Plate Fin Research Articles

Performance investigation on solar still with plate fins and latent heat energy storage

Solar still is a cheap and portable solar distillation system that can purify brackish water into potable water and is ideal for domestics use. Low productivity is a major issue that needs to be addressed in solar stills. In the present work, the efficiency of the fabricated single slope single basin solar still was enhanced by the incorporation of plate fins over the basin liner of the still. The daily productivity was further increased by attaching a latent heat energy storage unit to the still. Paraffin wax was used as phase change material (PCM) in the energy storage unit. Experiments were conducted on modified solar still for the following two cases (i) with mere plate fins and (ii) with plate fins and PCM. A 40.6% increase in productivity was observed for the solar still with mere fins and the productivity is increased by 94.51% for the solar still incorporated with both fins and PCM when compared with that of conventional still.

Algorithm for calculating finned plate radiators for the cooling system of automobile and tractor engines

The article describes the role of the radiator of the engine cooling system of automobiles and tractors, and disadvantages of the copper-soldered radiators design. In the creation of modern automobiles and tractors, it is necessary to develop radiator with optimal parameters in which the heat transfer process satisfies the existent condition. Main parameters of the radiator are: size, power consumption to overcome resistances, energy coefficient, and amount of heat released to the atmosphere. Equations to use in the development of an algorithm for water radiator calculation made from finned plates are suggested. The block diagram used to the development of the algorithm for calculating water radiator made from finned plates and calculation results compared with experimental data.

Influence of inlet velocity and heat flux on the thermal characteristic of various heat sink designs using CFD analysis

A heat sink is an important passive heat exchanger in the thermal management of electronic devices or systems. The study aims to analyze the influence of the inlet velocity and heat flux on the thermal characteristics (i.e., static temperature and heat transfer coefficient) of three heat sink designs. Computational fluid dynamics (CFD) analysis is carried out for the electronic cooling process. Three heat sink designs, namely, circular pin fin, plate fin, and rectangular fin are considered in this study. The influence of the inlet velocity and heat flux on the temperature distribution and heat transfer coefficient was analyzed. The results revealed that the use of circular pin resulted the highest temperature drop when the inlet velocity increased. The highest heat transfer coefficient was observed on the circular pin fin design during the cooling process. The heat flux demonstrated a linear correlation with the temperature for all heat sink designs. The effectiveness of the heat transfer was attributed by the heat sink design and inlet velocity of the airflow. Thus, the current results indicated the thermal characteristics of the heat sink are crucially influenced by the design and velocity of airflow in the cooling process.

Numerical Assessment of an Innovative Design of an Evacuated Tube Solar Collector Incorporated with PCM Embedded Metal Foam/Plate Fins

The objective of this manuscript is to study the possibility of improving the thermal performance of an Evacuated Tube Solar Collector (ETSC) with the integration of a Phase Change Material (PCM) incorporated into metallic foam and fitted with plate fins. A 2D mathematical model has been proposed. Two types of metal foams (copper and nickel) were inserted. In addition, the effect of metal foam pore size of on heat transfer was studied. The results were acquired through numerical simulations of four different cases; namely, Case 1: pure PCM, Case 2: with metal foam, Case 3: with fins and Case 4: with metal foam and fins. The evaluation procedure involved observing the total change in Heat Transfer Fluid (HTF) temperature and melted PCM fraction during a single day. The results proved that the thermal performance of ETSC is improved considerably by inserting metal foam and fins simultaneously. The time required for the whole process is improved by almost 9% compared to the case of pure PCM, and 2% compared to the case of inserting only plate fins. Results revealed that the pore size of the metal foams slightly affects the dynamic process of heat storage/release in the ETSC/PCM system.

Numerical investigation of melting enhancement for paraffin in an innovative finned-plate latent heat thermal energy storage unit

Latent heat thermal energy storage (LHTES) is essential for eliminating the discrepancy between energy supply and demand as well as for improving the utilization rate of low-grade industrial waste heat. This paper aims to solve the problem of long energy charge time in finned-plate LHTES device. In the present study, the LHTES unit is designed with three different orientations of the fin plates: A denotes a horizontal unit with fins; B and C denote vertical units with transverse and longitudinal fins, respectively. First, the melting process with different sizes and distributions of fins is investigated and the effect of fin thickness on the melting time is analysed. When obtaining the optimized fin parameters, two potential strengthening strategies (rippling fins and fins of non-equal length) are applied to further improve the melting performance of the device. The results show that long and thick fins can remarkably ameliorate the melting performance of paraffin, and the melting rate for the three orientations is of the order A>C>B. Compared with the finless structure, the melting rate increased by 4.52, 3.63, and 3.62 times for the three orientations of A, B, and C, respectively, for a fin length of 50 mm and fin number equal to 10. The use of rippling fins can reduce the melting time up to 4.1%, 5.4%, and 10.7% for the three orientations of A, B, and C, respectively, compared to using equal-length homogeneous fins with a thickness of 3 mm. Moreover, for orientations A and B, by adjusting fin length arrangement or using full fins, 11.4 and 46% reduction in melting time could be achieved compared with the configuration with a fin length of 50 mm and a thickness of 3 mm. The proposed innovative finned-plate LHTES device provides a useful reference and groundwork for the future large-scale utilization of the LHTES system.

Computer Assisted Design of Intelligent Electric Power Saving Dryer with Integrations of Steaming and Drying

The cost of existing relevant drying equipment is high and cannot meet the needs of steaming and drying of users. Aiming at the disadvantages of the electric driven hot air dryer with the highest market share, such as large heat loss and cannot meet the integration of steaming and drying, this scheme is based on solar heat collection and waste heat recovery to reduce the power consumption in the production process and realize the integration of steaming and drying, An innovative drying equipment equipped with waste heat recovery system and solar collector plate and optimized structure of carrier plate is designed. Rational use of plate fin heat exchanger to recover the heat in tail gas, heating with solar collector plate to reduce the power consumption in the heating process, and improving the structure of carrier plate to realize the two functions of steaming and drying at the same time will be the main breakthroughs. After calculation and measurement, a dryer with heat saving rate of 37.83% obtained.

Analytical and Experimental Investigation of a Plate Fin Heat Exchanger at Cryogenics Temperature

Plate-fin heat exchangers provide a broad range of applications in many cryogenic industries for liquefaction and separation of gasses because of their excellent technical advantages such as high effectiveness, compact size, etc. Correlations are available for the design of a plate-fin heat exchanger, but experimental investigations are few at cryogenic temperature. In the present study, a cryogenic heat exchanger test setup has been designed and fabricated to investigate the performance of plate-fin heat exchanger at cryogenic temperature. Major parameters (Colburn factor, Friction factor, etc.) that affect the performance of plate-fin heat exchangers are provided concisely. The effect of mass flow rate and inlet temperature on the effectiveness and pressure drop of the heat exchanger are investigated. It is observed that with an increase in mass flow rate effectiveness and pressure drop increases. The present setup emphasis the systematic procedure to perform the experiment based on cryogenic operating conditions and represent its uncertainties level.

Leveraging the entropy generation minimization and designed porous media for the optimization of heat sinks employed in low-grade waste heat harvesting

• A porous media model and optimization procedure to design heat sinks is presented • Different geometries of the heat sinks are treated within the same framework • Which geometry should be employed depends on operational conditions and size • Entropy generation is a reliable metric for low-grade waste heat recovery systems A comprehensive optimization procedure for the design of heat sinks used to harvest low-grade waste heat for secondary processes is proposed. A designed porous medium approach is used, providing modelling versatility and allowing for the treatment of several internal geometries within the same framework. Two applications, taken from the cooling of high concentration photovoltaic cells and membrane distillation, are used to illustrate the proposed procedure. Three internal heat sink geometries, namely plate fins, pin fins, and metal foams, are analyzed, and the selection as to which one is the more advantageous is shown to be dependent on size and operational conditions. Possible pitfalls of a traditional design procedure are pointed out, for heat transfer capability, under high heat load condition, should be emphasized over fluid friction avoidance. The entropy generation rate is then shown to be a reliable metric when designing for low-grade waste heat recovery, automatically focusing on either viscous dissipation or thermal resistance minimization without introducing any artificial figure of merit for that purpose.

Analysis of Performance of Plate Fin Heat Exchanger

Plate fin heat exchanger is a kind of smaller heat exchange device which has applications in cars, low temperatures, rockets space vehicles etc. The plate fin heat exchanger devices are mostly utilized for liquefaction of nitrogen. So that they are highly efficient because no liquid oxygen will be produced if the efficiency of the system is below the required value, and that is nearly 87%. That’s ‘why it is very necessary to check their efficiency before bringing them in actual application. This efficiency has been calculated here. The required heat exchanger has different shape and its effectiveness is tested experimentally in the heat and mass transfer lab. Experiment is carried out by putting the Quantity of hot and cold fluid same, but the result is obtained by taking different quantity of fluid for different experiment. It means that for one test quantity of both the fluid is taken same and this test is repeated for different quantity. So, in this way productiveness of the required exchanger is determined for different quantity.

Thermal performance evaluation of latent heat storage systems with plate fin-metal foam hybrid structure

The thermal performance of phase change materials (PCM) embedded with fins and metal foam is investigated. Plate fins are attached to the enclosure, and metal foam is embedded between adjacent fins to enhance heat transfer. To predict the melting behavior, a numerical model is established based on the enthalpy-porosity method, considering natural convection, flow resistance induced by metal foam, and non-equilibrium heat transfer. Nine cases considering various geometric parameters, heat transfer enhancement designs, and heated wall temperature are studied. Furthermore, a dimensionless theoretical model is derived to conclude the effect of combined parameters. It shows that the melting time reduces by 24.8 % as the fin height decreases from 80 mm to 50 mm, and the melting time becomes shorter with the decrease of fin thickness. However, the heat flux gets higher for higher fin height and thinner fin thickness. Moreover, the melting rate and heat flux become higher for higher fin volume fraction, lower metal foam porosity, and higher heated wall temperature. Furthermore, the theoretical model reveals that as Stefan number, fin efficiency, and the ratio of thermal diffusivity to the squared fin height become larger, the melting rate becomes higher.

Dynamic performance and multi-objective optimization of fin-concrete heat sinks

• A novel parametric dynamic thermal network of a fin-concrete ceiling is developed. • The optimal solutions set is used to design the finned plate layout. • Dynamic performance of heat sink is stabilized with high-density finned plate. In a passive nuclear plant, the main control room must provide self-support functions for 72 h after an accident occurs. In this isolation mode, the heat generated by indoor occupants and equipment should be removed by using concrete walls that are 610 mm thick, and the finned ceiling made of concrete should maintain thermal habitability. However, the finned ceiling design has not been studied in normal buildings, and the cooling storage effect of plate-shaped fins is usually ignored during the design phase. In this study, a novel parametric resistance–capacitance thermal network is proposed to simulate the thermal performance of different fin-plate layout forms in the case of an accident. An experiment was conducted on a 1200 mm × 1200 mm × 610 mm fin-concrete module for 72 h to validate the model under constant air temperature conditions. Based on the model, multi-objective optimization was conducted to obtain optimal solution sets by using a radial basis function approximation model. The results show that the optimal performance indicators can be classified into unsteady and quasi-steady states, in which the dominant factors for heat transfer include the heat transfer area and the thickness of the finned plate, respectively. Further, the optimal solution sets for different convection and heating conditions obtained through an optimization process are used to design a fin layout based on actual temperature control demands and cooling storage.

Performance comparison of single and double pass PV/T solar collectors integrated with rectangular plate fin absorber

Solar panel can act as a medium for transforming sunlight into electrical energy. Nevertheless, not all of the sunlight received on this device can be converted into electrical energy and the remainder will be dissipated into thermal energy. If a solar panel is continuously exposed to the sun, so its temperature will increase and thereby reduce its electrical efficiency. To deal with the issue, it may combine a PV panel with a thermal collector which is called a hybrid PV/T collector. Furthermore, in the present study the effects of fluid flow direction and mass flow rate on the thermal and electrical efficiency of the PV/T collectors are extensively analyzed. Single and double pass collectors with rectangular plate fin absorber were attached to backside of the PV panel. They were tested using a solar simulator with different flow rate ranging between 0.01 and 0.05 kg/s of the working fluid. The results show that the use of double pass PV/T air collector increase its performance compared with the single pass one. The highest values obtained from this type collector are found to be 73.23% in the thermal efficiency and 10.16% in the electrical efficiency with the working fluid mass flow rate of 0.048 kg/s.

Thermal performance of a corrugated heat dissipation fin design: A natural convection numerical analysis

This work is an extensive numerical study of the heat dissipation and cooling of a heat- generating vertical base using corrugated fins. The overall objective is to improve the heat transfer performance for passive heat sink applications. Three-dimensional numerical simulations were performed using FLUENT; the mass conservation equation, Navier–Stokes equations and the energy equation were solved using a finite volume approach. Various geometrical configurations were considered, where the aspect ratio of the thickness (AR) for corrugated fins was adopted as the key variable for improving heat transfer performance. The applied heat flux is in the range 811.55 to 4674.56W/m2. The results for the corrugated fins were compared to those for the conventional plate fins in terms of fluid flow, temperatures, heat transfer coefficients and weights. The results show that the proposed finned heat sinks can improve the heat transfer coefficient by up to 12.52% compared to the reference-finned plate. Additionally, the curved fin design can reduce the unit weight and thus the material use by up to 59% compared with the conventional fin design. Finally, the overall thermal efficiency of the proposed fins is around98%. The proposed design presents a suitable solution for industrial applications where the mass of the heat sink substrate is significant.

Effect of pin fin configuration on thermal performance of plate pin fin heat sinks

Flow behavior and heat transfer characteristics of air flow inside the plate pin fin heat sinks (PPFHS) are presented. The effects of pin fin shape, pin fin orientation, and ratio of distance between pin and plate fin center to pin fin size (S/Dp or S/Wp) on the flow pattern, heat transfer coefficient (HTC), pressure drop (ΔP) and thermal performance are investigated. Three types of pin fin shape, including a circular pin, square pin, and 45° square pin with pin fin sizes of 2.5, 3.0, and 3.5 mm, are used. The flow visualization used smoke to study the air flow behavior inside the PPFHS. The test runs were done at a heat flux of 14.81 kW/m2 and Reynolds number (Re) ranging between 1700 and 5200. Under the same pin fin frontal area, the HTC and ΔP of air inside the plate square pin fin heat sink (PSPFHS) was higher than that from the plate circular pin fin heat sink (PCPFHS) by an average of 12.52 and 15.05%, respectively. The decrease of the S/Dp or S/Wp from 2.25 to 1.61 caused the augmentation of the HTC and ΔP of air flow inside the PPFHS by about 11.77%–17.17% and 46.61%–50.52%, respectively. The average thermal performance factors (TPF) were 1.32, 1.44, and 1.42 for PCPFHS, PSPFHS, and the plate 45° square pin fin heat sink (P45oSPFHS), respectively. The correlations for Nusselt number (Nu) and friction factor (f) were also proposed.

Correction to: Effects of random laminate misalignment on macroscopic and microscopic elastic/viscoplastic behaviors of ultrafine plate–fin structures

In this study, the effects of random laminate misalignment on the macroscopic and microscopic elastic/viscoplastic behaviors of ultrafine plate–fin structures are statistically investigated adopting Monte Carlo simulation. To this end, a multiscale method that analyzes the elastic–viscoplastic behavior of ultrafine plate–fin structures with random laminate misalignment both macroscopically and microscopically is proposed based on the homogenization theory for nonlinear time-dependent materials combined with the substructure method. Using the method, Monte Carlo simulations for elastic and elastic–viscoplastic behaviors of ultrafine plate–fin structures subjected to uniaxial tension or simple shear are performed for many cases of random laminate misalignment. The obtained results reveal that the random laminate misalignment affects the microscopic behavior of ultrafine plate–fin structures more than the macroscopic behavior; microscopic stress and viscoplastic strain exhibit considerable variability depending on the laminate misalignment, and their maximum values can become about 30–50% higher than those in the case without laminate misalignment. This suggests the importance of considering random laminate misalignment in the design and strength/life prediction of ultrafine plate–fin structures.

Numerical Analysis of Optimizing a Heat Sink and Nanofluid Concentration Used in a Thermoelectric Solar Still: an Economic and Environmental Study

In this paper, mathematical modelling is performed for a group of fins in a heat sink in order to determine the optimum dimensionless thickness of the fins using 8 different types of cooling nanofluids including nanoparticles of aluminium, alumina, titanium, titanium dioxide, copper, copper oxide, iron and iron oxide (hematite) with water as the base fluid in a thermoelectric solar still. The heat sink is used to enhance thermoelectric cooling and heating to water. The flow crossing fins is considered laminar and fully developed. Copper with high thermal conductivity is considered as the material of flat plate fins. Different nanofluids with volume fractions of 1%, 3%, 5%, 7% and 9% with a nanoparticle diameter of 25, 50 and 75 nm are analyzed for fins with rectangular cross sections. Besides, the economic and environmental analysis is conducted on the thermoelectric solar still. It is also observed that the range of 3.65% to 3.95% is obtained for the optimum volume fraction in the used nanofluids. The carbon dioxide mitigation based on the environmental parameter and exergoenvironmental parameters in the solar still is about 23.78 tons of CO2 and 1.04 tons of CO2, respectively.

Optimization of Inclination Angle of Cavity and Characteristics of Attached Fins on the Absorber for Performance Enhancement of Solar Collectors

This research investigation was undertaken in ANDUAT, Kumarganj, Ayodhya, Uttar Pradesh, India to study the numerical optimization of natural convection heat suppression in a solar flat plate collector with straight fins. Optimal characteristics of an array of thin fins attached on the absorber plat were obtained by Particle Swarm Optimization algorithm (PSOA). Free convection considered dominant in the cavity. Governing equations contained continuity; momentum and energy are discretized by finite volume method. The medium is considered incompressible, whose free convection is dominant and Boussinesq approximation is applied. A simplified model of real systems is applied with free convection. Free convection problem is solved by SIMPLER algorithm. Two confined cavities with aspect ratios 30 and 60 are considered as flat plate solar collectors. The results indicate that significant reduction on the free convection heat loss can be obtained from solar flat plate collector by using plate fins, and an optimal plate fins configuration exit for minimal natural convection heat loss for a given range of Rayleigh number. Reduction of up to a maximum of 25% at 0 inclination angle was observed in aspect ratio 30. Results showed PSOA is able to obtain characteristics of attached adiabatic fins on the absorber plate also it can obtain optimal inclination angle of cavity to decrease heat losses from solar collectors. The results obtained provide a novel approach for improving design of flat plate solar collectors for optimal performance.

Heat Transfer Enhancement of Indirect Heat Transfer Reactors for Ca(OH)2/CaO Thermochemical Energy Storage System

The efficiency of a thermochemical energy storage system can be improved by optimizing the structure of the thermochemical energy storage reactor. We proposed two modified structures for indirect heat transfer thermochemical energy storage reactors for a Ca(OH)2/CaO system to improve their heat transfer performance. Our results showed that improving convective heat transfer offered varying effects on heat transfer performance in different reaction processes. For a half-plate pin fin sinks (HPPFHS) reactor and a plate pin fin sinks (PPFHS) reactor, enhancing the convective heat transfer process could improve the heat transfer performance in the dehydration process for a porosity of 0.5, and the time needed to complete reaction was reduced by around 33% compared with plate fin sinks (PFHS) reactor. As for the hydration process, because heat conduction along the bed dominated heat transfer performance, this method had little effect. Furthermore, we found that enhancing heat conduction along the bed and convective heat transfer had different effects on reaction process at different reaction areas. The HPPFHS reactor had a lower pressure drop along the HTF channel and exorbitant velocity of heat transfer fluid (HTF) was unnecessary. Under the condition of the bed porosity of 0.8, due to the lower thermal conductivity of material, both modified reactor structures had little effect on dehydration. However, because the temperature difference between bed and HFT was bigger, the PPFHS reactor could reduce the time of completing the hydration reaction by 20%. Above all, when planning to modify the reactor structure to improve the heat transfer performance to enhance the reaction process, the heat conditions along the bed, convective heat transfer between HTF and the bed and material parameters should be considered totally.

Computational Investigation on Natural Convection Heat Transfer in Vertical Plate Fin Arrays

Objectives: To perform computational studies on different combinations of plate fin arrays of different shapes for studying their performance in natural convection heat transfer. To compare the heat transfer performance of uniform notched fins with hybrid notched fins and also performance of normal notched fins with inverted notched fins. Methods: SolidWorks Flow Simulation software is used for the present computational studies. Three types of vertical plate fin arrays viz. plain rectangular fin, rectangular fin with square notch and rectangular fin with semi-circular notch are used with their seven combinations. These fin array combinations are: plain rectangular, rectangular square notched, rectangular semi-circular notched, rectangular inverted square notched, rectangular inverted semi-circular notched, hybrid rectangular square-semi-circular notched and hybrid rectangular inverted square-semi-circular notched. Findings: The highest average heat transfer coefficient of 7.82 W/m2K is found to be for inverted hybrid square-semicircular notched fin array. This value of heat transfer coefficient is about 8% higher than compared to that with plain rectangular plate fin array (7.25 W/m2K) subjected to same operating conditions. Average heat transfer coefficients for inverted plate fin array combinations are high as compared with the non-inverted combinations. Also, hybrid plate fin arrays, whether inverted or not, show higher heat transfer coefficient values as compared with uniform notched fin arrays. Novelty : Seven types of plate fin array combinations are studied computationally. SolidWorks Flow Simulation software is used very effectively for this 3D CFD analysis. The behaviour of fluid i.e. air during natural convection flow is studied using air flow velocity trajectories. Surface contours are effectively used for studying variation in surface temperature and heat transfer coefficient at all locations of fin arrays. Keywords Natural convection, plate fin array, heat transfer coefficient, CFD, heat transfer enhancement

Experimental study of natural convection from vertical cylinders with branched pin fins

In this study, the natural convection heat transfer phenomena from vertical cylinders with branched pin fins are experimentally investigated. Experiments are conducted to measure the heat transfer rates from finned cylinders to the surrounding air at various cylinder wall temperatures, fin pitch angles, and fin heights. The experimental results indicate that the thermal resistance of vertical cylinders with branched pin fins is 20% smaller than that of conventional vertical cylinders with plate fins. The thermal resistance per unit fin volume of the former is 40% smaller than that of conventional finned cylinders. Moreover, a correlation for the Nusselt number is obtained from the calculated thermal resistance values. The error between the predictions from the correlation and experimental results is less than 20%. In addition, the effects of fin length and fin pitch angle on the thermal resistance are investigated using the proposed correlation.