Usage of Microencapsulated Phase-Change Materials to Improve the Insulating Parameters of the Walls of Refrigerated Trailers

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

 

The paper presents results of an experimental investigation aiming at evaluating the performance of an improved insulation material, based on polyurethane foam enhanced by the dispersion of micro-encapsulated phase-change material (mPCM). This is intended for use in the walls of refrigeration trailers and suitable thermal conductivity coefficients are estimated from temperature measurements in suitably-constructed chambers, by comparisons with reference walls.

 Overall, and even though no striking results were obtained regarding the enhancement of insulating properties of the materials used so far, the work is interesting and may become a good starting point towards further integration of mPCM in insulation materials. The reviewer would be in favor of publication of the paper, provided the following points are taken into consideration by the authors :

 1)      Acronym PU has not been defined, first appearing in the abstract. Also acronym ATP, on line 173, should be defined.

2)      Line 276 : The reference should be to Figure 4 instead of Figure 3.

3)      Regarding the coefficient K, as defined in Eq. (1), this has the form of a thermal conductivity rather than a heat transfer coefficient, as extensively referred to in the manuscript. The latter term normally relates to a convection coefficient or, otherwise, if meant to represent an overall coefficient, it should include also convection on both sides of the wall. However, such a quantity can not be estimated with the measurements based on thermocouples T₁ and T₂ placed as shown in Fig. 5. Therefore, the authors should replace the term “heat transfer coefficient” with “thermal conductivity” (or some relevant term, to account for the units used) wherever it appears.

Comments on the Quality of English Language

  Language : overall it is good, however, some errors have been detected, for instance :

‒      Line 172 : sentence should read : “The researchers want to create …..”

‒      Line 290 : should be “heat flux” instead of “heat flow flux

‒     Lines 571-572 : sentence should read : “… it is worth conducting research which should focus on …..”

‒       Lines 573-578 : sentence too long.

Author Response

Dear Sir/Madame,

Thank you for writing the review and providing comments that directed improvements to the text. The comments provided have been taken into account in the next version of the article for review. We have corrected both editorial issues (concerning abbreviations used in the text, figure captions, minor linguistic errors), as well as taking into account the comment regarding the nomenclature of the designated value and introduced the phrase “thermal conductivity” instead of “heat transfer coefficient”.

Best regards

Reviewer 2 Report

Comments and Suggestions for Authors

The authors present in the manuscript their study on the usage of microencapsulated phase-change material to improve the insulating parameters of the walls of refrigerated trailers. The results showed that the implementation of PCM in the form of microcapsule in the structure of the walls of refrigerated trailers can bring real benefits in the form of improving the insulating properties of the walls, but within a limited scope and duration of operation, which depend primarily on the amount of phase change material used. Although these studies are not novel, the results are interesting to the community. Therefore, the manuscript is acceptable.

Author Response

Dear Sir/Madame,

Thank you for writing the review and providing comments directing improvements to the text.

Best regards.

Reviewer 3 Report

Comments and Suggestions for Authors

This manuscript presents a compelling exploration of "Usage of microencapsulated phase-change material to improve the insulating parameters of the walls of refrigerated trailers". While the methods employed in this study are not groundbreaking, they are deemed acceptable. It is important to highlight that several areas require correction within the manuscript.

11) The novelty and originality of this work should be highlighted in the last section of the introduction.

22) Discuss the limitations of the proposed approach and assess their impact on the conclusions of the work.

33) The literature review in the manuscript is outdated and lacks current references. It is recommended to enrich this section with more relevant and contemporary sources, such as: Surface modification of microencapsulated phase change materials with nanostructures for enhancement of their thermal conductivity; Recent advances in graphene-based phase change composites for thermal energy storage and management; Integration of phase change material and thermal insulation material as a passive strategy for building cooling in the tropics

44) The full terms of ‘mPCM’ and ‘PU’ should be spelled out at their first mention in the abstract and introduction, respectively.

55) Line 173: What does ‘ATP’ stand for?

66) Terms that have been abbreviated before should not be spelled out again. E.g., PCM, PU

77) In general, the grammar used in this paper can be improved. I suggest that some of the professional English language authors, or an editor, take a more active role in the re-writing and editing of the manuscript.

88) Line 276: ‘shown in Fig. 3.’ The mentioned figure is incorrect.

99) The decimal separator used in this work is inconsistent, i.e., both decimal point and decimal comma are used.

Author Response

Dear Sir/Madame

Thank you for writing the review and providing comments that directed improvements to the text. The comments provided have been taken into account in the next version of the article for review. We have corrected both editorial issues (concerning abbreviations used in the text, figure captions), as well as taking into account the comment regarding expanding the literature introduction. We are aware that there has been a lot of work currently and in previous years with the application of phase change materials, but in the introduction we tried to identify work focused on investigating its use in refrigerated transport, as well as the applicability of microencapsulated phase change materials. From the proposed literature we chose to cite work related to the application of microencapsulated phase change material in building, the other two proposals were in other areas of PCM research, in particular the improvement of its conductivity, which is the opposite of what we intended and discussed in the paper we wrote.

Best regards.