High-Temperature Structural Analysis on the Small-Scale PHE Prototype

PHE (Process Heat Exchanger) is a key component for transferring the high-temperature heat generated from a VHTR (Very High Temperature Reactor) to a chemical reaction for massive production of hydrogen. Korea Atomic Energy Research Institute has established a small-scale nitrogen gas loop for the performance test on VHTR components and has manufactured a small-scale PHE prototype made of Hastelloy-X of high-temperature alloy. A performance test on the PHE prototype is underway in the gas loop. In this study, in order to evaluate the high-temperature structural integrity of the PHE prototype under the test condition of the gas loop, structural analysis on the PHE prototype was carried out to gauge the stiffness of pipelines connected to the PHE prototype in the gas loop.

Comparisons of High-Temperature Structural Analysis Results on the Medium-Scale PHE Prototype under the Steady-State and Trip Conditions of a Small-Scale Gas Loop

PHE (Process Heat Exchanger) is a key component for transferring the high-temperature heat generated from a VHTR (Very High Temperature Reactor) to a chemical reaction for massive production of hydrogen. Recently, Korea Atomic Energy Research Institute (KAERI) has manufactured a medium-scale PHE prototype made of Hastelloy-X of high-temperature alloy and a performance test on the PHE prototype is scheduled in a small-scale nitrogen gas loop established at KAERI. In this study, in order to evaluate the high-temperature structural integrity of the PHE prototype under the steady-state and trip conditions of the gas loop before the performance test on the PHE prototype, elastic and elastic-plastic structural analyses on the PHE prototype were carried out and the analyses results were compared each other.

Size Effect of PHE Prototype on High-Temperature Structural Integrity

PHE (Process Heat Exchanger) is a key component for transferring the high-temperature heat generated from a VHTR (Very High Temperature Reactor) to a chemical reaction for massive production of hydrogen. Recently, Korea Atomic Energy Research Institute (KAERI) has manufactured a small-scale and a medium-scale PHE prototype made of Hastelloy-X of high-temperature alloy and a performance test on the PHE prototype is scheduled in a small-scale nitrogen gas loop established at KAERI. In this study, in order to compare the high-temperature structural integrity of the PHE prototypes under the normal test condition of the gas loop, high-temperature structural analyses on the PHE prototypes were carried out and the analyses results were compared to each other. As a result of comparisons, the high-temperature structural integrity of the medium-scale PHE prototype gets worse due to higher thermal expansion by a size effect.

High-Temperture Structural Analysis on a Small-Scale PHE Prototype Considering Mechanical Properties in the Heat-Affected Zone and in the Weld Zone

PHE (Process Heat Exchanger) is a key component in transferring the high temperature heat generated from a VHTR (Very High Temperature Reactor) to the chemical reaction for massive production of hydrogen. A performance test on a small-scale PHE prototype made of Hastelloy-X is currently undergoing in a small-scale gas loop at the Korea Atomic Energy Research Institute. Previous researches on the high-temperature structural analysis of the small-scale PHE prototype had been performed using parent material properties over the whole region. In this study, high-temperature elastic structural analysis considering mechanical properties in the weld zone was performed and the analysis result was compared with previous researches.

High-Temperature Structural Analysis of a Small-Scale PHE Prototype under the Test Condition of a Small-Scale Gas Loop

A process heat exchanger (PHE) is a key component for transferring the high-temperature heat generated from a very high-temperature reactor (VHTR) to a chemical reaction for the massive production of hydrogen. The Korea Atomic Energy Research Institute has designed and assembled a small-scale nitrogen gas loop for a performance test on VHTR components and has manufactured a small-scale PHE prototype made of Hastelloy-X alloy. A performance test on the PHE prototype is underway in the gas loop, where different kinds of pipelines connecting to the PHE prototype are tested for reducing the thermal stress under the expansion of the PHE prototype. In this study, to evaluate the high-temperature structural integrity of the PHE prototype under the test condition of the gas loop, a realistic and effective boundary condition imposing the stiffness of the pipelines connected to the PHE prototype was suggested. An equivalent spring stiffness to reduce the thermal stress under the expansion of the PHE prototype was computed from the bending deformation and expansion of the pipelines connected to the PHE. A structural analysis on the PHE prototype was also carried out by imposing the suggested boundary condition. As a result of the analysis, the structural integrity of the PHE prototype seems to be maintained under the test condition of the gas loop.