Tube Plate Research Articles

Research on measuring method of arc length of P-TIG welding in annular seam of tube plate

Research on measuring method of arc length of P-TIG welding in annular seam of tube plate

PREPARATION OF COMPONENTS FOR ORBITAL WELDING OF TITANIUM TUBES WITH TITANIUM CLAD STEEL SIEVE BOTTOM

The article presents the method of preparing the tube sheet of a heat exchanger made of B265 Grade 1 titanium-clad steel with B338 grade 2 titanium tubes allowing for the qualification of the TIG (Tungsten Inert Gas) orbital welding technology. A test plate was made of A516M Grade 485 unalloyed steel clad with B265 Grade 1 titanium using the explosive method. The 300 x 300 mm plate consisted of a layer of 60 mm thick non alloy steel and 5 mm titanium clad. It had 20 holes drilled in a triangular arrangement, into tubes with a diameter of 34.93 mm made of B338 Grade 2 titanium with a thickness of 0.7 mm were welded. In order to obtain mechanical restraint inside the holes in the test plates, the titanium tubes were rolled out. For rolling, a five-roller was used, equipped with a retaining collar which allows the tube to move freely during rolling. The tests carried out showed that the proposed technology for preparing tube – sieve bottom elements allow for the preparation of a test plate for the qualification of welding technology. The test plate made in accordance with the technological assumptions met all the requirements necessary to qualify the technology for welding tubes with tube plates. Both in the case of non-destructive testing and macrographic testing, there were no problems with compliance with the PN-EN ISO 15614-8:2005 standard.

Lightweight Reseach of Tube Sheet for Spiral Wound Heat Exchanger Based on ANSYS

Abstract Tube sheet is the key pressure-bearing part in the spiral wound heat exchanger, and the high-strength and light-weight tube sheet structure is of great engineering significance for the development of a large-scale heat exchanger. In order to further realize the lightweight of the spiral-wound heat exchanger, this paper analyzes the influence of the thickness of the heat exchanger tube sheet on its strength based on the Ansys software and proposes the optimization design method of the tube sheet based on the strength safety factor F, which solves the problem that the software cannot take the stress linearization result as the state variable in the optimization calculation. The optimization results show that the thickness of the tube sheet is reduced by 40%. At this time, the stress strength at the connection between the tube sheet and the head and the center of the tube sheet first exceeds the design bearing capacity, indicating that the strength conditions of the two places are the controlling factors of the thickness. The results are important for the lightweight design of heat exchanger tube plate and material saving.

Study of ultrasonic influence on heat transfer and resistance performance of round tube with twisted belt

Abstract In this study, ultrasonic technology is combined with twisted belts to explore the comprehensive performance, and this study also investigated the effect of different Reynolds numbers, ultrasonic frequencies, and number of transducers on the performance of circular and twisted band tubes. It was found that ultrasonic waves applied on the tube plate enhanced the heat transfer performance of the heat exchanger tubes, reduced the flow resistance, and improved the overall performance, and the lower the ultrasonic frequency, the better the heat transfer and resistance reduction ability, and at the experimental condition frequency of 21 kHz, the maximum increase of Nu is 19.06%. With the increase of Reynolds number, the better the ultrasonic enhancement heat transfer performance, but the worse the resistance reduction performance. For different heat exchanger tube structures, the synergistic enhanced heat transfer effect of ultrasonic waves with the twisted belt is better than round tubes, and the synergistic drag reduction effect with the round tube is better than the twisted tape round tube. When the installed ultrasonic transducers are two, the heat transfer performance of the heat exchanger tube is the best, and the maximum increase in the value of Nu was 28.06%.

Heat transfer performance study of Cu-ethanol/ethylene glycol/propylene glycol-water nanofluids in a wavy-walled tube heat exchanger

With the rapid consumption of nonrenewable energy sources, improving the heat transfer efficiency of conventional fixed tube plate heat exchangers, optimizing their structure, and finding more efficient coolants have become popular topics. In this paper, the cooling effect of ethanol/ethylene glycol/propylene glycol-water solution with a mass fraction of 50 % in a wavy-walled tube heat exchanger was investigated, while Cu nanoparticles with volume fractions of 1.5 % and 3.0 % were added to the cold working mass to form three different nanofluids. The effects of the three nanofluids at different volume fractions on the heat transfer performance of the wavy-walled tube heat exchanger were analyzed with numerical simulations, while the microscopic mechanism of the enhanced thermal conductivity of the nanofluids was investigated using molecular dynamics simulations. The results showed that the thermal conductivity of the nanofluids was greatly enhanced due to the formation of adsorption layers with different properties on the nanoparticle surfaces, and the Cu–ethylene glycol-water nanofluid showed the largest increase in thermal conductivity among the three nanofluids. It was also found that the shell-side pressure drop, convective heat transfer coefficient, and heat exchange quantity of the nanofluid in the wavy-walled tube heat exchanger significantly increased with an increase of volume fraction. The comprehensive heat transfer performance of the three nanofluids was found to be better compared to the base fluid. Cu-ethanol/EG/PG-water nanofluid with a volume fraction of 3.0 % increased the PEC of the heat exchanger by 10.4 %, 19.8 % and 27.6 %, respectively, at a volume flow rate of 1.53 m3/h. Therefore, the Cu-propylene glycol-water nanofluid had the best comprehensive heat transfer performance. Cu-ethanol-water nanofluid volume fraction of 3.0 % reaches a maximum PEC value of about 3.12 at Qv near about 2.0 m3/h, and Cu-EG-water nanofluid volume fraction of 3.0 % has a peak PEC value of about 4.07 at Qv of near about 2.0 m3/h. Therefore, the Cu-ethanol-water and Cu-ethylene glycol-water nanofluids are the optimal solutions for the combined heat transfer performance within the study.

Effect of operating temperature on the performance of expansion joints between tube and tube plate

Effect of operating temperature on the performance of expansion joints between tube and tube plate

Numerical Investigation of the Ultimate Load-Carrying Capacity of Square Concrete-Filled Steel Tube Columns Considering Initial Stresses Generated during Construction

During construction, newly cast concrete exerts lateral pressure on the steel plates of concrete-filled steel tube (CFST) columns, resulting in non-negligible initial circumferential stresses. Finite element analysis, in which lateral pressure is applied using a user-defined load subroutine, was conducted to comprehensively investigate the effects of initial stresses, including circumferential stresses, on the structural behaviors of a square CFST column under the action of compressive load. This study also provides guidance for the numerical simulation of CFST columns under complicated construction scenarios. The analysis revealed that the steel tube plates were more sensitive to lateral pressure, which should be limited during construction, compared with gravity loads. Under the action of compressive load, the presence of initial stresses altered the failure modes of the square CFST columns and reduced their ultimate load-carrying capacities (ULCCs). For columns with slenderness ratios of 18 and 37, the ULCCs were essentially inversely proportional to the initial stress ratio β, ranging from 0.1 to 0.5. However, for columns with a larger slenderness ratio of 55, the initial stress level did not influence their ULCCs. Finally, a simple method for calculating the ULCCs of square CFST columns considering initial stresses is proposed for design purposes.

Experimental Investigation of Tool Wear and Machining Quality of BTA Deep-Hole Drilling in Low-Carbon Alloy Steel SA-5083.

Nuclear power tube plates are made from the high-strength, low-carbon alloy steel SA-5083, which has high values of toughness and plasticity, though it is forged with poor consistency and entails serious work hardening. It requires a large number of deep holes with a high machining accuracy and high surface quality to be processed. However, the quality of the processed holes is often not up to the standard of the Boring and Trepanning Association (BTA) for the deep-hole drilling of tube plates; this has led to deep-hole processing becoming a bottleneck in the manufacture of steam generators for the main equipment of nuclear power islands. The variation laws of the diameter, roundness, perpendicularity, roughness, microhardness, and residual stress in relation to the feed, speed, and drilling depth are explored in the macro- and micro-dimensions; also explored is the wear morphology of BTA drills. The internal influence mechanisms between them are revealed in order to provide a scientific basis for the control of surface quality and machining accuracy as well as the optimization of process parameters. Our research results indicate that the guide block wear is mainly concentrated at the top 1-2 mm and that the drilling depth and feed have a great influence on the machining diameter. The hole wall roughness is between 0.3 and 0.6 μm, the maximum microhardness is about 2.15 times the hardness of the matrix material, and the residual stress is compressive stress. With increases in the feed and drilling depth, the hole diameter and the roughness increase. With an increase in the speed, the roughness decreases and the compressive stress of the BTA deep-hole drilling wall increases.

Improvement of the strength calculation of the tube plate of the shell-tube heat exchanger

The purpose of the article is to improve the strength calculation of the tube plate of the shell-and-tube heat exchanger, which is regulated by the interstate standard in force in Ukraine. On the basis of standard tables, dot plots of the change in coefficients were constructed and analyzed, which take into account the supporting effect of pipes Ф1, Ф2, Ф3 depending on the dimensionless parameter of the board-pipe system ω and the dependence of the stiffness coefficient of the perforated board on the coefficient of pressure effect on the tube plate from the side of the tube space ηТ. It is proposed to approximate these dependencies with simple mathematical equations. As a result, it was proposed to use the cubic regression Ф1 = 0,0422ω3 + 0,2305ω2 – 0,2367ω + 2,0179 to describe the dependence of Ф1 = f1(ω) in the range of ω from 0 to 3 and when changing ω from 3 to 11, apply quadratic regression Ф1 = – 0,0286ω2 + 1,8012ω – 0,6171. The dependence of Ф2 = f2(ω) in the range of changing ω from 0 to 0,5 due to a slight change in the function can be described by the linear equation Ф2 = 0.04ω, when changing ω from 0,5 to 2 - by the cubic regression Ф2 = 0,0133ω3 + 0,48ω2 – 0,4033ω + 0,1, and when changing ω from 2 to 11 – by cubic regression Ф2 = 0,0046ω3 – 0,1129ω2 + 1,8692ω – 1,8821. The dependence Ф3 = f3(ω) in the range of ω change from 0 to 0,5 is described by the linear equation Ф3 = 0,38ω, when ω changes from 0,5 to 3 – by cubic regression Ф3 = – 0,2296ω3 + 1,3541ω2 – 0,4884ω + 0,1233, and when ω changes from 3 to 11 – cubic regression Ф3 = – 0,0054ω3 + 0,1060ω2 + 0,7576ω + 1,6129. The discrete tabular dependence of ψ0 on ηТ can be approximated by cubic regression ψ0 = – 0,3419ηТ3 + 1,8834ηТ2 – 0,6915ηТ + 0,1153. The obtained formulas make it possible to abandon the use of standard tables and additional interpolation of intermediate values of the coefficients Ф1, Ф2, Ф3 and ψ0 when performing calculations, which in turn simplifies both the calculation itself and the development of appropriate computer programs. The average value of the errors of the performed approximations is in the range from 0% to 2.05%, which indicates a high level of coincidence of the regression equations with the actual values. The use of the proposed formulas for the dependences of the coefficients Ф1 = f1(ω), Ф2 = f2(ω), Ф3 = f3(ω) and ψ0 = f(ηТ) makes it possible to simplify the calculation of the tube plate of shell-and-tube heat exchangers for strength.

High-efficiency inspecting method for mobile robots based on task planning for heat transfer tubes in a steam generator

Many heat transfer tubes are distributed on the tube plates of a steam generator that requires periodic inspection by robots. Existing inspection robots are usually involved in issues: Robots with manipulators need complicated installation due to their fixed base; tube mobile robots suffer from low running efficiency because of their structural restricts. Since there are thousands of tubes to be checked, task planning is essential to guarantee the precise, orderly, and efficient inspection process. Most in-service robots check the task tubes using row-by-row and column-by-column planning. This leads to unnecessary inspections, resulting in a long shutdown and affecting the regular operation of a nuclear power plant. Therefore, this paper introduces the structure and control system of a dexterous robot and proposes a task planning method. This method proceeds into three steps: task allocation, base position search, and sequence planning. To allocate the task regions, this method calculates the tool work matrix and proposes a criterion to evaluate a sub-region. And then all tasks contained in the sub-region are considered globally to search the base positions. Lastly, we apply an improved ant colony algorithm for base sequence planning and determine the inspection orders according to the planned path. We validated the optimized algorithm by conducting task planning experiments using our robot on a tube sheet. The results show that the proposed method can accomplish full task coverage with few repetitive or redundant inspections and it increases the efficiency by 33.31% compared to the traditional planning algorithms.

Fibula pro tibia and cancellous allograft vitalised with autologous bone for non-union of the distal tibia diaphysis: Surgical technique

BackgroundThe management of medium-sized osseous defects and pseudoarthrosis of the tibia is challenging. This surgical technique aims to bridge medium-sized tibial defects using the fibula as a lead structure. The fibula and cancellous bone graft fuse with the tibia leading to synostosis. MethodsCortico-cancellous bone is harvested from the anterior iliac crest. The bone is shredded into small pieces of about 5 mm and mixed with stem cell-rich blood from the situs. Additionally, cancellous allografts can be used for expansion. The approach is extended along the interosseous membrane to reach the tibial defect. The pseudarthrosis is debrided and the tibial bone adjacent to the defect is decorticated. A 3.5 mm 1/3 tube plate is positioned to the fibula and fixed. Four quadricortical screws are positioned. Autograft is secured into the tibial bone defect and between the fibula and the tibia directly on the anterior surface of the interosseous membrane. Results15 patients were followed up for a mean of 17 months. Osseous consolidation was achieved in 73.3% of all cases. On average, bone healing has occurred 17 weeks postoperatively. These patients did not have any pain walking with full weight bearing and without any walking aids at the last follow-up. ConclusionThe fibula pro tibia procedure is a sufficient tool for treating non-unions of the mid and distal third of the tibia diaphysis in cases with a bony defect size of 1 cm–6 cm.

Study on heat transfer enhancement of nanofluid in a new type of heat exchangers

As one of the essential equipment in industrial production, improving the efficiency of heat exchangers to slow down energy consumption has become a popular topic. In this paper, the structure of a conventional fixed tube plate heat exchanger is optimized by numerical simulation, replacing the straight tube with a wavy wall tube. The impact of particle size of Cu-water nanofluid on the performance in the new heat exchanger (HEX) is also investigated. The results indicate that using the wavy wall tube enhances the flow field perturbation and improves the working mass’s flow state; adding nanoparticles in water can improve the heat transfer capacity of the fluid. It is also found that the shell process pressure drops (ΔP) and the heat transfer effect of the HEX increased with increasing of the fluid volume flow rate; at the same volume flow rate and the volume fraction of 0.5%, the ΔP of the Cu-water nanofluid in the HEX increases with increasing of the particle size. The heat transfer performance decreases gradually with increasing of the particle size. The smaller particle size of Cu nanoparticles can improve the efficiency of enhanced heat transfer to a larger extent.

Study of corrosion resistance of friction welding joints between tubes and tube plate

The cost of production and reliability of shell-and-tube heat exchangers is mainly determined by the features of the tube bundle and the joint between tube and tube plate (TTP) in particular. This paper provides a comparative analysis of the weld structure and electrode potential distribution of weld joints and base metal seams simulating the joint between heatexchange tube and tube plate (steel 5CrMo16) using the following welding methods: manual metal arc welding, gas tungsten arc welding and rotating friction welding. Comparison between macro- and microstructures of certain zones of tested welded joints, as well as values of electrode potential at specific points of the base metal and welded joints obtained by various methods, made it possible to conclude the effectiveness of application of specific ways of welding by their effect on corrosion resistance of given assembly.

Physical processes in fixing of heat-exchange tubes by means of roller-type rolling

The main physical processes in the "spindle — roller — pipe — tube plate" contact zone are considered. On the example of an experimental oscillograph chart, the stages of the process of fixing the pipe are considered in detail. The ways of setting the rolling machine to the required torque are analyzed. Keywords: pipe, roller, spindle, tube plate, rolling, torque, stress, oscillograph chart, temperature. kondrat.leonid@yandex.ru; mironova_lub@mail.ru

Study on TIG welding parameters for joining different kind of aluminium tube with a tube plate

Welding is a vital metal joining technique with a wide range of industrial uses. In this study, numerous process factors such as current, feed rate, and distance between tube and work piece, among others, were used to investigate in Tungsten Inert Gas (TIG) welding. We used Aluminum 6063 tube to Aluminum 6061 tube plate for this TIG welding. After the welding is finished, a radiographic test is performed to show any welding faults that might lead to defect-free welds. The most critical control factors that would result in better joint strength were identified to use a Taguchi L9 orthogonal matrix. Furthermore, the most relevant process parameter was determined using quantitative independent test (ANOVA). In addition, the mechanical tests were performed to determine the welding strength. The value of the best welded connection strength for tubes with holes welded at interference was found to be 318.716 MPa.

Rancang Bangun Alat Pencetak Briket Hidrolik dengan Sistem Gerak Rel

This study aims to design a hydraulic briquette press with a rail system to produce briquettes from coconut shell waste that is simple and easy to operate. Starting from designing the foundation (rail system), briquette tube table and piston pressing plate, to becoming a pressing tool using CAD software. The foundation was designed using square plate steel with size of 340 mm x 220 mm. The plate thickness of 4 mm and distance of 2 rails of 90 mm. The pressing tube plate consists of 2 tables which has 8 print tubes with a diameter of 22 mm and height 70 mm. The pressing piston plate uses a bolt connection so the piston can be set in line with the printing tube hole when the briquette press is operated. As a result, a hydraulic press with a table movement system in the form of a rail system was successfully built to make briquettes made from coconut shell charcoal with a capacity of 6.24 kg per hour. In one process, this tool produces 16 cylindrical briquettes with a diameter of 22 mm and a length of 50 mm.

Determining Chromium, Iron, and Nickel in a Nickel-Based Alloy by X-ray Fluorescence Spectroscopy

Nickel-based alloys have excellent corrosion resistance. They are also well-known for their mechanical properties, high temperature durability, and heat transfer performance. Because nickel-based alloys have these properties, they are widely used in creating nuclear safety level pressure equipment. It is the first-choice material for the heat exchanger tube plate and U-tube plate of the nuclear island steam generator, which has a profound impact on the safe operation of the reactor. Therefore, it is necessary to calibrate the main elements in nickel-based alloys. Accurate detection of the main elements in nickel-based alloys is important in ensuring the advancement of process research. A method for determining chromium, iron, and nickel in a nickel-based alloy by X-ray fluorescence spectroscopy is presented here. The detection range of chromium, iron, and nickel is 0.2–1.6 g/L, 0.2–2.3 g/L, and 0.5–3.3 g/L, respectively. After the three elements are corrected respectively, good correlation is obtained, R2 (chromium)= 0.999406, R2 (iron) = 0.999202, and R2 (nickel)= 0.999114. The relative standard deviations for chromium, iron, and nickel are 0.75%, 0.65%, and 0.65% respectively. The standard sample is tested to confirm the measured value is in agreement with the certified value.

Experimental and numerical stress and strain analysis of the boiler reversing chamber tube plate

Boilers are one of the most used units for both heat generation plants and industry systems. Their operation is subjected to different working loads and maintenance requirements. Exploitation experience points out critical boiler zones where failures and break downs typically occur. This paper analyzes critical zones in hot water fire-tube boiler. Experimental procedure was performed on the model of this type of boilers and its critical element. The tube plate of hot water boiler was identified as the most critical one. Experimental analysis and numerical model verification were performed using Aramis system based on 3-D digital image correlation method. Numerical analysis was done in ANSYS software package and verification of results was done based on measurements obtained by strain gauges and local measurements performed by the Aramis system. Stress-strain analysis indicates the critical zones of boiler tube plate. The character of change parameters such as strain and stress occurring in the critical zones can be verified both by experimental and numerical data. The paper presents a novel approach in experimental and numerical analyses that can be conducted in similar units and used for existing unit optimization, as well as for new product testing on different loads and provide opportunity for further development and improvement for practical industrial application.

Thermal Stress Analysis of Tube Plate and Tube Bundle of Multi-Tube Pass Spirally Corrugated Tubes Heat Exchanger

This paper analyses the thermal stress of multi-tube heat exchanger with spirally corrugated tubes using numerical simulations. The simulations are focused on the thermal stress of the tube bundle and tube plate, which have large temperature difference. In this paper, the heat exchanger design software HTRI is creatively used to calculated the temperature boundary conditions of the heat exchanger, which is difficult to obtain. Based on the indirect coupling method of ANSYS, the thermal stress intensity and thermal deformation between the tube bundle and the tube plate of the heat exchanger are caculated. And the calculation results can provide important references for the design and optimization of the heat exchanger.

Influence of diameter thickness ratio of main tube on bearing capacity of steel tube tower joints

In order to study the influence of steel tube diameter thickness ratio on the bearing capacity of steel tube angle steel tower joint, the finite element model of tube plate joint was established, and the failure mode and bearing capacity of the joint under different steel tube diameter thickness ratios were studied, and the influence law of steel tube diameter thickness ratio on the bearing capacity of steel tube tower joint was obtained, and the relationship between steel tube diameter thickness ratio and steel tube tower joint bearing capacity was established through regression analysis in this paper. The results show that angel steel tube plate K-type joint has two kinds of failure mode, and in a certain range, the bearing capacity of the joints increases with the increase of the steel tube diameter thickness ratio, and decreases after reaching the maximum bearing capacity.