Energy Analysis and Verification of a Constant-Pressure Elastic-Strain Energy Accumulator Based on Exergy Method

Round 1

Reviewer 1 Report

The paper proposed a rubber airbag charging/discharging energy storage efficiency model based on the exergy analysis method for a constant-pressure elastic strain energy accumulator. The problem addressed is timely. A number of researchers are working on the subject and relevant work has been sufficiently considered.

The proposed discritization approach is well formalized. There are some issues to clarify as follows:

·       This paper mainly focuses on an accurate energy storage efficiency model and the influence of the Mullins effect during the process of rubber airbag charging/discharging by exergy analysis. However, the novelty of the methods and findings needs to highlight in the conclusion part.

·       The constant-pressure elastic strain energy accumulator characteristic can expand and contract at a relatively constant pressure when charging/discharging. However, figure 2 only shows a part of the charge and discharge cycle. It should be interesting to report the entire cycle.

·       The quality of the figures 2 and 4 in the article is a little poor, and the content and form of the pictures are not standardized. It is recommended to reorganize and beautify them.

·       In Equations (1)-(2), the energy storage is given. Did the Authors actually use that? Along the text, the expressions for energy saving and efficiency are a little confusing.

·       In the first paragraph of the introduction, the Authors write "energy-saving" about energy storage elements. However, the paper only describe the hydraulic accumulator .That is a bit confusing. Is it necessary to add some other storage devices, such as gas storage devices?

·       Please, check the format in the following:

(1) Capital "Where" after each equation;

(2) The ring numbering should be replaced by another form.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

This paper presents a constant-pressure elastic strain energy accumulator based on the rubber material hyperelastic effect. However, I have the following comments:

-Please carefully check the similarity in the figures, especially Fig. 1.

-The main contributions of the paper should be clearly mentioned. Also they can be summarized in the last paragraph in Introduction section. 

-Quality of figures should be improved to enhance the overall quality of the paper. 

-Future work could be mentioned in the Conclusion section.

-I think equation (8) is not correct, please check.

Author Response

Detailed Response to Reviewers

Dear Editors and Reviewers,

Thank you for your letter and for the reviewers’ comments concerning our manuscript entitled “Energy Analysis and Verification of a Constant-Pressure Elastic Strain Energy Accumulator Based on Exergy Method” (ID: sustainability-1882721). Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our researches. We have studied comments carefully and have made correction which we hope meet with approval. The main corrections in the paper and the responds to the reviewer’s comments are as flowing:

Reviewer #2:

This paper presents a constant-pressure elastic strain energy accumulator based on the rubber material hyperelastic effect. However, I have the following comments:

• Please carefully check the similarity in the figures, especially Fig. 1.

Response:  According to the Reviewer’s suggestion. We have changed the corresponding pictures and reorganized them.

• The main contributions of the paper should be clearly mentioned. Also they can be summarized in the last paragraph in Introduction section.

Response:  According to the Reviewer’s suggestion. We have introduced the main contributions of the paper in the last paragraph in Introduction section. This paper mainly focuses on an accurate energy storage efficiency model and the influence of the Mullins effect during the process of rubber airbag charging/discharging by exergy analysis. More details could be found in the revised manuscript.

• Quality of figures should be improved to enhance the overall quality of the paper.

Response:  Thanks to Reviewer’s suggestion. We have changed the corresponding pictures and reorganized them.

• Future work could be mentioned in the Conclusion section.

Response:  Thanks to Reviewer’s suggestion. We have added some contents and briefly explained the future work.

• I think equation (8) is not correct, please check.

Response:  According to the Reviewer’s suggestion. We checked the equation (8) according to the context and confirmed that there is no problem. The calculation equation of the exergy efficiency of the entire system is the product of the two stages.

• Extensive editing of English language and style required.

Response:  Thanks to Reviewer’s suggestion. This paper has been polished and modified by LetPub before, and this time they also recheck and confirm it. We think there is no problem now.

We tried our best to improve the manuscript and made some changes in the manuscript. These changes will not influence the content and framework of the paper. And here we did not list the changes but you could find them in the revised paper.

We appreciate for Editors/Reviewers’ warm work earnestly, and hope that the correction will meet with approval.

Once again, thank you very much for your comments and suggestions.

Reviewer 3 Report

The work deals with important aspects of energy storage efficiency. The theme is innovative and new to the subject. As part of the work, a new constant pressure elastic strain energy accumulator based on the hyperelastic effect of rubber material was proposed. The results show that the proposed solution is highly effective. The introduction provides an insufficient literature review. There are no new current items. Please add a few. This will certainly enrich the overview of the current state of knowledge. Research part. The presentation of the model and the research object should be considered correct. The preparation process, research methodology and analysis of the results are good. There are no content errors. The work is very unusual and includes special cases of energy accumulators. The illustrations in chapters 2 and 3 are correct. The formulas used in Chapter 3 are correctly quoted and contain no errors. Descriptions of figures, e.g. chapter 4 figure 5, adjust the captions to the MDPI format. The course of the research description is very detailed. It contains a lot of information that allows you to recreate the research. The measuring system is described in detail. The analysis of the results shows that this solution is highly effective. The presented results are correctly selected and described. Some drawings could be in a larger format from 11 to 15. And others. The most important summary is included in points. Provide more figures.

Author Response

Detailed Response to Reviewers

Dear Editors and Reviewers,

Thank you for your letter and for the reviewers’ comments concerning our manuscript entitled “Energy Analysis and Verification of a Constant-Pressure Elastic Strain Energy Accumulator Based on Exergy Method” (ID: sustainability-1882721). Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our researches. We have studied comments carefully and have made correction which we hope meet with approval. The main corrections in the paper and the responds to the reviewer’s comments are as flowing:

Reviewer #3:

• The work deals with important aspects of energy storage efficiency. The theme is innovative and new to the subject. As part of the work, a new constant pressure elastic strain energy accumulator based on the hyperelastic effect of rubber material was proposed. The results show that the proposed solution is highly effective. The introduction provides an insufficient literature review. There are no new current items. Please add a few. This will certainly enrich the overview of the current state of knowledge.

Response:  Thanks to Reviewer’s suggestion. We have added some recent relevant reference, which will be helpful for our following research and ideas.

• Research part. The presentation of the model and the research object should be considered correct. The preparation process, research methodology and analysis of the results are good. There are no content errors. The work is very unusual and includes special cases of energy accumulators. The illustrations in chapters 2 and 3 are correct. The formulas used in Chapter 3 are correctly quoted and contain no errors. Descriptions of figures, e.g. chapter 4 figure 5, adjust the captions to the MDPI format. The course of the research description is very detailed. It contains a lot of information that allows you to recreate the research. The measuring system is described in detail. The analysis of the results shows that this solution is highly effective. The presented results are correctly selected and described. Some drawings could be in a larger format from 11 to 15. And others. The most important summary is included in points. Provide more figures.

Response:  Thanks to Reviewer’s suggestion. We have changed the corresponding pictures and reorganized them. And the existing figures are enough to explain the test results, so there is no need to add more figures.

We tried our best to improve the manuscript and made some changes in the manuscript. These changes will not influence the content and framework of the paper. And here we did not list the changes but you could find them in the revised paper.

We appreciate for Editors/Reviewers’ warm work earnestly, and hope that the correction will meet with approval.

Once again, thank you very much for your comments and suggestions.