Assessment of Weld Joint Efficiency for Rolled and Welded Joint for Intermediate Heat Exchanger in Sodium Cooled Fast Reactor

2014 ◽  
Vol 592-594 ◽  
pp. 1438-1442
Author(s):  
Suman Gupta ◽  
P. Chellapandi
Keyword(s):  
Heat Exchanger ◽  
Load Distribution ◽  
Welded Joint ◽  
Experimental Investigations ◽  
Tube Material ◽  
Allowable Stresses ◽  
Intermediate Heat Exchanger ◽  
Main Barrier ◽  
Maximum Stresses ◽  
Basic Strength

The tube to tubesheet joint in a heat exchanger is one of the most critical joint and it has to meet stringent requirements as it provides the main barrier between the tube side and shell side fluids of heat exchanger. This paper discusses the various kinds of tube to tubesheet joint in heat exchanger, joint configuration adopted in PFBR IHX, structural analysis of IHX, axial load distribution in tube rows and experimental verification in order to evaluate allowable strength of tube to tubesheet joint. In IHX, tubes in outer rows are under tension and maximum stresses are below the allowable stresses in the tubes. Detailed experimental investigations result shows that the rolled and welded joint is stronger than the basic strength of the tube material. However, the allowable tensile strength of the joint under mechanical loading considered is 0.95 times the allowable value for tubes as per ASME.

Thermal hydraulic investigations of intermediate heat exchanger in a pool-type fast breeder reactor

2008 ◽  
Vol 238 (7) ◽  
pp. 1577-1591 ◽  
Author(s):  
R. Gajapathy ◽  
K. Velusamy ◽  
P. Selvaraj ◽  
P. Chellapandi ◽  
S.C. Chetal ◽  
...  
Keyword(s):  
Heat Exchanger ◽  
Fast Breeder Reactor ◽  
Intermediate Heat Exchanger ◽  
Pool Type

scholarly journals A Numerical Strategy to Identify the FSW Process Optimal Parameters of a Butt-Welded Joint of Quasi-Pure Copper Plates: Modelling and Experimental Validation

2021 ◽  
Author(s):  
Monica Daniela IORDACHE ◽  
Claudiu BADULESCU ◽  
Malick DIAKHATE ◽  
Adrian CONSTANTIN ◽  
Eduard Laurentiu NITU ◽  
...  
Keyword(s):  
Welded Joint ◽  
Pure Copper ◽  
Correlation Method ◽  
Image Correlation ◽  
Experimental Investigations ◽  
Optimal Parameters ◽  
Friction Stir ◽  
Mass Scaling ◽  
Surface Response ◽  
Fsw Parameters

Abstract Determining the optimal parameters of the Friction Stir Welding (FSW) process, which are suitable for a given joint configuration, remains a great challenge and is often achieved through extremely time-consuming and costly experimental investigations. The present paper aims to propose a strategy for the identification of the optimal parameters for a butt-welded joint of 3-mm thick quasi-pure copper plates. This strategy is based on FEM (finite elements method) simulations and the optimal temperature that is supposedly known. A robust and efficient finite element model that is based on the Coupled Eulerian-Lagrangian (CEL) approach has been adopted and a temperature-dependent friction coefficient has been used. Besides, the mass scaling technique has been used to significantly reduce the simulation time. The thermo-mechanical behavior of the butt-welded joint was modeled using a Johnson-Cook plasticity model that was identified through lab tests at different temperatures. The results of the parametric study help to define the numerical surface response, and based on this latter one can found the optimal parameters, advancing (υa) and rotational (υr) speeds, of the FSW process. This numerical surface response has been validated with good agreement between the numerical prediction of the model and the experimental results. Furthermore, experimental investigations involving x-ray radiography, digital image correlation method, and fracture surface analysis have helped a better understanding of the effects of FSW parameters on the welded joint quality.

scholarly journals Thermal-Hydraulic Studies on the Shell-and-Tube Heat Exchanger with Minijets

Energies ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 3276 ◽  
Author(s):  
Jan Wajs ◽  
Michał Bajor ◽  
Dariusz Mikielewicz
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Waste Heat ◽  
Experimental Studies ◽  
Convection Heat Transfer ◽  
Test Facility ◽  
Experimental Investigations ◽  
Transfer Coefficients ◽  
Tube Heat Exchanger ◽  
Shell And Tube

In this paper a patented design of a heat exchanger with minijets, with a cylindrical construction is presented. It is followed by the results of its systematic experimental investigations in the single-phase convection heat transfer mode. Based on these results, validation of selected correlations (coming from the literature) describing the Nusselt number was carried out. An assessment of the heat exchange intensification level in the described heat exchanger was done through the comparison with a shell-and-tube exchanger of a classical design. The thermal-hydraulic characteristics of both units were the subjects of comparison. They were constructed for the identical thermal conditions, i.e., volumetric flow rates of the working media and the media temperatures at the inlets to the heat exchanger. The experimental studies of both heat exchangers were conducted on the same test facility. An increase in the heat transfer coefficients values for the minijets heat exchanger was observed in comparison with the reference one, whereas the generated minijets caused greater hydraulic resistance. Experimentally confirmed intensification of heat transfer on the air side, makes the proposed minijets heat exchanger application more attractive, for the waste heat utilization systems from gas sources.

Active Chemistry Control for Coolant Helium Applying High-Temperature Gas-Cooled Reactors

2008 ◽  
Author(s):  
Nariaki Sakaba ◽  
Shimpei Hamamoto ◽  
Yoichi Takeda
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Heat Exchanger ◽  
Chemical Composition ◽  
Structural Integrity ◽  
Carbon Deposition ◽  
Control Technology ◽  
Equilibrium Study ◽  
Intermediate Heat Exchanger ◽  
High Temperature Gas

Lifetime extension of high-temperature equipment such as the intermediate heat exchanger of high-temperature gas-cooled reactors (HTGRs) is important from the economical point of view. Since the replacing cost will cause the increasing of the running cost, it is important to reduce replacing times of the high-cost primary equipment during assumed reactor lifetime. In the past, helium chemistry has been controlled by the passive chemistry control technology in which chemical impurity in the coolant helium is removed as low concentration as possible, as does Japan’s HTTR. Although the lifetime of high-temperature equipment almost depends upon the chemistry conditions in the coolant helium, it is necessary to establish an active chemistry control technology to maintain adequate chemical conditions. In this study, carbon deposition which could occur at the surface of the heat transfer tubes of the intermediate heat exchanger and decarburization of the high-temperature material of Hastelloy XR used at the heat transfer tubes were evaluated by referring the actual chemistry data obtained by the HTTR. The chemical equilibrium study contributed to clarify the algorism of the chemistry behaviours to be controlled. The created algorism is planned to be added to the instrumentation system of the helium purification systems. In addition, the chemical composition to be maintained during the reactor operation was proposed by evaluating not only core graphite oxidation but also carbon deposition and decarburization. It was identified when the chemical composition could not keep adequately, injection of 10 ppm carbon monoxide could effectively control the chemical composition to the designated stable area where the high-temperature materials could keep their structural integrity beyond the assumed duration. The proposed active chemistry control technology is expected to contribute economically to the purification systems of the future very high-temperature reactors.

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