Impact of the Magnetic Field on the Performance of Heat Pipes Driven by a Photovoltaic–Thermal Panel with Nanofluids

Round 1

Reviewer 1 Report

In the manuscript titled “Impact of Magnetic Field on the Performance of Heat Pipes Driven by Photovoltaic-Thermal Panel with Nanofluids”, a two-dimensional dynamic heat transfer and fluid flow model was developed to describe the behavior of the photovoltaic cell and the performance of a hybrid solar collector photovoltaic-thermal solar panel system under different magnetic field gauss forces using nanofluids driving heat pipes thermal panel at different conditions. The author claimed that the model fairly predicted the key parameters under different nanofluids conditions, magnetic fields.

The work is structured badly, written poorly and the Introduction section does not meet the standards of scientific work. Due to the low English level, the work is difficult to understand. The references are cited incorrectly – much literature does not seem to have the correct reference in the References section. Moreover, the Literature section provides a lot of literal citations – this may be perceived as plagiarism. Besides, these citations are not grammatically and stylistically consistent. The developed model has essential errors in the basic equations and laws. The calculated physical quantities do not have the correct physical unit often. The Nomenclature section is also incorrect. There are many units errors, capital case/lowercase mistakes, etc.

Below please find some examples:

Section 1. Page 1. Line 39-40.

“all the tests are carried out with a Reynolds number range (2900 W/m 2).” - Reynolds number is a dimensionless number.

Section 2.2. Page 7. Line 278.

Eq. (4) is incorrect in terms of units. Energy/heat cannot be confused with the power/heat flow rate.

Section 2.3. Page 7. Line 297.

Eq. (8) is incorrect. This is not a Fourier Law as it should.

Section 2.3. Page 8. Line 311.

Eq. (10): Why does the author multiply DELTAT and (Tf-Tfin)? It results in K^2 unit which is senseless.

Section 2.3. Page 8. Line 322.

Eq. (12) for conversion efficiency etha:

As can be found in the Nomenclature section:

Qin [W/m2]

Qthermal [W]

P [W]

It does not result in dimensionless etha as it should.

Section 2.5. Page 9. Line 351-353.

“Reference [54] reported that magnetic nanofluids with a low concentration of nanoparticles can significantly enhance their thermal.” – “their thermal” what?

Section 2.6. Page 10. Line 412.

Eq. (20) for effective heat transfer coefficient is incorrect even in terms of physical units.

Section 4. Page 13. Line 505.

“The PV panel characteristics under consideration in this study were obtained from Fargali et al. [22].” - The reference [22] is not Fargali et al. but Sheikoleslami et al. There is more literature cited in the text that does not seem to have the correct reference.

Section 4. Page 15. Line 531-533.

“This can be interpreted as per equations (1) and (2) where the dynamic cell temperatures are expressed in terms of the heat balance across the PV cells.” - In equations (1) and (2) there are no temperature, heat balance nor solar radiation.

Section 5. Page 28. Line 761-762.

“The results of our model prediction were compared to the data of reference [49] at similar conditions and plotted in Figure 24.” - Figure 24 does not show any comparison of model and experimental data.

To sum up, the reviewed manuscript does not meet any standards of the scientific work. It looks like it was written in rush, with many substantive errors. The English is poor and the whole manuscript does not look reliable.

Author Response

Dear Reviewer-1

We greatly appreciate your valuable and great comments and the manuscript has been revised according to your comments.

Thank you again for your thorough review.

Below please find the summery requested:
Section 1. Page 1. Line 39-40.
“all the tests are carried out with a Reynolds number range (2900 W/m 2).” - Reynolds number is a dimensionless number.
Reynolds number has dimension has been corrected and revised in the text
Section 2.2. Page 7. Line 278.
Eq. (4) is incorrect in terms of units. Energy/heat cannot be confused with the power/heat flow rate.
Equation (4) has been corrected and revised in ten text
Section 2.3. Page 7. Line 297.
Eq. (8) is incorrect. This is not a Fourier Law as it should.
Equation (8) has been corrected and revised in the text
Section 2.3. Page 8. Line 311.
Eq. (10): Why does the author multiply DELTAT and (Tf-Tfin)? It results in K^2 unit which is senseless.
Equation (10) has been corrected and revised in the text
Section 2.3. Page 8. Line 322.
Eq. (12) for conversion efficiency etha: As can be found in the Nomenclature section: 2 Qin [W/m2] Qthermal [W] P [W]
It does not result in dimensionless etha as it should.
Equation (12) and other terms have been corrected and revised in the text
Section 2.5. Page 9. Line 351-353.
“Reference [54] reported that magnetic nanofluids with a low concentration of nanoparticles can significantly enhance their thermal.” – “their thermal” what?
Comment about reference [54] has been revised
2
Section 2.6. Page 10. Line 412.
Eq. (20) for effective heat transfer coefficient is incorrect even in terms of physical units.
Equation (20) has been corrected and revised in ten text
Section 4. Page 13. Line 505.
“The PV panel characteristics under consideration in this study were obtained from Fargali et al. [22].” - The reference [22] is not Fargali et al. but Sheikoleslami et al. There is more literature cited in the text that does not seem to have the correct reference.
Comment about Fargali has been corrected and revised in the text
Section 4. Page 15. Line 531-533.
“This can be interpreted as per equations (1) and (2) where the dynamic cell temperatures are expressed in terms of the heat balance across the PV cells.” - In equations (1) and (2) there are no temperature, heat balance nor solar radiation.
We have responded that Equation (1) and (2) combined to have the Tc the PV cell temperature.
Section 5. Page 28. Line 761-762.
“The results of our model prediction were compared to the data of reference [49] at similar conditions and plotted in Figure 24.” - Figure 24 does not show any comparison of model and experimental data.
Figure number has been corrected and revised in the text
To sum up, the reviewed manuscript does not meet any standards of the scientific work. It looks like it was written in rush, with many substantive errors. The English is poor and the whole manuscript does not look reliable
We have responded to this point and additional text has been added,

Author Response File: Author Response.pdf

Reviewer 2 Report

This article proposes a model for predicting the changes in the parameters and efficiency of the integrated photovoltaic-thermal solar panel heat pipe hybrid system under different solar irradiance, material properties, and magnetic field conditions. The article mainly has the following problems,

1. The introduction part of the article only lists the previous related research, but it does not summarize it well. It would be better to explain the significance of this research based on the problems existing in the previous research.
2. The figures are too simple, and the curves in some figures are too close to make it difficult to see clearly. Properly handle the chart so that the data in it can better reflect the changes.
3. The nanofluid concentration in the article is 5%, which is rarely used in practice. It is better to use low-concentration nanofluids for calculations.
4. In the model validation part of the article, the researches on low-concentration nanofluids and pulsating heat pipes were compared with the numerical results. However, the influence of the concentration on the nanofluid is not considered, and the difference between the pulsating heat pipe and the ordinary heat pipe is also ignored.
5. There are some obvious small errors in the formula of the mathematical model part, which may be caused by carelessness. It is better to check again.

Author Response

Dear Reviewer-2

Greatly appreciate your valuable comments and please note the following responses to your comments point by point;

1. We have revised the manuscripts accordingly.
2. Figures have been revised according to your remarks.
3. The nanofluids concentrations of 5% were used in this paper because of their relevance to this application. We did some simulations with lower nanofluids concentrations, however, the enhancement over the water-based fluid was not significant.
4. The validation of the model was limited to available heat pipe experimental data available in the literature under magnetic field. Other simulations were conducted using different magnetized nanofluids concentrations, however, we only conducted the validations based on available concentrations and experimental work on the type of heat pipes used. It's also important to note the scope of this study was only focused on the use of magnetized nanofluids in heat pipes driven by solar PV-Thermal applications and but not on the different types of heat pipes.
5.  Small errors in the mathematical model equations have been corrected.

Round 2

Reviewer 1 Report

The author does not provide a detailed description of what he has done during the review. Some of the inquiries have been corrected and some of them have not. I do not know if the calculations have been made according to the correct equations and just the equations in the text were wrong or all the calculations are wrong from the very beginning and at this point, I am not able to check it. The introduction section is still prepared without scientific standards.

Author Response

The original version of the paper had the mass and balance equations and they were correct , however, had minor typing errors in these equations as pointed out in the review process. These typing errors were corrected and revised in the paper, however, all calculations were done using the original mass and energy equations where they are correct and contain no typing errors.

In our opinion, the introduction section gives the appearance it is long but this subject matter is very important and crucial to enhancing the performance of heat pipes and the PV-Th hybrid system and in particular, this paper touched three important subjects; heat pipes, nanofluids, and magnetic field. Therefore, its important to present a review of the most important work done in these fields. Also in our opinion, that the introduction section is within the scientific standards as per publications by other authors and my own publications in highly indexed journals. Please also note that my publications in highly indexed have more than 10,000 reads according to Research Gate.,   

Reviewer 2 Report

This manuscript can be accepted in its current version

Author Response

The original version of the paper had the mass and balance equations and they were correct , however, had minor typing errors in these equations as pointed out in the review process. These typing errors were corrected and revised in the paper, however, all calculations were done using the original mass and energy equations where they are correct and contain no typing errors.

In our opinion, the introduction section gives the appearance it is long but this subject matter is very important and crucial to enhancing the performance of heat pipes and the PV-Th hybrid system and in particular, this paper touched three important subjects; heat pipes, nanofluids, and magnetic field. Therefore, its important to present a review of the most important work done in these fields. Also in our opinion, that the introduction section is within the scientific standards as per publications by other authors and my own publications in highly indexed journals. Please also note that my publications in highly indexed have more than 10,000 reads according to Research Gate.,