Experimental Study on Thermo-Mechanical Behavior of a Novel Energy Pile with Phase Change Materials Using Fiber Bragg Grating Monitoring
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThis paper presents a comprehensive study on the integration of Phase Change Materials (PCMs) into energy piles, evaluating their performance in terms of thermo-mechanical behavior. Overall, it is a well designed and presented research article with profound evidence to support the author's claims.
In details: the study's approach of integrating PCMs into energy piles is innovative and addresses the need for more efficient energy storage and transfer in geothermal applications. The experimental setup, including the model tank, temperature-controlled circulation system, and measurement system, is well-designed, providing a robust platform for the study. The thorough calibration of FBG sensors for temperature and strain and their strategic placement in the model piles demonstrate a high level of precision in data acquisition. As for the results, the authors have shown that PCM piles exhibit less temperature variation compared to ordinary piles. This is crucial for maintaining the operational efficiency of geothermal systems. The paper effectively quantifies this difference, offering specific temperature ranges observed in both types of piles. The analysis of thermal stresses and strains in PCM piles is a highlight of the paper. It provides detailed insights into how PCMs can mitigate the thermal expansion and contraction issues commonly faced in energy piles. The paper's use of FBG sensors for precise measurements is commendable.
Things could be improved:
The paper mentions different thermal expansion coefficients for ordinary and PCM piles but does not delve deeply into how these differences impact the overall structural integrity and performance of the piles under varying thermal loads. While the paper discusses the variation in pore water pressure, a more detailed exploration of how these changes impact the soil stability and structural integrity of the pile over time would be beneficial.
Figure legends could be more detailed, and some figures may be merged (17 & 18)
Author Response
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Author Response File: 
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Reviewer 2 Report
Comments and Suggestions for AuthorsThe manuscript introduces a novel energy pile utilizing phase change materials for improved thermo-mechanical performance. The experimental design and methodology have been clearly demonstrated and the schematics are easy to digest. Test results have been analyzed and presented in a systematic manner. The discussion and the limitations described in the last section are constructive for follow-up studies in the same field.
Author Response
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Reviewer 3 Report
Comments and Suggestions for AuthorsThe article is well-written, and interesting and describes valuable experimental research. It may be of interest to researchers dealing with PCM materials.
The article describes a complex measurement system and, according to the reviewer, the description of the measurement procedure should
be extended from the point of view of the used software and data processing. The article would benefit from the authors supplementing the above information, but it also deserves a high rating in its current form.
The experimental setup and methodology are meticulously designed and clearly illustrated. The meticulous calibration of Fiber Bragg Grating (FBG) sensors for temperature and strain,
taking into account their arrangement in the model stacks, enabled the acquisition of a large amount of precise data.
According to the reviewer, presenting information about the software used and the method of processing this large amount of data would be interesting from the experimental point of view.
The research results presented by the authors demonstrate that PCM piles exhibit less temperature fluctuation compared to conventional piles,
a critical factor in sustaining the operational efficiency of geothermal systems. The research presented in the article is valuable, and the article itself is written at a high level.
Adding the information proposed by the reviewer could be of interest to researchers specializing in experimental research.
Author Response
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