A Numerical Study of Dual-Inlet Air-Cooled PV/T Solar Collectors with Various Airflow Channel Configurations
Round 1
Reviewer 1 Report
In this work, a photovoltaic/thermal (PV/T) collector with a dual-air-inlet configuration is numerically investigated. This is an interesting topic, suitable for the readership of this journal. But the study requires major revisions in order to be considered for publication in SUSTAINABILITY. My comments are listed below.
MAJOR COMMENTS
1. The need for this study is not justified in the introduction. The authors state that "But these scholars had not deeply studied configuration change of the two-inlet air-cooled PV/T system. Therefore, in this paper some two-inlet air-cooled PV/T solar collection systems with various air flow channel configurations were studied." This is hardly a justification for this work. The authors need to clearly state what is novel about this work compared to many other works in the literature that covered the dual-air-inlet PVT/T configuration.
2. The abstract should be revised. Currently, the authors are mainly stating some general results in the abstract. The reader needs to understand the need for this work and its novel contributions from reading the abstract.
3. The keywords should also be revised to better reflect the content of this work. Some of the entries are too general (e.g., solar energy), while others are too specific and could have different meanings (e.g., two-inlet). An entry like "photovoltaic/thermal" should be part of the keywords, for example.
4. A full language revision of the manuscript is required, preferably by a native speaker or a professional editor.
5. In Eq 1, it is not clear what "effective utilization coefficient of solar energy" means for alpha. Typically, part of the input solar radiation will be lost due to optical losses by the glass cover and the material encapsulating the PV cells. But more importantly, in the first term to the right-hand side of the equation, the amount of solar radiation that actually reaches the PV cells is not accounted for (simply multiplying eta by G is equivalent to saying that all solar radiation reaches the PV cells, which is incorrect).
6. A lot of modeling details are ambiguous in this work. For example, how was the convective heat transfer coefficient computed between the PV panels and confined air in the channel? How is the electrical conversion efficiency of the PV cells computed? What are the input parameters in the simulations? What are the turbulence modeling details adopted in this work?
7. The authors also did not specify the computational package or code they used in developing this work.
8. The physical insight and justification for some of the results are lacking. For example, the discussion of Figs. 18-19 could be greatly expanded as there is much physics that should be uncovered in these figures.
9. There is nothing in this paper about the PV part of the PV/T collector (e.g., geometric effects on PV efficiency, power output, temperature). Instead, almost all focus is given to the effects of geometry on thermal performance.
MINOR COMMENTS
1. Please replace "systems" with "system" in the title.
2. Pleas replace "photo-thermal" and "photo-voltaic" with "photothermal" and "photovoltaic" throughout the manuscript.
3. There is inappropriate use of hyphens (-) throughout the manuscript that needs to be corrected.
Author Response
The comments from Reviewer 1
#1: The need for this study is not justified in the introduction. The authors state that "But these scholars had not deeply studied configuration change of the two-inlet air-cooled PV/T system. Therefore, in this paper some two-inlet air-cooled PV/T solar collection systems with various air flow channel configurations were studied." This is hardly a justification for this work. The authors need to clearly state what is novel about this work compared to many other works in the literature that covered the dual-air-inlet PVT/T configuration.
Response: Many thanks for this good suggestion. It is very important that the need for this study should be given in the introduction. We have collected again some literatures that covered the dual-air-inlet PV/T configuration. But there are not many scholars who study the multi-inlet and two-inlet air air-cooled PV/T solar collectors. The multi-inlet air-cooled PV/T systems can be divided into two types: the extra inlets are parallel to air channel and the extra inlets are perpendicular to air channel. The extra inlets mean the additional inlets comparing with the traditional single inlet PV/T solar collector. The advantages of the second type, extra inlets perpendicular to air channel, is more area for laying photovoltaic panels. And the elevation of thermal efficiency is not visible when the number of inlets is greater than 3. Moreover, the two-inlet air-cooled PV/T system is not only higher thermal efficiency and lower peak photovoltaic (PV) temperature, but also is easy to be implemented and does not add significant cost. According to the above discussion, our work studied the two-inlet air-cooled PV/T solar collectors with two inlets perpendicular to air channel, and analyzed the thermal performance of them when the configuration of air channel was changed.
All the researchers who studied the two-inlet air-cooled PV/T solar collectors did not pay much more attention to the configuration of air channel with two air inlets, such as the areas of two air inlets, lengths of the front and back air channels and angle of second PV panel. Therefore, the PV/T solar collectors with various air flow channel configurations are numerically analyzed with ANASY Fluent, and the heat transfer efficiency and flow characteristic are analyzed in this paper. All above are the novel contributions of this paper.
#2: The abstract should be revised. Currently, the authors are mainly stating some general results in the abstract. The reader needs to understand the need for this work and its novel contributions from reading the abstract.
Response: Yes, you are right. We should revise the abstract. The following is the rewritten abstract.
The multi-inlet air-cooled photovoltaic/thermal (PV/T) technology can not only avoid the poor heat transfer conditions of the single inlet PV/T air collector but also reduce the peak photovoltaic (PV) temperature and improve the utilization of solar energy. As air-cooled the PV/T collector uses no more than three inlets, the elevation of thermal efficiency is significantly effective. The air-cooled PV/T solar collectors with two side inlets were numerically analyzed. And with various air flow channel configurations, the heat transfer efficiency and flow characteristic are investigated. By increasing the area of the second inlet, thermal and electrical efficiency can be improved. When the length ratio of the front and back air channel was reduced, the averaged outlet temperature first decreases and then increases. There is minimum heat-exchanging quantity of the dual-air-inlet PV/T air collector. Increasing the angle between the photovoltaic panel and the bottom panel in the second part of the air channel can elevate the thermal efficiency of the dual-air-inlet PV/T air collector. But the average temperature of the photovoltaic panels increased, which reduced the photovoltaic efficiency.
#3: The keywords should also be revised to better reflect the content of this work. Some of the entries are too general (e.g., solar energy), while others are too specific and could have different meanings (e.g., two-inlet). An entry like "photovoltaic/thermal" should be part of the keywords, for example.
Response: Thank you for your advice. I have revised the keywords in our paper. The Updated keywords are “Photovoltaic/thermal; Air-cooled; Dual-air-inlet; Numerical simulation, air flow channel configuration”. All the words “two-inlet” in our paper were replaced by “Dual-air-inlet”.
#4: A full language revision of the manuscript is required, preferably by a native speaker or a professional editor.
Response: I am not confident about my English writing. So we revised the text carefully again.
#5: In Eq 1, it is not clear what "effective utilization coefficient of solar energy" means for alpha. Typically, part of the input solar radiation will be lost due to optical losses by the glass cover and the material encapsulating the PV cells. But more importantly, in the first term to the right-hand side of the equation, the amount of solar radiation that actually reaches the PV cells is not accounted for (simply multiplying eta by G is equivalent to saying that all solar radiation reaches the PV cells, which is incorrect).
Response: Thank you for your advice. We have revised the Eq 1. We know that the glass will reflect some sunlight. But it doesn't have much effect on our simulations and calculations. The transmission coefficient of the glass can be included in effective utilization coefficient of solar energy.
#6: A lot of modeling details are ambiguous in this work. For example, how was the convective heat transfer coefficient computed between the PV panels and confined air in the channel? How is the electrical conversion efficiency of the PV cells computed? What are the input parameters in the simulations? What are the turbulence modeling details adopted in this work?
Response: Thank you for your advice. The convective heat transfer coefficient computed between the PV panels and confined air in the channel is difficult to get. The photo-thermal efficiency can be calculated by Eq 5.
(5)
The photovoltaic efficiency can be calculated by Eq 4.
(4)
All the input parameters and adopted the turbulence model were given in Table 1 and the Eq 6 to 13.
#7: The authors also did not specify the computational package or code they used in developing this work.
Response: Thank you for your advice. The simulation was employed using ANASY Fluent. We have specified this computational package in our work.
#8: The physical insight and justification for some of the results are lacking. For example, the discussion of Figs. 18-19 could be greatly expanded as there is much physics that should be uncovered in these figures.
Response: Thank you for your advice. Some the discussions of Figs. 18-19 have been added.
#9: There is nothing in this paper about the PV part of the PV/T collector (e.g., geometric effects on PV efficiency, power output, temperature). Instead, almost all focus is given to the effects of geometry on thermal performance.
Response: Thank you for your advice. We should not neglect PV efficiency. An analysis of electrical efficiency was added in our work.
#10: Please replace "systems" with "system" in the title.
Response: Many thanks for this good suggestion. We have revised our title as: “A numerical study of the dual-air-inlet air-cooled PV/T solar collectors with various air flow channel configurations”.
#11: Pleas replace "photo-thermal" and "photo-voltaic" with "photothermal" and "photovoltaic" throughout the manuscript.
Response: Many thanks for this good suggestion. We have replace "photo-thermal" and "photo-voltaic" with "photothermal" and "photovoltaic" throughout the manuscript
#12: There is inappropriate use of hyphens (-) throughout the manuscript that needs to be corrected.
Response: Many thanks for this good suggestion. We have checked the full paper for the (-).
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Dear Authors,
The paper presents interesting aspects about air-cooled PV/T-s with, but there are several aspects which should be solved:
1. L18: “de-creases”; L19: ‘quan-tity” should be corrected; please check spelling and word separation throughout the paper;
2. I consider that too many details are given in the abstract, and the reader is not yet aware about the meaning of these details;
3. The two sentences from L46-49 can be compacted into 1 sentence.
4. I recommend explaining equation like this: where: alfa is …; G is …; ...
5. Using L for cross-sectional area ratio is rather unusual. L is mainly used for length.
6. How were the values in Tab. 1 chosen?
7. Please describe the software used for the numerical simulations.
8. In the text deg.K is used, while in the figures deg.C. Please uniform.
9. L 252 mentions “forced ventilation”. What are its characteristics (speed, air volume …)?
10. L 255: “This characteristic is consistent with the experimental result.” The experimental results are no presented in the paper.
11. L 325: “the photoelectric efficiency will increase”. With how much? The photoelectric effect is not studies in detail in the paper. Please describe this effect.
12. The paper only describes an horizontal orientation of the PVTs. But only seldom they are installed in this position. PVTs are usually tilted on roofs, or more often on vertical facades especially air-cooled ones. Please also analyze these 2 mounting possibilities.
I hope that my comments will be useful.
Sincerely,
Reviewer
Author Response
The comments from Reviewer 2
#1: L18: “de-creases”; L19: ‘quan-tity” should be corrected; please check spelling and word separation throughout the paper;
Response: Thank you for your advice. We have check spelling and separation throughout the paper. And keep all the word separation are correct.
#2: I consider that too many details are given in the abstract, and the reader is not yet aware about the meaning of these details;
Response: Thank you for your advice. We have revised the abstract.
#3: The two sentences from L46-49 can be compacted into 1 sentence.
Response: Thank you for your advice. We have combined the two sentences from L46-49.
#4: I recommend explaining equation like this: where: alfa is …; G is …; ...
Response: Thank you for your advice. We have revised equation explaining as you said.
#5: Using L for cross-sectional area ratio is rather unusual. L is mainly used for length.
Response: Thank you for your advice. X have been used for cross-sectional area ratio.
#6: How were the values in Tab. 1 chosen?
Response: Good question. We consider the height of the second inlet is smallest. Between 0.0081 and 0.045(the height of the first inlet) we picked five points which divided this distance into five equal sections.
#7: Please describe the software used for the numerical simulations.
The simulation was employed using ANASY Fluent. We have specified this computational package in our work.
#8: In the text deg.K is used, while in the figures deg.C. Please uniform.
Response: Thank you for your advice. Deg.C was used throughout our paper.
#9: L 252 mentions “forced ventilation”. What are its characteristics (speed, air volume …)?
Response: Thank you for your advice. The detail of the forced ventilation was shown in Table 1. You can find the values of Speed, the mass flow rate, density and specific heat capacity of air.
#10: L 255: “.” The experimental results are no presented in the paper.
Response: Thank you for your advice. We have modified the expression “This characteristic is consistent with the experimental result” as follow.
Its flow direction points downwards about 45 degrees below. And the air temperature in the middle layer is significantly reduced. The experiment carried out by Yang and Athienitis [24] shows that the temperature of the middle layer in the second air channel is cooled from 30 to 25 oC by the fresh air from the second inlet. Therefore, the flow characteristic exhibited by us is consistent with the experimental result.
#11: L 325: “the photoelectric efficiency will increase”. With how much? The photoelectric effect is not studies in detail in the paper. Please describe this effect.
Response: Thank you for your advice. The calculated photoelectric efficiency of all the conditions in our work have been given in Table 4, 6 and 8.
#12: The paper only describes an horizontal orientation of the PVTs. But only seldom they are installed in this position. PVTs are usually tilted on roofs, or more often on vertical facades especially air-cooled ones. Please also analyze these 2 mounting possibilities.
Response: Yes, you are right. The air-based PV/T systems are usually tilted on roofs or on vertical facades. In my opinion, for the Slanted and vertical air-based PV/T systems, natural convection plays more important role in flow. More inlets will intensify effect of the natural convection. The differential pressure generated by natural convection will absorb more fresh air to get into the air channel from the extra inlets. These studies are very interesting. And we will investigate them in our next work.
Author Response File: Author Response.pdf
Reviewer 3 Report
General Comments
This manuscript presents a study regarding A numerical study of the two-inlet air-cooled PV/T solar collection systems with various air flow channel configurations. The paper is aligned with the journal's scope.
In my opinion, this study can be considered for publication, but the manuscript needs to be revised and Authors should check the following comments for addressing mentioned issues.
The manuscript presents many language flaws such as unnecessary repetition of words and occasional mistakes. The text and grammar do not meet the criteria of a research paper. The entire manuscript must be re-written, preferably by a native speaker, taking into account the scientific nature of the text. Therefore, the text requires a thorough revision before any publication.
References: The references are not coherently formatted and must be thoroughly revised. The authors are advised to strictly follow the journal guidelines. Also References needed to be updated. I suggest the following:
Also, I suggest the following reference:
Energies 2021, 14(21), 6921; https://doi.org/10.3390/en14216921
The Conclusions section is too short and should be rewritten. The authors do not clearly summarize the actions taken and results.
Detailed Comments
1) I believe the title of the article is misspelled; is "solar collection systems" should be "solar collectors systems"
2) Sentence: When the inlet / outlet area ratio is reduced, air getting into the second inlet enhances the convection heat transfer and the temperature distribution in the second pipe is more uniform. - is incomprehensible to someone who does not know exactly what the article is about. The abstract should be written in such a way that the interested person will be well aware of its content when reading it.
3) Heat-exchanging quantity - what is this? heat flux, heat flux density? maybe better heat transfer..
4) Line 18: correct: de-creases
5) Line 19: correct heat-exchanging quan-tity
6) The authors present details in an abstract instead of generally writing about the results of the research.
7) Line 28: "Photovoltaic and photo-thermal solar collection system is a combination of photo-voltaic modules and thermal energy collection modules." - this sentence does not contain the correct technical wording of the devices only resulting from a literal translation.
8) Line 30: correct: pho-tovoltaic-thermal - there are many such errors at work. I don't mention them anymore; find them and correct them
9) Line 121: correct: 45mm
10) Line 152: correct: nel is ：
11) Line 153: please list the symbols of the parameters in question one by one
12) Line 165: Structured hexahedral meshes were generated to complete grid division of the computational model. - how was it done, what are the mesh parameters, was it used for this program? Please provide details
13) Line 177: correct 300W∙m-2
14) Line 182: correct 80 W∙m-2
15) Line 189: turbulence model is based on the standard k-ε, and the mesh has good adaptability. - How is the reader supposed to know this?
16) Line 72 and 394: computational fluid dynamics (CFD) repetition
17) Editing the text of the work leaves much to be desired. The text has different formatting, the authors do not use a space separating the abbreviation of the table, drawing and number; the authors do not follow the rules to separate or not the numerical value and the unit (e.g. degrees, cm, m) and many others. This needs to be significantly improved in the text of the work.
Author Response
The comments from Reviewer 3
#1: I believe the title of the article is misspelled; is "solar collection systems" should be "solar collectors systems"
Response: Thank you for your advice. We have rewritten the title of our article as: “numerical study of the dual-air-inlet air-cooled PV/T solar collectors with various air flow channel configurations”.
#2: Sentence: When the inlet / outlet area ratio is reduced, air getting into the second inlet enhances the convection heat transfer and the temperature distribution in the second pipe is more uniform. - is incomprehensible to someone who does not know exactly what the article is about. The abstract should be written in such a way that the interested person will be well aware of its content when reading it.
Response: Thank you for your advice. We have rewritten the Abstract.
The multi-inlet air-cooled photovoltaic/thermal (PV/T) technology can not only avoid the poor heat transfer conditions of the single inlet PV/T air collector but also reduce the peak photovoltaic (PV) temperature and improve the utilization of solar energy. As air-cooled the PV/T collector uses no more than three inlets, the elevation of thermal efficiency is significantly effective. The air-cooled PV/T solar collectors with two side inlets were numerically analyzed. And with various air flow channel configurations, the heat transfer efficiency and flow characteristic are investigated. By increasing the area of the second inlet, thermal and electrical efficiency can be improved. When the length ratio of the front and back air channel was reduced, the averaged outlet temperature first decreases and then increases. There is minimum heat-exchanging quantity of the dual-air-inlet PV/T air collector. Increasing the angle between the photovoltaic panel and the bottom panel in the second part of the air channel can elevate the thermal efficiency of the dual-air-inlet PV/T air collector. But the average temperature of the photovoltaic panels increased, which reduced the photovoltaic efficiency.
#3: Heat-exchanging quantity - what is this? heat flux, heat flux density? maybe better heat transfer..
Response: The heat-exchanging quantity is the total heat exchange between PV panels and air in the air flow channel. It can be calculated by the following equation.
#4: Line 18: correct: de-creases
Response: Thank you for your advice. We have already modified.
#5: Line 19: correct heat-exchanging quan-tity
Response: Thank you for your advice. We have already modified.
#6: The authors present details in an abstract instead of generally writing about the results of the research.
Response: Thank you for your advice. We have rewritten the Abstract.
#7: Line 28: "Photovoltaic and photo-thermal solar collection system is a combination of photo-voltaic modules and thermal energy collection modules." - this sentence does not contain the correct technical wording of the devices only resulting from a literal translation.
Response: Thank you for your advice. That sentence has been revised as “Photovoltaic and photothermal solar collection system is a combination of photovoltaic modules and thermal energy collection modules.”
#8: Line 30: correct: pho-tovoltaic-thermal - there are many such errors at work. I don't mention them anymore; find them and correct them
Response: Thank you for your advice. Maybe the editor locked the format of the words during typesetting. We have already modified them.
#9: Line 121: correct: 45mm
Response: Thank you for your advice. We have already modified it.
#10: Line 152: correct: nel is ：
Response: Thank you for your advice. We have already modified it.
#11: Line 153: please list the symbols of the parameters in question one by one
Response: Thank you for your advice. We have list the symbols of the parameters in all equations, and the “Nomenclature” has been given in our work.
#12: Line 165: Structured hexahedral meshes were generated to complete grid division of the computational model. - how was it done, what are the mesh parameters, was it used for this program? Please provide details
Response: Thank you for your advice. The structured hexahedral meshes were generated by using the ANSYS ICEM. The mesh parameters are maximum element size, minimum element size, maximum element growth rate, curvature factor and narrow area resolution. Our simulation was carried out by ANSYS Fluent, and these mesh parameters impact the quality of the calculation. On account of simple physical model, structured hexahedral meshes can be implemented easily. The mesh quality is good. Hence, it is not necessary to provide details of mesh parameters.
#13: Line 177: correct 300W∙m-2
Response: Thank you for your advice. We have already modified.
#14: Line 182: correct 80 W∙m-2
Response: Thank you for your advice. We have already modified.
#15: Line 189: turbulence model is based on the standard k-ε, and t. - How is the reader supposed to know this?
Response: Thank you for your advice. We have deleted the “he mesh has good adaptability”. The detail of the standard k-ε turbulence model has been given in our paper.
#16: Line 72 and 394: computational fluid dynamics (CFD) repetition
Response: Thank you for your advice. We have already modified.
#17: Editing the text of the work leaves much to be desired. The text has different formatting, the authors do not use a space separating the abbreviation of the table, drawing and number; the authors do not follow the rules to separate or not the numerical value and the unit (e.g. degrees, cm, m) and many others. This needs to be significantly improved in the text of the work.
Response: Thank you for your advice. After we finished the revisions, we must read our paper carefully and modify found errors.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
The authors have adequately responded to many comments from this reviewer, with few exceptions, as follows:
1. Although it has been somewhat improved, the Abstract still needs to be further revised. For example, the second sentence needs to be checked for language. Furthermore, the authors should end the abstract with an insightful future outlook regarding their proposed system design.
2. With regards to the authors' response to Comment #5 in the previous revision, please clearly mention this in your assumptions.
3. The authors' response to Comment #6 in the previous revision is unacceptable. The question remains: how were the convective heat transfer coefficients computed? In the presented equations, there are convective heat transfer coefficients between the insulation layer and air, between the PV cells and air, and between the PV cells and the ambient air. Details about the way the convective heat transfer coefficients are evaluated are not marginal since convective heat transfer dominates the behavior of the entire system.
4. In the title, please change 'of the dual-air-inlet air-cooled PV/T solar collectors' into 'of dual-inlet air-cooled PV/T solar collectors'.
Author Response
The comments from Reviewer 1
#1: Although it has been somewhat improved, the Abstract still needs to be further revised. For example, the second sentence needs to be checked for language. Furthermore, the authors should end the abstract with an insightful future outlook regarding their proposed system design.
Response: Thank you for your advice. You are right. I should further revised the abstract.
The multi-inlet air-cooled photovoltaic/thermal (PV/T) technology not only avoids the poor heat transfer conditions of single inlet PV/T air collectors, but also reduces photovoltaic (PV) peak temperature and improves solar energy utilization. Since air-cooled PV/T collectors use no more than three inlets, the increase in thermal efficiency is significantly more effective. Therefore, a numerical analysis of an air-cooled PV/T solar collector with two side inlets was performed. The heat transfer efficiency and flow characteristics were then investigated for various air channel configurations. Increasing the area of the second inlet improves thermal and electrical efficiency. As the length ratio of the front and rear air flow channels is reduced, the average outlet temperature first decreases and then increases. The heat-exchanging quantity of the dual-inlet air-cooled PV/T collector is minimal. The thermal efficiency of the dual-inlet air-cooled PV/T collector can be elevated by increasing the angle between the solar panel and the bottom plate. However, the average temperature of the solar panels increased and the photoelectric conversion efficiency decreased. This design will achieve a reduction in carbon emissions and an increase in the proportion of clean energy in a low or zero carbon green building.
#2: With regards to the authors' response to Comment #5 in the previous revision, please clearly mention this in your assumptions.
Response: Thank you for your advice. The following descriptions are stated in our paper.
“Usually the photovoltaic cell is covered by a layer of glass. The transmittance coefficient of glass is about 0.9. In this paper, we assume that the transmission coefficient of the glass can be included in both the effective utilization coefficient of solar energy and the photovoltaic efficiency.”
#3: The authors' response to Comment #6 in the previous revision is unacceptable. The question remains: how were the convective heat transfer coefficients computed? In the presented equations, there are convective heat transfer coefficients between the insulation layer and air, between the PV cells and air, and between the PV cells and the ambient air. Details about the way the convective heat transfer coefficients are evaluated are not marginal since convective heat transfer dominates the behavior of the entire system.
Response: Thank you for your advice. Maybe I didn't understand your last comment. The convective heat transfer coefficients in equation 1 could be computed by the following equations.
The convective heat transfer coefficient hamb is a function of wind velocity and is extrapolated by the following empirical relationship [26]. υ is the speed of air.
|
|
(2) |
The convective heat transfer coefficient htop and hbot can be computed by the following equation:
|
|
(3) |
where λair is thermal conductivity of air; Nu is Nusselt number of airflow; D is the equivalent diameter. Nu can be estimated by the following correlation [27]:
|
|
(4) |
where Re is Reynolds number; Pr is the Prandtl number; Tair and T denote to the mean air temperature and the wall temperature of the tube respectively; L is the length of the front and back PV module. This correlation can fully satisfy engineering calculation accuracy under the following conditions:
|
|
|
#4: In the title, please change 'of the dual-air-inlet air-cooled PV/T solar collectors' into 'of dual-inlet air-cooled PV/T solar collectors'.
Response: Good Suggestion! We have changed the title of our paper.
Author Response File: Author Response.pdf
Reviewer 2 Report
Dear Authors,
The paper was improved, but:
1. Please explain / detail / give examples of situations where the results can be used. Examples of horizontal installed PVT modules.
2. Also, the paper has almost 40% similitude with other sources!!!
I hope that my comments will be useful.
Sincerely,
Reviewer
Author Response
The comments from Reviewer 2
#1: Please explain / detail / give examples of situations where the results can be used. Examples of horizontal installed PVT modules.
Response: There are many situations where the horizontal air-based PV/T module can be used. Firstly, in order to reduce the use of electricity or fossil fuels, the horizontal air-based PV/T module is suitable for use in preheating fresh air in central air conditioning system in cold regions. Rectangular air duct is convenience for people to connect it with central air conditioning system. Secondly, in winter, the recreational vehicle (RV) or temporary simple room need for heating, the horizontal air-based PV/T module could be used as a heating system or just to preheat fresh air. Thirdly, shading is an important part in green building. The horizontal air-based PV/T module could be designed as a shading device which can be used for power generation and heat storage.
#2: Also, the paper has almost 40% similitude with other sources!!!
Response: I'm sorry about this. In order to guarantee the correctness of my writing, I have borrowed many other people's language expressions from the internet and literature. I have revised some expressions in my paper by consulting the comments proposed in the originality report.
Author Response File: Author Response.pdf
Round 3
Reviewer 2 Report
Dear Authors,
The paper was improved, but:
1. OK. Please add the indicated examples also to the paper.
2. The similarity of the paper is still 35%. Please improve pages 8..10 of the paper.
I hope that my comments will be useful.
Sincerely,
Reviewer
Author Response
The comments from Reviewer 2
#1: Please explain / detail / give examples of situations where the results can be used. Examples of horizontal installed PVT modules. Please add the indicated examples also to the paper.
Response: I have added the indicated examples to the article as you suggested. Thank you for your suggestion.
“In addition, horizontally positioned air-based PV/T modules have a wide range of applications. Firstly, in order to reduce the use of electricity or fossil fuels, the horizontal air-based PV/T module is suitable for use in preheating fresh air in central air conditioning system in cold regions. Rectangular air duct is convenience for workers to connect it with central air conditioning system. Secondly, in winter, the recreational vehicle or temporary simple room need for heating, the horizontal air-based PV/T module could be used as a heating system or just to preheat fresh air. Thirdly, shading is an important part in green building. The horizontal air-based PV/T module could be designed as a shading device which can be used for power generation and heat storage.”
#2: The similarity of the paper is still 35%. Please improve pages 8..10 of the paper.
Response: Thank you very much for your interest in our articles, we continue to work on revising the statements on pages 8 to 10.
Author Response File: Author Response.pdf
This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.
