Copper Tube Research Articles

Research on the Optimization of TP2 Copper Tube Drawing Process Parameters Based on Particle Swarm Algorithm and Radial Basis Neural Network

After rolling, TP2 copper tubes exhibit defects such as sawtooth marks, cracks, and uneven wall thickness after joint drawing, which severely affects the quality of the finished copper tubes. To study the effect of drawing process parameters on wall thickness uniformity, an ultrasonic detection platform for measuring the wall thickness of rolled copper tubes was constructed to verify the accuracy of the experimental equipment. Using the detected data, a finite element model of drawn copper tubes was established, and numerical simulation studies were conducted to analyze the influence of parameters such as outer die taper angle, drawing speed, and friction coefficient on drawing force, maximum temperature, average wall thickness, and wall thickness uniformity. To address the problem of the large number of finite element model meshes and low solution efficiency, the wall thickness uniformity was predicted using a radial basis function (RBF) neural network, and parameter optimization was performed using the particle swarm optimization (PSO) algorithm. The research results show that the RBF neural network can accurately predict wall thickness uniformity, and using the PSO optimization algorithm, the best parameter combination can reduce the wall thickness uniformity after drawing in finite element simulation.

Revolutionizing copper pipe durability: Shielding against corrosion with graphene oxide through electrophoretic application

This research endeavors to utilize electrophoretic deposition (EPD) to coat copper (Cu) pipes with graphene oxide (GO) nanosheets, aiming to bolster their resistance against corrosion. To achieve this, a stable aqueous colloidal suspension of GO was meticulously prepared via liquid exfoliation in deionized water. This suspension served as an electrolytic solution for EPD. The EPD process involved the meticulous application of varied operational parameters such as deposition time, applied voltage, and GO nanosheet concentration to facilitate anodic deposition on the copper pipe’s surface. To gauge the efficacy of the GO coating, evaluations were conducted to assess adhesive force and stabilization using specialized coating adhesion scratch testing equipment. Further analysis of the resulting film on the Cu pipe was executed employing X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy, and Fourier transform infrared spectroscopy (FT-IR). These methods provided detailed insights into the characteristics and properties of the GO material post-deposition. The study yielded noteworthy outcomes, revealing the achievement of a uniform, unbroken, and consistent coating film on the Cu pipe. This was accomplished by employing specific parameters as 60 s of deposition time, a GO concentration of 0.5 mg/mL, and a voltage of 20 V. Impressively, when subjected to a corrosive solution containing 3.5% sodium chloride, the corrosion protection exhibited a remarkable twofold enhancement compared to untreated copper tubing, boasting an efficiency (η) of 90.48%. These findings suggest that the Cu pipe, coated with GO using the EPD technique, holds significant promise for utilization in demanding industrial settings susceptible to corrosion challenges.

Experimental investigation of a novel approach to enhance heat transfer in double-tube heat exchangers through the utilization of a vibrating latex strip turbulator

This study introduces a novel approach aimed at mechanically influencing and distorting the boundary layer. This is achieved through the utilization of a wide, thin, elongated vibrating turbulator made of latex. The advanced vibrating turbulator continuously sweeps the inner tube perimeter, effectively breaking the boundary layer. Located within the test section is a concentric copper tube, defined by an outer diameter of 2.5cm and an inner diameter of 1.6cm. The effect of a number of parameters on the thermal characteristics of the heat exchanger, including the thickness of the latex turbulator, the width of the latex turbulator, the flow rate through the inner tube and the oscillation frequency, is investigated. The inner diameter of the tube sets the minimum width for the latex turbulator. The findings show a substantial rise in the heat transfer rate, reaching up to 504.5 %, when the rubber strip dimensions and frequency are optimized to a width of 22mm, thickness of 0.4mm, and frequency of 40Hz. Under these conditions, the thermal enhancement factor reaches a peak of 3.39. Moreover, the thermal performance decreases when the rubber thickness is increased.

Unveiling the fundamentals of flow boiling heat transfer enhancement on structured surfaces.

Micro- and nanostructured surfaces offer the potential to enhance two-phase heat transfer. However, the mechanisms behind these enhancements are not well-understood due to insufficient diagnostic methods, leading to reliance on trial-and-error surface development. We introduce in situ boroscopy to investigate microscale bubble dynamics during flow boiling nucleation and subsequent flow regime development. This method was applied in saturated flow boiling experiments within chemically etched aluminum and copper tubes. Although the surfaces have self-similar surface structures, our findings revealed varied heat transfer coefficient enhancements, with increases of up to 391% on aluminum and 41% on copper. Using boroscopy, we identified key mechanisms of heat transfer enhancement. We further used mercury porosimetry to determine the impact of pore size distribution on thermal performance. The boroscopy technique introduced here not only elucidates the underlying processes of flow boiling heat transfer enhancement but also has potential applications for the study of other two-phase phenomena.

Experimental study on the critical current in highly flexible REBCO cables under copper tube compaction

The Institute of Plasma Physics Chinese Academy of Sciences (ASIPP) is developing the high-current REBCO cable-in-conduit conductor (CICC) for use in the Central Solenoid (CS) coil of the next generation nuclear fusion device. The aim is to develop a CICC comprising six REBCO sub-cables to satisfy the requirements of operation with a current of around 46 kA and a peak field of up to 20 T. Sub-cables, as crucial components within CICCs, play a pivotal role in ensuring the mechanical support strength and current-carrying stability of the entire CS coil system. Therefore, a process was developed in this paper for the first time to make a sub-cable that meets the requirements by inserting the Highly Flexible REBCO Cable (HFRC) cable into a copper tube and compacting it. Meanwhile, the feasibility and reliability of this process were evaluated and optimized using experimental methods at 77 K and self-field. The result indicated that sub-cables without copper tape protection experienced a 25.42% degradation in critical current (IC). In contrast, when at least one protective layer of copper tape was used as a protective buffer between the HFRC cable and the inner wall of the copper tube, the IC remained stable within a 1% error margin after compaction. These findings demonstrate the feasibility of this sub-cable preparation process. Meanwhile, this compaction method provides a solid process foundation for the development of full-size conductors in future magnet applications.

Experimental and computational assessment of the heat transfer exchange in evacuated tube receiver using helical external fins

This study examines the performance of solar thermal systems with a longitudinal finned tube, utilizing both experimental and computational fluid dynamics (CFD) methods. The University of Technology in Baghdad manufactured two copper tubes, one with a smooth surface and the other with a longitudinal fin, for the experiments. The research examines thermal efficiency and useful energy extraction across varying flow rates of 2, 3, 5, and 6 LPM. The experimental results show significant differences in the performance of the smooth-surfaced tube compared to the helically finned tube at different flow rates. At 2 LPM, the smooth-surfaced tube shows a gradual increase in useful power from 248.7 W at 8:00 to 1506 W at 13:00, which corresponds to available solar energy to the collectors ranging from 2400 W to 3084 W, resulting in a thermal efficiency between 17 % and 20 %.In contrast, the finned tube has higher Qu values, starting at 442.15 W at 8:00 and 538.7 W at 13:00, while Qs range from 2415 W to 3087 W. Thus, the thermal efficiency of this tube ranges from 10 % to 52 %. Conversely, at higher flow rates, both systems show comparable thermal efficiencies. Comparative analysis between the experimental results and the ANSYS results indicates agreement within a reasonable margin of error, confirming the validity of the computational simulation procedure. The CFD results were consistent with the experimental data, showing a similar trend in thermal efficiency and useful energy extraction for both smooth tubes and finned tubes. A higher temperature difference typically indicates greater heat absorption and heat transfer efficiency, reflecting a more efficient use of solar radiation. The error rate between the experimental and ANSYS results was no >12 %. The study confirms the role of longitudinal fins in improving the efficiency of vacuum tube solar collectors.

Heat transfer analysis of CuO-ZnO/water hybrid nanofluid in a Shell and tube heat exchanger with various tube shapes

Heat exchangers are widely used in various applications, including heating and cooling systems. Adding nanoparticles to the base working fluid can enhance the fluid's thermophysical properties, thereby increasing the thermal performance of heat exchangers. Further heat transfer enhancement can be done by using a hybrid nanofluid, which contains two or more different nanoparticles. The findings of the paper can be utilized to enhance the thermal efficiency of a shell and tube heat exchanger with different tube shapes and by using CuO-ZnO/ water hybrid nanofluid as a working fluid. Numerical simulations were conducted to model thermal heat exchangers with different configurations. Copper tubes of circular, hexagonal, and elliptical geometry were considered for the experiment. The model is solved using Ansys software with a finite volume approach. The solver employs an upwind-based multidimensional linear approach and upwind discretization schemes. The water inlet velocity in the Shell ranges from 0.5m/sec to 3.2 m/sec at a Reynold number of 10,000 to 15,000 whereas the velocity of cold fluid in the tube varies from 1.4 to 2 m/sec. All experiments were conducted with a 0.01–0.1 %vol % CuO-ZnO (80:20)/ water hybrid nanofluid. The hybrid nanofluid on the tube side is used to cool hot fluid (water) on the shell side. Hybrid nanofluid inlet temperature was maintained at 30°C to cool hot water at 60°C. Hexagonal tube geometry increases the contact surface area, resulting in a 22.11 % increase in heat transfer rate compared to round tubes and an 18.42 % increase compared to round tubes. Experimental and numerical results for the convective heat transfer coefficient, Nusselt number, and pressure drop were also reported.

Numerical study of structural parameters of perforated baffle on heat transfer enhancement in coiled elastic copper tube heat exchanger

Numerical study of structural parameters of perforated baffle on heat transfer enhancement in coiled elastic copper tube heat exchanger

Experimental investigation of heat transfer enhancement, thermal efficiency, and pressure drop in forced convection of magnetic hybrid nanofluid (Fe₃O₄/TiO₂) under varied magnetic field strengths and waveforms

Applying a magnetic field to influence convective flow of ferrofluids has become an efficient method for enhancing heat transfer in thermal systems, particularly in straight tubes. This study investigates the heat transfer properties of Fe₃O₄/TiO₂ nanofluids within a heated copper tube under varied magnetic field strengths and waveforms. Optimal magnetic field conditions were determined at 4 V and 60 Hz across all waveform types, as higher frequencies and voltages increased magnetic field intensity, thereby reducing heat transfer rates. Magnetic waveforms exerted differential influences on pressure drop, indicating varied nanoparticle alignment and turbulence levels, impacting fluid flow dynamics and viscosity. Higher nanoparticle concentration (0.1% vol) correlated with increased pressure drops across sine, square, and triangular waveforms, suggesting heightened flow resistance and potential nanoparticle agglomeration, thus reducing thermal efficiency. Conversely, lower concentrations exhibited enhanced thermal performance due to improved nanoparticle dispersion and reduced thermal resistance. At 0.1% vol, heat transfer enhancement without a magnetic field was 16.5%. The introduction of magnetic field waveforms attenuated this enhancement: 15.3% (sine), 13.26% (square), and 12.59% (triangular). Conversely, at lower volume fractions, heat transfer enhancements with magnetic fields exceeded those without at 0.05% vol, enhancements were 20.92% (sine), 21.3% (square), and 21.34% (triangular); at 0.025% vol, enhancements were 22.07% (sine), 22.3% (square), and 21.32% (triangular); at 0.0125% vol, enhancements were 27.87% (sine), 28.21% (square), and 26.74% (triangular); and at 0.0065% vol, enhancements were 22.24% (sine), 22.3% (square), and 24.49% (triangular).

Functional failure analysis of the graphite crystallizer used in horizontal continuous casting process of copper tube

The presence of a particular type of white powder has emerged as a significant challenge in the horizontal continuous casting process of copper. This white powder leads to the blockage of the graphite crystallizer, resulting in a functional failure that adversely affects the mold’s lifespan, increases production costs, and reduces overall efficiency. The issue has posed significant challenges for engineers due to its complex and unclear formation mechanism. This investigation employed various experimental characterization methods to analyze the composition, element distribution, phase properties, and other relevant factors of the white powder. Meanwhile, a high-temperature experiment was also designed to examine the potential reactions between copper oxide (Cu2O) and the furnace lining (3Al2O3·2SiO2). It is found that the main component of the white powder blocking the inlet hole of the graphite mold is SiO2, which is traced back to the furnace lining. Under high temperatures, oxygen reacts with liquid copper to form Cu2O. Subsequently, this Cu2O reacts with Al2O3 in the furnace lining to produce CuAlO2. Meanwhile, SiO2 becomes isolated as Al2O3 is deprived. The resultant SiO2 accumulates at the inlet hole of the graphite mold due to rapid cooling. The accumulated SiO2 in the form of white powder blocks the inlet hole of the graphite mold, leading to functional failure of the graphite mold. To address this issue, several improvement measures are proposed including drying the raw and protective material, enhancing the sealing of the furnace, and reducing the holding time.

Enhancing conical solar still performance using high conductive hollow cylindrical copper fins embedded by PCM

The present study aims to enhance the efficiency of the conical solar distiller in producing water during both day and night. This will be achieved through design enhancements, such as increasing the surface area of the distiller to maximize solar energy absorption and improve condensation rates. High thermal-conductivity cylindrical fins have been used, and their role will be investigated. These fins may be hollow and extended, with or without the inclusion of phase change material (PCM). Consequently, copper tubes are positioned at the base of the distiller basin, both with and without the inclusion of phase-changing paraffin wax material inside the hollow tubes. A comparison is made between the performance of three configurations: the first configuration is traditional, the second configuration includes fins without the incorporation of PCM, and the third configuration includes PCM-based fins. This comparison is crucial as it provides a clear understanding of the impact of each design enhancement on the distiller’s performance. The study findings indicated that the arrangement with hollow fins filled with PCM had the highest level of freshwater output. Furthermore, the results showed that the combined output of conical solar distillers equipped with fins made of copper tubes, both with and without PCM, were 7.50 and 6.75 L/m2/day, respectively. The cumulative production of conventional conical distillers is 4.85 L/m2/day. Freshwater output improved by 54.64 and 39.17 % when using hollow copper tubes with and without PCM within 24 h, compared with the conventional configuration. During night-time hours, it was observed that the freshwater output of distilled water from salt water significantly improved by 550 % when utilizing copper tubes loaded with PCM, compared to distillation using empty copper tubes. The maximum daily efficiency of conical distillers with fins with and without PCM were 73.6 % and 80.3 %, respectively. These results showed that conical distillers using copper tubes hollow filled with PCM represent good options for obtaining higher performance than distillation.

THE INFLUENCE OF TRAINING AND WORK ENVIRONMENT ON EMPLOYEE PERFORMANCE AT PT SAMWON COPPER TUBE INDONESIA

The objective of this study is to determine the influence of training and work environment on employee performance at PT Samwon Copper Tube Indonesia in Tangerang Regency, Banten. The method used is quantitative. The sampling technique used is saturated sampling, meaning all members of the population are used as the sample, resulting in a sample of respondents in this study. Data analysis was conducted using validity tests, reliability tests, classical assumption tests, regression analysis, correlation coefficients, determination coefficients, and hypothesis testing. The study results indicate that training has a positive and significant effect on employee performance, with a regression equation showing a direct relationship. The coefficient of determination shows that part of the variation in employee performance can be explained by the training variable, and hypothesis testing results indicate a positive and significant influence of training on employee performance at PT Samwon Copper Tube Indonesia in Tangerang Regency, Banten. The work environment also has a positive and significant effect on employee performance, with a regression equation showing a direct relationship. The coefficient of determination shows that part of the variation in employee performance can be explained by the work environment variable, and hypothesis testing results indicate a positive and significant influence of the work environment on employee performance at PT Samwon Copper Tube Indonesia in Tangerang Regency, Banten. Training and work environment simultaneously have a positive and significant effect on employee performance, with a regression equation indicating the contribution of these two variables together. The coefficient of determination shows that a large portion of the variation in employee performance can be explained by training and work environment, while the remainder is influenced by other factors. Hypothesis testing results indicate a positive and significant influence of training and work environment simultaneously on employee performance at PT Samwon Copper Tube Indonesia in Tangerang Regency, Banten.

Freeform 3D deposition of small diameter copper tubes using a powder-binder feedstock

AbstractCopper is an interesting material for many applications including thermal management devices, which make often use of copper piping. This study proposes a method for the freeform deposition of a copper-binder feedstock, extruded through an additive manufacturing machine. Several tubes have been printed using a special nozzle and varying process parameters. The dimensional results of the deposited specimens at the green state and the physical properties of the tubes after debinding and sintering have been measured. The results demonstrate that piping in serpentine layout can be deposited by extrusion and sintered, even with sharp bends without significant ovalization of the cross-section.

Thermal Performance Solar Flat Plate Collector and Influence of Flow Pipe Design

Flat plate collectors are commonly utilized in both domestic and industrial applications to minimize energy consumption. In this study, solar flat plate collector (SFPC)) with corrugated flow pipe with ten turns placed over flat absorber plate and covered with single glass layer was fabricated and tested, in Al-Mussiab city, Babylon, Iraq (latitude 32.5◦N and longitude 44.3◦E). This research presents the effect flow pipe shape about the SFPC's thermal performance. The designed solar collector utilized employing of 12.5 mm-diameter corrugated copper tubing that extended 19500 mm in total length. According to different rates of water flow namely (50, 100, and 150 L/h). The results indicated that the working fluid's greatest temperature differential between the inlet and outlet of solar collector (12.9°C) at volumetric flow rate (50 L/h). The maximum thermal efficiency (Ƞth) rate of solar flat plate collector was (77%) at (150 L/ h). These results encourage the development of solar collector system and eventually help the sustainable use of solar power in home applications, including solar water heating system.

Some techniques for producing copper wire in late Classical and Hellenistic Macedonia

This paper discusses different techniques for making copper wire in the fourth and third centuries BCE in ancient Macedonia (Northern Greece). Wire was used to form stems on gilded wreaths, and to support berries, leaves and rosettes. Stems were made in one piece with the leaves, and are likely to have been formed in at least two ways: one involved cutting them out of sheet copper about 0.5 mm thick, which was creased and then hammered into shape; the other involves using copper rods 1mm square. Some of the square copper rods can be seen on the wreaths, and their regularity suggests they may have been formed on a swaging block. Berries were joined to the wreath circlets by round wires, formed in some cases, it is suggested, by hammering sheet metal around a central core; in other cases, these stems may have been formed by rolling a rod between stone slabs. No evidence, such as longitudinal striations, was found of drawing. Some examples of strip-twisted wire were found, but there are fewer cases of this than of wire formed by hammering. The most expensive gilded wreaths at Derveni, cist grave A, Phoinikas cist grave 5 and Sedes, sometimes had special features, such as gilded copper tubes (‘branches’) with smaller stems on either side, or square wires formed into spirals.

Evaluating the Thermal Performance of Shell-and-Tube Heat Exchangers: The Role of Flow Rate in Water-Based Systems

This research investigates the performance of water as a working fluid in the shell side of shell-and-tube heat exchangers (STHEs), explicitly analyzing how variations in flow rate influence the heat transfer coefficient, pressure drop, and friction factor characteristics. Experiments were conducted using an STHE with a SUS 201 stainless steel shell and a pure copper tube featuring an inner diameter of 10 mm and an outer diameter of 13 mm. The flow rates of the cold fluid varied at 9, 10, and 12 liters per minute (LPM), while the hot fluid flow was maintained at a constant rate of 6.67 LPM. A 600 W heater, regulated by a PID system, was utilized to evaluate thermal performance, with water serving as the hot fluid on the shell side and the cold fluid on the tube side. Results demonstrate a significant increase in both the heat transfer coefficient and the heat transfer rate with higher flow rates of the cold fluid, with the maximum heat transfer coefficient recorded at 12 LPM and the minimum at 9 LPM. The STHE exhibited high efficiency, with heat transfer rate differences between the shell and tube sides remaining below 5%. Although pressure fluctuations were observed with increasing flow rates, they did not substantially affect the friction factor, indicating a predominantly turbulent flow regime. These findings provide critical insights for optimizing heat transfer performance in STHEs, contributing to advancements in thermal management technologies and enhancing the design of efficient heat exchangers.

Analysis of the Development of Downstream Copper Industry in Indonesia to Obtain Maximum Added Value Using Dynamic Systems

This research aims to design a dynamic system model for the downstream copper processing industry. The secondary data obtained is data provided by the BKPM Strategic Investment Downstreaming Expert Team. Vensim software is used to simulate downstream development in the form of CLD and SFD from 2024 to 2045. The results of the value-added simulation resulted in an increase in the added value of copper cathode by 2.15 times, the added value of cathode slab by 1.62 times, the added value of copper billet by 1.65 times, the added value of copper bar &rods by 1.08 times, the added value of copper tube by 1.02 times, the added value of copper strip by 1.39 times, and the added value of copper wire by 1.58 times. After a sensitivity analysis of the selling price at CAGR and an increase in energy costs by 20%, there was a change in the average value-added margin, so that the increase in added value changed which resulted in an added value of copper cathode of 1.9 times, added value of cathode slab of 1.47 times, added value of copper billet of 1.49 times, added value of copper bar &rods of 1.26 times, added value of copper tube of 0.93 times, added value of copper strip of 0.98 times, and added value of copper wire of 1.44 times.

Design and Manufacturing of Thermosyphon Solar Water Heater Using Locally Available Materials in Nsanke Village

The weather conditions of Nsanke village starting from April to October emphasis the need for judicious utilization of warm water. We designed, constructed and tested a Solar Water Heater based on Thermosyphon principle in Nsanke village using locally available materials. Solar energy is received by two flat-plate collectors of 1.68 m2 each, consisting of absorber plate carrying copper tubes and placed in an insulated casing with a transparent glass cover of thickness 4 mm. The collectors are connected in series and are assumed to operate on the same efficiency. The resultant collector is connected to a storage tank, which is an association of two barrel nested overall and separated with an insulator. The radiation emitted by the absorber plates cannot escape through the glass, thus increasing its temperature. The system’s performance evaluation has shown that it can heat water from 23°C to at least 51°C on sunny days. The water heated flows into a storage tank through Thermosyphon principle. The Solar Water Heating System uses the Thermosyphon principle and can therefore be called Thermosyphon Solar Water Heater (TSWH) for simplicity. This system finds useful application in serving as a renewable energy resource in Nsanke village and neighboring villages.

Oscillating Heat Pipe Start-up and Flow Characteristics with Water as Working Fluid

Thermal management has grown more and more problematic as electronic components continue to get faster and smaller. One of the passive two-phase cooling systems are Oscillating heat pipe (OHP) that have the capacity to transmit a significant quantity of thermal energy across long distances. Oscillating heat pipe is a device that has the potential to satisfy this developing requirement. An investigation into the effects of orientation, filling ratio, and heat load on the initiation and characteristics of oscillatory motion, combining numerical simulations with experimental validation. A copper tube with a 2 mm inner diameter and a 2 mm wall thickness is used to fabricate the OHP. The condenser, evaporator, and adiabatic sections are designed with lengths of 50 mm, 50 mm, and 150 mm, respectively. Results showed that the onset of oscillation occurs more rapidly with increasing input heat flux values compared to lower heat input conditions. The amplitude variations of the temperature of evaporator raised with the raising of heating power. The curves for the higher heat inputs (60 and 80 watts) appear to have higher average evaporator temperatures throughout the test compared to the 40-watt curve. Oscillation movement in tubes is proportional to charge ratio, and it is observed that it rises as charge ratio increases. It demonstrates that in Closed-loop oscillating heat pipe, a sufficient charge ratio is required to maintain the motion of oscillation.

БАГАТОШАРОВІ ІНДУКТОРИ ДЛЯ УСТАНОВКИ ІНДУКЦІЙНОЇ ТЕРМООБРОБКИ АЛЮМІНІЄВИХ ЗЛИВКІВ ПРИ ПРЕСУВАННІ КАТАНКИ ДЛЯ СИЛОВИХ КАБЕЛІВ

On the basis of the developed mathematical model, computer (numerical) modeling of electrothermal processes in a multi-layer inductor installation, which is used for heating cylindrical aluminum ingots (blanks) before pressing the wire rod, as a basis for obtaining current-conducting cores of power cables from it, was carried out. Single-phase and three-phase multilayer inductors of the galette type were studied, as a result of which it was shown that the maximum value of the electrical efficiency of such an installation for both inductors is provided by their three-layer winding with a water-cooled copper tube of rectangular section. For both inductors, distributions along the radius and length of the aluminum blanks of the volumetric specific power and the specific linear power of heat release from the eddy currents induced in the blanks were obtained. For a three-phase inductor, such distributions were obtained when feeding it with voltages with phase shift angles of 120 and 60 degrees. The losses in the turns of the inductors and their distribution along the length and layers of both inductors were also studied. Ref. 8, fig. 7, tables 2.