Thermal Operation Maps for Lamm–Honigmann Thermo-Chemical Energy Storage—A Quasi-Stationary Model for Process Analysis^†

Round 1

Reviewer 1 Report

This study analyses the Lamm-Honigmann energy storage thermal cycle for understanding the process behaviours. The paper is well written. Few small items to be addressed before publication. The manuscript can be improved by considering the following: 

• Please update the abstract with the outcomes and quantitative results.
• Please strengthen the literature review with the limitations of the studies reported in the literature and gaps in the studies conducted so far.
• Please modify Fig 2 as the subtext are not readable as well as highlight the changes between the schemes of B and C.
• Please also highlight the developed method’s industrial applications/how industries can be benefitted from it.

Author Response

I appreciate your constructive feedback, thank you.

• The abstract will be updated with the outcomes and quantitative results, such as examplery reduction in thermal efficiency with driving temperature difference and values of mass flow rates, thermal efficiency and storage discharge time for a constant power charging and discharging scenario
• the introduction will be reworked, the cited literature will be better contextualized, their outcomes described more in detail to make clear the gap this study fills
• Figure2 will be adapted according to your suggestions
• industrial applications for the storage will be addressed in the reworked introduction

Reviewer 2 Report

In this paper, authors have done a lot of theoretical formula derivations, which help us understand the mechanical charging and discharging processes of the Lamm-Honigmann process. However, the poor writing formats and the unified horizontal and vertical pages cause difficulties for readers. This paper appears to be more of a technical report than journal paper. Besides, the correctness of the prediction model proposed in this paper, which claims to predict the power output/input and efficiency without the need of extensive simulation studies, needs to be verified by comparison with existing simulation or experimental studies. For the full text, the descriptions of the pictures are confusing, and numbering the subpictures will be a good way to illustrate them clearly. This paper cannot be published in current version.

Author Response

Thank you for your feedback.

• poor writing formats: we will try to structure the text a bit more by separating paragraphs; please, keep in mind, that the general format is given by the journal's template; the horizontal pages are intended to provide better readability of the derived formula's (to avoid too much line breaks within them); if this is not achieved i will turn them into vertical pages again
• technical report: We will try to clarify in the introduction that this paper intends to demonstrate how „a scientific analysis of the technical parameters of a seemingly highly non-linear and non-stationary system allows to reduce the complexity of the describing PDEs to such an extent that an analytical solution can be found. This solution then allows an exhaustive discussion on efficiency and operational features based on said parameters“. This is not a technical report.
• Correctness: Comparison to experiments will be done; here we mainly intend to highlight the methodology. Due to the complexity, up to now there are no numerical simulations which are more detailed than our approach.
• Description of pictures: we will improve that

Reviewer 3 Report

Paper is of current interest and falls in the scope of the journal, however, there are the following suggestions authors should address and then I welcome for publication:

1. Would you please emphasize the novelty and difference of present work with previous works more?
2.  Please check all manuscript for typo and punctuation mistakes,
3.  It is recommended that the wordings and grammar of English should be rechecked throughout the present.
4.  In the Introduction, the literature review was not logically organized and all literatures cited seem separate descriptions without connections. The readers can’t know what the state-of-art methodologies or gaps the current study plans to resolve or fill, and how significant or what contribution the current study is?
5.  Write the conclusion more precious

Author Response

Thank you for your constructive and precise feedback.

1. The introduction will be reworked and  the novelty of this work be addressed more precisely: this work is a scientific analysis of the technical parameters of a seemingly highly non-linear and non-stationary system that allows to reduce the complexity of the describing PDEs to such an extent that an analytical solution can be found. This solution then allows an exhaustive discussion on efficiency and operational features based on said parameters
2. see 3.
3. I will address the language and typo issues by handing it into our universitie's manuscript check if remaining time makes it possible
4. as mentioned in 1. the introduction will be reworked, the outcomes of the cited papers and their connections and application context will be drawn more clearly
5. The conclusion will be reworked and the discussed results be reflected there
   

Round 2

Reviewer 2 Report

The authors have revised the manuscript carefully and completely. The revised one looks more better which can be accepted.