CFD Simulation of an Industrial Spiral Refrigeration System

Round 1

Reviewer 1 Report

The reviewed work is interesting and contains elements of novelty. After removing minor editorial errors (for example an error in equation (2), no minus sign before the pressure gradient), the work can be published.

Author Response

We would like to thank the referee for their time and valuable comments. Changes have been highlighted in red in the revised document; details of the changes are provided in the attached pdf file (original comments in italics)

Author Response File: Author Response.pdf

Reviewer 2 Report

The paper presents the CFD analysis, supported by experimental measurement, of a cooling system for application in the food industry. The paper is well written and organised and is suitable for publication on Energies, provided that the authors address the following issues:

- section 2: a simplified layout of the measurement setup in industrial environment should be included. Figure 6 should be placed in this section and therefore renumbered as figure 1

-section 3: a list of assumptions is missing. The title of the section is misleading, considering that it includes not only the main equations of the problem but also the derivation of the properties of the pasty. A better title should be given.

-section 4: a schematic layout of the boundary conditions and initial conditions used should be provided. The size of mesh elements is not given.

-section 5: quality of Figure 5 and figure 7 should be improved. It is also not clear to me why the figures are placed after the references. In section 5.2 the heat transfer coefficient is discussed qualitatively, but the reference to the values simulated and a comparison with references, if any, should be added.

-section 5/6: the topic presented is definitely interesting for a wide readership, but some comments on how to generalise the approach followed and how it can contribute to the advancement in the field are missing.

Author Response

We would like to thank the referee for their time and valuable comments. Changes have been highlighted in red in the revised document; details of the changes are provided in the attached pdf file (original comments in italics)

Author Response File: Author Response.pdf

Reviewer 3 Report

1. Common words such as mechanical, cryogenic and impingement, etc. are only capitalized if it is used at the beginning of sentences.
2. Please avoid too many demonstrative pronouns, unclear adverbs and etc. such as this, these, and so, further. Ex) investigate these, To do this, etc.
3. In the last paragraph in chapter 1, the objective of this study is not clear.
4. (p.3, L117) What is 'complete unit'? Please show clear analysis target.
5. Author had mentioned the design of the spiral refrigerator system is introduced in section 2. But I think the section of the spiral cooling system design is omitted in the manuscript.
6. In chapter 2, order of sentences should be changed. (L117) The explanation of experimental research to provide validation part should be started before description of specific experimental method including introductions of measuring devices.
7. Numbering of figure and table in the body of manuscript should be entered in order.  Figure 6 was showed in first.
8. Please show specifications of freezer cabinet (dimension, temperature departure, devices, etc.)
9. The description of suggested spiral cooling system is insufficient. Specifications of each parts, cooling mechanism, etc, should be updated.
10. The explanation on cooling process of the spiral chiller in section 5.1 should be shifted to previous chapter. I suggest the body of manuscript is reconstructed. For example, After introduction part (before the explanation of validation), the general descriptaion, cooling mechanism and specification, etc. on suggested spiral cooling system should be mentioned.
11. It is too hard to verify that Figure 4 shows good agreement between the measured and numerically calculated profiles. The comparison of quantitative values or the other figures which can show more clear analysis results are needed.
12. The section 5.1 is seemed to disconnect with other sections in chapter 5.
13. Quantitative comparison in results of  this manuscript is omitted overall. How much difference is simulation results compared with experiment data? What are the average or maximum temperatures of each measuring points in the experiment? What is the meaning of values at any condition and time?
What do the results in each section mean?
14. The main objective of this study is to develop the CFD simulation to predict cooling characteristic of the spiral cooling system for Cornish pasties. If so, the results of the research should be focused on the performance analysis with various operation, Initial and boundary conditions of spiral cooling system. So I feel the lack of these research contents.

Based on above comments, I recommend the article should be returned back to author for major revision.

Author Response

​We would like to thank the referee for their time and valuable comments. Changes have been highlighted in red in the revised document; details of the changes are provided in the attached pdf file (original comments in italics)

Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

The revised manuscript was improved enough based on the comments. But the expression styles of figure used in the body of the manuscript should be unified. For example, figure or Figure (Capital issue), Figure 2a or Figure 2(a), Figure 2 or Fig. 2.