Counterflow Conditions Research Articles

Optimizing Minichannel Heat Sink Design: A Combined Numerical and Experimental Analysis of Inlet/Outlet Configurations and Pin Fin Enhancements

ABSTRACTThe present study investigated the effect of inlet location, counterflow and parallel flow configurations, and rib addition (pin fins) on the performance factor of minichannel heat sinks. Different rib spacings were investigated in Models D, E, and F, which are 5, 7, and 9 mm, respectively, all using counterflow. These models used ribs with a diameter of 1 mm. In addition, Models G and H were presented to explore different rib sizes (1.5 and 2 mm) while maintaining a rib spacing of 5 mm under counterflow conditions. All effects were studied numerically using ANSYS Fluent 19R3 under laminar coolant flow, with Reynolds numbers ranging from 1190 to 1900. The study also included fabricating two models: the conventional model and the optimized model, and comparing their results with the numerical results. The comparison indicated a satisfactory convergence between the experimental and numerical results. The results revealed that all modifications significantly improved the temperature distribution and overall performance factor (OPF). Model B outperformed the conventional model in terms of pressure drop and heat resistance, achieving improvements of 46% and 40%, respectively. Furthermore, Model D outperformed Model B in Nusselt number by 31.375%. Notably, Model D showed the highest OPF and most consistent core temperature among the models, confirming its status as the ideal design, with an OPF of 2 compared with the conventional model.

Comparative Study of Thermal Criteria and Fluid-Flow Criteria in Micro and Mini Channel Design Constrains with or without Insert Made of Aluminum Material

Through experimental and simulation results, a comparison between mini and micro channels with inserts or without inserts is conducted; in this case, water is the only working fluid used for present experimentation. In order to research the fluid flow and micro channel features, the results of fluid flowing inside the mini channel and micro channel with insert or without insert separately were admitted. Experiments were performed for various operating and design parameters under counter-flow conditions, with hot water moving into a concentric tube with a 30 mm diameter at 0.00078 kg/sec flow rate. The fluid is moving separately through mini channels with a 2 mm diameter and micro channels with lower than 1 mm dia. at a varying flow rate 0.00015 kg/sec to 0.0062 kg/sec. The working temperatures for hot water and cold fluid were 323 K and 303K, respectively. According to the results, the suggested design of the micro channel with insert performed better than a conventional mini channel, micro channel without insert and mini channel with inserts due to the better thermal conductivity of the aluminum material, effective diameter (1mm) to length ratio of micro channel in which heat exchanges with minimum volume ratio and the additional exposed area made possible by the rectangular shape of the insert, whereas micro channel with micro insert having rectangular shape showing best results as compared with the other designs of channel due to the rich heat passage and effective pressure drop and temperature. Experimentation and simulation results are coming in positive direction, it is directly observed from the error percentage i.e. 2.41% to 4.29%.

Thermal efficiency evaluation in shell-and-tube heat exchangers: A CFD-based parametric study

In this study, a novel approach was employed to enhance the performance of a Bowman brand EC-2028 shell-and-tube heat exchanger (STHE) by introducing perforated plates. The heat exchanger was first tested in a real system within a laboratory environment to establish baseline performance data. Computational fluid dynamics (CFD) analysis revealed that flow velocities in the middle tubes were higher due to their alignment with the main flow direction, resulting in decreased heat transfer efficiency. To address this issue, a perforated plate with concentric circles was introduced at the cold fluid entry. This plate, devoid of central holes, featured circles with radii of 9, 18, 27, 36, 45, 54, and 63 mm, each containing 6, 10, 17, 24, 30, 36, and 42 equidistant holes, respectively. The introduction of the perforated plate led to a decrease of approximately 0.33°C in the hot outlet temperatures, indicating an improvement in heat transfer efficiency. To further enhance performance, various configurations were tested by progressively closing holes from the innermost to the outermost circles. Eight different configurations, including the control, were evaluated under counterflow conditions. The CFD model was validated with experimental data before introducing the perforated plates, ensuring the accuracy of the simulations. The findings demonstrated significant improvements in heat transfer efficiency, with the optimized perforated plate configurations leading to more uniform flow distribution and reduced pressure drops. This study's novel approach of using perforated plates to modulate flow and enhance thermal performance highlights a new avenue for optimizing STHE designs, contributing to more efficient thermal management solutions in industrial processes.

Impact of Nanoparticles in Water Coolant on Heat Transfer Rate in Parallel and Counter Flow Heat Exchanger

A heat exchanger is a device used to transfer heat between two or more fluids. The fluids can be single or two phases depending on the exchanger type and may be separated by in -direct contact (the two most common kinds of heat exchanger are the shell-and-tube and plate/fin). In this research work double pipe heat exchanger was used to analyze the performance of water coolant for industrial applications. In Heat Exchanger the water coolant temperature increases due to increase in the temperature of oil in the tubes. Therefore, it may decrease the overall efficiency of the equipment resulting from degradation of the lubricant oil. In this regard, it is required some additives to be mixed with water coolant so that to enhance the heat transfer rate of the unit. Due to the excessive heating of the hydraulic oil in the turbine bearings, the material of the bearing found damage and deteriorate. Therefore, the aim of this study was to remove the heat from bearing oil, so that overall efficiency of heating equipment could be increased. In this research work Hydraulic oil was heated at 600C and 700C as per requirements of the industry. The experiments were conducted at both parallel and counter flow directions. Initially, a baseline experiment was carried out between hot oil and water coolant (without additives or nanoparticles). Besides the heat transfer rate between hot oil and water coolant with the additives (CuO and Al2O3) were observed at 1-3% proportion. It was concluded that the heat transfer rate of CuO was increased more than Al2O3 and plain water coolant due to more uniform temperature difference maintained between the inlet and outlet of cold and hot fluids due to the higher thermal conductivity of CuO. The maximum heat transfer rate was found to be 36.6 % at 60℃ and 38% at 70℃ with 3% of CuO additive in water coolant in the counter-flow condition.

Employing uniform and non-uniform inner twisted elliptical tubes in a double-pipe heat exchanger

Turbulent hydrothermal characteristics in a double-pipe heat exchanger with an internal twisted elliptical tube (TET) are investigated. The impacts of aspect ratio (AR = 1.4–2), uniform twist pitch (p = 100 mm-400 mm), and non-uniform twist pitch (five cases) on flow stream characteristics and heat transfer of parallel and counter-flows are investigated numerically. Utilizing a TET with a non-uniform twist pitch as an innovative approach yields noteworthy results, particularly in contrast to the traditional use of TETs with uniform twist pitch, owing to the longitudinal asymmetry. The outcomes depict that the pressure drop and heat transfer augment as the uniform twist pitch declines and the AR rises. The counter-flow has a more significant average Nusselt number than the parallel-flow by about 2–4 % without increasing the friction factor. Still, in some cases of non-uniform twist pitch, the average Nusselt number of the parallel flow is even 4 % higher than the counter-flow. The case with p = 100–200–400 mm (three parts with various twist pitches) and parallel-flow exhibits the most significant performance evaluation criterion (PEC) among the non-uniform twist pitch. As the aspect ratio increases from AR = 1.4 to AR = 2, the PEC factor in the counter-flow mode increases; however, there is an out-of-trend point at AR = 2 for the parallel-flow mode. The PEC factor augments about 8.47 % and 6.16 % for the counter-flow and the parallel-flow modes, respectively. The growth of TET twist pitch by 300 % reduces PEC by about 13.3 % in the counter-flow. The most significant PEC value is 1.166, which belongs to the case with the counter-flow condition and p = 100 mm.

An Experimental Investigation of the Effects of Using Hexagonal BN–Water Nanofluids on the Thermal Performance and Pressure Drop of a Concentric Tube Heat Exchanger

The thermal conductivity of recently produced hexagonal boron nitride (hBN)-containing nanofluids is comparatively higher than their viscosity, indicating that these materials belong to a relatively novel class. In this study, hBN–water nanofluids in stable and dispersed concentrations were used in parallel and counterflow experiments at volumes of 0.01%, 0.1%, and 1%, as well as at various flow rates and Reynolds numbers. When employing hBN–water nanofluid in a counter-flow heat exchanger instead of distilled water, the results showed a 16.7% increase in the overall heat transfer coefficient. The findings also showed that, in comparison to a counter-flow heat exchanger, employing hBN nanofluid as the cold fluid in a parallel-flow heat exchanger produced superior results in terms of an increase in heat transfer. The effects of nanofluid concentration on pressure drops were investigated through experiments conducted in both parallel- and counter-flow conditions.

Performance evaluation of turbulent circular heat exchanger with a novel flow deflector-type baffle plate

Experiments were conducted to investigate the performance of an axial flow tubular heat exchanger with a novel swirl flow of air created by the addition of circular baffle plates featuring trapezoidal air deflectors with various inclination angles. The tubes remained in identical longitudinal arrangement and maintained constant heat flux over their surface. Each baffle plate contained four deflectors with an equal inclination angle, generating an air swirl inside the circular duct containing the heated tubes that improved the air-side turbulence and thus the rate of heat transfer from the tubes' surfaces. The pitch ratio of the baffle plates was varied, and the Reynolds number was kept in the range of 16000–28000. Results from the study showed an average 7.4% improvement in performance enhancement criteria when the exchanger was fitted with a baffle plate featuring a deflector inclination angle of 30° and operated under counter flow conditions when compared to a parallel flow arrangement operating under similar experimental conditions.

Comparative analysis of fluid flow in mini channel with nano fluids and base fluid

Comparative study is carrying out between nano fluid Al2O3 + CuO + ZnO + H2O and water as solitary fluid through experimental and simulation result. The outcome of nano fluid and solo base fluid H2O flowing in middle rectangular mini channel with or without insert were admit, for study the conduct of fluid flow and heat exchange features. During composing of nano fluid 0.05%-0.1% volume fraction, 10–20 nm size nano particles were mixed with 0.5 ml CTAB surfactant. Experimentation were manage for different operating parameters under counter flow conditions, where nano fluid is flowing inside mini channel of 2 mm diameter with flow rate 0.0001562 to 0.006255 ml/min and hot water is flowing inside the concentric tube of 3.6 cm diameter with flow rate of 0.000782 ml/min. The operating temperature of nano fluid and hot water were 308 K and 323 K. As per obtained results, the proposed composition of nanofluid showed better performance than normal water due to better thermal conductivity and extra molecular area gain in nanofluid due to addition of nano particle with base fluid, where as better optimum results were observed in case of rectangular mini channel with macro insert compared with other geometry because of rich turbulency gain and extra exposed area due to macro insert.

Experimental and CFD analysis of fluid flow in rectangular strip based micro channel with nano fluid

Comparative analysis is conducted between nano fluid Al2O3 + CuO + H2O and water as basic fluid through simulation technique and validate it through experimental result. The effect of nano fluid (NF) and water were acknowledge which were flowing inside rectangular shape micro channel (RSMC) internally and externally time to time as per decided experiment sets with or without rectangular-strip micro-insert (RSMI), for observing the fluid flow behaviour, heat transfer attributes and performance characteristics. During preparation of nano fluid 0.05% − 0.1% volume fraction (vol.%), 10–20 nm size nano particles (NP) were taken with 0.5–0.75 ml CTAB as surfactant. Experimentation were conducted for diverse operating condition/parameters under counter-flow conditions, where NF is moving inside micro channel of less than 1 mm diameter having flow rate 0.0001562 to 0.006255 kg/sec. Hot fluid as water is moving inside the concentric-tube of 3.6 cm diameter with flow rate of 0.000782 kg/sec. The operating temperature of NF and hot fluid as water were 308 K and 323 K. As per observation, the results of proposed samples of NF with 0.1 vol% showed better performance than 0.05 vol% NF and water. It happens due to higher rate of thermal-conductivity achieved because NF gain extra molecular area with an addition of diverse NP with base fluid, where as better optimum results were observed with an enhancement of 8%-9% in case of RSMC with micro insert (M.I.) compared with other geometric model because high turbulency received due to extra-exposed area of M.I.. A close error percentage near about 4–5% was developed between experimental and simulation work. Thus it validates the present investigation.

Numerical investigation of the effect of hot-water outlet inclination angle on the temperature dilution in open channel flow

In this study, the authors investigated the environmental impact of discharging hot water from a thermal power plant into a water source for cooling. Three hundred forty-three runs using two-dimensional numerical ANSYS Fluent simulation model with (k- ε) turbulence model and open channel flow characteristics was applied in this research. The single port submerged discharge inclination angle was studied with different scenarios for the hot-water outlet (velocity and temperature) to determine the optimum inclination angle to increase cooling system efficiency and reduce hot water's environmental impact. It was discovered that by increasing the inclination angle and velocity of the hot-water outlet, the efficiency of cooling system is increased, as it increased the dilution of the hot water and reduced its environmental impact. Specifically, inclination angle of 15° increased the dilution by 80% and 86% in x and y directions, respectively compared to angle 90°. Additionally, the temperature variation in water body induced by hot-water outlet was reduced by counter flow at angle −15°. The velocity profile showed a recirculation region at the right side of the hot-water outlet, which was reduced at higher inclinations. A mathematical equation was developed to estimate the temperature value in the open channel water body based on the study parameters. Overall, the study found that increasing the inclination angle of the hot-water outlet can significantly improve the cooling system's efficiency and reduce the environmental impact of the hot water discharge. Counter flow conditions were unsuitable because they have less dilution than the normal flow conditions.

Experiment-based simulation of a cross-flow large-scale SOFC model

The multi-physical field full-coupling simulation of solid oxide fuel cell (SOFC) stack requires huge computational resources. Repeated iteration of highly non-linear calculation is easy to cause oscillation and lead to solution failure. At present, the simulation of SOFC stack models mainly focuses on the co-flow condition and counter-flow condition models. Most of them are simplified models that simplify the stack scale or physical field. In this paper, a SOFC decoupling model based on machine learning is established, and the full three-dimensional and multi-physical fields of the cross-flow large-scale SOFC stack are simulated. The model is divided into three parts for calculation, unit cell model, alternative mapping model, and cross-flow large-scale SOFC stack model. The alternative mapping model obtained by the BP neural network algorithm replaces the nonlinear multi-physics equations in the traditional model. Compared with the traditional method, the decoupling model can greatly reduce the computing resources and improve the stability of computing. In this paper, the experimental data of the single cell and the 30-layer stack are used to calibrate and verify the simulation results of stack. Studying the performance of the SOFC stack under different parameter conditions. Temperature, flow uniformity, gas mole fraction, and voltage distribution in the SOFC stack under different inlet flow rates and stack currents are obtained. Obtaining the output power and fuel utilization rate of the stack under different working conditions.

Heat transfer enhancement of water-cooled triply periodic minimal surface heat exchangers

Whether triply periodic minimal surface (TPMS) heat exchangers are applicable to cooling or cold storage systems as a cooler for supercritical carbon dioxide (SCO2) is undocumented. Here the conjugated heat transfer of SCO2 in TPMS Schoen-G heat exchanger and printed circuit heat exchanger (PCHE) was predicted based on three-dimensional steady turbulent Reynolds-averaged Navier-Stokes equations, energy equation and shear stress transport model using computational fluid dynamics software ANSYS CFX when SCO2 inlet temperature and pressure vary in 65–30 ℃ and (8–9)MPa. SCO2 in two heat exchangers is cooled under counter-flow conditions by a stream of cold water with given inlet temperature and mass flow rate. It was shown that the mean heat transfer coefficient of SCO2 in TPMS Schoen-G heat exchanger is larger than PCHE. As the inlet pressure rises, the friction factor increases and Nusselt number decreases in the heat exchangers due to decreased Reynolds number and Prandtl number, respectively. The friction factor ratio, Nusselt number ratio and performance evaluation criterion vary in the range of 0.38–0.50, 1.07–1.49, and 1.45–2.04 with Reynolds number and inlet temperature when the PCHE serves as a reference heat exchanger. The streamlines in TPMS Schoen-G heat exchanger are quite smooth even though the areas with a higher velocity appear. The streamlines in PCHE exhibit a spiral flow pattern to result in extra hydraulic loss. The heat transfer enhancement of TPMS Schoen-G heat exchanger is much better TPMS Schwarz-D heat exchanger at a Reynolds number higher than 16,000. The enhancement is attributed to a larger heat transfer surface area and more topological tortuosity without flow separation than PCHE.

Evaporative pre-cooling of a condenser airflow: investigation of nozzle cone angle, spray inclination angle and nozzle location

ABSTRACT In hot and dry areas, evaporative cooling can enhance the performance of air-cooled condensers. Pre-cooling of a condenser airflow in a channel by a spray nozzle has been studied numerically. The Eulerian-Lagrangian 3D equations for two-phase flow have been discretized using the finite volume method. An experimental setup has been prepared to validate the numerical model. The effects of nozzle cone angle, spray inclination angle, and nozzle location in the channel have been investigated on the outlet air temperature, droplet evaporation rate, and spray cooling efficiency. The results represent that, between four analyzed geometrical parameters, nozzle longitudinal location is the most important parameter and the spray inclination angle has the lowest degree of importance. Spray inclination angle analysis displays that the counter-flow condition of the nozzle is more efficient than co-flow and cross-flow conditions. The case with the nozzle height of 45 cm in the duct, spray inclination angle of 180 ∘ , and nozzle cone angle of 60 ∘ is the best case. The maximum and minimum spray cooling efficiencies among the cases are about 30.5% and 21%, respectively. Hence, the nozzle geometrical parameters can affect the evaporative cooling capacity up to 45%.

Heat transfer analysis of double tube heat exchanger with wavy inner tube

The effect of the design on the heat transfer is numerically investigated by using the wavy inner tube in a double-pipe heat exchanger. A wavy inner tube was used in the design to give a turbulent effect to the fluid along the inner tube of a double tube heat exchanger. In numerical study, ANSYS 12.0 Fluent code program was used, and the basic protection equations were solved for steady-state, 3-D and turbulent flow conditions. The study was examined at Reynolds numbers ranging from 2700-5300. The obtained results were compared with the experimental data performed under the same conditions. As a result of this comparison, after it was seen that the results obtained from the numerical analysis and the experimental results were compatible with each other, the wave number of the inner tube was increased and analyzed with the ANSYS fluent code program. When the data obtained as a result of the analyzes were evaluated, it was seen that the highest heat transfer was obtained from the 16 wave tube heat exchanger, which has the highest number of waves and under counter flow conditions. The increase in heat transfer increased by 270% compared to the straight tube.

Thermal and electrical performances of actively cooled concentrator photovoltaic system

• Reliable thermal management for CPV is mandatory for efficient/safe operation. • 3D heat transfer/thermal model for DL-MCHS coupled with CPV layers are developed. • Including and ignoring the header of DL-MCHS is considered in the simulation work. • Without headers, CPV/T system attained a lower average and local cell temperature. • With headers, electrical efficiency is improved while pumping power is augmented. The double-layer microchannel heat sink (DL-MCHS) is commonly applied for thermal management of high heat flux surfaces, including electronic chips and concentrator photovoltaic (CPV). However, most of the recent studies neglected the header effect in the simulation of the DL-MCHS. The current study compressively investigated the impact of considering the inlet and outlet headers on the CPV systems' performance. A three-dimensional conjugate heat transfer model of the fluid flow in the DL-MCHS coupled with the CPV layers' thermal model was employed. The thermal performances of DL-MCHS with and without considering the headers were evaluated. Parallel flow (PF) and counter flow (CF) conditions at a solar concentration ratio ( CR ) of 20 suns were studied. The results showed that the header section should be considered in the numerical model for obtaining a more realistic average and local silicon layer temperature profile, especially in the CF operation. For instance, the difference in solar cell temperature between including and ignoring the header section is about 13.86 K for CF operation at CR of 20 and 200 ml/hr coolant flowrate. The predicted pumping power and net gained electric power were also significantly affected by neglecting the headers in the numerical modelling. The electrical efficiency deviation reached about 23.5% at CF, while PF reported almost 4.0%.

Effects of flow pattern and hydrogen recirculation on consistency of current density distribution in a self-humidified polymer electrolyte membrane fuel cell analyzed by a segmented model

Distributions of water and oxygen concentration are the two main factors that influence the consistency of current density in a polymer electrolyte membrane fuel cell. While the former type is relevant to the ohmic loss, the latter one associated with the mass transfer loss. In a self-humidified condition, higher demand for water management is requested as membrane drying often appears. To investigate the effects of flow pattern and hydrogen recirculation on the consistency of current density, the cell is tested under five different conditions, and a quasi-three-dimensional transient non-isothermal model is developed to explain different experimental phenomena in this study. Differences of distributions of current density, resistance and reaction gases are examined by comparing co-flow with counter-flow conditions, humidified with self-humidified conditions and dead-ended anode with hydrogen recirculation conditions. The results show that consistency reduces with the cell current density increasing, and gas humification is significantly beneficial. In co-flow configurations, the standard deviation of local current density increases from 0.02 at 0.2 A cm−2 to 0.14 at 1.2 A cm−2 under the humidified condition, increasing from 0.38 at 0.2 A cm−2 to 0.26 at 1.2 A cm−2 under the self-humidified condition. The water distribution of the cell in counter-flow configuration is more uniform than that in the co-flow configuration under the whole current density conditions. Hydrogen recirculation can improve the water content of segments near the inlet gas channel in the anode, and the consistency is the best when the current density is larger than 0.4 A cm−2.

Experimental investigation on use of alternative innovative materials for sustainable cooling applications

ABSTRACT In hot regions, the main reason for the consumption of energy arises from cooling the buildings. The intensity of the sunlight also has a direct relation to the use of the cooling systems. In the present work, a humidification system is built with packing made of locally available novel materials, and the performance of the cooling pads has been accessed under both counter flow and cross flow conditions. Coconut coir and wood shaving are used as alternative materials for evaporative cooling, and the experiments are conducted using varied airflow rates and the performance parameters, such as heat flow rate, humidification efficiency, moisture flow rate, coefficient of performance (COP) and specific cooling capacity (SCC) have been tested and compared with the Celdek packing. Results indicated that wood shaving performed better than the coconut coir. Values of COP and SCC are found to be very close to Celdek packing. Humidification efficiency of wood shaving is at par with the Celdek packing with improved quality of indoor air. In addition, results indicated that the counter flow arrangement gave better results compared to cross flow.

Thermal Analysis of the Effects of Multifaceted Conditions on Performance of Shell-and-Tube Heat Exchanger

A shell-and-tube heat exchanger which was subjected to different flow configurations, viz. counter flow, and parallel flow, was investigated. Each of the flow configurations was operated under two different conditions of the shell, that is, an uninsulated shell and a shell insulated with fiber glass. The hot water inlet temperature of the tube was reduced gradually from 60 oC to 40 oC, and performance evaluation of the heat exchanger was carried out. It was found that for the uninsulated shell, the heat transfer effectiveness for hot water inlet temperature of 60, 55, 50, 45, and 40 oC are 0.243, 0.244, 0.240, 0.240, and 0.247, respectively, for the parallel flow arrangement. For the counter flow arrangement, the heat transfer effectiveness for the uninsulated shell are 2.40, 2.74, 5.00, 4.17, and 2.70%, respectively, higher than those for the parallel flow. The heat exchanger’s heat transfer effectiveness with fiber-glass-insulated shell for the parallel flow condition with tube hot water inlet temperatures of 60, 55, 50, 45, and 40 oC are 0.223, 0.226, 0.220, 0.225, and 0.227, respectively, whereas the counter flow condition has its heat transfer effectiveness increased by 1.28, 1.47, 1.82, 1.11, and 1.18%, respectively, over those of the parallel flow.

Thermal Analysis of the Effects of Multifaceted Conditions on Performance of Shell-and-Tube Heat Exchanger

A shell-and-tube heat exchanger which was subjected to different flow configurations, viz. counter flow, and parallel flow, was investigated. Each of the flow configurations was operated under two different conditions of the shell, that is, an uninsulated shell and a shell insulated with fiber glass. The hot water inlet temperature of the tube was reduced gradually from 60 oC to 40 oC, and performance evaluation of the heat exchanger was carried out. It was found that for the uninsulated shell, the heat transfer effectiveness for hot water inlet temperature of 60, 55, 50, 45, and 40 oC are 0.243, 0.244, 0.240, 0.240, and 0.247, respectively, for the parallel flow arrangement. For the counter flow arrangement, the heat transfer effectiveness for the uninsulated shell are 2.40, 2.74, 5.00, 4.17, and 2.70%, respectively, higher than those for the parallel flow. The heat exchanger’s heat transfer effectiveness with fiber-glass-insulated shell for the parallel flow condition with tube hot water inlet temperatures of 60, 55, 50, 45, and 40 oC are 0.223, 0.226, 0.220, 0.225, and 0.227, respectively, whereas the counter flow condition has its heat transfer effectiveness increased by 1.28, 1.47, 1.82, 1.11, and 1.18%, respectively, over those of the parallel flow.

Comparative analysis of thermal and fluid flow behaviour of diverse nano fluid using Al2O3, ZnO, CuO nano materials in concentric spiral tube heat exchanger

Present paper based on computational and experimental study, in which diverse parameters have been investigated for observing the fluid flow, thermal and performance attributes like thermal performance factor, NTU, effectiveness and fluid flow attributes like Reynolds number, Nusselt number, Friction factor, HTR etc of diverse composition of nanofluids in spiral tube having insert, CTHE with insert diameter and pitch distance 2 mm and 20 mm. During present investigation water used as the base fluid associated with diverse additives or nano particles in single and combined form like Zinc Oxide, Aluminium Oxide and Cupric Oxide to form diverse composition of nano fluids with 10 nm particle size and 0.08% volume fraction like Zinc Oxide with water, Aluminium Oxide with Zinc Oxide with water, Aluminium Oxide with water and Aluminium Oxide with Cupric Oxide with water to improve the thermal conductivity. Experimentation has been performed for diverse nanofluids at 31 OC with flow range 0.721 to 2.941 L/min, which flows in the spiral tube whereas, the hot fluids as water flows at 4.02 L/min across the shell side of test set up at 50 OC. Here comparative investigation has been drawn for diverse nanofluids for observing its fluid flow, thermal and performance attributes at diverse flow rate with turbulent flow under counter flow condition with Reynolds Number 4236 to 18540. The result predicted that out of four diverse nano fluids Aluminium Oxide and Cupric Oxide with water as base fluid shows best results for fluid flow, thermal and performance attributes, for flow rate range 0.721 to 2.941 L/min and Reynolds Number 4236 to 18540. It has been evaluated that from minimum to maximum Reynolds Number, HTR, Nusselt number, Friction factor and effectiveness and NTU varies from 1228.3 to 3316.4, 88.28–160, 0.0438–0.0306, 0.84–0.55, 4.66–1.96 for Aluminium Oxide and Cupric Oxide nano fluid.