The Failure of Titanium Clad Tube Sheet in Heat Exchanger by Fatigue Cracking and Corrosion

2019 ◽  
Keyword(s):  
Heat Exchanger ◽  
Fatigue Cracking ◽  
Tube Sheet ◽  
Clad Tube

Solid-particle erosion in the tube end of the tube sheet of a shell-and-tube heat exchanger

2006 ◽  
Vol 50 (8) ◽  
pp. 885-909 ◽  
Author(s):  
M. A. Habib ◽  
H. M. Badr ◽  
S. A. M. Said ◽  
R. Ben-Mansour ◽  
S. S. Al-Anizi
Keyword(s):  
Heat Exchanger ◽  
Solid Particle ◽  
Solid Particle Erosion ◽  
Tube Sheet ◽  
Particle Erosion ◽  
Tube Heat Exchanger ◽  
Shell And Tube

Investigation of a Shell and Tube Exchanger in Process Gas Heating Service

2008 ◽  
Author(s):  
M. A. Porter ◽  
D. H. Martens
Keyword(s):  
Heat Exchanger ◽  
Tube Sheet ◽  
Sulfur Recovery ◽  
Treatment Unit ◽  
Gas Treatment ◽  
Flexible Tube ◽  
Process Gas ◽  
Large Shell ◽  
Section Viii ◽  
Shell And Tube

The design requirements for a large shell and tube vertical heat exchanger (to be used in a sulfur recovery tail gas treatment unit) included startup, shutdown and upset conditions that would subject the exchanger to significant temperature changes. The exchanger was designed to the requirement of the ASME Boiler and Pressure Vessel Section VIII Division 1 [1]. A detailed analysis of the thermal profiles and related stresses was performed to confirm the use of a flexible tube sheet design. The heat exchanger uses high pressure superheated steam on the shell side to heat a low pressure process gas on the tube side. The heat exchanger was sized and thermally rated, using commercially available analysis software. The proposed design was analyzed by Finite Element methods that included both thermal and stress analysis. These evaluations confirmed that a flexible tube sheet design was satisfactory when using specific dimensions.

Analysis of the Gasket Damage and Sealing Performance for the Thread Ring Block Heat Exchanger

2019 ◽  
Author(s):  
Fakun Zhuang ◽  
Wen Sui ◽  
Guoshan Xie ◽  
Shanshan Shao ◽  
Zhiyuan Han ◽  
...  
Keyword(s):  
High Temperature ◽  
Heat Exchanger ◽  
Metallographic Analysis ◽  
Tube Sheet ◽  
Operational Conditions ◽  
Term Operation ◽  
High Temperature And Pressure ◽  
Sealing Performance ◽  
Temperature And Pressure ◽  
Gasket Material

Abstract The thread ring block heat exchangers, served at the high temperature and pressure, are the key equipment in the petrochemical industry. Due to the severe operational conditions and unsuitable assemble, internal leakage problem commonly occurs, especially for the seal gasket between the tube sheet and shell. Many failed gaskets are collected. Through a series of experiments including chemical composition, metallographic analysis, SEM and fracture analysis, the gasket damage and leakage causes are analyzed. For further interpretation, the gasket stress analysis is completed by the finite element method. It shows that the gasket stress is a main factor that affects the sealing performance for the thread ring block heat exchanger. Under long term operation at high temperature and pressure, the gasket stress between the tube sheet and shell becomes loose and creep. The gasket material also deteriorates with increasing time. Therefore, in order to prevent the internal leakage, the stress should be controlled in an appropriate range. And periodical inspection must be performed.

Modeling and Simulation of Cross-Flow Induced Vibration in a Multi-Span Tube Bundle

2004 ◽  
Author(s):  
Shahab Khushnood ◽  
Zaffar M. Khan ◽  
M. Afzaal Malik ◽  
Zafarullah Koreshi ◽  
Mahmood Anwar Khan
Keyword(s):  
Heat Exchanger ◽  
Tube Bundle ◽  
Cross Flow ◽  
Fatigue Cracking ◽  
Acoustic Resonance ◽  
Computer Code ◽  
Variable Geometry ◽  
Flow Induced Vibration ◽  
Two Phase ◽  
Tube Bundles

Flow-induced vibration in steam generator and heat exchanger tube bundles has been a source of major concern in nuclear and process industry. Tubes in a bundle are the most flexible components of the assembly. Flow induced vibration mechanisms, like fluid-elastic instability, vortex shedding, turbulence induced excitation and acoustic resonance results in failure due to mechanical wear, fretting and fatigue cracking. The general trend in heat exchanger design is towards larger exchangers with increased shell side velocities. Costly plant shutdowns have been the motivation for research in the area of cross-flow induced vibration in steam generators and process exchangers. The current paper focuses on the development of a computer code (FIVPAK) for the design (natural frequencies, variable geometry, tube pitch & pattern, mass damping parameter, reduced velocity, strouhal and damage numbers, added mass, wear work rates, void fraction for two-phase, turbulence and acoustic considerations etc.) of tube bundles with respect to cross flow-induced vibration. The code has been validated against Tubular Exchanger Manufacturers (TEMA), Flow-Induced Vibration code (FIV), and results on an actual variable geometry exchanger, specially manufactured to simulate real systems. The proposed code is expected to prove a useful tool in designing a tube bundle and to evaluate the performance of an existing system.

scholarly journals Ratcheting Assessment of a Fixed Tube Sheet Heat Exchanger Subject to In Phase Pressure and Temperature Cycles

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Khosrow Behseta ◽  
Donald Mackenzie ◽  
Robert Hamilton
Keyword(s):  
Heat Exchanger ◽  
Plastic Material ◽  
Sheet Thickness ◽  
Peak Stress ◽  
Material Model ◽  
Tube Sheet ◽  
Hardening Material ◽  
Perfectly Plastic ◽  
Inelastic Analysis ◽  
Plastic Shakedown

An investigation of the cyclic elastic-plastic response of an Olefin plant heat exchanger subject to cyclic thermal and pressure loading is presented. Design by analysis procedures for assessment of shakedown and ratcheting are considered, based on elastic and inelastic analysis methods. The heat exchanger tube sheet thickness is nonstandard as it is considerably less than that required by conventional design by formula rules. Ratcheting assessment performed using elastic stress analysis and stress linearization indicates that shakedown occurs under the specified loading when the nonlinear component of the through thickness stress is categorized as peak stress. In practice, the presence of the peak stress will cause local reverse plasticity or plastic shakedown in the component. In nonlinear analysis with an elastic–perfectly plastic material model the vessel exhibits incremental plastic strain accumulation for 10 full load cycles, with no indication that the configuration will adapt to steady state elastic or plastic action, i.e., elastic shakedown or plastic shakedown. However, the strain increments are small and would not lead to the development of a global plastic collapse or gross plastic deformation during the specified life of the vessel. Cyclic analysis based on a strain hardening material model indicates that the vessel will adapt to plastic shakedown after 6 load cycles. This indicates that the stress categorization and linearization assumptions made in the elastic analysis are valid for this configuration.

Research on Phased Array Ultrasonic Technique for Testing Tube to Tube-Sheet Welds of Heat Exchanger

2016 ◽  
Author(s):  
Weican Guo ◽  
Shengjie Qian ◽  
Zhangwei Ling ◽  
Dongsheng Hou
Keyword(s):  
Heat Exchanger ◽  
Ultrasonic Testing ◽  
Phased Array ◽  
Incomplete Fusion ◽  
Testing System ◽  
Ultrasonic Frequency ◽  
Ultrasonic Technique ◽  
Tube Sheet ◽  
Element Size ◽  
Array Probe

The tube to tube-sheet weld is the main connection structure of heat exchanger. This paper presents the phased array ultrasonic technique for testing the tube to tube-sheet welds of heat exchanger. The optimization analysis of phased array parameters and the simulation on the acoustic field with CIVA software were completed. The mentioned phased array parameters included array elements, array element size, deflection angle, ultrasonic frequency and so on. An ultrasonic testing system was designed and fabricated in accordance with the structure of heat exchange tube and fillet welds position. The ultrasonic C-scan was carried out by the ultrasonic testing system with its circumferential scanning by a mechanical scanning device while the axial electronic linear scanning by the phased array probe. At last, tests on samples with the porosity and incomplete fusion flaws were performed by the ultrasonic testing system. Experimental results showed that the phased array ultrasonic technique could effectively detect the porosity flaws and the incomplete fusion flaws in the tube to tube-sheet welds of heat exchanger.

Rational Analysis of Heat-Exchanger Tube-Sheet Stresses

1956 ◽  
Vol 23 (3) ◽  
pp. 468-473
Author(s):  
Yi-Yuan Yu
Keyword(s):  
Heat Exchanger ◽  
Present Method ◽  
Maximum Stress ◽  
Perforated Plate ◽  
Tube Sheet ◽  
Heat Exchanger Tube ◽  
Rational Analysis ◽  
Side Pressure ◽  
Limiting Values ◽  
Exchanger Tube

Abstract The paper presents a rational method of analysis of heat-exchanger tube-sheet stresses. While the tube sheet is taken to be a perforated plate on an elastic foundation in the manner of Gardner and Miller, it is also considered as part of an integrated indeterminate structure, and the interaction between the tube sheet and the connecting cylindrical shells and flange of the exchanger is determined so that a condition may be formulated which the edge rotation and edge moment of the tube sheet must satisfy. In general, neither the edge rotation nor the edge moment is zero; the edge of a tube sheet is therefore neither clamped nor simply supported. Application of the present method to four different types of heat exchangers is described in detail. To illustrate the method, Gardner’s example of a fixed-tube-sheet exchanger is recalculated. While Gardner’s method yields only the two limiting values of the maximum stress in the tube sheet, which differ by more than 100 per cent, the present method makes it possible to determine the exact value of this maximum stress. By means of the present method, the stresses in the other parts of the heat exchanger, namely, the tubes, shell, head, and flange, also can be calculated. As a consequence of the present analysis, it is found that, in the external-floating-head type of exchanger, the tube-sheet stress is not independent of the shell-side pressure, which is contrary to Gardner’s and Miller’s conclusions.

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