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

Abstract

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.

Macroscopic Structural Analysis on a 10 kW Class Lab-Scale Process Heat Exchanger Prototype under a High-Temperature Gas Loop Condition

“…For the FE model, the inflow/outflows of the primary and secondary coolants are shown in Figures 7 and 8 [8]. The inflow of the primary coolant into the PHE prototype and the outflow of the primary coolant from the PHE prototype, after the heat is transferred to the secondary coolant, are shown in Figure 7.…”

“…6.8 [11] were performed by imposing displacement constraint conditions at each end of the primary/secondary flow pipelines as shown in Figure 13, considering the pipeline stiffness of the small-scale nitrogen gas loop [8,12,13]. These conditions were established in previous work [8]. The bilinear stress-strain curve of Hastelloy-X for an elastic-plastic structural analysis extracted from a website [9] is shown in Figure 14.…”

Effect of mechanical properties in the weld zone on the structural analysis results of a plate-type heat exchanger prototype and pressurized water reactor spacer grid

“…Structural analysis using base material properties. Based on the thermal analysis results, a high-temperature structural analysis on the prototype was performed using the base material properties of Hastelloy 1 -X alloy and imposing the displacement constraint conditions [20] considering the pipeline stiffness of the gas loop as shown in Figure 14. A structural analysis of the prototype was carried out using ABAQUS Ver.…”

Thermostructural Analysis of Plate-Type Heat Exchanger Prototypes Considering Weld Properties

“…However, the chamfering (or rounding) along the edge of the prototypes is not considered in the FE model for the sake of simplicity. Figure 7 shows the input data of the primary/secondary flow plates for a thermal analysis under a gas loop test condition of 850 • C [6,12], and Figure 8 shows the displacement constraint conditions considering the pipeline stiffness of the small-scale nitrogen gas loop [13].…”

“…When a welded structure is loaded, the mechanical behavior of the welded structure might differ from the case of a structure with homogeneous mechanical properties. Nonetheless, structural analyses [3][4][5][6][7] of the plate-type PHE prototypes were carried out using only the parent material properties owing to a lack of mechanical properties in the weld zone. Usually, the best way to obtain the mechanical properties in the weld zone is by taking tensile test specimens from the fusion zone and HAZ, and by performing a standard tensile test.…”