scholarly journals Creep-Fatigue Design Applied to Molten Salt Solar Receivers

Author(s):  
Edward F. Radke ◽  
David T. Wasyluk ◽  
David J. Dewees ◽  
James M. Tanzosh

The development of solar energy for commercial power generation has been an active area of work for several decades. A limiting design consideration for solar receivers is creep-fatigue because of the high heat fluxes involved and the inherent cyclic nature of solar energy. Design activities and concerns are presented for a recent commercial molten salt receiver application. A critical review of available creep-fatigue data and methods is provided and supplemented with detailed inelastic analysis. Recommendations are made for both design and further material property development that would help to remove conservatism and increase reliability. Paper published with permission.

Author(s):  
Wen Wang ◽  
Xiaochun Zhang ◽  
Xiaoyan Wang ◽  
Maoyuan Cai

Abstract The structural integrity of reactor components is very essential for the reliable operation of all types of power plants, especially for components operating at elevated temperature where creep effects are significant and where components are subjected to high-temperature alteration and seismic transient loading conditions. In this article, a molten salt storage tank in high temperature thorium molten salt reactor (TMSR) is evaluated according to ASME-III-5-HBB high temperature reactor code. The evaluation based on 3D finite element analyses includes the load-controlled stress, the effects of ratcheting, and the interaction of creep and fatigue. The thermal and structural analysis and the application procedures of ASME-HBB rules are described in detail. Some structural modifications have been made on this molten salt storage tank to enhance the strength and reduce thermal stress. The effects of ratcheting and creep-fatigue damage under elevated temperature are investigated using elastic analysis and inelastic analysis methods for a defined representative load cycle. In addition, the strain range and the stress relaxation history calculated by elastic and inelastic methods are compared and discussed. The numerical results indicate that the elastic analysis is conservative for design and a full inelastic analysis method for estimating input for creep-fatigue damage evaluation need to be developed.


Author(s):  
B. Barua ◽  
M. C. Messner ◽  
M. D. McMurtrey

Abstract The Concentrating Solar Power (CSP) Gen3 Demonstration Roadmap has recognized Supercritical carbon dioxide (sCO2) Brayton Cycle as the best-fit power cycle as it provides thermal efficiency benefits relative to the conventional Steam-Rankine cycles. However, to enable the integration of sCO2 Brayton Power Cycle, it is necessary to increase the outlet temperature of current molten salt CSP systems from 565°C to approximately 720°C. Increasing the temperature of the salt brings significant material and engineering challenges. Creep-fatigue damage accumulation and ratcheting deformation are important design considerations for receivers operating at high temperature due to frequent transient loads caused by diurnal cycling and thermal shocks from transitions between sun and cloud cover. In this work, a reference thermomechanical model of a Gen3 CSP receiver is developed to evaluate different creep-fatigue and ratcheting design approaches identified in Section III, Division 5, of ASME Boiler and Pressure Vessel Code. The design methods are then ordered based on design margin and ease of use. Design by elastic perfectly-plastic analysis is found to be the most conservative among the methods. Elastic analysis is the easiest to perform but the design calculations are extremely complicated. In contrast, design calculations are straight forward in inelastic analysis method but it requires developing a sophisticated inelastic constitutive model describing the material behavior. Several recommendations are made for developing creep-fatigue and ratcheting design rules for CSP systems.


Author(s):  
M. Zugic ◽  
J. R. Culham ◽  
P. Teertstra ◽  
Y. Muzychka ◽  
K. Horne ◽  
...  

Compact, liquid cooled heat sinks are used in applications where high heat fluxes and boundary resistance preclude the use of more traditional air cooling techniques. Four different liquid cooled heat sink designs, whose core geometry is formed by overlapped ribbed plates, are examined. The objective of this analysis is to develop models that can be used as design tools for the prediction of overall heat transfer and pressure drop of heat sinks. Models are validated for Reynolds numbers between 300 and 5000 using experimental tests. The agreement between the experiments and the models ranges from 2.35% to 15.3% RMS.


1993 ◽  
Vol 115 (3) ◽  
pp. 284-291 ◽  
Author(s):  
S. H. Bhavnani ◽  
C.-P. Tsai ◽  
R. C. Jaeger ◽  
D. L. Eison

Liquid immersion cooling is rapidly becoming the mechanism of choice for the newest generation of supercomputers. Miniaturization at both the chip and module level places a severe constraint on the size of the heat sink employed to dissipate the high heat fluxes generated. A study was conducted to develop a surface that could augment boiling heat transfer from silicon surfaces under these constraints. The surface created consists of reversed pyramidal features etched directly on to the silicon surface. Experiments were conducted in a saturated pool of refrigerant-113 at atmospheric pressure. The inexpensive crystallographic etching techniques used to create the enhanced features are described in the paper. The main characteristics of interest in the present study were the incipient boiling superheat and the magnitude of the temperature overshoot at boiling incipience. Results were obtained for test sections with various cavity densities, and compared with data for the smooth untreated surface. It was found that incipient boiling superheat was reduced from a range of 27.0–53.0° C for the untreated silicon surface, to a range of 2.5–15.0° C for the enhanced surfaces. The overshoot also decreased considerably; from about 12.0–18.0° C for two classes of untreated surfaces, to a range of 1.5–5.3° C for the enhanced surfaces. The values of the incipient boiling superheat, and those of the overshoot decreased with a decrease in cavity mouth size. Two ratios of heat source surface area to the area of the enhanced surface were studied. The overshoot values obtained for these surfaces were compared with those observed for some commonly used enhanced surfaces. An elementary numerical study was conducted to estimate the magnitude of heat spreading.


2020 ◽  
Vol 6 (3) ◽  
pp. 53-57
Author(s):  
A. T. Abdukadirov ◽  
◽  
A. A. Shodiev

This article describes the project of a device proposed by the authors for converting solar energy into electrical energy, as well as for accumulating and storing energy through molten salt. It describes the main details and principle of operation of this device and its special significance in the field of energy as a renewable energy source, which has the highest efficiency


Author(s):  
T. Valente ◽  
C. Bartuli ◽  
G. Visconti ◽  
M. Tului

Abstract Reusable space vehicles, which must withstand re-entry into the Earth's atmosphere, require external protection systems (TPS) which are usually in the forms of rigid surface in areas of high or moderate working temperature. High heat fluxes and temperatures related to high performance hypervelocity flights also require the use of TPS materials having good oxidation and thermal shock resistance, dimensional stability, and ablation resistance. Components by these materials are usually fabricated, starting from either billets or plate stocks, by uniaxial hot pressing, and complex parts, such as low radius edges, are then obtained by electrical discharge machining technique. This article investigates an alternative fabrication technology, based on plasma spraying, to produce near net shape components. Results of experimental activities, such as optimization of plasma spraying parameters based on a DOE approach, are reported and discussed.


2021 ◽  
Author(s):  
Lars Rüpke ◽  
Zhikui Guo ◽  
Sven Petersen ◽  
Christopher German ◽  
Benoit Ildefonse ◽  
...  

Abstract Submarine massive sulfide deposits on slow-spreading ridges are larger and longer-lived than deposits at fast-spreading ridges1,2, likely due to more pronounced tectonic faulting creating stable preferential fluid pathways3,4. The TAG hydrothermal mound at 26°N on the Mid-Atlantic Ridge (MAR) is a typical example located on the hanging wall of a detachment fault5-7. It has formed through distinct phases of high-temperature fluid discharge lasting 10s to 100s of years throughout at least the last 50,000 years8 and is one of the largest sulfide accumulations on the MAR. Yet, the mechanisms that control the episodic behavior, keep the fluid pathways intact, and sustain the observed high heat fluxes of up to 1800 MW9 remain poorly understood. Previous concepts involved long-distance channelized high-temperature fluid upflow along the detachment5,10 but that circulation mode is thermodynamically unfavorable11 and incompatible with TAG's high discharge fluxes. Here, based on the joint interpretation of hydrothermal flow observations and 3-D flow modeling, we show that the TAG system can be explained by episodic magmatic intrusions into the footwall of a highly permeable detachment surface. These intrusions drive episodes of hydrothermal activity with sub-vertical discharge and recharge along the detachment. This revised flow regime reconciles problematic aspects of previously inferred circulation patterns and can be used as guidance to one critical combination of parameters that can generate substantive mineral systems.


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