average temperature 298 K. each geometry, friction factor...

Numerical results depicting the effects of diffusers on confined isothermal high-swirl jets are presented. The aim is analyze mixing between a non-swirling inner jet (natural gas) and swirling annular (primary air). This simple setup widely used in burners to promote stabilized flames lean mixtures. Flow patterns for sudden-expansion contrasted swirl number 1 expansion area ratio 4 transitional turbulence regime. Diffusers have important influence size location recirculation zones. Hence...

In engineering phase-change phenomena are found in a multitude of applications, ranging from refrigeration and air con-ditioning to steam turbines petroleum refining. This study investigates the flow moist circular duct where water vapour condenses contact with cold wall duct. The investigation delves into relationship between condensation mass transfer rate, heat bulk wall, temperature wall. volume fluid model coupled Lee evaporation-condensation was employed. Five simulations were carried...

In the present work, we study numerically freely propagating flame in stoichiometric propane–air mixture. The isothermal small tubes with one end fully open and second characterized by different degrees of opening are examined. degree was equal to: 0% (completely closed), 25%, 50%, 75% 100% (fully opened) tube cross-sectional area. Several mechanisms, such as thermal expansion burned gas which can leave opened left tube), frictional forces heat losses at walls, movement unburned mixture...