Electromagnetic Modeling and Thermal Analysis of a Non-Axisymmetric System for Induction Brazing

Round 1

Reviewer 1 Report

In my opinion, the reviewed paper is a Comsol software tutorial. The paper is in some sense an advertisement for Comsol software which shows the possibilities of this software. The paper presents step by step how to perform numerical calculations using this software.

The analytical formulas contained in the paper are generally known from the theory of electromagnetic field and thermodynamics. In addition, I doubt whether the inductance of an axisymmetric coil can be compared with the inductance of a C-shape coil. Inductance of the coil depends on the physical properties and on its shape.

The paper should include a comparison of numerical analysis with measurements. In the induction heating necessary is the verification of the results obtained from numerical calculations with measurement results.

The references are too poor.

Author Response

First of all we would like to thank you for the thorough review of our paper (energies-843371) and the useful remarks to improve it.

 

Reviewer 1

Comments to the Authors

(1) In my opinion, the reviewed paper is a Comsol software tutorial. The paper is in some sense an advertisement for Comsol software which shows the possibilities of this software. The paper presents step by step how to perform numerical calculations using this software.

 

(2) The analytical formulas contained in the paper are generally known from the theory of electromagnetic field and thermodynamics.

(3) In addition, I doubt whether the inductance of an axisymmetric coil can be compared with the inductance of a C-shape coil. Inductance of the coil depends on the physical properties and on its shape.

 

(4) The paper should include a comparison of numerical analysis with measurements. In the induction heating necessary is the verification of the results obtained from numerical calculations with measurement results.

 

(5) The references are too poor.

 

 

To Reviewer 1:

Thank you for your review of our paper (energies-843371) and the valuable recommendations.

About

(1) We have revised the introduction and conclusion sections as we have emphasized what is new in the presented research:

For the presented application of induction brazing, no studies have been performed related to 3D modeling of an asymmetric inductor and on this basis to obtain the dependences of change of R and L during the technological process. Determining the power losses that are related to the cooling of the inductor and the total power required are also included. All these parameters defined by us are basic for the design of power electronic devices that generate the necessary high-frequency energy.

 

(2) We accept the remark and have removed from the text expressions (1) and (2).

 

(3) At the beginning of section 3 we have added an explanation with the following text:

One of the advantages of using ^©Comsol is that it gives a direct result for the inductance and resistance of the winding (Global Evaluation option). In this section we want to check whether the results given by ^©Comsol are realistic by making a comparison with a real measurement on a prototype

 

(4) The implementation of power measurement at high frequency currents and voltages (about 100KHz) requires specific and quite expensive equipment, which we do not have. Therefore, a comparison of the heating time of the model and the actual device was used to verify the model. For future research, we plan to perform the verification based on calorimetric methods.

 

(5) New literature has been added, but as we have already noted in commentary (1), not many works have been published on the subject under consideration.

Reviewer 2 Report

Paper No.: energies-843371-v1

Paper Title: Electromagnetic Modeling and Thermal Analysis of Non-axisymmetric System for Induction Brazing

Short description of the paper:

The paper presents a research study about the procedure for electromagnetic and thermal modeling of the induction brazing system. The proposed procedure is implemented for the real existing brazing system. The research is oriented to the industrial brazing system analysis.

The presented research is very interesting but has some drawbacks. The writing style looks like a master thesis text rather than a scientific paper. Most important it is not clear what are the original scientific contributions in the presented research. After reading the paper, the overall impression is that it presents the application of the FEM tool for modeling the existing brazing system with defined construction. The obtained simulation results have not been used for improving the system design. Also, the new procedure of system modeling is not the topic of the research. So, the contributions of the paper are very questionable at least in the present form of the paper.

Based on the above conclusions, this reviewer can recommend the paper for the major revision concerning the specific comments given below.

Below are specific comments to the Authors.

Comments to the Authors:

1. The last sentence in the abstract is more appropriate for the conclusion section than for the abstract. Please, replace this sentence with one or two presenting the concrete results (numerical data are welcome) of the performed research study.
2. The paragraph in the introduction section in lines 71-82 is generally descriptive discussion about the simulation/model complexity and in such form more appropriate for some thesis text than for research paper. Please, reformulate this description reducing it and focusing on this what is important for your research here. If you want to emphasize that you aim to simplify the simulation model it can be mentioned in one-two sentences.
3. Are expressions (1) and (2) and their descriptions in section 2 really necessary? Mean, there are generally very well known the Maxwell equations which are note used for developing some new solving method or procedure because the solving method is note researched here, the existing FEA (Finite Element Analysis) tool (COMSOL) is used as solving engine. So, it is questionable what new and important information these expressions bring regarding the presented research.
4. Line 255, numerical results for L and R of modeled coil are given, but the only expression for L is presented (8), why not given expression for R or omitted for L?
5. Line 260, the value of R is given for different frequencies. How these results are obtained, by FEM tool or some calculation expression (if yes which expression)? The same question is for all numerical data in lines 254-267, please clarify how these data are obtained.
6. As this reviewer mentioned in the general paper overview above it is unclear what is the scientific contribution of the presented research study. For example, in paper section 4, lines 279-281 is stated: “Obtaining the useful results for understanding the brazing process is the main goal of this work. 279 Visualization of the invisible physical phenomena and its time dependence is one of the main 280 advantages of our approach.”. Is this the original scientific contribution of the research? Maybe can be FEM tools have never had been used before for the brazing system analysis, but this needs to be improved by the existing literature overview. So, please define what are the original scientific contributions of the presented research in a clear manner.

Author Response

First of all we would like to thank you for the thorough review of our paper (energies-843371) and the useful remarks to improve it.

Reviewer 2

Comments to the Authors

The paper presents a research study about the procedure for electromagnetic and thermal modeling of the induction brazing system. The proposed procedure is implemented for the real existing brazing system. The research is oriented to the industrial brazing system analysis.

The presented research is very interesting but has some drawbacks. The writing style looks like a master thesis text rather than a scientific paper. Most important it is not clear what are the original scientific contributions in the presented research. After reading the paper, the overall impression is that it presents the application of the FEM tool for modeling the existing brazing system with defined construction. The obtained simulation results have not been used for improving the system design. Also, the new procedure of system modeling is not the topic of the research. So, the contributions of the paper are very questionable at least in the present form of the paper.

Based on the above conclusions, this reviewer can recommend the paper for the major revision concerning the specific comments given below.

Below are specific comments to the Authors.

(1) The last sentence in the abstract is more appropriate for the conclusion section than for the abstract. Please, replace this sentence with one or two presenting the concrete results (numerical data are welcome) of the performed research study.

(2) The paragraph in the introduction section in lines 71-82 is generally descriptive discussion about the simulation/model complexity and in such form more appropriate for some thesis text than for research paper. Please, reformulate this description reducing it and focusing on this what is important for your research here. If you want to emphasize that you aim to simplify the simulation model it can be mentioned in one-two sentences.

(3) Are expressions (1) and (2) and their descriptions in section 2 really necessary? Mean, there are generally very well known the Maxwell equations which are note used for developing some new solving method or procedure because the solving method is note researched here, the existing FEA (Finite Element Analysis) tool (COMSOL) is used as solving engine. So, it is questionable what new and important information these expressions bring regarding the presented research.

(4) Line 255, numerical results for L and R of modeled coil are given, but the only expression for L is presented (8), why not given expression for R or omitted for L?

(5) Line 260, the value of R is given for different frequencies. How these results are obtained, by FEM tool or some calculation expression (if yes which expression)? The same question is for all numerical data in lines 254-267, please clarify how these data are obtained.

(6) As this reviewer mentioned in the general paper overview above it is unclear what is the scientific contribution of the presented research study. For example, in paper section 4, lines 279-281 is stated: “Obtaining the useful results for understanding the brazing process is the main goal of this work. 279 Visualization of the invisible physical phenomena and its time dependence is one of the main 280 advantages of our approach.”. Is this the original scientific contribution of the research? Maybe can be FEM tools have never had been used before for the brazing system analysis, but this needs to be improved by the existing literature overview. So, please define what are the original scientific contributions of the presented research in a clear manner.

 

 

To Reviewer 2:

Thank you for your review of our paper (energies-843371) and the valuable recommendations.

About

(1) We have revised the introduction and conclusion sections as we have emphasized what is new in the presented research:

For the presented application of induction brazing, no studies have been performed related to 3D modeling of an asymmetric inductor and on this basis to obtain the dependences of change of R and L during the technological process. Determining the power losses that are related to the cooling of the inductor and the total power required are also included. All these parameters defined by us are basic for the design of power electronic devices that generate the necessary high-frequency energy.

 

(2) We accept the remark and he text has been edited;

 

(3) We accept the remark and have removed from the text expressions (1) and (2);

 

(4) We accept the remark and have added an expression for R;

 

(5) R depends on the frequency and this is one of the advantages of using numerical modeling with ^©Comsol;

 

(6) The conclusion section has been revised, highlighting the main contributions of the manuscript:

There are FEM brazing models, but they are usually on axial-symmetric coils. We are presenting that this modeling method can also be used for windings with a more complex shape. We are presenting for the first time parameters change of the winding during the process (inductance and resistance) as well as brazing of different materials. These results are important for determining the parameters in the design of the power electronic converter. The main goal is to realize different combinations of brazing materials with one converter. Modeling helps us determine the limits of change in power and frequency so that we can design the converter.

 

Round 2

Reviewer 1 Report

In my opinion, the reviewed paper is still a Comsol  tutorial. The paper should include the experiment. Bibliography is still poor.

Author Response

First of all, we would like to thank you for the thorough review of our paper (energies-843371) and the useful remarks to improve it.

 

Reviewer 1

Comments to the Authors

1. In my opinion, the reviewed paper is still a Comsol tutorial.
2. The paper should include the experiment.
3. Bibliography is still poor.

 

To Reviewer 1:

Thank you for your review of our paper (energies-843371) and the valuable recommendations.

About

1. We accept that some parts of Description section sound like tutorial. This section is revised to make it more formal and suitable for its purpose.
2. Main goal of the article is focused on the brazing system modeling with implementation into the industrial practice. Our aim is formalizing the process definitions and put them into the more generalized method for problem solving like optimization and design consideration. Some experiential references are included in Validation section.
3. Reference section is updated.

 

Again, thank you all for the exact review. 

Reviewer 2 Report

The authors have answered to the reviewer's remarks in appropriate manner, so this reviewer can recommend the revised paper for publication.

Author Response

Thank you for your review and the expressed opinion, that the paper "Electromagnetic Modeling and Thermal Analysis of Non-axisymmetric System for Induction Brazing" (energies-843371) is suitable for publication in Energies.

Round 3

Reviewer 1 Report

References should be larger.