Increase In Heat Transfer Rate Research Articles

Thermal Performance Analysis of a Linear Fresnel Concentrating Solar Collector Absorber Tube

Linear Fresnel solar collectors are suitable for a wide range of applications, which include steam generation for power generation, industrial process heat, solar cooling, institutional and domestic hot water production etc. The thermal performance of a linear Fresnel solar collector absorber tube was investigated in this study for different fluid mass flow rates, heat flux intensities, heat transfer fluid inlet temperatures, ambient air temperatures and external loss heat transfer rate. Turbulent flow liquid water heat transfer fluid and uniform circumferential heat flux distribution boundary were considered under steady-state conditions. The fluid flow was considered incompressible. This study was limited to a first order model approximation for thermal performance of a linear Fresnel solar collector absorber tube. The heat transfer fluid and absorber tube material properties were considered constant and independent of temperature. The results indicated that the absorber tube outlet heat transfer fluid temperature decreased with an increase in the Reynolds number and increased with the heat flux intensities. Thermal efficiency increased with an increase in the heat transfer fluid mass flow rate and however, decreased with increase in pressure drop and the consequent pumping power requirement. It was also found that the thermal efficiency of the collector decreased with an increase in the fluid bulk inlet temperature and decreased with an increase in the external loss heat transfer rate.

Investigation of energy storage in parabolic rotary trough solar collectors using various porous fins with magnetic nanoparticles

The present study investigates the performance of various porous fin materials (copper, aluminum, bronze, and steel) with different porosities in a parabolic rotary trough solar collector driven by magnetic nanofluid. The nanofluid circulates in the rotary pipe and flows into the attached inner porous fin by a centrifugal force. This design enhances the heat transfer while reducing the pressure drop in the parabolic trough solar collector compared to previous configurations. Based on the results, the copper foam has the best performance among the studied materials, and the role of porous material is more salient in the rotational state than in the stationary one. Moreover, the increment of porosity causes more energy storage in the solar collector, while an optimal value is obtained for the rotational speed. The findings show that the heat transfer rate and pressure drop increase 3.7 times and 2.6 times in the optimal state of using copper porous fin with 97 % porosity in the rotary pipe with 0.6 rad/s angular velocity, respectively. Also, the energetic and exergetic performance increases from 71.6 % to 87.2 % and from 24.2 % to 40.5 %, respectively, and more than half of the lost energy is restored in the manipulated system.

CFD studies on thermal performance augmentation of heat sink using perforated twisted, and grooved pin fins

In the present study, a numerical investigation is conducted to observe the effect of forced convection heat transfer for various innovative shaped pin fin heatsink designs by altering the effect of various parameters on the fluid domain and the solid domain. The study illustrates the possible configuration of such heat sink design implementing Twisted and Grooved shaped innovative pin fins. Different perforation shapes and alignments are applied to extend the surface area resulting in increased heat transfer rate and hydrothermal performance factor (HTPF). Navier-Stokes's equations and RANS (Reynolds Averaged Navier-Stokes) based k−ε turbulence model govern the modeling of the study. Compared to available recent literature, the HTPF has increased by about 9% for Grooved Circular perforated pin fin at Reynolds number (Re) = 21367. The results showed an improvement of the average Nusselt number (Nu) by 32%. The grooved-shaped circular perforated heat sink has been observed with an improved HTPF of about 27% from the baseline case. Also, the Cu-Diamond composite on grooved circular perforated pin fin has shown improvement in HTPF by 33% at Re = 21367. Pressure drop has also been observed to be lowest in the case of the grooved fin with circular perforations. Hence, this design significantly benefits the HTPF.

Heat transfer augmentation through rectangular cross section duct with one corrugated surface: An experimental and numerical study

One of the techniques utilized to enhance the heat transfer rate within air ducts is creating turbulence inducing designs. In this work, turbulent air flow through a rectangular cross-sectional duct with one corrugated surface was experimentally and numerically investigated. Hydraulic and thermal behaviors of the system were evaluated at different Reynolds numbers. A test rig was constructed to experimentally investigate the performance. Also, a two-dimensional computational fluid dynamics simulation was performed using k-ε model to simulate fluid flow within the duct. The model was validated against previous results as well as the experimental results from this research. The computational and experimental findings were in reasonable agreement with a maximum error of less than 10%. The results showed that the existence of the corrugated surface considerably enhanced the heat transfer rate in all the studied cases, while slightly increasing the pressure drop. Consequently, a parametric study was performed to investigate the effect of different design parameters on the performance. The best performance was observed at a rib height to width ratio of 0.2, and groove length to width ratio of three, with a thermal enhancement factor of about 1.5. an empirical relation between Nusselt number and Reynolds number was established using the obtained results with a relative error value less than 8%. The study proved the value of using a corrugated surface as a means to increase heat transfer rate within rectangular air ducts.

Heat Transfer Augmentation: Experimental Study with Nanobubbles Technology

The experimental research on heat transfer characteristics is an ever-ending scheme since the life of all thermoelectronic devices relies on the effective management of thermal energy. In some cases, the gradient of temperature for heat transfer is to be minimum to avoid energy loss, but also there are numerous applications where the requirement of heat transfer to be maximum and could be achieved with a higher temperature difference between the heat transfer medium. In our current research, distilled water-ethylene glycol heat transfer fluid (HTF) was tested with different inlet mass flow rates and temperature as the hot fluid. Atmospheric air was chosen as the cold fluid. The natural convection heat transfer rate between hot and cold fluid streams was analyzed with and without the generation of micronanobubbles in the hot fluid. It was observed that compared to the base heat transfer fluid, the nanobubbles heat transfer fluid resulted in a 10–12% increase in heat transfer rate at hot fluid inlet temperatures of 28°C, 30°C, 32°C, 34°C, and 36°C. The method of generation of nanobubbles in HTF and their behavior are also highlighted.

Natural Convection With Surface Radiation From the Infrared Suppression Device and Estimation of Cooling Time: A Computational Analysis

AbstractThe thermofluid characteristics of the infrared suppression (IRS) device used in the marine gas turbine as an exhaust system are numerically investigated here. The prime objective is to observe the impact of convection united with surface radiation on the cooling of the IRS. Furthermore, the time taken to cool down the device is also estimated. A comparison exercise is also carried out to elucidate the impact of radiation considering the surface radiation and without it (taking only convection). The numerical solution of the Navier–Stokes equation, energy equation, and radiation equation, along with the turbulence equations, are performed using ANSYS FLUENT 15.0. Various relevant parameters are taken for the analysis, namely, Rayleigh number (Ra) (1 × 1010 ≤ Ra ≤ 1 × 1012), diameter ratio (DR) (1.01 ≤ DR ≤ 1.3), funnel overlapping (OL) (−20% ≤ OL ≤ 20%), and emissivity of the surface (ε) (0 ≤ ε ≤ 1). It is noticed that surface radiation has an enormous contribution to the total heat transfer and, thus, could not be neglected. The total heat transfer rate and mass flowrate increase with Ra and DR. Also, the contribution of convective heat transfer drops with the rise in emissivity. In addition, the convection united with surface radiation case reduces the cooling time (almost half) than the natural convection alone case.

Artificial neural network modeling to examine spring turbulators influence on parabolic solar collector effectiveness with hybrid nanofluids

Numerical simulation and artificial neural network modeling of turbulent flow inside a pipe equipped with two spring turbulator samples with two different scales and a segmental cross-section have been investigated. Increased heat transfer rate (HTR) due to the use of a spring turbulator is predicted for the TiO2Cu-Water hybrid nanofluid based on the single-phase model, feed-forward artificial neural network (ANN) and fitting method. The role of Reynolds number (Re), scale and volume fraction (ϕ) on Nusselt number (Nu), pressure drop (ΔP), performance evaluation coefficient (PEC), solar collector efficiency (η), and the field synergy principle (FSP), compared to simple pipe, is considered using the finite volume method. The results show that increasing the spring turbulator scale increased the contact surface of the working fluid and the spring turbulator. As a result, the flow turbulence is increased, which leads to better mixing of the nanofluid as the operating fluid of the solar collector absorber pipe. Finally, ANN outputs and fitting results are compared, and it has been observed that the obtained ANN could predict the targets accurately.

Evaluations on effect of volume fraction of injected air on exergo-economic performance of a shell and tube heat exchanger

Increasing heat transfer rate in heat exchangers is one of the topics interested by researchers which leads to economic savings. Various methods have been proposed in this field which are categorized into two main groups of active and passive techniques. Despite numerous investigations were conducted in this regards, very rare investigations have probed these methods from the economic viewpoints. Present study was carried out to investigate the effect of volume fraction (VF) of air bubbles on exergo-economic performance of horizontal shell and helically coiled tube exchanger (HSHTE). The air bubbles were injected into shell side via especial method. Holes with certain properties were fabricated on a plastic pipe with diameter of 3 mm for injecting air bubbles. Both counter flow and parallel flow were considered in this investigation. Present study showed that air injection has significant effect on thermal efficiency, exergy destruction and economic performance of the HSHTE. It was found that increment of VF increases number of thermal units, first law efficiently and exergy destruction increase by 4.5, 2.4 and 12.5 times, respectably. Furthermore, best values of Net profit per unit transferred heat load (դ p ) was about 9.3 × 10 −5 ($/J) which presented up to 13% better financial performance in comparison with parallel flow.

Influence of Micro-Textures on Cutting Insert Heat Dissipation

Metal machining is one of the most important manufacturing processes in today’s production sector. The tools used in machining have been developed over the years to improve their performance, by reducing the cutting forces, the friction coefficient, and the heat generated during the cutting process. Several cooling systems have emerged as an effective way to remove the excessive heat generated from the chip-tool contact region. In recent years, the introduction of nano and micro-textures on the surface of tools has allowed to further improve their overall performance. However, there is not sufficient scientific data to clearly show how surface texturing can contribute to the reduction of tool temperature and identify its mechanisms. Therefore, this work proposes an experimental setup to study the tool surface characteristics’ impact on the heat transfer rate from the tools’ surface to the cooling fluid. Firstly, a numerical model is developed to mimic the heat energy flow from the tool. Next, the design variables were adjusted to get a linear system response and to achieve a fast steady-state thermal condition. Finally, the experimental device was implemented based on the optimized numerical model. A good agreement was obtained between the experimental tests and numerical simulations, validating the concept and the implementation of the experimental setup. A square grid pattern of 100 μm × 100 μm with grooves depths of 50, 100, and 150 μm was introduced on cutting insert surfaces by laser ablation. The experimental results show that there is a linear increase in heat transfer rate with the depth of the grooves relatively to a standard surface, with an increase of 3.77% for the depth of 150 μm. This is associated with the increase of the contact area with the coolant, the generation of greater fluid turbulence near the surface, and the enhancement of the surface wettability.

Evaluation of Thermal Performance of Conically Shaped Micro Helical Tubes Using Non-Newtonian Nanofluids–A Numerical Study

Abstract Nowadays, the cooling and heating of micro-thermal devices have received a growing interest. To improve the thermal management of these micro-thermal devices, various efforts are being made by the researchers. In the present study, conically shaped micro helical tubes are used to investigate the coil side heat transfer rate and friction factor of non-Newtonian nanofluids under laminar flow conditions. For the numerical analysis, single-phase approach with commercial software ansys-fluent-19 has been utilized. Investigations encompass generalized Reynold numbers ranging from 306 to 2159 and four different curvature ratios (0.066, 0.076, 0.088, and 0.1) of conically shaped micro helical tubes. The inner diameter of the helical tube is 2 mm and contains 20 turns. Al2O3-based non-Newtonian nanofluids with volume concentrations of 0.0%, 0.1%, and 0.2% having base fluid of aqueous solution of carboxymethyl-cellulose (CMC) are used as the working fluid (hot) for the coil side, while in the shell side cold water is used. The results from numerical investigation are validated and found in good agreement with earlier experimental results. The results show that with the increase in the curvature ratio of conically coiled tubes both heat transfer rate and friction factor increase by 46% and 98% respectively, for base fluid at a curvature ratio of 0.1. Also, the present study reveals that adding nanoparticles to the base fluid enhances the heat transfer rate to a maximum value of 40%. Moreover, the maximum value of thermal performance factor (TPF) is found to be 1.52.

Improving performance evaluation coefficient and parabolic solar collector efficiency with hybrid nanofluid by innovative slotted turbulators

The goal of the present work was to define a new geometry of the twisted strip that could lead to the improvement of efficiency (η) in the solar collector (SC) by increasing heat transfer rate (HTR) and decreasing pressure drop (ΔP). CuO-SWCNT/water hybrid nanofluid has been used in nanoparticles volume fractions (ϕ) of 1% to 4%. The study was implemented in single phase for the Reynolds number (Re) varying from 4000 to 10,000. The governing equations were solved by the finite volume method (FVM), using the k-ω-SST turbulence model and SIMPLEC algorithm. Two samples of twisted strip with v-shaped cuts in different numbers and placement angles were investigated. The findings revealed that the highest efficiency in the pipe was related to the twisted strip with three v-shaped cuts equal to 2.46; meanwhile, for the pipe with the twisted strip containing two v-shaped cuts under the same conditions, this was 2.40. Increasing the number of cuts on the twisted strip (sample 3) improved the efficiency of the SC and decreased the pressure drop. In regard to the case of sample 3, at Re = 10000 and φ = 1%, the efficiency was increased by 2.22%, while the pressure drop was decreased by 4%.

Optimizing Thermo-Hydraulic Performance in Heat Exchanger with Gradient and Multi-Layered Porous Foams

In this study, the effect of gradient and multi-layered porous media is assessed for the optimized properties and arrangement in the tested novel baffle design arrangement, which results in further enhancement in its thermo-hydraulic performance. The computational study is carried out using ANSYS FLUENT; wherein the permeability and porosity for each layer is varied. It’s executed in two steps: case 1 – porous layers with variations implemented (constant, linear/stepwise, increasing/decreasing) and case 2 – porosity varied over the length. The findings show that the linear/stepwise increments in both cases give almost similar performance evaluation criteria (PEC) values. The increase in heat transfer rate and pressure drop can be compared using PEC, for better evaluation of the performance of different arrangements. With the simulation data genetic algorithm optimization model is used to find the optimal arrangement of the porous layers for both cases to maximize PEC further. The optimal arrangement for case 1 and case 2 taken individually, gives PEC of 2.425 and 2.401 respectively. And their simultaneous optimization gives highest PEC of 2.508. Additionally, to improve the heat transfer rate further, Al2O3 (5 w/v %) nanoparticles in water is tested with optimized conditions, which improves the PEC by almost double magnitude.

A two-phase model for studying the complex interplay between natural convection and magnetic field in aluminum-oxide/water nanofluid

While previous experimental studies revealed the existence of optimal heat transfer performance in natural convection of magnetohydrodynamic (MHD) nanofluid flows, it is believed that this phenomenon is not unique in different levels of magnetic flux density. In order to prove this speculation, we numerically investigate the influence of the magnetic field on steady natural convection of aluminum-oxide (Al2O3) nanofluids inside an enclosure. The MHD flow model without the consideration of nanofluids is well validated against theoretical, numerical, and experimental results. The nanofluid in the present investigation has temperature-dependent physical properties and is modeled by a two-phase mixture considering thermophoresis and Brownian diffusion. While varying the volume fraction of nanoparticles from 0 to 6%, we methodically examine the effect of the Hartmann number on the heat transfer performance through the thermal behavior map in terms of the Hartmann–Rayleigh plane. Depending on the combination of magnetic intensity and buoyancy-induced flow, the nanofluid heat transfer with the addition of various concentrations of nanoparticles can be categorized into two patterns separated by a critical Hartmann number: the presence of a maximum Nusselt number (Type A) and continuously increased heat transfer rates (Type B) over a wide range of the Rayleigh number from 103 to 106 and the Hartmann number from 0 to 300. Described by a piecewise-defined function, the critical Hartmann number is exponentially proportional to the Rayleigh number from 104 to 106 and rises linearly in a logarithmic scale with elevating the Rayleigh number from 103 to 104.

Unsteady magnetohydrodynamic nanofluid flow over a permeable exponentially surface manifested with non-uniform heat source/sink effects

Current research inspects the influences of two-dimensional unsteady nanofluid flow over a permeable exponential stretching sheet with the impact of magnetic field parameter, thermal radiation together with a non-uniform heat source or sink. The dimensional equations namely Partial differential equations (PDE’s) are transformed into dimensionless form as ordinary differential equations (ODE’s) by using the suitable transformations. The reframed ODE’s are solved numerically through the computer-based tool MATLAB with the bvp4c package. The derived results of velocity, temperature and species distributions are depicted graphically. Also, the numerical results of skin friction coefficients, heat transfer rate and mass transfer rate in terms of Nusselt number and Sherwood number are deployed via tables. The comparison of the present work with published work shows complete agreement for skin friction factor and Nusselt number. In absolute sense skin friction enhances as magnetic field parameter enhances. The Brownian motion and thermophoresis parameters play an essential role towards thermophysical flow field of nanofluids. Further, we noticed that both Brownian motion parameter and thermophoresis parameter cause an enhancement in the fluid temperature. Furthermore, the unsteady parameter causes increase in wall friction and heat transfer rate. However, the opposite trend is observed for the heat source/sink parameters.

New wellbore temperature control design for preventing failure and poor performance of logging tools in high pressure – high temperature wells

Failure and poor performance of logging tools in high pressure-high temperature wells; the associated technical consequences and the resultant high cost of logging operations are recurrent problems in the oil & gas industry worldwide. The aforesaid prompted this work to invent the “New Wellbore Temperature Control Design” for protection of logging tools against high bottom-hole temperatures. It hinges on the novel concept of thermal drainage radius and the temperature-drop effect of chilled oil-based mud to reduce bottom-hole temperature prior to logging. The methods applied include laboratory testing, mathematical modeling and design. The novel concept of “thermal drainage radius” quantified the radial extent of temperature-drop effect in the formation, away from the wellbore. Novel mathematical models were also invented. Laboratory results showed that the formation temperature-drop from bottom-hole temperature to thermal equilibrium temperature increased with bottom-hole temperature per chilled oil-based mud. The temperature-drop duration and temperature-rise duration increased with bottom-hole temperature per chilled oil-based mud. The temperature-rise duration increased with decrease in the temperature of the chilled oil-based mud per bottom-hole temperature. Job design results showed that when placed in the zone of interest in the wellbore the heat energy absorbed increased with quantity of the chilled oil based mud but the temperature rise duration decreased with increasing heat transfer rate from the formation and vice versa. Furthermore, results revealed that the higher the thermal conductivity of the formation, the longer the thermal drainage radius and vice versa. The logging operation should commence after placement of the chilled oil-based mud in the zone of interest (no circulation of the chilled oil-based mud) and be completed before the end of the temperature-rise duration. Oil-based mud is cheap and available in every country unlike the expensive vacuum flasks and thermal insulating jackets currently used for protecting logging tools against high temperature. The new wellbore temperature control design has global applicability.

RECENT IMPROVEMENTS OF THE OPTICAL AND THERMAL PERFORMANCE OF THE PARABOLIC TROUGH SOLAR COLLECTOR SYSTEMS

Parabolic trough solar collectors (PTSCs) are commonly used for applications that reach a temperature of up to 500 °C. Recently, improving the efficiency of PTSCs has been the focus of research because PTSCs have advantages, such as cost and size reduction and improved optical and thermal performance. This study summarizes relevant published research on the preparation, properties and experimental behavior of the optical and thermal properties of PTSCs. Analyzing of the thermal modeling method presents a steady and transient heat transfer analysis. Optical efficiency depends on material properties, such as mirror reflectance, glass cover transmittance, receiver absorption–emission, intercept factor, geometry factor and incidence angle. Also analyzed and discussed are the models used in computational fluid dynamics to study the physical properties of PTSCs. Lastly, studies on PTSC performance and enhancement, including novel designs, enhancement of passive heat transfer and laden flows of nanoparticles inside the absorber tube, are presented and examined separately. Nanofluids have illustrated their advantages and ability to increase heat transfer rates. Moreover, other works that aimed to enhance the optical and thermal efficiency of PTSCs are evaluated.

Numerical scrutinization of dropwise condensation heat transfer on an inclined surface

AbstractRecently, achieving an ameliorated heat transfer rate in dropwise condensation (DWC) has attracted the attention of many researchers. Several parameters, including chemical and physical properties of the substrate, inclination, and interfacial characteristics influence DWC heat transfer rate. The variation of inclination angle is followed by the change in droplet shape and consequently, the heat transfer rate are changed. In this study, the effect of droplet shape variation on diverse inclined substrates is simulated. Moreover, three‐dimensional mass, momentum, and energy equations considering the desired boundary conditions on the unstructured grid are utilized for the scrutinization of flow behavior and heat transfer for static and sliding droplets. For the sake of validation, the outcomes obtained from the simulation were compared with existent data in the literature and a proper agreement was attained. Regarding the outcomes, it was of concern that the influence of inclination angle on the droplet shape is more distinct at higher droplet volume; while no considerable change was seen on heat flux of small droplets by increasing the inclination angle. Furthermore, a higher heat transfer rate was noted by exceeding the inclination angle beyond a definite angle. Additionally, the increased heat transfer rate was affirmed by increasing the Marangoni number .

Magneto-hydrothermal analysis of copper and copper oxide nanoparticles between two parallel plates with Brownian motion and thermophoresis effects

Low thermal conductivity is the main constraint in heat transmission nowadays. In order to overcome this barrier and to improve the thermal conductivity of different base fluids, some researchers have introduced various types of solid particles also known as nanoparticles to base fluids. In this article, the authors investigated the copper and copper oxide nanoparticles by using water as a base fluid between two parallel plates. Also, the authors emphasized to investigate different shapes (like sphere, cylinder, blade, platelet, and brick) of the copper and copper oxide nanoparticles to present the comparative analysis of heat transfer phenomena. Additionally, the impacts of Brownian motion and thermophoresis over flow of fluid has also considered in this study. For this purpose, the authors used the Buongiorno's model in this work. The equations that governed the flow system have converted to dimensionless form by using suitable variables and then solved by HAM. Convergence analysis of the present model has been shown with the help of Figures. The outcomes show that the volume fraction coefficient of the nanoparticles has dual impact on axial velocity and has declining effect on radial velocity of the nanofluids flow. Also, the thermal profile is increased with the higher volume fraction coefficient. The augmented volumetric fraction has reduced the skin friction coefficient for both Cu and CuO nanofluids, while the boosted magnetic parameter and viscosity coefficient have reduced the skin friction coefficient for both Cu and CuO nanofluids. The percentage decrease between the skin friction coefficients of Cu and CuO nanofluids are 3%, 5%, and 7% for φ = 0.01, φ = 0.02 and φ = 0.03 respectively. The augmented volumetric fraction, Brownian motion, and thermophoresis parameters have enhanced the Nusselt number, whereas the augmented the viscosity coefficient has heightened the Nusselt number. Additionally, the dominant impact is found for Blades-shaped nanoparticles for both Cu and CuO nanofluids. For the blade-shaped nanoparticles when φ = 0.02 and φ = 0.03, there is a 1% increase in heat transfer rate between Cu and CuO nanoparticles.

Computational investigation of thermal behaviors of the automotive radiator operated with water/anti-freezing agent nanofluid based coolant

In this study, a 3D computational fluid dynamics (CFD) study was conducted in ANSYS (FLUENT) to examine the thermal performance of an automotive radiator using conventional and hybrid coolant with a Al2O3 nanoparticles (NPs) . A hybrid mixture of pure water H2Oand ethylene glycol (EG) in the volumetric proportion of , was coupled with Al2O3 nanoparticles with volume fraction of 1% - 4% at different inlet temperatures. The Reynolds number was varied from 4 000 to 8 000. From the numerical results obtained, it was found that an increase in nanoparticle volume fraction led to an increase in heat transfer rate and pressure drop in the automotive radiator. Also, it was found that at a Reynolds number of 8 000, using the hybrid mixture as a base fluid increased the Nusselt number by 55.6% in contrast to pure water. However, further suspension of 4% Vol. Al2O3 nanoparticles into existing hybrid mixture increased the Nusselt number by 70%. Furthermore, it was found that an increase in the inlet temperature of the radiator caused more enhancement in the heat transfer rate. For Re=8 000 4% vol. Al2O3-water nanofluid, the heat transfer rate was enhanced by 54.57% when increasing the inlet temperature from 60oC to 90oC. Therefore, it is recommended that automobile radiators be operated at a high inlet temperature with nanofluid containing a very high concentration of suitable nanoparticles and an anti-freezing agent in an adequate volumetric proportion to achieve better thermal performance.

Experimental study of convective heat transfer coefficient for pulsed fluidized bed using microcapsule phase change material

AbstractThe convective heat transfer coefficient in a pulsating cylindrical fluidized bed using microcapsule particle‐phase change material (MPCM) was examined experimentally. A solenoid on and off valve was used to provide the pulsation and was varied from 1 to 10 Hz. The test section in the bed was loaded with granular microparticle‐phase change material (MPCM) with an average diameter of 200 µm. The pulsation effect on the thermal field, thermal storage, and heat transfer coefficient was investigated for 1.5, 2, and 2.5 of minimum fluidization velocity. Results indicated that the amplitude of the oscillation decreases with increasing in pulsation frequency. An increase in heat transfer rate was shown to be related to the superficial velocity. The maximum performance was obtained for the frequency of 7 Hz at the velocity ratio of 2.5. The convective heat transfer increased by 17% for frequency pulsation of 7 Hz. Furthermore, the Duty cycle (η) is defined as the ratio of turn‐on duration to the total turn‐on and off duration for entering airflow to the solenoid valve. It was shown that the η > 0.4 led to better mixing and higher heat transfer. However, the pulsation effect was shown to disappear for the duty cycle of higher than 0.8. Comparison with the available experimental data of others for continuous flow was in good agreement.