Shell And Tube Heat Exchanger Research Articles

Comprehensive numerical investigation of the effect of various baffle design and baffle spacing on a shell and tube heat exchanger

This article explores the significance of Shell and Tube Heat Exchangers (STHX), with a focus on various baffle types such as Segmental, Double segmental, Helical, Disc-and-Doughnut, Clamping anti-vibration, and Flower-B. In this study, the commercial software ANSYS FLUENT is used to simulate the problem. The study evaluates their impact on heat exchanger performance using parameters like overall heat transfer coefficient (OHT), pressure drop (PD), and Performance Evaluation Criteria (PEC). Clamping anti-vibration, Flower-B, Helical, and Double segmental baffles exhibit reductions in shell side PD by 14%-28%. Despite OHT reductions in these designs, Disc-and-Doughnut baffles demonstrate a higher OHT (21%-24%) compared to Segmental baffles. Based on PEC values, Disc-and-Doughnut baffles are identified as the most favorable. Further investigation into different numbers of Disc-and-Doughnut baffles reveals increased OHT (17%-29%), PD (58%-59%), and cold water temperature (0.5%-1%). The STHX with Disc-and-Doughnut 10 baffles displays the highest PEC value, establishing it as the most effective STHX in the simulation.

Analysis of stream flow and its impact on thermal performance in shell-side of heat exchangers based on flow dead zone

The performance of shell-and-tube heat exchanger (STHE) is primarily determined by different flow paths on the shell-side. The flow path and its impact on the shell-side flow in segmental baffle shell-and-tube heat exchanger with clearance (SC-STHE) is investigated qualitatively and quantitatively, by adopting stream classification and dead zone analysis method. By utilizing Residence Time Distribution (RTD) curves, the influence of different streams on fluid flow and heat transfer is discussed to reveal the intricate interconnections within the shell-side of SC-STHE. Then the cases with baffle-tube clearance (0.2–1.0 mm) and baffle-shell clearance (1.0–5.0 mm) ranges are studied. The study identifies that optimal comprehensive performance is achieved with a baffle-tube clearance of 0.6 mm, resulting in a 3.5 % improvement compared to a clearance of 0.2 mm. An increase of baffle-shell clearance results in a reduction in comprehensive performance by 8.23 % to 19.54 %. The interactions among stream flows and potential mechanisms are discussed by analyzing the influence of each flow path on the flow dead zone volume. It is revealed that the presence of baffle-tube and baffle-shell clearances reduces the volume fraction of flow dead zones compared to structures without clearances. A-stream and E-stream are identified as pivotal, mutually influencing B-stream and C-stream while maintaining relative independence. The result indicates that an increase in baffle-tube clearance results in a 7.60 % expansion of the volume of the dead zone within the B-stream, while in the C-stream, it decreases by 2.58 %. Conversely, an increase in baffle-shell clearance reduces the volume of the dead zone in the B-stream by 5.04 % but increases it in the C-stream by 31.95 %. The flow dead zones are mainly distributed in the B-stream and C-stream regions, and the diversion effect of leakage flows improves the fluid stagnation but also leads to a decrease in turbulence intensity and flow velocity. This study reveals the complex interaction mechanisms among the stream flows, facilitating further analysis and optimization in STHE design.

An investigation shell and tube heat exchanger for cooling system: A case study of biodiesel plants using lauric acid

Shell and Tube Heat Exchanger (STHE) is a commonly used type of heat exchanger in various industries due to its cost-effectiveness and ease of maintenance. Continuous washing and maintenance of STHE play an important role in influencing both the quality and quantity of production from biodiesel plants. In this particular investigation, the STHE serves as a cooling medium for biodiesel production, with cooling water circulating on the tube side and biodiesel flowing on the shell side. This study focuses on removing silica crust buildup caused by cooling water in the Shell and Tube Heat Exchanger. Furthermore, a Clean-in-Place machine and a 10 % citric acid solution with variable washing times of 2 h, 4 h, 6 h, 8 h, 10 h, and 12 h were used for the cleaning process. The results indicate a significant 250 % increase in the volumetric flow rate of the cooling tower along with an increase in the overall Heat Transfer Coefficient after 10 h of washing. Further analysis at the hours mark showed consistent results, suggesting a steady state. Beyond this point, no additional temperature decrease was observed, with temperature stabilizing at 32 °C. The results of the Scanning Electron Microscope analysis show that the crust formed in the STHE comes from silica found in cooling water.

A meta-heuristic approach for reliability-based design optimization of shell-and-tube heat exchangers

This study introduces a new framework for optimizing Shell-and-Tube Heat Exchanger (STHE) layouts using a reliability-based design optimization (RBDO) approach. The framework combines a control variate-based surrogate model and a hybrid metaheuristic algorithm. The proposed hybrid algorithm, k-means clustering and whale optimization algorithm (kWOA), was evaluated using CEC’2020 and a case study for optimizing STHE design under static conditions. kWOA showed superior performance in minimizing STHE's total annual cost and solving benchmark functions effectively. In our case study, the RBDO framework optimized the STHE design under two scenarios with target failure probabilities of 1% and 5%, resulting in cost increases of 112% and 82%, respectively, compared to deterministic optimization (DO). The integration of the RBDO approach with the STHE mathematical model, considering factors like inlet flow temperatures, mass flow rates, and fouling resistance, demonstrated the framework's ability to balance the trade-off between cost and reliability under uncertainty. Hybrid control variate radial basis function (RBF) models and Monte Carlo Simulation (MCS) were used to assess safety levels, showing the RBDO framework's superiority in improving safety and significantly reducing failure probability from 89% to 1% and 5%. The RBDO framework offers a robust approach for designing STHEs that achieve optimal performance while ensuring high reliability under uncertain conditions.

Performance increasement in shell-and-tube heat exchangers reinforced with dimpled tubes: A correlation-based approach

Shell-and-tube heat exchangers (STHEs) are pivotal components in various industries, facilitating efficient heat transfer across fluid streams. The simulation of STHEs often demands a substantial number of computational cells, significantly when augmenting heat transfer surfaces by incorporating additional tubes or dimples. This study introduces a novel approach to mitigate the computational cost associated with STHE simulations. Correlations are designed to predict heat transfer within and outside the tubes, both in the presence and absence of dimples. These correlations are developed using the P-NTU thermal analysis method and a turbulence model that is carefully selected to align with the specific characteristics of STHEs. Following the validation of our approach, the correlations are applied to analyze the performance of various baffle arrangements within STHEs. Precisely, segmental, disk and donut baffle configurations, each featuring elliptical and teardrop dimples on the tube surfaces, are investigated. Furthermore, the impact of variations in shell and tube inlet mass flow rates on the overall performance of the heat exchanger is explored. The results reveal compelling findings. Elliptical dimples contribute to a remarkable enhancement in the performance evaluation criteria (PEC), yielding improvements of 36.7 % and 19.7 % for segmental as well as disk and donut baffle arrangements, respectively. Similarly, teardrop dimples exhibit their effectiveness, elevating the PEC by 51.5 % and 32.6 % in these same configurations under the specified working conditions. These findings contribute to the optimization of heat exchanger designs in diverse applications, fostering greater energy efficiency and environmental sustainability.

Hybrid optimization algorithm for enhanced performance and security of counter-flow shell and tube heat exchangers.

A shell and tube heat exchanger (STHE) for heat recovery applications was studied to discover the intricacies of its optimization. To optimize performance, a hybrid optimization methodology was developed by combining the Neural Fitting Tool (NFTool), Particle Swarm Optimization (PSO), and Grey Relational Analysis (GRE). STHE heat exchangers were analyzed systematically using the Taguchi method to analyze the critical elements related to a particular response. To clarify the complex relationship between the heat exchanger efficiency and operational parameters, grey relational grades (GRGs) are first computed. A forecast of the grey relation coefficients was then conducted using NFTool to provide more insight into the complex dynamics. An optimized parameter with a grey coefficient was created after applying PSO analysis, resulting in a higher grey coefficient and improved performance of the heat exchanger. A major and far-reaching application of this study was based on heat recovery. A detailed comparison was conducted between the estimated values and the experimental results as a result of the hybrid optimization algorithm. In the current study, the results demonstrate that the proposed counter-flow shell and tube strategy is effective for optimizing performance.

OPTIMIZATION OF SHELL AND TUBE HEAT EXCHANGER DESIGN WITH INCLINED BAFFLES

Shell and tube heat exchanger (STHeX) design development continues to be carried out to increase the effectiveness of a system. One way is to investigate the optimal baffle design. The new structure of STHeX with Inclined-Segmental Baffles is further investigated. The experiment was carried out using the numerical method Computing Fluid Dynamics (CFD) software with three-dimensional modeling. The results show that the heat change coefficient value is lower than conventional STHeX, However, the pressure drop value is reduced quite significantly. Therefore, it is necessary to know the overall heat transfer coefficient value per pressure loss (U/DeltaP). Hence, we get U/DeltaP values of 0.9 and 0.68 for STHeX with Inclined-Segmental Baffle and conventional STHeX, respectively. Thus, there is a significant increase ranging from 37-34%. It is concluded that STHeX with Inclined-Segmental baffles increases the U/DeltaP value significantly compared to conventional STHeX.

An innovative cost-effective numerical-analytical procedure to derive heat correlations for shell and tube heat exchangers equipped with smooth and dimple tubes

Nowadays, heat-exchangers in general and shell-and-tube heat-exchangers (STHEs) in particular have crucial influences on the performances of various industry processes. Apparently, the STHE designers wish to design STHEs with optimal performances under various operating conditions. Literature shows that previous research works relied entirely on either experiments or numerical simulations to calculate the hydrothermal performances of STHEs. Alternatively, this study introduces an innovative efficient procedure, which benefits from both numerical simulations and analytical approaches to accurately predict the STHE thermal performance at its wide ranges of proposed working conditions. This procedure involves three main steps. First, numerical simulations are utilized to develop accurate numerical-based correlations for both smooth and dimpled tubes for 3,000 < Re < 30,000 and 7 < Pr < 70 ranges. Second, the P-NTU analytical approach is used to construct a full STHE model based on its specific geometrical characteristics. Third, the developed correlations are suitably inserted in the P-NTU model to produce correlation for the entire STHE and calculate its thermal performance under various operating conditions. It is shown that the achieved results are as accurate as the experimental data. As the novelty, this study eliminates the need for expensive experimental setups and reduces the computational costs due to benefiting from analytical correlations. Since the present procedure is cost-effective, the designers are encouraged to design STHEs with more optimum thermal performances within their working condition ranges via suitable choices of various their design parameters, such as the tube type and size and the STHE general configuration. Fortunately, the present procedure can be similarly extended to design and optimize the thermal performances of other similar thermal equipment.

Power disassembly equipment for high efficiency heat transfer plate heat exchangers

Plate heat exchangers are realized by means of a heat transfer mechanism, in which heat is naturally transferred from the hot substance to the object with a lower temperature according to the laws of thermodynamics. Two liquids of different temperatures flow on the wall, heat transfer on the wall and convection of the liquid on the wall, thus promoting heat transfer between the two liquids. Under the same flow rate and power consumption conditions, its heat transfer coefficient is three times that of shell and tube heat exchangers, which is a key and efficient new equipment for effectively using effective resources and saving and developing new energy. However the heat supply plate heat exchanger has a tiny circulation surface and is easily obstructed. Regular maintenance and cleaning, troubleshooting, and plate replacement all necessitate frequent heat exchanger disassembly and installation. The requirements and challenges in dismantling and assembling the heat exchanger are very high, and manual disassembly is wasteful, making consistent force difficult to achieve. The current methods of disassembly and assembly are inefficient and incorrect. The intelligent mechanization of disassembly and assembly equipment is realized in this paper by driving, clamping, automatic control, distance measurement, sensing, and other systems. The problems of uneven force, low efficiency, and precision in plate heat exchanger disassembly and assembly are solved. Our power disassembly equipment for high efficiency heat transfer plate heat exchangers not only enhances disassembly efficiency and precision, but it also ensures the safe operation of the plate heat exchanger heating system, and the heat transfer efficiency and heat exchange efficiency are improved. Furthermore, it has a wide range of applications in the petroleum, chemical, and other industries.

Prediction model of a shell and tube heat exchanger based on the technique of artificial neural networks

The purpose of this paper is to report the proposal of a temperature prediction model methodology for a shell and tube heat exchanger using Artificial Neural Networks (RNAs). For the generation of the model, a set of historical data of five years was used, where 1633 readings from the equipment were obtained. The recorded data were the heat transfer coefficients and the fuel flow to predict the fluid temperature. The proposed methodology uses three stages. The first was the scaling of the data set between 0 and 1, this was done to facilitate the training of the RNA model: The second was to apply data mining techniques to create data clusters to model the behavior of the heat exchanger. The last stage was the evaluation of the prediction models. 5 proposals for Neural Network models were evaluated, these used 10 neurons in the hidden layer, the main difference between them was the number of clusters used in the training data that increased one by one. The average training errors obtained by the four types of data pools were 0.00220, 0.00190, 0.00133, 0.00098, and 0.00080. According to the results obtained, it was possible to conclude that the model that uses a greater number of clusters has a lower prediction error.

Study of fatigue fracture characteristics for duplex stainless steel STHE welded joint specimen

A shell and tube heat exchanger (STHE) welded joint is considered for fatigue fracture mechanism. The joint is made up of a protruding tube fabricated to a tubesheet by means of welding. A super duplex stainless steel (DSS) material is used for the tube and tubesheet. Fatigue test was newly conducted using the single tube test specimen. The initial cracking plane was moved from the minimum sectional-area plane that was perpendicular to the loading direction, and the crack growth was almost planar. Stress analysis is carried out using finite element method (FEM) and the stress distributions are carefully studied by comparing the simple perforated plate. In addition, three-dimensional crack propagation (CP) simulation is performed employing extended finite element method (X-FEM). Fracture phenomenon is verified using the experimental and numerical crack front geometries. The fracture mechanics parameter is evaluated and verified with empirical formulae. CP behaviors are carefully discussed based on the fracture mechanics parameter. The CP life is presented for three loading amplitudes. The FAT class of the STHE welded joint is studied based on the available design standards such as BS, IIW and JSSC. Finally, the fatigue fracture characteristics of the STHE welded joint specimen are shown through the experimental and numerical methods.

Thermo-hydraulic efficiency enhancing: Optimized ladder fold baffle structure with cam and circle tube bundle

In this article, the design and thermo-hydraulic efficiency of a shell and tube heat exchanger (STHE) having ladder fold baffle equipped by two configurations with pore and without pore considering two types of tube bundles, cam and circular, are investigated numerically. Three-dimensional STHE is simulated employing the Solid Works Flow Simulation software. A numerical approach is performed for different values of mass flow rate from 0.5 to 2 kg/s, baffle height of 0, 20, and 40, and baffle pitch of 85.7, 60, and 46.15. STHE pressure drop, heat transfer, and efficiency evaluation coefficient (EEC) for different arrangements have been performed to study the STHE fluid flow and heat transfer. Obtained results for a ladder fold baffle and two studied types of tube bundles, cam, and circle, are provided, and thermo-hydraulic performance is compared with the current baffle structure. Based on the obtained results, an increase of 12.2% and 17.4% in pressure drop with increasing baffle height from 0 to 20 mm and from 20 to 40 mm was observed for circular tube bundles without pores, respectively. Related values for the case with pore are 14% and 14%. These values for the cam tube bundle are 12% and 15% without pores and 3% and 9% with pores. In addition, at an angle of 0, 20, and 40° in the case without pore, the EEC factor increased by 2.31%, 15.67%, and 15.47% compared to the case with pore for the cam tube bundle. The perforated ladder fold baffle showed the best performance with pitch and height of 85.7 mm and 40 mm, respectively.

Numerical Simulation of Thermo-hydraulic Behaviour of Shell and Tube Heat Exchanger Equipped with Segmental Baffle and Helical Baffle

The baffle type and structure are critical to enhancing the comprehensive thermo-hydraulic behavior of shell-and-tube heat exchangers (STHX). In the study, Solidworks software was used to establish three-dimensional mesh models of STHX equipped with the segmental baffle and the continuous helical baffle, respectively. ANSYS software was adopted to study the effects of the baffle type and the baffle geometric parameters on the thermo-hydraulic characteristic of STHXs using the pressure drop of the shell side, the coefficient of heat transfer and isobaric JFP factor as the evaluation characteristics. For segmental baffles, better thermo-hydraulic performance could be obtained with a baffle spacing of 200 mm and a gap height of 0.4 D. For helical baffles, an optimized thermo-hydraulic performance could be obtained with a baffle pitch of 150 mm. By comparing the comprehensive thermo-hydraulic performances of STHXs equipped with two different baffles, it could be concluded that the isobaric JFP factor of STHX equipped with the helical baffle was 1.18 times that of STHX equipped with the segmental baffle under the different suitable flow rate.

Numerical assessment of hydraulic behavior and thermal efficiency of multiphase hybrid nanofluid in a shell-and-tube heat exchanger with inclined baffles

Improving the thermo-hydraulic performance of shell-and-tube heat exchangers (STHE) has always been the focus of researchers due to their wide applications in recent decades. This numerical study investigates the hydraulic behavior and thermal efficiency of turbulent multiphase flow of Fe3O4−MWCNT/water hybrid nanofluid (HN) in a shell-and-tube heat exchangers (STHE). The Reynolds number (Re) is 5000, 7500, 10000, and 12500 and the volume fraction of nanoparticles (φ) is 0, 2, and 4%. Numerical simulations are conducted using the k-ε turbulence model, two-phase mixture model, finite volume method (FVM), and PISO algorithm. The maximum value of the friction coefficient (FC) is 1.45, which corresponds to a baffle angle of 180º, φ = 4%, and Re = 5000. As the baffle angle is enhanced, the value of the average Nusselt number (Nuave) is intensified for all cases. The maximum value of the performance evaluation criteria (PEC) is about 1.55, which is related to a baffle angle of 180º and Re = 7500. For all the examined situations, the value of PEC is greater than one, indicating the effectiveness of the application of nanofluid and baffles at different angles. Hence, it is recommended to utilize baffles. The maximum value of thermal efficiency is about 37%, which occurs when the baffle angle is180º, φ = 4%, and Re = 5000.

An improved equilibrium optimizer for numerical optimization: A case study on engineering design of the shell and tube heat exchanger

The accurate design of the shell-and-tube heat exchanger (STHE) model is crucially important for industries such as process industries, oil refining, thermic devices, and power plants. However, determining its parameters is a challenging task due to the multimodality and nonlinearity of the cost function. Due to such nature, performing algorithms face the challenges of sluggish convergence speed and the proneness to local optima, making it difficult to reach satisfactory solutions. In line with the above challenges, this paper aims to contribute by developing an improved optimization algorithm that can effectively deal with such optimization issues. The proposed algorithm, named Levy-Opposition- Equilibrium Optimizer (LOEO), combines the Equilibrium Optimizer (EO) and the strategies of opposition learning (OL) and Levy flight learning (LFL) to overcome the dilemma of early convergence and getting trapped in local optima. It does this by employing the OL and LFL strategies after performing the EO phase to explore the search space in opposite directions and exploit the search space by means of the Levy distribution pattern, respectively. The proposed LOEO approach aims to enhance the algorithm's ability (provides enhanced exploration capability, effective search space exploitation, and enhanced convergence speed) and reach higher quality solutions to optimization problems. To assess the performance of the suggested LOEO, three stages of analysis are carried out. In the first stage, the performance of the proposed algorithm is investigated on some benchmark problems, including CEC 2005 and CEC 2020, using statistical verifications, convergence behavior, and the boxplot paradigm. The second stage involves the non-parametric Friedman test to assess the significance of results, where the results indicate that the LOEO outperforms the best existing one (equilibrium whale optimization algorithm (EWOA)) by an average rank of the Friedman test greater than 28% for CEC 2005 benchmark functions while outperforming enhanced EO (EEO) by 24% for CEC 2020. Finally, the LOEO's applicability is realized through determining the optimal design structure of the STHE model. The reported results indicate that the LOEO algorithm offers accurate performance compared to competing algorithms as it saves the cost of the device by 39.81% compared to the best existing results, and thus, it is commended to adopt for new applications.

Exergy and Energy Analysis of the Shell-and-Tube Heat Exchanger for a Poultry Litter Co-Combustion Process

Increasing production of poultry litter, and its associated problems, stimulates the need for generating useful energy in an environmentally friendly and efficient energy system, such as the use of shell-and-tube heat exchangers (STHE) in a fluidized-bed combustion (FBC) system. A holistic approach which involves the integration of the First Law of Thermodynamics (FLT) and Second Law of Thermodynamics (SLT) is required for conducting effective assessment of an energy system. In this study, the STHE designed by the CAESECT research group, which was integrated into the lab-scale FBC, was investigated to determine the maximum available work performed by the system and account for the exergy loss due to irreversibility. The effects of varying operating parameters and configuration of the space heaters connected to the STHE for space heating purposes were investigated in order to improve the thermal efficiency of the poultry litter-to-energy conversion process. Exergy and energy analysis performed on the STHE using flue gas and water media showed higher efficiency (75–92%) obtained via energy analysis, but much lower efficiency (12–25%) was obtained when the ambient conditions were factored into the exergy analysis, thus indicating huge exergy loss to the surroundings. From the obtained experimental data coupled with the simulation on parallel arrangement of air heaters, it was observed that exergy loss increased with increasing flue gas flow rate from 46.8–57.6 kg/h and with increasing ambient temperature from 8.8 °C to 25 °C. To lower the cost of STHE during final design, a larger temperature difference between the hot and cold flue gas is needed throughout the exchanger, which further increases the exergetic loss while maintaining an energy balance. In addition, this study also found the optimal conditions to reduce exergy loss and improve energy efficiency of the designed STHE. This study shows the possibility to evaluate energy systems using integration of exergy and energy analysis.

Numerical investigation of tubeside maldistribution in shell-and-tube heat exchangers

Shell-and-tube heat exchangers (STHE) are widely used in the process and energy industry. Maldistribution and the often resulting fouling in these STHE cause additional energy consumption and lower production throughput. Increased average wall shear stress, compared to that of the maldistributed case inside the tubes is expected to mitigate fouling. This can be achieved by a uniform distribution into the tubes. Field and laboratory data suggest that common crude oil fouling is profoundly mitigated above 10 Pa and is significantly reduced above a wall shear stress of 15 Pa [1]. Many STHE already have lower design shear stresses than those mentioned. Therefore, if maldistribution takes place, tubes with less flow velocity will have even more fouling. To investigate tubeside flow maldistribution, a parametric STHE model is studied with computational fluid dynamics (CFD). At first, a comparison between the standard k-ϵ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\epsilon$$\\end{document}-model and the new standard SST-model is performed to check if SST could provide improved simulation results. Afterward, a range of geometrical parameters will be investigated to find influencing quantities of maldistribution. The resulting velocity distributions are visualized and evaluated by using different statistical approaches. At least, a sensitivity analysis will be done to show how each parameter influences the tubeside flow distribution in STHE.

Investigation of a falling film tube bank heat exchanger with baffle design for water recovery applications

Shell and tube heat exchangers (STHE) are essential thermal equipment and widely used in daily life. A novel thermosyphon system called falling-film thermosyphon (FFTS) is introduced and integrated into STHE system, resulting in a better thermal performance. In this study, a rectangular solid tube bank of FFTS bundles with a baffle design is studied. The numerical simulation for heat and mass transfer of the FFTS heat exchanger is developed to predict the condensation rate of the vapor in the flue gas, and a lab-scale prototype is also built up in COMSOL. The prediction is validated with the experimental data from references, and the model's accuracy is verified within 10%-12% error. Also, the Non-dominated Sorting Genetic Algorithm, version 2 (NSGA-II) is implemented to improve the thermal performance of rectangular tube banks in this paper. Several parameters, e.g., baffle number, tube number, and tube space, are optimized. As a result, compact configurations with more baffles are preferred to enhance the performance associated with a high-pressure drop correspondingly. The optimized layout for the lab-scale prototype can increase by 18 to 32% condensation with a pressure loss of less than 200 Pa.

Experimental investigation of heat transfer characteristics for a shell and tube heat exchanger

Abstract In the present work, numerical investigations are conducted with 22 % cut segmental baffle heat exchanger (SB), 20°, 30°, and 40° helical baffles shell and tube heat exchangers (STHX) to estimate the overall heat transfer coefficient (OHTC), pressure drop (PD) and friction factor. Among the studied heat exchangers (HE), 40° helical baffles STHX provided the highest OHTC with minimum pressure drop. Hence, further investigations are conducted experimentally with 40° helical baffles STHX. OHTC increased by 2.65 % for 20° helical baffles, 5.37 % for 30° helical baffles, 9.78 % for 40° helical baffles when compared with 22 % cut segmental baffle heat exchanger. The deviation between experimental and numerical OHTC is 2.64 % 40° helical baffles.

Thermal performance enhancement of energy storage system using spiral-wired tube heat exchanger

ABSTRACT A well-design latent heat storage system substantially increases the acceptance and reliability of renewable energy resources and makes them available permanently. For this purpose, there are many ways to enhance the thermal performance of the latent heat storage system. In this work, it is suggested to use the spiral-wired tube, a finned tube with a coiled helical spiral connecting the fins end. The study includes a comparison between three different models of storage systems: shell and tube heat exchanger (STHX), shell and finned tube heat exchanger (SFTHX), and shell and spiral-wired tube heat exchanger (SSWTHX). The proposed models are designed and tested experimentally, and three-dimensional CFD models are developed based on the enthalpy-porosity method. The results proved that the sequence of the three models in terms of melting speed was SSWTHX, SFTHX and STHX, respectively. The distinctive design of SSWTHX improves heat transfer and thus improves the performance of the latent heat storage system. The change in the distribution of paraffin temperature was faster in SSWTHX, which gave the highest temperatures, and accelerated the melting process by 37.5% compared to STHX. While the melting time reduction of SFTHX compared with STHX reached 21.3%. There was a good agreement when the numerical results were compared to the experimental data.